Culture

Reservoirs in the heart of an ancient Maya city were so polluted with mercury and algae that the water likely was undrinkable.

Researchers from the University of Cincinnati found toxic levels of pollution in two central reservoirs in Tikal, an ancient Maya city that dates back to the third century B.C. in what is now northern Guatemala.

UC's findings suggest droughts in the ninth century likely contributed to the depopulation and eventual abandonment of the city.

"The conversion of Tikal's central reservoirs from life-sustaining to sickness-inducing places would have both practically and symbolically helped to bring about the abandonment of this magnificent city," the study concluded.

A geochemical analysis found that two reservoirs nearest the city palace and temple contained toxic levels of mercury that UC researchers traced back to a pigment the Maya used to adorn buildings, clayware and other goods. During rainstorms, mercury in the pigment leached into the reservoirs where it settled in layers of sediment over the years.

But the former inhabitants of this city, made famous by its towering stone temples and architecture, had ample potable water from nearby reservoirs that remained uncontaminated, UC researchers found.

The study was published in the Nature journal Scientific Reports.

UC's diverse team was composed of anthropologists, geographers, botanists, biologists and chemists. They examined layers of sediment dating back to the ninth century when Tikal was a flourishing city.

Previously, UC researchers found that the soils around Tikal during the ninth century were extremely fertile and traced the source to frequent volcanic eruptions that enriched the soil of the Yucatan Peninsula.

"Archaeologists and anthropologists have been trying to figure out what happened to the Maya for 100 years," said David Lentz, a UC professor of biological sciences and lead author of the study.

For the latest study, UC researchers sampled sediment at 10 reservoirs within the city and conducted an analysis on ancient DNA found in the stratified clay of four of them.

Sediment from the reservoirs nearest Tikal's central temple and palace showed evidence of toxic algae called cyanobacteria. Consuming this water, particularly during droughts, would have made people sick even if the water were boiled, Lentz said.

"We found two types of blue-green algae that produce toxic chemicals. The bad thing about these is they're resistant to boiling. It made water in these reservoirs toxic to drink," Lentz said.

UC researchers said it is possible but unlikely the Maya used these reservoirs for drinking, cooking or irrigation.

"The water would have looked nasty. It would have tasted nasty," said Kenneth Tankersley, an associate professor of anthropology in UC's College of Arts and Sciences. "There would have been these big algae blooms. Nobody would have wanted to drink that water."

But researchers found no evidence of the same pollutants in sediments from more distant reservoirs called Perdido and Corriental, which likely provided drinking water for city residents during the ninth century.

Today, Tikal is a national park and a UNESCO World Heritage site. Researchers believe a combination of economic, political and social factors prompted people to leave the city and its adjacent farms. But the climate no doubt played a role, too, Lentz said.

"They have a prolonged dry season. For part of the year, it's rainy and wet. The rest of the year, it's really dry with almost no rainfall. So they had a problem finding water," Lentz said.

Co-author Trinity Hamilton, now an assistant professor of biology at the University of Minnesota, worked on the analysis of ancient DNA from algae that sank to the reservoir bottom and was buried by centuries of accumulated sediment.

"Typically, when we see a lot of cyanobacteria in freshwater, we think of harmful algal blooms that impact water quality," Hamilton said.

Finding some reservoirs that were polluted and others that were not suggests the ancient Maya used them for different purposes, she said.

Reservoirs near the temple and palace likely would have been impressive landmarks, much like the reflecting pool at the National Mall is today.

"It would have been a magnificent sight to see these brightly painted buildings reflected off the surface of these reservoirs," said co-author Nicholas Dunning, head of geography in UC's College of Arts and Sciences.

"The Maya rulers conferred to themselves, among other things, the attribute of being able to control water. They had a special relationship to the rain gods," Dunning said. "So the reservoir would have been a pretty potent symbol."

UC's Tankersley said one popular pigment used on plaster walls and in ceremonial burials was derived from cinnabar, a red-colored mineral composed of mercury sulfide that the Maya mined from a nearby volcanic feature known as the Todos Santos Formation.

A close examination of the reservoir sediment using a technique called energy dispersive X-ray fluorescence spectrometry found that mercury did not leach into the water from the underlying bedrock. Likewise, Tankersley said, UC ruled out another potential source of mercury -- volcanic ash that fell across Central America during the frequent eruptions. The absence of mercury in other nearby reservoirs where ash would have fallen ruled out volcanoes as the culprit.

Instead, Tankersley said, people were to blame.

"That means the mercury has to be anthropogenic," Tankersley said.

With its bright red color, cinnabar was commonly used as a paint or pigment across Central America at the time.

"Color was important in the ancient Maya world. They used it in their murals. They painted the plaster red. They used it in burials and combined it with iron oxide to get different shades," Tankersley said.

"We were able to find a mineral fingerprint that showed beyond a reasonable doubt that the mercury in the water originated from cinnabar," he said.

Tankersley said ancient Maya cities such as Tikal continue to captivate researchers because of the ingenuity, cooperation and sophistication required to thrive in this tropical land of extremes.

"When I look at the ancient Maya, I see a very sophisticated people with a very rich culture," Tankersley said.

UC's team is planning to return to the Yucatan Peninsula to pursue more answers about this remarkable period of human civilization.

Below please find a summary and link(s) of new coronavirus-related content published today in Annals of Internal Medicine. The summary below is not intended to substitute for the full article as a source of information. A collection of coronavirus-related content is free to the public at http://go.annals.org/coronavirus.

Incidence and Severity of COVID-19 in HIV-Positive Persons Receiving Antiretroviral Therapy

Researchers from the Ministry of Health and the HIV Network of Excellence in Madrid, Spain, and Harvard T.H. Chan School of Public Health describe the incidence and severity of COVID-19 among 77,590 HIV-positive patients receiving antiretroviral therapy (ART). These authors conclude HIV-positive patients receiving tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) have a lower risk for COVID-19 and related hospitalization than those receiving other therapies. The authors' findings warrant further investigation of HIV ART in HIV preexposure prophylaxis studies and randomized trials among persons without HIV. Read the full text: https://www.acpjournals.org/doi/10.7326/M20-3689.

Media contacts: A PDF for this article is not yet available. Please click the link to read full text. The lead author, Julia del Amo, MD, PhD, can be reached through mlorenzo@mscbs.es.

An innovative, interactive cloud-based data portal debuted this week that lets academic researchers mine the world's largest and most comprehensive collection of scientific resources for studying pediatric solid tumors and their related biology. The Childhood Solid Tumor Network (CSTN) data portal on St. Jude Cloud was created to improve access to the detailed data available through the network, stimulating the research and development of novel, lifesaving therapies.

The CSTN includes wide-ranging data on 170 patient-derived samples representing 21 different childhood solid tumors, including neuroblastoma, rhabdomyosarcoma and rare tumors. The samples are orthotopic patient-derived xenografts, meaning the human tumor samples are implanted and grown in the corresponding location in mice.

The CSTN includes wide-ranging data on 170 patient-derived samples representing 21 different childhood solid tumors, including neuroblastoma, rhabdomyosarcoma and rare tumors. The samples are orthotopic patient-derived xenografts, meaning the human tumor samples are implanted and grown in the corresponding location in mice.

Tumor samples and related data are shared with academic researchers at no charge and with no obligation to collaborate. Michael Dyer, Ph.D., chair of the St. Jude Developmental Neurobiology department, and Alberto Pappo, M.D., of the St. Jude Oncology department, launched the network in 2013. The goal was to accelerate discoveries in the field. "There had been no significant improvement in outcomes for children with solid tumors in the past three decades," said Dyer, who is a Howard Hughes Medical Institute investigator. Pediatric solid tumors are developmental tumors. To understand how the tumor begins, grows and spreads, they need to be studied in the environment in which they develop.

"As interest in the network grew, we realized scientists needed to dig deeper into the data," Dyer said. "We created the interactive browser to make that possible." The CSTN data portal was unveiled this week at the annual meeting of the American Association for Cancer Research, which was held virtually.

Web-based data

The portal makes it easier for researchers to download and analyze the data themselves.

Available data and analytic tools include:

Next-generation, whole genome sequencing of the patient tumors, germline and the orthotopic patient-derived xenografts. These are presented as an interactive application, allowing for customized heatmaps to represent mutations and individual gene searches. Raw genomic sequences are also uploaded and available.

Interactive browsers for epigenetic and, in some cases, proteomic data

Histology images with tissue-specific stains and electron microscopy images at three magnifications for each sample

Clonal analysis of the matched patient samples and
orthotopic xenografts

Sample-level search and visualization of specific characterization data that let users filter by factors such as patient's age at diagnosis or primary versus recurrent tumors

Preclinical pharmacokinetic reports, tumor propagation protocols and more

Single-cell RNA sequencing of patient and patient derived-orthotopic xenografts is underway. Additional tumor samples and data are added to the network as they become available.

Academic researchers can also request cryopreserved cells from orthotopic patient-derived xenografts as well as fresh frozen tissue or cells and formalin-fixed paraffin-embedded tissue blocks.

As of June 2020, more than 200 researchers from more than 100 institutions worldwide have requested and received more than 1,500 tumor samples from the network.

"We feel the network and data portal are the best way to make the most of the tumor tissue samples that children and their parents have donated to provide resources to speed cures and understand the diseases," said Asa Karlstrom, Ph.D., of Developmental Neurobiology. She was co-first author of a report on the network data portal that was included in an AACR poster session.

BOZEMAN -- How many people in the U.S. have had COVID-19? Using a database of information collected after the 2009 H1N1 outbreak, a Montana State University researcher is helping develop a better understanding of the spread of the novel coronavirus.

Alex Washburne, a researcher in the Bozeman Disease Ecology Lab, which is housed in the College of Agriculture's Department of Microbiology and Immunology, published a paper on the subject this week in the journal Science Translational Medicine. The paper uses data from ILINet a database created by the Centers for Disease Control and Prevention in 2010 to count patients who check into medical clinics with influenza-like illnesses, or ILI. That type of data collection for the purpose of identifying trends is known as syndromic surveillance.

Influenza-like illnesses include any number of infections that carry symptoms similar to the seasonal flu -- such as fever, cough and sore throat. Both influenza-like H1N1 and non-influenza diseases like COVID-19 fall into that group. Monitoring trends in ILI clinic visits, Washburne said, could help better understand how quickly and extensively COVID-19 spread during the early days of its appearance in the U.S.

In collaboration with researchers at Pennsylvania State and Cornell universities, Washburne examined the number of ILI visits reported each week over the last decade and compared those historical trends to such visits during March 2020. They identified a surge in March 2020 ILI visits that parallels regional increases in COVID-19 cases.

By examining ILI data alongside the known regional prevalence of COVID-19, Washburne and his collaborators determined that there may have been many cases of the coronavirus disease that weren't initially identified as such.

Washburne and his colleagues estimate that as many as 87% of coronavirus cases were not diagnosed during early March, which could translate to around 8.7 million people based on the excess March ILI visits. The surge in ILI diminished quickly in the latter part of March, leading researchers to conclude that more cases of COVID-19 were being identified since fewer ILI reports were being logged in the database.

"Early on there seems to have been a low case detection rate, but as time went on that changed," said Washburne. "By the last week in March, as more and more testing was going on, that case detection rate increased significantly."

This is good news for scientists seeking to predict and prepare for future epidemics, said Washburne. A baseline has been established through a decade of ILI data collection that allows for the early detection of anomalous surges of ILI that deviate from the annual average.

With much of the research about COVID-19 happening as the pandemic unfolds, Washburne said syndromic surveillance like this shows researchers and the medical community one piece of a larger story. When coupled with COVID-19 testing efforts and serological surveys, which seek to identify the proportion of a population with immunity to an illness, this type of data collection and analysis can illuminate a piece of the puzzle that helps outline our understanding of coronavirus as a whole, he said, while also offering insight for future potential epidemics.

Washburne also said that syndromic surveillance using tools like ILINet could be applied in areas where widespread testing is too expensive.

"For communities that may not have the capacity for more large-scale testing, this may be able to help give them a picture of the movement of their epidemic in time and space," he said. "That way they can know when to implement actions like mask wearing and social distancing measures."

The practice of collecting data ahead of a potential outbreak is an investment in future public health, Washburne said. This research into COVID-19 wouldn't have been possible without the creation of the database after H1N1, so continuing to expanding the baseline data collected for other illnesses could be crucial in navigating future pandemics.

"All these different methods can be used to cross-validate each other," he said. "We know if our other methods don't work optimally, we have additional resources. Things like this can really help us be better prepared in the future."

A new study by UCLA professors offers a new way to understand how unfounded conspiracy theories emerge online. The research, which combines sophisticated artificial intelligence and a deep knowledge of how folklore is structured, explains how unrelated facts and false information can connect into a narrative framework that would quickly fall apart if some of those elements are taken out of the mix.

The authors, from the UCLA College and the UCLA Samueli School of Engineering, illustrated the difference in the storytelling elements of a debunked conspiracy theory and those that emerged when journalists covered an actual event in the news media. Their approach could help shed light on how and why other conspiracy theories, including those around COVID-19, spread -- even in the absence of facts.

The study, published in the journal PLOS ONE, analyzed the spread of news about the 2013 "Bridgegate" scandal in New Jersey -- an actual conspiracy -- and the spread of misinformation about the 2016 "Pizzagate" myth, the completely fabricated conspiracy theory that a Washington, D.C., pizza restaurant was the center of a child sex-trafficking ring that involved prominent Democratic Party officials, including Hillary Clinton.

The researchers used machine learning, a form of artificial intelligence, to analyze the information that spread online about the Pizzagate story. The AI automatically can tease out all of the people, places, things and organizations in a story spreading online -- whether the story is true or fabricated -- and identify how they are related to each other.

Finding the puzzle pieces

In either case -- whether for a conspiracy theory or an actual news story -- the narrative framework is established by the relationships among all of the elements of the storyline. And, it turns out, conspiracy theories tend to form around certain elements that act as the adhesive holding the facts and characters together.

"Finding narratives hidden in social media forums is like solving a huge jigsaw puzzle, with the added complication of noise, where many of the pieces are just irrelevant," said Vwani Roychowdhury, a UCLA professor of electrical and computer engineering and an expert in machine learning, and a lead author of the paper.

In recent years, researchers have made great strides in developing artificial intelligence tools that can analyze batches of text and identify the pieces to those puzzles. As the AI learns to identify patterns, identities and interactions that are embedded in words and phrases, the narratives begin to make "sense." Drawing from the massive amount of data available on social media, and because of improving technology, the systems are increasingly able to teach themselves to "read" narratives, almost as if they were human.

The visual representations of those story frameworks showed the researchers how false conspiracy theory narratives are held together by threads that connect multiple characters, places and things. But they found that if even one of those threads is cut, the other elements often can't form a coherent story without it.

"One of the characteristics of a conspiracy theory narrative framework is that it is easily 'disconnected,'" said Timothy Tangherlini, one of the paper's lead authors, a professor in the UCLA Scandinavian section whose scholarship focuses on folklore, legend and popular culture. "If you take out one of the characters or story elements of a conspiracy theory, the connections between the other elements of the story fall apart."

Which elements stick?

In contrast, he said, the stories around actual conspiracies -- because they're true -- tend to stand up even if any given element of the story is removed from the framework. Consider Bridgegate, for example, in which New Jersey officials closed several lanes of the George Washington Bridge for politically motivated reasons. Even if any number of threads were removed from the news coverage of the scandal, the story would have held together: All of the characters involved had multiple points of connection by way of their roles in New Jersey politics.

"They are all within the same domain, in this case New Jersey politics, which will continue to exist irrespective of the deletions," Tangherlini said. "Those connections don't require the same 'glue' that a conspiracy theory does."

Tangherlini calls himself a "computational folklorist." Over the past several years, he has collaborated regularly with Roychowdhury to better understand the spread of information around hot-button issues like the anti-vaccination movement.

To analyze Pizzagate, in which the conspiracy theory arose from a creative interpretation of hacked emails released in 2016 by Wikileaks, the researchers analyzed nearly 18,000 posts from April 2016 through February 2018 from discussion boards on the websites Reddit and Voat.

"When we looked at the layers and structure of the narrative about Pizzagate, we found that if you take out Wikileaks as one of the elements in the story, the rest of the connections don't hold up," Tangherlini said. "In this conspiracy, the Wikileaks email dump and how theorists creatively interpreted the content of what was in the emails are the only glue holding the conspiracy together."

The data generated by the AI analysis enabled the researchers to produce a graphic representation of narratives, with layers for major subplots of each story, and lines connecting the key people, places and institutions within and among those layers.

Quick build versus slow burn

Another difference that emerged between real and false narratives concerned the time they take to build. Narrative structures around conspiracy theories tend to build and become stable quickly, while narrative frameworks around actual conspiracies can take years to emerge, Tangherlini said. For example, the narrative framework of Pizzagate stabilized within a month after the Wikileaks dump, and it stayed relatively consistent over the next three years.

"The fact that additional information related to an actual conspiracy emerged over a prolonged period of time (here five and half years) might be one of the telltale signs of distinguishing a conspiracy from a conspiracy theory," the authors wrote in the study.

Tangherlini said it's becoming increasingly important to understand how conspiracy theories abound, in part because stories like Pizzagate have inspired some to take actions that endanger other people.

"The threat narratives found in conspiracy theories can imply or present strategies that encourage people to take real-world action," he said. "Edgar Welch went to that Washington pizzeria with a gun looking for supposed caves hiding victims of sex trafficking."

The UCLA researchers have also written another paper examining the narrative frameworks surrounding conspiracy theories related to COVID-19. In that study, which has been published on an open-source forum, they track how the conspiracy theories are being layered on to previously circulated conspiracy theories such as those about the perceived danger of vaccines, and, in other cases how the pandemic has given rise to completely new ones, like the idea that 5G cellular networks spread the coronavirus.

"We're using the same pipeline on COVID-19 discussions as we did for Pizzagate," Tangherlini said. "In Pizzagate, the targets were more limited, and the conspiracy theory stabilized rapidly. With COVID-19, there are many competing conspiracy theories, and we are tracing the alignment of multiple, smaller conspiracy theories into larger ones. But the underlying theory is identical for all conspiracy theories."

BUFFALO, N.Y. - Since early March and the start of the COVID-19 pandemic in the U.S., 911 calls for emergency medical services have dropped by 26.1 % compared to the past two years, a new study led by a University at Buffalo researcher has found.

But the study also found that EMS-attended deaths have doubled, indicating that when EMS calls were made, they often involved a far more serious emergency.

"The public health implications of these findings are alarming," said E. Brooke Lerner, PhD, first author on the paper and professor and vice chair for research in the Department of Emergency Medicine in the Jacobs School of Medicine and Biomedical Sciences at UB.

PHOTO: http://www.buffalo.edu/news/releases/2020/06/035.html

"When people are making fewer 911 calls but those calls are about far more severe emergencies, it means that people with urgent conditions are likely not getting the emergency care they need in a timely way," she said. "The result is increased morbidity and mortality resulting from conditions not directly related to exposure to SARS-CoV2."

This finding covered the six-week period that began on March 2, and this trend persisted through the end of May.

Delaying care

"The doubling of deaths and cardiac arrests during this relatively short period of time, from March through May, demonstrates that people who need emergency health care may be delaying care such that their lives are actually in jeopardy," said Lerner.

Lerner pointed to two possible causes: fear of contracting the virus at health care facilities and the impulse to not burden health care facilities with non-COVID-19 issues.

"This may mean that future consideration needs to be given to how we message the risks associated with seeking medical care during a pandemic," said Lerner. "At the same time that we are stressing how to stay safe from COVID-19, it may also be necessary to stress how important it is to continue to seek care for serious conditions unrelated to the novel coronavirus."
Lerner added that the findings echo those of studies in other countries, such as Italy, where there was an increase in heart attack fatalities during the height of the pandemic there.

A persistent trend

"The fact that this trend persists even as the pandemic in some areas has started to lessen in severity shows that the fear of accessing health care has continued," Lerner said.

One positive, unsurprising finding was that the rate of 911 calls related to injuries declined for the obvious reason that during times when regions were shutdown, there were fewer opportunities for driving and recreation-related injuries.

The study also revealed significant issues related to the financial viability of EMS in this type of environment.

"The financial strain on EMS agencies will have long-term ramifications for maintaining this important safety net for our communities, especially those agencies whose revenue is based solely on patient transports," said Lerner.

The study consisted of a comparative, retrospective analysis of standardized patient care records that are submitted by more than 10,000 EMS agencies across 47 states and territories nearly in real-time. Those data are submitted to the National Emergency Medical Services Information System (NEMSIS) database, which stores EMS data nationwide.

Fast facts

- Published in Science, the paper explains how NYUAD researchers used the method of helioseismology to measure the meridional flow (the flow of plasma in the latitudinal and radial directions) in the Sun's interior, which controls the solar cycle.

- Over the course of the 11-year solar cycle, the number of sunspots - dark patches on the surface of the Sun - reaches a maximum, and the latitudes at which sunspots emerge drift toward the equator.

- Helioseismology is the study of the solar interior using observations of sound waves on the Sun's surface, much like seismology is the study of the earth interior using earthquakes.

- According to a popular dynamo model, the meridional flow sets the period of the solar cycle and explains the drift of latitudes at which sunspots emerge.

In a newly-published study, researchers from the Center for Space Science at NYU Abu Dhabi (NYUAD) and colleagues used helioseismology and analyzed several data sources to find that the Sun's meridional flow is a single cell in each hemisphere that carries plasma toward the Sun's equator 200 thousand km below the surface. The meridional flow carries the solar plasma from the Sun's equator to its poles at the surface and back again towards the equator at the bottom of the convection zone, a process that determines the characteristics of the sunspot cycle.

The researchers' findings support the flux-transport dynamo model, which relies on the meridional flow to explain the 11-year duration of the sunspot cycle and the latitudinal drift of the location where sunspots emerge. Lead author Laurent Gizon and co-author Chris Hanson of the Center for Space Science at NYUAD report in the paper Meridional flow in the Sun's convection zone is a single cell in each hemisphere published in Science how they utilized helioseismology to infer the meridional flow (in the latitudinal and radial directions) over two solar cycles covering twenty-three years.

Two data sources agree during their overlap period of 2001-2011 that the meridional flow is a single cell in each hemisphere, carrying the plasma toward the equator at the base of the convection zone at a speed of less than 10 MPH.

The Sun's magnetic field is generated by motions of the convecting plasma below our star's surface. The latitude at which the magnetic field emerges through the solar surface (as sunspots) drifts toward the equator over the course of the 11-year solar cycle. During the solar cycle, the Sun's magnetic field builds-up in the solar interior, rises up, and leads to the formation of sunspots where it pierces the solar surface.

"We set out to reinforce our understanding of how sunspots, which are magnetized regions on the Sun, are formed during a solar cycle," said Gizon. "Our analysis supports the flux-transport dynamo model to explain the period of the sunspot cycle and the latitudes at which sunspots emerge."

Paper wasps eavesdrop on fighting rivals to rapidly assess potential opponents without personal risk. This new finding adds to mounting evidence that even mini-brained insects have an impressive capacity to learn, remember and make social deductions about others.

Many vertebrate animals--including some birds and fish and numerous primates--minimize the costs of conflict by using "social eavesdropping" to learn about the fighting ability of potential rivals before interacting with them personally.

Keeping track of a network of individually differentiated social relationships is thought to be cognitively challenging and, until recently, was considered to be beyond the reach of lowly insects like paper wasps, which have brains a million times smaller than the human brain.

But a growing body of evidence suggests that the miniature nervous systems of insects do not limit sophisticated behaviors. The capacity for complex insect behavior may be shaped more by social environment than brain size, according to University of Michigan biologist Elizabeth Tibbetts, senior author of a paper scheduled for publication June 25 in the journal Current Biology.

"It is surprising that wasps can observe and remember a complex network of social interactions between individuals without directly interacting with them," said Tibbetts, a professor in the U-M Department of Ecology and Evolutionary Biology. "Complex social relationships are thought to favor the evolution of large brains and increased social intelligence, but paper wasp brains are relatively small."

In the study, Tibbetts and her students collected female Polistes fuscatus paper wasps from sites around Ann Arbor, Michigan, in the early spring.

Unlike a honeybee colony--which has a single queen and multiple equally ranked female workers--paper wasp colonies contain several reproductive females called foundresses. These females battle their rivals and form complex, linear dominance hierarchies based on the outcomes of those fights. A wasp's rank in the hierarchy determines its share of reproduction, work and food.

In the laboratory, the researchers used enamel to mark all foundresses with unique color patterns on the thorax. Then, two at a time, "fighter" wasps were placed in a small container known as the fighting arena while two "bystander" wasps observed the pair through clear plastic partitions.

All trials were videotaped, and a research assistant assigned scores to each fighter using an aggression index that awards points for behaviors like biting, mounting, grappling and stinging. Dominance rank was determined using the number of mounts--a dominance behavior in which the dominant wasp drums her antennae on the subordinate while the subordinate crouches and lowers her antennae--during a fight.

Later, bystander wasps were paired in the fighting arena either with a wasp they had observed (experimental trial) or a fighter they had never seen before (control trial). Tibbetts and her students compared the behaviors in the experimental and control trials to determine the role of social eavesdropping.

They found that bystander wasps were more aggressive when paired with an individual that was the victim of lots of aggression in a previous bout, as well as individuals who initiated very little aggression in the previous fight.

By comparing experimental and control trials, the researchers were also able to reject non-eavesdropping explanations for the observations, including phenomena called priming and winner/loser effects.

"The results show that P. fuscatus wasps use social eavesdropping," Tibbetts said. "Bystanders observe other individuals fight, and they use information about the fight to modulate subsequent behavior."

In previous studies over more than a decade, Tibbetts and her colleagues showed that paper wasps recognize individuals of their species by variations in their facial markings, and they behave more aggressively toward wasps with unfamiliar faces.

They also demonstrated that paper wasps have surprisingly long memories and base their behavior on what they remember of previous social interactions.

But the previous work focused on how wasps use individual recognition during direct interactions and did not test--as this new study did--whether wasps learn about other individuals via observation alone.

Dolphins use unusual techniques to obtain food: One of them, called "shelling", is used by the dolphins in Shark Bay in Western Australia. Dolphins in this population trap fishes inside large empty gastropod shells. The shells are then brought to the surface and vigorously shaken so that the water drains out and the fish falls into their open mouth. Using the empty shell in this manner is comparable to tool use in humans.

Dolphins learn directly from their peers

It was previously thought the only way dolphins could learn new foraging methods while with their mother, a process known as vertical social transmission. However, a study initiated by Michael Krützen, director of the Department of Anthropology at the University of Zurich (UZH), has now shown that "shelling" is mainly passed on between peers rather than across generations - that is, via horizontal transmission. "Our results provide the first evidence that dolphins are also capable of learning from their peers as adults," says Krützen. The analysis of extensive behavioral, genetic and environmental data spanning more than a decade led to these findings.

Cultural behavior similar to that of great apes

"This is an important milestone. It shows that cultural behavior of dolphins and other toothed whales is much more similar to the behavior of great apes, including humans, than was previously thought," says Krützen. Gorillas and chimpanzees also learn new foraging techniques through both vertical and horizontal transmission. Although their evolutionary history and their environments are very different, there are striking similarities between cetaceans and great apes, according to Krützen: "Both are long-lived mammals with large brains that are capable of innovation and of passing on cultural behaviors."

Behavioral observation over more than 10 years

The researchers made their discovery between 2007 and 2018 in the Western Gulf Zone of Shark Bay, where they observed Indo-Pacific bottlenose dolphins (Tursiops aduncus) and documented how the shelling behavior was spread within the population. During this time, they identified more than 1,000 individuals from around 5,300 encounters with dolphin groups. "In total we documented 42 individual uses of shelling by 19 different dolphins," says study leader Sonja Wild, who completed her PhD at the University of Leeds, and is now a postdoc at the University of Konstanz.

Quicker adaptation to changing environments

This discovery that wild dolphins can learn new foraging techniques outside of the mother-calf bond significantly widens our understanding of how they can adapt to fluctuating environmental conditions through behavioral changes. "Learning from others allows for a rapid spread of novel behaviors across populations," says Wild.

For example, an unprecedented marine heatwave in 2011 was responsible for wiping out a large number of fish and invertebrates in Shark Bay, including the gastropods inhabiting the shells. "While we can only speculate as to whether the heatwave and subsequent prey depletion gave the dolphins a boost to adopt new foraging behavior from their associates, it seems quite possible that an abundance of dead shells may have increased learning opportunities for shelling behavior," says Sonja Wild.

What The Study Did: The possible association between chilblains and COVID-19 was investigated in this case series that included 31 patients.

Authors: Anne Herman, M.D., of the Université Catholique de Louvain in Brussels, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamadermatol.2020.2368)

Editor's Note: The article includes conflicts of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflicts of interest and financial disclosures, and funding and support.

A new study brings neural-level evidence that the continuous variation in natural speech makes the discrimination of phonemes challenging for adults suffering from developmental reading-deficit dyslexia.

This may compromise the learning of native language phonemes already at an early age for infants at familial risk for dyslexia.

Dyslexia is understood to stem from difficulties in phoneme processing. Natural speech has continuous acoustic variation, and the phonemes sound different depending on, for example, the word context or speaker identity. In order to effortlessly understand speech, the phonemes still have to be detected accurately.

"In our study, dyslexic participants had difficulties, particularly when acoustic variation was added to the speech sound stream. In the absence of this variation, neural speech sound processing did not differ between dyslexic and typical readers. This seems to reflect a difficulty in categorising speech sounds in the native language phoneme classes," Dr Paula Virtala from the University of Helsinki explains.

Understanding the neural mechanisms of dyslexia will help in targeting and designing rehabilitation for children with language development or reading problems, and in preventing future difficulties early in infants and small children at familial risk.

EEG revealed differences

The study, which was published recently in Scientific Reports, was conducted by recording the neural activity of 18 dyslexic and 20 typically reading adults with electroencephalography (EEG).

The participants listened to a stream of Finnish speech sounds at various pitch levels passively, with their attention directed away from the stimulation, and actively, by pressing a response button when detecting a change in the speech sounds.

Auditory event-related potentials differed between the two groups in both conditions. Dyslexic participants were also less accurate in detecting the changes.

"These kinds of studies conducted in adults allow for longer recording sessions and a broader range of methods compared to studies in children. We can utilise these findings in our longitudinal DyslexiaBaby study," Paula Virtala explains.

The DyslexiaBaby study is conducted in the Cognitive Brain Research Unit at University of Helsinki. It follows children's language development, particularly in families with dyslexia. The study is conducted in collaboration with Helsinki University Hospital and the University of Jyväskylä.

Monash University researchers have discovered that the devastating bacterial superbug Clostridioides difficile hijacks the human wound healing system in order to cause serious and persistent disease, opening up the development of new therapies to treat the disease.

Clostridioides difficile is the most common hospital-acquired disease and causes persistent and life-threatening gut infections - particularly in elderly and immunocompromised patients.

The infection is very difficult to treat, and often repeatedly reoccurs in patients even after they have been given powerful and debilitating antibiotics for many months. C. difficile is also highly resistant to antibiotics, which greatly complicates treatment.

A team based in the Monash Biomedicine Discovery Institute (BDI) found that C. difficile massively activates a human enzyme called plasminogen in order to destroy gut tissue and to help spread the infection throughout the patient. Ordinarily, plasminogen, and its active form plasmin, is deployed in a highly controlled fashion to break down scar tissue and help wounds heal.

"The results were a huge surprise, and revealed that the severe damage caused to the gut by C. difficile was actually caused by a human enzyme rather than a bacterial toxin," said study co-leader and infectious disease expert Prof Dena Lyras.

Given their findings, the researchers decided to investigate whether potent antibodies developed by the team and that inhibited the plasminogen / plasmin system could be used to treat the disease.

"We found that an antibody that prevented plasminogen from being activated dramatically stalled the progress of infection and tissue damage," said first author Milena Awad.

The researchers now aim to commercialise their antibodies in order to treat a range of bacterial and inflammatory diseases.

An advantage of targeting a human protein in an infectious disease is that resistance to the therapy is far less likely to occur.

"The antibody could have broad utility, since the plasminogen / plasmin system is dysregulated in a range of different serious inflammatory and infectious diseases - for example, the plasminogen system most likely is a driver of the devastating lung damage seen in COVID-19," said study co-leader and structural biologist Prof James Whisstock.

The basis of the construction industry clashes head-on with environmental sustainability. Extracting raw materials and turning them into building materials has high energetic costs. Granite production, totaling 614,000 tons in Spain in 2013, leaves behind it a series of residues that are difficult to manage. This is the case of granite sludge, the material that results from the mixture of dust particles given off during the cutting process and the water used to cool the blade. When granite sludge is dumped at a landfill and the water evaporates, the silicon dust ends up going into the atmosphere and can be inhaled, with negative health consequences. It can also interfere with normal soil mechanics.

Aiming to properly manage these residues and in doing so prevent health and environmental problems, three University of Cordoba research groups have joined forces to analyze the feasibility of using granite sludge to substitute conventional aggregates in self-compacting mortar.

In this vein, "it is possible to substitute up to 40% of conventional aggregates for granite sludge while still maintaining the mortar's qualities of durability, strength and compaction" according to the lead researcher working on the study, Angélica Lozano, from the the Construction Engineering group at UCO. Thus, granite sludge becomes a sustainable alternative to using conventional aggregates.

Working in synergy with each other are the groups of "Construction Engineering", "Materials and Applications" and "Plasma Physics: Characterization, Models and Applications", led by Professors José Ramón Jiménez, José María Fernández and Antonio Rodero respectively. Two aims are accomplished: managing a residue that is bad for our health, and the environmental sustainability of self-compacting concrete, currently one of the most sought-after materials in the building industry since it can be compacted without having to apply compaction energy. Despite the advantages of this new material, the need for a high percentage of aggregates to be extracted is not environmentally sustainable. However, using granite sludge will greatly help solve the problem of this lack of sustainability.

Three members of the BiRTE research group at the UPV/EHU's Faculty of Economics and Business have published an analysis of the evolution in electricity prices during a 16-year period (2002 to 2017); the article appears in Energy Economics, a journal positioned in the first decile in the field of Economics. The study set out to see how various factors linked to renewable energy affect the price of electricity. As a starting point, "the incorporating of this energy is known to exert a dual effect: firstly, it lowers the price, in other words, the energy that is transacted is cheaper, because renewable energy has a unit cost of production very close to zero. Secondly, however, it increases price volatility, fluctuations that occur in the price, because as it is an intermittent energy, availability and therefore generation cannot always be guaranteed", explained Aitor Ciarreta-Antuñano, lead researcher in the BiRTE research group and co-author of this publication.

However, the authors wanted to go one step further in the analysis of volatility and incorporate into the analysis the influence exerted by the regulatory framework, the policies that govern the setting up of renewable energy plants and the grants used to provide them with incentives. "The regulatory framework is crucial in the electricity market and, what is more, is greatly influenced by European directives. We wanted to see whether the periods in which there was uncertainty in this aspect have influenced the volatility of the price of electricity," said Ciarreta. To do this "we built a statistical model with the data on the electricity prices of the Spanish market that included the data on a 16-year period", to be able to see on the basis of which indicators volatility varied.

Increased volatility associated with regulatory uncertainty

The statistical analysis of the data revealed "a grouping or cluster of volatility in the specific period in which there was uncertainty in the regulatory framework in Spain". In the period analysed, from 2002 to 2017, the researcher highlights the differentiation of "phases in which there is a very stable regulatory framework, such as that which occurred between 2007 and 2012, when direct grants were awarded to generate renewable electrical power. However, in 2012, there was a change in the regulations which did not settle down until 2014 and these two years of regulatory uncertainty coincide with the period that saw the highest level of volatility in electricity prices, which has nothing to do with the fact that renewable energies lead to a certain volatility owing to their intermittent nature. Economic players are disrupted most by the uncertainty associated with regulatory policies", stressed the PhD-holder in Economics.

The period of regulatory uncertainty described was caused by various factors, as Ciarreta described. "From 2010 onwards the economic crisis also reached the electricity market and this crisis was accentuated by the high deficit growth occurring during the previous period, in which the degree of funding of renewables was regulated so that it ended up accounting for nearly 3% of GDP. The European Union was also putting pressure on Spain to control that deficit."

Faced with this situation, the government tried to put together a new system designed to promote renewable energies because Spain also had to meet the aims on reducing CO2 emissions. It took the country two years to establish the new system and when it was implemented uncertainty returned to the markets. "The rate of return offered by the new regulatory system was lower, and one may more or less agree with what had been established, but we can see that this did not affect the volatility of the price of electricity, uncertainty affects it much more. Investors derive more security from knowing what they have to comply with," said the researcher. And at the end of the day, citizens, too, are affected, because most of us are paying rates that depend on the daily market price", he added.

The researcher believes that the results obtained in this analysis should serve "as a wake-up call for regulators, so that they do not adopt measures to change regulations hastily, and that regulation should be kept as stable as possible. And if they make any changes, they should allow the players to react in such a way that uncertainty is not incorporated in electricity markets".

Starting university is an exciting phase for everyone. However, children from academic households exhibit significantly more stress during this period than those from non-academic families. A Swiss-German research team has found this out by analysing the hair of female first-year students. Study authors Professor Alex Bertrams from the University of Bern and Dr. Nina Minkley from Ruhr-Universität Bochum (RUB) have concluded that students may be stressed by the fear of jeopardising the social status of their families if they fail their degrees. They published their report in Frontiers of Psychiatry on 5 June 2020.

Stress hormone accumulates in the hair

In stressful situations, the body releases an increased amount of the hormone cortisol, which also reaches growing hair and is stored there if the levels remain high over a lengthy period of time. By analysing the hair, researchers can identify the phases when a person had more stress.

In order to find out whether the stress levels of young people from different family backgrounds differ when they're starting university, the research team recruited a total of 71 test persons. "The only inclusion criteria were that they started their first semester and that they had sufficiently long hair," explains Nina Minkley from the Behavioural Biology and Didactics of Biology research group at RUB. "In the end, this meant that we recruited almost only women, and we decided not to include the few eligible men to avoid falsifying the results."

Strands of hair and questionnaires

The participants supplied the research team with three thin strands of hair each, which were cut off near the scalp. Since a hair grows about one centimetre per month, the researchers examined the latest one and a half centimetres that had grown in the six weeks since the beginning of the semester. In addition, the participants filled out questionnaires in which they provided information about their parents' educational background. They were also asked about the stress they subjectively perceived.

It emerged that first-year students from academic households where at least one parent had a university degree exhibit higher stress levels than those from non-academic households, even though they didn't differ in other respects. The subjectively perceived stress levels, for example, were the same.

Stress due to impending loss of status

The research team interprets this result as an indication of female students from academic households being under greater pressure, because failing their study would result in a loss of status for them and their families. This is in line with findings in sociological studies, which have shown that children of academics tend to go to university even if their academic performance isn't expected to be successful, based on their school grades. "Children of non-academics, on the other hand, can only win and are therefore probably less stressed," concludes Minkley.