Hi! My name is Meghna Datta, and I’m a
freshman. I’m from Madison, Wisconsin, so North Carolina weather has been quite
the adjustment. Apart from the humidity, though, I’m so excited to be at Duke!
I’m an aspiring pre-med student with absolutely no idea what I want to major
in. And it’s funny that I’ve grown to love science as much as I do. Up until
tenth grade, I was sure that I would never, ever work in STEM.
My first love was the humanities. As a
child I was hooked on books (still am!) and went through four or five a week.
In high school, I channeled my love for words into joining my school’s speech
and debate team and throwing myself into English and history classes, until
being forced to take AP Biology my sophomore year completely changed my
trajectory.
Science had always bored me with its
seemingly pointless intricacies. Why would I want to plod through tedious
research when I could be covering a groundbreaking story or defending justice
in a courtroom instead? But the lure of biology for me was in its societal
impact. Through research, we’ve been able to cure previously incurable diseases
and revolutionize treatment plans to affect quality of life.
Meghna Datta repping the Devils
In AP Bio, understanding the mechanisms
of the human body seemed so powerful to me. Slowly, I began to entertain the
notion of a career in medicine, one of many scientific fields that works to
improve lives every day.
Now, the research going on at Duke
doesn’t cease to amaze me. Specifically, I’m interested in science for social
good. Be it sustainable engineering, global health, or data-driven solutions to
problems, I love to see the ways in which science intersects with social
issues. As I have learned, science does not need to be done in isolation behind
pipettes. Science is exciting and indicative of society’s shared sense of
humanity. At Duke, there’s no shortage of this environment.
As a blogger I’m so excited to see the
inspiring ways that peers and faculty are working to solve problems. And
because science isn’t a traditionally “showy” field, I am looking forward to
shining the spotlight on people at Duke who tirelessly research behind the
scenes to impact those at Duke and beyond. The research community at Duke has
so much to celebrate, and through blogging I’m excited to do just that!
Hoping to catch up with an old friend who is a professor at Duke, Richard Leakey accepted an invitation to speak at the university on Oct. 22, though he “gave up public speaking to a large extent many years ago.”
Richard E. Leakey visited Duke on Oct. 22, 2019.
Leakey, age 74, is a world-renowned pioneer in Paleoanthropology – the study of the human fossil record – and is also well-known for his involvement in Kenyan politics and lifelong efforts towards conservation and wildlife protection. Once, he famously burned twelve tons of elephant tusks that were confiscated from poachers, which gathered international attention and helped usher in a global ban on the ivory trade.
Leakey came to paleontology by heredity. He is one of an entire family of Paleo-pioneers. His mother, Mary, discovered a skull in Africa that was dated to 1.75 million years ago (MYA) in 1960. Leakey said that this “electrified interest in the origin story” – that is, the human origin story. When his father, Louis, showed that the “quite clever” ancient tools he had discovered were made around 1.75 MYA, the original idea that human origins began outside of Africa began to change.
Leakey said the British people were hoping that “if we had evolved … let it happen in England” and if not England, then Asia, but this was not to be the case. At first, Louis Leakey was ostracized because of his work and discoveries of human origins in Africa. This helped steer Richard away from academics because of the fights that he saw his father endure.
Leakey’s famous 1984 Kenyan discovery, “Turkana Boy,” a 1.5 million-year-old, nearly-complete specimen of Homo erectus. (Wikipedia)
Successfully achieving his self-described ambition to not finish high school, Richard Leakey was thrown out of school at age 16. Yet today he is accredited with many awards, has written at least eight books, and has advanced the Leakey family legacy of discovery. From 1968 to the present day, he and fellow workers have discovered enormous numbers of fossils of our ancestors along the East and West shores of Lake Turkana in Kenya, which have an age span from 4.5 MYA to our very recent ancestors, which Leakey calls “fossil us.”
Leakey described for the Duke audience in an overflowing auditorium at the Nasher Museum a scenario he facilitated with colleagues and students.
He had taken a group to a camp site to talk about evolution and asked them to perform some tasks. First, they were charged to make tools from stone. The following day, they were led to a freshly slaughtered goat. Leakey told his pupils to butcher the goat and remove the flesh from its carcass.
After several hours watching the individuals try to pull at the goat with their hands to no avail, Leakey suggested that they might use their new stone tools. So they did, but they still could not get through the animal’s tough hide, even with a blade.
He said that during human evolution, our imagination was turned on genetically and this gave early humans the “capability to think of things that weren’t.” There is lots of work to be done studying an ancient period over 3.5 million years that Leakey says lends itself to “early ancestry of speech, imagination, [and] cooperation.” He is hopeful for the knowledge and new understandings that will come from investigation of this period.
“Why not ask someone to help you?” Leakey prompted again, and within an hour, nothing was left of the goat. The exercise demonstrated that though other monkeys and apes use stone, it is the human’s vocal communication and sense of working together that sets us apart, says Leakey.
Leakey’s current project is a “mega-museum” to “cerebrate and celebrate the story of the African origin.” The origin story which his parents first provided crucial evidence for is hugely important to the African continent and to the people of Africa and because we have “desecrated our motherland,” he said. Leakey wants the museum to highlight stages of evolution, genetics, climate, ecology, other species, and extinctions.
An architectural rendering of Ngaren: The Museum of Humankind to be built near Nairobi. (Studio Libeskind )
Before moving into the panel and Q&A portion of his talk, which was moderated by Duke professors Steven Churchill and Anne Yoder, Leakey prompted the audience to think about climate change, asking why we do not think we need to save ourselves. If we die, then other species go with us.
“Don’t for a minute think that climate change isn’t a real crisis that we’re in together,” Leakey said, earning a round of applause.
The human body is populated by a greater number of microbes than its own cells. These microbes survive using metabolic pathways that vary drastically from humans’.
Arpita Bose’s research explores the metabolism of microorganisms.
Arpita Bose, PhD, of Washington University in St. Louis, is interested in understanding the metabolism of these ubiquitous microorganisms, and putting that knowledge to use to address the energy crisis and other applications.
Photoferrotrophic organisms use light and electrons from the environment as an energy source
One of the biggest research questions for her lab involves understanding photoferrotrophy, or using light and electrons from an external source for carbon fixation. Much of the source of energy humans consume comes from carbon fixation in phototrophic organisms like plants. Carbon fixation involves using energy from light to fuel the production of sugars that we then consume for energy.
Before Bose began her research, scientists had found that some microbes interact with electricity in their environments, even donating electrons to the environment. Bose hypothesized that the reverse could also be true and sought to show that some organisms can also accept electrons from metal oxides in their environments. Using a bacterial strain called Rhodopseudomonas palustris TIE-1 (TIE-1), Bose identified this process called extracellular electron uptake (EEU).
After showing that some microorganisms can take in electrons
from their surroundings and identifying a collection of genes that code for
this ability, Bose found that this ability was dependent on whether a light
source was also present. Without the presence of light, these organisms lost
70% of their ability to take in electrons.
Because the organisms Bose was studying can rely on light as a source of energy, Bose hypothesized that this dependence on light for electron uptake could signify a function of the electrons in photosynthesis. With subsequent studies, Bose’s team found that these electrons the microorganisms were taking were entering their photosystem.
To show that the electrons were playing a role in carbon
fixation, Bose and her team looked at the activity of an enzyme called RuBisCo,
which plays an integral role in converting carbon dioxide into sugars that can
be broken down for energy. They found that RuBisCo was most strongly expressed
and active when EEU was occurring, and that, without RuBisCo present, these organisms
lost their ability to take in electrons. This finding suggests that organisms
like TIE-1 are able to take in electrons from their environment and use them in
conjunction with light energy to synthesize molecules for energy sources.
In addition to broadening our understanding of the great diversity in metabolisms, Bose’s research has profound implications in sustainability. These microbes have the potential to play an integral role in clean energy generation.
Thomas Barlow ’21 finds inspiration in small everyday things most people overlook: a craggy lichen growing on a tree, a dead insect, the light reflected by a pane of glass. Where we might see a flower, Barlow looks past the showy pink petals to the intricate parts tucked within.
The 20-year-old is a Duke student majoring in biology. By day, he takes classes and does research in a lab. But in his spare time, he likes to take up-close photographs using objects he finds outside or around the lab: peach pits, fireflies. But also pipettes, pencils.
A handheld laser pointer and flitting fireflies become streaks of light in this long-exposure image in Duke Forest. By Thomas Barlow.
Barlow got interested in photography in middle school, while playing around with his dad’s camera. His dad, a landscape architect, encouraged the hobby by enlisting him to take photos of public parks, gardens and playgrounds, which have been featured on various architects’ websites and in national publications such as Architecture Magazine. But “I always wanted to get closer, to see more,” Barlow said.
In high school he started taking pictures of still lifes. But he didn’t just throw flowers and fruit onto a backdrop and call it art. His compositions were a mishmash of insects and plants arranged with research gadgets: glass tubes, plastic rulers, syringes, or silicon wafers like those used for computer chips.
“I like pairing objects you would never find
together normally,” Barlow said. “Removing them from their context and
generating images with interesting textures and light.”
Sometimes his mother sends him treasures from her garden in Connecticut to photograph, like the pale green wings of a luna moth. But mostly he finds his subjects just steps from his dorm room door. It might be as easy as taking a walk through Duke Gardens or going for one of his regular runs in Duke Forest.
Having found, say, a flower bud or bumblebee, he then uses bits of glass, metal, mirrors and other shiny surfaces — “all objects that interact with light in some interesting way” – to highlight the interaction of light and color.
“I used to be really obsessed with dichroic
mirrors,” pieces of glass that appear to change colors when viewed from
different angles, Barlow said. “I thought they were beautiful objects. You can
get so many colors and reflections out of it, just by looking at it in
different ways.”
In one pair of images, the white,
five-petaled flowers of a meadow anemone are juxtaposed against panels of
frosted glass, a pipette, a mechanical pencil.
Another image pair shows moth wings. One is zoomed in to capture the fine details of the wing scales. The other zooms out to show them scattered willy-nilly around a shimmering pink circle of glass, like the remnants of a bat’s dinner plate.
Luna moth wings and wing scales with dichroic mirror, Thomas Barlow
For extreme close-ups, Barlow uses his Canon
DSLR with a microscope objective mounted onto the front of a tube lens.
Shooting this close to something so small isn’t just a matter of putting a bug
or flower in front of the camera and taking a shot. To get every detail in
focus, he takes multiple images of the same subject, moving the focal point
each time. When he’s done he’s taken hundreds of pictures, each with a
different part of the object in focus. Then he merges them all together.
At high magnification, Barlow’s flower close-ups reveal the curly yellow stamens of a zinnia flower, and the deep red pollen-producing parts of a tiger lily.
“I love that you can see the spikey pollen
globules,” Barlow said.
Stomata and pollen on the underside of a tiger lily stamen, by Thomas Barlow
When he first got to Duke he was taking photos using a DIY setup in his dorm room. Then he asked some of the researchers and faculty he knew if there was anything photography-related he could do for their labs.
“I knew I was interested in nature
photography and I wanted to practice it,” Barlow said.
One thing led to another, and before long he
moved his setup to the Biological Sciences building on Science Drive, where he’s
been photographing lichens for Daniele Armaleo and Jolanta Miadlikowska, both
lichenologists.
“A lichen photo might not seem like anything special to an average person,” Barlow said. “But I think they’re really stunning.”
Many people turn to the Internet to find a Mr. or Ms. Right. But lemurs don’t have to cyberstalk potential love interests to find a good match — they just give them a sniff.
A study of lemur scents finds that an individual’s distinctive body odor reflects genetic differences in their immune system, and that other lemurs can detect these differences by smell.
Smell check: Fritz the ring-tailed lemur sniffs a tree for traces of other lemurs’ scents. Photo by David Haring, Duke Lemur Center.
From just one whiff, these primates are able to tell which prospective partners have immune genes different from their own. The ability to sniff out mates with different immune genes could make their offspring’s immune systems more diverse and able to fight more pathogens, said first author Kathleen Grogan, who did the research while working on her Ph.D. with professor Christine Drea at Duke University.
The results appeared online August 22 in the journal BMC Evolutionary Biology.
Lemurs advertise their presence by scent marking — rubbing stinky glands against trees to broadcast information about their sex, kin, and whether they are ready to mate.
Lemurs can tell whether a mate’s immune genes are a good genetic match by the scents they leave behind. Photo by David Haring, Duke Lemur Center
For the study, Grogan, Drea and colleagues collected scent secretions from roughly 60 lemurs at the Duke Lemur Center, the Indianapolis Zoo, and the Cincinnati Zoo. The team used a technique called gas chromatography-mass spectrometry to tease out the hundreds of compounds that make up each animal’s signature scent.
They also analyzed the lemurs’ DNA, looking for differences within a cluster of genes called MHC that help trigger the body’s defenses against foreign invaders such as bacteria and viruses.
Their tests reveal that the chemical cocktail lemurs emit varies depending on which MHC types they carry.
To see if potential mates can smell
the difference, the researchers presented lemurs with pairs of wooden rods
smeared with the bodily secretions of two unfamiliar mates and observed their
responses. Within seconds, the animals were drawn to the smells wafting from
the rods, engaging in a frenzy of licking, sniffing, or rubbing their own
scents on top.
In 300 trials, the team found that
females paid more attention to the scents of males whose immune genes differed
from their own.
MHC genes code for proteins that help the immune system recognize foreign invaders and distinguish “friend” from “foe.” Since different genetic versions respond to different sets of foreign substances, Grogan said, sniffing out genetically dissimilar mates produces offspring more capable of fighting a broad range of pathogens.
Just because females spent more time
checking out the scents of dissimilar males doesn’t necessarily make them more
likely to have kids together, Grogan said. Moving forward, she and her
colleagues plan to use maternity and paternity DNA test results from wild
lemurs living in Beza Mahafaly Reserve in Madagascar to see if lemur couples
are more different in their MHC type than would be expected by chance.
Similar results have been found in humans, but this is the first time the ability to sniff out partners based on their immune genes has been shown in such distant primate kin, said Grogan, who is currently a postdoctoral fellow at Pennsylvania State University.
“Growing evidence suggests that
primates rely on olfactory cues way more than we thought they did,” Grogan
said. “It’s possible that all primates can do this.”
This research was supported by the National Science Foundation (BCS #0409367, IOS #0719003), the National Institutes of Health (F32 GM123634–01), and the Duke University Center for Science Education.
CITATION: “Genetic Variation at MHC class II Loci Influences Both Olfactory Signals and Scent Discrimination in Ring-Tailed Lemurs,” Kathleen E. Grogan, Rachel L. Harris, Marylène Boulet, and Christine M. Drea. BMC Evolutionary Biology, August 22, 2019. DOI: 10.1186/s12862-019-1486-0
Earlier this year, the online DNA testing company Ancestry.com faced a media firestorm and social media backlash after posting a controversial ad on its YouTube page.
The DNA testing company Ancestry.com took down its ad, “Inseparable,” in April 2019 in response to criticism that it romanticized slavery.
Titled “Inseparable,” the 30-second ad depicted a white man in the antebellum South asking an
African-American woman to flee to the North with him. Before the woman can answer,
the piece cuts to a tagline: “Only you can keep the story going. Uncover the
lost chapters of your family history with Ancestry.” Many
criticized the ad’s historical inaccuracy, showcasing a rosier portrayal of a
complicated past. To extinguish flames, Ancestry completely pulled the ad from
its platforms.
A recent Duke study of dozens of other ads across multiple DNA testing companies shows that this isn’t the only example of mixed messaging about race and identity from the world of genetic ancestry tests.
The tests are quite simple: order a kit, send off a
saliva sample and receive an ethnicity estimate within weeks. A test taker’s
ethnicity is broken down into percentages based off their DNA matches compared
to a globally referenced DNA database. Kits can range in price from $79 to$400.
Sales of DNA testing kits had reached 12 million people by 2017, as reported by
ScienceLine.
As part of the six-week summer research program Story+, Duke students Dakota Douglas, Mona Tong and Madelyn Winchester analyzed the messaging in 90 video ads from the companies 23andMe, AncestryDNA and MyHeritageDNA to see what they promise consumers.
Many of the ads lured customers with promises of a newfound identity and possible family members, the team found. One Ancestry.com ad, entitled “Kyle,” depicts a customer whose childhood was steeped in German culture, but discovers as an adult that he is also part Scottish and Irish. He happily “traded in his lederhosen for a kilt,” completely forgoing his previous heritage and reducing a newly discovered culture to stereotypes.
“There were a lot of advertisements
similar to that one,” said team member Mona Tong. “Many found a new identity
embracing it fully despite a lack of any cultural connections.”
“Kyle” illustrates a
phenomenon described in a 2018 study from the
University of British Columbia, which found that people
tended to “cherry-pick” the results, identifying more with certain ethnicities
and cultures to appear different. Whites were more likely to see their results
as “transformational” than their nonwhite counterparts.
“It’s not a bad idea to test your genes
for medical reasons,” said Patricia Bass, the team’s project mentor. “However,
these ads can be misleading by assuming that someone’s cultural and racial
heritage are determined by genes.”
While the majority of subjects featured within the ads were white, the few ads that featured people of color often glossed over the complicated history of someone’s lineage or conveniently left out difficult topics. Ancestry’s “Anthem” ad detailed historical reenactments of an African tribal women, prohibition gangsters, a man fleeing England for America and Native Americans somberly heading to a new land. A voiceover speaks with inspiration ending with a shot of a biracial woman.
In marketing the idea that we
are all one, the ads fetishized
mixed-race subjects, while ignoring the genocide and displacement of people,
the team found.
The team hopes future
research will further examine the impact of these ads on people’s view of
identity. Importantly, one could note if there were any focus groups to test
these ads before release.
“It furthers the idea of colorblindness,”
Tong said. “It assumes that relationships are contingent upon common ancestry
and genes.”
“In a way, companies are trying to help
by focusing on the interconnectivity and commonalities between people,” Tong
said. “But it hurts more than it helps.”
Story+ is a six-week undergraduate research program offered through the John Hope Franklin Humanities Institute and Bass Connections, with support from the Duke University Libraries and Versatile Humanists at Duke.
For many years, the standard strategy for fighting against cancer has been to find it early with screening when the person is still healthy, then hit it with a merciless treatment regimen to make it go away.
But not all tumors will become life-threatening cancers. Many, in fact, would have caused no issues for the rest of the patients’ lives had they not been found by screening. These cases belong to the category of overdiagnosis, one of the chief complaints against population-level screening programs.
Scientists are reconsidering the way to treat tumors because the traditional hit-it-hard approach has often caused the cancer to seemingly go away, only to have a few cells survive and the entire tumor roar back later with resistance to previously effective medicine.
Dr. Marc Ryser, the professor who gave this meaty talk
In his May 23 talk to Duke Population Health, “Cancer Overdiagnosis: A Discourse on Population Health, Biologic Mechanism and Statistics,” Marc Ryser, an assistant professor at Duke’s Departments of Population Health Sciences and Mathematics, walked us through how parallel developments across different disciplines have been reshaping our cancer battle plan. He said the effort to understand the true prevalence of overdiagnosis is a point of focus in this shift.
Past to Future: the changing cancer battle plan Credit: Marc Ryser, edit: Brian Du
Ryser started with the longstanding biological theory behind how tumors develop. Under the theory of clonal sweeps, a relatively linear progression of successive key mutations sweeps through the tumor, giving it increasing versatility until it is clinically diagnosed by a doctor as cancer.
Clonal sweeps model, each shade is a new clone that introduces a mutation credit: Sievers et al. 2016
With this as the underpinning model, the battle plan of screen early, treat hard (point A) makes sense because it would be better to break the chain of progression early rather than later when the disease is more developed and much more aggressive. So employing screening extensively across the population for the various types of cancer is the sure choice, right?
But the data at the population level for many different categories of cancers doesn’t support this view (point B). Excluding the cases of cervical cancer and colorectal cancer, which have benefited greatly from screening interventions, the incidence of advanced cases of breast cancer and other cancers have stayed at similar levels or actually continued to increase during the years of screening interventions. This has raised the question of when screening is truly the best option.
Scientists are thinking now in terms of a “benefit-harm balance” when mass-screening public health interventions are carried out. Overdiagnosis would pile up on the harms side, because it introduces unnecessary procedures that are associated with adverse effects.
Thinking this way would be a major adjustment, and it has brought with it major confusion.
Paralleling this recent development on the population level, new biological understanding of how tumors develop has also introduced confusion. Scientists have discovered that tumors are more heterogeneous than the clonal sweeps model would make it appear. Within one tumor, there may be many different subpopulations of cancer cells, of varying characteristics and dangerousness, competing and coexisting.
Additional research has since suggested a more complex, evolutionary and ecological based model known as the Big Bang-mutual evolution model. Instead of the “stepwise progression from normal to increasingly malignant cells with the acquisition of successive driver mutations, some cancers appear to evolve more like a Big Bang, where the malignant ability is already concentrated in the founder cell,” Ryser said.
As the first cell starts to replicate, its descendants evolve in parallel into different subpopulations expressing different characteristics. While more research has been published in favor of this model, some scientists remain skeptical.
Ryser’s research contributes to this ongoing discussion. In comparing the patterns by which mutations are present or absent in cancerous and benign tumors, he obtained results favoring the Big Bang-mutual evolution model. Rather than seeing a neat region of mutation within the tumor, which would align with the clonal sweeps model, he saw mutations dispersed throughout the tumor, like the spreading of newborn stars in the wake of the Big Bang.
How to think about mutations within a tumor credit: NASA
The more-complicated Big Bang-mutual evolution model justifies an increasingly nuanced approach to cancer treatment that has been developing in the past few years. Known as precision medicine (point C), its goal is to provide the best treatment available to a person based on their unique set of characteristics: genetics, lifestyle, and environment. As cancer medicine evolves with this new paradigm, when to screen will remain a key question, as will the benefit-harm balance.
There’s another problem, though: Overdiagnosis is incredibly hard to quantify. In fact, it’s by nature not possible to directly measure it. That’s where another area of Ryser’s research seeks to find the answers. He is working to accurately model overdiagnosis to estimate its extent and impact.
Going forward, his research goal is to try to understand how to bring together different scales to best understand overdiagnosis. Considering it in the context of the multiscale developments he mentioned in his talk may be the key to better understand it.
Marijuana is becoming legalized and decriminalized to the point that more than 63 percent of Americans have access to medical and recreational cannabis. But researchers and policy experts still don’t know very much about the long-term health effects.
Meier investigates the relationship between cannabis use and IQ in a 38-year-long study that has been collecting data on a group of 1,000 people born in New Zealand since birth. Longitudinal studies like this that follow the same group of individuals across their lifespan are vital to understanding the effects of extended cannabis use on the human body, but they are difficult to conduct and keep funded. The 95 percent retention rate of this study is quite impressive and provides much-needed data.
Madeline Meier of Arizona State University
The researchers had tested the
babies’ IQ at early childhood, then conducted regular IQ and cannabis use assessments
between the ages of 18 and 38. They found that participants who heavily used
weed for extended periods of time experienced a significant IQ drop, as well as
other impairments in learning and memory skills. Specifically, users who had
three or more clinical diagnoses of cannabis dependency, defined as compulsive
use despite physical, legal, or social problems caused by the drug, showed an
average 6-point IQ drop over the years. Those who only tried the drug a few
times showed no decline, and those who never used weed showed a 1-point IQ increase.
Notably, however, the results
depended on age of onset and level of use. Meier emphasized that her results do
not support the common misconception that any amount of weed use can immediately
lead to IQ decline. To the contrary, Meier’s team found that short-term,
low-level use did not have any effect on IQ; only heavy users suffered the
negative effects. The age of onset of cannabis use was critical, too:
Adolescents were more vulnerable to the drug’s harms, with study participants
who started using as adolescents showing an 8-point drop in IQ points. Given
what we know about adolescents’ affinity for risky behavior, specifically
around experimentation with drugs, this finding is particularly worrisome.
In addition to causing cognitive impairment,
persistent cannabis use jeopardizes people’s psychosocial functioning as well. The
Dunedin longitudinal study has
also revealed that people who continued to use weed despite multiple dependency
diagnoses experienced downward social mobility, relationship problems,
antisocial workplace behavior, financial difficulties, and even higher numbers
of traffic convictions. In short, social life is likely to be perilous for heavy
weed users.
While some have
suggested that the harmful effects of weed might be caused not by the drug
itself but by the reduced years of education, low socioeconomic status, mental
health problems, or simultaneous use of tobacco, alcohol or other drugs among
weed users, Meier and her team found that the impairments persisted even when
these factors were accounted for. Cannabis alone was responsible for the
effects reflected in Meier’s research. In fact, there is limited evidence for
the opposite causational link: weed use may be the cause of mental health
problems rather than being caused by them. One study found a weak correlation
between years of marijuana use and depression, but Meier was careful to point
out that it would take “a lot of cannabis use to lead to clinically diagnosed
depression.”
Given this data, Meier called on the
policy-makers in the room to focus their efforts on delaying the onset of
cannabis use in youth and encouraging cessation (especially among adolescents).
In appealing to the researchers, she underlined the need for additional
longitudinal studies into the mechanisms and parameters of cannabis use that
produce long-term impairments.
As public and political support of marijuana legalization grows, we must be careful not to underestimate the dangers of the drug. Without knowing the full extent of the risks and benefits of weed, policy-makers cannot effectively promote public health, safety, and social equity.
Influenza is ubiquitous. Every fall, we line up to get our flu shots with the hope that we will be protected from the virus that infects 10 to 20 percent of people worldwide each year. But some years, the vaccine is less effective than others.
Every year, CDC scientists engineer a new flu virus. By examining phylogenetic relationships, which are based on shared common ancestry and relatedness, researchers identify virus strains to target with a vaccine for the following flu season.
Sometimes, they do a good job predicting which strains will
flourish in the upcoming flu season; other times, they pick wrong.
Pekosz’s work has identified why certain flu seasons saw less effective vaccines.
Andrew Pekosz, PhD, is a researcher at Johns Hopkins who examines why we fail to predict strains to target with vaccines. In particular, he examines years when the vaccine was ineffective and the viruses that were most prevalent to identify properties of these strains.
A virus consists of RNA enclosed in a membrane. Vaccines function
by targeting membrane proteins that facilitate movement of the viral genome
into host cells that it is infecting. For the flu virus, this protein is
hemagglutinin (HA). An additional membrane protein called neuraminidase (NA) allows
the virus to release itself from a cell it has infected and prevents it from
returning to infected cells.
The flu vaccine targets proteins on the membrane of the RNA virus. Image courtesy of scienceanimations.com.
Studying the viruses that flourished in the 2014-2015 and
2016-2017 flu seasons, Pekosz and his team have identified mutations to these
surface proteins that allowed certain strains to evade the vaccine.
In the 2014-2015 season, a mutation in the HA receptor conferred an advantage to the virus, but only in the presence of the antibodies present in the vaccine. In the absence of these antibodies, this mutation was actually detrimental to the virus’s fitness. The strain was present in low numbers in the beginning of the flu season, but the selective pressure of the vaccine pushed it to become the dominant strain by the end.
The 2016-2017 flu season saw a similar pattern of mutation, but in the NA protein. The part of the virus membrane where the antibody binds, or the epitope, was covered in the mutated viral strain. Since the antibodies produced in response to the vaccine could not effectively identify the virus, the vaccine was ineffective for these mutated strains.
With the speed at which the flu virus evolves, and the fact that numerous strains can be active in any given flu season, engineering an effective vaccine is daunting. Pekosz’s findings on how these vaccines have previously failed will likely prove invaluable at combating such a persistent and common public health concern.
“Gap maps” are the latest technology when it comes to organizing data. Although they aren’t like traditional maps, they can help people navigate through dense resources of information and show scientists the unexplored areas of research.
A ‘gap map’ comparing conservation interventions and outcomes in tropical mangrove habitats around the world turns out to be a beautiful thing.
At Duke’s 2019 Master’s Projects Spring Symposium, Willa Brooks, Amy Manz, and Colyer Woolston presented the results of their year-long Masters Project to create this map.
You’d never know by looking at the simple, polished grid of information that it took 29 Ph.D. students, master’s students and undergraduates nearly a full year to create it. As a member of the Bass Connections team that has been helping to support this research, I can testify that gap maps take a lot of time and effort — but they’re worth it.
Amy Manz, Willa Brooks, and Colyer Woolston present their evidence map (or gap map) at the 2019 Master’s Projects Spring Symposium
When designing a research question, it’s important to recognize what is already known, so that you can clearly visualize and target the gaps in the knowledge.
But sifting through thousands of papers on tropical mangroves to find the one study you are looking for can be incredible overwhelming and time-intensive. This is purpose of a gap map: to neatly organize existing research into a comprehensive grid, effectively shining a light on the areas where research is lacking, and highlighting patterns in areas where the research exists.
In partnership with World Wildlife Fund, Willa, Amy, and Colyer’s team has been working under the direction of Nicholas School of the Environment professors Lisa Campbell and Brian Silliman to screen the abstracts of over 10,000 articles, 779 of which ended up being singled out for a second round of full-text screening. In the first round, we were looking for very specific inclusion criteria, and in the second, we were extracting data from each study to identify the outcomes of conservation interventions in tropical mangrove, seagrass, and coral reef habitats around the world.
Coastal Mangroves (Photo from WikiCommons: US National Oceanic and Atmospheric Administration)
While the overall project looked at all three habitats, Willa, Amy, and Colyer’s Master’s Project focused specifically on mangroves, which are salt-tolerant shrubs that grow along the coast in tropical and subtropical regions. These shrubs provide a rich nursery habitat to a diverse group of birds and aquatic species, and promote the stability of coastlines by trapping sediment runoff in their roots. However, mangrove forests are in dramatic decline.
According to World Wildlife Fund, 35 percent of mangrove ecosystems in the world are already gone. Those that remain are facing intense pressure from threats like forest clearing, overharvesting, overfishing, pollution, climate change, and human destruction of coral reefs. Now more than ever, it is so important to study the conservation of these habitats, and implement solutions that will save these coastal forests and all the life they support. The hope is that our gap map will help point future researchers towards these solutions, and aid in the fight to save the mangroves.
This year’s team built a gap map that successfully mapped linkages between interventions and outcomes, indicating which areas are lacking in research. However, the gap map is limited because it does not show the strength or nature of these relationships. Next year, another Bass Connections team will tackle this challenge of analyzing the results, and further explore the realm of tropical conservation research.
Post by Robin A. Smith 
Post by Brian Du
