94.4 FINAL WEB
Transform your PDFs into Flipbooks and boost your revenue!
Leverage SEO-optimized Flipbooks, powerful backlinks, and multimedia content to professionally showcase your products and significantly increase your reach.
Yale Scientific
THE NATION’S OLDEST COLLEGE SCIENCE PUBLICATION • ESTABLISHED IN 1894
DECEMBER 2021
VOL. 94 NO. 4 • $6.99
THE
ENVIRONMENTAL
ISSUE
TABLE OF
VOL. 94 ISSUE NO. 4
8
The Greta Thunberg Effect
Hannah Huang
Researchers explore some of the social and psychological reasons why climate activists like Greta
Thunberg are so impactful.
10 Making Buildings More Energy Efficient
Could Save Lives
Bella Xiong
Buildings comprise a major source of the air pollution that is detrimental to our health. However,
a few efforts could help us decrease pollution emission, Yale researchers report.
12 Cook Stoves and Pollution Mortality
Risha Chakraborty and Arushi Dogra
A team of researchers quantified the relationship between pollution-related health impacts and
income in India, highlighting the immediate need to address pollution inequity.
15 The Temperature Toil
Angelica Lorenzo and Anna Calame
Recent research from SUNY Buffalo and the Yale School of Public Health points to a potential
relationship between exposure to extreme temperature and a greater number of mental healthrelated
emergency room visits.
18 The New Rumpelstiltskin: Spinning
Wood Into Plastic
Lucas Loman and Kayla Yup
Researchers at the Yale School of the Environment, University of Maryland and the University of
Wisconsin-Madison have created a biodegradable plastic alternative, using natural wood as their
raw material.
2 Yale Scientific Magazine December 2021 www.yalescientific.org
CONTENTS
More articles online at www.yalescientific.org & https://medium.com/the-scope-yale-scientific-magazines-online-blog
4
6
21
28
Q&A
NEWS
FEATURES
SPECIALS
How can Physics Teach Us About Climate Change? • Katherine Moon • 4
Mirror Mirror on the Wall... Is One Mirror Image Better Than Us All? •
Sherry Wang • 4
Cleave the Chlorine! • Sydney Hirsch • 6
Atmospheric Rivers • Crystal Liu • 7
Climate Change and Evolution • Isabel Trindade • 38
Can You Learn More Than a Fifth Grader? • Odessa Goldberg • 38
Unpacking the Cell's UPS • Alexandra Paulus • 39
Food Addiction Across Demographics • Lauren Chong • 39
A Tiny Molecule's Big Role in Brain Development • Neil Kadian • 40
Breaking Bonds with Computer Models • Madison Houck • 41
Cow Toilets 101 • Jack Litke • 21
The Fault in Our Stars • Ethan Olim and Anavi Uppal • 22
Wildfires and Ocean Blooms • Krishna Dasari and Nathan Wu • 24
Rationing Breaths • Catherine Zheng and Sophia Li • 26
The Bacterial Birth of 'Living Medicine' • Simona Hausleitner • 37
Scope: Positive Progress or Harmful Haste? • Annabel Wallace • 28
Undergraduate Profile: Elea Hewitt ('22) • Sophia David • 30
Alumni Profile: Paul Hanle ('75) • Sophia Burick • 31
Science in the Spotlight: Our Biggest Experiment by Alice Bell • Tori Sodeinde • 32
Science in the Spotlight: EVST 219: Philosophical Environmental Ethics •
Lucy Gilchrist • 33
Into the Newsroom: The Yale Program on Climate Change
Communication • Hannah Han • 34
Counterpoint: Do Hospitals Really Do No Harm? • Hannah Shi • 35
From the Archives: Yale Scientific Summer 1980 • 36
Synapse Essay Contest: When Sound Meets Chemistry • Marian Caballo • 42
www.yalescientific.org
December 2021 Yale Scientific Magazine 3
&MIRROR MIRROR ON THE
WALL... IS ONE MIRROR
BETTER THAN US ALL?
By Sherry Wang
By Katherine Moon
HOW CAN PHYSICS TEACH US
ABOUT CLIMATE CHANGE?
This year, the Nobel Prize in Physics was awarded to
three scientists, Syukuro Manabe, Klaus Hasselmann,
and Giorgio Parisi, for their contributions to the
understanding of complex systems. They each pioneered
research on modeling Earth’s climate and the nature of disorder
in physical systems. By awarding the prize to climate scientists
for the first time, the committee conveyed a clear message:
climate change study is a rigorous form of scientific research.
So, how have scientists used physics to analyze climate change?
In the 1960s, Manabe, now a climatologist at Princeton
University, created mathematical models of the Earth’s climate
to demonstrate how increased levels of carbon dioxide in the
atmosphere raise the surface temperature. German meteorologist
Hasselmann furthered the study by linking climate to the weather
as a chaotic system, ultimately supporting that human activity,
such as the generation of carbon dioxide emissions, is responsible
for the change in climate. Both models are now foundational to
the current understanding and research of climate change.
Meanwhile, Parisi, an Italian physicist at the Sapienza University of
Rome, focused on quantum field theory, a framework to construct
models of subatomic particles. He used this to discover patterns
from underlying disorder and fluctuations in complex systems. The
idea of analyzing irregularities in a complex system is analogous to
evaluating numerous variables in the Earth’s climate.
Physics teaches us about climate change through mathematical
models and complex systems. These physicists’ recognition by the Nobel
Committee emphasizes the rigorous scientific foundation underlying
the study of climate change, ultimately prompting us to take action. ■
The chemistry of molecule-making is quite particular:
sometimes, a reaction produces two mirrored versions
of a molecule, but only one remains sufficient for a
given application. In processes such as drug development,
using the wrong mirror image can have devastating biological
effects. Some catalysts can speed up a chemical reaction while
producing one mirror version preferentially over the other.
Historically, these catalysts have been made with toxic metals.
But the 2021 Nobel Prize in Chemistry was awarded to two
scientists—Benjamin List of the Max-Planck Institute for Coal
Research and David MacMillan of Princeton University— who
developed organic catalysts that are mirror image-selective,
helping to make reactions more environmentally friendly.
List discovered that the amino acid proline could replace the
function of metal catalysts while producing the more favored
mirrored version of a molecule. At the same time, MacMillan
designed small organic molecules that, like proline, had
catalytic functions and could generate one mirrored version
of a molecular product over the other. MacMillan officially
coined the term for this process: “asymmetric organocatalysis.”
This method of catalysis is eco-friendly: it decreases the
need to use toxic metals as catalysts and also decreases the
time of reaction. Approximately thirty-five percent of the
world’s gross domestic product depends on catalysis, so the
creation of a more efficient and environmentally sustainable
tool has major benefits. Production of the preferred mirrored
version through organocatalysis has revolutionized the field of
chemistry, one reaction at a time. ■
4 Yale Scientific Magazine December 2021 www.yalescientific.org
The Editor-in-Chief Speaks
ENVIRONMENTAL
SCIENCE AND JUSTICE
This summer, the UN’s Intergovernmental Panel on Climate Change released a
landmark report with bleak findings: that human activity is an “unequivocal”
culprit in warming our atmosphere; that even if we drastically reduce our
carbon emissions, temperatures will continue to rise by at least 1.5 degrees Celsius;
and that these rising temperatures will cause severe weather, which we have already
previewed in our increasingly strong storms, long draughts, and ever-raging wildfires.
This November, world leaders gathered at COP26, a UN climate conference. Dozens
of countries vowed to institute meaningful policy combating climate change—though
youth climate activists protested that these proposals were far from enough.
This issue of Yale Scientific is themed Environmental Science and Justice. As the last
one helmed by our 2021 masthead, we’re interested in how issues of the environment
embody key themes our publication has addressed this past year.
Science uncovers and innovates. It helps us identify parts of our ecosystem, aspects
of our lives, or segments of society most harmed by environmental degradation.
It also develops alternatives to our most harmful activities and provides us with
potential means to mitigate the worst effects of climate change.
But science cannot be untangled from humanity, who will ultimately feel the pain
of environmental degradation.The global response to climate change is social and
political, shaped by how government officials, activists, and everyday individuals
internalize the scientific evidence presented to them. And as extensive research can
corroborate, long, long histories of injustice mean that those most socioeconomically,
racially, or otherwise oppressed in society suffer most in environmental crises.
Environmental justice, a movement distinctly aware of these inequalities, with roots
in Black and Indigenous activism, must shape any response moving forward.
Even as environmental crises loom, life moves on. In this issue we also look at areas of
science not directly related to the environment. An article from Scope, our interdisciplinary
online blog, investigates the COVID-19 pandemic’s effect on science research publishing
(p. 28). We also feature work by high schooler Marian Caballo, winner of this year’s
Synapse essay contest, who shows us that the future of science journalism is bright (p. 42).
As always, and especially for the last issue of this masthead, I am grateful for
our readers and for the massive team that makes our publication. Thank you for
critically engaging with science and all its impacts—for the past year, for the many
years before, and for the many years this publication will see in the future. Whatever
fate our planet might face in the meantime, science, and science journalism, will
undoubtedly help shape it. Let’s make sure it’s for the better.
About the Art
Isabella Li, Editor-in-Chief
This cover appears chaotic from the
outset, but only represents a sliver of
the countless environmental issues
plaguing the world today. While
wildfires as well as air and ocean
pollution are crucial problems, this
semester’s issue delves into many more
injustices, their nuances, and ideas on
how to ameliorate them.
Sophia Zhao, Cover Artist
MASTHEAD
December 2021 VOL. 94 NO. 4
EDITORIAL BOARD
Editor-in-Chief
Managing Editors
News Editor
Features Editor
Special Sections Editor
Articles Editor
Online Editors
Copy Editors
Scope Editors
Newsletter Editor
PRODUCTION & DESIGN
Production Manager
Layout Editors
Art Editor
Cover Artist
Photography Editor
BUSINESS
Publishers
Operations Manager
Advertising Manager
Subscriptions Manager
OUTREACH
Synapse Presidents
Synapse Vice Presidents
Synapse Outreach Coordinators
Synapse Events Coordinator
WEB
Web Manager
Web Developer
Web Publisher
Social Media Coordinator
Web Designer
SENIOR STAFF WRITERS
Lauren Chong
Rayyan Darji
Krishna Dasari
STAFF
Ann-Marie Abunyewa
Hannah Barsouk
Breanna Brownson
Sophia Burick
Anna Calame
Risha Chakraborty
Allison Cho
Sophia David
Arushi Dogra
Chris Esneault
Sarah Feng
Lucy Gilchrist
Odessa Goldberg
Hannah Han
Simona Hausleitner
Alex Dong
Elisa Howard
Malia Kuo
Sydney Hirsch
Madison Houck
Abigail Jolteus
Neil Kadian
Catherine Kwon
Gina Lee
Sophia Li
Cathleen Liang
James Licato
Jack Litke
Crystal Liu
Lucas Loman
Angelica Lorenzo
Katherine Moon
Ethan Olim
Isabella Li
James Han
Hannah Ro
Jenny Tan
Cindy Kuang
Nithyashri Baskaran
Maria Fernanda Pacheco
Meili Gupta
Cathleen Liang
Alex Dong
Brianna Fernandez
Hannah Huang
Christina Hijiya
Tai Michaels
Beatriz Horta
Ishani Singh
AnMei Little
Catherine Zheng
Elaine Cheng
Sophia Zhao
Crystal Xu
Blake Bridge
Jared Gould
Brian Li
Sophia Zhuang
Lauren Chong
Alice Zhang
Sophia Li
Blake Bridge
Jared Gould
Athena Stenor
Anavi Uppal
Sophie Edelstein
Matt Tu
Brett Jennings
Eten Uket
Megan He
Siena Cizdziel
Dhruv Patel
Anavi Uppal
Kayla Yup
Alexandra Paulus
Noora Said
Hannah Shi
Anasthasia Shilov
Tori Sodeinde
Connie Tian
Isabel Trindade
Annabel Wallace
Sherry Wang
Jenny Wong
Nathan Wu
Bella Xiong
Lucy Zha
David Zhang
Lana Zheng
The Yale Scientific Magazine (YSM) is published four times a year by Yale
Scientific Publications, Inc. Third class postage paid in New Haven, CT
06520. Non-profit postage permit number 01106 paid for May 19, 1927
under the act of August 1912. ISN:0091-287. We reserve the right to edit
any submissions, solicited or unsolicited, for publication. This magazine is
published by Yale College students, and Yale University is not responsible
for its contents. Perspectives expressed by authors do not necessarily reflect
the opinions of YSM. We retain the right to reprint contributions, both text
and graphics, in future issues as well as a non-exclusive right to reproduce
these in electronic form. The YSM welcomes comments and feedback. Letters
to the editor should be under two hundred words and should include the
author’s name and contact information. We reserve the right to edit letters
before publication. Please send questions and comments to yalescientific@
yale.edu. Special thanks to Yale Student Technology Collaborative.
NEWS
The Environmental Issue
CLEAVE THE
CHLORINE!
Single-atom palladium
as a catalyst for the
removal of chlorine
from polluted water
BY SYDNEY HIRSCH
IMAGE COURTESY OF WIKIMEDIA
Anthropogenic pollutants—that is, those released by
human activities—are toxic and can pose serious risks
to human and ecological health. Chlorinated phenolic
compounds (CPs), often used in pesticides, herbicides, and various
other chemical products, are one such type of pollutant. These
compounds need to be removed from water systems by a process
known as hydrodechlorination. Conventional treatment methods
such as filtration, however, are not effective. As a result, scientists
have begun to explore electrocatalysis as an alternative technique
to cleave the chlorine from phenol, ridding systems of CPs.
Palladium-based catalysts offer a promising solution to catalyze
or promote this reaction. However, palladium (Pd) is a costly
material, and past experimentation with Pd nanoparticles (Pd nano
)
has demonstrated various limitations in dechlorination efficiency. A
team of researchers at Yale, including post-doctoral fellow Dahong
Huang and senior professor Jaehong Kim, devised an electrocatalytic
technique utilizing single-atom palladium (Pd 1
) that circumvents
both the cost and mechanistic issues posed by Pd nano
. Their efforts, in
collaboration with Brookhaven National Laboratory, yielded a system
fourteen times more efficient than Pd nano
at the atomic scale.
The researchers’ experiment consisted of mounting the Pd
single-atom catalyst (SAC) onto a reduced graphene oxide (rGO)
support, which allows for rapid electron transfer and sufficient
distribution of the SAC. Unlike Pd nano
loaded onto an analogous
support, in which many Pd atoms sit under the surface, all of the
palladium atoms on the Pd 1
/rGO are available for reaction. Thus,
the atomic efficiency of Pd 1
can reach one hundred percent.
In addition, Pd 1
uses less palladium than Pd nano
, making it costefficient
as well. In fact, it costs only seventeen cents to cover a square
meter of rGO with the palladium SAC, whereas Pd nanoparticles
run around thirty-seven dollars per square meter. This dramatic
reduction in cost is vital in the context of water treatment, as the
broader objective of this research seeks to find efficient and costeffective
ways to treat large volumes of water.
In previous research involving palladium-induced catalysis, scientists
also noticed that the catalyst could be deactivated by the products of
hydrodechlorination. This result was seen in experimentation with
Pd nano
, wherein the chloride released by the reduction reaction clung to
the palladium surface and prevented further catalytic activity. Kim and
his team recognized, however, that single-atom palladium circumvents
this “poisoning effect” since the unsaturated nature of the SAC allows
any adsorbed chloride to be released quickly and the reaction to
progress unhindered. The researchers demonstrated this phenomenon
experimentally. Throughout the electrocatalytic reaction, in which
chlorines were removed from the phenolic compounds, the chloride
ion concentration in solution remained close to one hundred percent,
indicating that the Pd 1
/rGO surface had not adsorbed chloride after
dechlorination of the phenols.
Additionally, phenol was the only product in solution, highlighting
the selectivity of this mechanism. “Imagine you have a pollutant like
chlorophenol in water and you’re trying to treat it. But water also
has a lot of other stuff in it. You don’t want your reduction power
to reduce the rest of the organics in water. We want a treatment
scheme that selectively destroys the pollutant, and this palladium
single atom-based material can selectively target reducing chlorocompounds,
which is the ultimate goal,” Kim said.
The presence of electron metal support interactions (EMSI)
between the Pd 1
atoms the rGO support promotes the catalytic
reaction. Electrons flow through the palladium-oxygen bonds and
transfer directly to what is adsorbed on the Pd 1
, whether it be a
chlorophenol (direct reduction) or a proton. In the latter, atomic
hydrogen is formed to reduce the chlorophenol, a process termed
indirect hydrogenation. With previous methods using Pdnano, two
atoms of hydrogen formed H 2
and thus failed to contribute to the
electrocatalytic hydrodechlorination. Pd 1
avoids this issue due to
its limited adsorption sites and spatial separation.
Kim’s research demonstrates the potential of palladium SACs in
becoming a prominent part of water treatment solutions. Before
considering the broader applications, however, there are many
smaller-scale steps to be taken in this line of work. “We need to
continue to test this material for a wide range of scenarios. At the
same time, we are not claiming that [palladium] is the best material,”
Kim said. “There are many other options for the metal as well as the
substrate, and we do not know what the best is.”
Future studies may continue to test the long-term stability
of SACs and optimize its properties for a given reaction,
ultimately working to detoxify environmental systems. “You
have just seen the tip of the iceberg,” Kim said. ■
6 Yale Scientific Magazine December 2021 www.yalescientific.org
The Environmental Issue
NEWS
ATMOSPHERIC
RIVERS
How global warming
influences the stability
of water vapor streams
IMAGE COURTESY OF PIXNIO
Not all rivers run on land. Atmospheric rivers (ARs)
are pathways of intense water vapor transport in the
extratropics, the mid-latitude areas beyond the tropics.
Seung Hun Baek and Juan Lora at Yale’s Department of Earth and
Planetary Sciences examined new models to evaluate the past and
future influences of human activity on AR fluctuations.
An AR can be advantageous or detrimental depending on
its strength. The Scripps Institution of Oceanography at the
University of California San Diego categorizes ARs based on a
five-level scale, ranging from “weak” to “exceptional” in strength
and “beneficial” to “hazardous” in impact. An AR of level two
(Moderate) can help replenish low reservoirs after a drought,
but ARs of four and five (Extreme and Exceptional) often lead
to heavy precipitation and floods.
Higher temperatures can strengthen ARs by increasing the
amount of water vapor in the air. Two important factors that
affect temperature are the warming effects of greenhouse gases
(GHGs) and the cooling effects of industrial aerosols, such as
smoke and particulate air pollutants. Baek and Lora showed that
there was little human-induced change in AR characteristics
from 1920-2005, as the effects of GHGs canceled out those of
aerosols. Compared to natural variability, human activity only
caused statistically significant changes in the North Atlantic and
the Southern Pacific, and these changes were small in scale.
However, when the scientists applied the same framework to
project future changes, they saw a drastically different picture.
Relative to the historical evaluation, they predicted far more
vigorous ARs from 2005-2080, simulating a roughly twentymillimeter
per month rainfall increase in many regions and over
one hundred percent more frequent extreme precipitation over
much of Europe. These natural disasters can lead to flooding,
property losses, and casualties.
Baek and Lora used the Representative Concentration Pathway
of 8.5 watts per square meter (RCP8.5) in their prediction model.
The RCPs were proposed by the United Nations Intergovernmental
Panel on Climate Change (IPCC) in its Fifth Assessment Report.
They represent a series of GHG concentration scenarios, and RCP8.5
corresponds to “very high GHG emissions.” In 2014, the IPCC stated
that without additional efforts to constrain emissions, the baseline
www.yalescientific.org
BY CRYSTAL LIU
condition would fall between RCP6.0 and 8.5. “[RCP8.5] is certainly
pessimistic, but it is possible and very worth thinking about, as we’ve
been following that trajectory relatively closely,” Lora said. Plus,
the models stay conceptually valid regardless of the numbers. “If
greenhouse gases went up less, the intensification of atmospheric
rivers would be less. But qualitatively it will still go up,” Baek said.
The researchers also evaluated the altitude of changes in AR
characteristics. Changes at a higher altitude, although smaller in
magnitude, closely mirror those at a lower altitude. “Mid-latitude
weather systems have a vertical structure that goes from the surface
up into the troposphere, so we want to understand how these [AR]
changes occur in the vertical direction as well,” Lora said.
With such large experiments came numerous challenges.
Collecting and analyzing the data was an especially arduous
task. “Atmospheric rivers use daily data, so it’s pretty high
resolution temporally. I think we analyzed or generated
something like twenty terabytes of data.” Baek said.
Lora, on the other hand, expressed words of gratitude. “Yale
maintains very good computing capabilities. [During the pandemic,]
we are lucky as computational scientists in that we run simulations
and analyses on computers that we can access remotely,” he said.
It is astonishing that industrial aerosols, an important air
pollutant, can cool the atmosphere. Can humans make use of
this property? Indeed, solar geoengineers have been considering
injecting aerosols into the stratosphere. This field has received
much attention recently, but its implementation is currently far
from reality due to its many unknown consequences. “Think
about the mass extinction event that killed the dinosaurs. A large
proportion of that was probably due to aerosols blocking the Sun.
So maybe it’s not [a path] we want to go down,” Lora said.
In future studies, the scientists hope to examine the influence
of global patterns, such as the El Niño–Southern Oscillation, on
atmospheric rivers. Several regional studies have observed these
phenomena, but simulations like the one in this paper can help
paint a global picture. The scientists also aim to elucidate the impact
of individual forcings, or perturbations to the Earth system, on
atmospheric rivers—not only to gain an insight on this elaborate
system, but also to shed light on the possible effects of solar
geoengineering and other human modifications to the atmosphere. ■
December 2021 Yale Scientific Magazine 7
FOCUS
The Environmental Issue
THE
GRETA
THUNBERG
EFFECT
Studying what makes an
ordinary teenager so
extraordinarily impactful
BY HANNAH HUANG
ART BY ANN-MARIE ABUNYEWA
Zooming with me from across the pond
in London, Anandita Sabherwal, a
PhD student at the London School of
Economics, explained how she arrived at the
topic of her latest publication in the Journal
of Applied Social Psychology.
“I was very interested in the idea of
social identity and social reference, and
who acts as a social reference when it
comes to climate activism,” she said.
Sabherwal had been sitting in her adviser’s
office, bouncing research ideas around with
him. Together, they came to the realization
that they should study the effect that Greta
Thunberg has had on climate activism.
That idea, coupled with a collaboration
with the Yale Program on Climate Change
Communication (YPCCC), led to their
recent paper, “The Greta Thunberg Effect:
Familiarity with Greta Thunberg predicts
8 Yale Scientific Magazine December 2021
intentions to engage in climate activism in
the United States.”
Thunberg, a teenage activist from Sweden,
has inspired countless people of all ages
from across the globe to both care about
and act against climate change. Sabherwal
and her colleagues wanted to know what
makes a young, seemingly ordinary
teenager so influential in convincing
people to partake in collective actions like
contacting government representatives,
donating time and money, and attending
strikes and protests—actions that help a
larger group and not just themselves.
Living, Learning, and Collaborating
Across Continents
Sabherwal’s interest in studying how
people react to communication about
climate change is driven by the many places
she’s lived in. Born and raised in India, she
saw how the water shortage crisis forced
women to walk ever-farther distances to get
water, even driving some farmers to suicide.
While studying at Yale-NUS College in
Singapore, she participated in a study abroad
program at Pomona College, where she was
surprised by how highly politicized climate
change is in the US—a characteristic that
she thinks is more exaggerated here than
anywhere else she’s lived. “Different political
groups don’t even agree on whether climate
change is worth discussing as a problem or
looking for solutions for, and that blew my
mind,” she said.
Now a new PhD student at the London
School of Economics, she has observed
that although people in the UK want to act,
there is an intention-action gap. “People
www.yalescientific.org
The Environmental Issue
FOCUS
want to do something, but they also don’t
want to sacrifice a lot of their privileges and
ways of life to get to that point,” she said.
From India to Singapore to the US to
the UK, she has seen and studied firsthand
how countries differ in how they
are affected by and deal with climate
change. “I realized that this would be
an amazing thing to study because
socially and psychologically, there is a
lot to unpack here,” she said. “Why do
different groups react so differently to the
same information? How do they adapt
differently based on their social status
and class? What impacts do they face?”
Sabherwal and her colleagues sought
to establish whether increased exposure
to Thunberg was predictive of increased
motivation to participate in collective
action against climate change. They also
wondered if collective efficacy—the idea
that working as a group can bring about
the accomplishment of specific goals—
was behind this effect.
The UK researchers first attempted
to study the Greta Thunberg Effect in a
sample of adults drawn heavily from the
East and West Coasts of the US; however,
their efforts were foiled by how well
people already knew Thunberg. “People
were already so exposed to her that when
we did an experiment exposing people
to Greta, it had no effect,” Sabherwal
said. “Everyone in our control group
knew Greta just as equally. People were
much more aware of Greta and much
less polarized on her than was nationally
representative.” Then, an encounter with
a former labmate from Sabherwal’s time
at Pomona led to the opportunity to
collaborate with the YPCCC.
YPCCC conducts annual surveys on
the US population and, fortunately, had
data that were more representative of
people’s opinions on climate change and
Thunberg. YPCCC’s data solved the
problem that UK researchers had run
into earlier. Moreover, because of how
politicized climate change is in the US,
there was a wide range of opinions on
climate change, which made the US data
an interesting sample on which to test the
researchers’ hypotheses.
What is So Special About Thunberg?
In the study, after participants were
asked how familiar they were with
www.yalescientific.org
Thunberg, they were also asked questions
measuring their belief in collective efficacy
(how likely was it that a group of ordinary
citizens, working together, could affect
the actions of government or businesses)
and questions measuring their intent to
engage in collective actions (how likely
the individual was to vote for a candidate,
attend a rally, listen to a speech, etc.).
As expected, they found that familiarity
with Thunberg induces people’s sense of
efficacy: they feel like if they work along
with others, they can make an impact.
This is because Thunberg has modeled
both collective action—leading and
supporting climate strikes, for example—
and worldwide impact, such as speaking
at high-profile events like United Nations
conferences.
Surprisingly, there was no difference
in the Greta Thunberg Effect across age
groups. The researchers had hypothesized
that her impact would be more apparent
in younger people, but they were glad
to see that she impacted all age groups
similarly.
What also stood out about Thunberg
was her appeal across the political
spectrum in the US. “Generally, if a leader
appeals to one political segment, they
backfire with the other political segment.
It’s not that the effect is just lowered.
It backfires,” Sabherwal said. “But we
found that Greta was also appealing to
conservatives, even if to a lesser extent
compared to liberals.” In light of these
findings, she posits that Thunberg’s
emphasis on intergenerational justice and
her lack of clear alignment to a specific
political party underlie her success.
Finally, to Sabherwal, Thunberg’s
humility and relatability allow her to
connect with the general public. Leaders
are typically elite in some way, whether
it be in educational background, power,
ABOUT THE AUTHOR
or wealth. Academic experts, government
leaders, and wealthy people are examples
of the types of elite leaders that abound
in the arena of climate change activism.
Elite leaders, however, can alienate
people in the general population for the
exact reasons they are conspicuous in the
first place. “Sure, Jeff Bezos can donate
twenty million dollars to climate change
research. I can’t do that,” Sabherwal said.
“But by always conveying that she’s just
like us, Greta has been able to be a leader
that we can look up to and say, ‘If Greta
can do it, we can do it too.’”
Fighting Anxiety with Action
As a researcher whose entire day is spent
focusing on climate change and seeing
how reluctant people are to change their
behavior, thinking about the future can be
anxiety-inducing, Sabherwal admitted.
But when a person like Thunberg says
there is still time to change, it gives her
great solace. “Greta inspired me to take
care of my anxiety by taking action, by
doing something about it, which I think
is a message she consistently gives,”
Sabherwal said. “Because unless you act,
it’s very easy to get overwhelmed by the
state of climate change right now.”
Sabherwal believes in Thunberg’s
unique power. “Most of us will change
because we know that the social norm has
changed. But there are a few individuals
that will change the social norm, and
that’s how societies change,” Sabherwal
said. As her recent study reveals, the Greta
Thunberg Effect is real and impactful.
Hopefully, it will continue to change
people’s minds, their actions, and our
society for the better because—to use one
of Thunberg’s trademark phrases—our
house is on fire, and we’re running out of
time to save it. ■
HANNAH HUANG
HANNAH HUANG is a sophomore in Davenport College. In addition to writing for YSM, she volunteers
with HAVEN Free Clinic and is part of the Davenport College Council.
THE AUTHOR WOULD LIKE TO THANK Anandita Sabherwal for her time and enthusiasm about her
research.
Sabherwal, A., Ballew, M. T., Linden, S., Gustafson, A., Goldberg, M. H., Maibach, E. W., Kotcher, J. E.,
Swim, J. K., Rosenthal, S. A., & Leiserowitz, A. (2021). The Greta Thunberg effect: Familiarity with Greta
Thunberg predicts intentions to engage in climate activism in the United States. Journal of Applied Social
Psychology, 51(4), 321–333. https://doi.org/10.1111/jasp.12737
December 2021 Yale Scientific Magazine 9
FOCUS
The Environmental Issue
MAKING BUILDINGS
MORE ENERGY-EFFICIENT
COULD SAVE LIVES
BY BELLA XIONG
Even before the pandemic, people spent
about ninety percent of their time
indoors. Given how many hours we
spend in these spaces, it is important to think
about how changes in building design or
operation impact indoor air quality.
The burning of fossil fuels contributes
to global warming by accumulating large
quantities of carbon dioxide and particulate
matter smaller than 2.5 microns in the
atmosphere. The latter is a pollutant with
one of the largest health effects—despite
its minuscule size, it can both cause
and exacerbate cardiovascular diseases,
respiratory diseases, and cancer.
While many factors contribute to emissions
of carbon dioxide and particulate matter—
wildfires and cars, for example—a major
source of air pollution originates from
buildings and building-related operations.
According to the US Energy Information
Administration, residential and commercial
buildings consume forty percent of all energy
in the US. This issue makes buildings an
important target for measures that increase
energy efficiency and reduce carbon dioxide
and pollution emissions.
Drew Gentner, Yale professor of Chemical
& Environmental Engineering, and Kenneth
Gillingham, professor of Economics, along
with their colleagues from Yale's Solutions
for Energy, Air, Climate & Health Center,
embarked on a necessary interdisciplinary
investigation. In their new study, published in
Science Advances in August, the researchers
used the Yale-NEMS (National Energy
Modeling System) model, which models the
effects of various building energy efficiency
scenarios they designed based on literature.
Leveraging their perspectives on the dynamics
How improving the energy efficiency
of buildings can impact air quality
of air pollution in indoor and outdoor spaces,
they investigated scenarios that could impact
carbon dioxide emissions associated with
energy use and energy-related emissions of
outdoor pollutants.
The project was motivated by the desire
to both improve human health and help us
tackle climate change. “It is not a new issue,
and we have known for a long time how
important it is, but quantifying the effects of
strategies to address climate change is more
relevant now than ever,” Gillingham said.
Energy Efficiency Scenarios
Gentner and Gillingham’s study
evaluated how energy efficiency measures
could improve building tightness, a
measure of outward and inward air
leakage in buildings. These energy
efficiency measures included changes to
infiltration, natural ventilation, and heat,
ventilation, and air conditioning (HVAC)
recirculation adoption. The researchers'
goal was to explore ways to reduce energy
losses associated with air leakage from
indoors to outdoors, and vice versa.
To do so, they created two scenarios:
“Intermediate EE” and “Optimistic EE.” The
“Intermediate EE” scenario provides close
to twenty percent increased efficiency on all
building appliances and equipment. In this
scenario, the annual efficiency improvement
from better building shells—which separate
the building’s interior spaces from its
exterior spaces—can achieve cumulative
improvements of more than fifty percent. The
“Optimistic EE” scenario is a more idealistic
model, allowing for fifty percent increased
efficiency in appliances and equipment, along
with more than sixty percent of cumulative
annual efficiency improvement from
increasing the quality of building shells.
These two scenarios are based on possible
future energy efficiency improvements
for building services and shell structure
materials. Shell structure materials are
used to secure the building composition by
transmitting applied forces on the surface.
The energy efficiency improvements
address space heating and cooling, water
heating, lighting, refrigeration, and culinary
services for residential and commercial
facilities. They also address building shell
efficiency improvements in the residential,
commercial, and industrial sectors for both
existing and new structures.
Another focus was improving
recirculation with filtration, which can
help mitigate indoor concentrations of
particulate matter. Considering how
energy efficiency is greatly related to
the emission of energy productionrelated
pollutants, these two scenarios
also provide estimates for how many
premature deaths in the United States
would be avoided in each case.
Using the outputs of the Yale-NEMS
model, along with the building energy
efficiency scenarios, the researchers
evaluated how concentrations of
particulate matter could change indoors as
a function of building tightness. The study
examined how the two building energy
efficiency scenarios would impact air
quality across the entire US housing stock.
The researchers explored the
interconnectivity of outdoor and indoor
air quality by looking at the changes in
infiltration while also considering the
10 Yale Scientific Magazine December 2021 www.yalescientific.org
The Environmental Issue
FOCUS
variations in indoor emissions across
houses in the US. These emissions are
closely related to cooking activities,
and the resulting concentrations are
impacted by the presence of particle
filtration—which, in turn, is related to
building HVAC systems.
Compared to the reference case of the
energy efficiency scenarios, the Yale-NEMS
model predicted that decreasing energyconsuming
activities could improve general
outdoor air quality. On a larger scale,
it also shows that indoor air quality
related to building energy efficiency
improvements depend largely
on indoor emissions and home
design characteristics. According
to the research team’s findings
and interpretation, by 2050, both
efficiency scenarios could yield a
six to eleven percent reduction in energyrelated
carbon dioxide emissions and an
eighteen to twenty-five percent reduction
in the main particulate matter emissions.
Ultimately, following the energy-saving
scenarios could reduce outdoor emissions,
potentially saving 3,700 to 7,800 lives per
year in the United States by 2050.
A Call to Action
Unfortunately, the study’s findings also
show that energy efficiency improvements
could negatively impact indoor air quality
in some homes. Due to lower air exchange
rates, infiltration caused by tightening the
building shell for energy efficiency gains
might result in greater exposure to indoor
contaminants in some buildings. The
observed changes in indoor air quality show
that it is essential to increase awareness
of indoor particulate matter emissions.
Because of this, indoor air filtration
improvements should also accompany
energy efficiency improvements. This might
be especially significant for low-income
housing, which tends to have inadequate
indoor air filtration due to the usage of
more health-damaging materials.
Still, even after accounting for changes
in indoor air quality, the thousands of
premature deaths that could be avoided
by improving the energy efficiency of
buildings should not be neglected.
Overall, estimates of public health
improvements reveal the urgency of
reducing the outdoor air or outdoor
pollutant emissions associated with energy
www.yalescientific.org
u s e .
“Attention to
ventilation strategies, indoor emissions,
and investments in interior air recirculation
systems with filtration, such as betterperforming
filters in HVAC systems,
require careful consideration from a policy
standpoint and can help to minimize
potential negative effects on indoor air
quality,” said Gentner. This could help to
improve indoor air quality even further,
preventing even more premature deaths.
Making buildings more energyefficient
can help us move toward a more
environmentally safe future. Going forward,
individuals also have an opportunity to
consider how personal housing choices can
affect air pollution. By choosing a more
environmentally sustainable option of
housing, for example, thousands of premature
deaths may be avoided each year. “This study
ABOUT THE AUTHOR
p r o v i d e s
guidance to
policymakers who are trying to
understand what it would mean to have
intensive energy efficiency improvements. It
tells us what the benefits could be, but also
what additional efforts are needed to achieve
the benefits,” said Gillingham.
To address climate change, we must
pay close attention to the impacts of
air pollution. This requires considering
emissions from a variety of sources.
Whether it is through improving
building efficiency, reducing air pollution
emissions, or changing personal choices,
each of us has a role to play. A tremendous
amount of work remains to be done, but
scientists like Gentner and Gillingham are
using what they know to combat climate
change by initiating conversations that
could lead to policy changes. ■
BELLA XIONG is a junior Neuroscience major in Trumbull college. In addition to writing for YSM, she
directs the Yale Helix Incubator and works for the Yale Medical School as a research assistant. Her research
involves using machine learning to predict patient outcomes after suffering an intracranial hemorrhage..
FURTHER READING
ART BY CATHLEEN LIANG
BELLA XIONG
K. T. Gillington., P. Huang., C. Buehler., J. Peccia., D. R. Gentner. (2021, August 20). The climate and health
benefits from Intensive Building Energy Efficiency Improvements. Science Advances. Retrieved November 6,
2021, from https://www.science.org/doi/10.1126/sciadv.abg0947.
Xing, Y.-F., Xu, Y.-H., Shi, M.-H., & Lian, Y.-X. (2016, January). The impact of PM2.5 on the human respiratory
system. Journal of thoracic disease. Retrieved November 6, 2021, from https://www.ncbi.nlm.nih.gov/
pmc/articles/PMC4740125/.
December 2021 Yale Scientific Magazine 11
FOCUS
The Environmental Issue
COOK STOVES AND
POLLUTION MORTALITY
Poorer Indian households face death from
pollution more than the rest of the world
BY RISHA CHAKRABORTY & ARUSHI DOGRA
Nowhere is the diversity in the
impacts of climate change more
obvious than in India. There,
great disparities in people’s access to
pollution-causing technologies ultimately
culminate in stark differences in health
and lifespan. Pollution is the single
greatest environmental cause of premature
mortality worldwide, but the proportion
of Indian babies and moms dying from it
vastly exceeds the global average.
While researchers have long studied
the tie between emission origin and
pollution spread, as well as the impacts
of this pollution on human health, these
disciplines had historically remained
unconnected. The question of why
families located in specific areas of India
disproportionately felt the impacts of
atmospheric pollution lingered.
To correlate the hotspots of
pollution-based premature mortality
with proximity to emission-causing
technologies in India, Narasimha
Rao, an associate professor at the Yale
School of the Environment, assembled
a team of researchers from Yale and
the International Institute for Applied
Systems Analysis with different areas
of expertise. Serving as climate justice
advocates, they sought to understand
the income-specific impacts of pollution
and to propose policies to address these
interconnected disparities in India.
The Integration of Models
Climate change models have existed as
long as climate data has been collected—for
nearly two centuries. The need for research
correlating specific emissions to public
health issues might seem obvious—after all,
while the causes of pollution inequity have
gone uninvestigated, pollution’s inequitable
health impacts have been theorized for
as long as we have known pollution to be
detrimental to health. However, as Rao
acknowledged, there has been a historical
lack of research in this field. “In science,
IMAGE COURTESY OF THE YALE SCHOOL OF MEDICINE
Professor Narasimha Rao of the Yale School of the
Environment
you can only ask the questions you can
answer, and this fell through the cracks of
intersection boundaries,” Rao said.
Prior to this study, Rao, as a footprinting
climatologist, lacked the tools to link
emissions to health markers, such as
respiratory illnesses and premature
mortality. Similarly, those working on
the health impacts of emissions did not
have the tools to understand the spatial
distribution of atmospheric pollution
according to location and consumption of
fuels and technologies. While many climate
researchers have thought about linking
these two areas, the fact that separate tools
are involved in creating each model meant
there was previously no way to pursue
the connection. Rao’s novel insight was to
devise an analytical framework where the
results from the emissions contribution
model would provide data to fuel the health
and socioeconomic impacts model, and
vice versa.
The linked contribution and impact model
Rao’s team created was a culmination of many
smaller models with different purposes, each
exchanging information with the others.
Rao worked on the aspect of the model
that linked spatial distributions of “point
sources”—people and industries—across
a region to the emissions from that region.
His team had a good understanding of
point sources’ emission generation patterns,
including the usage of fuels involved in
12 Yale Scientific Magazine December 2021 www.yalescientific.org
The Environmental Issue
FOCUS
transportation, heating, or making food in
cook stoves, and those that were indirectly
wasteful, such as generating food waste and
running electricity.
Once his team localized emissions
to these point sources, an atmospheric
model was implemented to reflect realistic
weather patterns, including air flows
and temperature changes, and deduce
the ultimate stabilized concentrations
of pollutants. Finally, an impact model
linked the pollutant concentrations
to individual exposure and mortality,
demarcated by age, sex, socioeconomic
status, and proximity to urban centers.
The impact model also mapped the
socioeconomic characteristics of people
and inferred their future energy demands;
for example, rising disposable income could
mean that individuals would buy more
polluting technologies, such as new fridges
or cars, or less polluting technologies,
such as gas stoves instead of biomass
stoves. These results would in turn provide
feedback to the emissions model. Thus,
the cyclical nature of the model pipeline
ensured that both the emissions and health
impacts could be modulated over time.
Not only was the model predictive over
time, but it was also highly generalizable
across global regions. “You can change out
the data and you’d represent a different part
of the world,” Rao said. Since the underlying
algorithm remained the same, it was simply
a matter of “plugging in” different data
points—adding or removing emissioncausing
technology contributions, changing
the population distribution, changing the
atmospheric characteristics—and “chugging”
to customize the model for any region.
The team chose to look at India as the
first application of the model because India
has a mix of income levels and polluting
technologies that makes the source and
extent of pollution unclear. The model
provided clear evidence for what might
have been superficially obvious: poorer
households in India disproportionately
face the impacts of pollution. The
pollution inequity is jarring—in fact,
the poorest decile of the population in
the country faces a mortality risk that is
nine times greater than that of the richest
decile in the country.
More importantly, the model highlighted
the exact sources of pollution that were
IMAGE COURTESY OF FLICKR
Pollution from cookstoves contributes to the premature deaths of nearly a million Indian mothers and babies.
causing families of lower socioeconomic
status to suffer premature mortality. The
most lethal sources of pollutant emissions
in India are biomass-burning cook
stoves, which cause indoor air pollution
and are primarily used by poorer, rural
Indian families who cannot afford
liquid petroleum gas stoves—the typical
choice for richer, urban-based families.
According to Rao, pollution from cook
stoves leads to nearly one million deaths
of Indian babies and mothers every year.
Moreover, the ambient air pollution that
is produced by public services such as
transportation and electricity generation far
exceeds any benefits these families receive
from these services. While they do not
consume electricity or use transportation
to the same magnitude as richer families,
poorer families face asymmetrically
exaggerated mortality risks.
The Role of Government
Climate researchers and public health
officials alike have recognized that this grim
narrative of inequity in pollution-attributed
mortality cannot continue. What policies
can be passed to address this disparity?
In Rao’s ideal world, addressing
pollution in its totality and switching
from pollution-causing fossil fuels to
clean energy within the next ten years is
imperative. “Biomass cook stoves need
to go away, since the health impacts of
indoor air pollution completely dwarf the
ambient air pollution,” Rao said. However,
poorer Indian households wouldn’t be able
to afford and reliably use clean fuels unless
the government provided it to them.
The government has taken a necessary
first step. “In the past decade, aggressive
policies have provided a free stove and a
free gas cylinder to fifty million households
in India," Rao said. "The problem is, the
fuel has continued to be expensive, so they
haven’t used those new stoves as much.
It's just a governance failure: we need
to make sure that the fuel is cheap.” He
acknowledged that some policies could
cause market failures or require public
investments. But since poorer people
suffer most from the exorbitant price of
clean fuels, the onus to provide cheap,
clean fuel is on the government.
According to Rao, one of the more feasible
solutions is to use targeted emissions
policies, where the costs of emission are
apportioned to the consumers of fuels. This
would incentivize lower fuel usage and in
turn decrease ambient air pollution.
The proposals don’t stop there. “We
need to address food waste and garbage
disposal in cities and areas that are affluent,
www.yalescientific.org
December 2021 Yale Scientific Magazine 13
FOCUS
The Environmental Issue
where most of the consumption waste is and wide. Accordingly, he joins the gamut implementation remains a challenge.
coming from. We need to create the policy
instruments for the costs to flow to the
right people,” Rao said. Such policies, along
with governments ensuring that clean fuels
are accessible to poorer households, could
reduce exposure to air pollutants.
By providing free stoves to a significant
proportion of India’s population, the Indian
government has shown that it has the capacity
to provide clean energy to poorer households.
It also seems like it has the capacity to
implement targeted emissions policies.
of an increasing force of researchers, who by
writing policy reports, publishing academic
papers, and making data available to nongovernmental
organizations, are increasingly
influencing governmental decisions.
“I like to think of myself as an academic
activist, as having the privilege of generating
[scientific] insights," he said. "I see it as
an obligation on my part to make those
insights available as broadly as possible.”
Clearly, “solving climate change” or
“fixing pollution” is much easier said
Nevertheless, Rao and his team shed
some much-needed light on the social
ramifications of pollution inequity and
mortality. Their work points to targeted
emissions policies and biomass cook stove
replacement policies as necessary, even
inevitable, solutions.
As scientists and climatologists continue
to embrace their roles as policy influencers
and activists, governmental inaction will
no longer remain an option. In this way,
Rao’s ideal world—one in which pollution
But capability doesn’t always translate than done. Even though the technology inequity is vanquished—just might
to action. “Unfortunately, the cliche is that to reduce emissions exists, its equitable become a reality. ■
there needs to be strong political support
for it. There is a cost that has to be paid,”
Rao said. And according to him, that is ART BY BREANNA BROWNSON
not something that scientific research
alone can repair. “Understanding people’s
dependence on the fuels, the nature of the ABOUT THE AUTHORS RISHA CHAKRABORTY AND ARUSHI DOGRA
lack of reliability of the fuel supply, and the
RISHA CHAKRABORTY is a first-year Neuroscience major prospect in Saybrook College. In addition
political economy of the fuel price setting to writing for YSM, Risha plays trumpet for the Yale Precision Marching Band and Undergraduate
and subsidies are essential,” he said.
Jazz Collective, volunteers for HAPPY (Hypertension Awareness and Prevention Program at Yale), and
Because of the results of the model, researches Parkinson’s Disease at Chandra Lab in the School of Medicine.
scientists now know the contributors and ARUSHI DOGRA is a sophomore in Jonathan Edwards College, prospectively majoring in MCDB and
victims of pollution, both geographically HSHM. Outside of YSM, Arushi is on the board of the Yale Hunger and Homelessness Action Project,
and in terms of socioeconomic is involved in Health & Education Advocates for Refugees, and conducts immuno-oncology research in
characteristics. For meaningful change the Katz Lab in the School of Medicine.
to occur, governments and the public THE AUTHORS WOULD LIKE TO THANK Dr. Narasimha Rao for his time and enthusiasm about his research.
must also internalize these findings. Rao’s FURTHER READING
current personal goal is to improve global Rao, N. D., Kiesewetter, G., Min, J., Pachauri, S., Wagner, F. (2021). Household contributions to and impacts
understanding of how to diffuse clean fuels from air pollution in India. Nature Sustainability, 4(10), 859–867.
and sustainable energy technologies fast
14 Yale Scientific Magazine December 2021 www.yalescientific.org
The Environmental Issue
FOCUS
BY ANNA CALAME
AND
ANGELICA LORENZO
ART BY NOORA SAID
Today, climate change is not only at our doorstep—it’s in our living rooms, on our kitchen tables, and even in
our pockets, through near-constant coverage on television news, newspapers, and social media. Climate stories
are often accompanied by aggressive images: wind- and rain-battered palms, neighborhoods swallowed up by
churning floodwaters, forests consumed by flames, disturbingly vibrant thermal maps.
While these photographs impactfully illustrate the physical devastation wrought by extreme weather, recent research
suggests they may fail to capture a less visible but key consequence of climate change: its impact on mental health.
Studies conducted by Eun-hye Yoo, associate professor of geography at SUNY Buffalo, and Kai Chen, assistant professor
of epidemiology at the Yale School of Public Health, identified a possible link between extreme temperatures and increased
mental health-related emergency room (ER) visits. Such an association, though still subject to further research,
may have meaningful implications for how we think about climate change.
www.yalescientific.org
December 2021 Yale Scientific Magazine 15
FOCUS
The Environmental Issue
PHOTOGRAPH COURTESY OF CATHLEEN LIANG
From left to right: Pin Wang; Yiqun Ma (PhD candidate); Lingzhi Chu (PhD candidate); Chengyi Lin (PhD
student); Kai Chen.
A Gap in the Literature
While climate research has increased
significantly over the past two decades,
not all ramifications of the impending
crisis have been investigated equally.
Yoo and Chen are seeking to address a
consequential gap in the literature: the
effect of extreme temperature, both hot
and cold, on mental disorders. To that end,
they co-authored two studies with other
collaborators on potential associations
between extreme temperature events and
ER visits for mental health reasons in New
York State. While the first study examined
a wider array of mental disorders,
the second study investigated specific
conditions, such as anxiety disorders,
mood disorders, substance abuse, and
dementia, as reasons for ER visits.
Though prior studies suggesting probable
links between heat and negative mental
health outcomes have been conducted,
the field remains relatively sparse in
comparison to the larger body of climate
research. To account for this, Yoo points
to the fact that psychologists are primarily
interested in analyzing individual
behaviors, while epidemiologists engage
almost exclusively with population-level
data. As a result, overlap between research
in environmental epidemiology and
mental disorders is relatively rare.
For their part, these two researchers
come to the field from different
backgrounds—Chen, an environmental
health epidemiologist, has long harbored
an interest in the health implications of
climate change, while Yoo’s area of expertise
is geographic information science and
spatial statistics. Nevertheless, they share
a deep concern for this under-investigated
correlation, and the two enjoy an amiable
relationship, each quick to credit the other
for their unique contributions to the study.
Exploring the Effects of Extreme
Temperature
To investigate the relationship between
exposure to extreme temperature and risk
of increased ER visits, the researchers
employed a time-series analysis. Timeseries
models, a common type of statistical
analysis, use a series of data points
collected at fixed time intervals to make
a prediction or estimate an association.
In Yoo and Chen’s studies, the model
consisted of two time series—temperature
and ER visits—which both varied daily.
“What we do in this model is try to find
an association between these two timeseries,”
Chen said. “But in the meantime,
there are a lot of other things going on
that may influence this relationship, so we
need to use our model to control them.”
Data on daily ER visits for mental health
disorders were collected from the New York
State Department of Health and compared
to climate and air pollution data obtained
from the National Center for Environmental
Information Climate Data Online System.
The ER records, dating from January 2009
to December 2016, included demographic
information like race, age, and sex, as
well as the primary diagnosis code, which
the researchers used to identify mental
disorders in ER patients. Daily precipitation
and minimum, average, and maximum
temperatures were examined as part of the
temperature time-series. Separate timeseries
analyses were conducted in ten labor
market regions in New York State, and a
meta-analysis was performed to pool the
result the whole state.
Notably, the model was designed to
consider any delayed effects on mental
health caused by temperature exposure.
While a lag period of seven days was used
to identify short-term exposure effects
on increased ER visits, their analysis
also evaluated this exposure-response
relationship for a longer period of
twenty-one days.
Climate Consequences for Mental
Health
The first study, which focused solely
on Erie and Niagara counties, indicated
a strong positive association between
maximum temperature and increased ER
visits for mental illness. Significant risk was
observed at temperatures above twenty-nine
degrees Celsius and below eight degrees
Celsius. Across all lag periods, heat effect
was found to elevate one’s risk of visiting
an ER for mental illness. For maximum
daily temperatures under eight degrees
Celsius, the researchers observed a delay of
zero to fourteen days between exposure to
extreme cold temperatures and increased
ER visit risk. In other words, the cold
effect on ER visits was not always evident
until up to fourteen days after exposure to
temperatures below eight degrees Celsius.
However, neither precipitation nor air
pollution were found by this study to alter
the observed temperature-mental illness
relationship.
Though the first study suggested
that extreme temperatures may induce
adverse mental health effects for people
16 Yale Scientific Magazine December 2021 www.yalescientific.org
The Environmental Issue
FOCUS
of all ages and races, it also indicated
a disproportionate effect for certain
subpopulations. Youth and elderly
populations, defined as ages zero to
nineteen and over sixty-four, respectively,
seemed more susceptible to heat effects.
Additionally, the model suggested greater
risk of ER visits for African Americans
ages fifty to sixty-four exposed to intense
heat as compared to other racial groups
in the same age category. Some posit that
the observed vulnerability of African
Americans, the elderly, and young people
to extreme temperatures may reflect
disparities in access to healthcare, housing,
and technology on a larger, societal scale.
To examine how differences in geography,
climate, and population impacted
exposure-response relationships, the
researchers expanded the study to include
ten different labor regions in New York
State. Unlike in the first study, they did not
find short-term exposure to extreme cold
to be associated with increased ER visits for
any mental disorder. However, the findings
did suggest a positive association between
maximum daily temperatures above 27.07
degrees Celsius and elevated risk for ER
visits. Diverging from the findings of the
first study, no racial group or age cohort
was observed to be more vulnerable to the
effects of heat than any other group.
The varying results between
northwestern New York counties and
New York State as a whole suggest that
the results of any particular analysis
are subject to geographic and climatic
limitations and that further expansion
of the study is required to make more
generalizable conclusions. Foremost,
both studies support the researchers’
hypothesis that extreme temperatures
increase one’s risk for visiting the ER for
mental health reasons.
New Possibilities for Public Health
Measures currently in place to
protect the public from the effects of
severe weather include radio warnings
of impending extreme temperatures,
required heating systems in New York
housing, and publicly available cooling
and heating centers in urban areas.
Unfortunately, such efforts often fail to
meet the needs of the most vulnerable
populations. Cooling and heating
www.yalescientific.org
centers are rarely adequate in number or
capacity in low-income, under-resourced
neighborhoods, the very areas where
they are needed most. Additionally,
unlike heating systems, air conditioning
in housing is not necessitated under
New York law. This places an additional
financial burden on tenants and, in many
cases, effectively removes their access to
such systems altogether.
Chen cautioned that while improving
existing measures is necessary, as
they provide immediate support to
vulnerable groups, adaptive actions
like air conditioning are ultimately
“double-edged swords.” Air conditioning
increases energy demand and emissions,
thus exacerbating climate change. Chen
and Yoo pointed instead to research
suggesting that the cultivation of green
spaces in so-called “heat islands,” urban
areas that retain high levels of heat, can
reduce temperatures naturally. By adding
green spaces, communities can promote
better mental and physical health without
compromising the environment.
Ultimately, however, most climate
research indicates that effective prevention
of climate change will require efforts on
a much larger, societal scale, including
the commitment of governments and
corporations to achieve net zero emissions.
An Expansive Research Landscape
Yoo and Chen know that their work
is far from done. For all the questions
this study answers, it raises just as many
ABOUT THE AUTHORS
new ones. Both highlighted the need
for future research to intimately involve
psychologists. “While we were working
on this study, I had a lot of conversations
with psychologists,” Yoo said. “We have
a lot of interesting hypotheses that need
to be verified, but in some cases, this
is hard to do with population data…
We need to combine population-level
studies with cohort studies.”
Yoo emphasized that future studies
should investigate new or more diverse
populations in different climatic regions
to better understand the variation
observed between the county- and statelevel
studies as well as discrepancies in
outcomes between subgroups.
Chen expressed particular interest in
further exploring how and why shortterm
exposure to extreme temperatures
can exacerbate more long-lasting, chronic
conditions. “That’s something we don’t
know much about,” Chen said. “There
must be something, through biological or
societal mechanisms, that can explain how
temperature [has this effect]. This is paving
the way for more research on this topic.”
As climate change accelerates, it seems
that the urgency of Yoo and Chen’s
research will only become more apparent.
Without a proper understanding of
how extreme temperature events might
increase potential for severe mental
health episodes, we cannot be adequately
prepared for the full range of climate
consequences. After all, as the oftrepeated
climate activism saying goes, the
climate is changing—why aren’t we? ■
ANNA CALAME
ANGELICA LORENZO
ANNA CALAME is a junior in Davenport College studying the history of science, medicine, and public
health. Outside of her work with the YSM, Anna is involved with Yale UAID, YaleBleeds, and the club
tennis and climbing teams.
ANGELICA LORENZO is a sophomore in Grace Hopper College majoring in Biomedical Engineering.
In addition to writing for YSM, Angelica is a percussionist in the Yale Symphony Orchestra, serves as
Professional Development Chair for the Yale Society of Women Engineers, climbs with YCT, and does
tissue engineering research in the Pober Lab.
THE AUTHORS WOULD LIKE TO THANK Professors Chen and Yoo for discussing their research
FURTHER READING
Yoo, E. H., Eum, Y., Gao, Q., & Chen, K. (2021). Effect of extreme temperatures on daily emergency room
visits for mental disorders. Environmental Science and Pollution Research, 1-14.
Yoo, E. H., Eum, Y., Roberts, J. E., Gao, Q., & Chen, K. (2021). Association between extreme temperatures
and emergency room visits related to mental disorders: A multi-region time-series study in New York,
USA. Science of The Total Environment, 148246.
December 2021 Yale Scientific Magazine 17
FOCUS
The Environmental Issue
THE NEW
RUMPELSTILTSKIN:
SPINNING WOOD
INTO PLASTIC
A sustainable
solution to
humanity’s
urgent waste
problem
BY LUCAS LOMAN AND KAYLA YUP
ART BY KATHERINE MOON
Avocado seeds, lobster shells, fish scales,
red algae, cactus leaves… and now, wood.
What do these items have in common?
As it turns out, researchers around the world
have turned to all these unexpected materials to
develop biodegradable alternatives to plastic.
Petrochemical plastics are plastics derived
from crude oil and natural gas. Such nonrenewable
resource-based plastics have pervaded
modern life—they can be found everywhere,
from fertilizers to packaging to clothing, and
are cemented as an integral part of society.
According to the International Energy Agency,
petrochemical feedstock now accounts for twelve
percent of oil demand around the world. But it is
not the quantity alone that renders plastic a global
issue—instead, it is the lack of biodegradability.
18 Yale Scientific Magazine December 2021 www.yalescientific.org
“
[...]
how could a balance
between degradability and
durability be achieved?
A potential solution may lie in
bioplastics, alternative materials
that use different biomass feedstock
to create bio-based plastics that are
biodegradable. A breakthrough study on
the creation of bioplastic from natural
wood was recently published in Nature
Sustainability, co-authored by Yuan
Yao, assistant professor of industrial
ecology and sustainable systems at the
Yale School of the Environment (YSE),
and Liangbing Hu, a professor at the
Center for Materials Innovation at the
University of Maryland.
The quest for a biodegradable plastic
to combat the billions of metric
tons of plastics accumulating in the
environment has led to the creation
of these bioplastics. Currently,
petrochemical plastics last for hundreds
to thousands of years due to the stable
long polymer chains they contain,
such as those found in polyethylene,
polystyrene, and polyvinyl chloridebased
plastics. Because previous
efforts to produce bioplastics have
been associated with the use of toxic
chemicals, weak mechanical strength,
and poor water stability, researchers
started to wonder: how could a balance
between degradability and durability
be achieved?
In this study, the research team reports
a method of fabricating lignocellulosic
bioplastic that not only demonstrated
recyclability and biodegradability, but
also dramatically improved durability.
“There are many people who have tried
to develop these kinds of polymers in
plastic, but the mechanical strands are
not good enough to replace the plastics
we currently use, which are made mostly
from fossil fuels,” Yao said in a Yale
School of the Environment News article.
Overall, their bioplastic showcases high
mechanical strength as well as improved
water and thermal stability.
”
Building Better Bioplastic
To create bioplastics, researchers
typically extract lignin and cellulose,
two organic polymers responsible for
plant structure, from wood. The team
performed a process called in situ lignin
regeneration, whereby instead of isolating
lignin and cellulose, they homogenized
wood powder, or made it uniform, to
form a high-density, viscous slurry.
Next, deep eutectic solvent (DES)—a
group of biodegradable and recyclable
substances—was used to dissolve lignin
and break apart the hydrogen bonds
between cellulose fibers. Water was then
added to the slurry for lignin regeneration
from the DES. Finally, the DES was
removed from the mixture through a
filtration and washing process, leaving
behind a stable cellulose-lignin material.
Through a simple casting process, the
team fabricated bioplastic films.
In sharp contrast to cellulose film,
lignocellulosic bioplastic was found to
be considerably more resistant to water
The Environmental Issue
FOCUS
damage. The researchers demonstrated
that it absorbed water at a much slower
rate than standard cellulose film. As a
result, lignocellulosic bioplastic samples
maintained their shape well past thirty days
of being submerged in water, far beyond
the point at which cellulose film degraded.
While the durability of lignocellulosic
bioplastic is critical for its large-scale
use, the most important characteristic
of this new bioplastic was its ability to
break down under the right conditions.
When the researchers subjected it
to an outdoor environment, they
found that exposure to sun, wind,
and rain was enough to completely
break it down within five months. For
comparison, PVC—a commonly-used
synthetic plastic—subjected to identical
conditions remained unchanged. “That
[characteristic] is what really makes
this plastic good: it can all be recycled
or biodegraded," Yao told the Yale
School of the Environment News. "We’ve
minimized all of the materials and the
waste going into nature.”
The more sustainable production
process of lignocellulosic bioplastic, in
addition to the material's impressive
physical properties, makes it a promising
replacement for less environmentally
friendly petrochemical plastics. This
bioplastic follows a closed-loop cycle
in which microorganisms in soil can
naturally degrade the material. Typical
www.yalescientific.org
December 2021 Yale Scientific Magazine 19
FOCUS
The Environmental Issue
plastics take hundreds of years to
decompose in nature, filling up landfills
and potentially leaching toxic chemicals
into groundwater; in contrast, this type of
bioplastic breaks down far more quickly
and poses less risk to communities and
nature in the process. The lignocellulosic
bioplastic can also be recycled.
Barbara Reck, a senior research
scientist at the Yale School of the
Environment, characterized the project’s
findings as an impressive innovation.
“A bioplastic is fully degradable under
regular outdoor conditions, offering
an opportunity to reduce putting a
much-needed end to the accumulation
of at least some plastics in the natural
environment,” she said.
The Future of Bioplastics
PHOTOGRAPH COURTESY OF PIXABAY
Synthetic plastics p ose a major threat to e cosystems once they are disp osed of, f illing up
landfills and polluting waterways.
a product that has a large environmental could elucidate the connection between
The environmentally friendly, closedloop
impact because of its persistence to the growth cycle of forests to the
cycle used to create this bioplastic one that might potentially be relatively manufacturing process of this bioplastic.
signals hope for a future where strong, benign,” Ashton said.
Such advances in the processability and
biodegradable bioplastics can be In determining a sustainable functionality of wood could motivate
produced from resource-abundant, production network, the team has better forest management practices
sustainable, and renewable biomass. continued to research how scaling up in addition to realizing the lower
Hu told the Yale School of the manufacturing for this bioplastic could environmental impact of using wood as
Environment News that the malleability impact forests. The issue with using wood a sustainable material.
of this bioplastic will allow for several byproducts is that large-scale production Considering our far-reaching reliance
applications. From being molded into a may require massive amounts of wood, on plastic in society, the discovery of
film for use in plastic bags to being shaped which could negatively impact forests a biodegradable, durable bio-based
for use in automobile manufacturing, this and local ecosystems.
plastic is worth its weight in gold.
bioplastic may help solve our society’s According to Yao, the research team In this way, the researchers are like
current dependence on plastic.
is responding to this potential issue Rumpelstiltskin—spinning something
Because this lignocellulosic bioplastic by working with a forest ecologist to valuable out of a natural material in
is made of biomass feedstock, its build forest simulation models, which ways we never thought possible. ■
production would entail the use of local
materials rather than nonrenewable
fossil fuels, which would further ABOUT THE AUTHORS
mitigate environmental damage. “It is
very promising to see the flexibility LUCAS LOMAN AND KAYLA YUP
in the biomass feedstocks used for LUCAS LOMAN is a sophomore Environmental Engineering major in Morse College. In addition
this process,” Reck said. “One can to writing for YSM, Lucas serves in the Energy and Environment Center of the Yale Policy
imagine a decentralized production Institute, as well as Yale Design for America’s Garden Club of New Haven project.
network that uses predominantly local KAYLA YUP is a first-year in Pierson College interested in studying Biomedical Engineering.
materials, which in turn would keep the Outside of YSM, Kayla serves as a copy editor for the Yale Herald, writes for the Yale Daily News,
overall environmental impacts [of the
and works for the Peabody Museum.
lignocellulosic bioplastics] rather low.” THE AUTHORS WOULD LIKE TO THANK Dr. Barbara Reck and Dr. Mark Ashton for providing
Yao’s team’s work on using wood as a commentary.
substitute for plastic presents significant
substitution potential for petroleum
derived plastics. Mark Ashton, Morris K.
Jesup Professor of Silviculture and Forest
Ecology and the Director of the Yale
FURTHER READING
Anusewicz, J. (25 March 2021). Turning Wood Into Plastic. Yale School of the Environment News.
Xia, Q., Chen, C., Yao, Y., Li, J., He, S., Zhou, Y., ... & Hu, L. (2021). A strong, biodegradable and recyclable
lignocellulosic bioplastic. Nature Sustainability, 1-9.
Xiao, S., Chen, C., Xia, Q., Liu, Y., Yao, Y., Chen, Q., Hartsfield, M., Brozena, A., Tu, K., Eichhorn, S. J., Yao, Y.,
Forests, further emphasized the benefits Li, J., Gan, W., Shi, S. Q., Yang, V. W., Lo Ricco, M., Zhu, J. Y., Burgert, I., Luo, A., … Hu, L. (2021). Lightweight,
of using bioplastic over petrochemical strong, moldable wood via cell wall engineering as a sustainable structural material. Science, 374(6566),
465–471.
plastics. “[Bioplastic usage can] mov[e]
20 Yale Scientific Magazine December 2021 www.yalescientific.org
COW TOILETS 101
TOILET-TRAINED COWS
The Environmental Issue
FEATURE
BY JACK LITKE
ART BY ANMEI LITTLE
Like those in all animals, the internal biological processes of
cattle create byproducts that must be peed, pooped,
or (rather notoriously) farted out. Collected waste
from the world’s 1.5 billion cows creates a mess for farmers
and scientists alike. In addition to the potent greenhouse
gases released from their farts, the solid and liquid waste
generated by these famously flatulent ruminants can
pollute water systems, reduce air quality, and contribute to
global warming. Urine contains nitrogen, which is naturally
converted into nitrous oxide, a greenhouse gas three-hundred
times more powerful than carbon dioxide. Globally, cattle urine
accounts for nearly 1.6 percent of greenhouse gas emissions.
Scientists from New Zealand and Germany think they may have
discovered a solution: toilet-training cows.
Lindsay Matthews, a researcher at the University of Auckland
and the project’s leader, has considered the possibility for a long
time. In a 2007 radio interview on the harmful environmental
effects of cow waste, the interviewer humorously suggested that
Matthews train cows to use the loo. The interviewer, thinking his
wacky suggestion would whiz by without much more than a laugh,
was shocked to hear that Matthews thought it possible.
Influenced by American behavioral psychologist B.F. Skinner,
Matthews and his team developed a backward-chaining—that is,
working backwards from the goal—three-step process for training cows.
First, they established a specially constructed latrine as the correct
place to “void.” Individual calves were given a diuretic and led into
the latrine. Every time a calf urinated, they were rewarded with either
a molasses drink or crushed barley—“Ben and Jerry’s [for] cattle,”
described Matthews. Training sessions, which lasted for no more than
forty-five minutes, were continued until the calves turned to receive the
reward after urination eighty percent of the time, or until eight or ten
sessions had been completed. At this stage in the training, Matthews
and his team were unsure whether they had only conditioned the
calves to expect reward upon urination, or whether they had also
established the latrine as the correct location for urination.
Next, the calves were allowed to roam freely in a segment outside
the latrine. Calves that moved into the latrine to micturate—that’s
jargon for urinate—were rewarded, while “accidents” outside the
latrine were punished with a three-second water spray. Calves
were considered sufficiently trained after three consecutive correct
urinations occurred during a session. By the end of the study,
eleven of sixteen calves were declared successfully trained.
Finally, a second section was opened leading to the latrine, forcing
the calves to control their reflexes over an extended time period
and distance. Remarkably, successfully trained calves urinated in
the latrine approximately seventy-two percent of the time without
any corrective intervention from the experimenters.
Matthews and his team hope that their research findings will be
implemented by large and small-scale operations around the world.
www.yalescientific.org
Matthews
acknowledges
that there will be s o m e
difficulties in scaling-up
the training, but
he thinks that modern technology exists to enable training on a large
scale. He suggests that young calves—who require more attention
than adult cows and can be kept individually—be monitored and
rewarded using machine vision. Maintaining the correct behavior
will require careful design and strategic positioning of the latrines,
but Matthews is optimistic that “[they] can crack it.”
Matthews suggests that punishment for urination outside may
not be required for training. During the training process, some of
the calves were successfully trained without the three-second water
spray. Of the calves that were punished, most immediately stopped
urinating, entered the latrine, and finished their business. “The
latent behavior was already there,” Matthews said, “The calves just
needed a reminder for it to be correctly expressed.”
The calves are like “kids who know the toilet, [and] know the
routine. They just get so distracted,” Matthews said.
He also thinks that training processes that reward for correct
behavior inherently punish incorrect behavior: the absence of a
reward during incorrect behavior is itself corrective. Matthews
and his team will further explore this possibility in the future, as
eliminating the punisher will facilitate training on a large scale.
Matthews’ research has demonstrated that these “dopey”
ruminants are actually quite intelligent. Through training, they
can gain an interoceptive awareness of their urinary systems
and learn to control their reflexes—often faster than an infant.
And we have a lot to gain when we don’t underestimate cows’
brainpower: Capturing eighty percent of cow urine will reduce
ammonia emissions by fifty-six percent and significantly reduce
the release of nitrous oxide. ■
December 2021 Yale Scientific Magazine 21
FEATURE
The Environmental Issue
THE FAULT IN
OUR STARS
Light pollution and the rise of
satellite megaconstellations
BY ETHAN OLIM AND ANAVI UPPAL
ART BY ANASTHASIA SHILOV
Far above the rush of everyday life, past our
fragile atmosphere, and across millions of miles
of space, billions of stars glow. While bright city
skylines already make it difficult for people in
urban areas to enjoy this beautiful night sky,
a new source of light pollution is on the rise:
satellite megaconstellations, also known as
satcons. Satcons are collections of thousands
of artificial satellites launched by commercial
companies, and they are lighting up the
night sky. Researchers from the University of
Regina, University of British Columbia, and
University of Toronto at Scarborough recently
collaborated on a predictive model for the
damage satcons will ultimately cause to their
research and to the night sky.
In the last few years, researchers have seen the
impacts of satcons grow both in their research
and in their everyday lives. Astronomer
Samantha Lawler moved to Saskatchewan in
2019 for a faculty position at the University
of Regina and was able to see the Milky Way
from her home for the first time. But she saw
something else as well: a growing number of
satellites whizzing by due to Starlink, a satellite
constellation operated by SpaceX with the
stated goal of providing worldwide internet
service. “I knew from my calculations that
this [was] going to be a big problem for a lot
of areas of research in astronomy,” Lawler said.
Astronomers often collect data by using
telescopes to take pictures of the sky in different
wavelengths of light, such as visible, infrared,
and radio. However, the recent increase in
satcons has resulted in an increasing number
of images being contaminated by satellite
streaks. While this can currently be corrected
for by taking several images of the same patch
of sky, this restorative measure will become
increasingly unreliable as more satcons are
launched and more images are contaminated.
Even telescopes in space aren’t immune to
22 Yale Scientific Magazine December 2021
www.yalescientific.org
satellite contamination—the historic Hubble
Space Telescope has to contend with it as well.
The future James Webb Space Telescope will
be one of only a few telescopes free from their
influence, due to its more distant orbits.
The brunt of the impact of satcons will likely
be felt by astronomers who study the skies in
visual wavelengths. As images become more
and more filled with satellite streaks, they will
contain fewer and fewer pixels of data that are
actually useful to researchers. For example, the
Vera Rubin observatory, a nearly $500 million
facility in Chile, has predicted that thirty
percent of its images will be severely impacted
by satellite trails. “The same science goals [in
visual astronomy] can happen, but they’re
going to take longer,” Lawler said.
Other types of astronomical research will feel
the impact of satcons as well. Near Earth object
observations, which involve monitoring for
asteroids potentially dangerous to our planet,
will become much more difficult as satellites
are mistaken for asteroids. Radio astronomy
will also be hit hard as commercial satellites
begin making noise at frequencies currently
reserved for research.
In most fields of astronomy, it will
simply take more data over more time to
reach the same findings. But getting access
to telescopes and observatories to take
data is already incredibly competitive for
researchers. “It just means that fewer people
are going to be able to get science results. We
don’t actually know what we’re going to miss,
and that’s pretty sad,” Lawler said.
To get an idea of the damage satcons will
cause, Lawler and two other researchers created
a model based on reflectivity estimates and
launch filings to the Federal Communications
Commission (FCC). Their model allows
anyone curious to enter a latitude, time of
day and year, and several other factors, and
view an estimate of what satcons will affect
their night sky. It is freely available at http://
megaconstellations.hanno-rein.de/.
In creating this model, researchers faced the
major challenge of modeling the reflectivity
of satellites without specification information
from the companies. As such, they used a
classic physicist trick: modeling every object as a
sphere. This allowed for surprisingly successful
predictions, creating data that matched with
observations better than more complicated
attempts. They also had to balance countless
other complex factors, including distribution
models for orbits. But their work will pay off:
such an accurate model will be extremely useful
to other researchers going forward.
www.yalescientific.org
It’s worth questioning how this problem
could be fixed instead of simply modeled
better. At first glance, there seems to be an
easy solution: regulate the corporations
launching the satcons. But unfortunately,
no regulations currently exist for low Earth
orbit. At the moment, industry is voluntarily
having some discussions about the issue:
this July, the National Science Foundation
hosted SATCON 2, a conference to facilitate
conversations between astronomers and
satellite operators. But “it just became
incredibly clear during the meeting: you
[corporations] don’t have to be here. You
don’t have to talk to us,” Lawler said.
Companies are ultimately under no
obligation to respect the night skies, and
never will be without a major change in
international regulation, which would take
years to implement. Meanwhile, SpaceX
continues to rapidly launch satellites into
space. “My hopes are not enormously high
that [regulation] will happen fast enough,”
said Hanno Rein, an astrophysicist at
University of Toronto at Scarborough.
Satcons are also causing enormous
environmental problems. Their launches
release an incredible amount of carbon into
the atmosphere.
And that’s not the end of the damage they
can cause. SpaceX alone plans to have 42,000
satellites that will be replaced every five years,
meaning that they will have to deorbit more
than twenty satellites per day. These satellites
will burn up in Earth’s atmosphere, depositing
six tons of aluminum and other materials into
our upper atmosphere daily and wreaking
untold environmental havoc.
One measure could help prevent this fate:
the global recognition of low Earth orbit as an
environment. This would force environmental
impact assessments to be conducted for these
satellites, giving governments a better idea of
their potential damage to the atmosphere.
The Environmental Issue
FEATURE
While researchers would much rather
return to their preferred areas of study,
satcons are not going away—so unfortunately,
neither is research into their effects, including
their climate and environmental impacts. For
example, teams have begun to look into what
huge quantities of deorbiting satellites might
imply for Earth’s atmospheric chemistry.
Research may also need to examine the
biological implications for animals that rely
on the night sky for navigation.
Astronomers will continue working
to mitigate the effects of satcons on their
research, including attempting to lower the
numbers of satellites launched. Additionally,
they will advocate for satellites to be launched
into orbits minimally destructive to research.
Finally, they will aim to make satelliteimpacted
research as useful as possible—
for example, work is being done to perfect
algorithms to remove satellite damage
from images. “Someone could describe it as
chemotherapy for your images. It’s not great,
not ideal, but it’s better than nothing,” Lawler
said, attributing the phrase to astrodynamicist
Moriba Jah at the University of Texas Austin.
Unfortunately, while these strategies help
mitigate the damage wrought by satcons, they
can never fully undo it.
The benefits brought by Starlink and
other satcon services are certainly worthy of
acknowledgment. But only a tiny fraction of the
world’s population will be able to afford these
services—Starlink internet service currently
costs $99 a month, plus a $499 upfront cost.
This creates a familiar system where wealthy
countries reap the rewards of technological
advancement while the entire world feels its
negative consequences. A tiny portion of the
Earth will gain faster internet service, and an
even tinier portion will line their pockets. But
untold volumes of astronomical research—
and perhaps more tragically, the sheer beauty
of the clear night sky—will be lost to all. ■
IMAGE COURTESY OF THE EUROPEAN ORGANIZATION FOR ASTRONOMICAL RESEARCH IN THE SOUTHERN HEMISPHERE
The Milky Way rising above the Paranol Observatory in Chile. The Paranol Observatory is one of many that
will soon have to contend with heavy interference from satcons.
December 2021 Yale Scientific Magazine 23
FEATURE
The Environmental Issue
WILDFIRES AND OCEAN BLOOMS
HOW AUSTRALIA'S FIRES TRIGGERED ALGAE BLOOMS
THOUSANDS OF MILES AWAY
BY KRISHNA DASARI AND NATHAN WU
ART BY TAI MICHAELS
From September 2019 to March
2020, Australia experienced one
of the worst recorded wildfire
seasons in its history. Spanning 18.6
million hectares, the wildfires were
responsible for massive ecological
and socioeconomic damage. Around
three billion animals were estimated
to have been displaced or killed,
causing a severe loss of biodiversity
that will prove difficult to recuperate
from. Furthermore, 715 million tons
of carbon dioxide and various aerosols
were released into the atmosphere over
the course of the bushfires, the effect of
which was felt around the world.
Despite the undeniably catastrophic
effects of these fires, their unprecedented
nature provided researchers with a
unique opportunity to study the global
impacts of wildfires—including their
previously under-studied consequences
for marine ecosystems. The researchers
hope that further research on this topic
can help us better predict and respond to
wildfires and their effects in the future.
Scientists Weiyi Tang and Joan
Llort, helming an international team
of researchers under biogeochemist
Nicholas Cassar and climatologist Richard
Matear, were intrigued by the relationship
between two known phenomena:
wildfires drag nutrients like iron into
the atmosphere, and iron deposition
can trigger phytoplankton blooms in
water given the right conditions. Further
motivated by the limited research on the
marine effects of wildfires, the scientists
used data from the bushfires to determine
their effects on phytoplankton blooms in
the South Pacific Ocean.
“[The bushfires] provided us with a
unique opportunity to see how and if
such wildfires could have an impact on
IMAGE COURTESY OF FLICKR
The Australian bushfires ravaged entire ecological systems, causing a terrible loss of biodiversity.
ocean ecosystems downwind. Very often
in science it’s very difficult to detect the
signal from the noise, but here we had an
unprecedented wildfire event, and so this
was a unique opportunity,” Cassar said.
To measure aerosols produced by
wildfires, the team used black carbon
aerosol optical depth (AOD) data
provided by the Copernicus Atmospheric
Monitoring Service (CAMS). Black
carbon AOD cannot actually be
measured directly, but is rather estimated
from overall AOD, which is in turn
measured spectroscopically by satellites
in the atmosphere. This data reflects
the concentration of all aerosols in a
given air column—not just black carbon
aerosols produced by fires. The CAMS
aerosol model uses meteorological
data to separate total AOD into many
subcategories, including black carbon,
dust, sulfate, and salt.
AOD values for these wildfires were
abnormal, reportedly over threehundred
percent higher than average
values since 2004. They indicated
eastward drift of black carbon into the
South Pacific Ocean, which was then
confirmed through modeling of air
trajectories from meteorological data.
To quantify phytoplankton growth
in the South Pacific, the team took
advantage of the fact that phytoplankton,
as photosynthetic organisms, produce
the green pigment chlorophyll a
(Chla). Chla concentrations could then
be estimated from publicly available
satellite observations as a proxy for
phytoplankton biomass. This satellite
data was subsequently confirmed by
marine floats deployed by Argo, an
international program that collects
ocean data with an array of below-thesurface
floats that occasionally surface
to transmit their data to satellites.
Just six months after the wildfires
started, Chla concentrations increased
by more than 150 percent compared
to historical concentrations in oceanic
regions along the path of aerosol
24 Yale Scientific Magazine December 2021 www.yalescientific.org
The Environmental Issue
FEATURE
transport. Furthermore, these increases
in concentration occurred just days to
weeks following spikes in black carbon
AOD, suggesting a connection between
wildfires and phytoplankton blooms,
and further revealing just how swiftly
events of this scale can impact the globe.
The international team also found that
aerosols collected at a station downwind
of bushfires had iron concentrations
over five times the median value of
concentrations observed at the same
station from 2016 to 2019, when smaller
wildfire events occurred. The formation
of blooms requires a variety of nutrients
and environmental conditions—iron
alone is not always sufficient. In this case,
the South Pacific Ocean likely had all the
sufficient conditions for phytoplankton
growth except for iron during the wildfire
season, meaning the iron deposits from
migrating aerosols were likely sufficient
to support the Chla concentration
increase observed in oceans. Thus, the
aerosols produced from the Australian
bushfires may provide an explanation for
the observed phytoplankton blooms in
the South Pacific.
Blooms can have varying ecological
effects depending on the type of
phytoplankton and the characteristics
of the body of water and environment.
In some scenarios, the blooms may,
in fact, benefit the climate. Through
photosynthesis, phytoplankton sequester
carbon dioxide from the atmosphere.
However, the authors have not yet been
able to determine if the carbon dioxide
sequestration is short-term, with carbon
dioxide quickly recycled back into the
atmosphere, or long-term, with carbon
dioxide exported to the deep ocean as
plankton biomass. In future wildfire
seasons, they hope to determine what
fraction of the carbon is sequestered
long-term by using sediment traps to
capture plankton biomass exported into
the ocean from blooms.
Further investigating long-term
sequestration effects will provide
important data that can be used to create
better climate models. Current climate
models do not sufficiently account for
the various and widespread effects of
wildfires. “You're expecting that the
frequency, the intensity, the duration
of some of these wildfires is going to
increase,” Cassar said. “And so, if we're
IMAGE COURTESY OF WIKIMEDIA COMMONS
Phytoplankton blooms occur across the world, such as
here in the Baltic Sea, with varying ecological effects.
going to project our climate in the
future, we need to understand how these
wildfires also impact ocean ecosystems
because of their role in the carbon cycle.”
With further testing at other wildfire
sites and more detailed biogeochemical
analysis, the team hopes they can develop
a better understanding of the climaterelated
impacts of wildfires that would
facilitate future climate predictions.
Because the oceans are
global, and because no
one owns them, there's a
real strong international
collaboration culture in
this space.
—Richard Matear
Ultimately, this project would have
been impossible without international
cooperation. The majority of the data,
including black carbon AOD data and
Chla concentration data, was sourced
from organizations and projects
producing publicly available atmosphere
and ocean data. This collaborative datasharing
and type of cooperation is typical
in the field of oceanography. “Because
the oceans are global, and because no
one owns them, there's a real strong
international collaboration culture in
this space,” Matear said. Such a spirit
of collaboration provides a model for
future climate research—international
cooperation is necessary to address this
global issue.
With this project, the research team
revealed the dynamic, interconnected
nature of our climate and ecology. In
fact, Matear and other climatologists are
changing the language they use to reflect
this connectivity. “I’m going to use the
word ‘earth system’ rather than ‘climate,’”
Matear said. “That’s probably a big
change that’s happening in the climate
modeling space, just acknowledging that
climate and carbon cycle processes are
intimately linked and you probably don’t
want to separate them.”
Climatological trends that may seem
small on paper, such as a global increase
in temperature by just two degrees
Celsius, can have far-reaching and
catastrophic effects. As weather patterns
and natural phenomena become more
severe due to climate change, so too do
the impacts they have on regions around
the world, on species nearing extinction,
and on delicate climate systems.
Today, humans have become deeply
entangled in this environmental web.
“We're such a successful species that we're
impacting our climate. We're impacting
the temperature of the atmosphere and
the likelihood of droughts in some
regions, so I think there's a local and
global impact of our species that we have
to take into account,” Cassar said.
It is vital to understand how local
perturbations by humans can cause
drastic changes on a global scale. This
study reveals just how much we have
yet to uncover about the connectivity
of Earth’s natural and artificial systems.
Cassar, Matear, and their team, for
example, observed links between
wildfires and phytoplankton populations
thousands of miles away. Future research
into this issue will require searching for
more unexpected connections between
climate-related phenomena. ■
www.yalescientific.org
December 2021 Yale Scientific Magazine 25
FEATURE
The Environmental Issue
RATIONING BREATHS
DISPARITIES IN THE VERY AIR WE BREATHE
BY SOPHIA LI AND CATHERINE ZHENG
ART BY HANNAH SHI
It’s in the very air we breathe.
Invisible gases, small but pervasive,
travel and lodge themselves in our
airways as we go through our daily
motions. The truth is, the air we breathe
is not equitable in its distribution.
Harmful pollutants such as nitrogen
dioxide (NO 2
) aggregate in particular
communities, leading to severe health
disparities and stark gradients in air
pollution maps. It has long been known
that low-income, urban neighborhoods
and communities of color experience
significantly worse air pollution
than higher-income, majority-white
neighborhoods. Sally Pusede’s group
from the University of Virginia took
this research a step further, conducting
a broad survey of the air pollution of
the United States and comparing it
with various external factors such as
days of the week and vehicle pollution
in order to locate specific drivers of the
disparities.
This project combined environmental
research with environmental justice
policy in hopes of elucidating intercommunity
disparities. It focused on
nitrogen dioxide, NO 2
, an air pollutant
commonly released from road vehicles
and fossil fuel combustion reactions.
NO 2
is also a key factor in atmospheric
oxidation and secondary pollution, as it
reacts with other chemicals in the air to
form pollutants that are not otherwise
directly emitted into the atmosphere,
such as ozone and acid rain. NO 2
has
been previously shown to increase levels
of respiratory irritation and can lead to
hospitalization due to impaired lung
function and shortened life expectancy.
The researchers used data from the
TROPospheric Ozone Monitoring
Instrument (TROPOMI), a satellite
launched in 2017 that maps NO 2
levels
almost daily, providing a high degree
of clarity for air pollutant emissions
at the city-level. “Prior to TROPOMI,
the satellite observations [regarding
NO 2
emissions] were too coarse to look
within a city, so you couldn’t go into a
city and look at how NO 2
is distributed.
With these finer scale observations,
we can now look at the steep gradients
within a city to the point where you can
look at a map of NO 2
and make out the
individual roads,” said Mary Angelique
G. Demetillo, a graduate student in
Pusede’s group.
With the TROPOMI data, they were
able to calculate mean NO 2
tropospheric
vertical column densities for each 1 x 1
km 2 area. Pusede’s group analyzed NO 2
data from 2018 to 2020 from fifty-two of
the largest cities, stopping right before
the start of the pandemic to eliminate any
changes in pollution caused by reduced
social activity. The cities sampled were
“urbanized areas,” so the data reflected
intra-urban, rather than suburban-urban,
differences. The data was classified by race,
ethnicity, and income to compare the air
pollution in low-income communities of
color to that of high-income, majoritywhite
neighborhoods and to quantify
inequalities in terms of NO 2
pollution.
“All of the data that we used was publicly
available, so anyone can use it, and it’s just
a question of what’s the best method and
how can we integrate all of these types of
datasets together. For me, that challenge
is pretty exciting,” Demetillo said.
Previous research in this field had
already established these existing
disparities, but Pusede’s group
wanted to look into the drivers of
these disparities. In this paper, they
compared the data between weekends
and weekdays, and cross-referenced
IMAGE COURTESY OF FLICKR
Air pollution emissions from diesel vehicles contribute
to elevated nitrogen dioxide levels in the atmosphere.
26 Yale Scientific Magazine December 2021
www.yalescientific.org
The Environmental Issue
FEATURE
IMAGE COURTESY OF NASA
The global three-year running mean of NO 2
levels from 2010-2012 taken directly from the NASA worldview page.
this with patterns in diesel truck traffic,
allowing them to see what proportion
of the atmospheric disparities were due
to diesel truck emissions. While diesel
trucks make up between three and five
percent of vehicles at any given time,
they contribute thirty to fifty percent of
air pollution from NO 2
and many other
harmful chemicals and particles. “People
who live in impacted communities have
long known that diesel trucks are a
major contributor to disparities, but
what we contribute here is really sort of
the quantification of those [disparities]
and the ability to see those [disparities]
across cities and in so many cities at the
same time,” Pusede said. Data regarding
diesel truck emissions was taken from
the Fuel-Based Inventory from Vehicle
Emissions, which provides information
on emission rates and fuel use.
The results of this study indicate
that in general, the air pollution in
lower-income communities of color
is twenty-eight percent higher than
that of high-income majority-white
neighborhoods. Some of the cities with
the highest inequalities were Phoenix,
Arizona (where NO 2
pollution was
forty-six percent higher for lower
income communities of color) and Los
Angeles, California (where pollution
was forty-three percent higher).
Regarding diesel truck emissions
specifically, air pollution decreases by
sixty-two percent on weekends—in part
because more vehicles are parked on
the weekends. Despite this, disparities
still remain, as NO 2
pollution in lowerincome
communities of color only falls
by thirty-seven percent.
www.yalescientific.org
This study only used data from 2018.
"[Over time] broadly speaking, there
have been really large gains in air quality
across the country, but disparities have
persisted throughout this time,” Pusede
said.
Just having this data in front of us
is not enough. Pusede’s group hopes
to influence policymakers with these
findings to induce changes that confront
and dismantle this inequality. And this
work doesn’t just relate to scientists.
“For sure it would take interdisciplinary
collaboration with people who work with
human activity data, urban planning,
maybe even historians to assess how the
placement of communities and roads
has contributed to the current-day air
pollution distribution,” Demetillo said.
These policies could take the form
of identifying specific areas in urban
regions that should be more highly
regulated for diesel truck traffic.
But even if diesel truck emissions were
effectively brought down to zero, there
would still be disparities in air pollution
from other sources. Thus, moving forward,
researchers must investigate other major
contributors to air pollution and its
unequal distribution, as well as patterns
affecting human exposure to it and the
causes of these disparities. Human activity
data shows us that patterns in activity
affect an individual’s exposure to pollution.
Meteorology affects the distribution
of NO 2
within the atmosphere, which
also affects our exposure to pollution.
Urban planning is a major factor in air
quality disparities, as the placement and
structuring of communities and roads
affects how pollution is distributed.
Closely analyzing satellite data is also
key to reducing inequality and lowering
air pollution. In this study, since the
data was so finely resolved spatially,
some temporal data was sacrificed: the
researchers used seasonal or annually
averaged data. However, they are now
looking into daily satellite observations,
which could provide more temporal data
regarding these disparities that their
current analysis could have missed.
Additionally, as NO 2
is not distributed
homogeneously in the horizontal
direction, there will be different levels
of exposure to NO 2
as you travel across
Earth’s surface. However, the satellite
data currently used takes an atmospheric
cross section that doesn’t account for
these horizontal gradients. Looking into
them with new satellite data will be yet
another important step forward in the
future of this research.
IMAGE COURTESY OF WIKIPEDIA
The Sentinel-5 Precursor satellite's mission is to measure
and monitor Earth's atmosphere. The TROPospheric
Ozone Monitoring Instrument (TROPOMI) is mounted
on the satellite and takes measures of atmospheric
nitrogen dioxide levels almost daily.
“I think an important part of this work
is incorporating local communities and
local governments into this work. Now
that we have a stronger technical grasp
on this data, we can better work with
those communities to address issues
that we might not even know they
are experiencing. I think their voices
and their perspectives would greatly
contribute to this work,” Demetillo said.
With more research into atmospheric
inequality with collaboration from
affected communities, policymakers,
and others in the field, we can look
forward to concrete changes to alleviate
disparities—as well as tackle pollution
as a whole. ■
December 2021 Yale Scientific Magazine 27
SCOPE
Science Communication
POSITIVE
PROGRESS
OR HARMFUL
HASTE?
HOW COVID-19 HAS REVOLUTIONIZED
THE SCIENTIFIC PUBLICATION PROCESS
From individuals’ eagerness to escape
the stagnancy of life under stayat-home
mandates, to the global
sense of urgency to produce a vaccine for
COVID-19, a focus on time has defined
the pandemic. Families wondered for
how many more months they would
have to delay reunions with loved
ones. Parents, especially those without
access to childcare or homeschooling
resources, anxiously awaited the return
of in-person schooling. In contrast,
research progressed at warp speed as the
scientific community furiously worked
towards understanding COVID-19 and
developing a vaccine.
The World Health Organization’s
(WHO) global database of literature
on COVID-19 contains over 350,000
documents, demonstrating the sheer
quantity of work that has been completed
on the singular topic in just under two
years. While the number of publications
has massively increased, so has
communication between researchers, as
the threat of the pandemic eliminated
many of the formalities that previously
prevented the sharing of pre-published
materials. However, the removal of the red
tape in scientific publishing has resulted
in many retracted studies, deemed
unjustified or simply incorrect after
publication. Thus, a question emerges:
how the desire to share new discoveries,
especially those essential to saving lives,
can be balanced with the need to conduct
research ethically and effectively.
COVID-19 has revolutionized the
publication process, forging new
networks of communication that expand
scientific discussion but can also obscure
the purpose of scientific journals.
Preprint servers, which allow for the
upload of unpublished manuscripts, have
become increasingly popular sources of
information. MedRxiv, a server partially
owned by Yale University, contains nearly
twenty-thousand papers on SARS-CoV-2
alone. The allure of these sites is clear:
they remove the middle-men of formal
publishing, allowing information to be
more easily disseminated. Furthermore,
while the publishing process for peerreviewed
scientific journals was arduous
in previous years, many of these journals
have adjusted their methods since the
onset of the pandemic. Some of these
new practices change how information
is shared, like allowing the public to
have free access to coronavirus content,
28 Yale Scientific Magazine December 2021 www.yalescientific.org
Science Communication
SCOPE
increasing the spread of useful data with
relatively few drawbacks.
Other modifications to the publication
process, specifically the rushed review
of submitted materials, fundamentally
alter what type of information journals
present. In the context of the pandemic,
rushing publication or modifying
how information is shared could be
a necessary price to pay for sharing
updates as quickly as possible. Thijs
Kuiken, a veterinary pathologist in the
Netherlands, notified the WHO when he
realized how rapidly the COVID-19 could
spread upon reading a manuscript he was
reviewing for The Lancet in January of
2020 at the start of the pandemic. Taking
such action would previously have been
highly unconventional due to strict
regulations about sharing unpublished
material, but the journal editors and
authors of the study supported his
decision considering the danger of the
virus. “There are no clear guidelines
or agreements about how reviewers
of scientific manuscripts should deal
with such crucial information during
public health emergencies,” Kuiken
remarked to the journal Science, in
reflecting upon how urgent findings are
shared within the scientific community.
Kuiken’s comments speak to the dire
need for a revision in how information
is communicated in the pandemic age.
Publications have certainly started to
change their ways. Holden Thorp, the editorin-chief
of Science, described this new rate of
publication as unprecedented in a New York
Times article.“It’s the same process going
extremely fast,” Thorp commented.
Kim Tingley, author of the article,
cautioned that this speed might not be
all beneficial. “The strength of traditional
academic journals… is that they have
the expertise to interrogate the validity of
highly specialized experimental methods
and the accuracy of the resulting data,”
Tingley wrote. In rushing the traditional
steps of publication, journals must, to
some degree, lower the level at which
they examine the validity of submitted
studies. Without an updated definition
of the role of scientific publications,
there exists a dangerous dissonance in
which journals maintain their perceived
standing as sources of near absolute
scientific authority but actually publish
materials that haven’t been reviewed to
the fullest extent. Preprint platforms
and accelerated publication methods
have offered easier and faster access to
information, but these changes have
occurred so rapidly that the expected
quality of information published has yet
to be updated, making studies potentially
seem more reliable than they actually are.
The consequences of hasty publication
are perhaps most obvious in the example
of the Surgisphere scandal. In June of
2020, The New England Journal of Medicine
(NEJM) and The Lancet, widely regarded
as two of the most prestigious medical
journals, were forced to retract two papers
that sourced data from Surgisphere after
the company denied the publications
access to the results they had collected.
NEJM’s retracted piece used
Surgisphere resources to assert that
COVID-19 patients on angiotensinconverting
enzyme (ACE) inhibitors and
other blood pressure drugs were not at
higher risk for death. The Lancet article
pointed to remarkably increased death
rates in COVID-19 patients treated
with hydroxychloroquine based on
Surgisphere data sourced from multiple
countries. The high repute of these
journals led many to trust the information
in both articles. The World Health
Organization (WHO), for example,
paused its trial testing the efficacy
of hydroxychloroquine as a possible
treatment for COVID-19 infections after
The Lancet’s study pointed to increased
death rates resulting from the drug.
Data emerging from Surgisphere was
quickly questioned because, as explained
by an article in Science, it seemed unlikely
that “a tiny company without much
publishing experience in big data analysis,
could have collected and analyzed tens
of thousands of patient records from
hundreds of hospitals.” These concerns
should have prevented the article from
being published in the first place.
Unfortunately, the pressure of the
pandemic overcame proper examination
of sources in the case of the Surgisphere
scandal, resulting in grave misconduct.
The retracted Lancet paper, for example,
only added to confusion surrounding
hydroxychloroquine, the malaria drug
that former President Trump pointed to
as a cure for the coronavirus on Twitter
and in press conferences. Twitter later
labeled Trump’s tweets as misinformation
and removed them from the platform,
and the use of hydroxychloroquine
was later rejected as a treatment for
COVID-19. Still, the rush to publish
research on the drug and the following
retraction of said research complicated
the already chaotic discussion around
treatments for
SARS-CoV-2.
While political discourse has
unfortunately seen a rise in disinformation
in recent years, the spread of false data is
far more concerning in journals such as
The Lancet, which are expected to only
publish papers with the highest degree of
scientific rigor. The ramifications of The
Lancet’s paper speak to the repeatedly
seen consequences of rushed publication
in the scientific community.
COVID-19 has drastically impacted
almost every aspect of the status quo,
including how scientific papers are
published. The destructive effects of
the pandemic have greatly complicated
journals’ aim both to share the everincreasing
updates on what we know
about COVID-19 and fully examine
each data point and source. Until a
balance can be struck between these two
goals, the onus will fall upon readers
to more critically examine what they
read, making scientific literacy more
important than ever. ■
BY ANNABEL WALLACE
ART BY MALIA KUO
THIS ARTICLE WAS ORIGINALLY PUBLISHED
IN SCOPE, YSM’S INTERDISCIPLINARY BLOG.
FOR MORE PIECES THAT PUT SCIENCE IN
CONVERSATION WITH SOCIETY, VISIT
HTTPS://MEDIUM.COM/THE-SCOPE-YALE-
SCIENTIFIC-MAGAZINES-ONLINE-BLOG.
www.yalescientific.org
December 2021 Yale Scientific Magazine 29
UNDERGRADUATE PROFILE
ELEA HEWITT
YC ’22
BY SOPHIA DAVID
Senior Elea Hewitt described herself during her gap year as
the happiest she had been in years. Returning to Yale from a
year spent on her family’s Oregon ranch, she has fascinating
perspectives on the intersection between farming and agriculture,
social justice, and sustainable environmental practices.
Hewitt grew up in rural Oregon in the Willamette Valley on her
family’s farm. Homeschooled until high school, Hewitt looks
back fondly on her primary education. She was taught
by her mother and given freedom to let her interests
guide her learning, which often took place outside.
Now an Environmental Studies major at Yale,
Hewitt has observed the continued relevance of
things she learned early on. For example, she
was already familiar with some of the concepts
in her Economics of Natural Resources class
because of experiences in her early childhood.
A gap year gave Hewitt the opportunity to
connect with her family farm in a way that she
never did while busy in high school. She enjoyed
spending days outside, being active, and caring
for the animals. Beef and lamb are the farm’s main
products, but they also have chickens, turkeys, and a
few ducks. Hewitt highlighted that one of the joys of the
ranch is stewarding Navajo-Churro sheep and maintaining
relationships with other breeders to preserve both the
breed and a familial cultural practice.
Currently, Hewitt’s family is working
to convert pastureland into multitiered
agroforestry silvopasture,
which combines tiers of trees and
other plants with livestock. They
plant chestnut trees at the top, then
hazelnut trees, then berries and
vines. At the bottom, they plant
ground cover, such as mushrooms
and sorel. Animals graze between
rows of plants, eating their fallen food,
pruning them, and providing manure to
help them grow. This method of planting
maximizes production value, allowing for the
cultivation of more calories per square acre. Most
importantly, because each plant requires and replenishes different
resources, it helps restore the soil’s nutritional balance.
Imbalances in soil nutrition have become a problem on many
large-scale farms. Although it may seem that industrialized
agriculture is more efficient than smaller scale farms, this is only
the case for the first ten to fifteen years. Over longer timelines, it
becomes extremely wasteful, costly, and inefficient due to problems
with soil quality, water contamination, and transport cost.
PHOTOGRAPHY BY LAUREN CHONG
Hewitt’s farming background has also made her aware of the
injustices that common industrial farming practices cause, to both
the planet and humans.
“Humans have lived on the planet for so long, but we’ve only
lived [in an industrialized way] way for two hundred years. It has
resulted in so much poverty and inequality. Industrial
agriculture is agribusiness, and there’s something
unethical about centering a business model
around something that is a basic need,”
Hewitt said. “However, due to the way
the agribusiness system developed
in America, there is little room for
a just transition at this point. An
overhaul centering Indigenous
and local agriculture production
pathways is necessary.”
Hewitt would like to see a
return to community-based food
production, with more people
involved in farming, more farmer’s
markets, and less reliance on food
sourced from afar. “I think society
would be a better place if more people
had experience with agriculture. I think there
is a disconnect from reality that exists today as a
result of peoples’ lived experiences which often center
around academic or non-physical work,” Hewitt said. “At the
end of the day, we have to remember that we’re human; we’re
animals. We have a body that was designed for work, and
it’s important to be well-rounded.”
Hewitt identified some changes she would like to
see here at Yale. First and foremost, she encourages
the university to hire more Indigenous faculty.
On the individual level, she wishes that each
Yale student could visit both the Yale Farm and
a landfill. Encouraging them to face a reality they
might not encounter on a daily basis, she believes such
experiences could leave a lasting impression, impacting
students’ future decisions. Hewitt also raised the idea of
creating a “climate credit,” which would require students to
gain environmental awareness, just as they are required to learn
about math or science. Elea expressed how this awareness is crucial;
ignoring it is no longer an option.
After college, Elea hopes to work on different types of farms,
work for a non-profit, and travel. She hopes to learn through these
diverse experiences before she eventually takes over her family’s
farm, where she will continue to implement Indigenous and
environmentally sustainable practices, working towards a more
socially just future. ■
PHOTOGRAPHY BY LAUREN CHONG
30 Yale Scientific Magazine December 2021 www.yalescientific.org
ALUMNI PROFILE
PAUL HANLE
PhD ’75
BY SOPHIA BURICK
From curating exhibits at the Smithsonian to teaching judges
about the facts of climate change, Paul Hanle (PhD ’75) has spent
decades helping the public appreciate the importance of science.
Hanle came to Yale in 1969 with the intention of earning his PhD
in physics but changed directions soon after. “I was interested in
both physics and how physicists think, where their
ideas come from, and how the circumstances in
which they work enable science to develop,”
Hanle said. He focused his studies on the
History of Science & Medicine and was
awarded his PhD in 1975.
After his fourth year of studies, Hanle
won a fellowship at the Smithsonian
Institution. He was appointed as a
curator at the soon-to-open National
Air and Space Museum in 1974. One
of his proudest accomplishments was
overseeing the creation of the Air and
Space Smithsonian magazine. “It was
extremely exciting and gratifying to create
something brand new,” Hanle said.
Hanle had been bitten by the museum bug. He went on
to lead two museums—the Maryland Science Center and the Academy
of Natural Sciences of Philadelphia. As CEO of the Maryland Science
Center, Hanle pursued new, creative routes of communicating scientific
knowledge. For example, he helped lead the Museum Film
Network, which produced the IMAX film To the Limit—a film
exploring human physiology through athletics. “It was a very
powerful strategy for conveying scientific information,”
Hanle said. “The audience didn’t necessarily know
they were learning science.” As president of the
Academy, Hanle opened an exhibit on dinosaurs that
brought museum visitation to record highs. Hanle’s
ingenuity in his leadership at these museums created
meaningful opportunities for the general public to
engage with scientific thought.
Hanle went on to become the first president of the
Biotechnology Institute, an organization centered
around getting kids excited about modern bioscience.
Each year, the organization grants BioGENEius
awards to students who completed outstanding science
projects, honoring them at an annual convention attended
by thousands of representatives from biotechnology companies.
While working at the Biotechnology Institute, Hanle advised
President Barack Obama’s 2009 Educate to Innovate initiative,
a bipartisan effort to advance the level of STEM education
available to kids across the country. “It was successful in helping
to raise the profile of the issue and getting companies to realize
that they had a stake in STEM education,” Hanle said.
www.yalescientific.org
IMAGE COURTESY OF PAUL HANLE
In 2011, Hanle shifted his work towards educating the public
about climate change. “In my view, it’s the greatest challenge to
humanity and the planet,” Hanle said. “It is truly existential.”
He became CEO of Climate Central, an organization focused on
communicating the scientific facts of climate change to the public.
One of their major projects involved getting local meteorologists
to incorporate information about the impact of climate
change on weather into their daily newscasts. “There’s a
maxim in communication about climate change—to
convey simple messages, repeated often, by trusted
messengers,” Hanle said. “Those three elements are
a very important way to reach people who might
otherwise not be reached.”
Climate Central’s impact is widespread;
figures generated by the organization illustrating
what rising sea levels would look like at iconic
places like the Gate of India and the White House
were used at the United Nations’ Climate Change
Conference in 2015 to emphasize to delegates the
dangers of rising temperatures.
In 2018, Hanle embarked on his latest effort: founding the
Climate Judiciary Project at the Environmental Law Institute.
The project’s mission is to educate judges about climate science
and its connection to environmental law. “I realized that a lot
of interesting things were happening in legal
cases around trying to hold emitters or
producers accountable for the effects
of climate change,” Hanle said. “It
seemed to me that one of the
crucial things we could do is to
educate these decision makers,
the judges, about the objective,
scientifically valid facts of
climate change.” The program
has received strong interest
from judges, and project
leaders are currently planning
to expand it internationally.
Hanle’s advice for getting people
to care about climate change is
simple: stick to the science. “If you
can convey the scientific facts objectively,
you might reach a broader audience,” Hanle
said. “That audience may include people who are not
necessarily sympathetic to social movements for climate action or
are even skeptics, but who might be convinced that there’s a really
serious problem about climate change that needs to be addressed
now.” Hanle’s work exemplifies how scientific communication and
education can be used to create positive change. ■
IMAGE COURTESY OF PAUL HANLE
December 2021 Yale Scientific Magazine 31
OUR BIGGEST EXPERIMENT
BY ALICE BELL
BY TORI SODEINDE
What do whales, fizzy water, and a 364-foot Ferris wheel have to do
with the climate crisis? In her new book, Our Biggest Experiment:
The Epic History of the Climate Crisis, author and climate activist
Alice Bell answers this question and many more as she explores the climate
crisis from a unique perspective, focusing not only on the future of the planet
but also on the history of how we reached this critical point.
Devoting each chapter to a different aspect of environmental history, Bell explains
the first weather maps, the advent of electricity, and even the origins of the term “tree
hugger”—trust me, it’s not what you’re expecting. Starting with scientist and activist
Eunice Foote’s 1856 experiment positing the effect of increased carbon dioxide on
atmospheric temperatures, Bell weaves together the story of how humans began
shaping the Earth. The book highlights several little-known but influential climate
scientists, including Foote and Guy Calendar, the English scientist who linked
Earth’s rising temperatures to rising carbon dioxide concentrations in the 1930s.
When trying to find ways to combat climate change, certain ideas crop up time
and time again, like the idea of a technofix, a new technological approach to the
problem of climate change that tends to oversimplify the problem and distract
from the root problems. “It’s almost a magician’s trick. It’s a way of looking at
shiny new tech… and not old tech that’s destroying the world,” Bell told Yale
Scientific. Despite the excitement surrounding alluring new ideas like cloud
seeding and artificial volcanoes, we must exercise caution. “All technology’s kind
of a double-edged sword. We have to think of how we apply it, who’s in charge,
and what other technologies we need alongside it,” Bell said.
One single solution will not solve the crisis, and focusing on futuristic quick fixes
can distract from the basic problems that need to be addressed, like our dependence
on and overuse of unrenewable energy sources. Bell remains hopeful but pragmatic:
today, our future will depend more on minimizing, rather than totally reversing,
climate change. Keeping the world half a degree colder might sound inconsequential,
but in reality, it equates to countless lives, homes, and livelihoods saved.
Bell stresses the importance of developing a personal connection to the
environment and climate. It’s easy to become cynical and apathetic when
thinking of the climate crisis as an ambiguous, ominous tide of change, but
forging personal connections to the environment—whether through planting
trees, joining environmental action groups, or investing in renewable
energy—can remind us of the close relationship between our lives and the
environment. If you’re unsure where to begin, reading Bell’s book could be
a good start. “It’s hard to feel like you understand [the climate crisis], but I
understood it more because of the history, and so I wanted to share that with
other people,” Bell said. With a more complete understanding of the past, we
can hopefully begin building a more sustainable future. ■
IMAGE COURTESY OF FLICKR
Melting ice sheets in the Arctic are evidence of the changing climate’s
influence on environment, human lives, and the future of the planet.
SCIENCE IN TH
32 Yale Scientific Magazine December 2021
www.yalescientific.org
EVST 219: PHILOSOPHICAL
ENVIRONMENTAL ETHICS
BY LUCY GILCHRIST
IMAGE COURTESY OF PIXABAY
Carbon emissions from power plants get trapped in the atmosphere,
creating a greenhouse effect that accelerates the planet’s warming.
Stephen Latham, JD, PhD, stumbled upon bioethics by happenstance in his
first job after law school. Now the director of Yale’s Interdisciplinary Center
for Bioethics, Latham is perhaps best known for his popular spring-term
course, Bioethics and Law. His new course this fall, Philosophical Environmental
Ethics, focuses on the philosophical questions relevant to the climate crisis.
First, Latham wants his students to understand the broad contours of the field
since the 1970s. “At that point, environmentalism was a fight against dumping stuff
into the water, or releasing stuff into the air,” Latham said. Early environmental
activists weren’t yet aware of greenhouse gases as a harbinger of climate change. They
decentralized human affairs in their discourse, focusing their concerns on animals
and ecosystems. Latham explained that the increasing visibility of the climate crisis
in the public and scientific imagination has shifted discussion back toward humans.
“Today, under pressure from the urgency of the need to do things about the climate,
people are thinking about how we can save the climate for ourselves,” Latham said.
Currently, most environmental discussions center on the extractive value of the
environment. “Philosophical environmental ethics raises slightly more technical
questions about how to value nature in itself,” Latham said. For example, the
“nonidentity problem” considers the responsibilities we have to future generations
who will only exist because of present-day choices about climate change. “If we
don’t do anything about climate change, people fifty years from now would be
looking back on us and saying, ‘You left us this horrible planet,’... but you could
point out to them that they only exist because we didn’t do anything about climate
change,” Latham said. Our current actions—or inactions—will decide who will
be left to reckon with the climate crisis in future years.
Topics in his course seem to beg for political action, and Latham hopes
his students will respond to the impulse. “I want people out there protesting
against more extraction of fossil fuels and in favor of renewable energy and
carbon capture and so on,” Latham said. However, he also realizes that the
ability to protest against climate change often comes from a place of privilege.
“It’s hard to say to someone who’s just getting by, ‘You have a moral obligation
to be thinking about climate change,’” Latham said.
But the target of Latham’s instruction are Yale students—privileged by their
education—who he hopes will leave his course equipped with the tools to address
climate change in their activism, careers, and personal lives. “I’m arming them
with arguments that they might be able to use in the future, whether it’s to a city
council or to their intransigent uncle over Thanksgiving dinner,” Latham said.
Trained as a lawyer and a scholar, Latham recognizes that the philosophical
perspective he can provide on environmental issues is only one piece of the puzzle.
Nevertheless, the ability to reason and write about our ethical responsibility to mend
the environment can help his students contribute to political and scientific action. ■
E SPOTLIGHT
www.yalescientific.org
December 2021 Yale Scientific Magazine 33
IMAGE COURTESY OF ANTHONY LEISEROWITZ
INTO THE
NEWSROOM
THE YALE PROGRAM ON CLIMATE
CHANGE COMMUNICATION
A CONVERSATION WITH YPCCC’S FOUNDER
AND DIRECTOR, ANTHONY LEISEROWITZ
BY HANNAH HAN
For some Americans, the phrase “climate change” conjures
images of barren lands crippled by drought and forests
decimated by wildfires. For others, climate change is a distant
thought, a phenomenon entirely unrelated to human activity.
For over a decade, the Yale Program on Climate Change
Communication (YPCCC) has studied Americans’ changing
perceptions of climate change and provided critical public
opinion surveys for news outlets such as CBS, NBC, CNN, and
The New York Times. YPCCC was founded in 2007 and is directed
by Anthony Leiserowitz, a senior research scientist at the Yale
School of the Environment.
Leiserowitz’s journey into the realm of climate change
communication was unanticipated—a confluence of his seemingly
disparate interests and serendipity. As an undergraduate,
Leiserowitz majored in International Relations, studying Cold
War politics. But in 1990, he was offered a position at the Aspen
Global Change Institution, a research center in Colorado,
surrounded by snow-capped mountains and dense conifer forests.
For four years, Leiserowitz immersed himself in climate studies
among the world’s leading environmental scientists, learning
about carbon pollution and climate models.
However, Leiserowitz eventually grew frustrated with the narrow
focus on natural science. “The only reason we have [global warming]
is because of people [and their decisions],” Leiserowitz said. “This
isn’t a natural science problem. This is a human science problem.”
This realization would guide the rest of his career. Leiserowitz
devoted himself to studying human responses to the climate
crisis, earning a master’s and doctorate in Environmental Science,
Studies, and Policy at the University of Oregon. He then spent
four years at Decision Research, a research institute in Oregon,
where he studied public risk perceptions and decision making,
seeking the answers to pivotal questions concerning the climate
crisis: How do people perceive the natural and social worlds?
What are the psychological and political factors that shape human
decision-making? How do we better communicate climate change
and engage people in climate science?
Leiserowitz founded YPCCC in 2007, when he was hired
by the Yale School of Forestry and Environmental Studies—
recently renamed as the Yale School of the Environment. The Yale
Program includes psychologists, geographers, political scientists,
sociologists, and others who conduct studies on public opinion
and engagement. YPCCC has spearheaded research on public
attitudes regarding climate change in more than 120 countries,
including the United States, China, India, and Brazil. The program
has also partnered with governments, media organizations, and
companies, including Facebook and Google, supporting their
climate change communication goals.
Leiserowitz reiterated that all of our lives are entangled with the
burning of fossil fuels: they are woven into the clothes we wear,
the electronics we purchase, and the appliances we use. Every time
we buy a product, we contribute to climate change. Every time we
vote, we choose leaders who will either support or oppose climate
policies. Multiply this by seven-and-a-half billion people, and the
need for large-scale messaging becomes clear.
“One of the major shifts that we’ve seen change over the past ten
years is recognizing how important communication is as a way
to engage the broader society itself,” Leiserowitz said. YPCCC’s
research has found that many people perceive global warming as a
remote issue. “Many Americans continue to think of climate change
as a distant problem—that this is about polar bears, or maybe
developing countries, but not the United States, not my state, not my
community, not my friends, not my family, not me,” Leiserowitz said.
As a result, the issue is often psychologically distant, blending into
the noisy background of people’s lives, where it doesn’t seem salient.
To engage a national audience in climate change, Leiserowitz also
founded Yale Climate Connections (YCC). A climate change news
service and national radio program, YCC broadcasts a new oneand-half-minute
story about climate change every day on more
than 680 frequencies nationwide. YCC’s listeners are not just located
in liberal regions of the U.S.; in fact, two-thirds of its stations are
located in congressional districts that voted for former president
Donald Trump. YCC’s stories feature the voices of Americans from
all backgrounds—racial justice activists, religious leaders, business
owners, doctors, farmers—communicating that climate change is
harming Americans right here and now.
Currently, Leiserowitz is working to build a Global Center for
Climate Change Communication at Yale to foster international
research and public engagement, at a scale equal to the size of
climate change itself. ■
Editor’s Note: Elsewhere, we covered a research article coauthored by
YPCCC researchers. See page 8.
34 Yale Scientific Magazine December 2021 www.yalescientific.org
COUNTERPOINT
DO HOSPITALS REALLY
DO NO HARM?
BY HANNAH SHI
IMAGE COURTESY OF YALE SCHOOL OF MEDICINE
do no harm.” All doctors swear by the ancient
Hippocratic oath. But we must ask ourselves, do
“First,
hospitals really do no harm? The production,
distribution, and eventual disposal of medical drugs and
equipment are major contributors to climate change. In fact, if
global healthcare was its own country, it would be the fifth largest
emitter on the planet. The severity of healthcare’s carbon footprint
contradicts the values of a system centered around protecting
human health. Physicians are contributing, whether they realize it
or not, to one of the largest public health crises in human history.
Yale Professor Jodi Sherman provides a solution as to how
healthcare can strive to “do no harm” on a global scale. Her
research focuses on creating sustainability metrics that help
inform administrative and physician decision-making towards
more environmentally sustainable operations. Sherman’s
recent paper published in British Medical Journal introduces
the idea of “planetary healthcare,” which expands the principle
of “first, do no harm” beyond the patient to the environment.
In an interview with Yale Scientific, Sherman isolated three
ways in which physicians can adopt this planetary healthcare
lens: first, reduce emissions from healthcare services; second,
match the supply and demand of healthcare services; and
third, reduce the demand for healthcare services.
On the first point, healthcare emissions are often embedded
in the products and spaces physicians use when providing care.
By using sustainability metrics, physicians can select drugs,
equipment, and procedures that are less polluting yet still
produce the same clinical outcome. For example, Sherman’s
work on tracking the life cycle of anesthesia drugs reveals
that certain gases, such as desflurane and nitrous oxide, are
significantly higher contributors to emissions compared to
other clinically similar options. In addition to guiding clinical
practices, empowering physicians with the environmental
information associated with certain medicines and products
used in treatments helps them leverage organizational
purchasing power to influence a more eco-friendly industry.
Secondly, healthcare resources are often inappropriately
utilized, which creates unsustainable practices that fail to match
supply and demand. “In the U.S. over fifty percent of healthcare is
devoted to five percent of the population with advanced chronic
disease… there are also alarming statistics on how much we
www.yalescientific.org
spend on end of life [care] and it’s not frequently the care patients
would choose if they were better informed,” Sherman said. It is
necessary to both mitigate excessive resource consumption while
also maximizing high value, clinically effective treatment, which
ultimately leads to more positive environmental outcomes.
Finally, it is imperative that we reduce our demand for healthcare
resources. This involves directing care resources upstream and
incorporating non-pharmacological and lifestyle methods to
preventing disease. Medical services contribute to only twenty
percent of health and wellbeing, while the rest is attributed to social
and environmental factors. Integrative healthcare aims to address
this other eighty percent of human wellbeing by informing patients
of healthier life choices (such as reducing alcohol consumption)
and alternative pain management strategies (such as acupuncture
and meditation). Moreover, consistent primary care enables early
prevention, detection, and treatment, leading to better health
outcomes. As such, it is important to invest in primary care and
public health so that preventative measures can reduce the demand
for acute treatment of advanced disease down the line.
Several sectors must come together if we wish to achieve netzero
emissions in healthcare. With the COVID-19 pandemic,
the world witnessed global mobilization and cooperation
in healthcare unlike anything ever seen before. “While we
had an increased need for emergency care and critical care,
and obviously increased consumption of personal protective
equipment and other healthcare resources, the global medical
community came together quickly, sharing information,
redesigning models of care, increasing access to telehealth,
and moving towards a circular economy—meaning, keeping
materials in use for longer,” Sherman said. “This begs the
question, why are we not doing this routinely?”
The pressures of the pandemic forced physicians to challenge
the culture of disposability and excess consumption of resources
within medicine. Medical practitioners safely succeeded
at efforts to adapt practices, increase communication, and
become better stewards of healthcare resources, proving
that rapid change in response to a crisis is possible. Indeed,
the world is now faced with a global crisis more urgent than
anything we have dealt with before. The lives of all people and
the planet are at stake. Doctors swore to “do no harm.” It is
now time to “do no harm” to our environment. ■
December 2021 Yale Scientific Magazine 35
FROM THE ARCHIVES Yale Scientific Magazine, Summer 1980
36 Yale Scientific Magazine December 2021 www.yalescientific.org
Microbiology
FEATURE
THE BACTERIAL BIRTH OF
LIVING MEDICINE
BY SIMONA HAUSLEITNER
Every year, millions of patients recover from life-threatening
surgeries and other medical procedures, only to get a
secondary infection caused by the presence of bacterial,
fungal, or viral particles on medical implants. In fact, the Centers
for Disease Control (CDC) estimates that healthcare-associated
infections account for an estimated 1.7 million infections
and 99,000 associated deaths each year in the United States
alone. Medical implants such as catheters, pacemakers, and
prosthetic joints act as ideal habitats for biofilms—bacterial
colonies that aggregate on smooth surfaces and remain
highly resistant to treatment with antibiotics.
In the past, the only methods for treatment involved
surgical removal of the implant or degradation of the
biofilm using enzymes, which often had toxic effects on
the human body. Researchers at Pulmobiotics, a spinoff
company from the Center of Genomic Regulation
in Spain, have recently developed a state-of-the-art
technique to solve this problem: “living medicine,” or the
introduction of genetically engineered bacteria to fight
the dangerous pathogens within the body.
In this technique, researchers decide on a “good
bacterium” to use, then remove specific genes
to eliminate the infectious or disease-causing
capability of the bacterium. They then equip the
bacteria with an engineered genetic platform
designed to secrete antibiofilm and bactericidal
enzymes—giving the bacteria the ability to
disintegrate or “fight” infectious biofilms.
Maria Lluch Senar, a biotechnologist who
formerly worked at the Center for Genomic
Regulation before founding Pulmobiotics
with her research partner Luis Serrano,
has been working with the bacterium
Mycoplasma pneumoniae for over ten
years in an attempt to characterize its
genome. Ultimately, the researchers sought to create a
bacterial chassis, a genetic framework that could house and support
exogenous DNA without interfering with the bacterium’s functional
purpose: targeting ventilator-associated pneumonia.
With a mortality rate of ten to fourteen percent, ventilatorassociated
infection is caused by pathogenic bacteria like
Staphylococcus aureus, which “grow in thick layers that are very
difficult to target by using conventional antibiotics because [the
antibiotics] cannot cross [the bacterial] barrier,” Senar said.
Thus, the lab aimed to engineer a bacterium that could fight
against biofilm infections: removing the pathogenic factors of M.
pneumoniae DNA while concurrently adding synthetic promoters
and sequences designed to destruct S. aureus biofilms in the lungs.
www.yalescientific.org
ART BY LANA ZHENG
The researchers chose to use M. pneumoniae for their microbial
chassis due to several favorable biological characteristics. The
bacterium, for example, had known activity in lungs. “When you
want to engineer a live biotherapeutic, it is important to look
for bacteria that is naturally present, or already colonizing, the
target organ,” Senar said. M. pneumoniae also had a genetic
advantage: “The strain has a unique genetic code
that prevents gene transfer,” Senar said. Moreover,
M. pneumoniae’s slow division allowed for an
expanded production time scale in the lab and
provided additional control over the
bacteria’s replication rate in vivo.
Thus, if there was a major
problem with the delivery
system of the chassis, it
was easier to contain the
spread of bacterial growth
and remove the bacteria
from the patient’s lungs.
However, the biggest
advantage of M. pneumoniae
was its
lack of a cell wall. The immune
s y s t e m ’ s pathogen recognition mechanisms
often target bacterial cell walls; thus, this feature of M.
pneumoniae would allow it to escape immune recognition,
preventing host elimination of the microbial chassis. This also
allows for a combined treatment approach: after the bacterial
chassis secretes biofilm-dispersing agents, antibiotics and
bacteriolytic enzymes can be co-administered to attack the cell
wall of S. aureus without damaging M. pneumoniae.
The researchers delivered the biofilm-fighting genes
to M. pneumoniae with plasmids, circular pieces of DNA
that can be transferred from cell to cell. They assembled
the plasmids from DNA fragments of genes of interest
using the Gibson method, a molecular cloning technique. Of
interest, the researchers delivered genes that drove continuous,
localized production of dispersin B, a hydrolytic enzyme that
breaks down S. aureus bacterial cells, to provide long-term
disruption of the biofilms. After genetically engineering their
M. pneumoniae, the researchers tested their chassis in mice
models to verify its safety and efficacy.
The research team is also looking beyond S. aureus biofilms. Due
to the natural ability of M. pneumoniae to colonize the respiratory
tract, bacterial therapies hold important future potential in many
medical therapies. “The 21st century is becoming the century of
synthetic biology,” said Senar, highlighting genetic engineering’s
increasing potential to create novel treatments for a wide range of
diseases, from cancer to chronic obstructive pulmonary disease. ■
December 2021 Yale Scientific Magazine 37
NEWS
Evolutionary Biology / Psychology
CLIMATE
CHANGE AND
EVOLUTION
WHAT WOOD FROGS TELL US
ABOUT ADAPTATION TO CLIMATE
CHANGE
BY ISABEL TRINDADE
CAN YOU
LEARN MORE
THAN A FIFTH
GRADER?
ATTITUDES TOWARDS LEARNING
IN CHILDREN AND ADULTS
BY ODESSA GOLDBERG
IMAGE COURTESY OF FLICKR
IMAGE COURTESY OF VERYWELLFAMILY
Loss of biodiversity is just one of many grave consequences
due to climate change. Recent research sheds light on a
species’ capacity to escape extinction by evolving rapidly at
microgeographic scales. A study from the Skelly Lab of the Yale
School of the Environment replicated research from 2001 that
investigated how various populations of wood frogs, Rana sylvatica,
exhibited differing embryonic development characteristics in
response to factors associated with climate change.
The study sought to understand how certain species
could adapt to climate change. “Wood frogs are a great
study system because they form natural metapopulations
and are highly adapted to cold and therefore sensitive to
warming,” said A. Andis, a PhD candidate in the Skelly
lab. Results showed that embryos in 2018 developed at rates
fourteen to nineteen percent faster than those in 2001 on
average. Further, there was variation among embryonic
development rates across frog populations separated only
by small geographic differences, a pattern found in both
the 2001 and 2018 studies. Several environmental factors
attributed to climate change, including canopy cover and
pond temperature, influenced development rates.
“When it comes to predicting conservation outcomes into the
future, [scientists] tend to [ignore] the capacity for organisms
to adapt and variation within species and populations,” Andis
said. This study provides some hope that organisms can mediate
the effects of human environmental impacts. However, this
capacity is limited—“too much change, too quickly” still has
disastrous effects. Some species, unfortunately, may already
be approaching this rate limit or have passed it already, a
phenomenon known as “extinction debt.” ■
How much do you think you can learn in a year’s time? At
the Cognition and Development Lab at Yale, researchers
compared children’s and adults’ attitudes towards how
much knowledge they believed one could acquire in one year. The
research was driven by previous findings showing that children
are more optimistic than adults when it comes to knowledge
acquisition attitudes. Research scientist Kristi Lockhart sought
to see if shortened time frames, methods of learning, or types of
knowledge affected this attitude. Who was more optimistic?
Apparently, children. “Even though they made a distinction
of what they could learn [with different methods of learning]
if you look at some of their scores, they are still above average
[compared to] the adults,” Lockhart said.
But this optimism is not without its limits. Children ages
five to seven still believe two-year-olds are unable to learn
anything, making a bigger distinction between themselves and
the two-year-olds than themselves and adults. Additionally,
they distinguish themselves specifically, displaying a selfenhancement
effect; in other words, each child believes they
will be able to learn more than their peers.
But the question remains: why are the children so
optimistic? Lockhart has a few theories. First, this optimism
may be necessary to keep children motivated in schools. It
may not be unfounded, as adults routinely underestimate
how much children can learn. Conversely, children may
maintain this level of optimism because they don’t yet have
the metacognitive skills to consider the effort required by
knowledge acquisition. In early life, children seem to learn
without consciously exerting effort, potentially causing them
to view knowledge acquisition as easy. ■
38 Yale Scientific Magazine December 2021
www.yalescientific.org
Cellular Biology / Epidemiology
NEWS
UNPACKING
THE CELL’S
UPS
THE ROLE OF VESICLE TETHERS IN
CELL MEMBRANE FUSION
BY ALEXANDRA PAULUS
FOOD
ADDICTION
ACROSS
DEMOGRAPHICS
HOW ENVIRONMENTAL CONTEXT
MIGHT INCREASE DISTRESS
BY LAUREN CHONG
IMAGE COURTESY OF ISTOCK
IMAGE COURTESY OF FLICKR
Vesicular transport is a vital process that allows
proteins to travel from one location to another in
package-like vesicles. When a vesicle reaches its
target membrane, it has two fates. It can undergo full fusion,
in which the vesicle completely fuses with the membrane
to deliver its cargo. Alternatively, it can undergo kiss-andrun,
in which the vesicle connects with the membrane before
rapidly reclosing. Seong An, a research associate at the Yale
School of Medicine, discovered that bridge-like vesicle
tethers, such as exocyst complexes, play an unexpected role
in fusion mode selectivity.
To investigate the exocyst’s role in the tethering process,
An first mutated Exo70, an exocyst subunit, so that it could
no longer directly bind to the membrane. Unexpectedly, this
did not prevent tethering—instead, it promoted kiss-and-run
over full fusion. When membrane binding by the mutated
Exo70 was “rescued” using optogenetics, a technique that
uses light to control protein function, full fusion occurred.
Finally, An found that in the absence of the exocyst, vesicles
that were optogenetically tethered to the membrane merely
underwent kiss-and-stay, a version of kiss-and-run in which
the vesicle remains at the membrane after fusing. “The
evidence suggests that membrane binding by Exo70 is not
necessary for tethering but vital for the mode of vesicle
fusion,” An said.
Further research may shed light on cellular processes such
as cell migration, as full fusion events play a role in membrane
expansion. “Now that we’re able to observe vesicle tethering
in real time, we can study what kind of impact membrane
fusion has physiologically,” An said. ■
What does it mean to be addicted to food—and is
food addiction the same for everyone? According
to a new study by the Yale School of Medicine
and University of Minnesota Medical School, rates of food
addiction—the compulsive consumption of foods high in
sugar and fat, leading to symptoms of distress—differ across
demographic and weight groups.
In the study, participants reported their views on
healthcare and food consumption as well as their clinical,
demographic, and body-mass index (BMI) information.
Those who had food addiction symptoms such as distress or
impairment as a result of their eating habits were placed into
the food addicted category.
Statistical analyses revealed people with obesity and
females were more likely to report distress related to the
food addiction symptoms after controlling for symptom
frequency. “Women might experience more pressure
related to food and weight, and therefore, [are] more likely
to experience symptoms of distress from eating,” lead
researcher and Yale postdoctoral fellow Meagan Carr said.
“People who are overweight and obese experience stigma
and prejudice, and so it’s also possible that they might have
more reactions to food addiction.”
Carr emphasized the need for a better understanding of
food addiction. “The data show that it may be better to move
beyond focusing on people’s individual choices around food,
and instead think about environmental context and other
contributors,” Carr said. ■
www.yalescientific.org
December 2021 Yale Scientific Magazine 39
NEWS
Neuroscience
A TINY MOLECULE’S
BIG ROLE IN BRAIN
DEVELOPMENT
How retinoic acid
regulates the connectivity
of the prefrontal cortex
BY NEIL KADIAN
There are more synapses in the human brain than there are
stars in the Milky Way. The developing brain manages to
wrangle and organize over one hundred trillion neural
connections—many orders of magnitude greater than the number
of base pairs in our genome. Deciphering how the body constructs
such mind-bogglingly complex cellular structures might demystify
psychiatric diseases and the evolution of the brain. In a recent
study published in Nature, researchers from the Yale School of
Medicine identified a small signaling molecule, retinoic acid, that
plays a key role in the development of the prefrontal cortex.
Located in the front of the human brain, the prefrontal cortex
regulates complex behavior, personality expression, and decision
making. Compared to other animals, anthropoid primates
possess enlarged prefrontal cortices. To identify genes that are
uniquely upregulated in the prefrontal cortex, the researchers
analyzed transcriptome data—information regarding gene
expression across different brain regions—from databases
including BrainSpan and PsychENCODE. They identified 125
protein-coding genes that are upregulated in the human frontal
lobe, which includes the prefrontal cortex and motor cortex,
during mid-fetal development, when gene differentiation
becomes highly enriched. Of the 125 genes identified, many were
associated with the small signaling molecule retinoic acid.
“Since retinoic acid-regulated genes are enriched in the prefrontal
cortex, we decided to analyze these genes more closely,” said Mikihito
Shibata, a co-first author of the study and associate research scientist
in neuroscience at the Yale School of Medicine. Retinoic acid is a
signaling molecule involved in the development of a plethora of
anatomical structures, including the spinal cord, heart, liver, eye,
and limbs. By micro-dissecting brain tissue, the researchers found a
clear gradient of retinoic acid in the brains of mid-fetal humans and
macaques: high levels saturated the prefrontal cortex in the front
of the brain, then sharply dropped after the prefrontal cortex and
continued decreasing towards the back.
The researchers identified similar gradients of retinoic acidsynthesizing
enzymes and receptors and an enrichment of
retinoic acid-degrading enzymes in the regions surrounding
the prefrontal cortex. These findings indicate that expression of
retinoic acid receptors and synthesizing and degrading enzymes
localize the molecule’s activity to the prefrontal cortex.
PHOTOGRAPHY BY HANNAH BARSOUK
But what happens when this network is disrupted? In mutant mice
that did not express retinoic acid receptors, retinoic acid signaling in
the prefrontal cortex decreased. When compared to normal mice,
these mutant mice expressed 4,768 genes differently in the mouse
equivalent of the prefrontal cortex. Intriguingly, many of these genes
are known to be responsible for synapse and axon development,
suggesting that retinoic acid regulates synapse and axon development
in mice. Levels of critical synapse proteins such as DLG4 and
synaptophysin were reduced, as well as the number of mushroom
dendritic spines, structures that receive inputs from other neurons.
Next, the researchers used diffusion tensor imaging (DTI), an
advanced MRI-based imaging technique, to observe the effect of
retinoic acid on long-range brain connections. In mutant mice
that did not express retinoic acid receptors, DTI identified a
reduction in connections between the mouse prefrontal cortex
and another brain region known as the thalamus.
The connection between the prefrontal cortex and thalamus is critical
for cognitive function, and abnormalities in the connection have been
implicated in psychiatric diseases such as schizophrenia. “Beyond
having an importance in understanding the evolution and development
of the prefrontal cortex, this paper has critical implications in the
way we conceptualize and possibly treat schizophrenia,” said Kartik
Pattabiraman, co-first author and a Child and Adult Psychiatry Fellow
in the Child Study Center at the Yale School of Medicine. “It’s thought
that schizophrenia is caused by disruption of the adolescent brain, but we
provide evidence that schizophrenia could instead be a developmental
disorder. To truly prevent it, we might have to intervene much earlier.”
On the other hand, in mice that did not express CYP26B1, an
enzyme that degrades retinoic acid, retinoic acid signaling expanded
beyond the prefrontal cortex. Connections between the thalamus and
the prefrontal cortex expanded to regions adjacent to the prefrontal
cortex, and the mouse prefrontal cortex developed characteristics
unique to the primate prefrontal cortex. Does this mean that
increasing neural retinoic acid activity could generate super intelligent
mice? “It’s probably more complex than that. But testing the behavior
of CYP26B1-deficient mice is a next step” Pattabiraman said.
In the future, Shibata and Pattabiraman are interested in
further exploring the role of retinoic acid, uncovering the
secrets of brain development and evolution, and identifying
new paradigms for clinical treatment. ■
40 Yale Scientific Magazine December 2021 www.yalescientific.org
PHOTOGRAPHY BY JENNY WONG
What do fuel cells, water splitting, and artificial
photosynthesis have in common? They’re all vital
technologies in the fight to transition away from
fossil fuels towards a brighter, cleaner energy future. They also all
require a specific type of chemical reaction to work. This reaction,
called a proton-coupled electron transfer (PCET) reaction,
is widespread across energy studies, as well as in biological
systems. In this reaction, protons and electrons are transferred
either simultaneously or one at a time. Understanding PCET
reactions is fundamental to a better understanding of how to
improve cutting-edge sustainable technologies.
Robert E. Warburton, an Arnold O. Beckman Postdoctoral
Fellow at Yale University working in the Hammes-Schiffer group,
has approached this important problem using computational
modelling. While previously his collaborators in the Mayer
lab had collected experimental data on the PCET reactions,
computational modeling can give deeper insight into these
systems. “If we want to understand how to control the chemistry,
we need to know what happens in between that initial and final
stage that you see in an experiment. And a lot of times that
happens on very short timescales,” Warburton said.
His main research goal was to examine how different materials
require different amounts of energy to undergo a PCET
reaction. Each material has a unique property called band gap.
Band gap is associated with the difference in energy between
the highest and lowest electron levels within the material.
Warburton initially hypothesized that a larger band gap would
make a PCET reaction have a larger bond dissociation free
energy (BDFE), which measures how hard it is to break a bond.
Specifically, Warburton’s study focused on how defects in
materials could affect the reaction. Defects could cause the
material to react all at one site: PCET can occur at either low
electron levels or, in the case of a defect, high electron levels that
carry a positive charge. Typically, only one value is reported for
the BDFE, so it’s important to consider how the defects in the
material could impact its actual performance.
Some of the titanium oxide (TiO 2
) metal oxides transferred
the electron from the valence band, a lower electron energy level
where the outermost electrons of the material lay, and some
transferred the electron from the conduction band, a higher
www.yalescientific.org
BREAKING BONDS
WITH COMPUTER
MODELS
A new approach for
understanding protoncoupled
electron transfer
BY MADISON HOUCK
Computational Chemistry
NEWS
electron energy level to which some of these electrons jump. TiO 2
is an ideal material to study this because its conduction band has
a different orbital shape than the valence band. The conduction
band, more closely associated with titanium, has an electron
cloud, or orbital, that is shaped like a flower. The valence band,
more closely associated with oxygen, has an orbital that is shaped
like a peanut. Warburton’s model showed a significant difference
between the BDFE of the valence and conduction bands.
Although these results confirmed Warburton’s hypothesis, he and
his collaborators concluded that the model was too simple. While
there certainly was a relationship between the band gap and the
energy of the bond, that wasn’t the whole picture. “We saw the big
result that is interesting and compelling, but we don’t necessarily
have a straightforward answer as to why. So really the hard part
about this was doing the analysis and sensitivity,” Warburton said.
In order to have a more complete model, Warburton and his
colleagues incorporated another theoretical framework, called
Marcus theory. Marcus theory deals with the rearrangement of atoms
in the material during electron transfer. More specifically, an electron
transfer can only occur if there is enough energy to rearrange chemical
bonds in the surrounding environment to accommodate the transfer.
Including these effects in the model made it more complicated but
better able to explain experimentally observed behavior.
Warburton says his work is far from over. “All we’ve been
looking at so far is reaction energies and thermodynamics—
basically how favorable the processes are. Now we want to start
looking at the kinetics of these reactions, so how fast they go,”
he said. Further down the line, his results could one day help us
understand why there may be gaps between the theoretical and
actual performance of materials. Armed with this understanding,
engineers and scientists can choose the optimal material for green
technologies. Although this research seems incredibly specific,
the applications are far-reaching and could impact the way we
design green technologies in coming years.
Warburton’s postdoctoral research is supported by the Arnold
and Mabel Beckman Foundation through an Arnold O. Beckman
Postdoctoral Fellowship. This research study was also supported
as part of the Center for Molecular Electrocatalysis, an Energy
Frontier Research Center funded by the U.S. Department of
Energy, Office of Science, Basic Energy Sciences. ■
December 2021 Yale Scientific Magazine 41
SYNAPSE
Essay Contest Winner
WHEN SOUND
MEETS
CHEMISTRY:
SONOCHEMICAL
SUPERPOWERS
BY MARIAN CABALLO
ART BY ELAINE CHENG
42 Yale Scientific Magazine December 2021 www.yalescientific.org
Essay Contest Winner
SYNAPSE
Sound is powerful. I am personally moved
by the sounds of my favorite artists—
from the catchy tunes of Taylor Swift to
the chill-inducing crescendos of my favorite
Hans Zimmer film scores. But just as sound
waves can emotionally destroy us as humans
(causing surges in dopamine or even firing
up our cerebellums), recent experiments
have demonstrated acoustics' efficiency and
promise for manipulating tangible objects in
(literally) groundbreaking ways.
Acoustics—the “science concerned with the
production, control, transmission, reception,
and effects of sound”—is expansive and
interdisciplinary. Considered a branch of
physics, acoustics presents itself in biological
systems, technology, infrastructure, and even
human behavior. Acoustic manipulation is
most known for being emotional, shockingly
levitational, and, most unusually, chemical.
But how can sound—which seems so
uninterestingly ubiquitous—possibly be so
impactful on a molecular level?
The study of sonochemistry merges sound
and chemistry through the ultrasonic alteration
of chemical reactions. In 2013, professors
Manish Keswani and Reyes Sierraat at the
University of Arizona College of Engineering
used sound waves to destroy eleven million
liters of toxic chemical stockpile, breaking fireextinguishing
foam down to carbon dioxide
and water. The sonochemical process that
occurred was sonolysis: the employment of
ultrasonic waves to decompose a substance.
Ultrasounds vibrate at frequencies that
exceed the human upper limit of hearing
(greater than 20,000 Hz). When ultrasonic
waves propagate into liquids, they experience
alternating periods of rarefaction (lowpressure)
and compression (high-pressure)
cycles, like all sound waves. However, in the
low-pressure cycle, the intense ultrasonic
waves create small bubbles or “cavities.”
When the cavities can no longer absorb
or accommodate energy, they violently
implode—releasing high amounts of heat,
energy, and destructive free radicals (unstable
atoms best known for harmful oxidation
in humans). This process, termed acoustic
cavitation, goes on to affect proximate
substances in many ways. According to
Dr. Alexey Peshkovsky’s blog post on
sonomechanics, effects include “sterilization,
polymerization, desulfurization, long-chain
molecule degradation,” among others.
This phenomenon, which can decompose
stubborn toxins, is promising for
environmental preservation. In the case of the
fire-extinguishing foam experiment, the heat
energy from cavitation broke bonds keeping
the perfluoroalkyl sulfonates and carboxylates
(PFCs) intact. PFCS are incredibly difficult to
break down; the EPA has reported numerous
health concerns due to widespread human
exposure and observed toxicity in animal
models. Sonolysis is not only powerful enough
to destroy these persistent PFCs, but also
cost-effective for commercial use. Sonolysis
has also been used for water purification as it
rapidly degrades pollutants without producing
or using additional chemicals. Though this
use of sonolysis is not extremely developed
or widespread, studies have revealed it to be
a potentially effective and low-energy tool.
With experiments showing acoustic cavitation
reducing E. coli’s ability to divide, it may also
prove useful for bacterial eradication in oceans.
Commercial ultrasonic technologies have
existed since the 1970s. The instruments
set off random cavitation to clear debris
from jewelry, scientific samples, surgical
instruments, lenses, and even musical
instruments. Megasonic technology is
another option, employing higher frequency
waves to produce less dangerous and more
controlled cavitation. Since ultrasound also
has the ability to atomize liquids, it has been
used to disinfect hospital surfaces as well.
High-power ultrasound can pose dangers
to humans due to extreme temperatures
that may cause burns. Under professional
supervision, however, sonochemistry has
a reassuring safety record. In fact, medical
scientists and surgeons use sonolysis for
various applications, such as an FDAapproved
and non-invasive cavitation
procedure to eliminate fat (called ultrasonic
fat cavitation). Lithotripsy removes kidney
stones through ultrasonic cavitation as
shock waves break the kidney stones into
more-passable stones. If cavitation bubbles
are deliberately imploded next to diseased
tissue, they can also deliver drugs directly to
the blighted area. Ultrasonic technology even
has the ability to inject new DNA through
gene-loaded microbubbles through a process
called sonoporation. By embedding magnetic
particles into the bubbles, scientists can move
each gene-loaded bubble to targeted locations
electromagnetically. It can even combat
cancer: high-intensity focused ultrasound
(HIFU) is a non-invasive cancer therapy that
destroys cancerous tissue.
Sonochemistry has also proved to be
beneficial in nanomaterial synthesis, a
revolutionary process of creating extremely
small technology with applications in
healthcare, electronics, and beyond.
For example, Fe 3
O 4
NPs (magnetite
nanoparticles)—key for biomedical
applications like biosensors—can be formed
through ultrasound irradiation. Similarly,
sonochemistry has been used to form AuNPs
(gold nanoparticles). Gold nanoparticles,
both costly and difficult to make, are sought
after due to their ability to penetrate cell
membranes without causing damage.
Ultrasonic nanomaterial synthesis is generally
precise and cost-effective, eliminating the
need for complex equipment or facilities.
Thus, sonochemical synthesis may make
AuNPs more accessible if widespread.
Considering that nanomaterials are 100,000
times smaller than the width of a hair strand
and therefore require an arduous production
process, sonochemical synthesis methods will
only become more valuable as demand for
nanoparticles increases.
Sonochemistry has other miscellaneous uses.
Cavitation can emit light through a mysterious
phenomenon called sonoluminescence. In the
1990s, some scientists theorized that bubble
temperatures during sonoluminescence
exceed two million degrees Fahrenheit and can
therefore cause nuclear fusion. Though little
evidence supports this theory, the idea went on
to play a central role in the 1996 Keanu Reeves
science fiction film Chain Reaction. Food
engineers may also benefit from the wonders
of sonochemistry. One investigation showed
that the use of ultrasound as a processing aid
in yogurt can reduce production time by up to
forty percent. Ultrasonic cavitation has even
been used to brew tastier coffee by rupturing
the cell walls of coffee grounds to release more
triglycerides and caffeine at a faster rate.
So, as you jam out to the soul-crushing,
heart-squeezing sounds of your favorite
artists, recall that sound can have just
as much physical power—thanks to the
interdisciplinary study of sonochemistry. ■
Marian Caballo, a senior at Bronx High School
of Science, is the winner of the 2021 Yale Synapse
Essay Contest for high school students.
www.yalescientific.org
December 2021 Yale Scientific Magazine 43
YSEA’s 2021 Awardees for Outstanding Academic Achievement
Kudos to the YSEA Award Winners!
Your achievements inspire all of us in the Yale STEM community.
Your achievements inspire all of us in the Yale STEM community
Judith Rodin
YSEA Award for Meritorious Service to Yale University:
Judith Rodin, Ph.D. Professor of Psychiatry, School
of Medicine, and President Emerita, University of
Pennsylvania
In recognition of her outstanding service in a variety
of roles including Professor of Psychology, Psychiatry
and Medicine; Dean of the Graduate School of Arts and
Sciences; and as University Provost.
Susan Hockfield
YSEA Award for Distinguished Service to Industry, Commerce or
Education:
Susan Hockfield, Ph.D. Professor of Neuroscience and President
Emerita, Massachusetts Institute of Technology; Joint Professor of
Work and Organization Studies, MIT Sloan School of Management.
To honor her many contributions to industry and academia at Yale
as Professor Neurobiology; Dean of the Graduate School of Arts and
Sciences; and Provost; and as University President of MIT.
Jerry Chow
YSEA Award for Advancement of Basic and Applied
Science:
Jerry Chow, Ph.D. (Yale Physics 2010), Director of
Quantum Hardware Systems Development, Thomas J.
Watson Research Center.
For his work on quantum computing and architecture,
including quantum error correction and quantum
machine learning.
THANK YOU!
For contributing to Yale’s rich tradition in STEM.