Culture

Fossilized jaw bone fragments of a rat-like creature found at the Petrified Forest National Park in Arizona last year by a Virginia Tech College of Science Ph.D. candidate are in fact a newly discovered 220-million-year-old species of cynodont or stem-mammal, a precursor of modern-day mammals.

The finding of this new species, Kataigidodon venetus, has been published today in the journal Biology Letters by lead author Ben Kligman, a doctoral student in the Department of Geosciences.

"This discovery sheds light on the geography and environment during the early evolution of mammals," Kligman said. "It also adds to evidence that humid climates played an important role in the early evolution of mammals and their closest relatives. Kataigidodon was living alongside dinosauromorphs and possibly early dinosaurs related to Coelophysis -- a small bipedal predator -- and Kataigidodon was possibly prey of these early dinosaurs and other predators like crocodylomorphs, small coyote-like quadrupedal predators related to living crocodiles."

Kligman added that finding a fossil that is part of Cynodontia, which includes close cousins of mammals, such as Kataigidodon, as well as true mammals, from Triassic rocks is an extremely rare event in North America. Prior to Kligman's discovery, the only other unambiguous cynodont fossil from the Late Triassic of western North America was the 1990 discovery of a braincase of Adelobasileus cromptoni in Texas. Note that 220 million years ago, modern day Arizona and Texas were located close to the equator, near the center of the supercontinent Pangaea. Kataigidodon would have been living in a lush tropical forest ecosystem.

Kligman made the discovery while working as a seasonal paleontologist at Petrified Forest National Park in 2019. The two fossil lower jaws of Kataigidodon were found in the Upper Triassic Chinle Formation. Because only the lower jaws were discovered and are quite small -- half an inch, the size of a medium grain of rice -- Kligman only has a semi-picture of how the creature looked, roughly 3.5 inches in total body size, minus the tail.

Along with the jawbone fossils, Kligman found incisor, canine, and complex-postcanine teeth, similar to modern day mammals. Given the pointed shape of its teeth and small body size, it likely fed on a diet of insects, Kligman added. (Why are jaw fossils commonly found, even among small specimens? According to Kligman, the fossil record is "biased" toward only preserving the largest and most robust bones in a skeleton. The other smaller or more fragile bones -- ribs, arms, feet -- disappear.)

Kligman carried out field work, specimen preparation, CT scanning, conception, and design of the study
and drafting of the manuscript. He added that he and his collaborators only discovered the fossils were of a new species after reviewing the CT scan dataset of the jaws and comparing it to other related species.

"It likely would have looked like a small rat or mouse. If you were to see it in person you would think it is a mammal," Kligman added. Does it have fur? Kligman and the researchers he worked with to identify and name the creature actually don't know. "Triassic cynodonts have not been found from geological settings which could preserve fur if it was there, but later nonmammalian cynodonts from the Jurassic had fur, so scientists assume that Triassic ones did also."

The name Kataigidodon venetus derives from the Greek words for thunderstorm, "kataigidos," and tooth, "odon," and the Latin word for blue, "venetus," all referring to the discovery location of Thunderstorm Ridge, and the blue color of the rocks at this site. Kligman didn't name the creature, though. That task fell to Hans Dieter-Sues, coauthor and curator of vertebrate paleontology at the Smithsonian National Museum.

Additional collaborators include Adam Marsh, park paleontologist at Petrified Forest National Park, who found the jaw fossils with Kligman, and Christian Sidor, an associate professor at the University of Washington's Department of Biology. The research was funded by the Petrified Forest Museum Association, the Friends of Petrified Forest National Park, and the Virginia Tech Department of Geosciences.

"This study exemplifies the idea that what we collect determines what we can say," said Michelle Stocker, an assistant professor of geosciences and Kligman's doctoral advisor. "Our hypotheses and interpretations of past life on Earth depend on the actual fossil materials that we have, and if our search images for finding fossils only focuses on large-bodied animals, we will miss those important small specimens that are key for understanding the diversification of many groups."

With Kataigidodon being only the second other unambiguous cynodont fossil from the Late Triassic found in western North America, could there be more new species out there waiting to be found?

Kligman said most likely. "We have preliminary evidence that more species of cynodonts are present in the same site as Kataigidodon, but we are hoping to find better fossils of them," he added.

A world-first study on the Great Barrier Reef shows crown-of-thorns starfish have the ability to find their own way home--a behaviour previously undocumented--but only if their neighbourhood is stocked with their favourite food: corals.

Australian researchers observed the starfish emerging from their shelters in the afternoons so they could feed on coral during the night before returning home at dawn.

"The crown-of-thorns starfish often partied all night, slept-in and only those with a well-stocked larder found their way home--so it's very much a teenager model of behaviour," said lead author Dr Scott Ling from the Institute for Marine and Antarctic Studies at the University of Tasmania.

"Their preferred prey is Acropora corals," said co-author Professor Morgan Pratchett from the ARC Centre of Excellence for Coral Reef Studies at James Cook University (CoralCoE at JCU). Acropora is an important coral species--for the past two million years they have been the building blocks of reefs across the world.

"When populations of Acropora dropped, the starfish didn't return home," Prof Pratchett said. "Their behaviour is directly linked to the local abundance of Acropora."

The results of the study show healthy reefs with a high cover of these corals may encourage crown-of-thorns aggregations and outbreaks. The outbreaks cause extensive, widespread and sustained coral loss throughout the Indo-Pacific region.

Similar examples of predator infestations driving environmental devastation include sea urchins overgrazing on kelp forests and coral reef fishes munching through patches of seagrass.

The researchers used in-situ time-lapse photography to track the movements of 58 starfish in the northern and southern Great Barrier Reef during an outbreak in 2015. In the absence of their preferred Acropora coral prey, starfish were typically homeless and instead roamed up to 20 metres per day.

"Unlike sea urchins that can switch diet once they overgraze kelp forests, results of the time-lapse monitoring indicate that the starfish will consume available Acropora and ultimately eat themselves out of house and home before dispersing in search of new feeding grounds," Dr Ling said.

Previous outbreaks on the Great Barrier Reef were recorded in 1962, 1979, 1993 and 2009. Though mass-coral bleaching due to global warming is now the greatest threat to coral reefs worldwide, the combined impact of mass-bleaching and crown-of-thorns outbreaks is potentially catastrophic for coral reefs.

"By better understanding the behaviour of these starfish we can help prevent and control their outbreaks, which will help alleviate the pressures on coral reefs," Prof Pratchett said.

Gentoo penguins should be reclassified as four separate species, say scientists at the Milner Centre for Evolution at the University of Bath, after analysing the genetic and physical differences between populations around the southern hemisphere.

The researchers say that counting them as four separate species will aid in their conservation because it will make it easier to monitor any decline in numbers.

Gentoo penguins, with the Latin name Pygoscelis papua, live in a range of latitudes in the southern hemisphere and are currently split into two subspecies, P. p. ellsworthi and P. p. papua.

The researchers suggest these two sub species should be raised to species level and two new species created, which they have named P. poncetii after the Australian seabird conservationist Sally Poncet, and P. taeniata in recognition of a former proposal for this name dating to the 1920s.

Their study, published in the journal Ecology and Evolution, looked at the genomes of populations living in the Falkland Islands and South Georgia in the southern Atlantic Ocean, the South Shetland Islands in the Antarctic and Kerguelen Islands in the Indian Ocean.

They used genome data to create an evolutionary tree to understand the relationship between the different populations. When they combined these data with measurements of museum specimens from each of the populations, they found clear morphological (physical) and genetic differences between the four populations.

Dr Jane Younger, Prize Fellow from the Milner Centre for Evolution at the University of Bath, led the study. She said: "For the first time, we've shown that these penguins are not only genetically distinct, but that they are also physically different too.

"Gentoos tend to stick close to their home colonies, and over hundreds of thousands of years have become geographically isolated from each other to the point where they don't interbreed with each other, even though they could easily swim the distance that separates them.

"The four species we propose live in quite different latitudes - for example P. ellsworthi lives on the Antarctic continent whereas P. poncetii, P. taeniata and P. papua live further north where conditions are milder, and so it's not that surprising that they have evolved to adapt to their different habitats."

PhD student Josh Tyler said: "They look very similar to the untrained eye, but when we measured their skeletons we found statistical differences in the lengths of their bones and the sizes and shape of their beaks.

"It's a similar story to giraffes, which were revealed in 2016 to be four genetically distinct species."

The scientists say that regarding the four populations as separate species, gives conservationists a better chance of protecting their diversity because if there's a decline in one of them it will change the threat status as defined by the IUCN Red List.

Dr Younger said: "Currently gentoo penguins are fairly stable in numbers, however there is some evidence of the northern populations moving further south as the climate gets warmer, so we need to watch them closely."

The proposed changes to the classification of gentoos will be reviewed by an international committee of scientists which will assess all the evidence in the scientific literature before the new taxonomy is accepted.

Investigations of deceased COVID-19 patients have shed light on possible lung damage caused by the virus.

The study, published today in The Lancet's eBioMedicine, by King's College London in collaboration with University of Trieste and the International Centre for Genetic Engineering and Biology in Italy, shows the unique characteristics to the SARS-CoV-2 virus and may explain why patients suffer from 'long COVID'.

Patients with COVID-19 can experience symptoms such as blood clotting and loss of smell and taste. Some who survive the infection can experience the effects of the disease for months - known as 'long COVID' - with a feeling of fatigue and lack of breath. There have been a limited number of studies that have analysed the organs of COVID-19 patients which means the characteristics of the disease are still largely unknown.

Researchers analysed the organs of 41 patients who died of COVID-19 at the University Hospital of Trieste, Italy, from February to April 2020, at the start of the pandemic. The team took lung, heart, liver, and kidney samples to examine the behaviour of the virus.

Findings show extensive lung damage in most cases, with patients experiencing profound disruption of the normal lung structure and the transformation of respiratory tissue into fibrotic material.

Almost 90% of patients showed two additional characteristics that were quite unique to COVID-19 compared to other forms of pneumonia. First, patients showed extensive blood clotting of the lung arteries and veins (thrombosis). Second, several lung cells were abnormally large and had many nuclei, resulting from the fusion of different cells into single large cells. This formation of fused cells (syncytia) is due to the viral spike protein, which the virus uses to enter the cell. When the protein is present on the surface of cells infected by the COVID-19 virus, it stimulates their fusion with other normal lung cells, which can be a cause for inflammation and thrombosis.

Additionally, research showed the long-term persistence of the viral genome in respiratory cells and in cells lining the blood vessels, along with the infected cell syncytia. The presence of these infected cells can cause the major structural changes observed in lungs, which can persist for several weeks or months and could eventually explain 'long COVID'.

The study found no overt signs of viral infection or prolonged inflammation detected in other organs.

Professor Mauro Giacca, at the British Heart Foundation Centre at King's College London, said: "These findings are very exciting. The findings indicate that COVID-19 is not simply a disease caused by the death of virus-infected cells but is likely the consequence of these abnormal cells persisting for long periods inside the lungs."

The team is now actively testing the effect of these abnormal cells on blood clotting and inflammation and are searching for new drugs that can block the viral spike protein which causes cells to fuse.

Over the course of only a century, humanity has made an observable impact on the genetic diversity of the lion population. That's the conclusion of a recently published study by Drs. Caitlin Curry and James Derr from the Texas A&M University College of Veterinary Medicine & Biomedical Sciences.

By comparing the DNA of lions today to lions from 100 years ago, they found that there is clear genetic evidence of recent population fragmentation, which is when groups of a species are isolated from each other. This fragmentation could ultimately have a long-term impact on the genetic health of the iconic species. The research was published in the journal Molecular Biology and Evolution.

"I was surprised at what we found -- surprised and disappointed, because it's not what I wanted to see," Derr said. "I really wanted to be able to tell everyone that the management we've been doing for the last 100 years is perfect and to keep doing what we've been doing and everything will be fine. But that's not the take-home lesson; unfortunately, that's not the story we can tell.

Curry and Derr started their study with one overarching question: Has the genetic structure of lion populations changed over the last 100 years?

There have been several studies on modern lions, so gathering data for the modern populations was straightforward. Curry pulled together DNA data from three previously published studies on lions that lived between 1990-2012.

The historical populations, against which they wanted to compare the modern lion DNA, provided more of a challenge. Fortunately, scientists have a way to turn back time. Many of those lion remains still reside perfectly preserved in collections around the world. Curry used DNA extracted from bones, teeth and hides of 143 lions that lived between 1880-1949 to create a historical population data set.

Both population data sets cover the same geographical range from India to Southern Africa where lions are found. Scientists call this type of analysis, comparing data from the same space at different times, a spatiotemporal study.

No Room To Roam

It has been understood for a long time that female lions tend to stay close to the pride in which they were born, while males travel great distances to find new prides. Therefore, males are almost exclusively responsible for the movement of genes in the population, which helps keep genetic diversity within the species high.

As the human population continues to rapidly grow across Africa and more and more barriers to lion movement have gone up in the form of cities, fences and farmland, male lions haven't been able to travel the distances they once could.

According to Curry, while lions are still genetically diverse right now, the results in the DNA were more pronounced than she expected.

"In the historical population, you couldn't easily identify where a lion was from based on its nuclear DNA. This is due to high historical levels of gene flow across the population," she said. "But in the modern population, you can determine the general area, or sub-population, for most of the lions. But, even with sub-populations being more isolated, the overall level of genetic diversity is still considered high across all lion populations."

Consequences Of Low Genetic Diversity

If lions are still generally genetically healthy today, then why does this matter?

"Over the last 100 years or so, we have restricted the natural movements of many species," Derr said. "This isolation leads to reduced gene flow and ultimately may result in reducing genetic diversity to a level that threatens the survival of local populations."

Perhaps the most well-known example of what happens with a lack of genetic diversity is another large cat, the African cheetah.

According to genetic analysis, scientists believe cheetahs have suffered two large bottleneck events, or events that lead to a rapid shrinking of the gene pool. When these events happen, it results in the breeding of closely related individuals in the population, or inbreeding, creating very low genetic diversity.

This has led to a current cheetah population that, even in the wild, struggles to fend off new diseases, has difficulty breeding, and faces other significant health problems.

A Story Of Hope

But that fate can still be avoided in lions, especially now that experts are armed with proof that lion populations have been significantly impacted by isolation and subdivision.

"This should not be a disheartening story but rather one of hope," Curry said. "Yes, we see a decrease in genetic diversity across lion populations over the past century. But, currently, compared with other mammalian species, lion genetic diversity is still considered high across all lion populations.

"With responsible management focused on giving prides enough space to breed and allowing males to move more freely between isolated pockets, it is possible to increase the genetic diversity and reduce population sub-division across lion populations."

There have been multiple reintroduction programs bringing lions back to areas where lions once roamed, and coexistence strategies are increasingly being integrated into wildlife conservation programs.

"The positive take-home message is now that we've documented this and we understand it, policies can be tailored to manage these populations differently," Derr said. "We know now that you can't treat all lions the same. Now we have the responsibility to manage these animals, and many other managed wildlife species, in ways that better reflects their current biology."

The advent of genome science has given researchers an unprecedented ability to understand the root causes of a host of conditions. Justin Cotney, assistant professor of genetics and genome sciences in the UConn School of Medicine, has used this technology to identify a suite of genes and regulatory elements critical to normal heart development.

In a paper published in the October issue of Circulation Research, Cotney outlines the importance of "hub genes" in heart development. Hub genes operate like the hub of a wheel; they serve as the center from which many other "spokes" radiate and follow their lead in terms of when and to what extent they are expressed.

By studying a massive dataset of 125,000 control patients' genomes amassed from other studies in the Genome Aggregation Database (gnomAD), Cotney and his team identified a set of genes and regulators critical for heart development. These genes experience infrequent mutations, leading the researchers to conclude they are important to healthy development.

"You can't be a normal, healthy human with a mutation in these genes," Cotney says.

The heart develops between the first four to eight weeks of embryonic development. The researchers isolated this timeframe and looked at which parts of the genome were active.

"If you want to understand how the heart is built, that's where you need to look," Cotney says.

The genome contains approximately three meters of DNA within the six-micrometer nucleus. This means the DNA must be tightly packed when it is not in use. The researchers used machine learning to determine which sections of the DNA unraveled during this timeframe as indicated by histone modifications.

Cotney's team identified more than 100,000 regulatory sequences that are active during human heart development. More than 13,000 of these, around 10% of the total, had never been annotated as active in any human tissue or developmental stage. Their analysis of these regulatory elements and gene expression implicated more than 200 novel genes for heart development many likely to involved in congenital heart defects.

"There's still a lot about the genome we don't know," Cotney says.

Since these genes are involved in heart-specific expression, they also play a key role in the development of congenital heart defects, one of the most common birth defects. Other studies of the genetic mechanisms responsible for congenital heart defects have highlighted other genes than the ones captured by Cotney's study.

"These genes were generally being ignored to date, but we're saying it's something people should pay attention to," Cotney says.

By flagging these genetic elements, clinicians looking at a congenital heart defect patient's genome can identify which parts of their genome are likely responsible for the condition.

It is unlikely a single mutation causes a congenital heart defect. These genes are part of gene expression networks meaning when a defect occurs, it is likely the result of several related mutations.

Other studies have shown disrupting a single regulator rarely has a noticeable effect on an organism. Many regulatory elements are redundant, so if one is switched off, the organism can still develop normally.

While scientists have developed a rich database on the genes implicated in craniofacial development, that kind of knowledge about the heart is sorely lacking, making Cotney's work a groundbreaking contribution to the science.

"It's really one of the most comprehensive studies of chromatin and gene expression during human heart development," Cotney says.

The researchers have filed a patent for their findings that can be useful for companies that use genetic screening to diagnose congenital heart defects. Until now, they have been looking at other genes which are less precise indicators of the underlying problems. Furthermore, the industry lacks agreement on which genes are most relevant.

"What we found is quite novel," Cotney says. "We think the combination of these genes will be important in the future for the diagnosis of congenital heart defects."

The next step for this research is to look at the affected population to see if these genes are mutated as the researchers predict they will be. The team will also conduct experiments mutating certain parts of the genome to determine the influence they have on development.

"I think we're just scratching the surface," Cotney says.

These findings also have implications for evolutionary research looking at the hearts of other organisms, as the heart is one of the most rapidly evolving organs.

"We knew the power of our method to pull out the relevant biological information," Cotney says. "All that information was missing."

LOGAN, UTAH, USA -- Plastic has become ubiquitous in modern life and its accumulation as waste in the environment is sounding warning bells for the health of humans and wildlife. In a recent study, Utah State University scientist Janice Brahney cited alarming amounts of microplastics in the nation's national parks and wilderness areas.

Bioengineers around the world are working to develop plastic-eating "super" enzymes that can break down the man-made material's molecular structure faster to aid recycling efforts. In another research effort published in 2019, entomologists noted leaf-cutter bees were using plastic waste to construct their nests. The researchers suggested such behavior could be an "ecologically adaptive trait" and a beneficial recycling effort.

Not so fast, says USU evolutionary ecologist Joseph Wilson. Just because bees can use plastic, doesn't mean they should.

Wilson and undergraduate researcher Sussy Jones, along with colleagues Scott McCleve, a naturalist and retired math teacher in Douglas, Arizona, and USU alum and New Mexico-based independent scientist Olivia Carril '00, MS'06, jointly authored an observational paper in the Oct. 9, 2020 issue of 'Science Matters', exploring the nest building behavior of bees in the genus Megachile.

"Leaf-cutter bees are among the most recognizable of solitary bees, because of their habit of cutting circles out of leaves to build their cylindrical nests," says Wilson, associate professor of biology at USU-Tooele. "We've heard reports of these bees using plastic, especially plastic flagging primarily in construction and agriculture, and we decided to investigate."

The researchers don't yet know how widespread the use of plastic by leaf-cutter bees is and they also know little about plastic's effects on the insects.

"Building from plastic could change the dynamics and environment of the bee's nest cells, because plastic doesn't breathe like natural materials," says Wilson, who produced a video about the phenomenon. "In the 1970s, some researcher let leaf-cutter bees nest in plastic straws and found ninety percent of the bees' offspring died because of fungal growth. The plastic sealed in the moisture and didn't allow gas exchange."

To deter bees' use of flagging, Wilson suggests use of fabric ribbons made from natural fibers.

"These materials are biodegradable and, if used by bees, will likely avoid the harmful moisture-capturing effects of plastic," he says.

WASHINGTON, November 3, 2020 -- Certain molecules bind tightly to the surface of ice, creating a curved interface that can halt further ice growth. Some insects, plants, and sea-dwelling creatures contain protein molecules of this type that act as natural antifreeze agents, allowing the organisms to withstand freezing temperatures.

In The Journal of Chemical Physics, by AIP Publishing, scientists report a computational method to model ice binding using a biasing technique to drive the formation of ice in the simulation.

Antifreeze proteins act by binding to an existing interface between ice and liquid water. The resulting curved surface stops the growth of ice. There are also ice-nucleating molecules that catalyze the formation of ice from supercooled liquid water.

Both phenomena require an understanding of the way that molecules bind to ice. Understanding ice binding is important for applications as diverse as cryopreservation of organs and climate modeling, but no computational methods to efficiently model this phenomenon have existed to date.

"The central advantage of the ice-biasing simulation approach is that it simultaneously identifies the ice-binding surface, the face of ice it binds to, and the mode of binding," said author Valeria Molinero.

The investigators created two types of models. One type is an all-atom model that contains all the atoms in the liquid and ice phases of water as well as in the antifreeze-type molecule. The other type of model studied is called a coarse-grained model, which saves computational resources by blending atoms together into simpler structures.

The study looked at a number of molecules that bind ice, including polyvinyl alcohol, a synthetic ice-recrystallization inhibitor, as well as natural antifreeze proteins, such as one from the beetle Tenebrio molitor. Proteins present a simulation challenge, since they have very small surfaces that bind ice. This limits the size of the ice crystal they can bind.

Some systems possess more than one location where ice can bind. This is the case for the natural antifreeze protein in the sea-ice diatom Frailariopsis cylindrus. To determine whether a protein like this has more than one ice-binding surface, IBS, the investigators developed a method they dubbed "cap and repeat."

"In this strategy, we first performed a biased simulation to detect an IBS. Then, we cap that IBS to prevent ice formation on it and perform a second biasing simulation to find out whether ice forms in other sites," said Molinero.

The methods developed in this study show great promise for a number of applications, including finding molecules to protect frozen tissues during storage, furthering the understanding of natural antifreeze proteins, and in climate models, where ice nucleation in the atmosphere plays a key role.

Over 70 percent of U.S. adults have overweight or obesity. While primary care physicians (PCPs) are often the most immediate source of counseling for those trying to lose weight, most PCPs do not have the time, training, or support to guide their patients through a comprehensive weight loss program. Additionally, studies of online weight loss programs have found mixed levels of success. Population health management programs, which are delivered by non-clinical staff members, have emerged as supplemental support systems that offer outreach for preventive and chronic condition care needs, outside of primary care visits. Researchers from Brigham and Women's Hospital paired an online weight loss program with a phone- and email-based population health management program, a two-pronged strategy previously unexplored, and determined that patients in the combined program had greater weight loss over 12 months than patients in the other two groups. Findings are published in the JAMA.

"Population health managers are already doing outreach to people who would benefit from weight loss, such as patients with hypertension or type 2 diabetes," said corresponding author Heather Baer, ScD, an associate epidemiologist in the Division of General Internal Medicine and Primary Care at the Brigham. "The idea was to leverage population health management, which is a strategy that's been implemented at the Brigham and in other institutions, to see if it could be integrated with an online weight loss program and be sustainable over time."

The study followed 840 patients in the Brigham's Primary Care Center of Excellence, a network of 15 practices, between 2016 and 2019. Participants, all of whom either had overweight or obesity and hypertension or type 2 diabetes, were divided into three study groups. The "usual care" group received general information about weight management in the mail; the "online only" group participated in an online weight-loss program, which included meal plans, activity trackers, and progress reporting features; and the "combined intervention" group participated in the online program while receiving additional outreach and support from non-clinical staff members monitoring their progress.

Over the course of 12 months, the usual care, online only, and combined intervention groups lost an average of 2.7 pounds, 4.1 pounds, and 6.9 pounds, respectively. The researchers found that the combined intervention produced a small but statistically significant increase in weight loss compared to the other two methods. Moreover, participants in the combined intervention group decreased their body weight by an average of 3 percent, a statistically significant difference from the 1.4 and 1.9 percent decreases found in the usual care and online only groups.

The researchers acknowledge that while the amount of weight loss is fairly low, clinically significant health benefits are associated with a 3-5 percent decrease in weight among individuals with overweight or obesity. Approximately one third of participants in the combined intervention group lost 5 percent or more of their weight, compared to only 14.9 and 20.8 percent of participants in the usual care and online only groups, respectively. Moreover, the weight loss in the combined intervention group was also found to be maintained at 18 months, in spite of the fact that active interventions ceased after 12 months.

"Our findings suggest that the combined intervention facilitates potentially sustainable weight loss in the long term," Baer said. She notes that the generalizability of the team's findings is limited, given that the the majority of participants were white, well-educated, and English-speaking. Nevertheless, the combined intervention approach may offer an effective form of weight management that is more easily available to some patients who may face barriers in accessing traditional in-person care.

The results are especially notable as health care increasingly shifts to virtual forms amidst the COVID-19 pandemic. "We knew that online weight loss programs can be more convenient, accessible, and cheaper for patients, but now both physicians and patients have become more comfortable with the idea of care being delivered virtually," Baer said. "Virtual care is going to stay with us post-pandemic, and this study provides more evidence that even pre-pandemic, virtual care for some conditions is working."

What The Study Did: This observational study estimates the 10-year risk for disease progression, surgery, metastasis, and cause-specific and all-cause mortality among African American men with low-risk prostate cancer managed with active surveillance.

A novel method to sample earwax could be a cheap and effective way to measure the hormone cortisol, according to a study led by researchers at UCL and King's College London.

The findings, published in the academic journal Heliyon, could point to new ways of monitoring depression and stress-linked conditions.

The new device can be used at home without clinical supervision, facilitating medical check-ups while maintaining social distancing due to COVID-19, and may also have the potential to measure glucose or COVID-19 antibodies that accumulate in earwax.

Lead researcher Dr Andres Herane-Vives (UCL Institute of Cognitive Neuroscience and Institute of Psychiatry, Psychology & Neuroscience, King's College London) said: "Cortisol sampling is notoriously difficult, as levels of the hormone can fluctuate, so a sample might not be an accurate reflection of a person's chronic cortisol levels. Moreover, sampling methods themselves can induce stress and influence the results.

"But cortisol levels in earwax appear to be more stable, and with our new device, it's easy to take a sample and get it tested quickly, cheaply and effectively."

Cortisol has been considered as a possible biomarker, or objective biological measure, for depression, but researchers have been stymied by challenges in accurately measuring cortisol levels. The most common technique is with hair samples, but they are more subject to short-term fluctuations in cortisol, and not everyone has enough hair for a reliable sample.

It is also more time-consuming and expensive to analyse hair samples, compared to earwax, but until now there has not been a reliable and non-stressful method to sample earwax.

To develop the new device, Dr Herane-Vives was inspired by another natural wax, honeycomb from bees, as it is known to be well-preserved and resistant to bacterial contamination. Earwax has similar properties, making it well suited for home sampling, as samples can be sent to a lab by post without much risk of contamination.

The novel earwax self-sampling device is similar to a cotton swab, but with a brake that stops the swab from going too far into the ear and causing damage. The tip is covered with a sponge of organic material, with a solution that has been tested to be the most effective and reliable at taking samples.

In their pilot study, Dr Herane-Vives and a team of researchers from the UK, Chile and Germany brought in 37 study participants to test different cortisol sampling techniques. The research team sampled participants' earwax using a standard syringe procedure, known to be somewhat painful, and then followed up a month later by using the same sampling in one ear, and the novel sampling technique in the other ear, which the participants could administer themselves. The researchers also analysed hair and blood samples from the same participants.

The researchers found that earwax samples yielded more cortisol than hair samples, and the new technique was the fastest and potentially cheapest method. The novel technique was the least influenced by confounding factors such as stressful events or alcohol consumption contributing to cortisol fluctuations over the previous month. In another recent study, participants rated the new self-sampling device as more comfortable than traditional methods.

Dr Herane-Vives is now setting up a company, Trears, to bring his earwax sampling device to market, with support from the UCL Hatchery startup incubator.

He and his team are also investigating whether the device could be useful to measure glucose levels from earwax samples, for monitoring of diabetes, and potentially even COVID-19 antibodies.

Dr Herane-Vives said: "After this successful pilot study, if our device holds up to further scrutiny in larger trials, we hope to transform diagnostics and care for millions of people with depression or cortisol-related conditions such as Addison's disease and Cushing syndrome, and potentially numerous other conditions."

New findings from researchers at Washington University School of Medicine in St. Louis suggest the eye's cornea can resist infection from the novel coronavirus. Although the herpes simplex virus can infect the cornea and spread to other parts of the body in patients with compromised immune systems, and Zika virus has been found in tears and corneal tissue, SARS-CoV-2, the virus that causes COVID-19, does not appear to replicate in the human cornea.

The researchers have yet to determine, however, whether other tissue in and around the cornea, such as the tear ducts and the conjunctiva, are vulnerable to the virus.

The new findings are published Nov. 3 in the journal Cell Reports.

"Our findings do not prove that all corneas are resistant," said first author Jonathan J. Miner, MD, PhD. "But every donor cornea we tested was resistant to the novel coronavirus. It's still possible a subset of people may have corneas that support growth of the virus, but none of the corneas we studied supported growth of SARS-CoV-2."

Miner, an assistant professor of medicine, of molecular microbiology and of pathology and immunology, teamed up with ophthalmologist Rajendra S. Apte, MD, PhD, to study mouse and human corneas exposed to the herpes simplex, Zika and SARS-CoV-2 viruses.

"Some COVID-19 patients get eye symptoms, such as conjunctivitis (pinkeye), but it's not clear that the viral infection itself causes that; it could be related to secondary inflammation," said Apte, the Paul A. Cibis Distinguished Professor in the John F. Hardesty Department of Ophthalmology & Visual Sciences. "The cornea and conjunctiva are known to have receptors for the novel coronavirus, but in our studies, we found that the virus did not replicate in the cornea."

Prior research in human and mouse corneal tissue had demonstrated that Zika virus could be shed in tears, and the researchers wanted to learn whether the cornea might serve as an entry point for SARS-CoV-2. Apte, Miner and their colleagues tested that by exposing the eye tissue to the different viruses and observing whether they could grow in and replicate. They also identified key substances in corneal tissue that can promote or inhibit viral growth.

One inhibitor they identified is called interferon lambda. They found that interferon lambda prevented efficient growth of Zika virus and herpes simplex virus in the cornea. But with SARS-CoV-2, levels of the substance had not effect on whether the virus could replicate. It simply could not gain a foothold whether interferon lambda was present or not.

That's reassuring to Apte, also a professor of developmental biology and of medicine, who said it suggests COVID-19 probably cannot be transmitted through a cornea transplant or similar procedures in the eye.

"Our data suggest that the novel coronavirus does not seem to be able to penetrate the cornea," Apte said.

Miner added, however, that because of unknowns involving the tear ducts and the conjunctiva, it's too soon to dismiss the importance of eye protection.

"It's important to respect what this virus is capable of and take appropriate precautions," he said. "We may learn that eye coverings are not necessary to protect against infection in the general community, but our studies really are just the beginning. We need larger clinical studies to help us better understand all the potential routes of SARS-CoV-2 transmission, including the eye."

Professor Xie Guangming's group in the College of Engineering at Peking University has found a simple yet previous unknown rule, explaining how do schooling fish save energy in collective motion. The related work has been published in Nature Communications.

Collective behaviour has drawn a great interest to biologists. A well-known example is that geese fly in "V"-shape or "-"-shape formations in long-distance migrations to reduce drag and thus to save energy. Similarly, as it is a common phenomenon that fish swim in schools, can fish also save energy by swimming in groups? Since Daniel Weihs (1973) proposed a possible energy-saving mechanism for schooling fish, the investigation of energy-saving mechanisms in collective underwater swimming has attracted a long and widespread interest among biologists and roboticists. The former want to reveal the essential mechanisms behind natural phenomena, while the latter want to learn from nature and apply them in the field of engineering. However, it is still not known whether, and if so, how, schooling fish can save energy by interacting with the vortices shed by neighbours.

Professor Xie's group used the high fidelity bio-inspired robotic fish developed by themselves as a physical experimental model to explore the mechanism. They conducted over 10,000 trials on collective swimming robotic fish in the low-turbulence flow tank platform at the State Key Laboratory of Turbulence and Complex Systems, Peking University. A simple rule was found to explain how the follower can save energy by adjusting its body undulation relative to the leader. In order to verify whether this rule is also adopted by real fish, Professor Xie's group, together with Professor Iain D. Couzin's group at the Max-Planck-Institute of Animal Behaviour, Germany, analysed the relationship between the formation and relative undulations of fish bodies at different swim speeds, and verified that this simple rule is also used by real fish for saving energy. In particular, after impairing the vision and lateral line perception in real fish, they found that real fish do not require complex perception and brain processing to adopt this rule, indicating this rule might be universal in biological systems.

These results not only suggest a potential energy-saving mechanism for fish school, but also can inspire roboticists to design control algorithms for underwater robot swarm.

Few beef producers in the temperate climate of southern Australia will have encountered the parasitic buffalo fly (Haematobia irritans exigua), a scourge of the cattle industry in the country's tropical and subtropical north - but maintaining this state of affairs, and also lifting a burden off the northern industry, has become a race against time, and climate.

Buffalo fly is a serious animal health and production challenge, costing the northern Australian cattle industry almost $100 million a year in treatments and lost production. But control of the pest with insecticides is running into increasing resistance, plus there is a need to protect Australian beef's 'clean green' reputation and so minimise the need for pesticides.

Over the past century the buffalo fly has been creeping southwards through Queensland to northern New South Wales and modelling shows that, aided by climate change, it could reach as far south as South Australia and south-west Western Australia by 2030. The blood-sucking fly causes large, painful sores and distressed animals can be distracted from feeding enough to seriously affect growth.

The only obstacle in its path is a joint university, industry and Queensland Government biological control project using the insect-infecting bacterium, Wolbachia - the same agent that has been used so successfully to suppress mosquito-transmitted dengue fever in humans.

The project is led by Dr Peter James from the Queensland Alliance for Agriculture and Food Innovation (QAAFI) at The University of Queensland, who explains the key is using the Wolbachia bacterium to break the fly's breeding cycle. If this can be sustained it presents an opportunity to both suppress the buffalo fly population in the north and stop its spread southwards.

The buffalo fly is a formidable foe, having been introduced from Asia into the Northern Territory in the late 1830s, but the chink in its armour is it weakens in cold weather. Its populations tend to shrink into localised pockets. Dr James says if Wolbachia can be used to further stress the buffalo fly in winter, then a local eradication strategy starts to become a real possibility.

But there are some considerable technical challenges still to overcome. Because the bacterium is spread vertically from mother to offspring, not transferred sideways amongst flies, buffalo flies have to be artificially infected by microinjection. With mosquitoes, this is usually done by microinjection into the eggs. That approach hasn't been able to be used for buffalo fly because the eggs are extremely hard: "When we started micro-injecting eggs, as is done with mosquitoes, we were blunting needles and damaging the eggs like you wouldn't believe. Needles were even breaking," says Dr James.

"So from there we looked at micro-injecting adult flies or pupae, the idea being the bacterium would still spread through the insect and get into the germinal tissue of the females."

He says the main thing is to establish the bacterium in the population because once flies are infected, three control scenarios open up. While Wolbachia is a maternally transmitted bacterium, through eggs, male flies can still be used to manipulate this.

If a Wolbachia infected male mates with a healthy female the eggs will be infertile and so no offspring. Conversely, if a healthy male mates with an infected female the mating will be successful with eggs and offspring produced, but they will be carrying Wolbachia and help to spread it through the buffalo fly population. Dr James says the advantage of this is that it saves researchers having to otherwise breed and release millions of infected or sterile flies.

"But Wolbachia also has a whole lot of other impacts on fly population fitness. We have shown that just the presence of the bacterium can shorten the buffalo flies' lifespan, reduce the number of eggs laid, and the number of pupae that hatch. There are probably also other fitness penalties that we haven't yet identified. If you start to add up all these impacts, that can be a heavy load on survivability.

"And this is where the winter factor comes. In many areas the buffalo fly only just hangs on in low numbers through winter so even Wolbachia's effect on population fitness could be enough to wipe out these populations if the bacterium is deployed strategically."

A second approach is to use Wolbachia to block transmission of the Stephanofilaria nematode transmitted by buffalo flies and associated with the development of buffalo fly lesions on the cattle. Similar to the way that Wolbachia blocks transmission of dengue virus, zika virus and a number of other viruses transmitted by mosquitoes, it has also been shown to block transmission of some nematodes closely related to Stephanofilaria. Spread of Wolbachia through the buffalo fly population could block the nematode and alleviate lesion development

A third option being explored is to breed and release sterile males.

"Again, the idea is to use the sterile males strategically by releasing them into those overwintering areas that are already in a weakened state. This could stop or slow the build-up of buffalo fly in the next season or stop the southerly spread or even provide the basis of local eradication strategies."

Dr James says the challenge now is to improve the consistency and persistence of Wolbachia infection. Since the Wolbachia project started in 2017 researchers have achieved the first big challenge of taking different Wolbachia strains from mosquitoes and also fruit fly and introducing them into a whole new species, the buffalo fly: "Wolbachia has been carried across generations in a number of instances, but we have yet to produce a stably infected strain," he explains.

"But we have reached the stage where we can start finessing the approach. For example we have a project looking at ways to immunosuppress the fly to favour Wolbachia infection.

"We've built up a reasonable toolbox so I am confident we are close to providing sustainable biological control that will deliver economic animal welfare relief to the northern cattle industry, and save the southern industry from ever having to endure the same burden."

Ants use their own acid to disinfect themselves and their stomachs. A team from Martin Luther University Halle-Wittenberg (MLU) and the University of Bayreuth has found that formic acid kills harmful bacteria in the animal's food, thereby reducing the risk of disease. At the same time, the acid significantly influences the ant's intestinal flora. The new study was published in the journal eLife.

Formic acid is one of the simplest organic acids. It is produced in a special gland in the abdomen of numerous species of ant. "There was a long-standing assumption that the acid only served to ward off predators, for example insects and birds," says Dr Simon Tragust from the Institute of Biology at MLU, who co-led the new study alongside Professor Heike Feldhaar from Bayreuth. A couple of years ago he was able to show that ants also use the acid in brood care, for example, to disinfect their brood and prevent the spread of harmful fungi.

The new study was based on an observation of the animals' behaviour. "Whenever ants swallow food or water, they start cleaning their hindquarters afterwards," says Tragust. The researcher wanted to figure out why they do that. "For one thing, the behaviour didn't seem to be linked to digestion, because ants do this even after they have only ingested water," he adds.

Through several experiments the team was able to show that ants disinfect themselves on the inside. "When the ants were able to access the acid, their chances of survival increased significantly after eating food enriched with pathogenic bacteria," explains Tragust. What's more, the beneficial effect was not limited to an individual animal. Ants pass food from their mouth to the mouths to their nest mates. "This is a major potential source of infection," says Tragust. If the ant passing on the food has previously ingested the acid, the receiving ant had a lower risk of falling ill. According to Tragust, this behaviour might reduce the spread of infection within the ant colony.

The results of the new study also explain why some ants have very few bacteria in their digestive tracts; those that are present are primarily acid-resistant microbes. "Acid swallowing acts as a filter mechanism, structuring the ant's microbiome," explains Tragust. Ants are one of just a handful of animals with extremely acidic stomachs. "Otherwise this is only known to occur in humans and a few other vertebrates," says Tragust. Unlike ants, stomach acid in humans is produced directly in the stomach, but the effects are the same: The acid kills germs in the food and influences the microbiome of the gut.

Incidentally, how formic acid precisely works is still a mystery, but it and other organic acids have long been used as additives in animal feed to kill harmful germs.