Earth

Archaeologists with the University of Cincinnati have discovered two Bronze Age tombs containing a trove of engraved jewelry and artifacts that promise to unlock secrets about life in ancient Greece.

The UC archaeologists announced the discovery Tuesday in Greece.

Jack Davis and Sharon Stocker, archaeologists in UC's classics department, found the two beehive-shaped tombs in Pylos, Greece, last year while investigating the area around the grave of an individual they have called the "Griffin Warrior," a Greek man whose final resting place they discovered nearby in 2015.

Like the Griffin Warrior's tomb, the princely tombs overlooking the Mediterranean Sea also contained a wealth of cultural artifacts and delicate jewelry that could help historians fill in gaps in our knowledge of early Greek civilization.

UC's team spent more than 18 months excavating and documenting the find. The tombs were littered with flakes of gold leaf that once papered the walls.

"Like with the Griffin Warrior grave, by the end of the first week we knew we had something that was really important," said Stocker, who supervised the excavation.

"It soon became clear to us that lightning had struck again," said Davis, head of UC's classics department.

The Griffin Warrior is named for the mythological creature -- part eagle, part lion -- engraved on an ivory plaque in his tomb, which also contained armor, weaponry and gold jewelry. Among the priceless objects of art was an agate sealstone depicting mortal combat with such fine detail that Archaeology magazine hailed it as a "Bronze Age masterpiece."

Artifacts found in the princely tombs tell similar stories about life along the Mediterranean 3,500 years ago, Davis said. A gold ring depicted two bulls flanked by sheaves of grain, identified as barley by a paleobotanist who consulted on the project.

"It's an interesting scene of animal husbandry -- cattle mixed with grain production. It's the foundation of agriculture," Davis said. "As far as we know, it's the only representation of grain in the art of Crete or Minoan civilization."

Like the grave of the Griffin Warrior, the two family tombs contained artwork emblazoned with mythological creatures. An agate sealstone featured two lion-like creatures called genii standing upright on clawed feet. They carry a serving vase and an incense burner, a tribute for the altar before them featuring a sprouting sapling between horns of consecration, Stocker said.

Above the genii is a 16-pointed star. The same 16-pointed star also appears on a bronze and gold artifact in the grave, she said.

"It's rare. There aren't many 16-pointed stars in Mycenaean iconography. The fact that we have two objects with 16 points in two different media (agate and gold) is noteworthy," Stocker said.

The genius motif appears elsewhere in the East during this period, she said.

"One problem is we don't have any writing from the Minoan or Mycenaean time that talks of their religion or explains the importance of their symbols," Stocker said.

UC's team also found a gold pendant featuring the likeness of the Egyptian goddess Hathor.

"Its discovery is particularly interesting in light of the role she played in Egypt as protectress of the dead," Davis said.

The identity of the Griffin Warrior is a matter for speculation. Stocker said the combination of armor, weapons and jewelry found in his tomb strongly indicate he had military and religious authority, likely as the king known in later Mycenaean times as a wanax.

Likewise, the princely tombs paint a picture of accumulated wealth and status, she said. They contained amber from the Baltic, amethyst from Egypt, imported carnelian and lots of gold. The tombs sit on a scenic vista overlooking the Mediterranean Sea on the spot where the Palace of Nestor would later rise and fall to ruins.

"I think these are probably people who were very sophisticated for their time," she said. "They have come out of a place in history where there were few luxury items and imported goods. And all of a sudden at the time of the first tholos tombs, luxury items appear in Greece.

"You have this explosion of wealth. People are vying for power," she said. "It's the formative years that will give rise to the Classic Age of Greece."

The antiquities provide evidence that coastal Pylos was once an important destination for commerce and trade.

"If you look at a map, Pylos is a remote area now. You have to cross mountains to get here. Until recently, it hasn't even been on the tourist path," Stocker said. "But if you're coming by sea, the location makes more sense. It's on the way to Italy. What we're learning is that it's a much more central and important place on the Bronze Age trade route."

The princely tombs sit close to the palace of Nestor, a ruler mentioned in Homer's famous works "The Iliad" and "The Odyssey." The palace was discovered in 1939 by the late UC Classics professor Carl Blegen. Blegen had wanted to excavate in the 1950s in the field where Davis and Stocker found the new tombs but could not get permission from the property owner to expand his investigation. The tombs would have to wait years for another UC team to make the startling discovery hidden beneath its grape vines.

Excavating the site was particularly arduous. With the excavation season looming, delays in procuring the site forced researchers to postpone plans to study the site first with ground-penetrating radar. Instead, Stocker and Davis relied on their experience and intuition to focus on one disturbed area.

"There were noticeable concentrations of rocks on the surface once we got rid of the vegetation," she said.

Those turned out to be the exposed covers of deep tombs, one plunging nearly 15 feet. The tombs were protected from the elements and potential thieves by an estimated 40,000 stones the size of watermelons.

The boulders had sat undisturbed for millennia where they had fallen when the domes of the tombs collapsed. And now 3,500 years later, UC's team had to remove each stone individually.

"It was like going back to the Mycenaean Period. They had placed them by hand in the walls of the tombs and we were taking them out by hand," Stocker said. "It was a lot of work."

At every step of the excavation, the researchers used photogrammetry and digital mapping to document the location and orientation of objects in the tomb. This is especially valuable because of the great number of artifacts that were recovered, Davis said.

"We can see all levels as we excavated them and relate them one to the other in three dimensions," he said.
UC's team will continue working at Pylos for at least the next two years while they and other researchers around the world unravel mysteries contained in the artifacts.

"It has been 50 years since any substantial tombs of this sort have been found at any Bronze Age palatial site. That makes this extraordinary," Davis said.

Job enrichment may be an important tool for retaining seasonal frontline staff, according to a new University of Waterloo study.

"Managers can use job enrichment to make work more engaging and to develop a bond between staff and the organization," says David Drewery, a PhD candidate in Waterloo's Department of Recreation and Leisure Studies. "Job enrichment aims to design work conditions in ways that maximize meaning, responsibility and knowledge."
The study surveyed 124 seasonal student workers who had just completed a four-month-long summer job to find out whether they intended to return the following year, and the motivations behind their intentions.

It found that positive feelings about work in general (work engagement) and a psychological attachment to the organization accounted for a strong desire to return to work. Both work engagement and organizational commitment were higher when students perceived that their jobs were enriched.

"Commitment was particularly important, which means that simply making work 'fun' is not enough to retain staff," said Drewery. "Staff need to find their work meaningful, and must feel a deep connection to the organization.

"Retaining contingent staff is a key management issue because turnover is very expensive," Drewery said. "We already know that job enrichment can have great benefits for full-time employees, but this is the first study to show that part-time and casual frontline staff also benefit from job enrichment."

The research did not study the role of compensation in job retention, but rather other motivations of employees who were at the beginning of their careers.

"These results show that managers need to set clear expectations, remind frontline staff of the positive impact they have on their clients, give staff the tools they need and then trust them to use them appropriately," said Drewery. "These are the building blocks of job enrichment."

The study, Retaining contingent frontline staff through job enrichment: the case of seasonal student workers, was authored by David Drewery and published in Managing Sport and Leisure.

Natural gas has become the largest fuel source for generating electricity in the United States, accounting for a third of production and consumption of energy. However, the environmental and socioeconomic impacts of natural gas have not been considered comprehensively. A new study estimated the cumulative effects of the shale gas boom in the Appalachian basin in the early 2000s on air quality, climate change, and employment. The study found that effects on air quality and employment followed the boom-and-bust cycle, but effects on climate change will likely persist for generations to come. The study, which also considered how to compensate for these effects, provides insights for long-term decision making in this field.

The study, by researchers at Carnegie Mellon University (CMU), Princeton University, and Stanford University, appears in nature sustainability.

"While gas development has boosted aspects of the regional economy, private firms have not faced the full costs of natural gas development," explains Nicholas Z. Muller, Associate Professor of Economics, Engineering, and Public Policy at CMU's Tepper School of Business, who coauthored the study. "In our work, we sought to evaluate the cumulative and disparate impacts of current energy systems to inform policymaking."

Rapid increases in natural gas production in the United States, resulting from advancements in horizontal drilling and hydraulic fracturing (a well-stimulation technique that injects pressurized liquids into a bedrock formation) have dramatically altered world energy markets and the domestic energy outlook. The United States has been the largest natural gas consumer and producer over the past decade, comprising 20 percent of the world market, and the domestic shale gas market has contributed to price volatility and a shift in global flows of natural gas.

In this study, researchers analyzed the shale gas boom and decline in the Appalachian basin, the largest natural gas basin in the United States in terms of reserves and production, from 2004 to 2016. Over this period, volumes of regional shale production increased annually and drilling peaked in 2013. Regional natural gas consumption of electric power and processing volumes also rose. Shale gas production exceeded regional demand, leading to substantial amounts of exports to other parts of the country.

Specifically, the researchers examined premature mortality from fine particulate matter and secondary particulate matter formed from the atmospheric oxidation of nitrogen oxides and volatile organic compound emissions. They also estimated the change in global mean temperature from carbon dioxide and methane emissions, as well as the effects on employment associated with the development of natural gas.

The study estimated that shale gas production degraded air quality, resulting in 1,200 to 4,600 premature deaths (costing $2.3 billion to $61 billion), while boosting employment by 469,000 job years or jobs lasting a year (yielding wage income valued at $8 billion to $33 billion). The authors surmised that these results are in line with the boom-and-bust cycle of shale gas development. But the study also found that natural gas production affected climate (at a cost of from $12 billion to $94 billion, depending on assumptions regarding social costs) in ways that will persist for generations to come, well beyond the period of natural gas activity in the region.

"Our study provides insight on the cumulative socioeconomic and environmental impacts of natural gas systems," says Jared L. Cohon, former President of CMU, another coauthor. "The argument that natural gas may serve as a bridge fuel is in part premised on its comparative climate advantage over coal and cost advantage over renewables and other energy technologies. However, this is unsupported if natural gas prices do not reflect the actual economics for producing firms or the costs of damages to climate and air quality."

The study also found that employment effects were concentrated in rural areas where natural gas production occurred, but 76 percent of the cumulative premature mortality due to air pollution was downwind of those areas in urban areas of the United States. The cumulative effects of methane and carbon dioxide emissions on global mean temperature over a 30-year time period were nearly equivalent, but over the long term, the cumulative climate impact was largely due to carbon dioxide, according to the study.

The authors estimated that a tax on production of natural gas of $2 per thousand cubic feet (mcf) of gas would compensate for the cumulative effects of climate and air quality across the supply chain. This is considerably greater than the current fee of $0.08/mcf. The authors were not advocating for such a tax to be implemented absent similiar policies on other energy fuels.

"One of our goals was to assess tradeoffs between different impacts, and comparing physical impacts reveals the implied tradeoffs involved with decisions about natural gas development," according to Erin N. Mayfield, Postdoctoral Scholar at CMU, who led the study. "Based on our cumulative estimates of premature mortality from air pollution and employment, we concluded that the implied tradeoff is 217 job years per premature mortality at a systems level, or equivalently, three job years per years of life lost."

Among the study's limitations, the authors note, are that estimates of the impact of air pollution do not include all impacts associated with this type of pollution, and health impacts from natural gas extend beyond those associated with air pollution and were not considered in the study.

Researchers from the University of Copenhagen have discovered a surprising phenomenon in a process by which certain gas molecules produce harmful particles. The impact of this phenomenon is likely to increase in urban areas as pollution decreases. This knowledge can serve to help politicians adopt better measures to combat air pollution and contribute to improve climate models.

Despite the clear public health benefits from reduced NOx emissions in urban areas, primarily due to diesel emissions, a reduction in NOx gases does not mean that we have completely removed air pollution. Other airborne health hazards are present, including ultrafine particles. Research from the University of Copenhagen, Denmark, suggests that as NOx levels fall, we may be exposed to more particles than researchers had previously believed.

"We have found a fundamental shortcoming in the models that assess and predict air pollution. Our discovery allows us to improve these models and provide politicians with a stronger foundation for making greener decisions," says Professor Henrik G. Kjærgaard of the Department of Chemistry, University of Copenhagen.

He and colleague Kristian Holten Møller, in collaboration with researchers from Caltech, have discovered a special mechanism in the process by which certain molecules create particles in the atmosphere. As VOCs (volatile organic compounds) degrade, these molecules create radicals in both right- and left-handed form - a phenomenon in chemistry known as chirality. The researchers have demonstrated that one of these forms can create particles up to 1000 times faster than the other.

"Previously, no one knew that right- and left-handedness made a difference in how many airborne particles were created. This is important because ultimately, the amount of particles directly correlates with the number of air pollution-related deaths," according to Department of Chemistry postdoc Kristian Holten Møller.

The mechanism occurs when a VOC molecule is degraded in the atmosphere by reacting with itself instead of with other molecules. When this self-reaction occurs, molecular radicals grow larger and larger as they absorb more and more oxygen, eventually developing into ultrafine particles. This process occurs with very different rates depending on whether the radicals have a right- or left-handed form. Subsequently, widely varying amounts of particles are created.

Fewer NOx gases results in more particles

While VOC molecules are released in forested areas as tree and plant odors, they are also released as anthropogenic pollution. In urban areas, VOCs originate from many different sources, such as cars, solvents, detergents, paints and cosmetics products.

Henrik G. Kjærgaard's previous research has demonstrated that with a certain level of NOx in the air, the newly discovered phenomenon does come into play:

"Urban NOx gases limits this oxidation and prevent radicals from growing into particles. However, as we reduce NOx emissions, particles formed via oxidation are likely to become more prominent in cities," Kjærgaard says.

He emphasizes that keeping diesel vehicles in cities is no solution whatsoever, "Diesels not only emit NOx - they emit particles directly. We are are in no way implying that it is a good idea to keep diesel vehicles in urban areas."

According to the researchers, one possible solution is to regulate VOC emissions and replace the VOCs responsible for the most particles with others that have a lesser effect. They underscore that it is a complex area to regulate and that more knowledge is needed about how various VOCs create particles.

Path to more accurate climate models

The researchers also point out that this discovery will help to develop more accurate climate models. Ultrafine particles affect climate by either reflecting or absorbing sunlight. Their presence gives rise to the greatest source of uncertainty in global climate models.

"With the enormous differences between right- and left-handed radicals, uncertainties arise in climate models if failing to distinguish between their form - as is the case today. This leads to an over- or underestimation of the number of particles created in the atmosphere," says Kristian Holten Møller.

Washington, DC - December 17, 2019 - Weight gain and diet have long been known to shuffle the population of gut microbes. More recently, studies have also connected weight gain and diet to changes in the intestinal endocannabinoid system (eCB), a complex network of metabolites and receptors that help regulate appetite and metabolism, among other chores. A new study in mSystems, an open-access journal of the American Society for Microbiology, investigates the relationship between microbiota and the eCB system.

The two systems change in parallel in response to dietary changes, but their relationship to each other isn't well understood. "We have data that shows if we change the endocannabinoid system [as through genetic modification], we can modulate the microbiota," says scientist Alain Veilleux at Laval University in Quebec, Canada. "And if we modulate the gut microbiota, like by using probiotics, we see that the endocannabinoid system is also altered. They have a kind of bi-directional relationship." It's not clear if one changes first in response to a high-fat, high-sugar diet, he says.

This week in mSystems, Veilleux and his colleagues report on these findings and others from a new study designed to investigate the relationship between the microbiota and the eCB system in the small intestine and cecum. Using experiments conducted on mice that were fed a diet high in sugar and fat for two months, the researchers identified, for the first time, potential interactions between the specific bacterial genera and the eCB system.

Notably, several of those connected changes were observable in some parts of the small intestine almost immediately after beginning the experiment. "The gut microbiota and eCB system had similar profiles after three days that they had after 60 days," says Veilleux. As early as three days after feeding, the researchers found that decreased abundances of bacterial genera including Barnesiella, Defluviitalea, and Eubacterium, corresponded to simultaneous upticks in a few molecules that modulate eCB activity.

Scientists first began to probe the eCB system in the 1980s with investigations designed to look for the body's receptors for tetrahydrocannabinol, or THC, the primary psychoactive ingredient in cannabis. In the decades since then, subsequent studies have shown a significant role for endocannabinoids in a variety of bodily functions, including sleep, immunity, appetite, and mood.

At Laval, Veilleux's research focuses on the functions of the small intestine in metabolic diseases. For the new study, he collaborated with researcher Vincenzo Di Marzo, also at Laval, whose lab focuses on understanding the "Microbiome-Endocannabinoidome Axis," with the goal of finding new medical treatments for conditions related to metabolism.

Veilleux says the new findings, which reveal some connections between these two influential systems, can help them move toward that goal. "Our study helps us focus more on what happens when we change the diet," he says. Ultimately, "we want to make it possible to design better nutritional or pharmaceutical strategies to prevent or correct the alterations we see, and to help treat metabolic complications."

Glycine receptors are one of the most widely distributed inhibitory receptors in the central nervous system and have important roles in a variety of physiological processes. Researchers from Max Planck Florida Institute for Neuroscience (MPFI), University of Toyama, Yamagata University, Cairo University, RIKEN Center for Integrative Medical Sciences and Setsunan University joined forces to further study glycine receptors, particularly glycine receptor alpha-4 (Glra4), during development. In a recent publication in the journal Reproduction, they demonstrated that Glra4 is not a brain exclusive gene, as was believed, but on the contrary, it facilitates the early embryonic development in mice.

Hirofumi Nishizono first author of this publication and research associate of Yasuda Lab, explained that in order to fully understand the function of a specific gene, it is necessary to study a condition where this gene is deleted. By applying in vitro fertilization in combination with CRISPR/Cas9 genome editing system to mouse embryos, the team generated a genetically modified mouse in which the Glra4 gene has been disrupted. One of the remarkable results show that Glra4 plays a critical role in the early development of fertilized eggs, facilitating the development of the blastocyst, a structure formed in the early development of mammals, maintaining embryo quality and litter size in mice. Interestingly, they have also shown that different types of glycine receptors are expressed not only in mouse fertilized eggs but also in fertilized eggs of humans and bovine, suggesting that the role of these receptors in early embryonic development is conserved across species. Moreover, while Glra4 is a pseudogene in humans, they use a different type of glycine receptors (GLRA2), which are active in humans, for this process.

Nishizono is currently investigating the effects of the disruption of glycine receptors in the brain. He is conducting behavioral tests to evaluate if the deletion of Glra4 affects brain function of mice. Some preliminary data indicate that the deletion of Glra4 is associated with phenotypes related to psychiatric disorders. Yasuda Lab will continue to produce genetically modified mice to investigate the role of different molecules involved in learning and memory as well as various brain disorders.

WASHINGTON--Scientists have captured the birth of a high-speed ice feature for the first time on top of a Russian glacier.

In a remote archipelago of the Russian Arctic, Vavilov Ice Cap had been moving at a glacial pace for decades. Then, in 2013, it suddenly started spewing ice into the sea, flowing in what scientists call a glacial surge. But a new study suggests this surge has now become something entirely different.

The authors of the new study published in the AGU journal Geophysical Research Letters have documented what they believe is the first observation of a transition from a glacial surge to a longer-lasting flow called an ice stream. Watch a video of the ice stream flow here.

Ice streams and glacial surges were believed to be separate phenomena driven by different mechanisms. But if the authors of the new study are correct, glacial surges could instead be an early stage of an ice stream. If surging ice can form an ice stream on a glacier like Vavilov, then other ice caps might also experience similar rapid ice loss, said Whyjay Zheng, a Ph.D. candidate at Cornell University and the lead author of the new study.

"If that's true, we probably have to revise our predictions for the impact of global sea level rise in the future," he said.

From the time the surge at Vavilov began in 2013 until the spring of 2019, the ice cap lost 9.5 billion tons of ice, or 11 percent of the ice mass of the entire glacier basin.

Ice streams have been documented before in Greenland and Antarctica, where the ice sheets tend to be larger and their flow less constrained by bedrock features. To see an ice stream in a smaller ice cap like Vavilov would be unusual and perhaps unprecedented, according to the study's authors. And as far as the researchers know, no one has observed one being formed.

"If you look at the satellite images, it seems like the entire west wing of the ice cap is just dumping into the sea," Zheng said. "No one has ever seen this before."

A glacier in transition

Zheng and other researchers at Cornell had been monitoring satellite images of this area since 2015, documenting the elevation change of the ice in a separate study. After the initial glacial surge, Zheng said, they decided to keep an eye on how the ice cap changed over time.

When the researchers analyzed the satellite images to see how the surge had progressed, they found that Vavilov was still collapsing. But by 2017, the way it was collapsing had changed.

From 2013 to 2016, Vavilov Ice Cap flowed in what appeared to be a typical glacial surge. Ice at the glacier's edge where it met the Arctic Sea bulged outward in a wide fan shape, surging forward for about 10 kilometers at a maximum speed of 26 meters per day.

Then, in 2017, the ice fan stopped advancing. Instead, dark stripes appeared on the satellite images, indicating crevasses that had formed at the edges of the still fast-flowing ice.

Glacial surges transport massive amounts of ice in a short amount of time, typically a few months to several years. On the other hand, ice streams can maintain a constant, rapid flow for decades to centuries.

An ice stream is characterized by its long-lasting flow, but also by features called shear margins that form at the edges of the flowing ice. When the study's authors saw these dark stripes, Zheng said, "We thought, wow, this is totally similar to an ice stream."

This was the first clue that what the researchers were seeing was an ice stream forming from the initial glacial surge. To find further evidence, the study's authors used the satellite data to calculate the elevation change and speed of the glacier over time.

The authors found that after the 2017 transition period, the shape of the glacier's flow resembled an ice stream, indicated by its gentle slope and narrow width. The location of the fastest-flowing ice also changed after 2017, with the maximum speed shifting from the upper part of the glacier (typical of a surge) to the end point, or terminus, of the glacier (typical of a stream).

A matter of time

Not much is known about the formation and behavior of ice streams. Because of their remote locations, long-term observations of ice streams are scarce, according to the authors of the new study. While we know that ice streams tend to last for a long time--decades to hundreds of years--no one knows the average lifespan of these glacier features.

Denis Felikson, a cryospheric scientist at NASA Goddard Space Flight Center who was not involved in the research, said it will be interesting to watch Vavilov for the next several years to see whether the ice flow lasts long enough to classify as an ice stream. But, he said, he believes the new study shows strong evidence for a transition from a glacial surge to an ice stream.

"It's really exciting that they found this and are documenting it, because we have very limited understanding of how these glacier behaviors work," Felikson said. "There are some theories on how ice streams form, but to actually observe the possibility of that happening is unique and exciting."

This press release was written by Sara Edwards, AGU public information intern.

Children who think poorly of themselves often underachieve in school. A new Dutch study tested whether a simple mental activity--having children with low self-confidence say favorable, encouraging words to themselves--could boost their achievement. The study found that children who engaged in this kind of self-talk improved their math performance when the talk focused on effort, not ability.

The study was done by researchers at Utrecht University, the University of Applied Sciences Leiden, the University of Amsterdam, and the University of Southampton. It appears in Child Development, a journal of the Society for Research in Child Development.

"Parents and teachers are often advised to encourage children to repeat positive self-statements at stressful times, such as when they're taking academic tests," notes Sander Thomaes, professor of psychology at Utrecht University, who led the study. "But until now, we didn't have a good idea of whether this helped children's achievement. We discovered that children with low self-confidence can improve their performance through self-talk focused on effort, a self-regulation strategy that children can do by themselves every day."

Researchers examined 212 children in grades 4 to 6 (ages 9 to 13 years) from schools in middle-class communities in the Netherlands. They chose this age because in late childhood, negative perceptions of competence on school tasks become increasingly prevalent. The children were instructed to take a math test because math performance is compromised by negative beliefs about one's competence.

In the study, the children first reported their beliefs about their competence. A few days later, they worked in their classrooms on the first half of a standardized math test. Immediately after completing the first half of the test, they were randomly assigned to silently take part in either self-talk focused on effort (e.g., "I will do my very best!"), self-talk focused on ability ("I am very good at this!"), or no self-talk. Afterwards, they completed the second half of the math test.

Children who took part in self-talk focused on effort improved their performance on the test compared to children who did not engage in self-talk focused on effort. The benefits of self-talk were especially pronounced among children who held negative beliefs about their competence. In contrast, children who engaged in self-talk focused on ability did not improve their math scores, regardless of their beliefs about their competence.

"Our study found that the math performance of children with low self-confidence benefits when they tell themselves that they will make an effort," explains Eddie Brummelman, assistant professor of child development at the University of Amsterdam, who coauthored the study. "We did not find the same result among children with low self-confidence who spoke to themselves about ability. Self-talk about effort is the key."

The authors note that their findings apply only to children in fourth to sixth grades and may not be applicable to children of other ages. They also note that the study was done in the Netherlands, and that children's response to self-talk may differ in other countries and cultures.

Teenage girls who experience clinical levels of anxiety could be at greater risk of eating disorders, according to associations identified in a study completed by researchers at the University of Bristol with UCL.

Published today [18 December] in European Eating Disorders Review, the new research looked at anxiety disorder pathology and engagement with severe levels of fasting (not eating for an entire day) in 2,406 teenage girls of Bristol's Children of the 90s study.

Data collected at three time points between the ages of 13 and 18 revealed that the risk of regular fasting in girls who met criteria for an anxiety disorder two years earlier was twice that of girls who did not have an anxiety disorder, even after statistical adjustment for other factors known to increase risk of disordered eating behaviour. Fasting in turn was predictive of anorexia nervosa development in the sample, supporting the possibility that anxiety increases risk of early symptoms of eating disorder syndromes.

It is estimated that up to 1.5 million people in the UK have some kind of eating disorder though currently there is not enough research to reveal the true prevalence. This new study is one of a portfolio of work (led by principal investigators Dr Nadia Micali and Dr Stephanie Zerwas) that uses data from the leading Bristol-based health study, Children of the 90s, to predict who might be at risk - which will help direct prevention efforts.

Dr Caitlin Lloyd, Senior Research Associate in Public Health in the Bristol Medical School (PHS) and lead author of the newly published study, who completed the research as part of her PhD at the University of Bristol, commented: "While we have known there is a link between anxiety disorders and anorexia nervosa for some time, these new findings support anxiety preceding the onset of severe restrictive eating, and as such may help inform the identification of individuals at greater risk of eating disorders.

"Our findings did not examine for causal links so it is important that future studies look at the reasons behind the associations we have found. Similar work should also include young men, to determine whether the association holds in this population too.

"Increasing our understanding of disordered eating behaviours and eating disorders is a necessary step in improving outcomes of prevention efforts. This is particularly important given the high burden of eating disorders, and their associated risks, with anorexia having one of the highest mortality rates of all psychiatric disorders."

Dr Nadia Micali, NIHR Clinician Scientist at UCL Great Ormond Street Institute of Child Health at University College London, added: "The findings confirm what we often see in the clinic, which is that anxiety and restrictive eating fuel each other, and highlight how important it is to treat both anxiety and eating behaviours."

Beat Eating Disorders Director of External Affairs, Tom Quinn said: "This research makes an important contribution to our understanding of how anorexia develops and who may be most at risk. This study should support vital early intervention for eating disorders, and long-term, we hope this research could play a role in helping to prevent these serious illnesses from developing in the first place. We also need more longitudinal studies like this to be funded, as there is still a lot more left to learn about how eating disorders develop."

By combining RNA sequencing, bioinformatics and mathematical modeling, University of California San Diego School of Medicine and Moores Cancer Center researchers identified a sudden transcriptomic switch that turns healthy liver tissue cancerous. The finding was used to develop a quantitative analytical tool that assesses cancer risk in patients with chronic liver disease and to predict tumor stages and prognosis for patients with liver cancer.

In the December 16, 2019 online edition of the Proceedings of the National Academy of Science (PNAS), Gen-Sheng Feng, PhD, professor of in the Department of Pathology and Section of Molecular Biology, Division of Biological Sciences at UC San Diego, and team describe developing a tumorigenic index score that identifies a shift from healthy to malignant cells.

"Because we do not have an effective drug to treat liver cancer in its late stages, early detection of liver cancer, when a tumor is less than 10 millimeters, allows oncologists to better treat, surgically remove and kill cancer cells," said Feng, senior author on the paper. "For the first time, we have a mathematical equation that can predict when healthy liver cells become cancerous and, importantly, we are able to detect cancer cells before tumors are visible in a standard clinical setting."

The new analytical tool focused on the analysis of transcription factor clusters. Transcription factors are proteins that bind to specific DNA sequences in order to direct which genes should be turned on or off in a cell. By quantitatively measuring changes in transcription factors together with downstream target genes as a unit (transcription factor clusters), the research group interrogated RNA-sequencing data collected in the pre-cancer and cancer stages of mouse models with different forms of liver cancer and chronic liver diseases like steatosis, fibrosis and cirrhosis.

The analysis found 61 transcription factor clusters that were either up- or down-regulated in mice with cancer, even identifying transcription factors that have not been previously reported in liver cancer.

Gaowei Wang, PhD, a computational biologist and postdoctoral fellow in Feng's lab, helped design a comprehensive analysis of a liver cell transcriptome -- the entire collection of RNA sequences in a cell. This allowed the team to compare expression of transcription factor clusters in healthy livers and those with chronic liver diseases at various stages to identify when cells became cancerous in mice.

After developing the math model using mouse data, researchers applied the analytical tool to a public database to re-analyze human patient data and were able to identify which people had cancer and which had chronic liver disease. In patients with cirrhosis, who are at high risk of developing cancer, they could see a positive tumor index score and in some cases tumor nodules that were not yet visible in the clinic.

"This mathematical approach can be developed into a risk assessment and early diagnostic tool of liver cancer development for a larger population of people living with chronic liver disease, particularly those with cirrhosis," said Feng. "The analysis of individuals at high risk may have an important application in precision medicine. And, with further development and optimization, this tool might be modified to predict the development of other cancers."

According to the American Cancer Society, more than 700,000 new cases of liver cancer are diagnosed globally and 600,000 deaths occur each year, making it among the leading causes of cancer death in the world. In 2019, an estimated 42,000 new cases of liver cancer will be diagnosed and 31,000 people will die in the United States alone.

Further testing is needed before it can be used in a clinical setting. The next step is to analyze liver biopsies, with the ultimate goal of using blood samples to predict risk and stage liver cancer, said Feng.

HOUSTON -- (Dec. 16, 2019) -- In the first study of its kind, researchers have discovered that events from 20,000 years ago or more are still impacting the diversity and distribution of mammal species worldwide.

"Our study shows that mammal biodiversity in the tropics and subtropics today is still being shaped by ancient human events and climate changes," said study lead author John Rowan of the University of Massachusetts Amherst. "In some cases, we found that ancient climate or human events were more important than their present-day counterparts in explaining present patterns of biodiversity."

The research is available online this week in the Proceedings of the National Academy of Sciences. The authors spent more than five years compiling and analyzing data about the diets, body sizes and variety of species in 515 mammal communities -- each with multiple species -- in the tropical and subtropical regions of the Americas, Africa and Asia. Separate statistical analyses were conducted for each community to determine how well recent and ancient events -- both climatic and human -- could account for present-day diets, body sizes and species variation.

Study co-author Lydia Beaudrot of Rice University said the study findings are especially important given the increasing questions ecologists face about how anthropogenic climate change and other human impacts will affect biodiversity this century.

"If current climate is what's most important for where you see species, then as climate changes, we might expect species to track climate to the best of their abilities," she said. "This study suggests things are more complex, and that we will need to take legacy effects into consideration when making predictions about how climate change will affect species distributions."

Beaudrot, an assistant professor of biosciences at Rice, said the study stemmed from discussions that began in 2013 when she was a graduate student at the University of California, Davis, working on research and grant applications with senior co-author Jason Kamilar, now an associate professor of anthropology at UMass Amherst, and with co-author Kaye Reed, a president's professor and the director of the School of Human Evolution and Social Change at Arizona State University (ASU). Rowan, who was then a graduate student of Reed's, is now a postdoctoral fellow working with Kamilar.

As an ecologist, Beaudrot said it was particularly surprising to see that historic climate does a better job than current climate of explaining the communities that are present today.

"As an ecologist, I'm typically focused on the present day, but this study demonstrates the importance of interdisciplinary research for advancing science," she said. "When ecologists, paleoecologists and anthropologists combine forces, we can generate and test more complex and interesting questions that generate surprising new findings."

The study also found that ancient human events were also still reflected in mammal biodiversity patterns. For example, most large-bodied mammals in South America went extinct when humans first appeared on the continent about 12,000 years ago.

"When you're looking at what explain mammal communities today in the Neotropics, these historical human impacts are a better predictor than current or past climate," she said.

Beaudrot said the reason it took so many years to complete the study was that the team had to create the database that would allow them to make comparisons across mammal communities worldwide. Most of the profiled communities are in national parks, places where conservationists have worked for years observing mammals.

"One reason the NSF (National Science Foundation) funded us was to bring all of that together and create this database," Beaudrot said. "It was a huge effort, especially on John's part, and going forward there is so much that can be done to add to what we already have. For example, the mammal communities that are most affected by climate change today are near the poles. We started in the tropics and subtropics because that's where you find most national parks, but we want to continue adding to this, for as many communities in as many places as we can."

The data can give scientists a clearer idea of what happened in the past and how it affected the present, but it doesn't paint a clear picture for the future, she said.

"Predicting how species will respond to climate change is very hard," Beaudrot said. "We already knew that, and this work suggests that it's perhaps even more complex than we thought."

Gold nanoparticles, which are supposed to be stable in biological environments, can be degraded inside cells. This research conducted by teams from the CNRS, l'Université de Paris, Sorbonne Université, and l'Université de Strasbourg will be published in PNAS on December 16 2019, and reveals the ability of cells to metabolize gold, which is nevertheless not essential for their functioning. This study opens the way for a better understanding of the life cycle of gold nanoparticles in organisms.

Gold nanoparticles possess unique optical properties that are used in nanomedicine for anti-cancer therapy and imaging. They are also included in cosmetic and food formulas. Yet their long-term fate in cells remained unclear, even though it was generally accepted that gold nanoparticles remained intact indefinitely in the lysosome, the cell's "waste recycling centre."

Contrary to the current paradigm, scientists from the laboratoire Matière et Systèmes Complexes (CNRS/Université de Paris), laboratoire Matériaux et Phénomènes Quantiques (CNRS/Université de Paris), Institut de minéralogie, de physique des matériaux et de cosmochimie (CNRS/Sorbonne Université/ Muséum national d'Histoire naturelle/IRD), and Institut de physique et chimie des matériaux de Strasbourg (CNRS/Université de Strasbourg) tracked the evolution of gold nanoparticles for 6 months in a cellular environment, and showed that they underwent significant transformations after a few weeks. By measuring the expression of over 18,000 genes over time, they revealed a biological process that includes mechanisms of detoxification and cell protection, which are also involved in the degradation of other nanomaterials. They also observed both the presence of non-degraded nanoparticles and degradation products in the form of nanoleaves (see image).

Nanoleaves had already been observed nearly 50 years ago in patients suffering from rheumatoid polyarthritis who had been treated with another form of gold (ionic gold or "gold salts") to relieve pain in their joints. Consequently, there is a shared metabolism of degradation between gold salts and gold nanoparticles.

This unexpected result, which generalises the fate of gold nanoparticles in organisms, could help in the future to better evaluate the toxicity of gold nanoparticles and their capacity to be eliminated from the organism. This interdisciplinary work also highlights that gold, whatever its initial form, can be metabolized by mammals despite not being essential to their survival.

A new survey of the activity of nearly 60,000 neurons in the mouse visual system reveals how far we have to go to understand how the brain computes. Published today in the international journal Nature Neuroscience, the analysis led by researchers at the Allen Institute reveals that more than 90% of neurons in the visual cortex, the part of the brain that processes our visual world, don’t work the way scientists thought — and it’s not yet clear how they do work.

“We thought that there are simple principles according to which these neurons process visual information, and those principles are in all the textbooks,” said Christof Koch, Ph.D., Chief Scientist and President of the Allen Institute for Brain Science, a division of the Allen Institute, and co-senior author on the study along with R. Clay Reid, M.D., Ph.D., Senior Investigator at the Allen Institute for Brain Science. “But now that we can survey tens of thousands of cells at once, we get a more subtle — and much more complicated — picture.”

Nearly 60 years ago, two neuroscientists, David Hubel and Torsten Wiesel, made groundbreaking discoveries about how mammals’ brains perceive the visual world around us. Their work uncovered individual neurons that switch on only in response to very specific kinds of images.

Hubel and Wiesel made their discoveries by showing simple pictures — things like a black bar or dot on a white background — to cats and monkeys. The general principle they uncovered says that as you view the world around you, specific neurons in your brain are responsible for recognizing exact parts in a particular region of that scene and the recognition gets more specialized and fine-tuned in higher-order parts of the brain.

Say you’re in a park: One set of neurons will fire a rapid electrical response to a dark tree branch in a precise spot in your line of sight. Other neurons switch on only when a bird flies across your field of vision from left to right. Your brain would then stitch together information from the “tree branch” neurons and the “moving bird” neurons to get a complete picture of the world around you, or so the theory goes.

Hubel and Wiesel’s findings were recognized by a Nobel Prize in Physiology or Medicine and formed the backbone of the neural networks that underlie most computer vision applications. In the past decade, with the advent of new neuroscience methods that enable the study of more and more brain cells at once, scientists have come to understand that this model of how our brains see is likely not the whole story — some neurons clearly don’t follow the classic model of tuning into specific features.

But it wasn’t clear just how incomplete the story was.

Brain activity variability

The new study is the first large-scale analysis of the publicly available data from the Allen Brain Observatory, a broad survey that captures the activity of tens of thousands of neurons in the mouse visual system. The researchers analyzed the activity of nearly 60,000 different neurons in the visual parts of the cortex, the outermost shell of the brain, as animals see different simple images, photos and short video clips — including the opening shot from the classic Orson Welles movie “Touch of Evil” (chosen because it has a lot of movement and is a single shot with no cuts).

1950s and 60s neuroscience studies, by necessity, were like fishing expeditions — researchers hunted through the brain with a single electrode until they found a neuron that reliably responded to a certain image. It’s akin to trying to watch a widescreen movie through a few scattered pinholes, Koch said — it would be impossible to get a complete picture. The Allen Brain Observatory dataset doesn’t capture the activity of every neuron under every scenario, but it allows researchers to study more neurons at once, including those with more subtle responses.

The researchers’ new analysis found that less than 10% of the 60,000 neurons responded following the textbook model. Of the rest, about two-thirds showed some reliable response, but their responses were more specialized than the classic models would predict. The last third of neurons showed some activity, but they didn’t light up reliably to any of the stimuli in the experiment — it’s not clear what these neurons are doing, the researchers said.

“It’s not that the previous studies were all a big mistake, it’s just that those cells turn out to be a very small fraction of all neurons in the cortex,” said Saskia de Vries, Ph.D., an Assistant Investigator at the Allen Institute for Brain Science who led the study along with Jérôme Lecoq, Ph.D., and Michael Buice, Ph.D. “It turns out that the mouse visual cortex is much more complex and richer than we previously thought, which underscores the value of doing this type of survey.”

That these more variable, less specific neurons exist is not news. But it was a surprise that they dominate the visual parts of the mouse brain, the researchers said.

How the brain computes

It’s not yet clear how these other neurons contribute to processing visual information. Other research groups have seen that locomotion can drive neuron activity in the visual part of the brain, but whether the mice were running or still only explains a small amount of the variability in visual responses, the researchers found.

Their next steps are to run similar experiments with more natural movies, offering the neurons a larger set of visual features to respond to. Buice has made a 10-hour specialized reel of clips from pretty much every nature documentary he could get his hands on.

The researchers also point out that the classic model came from studies of cats and primates, animals which both evolved to see their worlds in sharper focus at the center of their gaze than did mice. It’s possible that mouse vision is just a completely different ballgame than ours. But there are still principles from these studies that might apply to our own brains, said Buice, an Associate Investigator at the Allen Institute for Brain Science.

“Our goal was not to study vision; our goal was to study how the cortex computes. We think the cortex has a structure of computation that’s universal, similar to the way different types of computers can run the same programs,” Buice said. “In the end, it doesn’t matter what kind of program the computer is running; we want to understand how it runs programs at all.”

AMHERST, Mass. - In what the authors believe is one of the first studies to examine climate change impact on the timing of bird migration on a continental scale, researchers report that spring migrants were likely to pass certain stops earlier now than they would have 20 years ago. Also, temperature and migration timing were closely aligned, with the greatest changes in migration timing occurring in the regions warming most rapidly. Timing shifts were less apparent in fall, they add.

Writing in Nature Climate Change, lead researcher Kyle Horton at Colorado State University (CSU), with artificial intelligence researcher Dan Sheldon at the University of Massachusetts Amherst and senior author Andrew Farnsworth of the Cornell Lab of Ornithology, describe how they analyzed 24 years of radar data from the National Oceanic and Atmospheric Administration (NOAA) for this study of nocturnal bird migration.

Horton describes the breadth of the research, which observed nighttime migratory behaviors of hundreds of species representing billions of birds, as "critically important" to understanding and learning more answers about shifting migration patterns. "To see changes in timing at continental scales is truly impressive, especially considering the diversity of behaviors and strategies used by the many species the radars capture," he says, adding that the observed shifts do not necessarily mean that migrants are keeping pace with climate change.

Farnsworth says the team's research answered, for the first time, key questions on birds and climate change. "Bird migration evolved largely as a response to changing climate," he points out. "It's a global phenomenon involving billions of birds annually. And it's not a surprise that birds' movements track changing climates. But how assemblages of bird populations respond in an era of such rapid and extreme changes in climate has been a black box. Capturing scales and magnitudes of migration in space and time has been impossible until recently."

Horton says that this access to the data and cloud computing greatly enhanced the team's ability to synthesize the findings. "To process all of these data, without cloud computing, it would have taken over a year of continuous computing," he notes. Instead, the team crunched the numbers in about 48 hours.

As Sheldon at UMass Amherst points out, these bird flights have been recorded for decades by the National Weather Services' network of constantly scanning weather radars, but until recently these data have been mostly out of reach for bird researchers, partly because the sheer magnitude of information and lack of tools to analyze it made only limited studies possible.

For this study, Amazon Web Services provided access to the data. Also, a new tool, "MistNet," developed by Sheldon and colleagues at UMass Amherst with others at the Cornell Lab uses machine learning to extract bird data from the radar record and to take advantage of the decades-long radar data archives. The name refers to the fine, almost invisible, "mist nets" that ornithologists use to capture migratory songbirds.

As Sheldon explains, MistNet automates the processing of a massive data set that has measured bird migration over the continental U.S. for over two decades, with excellent results when compared to humans working by hand. It uses computer vision techniques to differentiate birds from rain on the images, a major hurdle that had challenged biologists for decades. "Historically, a person had to look at each radar image to determine whether it contained rain or birds," he notes. "We developed 'MistNet,' an artificial intelligence system to detect patterns in radar images and remove rain automatically."

Sheldon's group made earlier maps of where and when migration occurred over the past 24 years and animated these to illustrate, for example, the most intensive migration areas in the continental United States in a corridor roughly along and just west of the Mississippi River. MistNet also allows researchers to estimate flying velocity and traffic rates of migrating birds.

Horton at CSU says that the lack of change in fall migration patterns was a little surprising, though migration also tends to be a "little bit messier" during those months. "In the spring, we see bursts of migrants, moving at a fairly rapid pace, ultimately to reach the breeding grounds," he explained. "However, during the fall, there's not as much pressure to reach the wintering grounds, and migration tends to move at a slower, more punctuated pace."

A combination of factors makes fall migration more challenging to study, he adds. In the fall, birds are not competing for mates and the pace to reach their destination is more relaxed. There's also a wider age range of birds migrating, as the young eventually realize they need to migrate, too.

Horton said the findings have implications for understanding future patterns of bird migration, because the birds rely on food and other resources as they travel. Under climate change, the timing of blooming vegetation or emergence of insects may be out of sync with the passage of migratory birds. They say even subtle shifts could have negative consequences for the health of migratory birds. In the future, the researchers plan to expand their data analysis to include Alaska, where climate change is having more serious impacts than in the lower 48 states in the U.S.

WASHINGTON -- A team of neuroscientists at Georgetown University Medical Center have found, in animal models, that they can "switch off" epileptic seizures. The findings, published online in Proceedings of the National Academy of Sciences (PNAS), provide the first evidence that while different types of seizures start in varied areas of the brain, they all can be controlled by targeting a very small set of neurons in the brain or their tendril-like neuronal axons.

Zeroing in on specific neurons suggests that treatment for epilepsy can be improved, researchers say. For example, the deep brain stimulation used today could be minutely targeted at the cell body of these neurons or at the areas their axons touch, depending on the type of seizure, says the study's senior investigator, Patrick A. Forcelli, PhD, an assistant professor in neuroscience and in pharmacology and physiology at Georgetown.

"We have found a major choke point in epilepsy circuits in rat brains that we believe can be harnessed to disrupt the onset of seizures or to stop their propagation within the brain," he says. "Circuit-based therapy for people will help offset the known side effects that come with drug therapy and other techniques."

According to the CDC, in the U.S., about 3 million adults and almost 500,000 children have epilepsy, making the incidence about 1% of the population, and the fourth most common brain disorder. (Epilepsy is diagnosed when a person has had more than one seizure.)

Seizures occur when nerve cells in the brain misfire. While there are about 30 specific types of seizures, there are two main categories: focal, which start in particular areas of the brain, and generalized, which occur when nerve cells on both sides of the brain misfire. Within this category are tonic-clonic (formerly known as grand mal) convulsive seizure and absence (formerly known as petit mal).

Researchers have known for about 30 years that while inhibiting a certain area of the brain, the substantia nigra pars recticulata (SNpr) can help stop a seizure, the circuits by which the SNpr controls a seizure have remained unclear. The SNpr is a small area deep within the brain. "It is usually thought to be involved in movement and movement disorders," says Forcelli. "We knew targeting SNpr can stop a seizure, but we didn't know how. Neurons in this area have axonal projections that go to many different parts in the brain."

This study, he says, is built upon the pioneering work done at GUMC in the 1980s when researchers, led by Karen Gale, PhD, "built a metaphorical Rand McNally-type atlas of neuronal pathways involved in seizures and epilepsy - these maps have moved forward both basic biology and for pharmacological treatment of epilepsy." The aim of his research is "to make a "Google maps" version with higher resolution and the ability to zoom in on each address, to improve brain stimulation therapy," says Forcelli.

With his team, Forcelli used four models of experimental epilepsy in seizure-prone rats, designed to reflect a different type of seizure (absence, forebrain tonic-clonic, brainstem tonic-clonic, and limbic) seen in human epilepsies.

They were able to stop these seizures by placing light-sensitive ion channels into neurons in the SNpr; when exposed to light, the neurons can be turned on or off. They found that seizures could be turned off by either silencing activity of the SNpr cell bodies or, in some cases, the areas that these neurons project to.

"We can't target therapy if we don't know how the circuits work. Discovering that silencing one area that a SNpr projects to can turn off specific seizures suggests a much more targetable therapy. For example, deep brain stimulation could be aimed at that area," Forcelli says.

"These findings clarify a long-standing question in the field: the role these individual SNpr neural pathways play in the control of seizures," he says.