Category: Science

Hikers appear to have a strong negative influence on the movement of wildlife, research finds.

A study of Glacier National Park hiking trails during and after a COVID-19 closure adds evidence to the theory that humans can create a “landscape of fear,” as do other apex predators. Their presence seems to change how species use an area.

Researchers found that when human hikers were present, 16 out of 22 mammal species—predators and prey alike—changed where and when they used areas. Some completely abandoned places they previously used, others used them less frequently, and some shifted to more nocturnal activities to avoid humans.

“When the park was open to the public, and there were a lot of hikers and recreators using the area, we saw a bunch of changes in how animals were using that same area,” says Daniel Thornton, wildlife ecologist at Washington State University and senior author of the study in the journal Scientific Reports.

“The surprising thing is that there’s no other real human disturbance out there because Glacier is such a highly protected national park, so these responses really are being driven by human presence and human noise.”

The researchers had also expected to find an effect known as “human shielding,” in which human presence causes large predators to avoid an area, providing opportunity for smaller predators and perhaps some prey species to use an area more frequently. In this case, they found this potential effect for only one species, red fox. The foxes were more present on and near trails when the park was open–perhaps because their competitors, coyotes, avoided those areas when humans were around.

Several species showed a decline in use of trail areas when the park was open, including black bear, elk, and white-tailed deer. Many decreased their day-time activities, including mule deer, snowshoe hare, grizzly bears, and coyotes. A few, including cougars, seemed indifferent to human presence.

While the influence of low-impact recreation is concerning, the researchers emphasize that more research is necessary to determine if it has negative effects on the species’ survival.

“This study does not say that hiking is necessarily bad for wildlife, but it does have some impacts on spatiotemporal ecology, or how wildlife uses a landscape and when,” says Alissa Anderson, a recent master’s graduate and first author of the study. “Maybe they are not on the trails as much, but they’re using different places, and how much does that actually impact species’ ability to survive and thrive in a place, or not? There are a lot of questions about how this actually plays into population survival.”

The study came about in part because of the pandemic. Both humans and wildlife like to use trails, so the researchers had set up an array of camera traps near several trails to study lynx populations in Glacier National Park when COVID-19 hit. In an effort to keep the virus from spreading to the nearby Blackfeet Indian Reservation, the eastern portion of the park was closed in 2020 with only minimal access allowed to administrators and researchers.

This allowed Anderson, Thornton, and coauthor John Waller of Glacier National Park to conduct a natural experiment. They captured images in summer of 2020 when the park was closed as well as in 2021 when it opened again.

Glacier, which covers nearly 1,600 square-miles of northwestern Montana, sees more than 3 million human visitors a year. It is also home to diverse range of animals with almost the full complement of mammal species that has existed in the region historically.

Thornton says park managers are faced with a balancing act between conservation and public use missions.

“It’s obviously important that people are able to get out there, but there might be a level of which that starts to be problematic,” he says. “Some additional research could help get a better understanding of that and help develop some guidelines and goals.”

This study received support from the Glacier National Park Conservancy and the US Department of Agriculture.

Source: Washington State University

A new study of tectonic plate thickness across the Denali Fault in Alaska begins to fill major gaps in understanding about how geological faults behave and appear as they deepen.

When the rigid plates that make up the Earth’s lithosphere brush against one another, they often form visible boundaries, known as faults, on the planet’s surface.

Strike-slip faults, such as the San Andreas Fault in California or the Denali Fault in Alaska, are among the most well-known and capable of seriously powerful seismic activity.

Studying these faults can help geoscientists not only better understand the process of plate tectonics, which helped form the planet’s continents and mountains, but also better model their earthquake hazards.

The problem is that most studies on these types of faults are (quite literally) shallow, looking only at the upper layer of the Earth’s crust where the faults form.

For the new study, seismologists dug deeper into the Earth, analyzing how the part of the fault that’s near the surface connects to the base of the tectonic plate in the mantle. The scientists found that changes in how thick the plate is and how strong it is deep into the Earth play a key role in the location of Alaska’s Denali Fault, one of the world’s major strike-slip faults.

The findings could eventually help lead future researchers to develop better earthquake models on strike-slip faults, regions with frequent and major earthquakes.

“That means when geoscientists model earthquake cycles, they’ll have new information on the strength of the deeper rocks that would be useful for understanding the dynamics of these faults, how stress will build up on them, and how they might rupture in the future,” says Karen M. Fischer, geophysics professor at Brown University and author of the study in Geophysical Research Letters.

The paper focuses primarily on the Denali Fault, a 1,200-mile-long fault that arcs across most of Alaska and some of Western Canada. In 2002, it was the site of a magnitude 7.9 earthquake that sloshed lakes as far away as Seattle, Texas, and New Orleans.

The researchers used new data from a cutting-edge network of seismic stations to create a new 3D model of seismic wave velocities throughout Alaska. With this innovative tool, the researchers discovered changes in the thickness and internal strength of the tectonic plate that Alaska sits on. The model shows how these changes in plate strength, that extend as deeply as about 80 kilometers (about 49.7 miles), feed back into the mechanics of where the Denali fault line is produced.

Geoscientists have known that the Earth’s crust that is south of the Denali Fault is thicker, while north of the fault, the crust is thinner. What’s been less clear is data on changes in the deeper, mantle portion of the plate.

In the new study, the researchers documented for what is believed to be the first time that the Denali Fault forms because of an increase in strength on the northern side of the fault that goes all the way through the upper plate.

They found that when they looked at the base of the plate or lithosphere, the lithosphere is stronger and thicker on the northern side of the fault vs. being much thinner and weaker on the southern side. The deeper part of the plate to the north can act almost as a backstop, they describe in the paper. They conclude that the fault at the surface formed and stayed at the edge of this thicker, stronger lithosphere.

“There has been this controversy that faults in the shallower brittle crust wouldn’t connect to structures in the deepest part of the plate, but here we show that they do,” says lead author Isabella Gama, who completed the work last year while she was a PhD student in Brown’s earth, environmental, and planetary sciences department.

“And this could mean a variety of things. For example, it means that we could expect earthquakes occurring deeper than previously thought for strike-slip faults such as the Denali fault, and that plate motions could occur on clear boundaries that extend from shallow faults all the way to the base of the plate.”

The scientists’ avenue of research opened up when IRIS, a research consortium funded by the National Science Foundation and dedicated to exploring the Earth’s interior, deployed the EarthScope Transportable Array in Alaska from 2014 to 2021. The advanced technology—a large collection of seismographs installed temporarily at sites across the US—gave researchers like Gama and Fischer the capability to measure properties of the deeper crust and mantle that hadn’t been possible before.

The researchers next plan to look closer at other strike-slip fault lines around the world to see if they can find similar variations in the structure of tectonic plates the deeper they go.

Other well-known strike-slip fault lines include the San Andreas Fault in California and the Anatolian Fault in Turkey, both of which have caused major earthquakes in the past. The San Andreas Fault, for instance, caused the earthquake of 1906 in San Francisco that killed thousands.

“We hope that projects such as the EarthScope Transportable Array will continue to receive support so that we can obtain higher-resolution images of the Earth’s interior from anywhere on the planet,” Gama says. “We hope to gain a better understanding of plate tectonics by using these images and will begin by investigating how other strike-slip faults appear and behave, looking for parallels with Alaska. This information could then be fed back into improving models for how earthquakes occur.”

The National Science Foundation EarthScope Program funded the work.

Source: Brown University

People high in antagonistic personality traits—Machiavellianism, narcissism, and psychopathy—are more likely to endorse negative beliefs about homosexual and transgender people, research finds.

Those negative beliefs include the conviction that gay men should not be allowed to work with children and that gender affirmation surgery is morally wrong.

In an article in the Journal of Homosexuality, University of Oregon doctoral students Cameron Kay and Sarah Dimakis share insights into what types of people harbor prejudice against gay, nonbinary and transgender people, and why.

They report that much of the difference in the beliefs seen between people low in antagonistic personality traits and people high in antagonistic personality traits can be explained by the morals they emphasize or de-emphasize.

“People high in these traits seem to adopt these beliefs because they downplay the importance of equality and are less interested in protecting others,” says Kay, a personality psychologist.

“I’m really interested in why and how we categorize people as good or bad,” says Dimakis, a social psychologist who focuses on morality. “So, how we observe people’s behavior, make inferences about what they’re thinking, and then use that information to get the sense of who they are, whether they are a good person or someone to avoid.”

While this is not Kay and Dimakis’ first personality-based project, it hasn’t been without its challenges. For Dimakis, a difficulty has been gathering a balanced, representative sample.

“We’re not just looking for people who don’t hold prejudicial beliefs,” Dimakis says. “We also need to collect a sample of people who do hold prejudicial beliefs, and those people are difficult to obtain in the traditional samples that you can gather easily from undergraduate students.”

For Kay, gathering people with those prejudicial beliefs also has its flip side regarding the ethical restraints of the project.

“I think most people would agree that these beliefs are terrible,” Kay says. “You’re trying to assess these beliefs and you’re having to ask people, ‘Okay, do you believe in this thing?’ It can often be kind of a difficult situation.”

Kay says the findings from the project can help the psychology field develop solid concepts of prejudice and expand the connection between personality and prejudicial beliefs.

“At the broadest level, there is very little conceptualization of prejudice within personality,” Kay says. “It isn’t really thought of as an aspect of personality. In the past, people have shown that certain personality traits are associated with racism or associated with xenophobia towards immigrants, and this is kind of an additional piece in that puzzle, telling us there is a way we can predict prejudice. It’s through personality.”

Source: University of Oregon

Astronomers have captured a radio signal from a distant galaxy at a specific wavelength known as the 21 cm line.

With the help of the Giant Metrewave Radio Telescope in India, this is the first time this type of radio signal has been detected at such a large distance.

How do stars form in distant galaxies? Astronomers have long been trying to answer this question by detecting radio signals emitted by nearby galaxies. However, these signals become weaker the further away a galaxy is from Earth, making it difficult for current radio telescopes to pick up.

“A galaxy emits different kinds of radio signals. Until now, it’s only been possible to capture this particular signal from a galaxy nearby, limiting our knowledge to those galaxies closer to Earth,” says Arnab Chakraborty, a postdoctoral researcher at McGill University under the supervision of Matt Dobbs, a professor in the physics department.

“But thanks to the help of a naturally occurring phenomenon called gravitational lensing, we can capture a faint signal from a record-breaking distance. This will help us understand the composition of galaxies at much greater distances from Earth.”

“It’s the equivalent to a look-back in time of 8.8 billion years.”

For the first time, the researchers were able to detect the signal from a distant star-forming galaxy known as SDSSJ0826+5630 and measure its gas composition. The researchers observed the atomic mass of the gas content of this particular galaxy is almost twice the mass of the stars visible to us.

The signal the team detected was emitted from this galaxy when the universe was only 4.9 billion years old, allowing the researchers to glimpse into the secrets of the early universe.

“It’s the equivalent to a look-back in time of 8.8 billion years,” says Chakraborty.

“Gravitational lensing magnifies the signal coming from a distant object to help us peer into the early universe. In this specific case, the signal is bent by the presence of another massive body, another galaxy, between the target and the observer.

“This effectively results in the magnification of the signal by a factor of 30, allowing the telescope to pick it up,” says coauthor Nirupam Roy, an associate professor in the physics department at the Indian Institute of Science.

According to the researchers, these results demonstrate the feasibility of observing faraway galaxies in similar situations with gravitational lensing. It also opens exciting new opportunities for probing the cosmic evolution of stars and galaxies with existing low-frequency radio telescopes.

The study appears in the Monthly Notices of the Royal Astronomical Society.

The Giant Metrewave Radio Telescope was built and is operated by NCRA-TIFR. The research was funded by McGill University and the Indian Institute of Science.

Source: McGill University

Researchers are developing a dissolvable patch that uses antibodies grown from tobacco plants could prevent unwanted pregnancies and HIV.

When it comes to birth control options for women, little has changed in the past couple of decades. In fact, according to Planned Parenthood, there are only three birth control methods that are over 95% effective at preventing an unintended pregnancy: the birth control implant, the intrauterine device (IUD), and the birth control shot. All of them require time at a doctor’s office, and none of them protects against getting or spreading sexually transmitted infections. The “newest” of the trio—the Depo-Provera shot—started to become available to women in the 1990s.

“There’s a need for good on-demand nonhormonal contraceptives,” says Deborah Anderson, professor of medicine at the Boston University Chobanian & Avedisian School of Medicine. Anderson leads the university’s Contraceptive Research Center, which is one of only three federally mandated contraceptive labs in the country.

Anderson is working on the use of monoclonal antibodies—lab-made proteins that act like the body’s natural antibody defense system—as a means of protection. She calls her manufactured antibodies “plantibodies,” because they’re grown in tobacco plants.

Her team’s lab-made contraceptive and STI-prevention antibodies, though far from hitting the shelves of your local pharmacy, have been under development for more than a decade, with promising results coming from the first phases of clinical trials last year.

“Our ultimate goal is to have a contraceptive that also protects women against sexually transmitted infections,” Anderson says.

The center’s products are administered as topical films—almost like a Listerine strip—that go inside the vagina, dissolve, and quickly release monoclonal antibodies. The contraceptive film releases antibodies that target sperm, rendering them immobile before they can reach the ovaries. An STI-prevention film contains antibodies against herpes simplex virus (HSV) and human immunodeficiency virus (HIV), two viruses that, once contracted, stay with a person for life.

The two lines of monoclonal antibodies are being tested separately, with the goal of combining them to make an effective reversible birth control—that also provides protection from HIV and HSV. The research team is also working to make birth control applicable to people who don’t have vaginas.

“There is an enormous gender disparity in the use of and adherence to contraception,” says Matt Geib, a PhD student in the Boston University College of Engineering’s materials science and engineering division. He works with Anderson on optimizing the material of their dissolvable birth control film and is also researching how to use the antibodies in personal lubricants that can be marketed to men. “The burden most often lands directly on people who could get pregnant,” he says.

Abortion has become heavily restricted in the United States and some policymakers have also proposed limiting access to reproductive health care, including birth control. The race to create noninvasive, nonhormonal, reversible contraception has become even more urgent, Anderson says.

“Unintended pregnancies have so many adverse effects on women physically, economically, and psychologically,” Anderson says. “A lot of young women find themselves without protection.” It’s been estimated that about 48% of pregnancies worldwide are unintended, she points out.

“There is a huge gap in both accessibility of contraception and education on fertility management,” says Emilie Mausser, a PhD candidate in the medical school’s molecular and translational medicine program, who focuses on better understanding how the monoclonal antibodies interact with immune cells in the vagina, and how to make them more effective. “People should be able to access many contraceptive options and choose one that’s best for them,” she says.

The idea of using monoclonal antibodies as a means of contraception may sound revolutionary, but these sperm-attacking proteins have a surprisingly long history. Anderson was part of a team of scientists in the 1980s that tested over 200 monoclonal antibodies against sperm. The group narrowed the list down to the two most effective, Anderson says, and the one used in her work today is one of those original two.

Anderson partners with a small company in San Diego, California, ZabBio, to cultivate antibodies using tobacco plants. The leaves of the plant act almost like a Petri dish—the plant’s cells are given the human antibody genes, and the leaves produce the antibodies. Anderson and ZabBio used this technique to make anti-HIV and anti-HSV plantibodies first, and contraception plantibodies came next.

Data from the first clinical trial using plantibodies against HIV and HSV showed that it was safe and offered protection for 24 hours and possibly longer. They also tested the participants’ blood to make sure the antibodies were localized to the vagina, finding no trace of them elsewhere in the body. Those findings appear in PLOS Medicine.

The team recently completed a second clinical trial with the contraceptive antibody film. One of the methods used to test the effectiveness of a contraceptive is a postcoital test, Anderson says. Her lab partnered with Eastern Virginia Medical School, where eight heterosexual couples were evaluated, given an ovulation kit, and returned to the clinic for three consecutive months at peak fertility.

All of the women in the study were ligated (commonly called having their “tubes tied”), so there was no risk of accidental pregnancy; all of the men involved were fertile. The women would insert the contraception film, have sex, and then return to the clinic within two hours. They saw that in the month when the women applied the product, there were essentially zero motile (or moving) sperm in their cervical mucus, compared to about 50 per microscope field when it wasn’t used in the first and third month of the test.

“It was about as clear-cut as you can get,” Anderson says. The paper with those results is expected to be published soon.

She estimates that it will be another 5 to 10 years before their work is available to the public. By the end of the latest round of NIH funding, the team hopes to be ready to run a large efficacy clinical trial—when products are given to hundreds of women for real-life use, with close monitoring.

In the meantime, Anderson and the team plan to work on combining their contraception antibody with the STI-preventing antibodies, and create more birth control options for men—aiming to take the burden off women and make on-demand birth control more accessible to everyone.

“I am hoping that the future holds a wealth of new contraception options, not just male birth control,” Geib says. “We should always strive to give everyone an option. I hope that the future of contraceptives will hold less invasive, more effective, and more equitable options.”

A grant from the National Institutes of Health’s National Institute of Child Health and Human Development will support additional work on the project.

Source: Boston University

A new behavioral model explains a long-standing health care mystery: Why do so many terminally ill patients undergo intense last-ditch end-of-life treatments with little chance of meaningful life extension?

Surveys repeatedly indicate that nearly all people would rather die peacefully at home, yet painful, long-shot treatments remain common, and efforts to reduce usage have failed.

Previous analyses have mostly emphasized patients’ treatment preferences at the end of life. The new model, named the Transtheoretical Model of Irrational Biomedical Exuberance (TRIBE), focuses squarely on clinician psychology and family dynamics.

“Old models tended to assume that clinicians were purely rational agents, leading patients toward logical choices,” says Paul R. Duberstein, chair of the department of health behavior, society, and policy at the Rutgers University School of Public Health, and lead author of the study in the journal Social Science and Medicine.

“Once doctors have recommended a treatment or procedure, there’s enormous pressure on patients to undergo it.”

The TRIBE model combines two older theories—Socioemotional Selectivity Theory and Terror Management Theory—to explain why this happens. The model shows how emotional pressures on doctors and complex family dynamics provoke excessive efforts to cure incurable conditions.

“This model incorporates research showing that clinicians are emotional beings, like all people, and these emotions strongly impact their patients’ choices,” Duberstein says.

“Doctors hate to ‘give up’ on patients, so they often recommend treatments with very little chance of success. That won’t change until we improve medical education and the culture of irrational biomedical exuberance.”

“Irrational exuberance” is a term that economist Alan Greenspan famously used to describe investor sentiment in the lead-up to the dot-com crash, but Duberstein and his colleagues say it has long affected doctors and patients as much as it has affected Wall Street.

They read of one-in-a-million cures and irrationally believe that they or their patients will be that one in a million—just as people who purchase lottery tickets think they’ll be the lucky winners.

Pointing out the irrationality of the choice doesn’t affect doctors any more than it affects lottery players. Indeed, the researchers believe, it affects doctors less because, unlike gambling, which is often portrayed as a vice, the struggle to preserve life is typically portrayed as a virtue.

Motives to prescribe long-shot treatments are noble—to avoid death, save a life, “do all we can,” “fight a battle,” and “never give up.” In this view, failing to prescribe long-shot treatments is tantamount to abandoning patients and, for patients, failing to try these treatments is tantamount to abandoning loved ones.

The authors call for new approaches to clinical care and public education that will address the emotions that fuel useless treatments at the end of life.

“At some level, every patient death is a potential source of shame for doctors and a source of guilt for surviving family members,” Duberstein says. “By changing the culture of medical education and broader cultural attitudes toward death, we can address the emotions and family dynamics that have prevented too many patients from receiving quality care in their final days and weeks of life.”

Additional coauthors are from Tulane University, the University of Rochester, and Rowan University.

Source: Rutgers University

Climate change threatens the breeding success of songbirds, a new study shows.

Spring is normally the sweet spot for breeding songbirds in California’s Central Valley—not too hot, not too wet. But climate change models indicate the region will experience more rainfall during the breeding season, and days of extreme heat are expected to increase. Both changes are bad for songbird breeding.

The new study in the journal Biological Conservation details how extreme heat and rainfall patterns have affected songbirds along the Putah Creek Nestbox Highway in Yolo County.

While centered in the Central Valley, the study serves as a warning for other Mediterranean ecosystems.

“The changes happening in California’s Central Valley—increasing temperatures, wetter springs, greater variability—those impacts are happening across Mediterranean landscapes,” says lead author Jason Riggio, a postdoctoral scholar with the University of California, Davis Museum of Wildlife and Fish Biology. “In spaces where birds are already in an extremely variable climate, small changes will make a big difference.”

The study also offers signs that some birds adapt to modified systems. For example, western bluebirds and tree swallows are finding as much reproductive success in orchards near Putah Creek as in their natural habitat.

For these species, the orchards are not the ecological traps researchers initially expected them to be. Other species prefer to build their homes in riparian forest and grassland habitats.

Pockets of songbird breeding success

Climate models predict that regional precipitation is expected to decrease from October to January and to increase from February to April—pushing into the birds’ breeding season. Also, an estimated 5.4 degrees Fahrenheit (3 degrees Celsius) increase in average maximum temperature by 2100 will challenge species already at their temperature limits.

To study the impacts of these changes on songbirds, the researchers analyzed 11 years-worth of data collected by Nestbox Highway project staff and its cadre of undergraduate interns from the Museum of Fish and Wildlife. This included 2,305 nesting attempts and more than 7,100 nestlings across four species of cavity-nesting songbirds—western bluebirds, house wrens, tree swallows, and ash-throated flycatchers.

They found that bird fitness declined amid extreme precipitation or temperatures. Wetter nesting periods lowered reproductive success and nestling weight in house wrens, tree swallows, and western bluebirds. Higher temperatures during the breeding season also resulted in lower reproductive success and nestling weight for all four species.

“Across these results, it appears the effects of climate change in California’s Central Valley—and in Mediterranean systems globally—are likely to have broad and mostly negative impacts on cavity-nesting songbird reproduction,” Riggio says.

He adds that there are still pockets of songbirds doing well in both natural and modified habitats, and that protecting the fragments of habitat left can benefit species confronting environmental changes.

The Nestbox Highway

Study coauthor Melanie Truan, a research ecologist with the UC Davis Museum of Wildlife and Fish Biology, began the Nestbox Highway in 2000 as a graduate student in an effort to bring songbirds back to Putah Creek.

Many native cavity-nesting songbirds had lost their nesting opportunities as non-native birds increased and as large trees with the holes they favored were replaced by agricultural and other land uses. Western bluebirds, once abundant in the region, had become largely non-existent in the area.

Researchers installed 100 nestboxes that first year, attracting a family of bluebirds, among other birds. Now, more than 200 boxes draw hundreds of bluebirds—and several other bird species—to Putah Creek and the surrounding region. Staff and undergraduate interns check the boxes weekly to record the progress of nesting attempts, eggs, and nestlings. Before fledging, all nestlings are measured and banded.

“The Nestbox Highway project is the most uplifting and encouraging part of what I do,” says Truan. “I’m so happy this project that started as a let’s-see-what-happens conservation and education project is turning into something that can provide data for research.”

The study also highlights the importance of long-term data sets to help unravel the impacts of climate and land-use change on birds and other species.

The Solano County Water Agency funded the work. It would not have been possible without the support of participating landowners and land managers, and the interns and staff of the UC Davis Museum of Wildlife and Fish Biology.

Source: UC Davis

A new study provides a glimpse into dinosaur and bird diversity in Patagonia during the Late Cretaceous, just before the non-avian dinosaurs went extinct.

Fossils researchers have discovered represent the first record of theropods—a dinosaur group that includes both modern birds and their closest non-avian dinosaur relatives—from the Chilean portion of Patagonia.

The finds include giant megaraptors with large sickle-like claws and birds from the group that also includes today’s modern species.

“The fauna of Patagonia leading up to the mass extinction was really diverse,” says lead author Sarah Davis, who completed the work as part of her doctoral studies with Julia Clarke, professor at the University of Texas at Austin Jackson School of Geosciences geological sciences department. “You’ve got your large theropod carnivores and smaller carnivores as well as these bird groups coexisting alongside other reptiles and small mammals.”

The study appears in the Journal of South American Earth Sciences.

Since 2017, members of the Clarke lab, including graduate and undergraduate students, have joined scientific collaborators from Chile in Patagonia to collect fossils and build a record of ancient life from the region. Over the years, researchers have found abundant plant and animal fossils from before the asteroid strike that killed off the dinosaurs.

The new study focuses specifically on theropods, with the fossils dating from 66 to 75 million years ago.

Non-avian theropod dinosaurs were mostly carnivorous, and include the top predators in the food chain. This study shows that in prehistoric Patagonia, these predators included dinosaurs from two groups—megaraptors and unenlagiines.

Reaching over 25 feet long, megaraptors were among the larger theropod dinosaurs in South America during the Late Cretaceous. The unenlagiines—a group with members that ranged from chicken-sized to over 10 feet tall—were probably covered with feathers, just like their close relative the velociraptor. The unenlagiinae fossils described in the study are the southernmost known instance of this dinosaur group.

The bird fossils were also from two groups—enantiornithines and ornithurines. Although now extinct, enantiornithines were the most diverse and abundant birds millions of years ago. These resembled sparrows—but with beaks lined with teeth. The group ornithurae includes all modern birds living today. The ones living in ancient Patagonia may have resembled a goose or duck, though the fossils are too fragmentary to tell for sure.

The researchers identified the theropods from small fossil fragments; the dinosaurs mostly from teeth and toes, the birds from small bone pieces. The enamel glinting on the dinosaur teeth helped with spotting them among the rocky terrain, Davis says.

Some researchers have suggested that the Southern Hemisphere faced less extreme or more gradual climatic changes than the Northern Hemisphere after the asteroid strike. This may have made Patagonia, and other places in the Southern Hemisphere, a refuge for birds and mammals and other life that survived the extinction.

Davis says that this study can aid in investigating this theory by building up a record of ancient life before and after the extinction event.

These past records are key to understanding life as it exists today, says coauthor Marcelo Leppe, the director of the Antarctic Institute of Chile.

“We still need to know how life made its way in that apocalyptic scenario and gave rise to our southern environments in South America, New Zealand, and Australia,” he says. “Here theropods are still present—no longer as dinosaurs as imposing as megaraptorids—but as the diverse array of birds found in the forests, swamps and marshes of Patagonia, and in Antarctica and Australia.”

Additional coauthors are from the University of Chile, Major University, the University of Concepción, and the Chilean National Museum of Natural History.

Source: UT Austin

WASHINGTON — Engineers are troubleshooting thruster problems on a cubesat launched last month to search for water ice at the moon, the latest in a series of technical issues among small satellites recently launched to the moon and beyond.

In a Jan. 12 update, NASA’s Jet Propulsion Laboratory said that three of four thrusters on the Lunar Flashlight cubesat were underperforming, or producing less thrust than expected. One explanation, JPL said, was that there are obstructions in lines feeding propellant to the thrusters, reducing the amount of propellant reaching the thrusters and thus the thrust they produce.

Spacecraft controllers are planning to operate the thrusters for longer periods, hoping that will help clear any obstructions. If the thrusters’ performance can’t be restored, project managers are considering alternative approaches that would allow the spacecraft to reach the moon and carry out its mission. The spacecraft will need to start daily maneuvers in February to be able to enter orbit around the moon in about four months.

Lunar Flashlight is designed to go into a near-rectilinear halo orbit, similar to that used by the CAPSTONE cubesat that arrived at the moon in November and the future lunar Gateway. The orbit will take the cubesat as close as 15 kilometers above the surface at the south pole, where it to use lasers to look for water ice that may exist on the surface.

The cubesat’s propulsion system uses a “green” propellant called Advanced Spacecraft Energetic Non-Toxic (ASCENT), formerly known as AF-M315E. The propellant was successfully demonstrated on NASA’s Green Propellant Infusion Mission launched in 2019, but Lunar Flashlight is the first time ASCENT has been used on a mission beyond Earth orbit.

A change in propulsion systems for Lunar Flashlight during its development to one provided by the Georgia Institute of Technology caused the cubesat to miss its original launch opportunity as a secondary payload on the inaugural Space Launch System mission, Artemis 1. The cubesats had to be delivered to NASA to be installed on the rocket by the fall of 2021, and Lunar Flashlight’s propulsion system was not ready in time. NASA instead procured a rideshare launch opportunity, ultimately launching the spacecraft on a Falcon 9 Dec. 11 along with the Hakuto-R lunar lander from Japanese company ispace.

Artemis 1 launched Nov. 16 with 10 cubesat secondary payloads. More than half of them have experienced significant problems during launch. One example is LunaH-Map, a NASA-funded cubesat also designed to go into orbit to look for water ice. It has suffered a problem with a stuck valve in its electric thruster that is jeopardizing its ability to go into lunar orbit.

The mission’s principal investigator, Craig Hardgrove, said in mid-December that engineers thought that heating the valve would allow it to open and restore the thruster to normal operations. The mission has until mid-January to fix the thruster to enable the spacecraft to go into orbit around the moon, after which he said will instead look at opportunities to perform an asteroid flyby.

Several other cubesats have either reported problems or have failed to communicate at all with Earth. There is no obvious technical issue linking the problems with the cubesats.

In a new study, ants did not adjust their behavior in response to warming temperatures.

Instead, they persisted in less-than-ideal microhabitats even when optimal ones were present.

The findings suggest ants may not be able to adjust their behavior in response to warming ecosystems.

Ants are ectotherms—animals whose body temperature depends on the environment. While these animals experience a range of temperatures in daily life, most ectotherms prefer habitats that are slightly cooler than the so-called optimal functioning temperature in which an ectothermic animal is able to best perform all of life’s functions.

If it encounters an environment warmer than the optimal point, an ectotherm risks approaching the lethal end of its physiology’s spectrum. In other words, if it gets too hot, ectotherms will die.

Little is known, however, about how—or if—insect ectotherms will adjust their behavior to avoid warmer but sublethal temperature ranges—where functioning is physiologically possible but not optimal—which are increasingly likely due to global climate change.

To learn more about how insect species may respond to those warmer, sublethal temperatures, researchers at North Carolina State University studied five species of ants common in North Carolina.

The researchers counted and collected ants in forest ecosystems and measured air temperatures at the collection sites to identify the distribution of available microhabitats. The researchers also used a unique ant thermometer to measure the temperature of the ants themselves (which varied by ant color and body size). Lastly, to determine each species’ preferred temperature, the researchers collected some ants for the lab and placed them in a rectangular chamber with a controlled temperature gradient.

The researchers found that ants in the lab did have distinct thermal preferences, but ants in the field were active in their preferred climates only slightly more often than expected by chance. Instead, most species were collected in sites that were warmer than preferred, suggesting lack of awareness or some limitation in their ability to adjust to increasing temperatures.

“It’s interesting that the worker ants we observed were willing to put themselves in uncomfortable situations while foraging,” says Sara Prado, an adjunct professor and coauthor of the study in the Journal of Animal Ecology.

“I wonder if the food was ‘profitable’ enough for the ants to stretch their comfort levels, or if they are simply willing to sacrifice their well-being for the sake of the colony.”

“Warmer times and places make warmer ants, and they’re not adjusting their activity to match their preferred conditions,” says coauthor Elsa Youngsteadt, a professor of applied ecology.

“For now, this may be a tradeoff that works out fine for them. But if you think of the huge biomass of ants underfoot, their metabolic rates are all creeping upward as the climate changes. Even if it doesn’t kill them outright, what does that amped-up metabolism mean for their life cycle and even the whole forest ecosystem?”

Youngsteadt plans to further investigate this question with urban ants that are effectively living in the future of climate change in comparatively warm cities.

Additional coauthors are from Cornell University and NC State. The USDA National Institute of Food and Agriculture and North Carolina State University supported the work.

Source: NC State