Romantic relationships mitigate effects of trauma on alcohol use among college students

VIRGINIA COMMONWEALTH UNIVERSITY

Research News

 

Students who have been exposed to interpersonal trauma —  physical assault, sexual assault or unwanted sexual experiences — prior to college are more likely to engage in risky alcohol use. But romantic relationships mitigate these effects of trauma on a student’s drinking behavior, according to a new study led by Virginia Commonwealth University researchers.

The study investigates whether romantic relationships might play a role in mitigating or exacerbating the effects of trauma exposure on alcohol use among college students. It found that students who experienced interpersonal trauma during college consumed more alcohol than those without interpersonal trauma exposure, and that their drinking was more pronounced for those in a relationship with a partner with higher levels of alcohol use. It also found that a student’s satisfaction in their romantic relationship did not change the association between interpersonal trauma and alcohol use.

Previous research has found that college students who have been exposed to interpersonal trauma are more likely to engage in risky alcohol use. Yet not everyone who experiences interpersonal trauma goes on to misuse alcohol, raising questions about what factors might play a role in the interaction of trauma and drinking.

The study, “A Longitudinal Study of the Moderating Effects of Romantic Relationships on the Associations Between Alcohol Use and Trauma in College Students,” will be published in a forthcoming issue of the journal Addiction. It explores whether three aspects of romantic relationships — relationship status, relationship satisfaction and partner alcohol use — change the associations between interpersonal trauma and alcohol use.

“These findings are important because they help elucidate the ways that romantic relationships can improve or undermine health habits, particularly concerning alcohol consumption,” said lead author Rebecca Smith, a doctoral student in the Department of Psychology in the College of Humanities and Sciences. “A better understanding of the ways that social relationships can influence health behaviors might encourage people to carefully consider the people with whom they spend time. Moreover, these findings help us better understand alcohol use risk and protective factors across the lifespan, which can be used to inform prevention and treatment programs.”

Jessica Salvatore, Ph.D., an assistant professor in the Department of Psychology and the senior author on the study, said the findings “underscore the double-edged role that relationships and partners have on health behaviors in college.”

“On the one hand, we found that involvement in a committed relationship buffered the effects of interpersonal trauma exposure on students’ alcohol use,” she said. “On the other, we found that involvement with a heavier drinking partner amplified the association between exposure and alcohol use.”

Smith said she was surprised that relationship satisfaction was not a significant moderator of the associations between interpersonal trauma and alcohol use.

“Based on previous research suggesting that involvement in satisfying relationships is protective against stress and problematic drinking, we had hypothesized that high relationship satisfaction would buffer against the effects of interpersonal trauma on alcohol use,” she said.

The study relied on data collected through Spit for Science, a universitywide project at VCU in which student volunteers provide information on alcohol, substance use, emotional health and more, and contribute DNA samples that provide insight into the role of genetics. The study involved nearly 9,000 students who participated in Spit for Science between 2011 and 2014.

Participants completed baseline assessments during the fall of their freshman year and were invited to complete follow-up assessments every spring thereafter. Participants were included in the study if they completed surveys at baseline and at least one follow-up assessment.

“Each year, participants answered questions about stressful life events they may have experienced, their quantity and frequency of alcohol consumption, and their romantic relationships,” Smith said. “This allowed us to look at the interplay between interpersonal trauma, alcohol use and romantic relationship characteristics over time.”

The study’s findings could be valuable for efforts to increase awareness and education for college students about the ways in which our social ties can promote or undermine health behaviors, like alcohol use, Smith said.

Additionally, she said, the findings could be applied as part of treatment to reduce unsafe drinking.

“We know from previous research that exposure to interpersonal trauma is associated with risky alcohol use, so romantic partners can be included in treatment planning and aftercare to help trauma survivors cope with traumatic events in healthier ways and reduce engagement in risky drinking behaviors,” she said.

In addition to Smith and Salvatore, the study’s co-authors include Danielle Dick, Ph.D., Distinguished Commonwealth Professor in the Departments of Psychology and Human and Molecular Genetics at VCU; Ananda Amstadter, Ph.D., associate professor in the Virginia Institute for Psychiatric and Behavioral Genetics at VCU; Nathaniel Thomas, a doctoral student in the Department of Psychology; and the Spit for Science Working Group.

Urgent shortage of evidence for safe withdrawal from antidepressants

UNIVERSITY OF SOUTHAMPTON

Research News

 

A new study has highlighted that while much is known about the ever increasing uptake of antidepressant medications around the world, there is very little evidence on safe and effective approaches to discontinuing treatment.

In 2020 there were 78 million prescriptions for antidepressants in England and about half of patients treated have taken them for at least two years. Guidelines typically recommend that antidepressants be taken for up to 6 to 12 months after improvement, or for up to two years in people at risk of relapse, but many people take antidepressants for much longer. Surveys of antidepressant users suggest that up to a half of people on long-term antidepressant prescriptions have no clear medical reason to keep taking them. Long-term use can put people at risk of adverse events such as sleep disturbance, weight gain, sexual dysfunction, bleeding, and gastrointestinal problems, as well as feeling emotionally numb and unable to deal with problems in life without their medication.

In this new study for Cochrane, an international research team, including Professor Tony Kendrick from the University of Southampton, looked at the findings from 33 randomised control trials that included 4,995 participants who were prescribed antidepressants for 24 weeks or longer. In 13 studies, the antidepressant was stopped abruptly; in 18, it was stopped over a few weeks (known as 'tapering'); in four, psychological therapy support was also offered; and in one study, stopping was prompted by a letter to GPs with guidance on tapering. Most tapering schemes lasted four weeks or less and none of the studies used very slow tapering schemes beyond a few weeks - in contrast to new guidelines from the UK Royal College of Psychiatrists that recommend tapering over months or years to safely stop.

The authors were unable to make any firm conclusions about effects and safety of the approaches studied and did not have confidence in the results due to the low certainty of evidence they provided.

'We know the rise in long-term antidepressant use is a major concern around the world,' says lead author Dr Ellen Van Leeuwen from the University of Ghent, Belgium. 'As a GP myself, I see first-hand the struggles many patients have coming off antidepressants. It's of critical concern that we don't know enough about how to reduce inappropriate long-term use or what the safest and most effective approaches are to help people do this. For example, there are over 1,000 studies looking at starting antidepressants, yet we found only 33 trials around the world that examined stopping them. It's clear that this area needs urgent attention.'

Co-author Tony Kendrick, Professor of Primary Care at the University of Southampton is leading the REDUCE trial, testing online and psychologist telephone support for patients withdrawing from long-term antidepressants. He says "More than one in ten adults in England are now taking antidepressants but surveys of long-term users suggest that between a third and a half of these have no evidence-based reason to continue taking them, and they are associated with increasing side effects in the longer term."

A key issue identified by the research team is that previous studies have not distinguished between symptoms of a return of depression and withdrawal symptoms from the medication.

The difficulty of distinguishing between these symptoms presents a real challenge for patients, doctors and researchers alike - often resulting in inappropriate continuation of antidepressant medication and uncertain evidence on which to base healthcare decisions.

Dr Kendrick continues, "Antidepressants are often difficult to stop due to withdrawal symptoms. More research is needed to establish the incidence of withdrawal symptoms in patients, and large randomised controlled trials are needed to test different tapering strategies.

"Ultimately we really need more deprescribing studies - especially in primary care given that's where most prescribing takes place - before we can make more definitive conclusions. In the meantime, we hope this review provides a starting point to help GPs openly discuss continuing or stopping antidepressants with their patients. We also want to raise awareness that withdrawal symptoms from antidepressants are common and can be mistaken for relapse of the underlying condition. Experiencing withdrawal symptoms isn't a sign that the patient has relapsed - it might be that they need to taper more gradually down to much lower doses instead, before eventually stopping."

WTF

Cannabis use disorder rate rose among pregnant women between 2001-2012

Study finds resulting adverse outcomes for infants: preterm births, low birth weight and small size

UNIVERSITY OF CALIFORNIA - SAN DIEGO

Research News

 

A study of almost 5 million live births in California by researchers at the Herbert Wertheim School of Public Health and Human Longevity Science at University of California San Diego reports that babies born to mothers diagnosed with cannabis use disorder were more likely to experience negative health outcomes, such as preterm birth and low birth weight, than babies born to mothers without a cannabis use disorder diagnosis.

The findings are published online in the April 22, 2021 issue of the journal Addiction. The National Institute on Drug Abuse, part of the National Institutes of Health, funded the study.

Cannabis use disorder is a diagnostic term with specific criteria that defines continued cannabis use despite consequent, clinically significant impairments. The research team, led by first author Yuyan Shi, PhD, associate professor at The Herbert Wertheim School of Public Health, conducted a retrospective cohort study of 4.83 million mothers who delivered live, single births in California from 2001 to 2012.

They identified 20,237 women who were discharged after delivery with a diagnosis of cannabis use disorder. Not all people who use cannabis meet the criteria for cannabis use disorder. The study authors stated the actual incidence of cannabis use disorder is likely higher than reported numbers.

The researchers found that diagnoses of cannabis use disorder, based on medical records at time of delivery, rose from 2.8 to 6.9 per 1000 deliveries from 2002 to 2012. Compared to a matched control group of 40,474 mother-infant pairs, infants born to women with cannabis use disorder were more likely to be born preterm, have a low birth weight and be small for their gestational age -- all factors that can require greater or more intense medical care or presage later health issues.

Additionally, researchers found that, though rare overall (less than 1 percent), the risk of infant mortality was greater for infants born to women with cannabis use disorder. These infants were 35 percent more likely to die within a year of birth than infants in the control group. Conversely, these infants were also less likely to be hospitalized within the first year of life than control group infants.

"Because we are looking only at medical records, there is a lot we don't know about the mothers and infants in this study," said first author Shi, "but our analysis supports the recommendation that health professionals screen for and address cannabis use disorders in their pregnant clients -- to protect both their health and potentially the health of their infants."

Currently, screening for cannabis use or related disorders is not standard practice during pregnancy health care, though marijuana is the illicit drug most commonly used by pregnant women, typically to self-treat depression, anxiety, stress, pain, nausea and vomiting, often during the first trimester. It is also not standard of care to provide counsel on the lack of safety data around cannabis use during pregnancy. Both strategies may be helpful, as well as encouraging patients to discontinue use of cannabis during pregnancy and while breastfeeding and referring to treatment when appropriate.

According to a 2018 published study, approximately 7 percent of pregnant women self-reported marijuana use, with rates as high as 10 percent among women ages 18 to 25. Rates based on urine toxicology were even higher, with 19 percent of pregnant women ages 18 to 25 screening positive for marijuana use.

Previous research has found that tetrahydrocannabinol (THC), the psychoactive compound in cannabis, can reach fetuses and infants through the placenta and breastmilk, respectively. THC disrupts the normal function of the endocannabinoid system, which has been shown to play a key role in pregnancy, including implantation of the embryo in the uterus and maintenance of the placenta.

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Co-authors include: Bin Zhu, UC San Diego; and Di Liang, UC San Diego and Fudan University, China.

Immune system, not COVID virus, may pose greatest risk to pregnant women

YALE UNIVERSITY

Research News 

For reasons not yet clear, pregnant women infected with the virus that causes COVID-19 are more likely to experience preterm births, pre-eclampsia, and other neonatal problems than non-infected women.

A team of Yale scientists decided to investigate whether the virus could be affecting placental tissue of infected expectant mothers. Their analysis found that while evidence of the virus in the placenta is rare, the placenta in infected mothers tended to exhibit a much higher level of immune system activity than those of non-infected pregnant women, they report April 22 in the journal Med.

"The good news is the placenta is mounting a robust defense against an infection that is far distant, in lungs or nasal tissue," said Shelli Farhadian, assistant professor of internal medicine (infectious diseases) and neurology at Yale and co-corresponding author. "On the other hand, the high level of immune system activity might be leading to other deleterious effects on the pregnancy."

The team headed by Farhadian and Akiko Iwasaki, the Waldemar Von Zedtwitz Professor of Immunobiology at Yale, analyzed blood and placental tissue in 39 infected and as well as COVID-free expectant mothers at different stages of pregnancy. While they found evidence of the virus in only two samples of placental tissue, they did find ACE2 receptors -- which the SARS-CoV-2 virus uses to enter cells -- in the placentas of most women during the first trimester of pregnancy. Those receptors had largely disappeared in healthy women at later stages of pregnancy.

"It is very important to closely monitor expectant mothers who become infected early in pregnancy," Farhadian said.

Immune system activity in the placenta during infections like COVID-19 has not been extensively studied and it is not known whether other types of infections would behave similarly to SARS-CoV-2, she said.

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Alice Lu-Culligan is lead author of the study, which was primarily funded by the National Institutes of Health and the Emergent Ventures Fund at the Mercatus Center at George Mason University.

Pregnant women with COVID-19 face high mortality rate

Worldwide study also found that 11% of babies contracted the novel coronavirus from their mothers

UNIVERSITY OF WASHINGTON SCHOOL OF MEDICINE/UW MEDICINE

Research News

 

In a worldwide study of 2,100 pregnant women, those who contracted COVID-19 during pregnancy were 20 times more likely to die than those who did not contract the virus.

UW Medicine and University of Oxford doctors led this first-of-its-kind study, published today in JAMA Pediatrics. The investigation involved more than 100 researchers and pregnant women from 43 maternity hospitals in 18 low-, middle- and high-income nations; 220 of the women received care in the United States, 40 at UW Medicine. The research was conducted between April and August of 2020.

The study is unique because each woman affected by COVID-19 was compared with two uninfected pregnant women who gave birth during the same span in the same hospital.

Aside from an increased risk of death, women and their newborns were also more likely to experience preterm birth, preeclampsia and admission to the ICU and/or intubation. Of the mothers who tested positive for the disease, 11.5% of their babies also tested positive, the study found.

Although other studies have looked at COVID-19's effects on pregnant women, this is among the first study to have a concurrent control group with which to compare outcomes, said Dr. Michael Gravett, one of the study's lead authors.

"The No. 1 takeaway from the research is that pregnant women are no more likely to get COVID-19, but if they get it, they are more likely to become very ill and more likely to require ICU care, ventilation, or experience preterm birth and preeclampsia," he said. Gravett is a professor of obstetrics and gynecology at the University of Washington School of Medicine. Co-investigator Dr. Lavone Simmons is a UW acting assistant professor of OB-GYN.

One caveat, Gravett noted, was that women whose COVID-19 was asymptomatic or mild were not found to be at increased risk for ICU care, preterm birth or preeclampsia. About 40% of the women in this study were asymptomatic. Pregnant women who were obese or had hypertension or diabetes were at the greatest risk for severe disease, the findings showed.

Babies of the women infected with COVID-19 were more likely to be born preterm; but their infections were usually mild, the study found. Breastfeeding seemed not to be related to transmitting the disease. Delivery by Caesarean section, however, might be associated with an increased risk of having an infected newborn, the study found.

Gravett suggested that these and parallel research findings compelled U.S. states' decisions to open vaccine eligibility to pregnant women - who were initially considered a population at low risk for severe COVID-19.

"I would highly recommend that all pregnant women receive the COVID-19 vaccines," based on this research, he said.

The study demonstrates the importance of collecting large-scale, multinational data quickly during a health crisis, Gravett said. Researchers were able to complete the investigation and report findings in only nine months, using infrastructure already in place from the INTERGROWTH-21st Project, which emerged in 2012 to study fetal growth and neonatal outcomes

Why the human body has not evolved to make childbirth easier -- or has it?

UNIVERSITY OF TEXAS AT AUSTIN

Research News

 

IMAGE: RESEARCHERS USED FINITE ELEMENT ANALYSIS, TYPICALLY DEPLOYED TO TEST STRUCTURES FOR STRESS EVENTS LIKE EARTHQUAKES, TO STUDY THE PELVIC FLOOR IN WOMEN. view more 

CREDIT: THE UNIVERSITY OF TEXAS AT AUSTIN.

AUSTIN, Texas -- Despite advances in medicine and technology, childbirth isn't likely to get much easier on women from a biological perspective.

Engineers at The University of Texas at Austin and University of Vienna revealed in new research a series of evolutionary trade-offs that have created a near-perfect balance between supporting childbirth and keeping organs intact on a day-to-day basis. Human reproduction is unique because of the comparatively tight fit between the birth canal and baby's head, and it is likely to stay that way because of these competing biological imperatives.

The size of the pelvic floor and canal is key to keeping this balance. These opposing duties have constrained the ability of the pelvic floor to evolve over time to make childbirth easier because doing that would sacrifice the ability to protect organs.

"Although this dimension has made childbirth more difficult, we have evolved to a point where the pelvic floor and canal can balance supporting internal organs while also facilitating childbirth and making it as easy as possible," said Krishna Kumar, an assistant professor in the Cockrell School of Engineering's Department of Civil, Architectural and Environmental Engineering who led the research published this week in the journal Proceedings of the National Academy of Sciences.

The pelvic floor in women is a band of muscles that stretches across the bottom of the abdomen from the tailbone to the pubic bone. It supports pelvic organs, including the uterus, bladder and bowel, and it helps stabilize the spine.

A larger pelvic floor and canal would facilitate easier childbirth. But the larger it becomes without additional bones or tissue to support it, the more likely it is to deform under the weight of organs and cause them to fall downward.

These trade-offs, referred to as the pelvic floor hypothesis, were known in the scientific community. But the theory had been difficult to test until this research team used engineering tools to investigate it.

Kumar first started thinking about the problem by comparing the pelvic floor to a trampoline. A bigger trampoline will drop further as weight is applied, whereas a smaller trampoline will hold its structure better.

In addition to studying the size of the pelvic floor, the researchers also looked at thickness. In theory, a thicker pelvic floor could continue to support organs and an expanded size for childbirth. But it did not turn out that way.

"We found that thicker pelvic floors would require quite a bit higher intra-abdominal pressures than humans are capable of generating to stretch during childbirth," said Nicole Grunstra, an affiliated researcher at the University of Vienna's Unit for Theoretical Biology in the Department of Evolutionary Biology. "Being unable to push the baby through a resistant pelvic floor would equally complicate childbirth, despite the extra space available in the birth canal, and so pelvic floor thickness appears to be another evolutionary 'compromise,' in addition to the size of the birth canal."

The team got to this conclusion by applying principles common in civil engineering. Kumar used a Finite Element analysis, a computerized model often deployed to test the design of structures to see whether they will break or wear down when facing high levels of pressure and stress. In this case, Finite Element analysis allowed the team to model the pelvic floor, change its parameters and see how it responds to the stresses of childbirth and protecting organs, which is otherwise impossible to test using clinical data.

This is the first time Finite Element analysis has been used to explore an evolutionary question. However, it isn't the first time Kumar has applied engineering tools to biology.

While at the University of Cambridge in the U.K., where he met his co-authors who are now at the University of Vienna, Kumar applied a transportation analysis technique to herpes to learn more about how it first spread among humans.

This collaboration shows that engineering approaches and tools are relevant to important problems that, at first glance, may seem well outside the discipline, said Kumar, whose primary research involves numerical models for earthquakes, landslides and other disasters.

"You can abstract all the biology away, and it comes down to what happens if you apply stress, what does it do to bodies and structures with different material properties," Kumar said. "If you squint your eyes, a large landslide can look like a pelvic floor."

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Mars has right ingredients for present-day microbial life beneath its surface, study finds

BROWN UNIVERSITY

Research News

 

IMAGE: JESSE TARNAS, A BROWN UNIVERSITY GRADUATE AND POSTDOCTORAL RESEARCH AT NASA'S JET PROPULSION LABORATORY, WORK IN CANADA'S KIDD CREEK MINE. WATER IN THE DEPTHS OF THE MINE THAT HASN'T SEEN... view more 

CREDIT: JESSE TARNAS

PROVIDENCE, R.I. [Brown University] -- As NASA's Perseverance rover begins its search for ancient life on the surface of Mars, a new study suggests that the Martian subsurface might be a good place to look for possible present-day life on the Red Planet.

The study, published in the journal Astrobiology, looked at the chemical composition of Martian meteorites -- rocks blasted off of the surface of Mars that eventually landed on Earth. The analysis determined that those rocks, if in consistent contact with water, would produce the chemical energy needed to support microbial communities similar to those that survive in the unlit depths of the Earth. Because these meteorites may be representative of vast swaths of the Martian crust, the findings suggest that much of the Mars subsurface could be habitable.

"The big implication here for subsurface exploration science is that wherever you have groundwater on Mars, there's a good chance that you have enough chemical energy to support subsurface microbial life," said Jesse Tarnas, a postdoctoral researcher at NASA's Jet Propulsion Laboratory who led the study while completing his Ph.D. at Brown University. "We don't know whether life ever got started beneath the surface of Mars, but if it did, we think there would be ample energy there to sustain it right up to today."

In recent decades, scientists have discovered that Earth's depths are home to a vast biome that exists largely separated from the world above. Lacking sunlight, these creatures survive using the byproducts of chemical reactions produced when rocks come into contact with water.

One of those reactions is radiolysis, which occurs when radioactive elements within rocks react with water trapped in pore and fracture space. The reaction breaks water molecules into their constituent elements, hydrogen and oxygen. The liberated hydrogen is dissolved in the remaining groundwater, while minerals like pyrite (fool's gold) soak up free oxygen to form sulfate minerals. Microbes can ingest the dissolved hydrogen as fuel and use the oxygen preserved in the sulfates to "burn" that fuel.

In places like Canada's Kidd Creek Mine, these "sulfate-reducing" microbes have been found living more than a mile underground, in water that hasn't seen the light of day in more than a billion years. Tarnas has been working with a team co-led by Brown University professor Jack Mustard and Professor Barbara Sherwood Lollar of the University of Toronto to better understand these underground systems, with an eye toward looking for similar habitats on Mars and elsewhere in the solar system. The project, called Earth 4-D: Subsurface Science and Exploration, is supported by the Canadian Institute for Advances Research.

For this new study, the researchers wanted to see if the ingredients for radiolysis-driven habitats could exist on Mars. They drew on data from NASA's Curiosity rover and other orbiting spacecraft, as well as compositional data from a suite of Martian meteorites, which are representative of different parts of the planet's crust.

The researchers were looking for the ingredients for radiolysis: radioactive elements like thorium, uranium and potassium; sulfide minerals that could be converted to sulfate; and rock units with adequate pore space to trap water. The study found that in several different types of Martian meteorites, all the ingredients are present in adequate abundances to support Earth-like habitats. This was particularly true for regolith breccias -- meteorites sourced from crustal rocks more than 3.6 billion years old -- which were found to have the highest potential for life support. Unlike Earth, Mars lacks a plate tectonics system that constantly recycle crustal rocks. So these ancient terrains remain largely undisturbed.

The researchers say the findings help make the case for an exploration program that looks for signs of present-day life in the Martian subsurface. Prior research has found evidence of an active groundwater system on Mars in the past, the researchers say, and there's reason to believe that groundwater exists today. One recent study, for example, raised the possibility of an underground lake lurking under the planet's southern ice cap. This new research suggests that wherever there's groundwater, there's energy for life.

Tarnas and Mustard say that while there are certainly technical challenges involved in subsurface exploration, they aren't as insurmountable as people may think. A drilling operation wouldn't require "a Texas-sized oil rig," Mustard said, and recent advances in small drill probes could soon put the Martian depths within reach.

"The subsurface is one of the frontiers in Mars exploration," Mustard said. "We've investigated the atmosphere, mapped the surface with different wavelengths of light and landed on the surface in half-a-dozen places, and that work continues to tell us so much about the planet's past. But if we want to think about the possibility of present-day life, the subsurface is absolutely going to be where the action is."

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The research was supported by the Canadian Institute for Advanced Research.

CAPTION

New research showing that the subsurface of Mars is potentially habitable will be featured on the cover of the journal Astrobiology.

CREDIT

Astrobiology/NASA/JPL/University of Arizona

 

Fat-footed tyrannosaur parents could not keep up with their skinnier adolescent offspring

TAYLOR & FRANCIS GROUP

Research News

 

IMAGE: ARTISTIC RECONSTRUCTION OF A TYRANNOSAUR CREATING FOOTPRINTS. IMAGE COURTESY OF JOSÉ VITOR SILVA. view more 

CREDIT: VITOR SILVA

New research by the University of New England's Palaeoscience Research Centre suggests juvenile tyrannosaurs were slenderer and relatively faster for their body size compared to their multi-tonne parents.

The research, published in the Journal of Vertebrate Paleontology, analysed a collection of fossilised tyrannosaur footprints to learn more about the way these animals aged and how they moved.

UNE PhD student and study leader, Nathan Enriquez -- in international collaboration with the Philip J. Currie Dinosaur Museum, University of Alberta, Royal Ontario Museum, University of Bologna and the Grande Prairie Regional College -- believes the findings contribute a new line of evidence to previous findings based on bone anatomy and computer models of muscle masses.

"The results suggest that as some tyrannosaurs grew older and heavier, their feet also became comparably more bulky," Mr Enriquez said.

"Fully grown tyrannosaurs were believed to be more robust than younger individuals based on their relatively shorter hind limbs and more massive skulls, but nobody had explored this growth pattern using fossil footprints, which are unique in that they can provide a snapshot of the feet as they appeared in life, with outlines of the soft, fleshy parts of the foot that are rarely preserved as fossils.

Footprints can be ambiguous and hard to interpret correctly -- the shape of a footprint may be influenced by the type of ground surface that is stepped on and the motions of the animal making the footprints. In addition, the exact identity of the animal may not always be clear. These challenges have previously limited the use of fossil footprints in understanding dinosaur growth.

The answer lay in the Grande Prairie region of Northern Alberta, Canada, where the research team worked with well-preserved samples of footprints of different sizes that are suggested to belong to the same type of animal.

"We explored a remote dinosaur footprint site where we discovered a new set of large carnivorous dinosaur footprints within very similar rocks to those which have produced tyrannosaur tracks in the past," Mr Enriquez said.

"Based on the relatively close proximity between these discoveries and their nearly equivalent ages -- about 72.5 million years old -- we suggest they may indeed belong to the same species.

"We were also careful to assess the quality of preservation in each footprint, and only considered specimens which were likely to reflect the shape of the actual feet that produced them."

Once the team had a suitable sample, they analysed the outlines of each specimen using a method called geometric morphometrics. This process removes the effect of overall size differences between each footprint and shows what the most important differences in track shape are.

"The greatest difference in shape was found to be the relative width and surface area of the heel impression, which significantly increased in size between smaller and larger footprints," Mr Enriquez said.

"The smaller tracks are comparably slender, while the biggest tyrannosaur tracks are relatively broader and had much larger heel areas. This makes sense for an animal that is becoming larger and needs to support its rapidly increasing body weight. It also suggests the relative speed of these animals decreased with age.

"Increasingly bulky feet in the adults aligns with previous suggestions that juvenile tyrannosaurs would have been faster and more agile for their body size in comparison to their parents, and means that we can add footprints as another line of evidence in the debate over tyrannosaur growth.

"Lastly, it demonstrates the usefulness of footprints for investigating a potentially wider range of ideas about the lives of extinct species than has been considered previously."

CAPTION

Photograph of a large theropod track natural cast that was discovered during the field season.

CREDIT

Journal of Vertebrate Paleontology

CAPTION

Footprint size comparison from young to old

CREDIT

Journal of Vertebrate Paleontology

What Parkinson's disease patients reveal about how art is experienced and valued

Impaired motor function, like that experienced with Parkinson's disease, impacts art perception and valuation, Penn Medicine research finds

UNIVERSITY OF PENNSYLVANIA SCHOOL OF MEDICINE

Research News

 

PHILADELPHIA-- Art appreciation is considered essential to human experience. While taste in art varies depending on the individual, cognitive neuroscience can provide clues about how viewing art affects our neural systems, and evaluate how these systems inform our valuation of art. For instance, one study shows that viewing art activates motor areas, both in clear representations of movement, like Adam and Eve in Michelangelo's Expulsion from Paradise, and in implied movement through brush strokes, like in Franz Kline's gestural paintings.

Altered neural functioning, like that experienced in patients with Parkinson's disease, changes the way art is both perceived and valued, according to a study published recently in The Journal of Cognitive Neuroscience by researchers from the Penn Center for Neuroaesthetics at the University Pennsylvania's Perelman School of Medicine. They found that people with neurological motor dysfunction demonstrated decreased experiences of motion in abstract art and enhanced preferences for high-motion art, compared to a healthy control group.

"People can experience movement in abstract art, even without implied movement, like brush strokes," says author Anjan Chatterjee, MD, a professor of Neurology and director of the Penn Center for Neuroaesthetics. "These representations of movement systematically affect people's aesthetic evaluations, whether they are healthy individuals or people with Parkinson's disease."

The study examined the aesthetic experiences of 43 people with Parkinson's disease and 40 controls in the same age group. The subjects made motion and aesthetics judgements about 10 Jackson Pollock and 10 Piet Mondrian paintings. Using seven-point Likert scales, participants rated the paintings along nine categories: Liking, Beauty, Interest, Familiarity, Motion, Complexity, Balance, Color-Hue, and Color-Saturation. The Color dimensions served as relatively objective control ratings.

People with Parkinson's disease demonstrated stable and internally consistent preferences for abstract art, but their perception of movement in the paintings was diminished compared to controls. This finding provides evidence that the brain's motor system is involved in translating nonrepresentational information from static visual cues in the image into representations of movement.

For example, Mondrian paintings receiving the highest motion ratings in this study contained more visual elements, overlapping lines, repetition, and many small areas of contrasting colors. Mondrian's final Boogie-Woogie paintings, inspired by the New York jazz scene, are viewed as dynamic and rhythmic, despite an absence of gestural brushwork. The feeling of movement brought about by works like these likely results from the way these visual elements are interpreted, leading to abstract representations of movement rather than simulations of specific bodily actions. Similarly, Pollock paintings may be felt as dynamic because the increasing number of overlapping colors and the manner of paint application leads to more repetition, curvature, and contrast, which are thought to evoke feelings of movement.

"Our findings are particularly significant because, previously, it was posited that viewing abstract art stimulated the motor system because people could envision the gestures the artist took when painting," says lead author, Stacey Humphries, PhD, a postdoctoral researcher in the department of Neurology. "But our research shows that even without those representations of movement, the motor system can interpret static visual clues as movement and in turn impact the viewer's aesthetic appreciation."

The motion effects cannot be attributed purely to greater complexity in the higher motion paintings. Researchers found no significant differences in the complexity ratings or the relationship between complexity and liking of art given by patients and controls.

The researchers note that the patients participated while on their usual medication. One factor not yet considered is the effect that dopaminergic medication might have on aesthetic experiences. Dopamine plays a significant role in the normal functioning of the brain's reward system, which is consequently disturbed in Parkinson's disease.

The fundamental insight of the study is that the brain's ability to construct abstract representations of movement influences people's aesthetic experiences of art.

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This study was supported by the Smith Family Fund.

Penn Medicine is one of the world's leading academic medical centers, dedicated to the related missions of medical education, biomedical research, and excellence in patient care. Penn Medicine consists of the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania (founded in 1765 as the nation's first medical school) and the University of Pennsylvania Health System, which together form a $8.9 billion enterprise.

The Perelman School of Medicine has been ranked among the top medical schools in the United States for more than 20 years, according to U.S. News & World Report's survey of research-oriented medical schools. The School is consistently among the nation's top recipients of funding from the National Institutes of Health, with $496 million awarded in the 2020 fiscal year.

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Machine learning model generates realistic seismic waveforms

New research could reduce manual labor and improve earthquake detection

DOE/LOS ALAMOS NATIONAL LABORATORY

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IMAGE: SEISMOGEN, A MACHINE LEARNING TECHNIQUE DEVELOPED AT THE LABORATORY, IS CAPABLE OF GENERATING HIGH-QUALITY SYNTHETIC SEISMIC WAVEFORMS. THE TECHNIQUE COULD SAVE TEDIOUS AND INTENSIVE MANUAL LABELING EFFORT AND HELP IMPROVE... view more 

CREDIT: LOS ALAMOS NATIONAL LABORATORY

LOS ALAMOS, N.M., April 22, 2021--A new machine-learning model that generates realistic seismic waveforms will reduce manual labor and improve earthquake detection, according to a study published recently in JGR Solid Earth.

"To verify the e?cacy of our generative model, we applied it to seismic ?eld data collected in Oklahoma," said Youzuo Lin, a computational scientist in Los Alamos National Laboratory's Geophysics group and principal investigator of the project. "Through a sequence of qualitative and quantitative tests and benchmarks, we saw that our model can generate high-quality synthetic waveforms and improve machine learning-based earthquake detection algorithms."

Quickly and accurately detecting earthquakes can be a challenging task. Visual detection done by people has long been considered the gold standard, but requires intensive manual labor that scales poorly to large data sets. In recent years, automatic detection methods based on machine learning have improved the accuracy and efficiency of data collection; however, the accuracy of those methods relies on access to a large amount of high?quality, labeled training data, often tens of thousands of records or more.

To resolve this data dilemma, the research team developed SeismoGen based on a generative adversarial network (GAN), which is a type of deep generative model that can generate high?quality synthetic samples in multiple domains. In other words, deep generative models train machines to do things and create new data that could pass as real.

Once trained, the SeismoGen model is capable of producing realistic seismic waveforms of multiple labels. When applied to real Earth seismic datasets in Oklahoma, the team saw that data augmentation from SeismoGen?generated synthetic waveforms could be used to improve earthquake detection algorithms in instances when only small amounts of labeled training data are available.

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The Paper: SeismoGen: Seismic Waveform Synthesis Using GAN with Application to Seismic Data Augmentation, Tiantong Wang, Daniel Trugman, and Youzuo Lin. Published in JGR Solid Earth. April, Volume 126, Issue 4, e2020JB020077, 2021. DOI: 10.1029/2020JB020077

The Funding: The research was supported by the Center for Space and Earth Science and the Laboratory Directed Research and Development program under project number of 20210542MFR at Los Alamos National Laboratory.

About Los Alamos National Laboratory

Los Alamos National Laboratory, a multidisciplinary research institution engaged in strategic science on behalf of national security, is managed by Triad, a public service oriented, national security science organization equally owned by its three founding members: Battelle Memorial Institute (Battelle), the Texas A&M University System (TAMUS), and the Regents of the University of California (UC) for the Department of Energy's National Nuclear Security Administration.

Los Alamos enhances national security by ensuring the safety and reliability of the U.S. nuclear stockpile, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to energy, environment, infrastructure, health, and global security concerns.