The far-reaching effects of mutagens on human health

ARIZONA STATE UNIVERSITY

Research News

 

IMAGE: MICHAEL LYNCH IS THE DIRECTOR OF THE BIODESIGN CENTER FOR MECHANISMS OF EVOLUTION AND PROFESSOR AT ASU'S SCHOOL OF LIFE SCIENCES. view more 

CREDIT: THE BIODESIGN INSTITUTE AT ARIZONA STATE UNIVERSITY

In order to survive, flourish and successfully reproduce, organisms rely on a high degree of genetic stability. Mutagenic agents, which can threaten the integrity of the genetic code by causing mutations in DNA, pose a serious risk to human health. They have long been implicated in a range of genetically inherited afflictions, as well as cancer, aging and neurodegenerative diseases like Alzheimer's.

It now appears that mutagenic threats to a cell's subtle machinery may be far more widespread than previously appreciated. In a new study, Michael Lynch and his colleagues demonstrate that DNA mutation itself may represent only a fraction the health-related havoc caused by mutagens.

The study highlights the ability of mutagenic compounds to also affect the process of transcription, during which a DNA sequence is converted (or transcribed) to mRNA, an intermediary stage preceding translation into protein.

The research findings, (which highlight mutagenic transcription errors in yeast, worms, flies and mice), suggest that the harmful effects of mutagens on transcription are likely much more pervasive than previously appreciated--a fact that may have momentous implications for human health.

"Our results have the potential to completely transform the way we think about the consequences of environmental mutagens," Lynch says.

Professor Lynch is the director of the Biodesign Center for Mechanisms in Evolution and a researcher in ASU's School of Life Sciences.

The research results appear in the current issue of the journal PNAS.

Cells under threat

Due to their important role in disease processes, mutagenic compounds have long been a topic of intensive scientific study. Such agents include sunlight and other sources of radiation, chemotherapeutics, toxic byproducts of cellular metabolism, or chemicals present in food and water.

Mutagens can inflict damage to the DNA, which can later snowball when cells divide, and DNA replication multiplies these errors. Such mutations, if not corrected through DNA proofreading mechanisms, can be passed to subsequent generations and depending on the location at which they appear along the human DNA strand's three billion letter code may seriously impact health, in some cases, with lethal results.

But even if repaired prior to replication, transiently damaged DNA can also interfere with transcription--the process of producing RNA from a DNA sequence. This can happen when RNA polymerase, an enzyme that moves along a single strand of DNA, producing a complementary RNA strand, reads a mutated sequence of DNA, causing an error in the resulting RNA transcript.

Because RNA transcripts are the templates for producing proteins, transcription errors can produce aberrant proteins harmful to health or terminate protein synthesis altogether. It is already known that even under the best of conditions, transcript error rates are orders of magnitude higher than those at the DNA level.

RNA: a string of errors?

While the existence of transcription errors has long been recognized, their quantification has been challenging. The new study describes a clever technique for ferreting out transcription errors caused by mutagens and separating these from experimental artifacts--mutations caused during library preparation of RNA transcripts through processes of reverse-transcription and sequencing.

The method described involves the use of massively parallel sequencing technology to identify only those errors in RNA sequence directly caused by the activity of a mutagen. The results demonstrate that at least some mutagenic compounds are potent sources of both genomic mutations and abundant transcription errors.

The circular sequencing assay outlined in the study creates redundancies in the reverse-transcribed message, providing a means of proofreading the resultant linear DNA. In this way, researchers can confirm that the transcription errors observed are a result of the mutagen's effects on transcription and not an artifact of sample preparation.

The DNA molecule has been shown to be particularly vulnerable to a class of mutagens known as alkylating agents. One of these, known as MNNG, was used to inflict transcriptional errors on the four study organisms. The effects observed were dose-dependent, with higher levels of mutagen causing a corresponding increase in transcriptional errors.

Hidden mistakes may be costly to health

Transcription errors differ from mutations in the genome in at least one vital respect. While DNA replication during cell division acts to amplify mutations to the genome, transcription errors can accumulate in non-dividing cells, with a single mutated DNA template giving rise to multiple abnormal RNA transcripts.

The full effects of these transcription errors on human health remain largely speculative because they have not been amenable to study until now. Using the new technique, researchers can mine the transcriptome--the full library of a living cell's RNA transcripts, searching for errors caused by mutagens.

While the new research offers hope for a more thorough understanding of the relationship between various mutagens and human health, it is also a cautionary tale. A preoccupation with mutational defects in DNA sequence may have blinded science to the potential effects of agents that result in transcription errors without leaving permanent traces in the genome.

This fact raises the possibility that a broad range of environmental factors as well as chemicals and foods deemed safe for human consumption are in need of careful reevaluation based on their potential for producing transcriptional mutagenesis. Further, transcriptional errors in both dividing and non-dividing cell types are likely key players in the complex processes of physical aging 

Beyond changing DNA itself, mutagens also cause errors in gene transcription

The discovery that toxic stressors can cause errors in gene transcription opens new avenues of research on diseases such as Alzheimer's and Parkinson's and sheds light on the potential role of the "transcriptome" in aging.

UNIVERSITY OF SOUTHERN CALIFORNIA

Research News

 

IMAGE: ASSISTANT PROFESSOR MARC VERMULST view more 

CREDIT: USC/STEPHANIE KLEINMAN

Exposure to mutagens, or mutation-causing agents, can not only bring about changes in DNA but also appear to induce errors when genes are transcribed to make proteins, which may be an important factor in age-related diseases.

USC Leonard Davis School of Gerontology Assistant Professor Marc Vermulst and colleagues made the discovery by using state-of-the-art circle sequencing techniques to determine how frequently molecules called RNA polymerases make mistakes when they read (or "transcribe") our DNA. RNA polymerases transcribe DNA to make temporary copies of genes, which are then used to build all of the proteins required to keep us alive and healthy.

Transcription errors vastly outnumber DNA mutations

Vermulst compared our cells to a busy kitchen, teeming with hundreds of chefs that are all making dishes out of a single recipe book. Because it's so busy, they cannot take the recipe book with them when an order comes in. So instead they send the kitchen staff to the recipe book to read the recipes as carefully as possible and then bring the instructions to the chefs. Our cells work in a very similar manner. When an "order" for a protein comes in, RNA polymerases are sent to our genome (or in other words, our recipe book), to make a temporary copy of a gene. That temporary copy is then brought to the chefs, who cook the protein just like the message they received dictates. In this example, transcription errors could be an incorrect amount or ingredient that wasn't properly recorded by the person jotting down the recipe.

"The molecule doing the reading and writing is what's introducing the errors, even if the DNA itself isn't mutated," he explained.

To demonstrate that a mutagen - an agent that can cause a genetic mutation - can induce these errors, Vermulst and his team exposed yeast cells to the chemical N-Methyl-N?-nitro-N-nitrosoguanidine (MNNG), then screened for transcription errors. The cells exposed to MNNG displayed many more transcription errors than the unexposed cells, and in addition, the rate of transcription errors vastly outnumbered the rate of DNA mutations. The team confirmed similar results when the experiments were repeated in cells from the worm species C. elegans, fruit fly D. melanogaster and mice.

DNA mutations occur when the genome is inaccurately copied during cell division, leaving the newly formed cells with a mistake in their DNA. However, a few types of cells, including neurons and muscle cells, rarely divide in adults. These cells all still need to transcribe proteins, which means that harmful errors within these cells are much more likely to arise from transcription, Vermulst explained.

"There are a hundredfold more transcription errors being made for every DNA mutation that eventually arises," he said.

A possible role in several diseases

The genes that code for a protein not only instruct which amino acids to put in what order but also control the specific shape into which the finished protein folds itself. Transcription errors often cause proteins to misfold into a dysfunctional shape, which can result in clusters, or plaques, of nonfunctioning proteins that hinder healthy cell function. This raises questions of how these errors may play roles in diseases such as Alzheimer's, Parkinson's, amyotrophic lateral sclerosis (ALS) and others, Vermulst said.

In future research, Vermulst is pushing for more investigation into whether other substances known to cause DNA mutations also affect transcription, as well as if there are any substances previously thought of as safe that may be in fact inducing transcription errors.

"This is potentially a really important finding in the context of genetic toxicology: a new mechanism by which all these molecules - from exposures in our environment or from our lifestyle choices - can result in pathology," he said. "There could potentially be molecules that we're eating and drinking that are deemed safe because they don't result in any genetic changes, but do result in transcription errors, that have gone completely unnoticed because nobody had a tool to see whether or not that was happening."

He also hopes that the research will make new links between established pillars of aging research - DNA damage, mitochondrial dysfunction, oxidative species and others - and connect them in a mechanistic way to detrimental outcomes such as Alzheimer's, Parkinson's and cancer. It may also help identify sources of the symptoms in DNA repair deficiency disorder, in which patients are unable to repair damage to their genome properly and often results in accelerated aging or increased cancer risk.

While recent years have seen increased interest in the "transcriptome" - the entirety of what is transcribed from a genome - Vermulst wants to focus on the accuracy of what's being transcribed and not just the amount of each protein produced. He hopes this quality-over-quantity approach offers new insight into the fundamental processes of diseases.

"If you've done the same thing a hundred times and you don't get a solution for your problem, it might be something that you've overlooked," he said. "So we're trying to find this something else."

###

Vermulst's co-corresponding author for the study was Michael Lynch of Arizona State University, and first author was Clark Fritsch of the University of Pennsylvania. Other coauthors included Berenice Benayoun, Prakroothi S. Danthi, Eric McGann, Jessica LaGosh and Claire Chung of the USC Leonard Davis School; Jean-Francois Gout of Mississippi State University; Suraiya Haroon, Atif Towheed, Yuanquan Song and Douglas Wallace of the Children's Hospital of Philadelphia; Xinmin Zhang of BioInfoRx, Inc.; and Stephen Simpson and Kelley Thomas of the University of New Hampshire.

The study, "Genome-wide surveillance of transcription errors in response to genotoxic stress," appeared online in Proceedings of the National Academy of Sciences on December 21, 2020. This research was supported by the National Institute on Aging Award R01AG054641 and American Federation for Aging Research young investigator award in Alzheimer's disease to Vermulst; the Multidisciplinary University Research Initiative Awards W911NF-09-1-0444 from the US Army Research Office and NIH Award R35-GM122566-01 to Lynch; and Environmental Toxicology Training Grant T32ES019851 by the National Institute of Environmental Health Sciences to Fritsch.

Deep, slow-slip action may direct largest earthquakes and their tsunamis

PENN STATE

Research News

 

IMAGE: MAP OF THE CASCADIA SUBDUCTION ZONE. view more 

CREDIT: PUBLIC DOMAIN

Megathrust earthquakes and subsequent tsunamis that originate in subduction zones like Cascadia -- Vancouver Island, Canada, to northern California -- are some of the most severe natural disasters in the world. Now a team of geoscientists thinks the key to understanding some of these destructive events may lie in the deep, gradual slow-slip behaviors beneath the subduction zones. This information might help in planning for future earthquakes in the area.

"What we found was pretty unexpected," said Kirsty A. McKenzie, doctoral candidate in geoscience, Penn State.

Unlike the bigger, shallower megathrust earthquakes that move and put out energy in the same direction as the plates move, the slow-slip earthquakes' energy may move in other directions, primarily down.

Subduction zones occur when two of the Earth's plates meet and one moves beneath the other. This typically creates a fault line and some distance away, a line of volcanoes. Cascadia is typical in that the tectonic plates meet near the Pacific coast and the Cascade Mountains, a volcanic range containing Mount St. Helens, Mount Hood and Mount Rainier, forms to the east.

According to the researchers, a megathrust earthquake of magnitude 9 occurred in Cascadia in 1700 and there has not been a large earthquake there since then. Rather, slow-slip earthquakes, events that happen deeper and move very short distances at a very slow rate, happen continuously.

"Usually, when an earthquake occurs we find that the motion is in the direction opposite to how the plates have moved, accumulating that slip deficit," said Kevin P. Furlong, professor of geosciences, Penn State. "For these slow-slip earthquakes, the direction of movement is directly downward in the direction of gravity instead of in the plate motion directions."

The researchers have found that areas in New Zealand, identified by other geologists, slow slip the same way Cascadia does.

"But there are subduction zones that don't have these slow-slip events, so we don't have direct measurements of how the deeper part of the subducting plate is moving," said Furlong. "In Sumatra, the shallower seismic zone, as expected, moves in the plate-motion direction, but even though there are no slow-slip events, the deeper plate movement still appears to be primarily controlled by gravity."

Slow-slip earthquakes occur at a deeper depth than the earthquakes that cause major damage and earth-shaking events, and the researchers have analyzed how this deep slip may affect the timing and behavior of the larger, damaging megathrust earthquakes.

"Slow-slip earthquakes rupture over several weeks, so they are not just one event," said McKenzie. "It's like a swarm of events."

According to the researchers, in southern Cascadia, the overall plate motion is about an inch of movement per year and in the north by Vancouver Island, it is about 1.5 inches.

"We don't know how much of that 30 millimeters (1 inch) per year is accumulating to be released in the next big earthquake or if some movement is taken up by some non-observable process," said McKenzie. "These slow-slip events put out signals we can see. We can observe the slow-slip events going east to west and not in the plate motion direction."

Slow-slip events in Cascadia occur every one to two years, but geologists wonder if one of them will be the one that will trigger the next megathrust earthquake.

The researchers measure surface movement using permanent, high-resolution GPS stations on the surface. The result is a stair step pattern of loading and slipping during slow-slip events. The events are visible on the surface even though geologists know they are about 22 miles beneath the surface. They report their results in Geochemistry, Geophysics, Geosystems.

"The reason we don't know all that much about slow-slip earthquakes is they were only discovered about 20 years ago," said Furlong. "It took five years to figure out what they were and then we needed precise enough GPS to actually measure the motion on the Earth's surface. Then we had to use modeling to convert the slip on the surface to the slip beneath the surface on the plate boundary itself, which is bigger."

The researchers believe that understanding the effects of slow-slip earthquakes in the region at these deeper depths will allow them to understand what might trigger the next megathrust earthquake in the area. Engineers want to know how strong shaking in an earthquake will be, but they also want to know the direction the forces will be in. If the difference in direction of slow-slip events indicates a potential change in behavior in a large event, that information would be helpful in planning.

"More fundamentally, we don't know what triggers the big earthquake in this situation," said McKenzie. "Every time we add new data about the physics of the problem, it becomes an important component. In the past, everyone thought that the events were unidirectional, but they can be different by 40 or 50 degrees."

While the slow-events in Cascadia are shedding light on potential megathrust earthquakes in the area and the tsunamis they can trigger, Furlong thinks that other subduction zones may also have similar patterns.

"I would argue that it (differences in direction of motion) is happening in Alaska, Chile, Sumatra," said Furlong. "It is only in a few that we see the evidence of it, but it may be a universal process that has been missed. Cascadia exhibits it because of the slow-slip events, but it may be fundamental to subduction zones."

###

Also working on this project was Matthew W. Herman, assistant professor of geology, California State University, Bakersfield.

The National Science Foundation supported this work.

 

A groggy climate giant: subsea permafrost is still waking up after 12,000 years

New research suggests slow but substantial greenhouse gas release from submarine permafrost

IOP PUBLISHING

Research News

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IMAGE: ARTISTIC DIAGRAM OF THE SUBSEA AND COASTAL PERMAFROST ECOSYSTEMS, EMPHASIZING GREENHOUSE GAS PRODUCTION AND RELEASE. view more 

CREDIT: ORIGINAL ARTWORK CREATED FOR THIS STUDY BY VICTOR OLEG LESHYK AT NORTHERN ARIZONA UNIVERSITY.

In the far north, the swelling Arctic Ocean inundated vast swaths of coastal tundra and steppe ecosystems. Though the ocean water was only a few degrees above freezing, it started to thaw the permafrost beneath it, exposing billions of tons of organic matter to microbial breakdown. The decomposing organic matter began producing CO2 and CH4, two of the most important greenhouse gases.

Though researchers have been studying degrading subsea permafrost for decades, difficulty collecting measurements and sharing data across international and disciplinary divides have prevented an overall estimate of the amount of carbon and the rate of release. A new study, led by Ph.D. candidate Sara Sayedi and senior researcher Dr. Ben Abbott at Brigham Young University (BYU) published in IOP Publishing journal Environmental Research Letters, sheds light on the subsea permafrost climate feedback, generating the first estimates of circumarctic carbon stocks, greenhouse gas release, and possible future response of the subsea permafrost zone.

Sayedi and an international team of 25 permafrost researchers worked under the coordination of the Permafrost Carbon Network (PCN), which is supported by the U.S. National Science Foundation. The researchers combined findings from published and unpublished studies to estimate the size of the past and present subsea carbon stock and how much greenhouse gas it might produce over the next three centuries.

Using a methodology called expert assessment, which combines multiple, independent plausible values, the researchers estimated that the subsea permafrost region currently traps 60 billion tons of methane and contains 560 billion tons of organic carbon in sediment and soil. For reference, humans have released a total of about 500 billion tons of carbon into the atmosphere since the Industrial Revolution. This makes the subsea permafrost carbon stock a potential giant ecosystem feedback to climate change.

"Subsea permafrost is really unique because it is still responding to a dramatic climate transition from more than ten thousand years ago," Sayedi said. "In some ways, it can give us a peek into the possible response of permafrost that is thawing today because of human activity."

Estimates from Sayedi's team suggest that subsea permafrost is already releasing substantial amounts of greenhouse gas. However, this release is mainly due to ancient climate change rather than current human activity. They estimate that subsea permafrost releases approximately 140 million tons of CO2 and 5.3 million tons of CH4 to the atmosphere each year. This is similar in magnitude to the overall greenhouse gas footprint of Spain.

The researchers found that if human-caused climate change continues, the release of CH4 and CO2 from subsea permafrost could increase substantially. However, this response is expected to occur over the next three centuries rather than abruptly. Researchers estimated that the amount of future greenhouse gas release from subsea permafrost depends directly on future human emissions. They found that under a business-as-usual scenario, warming subsea permafrost releases four times more additional CO2 and CH4 compared to when human emissions are reduced to keep warming less than 2°C.

"These results are important because they indicate a substantial but slow climate feedback," Sayedi explained. "Some coverage of this region has suggested that human emissions could trigger catastrophic release of methane hydrates, but our study suggests a gradual increase over many decades."

Even if this climate feedback is relatively gradual, the researchers point out that subsea permafrost is not included in any current climate agreements or greenhouse gas targets. Sayedi emphasized that there is still a large amount of uncertainty about subsea permafrost and that additional research is needed.

"Compared to how important subsea permafrost could be for future climate, we know shockingly little about this ecosystem," Sayedi said. "We need more sediment and soil samples, as well as a better monitoring network to detect when greenhouse gas release responds to current warming and just how quickly this giant pool of carbon will wake from its frozen slumber."

https://iopscience.iop.org/article/10.1088/1748-9326/abcc29

CAPTION

The coastline of the Bykovsky Peninsula in the central Laptev Sea, Siberia retreats during summer, when ice-rich blocks of permafrost fall to the beach and are eroded by waves

This research was funded by the U.S. National Science Foundation and by BYU Graduate Studies.

Summary of the key scientific points:

• Subsea permafrost has been thawing since the end of the last glacial period (~14,000 years ago) when it began to be inundated by the ocean
• An international team of 25 permafrost researchers estimate that the subsea permafrost region currently traps 60 billion tons of methane and 560 billion tons of organic carbon in sediment and soil. However, the exact amount of these carbon stocks remains highly uncertain.
• This carbon is already being released from the subsea permafrost region, though it remains unclear whether this is a natural response to deglaciation or if anthropogenic warming is accelerating greenhouse gas production and release.
• The researchers estimate that currently, the subsea permafrost region releases approximately 140 million tons of CO2 and 5.3 million tons of CH4 to the atmosphere each year. This represents a small fraction of total anthropogenic greenhouse gas emissions--approximately equal to the greenhouse gas footprint of Spain.
• Experts predict a gradual increase in emissions from subsea permafrost over the next three hundred years rather than an abrupt release.
• The amount of greenhouse gas increase depends on how much human emissions are reduced. Experts estimate that approximately ¾ of the extra subsea emissions can be avoided if humans actively reduce their emissions compared to a no mitigation scenario.
• This climate feedback is still virtually absent from climate policy discussions, and more field observations are needed to better predict the future of this system.

CAPTION

The coastline of the Bykovsky Peninsula in the central Laptev Sea, Siberia retreats during summer, when ice-rich blocks of permafrost fall to the beach 

Quotes from other co-authors:

"I think there are three important messages from this study. First, subsea permafrost is probably not a climate time bomb on a hair trigger. Second, subsea permafrost is a potentially large climate feedback that needs to be considered in climate negotiations. Third, there is still a huge amount that we don't know about this system. We really need additional research, including international collaboration across northern countries and research disciplines."

Dr. Ben Abbott, senior researcher on the project, Brigham Young University

"This work demonstrates the power of science synthesis and networking by bringing together experts across a range of disciplines in order to assess our state of knowledge based on observations and models currently available. While scientific work will continue to be done to test these ideas, bringing knowledge together with this expert assessment provides an important baseline for shaping future research on subsea permafrost greenhouse gas emissions."

Dr. Ted Schuur, Lead investigator of the Permafrost Carbon Network, Northern Arizona University

"This expert assessment is a crucial contribution to the scientific literature in advancing our knowledge on subsea permafrost and potential greenhouse gas emissions from this so far understudied pool. Bringing together scientists from multiple disciplines, institutions, and countries has made it possible to move beyond individual datapoints or studies providing a much more comprehensive estimate of subsea permafrost. "

Dr. Christina Schädel, Co-Investigator of the Permafrost Carbon Network, Northern Arizona University

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High resolution versions of the photos and illustrations are available at this link.

Study sets baseline for sleep patterns in healthy adult dogs

NORTH CAROLINA STATE UNIVERSITY

Research News

 

A new canine sleep study from North Carolina State University could serve as a baseline for research on chronic pain and cognitive dysfunction in dogs, potentially improving detection and treatment of these conditions.

"The study was necessary because research on dogs and sleep has outpaced our basic knowledge about what a 'normal' sleep/wake cycle looks like," says Margaret Gruen, assistant professor of behavioral medicine at NC State and corresponding author of the work. "The studies currently available are over 20 years old, only followed small numbers of dogs or dogs that were not in a home environment, and didn't really capture data that is relevant to how dogs live (and sleep) now. We designed the study to update these findings and fill the knowledge gap.

"And for me, someone interested in how dogs develop and age, it's a critically missing gap: we talk about a symptom of age-related cognitive dysfunction in dogs as being a disruption in the sleep/wake cycle without really understanding where the baseline is."

The study followed 42 healthy adult dogs - 21 male and 21 female - ranging in age from 2 to 8 years old. The dogs wore activity monitors on their collars for a two-week period, and their owners filled out a questionnaire on the dogs' sleep patterns. Functional linear modeling of the activity data showed that most dogs have two activity peaks during the day: a shorter window from 8 a.m. to 10 a.m., followed by a midday lull and a longer active period from about 5 p.m. to 11 p.m. All dogs were more active during weekends than weekdays.

"Since most of the participants were pets of people who work outside the home, we saw that the dogs were most active when human interaction happens," Gruen says. "There were the occasional outliers - we did capture some midday 'zoomies' - but the pattern held true on average across 14 days for each dog. These findings aren't surprising - they line up with many of the assumptions we've been making, but now the data are characterized and documented."

The research revealed that weight and sex had an effect on the active periods; lighter dogs tended to be more active in a short period just after midnight, while female dogs seemed to be more active during the evening peak than males. Even in these healthy adult dogs, age had an effect; older dogs were less active during the peak activity times.

"Our hope is that this will serve as a foundational study for future work on the relationship between pain, cognitive dysfunction and sleep disruption, and as a study that is relevant to the way dogs live now," Gruen says. "By establishing norms, we can better identify abnormalities and intervene earlier in the process. We can also use this as a baseline to evaluate development of adult sleep patterns in puppies."

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The research appears in Scientific Reports. NC State graduate student Hope Woods is first author. Duncan Lascelles, professor of translational pain research and management at NC State, also contributed to the work. Evolutionary anthropologist David Samson and his team, from the University of Toronto, Canada, created the functional linear models.

Note to editors: An abstract follows.

"Let sleeping dogs lie: A functional linear modeling approach to sleep-wake cycles in dogs"

DOI: 10.1038/s41598-020-79274-2

Authors: Margaret Gruen, Hope Woods, Duncan Lascelles, North Carolina State University; Ming Fei Li, Ujas Patel, David Samson, University of Toronto, Canada

Published: Online Dec. 17, 2020 in Scientific Reports

Abstract: The study of companion (pet) dogs is an area of great translational potential, as they share many conditions that afflict both dogs and humans. These include conditions that affect sleep, including chronic pain and cognitive dysfunction. Significant advancements have 

 

Do I know you? Researchers evaluate how masks disrupt facial perception

Study conducted by Ben-Gurion University of the Negev researchers

AMERICAN ASSOCIATES, BEN-GURION UNIVERSITY OF THE NEGEV

Research News

 

IMAGE: THE IDENTIFICATION OF PEOPLE WEARING MASKS HAS OFTEN PRESENTED A UNIQUE CHALLENGE DURING THE PANDEMIC. A NEW STUDY BY RESEARCHERS FROM BEN-GURION UNIVERSITY OF THE NEGEV (BGU) IN ISRAEL AND... view more 

CREDIT: CHICAGO FACE DATABASE (MA ET AL., 2015)

BEER-SHEVA, Israel...December 21, 2020 - The identification of people wearing masks has often presented a unique challenge during the pandemic. A new study by researchers from Ben-Gurion University of the Negev (BGU) in Israel and York University in Canada reveals the impact of this predicament and its potentially significant repercussions.

The findings were just published in the journal Scientific Reports.

"For those of you who don't always recognize a friend or acquaintance wearing a mask, you are not alone," according to the researchers Prof. Tzvi Ganel, head of the Laboratory for Visual Perception and Action at the BGU Department of Psychology, and Prof. Erez Freud, who earned his Ph.D. at BGU and is now a faculty member at York University in Toronto, Ontario.

"Faces are among the most informative and significant visual stimuli in human perception and play a unique role in communicative, social daily interactions," the researchers note. "The unprecedented effort to minimize COVID-19 transmission has created a new dimension in facial recognition due to mask wearing."

To examine the effects of wearing masks, Prof. Ganel and Prof. Freud used a modified version of the Cambridge Face Memory Test, the standard for assessing facial perception, which included masked and unmasked faces. The study was conducted online with a large group of nearly 500 people.

The researchers found that the success rate of identifying someone wearing a mask was reduced by 15%. "This could lead to many errors in correctly recognizing people we know, or alternatively, accidently recognizing faces of unfamiliar people as people we know," says Prof. Galia Avidan who is a member of the BGU Department of Psychology and the Department of Cognitive and Brain Sciences, and an expert on facial recognition and perception. "Face masks could be even more challenging to people whose face recognition skills are not ideal to begin with and cause greater impairment."

The research team also found that masks specifically interfered with extracting a holistic impression of faces and led to feature-by-feature processing which is a less accurate and more time-consuming strategy.

"Instead of looking at the entire face, we're now forced to look at eyes, nose, cheeks, and other visible elements separately to construct an entire facial face percept - which we used to do instantly," the researchers say.

These changes in performance, along with the alteration along the processing style of faces, could have significant effects on activities of daily living, including social interactions, as well as other situations involving personal interactions, such as education.

"Given that mask wearing has rapidly become an important norm in countries around the globe, future research should explore the social and psychological implications of wearing masks on human behavior," Ganel says. "The magnitude of the effect of masks that we report in the current study is probably an underestimation of the actual degree in performance dropdown for masked faces."

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In addition to the BGU researchers, the Canadian team included Prof. Erez Freud who led the study, Andreja Stajduhar, and Prof. Shayna Rosenbaum of York University Department of Psychology and the Centre for Vision Research.

This study was supported by the Israel Science Foundation (Grant no. 296/15) and by the Vision Science to Applications (VISTA) program funded by the Canada First Research Excellence Fund (CFREF, 2016-2023) and by the Natural Sciences and Engineering Research Council of Canada.

About American Associates, Ben-Gurion University of the Negev

American Associates, Ben-Gurion University of the Negev (AABGU) plays a vital role in sustaining David Ben-Gurion's vision: creating a world-class institution of education and research in the Israeli desert, nurturing the Negev community and sharing the University's expertise locally and around the globe. Activities include showcasing BGU's academic excellence and cutting-edge research through educational programs, events and informative communications. AABGU's main purpose is to support Ben-Gurion's vision and the university that bears his name by creating a community of Americans committed to improving the world tomorrow from the heart of the Israeli desert today. For more information visit http://www.aabgu.org.

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Study published on the well-being of small business workers during COVID-19

The team hopes the results of the survey will encourage organizations to approach emergency preparedness as a health and safety issue.

UNIVERSITY OF COLORADO ANSCHUTZ MEDICAL CAMPUS

Research News

 

(AURORA, Colo.) December 21, 2020 - As the pandemic was starting to take hold, researchers from the Center for Health, Work & Environment (CHWE) at the Colorado School of Public Health (ColoradoSPH) performed a study to better understand the impact of COVID-19 on the well-being of workers in Colorado. The team evaluated changes to employees' work and home life resulting from COVID-19 and individual perceptions of workplace safety and health climates. These climates reflect employee perceptions of how committed their employer is to their safety and health. They are commonly used as an indicator of organizational safety and health cultures.

This study, published in the Journal of Occupational and Environmental Medicine, examined whether safety and health climates were related to employee well-being during the COVID-19 pandemic in a sample of small businesses. CHWE has become an expert in the field of small business safety and health research based on its Small + Safe + Well (SSWell) study, a four-year, Total Worker Health® intervention. The research group distributed a COVID-specific employee survey to the existing employer group of SSWell organizations and received responses from 491 employees from 30 small businesses across Colorado.

"When the pandemic hit last spring, we knew that work changed significantly. We wanted to understand how the small businesses in our SSWell study were responding to the pandemic and how this was related to their employees' health," said Dr. Natalie Schwatka, one of the lead researchers and assistant professor at the ColoradoSPH.

"We learned that when employees perceived strong health and safety climates, they also reported better well-being," says Dr. Carol Brown, lead researcher and deputy director of CHWE. Employee perceptions of safety and health climates were significantly, positively related to their self-reported well-being during the first wave of COVID-19, even when there were changes to childcare, the ability to work, and limited social contacts.

"Safety and health climates may influence employee well-being even when other disruptions occur, suggesting that during emergencies, small businesses with strong climates may be better prepared to maintain employee well-being," according to Dr. Schwatka.

The team hopes the results of the survey will encourage organizations to approach emergency preparedness as a health and safety issue. "Businesses cannot always predict when an emergency is going to happen, but they can create a working environment that supports their employees' health, safety, and well-being" says Dr. Schwatka. "In doing so, they have laid a foundation for how to successfully respond to an emergency."

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About the Center for Health, Work and Environment

The Center for Health, Work and Environment (CHWE) at the Colorado School of Public Health is one of six Centers of Excellence for Total Worker Health® and houses the Mountain & Plains Education and Research Center, one of 18 centers of its kind supported by the National Institute for Occupational Safety and Health (NIOSH). Main offices for the Center are located at the University of Colorado Anschutz Medical Campus in Aurora, Colorado. The Center team works with faculty, students, and community partners on numerous projects in occupational and environmental health, safety, and well-being.

About the Colorado School of Public Health

The Colorado School of Public Health is the first and only accredited school of public health in the Rocky Mountain Region, attracting top tier faculty and students from across the country, and providing a vital contribution towards ensuring our region's health and well-being. Collaboratively formed in 2008 by the University of Colorado, Colorado State University, and the University of Northern Colorado, the Colorado School of Public Health provides training, innovative research and community service to actively address public health issues including chronic disease, access to health care, environmental threats, emerging infectious diseases, and costly injuries.
Learn more and follow Colorado SPH's updates on Facebook, Twitter and Instagram.

 

Archaeology: The aroma of distant worlds

LUDWIG-MAXIMILIANS-UNIVERSITÄT MÜNCHEN

Research News

 

Exotic Asian spices such as turmeric and fruits like the banana had already reached the

Mediterranean more than 3000 years ago, much earlier than previously thought. A team of researchers working alongside archaeologist Philipp Stockhammer at Ludwig-Maximilians-Universität in Munich (LMU) has shown that even in the Bronze Age, long-distance trade in food was already connecting distant societies.

A market in the city of Megiddo in the Levant 3700 years ago: The market traders are hawking not only wheat, millet or dates, which grow throughout the region, but also carafes of sesame oil and bowls of a bright yellow spice that has recently appeared among their wares. This is how Philipp Stockhammer imagines the bustle of the Bronze Age market in the eastern Mediterranean. Working with an international team to analyze food residues in tooth tartar, the LMU archaeologist has found evidence that people in the Levant were already eating turmeric, bananas and even soy in the Bronze and Early Iron Ages. "Exotic spices, fruits and oils from Asia had thus reached the Mediterranean several centuries, in some cases even millennia, earlier than had been previously thought," says Stockhammer. "This is the earliest direct evidence to date of turmeric, banana and soy outside of South and East Asia." It is also direct evidence that as early as the second millennium BCE there was already a flourishing long-distance trade in exotic fruits, spices and oils, which is believed to have connected South Asia and the Levant via Mesopotamia or Egypt. While substantial trade across these regions is amply documented later on, tracing the roots of this nascent globalization has proved to be a stubborn problem. The findings of this study confirm that long-distance trade in culinary goods has connected these distant societies since at least the Bronze Age. People obviously had a great interest in exotic foods from very early on.

For their analyses, Stockhammer's international team examined 16 individuals from the Megiddo and Tel Erani excavations, which are located in present-day Israel. The region in the southern Levant served as an important bridge between the Mediterranean, Asia and Egypt in the 2nd millennium BCE. The aim of the research was to investigate the cuisines of Bronze Age Levantine populations by analyzing traces of food remnants, including ancient proteins and plant microfossils, that have remained preserved in human dental calculus over thousands of years.

The human mouth is full of bacteria, which continually petrify and form calculus. Tiny food particles become entrapped and preserved in the growing calculus, and it is these minute remnants that can now be accessed for scientific research thanks to cutting-edge methods. For the purposes of their analysis, the researchers took samples from a variety of individuals at the Bronze Age site of Megiddo and the Early Iron Age site of Tel Erani. They analyzed which food proteins and plant residues were preserved in the calculus on their teeth. "This enables us to find traces of what a person ate," says Stockhammer. "Anyone who does not practice good dental hygiene will still be telling us archaeologists what they have been eating thousands of years from now!"

Palaeoproteomics is the name of this growing new field of research. The method could develop into a standard procedure in archaeology, or so the researchers hope. "Our high-resolution study of ancient proteins and plant residues from human dental calculus is the first of its kind to study the cuisines of the ancient Near East," says Christina Warinner, a molecular archaeologist at Harvard University and the Max Planck Institute for the Science of Human History and co-senior author of the article. "Our research demonstrates the great potential of these methods to detect foods that otherwise leave few archaeological traces. Dental calculus is such a valuable source of information about the lives of ancient peoples."

"Our approach breaks new scientific ground," explains LMU biochemist and lead author Ashley Scott. That is because assigning individual protein remnants to specific foodstuffs is no small task. Beyond the painstaking work of identification, the protein itself must also survive for thousands of years. "Interestingly, we find that allergy-associated proteins appear to be the most stable in human calculus", says Scott, a finding she believes may be due to the known thermostability of many allergens. For instance, the researchers were able to detect wheat via wheat gluten proteins, says Stockhammer. The team was then able to independently confirm the presence of wheat using a type of plant microfossil known as phytoliths. Phytoliths were also used to identify millet and date palm in the Levant during the Bronze and Iron Ages, but phytoliths are not abundant or even present in many foods, which is why the new protein findings are so groundbreaking - paleoproteomics enables the identification of foods that have left few other traces, such as sesame. Sesame proteins were identified in dental calculus from both Megiddo and Tel Erani. "This suggests that sesame had become a staple food in the Levant by the 2nd millennium BCE," says Stockhammer.

Two additional protein findings are particularly remarkable, explains Stockhammer. In one individual's dental calculus from Megiddo, turmeric and soy proteins were found, while in another individual from Tel Erani banana proteins were identified. All three foods are likely to have reached the Levant via South Asia. Bananas were originally domesticated in Southeast Asia, where they had been used since the 5th millennium BCE, and they arrived in West Africa 4000 years later, but little is known about their intervening trade or use. "Our analyses thus provide crucial information on the spread of the banana around the world. No archaeological or written evidence had previously suggested such an early spread into the Mediterranean region," says Stockhammer, although the sudden appearance of banana in West Africa just a few centuries later has hinted that such a trade might have existed. "I find it spectacular that food was exchanged over long distances at such an early point in history."

Stockhammer notes that they cannot rule out the possibility, of course, that one of the individuals spent part of their life in South Asia and consumed the corresponding food only while they were there. Even if the extent to which spices, oils and fruits were imported is not yet known, there is much to indicate that trade was indeed taking place, since there is also other evidence of exotic spices in the Eastern Mediterranean - Pharaoh Ramses II was buried with peppercorns from India in 1213 BCE. They were found in his nose.

The results of the study have been published in the journal PNAS. The work is part of Stockhammer's project "FoodTransforms--Transformations of Food in the Eastern Mediterranean Late Bronze Age," which is funded by the European Research Council. The international team that produced the study encompasses scientists from LMU Munich, Harvard University and the Max Planck Institute for the Science of Human History in Jena. The fundamental question behind his project - and thus the starting point for the current study - was to clarify whether the early globalization of trade networks in the Bronze Age also concerned food. "In fact, we can now grasp the impact of globalization during the 2nd millennium BCE on East Mediterranean cuisine," says Stockhammer. "Mediterranean cuisine was characterized by intercultural exchange from an early stage."

Social media use by young people in conflict-ridden Myanmar

MARY ANN LIEBERT, INC./GENETIC ENGINEERING NEWS

Research News

 

IMAGE: EXPLORES THE PSYCHOLOGICAL AND SOCIAL ISSUES SURROUNDING THE INTERNET AND INTERACTIVE TECHNOLOGIES. view more 

CREDIT: MARY ANN LIEBERT, INC., PUBLISHERS

New Rochelle, NY, December 21, 2020--Myanmar youth rely heavily on Facebook for news and information. This can be a platform for disseminating fake news and hate speech. With poor digital literacy skills, these youths may be susceptible to disinformation campaigns and other online dangers, according to the peer-reviewed journal Cyberpsychology, Behavior, and Social Networking. Click here (http://doi.org/10.1089/cyber.2020.0131) to read the article now.

Facebook and its sister app Messenger were used by 87.4% and 71.4% of Myanmar youth living in conflict-affected areas. Overall, 58% of respondents indicated that they use social media, mainly Facebook, to read news.

The results "suggest that young people living in conflict-affected areas of Myanmar are aware of the proliferation of fake news on social media, and often check the accuracy of the news they receive from this medium," states Dr. Brad Ridout, The University of Sydney, and coauthors. "However, the overreliance on Facebook for checking news accuracy, combined with poor literacy skills and low levels of trust in traditional and state-run media, may have a negative impact on the information ecosystem within which young people in Myanmar exist."

"Teaching young people media and information literacy has always been an important tool, to give them the critical thinking skills to properly navigate the information they are exposed to in everyday life. Digital networks that have enabled trans-border and trans-media information availability makes this education more important now than ever before to encourage us all to call into question the information encountered online," says Editor-in-Chief Brenda K. Wiederhold, PhD, MBA, BCB, BCN, Interactive Media Institute, San Diego, California and Virtual Reality Medical Institute, Brusse (https://home.liebertpub.com/publications/cyberpsychology-behavior-and-social-networking/10) is an authoritative peer-reviewed journal published monthly online with Open Access options and in print that explores the psychological and social issues surrounding the Internet and interactive technologies. Complete tables of contents and a sample issue may be viewed on the Cyberpsychology, Behavior, and Social Networking (https://home.liebertpub.com/publications/cyberpsychology-behavior-and-social-networking/10) website.

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About the Publisher

Mary Ann Liebert, Inc., publishers (https://www.liebertpub.com/) for establishing authoritative peer-reviewed journals in many promising areas of science and biomedical research. A complete list of the ) 90 journals, books, and newsmagazines is available on the Mary Ann Liebert, Inc., publishers (https://www.liebertpub.com/website.

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