Culture

A team of archaeologists in north-west the Kingdom of Saudi Arabia has uncovered the earliest evidence of dog domestication by the region's ancient inhabitants.

The discovery came from one of the projects in the large-scale archaeological surveys and excavations of the region commissioned by the Royal Commission for AlUla (RCU).

The researchers found the dog's bones in a burial site that is one of the earliest monumental tombs identified in the Arabian Peninsula, roughly contemporary with such tombs already dated further north in the Levant.

Evidence shows the earliest use of the tomb was circa 4300 BCE and received burials for at least 600 years during the Neolithic-Chalcolithic era - an indication that the inhabitants may have had a shared memory of people, places and the connection between them.

"What we are finding will revolutionize how we view periods like the Neolithic in the Middle East. To have that kind of memory, that people may have known for hundreds of years where their kin were buried - that's unheard of in this period in this region," said Melissa Kennedy, assistant director of the Aerial Archaeology in the Kingdom of Saudi Arabia (AAKSAU) - AlUla project.

"AlUla is at a point where we're going to begin to realize how important it was to the development of mankind across the Middle East," said the AAKSAU director, Hugh Thomas.

This is the earliest evidence of a domesticated dog in the Arabian Peninsula by a margin of circa 1,000 years.

The findings are published in the Journal of Field Archaeology.

The project team, with Saudi and international members, focused its efforts on two above-ground burial sites dating to the 5th and 4th millennia BCE and located 130 kilometers apart, one in volcanic uplands and the other in arid badlands. The sites were above ground, which is unique for that period of Arabian history, and were positioned for maximum visibility.

The research team detected the sites by using satellite imagery and then by aerial photography from a helicopter. Ground fieldwork began in late 2018.

It was in the volcanic uplands site that 26 fragments of a single dog's bones were found, alongside with bones from 11 humans - six adults, an adolescent and four children.

The dog's bones showed signs of arthritis, which suggests the animal lived with the humans into its middle or old age.

After assembling the bones, the team then had to determine that they were from a dog and not from a similar animal such as a desert wolf.

The team's zoo archaeologist, Laura Strolin, was able to show it was indeed a dog by analyzing one bone in particular, from the animal's left front leg. The breadth of this bone was 21.0 mm, which is in the range of other ancient Middle Eastern dogs. In comparison, the wolves of that time and place had a breadth of 24.7 to 26 mm for the same bone.

The dog's bones were dated to between circa 4200 and 4000 BCE.

Rock art found in the region indicates that the Neolithic inhabitants used dogs when hunting ibex, and other animals.

The fieldwork uncovered other noteworthy artefacts, including a leaf-shaped mother-of-pearl pendant at the volcanic uplands site and a carnelian bead found at the arid badlands site.

The researchers expect more findings in future as a result of the massive survey from the air and on the ground, and multiple targeted excavations in the AlUla region undertaken by the AAKSAU and other teams, which are operating under the auspices of the Royal Commission for AlUla (RCU). The AAKSAU team is led by researchers from the University of Western Australia in Perth, Australia.

The researchers note that AlUla is a largely unexplored area located in a part of the world that has a fertile archaeological heritage of recognized global value.

"This article from RCU's work at AlUla establishes benchmarks. There is much more to come as we reveal the depth and breadth of the area's archaeological heritage," said Rebecca Foote, Director of Archaeology and Cultural Heritage Research for RCU.

It's like something out of science fiction. Research led by Bigelow Laboratory for Ocean Sciences has revealed that a group of microbes, which feed off chemical reactions triggered by radioactivity, have been at an evolutionary standstill for millions of years. The discovery could have significant implications for biotechnology applications and scientific understanding of microbial evolution.

"This discovery shows that we must be careful when making assumptions about the speed of evolution and how we interpret the tree of life," said Eric Becraft, the lead author on the paper. "It is possible that some organisms go into an evolutionary full-sprint, while others slow to a crawl, challenging the establishment of reliable molecular timelines."

Becraft, now an assistant professor of biology at the University of Northern Alabama, completed the research as part of his postdoctoral work at Bigelow Laboratory and recently published it in the Nature publishing group's ISME Journal.

The microbe, Candidatus Desulforudis audaxviator, was first discovered in 2008 by a team of scientists, led by Tullis Onstott, a co-author on the new study. Found in a South African gold mine almost two miles beneath the Earth's surface, the microbes acquire the energy they need from chemical reactions caused by the natural radioactive decay in minerals. They inhabit water-filled cavities inside rocks in a completely independent ecosystem, free from reliance on sunlight or any other organisms.

Because of their unique biology and isolation, the authors of the new study wanted to understand how the microbes evolved. They searched other environmental samples from deep underground and discovered Candidatus Desulforudis audaxviator in Siberia and California, as well as in several additional mines in South Africa. Since each environment was chemically different, these discoveries gave the researchers a unique opportunity to look for differences that have emerged between the populations over their millions of years of evolution.

"We wanted to use that information to understand how they evolved and what kind of environmental conditions lead to what kind of genetic adaptations," said Bigelow Laboratory Senior Research Scientist Ramunas Stepanauskas, the corresponding author on the paper and Becraft's postdoctoral advisor. "We thought of the microbes as though they were inhabitants of isolated islands, like the finches that Darwin studied in the Galapagos."

Using advanced tools that allow scientists to read the genetic blueprints of individual cells, the researchers examined the genomes of 126 microbes obtained from three continents. Surprisingly, they all turned out to be almost identical.

"It was shocking," Stepanauskas said. "They had the same makeup, and so we started scratching our heads."

Scientists found no evidence that the microbes can travel long distances, survive on the surface, or live long in the presence of oxygen. So, once researchers determined that there was no possibility the samples were cross-contaminated during research, plausible explanations dwindled.

"The best explanation we have at the moment is that these microbes did not change much since their physical locations separated during the breakup of supercontinent Pangaea, about 175 million years ago," Stepanauskas said. "They appear to be living fossils from those days. That sounds quite crazy and goes against the contemporary understanding of microbial evolution."

What this means for the pace of microbial evolution, which often happens at a much more accelerated rate, is surprising. Many well-studied bacteria, such as E. coli, have been found to evolve in only a few years in response to environmental changes, such as exposure to antibiotics.

Stepanauskas and his colleagues hypothesize the standstill evolution they discovered is due to the microbe's powerful protections against mutation, which have essentially locked their genetic code. If the researchers are correct, this would be a rare feature with potentially valuable benefits.

Microbial enzymes that create copies of DNA molecules, called DNA polymerases, are widely used in biotechnology. Enzymes with high fidelity, or the ability to recreate themselves with little differences between the copy and the original, are especially valuable.

"There's a high demand for DNA polymerases that don't make many mistakes," Stepanauskas said. "Such enzymes may be useful for DNA sequencing, diagnostic tests, and gene therapy."

Beyond potential applications, the results of this study could have far-reaching implications and change the way scientists think about microbial genetics and the pace of their evolution.

"These findings are a powerful reminder that the various microbial branches we observe on the tree of life may differ vastly in the time since their last common ancestor," Becraft said. "Understanding this is critical to understanding the history of life on Earth."

Every year, our planet encounters dust from comets and asteroids. These interplanetary dust particles pass through our atmosphere and give rise to shooting stars. Some of them reach the ground in the form of micrometeorites. An international program conducted for nearly 20 years by scientists from the CNRS, the Université Paris-Saclay and the National museum of natural history with the support of the French polar institute, has determined that 5,200 tons per year of these micrometeorites reach the ground. The study will be available in the journal Earth & Planetary Science Letters from April 15.

Micrometeorites have always fallen on our planet. These interplanetary dust particles from comets or asteroids are particles of a few tenths to hundredths of a millimetre that have passed through the atmosphere and reached the Earth's surface.

To collect and analyse these micrometeorites, six expeditions led by CNRS researcher Jean Duprat have taken place over the last two decades near the Franco-Italian Concordia station (Dome C), which is located 1,100 kilometres off the coast of Adélie Land, in the heart of Antarctica. Dome C is an ideal collection spot due to the low accumulation rate of snow and the near absence of terrestrial dust.

These expeditions have collected enough extraterrestrial particles (ranging from 30 to 200 micrometres in size), to measure their annual flux, which corresponds to the mass accreted on Earth per square metre per year.

If these results are applied to the whole planet, the total annual flux of micrometeorites represents 5,200 tons per year. This is the main source of extraterrestrial matter on our planet, far ahead of larger objects such as meteorites, for which the flux is less than ten tons per year.

A comparison of the flux of micrometeorites with theoretical predictions confirms that most micrometeorites probably come from comets (80%) and the rest from asteroids.

This is valuable information to better understand the role played by these interplanetary dust particles in supplying water and carbonaceous molecules on the young Earth.

Short pieces of DNA--jumping genes--can bounce from one place to another in our genomes. When too many DNA fragments move around, cancer, infertility, and other problems can arise. Cold Spring Harbor Laboratory (CSHL) Professor & HHMI Investigator Leemor Joshua-Tor and a research investigator in her lab, Jonathan Ipsaro, study how cells safeguard the genome's integrity and immobilize these restless bits of DNA. They found that one of the jumping genes' most needed resources may also be their greatest vulnerability.

The mammalian genome is full of genetic elements that have the potential to move from place to place. One type is an LTR retrotransposon (LTR). In normal cells, these elements don't move much. But if something happens to allow them to move, say during sexual reproduction or in cancerous cells Joshua-Tor says:

"Sometimes they jump into very important spots, either genes themselves or in areas of the genome that is important for regulating genes."

In this study, Joshua-Tor and Ipsaro examined a mouse protein called Asterix/Gtsf1 that immobilizes LTRs. To understand how this protein locks down LTRs, Ipsaro used several techniques, including cryo-EM, to take a closer look at the protein structure. Joshua-Tor says:

"Structure just informs us in many ways, like how things work. If you can see something, you have a way better idea of how it works."

Ipsaro found Asterix/Gtsf1 binds directly to a particular class of RNA called transfer RNA (tRNA). tRNAs normally are part of the cell's protein manufacturing machinery. LTRs have borrowed that part of the protein-making machinery to replicate their genetic material. Asterix/Gtsf1 overrides what the LTRs are trying to do by freezing the otherwise mobile element in place, shutting down their ability to move. Ipsaro says:

"It's trying to copy and paste itself all over the genome. A part of it evolutionarily has depended on tRNA binding in order to replicate."

Instead of freezing the entire genome, scientists think Asterix/Gtf1 is using tRNAs to suppress small specific regions, like LTRs. Researchers are trying to figure out how cells protect themselves against these and other types of mobile genetic elements. They hope that someday they might tame an overly restless genome, preventing new mutations in the germline and in tumors.

COLUMBUS, Ohio - It's one thing to decide among two or three snacks available at a friend's house. But what do people do when they're faced with a vending machine offering 36 different options?

A new study using eye-tracking technology suggests that the amount of time people spend looking at individual items may actually help them decide. Findings showed that people tended to choose snacks they spent more time looking at, sometimes even over snacks that they rated more highly.

"We could do pretty well predicting what people would choose based just on their ratings of the snacks available to them. But we could do an even better job by accounting for how much they looked at each item," said Ian Krajbich, co-author of the study and associate professor of psychology and economics at The Ohio State University.

But the amount of time people spend looking at individual items isn't the whole story of how people decide when they have many alternatives, Krajbich said.

"It's a little more complicated than that," he said.

Krajbich conducted the study with lead author Armin Thomas of Technische Universität Berlin and Felix Molter of Freie Universität Berlin. The research was published this week in the journal eLife.

The study involved 49 people who said they were fans of snack foods and who agreed to fast for at least four hours before the study - to make sure the task was relevant to them.

On a computer screen, the participants were shown sets of 9, 16, 25 or 36 different snack foods and asked to choose which snack they would like to eat the most at the end of the experiment.

They did this multiple times over the course of the experiment. An eye tracker recorded exactly where they looked while making these choices.

After the experiments, participants rated how much they liked all 80 snacks that were part of the study.

The results showed that people didn't look carefully at all the items before making a choice, or even just look at each item until they found one of their favorites. Instead, they looked around in a way that at first glance looked random, but depended on the physical location of the items as well as how much they were liked.

"There is this peripheral screening process where people learn to avoid even looking directly at the snacks they don't really like," Krajbich said.

"This is not something that we see in studies where participants only have two alternatives. It only occurs when they have lots of options."

One of the leading theories among researchers is that when people are presented with many choices, they scan until they find something that is "good enough" - in this case a snack they will enjoy, regardless of whether it is their favorite.

But that's not what happened, Krajbich said. If this "satisficing" model were true, people would quit looking as soon as they found a snack that was good enough. But results showed that participants chose the last snack they looked at only about 45% of the time.

Instead, what seemed to happen most often is that people would look through the items, often going back and forth between them, until one item stood out from the others - often the snack they looked at the most.

"People made a choice when they concluded the best option was sufficiently better than the next-best option," he said.

Where the snacks appeared in the display - left or right, top or bottom - didn't play much of a role in people's decision-making. Participants often started searching in the top left of the display and then looked left to right, top to bottom - but only to a limited extent.

"Pretty quickly their attention gets drawn to their higher-value options. That influences their search process and their gaze starts to jump around less predictably," he said.

CHAMPAIGN, Ill. -- Avian brood parasites lay their eggs in the nests of other bird species, forcing the hosts to do the hard work of raising the unrelated young. A team of scientists wanted to simulate the task of piercing an egg - a tactic that only a minority of host birds use to help grasp and eject the foreign eggs. Their study offers insight into some of the physical challenges the discriminating host birds face.

The new findings appear in the Journal of Experimental Biology.

Take cowbirds, for example. Their eggs look nothing like the host birds' eggs, "yet most of their hosts do not reject the parasite eggs," said study co-author Mark Hauber, a professor of evolution, ecology and behavior at the U. of I. and a brood parasitism expert. "One explanation is that the cowbird eggshell is too thick and strong for a small host's beak to pierce."

To determine whether the difficulty of piercing a brood parasite's egg played a role in whether the host bird tried to eject it, Daniel Clark, an undergraduate student working in Hauber's laboratory, teamed up with another professor in the same department, Philip Anderson, an expert in the biomechanics of piercing, slashing and stabbing. Anderson has previously studied the characteristics that contribute to the cutting and crushing ability of teeth and the piercing power of viper fangs and cactus spines.

The team used chicken eggs in the experiments because collecting and destroying wild bird eggs would be ethically problematic and difficult to standardize. The researchers wanted to determine which elements influenced an egg's ability to withstand being pierced.

"The factors we specifically looked at in the paper were the presence of a nest, the sharpness of the bird's beak and the speed at which it struck the egg," Clark said.

The team measured the energy required to pierce the eggs under different conditions: with and without a nest supporting the egg, with a piercing object approaching the eggs at high or low speeds, and with dull or sharp objects. The researchers used the sharp end of a nail to simulate a sharp beak, and the nail head as a proxy for a dull beak. The experiments involved either a fast-swinging pendulum-mounted nail or a materials-testing device that slowly pushed the nail into the egg.

The researchers said they were surprised to find that the dull end of the nail did a better job of piercing the egg than the sharp end, particularly when striking the egg at a higher speed.

"My lab has done a lot of research on puncture and cutting mechanics, but we've always been looking at soft materials such as skin or muscle," Anderson said. "An eggshell is brittle - more like ceramic than skin. If you're trying to break something brittle, like glass, it makes more sense to use a hammer than a knife, so this result is not as surprising at it seemed at first."

The experiments also revealed that nests absorb some of the energy of the nail strike, particularly when the nail moves at slower speeds.

"In the slow-moving experiment, the nest mattered a lot, but the sharpness or dullness of the nail mattered less," Clark said. "In the fast-moving experiment, the nest mattered less but the sharpness of the nail ended up mattering a lot."

The team also discovered that the act of repeatedly striking eggs dulled even the sharp end of a steel nail.

"This shows that biological surfaces are a lot more tough and durable than we think," Clark said.

If pecking at a foreign egg rapidly in the bottom of a nest damages its beak, the host bird might reduce its ability to preen, weave its own nest or feed itself and its young. These findings offer clues to the factors that influence how - and whether - a host bird responds to the arrival of a foreign egg in its nest, the researchers said.

"Our experiments help us to understand the long-standing conundrum of why most hosts of the cowbird and its conspicuous egg have not evolved to eject the parasitic egg from the nest," Hauber said.

Past surveys have shown that more than 80% of dog owners report observing jealous behaviors from their dogs--vocalizations, agitated behavior, pulling on a leash--when they give attention to other dogs. New research published in the journal Psychological Science supports these observations and finds that dogs also exhibit jealous behaviors when they merely imagine that their owner is interacting with a potential rival, in this case, a highly realistic artificial dog.

"Research has supported what many dog owners firmly believe--dogs exhibit jealous behavior when their human companion interacts with a potential rival," said Amalia Bastos with the University of Auckland and lead author on the paper. "We wanted to study this behavior more fully to determine if dogs could, like humans, mentally represent a situation that evoked jealousy."

Dogs appear to be one of the few species that might display jealous behaviors in ways similar to a human child showing jealousy when their mother gives affection to another child. In humans, jealousy is closely linked with self-awareness, which is one reason animal-cognition researchers are so interested in studying jealousy and other secondary emotions in animals.

To test how and when dogs display jealous behavior, the researchers presented 18 dogs with situations where they could imagine a social interaction between their human companion and either a realistic fake dog or a fleece cylinder. The fake dog served as a potential rival for attention while the cylinder served as a control.

In the experiment, the dogs observed the fake-dog rival positioned next to their owner. A barrier was then placed between the dog and the potential rival obscuring them from view. Despite blocking the line of sight, the dogs forcefully attempted to reach their owners when they appeared to stroke the rival fake dog behind the barrier. In a repeat experiment using a fleece cylinder rather than a fake dog, the dogs pulled on the lead with far less force.

Through their study, Bastos and her colleagues found that dogs showed three human-like signatures of jealous behavior. Jealous behavior emerged only when their owner interacted with a perceived social rival and not an inanimate object; occurred as a consequence of that interaction and not due to a potential rival's mere presence; and emerged even for an out-of-sight interaction between their owner and a social rival.

"These results support claims that dogs display jealous behavior. They also provide the first evidence that dogs can mentally represent jealousy-inducing social interactions," said Bastos. "Previous studies confounded jealous behavior with play, interest, or aggression, because they never tested the dogs' reactions to the owner and the social rival being present in the same room but not interacting."

"There is still plenty of work to do to establish the extent of the similarities between the minds of humans and other animals, especially in terms of understanding the nature of nonhuman animals' emotional experiences," said Bastos. "It is too early to say whether dogs experience jealousy as we do, but it is now clear that they react to jealousy-inducing situations, even if these occur out-of-sight."

Charles Darwin, the British naturalist who championed the theory of evolution, noted that corals form far-reaching structures, largely made of limestone, that surround tropical islands. He didn't know how they performed this feat.

Now, Rutgers scientists have shown that coral structures consist of a biomineral containing a highly organized organic mix of proteins that resembles what is in our bones. Their study, published in the Journal of the Royal Society Interface, shows for the first time that several proteins are organized spatially - a process that's critical to forming a rock-hard coral skeleton.

"Our research revealed an intricate network of skeletal proteins that interact spatially, which likely applies to all stony corals," said Manjula P. Mummadisetti, who led the research while she was a postdoctoral associate in the Rutgers Environmental Biophysics and Molecular Ecology Laboratory led by senior author Paul G. Falkowski. She is now a senior scientist at AVMBioMed in Pottstown, Pennsylvania. "It's important to understand the mechanisms of coral biomineralization and how these invaluable animals persist during the era of anthropogenic climate change."

"Our findings suggest that corals will withstand climate change caused by human activities, based on the precision, robustness and resilience of their impressive process for forming rock-hard skeletons," said Falkowski, a Distinguished Professor in the School of Arts and Sciences and School of Environmental and Biological Sciences at Rutgers University-New Brunswick.

Coral reefs protect shorelines threatened by erosion and storms, and provide fish habitat, nursery and spawning grounds. Indeed, coral reefs provide food for about a half-billion people, who also depend on them to make a living. However, warming ocean waters from climate change put corals at risk from deadly bleaching and disease. More acidic ocean waters, sea-level rise, unsustainable fishing, vessels that damage reefs, invasive species, marine debris and tropical cyclones pose additional threats, according to the National Oceanic and Atmospheric Administration.

Rutgers scientists studied the spatial interactions of the proteins embedded within the skeleton of Stylophora pistillata, a common stony coral in the Indo-Pacific. Stony corals have evolved over more than 400 million years, forming enormous reefs in shallow subtropical and tropical seas. They've been called the "rainforests of the sea."

Predicting the survival of corals based on how they adapted to global climate change over millions of years requires understanding, among other things, how they build reefs by secreting calcium carbonate. That process is called biomineralization.

The scientists showed that several proteins work together to create optimal conditions for biomineralization. These proteins are not located randomly but are well-organized spatially, which the scientists detailed for the first time. The scientists revealed the spatial patterns as new mineral is formed between the living tissue of the animal and its base or an older skeleton.

Piping plovers, charismatic shorebirds that nest and feed on many Atlantic Coast beaches, rely on different kinds of coastal habitats in different regions along the Atlantic Coast, according to a new study by the U.S. Geological Survey and U.S. Fish and Wildlife Service.

The Atlantic Coast and Northern Great Plains populations of the piping plover were listed as federally threatened in 1985. The Atlantic coast population is managed in three regional recovery units, or regions: New England, which includes Massachusetts and Rhode Island; Mid-Atlantic, which includes New York and New Jersey; and Southern, which includes Delaware, Maryland, Virginia, and North Carolina.

While the Atlantic populations are growing, piping plovers have not recovered as well in the Mid-Atlantic and Southern regions as they have in the New England region. The habitat differences uncovered by the study may be a factor in the unequal recovery.

"Knowing piping plovers are choosing different habitat for nesting up and down the Atlantic Coast is key information that resource managers can use to refine recovery plans and protect areas most needed for further recovery of the species," said Sara Zeigler, a USGS research geographer and the lead author of the study. "It will also help researchers predict how climate change impacts, such as increased storm frequency, erosion and sea-level rise, could affect habitat for this high-profile shorebird."

The researchers found that piping plovers breeding in the New England region were most likely to nest on the portion of the beach between the high-water line and the base of the dunes. By contrast, plovers in the Southern region nested farther inland in areas where storm waves have washed over and flattened the dunes - a process known as 'overwash.' In the Mid-Atlantic region plovers used both habitats but tended to select overwash areas more frequently.

In general, overwash areas tend to be less common than backshore -- shoreline to dunes -- habitats. Nesting pairs that rely on overwash features, such as those in the Mid-Atlantic and Southern regions, have more limited habitat compared to birds in New England that have adapted to nesting in backshore environments.

The authors suggest that the differences in nesting habitat selection may be related to the availability of quality food. Piping plover chicks, which cannot fly, must be able to access feeding areas on foot. In New England, piping plovers can find plenty of food along the ocean shoreline, so they may have more options for successful nesting. However, ocean shorelines along the Southern and Mid-Atlantic regions may not provide enough food, forcing adults and chicks to move towards bay shorelines on the interiors of barrier islands to feed. This would explain why so many nests in these regions occurred in overwash areas, which are scarcer than backshore areas but tend to provide a clear path to the bay shoreline.

In all three regions, plovers most often chose to nest in areas with sand mixed with shells and with sparse plant life. These materials match the species' sandy, mottled coloring and help the birds blend into the environment, enhancing the camouflage that is their natural defense against predators. Piping plover adults may avoid dense vegetation because it may impede their ability to watch for foxes, raccoons, coyotes and other predators.

The U.S. Atlantic Coast population of piping plovers increased from 476 breeding pairs when it was listed in 1985 to 1,818 pairs in 2019, according to the USFWS. The population increased by 830 breeding pairs in New England but only 349 and 163 pairs in the Mid-Atlantic and Southern regions respectively.

"This study will help us tailor coastal management recommendations in each region," said Anne Hecht, a USFWS endangered species biologist and a co-author of the paper. "We are grateful to the many partners who collected data for this study, which will help us be more effective in our efforts to recover the plover population."

"This research will fuel further studies on piping plovers, their habitat-use and food resources," Zeigler added. "Refining the models used in this research will help researchers predict habitat availability with future changes in shorelines, sea level and beach profiles."

WHAT:

The COVID-19 pandemic is affecting people with or at risk for HIV both indirectly, by interfering with HIV treatment and prevention services, and directly, by threatening individual health. An effective response to these dual pandemics requires unprecedented collaboration to accelerate basic and clinical research, as well as implementation science to expeditiously introduce evidence-based strategies into real-world settings. This message comes from a review article co-authored by Anthony S. Fauci, M.D., director of the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, and colleagues published in the Journal of Infectious Diseases.

By disrupting critical health care services, the COVID-19 pandemic threatens the substantial progress made in reducing the global burden of HIV. The authors note that the toll of COVID-19 on the HIV pandemic could be mitigated by increasing access to HIV treatment, for example, by prescribing multiple months of medication, and ensuring that HIV testing and prevention services are maintained.

Many questions remain as to whether people with HIV are more at risk for infection with SARS-CoV-2, the virus that causes COVID-19, and for developing severe COVID-19, as evidence to date is mixed. Rates of infection with SARS-CoV-2 are similar in people with and without HIV. However, populations that are disproportionately affected by HIV--including Black/African American and Hispanic/Latinx populations--also are at increased risk for acquiring SARS-CoV-2 infection and for developing severe COVID-19. Multiple factors contribute to the burden on these populations, including systemic health disparities, socio-economic inequalities and a higher prevalence of comorbidities.

While HIV infection itself does not appear to increase risk for severe COVID-19, mounting evidence indicates that specific comorbidities in people with HIV are linked to greater COVID-19 severity. Even when HIV is well-controlled with treatment, people with HIV bear a significant burden of numerous comorbidities, many of which have also emerged as risk factors for severe COVID-19. These comorbidities include certain cancers, chronic kidney disease, chronic obstructive pulmonary disease, cardiovascular disease, obesity and type 2 diabetes.

Accelerated development and clinical testing of prevention and treatment strategies are urgently needed to mitigate the juxtaposition of the HIV and COVID-19 pandemics, the authors conclude. This includes basic research on the interactions between HIV and SARS-CoV-2 at both the cellular and molecular levels, as well as clinical studies to evaluate outcomes for people with HIV and SARS-CoV-2 co-infections, including the impact of comorbidities.

April 8, 2021 - Routinely collected data on patients undergoing spinal fusion surgery do not provide a valid basis for assessing and comparing hospital performance on patient safety outcomes, reports a study in Spine. The journal is published in the Lippincott portfolio by Wolters Kluwer.

At a time when hospitals are increasingly subject to online rankings or "pay-for-performance" reimbursement programs, metrics based on hospital administrative data are "unreliable for profiling hospital performance," concludes the new research by Jacob K. Greenberg, MD, MSCI, of Washington University in St Louis and colleagues. They write, "These results provide important insights into the advisability of using administrative billing data to benchmark hospital quality in spine surgery."

Study finds unacceptably low hospital 'rankability' for spinal fusion

The researchers analyzed more than 367,000 spinal fusion surgery procedures performed in nine states between 2010 and 2017, drawn from nine state inpatient databases. Performed in patients with degenerative spine disease, spinal fusion is a common and costly inpatient surgical procedure. The study included data on approximately 154,000 procedures in the upper (cervical) spine and 213,000 in the lower (thoracic and lumbar) spine.

The analysis focused on serious complications such as return to the operating room, myocardial infarction (heart attack), death, or prolonged hospital stay. The study was designed to determine whether a metric based on publicly available information from state inpatient databases would be reliable for benchmarking and comparing performance between hospitals.

The researchers calculated a risk/reliability-adjusted complication rate to account for differences in the characteristics (case mix) of patients treated at each hospital. They then used a "rankability" measure to assess whether the metric could distinguish true differences in hospital performance from random fluctuations due to chance (signal-to-noise ratio).

Overall, 4.4 percent of patients undergoing cervical spinal fusion had serious complications. For this group of patients, rankability was consistently low - indicating that "rank-based profiling efforts would lead to widely varying results over time," Dr. Greenberg and colleagues write.

For patients undergoing thoracic and lumbar spinal fusion, the serious complication rate was 7.7 percent. Rankability was higher than for cervical spinal fusion. However, the metric's ability to compare complication rates between hospitals was still just slight to moderate depending on the year, indicating most differences across hospitals were due to chance.

The authors noted that rankability increases with the volume of spinal fusion procedures performed. However, only about one-third of hospitals performed sufficient numbers of thoracic-lumbar fusions to produce reliable estimates. Less than five percent performed enough cervical fusions for reliable rankings.

Medicare, Medicaid, and private insurers increasingly use complication rates or other safety metrics to adjust payments to doctors and hospitals for various conditions and procedures. Complication rates are not yet used in national benchmarking for spine surgery, but are widely used for hip and knee replacement surgery. "While payers are increasingly focused on implementing pay-for-performance measures, quality metrics must reliably reflect true differences in performance among the hospitals profiled," according to the authors.

The new analysis - including hundreds of thousands of procedures performed at hospitals across the United States - suggests that state inpatient data on complications are inappropriate for use in ranking and comparing hospital performance for spinal fusion procedures. Dr. Greenberg and colleagues conclude: "These results indicate that such metrics derived from administrative billing data should not be used in high-stakes applications, such as public reporting or pay-for-performance."

In a medical records study covering thousands of children, a U.S.-Canadian team led by researchers at Johns Hopkins Medicine concludes that while surgery to correct congenital heart disease (CHD) within 10 years after birth may restore young hearts to healthy function, it also may be associated with an increased risk of hypertension — high blood pressure — within a few months or years after surgery.

Waste materials from the pulp and paper industry have long been seen as possible fillers for building products like cement, but for years these materials have ended up in the landfill. Now, researchers at UBC Okanagan are developing guidelines to use this waste for road construction in an environmentally friendly manner.

The researchers were particularly interested in wood-based pulp mill fly ash (PFA), which is a non-hazardous commercial waste product. The North American pulp and paper industry generates more than one million tons of ash annually by burning wood in power boiler units for energy production. When sent to a landfill, the producer shoulders the cost of about $25 to $50 per ton, so mills are looking for alternative usages of these by-products.

"Anytime we can redirect waste to a sustainable alternative, we are heading in the right direction," says Dr. Sumi Siddiqua, associate professor at UBC Okanagan's School of Engineering. Dr. Siddiqua leads the Advanced Geomaterials Testing Lab, where researchers uncover different reuse options for industry byproducts.

This new research co-published with Postdoctoral Research Fellow Dr. Chinchu Cherian investigated using untreated PFA as an economically sustainable low-carbon binder for road construction.

"The porous nature of PFA acts like a gateway for the adhesiveness of the other materials in the cement that enables the overall structure to be stronger and more resilient than materials not made with PFA," says Dr. Cherian. "Through our material characterization and toxicology analysis, we found further environmental and societal benefits that producing this new material was more energy efficient and produced low-carbon emissions."

But Dr. Siddiqua notes the construction industry is concerned that toxins used in pulp and paper mills may leach out of the reused material.

"Our findings indicate because the cementation bonds developed through the use of the untreated PFA are so strong, little to no release of chemicals is apparent. Therefore, it can be considered as a safe raw material for environmental applications."

While Dr. Cherian explains that further research is required to establish guidelines for PFA modifications to ensure its consistency, she is confident their research is on the right track.

"Overall, our research affirms the use of recycled wood ash from pulp mills for construction activities such as making sustainable roads and cost-neutral buildings can derive enormous environmental and economic benefits," she says. "And not just benefits for the industry, but to society as a whole by reducing waste going to landfills and reducing our ecological footprints."

In the meantime, while cement producers can start incorporating PFA into their products, Dr. Cherian says they should be continually testing and evaluating the PFA properties to ensure overall quality.

EVANSTON, Ill. -- Five-star ratings are no guarantee to lead you to the perfect barber who truly understands your hair or to the espresso machine that brews a perfect cup of coffee.

That's because most products online are now rated positively, making it harder than ever to truly discern whether they will succeed in the marketplace.

A new study from Northwestern University Kellogg School of Management and the University of Massachusetts Boston was able to predict the success of movies, commercials, books and restaurants by relying on the "emotionality" of reviews instead of the star rating.

The researchers explored box office revenue of 2,400 movies, sales of 1.6 million books and real-world reservations at more than 1,000 restaurants. In their analysis, emotion reigned supreme; in fact, higher star ratings were either a weaker signal of success or negatively related to success.

"One attractive aspect of online purchasing is that consumers have reviews at their fingertips," said Derek D. Rucker, the Sandy & Morton Goldman Professor of Entrepreneurial Studies in Marketing at Kellogg and co-author of the study.

"However, this research demonstrates a 'positivity problem': Most reviews are positive. In this 'sea of positivity,' how do people distinguish products?" Rucker said.

On Amazon.com, for example, the average star rating is approximately 4.2 out of 5 with well over half of the reviews being five-star ratings. Nearly half of all Yelp reviews are five-star ratings, and recent research indicates that nearly 90% of Uber ratings may be five stars.

Indeed, the study found that review ratings were overwhelmingly four and five stars, a few one-star ratings, and few ratings in between.

Clues to success, it turns out, may rest in the very language consumers use.

Across four large-scale studies, the researchers used computational linguistics to assess the emotionality of reviews -- that is whether the reviews suggested the person writing it had an emotional reaction to the product.

In one study, they looked at the movie industry and examined 13 years of Metacritic reviews from 2005 to 2018. Star ratings, they found, were a significant negative predictor of box office success. Emotionality, however, was a significant positive predictor.

The researchers also were able to predict the success of books on Amazon using the same model based on 20 years of data from 1995 to 2015. They found that 91% of books received a positive rating (four or five stars). The average star rating was an unreliable and sometimes even negative predictor of purchases; however, greater emotionality was predictive of more sales in 93% of genres.

They also examined television commercials. For both the 2016 and 2017 Super Bowls, they obtained real-time tweets the day those ads aired and they measured the subsequent gain in Facebook followers. Then, they compared their own model, which incorporates text emotionality, to the USA Today Ad Meter survey, a popular Super Bowl rating system. The USA Today rating was not predictive of the number of new followers. But the greater the emotionality of tweets, the more Facebook followers a company gained over the following two weeks.

Another domain they turned their attention to was restaurants. Relying on Yelp reviews, the researchers examined whether star ratings or emotionality was a better predictor of table reservations.

Although the average star rating did predict more table reservations, the emotional analysis of restaurant reviews eclipsed the predictive ability of star ratings.

A positive and highly emotional review might read: "I love this restaurant, it is absolutely wonderful." In contrast, a position, but less emotional review might read: "This restaurant is excellent, dinner was flawless."

"This research shows just how pervasive the positivity problem is in online reviews. This work also advances our understanding of emotionality -- a construct considered of significant importance across the social sciences -- by revealing it can predict behavior and marketplace success," explained lead author Matt Rocklage, assistant professor of marketing at University of Massachusetts Boston.

"This work could also lay the foundation for alternatives to star ratings. Firms might ask for a future 'emotional star rating' to understand the attention to the emotionality of individuals' attitudes," said Loran Nordgren, professor of management and organizations at Kellogg and co-author of the paper.

Astronomers at Western University have discovered the most rapidly rotating brown dwarfs known. They found three brown dwarfs that each complete a full rotation roughly once every hour. That rate is so extreme that if these "failed stars" rotated any faster, they could come close to tearing themselves apart. Identified by NASA's Spitzer Space Telescope, the brown dwarfs were then studied by ground-based telescopes including Gemini North, which confirmed their surprisingly speedy rotation.

Three brown dwarfs have been discovered spinning faster than any other found before. Astronomers at Western University in Canada first measured the rotation speeds of these brown dwarfs using NASA's Spitzer Space Telescope and confirmed them with follow-up observations with the Gemini North telescope on Maunakea in Hawai'i and the Carnegie Institution for Science's Magellan Baade telescope in Chile. Gemini North is one of the pair of telescopes that make up the international Gemini Observatory, a Program of NSF's NOIRLab.

"We seem to have come across a speed limit on the rotation of brown dwarfs," said Megan Tannock, the Western University physics and astronomy graduate student who led the discovery. "Despite extensive searches, by our own team and others, no brown dwarfs have been found to rotate any faster. In fact, faster spins may lead to a brown dwarf tearing itself apart."

Brown dwarfs are, simply put, failed stars. They form like stars but are less massive and more like giant planets [1].

Tannock and Western University astronomer Stanimir Metchev worked with international collaborators to find three rapidly rotating brown dwarfs spinning around their axes once every hour. This is approximately 10 times faster than normal [2], and about 30 percent faster than the most rapid rotations previously measured in such objects.

The astronomers used large ground-based telescopes, Gemini North in Hawai'i and Magellan Baade in Chile, to confirm the rapid rotations. They did this by measuring alterations in the brown dwarfs' light caused by the Doppler effect and using a computer model to match those alterations to spin rates [3]. The researchers found that these brown dwarfs spin with speeds of about 350,000 kilometers per hour (around 220,000 miles per hour) at their equator, which is 10 times faster than Jupiter.

"These unusual brown dwarfs are spinning at dizzying speeds," said Sandy Leggett, an astronomer at Gemini North who studies brown dwarfs. "At about 350,000 kilometers per hour, the relatively weak gravity of the brown dwarfs is barely holding them together. This exciting discovery by the Tannock team has identified rotational limits beyond which these objects may not exist."

The team first identified the rapid rotation rates by using NASA's Spitzer Space Telescope to measure how quickly the brightness of the objects varied. "Brown dwarfs, like planets with atmospheres, can have large weather storms that affect their visible brightness," explained Metchev. "The observed brightness variations show how frequently the same storms are seen as the object spins, which reveals the brown dwarf's spin period."

The team's results will appear in an upcoming issue of The Astronomical Journal.