Culture

For patients who have inflammatory bowel syndrome (IBS), the condition is literally a pain in the gut. Chronic -- or long-term -- abdominal pain is common, and there are currently no effective treatment options for this debilitating symptom. In a new study in ACS Pharmacology & Translational Science, researchers identify a new potential source of relief: a molecule derived from spider venom. In experiments with mice, they found that one dose could stop symptoms associated with IBS pain.

The sensation of pain originates in electrical signals carried from the body to the brain by cells called neurons. Tiny channels in the surfaces of neurons help them transmit these signals by allowing positively charged sodium ions to pass into the cell. There are numerous types of sodium channels, and some pain-killing drugs work by blocking them. However, existing treatments interfere with channels indiscriminately and can only be used briefly -- not for chronic pain. Stuart Brierley, Glenn King and colleagues wanted to find a way to selectively target the channels activated during chronic IBS pain.

The researchers focused on a particular sodium channel they suspected was responsible for chronic IBS pain. Then, to block it, they turned to the richest known source of molecules that alter the activity of sodium channels: spider venom. In the venom of a Peruvian tarantula, they discovered a molecule that they named Tsp1a, which had promising blocking activity. To test its potential as a treatment, the researchers used mice that had an IBS-related condition, and they monitored the mice during the experiment to detect a reflex associated with pain. A single Tsp1a treatment delivered into the mice's colons significantly reduced the occurrence of this reflex, indicating pain relief. What's more, Tsp1a appeared highly selective and did not interfere with other body functions, suggesting it could be used safely in humans. While Tsp1a shows promise as a potential treatment for chronic IBS pain, thorough studies of its activity in the body and the immune system's reaction to it will be critical, the researchers write.

Air quality varies greatly within regions and cities around the world, and exposure to air pollution can have severe health impacts. In the U.S., people of color are disproportionately exposed to poor air quality. A cover story in Chemical & Engineering News, the weekly newsmagazine of the American Chemical Society, highlights how scientists and community activists are using new technologies to gather data that could help address this inequity.

Despite the success of the U.S. Clean Air Act in improving ambient air quality over the past 50 years, discriminatory housing, loan and other policies -- known as redlining -- have limited where people of color can live. That means they are more likely to live near "pollution hot spots," such as warehouses, freeways and ports, writes Senior Correspondent Katherine Bourzac. As a result, communities of color have a higher risk of developing cardiovascular disease, asthma and other health issues. Although regulatory air monitors are being operated by federal and local agencies, they typically can't capture air-quality differences within cities.

To fill the gaps, researchers are combining air-pollution measurement technologies with land-use data, modeling studies and other data collection methods. For example, scientists studying air quality in Houston using satellites and U.S. Census Bureau data determined that majority Black, Hispanic and Latino neighborhoods had 37% higher levels of nitrogen dioxide than majority white communities. Scientists hope that higher resolution data from satellites and ground-based tools will help policymakers mitigate inequity and adverse health effects due to air pollution.

Previous research was falsely reassuring; captured only 2% of cirrhosis patients

Findings underscore lack of access to health care for Black patients

Cirrhosis is leading cause of death and affects more than 600,000 people in U.S.

CHICAGO --- Black patients with cirrhosis - late-stage liver disease - are about 25% more likely to die compared to non-Hispanic white patients and four times less likely to receive a liver transplant, reports a new Northwestern Medicine study.

Estimates of racial disparity in cirrhosis have been limited by a lack of large-scale longitudinal data, which track patients from diagnosis to death and/or transplant.

The paper is one of the first to link all seven large liver centers in Chicago with the death registry and transplant registry to examine racial disparities in cirrhosis on a population level. Previous surveillance of outcomes by race has been through the transplant registry alone, which only captures about 2% of those with cirrhosis, and therefore does not lend itself to understand the true disparity affecting patients with cirrhosis.

"The findings underscore broader societal issues of access to health care for our Black patients," said senior study author Dr. Daniela Ladner, professor of surgery at Northwestern University Feinberg School of Medicine and a Northwestern Medicine transplant surgeon. "We need to support our Black community to find the way to optimal care, including offering transplants at the same rate as all other patients."

The study did not examine the cause of the disparity, but other research has shown the reasons are a combination of structural (lack of resources such as medical specialists, pharmacies, transportation, safe housing) and institutional (policies and practices that disadvantage or prioritize certain groups over others).

The paper was published recently in Hepatology.

Cirrhosis is a common disease thought to affect more than 600,000 people in the U.S. and is a leading cause of death in adults. It is caused by chronic viral infections of the liver (hepatitis B and hepatitis c), fatty liver disease and alcohol use disorder.

Previous research has addressed the small group of patients who are listed for liver transplant (

"The findings from this study should prompt quality initiatives at each of the liver centers in this study to examine what barriers to care are contributing the most to the disparities we found," said co-lead author Dr. Nikhilesh Mazumder, a Northwestern Medicine transplant hepatology fellow. "Further research is needed to verify these results on a national level, so we can address this disparity nationwide."

One remedy, the authors said, is targeted interventions to facilitate health care access for Black patients such as the African American Transplant Access Program at Northwestern Medicine. This program is directed by transplant surgeon and co-lead author Dr. Dinee Simpson, assistant professor of surgery at Feinberg and a Northwestern Medicine transplant surgeon.

"We must recognize that health equity is not attainable for everyone if we treat them the same, because different groups face different barriers," Simpson said. "We must research the barriers our Black patients face and be willing to address them with creative solutions. This must happen at the institutional level and the structural level for better health to be realized in this community."

Among patients listed for liver transplants, there were no differences among patient outcomes, the study found.

It is also important to continue to study Black disparities to find the best solutions to resolve them, the authors said. Population-based cohorts such as the Chicago Area Patient-Centered Outcomes Research Network, spearheaded by co-author Dr. Abel Kho, that combine electronic health records from 10 health care systems, allow for these population-based studies.

BUFFALO, N.Y. -- The giant plumose anemone is an animal, but it looks a bit like an underwater cauliflower. Its body consists of a stalk-like column that attaches to rocks and other surfaces on one end, and to a crown of tentacles on the other.

The anemones use these feelers to collect and shove food into their mouths, and a new study provides an in-depth look into the rich diversity of prey the anemones are catching. This includes a surprising menu item: ants, specifically the pale-legged field ant, Lasius pallitarsis. And the occasional spider.

The research was published on June 15 in the journal Environmental DNA. The study focused on giant plumose anemones, known to scientists as Metridium farcimen, that were fixed to the sides and undersides of floating docks in the region of the San Juan Archipelago in the northwestern part of the state of Washington.

The team used a method called DNA metabarcoding to identify the gut contents of a dozen giant plumose anemones. The species' diet was heavy on arthropods, especially crabs (presumably larvae, researchers say), and also included barnacles (larvae or molts), copepods and insects.

"We've greatly expanded the list of things we know that they eat. They're eating whatever they can catch, whatever isn't too big or too small, whatever can't swim away," says first author Christopher Wells, PhD, a postdoctoral researcher in the University at Buffalo Department of Geology. "One of the most surprising results is that in addition to all the usual suspects you'd find in marine plankton, we also found that a part of the diet, about 10% at the time of the study, consisted of ants, which are not marine."

By digging into the natural history of the pale-legged field ant, the researchers came up with a possible explanation for how these ants became part of the marine food chain.

"It's timed with the reproductive portion of the lifespan," Wells says, noting that the study was conducted during the month of August, when the ants have mating flights. "They produce winged queens and drones, which mate and make new colonies. They're not strong fliers and the wind pushes them around, potentially into the water."

The team's results indicate that giant plumose anemones also eat the occasional hapless spider, along with a few insects in addition to ants that may wander too close to the water's edge and drown.

The study was a collaboration between Wells; Gustav Paulay, PhD, at the Florida Museum of Natural History; Bryan Nguyen, PhD, at George Washington University; and Matthieu Leray, PhD, at the Smithsonian Tropical Research Institute. Wells, now in the Department of Geology in the UB College of Arts and Sciences, conducted the research at Friday Harbor Laboratories while completing a PhD at the University of Washington.

By extracting genetic material from a slushy mix of partially digested food, the researchers were able to work backward, comparing their results to information stored in databases about the DNA of varied organisms.

"Part of our research was using this method, DNA metabarcoding, and comparing it to traditional techniques where you wash out or cut open an anemone and then identify what you can see. The trouble is when you do that, you can't identify everything," Wells says. "You might say, 'That looks like it's a copepod antenna,' but you can't tell what species it is.

With DNA metabarcoding, you can identify what species' antennae that is. We were able to identify a lot more diversity using metabarcoding."

Knowing what an animal eats is indispensable when trying to understand how marine communities function.

"When a plankton community floats overtop a bed of anemones, the plankton is filtered by millions of grasping tentacles," Wells says. "This can drastically change the composition of the plankton community, which is food for many economically important animals such as bivalves and fish."

Anemones found in close proximity to one another had varied diets, but, "I don't think that's because they're choosing different things to eat," Wells says. "They eat what they can, and it's very patchy what they get, depending on what's there."

While the researchers were able to identify many of the species preyed on by the giant plumose anemone, Paulay, curator of invertebrate zoology at the Florida Museum of Natural History, noted they were unable to match a substantial portion of DNA sequences with any known organisms, underscoring how much is left to be discovered in the oceans.

How long do virus-laden particles persist in an elevator after a person infected with COVID-19 leaves? And is there a way to detect those particles? A group of electrical engineers and computer scientists at KAUST set out to answer these questions using mathematical fluid dynamics equations.

"We found1 that virus-laden particles can still be detected several minutes after a short elevator trip by an infected person," says KAUST electrical engineer Osama Amin.

The team's equations and breath simulations suggest that a biosensor's ability to detect a virus improves when placed on an elevator wall that can reflect particles. Also, to protect future occupants, the amount of particles in the air can be reduced by making the other three walls absorptive.

Amin and his colleagues at KAUST have been working on developing a nontraditional communication concept called "communication via breath." The concept2 models chemical and biological molecules emitted in exhaled breath as if they are information carriers in a communication system that can be detected on the other end by a "receiver," in this case a biosensor.

"This kind of study requires input from researchers with varied expertise in theoretical channel modeling, system design and integration, and machine learning schemes," says Amin.

In their previous work, they used equations to understand how exhaled molecules disperse in open spaces3. They also proposed4 a sensing system that can detect molecules exhaled from people's breath at mass gatherings.

In their current work, they developed a model and simulations that describe what happens to molecules exhaled in breath within a closed room over space and time. Their modeling took into consideration the abilities of walls to absorb or reflect particles. Once their models were able to describe, solve and simulate virus-laden particle concentration in a small room over space and time, the researchers worked on calculating the probability of a biosensor being able to detect those particles.

The calculations assumed the deployment of a biosensor that uses antibodies to bind to a specific virus and initiate a signal. They also accounted for parameters such as aerosol sampling time and volume, sampling efficiency and the probability of the antibodies binding to a virus.

"Our study provides vital mathematical and simulation gears for our leading research on communication via breath, which we hope will be used for more analyses and system designs," says KAUST computer scientist Basem Shihada.

The team is now developing an aerosol sampling and detection prototype for organic chemicals exhaled in breath. "We also plan on proposing mechanisms that reduce the probability of infection in small spaces, including ventilation mechanisms, periodical air sanitization and the design of absorptive and reflective walls," says Shihada.

Researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) of the Chinese Academy of Sciences have discovered a 120-million-year-old partial fossil skeleton of a tiny extinct bird that fits in the palm of the hand and preserves a unique skull with a mix of dinosaurian and bird features.

The two-centimeter-long (0.75 inch) skull of the fossil shares many structural and functional features with the gigantic Tyrannosaurus rex, indicating that early birds kept many features of their dinosaurian ancestors and their skulls functioned much like those of dinosaurs rather than living birds.

Their findings were published in Nature Communications on June 23.

The bird was deposited 120 million years ago in a shallow lake in what is today Liaoning Province in northeastern China.

Through detailed reconstruction of the bird family tree, the researchers demonstrated that the new fossil bird species belongs to an extinct group of birds called enantiornithines, or "opposite birds." They are the most diverse group of birds from the time of the dinosaurs in the Cretaceous and have been found all over the world.

In living birds, the quadrate is one of the most movable bones in the skull and allows for the unique feature of living birds known as "kinetic skull," which allows the upper jaw to move independently of the brain and the lower jaw.

In contrast with living birds, however, the skull of this new "opposite bird", as well as those of dinosaurs like Tyrannosaurus rex and the close dinosaurian relatives of birds (e.g., troodontids and dromaeosaurs), is not kinetic. Instead, its bones are "locked up" and unable to move.

The temporal regions (sides) of the skull of this bird fossil are very different from living birds. This new species has two bony arches for jaw muscle attachment like those found in reptiles such as lizards, alligators, and dinosaurs, making the rear of the skull rigid and resistant to movement among the bones.

"When reconstructing all parts of the skull three-dimensionally from the high resolution CT scans of the fossil, I had a problem figuring out one bone in particular," said Dr. WANG Min, the lead and corresponding author of the study. He said his colleague Dr. Thomas Stidham proposed that the bone was the pterygoid and looked "exactly like that of the dromaeosaur Linheraptor." The fossil has the first well-preserved pterygoid bone found in an early bird.

The researchers compared CT scans of the bird skull to scans of the skull of the well-known dromaeosaur Linheraptor from Inner Mongolia, China. The results showed that many other features of the rear portion of the skull, including the shape of the basisphenoid bone and its connections with other skull bones, also resemble dromaeosaurs rather than living birds.

"The fossil bird and dinosaurs also lack the discrete contact between the pterygoid and quadrate near the palate that is used in skull kinesis in living birds. In combination with the 'locked up' temporal bones, the difference in the palate structure also points to the absence of kinesis among early birds," said Dr. Stidham, co-author of the study.

Furthermore, the team's discovery and meticulous anatomical research help to reinforce the already well-supported contention, based on many different lines of evidence, that birds are not only living dinosaurs, but evolved from the branch of dinosaurs that includes troodontids and dromaeosaurs like the "four-winged" Microraptor and swift Velociraptor.

"Having a 'dinosaur' skull on a bird body certainly did not stop the enantiornithines, or other early birds, from being highly successful in places all around the world for tens of millions of years during the Cretaceous," said Dr. WANG.

The stink of ammonia in urine, sweat, and rotting meat repels humans, but many insects find ammonia alluring. Now, UConn researchers have figured out how the annoying insects smell it, a discovery that could lead to better ways to make them buzz off.

The sense of smell is enormously important. Mammals devote a third of their genetic code to odor receptors found in the nose, and have more than 1,000 different kinds that allow us to smell an estimated trillion different odors.

Flies don't have noses. Instead, they smell with their antenna. Each antenna is covered with tiny hairs called sensilla. Each sensilla contains a few neurons--fly brain cells. Each neuron expresses one type of odor receptor, and they all fall into two main classes. Or so scientists thought.

But recent work by UConn neuroscientist Karen Menuz and her colleagues, reported online in June in Current Biology, identified a new type of odor neuron devoted to sniffing ammonia. And the receptor it uses is unlike any other odor receptor known.

Flies and other insects use the scent of ammonia to find food sources. Mosquitoes find humans to bite by following the faint scent of ammonia in our sweat, along with other clues. Many crop pests do the same, locating fruit and agricultural products to infest and consume.
"When an odor binds to a receptor, the cell depolarizes, and sends a signal saying 'hey, the odor is here!' Insects are small, and odors come in plumes, so most insects will fly straight as long as the concentration is the same or growing. If they lose the odor plume, they'll do a casting behavior, flying in zig zags to find it," Menuz says.

Knowing exactly how the insects smell ammonia might yield effective ways to block them from following that scent plume--and from finding us and our crops.

But figuring out exactly how and what a fly smells is tricky. Menuz and her colleagues are able to gently hold a fly down and use incredibly fine pieces of glass to probe individual neurons in sensilla on the fly's antenna. Then they let the ammonia waft.

They probed all three types of scent neurons in the flies' sensilla, but they didn't respond to ammonia. But the fly was obviously smelling it. So the researchers realized there had to be a fourth scent neuron they hadn't known was there. And they found it--but it didn't seem to have the usual odor receptors on it. It was covered in ammonia transporter (Amt) a molecule that is known to allow ammonia in and out of cells.

No one had ever known a transporter molecule to also act as an odor receptor. But there it was. When they selectively killed off only that type of neuron, the flies did not respond to ammonia at all. And when the team forced scent neurons that don't normally respond to ammonia to express Amt on their surfaces, those neurons began responding to ammonia, too.

The team hopes to learn whether mosquitoes use the same system to smell ammonia. If it's used by both mosquitoes and flies, it's a good bet the Amt receptor-as-sniffer is used by all insects, and developing ways to block Amt could be an effective way to protect people and crops from pests attracted to ammonia.

A new biocompatible polymer-based composite material could soon replace metal plates in treating difficult and unstable fractures. Developed at KTH Royal Institute of Technology in Stockholm, the newly-developed material is as strong as dental composites yet non-toxic.

The material and a surgical method, which were published in Advanced Functional Materials, will be used in clinical studies in 2023 and 2024, with a focus on hand fractures.

Michael Malkoch, professor of fibre and polymer technology at KTH, says that the material and method, AdhFix, will enable customized plating for fixation of fractures with a more comfortable, less complicated recovery. Collarbone and rib fractures in particular are ideally suited for the proposed treatment, since such injuries are not easy to stabilize.

Metal plates cannot be easily customized in shape, and they tend to adhere to soft tissue, resulting in debilitating complications, says Malkoch. For example, researchers in the U.S. have found that nearly 64 percent of finger fractures treated with metal plates result in mobility complications.

The alternative surgical method, AdhFix, combines screws with a build-up of the polymer/hydroxyapatite composite instead. The composite is shaped in situ before being rapidly cured on demand via high-energy visible-light-induced thiol-ene coupling chemistry.

Evaluations on human cadaver hands with proximal phalanx fractures show that AdhFix withstands the forces from finger flexing exercises. In models of in vivo femur fractures in rats, the methodology supported bone healing without degradation, adverse effects or soft-tissue adhesions.

"No fracture is the same as the other, this is one of the absolute advantages of the material," says Malkoch. "A surgeon can tailor the fixation plate according to the patient's bone shape and the structure of the fracture. The hospital also does not have to store metal plates."

Malkoch says the material and method also may be applied to veterinary care as well. Animals with metal plates are known to avoid going outdoors in cool temperatures because the metal conducts the cold differently than the KTH researchers' composite.

Researchers from Charité - Universitätsmedizin Berlin and the University of California in San Francisco were able to show for the first time that a very low calorie diet significantly alters the composition of the microbiota present in the human gut. In a current Nature* publication, the researchers report that dieting results in an increase of specific bacteria - notably Clostridioides difficile, which is associated with antibiotic-induced diarrhea and colitis. These bacteria apparently affect the body's energy balance by exerting an influence on the absorption of nutrients from the gut.

The human gut microbiome consists of trillions of microorganisms and differs from one person to the next. In persons who are overweight or obese, for instance, its composition is known to be different to that found in individuals with a normal body weight. Many of us will, at some point in our lives, try dieting in order to lose weight. But what effect does such a drastic change in diet have on our bodies? An international team of researchers co-led by Charité has addressed this question. "For the first time, we were able to show that a very low calorie diet produces major changes in the composition of the gut microbiome and that these changes have an impact on the host's energy balance," says Prof. Dr. Joachim Spranger, Head of Charité's Department of Endocrinology and Metabolic Diseases and one of the study's lead authors.

To explore the effects of dieting, the team studied 80 older (post-menopausal) women whose weight ranged from slightly overweight to severely obese for a duration of 16 weeks. The women either followed a medically supervised meal replacement regime, consuming shakes totaling less than 800 calories a day, or maintained their weight for the duration of the study. The participants were examined at the Experimental and Clinical Research Center (ECRC), a facility jointly operated by Charité and the Max Delbrück Center for Molecular Medicine (MDC). Regular stool sample analysis showed that dieting reduced the number of microorganisms present in the gut and changed the composition of the gut microbiome. "We were able to observe how the bacteria adapted their metabolism in order to absorb more sugar molecules and, by doing so, make them unavailable to their human host. One might say we observed the development of a 'hungry microbiome'," says the study's first author, Dr. Reiner Jumpertz von Schwartzenberg, a researcher and clinician at the Department of Endocrinology and Metabolic Diseases whose work on the study was funded by the Clinician Scientist program operated by Charité and the Berlin Institute of Health (BIH).

Stool samples, which had been collected before and after dieting, were then transferred into mice which had been kept under germ-free conditions and, as a result, lacked all gut microbiota. The results were staggering: Animals which received post-dieting stools lost more than 10 percent of their body mass. Pre-diet stools had no effect whatsoever. "Our results show that this phenomenon is primarily explained by changes in the absorption of nutrients from the animals' guts," says Prof. Spranger. He adds: "This highlights the fact that gut bacteria have a major impact on the absorption of food."

When the researchers studied stool composition in greater detail, they were particularly struck by signs of increased colonization by a specific bacterium - Clostridioides difficile. While this microorganism is commonly found in the natural environment and in the guts of healthy human beings and animals, its numbers in the gut can increase in response to antibiotic use, potentially resulting in severe inflammation of the gut wall. It is also known as one of the most common hospital-associated pathogens. Increased quantities of the bacterium were found both in participants who had completed the weight loss regimen and in mice which had received post-dieting gut bacteria. "We were able to show that C. difficile produced the toxins typically associated with this bacterium and that this was what the animals' weight loss was contingent upon," explains Prof. Spranger. He adds: "Despite that, neither the participants nor the animals showed relevant signs of gut inflammation."

Summing up the results of the research, Prof. Spranger says: "A very low calorie diet severely modifies our gut microbiome and appears to reduce the colonization-resistance for the hospital-associated bacterium Clostridioides difficile. These changes render the absorption of nutrients across the gut wall less efficient, notably without producing relevant clinical symptoms. What remains unclear is whether or to which extent this type of asymptomatic colonization by C. difficile might impair or potentially improve a person's health. This has to be explored in larger studies." Results from the current study, which also received funding from the German Center for Cardiovascular Disease (DZHK), might even give rise to treatment options for metabolic disorders such as obesity and diabetes. For this reason, the researchers will now explore how gut bacteria might be influenced in order to produce beneficial effects on the weight and metabolism of their human hosts.

A new article published in the Journal of the Association for Consumer Research presents a neural model of maladaptive consumption.

Consumption (of, for instance, substances, food, and online media) is driven mainly by expected rewards that stem from the ability of the consumption act to satisfy intrinsic (e.g., curiosity) and extrinsic (e.g., job performance) needs. In the article, "A Triple-System Neural Model of Maladaptive Consumption," the authors define maladaptive consumption as a state of compulsive seeking and consumption of rewarding products or experiences, which are sustained despite the negative consequences of such behaviors.

"Understanding the neural basis of maladaptive consumption is important because it can serve as a basis for developing policies that minimize the chances of maladaptive consumption and serve to protect consumers, especially vulnerable populations, like children," note authors Ofir Turel and Antoine Bechara. Getting into the brain networks that govern maladaptive decision making in response to rewarding products/services can lead to interventions that reduce maladaptive consumption post hoc and ethical guidelines for marketers and service providers to decide when it is ethical to use habit-forming mechanisms, such as reward variability, to entice consumers into maladaptive consumption.

The proposed model includes three neural systems, among which the interaction may drive maladaptive behaviors. These include the impulsive system which mediates reward expectation and management, in form of dopamine release; the reflective system, which largely engages the prefrontal cortex (which is responsible for self-control and long-term planning); and the interoceptive-awareness system (which includes that insula, that responds to body interoceptive signals elicited by withdrawal and reward deprivation, leading to urges).

Since these brain regions often operate in an interrelated neural network rather than in isolation, a holistic perspective focusing on the interactions among these brain regions would help provide a better understanding of underlying mechanisms of consumption decisions. The paper proposes that maladaptive behaviors may arise from abnormal activity in any one or a combination of these three neural systems or connectivity among the brain systems.

This model can inform other neural representations of maladaptive consumption, which assumes that maladaptive behaviors results from an overactive reward system and/or an underactive self-control system, and the consequent transitioning from goal-directed to automatic and habitual behaviors. "The triple model supplements this view and suggests that situational conditions, such as deprivation, can exacerbate the reliance on habit-controlled processes," write the authors.

The model extends the neuro-marketing view of the brain underpinnings of normal consumption to the case of maladaptive consumption and provides insights for marketers, consumer rights advocates, and regulators. Such a model may inform research on binge-watching and other common excess consumptions, such as pornography, and help explain why some people engage in such behaviors and how they respond to advertising.

Newspapers regularly carry stories of terrifying shark attacks, but in a paper published today, Oxford-led researchers reveal their discovery of a 3,000-year-old victim - attacked by a shark in the Seto Inland Sea of the Japanese archipelago.

The research in Journal of Archaeological Science: Reports, shows that this body is the earliest direct evidence for a shark attack on a human and an international research team has carefully recreated what happened - using a combination of archaeological science and forensic techniques.

The grim discovery of the victim was made by Oxford researchers, J. Alyssa White and Professor Rick Schulting, while investigating evidence for violent trauma on the skeletal remains of prehistoric hunter-gatherers at Kyoto University. They came upon No24, from the previously excavated site of Tsukumo, an adult male riddled with traumatic injuries.

'We were initially flummoxed by what could have caused at least 790 deep, serrated injuries to this man,' say the Oxford pair. 'There were so many injuries and yet he was buried in the community burial ground, the Tsukumo Shell-mound cemetery site.'

They continue, 'The injuries were mainly confined to the arms, legs, and front of the chest and abdomen. Through a process of elimination, we ruled out human conflict and more commonly-reported animal predators or scavengers.'

Since archaeological cases of shark reports are extremely rare, they turned to forensic shark attack cases for clues and worked with expert George Burgess, Director Emeritus of the Florida Program for Shark Research. And a reconstruction of the attack was put together by the international team.

The team concluded that the individual died more than 3,000 years ago, between 1370 to 1010 BC. The distribution of wounds strongly suggest the victim was alive at the time of attack; his left hand was sheared off, possibly a defence wound.

Individual No 24's body had been recovered soon after the attack and buried with his people at the cemetery. Excavation records showed he was also missing his right leg and his left leg was placed on top of his body in an inverted position.

According to the pair, 'Given the injuries, he was clearly the victim of a shark attack. The man may well have been fishing with companions at the time, since he was recovered quickly. And, based on the character and distribution of the tooth marks, the most likely species responsible was either a tiger or white shark.'

Co-author Dr Mark Hudson, a researcher with the Max Planck Institute, says, 'The Neolithic people of Jomon Japan exploited a range of marine resources... It's not clear if Tsukumo 24 was deliberately targeting sharks or if the shark was attracted by blood or bait from other fish. Either way, this find not only provides a new perspective on ancient Japan, but is also a rare example of archaeologists being able to reconstruct a dramatic episode in the life of a prehistoric community.'

By José Tadeu Arantes | Agência FAPESP – Mathematical models that describe the physical behavior of magnetic materials can also be used to describe the spread of the novel coronavirus that causes COVID-19.

This is the conclusion of a study conducted in Brazil by researchers affiliated with São Paulo State University (UNESP) in Rio Claro and Ilha Solteira and reported in an article published in Physica A: Statistical Mechanics and its Applications.

The study was part of a project led by Mariano de Souza, a professor at UNESP’s Rio Claro Physics Department, and of the PhD research of Isys Mello, whose thesis advisor is Souza, last author of the article. Another co-author is Antonio Seridonio, a professor at UNESP’s Ilha Solteira Physics and Chemistry Department.

The central idea of the study was an analogy between concepts in magnetism and epidemiology in which electron interaction is compared with interaction among people. “We used the Ising model, widely used in several areas of physics, to demonstrate the importance of social distancing and isolation in reducing the rate at which the virus spreads,” Souza told Agência FAPESP.

The magnetic behavior intrinsic to electrons is associated with spin. Simply put, spin can be imagined as a tiny magnet “pointing up” toward the sky or “down” to the ground, so that an electron may spin up or spin down. Spins may interact, depending on the material, and this interaction is quantified in terms of exchange energy.

“We imagined that infected people were ‘spin-up’ and non-infected people were ‘spin-down’. We considered contact between an infected person and a non-infected person analogous to energy exchange in magnetism,” Souza explained.

Using other more complex concepts from physics such as the Bethe lattice (see figure) and percolation theory, the group demonstrated the key role played by social distancing and quarantine in mitigating transmission of the virus.

“We considered that all those who come into contact with each other form a network, and that contact between infected and non-infected people is likely to spread the virus. For example, imagine the first infected person [patient zero] is in contact with other people and fails to take proper precautions [social distancing, face covering, hand hygiene etc]. The members of this group who are infected by the virus may transmit it to relatives, friends and other contacts, and these, in turn, may spread it to others, forming a ‘contact network’ that corresponds to a Bethe lattice in condensed matter physics,” Souza said.

“If patient zero had taken all the necessary precautions, they would have avoided transmitting the virus to all these people who were indirectly infected by them,” he added.

Flavoring can change how the brain responds to e-cigarette aerosols that contain nicotine, according to Penn State College of Medicine researchers. Andrea Hobkirk and her team used functional magnetic resonance imaging (MRI) to understand how the brain's reward areas react to e-cigarette aerosol with and without flavor.

"There are nearly 12 million e-cigarette users in the United States," Hobkirk, an assistant professor of psychiatry and behavioral health at Penn State College of Medicine, said. "The vast majority use e-cigarettes with menthol, mint, fruity and dessert-type flavors. Although regulations that limit the sale of flavored e-cigarettes may help curb use among youth, they might also stop adults from using e-cigarettes as a smoking reduction or cessation aid. We are trying to understand how flavor influences e-cigarette reward and satisfaction for smokers and the risk of nicotine addiction for non-smokers."

The team first developed a device to deliver e-cigarette aerosols during brain scanning. Next, the research team used this new device to deliver aerosols containing a low dose of nicotine to nine adult female smokers during a single laboratory visit. One aerosol had a strawberry-vanilla flavor, and the other aerosol was flavorless. The team compared the strength of brain activation and reward brain region involvement between flavored and unflavored aerosols.

"For our study, we were interested in looking first at, for smokers, how flavor might affect their response to nicotine e-cigarettes," Hobkirk said. "We recruited smokers who had never used e-cigarettes before or were not regular e-cigarette users. What we were interested in is figuring out whether or not flavor changed how they perceived or how their brain responded to this e-cigarette use."

The researchers found that the strawberry-vanilla aerosol engaged the brain's taste region. In contrast, the unflavored aerosol engaged the brain's reward region, similar to observations during cigarette smoking. The researchers published their results in the journal Experimental and Clinical Psychopharmacology.

The researchers also assessed patterns of neural activity between brain regions. Stronger connectivity between two brain regions typically means that these regions are working together. They found that key brain reward regions were strongly connected with flavored aerosol and not unflavored.

The findings suggest that, for smokers, unflavored e-cigarettes may mimic the typical smoking experience more than flavored e-cigarettes.

"We found that for smokers who had never really used e-cigarettes before, the flavor did not make the experience more rewarding for them, at least in terms of what we saw in the brain," Hobkirk said. "It did not make the experience of breathing in these aerosols more like a smoking experience. Typically, that's what smokers are looking for when they're trying to transition over to a healthier product. They want something that gives all the similar rewarding and sensory-motor effects of their regular combustible cigarette, but without all the harmful effects that come in the toxins of a cigarette. We found that adding flavor doesn't necessarily do that for these smokers, at least what we saw in their response to them in the brain. This could suggest that, potentially, smokers do not necessarily need these flavors to make the transition from a combustible cigarette to an e-cigarette."

Researchers from Bentley University have been exploring how readers at partisan news sites respond to news events that challenge their worldview.

In a forthcoming paper in the journal ACM Transactions on Social Computing, they report results of a study that examines reader comments on stories surrounding the 2017 Roy Moore Alabama senate race at two partisan news sites: a left-leaning news site (Daily Kos) and a right-leaning news site (Breitbart). They consider the alleged sexual misconduct of Mr. Moore as a challenging news event for the right-leaning readers; and the subsequent nomination of Mr. Moore as the Republican candidate as a challenging news event for the left-leaning readers.

Their analysis identifies the obstacles that readers face as they try to make sense of news events they find challenging. The comments they contribute show that some readers question the motives of different actors in the story, others provide erroneous arguments to diffuse the story, yet others engage in personal attacks. The researchers describe these as breakdowns that prevent a group from acknowledging the new event.

The study adds to our understanding of political discourse and polarization. "We are still trying to understand the causes of disinformation and political echo chambers. Our study provides a window into how deliberation can break down in closed groups," says Dr. Sandeep Purao, one of the lead researchers.

"The processes underlying social representations are difficult to examine. The reader comments allow us this opportunity," says Dr. David Murungi, a professor who also participated in the study. "The reader comments tend to be complex. Although we can judge them to be problematic, it is often hard to name what the problems are," says Dr. David Yates, another professor who participated in the study.

The results of the study are being published in the journal ACM Transactions on Social Computing. The team continues to empirically investigate the problem of disinformation and political discourse, and is moving to explore potential solutions to combat misinformation.

NEW YORK CITY, June 23, 2021 -- From amoebas to zebras, all living things evolve. They change over time as pressures from the environment cause individuals with certain traits to become more common in a population while those with other traits become less common.

Cancer is no different. Within a growing tumor, cancer cells with the best ability to compete for resources and withstand environmental stressors will come to dominate in frequency. It's "survival of the fittest" on a microscopic scale.

But fitness -- how well suited any particular individual is to its environment -- isn't set in stone; it can change when the environment changes. The cancer cells that might do best in an environment saturated with chemotherapy drugs are likely to be different than the ones that will thrive in an environment without those drugs. So, predicting how tumors will evolve over time, especially in response to treatment, is a major challenge for scientists.

A new study by researchers at Memorial Sloan Kettering in collaboration with researchers at the University of British Columbia/BC Cancer in Canada suggests that one day it may be possible to make those predictions. The study, published June 23, 2021, in the journal Nature, was led by MSK computational biologist Sohrab Shah and BC Cancer breast cancer researcher Samuel Aparicio. The scientists showed that a machine-learning approach, built using principles of population genetics that describe how populations change over time, could accurately predict how human breast cancer tumors will evolve.

"Population genetic models of evolution match up nicely to cancer, but for a number of practical reasons it's been a challenge to apply these to the evolution of real human cancers," says Dr. Shah, Chief of Computational Oncology at MSK. "In this study, we show it's possible to overcome some of those barriers."

Ultimately, the approach could provide a means to predict whether a patient's tumor is likely to stop responding to a particular treatment and identify the cells that are likely to be responsible for a relapse. This could mean highly tailored treatments, delivered at the optimal time, to produce better outcomes for people with cancer.

A Trifecta of Innovations

Three separate innovations came together to make these findings possible. The first was using realistic cancer models called patient xenografts, which are human cancers that have been removed from patients and transplanted into mice. The scientists analyzed these tumor models repeatedly over extended timeframes of up to three years, exploring the effects of platinum-based chemotherapy treatment and treatment withdrawal.

"Historically, the field has focused on the evolutionary history of a cancer from a single snapshot," Dr. Shah says. "That approach is inherently error prone. By taking many snapshots over time, we can obtain a much clearer picture."

The second key innovation was applying single-cell sequencing technology to document the genetic makeup of thousands of individual cancer cells in the tumor at the same time. A previously developed platform allowed the team to perform these operations in an efficient and automated fashion.

The final component was a machine-learning tool, dubbed fitClone, developed in collaboration with UBC statistics professor Alexandre Bouchard-Côté, which applies the mathematics of population genetics to cancer cells in the tumor. These equations describe how a population will evolve given certain starting frequencies of individuals with different fitnesses within that population.

With these innovations in place, the scientists were able to create a model of how individual cells and their offspring, or clones, will behave. When the team conducted experiments to measure evolution, they found close agreement between these data and their model.

"The beauty of this model is it can be run forwards to predict which clones are likely to expand and which clones are likely to get outcompeted," Dr. Shah says.

In other words, how the cancer will evolve is predictable.

A Foundation for the Future

The particular types of genetic changes the team looked at are called copy number changes. These are differences in the number of particular DNA segments in cancer cells. Up until now, the significance of these sorts of changes hasn't been clear, and researchers have had doubts about their importance in cancer progression.

"Our results show that copy number changes have a measurable impact on fitness," Dr. Shah says.

For example, the scientists found that, in their mouse models, treatment of tumors with platinum chemotherapy led to the eventual emergence of drug-resistant tumor cells -- similar to what happens in patients undergoing treatment. These drug-resistant cells had distinct copy number variants.

The team wondered: What would happen to the tumor if they stopped treatment? Turns out the cells that took over the tumor in the presence of chemotherapy declined or disappeared when the chemotherapy was taken away; the drug-resistant cells were outmatched by the original drug-sensitive cells. This behavior indicates that drug resistance has an evolutionary cost. In other words, the traits that are good for resisting drugs aren't necessarily the best for thriving in an environment without those drugs.

Ultimately, Dr. Shah says, the goal is to one day be able to use this approach on blood samples to identify the particular clones in a person's tumor, predict how they are likely to evolve, and tailor medicines accordingly.

"This study is an important conceptual advance," Dr. Shah says. "It demonstrates that the fitness trajectories of cancer cells are predictable and reproducible."