Identifying risk factors for elevated anxiety in young adults during COVID-19 pandemic

Findings on impact of childhood temperament could help with anxiety prevention efforts

NIH/NATIONAL INSTITUTE OF MENTAL HEALTH

Research News

A new study has identified early risk factors that predicted heightened anxiety in young adults during the coronavirus (COVID-19) pandemic. The findings from the study, supported by the National Institutes of Health and published in the Journal of the American Academy of Child and Adolescent Psychiatry, could help predict who is at greatest risk of developing anxiety during stressful life events in early adulthood and inform prevention and intervention efforts.

The investigators examined data from 291 participants who had been followed from toddlerhood to young adulthood as part of a larger study on temperament and socioemotional development. The researchers found that participants who continued to show a temperament characteristic called behavioral inhibition in childhood were more likely to experience worry dysregulation in adolescence (age 15), which in turn predicted elevated anxiety during the early months of the COVID-19 pandemic when the participants were in young adulthood (around age 18).

"People differ greatly in how they handle stress," said Daniel Pine, M.D., a study author and chief of the National Institute of Mental Health (NIMH) Section on Development and Affective Neuroscience. "This study shows that children's level of fearfulness predicts how much stress they experience later in life when they confront difficult circumstances, such as the pandemic."

Behavioral inhibition is a childhood temperament characterized by high levels of cautious, fearful, and avoidant responses to unfamiliar people, objects, and situations. Previous studies have established that children who display behavioral inhibition are at increased risk of developing anxiety disorders later. However, less research has investigated the specific mechanisms by which a stable pattern of behavioral inhibition in childhood is linked to anxiety in young adulthood.

The authors of this study hypothesized that children who demonstrate a stable pattern of behavioral inhibition may be at greater risk for worry dysregulation in adolescence--that is, difficulties managing worry and displaying inappropriate expressions of worry--and this would put them at greater risk for later heightened anxiety during stressful events like the pandemic.

In the larger study, behavioral inhibition was measured at ages 2 and 3 using observations of children's responses to novel toys and interaction with unfamiliar adults. When the children were 7 years old, they were observed for social wariness during an unstructured free play task with an unfamiliar peer. Worry dysregulation was assessed at age 15 through a self-report survey. For the current study, the participants, at an average age of 18, were assessed for anxiety twice during the early months of the COVID-19 pandemic after stay-at-home orders had been issued (first between April 20 and May 15 and approximately a month later).

At the first assessment, 20% of the participants reported moderate levels of anxiety symptoms considered to be in the clinical range. At the second assessment, 18.3% of participants reported clinical levels of anxiety. As expected, the researchers found that individuals with high behavioral inhibition in toddlerhood who continued to display high levels of social wariness in childhood reported experiencing dysregulated worry in adolescence, and this ultimately predicted increased anxiety in young adulthood during a critical stage of the pandemic. This developmental pathway was not significant for children who showed behavioral inhibition in toddlerhood but displayed low levels of social wariness later in childhood.

"This study provides further evidence of the continuing impact of early life temperament on the mental health of individuals," said Nathan A. Fox, Ph.D., Distinguished University Professor and director of the Child Development Lab at the University of Maryland, College Park, and an author of the study. "Young children with stable behavioral inhibition are at heightened risk for increased worry and anxiety, and the context of the pandemic only heightened these effects."

The findings suggest that targeting social wariness in childhood and worry dysregulation in adolescence may be a viable strategy for the prevention of anxiety disorders. The findings also suggest that targeting dysregulated worry in adolescence may be particularly important for identifying those who might be at risk for heightened anxiety during stressful life events like the COVID-19 pandemic and preventing that heightened anxiety.

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Reference:
Zeytinoglu, S., Morales, S., Lorenzo, N., Chronis-Tuscano, A., Degnan, K. A., Almas, A. N., Henderson, H., Pine, D. S., Fox, N. A. (2021) A Developmental Pathway from Early Behavioral Inhibition to Young Adults' Anxiety During the COVID-19 Pandemic. Journal of the American Academy of Child and Adolescent Psychiatry. doi: 10.1016/j.jaac.2021.01.021

About the National Institute of Mental Health (NIMH):

The mission of the NIMH is to transform the understanding and treatment of mental illnesses through basic and clinical research, paving the way for prevention, recovery and cure. For more information, visit the NIMH website.

About the National Institutes of Health (NIH):

NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit the NIH website.

NIH...Turning Discovery Into Health®

#ASTROPORN

NASA's TESS discovers new worlds in a river of young stars

NASA/GODDARD SPACE FLIGHT CENTER

 NEWS RELEASE 12-FEB-2021

Research News

 

IMAGE: THIS ILLUSTRATION SKETCHES OUT THE MAIN FEATURES OF TOI 451, A TRIPLE-PLANET SYSTEM LOCATED 400 LIGHT-YEARS AWAY IN THE CONSTELLATION ERIDANUS. view more 

CREDIT: CREDIT: NASA'S GODDARD SPACE FLIGHT CENTER DOWNLOAD HIGH-RESOLUTION IMAGES FROM NASA'S SCIENTIFIC VISUALIZATION STUDIO

Using observations from NASA's Transiting Exoplanet Survey Satellite (TESS), an international team of astronomers has discovered a trio of hot worlds larger than Earth orbiting a much younger version of our Sun called TOI 451. The system resides in the recently discovered Pisces-Eridanus stream, a collection of stars less than 3% the age of our solar system that stretches across one-third of the sky.

The planets were discovered in TESS images taken between October and December 2018. Follow-up studies of TOI 451 and its planets included observations made in 2019 and 2020 using NASA's Spitzer Space Telescope, which has since been retired, as well as many ground-based facilities. Archival infrared data from NASA's Near-Earth Object Wide-Field Infrared Survey Explorer (NEOWISE) satellite - collected between 2009 and 2011 under its previous moniker, WISE - suggests the system retains a cool disk of dust and rocky debris. Other observations show that TOI 451 likely has two distant stellar companions circling each other far beyond the planets.

"This system checks a lot of boxes for astronomers," said Elisabeth Newton, an assistant professor of physics and astronomy at Dartmouth College in Hanover, New Hampshire, who led the research. "It's only 120 million years old and just 400 light-years away, allowing detailed observations of this young planetary system. And because there are three planets between two and four times Earth's size, they make especially promising targets for testing theories about how planetary atmospheres evolve."

A paper reporting the findings was published on Jan. 14 in The Astronomical Journal and is available online.

Stellar streams form when the gravity of our Milky Way galaxy tears apart star clusters or dwarf galaxies. The individual stars move out along the cluster's original orbit, forming an elongated group that gradually disperses.

In 2019, a team led by Stefan Meingast at the University of Vienna used data from the European Space Agency's Gaia mission to discover the Pisces-Eridanus stream, named for the constellations containing the greatest concentrations of stars. Stretching across 14 constellations, the stream is about 1,300 light-years long. However, the age initially determined for the stream was much older than we now think.

Later in 2019, researchers led by Jason Curtis at Columbia University in New York City analyzed TESS data for dozens of stream members. Younger stars spin faster than their older counterparts do, and they also tend to have prominent starspots - darker, cooler regions like sunspots. As these spots rotate in and out of our view, they can produce slight variations in a star's brightness that TESS can measure.

The TESS measurements revealed overwhelming evidence of starspots and rapid rotation among the stream's stars. Based on this result, Curtis and his colleagues found that the stream was only 120 million years old - similar to the famous Pleiades cluster and eight times younger than previous estimates. The mass, youth, and proximity of the Pisces-Eridanus stream make it an exciting fundamental laboratory for studying star and planet formation and evolution.

"Thanks to TESS's nearly all-sky coverage, measurements that could support a search for planets orbiting members of this stream were already available to us when the stream was identified," said Jessie Christiansen, a co-author of the paper and the deputy science lead at the NASA Exoplanet Archive, a facility for researching worlds beyond our solar system managed by Caltech in Pasadena, California. "TESS data will continue to allow us to push the limits of what we know about exoplanets and their systems for years to come."

The young star TOI 451, better known to astronomers as CD-38 1467, lies about 400 light-years away in the constellation Eridanus. It has 95% of our Sun's mass, but it is 12% smaller, slightly cooler, and emits 35% less energy. TOI 451 rotates every 5.1 days, which is more than five times faster than the Sun.

CAPTION

The Pisces-Eridanus stream spans 1,300 light-years, sprawling across 14 constellations and one-third of the sky. Yellow dots show the locations of known or suspected members, with TOI 451 circled. TESS observations show that the stream is about 120 million years old, comparable to the famous Pleiades cluster in Taurus (upper left).

CREDIT

Credit: NASA's Goddard Space Flight Cente

TESS spots new worlds by looking for transits, the slight, regular dimmings that occur when a planet passes in front of its star from our perspective. Transits from all three planets are evident in the TESS data. Newton's team obtained measurements from Spitzer that supported the TESS findings and helped to rule out possible alternative explanations. Additional follow-up observations came from Las Cumbres Observatory - a global telescope network headquartered in Goleta, California - and the Perth Exoplanet Survey Telescope in Australia.

Even TOI 451's most distant planet orbits three times closer than Mercury ever approaches to the Sun, so all of these worlds are quite hot and inhospitable to life as we know it. Temperature estimates range from about 2,200 degrees Fahrenheit (1,200 degrees Celsius) for the innermost planet to about 840 F (450 C) for the outermost one.

TOI 451 b orbits every 1.9 days, is about 1.9 times Earth's size, and its estimated mass ranges from two to 12 times Earth's. The next planet out, TOI 451 c, completes an orbit every 9.2 days, is about three times larger than Earth, and holds between three and 16 times Earth's mass. The farthest and largest world, TOI 451 d, circles the star every 16 days, is four times the size of our planet, and weighs between four and 19 Earth masses.

Astronomers expect planets as big as these to retain much of their atmospheres despite the intense heat from their nearby star. Different theories of how atmospheres evolve by the time a planetary system reaches TOI 451's age predict a wide range of properties. Observing starlight passing through the atmospheres of these planets provides an opportunity to study this phase of development and could aid in constraining current models.

"By measuring starlight penetrating a planet's atmosphere at different wavelengths, we can infer its chemical composition and the presence of clouds or high-altitude hazes," said Elisa Quintana, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "TOI 451's planets offer excellent targets for such studies with Hubble and the upcoming James Webb Space Telescope."

Observations from WISE show that the system is unusually bright in infrared light, which is invisible to human eyes, at wavelengths of 12 and 24 micrometers. This suggests the presence of a debris disk, where rocky asteroid-like bodies collide and grind themselves to dust. While Newton and her team cannot determine the extent of the disk, they envision it as a diffuse ring of rock and dust centered about as far from the star as Jupiter is from our Sun.

The researchers also investigated a faint neighboring star that appears about two pixels away from TOI 451 in TESS images. Based on Gaia data, Newton's team determined this star to be a gravitationally bound companion located so far from TOI 451 that its light takes 27 days to get there. In fact, the researchers think the companion is likely a binary system of two M-type dwarf stars, each with about 45% of the Sun's mass and emitting only 2% of its energy.

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TESS is a NASA Astrophysics Explorer mission led and operated by MIT in Cambridge, Massachusetts, and managed by NASA's Goddard Space Flight Center. Additional partners include Northrop Grumman, based in Falls Church, Virginia; NASA's Ames Research Center in California's Silicon Valley; the Center for Astrophysics | Harvard & Smithsonian in Cambridge, Massachusetts; MIT's Lincoln Laboratory; and the Space Telescope Science Institute in Baltimore. More than a dozen universities, research institutes, and observatories worldwide are participants in the mission.

NASA's Jet Propulsion Laboratory in Southern California manages NEOWISE for NASA's Science Mission Directorate in Washington. Ball Aerospace & Technologies Corp. of Boulder, Colorado, built the spacecraft. Science data processing takes place at IPAC at Caltech in Pasadena. Caltech manages JPL for NASA.

By Francis Reddy
NASA's Goddard Space Flight Center, Greenbelt, Md.

#ASTROPORN

Hubble uncovers concentration of small black holes

NASA/GODDARD SPACE FLIGHT CENTER

Research News

 

IMAGE: THE AMOUNT OF MASS A BLACK HOLE CAN PACK AWAY VARIES WIDELY FROM LESS THAN TWICE THE MASS OF OUR SUN TO OVER A BILLION TIMES OUR SUN'S MASS. MIDWAY... view more 

CREDIT: NASA, ESA, T. BROWN, S. CASERTANO, AND J. ANDERSON (STSCI)

Astronomers found something they weren't expecting at the heart of the globular cluster NGC 6397: a concentration of smaller black holes lurking there instead of one massive black hole.

Globular clusters are extremely dense stellar systems, which host stars that are closely packed together. These systems are also typically very old -- the globular cluster at the focus of this study, NGC 6397, is almost as old as the universe itself. This cluster resides 7,800 light-years away, making it one of the closest globular clusters to Earth. Due to its very dense nucleus, it is known as a core-collapsed cluster.

At first, astronomers thought the globular cluster hosted an intermediate-mass black hole. These are the long-sought "missing link" between supermassive black holes (many millions of times our Sun's mass) that lie at the cores of galaxies, and stellar-mass black holes (a few times our Sun's mass) that form following the collapse of a single massive star. Their mere existence is hotly debated. Only a few candidates have been identified to date.

"We found very strong evidence for an invisible mass in the dense core of the globular cluster, but we were surprised to find that this extra mass is not 'point-like' (that would be expected for a solitary massive black hole) but extended to a few percent of the size of the cluster," said Eduardo Vitral of the Paris Institute of Astrophysics (IAP) in Paris, France.

To detect the elusive hidden mass, Vitral and Gary Mamon, also of IAP, used the velocities of stars in the cluster to determine the distribution of its total mass, that is the mass in the visible stars, as well as in faint stars and black holes. The more mass at some location, the faster the stars travel around it.

The researchers used previous estimates of the stars' tiny proper motions (their apparent motions on the sky), which allow for determining their true velocities within the cluster. These precise measurements for stars in the cluster's core could only be made with Hubble over several years of observation. The Hubble data were added to well-calibrated proper motion measurements provided by the European Space Agency's Gaia space observatory which are less precise than Hubble's observations in the core.

"Our analysis indicated that the orbits of the stars are close to random throughout the globular cluster, rather than systematically circular or very elongated," explained Mamon. These moderate-elongation orbital shapes constrain what the inner mass must be.

The researchers conclude that the invisible component can only be made of the remnants of massive stars (white dwarfs, neutron stars, and black holes) given its mass, extent, and location. These stellar corpses progressively sank to the cluster's center after gravitational interactions with nearby less massive stars. This game of stellar pinball is called "dynamical friction," where, through an exchange of momentum, heavier stars are segregated in the cluster's core and lower-mass stars migrate to the cluster's periphery.

"We used the theory of stellar evolution to conclude that most of the extra mass we found was in the form of black holes," said Mamon. Two other recent studies had also proposed that stellar remnants, in particular, stellar-mass black holes, could populate the inner regions of globular clusters. "Ours is the first study to provide both the mass and the extent of what appears to be a collection of mostly black holes in the center of a core-collapsed globular cluster," added Vitral.

The astronomers also note that this discovery raises the possibility that mergers of these tightly packed black holes in globular clusters may be an important source of gravitational waves, ripples through spacetime. Such phenomena could be detected by the Laser Interferometer Gravitational-Wave Observatory experiment, which is funded by the National Science Foundation and operated by Caltech in Pasadena, California and MIT in Cambridge, Massachusetts.

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The Hubble Space Telescope is a project of international cooperation between NASA and ESA (European Space Agency). NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Image Credit: NASA, ESA, T. Brown, S. Casertano, and J. Anderson (STScI)

Science Credit: NASA, ESA, and E. Vitral and G. Mamon (Institut d'Astrophysique de Paris (IAP))

 

Computer love

Psychology professor's 'couple simulation' model helps us dive into the mysteries of mate selection

UNIVERSITY OF CALIFORNIA - SANTA BARBARA

Research News

 

In your quest for true love and that elusive happily ever after, are you waiting for the "right" person to come along, or do you find yourself going for the cutest guy or girl in the room, hoping things will work out? Do you leave your options open, hoping to "trade-up" at the next opportunity, or do you invest in your relationship with an eye on the cost-benefits analysis?

For something so fundamental to our existence, mate selection remains one of humanity's most enduring mysteries. It's been the topic of intense psychological research for decades, spawning myriad hypotheses of why we choose whom we choose.

"Mate choice is really complicated, especially in humans," said Dan Conroy-Beam(link is external), an assistant professor in the Department of Psychological and Brain Sciences at UC Santa Barbara, and author of a paper(link is external) in the journal Personality and Social Psychology Review. "And there have been a lot of people who have proposed abstract ideas about how it might happen."

One line of thinking, for instance, posits that we assess potential mates against an internal threshold of preferred qualities and attributes -- a "minimum bar," that they have to meet to be considered a potential partner.

"And we learn where that minimum bar is based on how other people treat us," he said. Another model describes the dating market somewhat like the European social dances of the 18th century.

"One side approaches the other side and they get these kinds of temporary relationships going," Conroy-Beam said. "And basically you stay in a relationship until you get a better offer and everybody kind of recurrently ditches their partners for better ones."

But these mate selection models, and others like them, don't capture a lot of the nuance that goes into real-life mate selection, Conroy-Beam noted.

"When you have a system that is particularly complicated like human mating markets are, verbal models are sometimes not such a great way to understand what's going on," he said. Competing desires and social dynamics play heavily into mate selection, he explained, adding layers of complexity and moving parts that can't be captured or quantified.

So what can hold human-like multiple levels of detail and complexity? The next best thing: a computer simulation. In an effort to move understanding of mate choice forward, Conroy-Beam has developed a new approach -- called "couple simulation" -- that essentially test-drives models of mate selection against the attributes and priorities of a sample of real-life couples.

"The real advantage that we have here is that we're going away from just these verbal models and into explicit computational models," he said. "We're directly simulating people's real choices; we're removing the limits of doing this in our own heads because we have computers that can keep track of all the very complicated interactions that are going on."

Sim Dating

The process begins by measuring the traits and preferences of a population of a few hundred couples -- real people who have made real-life mate choices. That data is crunched into simulated copies of each person -- "avatar agents" that have the same attributes and desires as their human counterparts, except in the simulated world they're single.

"We break them up and throw all these little agents into the market," said Conroy-Beam, who received support for his research from the National Science Foundation's Early CAREER program. "Then we run various algorithms and see which ones do the best job at putting them back together with the agent representing their real-world partner."

The algorithms represent different models of mate selection, which dictate the rules by which the agents can interact, based on the predictions of the model. In addition to the Aspiration Threshold Model (minimum bar) and the Gale-Shapley Algorithm (optimizing stable pairs), the team also used the Kalick-Hamilton Model (KHM), which assumes people choose mates according to their attractiveness, and a new model Conroy-Beam proposed called the Resource Allocation Model (RAM).

"It's thinking about mate choice in terms of investment of limited resources," he said. "So you've only got so much time and so much money and so much energy that you can dedicate to potential partners. And so your question as the person who's looking for a partner is 'who deserves most of these limited resources?'"

Conroy-Beam's model, it turns out, proved to be the most accurate, correctly matching approximately 45% of the couples in the simulated market in the very first runs of couple simulation. What makes the Resource Allocation Model work so well?

"There are a number of differences between RAM and the other models," he said. "The other models treat attraction like an on/off switch, but RAM allows for gradients of attraction. It also incorporates reciprocity: the more a potential mate pursues you, the more you pursue them in return," he said. The Gale-Shapley algorithm came in second, followed by the aspirational threshold model and then the KHM (attractiveness). Random pairings came in last.

It's still early days for couple simulation; after all, Conroy-Beam said, 45% right is still 55% wrong. For a first pass, however, 45% accuracy is impressive, and according to the study, the people in this cohort also report having higher-quality relationships (more satisfied, more committed, more love, less jealous) than the people in the inaccurately paired couples.

Conroy-Beam and his team at the Computational Mate Choice Lab at UCSB will continue to refine their models, which he calls "really rough sketches," to increase accuracy. They're hoping to soon conduct a longer term longitudinal study to see if couples that are accurately predicted differ in longevity.

"We hope to do this across cultures as well as to incorporate same-sex couples in the near future," he said. "We also have plans in the next couple of years to try to apply this to single people to prospectively predict their future relationships."

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This research was supported by NSF Early CAREER award 1845586

'Sex, lasers and male competition:' fruit flies win genetic race with rivals

Males with most impressive adornments have sperm that outcompetes rivals who mate first

"There aren't many studies more interesting than this one," Benoit said. "Sex, lasers, and male competition, which could describe most 1980s action movies."

UNIVERSITY OF CINCINNATI

Research News

 

IMAGE: UC RESEARCHERS STUDIED THE SEX COMBS OF THE FRUIT FLY DROSOPHILIA BIPECTINATA. view more 

CREDIT: MICHAL POLAK/UC

Scientists have accepted natural selection as a driver of evolution for more than 160 years, thanks to Charles Darwin.

But University of Cincinnati biologist Michal Polak says Darwin's book "The Descent of Man" only tells part of the story. Sometimes when the victor vanquishes his sexual rival, the quest to pass genes to the next generation is just beginning.

According to a new UC study published in the journal Current Biology, male fruit flies with the most impressive sexual ornamentation also have super sperm that can outcompete that of rivals in the post-mating fertilization game.

UC studied Drosophila bipectinata, a tiny red-eyed fruit fly from the South Pacific. The male's forelegs have a distinctive "sex comb," dark bristles that female fruit flies find appealing -- like the colorful train of a male peacock. Scientists previously found that female flies prefer males with more robust sex combs, which the males use to grasp the female's abdomen before mating.

UC researchers found a strong link between the most impressive sex combs and that male's competitive success at passing on his genes even after a female fly has mated with other flies. And this competitive edge persisted even after the male's sex comb was surgically removed with a high-precision laser in UC experiments.

"This is the first robust demonstration of a genetic link between a traditionally Darwinian trait and success in postcopulatory sexual competition," Polak said. "That's the surprising link: precopulatory and postcopulatory fitness."

CAPTION

UC biologist Michal Polak studies the competitive race to pass on 

genes that takes place after multiple males mate with a female.

CREDIT

Andrew Higley/UC Creative

In his groundbreaking 1859 book "On the Origin of Species," Darwin framed the idea of natural selection by describing how the "fittest" animals pass on their genes to the next generation. This fitness is manifested in having the largest antlers, the most vibrant colors or the vigor to defend a territory.

But Darwin's theory was incomplete, Polak said, because it failed to recognize that sexual selection continues during and after mating. Female fruit flies are promiscuous, often choosing multiple mates. Fruit flies are hardly alone in that regard, Polak said.

"Promiscuity is much more common across animal species than once was thought," Polak said. 

Scientists living in prim and proper Victorian England did not give enough consideration to the microscopic race to fertilize that begins after mating among multiple successful suitors.

"You have to consider the social context in which Darwin was living," Polak said. 

What females gain from mating with multiple suitors is not always clear, Polak said. But when they do, postcopulatory sexual selection provides a competitive edge.

"It's evident even in primates. Female chimpanzees and bonobos are promiscuous, so the males have large testes that produce big volumes of sperm," Polak said.

"And you have species like gorillas where females are not promiscuous. Silverback males enforce monogamy. And lo and be hold, their testes are much smaller relative to body size compared to chimps."

And if you're wondering, the relative size of human testes falls somewhere between gorillas and chimps, Polak said.

Polak, a professor of biology in UC's College of Arts and Sciences, decided to study this species of fruit fly after encountering it while conducting fieldwork in Queensland, Australia.

"I was watching these flies mate on a fruit and looked under the microscope and saw these beautiful sex combs. I thought it would make a good model system to study," Polak said.

"Sexual selection picks up on these traits and they become really exaggerated," he said.

CAPTION

UC researchers found a link between a fruit fly's sexual ornamentation and its success over rivals in fertilizing eggs. Pictured are UC graduate Kassie Hooker, left, and UC biologists Joshua Benoit and Michal Polak.

CREDIT

Andrew Higley/UC Creative

For their study, UC biologists artificially selected males with the largest and smallest sex combs in 11 successive generations of fruit flies to create high and low genetic lines.

Kassie Hooker from 2012 to 2015 worked in Polak's lab as an undergraduate biology student, undertaking the arduous task of categorizing generations of male fruit flies based on the size of the sex combs on their legs. By counting the teeth in each comb, she separated the males with the largest and smallest sex combs to create distinct genetic lines.

To show that the male fruit fly's sex comb doesn't provide any reproductive benefit in mating, researchers used ultraprecise lasers to trim the sex comb in the high line males to mimic those found in the low line males. But these postsurgical males continued to fertilize more eggs even when females mated with lower-line males first.

The research was supported by the National Science Foundation.

UC assistant professor Joshua Benoit, a study co-author, analyzed the RNA of the flies and identified seminal fluid genes that may be responsible for giving high-line males a fertilization advantage.

"There aren't many studies more interesting than this one," Benoit said.

"Sex, lasers, and male competition, which could describe most 1980s action movies."

Darwin proposed the theory of sexual selection to account for the evolution of male weaponry and extravagant ornamental displays, Polak said. But UC's study found a far more complex and interesting battle among the sexes.

"We established a link between Darwinian traits and the postcopulatory arena, which Darwin didn't recognize was important in evolution at all," Polak said.

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Electric transmission operators could benefit from temperature-dependent resource adequacy modeling

A new paper evaluates the PJM Interconnection, the largest electric transmission system operator by installed generation capacity and load in North America

CARNEGIE MELLON UNIVERSITY

Research News

How much does a power system's reliability depend on the temperature? Electric power system generator resource adequacy modeling is designed to help determine capacity requirements for electric power system operators across the United States. While calculating resource adequacy requirements has been done for a century, it requires ongoing attention as the generation mix is constantly expanding and changing. A new paper contributes to these ongoing reliability considerations by using a unique data set to determine how both low and high temperatures reduce the reliability of coal, gas, diesel, hydroelectric, and nuclear power generators and thus affect the amount of generation markets should contract for.

The paper, "Resource Adequacy Implications of Temperature-dependent Electric Generator Availability," by researchers at Carnegie Mellon University, was published in Applied Energy.

"Our focus is on better understanding the determinants of generator availability and incorporating these considerations into resource adequacy modeling," says Jay Apt, a Professor and Co-Director of the Carnegie Mellon Electricity Industry Center, who co-authored the paper. "Ultimately, this could improve a system operator's ability to determine how much generation is needed when the temperature is very cold or very hot."

The researchers evaluated the PJM Interconnection, the largest electric transmission system operator by installed generation capacity and load in North America, by making use of observed temperature-dependent forced outage rates over 25 years. Current grid resource adequacy modeling assumes that generator failures are unrelated to temperature, though this presents substantial resource adequacy risk. For example, in PJM's case, extreme weather events such as the Polar Vortex cold snap of 2014 added significant stress to the electric grid, suggesting that contrary to prevailing assumptions, generator failures are correlated. Further, assuming unconditional independence can lead to underestimating power system capacity requirements.

The researchers first determined that extreme temperatures, both hot and cold, resulted in less output from PJM's fleet. They then computed capacity requirements for PJM in two different scenarios for a 12-month period in 2018 and 2019. The first represented current practices wherein unconditional independence is assumed, and the second allowed for generator availability to depend on temperature. Additionally, they explored how accelerating changes to the resource mix (i.e.; moving from fossil fuels to solar and wind energy) and future temperature increases under climate change may affect resource adequacy at PJM.

Given the strong seasonality of extreme temperatures, the researchers considered whether monthly procurement targets would help PJM reduce capacity requirements as opposed to the current annual procurement model. They observed the accumulated loss of load expectation (LOLE) - the probability of a blackout due to insufficient power generation - during each calendar month under an annual procurement approach, using both unconditional and temperature-dependent forced outage rates. After accounting for temperature dependence of generator availability, they determined that monthly capacity procurement targets would substantially reduce annual average reserve procurement in PJM with negligible effect on LOLE. This, they explained, is because spring and fall months experience mild temperatures, leading to both lower loads and increased generator availability.

Ultimately, this analysis demonstrates the importance of considering temperature-dependent conditions in resource adequacy modeling. The sort of monthly or seasonal capacity procurement the authors propose could reduce PJM's reserve margin from the 26.6% reserve margin PJM procured in 2018-19 to 22.9%, representing a $315 million annual economic benefit. The authors note that further research is needed to account for the risk of lost load from generator outages during sustained extreme weather events, incorporate demand response resources, quantify operational flexibility needs, and allow system operators to better understand the value of procuring operating reserves.

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Summarized from "Resource Adequacy Implications of Temperature-dependent Electric Generator Availability," by Murphy, Sinnott (Carnegie Mellon University), Lavin, Luke (Carnegie Mellon University), and Apt, Jay (Carnegie Mellon University). It appears in Applied Energy, Volume 262, March 2020, published by Elsevier.

Copies of this paper are available to credentialed journalists upon request; please contact Elsevier's Newsroom at newsroom@elsevier.com or +31 20 485 2719.

Applied Energy provides a forum for information on innovation, research, development, and demonstration in the areas of energy conversion and conservation, the optimal use of energy resources, analysis and optimization of energy processes, mitigation of environmental pollutants, and sustainable energy systems. The journal publishes original papers, review articles, technical notes, and letters to the editor.

Authors are encouraged to submit manuscripts that bridge the gaps between research, development, and implementation. The breadth of coverage ranges from innovative technologies and systems of both fossil and renewable energy to the economic industrial and domestic use of energy with no or minor impact on the environment. Applied Energy is also concerned with the attendant problems of modeling and forecasting, conservation strategies, and the environmental, social, and economic impacts of energy policies and usage, including climate change mitigation and other environmental pollution reduction.

Study contradicts belief that whales learn songs from one another

New study calls into question widely held beliefs of imitation and cultural transmission among humpbacks. The provocative findings will probably make other whale researchers livid or dismissive, says UB researcher

UNIVERSITY AT BUFFALO

Research News

 

BUFFALO, N.Y. - Humpback and bowhead whales are the only mammals other than humans thought to progressively change the songs they sing through a process of cultural learning.

But maybe the humpbacks are no longer part of that trio. Humpbacks might be singing songs that are not as "cultured" as once assumed.

A new study by a University at Buffalo researcher is directly contradicting the widely accepted cultural transmission hypothesis suggesting that whales learn their songs from other whales.

"It seems like that is not correct," says Eduardo Mercado, a professor of psychology in UB's College of Arts and Sciences. "Our findings indicate that neither cultural transmission nor social learning contributes significantly to how humpback whales change their songs over time.

"I think the results are provocative and will probably make other whale researchers livid or dismissive, but at least the discussion won't be boring!"

The study, published Tuesday (Feb. 9) in the Journal of Comparative Psychology, analyzed songs from groups of humpbacks that were not in acoustic contact with each other, yet still produced acoustically comparable songs.

"The idea that humpback whales are a distinguished part of the animal kingdom because of their ability to culturally learn songs is apparently not true," says Mercado. "But to me, what the whales are doing is actually more impressive.

"Cultural transmission implies that what's heard is copied. That means it doesn't matter what is heard or what is copied. But what we found is very specific and precise, without a trace of arbitrary vocalization. The songs change over time in a fashion that's even more precise than what humans do when language develops."

The talented club DJ serves as an appropriate metaphor for changing whale song.

"DJs can't just randomly go from one song to the next," says Mercado. "They have to think about beat matching, tempo and mood in order to maintain a continuous flow.

"I think that might be true of the whales. When they make changes, they do so in relation to what preceded it. They're basically beat matching when they change songs - and we found similarities in populations that had no social contact or genetic links."

Mercado says existing research claims that humpback populations isolated from one another do not change their songs in the same way. Each population is original, taking their songs in original directions.

"These things are not true," says Mercado. "I compare songs over 40 years and compare populations that have never been in contact with one another, and they're doing basically the same thing."

Despite large and sometimes rapid changes, whales often end up singing similar songs, according to Mercado. The cultural transmission hypothesis is attractive in part because it's hard to imagine what mechanism might instigate the song variation.

But previous research has relied heavily on subjectively defined categories. Songs sounding like a human snore would be placed in a "snore" category. Any subsequent analysis would depend on how well the categories captured the intricacies of the song.

"I didn't categorize things at all and used purely acoustic measurements," says Mercado, who specifically chose published records of data to avoid any suggestion of cherry picking the data. "This paper is based on direct measurements of sound features without any categorization or subjective labeling."

Mercado says the results of the current study question the role of vocal imitation and cultural transmission in humpback whale song, but they do not resolve why the songs are changing.

"These results tell me that whales are sophisticated in ways that researchers and observers hadn't previously considered," says Mercado. "What we're hearing is a level of acoustic sophistication which is beyond the ability of humans.

"That's something that deserves both appreciation and further study. I'd like to examine why whale song changes and explore the benefit of that change."

 

Study suggests sounds influence the developing brain earlier than previously thought

JOHNS HOPKINS MEDICINE

Research News

 

FOR IMMEDIATE RELEASE

Scientists have yet to answer the age-old question of whether or how sound shapes the minds of fetuses in the womb, and expectant mothers often wonder about the benefits of such activities as playing music during pregnancy. Now, in experiments in newborn mice, scientists at Johns Hopkins report that sounds appear to change "wiring" patterns in areas of the brain that process sound earlier than scientists assumed and even before the ear canal opens.

The current experiments involve newborn mice, which have ear canals that open 11 days after birth. In human fetuses, the ear canal opens prenatally, at about 20 weeks gestation.

The findings, published online Feb. 12 in Science Advances, may eventually help scientists identify ways to detect and intervene in abnormal wiring in the brain that may cause hearing or other sensory problems.

"As scientists, we are looking for answers to basic questions about how we become who we are," says Patrick Kanold, Ph.D., professor of biomedical engineering at The Johns Hopkins University and School of Medicine. "Specifically, I am looking at how our sensory environment shapes us and how early in fetal development this starts happening."

Kanold started his career in electrical engineering, working with microprocessors, a natural conduit for his shift to science and studying the circuitry of the brain.

His research focus is the outermost part of the brain, the cortex, which is responsible for many functions, including sensory perception. Below the cortex is the white brain matter that in adults contains connections between neurons.

In development, the white matter also contains so-called subplate neurons, some of the first to develop in the brain -- at about 12 weeks gestation for humans and the second embryonic week in mice. Anatomist Mark Molliver of Johns Hopkins is credited with describing some of the first connections between neurons formed in white matter, and he coined the term subplate neurons in 1973.

These primordial subplate neurons eventually die off during development in mammals, including mice. In humans, this happens shortly before birth through the first few months of life. But before they die off, they make connections between a key gateway in the brain for all sensory information, the thalamus, and the middle layers of the cortex.

"The thalamus is the intermediary of information from the eyes, ears and skin into the cortex," says Kanold. "When things go wrong in the thalamus or its connections with the cortex, neurodevelopmental problems occur." In adults, the neurons in the thalamus stretch out and project long, armlike structures called axons to the middle layers of the cortex, but in fetal development, subplate neurons sit between the thalamus and cortex, acting as a bridge. At the end of the axons is a nexus for communication between neurons called synapses. Working in ferrets and mice, Kanold previously mapped the circuitry of subplate neurons. Kanold also previously found that subplate neurons can receive electrical signals related to sound before any other cortical neurons did.

The current research, which Kanold began at his previous position at the University of Maryland, addresses two questions, he says: When sound signals get to the subplate neurons, does anything happen, and can a change in sound signals change the brain circuits at these young ages?

First, the scientists used genetically engineered mice that lack a protein on hair cells in the inner ear. The protein is integral for transforming sound into an electric pulse that goes to the brain; from there it is translated into our perception of sound. Without the protein, the brain does not get the signal.

In the deaf, 1-week-old mice, the researchers saw about 25% - 30% more connections among subplate neurons and other cortex neurons, compared with 1-week-old mice with normal hearing and raised in a normal environment. This suggests that sounds can change brain circuits at a very young age, says Kanold.

In addition, say the researchers, these changes in neural connections were happening about a week earlier than typically seen. Scientists had previously assumed that sensory experience can only alter cortical circuits after neurons in the thalamus reach out to and activate the middle layers of the cortex, which in mice is around the time when their ear canals open (at around 11 days).

"When neurons are deprived of input, such as sound, the neurons reach out to find other neurons, possibly to compensate for the lack of sound," says Kanold. "This is happening a week earlier than we thought it would, and tells us that the lack of sound likely reorganizes connections in the immature cortex."

In the same way that lack of sound influences brain connections, the scientists thought it was possible that extra sounds could influence early neuron connections in normal hearing mice, as well.

To test this, the scientists put normal hearing, 2-day-old mouse pups in a quiet enclosure with a speaker that sounds a beep or in a quiet enclosure without a speaker. The scientists found that the mouse pups in the quiet enclosure without the beeping sound had stronger connections between subplate and cortical neurons than in the enclosure with the beeping sound. However, the difference between the mice housed in the beeping and quiet enclosures was not as large as between the deaf mice and ones raised in a normal sound environment.

These mice also had more diversity among the types of neural circuits that developed between the subplate and cortical neurons, compared with normal hearing mouse pups raised in a quiet enclosure with no sound. The normal hearing mice raised in the quiet enclosure also had neuron connectivity in the subplate and cortex regions similar to that of the genetically-engineered deaf mice.

"In these mice we see that the difference in early sound experience leaves a trace in the brain, and this exposure to sound may be important for neurodevelopment," says Kanold.

The research team is planning additional studies to determine how early exposure to sound impacts the brain later in development. Ultimately, they hope to understand how sound exposure in the womb may be important in human development and how to account for these circuit changes when fitting cochlear implants in children born deaf. They also plan to study brain signatures of premature infants and develop biomarkers for problems involving miswiring of subplate neurons.

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Funding for the research was provided by the National Institutes of Health's National Institute on Deafness and other Hearing Disorders (R01DC009607) and the National Institute of General Medical Sciences (R01GM056481).

Other scientists who contributed to the work include Xiangying Meng and Didhiti Mukherjee at Johns Hopkins and Joseph Kao of the University of Maryland School of Medicine. DOI: 10.1126/sciadv.abc9155

Dark-skinned teens, females prime targets of acne's psychological fallout

Acne treatment requires multidisciplinary approach, researchers say

UNIVERSITY OF CALIFORNIA - RIVERSIDE

Research News

 

A more aggressive approach to treating acne that marries the disciplines of psychology and dermatology is needed, according to two UC Riverside psychology researchers.

They also assert that women and people with darker skin disproportionately suffer from acne's psychological impacts.

"Acne is pervasive, physically harmless, and painless, so we all-too-often underestimate its impacts as the quintessential nuisance of adolescence and puberty," said UCR psychology professor Misaki Natsuaki, who authored the paper along with Tuppett Yates, also a UCR psychology professor.

The insinuation, including by developmental scientists, can be that hurtful monikers such as "pizza face" and "crater face" are best shrugged off.

But psychological effects of acne among adolescents are often "toxic," the researchers say. In advocating for a reconsideration of treatment, they allude to the prevalence of acne among adolescents - 20% suffer from moderate to severe acne, and 85% experience recurrent bouts.

"Acne can leave psychological scars, especially during adolescence when physical appearance becomes more salient for self-esteem, and internalizing psychopathology such as depression gains prominence," Natsuaki said.

Numerous studies show direct links between acne and depression, anxiety, and suicidal thoughts. Teens with acne have more difficulty forming friendships, finding romantic partners, and feeling connected to school. When shown a photograph of a teenager with facial acne, 65% of adolescents said skin was the first thing they notice. In a photo of a clear-skinned teen, youth said they noticed the skin first only 14% of the time. Young people attribute to adolescents who suffer acne traits such as "nerdy," "stressed," and "lonely."

And research has shown females experience negative psychological impacts at a rate higher than males.

"Aesthetic ideals of clear and unblemished skin are held by both sexes," the researchers wrote in their recent paper, "Adolescent Acne and Disparities in Mental Health," published by the journal Child Development Perspectives. "But females experience greater social pressure to attain these ideals than males."

Adolescents with darker skin color, many of whom come from ethnic-racial minority backgrounds in the United States, are likely to suffer disproportionate effects of acne because of heightened incidence of post-acne scarring and hyperpigmentation.

The authors argue that structural systems of inequality, which fuel health care disparities in the United States, further exacerbate acne and related psychosocial distress among individuals receiving public health insurance, who are more likely to belong to one or more ethnic-racial minority groups. The complex infrastructure of the health insurance system, uneven geographical density of health care providers, and reluctance to provide dermatology appointments to children with public insurance all contribute these disparities, the researchers wrote. In one study, only 29% of dermatology clinics schedule appointments with children on public insurance, whereas 96% of children with private insurance received appointments.

"According to dermatology research, the psychological burden of acne is on par with that of other serious illnesses, such as diabetes," Yates said. "Acne is a medical condition with clear psychological effects - effects that are non-randomly distributed as a function of gender, skin color, and socioeconomic status."

"So effective acne treatment rests at the intersection of medicine, psychology, and sociology."

The recently published study is a follow-up to a study Natsuaki published this past year. In that study, Natsuaki suggested that an effective-but-tightly-regulated acne medication, isotretinoin, should be revisited. Isotretinoin was associated with a higher incidence of adolescent suicide - a link some say was unwarranted - and Natsuaki asserted the benefits of the drug outweigh its risks.

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The research by Natsuaki and Yates was supported by a grant from the Academic Senate of the University of California.