YSM Issue 87.4
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Yale Scientific
Established in 1894
THE NATION’S OLDEST COLLEGE SCIENCE PUBLICATION
OCTOBER 2014 VOL. 87 NO. 4
WHY MIDGES MATTER
Computers model swarm behavior
FIGHTING OPIATE ADDICTION
The intersection of science and policy
women in science
building a vibrant community at Yale
q a
&
BY SIENNA LI
The 2014 Rio World Cup saw the
gathering of top soccer stars from around
the globe. There was one new player in
particular that caused quite a stir. His
name? The Brazuca. This soccer ball,
made especially by Adidas for the 2014
World Cup, proved to be a star performer
in the games, rehabilitating Adidas’ image
after the poorly-received Jabulani ball of
2010.
The Brazuca has been praised for its
predictability and consistency on the
field. Its design incorporates a number
of new features to improve the ball’s
performance. Most noticeably, the
new ball has only six panels, versus the
Jabulani’s eight and a standard ball’s thirtytwo.
Fewer panels means fewer stitches,
which cuts down on friction between the
air particles and the surface of the ball
What makes the World Cup ball special?
IMAGE COURTESY OF NATIONAL GEOGRAPHIC
The new Brazuca ball design, with six panels
and a rough surface, moves through the air
predictably and with astonishing accuracy.
when it is in motion. Less friction results
in decreased turbulence and makes the
ball’s movement more predictable.
However, smoother balls tend to
experience more drag, a force that
causes the ball to swerve unexpectedly.
The Jabulani’s practically uninterrupted,
8-paneled surface was too smooth, causing
it to dip randomly in the air. To counter
this effect, the Brazuca is covered with
little bumps that create a rough surface.
Players are thus able to get a better grip
on the ball, and there is reduced drag.
The Brazuca also features long, deep
seams along its panels that disrupt the
smoothness of the ball to enhance its
aerodynamic movement.
The Brazuca was well-received at the
2014 World Cup, garnering positive
reviews from players, coaches, and fans
alike. The question now is: what’s next for
soccer ball design?
What happens in the brain when we watch a movie?
BY AMANDA MEI
Next time you find yourself in a movie
theater, consider this: You are probably
sharing more than an armrest or a bag of
popcorn with the person next to you; you
are likely sharing brain activity, too.
In one fMRI study, moviegoers who
watched The Good, the Bad, and the
Ugly experienced increases and decreases
of neural activity in tandem. As much as
70 percent of their cerebral cortex was
synchronized at any given moment. This
synchronization happened especially in
brain regions responsible for processing
sights and sounds, but was also evident
in regions associated with emotion.
Researchers observed correlations in the
fusiform face area when subjects saw faces
on screen. They saw synchronized activity
in the limbic system’s cingulate gyrus, which
connects actions with emotional responses.
ART BY CHRISTINA ZHANG
Moviegoers may experience similar
increases and decreases in neural activity
when they watch visually-stimulating
movies together.
But why does this happen? Researchers
attribute these correlations to the fact
that people watching the same movies
experience the same stimuli.
Movies that direct audience attention
with structural devices are more likely
than unstructured videos to elicit brain
synchronization. Cuts and angle shifts
greatly influence viewers’ eye movements,
and information collected by retinal cells
passes through the thalamus into the visual
cortex at the back of the brain. Regions of
the visual cortex have functions ranging
from pattern recognition to motion
perception. As a result, movies that exert
more control over viewers’ perception have
a greater impact on their brain activity.
Unstructured videos like comedy shows, by
contrast, elicit only 5 to 20 percent cortical
synchronization among viewers.
Great films may not be mind control,
but they certainly come close.
5
NEWS
Letter from the editor
Yale Scientific
Established 1894
CONTENTS
OCTOBER 2014 VOL. 87 ISSUE NO. 4
ON THE COVER
6
6
7
7
8
9
10
11
25
26
27
28
30
32
34
35
36
37
38
Ancient arthropod unearthed
Mapping human perception
Robert Langer speaks at Yale
Microscopy advances
Students tackle design challenges
Ancient barley and drought
David Rand on cooperation
Immune system against herpes
FEATURES
Virology
Man-made meningitis
Geology
Death Valley’s sailing stones
Medicine
Hope for damaged hearts
Epidemiology
Mystery pandemic: Ebola
Microbiology
Reinventing the human embryo
Cryptography
Quantum computing
Undergraduate Profile
Yetunde Meroe MC ’16
Alumni Profile
David Spiegel YC ’67
Mythbusters
The not-so-simple weather
Unsolved Mysteries
The Mpemba Effect
Science in the Spotlight
Quack Echo, Wormholes
18
12
Deadly
21 Euphoria
Finding Equilibrium
Female scientists at Yale have been pushing tirelessly for decades to
promote the integration of women into Yale’s scientific community.
Advocates from undergrads to long-term faculty members to
administrators are working to overcome the remaining obstacles.
The Science of
Swarms
Nicholas Ouellette is one
of a growing number of
scientists studying the
science of swarms. These
researchers hope that by
understanding how animals
swarm, they can inform
such far-flung disciplines as
robotics, computer design,
and physics.
To help opioid addicts,
doctors are prescribing
buprenorphine, a drug that
eases painful withdrawal
symptoms. However, some
clinicians, policymakers,
and insurance companies
disagree on how available
buprenorphine should be,
and science is speaking up
with the facts.
IMAGE COURTESY OF FREE PRESS
15
IMAGE COURTESY OF NATURE
IMAGE COURTESY OF DAILY MAIL
A Smarter Way to Track Nutrition
IMAGE COURTESY OF SAN DIEGO FOOD BANK
Researchers at the Yale School of Public Health have
recently discovered a way to find out in only one minute
if you’ve been eating your fruits and vegetables. The
next time you visit your doctor, you might want to think
twice before sugarcoating your diet.
More articles available online at www.yalescientific.org
www.yalescientific.org
October 2014
Yale Scientific Magazine
3
CRIME
JUSTICE
& SCIENCE
there are approximately 12 million
crimes committed in the united
states every year. one out of
every five people is a victim of a
felony crime in the us. no other
nation on earth has a higher crime
rate. The Us has an estimated
backlog of 400,000 unprcoessed
rape kits, each representing a
rape victim who will be severely
handicapped in their fight for
justice. the us has seen a surge in
arrests over the last four decades.
forensic scientists can determine
a person’s sex, age, and race by
examining a single strand of hair.
crime is a
problem.
science is a
solution.
ART BY SURYABRATA DUTTA AND NICOLE TSAI
F R O M T H E E D I T O R
Crime, Justice, and Science
Welcome back to another semester with the Yale Scientific. The entire masthead is excited
to continue expanding its print and online coverage, and we are thrilled to begin working
with the Class of 2018.
To explain the story behind this issue, I should pull back the curtain on our usual editorial
process: in selecting the themes for each issue, we always pick a theme first and pitch articles
topics afterwards. But with the start of a new academic year, for this issue we decided to
take a different approach: we heard article pitches first and let a theme come to us.
And so, at a time not long after the execution of an American journalist and the Ferguson
shooting that sparked national outrage, several of our articles came to converge on one
central question, one that seemed to reflect a pressing issue on the minds of many Yalies—
crime and justice.
For many scientists, this theme represents volumes of questions that we can spend
lifetimes unraveling. How does changing technology redefine the law? What is science’s
role in tracking and analyzing crime? And how can scientists help citizens—not just victims
of crime, but also the perpetrators themselves—achieve justice?
Many research questions are devoted to technologies that deter or track down crime:
advances in forensic science that aid law enforcement, for example, or the use of quantum
cryptography as a new defense against cyber attacks. Other scientific solutions are less blackand-white:
In the wake of a New Haven “heroin epidemic” this year, Dr. David Fiellin at
the Yale School of Medicine recently co-authored a paper on a controversial drug that treats
opiate addiction (pg. 22). The drug mitigates withdrawal symptoms, but it’s also vulnerable
to abuse if improperly prescribed. And while there are no clear answers to combating opioid
addiction just yet, the numerous debates on the drug’s availability reveal that “justice” is a
loaded word. More often than not, finding the fairest scientific outcome depends on who
you ask to be the judge.
In their efforts to tackle crime and injustice, members of the scientific community have
also been creating change from within. With exclusive interviews from Drs. Joan Steitz and
Vivan Irish, this issue’s cover story on page 18 highlights the growing network of women
scientists at Yale.
We hope you enjoy reading this issue of the Yale Scientific on “Crime, Justice, and Science,”
and we thank you for your continued support.
A B O U T T H E A R T
Rebecca Su
Editor-in-Chief
The cover of this issue, photographed by Katherine Lin, features
a group of undergraduate women majoring in science and
engineering at Yale. The photo was taken at Kroon Hall, the
School of Forestry and Environmental Studies. Pictured from
left to right are Nicole Tsai (SY ’16), Rachel Yost-Dubrow (ES
’16), Aurora Xu (MC ’16), Tessa Adler (ES ’17), Liz Vincent (MC
’15), Sara Torres (ES ’15), Marion Hirshberg (PC ’16), Genevieve
Sertic (PC ’18), and Myka Perusek (SM ’17).
Editorial apology: Issue 87.3 incorrectly attributed the photo of Professor Brian Scassellati on pg.
13 to Shuncong Gu. This photo was taken by Logan Stone (DC ’15).
Editor-in-Chief
Managing Editors
News Editor
Features Editor
Articles Editor
Online Editors
Copy Editors
Yale Scientific
M A G A Z I N E
Established in 1894
OCTOBER 2014 VOL. 87 NO. 4
Production Manager
Layout Editors
Associate Layout Editors
Arts Editor
Photography Editor
Webmaster
Publisher
Advertising Manager
Distribution Manager
Subscriptions Manager
Synapse Director
Science on Saturdays Coordinator
Volunteer Coordinator
Senior Business Advisor
Senior Editorial Advisor
Staff
Tessa Adler
Milana Bochkur Dratver
Amanda Buckingham
Patrick Demkowicz
Suryabrata Dutta
Malini Gandhi
Yuki Hayashi
Emma Healy
Lidiya Kukova
Annalisa Leinbach
Sienna Li
Advisory Board
Kurt Zilm, Chair
Priyamvada Natarajan
Fred Volkmar
Stanley Eisenstat
Melinda Smith
Peter Kindlmann
Werner Wolf
John Wettlaufer
William Summers
Jeremiah Quinlan
Sean Barrett
Carl Seefried
Audrey Luo
Amey Mahajan
Jacob Marks
Casey McLaughlin
Amanda Mei
Zachary Miller
Theresa Oei
Christopher Paolini
Isabelle Rossi De Leon
Kevin Salinas
Genevieve Sertic
Rebecca Su
Chanthia Ma
Naaman Mehta
Andrew Qi
Payal Marathe
Julia Rothchild
Grace Cao
Jason Young
Christina de Fontnouvelle
Jiahe Gu
Kevin Wang
Carrie Cao
Rachel Lawrence
Aparna Nathan
Aviva Abusch
Sofia Braunstein
Allison Cheung
Jenna DiRito
Nicole Tsai
Katherine Lin
Claudia Shin
Aurora Xu
Jasper Han
Adam Pissaris
Mina Himwich
Emma Graham
Zachary Mankoff
Claudia Shin
Karthik Ardhanareeswaran
Jessica Hahne
Danielle Stamer
Theresa Steinmeyer
Andrew Sung
Jessica Tantavit
Laurie Wang
Kathryn Ward
Summer Wu
Rachel Yost-Dubrow
Christina Chi Zhang
Holly Zhou
Chemistry
Astronomy
Child Study Center
Computer Science
Ecology & Evoluntionary Biology
Electrical Engineering
Emeritus
Geology & Geophysics
History of Science, Medicine & Public Health
Physics
Undergraduate Admissions
Yale Science & Engineering Association
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 200 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 ysm@yale.edu.
NEWS
in brief
paleontology
Ancient Thylacocephala fossil unearthed
IMAGE COURTESY OF DEREK BRIGGS
A color-marked image of the
Thylacares brandonensis fossil, which
allows the structures to be clearly
defined from surrounding rock.
A recent paper published in BMC
Evolutionary Biology, coauthored by former
Peabody Director and Professor of
Geology & Geophysics Derek Briggs,
reports the discovery of a novel ancient
arthropod Thylacares brandonensis. After
unearthing the creature in Wisconsin, the
research group came across a conundrum:
although their fossils resembled
thylacocephalans, an extinct class of
crustaceans (the group that includes living
crabs and lobsters), the rocks in which the
fossils were found dated from the Silurian
era (around 435 million years ago), which
is millions of years older than previous
discoveries of Thylacocephala.
Under technological probing by Joachim
and Carolin Haug, formerly in the Briggs
lab and now in Munich, the origins of
the fossil emerged from their dusty
surroundings into new light. The research
team used macro-lens cameras, crosspolarized
lighting, Adobe Photoshop,
Blender 3D modeling, and more to
produce an image of the fossil that could
be closely analyzed.
Critical features were revealed,
showing that the fossil belonged with the
Thylacocephala, extending the chronological
reach of the group millions of years
further back. Furthermore, using detailed
models alongside their own expertise, the
research team was able to describe the
creatures’ probable habits and lifestyle,
such as how the spiny front limbs were
used to capture its prey.
Every child played in a sandbox looking
for dinosaur bones, but as evidenced by
the discovery of Thylacares brandonensis,
paleontologists have more than shovels
in their toolboxes today. 3D printers,
microscopes, and manipulated light are
employed alongside more traditional
means to extend the scope of what can be
known about ancient life on Earth.
By Kathryn Ward
cognitive science
Mapping human perception of groups
PHOTO BY THERESA STEINMEYER
Yale Professor Joshua Knobe’s
most recent research attempts to
illuminate how we attribute mentalities
to groups of people in comparison to
individuals.
We are often warned to “stay off the
bandwagon,” or to avoid conforming with
a certain group mentaility.
The psychology of groups and how
individuals perceive groups has long been
a mystery, but recent research by Professor
of Cognitive Science and Philosophy
Joshua Knobe reveals another aspect of
human complexity.
Knobe’s study involved two experiments.
The first revealed that a designated group
of test subjects, referred to as perceivers,
attributed a particular mentality to an
entire group but did not ascribe that same
mindset to individuals within the group.
For example, these “people can think that
an organization knows how to build a
space shuttle even if no member of the
organization knows how to build a space
shuttle.”
The second experiment that Knobe’s
team conducted demonstrated that the
brain does not distinguish between a group
and an individual when assigning a certain
mentality—shown by the activation of the
right temporo-parietal junction, a region
typically associated with theory of mind—
when attributing thoughts to corporations.
Some psychologists argue that when
people say “the Catholic Church believes
capital punishment is morally wrong,”
they are not actually attributing a belief
to the Catholic Church, but rather they
are merely using the word “believe”; this
study, however, provides direct evidence
against this argument.
These findings could have major political
and economic implications as they relate
to how people perceive and interact with
governments and corporations. They set
the stage for future research, which will
further advance our understanding of the
human mind.
By Sofia Braunstein
6 Yale Scientific Magazine October 2014 www.yalescientific.org
biomedical engineering
Robert Langer touts entrepreneurship
in brief
NEWS
Dr. Robert Langer, the David H. Koch
Institute Professor at MIT, is the most
cited engineer in history; his contributions
to the fields of drug delivery and tissue
engineering have led to over 1,050 patents
and dozens of successful businesses.
On September 19 th , Langer delivered a
speech in the Cohen Auditorium outlining
some of the discoveries from his career.
Throughout his talk, he emphasized the
many contributions of the students and
collaborators whose ingenuity drove their
projects forward. Two of his former
students, Professors Mark Saltzman and
Laura Niklason, are now distinguished Yale
faculty members.
Langer began his speech by describing his
first major innovation, when he envisioned
injectable polymers that would slowly allow
a drug to diffuse into surrounding tissue.
He soon created a working polymer in the
lab and published his results in Nature in
1976.
However, most of Langer’s
contemporaries were not convinced; many
argued that the polymers’ slow diffusion
would render his invention irrelevant. It
took six years to get the procedure funded
and approved, but it was finally used to treat
a patient at Boston Children’s Hospital in
1982. He went on to found Enzytech to
continue this research.
This first project is one example of
Langer’s many successes, each of which
required incredible amounts of persistence
and healthy amounts of disregard for the
skepticism of pessimistic peers.
Some of Langer’s most successful
innovations took over a decade to produce,
adjust, and patent. To this end, Langer
noted that, “it’s all about perseverance in
the face of rejection.” Langer certainly
has persevered, forging breakthrough
technologies and encouraging the careers
of brilliant new researchers in the process.
By Rachel Yost-Dubrow
IMAGE COURTESY OF JOHN CURTIS
Robert Langer, the David H. Koch
Institute Professor at MIT, spoke
passionately about breakthrough
biomedical technologies.
cell biology
Microscopy innovation advances cell research
Microscopy has come a long way
throughout the career of Thomas Pollard,
Sterling Professor of Molecular, Cellular,
and Developmental Biology.
When he first started working as an
undergraduate student in the 1960s, the
only technique available to him was visible
light microscopy. Fifty years later, his
research team has developed a microscope
that goes far beyond just magnifying
organisms.
While regular microscopes yield only
qualitative data, Pollard’s calibrated
microscope shines light into a cell sample
and measures the amount of photons
emitted back, indicating the number of
molecules that accumulate and disappear
during endocytosis, the process by which
cells engulf extracellular molecules. Pollard
explained, “my colleague Julien Berro,
now Assistant Professor of Molecular
Biophysics and Biochemistry, improved the
time resolution of quantitative microscopy
by taking data from different endocytosis
events and lining them up precisely on
the same time scale to give much better
data than in any individual event.” This
“temporal super-resolution” method
allows researchers to follow endocytosis
with an unprecedented degree of precision.
Pollard’s team is also collaborating
with Professor of Cell Biology Joerg
Bewersdorf to use super-resolution
microscopy to distinguish the positions
of several different proteins at sites of
endocytosis and cytokinesis.
These advances in microscopy enable
greater understanding of cellular processes
and the structures involved in them.
Pollard’s work is applicable to biological
research on diverse cell types, and the next
step is to see calibrated microscopes used
to investigate live animal cells.
By Jessica Tantivit
PHOTO BY HOLLY ZHOU
Thomas Pollard, Sterling
Professor of Molecular, Cellular, and
Developmental Biology, studies the
molecular bases of cellular movement.
www.yalescientific.org
October 2014
Yale Scientific Magazine
7
NEWS
biomedical engineering
MENG 404 project wins design competition
BY MILANA BOCHKUR DRATVER
From concept to creation, learning at Yale
transcends the confines of a classroom.
Through their work in the Medical Device
Design Course (MENG 404), a team of Yale
students won the first place prize of $10,000
in the BMEStart competition. Natalie Pancer
(YC ’14), Andrew Crouch (YC ’14), Brian
Loeb (YC ’14), Raja Narayan (YSPH ’14),
and Kristi Oki (YC ’14) developed a novel
method of preserving and transporting the
small intestine during the transplant process.
The BMEStart Competition, sponsored
through VentureWell, aims to distinguish
excellent undergraduate feats in biomedical
engineering. The Intestine Perfusion,
Preservation, and Transportation Device
(IPPTD) is a revolutionary design expected
to improve the current standard of care in
intestinal transplants.
Currently, many intestinal transplants
do not remain functional after the transfer
Clever device tackles challenges in organ transplantation
process. Once the organ is collected, it is placed in a plastic bag
with a standard solution and moved using an ice cooler. Though
it typically works for other organs, this system cannot support the
many blood vessels throughout the small intestine, resulting in tissue
damage and death. With the support of Professor of Surgery and
Director of Surgical Research John
Geibel and others at the Yale School
of Medicine, the team of students
sought to improve the technique.
The team invented a pump
perfusion system to help the
carrying solution reach more blood
vessels. The IPPTD is composed of
two pumps that suffuse the small
intestine from the inside with a
specialized solution: a closed loop
for the lumen and an open system
for the vasculature. This approach
helps to remove cellular waste
product and harmful oxidizing
agents from the intestine, increasing
the viability of the transplanted
organ. In addition, the team developed a more stable container to
steady the intestine during transportation, preventing mechanical
damage.
After designing the device, the students ran experiments to prove
its potential. Collaborating with engineers, professors, and surgeons,
the students were able to build and test a prototype. Using pig
intestines, the team compared the traditional method with their new
device. Partnering with the Department of Pathology, they showed
that the intestine transported using the IPPTD
was more intact and had sustained less damage
after arriving at its destination than the control
intestine.
The team not only won the BMEStart
Competition, but also presented at the Society
for Surgery of the Alimentary Tract meeting
this past May. The product is in the process
of gaining a full patent and is being further
developed for clinical use.
The pilot course MENG 404 was a success.
Taught by Assistant Director of the Center
for Engineering Innovation and Design
Joseph Zinter and former School of Medicine
research scientist Richard Fan , the class was
intended to spur undergraduate innovation in
medicine. “[We] wanted to design a class that
could help Yale engineering students get a
better understanding of the practical aspects of
bridging engineering and medicine, and see if
[they] could find new interesting opportunities
for innovation,” Fan explained.
At the beginning of the semester, several doctors presented issues
they had observed in the clinic. Students then formed teams to focus
on specific cases. Pancer, Crouch, Loeb, Narayan, and Oki found
Geibel’s pitch on intestine transport to be the most interesting
and joined together to tackle the
challenge of increasing small
intestine transplant success.
The entire process proved to
be rewarding for instructors and
students alike. Loeb reflected on his
experience: “This was an incredible
view of the design process from
start to finish. I’ll now always be
able to look at products and have a
deeper appreciation for what goes
into them—or what can make
them better!”
IMAGE COURTESY OF RAJA NARAYAN
Brian Loeb (YC ‘14) poses with the
transport device.
IMAGE COURTESY OF NATALIE PANCER
Members of the student team. From left to right: Raja Narayan,
Kristi Oki, Andrew Crouch, Natalie Pancer, and Brian Loeb.
Pancer dubbed this project “the
most amazing experience of [her]
Yale career” because she was able
to work on a “hands-on project
that actually affects people.” “This was a course designed to take
real world problems, put engineering students on them, and see if
they could come up with a solution in a very short period of time,”
described Geibel. “I was very excited by how it worked out.”
Other teams last fall advanced home monitoring for epilepsy,
new tools for oral surgery, and mechanisms for subcutaneous drug
delivery. Now in its second year, the course will offer a new group
of students the opportunity to solve real-world medical challenges.
8 Yale Scientific Magazine October 2014 www.yalescientific.org
anthropology
Yale team explores social impact of drought
Carbon isotopes reveal link between climate, agriculture, and civilization
BY AMANDA BUCKINGHAM
NEWS
The fluctuations, proliferations, and collapses in ancient civilizations
have typically been viewed through cultural and political lenses. Yet,
just as climate change today is a hot-button issue, ancient man also
grappled with his environment. The extent to which local variations
in climate impact the agricultural production of ancient civilizations
has been little understood—until now. A team of scientists including
Frank Hole, Professor Emeritus of Anthropology, published a paper
this past August on drought-stress patterns in ancient and modern
agricultural systems of the Fertile Crescent. By measuring the ratio
of carbon-13 to carbon-12 found in barley grains, the team was
able to make conclusions about local climate change over time—
providing a new angle with which to analyze history.
According to Hole, the seeds of the project were sown in the late
1980s, when he surveyed a climatically sensitive region of Syria.
Hole inferred that population increases at certain points in history
stemmed from wetter climes. Others, such as Yale Professor of
Near Eastern Archaeology Harvey Weiss, linked the collapse of the
Akkadian Empire to the 4200 BP (before present) aridification event,
a period of intense drought.
There was one problem: conventional methods of drought
analysis, such as analyzing lake cores, are only indirectly applicable
when looking at inland, dry regions. Simone Riehl, lead author on the
paper, decided to apply stable isotopic dating to barley grain in order
to directly link archaeological sites with climate for the first time.
“The challenge was being able to collect modern barley from
across the Fertile Crescent region. It’s unprecedented,” Hole said.
Starting in 2000, the team collected data—barley grains—from
hundreds of agricultural fields in the Fertile Crescent region.
Ultimately, the team also selected barley grain from 33 archaeological
sites, spanning roughly 9500 years from the Aceramic Neolithic
(10,000 BC) to the Iron Age (500 BC), to compare with the modern
samples. Sites were selected to reflect different climatic environments:
Coastal, Euphrates (further inland but with access to a river), Khabur,
and inland sites without river access.
PHOTO BY LIDIYA KUKOVA
Frank Hole, Professor Emeritus of Anthropology at Yale, and a team
of scientists were the first to link archaeological sites with climate
fluctuations in ancient regions using isotopic dating of barley grain.
Barley was chosen as the target grain because of its droughttolerance
and economic significance—properties that increased the
likelihood of its detection at target sites. Archaeological material
underwent a process called flotation—pioneered by Hole for plant
remains in the 1960s in his kitchen sink—in which water is used to
isolate charred materials such as seeds, which can be run through
several graduated sieves for collection. The team determined the
grains’ carbon-13 to carbon-12 ratio, which when high is an indicator
of drought stress. During drought, C3 plants such as barley close their
stomata to conserve water. This process increases the sequestration
of carbon, which in turn raises the ratio of carbon-13. This ratio
was calibrated to reflect changes in the concentration of atmospheric
carbon dioxide over time.
Data analysis showed that drought stress was not a major factor in
the lives of those in coastal regions. Even the most severe droughts,
such as the 4200 BP event, caused only moderate stress in most
coastal sites, in contrast with strong-to-moderate drought stress in
inland regions. One aspect
of note is the high local
variability of isotope ratio
between inland regions
compared to coastal ones.
The team concluded that
this phenomenon is a result
of differential irrigation
patterns. Further, some
crops in irrigated sites did
not receive irrigation water.
The data was ultimately
used to trace water
availability over time,
buttressing what was
already known about
climatic trends while
providing new insights.
Conditions during the
Middle Holocene (10,000-
4000 BC) were more
PHOTO BY LIDIYA KUKOVA
Samples of barley grains collected
from various sites in the Fertile
Crescent region, used to chronicle
climatic fluctuations in ancient times.
favorable than in any subsequent time. Ensuing periods of drought
can be linked to the fluctuations in settlements, particularly those
in arid regions. In around 2200 BC, a strong and persistent drought
led to the ‘collapse’ of the Akkadian Empire. This was followed by
further drought during the Middle Bronze Age and another dry spell
during the Late Bronze Age.
Overall, the mean past values for the calibrated carbon-13 to
carbon-12 ratio suggest lower drought stress than today, while the
minima values (reflecting higher levels of drought stress) are more
similar to modern climate values. Hole hopes this data will help create
an “integrated history,” incorporating climatic variations and their
impact on agriculture with known cultural and political factors—all
of which play a role in shaping civilizations.
www.yalescientific.org
October 2014
Yale Scientific Magazine
9
NEWS
psychology
Why bother getting along?
BY AMEYA MAHAJAN
David Rand explores what motivates human cooperation
Professor David Rand is a modern Renaissance man. An Assistant
Professor of Psychology, Economics and Management, with work
published in Nature, Science, the New York Times, and Wired, his
research on human cooperative behavior spans several disciplines
with applications in many more.
Rand’s research arises from the grand question of cooperation—
why does it exist? He defines cooperation as
“one agent paying a cost to benefit another,”
whether that cost is time, money or effort.
Because cooperation requires individuals to
bear costs from which they themselves do
not benefit, from an evolutionary perspective
(in which agents serve only themselves in
order to survive), cooperation should not
exist. Furthermore, standard economic
models assume that agents act selfishly and
rationally, again contradicting the existence
of cooperation.
To understand why cooperation does in fact
exist, Rand draws heavily from game theory,
sometimes combining it with evolutionary
biology using a set of mathematical
formalisms known as “evolutionary game
theory.” He is particularly interested in
why people (rather than other organisms)
cooperate, and aims to inform public policy
with his work. He is conducting field studies in collaboration with
energy and utilities companies to further this end, using the results of
cooperative behavior experiments to shape policy decisions.
Rand’s path toward studying cooperation was not always clearly
defined. As an undergraduate at Cornell, he began as a computer
science major, but soon switched to biology with a focus in
computational biology, which he describes as “a mix of applied
math, biology, and computer science.” After working at a startup
creating mathematical models of biological phenomena, he attended
graduate school at Harvard in Systems Biology; there, he took a
class in evolutionary game theory and thought, “This is awesome!”
Speaking from his own experience as an undergraduate, Rand
encourages students from economics, psychology, biology, and
IMAGE COURTESY OF DAVID RAND
Professor Rand and his team members comprise the Human
Cooperation Lab at Yale.
IMAGE COURTESY OF DAVID RAND
David Rand, Assistant Professor of
Psychology, Economics and Management
studies human cooperative behavior.
applied mathematics to learn more about cooperative behavior.
Part of what has made Rand so successful in his field is how he
picks projects to study. He emphasizes prioritizing, saying that “after
you’ve been [studying] this for a while, you can generate lots of
ideas... The challenge is cultivating a ‘sense of aesthetic taste’ for
which of those many ideas are actually worth pursuing.”
After selecting an intriguing project, he
employs one of two research methods: either
behavioral or computational. Regarding
behavioral methods, he highlights the
importance of designing an experiment well.
“You need to have a good idea of how
you’re going to analyze the data once you’ve
collected it... your experimental design can
become flawed if you don’t consider what
will give you the most insight until afterward,”
he warned.
On computational methods, Rand
underscores the idea that a very simple model
can produce complex phenomena. “We’re
not so much looking at what exact numerical
coefficients in an equation create these
phenomena, instead we’re saying, ‘look, this is
what’s possible based on certain fundamental
assumptions,’” he said.
Rand also points out the importance of
computer programming in sciences: “Everyone should take an
intro programming class... It’s a super useful skill, both in academic
and private sectors.” He is making good on his advice, teaching a
course next semester that teaches computational modeling of social
interactions to students majoring in social sciences that do not have
prior programming experience.
In addition to his academic work, Professor Rand is an avid
musician. He began playing in punk bands in high school, and
even earned a record deal before he started graduate school. With
a nostalgic smile, Rand calls his current situation a “sad story,” as he
has had less time to play music given the sheer quantity of academic
work he pursues. He points out the strong parallels between music
and academia—finding an idea that others have not pursued yet,
creating and capturing this idea, and then sharing it with other people
are all parts of both academic and musical processes.
Rand downplays his rise to fame, claiming that he was extremely
fortunate to have an advisor in graduate school who could get papers
into top journals, describing the process as “riding [my advisor’s]
coattails.” He also attributes some of his success to the field of
cooperative behavior itself: “This is what’s hot right now. I’m just
lucky to be studying it at the right time.”
Looking forward, Rand is excited to see the developments his
first crop of graduate students will create in the field of cooperative
behavior and the implementation of his research findings in public
policy.
10 Yale Scientific Magazine October 2014 www.yalescientific.org
Defending against herpes
BY PATRICK DEMKOWICZ
For two billion years, viruses have wreaked havoc on virtually all
forms of life. While the public’s attention has been focused on the
recent Ebola outbreak in West Africa, common viruses like Herpes
Simplex Type II (HSV-2) pose
a greater threat of widespread
infection throughout the world.
According to the CDC, 16.2
percent of all Americans are
infected with HSV-2, a rate that
has remained steady during the
last decade. In August, associate
research scientist Norifumi Iijima,
Ph.D and Yale Professor of
Immunobiology Akiko Iwasaki
published a study providing
evidence that a network of
immune cells residing in the
mucosa of the mouse vagina is
required for full protection from lethal infection. These findings
offer key insights into developing the first HSV-2 vaccine for use in
humans.
Most vaccines against viral infection contain weakened or killed
viruses. The immune system makes quick business of these easy
targets. After this suppressed infection, the body is left with a pool
of proteins, known as antibodies, which fit lock-and-key with the
virus. When a real infection occurs, those antibodies quickly knock
out the intruders and alert a more comprehensive response. Herpes
has evolved to counter this
defense. Professor Iwasaki
explained the difficulties faced
in developing a herpes vaccine:
“In the case of herpes, because
neutralizing antibodies are
basically destroyed by the viral
coat protein, that strategy is
very difficult to implement.”
The Iwasaki group has long
recognized the old aphorism,
“Location, location, location.”
The key members of the
protective network described
in the study are known as CD4
tissue resident (T RM
) T cells.
They provide a similar sort of
“immunological memory” as
non-cellular antibodies in the
bloodstream, but issue a rapid
immune response at the very site of infection. Like the muscle reflex
retained in one’s hand after touching a hot stove, these cells react
before the rest of the body even recognizes the danger. “Ultimately,
we want to apply this to a vaccine,” said Professor Iwasaki. Her group
immunology
NEWS
New insights for vaccine development
PHOTO BY SURYABRATA DUTTA
Associate Research Scientist Noriformi Iijima, Ph.D, works in the
Iwasaki lab.
is well known for devising the “prime and pull” paradigm, which
recruits circulating CD8 T cells to the vagina to establish CD8 T RM
.
However, little was previously known about CD4 T RM
. This study
is critical in understanding how to
apply a method similar to “prime
and pull” to CD4 cells.
The study demonstrates that
CD4 cells converse chemically
with macrophages, cells that
engulf foreign materials and
invaders, in such a way that the
CD4 cells maintain a steadystate
population. Specifically, the
macrophages secrete CCL5, a
signaling molecule known as a
chemokine. The study indicates
that macrophages stimulate
CD4 cells to secrete an antiviral
cytokine that in turn stimulates the macrophages to produce more
CCL5. This sequence of events is referred to as a self-sustaining or
“positive feedback loop.” Understanding this maintenance process
is only half the battle in applying “prime and pull” to CD4 cells. “We
don’t have a good way to establish CD4 memory T cells, although
I don’t think it’s a big hurdle,” Iwasaki said. Furthermore, she cites
the challenge of balancing safety with efficacy.
Nevertheless, Iwasaki is used to simultaneously tackling a variety of
daunting challenges. She has much to owe to her hands-off style of
management, which in turn
encourages the creativity
of her lab members. “You
can’t focus on everything
at the same time,” said
Iwasaki. “The people in the
lab are very independent
and self-driven.” This style
has enabled her to maintain
an impressive record of
discovery, even while
raising a family. When asked
what she looks forward
to pursuing, she mentions
possibly partnering with a
vaccine company to bring
PHOTO BY SURYABRATA DUTTA
Associate Research Scientist Iijima, Ph.D, and Yale Professor of
Immunobiology Iwasaki published a recent study characterizing CD4 cells.
her work to the clinical
setting. She is also excited
about investigating the
immunological effects of
the “virome,” in particular, the endogenous retroviruses whose
precursors are the DNA in our genomes remaining from viral
infections during the course of primate evolution. In her own
words, “It’s really cool.”
www.yalescientific.org
October 2014
Yale Scientific Magazine
11
The Science of
How Physicists, Engineers,
and Computer Scientists
are Learning from Midges
As evening falls at Mason Laboratory, after students have shuffled out and most
labs have locked up for the night, a single fly takes off. Buzzing around erratically,
almost confusedly, it looks lost at first. Soon, though, it is joined by another fly,
and then a third. As more and more take flight, something strange happens. With seven or
eight flies in the air, the scene is still chaotic—a loose-knit flurry of individual flies.
But as a few more join—a ninth, tenth, and eleventh—the turmoil transforms. The ball of
flies becomes uniform, and individuals get lost in the whirling, bustling mass.
The flies have formed a swarm.
The Power of Ten
How such order can emerge from chaos
is the subject of recent research by Nicholas
Ouellette, Associate Professor of Mechanical
Engineering at Yale. Ouellette’s lab studies
the science of swarms—or, more generally,
the dynamics of collective animal behavior.
Using a colony of midges, a type of small
fly, as a model system, Ouellette and his
colleagues are trying to figure out answers to
questions like how many individuals it takes
to make a swarm. Their surprising answer
was published last month in the Journal of the
Royal Society Interface: just ten. And this is only
one of many surprising and enlightening
results emerging from the nascent science of
swarms.
But what exactly is a swarm? “That is a much
deeper question than you might expect,” says
Ouellette. While most of us have an intuitive
notion of what it means to swarm—think
bees—defining the notion precisely is much
trickier. Ouellette distinguishes between
swarms and other animal groupings like
flocks or schools, which tend to move as
units. “A swarm is a collective behavior
that doesn’t show net ordering,” he says.
But Ouellette acknowledges that many
other researchers would disagree. In fact,
defining “swarm” fruitfully is an active area
of Ouellette’s research, and a focus for other
swarm scientists as well.
Unanswered Questions
The appeal of swarming for scientists is the
rise of complex patterns and behavior from
the collective action of many individuals.
This phenomenon, known as emergence, is
a key feature of swarms. For Ouellette and
other researchers, connecting the emergent
properties with the underlying individual
behaviors is a consuming problem. “What
kind of local interactions do you need
to make a swarm?” Ouellette asks in his
research. “And how would you model that?”
With the right local interactions and
enough individuals, a swarm results. At this
point, the collection of animals exhibits
macroscopic properties that truly belong
to the group as a whole, rather than its
members. Ouellette makes the analogy to
thermodynamics, where thinking in terms
of macroscopic properties is more familiar.
Temperature and pressure are natural
examples. Similar measures can be used to
characterize swarms, except the individuals
are flies, bees, or birds rather than molecules.
But this is a very big difference, and
perhaps the most interesting research
questions focus on these contrasts between
swarms and chemical or physical systems.
While chemists can accurately think of
their particles as bouncing about at random,
swarm scientists cannot. Midges fly under
their own power; they are active agents
rather than passive particles. And while the
large-scale behaviors of chemical aggregates
are generally well understood, animal
swarms remain more mysterious. Ouellette
uses empirical approaches, like filming and
tracking the midges, to shed light on how
they form and behave. His lab has worked
to evaluate which models of swarming
match up best with biological reality.
They also ask questions like the one about
the size of swarms. To determine the
minimum number of midges in a swarm,
Ouellette and postdoctoral researcher
James Puckett, now an Assistant Professor
12 Yale Scientific Magazine October 2014 www.yalescientific.org
Swarms
by zachary miller
art by christopher paolini
of Physics at Gettysburg College, recorded
many swarms of midges of various sizes.
They measured characteristic properties of
these swarms, including the average distance
from one midge to another and the average
velocity of each midge. By plotting each
property against swarm size, they could
better understand how a group of midges
becomes a swarm. They found that every
property they examined leveled off rapidly,
having a consistent value for large swarms
of any size. Once the number of midges
reaches a sort of critical mass, a swarm
forms, and its characteristics remain similar
no matter how many more flies are added.
Somewhat surprisingly, in each case this
leveling off occurred for swarms of less
than ten individuals. Thus, they conclude, it
only takes ten midges to behave like a swarm
of many more.
The surprises, uncertainties, and hazy
definitions all reflect the novelty of swarm
science. Although humans have observed
and interacted with herds, flocks, and
swarms for millennia, only recently have
these phenomena—and the differences
between them—become accessible to
www.yalescientific.org
scientists. Ouellette believes that tools for
studying swarms have allowed the field to
grow rapidly in recent years. These tools
include inexpensive and easily accessible
digital imaging technologies for recording
swarming behaviors, and computer vision
programs that allow researchers to track
individuals within a swarm.
The Appeal of Swarms
Ouellette himself became interested in
swarming after developing computer vision
tools for the study of fluid mechanics.
Following particles in a swirling pool isn’t
so different from tracking midges flying
IMAGE COURTESY OF NICHOLAS OUELLETTE
The reconstructed flight paths of midges
in a single swarm. Each color represents a
different individual.
in a cloud. The parallels made it easy to
dip into biology. His progression isn’t
uncommon; Ouellette says that thanks to
technological advances, “physicists and
engineers have a lot of opportunities to look
at classically biological problems.” The mix
of backgrounds among swarm scientists
and the fertile intellectual ground they are
exploring make for a heady combination.
The explosion of interest among researchers
is mirrored by the popularity of books like
The Perfect Swarm by Len Fisher or Peter
Miller’s The Smart Swarm. “Any time you have
a problem with a real interdisciplinary focus,
scientists get excited,” Ouellette says.
Studying swarms isn’t only an intellectual
exercise, though. While the field is still
very young and focused on exploring
basic concepts, according to Ouellette,
the applications for its findings are
already exciting interest. The relevance of
swarms for robotics is possibly most clear.
Borrowing from the behavior of such
simple animals as midges, engineers could
build artificial swarms that exhibit complex
behaviors without complex programming.
Indeed, a number of researchers have
October 2014
Yale Scientific Magazine
13
FOCUS
entomology
already made forays into robot swarms. A
team of Hungarian engineers, for example,
recently conquered the challenge of building
drones that can form a self-organized swarm
in outdoor conditions. Ouellette says that
autonomous robotic systems like this are
the first real applications of swarm science.
It isn’t hard to imagine how robot swarms
could be put to use. Imagine small robocoptors
patrolling disaster areas, looking for
survivors, or agricultural robots swarming
through fields harvesting crops. It may
be telling that Ouellette’s own research
is supported by a grant from the U.S.
Army. Certainly, robot swarms could see
deployment on the battlefield. Part of the
appeal of robot swarms in such contexts is
their resilience.
If each individual robot contains the same
simple programming, and the more complex
behaviors are emergent, then individuals are
expendable. As long as enough individuals
(maybe ten, if Ouellette’s work applies
beyond midges) remain, the swarm will not
even notice the difference. Its behavior will
remain the same. Ouellette says that this
makes robot swarms “very fault-tolerant,”
a useful property for systems subjected to
harsh environments or for those with very
important functions.
This fault tolerance could make the
lessons of swarm science even more widely
applicable. Network control systems and
other computer applications seem especially
likely to incorporate them, Ouellette suspects.
But for now, his attention is turned to the
fundamentals of swarming behavior. Each
evening when his midges swarm, he will
turn on his cameras and computers—cutting
edge tools designed to tackle the toughest
problems in fluid dynamics—and hope to
glean a bit more insight into their remarkable
behavior. Perhaps that’s something to think
about the next time you bat away a cloud of
flies.
‘
Physicists
‘
IMAGE COURTESY OF NICHOLAS OUELLETTE
Nicholas Ouellette, Associate Professor of Mechanical Engineering at Yale,
uses computer modeling to simulate and examine swarm behavior.
and engineers have
a lot of opportunities to
look at classically biological
problems.
Nicholas Ouellette
ABOUT THE AUTHOR
ZACHARY MILLER
ZACHARY MILLER is a sophomore in Saybrook College studying Ecology and
Evolutionary Biology and Applied Mathematics. He is currently researching the
ecology and evolution of Greek lizards with Professor Oswald Schmitz and
doctoral student Colin Donihue.
THE AUTHOR WOULD LIKE TO THANK Professor Ouellette for his willingness
to give phone interviews while on sabbatical, and for the lucid explanations of
his research.
IMAGE COURTESY OF ARKIVE WEBSITE
An adult midge of the species Chironomus
riparius. Professor Ouellette’s lab maintains
a colony of these insects to study how they
swarm.
FURTHER READING
Kelley, Douglas H., and Nicholas T. Ouellette. “Emergent Dynamics of Laboratory
Insect Swarms.” Scientific Reports 3 (2013): 1073.
14 Yale Scientific Magazine October 2014 www.yalescientific.org
nutrition
FOCUS
A Smarter Way to Track
By Kevin Wang
Art by Laurie Wang
Nutrition
Staying loyal to a diet is challenging, but
keeping track of precisely what you
eat while you are dieting may be even
harder. Few people have time to stop in the
middle of the day to recall exactly how many
apple slices they had with breakfast, or how
many calories were in the Caesar salad they
ate for lunch. Fortunately, these questions
may soon be a thing of the past.
A Revealing Class of Molecules
Drs. Brenda Cartmel and Susan Mayne,
faculty members in the Chronic Disease
Epidemiology department at the Yale School
of Public Health, collaborated with scientists
from the University of Utah in a recent study
that establishes a novel way of finding out
the amount of fruits and vegetables people
have eaten. Their new method relies on
measuring the amount of a certain type of
pigment, called carotenoids, in a person’s
skin. Carotenoids give many modern birds
and fishes their colors. Beta-carotene and
alpha-carotene, which make carrots yelloworange,
have also been shown to produce
a yellow coloring in people’s palms when
ingested at high levels.
Humans cannot make their own
carotenoids, so we instead get them by
eating fruits and vegetables, which are the
best sources of these molecules. Because the
carotenoids we eat end up as deposits in our
tissues, they are prime biological markers of
vegetable and fruit intake.
Carotenoids have been a major area of
clinical study, but also of mystery. On the
one hand, carotenoids seem to be promoters
of good health: people who ingest them
also have a reduced risk of cardiovascular
disease. On the other hand, carotenoid
supplements have not been found to provide
the health benefits that fruits and vegetables
offer. It seems that there is something
about fruits and vegetables as a whole, not
just the carotenoids contained within them,
that delivers significant health benefits.
Carotenoid supplements—that is, those
not eaten as part of fruits or vegetables—
have been shown either to have no effect or
actually to increase the risk of lung cancer in
smokers, at least in the case of the carotenoid
beta carotene.
A Novel Approach
Since carotenoids have the potential to be
objective measures of fruit and vegetable
intake, scientists have been trying to find
reliable and efficient ways of measuring
them. Traditionally, carotenoid levels have
been measured by taking blood samples
and performing chemical analyses, but this
www.yalescientific.org
October 2014
Yale Scientific Magazine
15
FOCUS
nutrition
procedure is invasive, expensive, and often
requires long periods of time to analyze
results. The new procedure, which Cartmel
and Mayne have developed in conjunction
with physicists from the University of Utah,
is non-invasive. Whereas blood measurement
requires puncturing someone’s skin with a
needle, Cartmel and Mayne created a way to
measure carotenoid levels by simply placing a
beam of laser light on someone’s hand. They
used Raman Resonance Spectroscopy, which
works by directing a laser beam onto the skin
to excite carotenoid molecules. A detector in
the instrument registers the signals that these
excited molecules emit. In that way, it is able
to measure carotenoid levels.
With the help of one of Cartmel’s
colleagues, Yale School of Public Health
Research Associate Maura Harrigan, I
experienced Raman Resonance Spectroscopy
myself. I met with Harrigan at the Yale-
New Haven Hospital, where the apparatus
is housed. I was able to obtain my own
carotenoid reading, and perform a reading on
her as well. The laser is essentially a bulkier
version of the laser pointer you might see
your biology professor using during lecture,
‘
‘
We
can use this as a
method of assessing
the success of an
intervention.
Brenda Cartmel
but we took special precautions and wore
safety glasses just to be safe. The laser is
linked to a machine, which in turn is linked
to a computer that displays the readings.
First, Harrigan handed me a collection
of small skin tone plates, and I was allowed
to pick the skin color that I thought best
matched the color of the underside of my
forearm. Next, the bulky area of my palm,
which is called the thenar eminence, was
cleaned with an alcohol swab. The laser
was then placed on my palm. The machine
took it from there and subsequently spat the
data onto the computer screen. The whole
process took less than a minute.
In collaboration with colleagues from the
USDA, Cartmel and Mayne found that this
extremely fast laser scanning method was
effective in measuring carotenoid levels
and changes in fruit and vegetable intake.
To verify their findings, they correlated
carotenoid levels with manipulation of fruit
and vegetable intake, then compared those
results to the results of a conventional
blood test. From this comparison the team
concluded that skin carotenoids are a reliable
indicator of changes in fruit and vegetable
consumption.
Moreover, skin carotenoids are likely better
than blood carotenoids as a marker of usual
Dr. Brenda Cartmel
Dr. Susan T. Mayne
IMAGE COURTESY OF BRENDA CARTMEL
Dr. Brenda Cartmel is Senior Research Scientist and Lecturer
in Epidemiology at Yale School of Public Health. Her research
focuses on cancer prevention and survivorship.
IMAGE COURTESY OF BRENDA CARTMEL
Dr. Susan T. Mayne is C.E.A. Winslow Professor of
Epidemiology at Yale School of Public Health, Associate Director
of Population Sciences at Yale Cancer Center, and Department
Chair of Chronic Disease Epidemiology at Yale School of Public
Health.
16 Yale Scientific Magazine October 2014 www.yalescientific.org
The take-home message: “Eat more fruits and vegetables!”
fruit and vegetable ingestion. The explanation
for this observation is very simple: blood is a
transport medium and so changes with daily
diet fluctuations. In contrast, skin is a storage
medium, so carotenoids are more likely to
reflect a person’s usual intake.
These results are only the most recent
developments among years of research that
Cartmel and Mayne have carried out in this
area. In 2010, they established that the skin
test was as reliable, if not more reliable, an
indicator for carotenoid levels as the blood
test in the absence of dietary intervention.
This laid the groundwork for their 2012
study that showed that a correlation between
skin carotenoid levels and fruit and vegetable
intake also exists in preschool-age children.
IMAGE COURTESY OF TOP-NEWS.IN
drugs, disease treatment, and intensive
care, while there is far less emphasis on
disease prevention, nutrition therapy,
and lifestyle medicine. Part of the
reason that nutrition therapy has been
pushed to the sidelines by the medical
establishment is that tracking nutrition
and dietary habits is so challenging
for both physicians and patients. “We
can use this as a method of assessing
the success of an intervention. For
the most part, people have used
self-report, but this is a much more
objective measure,” Cartmel says.
Personalized medicine has been
emerging as one of the hottest areas in
medicine, and Cartmel’s findings will
nutrition
FOCUS
contribute to this field by enabling personalized
feedback from doctors. “You could say [to
patients], ‘Look, your skin carotenoid levels
have increased. You’ve done a great job with
your diet.’ It could be a way to provide positive
feedback,” Cartmel says.
At the most fundamental level, there is one
message that Cartmel says she wants to convey
to people after seeing the results of this study:
“Eat more vegetables and fruits!” The repeatedly
proven health benefits of vegetables and fruits
coupled together with this new objective and
reliable measure of vegetable and fruit intake
have made following a healthy diet easier than
ever.
Physicians also now have a foolproof,
objective way of finding out what patients are
eating or not eating. So watch out: it’s time to
eat up or fess up.
PHOTO COURTESY OF BRENDA CARTMEL
The original laser used for Raman Resonance
Spectroscopy in Cartmel and Mayne’s 2010 study
to validate the reliability of skin tests.
Only the Beginning
From here, Cartmel hopes to test the
carotenoid-measuring procedure in various
ethnic groups. Her recent study was
conducted only on Caucasian subjects,
and people of other ethnicities differ from
Caucasians in the levels of a pigment called
melanin in their skin. Because the test
examines pigments in skin, varying levels of
melanin could affect the outcomes for nonwhite
people.
In addition to providing both doctors
and patients with an improved method
of tracking fruit and vegetable intake, the
results of this study have much broader
implications.
In the U.S. healthcare system, an
overwhelming amount of attention is given to
ABOUT THE AUTHOR
KEVIN WANG
KEVIN WANG is a sophomore in Ezra Stiles. He is a prospective Molecular,
Cellular, and Developmental Biology major and the current copy editor of
the Yale Scientific Magazine. He has been writing for the magazine since his
freshman year.
THE AUTHOR WOULD LIKE TO THANK Dr. Cartmel and Ms. Harrigan for
their time, enthusiasm, and generosity.
FURTHER READING
Mayne, Susan T. et al. “Resonance Raman spectroscopic evaluation of skin
carotenoids as a biomarker of carotenoid status for human studies.” Archives
of Biochemistry and Biophysics 539, no. 2 (2013): 163-170.
www.yalescientific.org
October 2014
Yale Scientific Magazine
17
FINDING
EQUILIBRIUM
expanding the network of
female scientists at Yale
By Tessa Adler // Art by Audrey Luo
As a young girl, Joan Steitz didn’t plan on becoming a
scientist. She didn’t imagine doing research. She didn’t
anticipate making a breakthrough that would illuminate
how RNA is processed in early stages. She didn’t foresee a
career in science because she had never seen a female scientist
before. But her effort and successes repeatedly earned the
respect of important figures in science.
These people included her lab
director, Dr. James Watson, who
earlier had discovered the doublehelical
structure of DNA. In 1970,
Steitz became a faculty member in
the Molecular Biochemistry and
Biophysics Department at Yale.
Within ten years, she had discovered
an entirely new kind of small RNA
and showed how it is involved in
cutting out the unused portions of
messenger RNA, and piecing back
together the parts that need to be
kept.
For decades, Steitz didn’t question
the disparity between men and women
in her field. “It was always men, and
few women, and that’s just the way it
was, and I didn’t think about it,” said
Steitz. That changed in 2005, when
she co-authored a report documenting
the gender bias in sciences.
Dr. Vivian Irish, a developmental
geneticist who researches flowering
plants, is another female scientist at
Yale who has witnessed changes in
the gender balance over time. For 21
years, she’s worked for the Molecular,
Cellular, and Developmental Biology
Department at Yale. She works
mostly with a white flower species
called Arabidopsis thaliana, and seeks
to discover the patterning events in
development that give rise to floral
organs. “When I was a graduate
student, there was a very different
perception of women in science,”
said Irish. But she got lucky: while
conducting her graduate work at
Harvard, Irish found herself working
in a lab that had an abnormally large
percentage of women. “Once a
number of very bright and capable
women started working there, it made
it more attractive for more women to
join the group,” she explained.
Every year, Steitz has made it a goal
to try to teach one of the three core
courses that undergraduates majoring
in MB&B are required to take. If she
didn’t, most MB&B undergraduates
would graduate from Yale without
having been taught by a single female
professor in their field of study. “For
decades, I’ve been the only woman
who teaches these undergrads, just
because that reflects the complexion
of our department,” she said.
Steitz has been at Yale for 44 years,
but she continues teaching. I asked her
FOCUS
women
DR.
VIVIAN
IRISH
Dr. Vivian Irish, developmental
geneticist in the Molecular,
Cellular, and Developmental
Biology Department at Yale.
PHOTO BY KAT LIN
DR.
JOAN
STEITZ
Dr. Joan Steitz, researcher
at the Yale School of Medicine
and Molecular Biochemistry
and Biophysics Department.
IMAGE COURTESY OF YALE MEDICINE
whether she had been deterred from retiring
by the lack of any other female professors to
take over for her. “Oh, yes,” she replied. “I
just felt so awful that my department, which
I think the world of, wasn’t setting itself up
to be as optimal as possible to train young
women.”
By Women, For Women
As the years have gone by, women have
improved the climate at Yale by building
groups that offer support and provide
resources to women scientists. These
communities have recognized the problem
of the early withdrawal of many young
women from the sciences, and are working to
keep their interest alive. These groups have
also advocated for higher representation of
women on the faculty.
While female faculty members are
constantly reminded of the unequal gender
ratios in their departments, the administration
may not be as overtly conscious of the
problem. The Women Faculty Forum (WFF)
works to change this. Established in 2001 to
recognize the presence of women at Yale,
WFF organizes a variety of workshops and
programs and reports annually on the status
of women at Yale. “They let Yale know
whether progress is actually being made,”
said Steitz.
There are increasing numbers of female
scientists at Yale, but progress has been slow.
According to the WFF report, from 1982 to
2012 the percentage of female term faculty
members in the physical sciences rose from
8 percent to 33 percent. In the biological
sciences, the increase over the same thirtyyear
period was from 17 percent to 37
percent. Irish has witnessed these changes
during her 21-year-long time with the MCDB
department. “Slowly, we’re increasing the
number of women,” she says, “but it’s really
not at a rapid rate. Certainly not 50-50.”
While WFF promotes the interests of
female faculty members, other groups
advocate for the aspiring female scientists
among us. Women in Science at Yale (WISAY)
focuses on community-building, networking,
career development, and mentoring.
Established by three female graduate
students in 1999, the group has grown to
encompass hundreds of women across the
scientific disciplines, from freshmen to postdocs
to professors. UWISAY, Undergraduate
Women in Science at Yale, was founded in
2009 as a sister organization to provide a
community specifically for undergraduates.
WISAY and UWISAY organize dinners,
speakers, panels, ice cream socials, and
conferences throughout the year, and work
to build mentorship bonds between women
at different stages in their scientific careers.
“At least once a year I talk to those groups,”
said Steitz. “And they’re good! They provide
networking opportunities for women who
feel lonesome otherwise in the sciences.”
The feeling of being lonesome or lacking
solidarity has been a major problem for
women in science. Although many women
at Yale are not directly involved in groups
like WISAY and UWISAY, the mere
existence of these organizations helps to
combat the feeling of isolation that many
women in the sciences still experience. Ivy
Wanta, a sophomore physics major who did
research at CERN last summer, is the Co-
Chair of Mentoring for UWISAY. She only
really started getting involved this year, but
somehow she felt like a part of it all along.
“Even when I wasn’t involved, I felt better
knowing that this group exists,” she said.
“That concept in itself was helpful to me.”
Cultivating Early Interest
Besides providing awareness, organizations
like WISAY are actively employing strategies
to keep girls in the sciences. As Wanta noted,
the number of girls intending to major in
physics drops off very early: a large number
of women decide to drop the science after
just one semester in college, or even after
shopping period. “That’s one of the good
things about the mentoring program, is
that you’re immediately reaching freshmen,
which I think is really important,” she said.
Another way to encourage young
freshman women in science is by providing
more female role models in the introductory
science courses. Of the seven professors I
have had in my introductory STEM courses,
Irish is the first woman. Her motivation to
teach the “Genes and Development” module
of the Introductory Biology sequence
was not to improve the representation of
IMAGE COURTESY OF SCILOGS
Rosie the Riveter, the symbol of the
WWII integration of women into the labor
force, framed on a technologically-oriented
background.
20 Yale Scientific Magazine October 2014 www.yalescientific.org
women
FOCUS
IMAGE COURTESY OF RACI.ORG
‘
Actively inviting and
welcoming women into the
sciences is key to continuing ‘the momentum.
women; she genuinely enjoys teaching at the
introductory level. “But as soon as I said I
was interested, everybody was saying, ‘That
will be great, we need women teaching
this,’” she recalled.
The Perspectives on Science and
Engineering program, a supplementary
course for freshmen seriously interested in
STEM fields, also endeavors to captivate
the interest of freshman women in science.
Last fall, three of the five speakers for
the program were women, and this fall,
all of them are women. William Segraves,
Associate Dean for Science Education at
Yale, said, “It’s been important for women
to be well-represented in the course—it’s
part of how we’re hoping to change what
our nation’s future STEM faculty looks
like.”
Faculty in this program have also
thrown their weight behind the cause. In
Perspectives on Science and Engineering
last year, Ecology and Evolutionary Biology
Professor Richard Prum—one of a minority
of men lecturing as part of PSE—gave the
first class. He diverged from the content of
his lecture, which was about the Evolution
of Beauty, at the end of his talk. His last
slide depicted three female scientists. One
woman posed with dinosaur fossils, another
kneeled to collect measurements, and a third
walked through the jungle
in full field attire. The title
of the slide was “Advice for
Young Women Scientists.”
Two unforgettable bullet
points read: “You belong
here,” and “Science needs
Women!”
Spreading the Word
Actively inviting and welcoming women
into the sciences is key to continuing the
momentum. “It’s really necessary to have
men talking about wanting more women in
science also,” said Wanta. “Not just women
saying, ‘We need more of us!’ But men
saying, ‘We need more of you!’”
Spreading the message to Yale’s entire
community is necessary for women to be
fully integrated in the sciences. “I think that
the university definitely could host more
events, in a way where it’s not obviously
targeted just at women,” said Wanta.
Sponsoring campus-wide symposia, panels,
reports, workshops, would be a way to
include everyone in the movement.
Steitz has spent decades as the only woman
teaching undergrads in MB&B, going out of
her way to ensure that the undergraduates
in her department see a female face. After
all these years, her stubborn persistence
might not be necessary for much longer. In
the past year, the department hired a new
female professor who could teach the class.
“Now I feel like I could retire, because there
would be at least one woman to take over,”
Steitz said.
I asked Steitz whether she believed that
the status of women in science would
continue to rise. “I think we’ll do better.
It’ll just take a long time,” she said. “If you
bring it to people’s attention, then things
change faster.”
ABOUT THE AUTHOR
TESSA ADLER
TESSA ADLER is a sophomore Ecology & Evolutionary Biology major. She
works in Professor Jetz’s lab on the Map of Life project, researching the global
distribution of terrestrial species.
THE AUTHOR WOULD LIKE TO THANK all of her interviewees for the work
they’ve done to advance the cause of women in science. She would also like
to personally thank her mentors Jessica Brown, Joan Steitz, and Wenqing Xu.
FURTHER READING
Reuben, Ernesto, Paola Sapienza, and Luigi Zingales. “How stereotypes impair
women’s careers in science.” Proceedings of the National Academy of Sciences
111, no. 12 (2014): 4403-4408.
www.yalescientific.org
October 2014
Yale Scientific Magazine
21
by theresa steinmeyer
art by carrie cao & katherine lin
DEADLY
EUPHORIA
For opioid addicts, it’s all too tempting to give the drug
one more try. A heroin euphoria— temporary warmth, dulled
senses, painlessness—slips away after 10 or 15 minutes,
abandoning the addict to several days of withdrawal symptoms
that could fade with the easy pleasure of one more dose.
It’s no surprise, then, that the odds of
relapse for those with opioid addiction
are grim: according to a 2010 study, nine
out of ten patients relapse. Over half of
those relapses occur within the first week.
Nationally, opioid addiction is on the rise—
the National Institute on Drug Abuse found
in 2012 that nearly 670,000 people had used
heroin, the most commonly abused opioid,
within the past year, with over 150,000 new
heroin users that same year alone.
To prevent death—and in the long-term, to
help patients recover from persistent opioid
use disorders—scientists are exploring
treatments that may ease opioid withdrawal
symptoms, including a medication called
buprenorphine. The research raises a host
of questions from policymakers, whose
decisions impact the medication’s availability,
and insurance companies, who decide
when to help patients pay for it. How
freely should drugs like buprenorphine be
available? To what extent should they merit
reimbursement? How can abuse of these
drugs be prevented?
In a recent review, a team of researchers set
out to give clinicians and policymakers the
facts on buprenorphine. With Wayne State
University professor Mark Greenwald and
Yale professor David Fiellin, this team aimed
to address concerns about the safety and
necessity of larger doses of buprenorphine
for clinicians and policymakers, and to
defend the availability of buprenorphine.
The Challenges of Fighting Addiction
In order to understand how buprenorphine
can help patients recover from opioid
addiction, one needs to understand why this
addiction is so difficult to manage. When
a patient develops an opioid addiction,
nerve receptors in the brain and other areas
of the body get used to receiving opioid
molecules. The body tries to adjust itself
to the presence of these molecules, and in
turn, it becomes physically dependent on the
opioid to maintain an internal status quo. As
the body adapts to the opioid, it craves more,
and more, and more.
“You’re resetting the thermostat on your
neurobiology,” said Mark Greenwald, a
professor at Wayne State University who has
done extensive research on substance abuse.
“Those adaptations have a price when all of
a sudden you stop using it.”
So what happens to the body when the
opioid supply is cut off? A host of withdrawal
symptoms hit: anxiety, insomnia, or muscle
aches, followed by dilated pupils or vomiting.
To ease the transition between addiction and
abstinence, patients are tapered gradually
off of medications to treat withdrawal
22 Yale Scientific Magazine October 2014 www.yalescientific.org
symptoms and receive therapy and assistance
from physicians—but recovery still isn’t easy.
It’s all too tempting for addicted patients to
put a stop to these symptoms by returning to
the illicit drugs.
The solution? Help the body stop those
withdrawal symptoms so that the patient can
recover without the temptation of returning
to illegal drugs. “To give the old analogy,
it’s sort of a lock and key,” Greenwald said.
The buprenorphine drug binds to the same
receptors that were previously filled by the
opioid particles. In doing so, buprenorphine
performs similarly to how an illegal opioid
would in the body. This reduces the severity
of the withdrawal symptoms that the patient
experiences. The more opioid-hungry
receptors the buprenorphine occupies, the
less craving the recovering addict has for the
illegal drugs.
“What we try and do with [buprenorphine]
is to reduce the availability of those
receptors,” Greenwald said. “It will provide a
safer replacement that helps start the person
on the right track.”
A Scientific Call to Action
Greenwald and his team found that in
order to be effective against withdrawal
symptoms, buprenorphine had to be able
to occupy at least half of the receptors that
would otherwise be craving opioids. “Higher
doses are generally demonstrated to produce
greater reductions in illegal opioid use,”
Greenwald said.
addiction
FOCUS
But here’s the problem: the question of
how much buprenorphine each patient
ought to receive doesn’t have a one-sizefits-all
answer. Individual patients may
require different amounts of buprenorphine
to block enough receptors in order to
adequately ease their withdrawal symptoms.
And buprenorphine is often used as just one
component of a multi-faceted treatment
approach, which may also include therapy
or treatment for other psychiatric problems.
Even patients’ environments—whether
their peers are using or encouraging them to
return to opioid use—can impact their odds
of successful recovery.
Clinicians have to toe a fine line in
deciding how much buprenorphine to
provide to patients. Recovering addicts need
ART BY ANNALISA LEINBACH
Buprenorphine provides a solution for recovering addicts by mitigating withdrawal symptoms so that the patient can
recover without the temptation of relapse. However, the question of how much buprenorphine to prescribe doesn’t
have a one-size-fits-all answer.
www.yalescientific.org
October 2014
Yale Scientific Magazine
23
FOCUS
addiction
enough buprenorphine to ease withdrawal
symptoms as they detoxify their bodies, or
to prevent opioid cravings and highs during
maintenance—but since buprenorphine
provides a sensation similar to other opioids,
it could become a source of recreational
abuse.
Safety is an issue. Since buprenorphine
is designed to make the body feel like it is
under the influence of opioids, there is a
risk that people might abuse it recreationally.
Richard Schottenfeld, professor of
psychiatry at the Yale School of Medicine,
has worked with opioid addiction and
buprenorphine. He’s watched the debate
over the availability of the buprenorphine.
Like other medications used to treat opioid
addiction, buprenorphine “does have some
abuse potential on the street,” he said. “If
it’s not used as prescribed, it can cause some
problems.”
Policymakers and insurance companies are
wary of the costs and safety quandaries of
buprenorphine. Many insurance companies
are reluctant to cover an unlimited amount
of the medication, and policymakers are
concerned about making it too widely
available or endorsing high dosages. They’re
wondering where the limits ought to be
drawn on how much buprenorphine can be
provided and reimbursed.
Weighing the Risks
When Greenwald and his team
put together their review of recent
buprenorphine research, they did so with the
intention of injecting scientific data into the
controversy. “It had come to our attention
that some policymakers were limiting
the reimbursement for higher doses of
buprenorphine,” Greenwald said, referring
to Medicaid and some third-party insurance
companies. “If you’re paying for somebody
to receive treatments, your eye is on the
bottom line... [but] that should not be the
driving factor in our scientific decisions.”
“The impetus for doing this re-analysis
was to try to come to a clearer overall
understanding of what the data were telling
us,” he said. But that research was hard to
gather. The researchers faced an ethical
obstacle: although they wanted to work
with as large a sample size as possible, they
couldn’t research the behavior of patients
trying to recover from opioid addiction
at the risk of harming these patients’
recoveries. Instead, Greenwald and his fellow
9 out of10
opioid addicts relapse.
Over 50% of these
relapses occur in the
first week.
researchers could only study the behavior of
participants who were not currently seeking
treatment for opioid addiction. Their study
had to exclude patients for other reasons
as well—such as those dealing with other
psychiatric disorders that might affect their
receptor abilities and therefore distort the
research findings. Although there has been
substantial research to prove the usefulness
and relative safety of buprenorphine, there’s
still much left to discover.
So, how should policymakers and clinicians
weigh the risks of buprenorphine abuse
and the cost of its administration against
its potential benefits? Schottenfeld realizes
that buprenorphine needs to be widely
available enough that patients who need it
can access it. Weighing the potential benefits
of the medication as a means of decreasing
opioid addiction against the chance of
abuse, Schottenfeld believes that insurance
coverage ought to be considered separately
from how much buprenorphine a patient can
receive. “I wouldn’t personally come up and
say, ‘well, here’s a blanket way of giving it so
we can avoid abuse possibilities,’” he said.
Greenwald’s paper adopts a “use it or
lose it” attitude: either the patient uses the
drug appropriately to work toward opioid
abstinence, or clinicians might consider
cutting back on the amount of the drug that
should be made available to the patient.
But perhaps the best way to evaluate the
availability of buprenorphine is by weighing
the gravity of the consequences if it’s not
used.
“Opioid disorders are often chronic and
lifetime disorders,” Schottenfeld said. As
he puts it, if patients with hypertension,
diabetes, or other lasting medical problems
may need lifelong medication, then patients
struggling with opioid addiction ought to
be able to receive extended medications as
well if necessary. Over a 30-year period,
Schottenfeld said that half of patients with
untreated opioid use disorders ultimately die
from causes related to addiction.
“It’s important to keep that in mind,” he
said. “This really is a lethal disease that we’re
treating.”
ABOUT THE AUTHOR
THERESA STEINMEYER
THERESA STEINMEYER is in the Trumbull College Class of 2016. She is an
English major from Chicago, IL.
THE AUTHOR WOULD LIKE TO THANK Dr. Mark Greenwald and Dr. Richard
Schottenfeld for their time and enthusiasm.
FURTHER READING
Greenwald, Mark K., Sandra D. Comer, and David A. Fiellin. 2014.
“Buprenorphine maintenance and mu-opioid receptor availability in the
treatment of opioid use disorder: Implications for clinical use and policy.” Drug
and Alcohol Dependence. doi: 10.1016/j.drugalcdep.2014.07.035
24 Yale Scientific Magazine October 2014 www.yalescientific.org
The Vice and Virtue of Science
On September 14, Glenn
Adam Chin, a former head
pharmacist at the New England
Compounding Center (NECC),
was arrested and put under
criminal investigation. His
crime was related to a deadly
meningitis outbreak that
occurred across the country in
2012. This incident that killed 64
people and affected more than
680 others is a reminder of the
potential criminal use of science.
Chin has been accused of
several unsafe practices in
his lab, which likely sparked
the meningitis outbreak.
Using improperly sterilized
equipment and inaccurate
testing procedures, as well as
failing to maintain hygiene in
sterile clean rooms, caused
fungal contamination of the
drug methylprednisolone acetate (MPA), meant to be injected into
patients experiencing inflammation of the back. Chin has been
further accused of mislabeling the drug in an attempt to get more
physicians to use it on their patients. This incident has shed light on
faults in the current drug regulation system, and on science’s ability
to cause deathly large-scale outcomes.
MPA is an anti-inflammatory glucocorticoid that decreases the
patient’s immune response to diverse stimuli, which in turn increases
susceptibility to infections. When physicians injected MPA into
patients, the contaminating fungi were given direct access to the
bloodstream, and were thus
quickly able to invade the central
nervous system.
This exacerbated normal
meningitis
symptoms.
Contaminated MPA, then, was
a double hit for patients: A
weakened immune system on top
of direct injection of fungi caused
a sudden, drastic outbreak of
fungal meningitis. According to
the Center for Disease Control and
Prevention (CDC) and the Food
and Drug Administration (FDA), a
type of fungus called Exserohilum
rostratum was found in affected
meningitis patients associated with
this outbreak.
epidemiology
FEATURE
Man-Made Meningitis
the vice and virtue of science
BY YUKI HAYASHI
IMAGE COURTESY OFSPACE COAST DAILY
Improperly sterilized methylprednisolone acetate (MPA) was
mislabeled and shipped from the New England Compounding Center
to 23 different states.
Meningitis, which can be
viral, bacterial, or fungal, causes
inflammation of the meninges,
the protective membranes
covering the brain and spinal
cord. Functioning as protective
layers, the meninges allow the
brain to float in a liquid known
as cerebrospinal fluid (CSF). The
inflammation of the meninges
causes abnormal circulation
and reabsorption of CSF. This
increases pressure inside the
skull, which compresses brain
structures and oftentimes
restricts blood flow, ultimately
damaging the brain and spinal
cord. Although the exact
mechanism is unclear, high
intracranial pressure is known
to cause painful headaches often
accompanied by blurred vision.
Other symptoms of meningitis
include high fever, stiff neck, vomiting, nausea, and confusion.
It is hard to imagine how a drug compounded at one center could
have had such a large affect across the country. The NEEC, located
in Massachusetts, acted as a mass manufacturer that shipped drugs to
hospitals across the country. In fact, the contaminated vials of MPA
were shipped to 23 states, thereby causing a countrywide outbreak.
Furthermore, NECC was classified as a compounding pharmacy, not
a drug manufacturer, and therefore was not subject to strict FDA
regulations. This reveals a potential blind spot in the FDA’s regulation
practices, and an open door for criminal uses of science.
There is no doubt that science
has advanced us in many ways,
but the fungal meningitis outbreak
demonstrates that when put in
the wrong hands, science can
be dangerous. Whether or not
Chin’s poor lab practices were
intentional, measures must be
taken to prevent similar outbreaks
from occurring in the future. For
instance, supervisorial pharmacists
should check all sterilization
of medications, both in the lab
and at hospitals as necessary. As
technology progresses, scientists
IMAGE COURTESY OF DAILYMAIL.CO.UK
Glenn Adam Chin has been implicated in the deaths of 64
people, all of whom died from fungal meningitis.
must be extra careful to maximize
the wonders of science and
minimize its vices.
www.yalescientific.org
October 2014
Yale Scientific Magazine
25
FEATURE
geology
d e at h
va l l e y’S
BY GENEVIEVE SERTIC
PHOTO BY LIDIYA KUKOVA
For nearly a century, scientists have struggled with the mystery of
the sailing stones of Death Valley. These massive rocks, weighing up
to 320 kilograms, scraped out tracks as long as 224 meters in parallel
formation, giving the valley its second name, “Racetrack Playa.”
What scientists did not understand was how these immense stones
managed to move, or “sail.” No forces powerful enough seemed to
exist in the environment.
Finally, at the end of August, a team of researchers from the
Scripps Institute of Oceanography published their surprising
findings from three years of observations in Death Valley, during
which they quite literally saw the process in motion. This discovery
finally emerged after years of debate within the scientific community
over conflicting theories about the sailing stones, and the answer is
of interest to scientists and tourists alike.
It is not pure force, but rather the right combination of conditions
that thrusts these massive stones along the lakebed. The Scripps
team found that the rocks only move when a thin layer of ice forms
overnight from rainwater runoff from the surrounding mountains.
The next day, when the sun shines down on Death Valley, the thin ice
sheet breaks up into panels, which flow steadily in the direction of
even a light wind. The panels push the massive rocks along with them
at about two to five meters per minute.
The rainwater runoff must be seven millimeters to form
“windowpane” ice three to six millimeters thick—thin enough to be
broken into panels, but still strong enough push the sailing stones
forward. The exact movement of the
sailing stones depends on the magnitude
and direction of the wind. Light, steady
breezes of four to five meters per second
help the rocks move along their path.
Some previous theories had predicted
ice and wind to play a role in the sailing
stones, but not in the same way that
the researchers discovered. Powerful
wind, thick ice sheets, and algal films
that reduce the friction between the
rocks and the lakebed were all previous
conjectures. However, the researchers
found that the wind that sweeps through
the dry lake does very little to move the
s a i l i n g sto n e s
rocks. The ice sheets that form are not thick enough to move the
rocks directly. And only winds of up to 80 meters per second—about
as fast as a NASCAR race car—could move the stones even with the
help of an algal film. Only thin, floating ice panels pushed with a
gentle breeze are able to move the stones.
Led by paleobiologist Richard Norris, the Scripps team started
their work on Racetrack Playa in 2011. To measure the movement of
the rocks, they monitored the stones and environmental conditions
with time-lapse cameras, GPS systems, and a weather station that
measured the velocity of gusts every second. Because the National
Park Service did not allow the researchers to use the native rocks in
the playa for their experiment, the team attached the GPS systems to
15 rocks similar to those in Racetrack Playa and placed them in the
dry lake. Dr. Norris and the other researchers were not expecting to
actually see any motion because the rocks seldom move—at most
once every decade. It was by pure chance that they were present
when the phenomenon occurred on December 21 last year. The
researchers heard the ice begin to crack around noon and saw the
spectacle firsthand.
The discovery has explained other phenomena surrounding the
sailing stones of Death Valley as well. In some areas, the ice panels
themselves scrape through the sand and leave tracks in their wake,
which explains why there are some trails with no stone marking the
end. Some pairs of rocks also lose synchronization with each other
along their trails, which is likely a result of splitting ice sheets that
maneuver around one stone but not the
other.
The sailing stones were a mystery
to the public as well as to scientists.
Visitors to Death Valley now have an
explanation for the tourist attraction,
and scientists now have a case study of
a surprising force of nature: thin panels
of ice floating on water that together
force massive rocks hundreds of meters
IMAGE COURTESY OF INQUISITR WEBSITE
The sailing stones of Death Valley have perplexed
scientists for decades. Now, researchers think they
have found an explanation for how a light breeze is
enough to move these massive rocks.
forward. The rocks look the same as
before—sitting motionlessly at the end of
the tracks streaking the playa—but now
we understand the story that these sailing
stones tell.
26 Yale Scientific Magazine October 2014 www.yalescientific.org
As children, we check for monsters under the bed, sharks in the
ocean, and snakes in the garden. Afraid of danger from the outside
world, we rarely consider the potential for destruction within our own
bodies. For 17.3 million people annually, this destruction occurs when
the very organ that pumps their blood fails. In fact, cardiovascular
disease is the world’s leading cause of death. Fortunately, modern
medicine is providing a new hope: a drug called LCZ696.
The drug began clinical trials five years ago, in December 2009.
The company Novartis created it to treat chronic heart failure.
Researchers were astounded by the success of
LCZ696: It performed better in early clinical
trials than any prior heart failure drug has
performed. LCZ696 is effective because
it uses an innovative biological
technique. Rather than relying on the
inhibition of a singular enzyme, it
combines two antihypertensives,
or chemical components that
reduce blood pressure.
Chronic heart failure
occurs when the heart
medicine
FEATURE
Hope for Damaged Hearts
revolutionizing heart failure medication
BY EMMA HEALY
cannot maintain
adequate blood flow,
which leads to fatigue,
shortness of breath,
and increased heart rate.
Long-term effects of the
condition are also serious,
sometimes even fatal. Ischemic
heart disease and cardiac arrest
are not uncommon. Given the
severity of the chronic heart failure
and its high prevalence around the
world, developing effective drugs is an
important medical goal.
The standard treatment for heart failure
right now is enalapril, an angiotensinconverting
enzyme (ACE) inhibitor. ACE is
an enzyme secreted by the lungs and kidneys
that causes the constriction of blood vessels,
thereby increasing blood pressure. By inhibiting ACE, enalapril
reduces constriction and decreases strain on failing hearts.
Up until the clinical trials of LCZ696, enalapril was the best
treatment option for heart failure, and its long-term use decreased
the relative risk of death for patients by about 16 percent. LCZ696
could potentially reduce relative risk of death by 20 percent. This
increase in survival rate is significant, especially considering the
number of people affected by heart failure.
LCZ696 differs from enalapril because it combines two
components: valsartan and sacubitril. Both of these substances
are antihypertensives, meaning that they lower blood pressure, but
each functions differently. Valsartan is similar to enalapril in that it
blocks the functioning of angiotensin. Where enalapril blocks ACE
from converting angiotensin into its active form, valsartan blocks
angiotensin from binding to its receptor. Both approaches reduce
blood pressure by acting on the same molecular pathway.
Sacubitril is entirely unlike valsartan and enalapril—it inhibits
another enzyme, neprilysin, which is normally responsible for
inactivating several peptide hormones in the body. Two of the
hormones that neprilysin inactivates are involved in the natural
reduction of blood volume. In response to
high blood pressure, heart muscle cells
secrete these peptides to reduce blood
volume, but neprilysin prevents this from
happening. By inhibiting neprilysin,
Sacubitril increases the blood level
of these hormones, thereby
decreasing blood pressure. On
their own, neither Valsartan
nor Sacubitril is sufficient
to treat heart failure. But
in combination, they
appear to be extremely
successful.
In trials, LCZ696
was more effective
than other medications,
better preventing
cardiovascular-related
deaths and hospitalizations.
This accomplishment is
monumental because heart failure
has a poor prognosis; even with
modern medications, approximately
50% of individuals with CHF will
die within 5 years of initial diagnosis.
Beyond living longer and undergoing fewer
hospitalizations, LCZ696 subjects were
better able to handle the medication’s side
effects. A common problem with enalapril is
that patients have to discontinue taking the
drug because of severe side effects.
Novartis may change these standards when it releases LCZ696
to the public. Based on the first clinical trial, the drug is extremely
promising and produces significantly better results than enalapril.
It might be too soon for heart failure patients to rejoice, however,
as LCZ696 is not projected to be released to the public until 2015.
Additionally, there are still hurdles to overcome. LCZ696 will
probably be expensive. Analysts have predicted that it might cost a
patient as much as $2,500 a year, as opposed to generic drugs that
could cost as little as $48 per year. Nevertheless, the development of
LCZ696 is a leap forward in the treatment of heart failure.
IMAGE COURTESY OF LIFESTYLES55 WEBSITE
LCZ696 treats heart failure by reducing
blood pressure. Heart failure is a serious
disease, killing millions of people annually.
www.yalescientific.org
October 2014
Yale Scientific Magazine
27
FEATURE
epidemiology
MYSTERY PANDEMIC:
Deadliest Ebola Outbreak to Date
BY THERESA OEI
INFOGRAPHIC BY NICOLE TSAI
The recent Ebola scare at Yale-New Haven Hospital has brought
the Ebola outbreak to the attention of the entire Yale community.
National hysteria has spread as three confirmed cases have been
reported in the US as of mid-October. But West Africa has borne
the brunt of this outbreak, starting with the first case in December
2013. As of October 15, the virus had killed more than 4,493 people
in Sierra Leone, Senegal, Guinea, Liberia, and Nigeria. Reported
cases were at approximately 8,997, but underreporting was, and
still is, highly probable. Every day, Ebola-related morbidity and
mortality increases. The CDC predicts 10,000 new cases per week by
December. The outbreak has certainly reached pandemic proportions
and a serious global response is underway.
Frantic international efforts demonstrate how this outbreak has
blossomed into a modern pandemic. From its innocuous beginnings
in a bat reservoir to the infection of thousands throughout West
Africa and now, a few cases in the US and Europe, the virus has
proven its malignancy. However, Ebola is still a mystery to many
researchers and treatment for the disease is limited. It is now more
important than ever that the true science behind Ebola—what is
known and what remains a mystery—is clearly understood.
Most people are concerned, rightfully so, with how the virus is
transmitted. Ebola is a zoonotic virus that resides in bat reservoirs,
usually without any obvious symptoms. There are five identified
strains of Ebola, all in the family Flovidiae and the genus Ebolavirus.
All five cause disease in humans and nonhuman primates. Each
strain has a different level of virulence, or rate of death, among those
Statistics courtesy of the CDC
updated October 18, 2014
infected. The virus is transferred harmlessly among the primary host
population, comprised of migratory fruit bats. But when it invades
the secondary host, non-human primates or humans, it starts to show
pathological effects.
The incubation period ranges from a few days to three weeks,
and the virus remains alive and contagious even after the death
of the individual. This increases transmission of the virus during
funeral rituals for the deceased, which may involve cleansing of the
corpse. The disease is spread through bodily fluids, including blood,
feces, and vomit. Unlike some infectious diseases, the Ebola virus
is not transmitted through aerosols, meaning it is less likely to be
transmitted unknowingly than the flu or common cold.
Dr. James Childs, a zoonotic disease specialist at the Yale School
of Public Health, completed a four-week stint in Zaire (now the
Democratic Republic of the Congo) during the 1995 Ebola outbreak.
According to him, the 1995 virus was nearly identical to the virus
isolated in 1976 near the same location. Mutation of the virus is
possible, and would lead to greater viral diversity. Scientists stipulate
that it is unlikely that any mutations will lead to aerosol transmission
of the Ebola virus, which would alter its transmission route – and its
transmission rate.
Looking closely at the symptoms and potential treatments for
Ebola further demonstrates why so much of the disease remains a
mystery even to medical professionals. The symptoms in humans
include fever, vomiting, nausea, headache, sore throat, and internal
as well as external hemorrhaging. Although these symptoms may
28 Yale Scientific Magazine October 2014 www.yalescientific.org
epidemiology
FEATURE
not all occur simultaneously, their onset is quick and debilitating.
The disease typically begins with fever, headaches, and sore throat.
Gastrointestinal problems, including vomiting, nausea, and diarrhea,
are quick to follow. These GI issues have been particularly prominent
in this current outbreak. The virus’ access to the vascular system
can cause capillary leakage resulting in bleeding under the skin,
within internal organs, and from mucosal membranes. In early
stages, symptoms are difficult to distinguish from those of other
parasitic diseases or viral infections, such as malaria, typhoid fever,
or meningitis, which are all common in West Africa. This makes
identifying cases more challenging, and leads to misdiagnosis,
improper barrier techniques, and underreporting.
Once a case of Ebola is identified, basic treatment might include
providing fluids, stabilizing electrolytes, and maintaining blood
pressure. Of course in low-income areas, even these basic medical
supplies might not be available. Another major issue relating to
treatment is that infected patients are highly susceptible to other
infections. Managing opportunistic infections is a major obstacle in
Ebola treatment. There is no proven cure for Ebola. Vaccines are
currently under research and development. None of these vaccines
are commercially available even though one has been released for
emergency use in West Africa. Monoclonal antibody therapy is
another treatment that has been used experimentally, although the
patient sample size is small, which precludes concrete conclusions
on its effectiveness. Transfusion of plasma from recovered cases
to those clinically ill has shown promising results in past outbreaks.
Still, no treatment is altogether comforting for patients suffering the
horrendous symptoms of Ebola.
Scientists believe the 2014 outbreak began with a single infected
bat that bit a two-year-old toddler in the village Meliandoua in eastern
Guinea. In less than a week, the infected toddler and his mother had
died. The virus spread to mourners at their funeral.
Childs emphasized the importance of contact-trace history and
quarantine in controlling spread of the disease. This is traditional
strategy for managing Ebola outbreaks. Previously, outbreaks were
isolated to smaller rural communities and the trace history and
quarantining strategy was effective. However, the 2014 outbreak has
already reached major cities, even traveling internationally through
infected airplane passengers. As the number of cases grows, a trace
history becomes more difficult to establish. According to Childs,
the logistics of tracking individuals, quarantining, and providing
adequate care are extraordinary obstacles in areas that lack even basic
infrastructure. Additionally, poor health systems face a dearth of
facilities and financial resources compounded by a lack of trained
medical personnel. Untrained health workers may exacerbate the
problem by contributing to further spread of the disease because
of unsanitary or unsafe medical practices. The president of Sierra
Leone’s request for more hospital beds indicates that infected
individuals are turned away from overflowing hospitals and must
return to their local communities, where they will continue to spread
the disease.
Cultural issues also affect response to the disease: funeral rites for
the deceased, stigma of reporting, and mistrust of the healthcare
system all contribute to the problem. While the global response to
the Ebola outbreak has crawled along at a frustrating pace, picking
up speed only with international hysteria, the extraordinary potential
for human morbidity and mortality is now more broadly-recognized.
Hopefully, this will spark swift action.
Since the discovery of the Ebola virus in 1976 in the Democratic
Republic of the Congo, there have been 25 outbreaks in Africa.
The most deadly of these was a 1976 outbreak, which claimed 280
lives. The current 2014 outbreak, however, has dwarfed all previous
outbreaks combined. The epidemiology of the Ebola virus, its deadly
symptoms, and lack of adequate treatment options have created a
perfect pandemic storm.
West Africa
2014 Outbreak
March 25 Initial outbreak
reported in Guinea
April 16 Suspected patient
Zero, two-year-old from Guinea,
published in NEJM
July 30 Peace Corps removes
workers from Sierra Leon,
Guinea, and Liberia
September 30 Thomas Duncan
is first diagnosed Ebola case in
United States
October 8 Duncan dies of Ebola
in Dallas, Texas
October 14 Two healthcare
workers at Texas Presbyterian
Hospital tested positive for Ebola
www.yalescientific.org
October 2014
Yale Scientific Magazine
29
REINVENTING
BY ISABELLE ROSSI DE LEON
the human embryo
Leigh syndrome is an incurable neurological disease caused
by mutations to mitochondrial DNA, the circular DNA that
governs mitochondria’s ability to power the cell. The disorder
disrupts cellular respiration and results in rapid loss of muscle
movement and mental capabilities, often leading to premature
death. Leigh syndrome is passed on from mother to child by
the diseased mitochondria present in the egg, making it nearly
impossible for affected mothers to have healthy children.
However, there may be hope for women suffering from Leigh
syndrome and other mitochondrial diseases. This hope comes
in the form of the three-parent embryo, a recent scientific
innovation currently awaiting governmental approval for
human trials. The advent of a technique called mitochondrial
replacement, which creates three-parent embryos, has brought
survivors of Leigh syndrome several steps closer to having
biological children without the mother’s diseased mitochondria.
Mitochondria possess a small amount of DNA separate from the
cell’s nuclear chromosomes, a remnant from when the organelles
were free-living cells in the primordial world. Mutations in the
mitochondrial DNA can result in severe, often fatal diseases—
Leigh syndrome is just one manifestation of that. Without a
functional way to produce cellular energy, entire organisms are
at risk. In addition, because these mitochondrial diseases are
passed from a mother to her offspring in the embryo, they are
impossible to prevent and treat without altering the embryo.
Mitochondrial replacement combines two parents’
nuclear DNA, as in a normal embryo, and the mitochondria
from a third, healthy donor egg. The embryo then grows
into a child completely free of mitochondrial disease.
Of course, there are a multitude of safety and ethical issues
preventing the immediate use of mitochondrial replacement.
It is illegal in many countries to alter inheritable human DNA,
though mitochondrial replacement would not result in any
changes to nuclear DNA. Likewise, there are a variety of safety
concerns for both mother and child, including catastrophic
birth defects. Despite these hurdles, scientists are working to
make the three-parent embryo a reality within the next two years.
The numerous functions of mitochondria make it apparent why this
new therapy is an exciting advancement for the medical community.
Mitochondria take in glucose and other nutrients and produce
adenosine triphosphate (ATP), a molecule that retains and conveys
chemical energy within cells. A constant supply of ATP is necessary for
eukaryotic cells to survive, and thus for organisms, including humans,
to function properly. Mitochondria can lose their ability to produce
ATP via cellular respiration from changes in mitochondrial DNA.
IMAGE COURTESY OF BIOTE 21 WEBSITE
Mitochondrial DNA encodes much more than the structures
necessary to create cellular energy. The circular DNA plays a
role in many other normal cell functions as well.
However, mitochondria are not solely energy producers. The
organelles play a major role in each cell’s metabolic pathways, and the
3,000 genes encoded in mitochondrial DNA regulate everything from
detoxification to hormone synthesis. Mutations to mitochondrial
DNA thus have far-reaching effects. It makes sense that Leigh
syndrome and other mitochondrial diseases display such varied,
serious symptoms; these conditions tend to negatively impact cells of
the heart, brain, liver, kidneys, and skeletal muscles, resulting in severe
symptoms ranging from developmental delay to cardiac disease.
30 Yale Scientific Magazine October 2014 www.yalescientific.org
IMAGE COURTESY OF ACCELERATING SCIENCE
Mitochondrial diseases are passed on from mother to child in the
embryo. Though sperm do have mitochodria (they need energy to
propel themselves to the egg), paternal mitochondria—along with all
mitochondrial DNA—is usually lost immediately after fertilization.
The mother’s egg, on the other hand, contains a multitude of
mitochondria that become an intrinsic part of the embryo, and
eventually a part of the mature organism. Mitochondria are matrilineal,
meaning that they pass from mother to daughter completely
unaltered for generations. This is unfortunate for women afflicted
with Leigh syndrome, because they cannot naturally conceive healthy
children. This is where mitochondrial replacement comes into play.
Scientists in the U.S. and abroad are testing several methods of
mitochondrial replacement to create three-parent embryos and allow
mothers with mitochondrial diseases to have their own biological
children. One procedure, pronuclear transfer (PNT), completes invitro
fertilization using the two primary parents’ gametes. At the
same time, the father’s sperm is used to fertilize a donor egg with
healthy mitochondria. Pronuclei, or the nuclei from the cells involved
in fertilization, are removed from the primary parents and deposited
into the second embryo. The embryo is eventually transferred to the
mitochondrial replacement
is legalized and is successful
‘‘If
in clinical trials, [it] will likely
come to the surface as the
safest and most effective way
to prevent mitochondrial
disease from passing through
successive generations.”
mother with the hope of a successful birth of a disease-free baby.
Two additional methods of mitochondrial replacement include
Maternal Spindle Transfer and Nuclear Genome Transfer, both
of which utilize the mother’s nuclear DNA directly from the egg.
The donor egg’s nuclear DNA is removed, and the mother’s nuclear
DNA replaces the discarded donor DNA. The new egg with healthy
mitochondria and the mother’s nuclear DNA is fertilized with sperm
from the father in-vitro, and the egg is then transferred to the mother.
If mitochondrial replacement is legalized and is successful
in clinical trials, one of these three methods—PNT, Maternal
Spindle Transfer, or Nuclear Genome Transfer—will likely come
to the surface as the safest and most effective way to prevent
mitochondrial disease from passing through successive generations.
Of course there are a multitude of risks for women receiving invitro
fertilization after mitochondrial replacement. First and foremost,
pregnancy and delivery of a child is not guaranteed. The general
in-vitro fertilization treatment is not entirely safe, and the addition
of chemicals used in mitochondrial manipulation is speculated
to increase the risk of harmful effects for the mother. Because
mitochondrial replacement has yet to be tested in humans, scientists
are unsure if the mother’s body will react negatively to the implanted
three-parent embryo. Moreover, the three-parent child may not be
perfectly healthy, and may instead be born with damaged physiology.
While it is true that three-parent children would avoid
inheriting Leigh syndrome, they could potentially face other lethal
complications. It is possible that birth defects and other negative
reactions to the reagents used in the procedure will occur. In fact,
mitochondrial replacement might even result in mitochondrial disease
as a result of incomplete mitochondrial transfer or incompatibility.
A variety of diseases can also be caused by epigenetic changes that
occur during mitochondrial replacement. These modifications do not
affect DNA directly, but instead modify DNA expression through
chemical reactions such as DNA methylation. Unfortunately, such
detrimental epigenetic changes can be passed on to future generations.
Governments around the globe prohibit genetic modifications in
humans for ethical reasons. Even the limited germ line modification
entailed by mitochondrial replacement has caused disputes. On
one side, opponents of the new therapy argue that if scientists
can modify DNA in the embryo, there is nothing stopping them
from creating “designer babies.” But in general, opposition to the
three-parent embryo remains relatively quiet for now; proponents
are looking ahead to the potential of mitochondrial replacement in
helping patients of mitochondrial diseases live more fulfilling lives.
www.yalescientific.org
October 2014
Yale Scientific Magazine
31
FEATURE
cryptography
Q
U A N T U M
C O M P U T I N G
An uncertain future for information security
BY JACOB MARKS
On September 10th, news broke that roughly five million Gmail
accounts had been hacked, and their passwords had been stolen .
This followed on the heels of a cyber attack against Community
Health System, Inc., in which personal data of more than four
million patients was compromised , and came soon after a credit card
theft that affected Home Depot locations all over the world, making
the home improvement store the largest retailer yet to succumb to
computerized security theft.
Every day, it seems,
governments and corporations
fall victim to data leaks caused by
anonymous online crusaders or
foreign terrorist organizations—
leaks which call into question the
efficacy of modern computer
security measures. But quantum
cryptography, the use of
quantum mechanical principles
to make and break codes,
could irrevocably alter the way
cyber crimes are committed
and defended against. If
recent advances in quantum
key distribution come to full
fruition, they could reconfigure
the cybercrime landscape,
and give renewed hope for
information security.
Deriving from the Greek
words kryptos, for ‘hidden’, and graphein, for ‘writing’, cryptography
is defined as the science of writing secret codes . For thousands
of years, the practice has been used to protect state secrets and to
transmit war strategies. The ancient Greeks wrote messages along
cloth wound around sticks of a specific diameter, and the Romans
developed the first substitution cipher, called the Caesar Shift, in
which each letter in a message was shifted forward a certain number
of places. Later ciphers, such as those produced by the Enigma
machines used by German forces in World War II, involved multiple
substitution schemes, or arrangements of the alphabet to encrypt
messages.
But the advent of the computer in the latter half of the twentieth
century spurred a cryptographic revolution couched in a new type of
security By allowing for the electronic transmission of large quantities
of data, the computer introduced the need to securely transmit
information at a distance. In the past, sender and receiver shared
special knowledge about how
the message was encrypted—
such as the diameter of
the stick. But computers
necessitated a cryptosystem
that could securely transmit
information between people
who did not share a previously
agreed upon key.
The solution, public-key
cryptography, makes use of a
one-way problem—something
that is easy to solve in one
direction, but hard to solve
in the other. RSA, one of the
IMAGE COURTESY OF WIKIPEDIA
D-wave: D-Wave Two, pictured above, is the world’s most complex
quantum computer. Created in 2013, D-Wave Two is comprised of 512
qubits, and performs an optimization algorithm orders of magnitude
faster than classical computers.
IMAGE COURTESY OF 33RD SQUARE
most widely-used public key
cryptosystems, is rooted in the
assumption that it is easy for a
computer to multiply two large
prime numbers, but much
harder for it to factor the result
into the two initial primes. However, public key systems like this rely
on the limited computing power of cryptanalysts, or code-breakers.
Although hard to solve, the problem of factorization is certainly
possible, and as computing power has increased, the key length
needed to ensure information security has increased as well. In 2009,
a 768 bit RSA key (an integer represented by a string of 768 0s and
1s), was successfully factored by Thorsten Kleinjung and colleagues
, and some people believe that the 1024 bit RSA keys now in use will
32 Yale Scientific Magazine October 2014 www.yalescientific.org
cryptography
FEATURE
be breakable in the near future using only classical computers.
Furthermore, quantum computing, a subset of quantum
cryptography, threatens to dissolve public-key cryptography
entirely. Quantum computers use qubits , the quantum analog of
classical bits, to perform operations on data. Whereas bits can take
the value of either 0 or 1, qubits exhibit the quantum property of
superposition. This means that they can simultaneously be 0 and
1, or any combination of the two. As a result, quantum computers
can theoretically use Shor’s algorithm , an algorithm developed by
Peter Shor in 1994 for the efficient factorization of prime numbers.
In short, quantum computers may be able to solve the one-way
problem that is the very foundation for public-key encryption.
Because of this, perceptions of quantum cryptography are often
skewed. “Most people think that quantum cryptography will limit
information privacy”, Yale Professor of Applied Physics Steven
Girvin acknowledges, “but the truth is that it will actually enhance
privacy.” Although quantum computing may one day be used to
break existing public key cryptosystems, quantum key distribution
‘
Most
people think that
quantum cryptography will
limit information privacy
but the truth is that it will
actually enhance privacy
Steven Girvin
could replace these flawed alternatives and pave the way for secure
communication, even over public channels.
Quantum key distribution, or QKD, is a subset of quantum
cryptography that allows two parties to produce a shared random
key , which they can then use to encrypt and decrypt private
messages. It is split into two main branches, superposition, and
quantum entanglement, the concept that particles are produced
whose states cannot be described independently, and respectively.
The most successful implementation of QKD, BB84 , falls into the
first category. Named after Bennett and Brassard, BB84 uses photon
polarization states to transmit information from sender to source.
The sender selects two complementary states, each described by two
bases. By the Heisenberg uncertainty principle, which states that
it is impossible to measure two interdependent physical quantities
simultaneously, only one of the two states can be known.
For each photon, the sender chooses a random bit (0 or 1), and one
of the two bases that describe the state, and prepares the state of the
photon based on both of these random choices. The recipient must
also randomly choose a basis in which to measure the photon, and
when the sender and recipient use the same basis, they will observe
the same state. The resulting string of shared choices becomes their
key, and the rest of the photons are discarded.
One of the benefits of this system is that it is impervious to
eavesdroppers. Due to the no cloning theorem , the act of observing a
system changes its state, so if an eavesdropper intercepts transmitted
photons, the sender and receiver will know they are being spied on.
Dr. Girvin expounds, “there are no quantum Xerox machines; you
can’t copy quantum information.”
In the past few years, BB84 and protocols involving quantum
entanglement have been used to successfully distribute keys through
air, and via optical fibers, reaching distances of up to 148 kilometers.
QKD was used to secure the results of a 2007 Swiss election, and the
Chinese government uses QKD to protect state secrets.
Although companies such as ID Quantique offer quantum key
distribution services, the system has not been universally adopted
due to its lack of robustness, range, and reasonable price. But this
is bound to change. Battelle is working on building a 650 kilometer
optical fiber for QKD, and the Chinese government plans to
complete construction on a 2000 kilometer link between Beijing and
Shanghai by 2016. If researchers succeed in their goal of expanding
quantum key distribution to satellites, we will soon have a secure
communication network connecting disparate parts of the globe .
If quantum key distribution matures into a feasible cryptosystem,
and is adopted as the standard, then it will free us from the limitations of
existing public-key systems, and render the code-breaking capabilities
of quantum computers worthless. It is important to realize, however,
that cryptography is only one aspect of information security. “The
biggest security problem today is people”. Dr. Fischer, who teaches
a course at Yale on computer security cautions, “the easiest way to
break in is to trick or bribe someone into giving you the access to
the data. Even the most sophisticated technological measures can’t
prevent this” . Instead of breaking codes through brute force and
computational power, cyber criminals will turn to manipulation to gain
access to sensitive
information.
In theory, a
successful attack
against quantum
cryptography would
violate the laws
of physics. There
could, however, be
attacks based on
the physical objects
used to transmit
the data, such as
the detector used
IMAGE COURTESY OF WIKIMEDIA
The Caesar Shift Cipher, invented by the Romans, was the first
substitution cipher. Each letter in the alphabet was shifted forward a
pre-set number of places, with z looping back to a.
IMAGE COURTESY OF WIKIPEDIA
The Scytale is a type of transposition
cipher used in ancient Greece, which involved
wrapping cloth around a stick.
for observing the photons. Unless we are wrong about the laws of
physics, quantum key distribution has the potential to be both secure,
and feasible. Where humans are involved, cryptosystems can always
be broken. Nonetheless, quantum cryptography may reconfigure the
relationship between code-makers and code-breakers.
www.yalescientific.org October 2014 Yale Scientific Magazine 33
FEATURE
undergraduate profile
Yetunde Meroe (MC ’16)
AN EPICUREAN ENGINEER
BY MINA HIMWICH
Yetunde Meroe (MC ‘16) takes her food seriously.
As a chemical engineering major, Meroe ties her passion for
engineering and industry to a love for food and an interest in social
outreach. Her work as a Lazarus fellow at the Yale Farm this past
summer illustrates her desire to unite these diverse fields. “Food is
tied to everything in society – you can’t remove it from anything,” she
said. Meroe, who grew up in Ghana, plays a variety of different roles
at Yale, including Student Manager at the Afro-American Cultural
Center and President of the Yale Women’s Rugby Football Club. In
her scientific pursuits, she is set on using her engineering background
to make a positive contribution in communities similar to her home
community in Ghana.
The Lazarus internship, a fellowship that involves working at
the Yale Farm, gives students from a variety of backgrounds the
opportunity to experience different social, economic, culinary,
and scientific aspects of food. Meroe took her summer work very
seriously, and realized that she could use engineering to improve
conditions of food and agriculture back home. “You get a little bit
of everything [through the internship], and it really helped me look at
the importance of food in a different way,” Meroe said.
During the summer, Meroe participated in a wide variety of foodrelated
activities, including canvassing for free public school meals,
visiting public schools to see their food production process, working
in an industrial kitchen, and sailing on an oyster boat. She also took
classes on cultural economics and soil chemistry. The program was a
small group of only six students. “You get to know them very well,”
Meroe said.
Two components of her summer fellowship stood out to her in
particular. “I think the most enlightening part for me was the soil class,
and also going to a food depot, which serves Yale, up in Hartford,”
Meroe said. The food depot is a wholesale food seller, where large
amounts of food are sold in bulk. “In Ghana, we don’t have anything
like that. It was interesting trying to envision something like that back
home,” Meroe added.
In fact, home is never far from Meroe’s mind. In her conversations
at school, especially in her engineering courses, she pays attention
to how different systems or models might work in Ghana. When a
new idea is introduced, she always tries to envision it working back
home. Meroe’s summer research project focused on improving the
soil quality of semi-arid locations, specifically northern Ghana. This
gave her additional insight into the potential for new soil engineering
systems in her home country. “This gave me that connection more
than any other experience I’ve had at Yale. I was really appreciative
of that,” she said.
Building off of her soil research, Meroe is considering a thesis
involving soil science. “This summer has really made me start thinking
about a lot of things I would never have considered before,” Meroe
said. “I was so anti-grad school before this summer.” However, she
is now applying to the five-year Master’s program at the School of
Forestry, from which she would graduate with a master’s degree
in Environmental Management. Meroe is further considering a
concentration in either energy or industrial systems.
Meroe looks back on her internship at the Yale Farm with nothing
but positivity. “The best thing is to try different things,” Meroe said.
“I didn’t think this summer would be as transformative as it was. It
was getting in touch with your food, getting to know where your food
comes from. No matter what you think you’ll do in the future, that is
a transformative process in itself.” For her, of course, the experience
did lead to an ignited passion for using her academic background to
make a real difference in the world.
Meroe recommends getting involved in the community: “There are
so many opportunities, especially if you’re interested in food access,
food justice, and the social aspect of food. New Haven is a good
place to be to educate yourself on the issues of what’s being done,
and there are exciting things related to food activism – it’s a great
place to be.”
IMAGES COURTESY OF YETUNDE MEROE
LEFT: Meroe thoroughly enjoined her work at the Yale Farm this
past summer, and she loved getting to know the other Lazarus fellows.
RIGHT: Meroe tends to plants at the Yale Farm. The Lazarus
fellowship gave her the opportunity to learn about soil science and
the effects of soil variation on growing food.
34 Yale Scientific Magazine October 2014
www.yalescientific.org
David Spiegel (YC ’67)
BY SUMMER WU
In The Fault in Our Stars, Hazel, a 16-year-old girl diagnosed with
terminal cancer, falls in love with Gus, a philosophical 17-year-old
boy she meets at a cancer support group. Had it not been for Dr.
David Spiegel, a 1967 Yale graduate, Hazel and Gus would never
have met. Among his plethora of projects, Spiegel, alongside his
mentor, existential psychiatrist Irvin Yalom, started the first cancer
support group in 1976. This psychosocial approach to cancer care
was immensely successful, and it led to the ubiquity of cancer
support groups we see today.
Spiegel is currently a professor of psychiatry and behavioral
sciences at Stanford University. His fascination with the brain can be
traced back to his undergraduate years, when he fell in love with—
and decided to major in—philosophy. “Philosophy helped me better
think about how people are structured,” Spiegel said. Still, he knew
he wanted to enter a field with the potential to create new knowledge.
“Being a philosopher would be great—teaching freshmen Plato,
not so much,” Spiegel added. Ultimately, his desire to gain a deeper
understanding of human beings led him to the intersection of
medicine and philosophy.
After completing medical school and residency at Harvard in 1974,
Spiegel dove into the research of mind-body interactions at Stanford.
In his first cancer support group, specifically for women with breast
cancer, he observed the effects of group psychotherapy on cancer
outcomes. “Existence is fleeting—we don’t appreciate what it is to
exist until we contemplate the idea that we won’t,” Spiegel said. “We
work with people who are facing that and see if it can be a period
of growth.”
In the groups, Spiegel led discussions on detoxifying death, grieving
over losses, and living with the knowledge that death is inevitable.
The process is anything but easy: “It’s like looking into the Grand
Canyon when you’re afraid of heights,” Spiegel said. But he added
that “facing the worst” helps cancer patients gain strength. He soon
noticed a pattern in the support group: at first, the women tried to
guard their thoughts, but once they discovered that opening up made
IMAGE COURTESY OF DAVID SPIEGEL
In the 1960s, Spiegel (far right) was a member of Calhoun College.
alumni profile
FEATURE
FROM PHILOSOPHY TO MEDICINE
IMAGE COURTESY OF STANFORD SCHOOL OF MEDICINE
Today, Spiegel conducts research in two primary areas:
psychotherapy for cancer patients and hypnosis.
them feel better, they began to communicate more with each other
and with their families. Being surrounded by a group of women with
advanced cancer fostered a sense of community for each woman.
In 1989, Spiegel published the results of his groundbreaking study
on support groups, which found that group psychotherapy extends
the lives of cancer patients by an average of 1.5 years. Since then,
his paper has been cited more than 2,600 times. In 2012, he was
inducted into the Institute of Medicine of the National Academies
for the significance and influence of his research. “We found that
depression, social support, and sleep disruption all predict survival,”
Spiegel said, summarizing his major findings.
Spiegel also specializes in research on hypnosis. One of his current
projects uses fMRI to detect differences in the brain during high and
low hypnotic activity. “It’s lots of fun—we put students in a scanner,
then hypnotize them!” he said.
At Yale, Spiegel took Directed Studies, played guitar for Neck,
the Indian Folk Music Club, and was an active member of both
the debate team and the Yale Political Union. His most difficult
class was organic chemistry. He found the interaction between his
courses in medicine and his courses in philosophy fascinating. “I kept
wandering elsewhere and getting drawn back to human psychology,”
Spiegel said.
Spiegel intends to continue his passionate pursuit of understanding
how the mind affects the body. In addition, he would like to see
techniques such as hypnosis taken more seriously. According to
Spiegel, hypnosis is often portrayed as a “stupid stage show rather
than a therapeutic tool.” He hopes to harness the massive reach of
the Internet to disseminate tools that patients can use to deal with
trauma.
When asked whether he has any advice for current Yale students
hoping to follow in his footsteps, Spiegel replied: “Pose yourself a
question, and acquire the education.” From seeking an interdisciplinary
understanding of philosophy and medicine to spearheading a new
forefront of psychotherapy, Spiegel exemplifies his own counsel.
www.yalescientific.org
October 2014
Yale Scientific Magazine
35
FEATURE
meteorology
MYTHbusters
The Not-So-Simple
WEATHER
BY JENNA DIRITO
As much as people might try to deny it, winter is coming to the
northeast. And according to The Old Farmer’s Almanac, it is going to
be brutal. There may be some hope, however, for those who despise
the cold: The National Oceanic and Atmospheric Administration
(NOAA) is predicting a milder winter. Most importantly, what arises
from this discrepancy is the notion that predicting the weather is
much more complicated and nuanced than the public knows.
The almanac predicts “below-normal temperatures” for almost
75 percent of the country, with the Northern Plains and the Great
Lakes being hit the hardest. It also suggests that the eastern coastal
region has a snowy winter ahead. While NOAA is not set to release its
detailed winter forecast until mid-October, the patterns it is picking
up as of now do not seem to indicate a harsh winter. Historically,
The Old Farmer’s Almanac has been more accurate than NOAA, but
both of these systems are only predictions. The methods each uses
reveal the complex science of weather prediction.
The Old Farmer’s Almanac was first published by Robert B. Thomas
in 1972. Like other almanacs of its time, it predicted sunsets, sunrises,
tides, weather, and an abundance of other natural occurrences. This
particular almanac, however, was said to be accurate 80 percent
of the time, almost twice as often as any competing publication.
Thomas had devised a secretive weather forecasting formula based
on a complicated system of observed natural cycles. To this day, the
formula is hidden away in a black tin box.
NOAA prides itself on pursuing forecasts from a wholly scientific—
and entirely transparent—approach. Researchers use the North
Atlantic Oscillation index to predict winter weather and precipitation.
This index,
however, can
only predict
forecasts three
or four weeks
in advance, as
opposed to
predictions
months ahead
of time by the
Almanac. The
NOAA collects
data from a
series of 120
forecast centers
and relies on
information
gathered from
various weather
IMAGE COURTESY OF NOAA
NOAA uses advanced satellite technology to
receive the most up-to-date weather forecasts.
satellites located from Maryland to Hawaii. They gather information
on everything from cloud systems to city lights, fires, effects of
pollution, auroras, sand and dust storms, snow cover, ice mapping,
boundaries of ocean currents, and energy flows.
The NOAA also has Doppler weather radars to detect precipitation
velocity via application of the Doppler Effect. Atmospheric objects
that move
toward the
radar produce
a positive shift
in the frequency
of the radar
signal while
outbound
objects provide
a negative shift.
The changes
in frequency
IMAGE COURTESY OF NOAA
effectively allow
IMAGE COURTESY OF NOAA
meteorologists
NOAA’s advanced technology can receive to see motion in
updated, accurate pictures of developing weather,
the atmosphere,
like the storm system pictured here.
and to track
storms. At any
given time, NOAA is running advanced algorithms that are updating
the weather outcomes. This is part of the reason why a weatherman’s
prediction is always changing.
Weather satellites used by NOAA carry radiometers that
continuously scan the Earth to form images and create weather
models. Radiometers are usually comprised of infrared or microwave
radiation detectors, small telescopes, and scanning devices. The
satellites produce images in less than a minute. These images are
delivered in the form of electric voltages. Many of the satellites
that transmit images to the Internet or television stations are in a
geostationary orbit, rotating with the speed of the Earth to allow
a continuous view of the same geographic area. This complicated
technology reflects another reason why weather forecasts are
frequently updated.
Each of these technologies has its own advantages. While The
Old Farmer’s Almanac is more of a general speculation on a longterm
basis, it boasts a great deal of accuracy. Government scientists
working with NOAA maintain an image of reputability, but their
“long-term” predictions, really 90 days at max, have at most 60
percent accuracy. NOAA, however, is able to give an incredibly
detailed forecast in the short-term. Researchers there are making
tremendous advances in predicting the extent and timing of extreme
weather, which has become an increasing threat worldwide.
Overall, it is important to acknowledge that meteorology is by
no means an exact science, and to dispel the myth that any weather
forecast is simple. In reality, the science of weather prediction is
anything but straightforward. Weather patterns evolve. The algorithms
behind forecasting the weather are tremendously complicated,
and accordingly, weather forecasting technology is advancing at an
exponential rate. Still, uncertainty regarding the weather persists.
36 Yale Scientific Magazine October 2014 www.yalescientific.org
www.yalescientific.org
Unsolved Mysteries The Mpemba Effect
?
BY KEVIN SALINAS
Boiling water freezes more quickly than does water at This theory was one
room temperature. Discovered in 1969 and labeled the of the first proposed,
“Mpemba Effect,” this phenomenon remains a mystery to but it became one of
scientists. The Mpemba Effect went relatively unnoticed the first in a long chain
throughout early human history. References by Aristotle of theories to be tested
and René Descartes demonstrate a vague awareness of the since 1970. During initial
effect, but provide no explanation.
experiments conducted,
Since the Mpemba Effect caught the attention of a Mpemba, working with Dr.
Tanzanian high school student nearly 50 years ago, various Osborne, compared various
attempts have been made to understand the phenomenon. heated beakers of water to
Results from different experiments vary, and no single those that were not heated. They
theory has been substantial. Two major explanations found that evaporation causes only
involve the processes of evaporation and supercooling, slight changes in volume. No more than 30 percent of the
though neither has sufficient empirical support.
cooling could be attributed to this volume loss. There had
The discovery of the Mpemba Effect is a story of its to be other causes for the effect, they both concluded.
own, taking place before the great scientific debates that On the other hand, supercooling is a theory based on
this bizarre phenomenon has sparked. Erasto Mpemba was the fact that water temperature sometimes drops below
making ice cream one day in high school. He mixed boiled the freezing point before it turns into ice. Professor James
milk and sugar just as the rest of the class did, but rather Brownridge at Binghamton University found that water in
than waiting until the milk cooled, Mpemba put his hot sealed containers will almost always drop below the freezing
milk in the refrigerator right away. He later checked on his temperature before becoming ice. He also found that the
bag and realized that it became ice cream before any of the magnitude of supercooling is smaller for hot water than it
other bags. His teacher told him that this should not have is for cool water. In other words, hot water does not have to
happened, and dismissed the episode. But Mpemba would drop as far below the freezing point, and thus it will freeze
not take that as an answer.
more quickly than cold water. There are no explanations as
Soon after this incident Dr. Denis Osborne, a physics to why hot water supercools to a lesser extent than water at
professor, visited Mpemba’s school. He did not have an room temperature, which only adds more to this mystery.
answer when Mpemba asked why hot water freezes faster Despite many attempts and explorations, scientists have
than cold water. However, he was so intrigued by the fallen short of finding a definitive explanation for the
question that he began to work with Mpemba to solve the Mpemba Effect.
conundrum. This was more than 40 years ago.
Still, the Mpemba Effect remains a very real phenomenon
Since then, many scientists have searched for an with impacts outside of the lab. Besides Mpemba’s ice
explanation, but have failed to reach a consensus. One cream observation, this effect can be seen in other aspects
theory is based on the process of evaporation. Hot water of daily life. The recent fad of making “instant snow” on
will evaporate more quickly than cold water, with a greater chilly days by throwing boiling water up into the air is a
change in volume in a given time. Evaporation causes heat manifestation of the Mpemba Effect. Room temperature
loss, and lower mass also makes it easier to reduce the water thrown up into cold air results in nothing more than
temperature of water and to get the water to freeze. Thus, the water falling to the ground. Despite such interesting
some scientists theorized that rate of evaporation may be observations, the Mpemba Effect remains an unsolved
at the root of the Mpemba Effect.
mystery.
October 2014
ART BY RACHEL LAWRENCE
Yale Scientific Magazine
37
FEATURE
TV show review
SCIENCE IN THE
SPOTLIGHT
TV SHOW REVIEW : DUCK QUACKS DON’T ECHO
BY DANIELLE STAMER
“Duck Quacks Don’t Echo” promises to excite viewers with facts
that range from shocking to outrageous. The hosts, comedians Tom
Papa, Michael Ian Black, and Seth Herzog, compete
in this National Geographic program to present
the most interesting fact to the audience in order
to win the coveted “Golden Quack.” While “Duck
Quacks” presents fun facts in a highly entertaining
manner, it only occasionally addresses the scientific
basis of these facts. The hosts’ primary focus is on
the spirit and hilarity of competition, which forces
them to sacrifice scientific complexity. Still, the
program undoubtedly inspires curiosity, and every
episode is enjoyable in its own way.
The show draws facts from a variety of disciplines.
For surprising facts, like “redheads have a higher pain
tolerance than non-redheads,” the hosts interview
an expert (in this case, a geneticist from a research
university), who describes the science involved.
Then they conduct an experiment to demonstrate
the fact’s validity, and use a careful description of the procedure,
materials, controls, and results. The interview, too, introduces complex
concepts like genetics, evolutionary psychology, and chemistry in
TV SHOW REVIEW : THROUGH THE WORMHOLE
BY MALINI GANDHI
a clear – albeit oversimplified – manner. Other facts, such as “you
can scale a wall using vacuum cleaners,” may not be mind-blowing
findings, but are neat demonstrations of physics.
“Duck Quacks” commonly cuts the science to put
the hosts in silly situations, such as a hovercraft
race for the fact “you can make a hovercraft using
household items,” or a trivia competition in which
the hosts merely list facts. This is a shame because
the show has great potential to use science to
explain the unbelievable.
Despite its flaws, “Duck Quacks” is definitely
entertaining, especially with the laugh-out-loud
banter between the hosts, who lead each episode
with enthusiasm and energy. Although the show
may skimp on the science for broader appeal, it
remains exciting. Given that it premiered in January,
the program will hopefully continue to grow and
improve as it gains viewership. By showing the
simple “what,” the show at least encourages viewers
to discover the complex “why” on their own. “Duck Quacks Don’t
Echo” might just scratch the surface of science, but it definitely
meets any trivia-nut’s fill.
IMAGE COURTESY OF AMAZON
Morgan Freeman’s iconic voice announcing “space…time…life
itself ” echoes through the television series “Through the Wormhole.”
Filled with the dappled glow of galaxies and the spiraling of particle
collisions, the show is a vivid, mind-bending dance of physics and
philosophy.
The series, which premiered on Science Channel in 2010 and is
hosted by Freeman, draws on astrophysics and cosmology to tackle
the big questions of existence — questions about where we come
from, where we are going, and the elegant ways in which our universe
works. While the show
sometimes suffers
from an overblown
tone and wishy-washy
scientific explanations,
it excels in presenting
complex, abstract
topics in an accessible,
entertaining way.
IMAGE COURTESY OF GOOGLE PLAY Each episode
focuses on a mystery
of our universe. A more standard topic might be black holes, while
a funkier, less conventional topic might be whether or not aliens
worship gods. All the episodes emphasize the intersection of science
and philosophy. This tone is established in the premiere episode,
“Is there a Creator?” which uses science to examine the age-old
philosophical debate about God. The theme is also beautifully
rendered in the episode “Is Time Travel Possible?” which artfully
explains the theory of relativity and also explores philosophical
paradoxes of time travel.
One of the show’s notable strengths is its use of colorful analogies
to make tough concepts understandable. In the episode “Is There a
Shadow Universe?” which tackles dark matter, the self-interaction
of dark matter when galaxy clusters collide is illustrated by two
physicists having a spaghetti-and-meatball food fight. These quirky,
real-life comparisons add an engaging element of humor to the show.
Of course “Through the Wormhole” is not without its faults.
It tends towards the sensational, with Freeman melodramatically
introducing dark matter with “Could shadows threaten our world
of light?” The scientific explanations are often hand-wavy, which,
though appropriate for the show’s tone and audience, may frustrate
physics majors.
Regardless, “Through the Wormhole,” which wrapped up its
fifth season in July, succeeds at engaging audiences with beautiful,
elegant questions so often distanced from the public by high-level
mathematics. The show ultimately challenges us to think deeply
about the universe and our place in it.
38 Yale Scientific Magazine October 2014 www.yalescientific.org
Mysteries
of the Mind
BY ANDREW SUNG
cartoon
FEATURE
advertisement