HIV vaccine candidate's mysteries unlocked 20 years later

Highly effective cytomegalovirus-based vaccine explained in new scientific studies

OREGON HEALTH & SCIENCE UNIVERSITY

Research News

 

About two decades after first devising a new kind of vaccine, Oregon Health & Science University researchers are unlocking why it stops and ultimately clears the monkey form of HIV, called SIV, in about half of nonhuman primates - and why it's a promising candidate to stop HIV in people.

In scientific papers that were simultaneously published today in the journals Science and Science Immunology, creators of the cytomegalovirus, or CMV, vaccine platform describe the unusual biological mechanisms through which it works.

The findings also helped fine-tune VIR-1111, the CMV-based experimental vaccine against HIV that was developed at OHSU and is now being evaluated in a Phase 1 clinical trial. The trial is being conducted by Vir Biotechnology, which licensed the CMV vaccine platform technology from OHSU.

"Knowing the mechanism that the CMV-based SIV vaccine uses to work in rhesus macaques gives us a way to judge the potential of a human vaccine very quickly," said Louis Picker, M.D., the associate director of the OHSU Vaccine and Gene Therapy Institute and a professor of pathology/molecular microbiology and immunology in the OHSU School of Medicine. "If you have the wrong genes in the CMV vaccine, the critical immune response needed for efficacy won't develop. You have to thread the CMV vaccine's needle exactly if you want a high degree of protection, and you have to know what you're looking for."

Two of the papers describe that the cytomegalovirus vaccine needs to generate an unusual type of CD8-positive T cell response called MHC-E-restricted T cells to effectively fight off SIV in monkeys.

"We knew for a while that we have unusual T cell responses in monkeys that receive our CMV vaccine against SIV," said Klaus Frueh, Ph.D., a professor of molecular microbiology and immunology in the OHSU School of Medicine and OHSU Vaccine and Gene Therapy Institute. "But we didn't know if they were important for protection against SIV. This research shows clearly that, without this special MHC-E-restricted T cell response, we don't have protection."

The study published in Science Immunology shows that the vaccine was only able to generate these special T cells to fight off SIV if eight specific genes were missing or inactivated from the natural form of monkey CMV. And a corresponding paper published via Science's First Release describes how a specific cytomegalovirus protein known as Rh67 is required to generate MHC-E-restricted T cells to protect against SIV. Together, these papers suggest how a CMV-based vaccine needs to be designed to create these unconventional T cell responses.

And, in a separate Science Immunology paper that was also published today, a research team led by Andrew J. McMichael, Ph.D., of Oxford University looked into whether what has been learned from nonhuman primate experiments could be transferrable to humans. These researchers showed that MHC-E-restricted CD8-positive T cells could be increased and suppress HIV in laboratory cell cultures.

This new research is being published as the OHSU Vaccine and Gene Therapy Institute celebrates the 20th anniversary of its first building opening for research in April 2001. Picker and Frueh moved to Oregon to help start the institute: Picker has led its vaccine program since its founding, and Frueh joined forces with Picker in 2006. Picker first received a $3.5 million grant from the National Institutes of Health in 2004 to develop a CMV-based HIV vaccine. Picker says the following in a May 25, 2004, OHSU announcement about the grant: "We believe a persistent viral vector could produce a superior and more durable anti-HIV immune response that would, in effect, hold the line against HIV."

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The following funding was awarded to OHSU in support of the research described in these three studies: the National Institute of Allergy and Infectious Diseases (grants P01 AI094417, U19 AI128741, UM1 AI124377, R37 AI054292, R01AI140888, R01 AI059457), National Institutes of Health Office of the Director (grant P51 OD011092); National Cancer Institute (contract HHSN261200800001E), and the Bill & Melinda Gates Foundation-supported Collaboration for AIDS Vaccine Discovery (OPP1033121).

In the interest of ensuring the integrity of our research and as part of our commitment to public transparency, OHSU actively regulates, tracks and manages relationships that our researchers may hold with entities outside of OHSU. In regards to this research, OHSU and several individuals have a significant financial interest in Vir Biotechnology Inc., a company that may have a commercial interest in the results of this research and technology. These individuals include Picker, Frueh, Sacha, Malouli, Hansen and Hancock.

The three studies are:

* Cytomegaloviral determinants of CD8+ T cell programming and RhCMV/SIV vaccine efficacy, Science, via First Release, March 25, 2021, https://science.sciencemag.org/content/early/2021/03/24/science.abe9233

* Modulation of MHC-E transport by viral decoy ligands is required for RhCMV-SIV vaccine efficacy, Science Immunology, , March 25, 2021, https://immunology.sciencemag.org/content/6/57/eabg5413.full

* HLA-E restricted Gag specific CD8+ T cells can suppress HIV-1 infection, offering vaccine opportunities, Science Immunology, March 25, 2021, https://immunology.sciencemag.org/content/6/57/eabg1703

Related OHSU News stories:

* Jan. 6, 2021, OHSU-developed HIV vaccine tech tested in humans for first time, https://news.ohsu.edu/2021/01/06/ohsu-developed-hiv-vaccine-tech-tested-in-humans-for-first-time

* July 17, 2019, HIV vaccine nears clinical trial following new findings, https://news.ohsu.edu/2019/07/17/hiv-vaccine-nears-clinical-trial-following-new-findings

* Jan. 25, 2017, Vaccine technology developed by OHSU scientists acquired by industry leaders, https://news.ohsu.edu/2017/01/25/vaccine-technology-developed-by-ohsu-scientists-acquired-by-industry-leaders

* Sept. 11, 2013, OHSU AIDS vaccine candidate appears to completely clear virus from the body, https://news.ohsu.edu/2013/09/11/ohsu-aids-vaccine-candidate-appears-to-completely-clear-virus-from-the-body

Distinctively Black names found long before Civil War

Study refutes belief that the naming practice is more recent

OHIO STATE UNIVERSITY

Research News

 

IMAGE: ABE LIVINGSTON, A FORMER SLAVE, WAS PHOTOGRAPHED IN TEXAS IN THE 1930S view more 

CREDIT: LIBRARY OF CONGRESS

COLUMBUS, Ohio - Long before Tyrone, Jermaine and Darnell came along, there were Isaac, Abe and Prince.

A new study reveals the earliest evidence of distinctively Black first names in the United States, finding them arising in the early 1700s and then becoming increasingly common in the late 1700s and early 1800s.

The results confirm previous work that shows the use of Black names didn't start during the civil rights movement of the 1960s, as some scholars have argued, said Trevon Logan, co-author of the study and professor of economics at The Ohio State University.

"Even during slavery, Black people had names that were unlikely to be held by whites. It is not just a recent phenomenon," Logan said.

Logan conducted the study with Lisa Cook of Michigan State University and John Parman of the College of William and Mary. It was published online this month in the journal Historical Methods.

The study focuses on names for Black males, partly because earlier research suggests less distinctiveness of Black women's names historically.

This research is a follow-up to a 2014 study by the same researchers that found distinctive Black names were being used in the period following the Civil War.

It was more difficult to find records that document the names of the enslaved, Logan said. Many official records only list slaves as numbers without names.

The researchers found three sources that did contain the names of enslaved people in the United States. Two of the three sources also included the names of the buyers or sellers of the enslaved, which allowed comparisons between Black and white names. The researchers supplemented the evidence of racial name distinctiveness by analyzing white names in the 1850 Census.

The names given Blacks in the United States were distinctively African American, Logan said. None of them had roots in Africa. Many of them had Biblical origins, like Abraham and Isaac. Other Black names that appeared more frequently in one or more of the data sets included Titus and Prince.

Results showed a clear increase in the use of Black names over the period of the study. In one data set, 3.17% of enslaved males born between 1770 to 1790 were likely to hold a Black name, but that increased to 4.5% of those born between 1810 and 1830.

And they were truly distinctive from white people. Depending on the data source, enslaved people were more than four to nine times as likely to have a Black name than was a slave owner.

The appearance of distinctively Black names wasn't only the result of more African Americans using them, Logan said.

"Our results suggest a strong decline in the use of Black names among whites over time," he said. "The actions of both Black and white people fed into the process that resulted in distinctive Black names."

For white people born before 1770, more than 4.75% held Black names, but that declined to less than 2% for those born from 1810 to 1830.

Many of the Black names identified in this study were the same that the researchers found in the post-Civil War period, but there were some differences.

"Post-emancipation we found more Blacks being named Master and Freeman, which for obvious reasons were not found in the antebellum era," Logan said.

While this study revealed the existence and growth of Black names in the United States, it can't answer why it happened, Logan said.

"We believe these naming practices could say something about culture, about family, and about social formation among Black people of the time," Logan said.

"But we don't have any records of people talking about it at the time, so we're not sure. We know there's this pattern, but we can't say for sure what it means."

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Contact: Trevon Logan, Logan.155@osu.edu

Written by Jeff Grabmeier, 614-292-8457; Grabmeier.1#@osu.edu

Stressed brain linked to broken heart



EUROPEAN SOCIETY OF CARDIOLOGY

Research News






IMAGE: SCAN OF BRAIN OF SOMEONE WHO DID NOT DEVELOP TTS view more

CREDIT: EUROPEAN HEART JOURNAL

Heightened activity in the brain, caused by stressful events, is linked to the risk of developing a rare and sometimes fatal heart condition, according to research published today (Friday) in the European Heart Journal [1].

The study found the greater the activity in nerve cells in the amygdala region of the brain, the sooner the condition known as Takotsubo syndrome (TTS) can develop. The researchers suggest that interventions to lower this stress-related brain activity could help to reduce the risk of developing TTS; these could include drug treatments or techniques for lowering stress.

TTS, also known as "broken heart" syndrome, is characterised by a sudden temporary weakening of the heart muscles that causes the left ventricle of the heart to balloon out at the bottom while the neck remains narrow, creating a shape resembling a Japanese octopus trap, from which it gets its name. Since this relatively rare condition was first described in 1990, evidence has suggested that it is typically triggered by episodes of severe emotional distress, such as grief, anger or fear, or reactions to happy or joyful events. Patients develop chest pains and breathlessness, and it can lead to heart attacks and death. TTS is more common in women with only 10% of cases occurring in men. [2]

The amygdala is the part of the brain that controls emotions, motivation, learning and memory. It is also involved in the control of the autonomic nervous system and regulating heart function.

"The study suggests that the increased stress-associated neurobiological activity in the amygdala, which is present years before TTS occurs, may play an important role in its development and may predict the timing of the syndrome. It may prime an individual for a heightened acute stress response that culminates in TTS," said Dr Ahmed Tawakol, co-director of the Cardiovascular Imaging Research Center at Massachusetts General Hospital and Harvard Medical School (Boston, USA), who led the study.

"We also identified a significant relationship between stress-associated brain activity and bone marrow activity in these individuals. Together, the findings provide insights into a potential mechanism that may contribute to the 'heart-brain connection'."

In the first study to look at brain scans using F-fluorodeoxyglucose positron emission tomography/computed tomography (PET-CT) to assess brain activity before TTS develops, Dr Tawakol and colleagues analysed data on 104 people with an average age of 68 years, 72% of whom were women.

The patients had undergone scans at Massachusetts General Hospital (Boston, USA) between 2005 and 2019. Most of them had the scans to see if they had cancer and the scans also assessed the activity of blood cells in bone marrow. The researchers matched 41 people who went on to develop TTS between six months and five years after the scan with 63 who did not. The interval between the scan, the onset of TTs, last follow-up or death was an average (median) of 2.5 years for the 104 patients.

Dr Tawakol said: "Areas of the brain that have higher metabolic activity tend to be in greater use. Hence, higher activity in the stress-associated tissues of the brain suggests that the individual has a more active response to stress. Similarly, higher activity in the bone marrow reflects greater bone marrow metabolism. The PET/CT scans produce images that reflect the distribution of glucose metabolism. The brain images thereby yield a map of brain metabolic activity: the higher the values, the greater the activity in those brain regions."

The researchers found that people who went on to develop TTS had higher stress-related amygdalar activity on initial scanning (measured as a ratio of amygdalar activity to activity of brain regions that counter stress) compared to individuals who did not subsequently develop TTS. Further, the higher the amygdalar signal, the greater the risk of developing TTS. Among the 41 patients who developed TTS, the average interval between the scan and TTS was 0.9 months, whereas among the control group of 63 patients, the average interval between the scan and last follow-up or death was 2.9 years.

"It was notable that among the 41 patients who developed TTS, the top 15% with the very highest amygdalar activity developed TTS within a year of imaging, while those with less elevated activity developed TTS several years later," said Dr Tawakol.

He said future studies should investigate whether reducing stress-related brain activity could decrease the chances of TTS recurring among patients who have experienced TTS previously.

"These findings add to evidence of the adverse effect of stress-related biology on the cardiovascular system. Findings such as these underscore the need for more study into the impact of stress reduction or drug interventions targeting these brain regions on heart health. In the meantime, when encountering a patient with high chronic stress, clinicians could reasonably consider the possibility that alleviation of stress might result in benefits to the cardiovascular system."

The process by which stress induces TTS is not well understood but may involve a multi-organ mechanism starting with activation of the stress-sensitive tissues of the brain. This brain activity in turn triggers several further events, including release of stress hormones, activation of the sympathetic nervous system and release of inflammatory cells, each of which can contribute to the development of TTS.

Limitations of the study include that it was a single-centre, retrospective study that consisted mainly of patients with a diagnosis of cancer, a known TTS risk factor, which may limit the generalisability of the findings. The researchers were unable to measure instantaneous changes in brain activity in response to a stressful event that led to TTS and so cannot directly show a causal relationship. Nor were they able to measure changes in activity in other regions of the brain, which could also play a role.




CAPTION

Scan of brain in person who developed TTS

CREDIT

European Heart Journal

An accompanying editorial by researchers not involved with this study has already been published [3].

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[1] "Stress-associated neurobiological activity associates with the risk for and timing of subsequent Takotsubo syndrome", by Azar Radfar et al. European Heart Journal. doi:10.1093/eurheartj/ehab029

[2] TTS affects less than 3% of people who suffer a heart attack and tends to occur between the ages of 60-75.

[3] "Brain-heart connection in Takotsubo syndrome before onset", by Hideaki Suzuki, Satoshi Yasuda, Hiroaki Shimokawa. European Heart Journal. doi:10.1093/eurheartj/ehab026




CAPTION

Image of TTS heart showing the classic Japanese octopus trap shape

CREDIT

European Heart Journal

Preservative used in hundreds of popular foods may harm the immune system

New science suggests the FDA should test all food chemicals for safety

ENVIRONMENTAL WORKING GROUP

Research News

 

WASHINGTON - A food preservative used to prolong the shelf life of Pop-Tarts, Rice Krispies Treats, Cheez-Its and almost 1,250 other popular processed foods may harm the immune system, according to a new peer-reviewed study by Environmental Working Group.

For the study, published this week in the International Journal of Environmental Research and Public Health, EWG researchers used data from the Environmental Protection Agency's Toxicity Forecaster, or ToxCast, to assess the health hazards of the most common chemicals added to food, as well as the "forever chemicals" known as PFAS, which can migrate to food from packaging.

EWG's analysis of ToxCast data showed that the preservative tert-butylhydroquinone, or TBHQ, has been found to harm the immune system both in both animal tests and in non-animal tests known as high-throughput in vitro toxicology testing. This finding is of particular concern during the coronavirus pandemic.

"The pandemic has focused public and scientific attention on environmental factors that can impact the immune system," said Olga Naidenko, Ph.D., EWG vice president for science investigations and lead author of the new study. "Before the pandemic, chemicals that may harm the immune system's defense against infection or cancer did not receive sufficient attention from public health agencies. To protect public health, this must change."

TBHQ

TBHQ is a preservative that is pervasive in processed foods. It has been used in foods for many decades and serves no function besides increasing a product's shelf life. Using new non-animal test results from ToxCast, EWG found that TBHQ affected immune cell proteins at doses similar to those that cause harm in traditional studies. Earlier studies have found that TBHQ might influence how well flu vaccines work and may be linked to a rise in food allergies.

PFAS

Using ToxCast, EWG analyzed all publicly available studies that show how PFAS migrate to food from packaging materials or processing equipment. This is the first known compilation of available research on PFAS migration from packaging to food. In 2017, nationwide tests showed that many fast-food chains used food wrappers, bags and boxes coated with highly fluorinated chemicals.

Human epidemiological studies show that PFAS suppresses immune function and decreases vaccine efficacy. Recently published research has also found a link between high levels of PFAS in the blood and the severity of Covid-19.

Surprisingly, for most PFAS, the ToxCast results did not match previous animal and human test data. This illustrates the limitations of this new chemical testing method. More research is needed to understand how PFAS harm the immune system.

Food Chemicals Regulation

The Food and Drug Administration's approach to the regulation of food additives does not consider the latest science on the health harms of additives that may be legally added to processed foods manufactured in the U.S. Last year, EWG published Food Additives State of the Science, which highlighted additives known to increase the risk of cancer, harm the nervous system and disrupt the body's hormonal balance.

Chemicals linked to health harms can be legally added to packaged foods because the FDA frequently allows food manufacturers to determine which chemicals are safe. Additives like TBHQ were approved by the FDA decades ago, and the agency does not consider new science to reassess the safety of food chemicals.

"Food manufacturers have no incentive to change their formulas," said Scott Faber, senior vice president for government affairs at EWG. "Too often, the FDA allows the food and chemical industry to determine which ingredients are safe for consumption. Our research shows how important it is that the FDA take a second look at these ingredients and test all food chemicals for safety."

Less Toxic Food Preservatives

Processed foods can be made without these potentially harmful ingredients, so shoppers should read labels carefully. TBHQ is often, though not always, listed on the ingredient label. It will be listed if it has been added to the product during manufacturing. But it can also be used in food packaging, particularly plastic packaging, in which case it may migrate to food.

EWG's Food Scores database helps consumers find products made with healthier alternatives, and our Healthy Living app allows shoppers to scan products while in stores to choose a better option.

EWG recommends that immunotoxicity testing be prioritized for chemicals in food and food contact materials in order to protect public health from their potential harm to the immune system.

EWG also calls on the FDA to close the regulatory loophole that allows potentially unsafe food additives to remain on the market. The FDA should also promptly review additives like TBHQ to reflect new science.

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The Environmental Working Group is a nonprofit, non-partisan organization that empowers people to live healthier lives in a healthier environment. Through research, advocacy and unique education tools, EWG drives consumer choice and civic action. Visit http://www.ewg.org for more information.

California's targeted, sector-based policies could reduce diesel emissions nationwide

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE

Research News

 

Compared to the rest of the United States, California has drastically reduced emissions of diesel particulate matter (DPM) from diesel-powered vehicles. The state has achieved this by systematically targeting high-emitting sectors with stringent and effective policies that go beyond federal standards. In a Policy Forum, Meagan Schwarzman and colleagues argue that a similar approach to emissions standards could serve as a model for reducing DPM emissions nationwide and improve health in the communities disproportionately impacted by diesel particulate pollution. While diesel is the fuel that drives much of the modern economy, powering trucks, buses, trains, ships and agricultural equipment, diesel exhaust is a known carcinogen and a significant contributor to harmful particulate air pollution in urban areas. Due to these public health impacts, efforts to reduce DPM emissions have been implemented in countries worldwide. Recently, however, the U.S. federal administration has attempted to roll back, weaken or eliminate the policies and standards that govern diesel emissions at the federal level and is moving to limit the ability of individual states to set their own emissions standards that go beyond the federal guidelines. Here, Schwarzman et al. show that California - the U.S.'s most populous state and the world's 5th largest economy - has continued to reduce DPM emissions for more than 30 years by regulating DPM air pollution more stringently than the federal government through targeted, sector-based policy. To understand the impact of California's policies, the authors evaluated DPM emissions data from the Environmental Protection Agency's national emissions inventory to compare mobile-source DPM emissions in California versus in the rest of the U.S. for the period spanning 1990 to 2014. Despite a steady rise in diesel fuel consumption, California reduced overall mobile-source DPM emissions by 78% compared to a 51% reduction in the rest of the U.S. The analysis highlights opportunities for the U.S. to reduce DPM emissions by adopting policies similar to California's. The findings also underscore the need to protect states' authority to set their own emissions standards.

 

Warm water has overlooked importance for cold-water fish, like salmon and trout

OREGON STATE UNIVERSITY

Research News

 

IMAGE: ARCTIC GRAYLING IN EPHEMERALLY WARM LAKE OUTLET, LITTLE TOGIAK RIVER, ALASKA. view more 

CREDIT: JONNY ARMSTRONG

CORVALLIS, Ore. - Warm river habitats appear to play a larger than expected role supporting the survival of cold-water fish, such as salmon and trout, a new Oregon State University-led study published today found.

The research has important implications for fish conservation strategies. A common goal among scientists and policymakers is to identify and prioritize habitat for cold-water fish that remains suitably cool during the summer, especially as the climate warms.

This implicitly devalues areas that are seasonally warm, even if they are suitable for fish most of the year, said Jonny Armstrong, lead author of the paper and an ecologist at Oregon State. He called this a "potentially severe blind spot for climate change adaptation."

"Coldwater fish like trout and salmon are the polar bears of river ecosystems - iconic species that are among the most vulnerable to climate change," Armstrong said. "A huge challenge for conservation is to figure out how to help these fish survive a warmer future. The conclusion is that we should not waste money on warm habitats and instead focus on saving the coldest places, such as high mountain streams, which are already the most pristine parts of basins. Most people agree we should give up on places that are warm in summer, but forget that these places are actually optimal for much of the year."

In the new paper, published in Nature Climate Change, Armstrong and collaborators at Oregon State and several federal agencies, show that warm river habitats, typically lower in basins, provide pulses of growth potential during the spring and fall, so-called shoulder seasons, when the rivers are not at peak summer temperatures. Foraging in these warm habitats can provide fish the needed energy to travel to cooler parts of the river during the summer and to reproduce.

"The synergy between cold water and warm water is really important," said Armstrong, an assistant professor in the Department of Fisheries and Wildlife in the College of Agricultural Sciences. "We're not saying cold water is not important. We're saying that warm portions of basins are also important because they grow fish during the shoulder seasons. Conserving this habitat is critical for unlocking the full potential of rivers to support fisheries.

"In a warmer future, many fish will need fish to take a summer vacation and move to cold places to survive the hottest months of the year. Their ability to do that could often depend on how much energy they can get in the spring and how well they can feed in the fall to bounce back. The places that are stressfully warm in summer are just right in spring and fall, and there is growing evidence that they can fuel fisheries"

For the study, the researchers used data from another team of scientists that used remote sensing technology to obtain river water temperature data across entire landscapes throughout the year. That team compiled data for 14 river basins in Oregon, Washington and Idaho.

The OSU-led team plugged these temperature data into a "bioenergetics model" that predicts fish growth potential based on equations derived from lab studies. This provided new insights into how growth opportunities shift across river basins throughout the year, and how a large fraction of total growth potential can accrue during the spring and autumn in places that are too hot during summer.

To explore how these warm habitats could contribute to fisheries, the team created a simulation model in which virtual rainbow trout were given simple behavior rules and allowed to forage throughout the year in a basin with cold tributaries and a warm, productive main-stem river. Their simulations showed the majority of fish moved into cooler waters in the summer and exhibited meager growth rates. However, outside summer, the simulation showed the fish resided primarily in seasonally warm downstream habitats, which fueled the vast majority of their growth.

"In conservation, we often judge streams by their summer conditions; this is when we traditionally do field work, and this is the season we focus on when planning for climate change," Armstrong said. "We place value on places that hold fish during summer and devalue those that don't. Our simulation showed why this can be a problem - the portions of rivers that contribute most to growth may not be the places where fish are found during summer, so they get written off."

The simulations reveal the synergy between seasonally warm and perennially cool habitats and that fish that lived in these two types of habitats grew much more than fish that were restricted to either habitat alone, Armstrong said.

"We think of things in this binary way - it's either warm-water habitat or its cold-water habitat," Armstrong said. "And we have definitions for fish - it's either a warm-water fish or a cold-water fish. But the places we think of as warm are, in fact, cold way more than they are warm."

He then mentioned an example using rivers in Oregon, including the Willamette, a tributary of the Columbia River that runs nearly 200 miles from Eugene to Portland.

"When it's warm enough for humans to swim, it's bad for cold-water fish. But there's only like six weeks of the year where it is comfortable to go swimming in Oregon," Armstrong said. "That speaks to the fact that we write off places because they get too hot through the lens of August. They're actually pretty nice for most of the year if you're a cold-water fish. And fish don't necessarily have to live there in August, just like you don't have to go swimming in the Willamette in December."

CAPTION

Westslope cutthroat trout and bull trout in Glacier National Park. An example of coldwater fish in summer habitat.

CREDIT

Jonny Armstrong

This research is continuing in the field at Upper Klamath Lake in Southern Oregon, where Armstrong and a team of researchers are tracking the movement and feeding behavior of redband trout as water temperature changes.

Co-authors of the paper are Aimee Fullerton and Chris Jordan of the National Oceanic and Atmospheric Administration Northwest Fisheries Science Center; Joseph Ebersole of the Environmental Protection Agency; James Bellmore, Brooke Penaluna and Gordon Reeves of the U.S. Forest Service Pacific Northwest Research Station; and Ivan Arismendi of Oregon State.

 

Tired of video conferencing? Research suggests you're right to question its effectiveness

A new study suggests that non-visual communication methods that better synchronize and boost audio cues are in fact more effective

CARNEGIE MELLON UNIVERSITY

Research News

 

In the year since the coronavirus pandemic upended how just about every person on the planet interacts with one another, video conferencing has become the de facto tool for group collaboration within many organizations. The prevalent assumption is that technology that helps to mimic face-to-face interactions via a video camera will be most effective in achieving the same results, yet there's little data to actually back up this presumption. Now, a new study challenges this assumption and suggests that non-visual communication methods that better synchronize and boost audio cues are in fact more effective.

Synchrony Promotes Collective Intelligence

Researchers from Carnegie Mellon's Tepper School of Business and the Department of Communication at the University of California, Santa Barbara, have studied collective intelligence--the ability of a group to solve a wide range of problems--and how synchrony in non-verbal cues helps to develop it. There are many forms of synchrony, but the common view is that synchrony occurs when two or more nonverbal behaviors are aligned. Essentially, conversation is what happens when at least two speakers take turns sharing their thoughts, and nonverbal cues are how they establish when and how to take these turns.

Previous research has shown that synchrony promotes collective intelligence because it improves joint problem solving. So it's not too far-fetched that many would assume that if a conversation can't take place face-to-face, it would be best simulated with both video and audio software.

The researchers focused on two forms of synchrony: facial expression synchrony and prosodic synchrony. Facial expression synchrony is pretty straightforward and involves the perceived movement of facial features. Prosodic synchrony, on the other hand, captures the intonation, tone, stress, and rhythm of speech. They hypothesized that during virtual collaboration, collective intelligence would develop through facial expression synchrony when the collaborators had access to both audio and visual cues. Without visual cues, though, they predicted that prosodic synchrony would enable groups to achieve collective intelligence instead.

Collective Intelligence Is Achievable With or Without Video, but Even More So Without

"We found that video conferencing can actually reduce collective intelligence," says Anita Williams Woolley, Associate Professor of Organizational Behavior and Theory at Carnegie Mellon's Tepper School of Business, who co-authored the paper. "This is because it leads to more unequal contribution to conversation and disrupts vocal synchrony. Our study underscores the importance of audio cues, which appear to be compromised by video access."

Woolley and her colleagues pulled together a large, diverse sample of 198 individuals and divided them into 99 pairs. Forty-nine of these pairs formed the first group, which were physically separated with audio capabilities but not video capabilities. The remaining 50 pairs were also physically separated but had both video and audio capabilities. During a 30-minute session, each duo completed six tasks designed to test collective intelligence. As Woolley points out, the results challenge the prevailing assumptions.

The groups with video access did achieve some form of collective intelligence through facial expression synchrony, suggesting that when video is available, collaborators should be aware of these cues. However, the researchers found that prosodic synchrony improved collective intelligence whether or not the group had access to video technology and that this synchrony was enhanced by equality in speaking turns. Most strikingly, though, was that video access dampened the pairs' ability to achieve equality in speaking turns, meaning that using video conferencing can actually limit prosodic synchrony and therefore impede upon collective intelligence.

Specifically, groups regulate speaking turns via a set of interaction rules, which include yielding, requesting, or maintaining turns. Collaborators often subtly communicate these rules through nonverbal cues such as eye contact or vocal cues, such as altering volume and rate. However, visual nonverbal cues appear to enable some collaborators to dominate the conversation. By contrast, the study shows that when groups have audio cues only, the lack of video does not prevent them from communicating these interaction rules but actually helps them to regulate their conversation more smoothly by engaging in more equal exchange of turns and by establishing improved prosodic synchrony.

What does this mean for organizations whose members are still physically separated by the COVID-19 pandemic? It might be worth it to disable the video function in order to promote better communication and social interaction during collaborative problem solving.

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Summarized from "Speaking out of turn: How video conferencing reduces vocal synchrony and collective intelligence," by Tomprou, Maria (Carnegie Mellon University) Kim, Young Ji (University of California, Santa Barbara), Chikersal, Prerna (Carnegie Mellon University), Williams Woolley, Anita (Carnegie Mellon University), and Dabbish, Laura A. (Carnegie Mellon University). It appears in PLoS One, published by the Public Library of Science. Copyright 2021. All rights reserved.

Changes in ocean chemistry show how sea level affects global carbon cycle

New analysis of strontium isotopes reveals how the global carbon cycle has responded to changes in climate and sea level through geologic time

UNIVERSITY OF CALIFORNIA - SANTA CRUZ

Research News

 

IMAGE: THESE ILLUSTRATIONS SHOW HOW CHANGES IN SEA LEVEL AFFECT CARBONATE DEPOSITION AND OTHER PROCESSES IN THE GLOBAL CARBON CYCLE. view more 

CREDIT: ILLUSTRATIONS BY MADDISON WOOD

A new analysis of strontium isotopes in marine sediments has enabled scientists to reconstruct fluctuations in ocean chemistry related to changing climate conditions over the past 35 million years.

The results, published March 26 in Science, provide new insights into the inner workings of the global carbon cycle and, in particular, the processes by which carbon is removed from the environment through the deposition of carbonates.

"Strontium is very similar to calcium, so it gets incorporated into the calcium carbonate shells of marine organisms," explained lead author Adina Paytan, research professor in the Institute of Marine Sciences at UC Santa Cruz.

Paytan and her coauthors looked at the ratios of different isotopes of strontium, including radiogenic isotopes (produced by radioactive decay) and stable isotopes, which provide complementary information about geochemical processes. They found that the stable isotope ratio of strontium in the ocean has changed considerably over the past 35 million years, and it is still changing today, implying large changes in seawater strontium concentration.

"It's not in a steady state, so what's coming into the ocean and what's leaving don't match," Paytan said. "The strontium composition of seawater changes depending on how and where carbonates are deposited, and that is influenced by changes in sea level and climate."

The fluctuations in strontium isotope ratios analyzed in this study reflect the combined effect of shifts in the global balance of geologic processes including weathering of rocks on land, hydrothermal activity, and the formation of carbonate sediments in both deep-sea and shallow, nearshore marine environments.

Carbonate deposition in the open ocean comes from marine plankton like coccolithophores and foraminifera, which build their shells of the calcium carbonate mineral calcite. In shallow water on the continental shelves, hard corals are more abundant, and they build their skeletons of a different mineral of calcium carbonate, aragonite, which incorporates more strontium than calcite does.

"When corals form, they remove strontium, and when they are exposed, this strontium washes out and goes back into the ocean," Paytan said. "With changes in sea level, more or less of the continental shelf where corals grow is exposed, so that impacts the strontium composition of seawater."

Carbonate deposition also feeds back into the climate system, because the ocean absorbs carbon dioxide from the atmosphere, and carbonate deposition on geological timescales removes carbon from the system. The global carbon cycle and atmospheric carbon dioxide are tightly coupled to climate change, both in the long-term and during the recurring ups and downs of recent ice age cycles.

"The new type of information we can read from the stable strontium isotopes now allows us to take a close look at the business end of the global carbon cycle, when carbon is removed from the environment and laid down into marine carbonate beds," said coauthor Mathis Hain, assistant professor of Earth and planetary sciences at UCSC.

"These findings throw open a new window to let us see how the global carbon cycle adjusted to sea level and climate change through geologic time," he added. "We will need these insights in guiding our response to our current climate emergency and to mitigate the worst effects of ocean acidification."

The researchers were able to reconstruct a robust and detailed record of strontium isotope variations in seawater based on an analysis of marine barite extracted from deep-sea sediment cores.

"Records like this are critical to understanding how our earth operates over geologic times," said coauthor Elizabeth Griffith at Ohio State University. "Our international team worked together to both create this unique record and explain its significance through mathematical modeling, so we can reconstruct changes in the past when the climate conditions were different. The hope is to gain insight into how our blue planet might operate in the future."

CAPTION

Marine barite extracted from deep-sea sediment cores, seen here in a scanning electron microscope image, provides a record of variations in ocean chemistry over geologic time.

CREDIT

Adina Payta

In addition to Paytan, Hain, and Griffith, the coauthors of the paper include Anton Eisenhauer and Klaus Wallmann at the GEOMAR Helmholtz Center for Ocean Research in Germany, and Andrew Ridgwell at UC Riverside. This work was supported by the National Science Foundation.

BEFORE CRISPR

Plant gene found in insect, shields it from leaf toxins

CELL PRESS

Research News

 

IMAGE: THIS IMAGE SHOWS A WHITEFLY ON A LEAF view more 

CREDIT: JIXING XIA AND ZHAOJIANG GUO

Millions of years ago, aphid-like insects called whiteflies incorporated a portion of DNA from plants into their genome. A Chinese research team, publishing March 25th in the journal Cell, reveals that whiteflies use this stolen gene to degrade common toxins plants use to defend themselves against insects, allowing the whitefly to feed on the plants safely.

"This seems to be the first recorded example of the horizontal gene transfer of a functional gene from a plant into an insect," says co-author Ted Turlings (@FARCE_lab), a chemical ecologist and entomologist at the University of Neuchâtel, in Switzerland. "You cannot find this gene, BtPMaT1, which neutralizes toxic compounds produced by the plant, in any other insect species."

Scientists believe that plants probably use BtPMaT1 within their own cells to store their noxious compounds in a harmless form, so the plant doesn't poison itself. The team, led by Youjun Zhang from the Institute of Vegetables and Flowers at the Chinese Academy of Agricultural Sciences, used a combination of genetic and phylogenetic analyses, to reveal that roughly 35 million years ago, whiteflies stole this defense gene, granting the insect the ability to detoxify these compounds for themselves.

"We think a virus within the plant may have taken up this BtPMaT1 gene and, after ingestion by a whitefly, the virus then must have done something inside the insect whereby that gene was integrated into the whiteflies genome," says Turlings. "Of course, this is an extremely unlikely event, but if you think about millions of years and billions of individual insects, viruses, and plants across time, once in a while this could happen, and if the acquired gene is a benefit to the insects, then it will be evolutionarily favored and may spread."

Whiteflies have become a major agricultural pest worldwide, able to attack at least 600 different species of plants worldwide. "One of the questions we've been asking ourselves is how these insects acquired these incredible adaptations to circumvent plant defenses, and with this discovery we have revealed at least one reason as to why," Turlings says.

Using this knowledge, Turlings' Chinese colleagues created a strategy to undo the whiteflies' stolen superpower. They developed a small RNA molecule that interferes with the whiteflies' BtPMaT1 gene, making the whiteflies susceptible to the plant's toxic compounds.

"The most exciting step of this design was when our colleagues genetically manipulated tomato plants to start producing this RNA molecule" says Turlings. "Once the whiteflies fed on the tomatoes and ingested the plant-produced RNA, their BtPMaT1 gene was silenced, causing 100% mortality of the insect, but the genetic manipulation had no impact on the survival of other insects that were tested."

With focused efforts to produce genetically modified crops that are able to silence the whitefly gene, this could function as a targeted strategy for pest control to combat agricultural devastation caused by whitefly populations.

"There are definitely still some hurdles this method needs to get over, most notably the skepticism about using transgenic plants," he says "But in the future, I do see this as a very clear way of controlling whiteflies because now we know exactly the mechanism behind it, and we are equipped to deal with possible changes in the whitefly gene that may arise.

CAPTION

This image shows a whitefly feeding on a leaf

CREDIT

Jixing Xia and Zhaojiang Guo

This research was supported by the National Key R & D Program of China, the National Natural Science Foundation of China, the China Agriculture Research System, the Beijing Key Laboratory for Pest Control and Sustainable Cultivation of Vegetables, and the Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences.

Cell, Xia et al.: "Whitefly hijacks a plant detoxification gene that neutralizes plant toxins" https://www.cell.com/cell/fulltext/S0092-8674(21)00164-1

Cell (@CellCellPress), the flagship journal of Cell Press, is a bimonthly journal that publishes findings of unusual significance in any area of experimental biology, including but not limited to cell biology, molecular biology, neuroscience, immunology, virology and microbiology, cancer, human genetics, systems biology, signaling, and disease mechanisms and therapeutics. Visit: http://www.cell.com/cell. To receive Cell Press media alerts, contact press@cell.com.

PFAS FOREVER CHEMICALS

Exposure to flame retardants early in pregnancy linked to premature birth

NYU LANGONE HEALTH / NYU SCHOOL OF MEDICINE

Research News

 Expectant women are more likely to give birth early if they have high blood levels of a chemical used in flame retardants compared with those who have limited exposure, a new study finds.

These polybrominated diphenyl ethers (PBDEs) are used in the manufacture of furniture, carpeting, and other products to reduce flammability. Previous studies have found that the substances can leach into household dust and build up in the body where they may interfere with the thyroid, an organ that secretes brain-developing hormones. Childhood exposure to PBDEs has been linked to learning disabilities, autistic symptoms, and behavioral issues, among other developmental problems.

In an investigation led by an NYU Long Island School of Medicine researcher, nearly all pregnant women enrolled in the study had detectable levels of PBDEs in their blood. The findings revealed that women with concentrations above 4 nanograms per milliliter of blood were roughly twice as likely to deliver their children early via cesarean section or intentionally induced labor due to safety concerns for the mother or infant. By contrast, there was no elevated risk for preterm birth among women with PBDE levels below that threshold.

"Our findings illustrate that flame retardants may have a tremendous impact on childbirth even if exposure occurred early on in the pregnancy," says study lead author Morgan Peltier, PhD. "Although PBDE chemicals are used with good intentions, they may pose a serious health concern that may have lasting consequences for children." Peltier is an associate professor in the departments of Clinical Obstetrics, Gynecology, and Reproductive Medicine at NYU Long Island School of Medicine, part of NYU Langone Health.

According to Peltier, preterm birth is a leading cause of newborn death and occurs annually in about 15 million pregnancies worldwide. Experts have linked the phenomenon to long-term neurological disorders including cerebral palsy, schizophrenia, and learning problems that can extend into adulthood. Earlier research has pointed to PBDE exposure as a possible culprit behind preterm birth. However, these investigations only looked at exposure to the chemicals late in pregnancy and only examined white and African-American mothers.

The new study, published online Dec. 1 in the Journal of Perinatal Medicine, is the first to explore the link between PBDE exposure in the first trimester of pregnancy, says Peltier. He notes that the investigation looked at a wider demographic group as well, adding Asian and Hispanic women to the analysis.

For the study, the research team analyzed blood samples from 3,529 California women, 184 of whom delivered their infants early. They measured the samples for levels of PBDE-47, a form of the chemical that commonly builds up in the household. The investigators then divided the mothers into four groups based on their amount of exposure.

The study also accounted for other risk factors linked to preterm birth, such as the mother's ethnicity, age, and whether she smoked during pregnancy.

Among the study findings, the group with the highest PBDE levels had a 75 percent increased risk for a spontaneous preterm birth compared with women who had the lowest exposure. Such births occur when women suddenly go into early labor after an otherwise normal pregnancy.

According to Peltier, the study findings also challenged previous beliefs about the role of thyroid hormones in the association between PBDEs and preterm birth. As part of the investigation, the researchers measured blood levels of thyroid stimulating hormone (TSH), a substance used to assess thyroid activity. If flame retardants indeed prevent the organ from working properly, thereby disrupting hormone function, then TSH levels should rise, says Peltier.

However, the study revealed that TSH levels remained normal, suggesting that another mechanism must be at work. Peltier says a possible explanation is that PBDEs may interfere with hormones in the placenta instead of the thyroid.

Peltier adds that the research team next plans to follow the children born to mothers in the study over time to explore how preterm birth linked to flame retardants may affect their long-term brain development.

He cautions that the findings do not prove a direct cause and effect, but strengthen the association between so-called endocrine disrupting chemicals and spontaneous premature birth.

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Funding for the study was provided by National Institutes of Health grant R01 ES023116.

In addition to Peltier, other NYU Langone researchers included Yuko Arita, D.D.S., Ph.D; and Ali Mahfuz, MBA. Other study co-investigators are Michael Fassett, MD, at Kaiser Permanente Southern California-West Los Angeles Medical Center; Vicki Chiu, MS; Jiaxiao Shi, PhD; Harpreet Takhar MPH; Gildy Lopez, MPH; and Darios Getahun; MD, PhD, at Kaiser Permanente Southern California in Pasadena; and Ramkumar Menon, PhD, at the University of Texas in Galveston.

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