Culture

New research from the Georgia Institute of Technology finds that elephants dilate their nostrils in order to create more space in their trunks, allowing them to store up to nine liters of water. They can also suck up three liters per second -- a speed 30 times faster than a human sneeze (150 meters per second/330 mph).

The Georgia Tech College of Engineering study sought to better understand the physics of how elephants use their trunks to move and manipulate air, water, food and other objects. They also sought to learn if the mechanics could inspire the creation of more efficient robots that use air motion to hold and move things.

While octopus use jets of water to move and archer fish shoot water above the surface to catch insects, the Georgia Tech researchers found that elephants are the only animals able to use suction on land and underwater.

The paper, "Suction feeding by elephants," is published in the Journal of the Royal Society Interface.

"An elephant eats about 400 pounds of food a day, but very little is known about how they use their trunks to pick up lightweight food and water for 18 hours, every day," said Georgia Tech mechanical engineering Ph.D. student Andrew Schulz, who led the study. "It turns out their trunks act like suitcases, capable of expanding when necessary."

Schulz and the Georgia Tech team worked with veterinarians at Zoo Atlanta, studying elephants as they ate various foods. For large rutabaga cubes, for example, the animal grabbed and collected them. It sucked up smaller cubes and made a loud vacuuming sound, or the sound of a person slurping noodles, before transferring the vegetables to its mouth.

To learn more about suction, the researchers gave elephants a tortilla chip and measured the applied force. Sometimes the animal pressed down on the chip and breathed in, suspending the chip on the tip of trunk without breaking it. It was similar to a person inhaling a piece of paper onto their mouth. Other times the elephant applied suction from a distance, drawing the chip to the edge of its trunk.

"An elephant uses its trunk like a Swiss Army Knife," said David Hu, Schulz's advisor and a professor in Georgia Tech's George W. Woodruff School of Mechanical Engineering. "It can detect scents and grab things. Other times it blows objects away like a leaf blower or sniffs them in like a vacuum."

By watching elephants inhale liquid from an aquarium, the team was able to time the durations and measure volume. In just 1.5 seconds, the trunk sucked up 3.7 liters, the equivalent of 20 toilets flushing simultaneously.

An ultrasonic probe was used to take trunk wall measurements and see how the trunk's inner muscles work. By contracting those muscles, the animal dilates its nostrils up to 30 percent. This decreases the thickness of the walls and expands nasal volume by 64 percent.

"At first it didn't make sense: an elephant's nasal passage is relatively small and it was inhaling more water than it should," said Schulz. "It wasn't until we saw the ultrasonographic images and watched the nostrils expand that we realized how they did it. Air makes the walls open, and the animal can store far more water than we originally estimated."

Based on the pressures applied, Schulz and the team suggest that elephants inhale at speeds that are comparable to Japan's 300-mph bullet trains.

Schulz said these unique characteristics have applications in soft robotics and conservation efforts.

"By investigating the mechanics and physics behind trunk muscle movements, we can apply the physical mechanisms -- combinations of suction and grasping -- to find new ways to build robots," Schulz said. "In the meantime, the African elephant is now listed as endangered because of poaching and loss of habitat. Its trunk makes it a unique species to study. By learning more about them, we can learn how to better conserve elephants in the wild."

AMES, Iowa - An unexpected discovery by an Iowa State University researcher suggests that the first humans may have arrived in North America more than 30,000 years ago - nearly 20,000 years earlier than originally thought.

Andrew Somerville, an assistant professor of anthropology in world languages and cultures, says he and his colleagues made the discovery while studying the origins of agriculture in the Tehuacan Valley in Mexico. As part of that work, they wanted to establish a date for the earliest human occupation of the Coxcatlan Cave in the valley, so they obtained radiocarbon dates for several rabbit and deer bones that were collected from the cave in the 1960s as part of the Tehuacan Archaeological-Botanical Project. The dates for the bones suddenly took Somerville and his colleagues in a different direction with their work.

The date ranges for the bone samples from the base of the cave ranged from 33,448 to 28,279 years old. The results are published in the academic journal Latin American Antiquity. Somerville says even though previous studies had not dated items from the bottom of the cave, he was not expecting such old ages. The findings add to the debate over a long-standing theory that the first humans crossed the Bering Land Bridge into the Americas 13,000 years ago.

"We weren't trying to weigh in on this debate or even find really old samples. We were just trying to situate our agricultural study with a firmer timeline," Somerville said. "We were surprised to find these really old dates at the bottom of the cave, and it means that we need to take a closer look at the artifacts recovered from those levels."

Somerville says the findings provide researchers with a better understanding of the chronology of the region. Previous studies relied on charcoal and plant samples, but he says the bones were a better material for dating. However, questions still remain. Most importantly, is there a human link to the bottom layer of the cave where the bones were found?

To answer that question, Somerville and Matthew Hill, ISU associate professor of anthropology, plan to take a closer look at the bone samples for evidence of cut marks that indicate the bones were butchered by a stone tool or human, or thermal alternations that suggest the bones were boiled or roasted over fire. He says the possible stone tools from the early levels of the cave may also yield clues.

"Determining whether the stone artifacts were products of human manufacture or if they were just naturally chipped stones would be one way to get to the bottom of this," Somerville said. "If we can find strong evidence that humans did in fact make and use these tools, that's another way we can move forward."

Year-long journey to even find the bones

Not only was this discovery unexpected, but the process of tracking down the animal bones to take samples was more than Somerville anticipated. The collection of artifacts from the 1960s Tehuacan Archaeological-Botanical Project was distributed to different museums and labs in Mexico and the United States, and it was unclear where the animal bones were sent.

After a year of emails and cold calls, Somerville and his collaborator, Isabel Casar from the National Autonomous University of Mexico, had a potential lead for a lab in Mexico City. The lab director, Joaquin Arroyo-Cabrales, agreed to give Somerville and Casar a tour to help search for the missing collection. The tour proved to be beneficial. Among the countless boxes of artifacts, they found what they were looking for.

"Having spent months trying to locate the bones, we were excited to find them tucked away on the bottom shelf in a dark corner of the lab," Somerville said. "At the time, we felt that was a great discovery, we had no idea it would lead to this."

Once he located the bones, Somerville got permission from the Mexican government to take small samples - about 3/4 inch in length and 1/4 inch in width - from 17 bones (eight rabbits and nine deer) for radiocarbon dating. If closer examination of the bones provides evidence of a human link, Somerville says it will change what we know about the timing and how the first people came to America.

"Pushing the arrival of humans in North America back to over 30,000 years ago would mean that humans were already in North America prior to the period of the Last Glacial Maximum, when the Ice Age was at its absolute worst," Somerville said. "Large parts of North America would have been inhospitable to human populations. The glaciers would have completely blocked any passage over land coming from Alaska and Canada, which means people probably would have had to come to the Americas by boats down the Pacific coast."

Key takeaways

The surgical simulator can realistically simulate multiple trauma scenarios at once, compared with traditional simulators that can only simulate one or a limited number of conditions.

Trauma team members who tested the simulator preferred it for its realism, physiologic responses, and feedback.

The benefits of this innovative simulator may be able to extend to other surgical procedures and settings.

CHICAGO (June 1, 2021): Simulators have long been used for training surgeons and surgical teams, but traditional simulator platforms typically have a built-in limitation: they often simulate one or a limited number of conditions that require performance of isolated tasks, such as placing an intravenous catheter, instead of simulating and providing opportunities for feedback on the performance of multiple interventions that a trauma victim may require at the same time. To overcome this limitation, the Advanced Modular Manikin (AMM), an innovative simulation platform that allows integration of other simulation devices, was developed and field testing was conducted, with support from the Department of Defense (DoD).

The DoD subcontracted with the American College of Surgeons (ACS) Division of Education to conduct field testing of the AMM. The results have been published online in advance of print by the Journal of the American College of Surgeons. Robert M. Sweet, MD, FACS, MAMSE, of the department of surgery at the University of Washington, served as principal investigator (PI) of the DoD contract to build the AMM. Ajit K. Sachdeva, MD, FACS, FRCSC, FSACME, MAMSE, Director, Division of Education, American College of Surgeons, served as the PI for the subcontract to conduct field testing.

The investigators reported that members of trauma teams at a testing site preferred the integrated AMM platform including a "peripheral" simulator over the "peripheral" simulator alone, in terms of realism, physiologic responses, and feedback they receive on the multiple and overlapping interventions they perform on a simulated trauma patient. Corresponding study author Dimitrios Stefanidis, MD, PhD, FACS, FASMBS, FSSH, of the department of surgery at Indiana University School of Medicine, Indianapolis, described the AMM as "more of a platform rather than a manikin."

The DoD supported development of the AMM through a contract with the University of Minnesota and the University of Washington. The goal was to create an open-source simulation platform that permits integration of a number of simulators, known as "peripherals," into a singular, comprehensive training platform. A Steering Committee composed of leaders and staff of the ACS Division of Education and the Research and Development Committee of the ACS-Accredited Education Institutes, along with leaders from the Development Team of the AMM Project created the model for field testing the AMM.

"The AMM platform, along with the 'peripherals,' can help to address the need for more robust simulators that focus on open procedures and interprofessional teamwork," Dr. Sachdeva explained. "The ability to integrate the anatomic and physiologic elements of the simulation is an important advance. The experience with the trauma scenario may readily be extended to other surgical procedures and settings."

Corresponding author Dr. Stefanidis explained that with most traditional simulators, instructors have to manipulate vital signs to respond to specific actions of the learner. He pointed out that the AMM promotes "a learner experience that is more based on the actual physiology of what's happening to the patient." The AMM platform allows different members of the trauma team to perform different tasks concurrently--one inserts a breathing tube, another starts an intravenous line, another performs a splenectomy. "All of these interventions impact the physiology," he said.

The researchers evaluated team experience ratings of 14 trauma teams consisting of 42 individual members who performed tasks on the integrated AMM platform and the standalone "peripheral" simulator. Team experience ratings were higher for the integrated AMM platform as compared with the standalone "peripheral" simulator. Among the team members, surgeons and first responders rated their experience significantly higher than anesthesiologists, who noted higher workload ratings. In focus groups, the team members said they preferred the AMM platform because of its increased realism, and for the way it responded physiologically to their actions and the feedback it provided.

Dr. Stefanidis explained how the AMM can potentially aid in training trauma teams. "Trauma requires exemplary teamwork," he said. "When we see patients who are injured, there are typically multiple providers who take care of them simultaneously--trauma surgeons, emergency room physicians, anesthesiologists, orthopedic surgeons, neurosurgeons, nurses, respiratory therapists, etc. So, it's extremely important to also be able to train these teams in a low-stress simulation environment, such as by using the AMM, where they can hone their skills, individually and as a team, and perform at their best when faced with the very high-stress clinical environment."

The AMM platform offers other benefits for improving the training and proficiency of trauma teams, said the field study PI, Dr. Sachdeva. "Specific training models could be standardized and the situation made increasingly complex in this safe simulation environment," he said.

Berkeley -- Global land-use changes -- including forest fragmentation, agricultural expansion and concentrated livestock production -- are creating "hot spots" favorable for bats that carry coronaviruses and where conditions are ripe for the diseases to jump from bats to humans, finds an analysis published this week by researchers at the University of California, Berkeley, the Politecnico di Milano (Polytechnic University of Milan) and Massey University of New Zealand.

While the exact origins of the SARS-CoV-2 virus remain unclear, scientists believe that the disease likely emerged when a virus that infects horseshoe bats was able to jump to humans, either directly through wildlife-to-human contact, or indirectly by first infecting an intermediate animal host, such as the pangolin, sometimes known as the scaly anteater. Horseshoe bats are known to carry a variety of coronaviruses, including strains that are genetically similar to ones that cause COVID-19 and severe acute respiratory syndrome (SARS).

The new study used remote sensing to analyze land use patterns throughout the horseshoe bat's range, which extends from Western Europe through Southeast Asia. By identifying areas of forest fragmentation, human settlement and agricultural and livestock production, and comparing these to known horseshoe bat habitats, they identified potential hot spots where habitat is favorable for these bat species, and where these so-called zoonotic viruses could potentially jump from bats to humans. The analysis also identified locations that could become easily become hot spots with changes in land use.

"Land use changes can have an important impact on human health, both because we are modifying the environment, but also because they can increase our exposure to zoonotic disease," said study co-author Paolo D'Odorico, a professor of environmental science, policy and management at UC Berkeley. "Every formal land use change should be evaluated not only for the environmental and social impacts on resources such as carbon stocks, microclimate and water availability, but also for the potential chain reactions that could impact human health."

Most of the current hot spots are clustered in China, where a growing demand for meat products has driven the expansion of large-scale, industrial livestock farming. Concentrated livestock production is particularly concerning because the practice brings together large populations of genetically similar, often immune-suppressed animals that are highly vulnerable to disease outbreaks, the researchers said.

The analysis also found that parts of Japan, the north Philippines and China south of Shanghai are at risk of becoming hot spots with further forest fragmentation, while parts of Indochina and Thailand may transition into hot spots with increases in livestock production.

"The analyses aimed to identify the possible emergence of new hot spots in response to an increase in one of three land use attributes, highlighting both the areas that could become suitable for spillover and the type of land use change that could induce hot spot activation," said study co-author Maria Cristina Rulli, a professor in hydrology and water and food security at the Politecnico di Milano in Italy. "We hope these results could be useful for identifying region-specific targeted interventions needed to increase resilience to coronavirus spillovers."

Human encroachment into natural habitat can also can indirectly increase exposure to zoonotic disease by reducing valuable biodiversity. When forest lands become fragmented and natural habitats are destroyed, species that require very specific habitat to survive, called "specialists," may dwindle or even go extinct. Without competition from specialists, "generalist" species, which are less picky about their habitat, can take over.

Horseshoe bats are a generalist species and have often been observed in areas characterized by human disturbance. Earlier work by Rulli, D'Odorico and study co-author David Hayman has also linked forest fragmentation and habitat destruction in Africa to outbreaks of the Ebola virus.

"By creating conditions that are disadvantageous to specialist species, generalist species are able to thrive," D'Odorico said. "While we are unable to directly trace the transmission of SARS-CoV-2 from wildlife to humans, we do know that the type of land use change that brings humans into the picture is typically associated with the presence of these bats who are known to carry the virus."

While China has been a leader in tree planting and other greening efforts over the past two decades, many of the trees have been planted in discontinuous land areas or forest fragments. To tilt the ecological balance back in favor of specialist species, creating continuous areas of forest cover and wildlife corridors are more important than increasing total tree cover.

"Human health is intertwined with environmental health and also animal health," D'Odorico said. "Our study is one of the first to connect the dots and really drill down into the geographic data on land use to see how humans are coming into contact with species that might be carriers."

By ensuring ethnic diversity in a largescale genetic study, an international team of researchers, including a University of Massachusetts Amherst genetic epidemiologist, has identified more regions of the genome linked to type 2 diabetes-related traits.

The findings, published May 31 in Nature Genetics, broaden the understanding of the biological basis of type 2 diabetes and demonstrate that expanding research into different ancestries yields better results. Ultimately the goal is to improve patient care worldwide by identifying genetic targets to treat the chronic metabolic disorder. Type 2 diabetes affects and sometimes debilitates more than 460 million adults worldwide, according to the International Diabetes Federation. About 1.5 million deaths were directly caused by diabetes in 2019, the World Health Organization reports.

Cassandra Spracklen, assistant professor of biostatistics and epidemiology in the UMass Amherst School of Public Health and Health Sciences, is part of the international MAGIC collaboration. That group of more than 400 global academics conducted the genome-wide association meta-analysis, led by the University of Exeter in the United Kingdom.

"Our findings matter because we're moving toward using genetic scores to weigh up a person's risk of diabetes," says Spracklen, one of the paper's lead authors.

Up to now, some 88% of genomic research of this type has been conducted in white European-ancestry populations. "We know that scores developed exclusively in individuals of one ancestry don't work well in people of a different ancestry," Spracklen adds.

The team analyzed data across a wide range of cohorts, encompassing more than 280,000 people without diabetes. Researchers looked at glycemic traits, which are used to diagnose diabetes and monitor sugar and insulin levels in the blood.

The researchers incorporated 30 percent of the overall cohort with individuals of East Asian, Hispanic, African-American, South Asian and sub-Saharan African origin. By doing so, they discovered 24 more loci - or regions of the genome - linked to glycemic traits than if they had conducted the research in Europeans alone.

"Type 2 diabetes is an increasingly huge global health challenge- with most of the biggest increases occurring outside of Europe," says Inês Barroso, professor of diabetes at the University of Exeter, who led the research. "While there are a lot of shared genetic factors between different countries and cultures, our research tells us that they do differ in ways that we need to understand. It's critical to ensuring we can deliver a precision diabetes medicine approach that optimizes treatment and care for everyone."

First author Ji Chen, a data science expert at the University of Exeter, adds: "Beyond the moral arguments for ensuring research is reflective of global populations, our work demonstrates that this approach generates better results."

Though some loci were not detected in all ancestries, the team found it is useful to capture information about the glycemic trait in individual ancestries.

"This is important as increasingly healthcare is moving toward a more precise approach," Spracklen says. "Failing to account for genetic variation according to ancestry will impact our ability to accurately diagnose diabetes."

The quality of a sewn garment is dependent on the quality of its seams that are the basic structural element. The factors affecting seam quality in garments include sewing thread type and stitch density. Making the right choice of these helps in getting quality seams in garments. However, the choice of suitable sewing threads and stitch densities for particular fabrics can only be determined through testing.

Dr. Patience Danquah Monnie, from the University of Cape Coast, Ghana, with fellow researchers, conducted research aimed to determine sewing thread brand and stitch density suitable for seams for a selected fabric (79% polyester and 21% cotton) for public basic school uniforms in Ghana. For the research, a 2×3 factorial design was employed involving two brands of sewing threads labelled A? and B?, with three range of stitch density, 10, 12 and 14. There were a total of 81 specimens prepared from the selected fabric. The parameters, under investigation in the research, included fabric weight, strength and elongation, seam strength, seam elongation and efficiency.

With the help of the Predictive Analytic Software (SPSS), the gathered data was analyzed. For the fabric, means and standard deviations of the yarn count, weight, strength, elongation and the linear density of the sewing threads were determined. Analysis of Variance and Independent samples t-test at 0.05 alpha levels were employed in testing the hypotheses.

The researchers found that the differences for seam strength, efficiency and elongation were significant for the two sewing thread brands and the three stitch densities in both warp and weft directions of the fabric sample. The sewing thread brand B? with stitch density 14 performed best in terms of seam strength, elongation and efficiency. Concluding the research findings, sewing thread brand B? and 14 stiches per inch (SPI) were found suitable for seams for the fabric selected for Ghanaian public basic school uniforms as they had greater strength, efficiency and elongation than thread A? and SPIs 10 and 12.

It is recommended that members of the Association of Ghana Apparel Manufacturers (AGAM) and Tailors and Dressmakers Association use sewing thread brand B? with 14 SPI in uniform production in Ghana to achieve quality seams in uniforms.

You may think a little white lie about a bad haircut is strictly for your friend's benefit, but your brain activity says otherwise. Distinct activity patterns in the prefrontal cortex reveal when a white lie has selfish motives, according to new research published in JNeurosci.

White lies -- formally called Pareto lies -- can benefit both parties, but their true motives are encoded by the medial prefrontal cortex (MPFC). This brain region computes the value of different social behaviors, with some subregions focusing on internal motivations and others on external ones. Kim and Kim predicted activity patterns in these subregions could elucidate the true motive behind white lies.

The research team deployed a stand in for white lies, having participants tell lies to earn a reward for themselves, for an unknown person, or for both. The team used fMRI to measure the MPFC activity of participants and, by comparing the brain activity of white lies with the selfish and altruistic lies, they could predict the true motivation for the lies. Selfish white lies elicited greater activity in the ventral and rostral MPFC. Activity patterns in the ventral subregion was similar to that of selfish lies, while activity patterns in the rostral subregion was dissimilar to altruistic lies.

Below please find summaries of new articles that will be published in the next issue of Annals of Internal Medicine. The summaries are not intended to substitute for the full articles as a source of information. This information is under strict embargo and by taking it into possession, media representatives are committing to the terms of the embargo not only on their own behalf, but also on behalf of the organization they represent.

1. Tai chi about equal to conventional exercise for reducing belly fat in middle-aged and older adults

HD video soundbites of the author discussing the findings are available to download at http://www.dssimon.com/MM/ACP-tai-chi

Abstract: https://www.acpjournals.org/doi/10.7326/M20-7014

URL goes live when the embargo lifts

A randomized controlled trial found that tai chi is about as effective as conventional exercise for reducing waist circumference in middle-aged and older adults with central obesity. Central obesity, or weight carried around the midsection, is a major manifestation of metabolic syndrome and a common health problem in this cohort. The findings are published in Annals of Internal Medicine.

Tai chi is a form of mind-body exercise often described as "meditation in motion." It is practiced in many Asian communities and is becoming increasingly popular in Western countries, with more than 2 million people practicing it in the United States. While it is known to be a suitable activity for older people including those who are not active, there previously has been little evidence on tai chi's health benefits.

Researchers from the University of Hong Kong randomly assigned more than 500 adults over 50 with central obesity to a regimen of tai chi, conventional exercise, or no exercise over 3 months. Participants in the tai chi and exercise groups met for instructor-led workouts for 1 hour 3 times a week for 12 weeks. The tai chi program consisted of the Yang style of tai chi, the most common style adopted in the literature, and the conventional exercise program consisted of brisk walking and strength training activities. Waist circumference and other indicators of metabolic health were measured at baseline, 12 weeks, and 38 weeks. The researchers found that both the tai chi intervention and conventional exercise intervention group had reductions in waist circumference, relative to control. The reduction in waist circumference had a favorable impact on HDL cholesterol, or so-called good cholesterol, but did not translate into detectable differences in fasting glucose or blood pressure.

According to the study authors, their findings are good news for middle-aged and older adults who have central obesity but may be averse to conventional exercise due to preference or limited mobility.

Media contacts: For an embargoed PDF, please contact Angela Collom at acollom@acponline.org. To speak with the corresponding author, Parco M. Siu, PhD, please email pmsiu@hku.hk.

2. COVID-19 disease and cost burden especially high among older adults, particularly those of color

Abstract: https://www.acpjournals.org/doi/10.7326/M21-1102

Editorial: https://www.acpjournals.org/doi/10.7326/M21-2187

URL goes live when the embargo lifts

A retrospective observational study found that the COVID-19 disease burden among adults aged 65 years or older was substantially higher than in the general U.S. population, especially among those of non-White race/ethnicity. The findings are published in Annals of Internal Medicine.

Researchers from the Centers for Disease Control and Prevention (CDC) used Medicare claims data for 28.1 million fee-for-service beneficiaries to examine the characteristics and medical costs of older adults who were diagnosed with COVID-19 from April through December 2020. The data showed that the hospitalization rate was more than 60 times higher, and the mortality rate was 2.5 times higher (4.2%) for older adults compared to the general population. The average cost per COVID-19-related hospitalization was considerable ($21,752) among those older adults, but the costs of COVID-19-related hospitalization decreased with age for the 5 medical outcomes considered. According to the authors, possible reasons include higher mortality rates among older patients, resulting in shorter hospital stays and lower costs (inpatient length of stay was shorter among patients aged ?75 years than among those aged 65 to 74 years); the lower likelihood of younger adults to become seriously ill (those who reached the point of hospitalization may have had substantial risks and complications); and less aggressive care with increasing age.

The data also showed that people of color accounted for a disproportionate share of hospitalizations and deaths during the pandemic. Black, Hispanic, and Asian/Pacific Islander older adults had higher probability of death and receiving ventilator support during hospitalization than non-Hispanic White patients. This finding highlights the importance of identifying effective strategies to promote COVID-19 vaccine uptake among non-White persons aged 65 years or older to mitigate the increased disease and economic burden.

Media contacts: For an embargoed PDF, please contact Angela Collom at acollom@acponline.org. To speak with the corresponding author, Yuping Tsai, PhD, please contact Kristen Nordlund at hok4@cdc.gov.

3. Financial penalties not associated with improvements in quality of outpatient dialysis centers

Abstract: https://www.acpjournals.org/doi/10.7326/M20-6662

URL goes live when the embargo lifts

An observational study found that performance-based financial penalties under the Centers for Medicare & Medicaid Services (CMS) End-Stage Renal Disease Quality Incentive Program (ESRD-QIP) were not associated with improvement in the quality of outpatient dialysis centers. The penalties also did not seem to affect any of the individual outcome measures studied. The findings are published in Annals of Internal Medicine.

There are 500,000 patients on dialysis in the United States today. CMS spends about $100,000 per person/year for patients on dialysis, which is about 6-7% of the total Medicare budget and almost 1% of the total federal government budget. In 2012, the CMS started levying performance-based financial penalties against outpatient dialysis centers under the mandatory ESRD-QIP program. For many reasons, including the complexity of the program, it's effect on quality has never been measured.

Researchers from the Center for Healthcare Outcomes and Policy and the University of Michigan studied publicly available Medicare data to determine whether penalization was associated with improvement in dialysis center quality. The data showed that 1,109 (19.0%) outpatient dialysis centers received penalties in 2017 based on performance in 2015. Penalization was not associated with improvement in total performance scores in 2017 or 2018. This was consistent across a range of different types of centers and individual quality metrics included in the program's total performance score. According to the authors, these findings are significant because they can help Medicare improve the program, which has broad implications for the quality of outpatient dialysis in the United States.

Media contacts: For an embargoed PDF, please contact Angela Collom at acollom@acponline.org. To speak with the corresponding author, Kyle H. Sheetz, MD, MSc, please contact Kara Gavin at kegavin@med.umich.edu.

A new study published in Proceedings of National Academics of Sciences finds that individuals who falsely believe they are able to identify false news are more likely to fall victim to it. In the article published today, Ben Lyons, assistant professor of communication at the University of Utah, and his colleagues examine the concern about the public's susceptibility to false news due to their inability to recognize their own limitations in identifying such information.

"Though Americans believe confusion caused by false news is extensive, relatively few indicate having seen or shared it," said Lyons. "If people incorrectly see themselves as highly skilled at identifying false news, they may unwittingly be more likely to consume, believe and share it, especially if it conforms to their worldview."

Lyons and his colleagues used two large nationally representative surveys with a total of 8,285 respondents. Individuals were asked to evaluate the accuracy of a series of Facebook headlines and then rate their own abilities to discern false news content. Lyons used these two measures to assess overconfidence among respondents and how it is related to beliefs and behaviors.

"Our results paint a worrying picture. Many people are simply unaware of their own vulnerability to misinformation."

The vast majority of respondents--about 90 percent--reported they are above average in their ability to discern false and legitimate news headlines. Three in four individuals overestimated their ability to distinguish between legitimate and false news headlines and respondents placed themselves 22 percentiles higher than their score warranted, on average. About 20 percent of respondents rated themselves 50 or more percentiles higher than their score warranted.

"Using data measuring respondents' online behavior, we show that those who overrate their ability more frequently visit websites known to spread false or misleading news. These overconfident respondents are also less able to distinguish between true and false claims about current events and report higher willingness to share false content, especially when it aligns with their political leanings."

Prior research suggests it may be individuals' lack of skill itself that drives engagement with false news and finds that people who are worse at discerning between legitimate and false news are worse at doing so in their browsing habits. However, Lyons' analysis also shows that inflated perceptions of ability are independently associated with engaging with misinformation, suggesting the perceptual gaps are an additional source of vulnerability.

These results provide new evidence of an important potential mechanism by which people may fall victim to misinformation and disseminate it online. Although the design does not identify the causal effect of overconfidence, these findings suggest that the mismatch between one's perceived ability to spot false stories and people's actual abilities may play an important and previously unrecognized role in the spread of false information online.

After publication, find the full study here.

Very high atmospheric CO2 levels can explain the high temperatures on the still young Earth three to four billion years ago. At the time, our Sun shone with only 70 to 80 per cent of its present intensity. Nevertheless, the climate on the young Earth was apparently quite warm because there was hardly any glacial ice. This phenomenon is known as the 'paradox of the young weak Sun.' Without an effective greenhouse gas, the young Earth would have frozen into a lump of ice. Whether CO2, methane, or an entirely different greenhouse gas heated up planet Earth is a matter of debate among scientists. New research by Dr Daniel Herwartz of the University of Cologne, Professor Dr Andreas Pack of the University of Göttingen, and Professor Dr Thorsten Nagel of the University of Aarhus (Denmark) now suggests that high CO2 levels are a plausible explanation. This would also solve another geoscientific problem: ocean temperatures that were apparently too high. The article "A CO2 greenhouse efficiently warmed the early Earth and decreased seawater 18O/16O before the onset of plate tectonics" appears in the Proceedings of the National Academy of Sciences.

A much-debated question in earth science concerns the temperatures of the early oceans. There is evidence that they were very hot. Measurements of oxygen isotopes on very old limestone or siliceous rocks, which serve as geothermometers, indicate seawater temperatures above 70°C. Lower temperatures would only have been possible if the seawater had changed its oxygen isotope composition. However, this was long considered unlikely.

Models from the new study show that high CO2 levels in the atmosphere may provide an explanation, since they would also have caused a change in the ocean's composition. 'High CO2 levels would thus explain two phenomena at once: first, the warm climate on Earth, and second, why geothermometers appear to show hot seawater. Taking into account the different oxygen isotope ratio of seawater, we would arrive at temperatures closer to 40°C,' said Daniel Herwartz of the University of Cologne. It is conceivable that there was also a lot of methane in the atmosphere. But that would not have had any effect on the composition of the ocean. Thus, it would not explain why the oxygen geothermometer indicates temperatures that are too high. 'Both phenomena can only be explained by high levels of CO2,' Herwartz added. The authors estimate the total amount of CO2 to have totalled approximately one bar. That would be as if today's entire atmosphere consisted of CO2.

'Today, CO2 is just a trace gas in the atmosphere. Compared to that, one bar sounds like an absurdly large amount. However, looking at our sister planet Venus with its approximately 90 bar of CO2 puts things into perspective,' explained Andreas Pack from the University of Göttingen. On Earth, CO2 was eventually removed from the atmosphere and the ocean and stored in the form of coal, oil, gas, and black shales as well as in limestone. These carbon reservoirs are mainly located on the continents. However, the young Earth was largely covered by oceans and there were hardly any continents, so the storage capacity for carbon was limited. 'That also explains the enormous CO2 levels of the young Earth from today's perspective. After all, roughly three billion years ago, plate tectonics and the development of land masses in which carbon could be stored over a long period of time was just picking up speed,' explained Thorsten Nagel from Aarhus University.

For the carbon cycle, the onset of plate tectonics changed everything. Large land masses with mountains provided faster silicate weathering, which converted CO2 into limestone. In addition, carbon became effectively trapped in the Earth's mantle as oceanic plates were subducted. Plate tectonics thus caused the CO2 content of the atmosphere to drop sharply. Repeated ice ages show that it became significantly colder on Earth. 'Earlier studies had already indicated that the limestone contents in ancient basalts point to a sharp drop in atmospheric CO2 levels. This fits well with an increase in oxygen isotopes at the same time. Everything indicates that the atmospheric CO2 content declined rapidly after the onset of plate tectonics,' Daniel Herwartz concluded. However, in this context 'rapidly' refers to several hundred million years.

Art Garfunkel once described his legendary musical chemistry with Paul Simon, "We meet somewhere in the air through the vocal cords ... ." But a new study of duetting songbirds from Ecuador, the plain-tail wren (Pheugopedius euophrys), has offered another tune explaining the mysterious connection between successful performing duos.

It's a link of their minds, and it happens, in fact, as each singer mutes the brain of the other as they coordinate their duets.

In a study published May 31 in Proceedings of the National Academy of Sciences, a team of researchers studying brain activity of singing male and female plain-tailed wrens has discovered that the species synchronizes their frenetically paced duets, surprisingly, by inhibiting the song-making regions of their partner's brain as they exchange phrases.

Researchers say that the auditory feedback exchanged between wrens during their opera-like duets momentarily inhibits motor circuits used for singing in the listening partner, which helps link the pair's brains and coordinate turn-taking for a seemingly telepathic performance. The study also offers fresh insight into how humans and other cooperative animals use sensory cues to act in concert with one another. 

"You could say that timing is everything," said Eric Fortune, co-author of the study and neurobiologist at New Jersey Institute of Technology's Department of Biological Sciences. "What these wrens have shown us is that for any good collaboration, partners need to become 'one' through sensory linkages. The take-home message is that when we are cooperating well... we become a single entity with our partners."

"Think of these birds like jazz singers," added Melissa Coleman, the paper's corresponding author and associate professor of biology at Scripps College. "Duetting wrens have a rough song structure planned before they sing, but as the song evolves, they must rapidly coordinate by receiving constant input from their counterpart.

"What we expected to find was a highly active set of specialized neurons that coordinate this turn-taking, but instead what we found is that hearing each other actually causes inhibition of those neurons -- that's the key regulating the incredible timing between the two."

For the study, the team had to travel to the heart of the plain-tail wren music scene, within remote bamboo forests on the slopes of Ecuador's active Antisana Volcano. Camped at the Yanayacu Biological Station's lab, the team made neurophysiological recordings of four pairs of native wrens as they sang solo and duet songs, analyzing sensorimotor activity in a premotor area of the birds' brains where specialized neurons for learning and making music are active.

The recordings showed that during duet turn-taking -- which often take the form of tightly knit call-and-answer phrases, or syllables, that together sound as if a single bird is singing -- the birds' neurons fired rapidly when they produced their own syllables. 

Yet, as one wren begins to hear their partner's syllables sung in the duet, the neurons quiet down significantly. 

"You can think of inhibition as acting like a trampoline," explained Fortune. "When the birds hear their partner, the neurons are inhibited, but just like rebounding off a trampoline, the release from that inhibition causes them to swiftly respond when it's their time to sing."

Next, the team played recordings of wrens duetting while they were in a sleep-like state, anesthetized with a drug that affects a major inhibitory neurotransmitter in the wrens' brains that is also found in humans, gamma-aminobutyric acid (GABA). The drug transformed the activity in the brain, from inhibition to bursts of activity when the wrens heard their own music. 

"These mechanisms are shared or similar to what happens in our brains because we are doing the same kind of things," said Fortune. "There are similar brain circuits in humans that are involved in learning and coordinating vocalizations."

Fortune and Coleman say the results offer a fresh look into how the brains of humans and other cooperating animals use sensory cues to act in concert with each other, from flowing musical and dance performances, or even the disjointed feeling of inhibition commonly experienced today during video conferencing.

"These days, inhibition is occurring at all the wrong times when we have poor internet connections during our Zoom, WebEx, and Facetime conferences. The delays affect the sensory information that we rely on for coordinating the timing of our conversations," said Coleman. "I think this study is important for understanding how we interact with the world whenever we are trying to produce a single behavior as two performers. We are wired for cooperation, the same way as these jazz singing wrens."

Three groups (Dr. James Birchler's group from University of Missouri, Dr. Jan Barto's group from Institute of Experimental Botany of the Czech Academy of Sciences and Dr. HAN Fangpu's group from the Institute of Genetics and Developmental Biology of the Chinese Academy of Sciences) recently reported a reference sequence for the supernumerary B chromosome in maize in a study published online in PNAS (doi:10.1073/pnas.2104254118).

Supernumerary B chromosomes persist in thousands of plant and animal genomes despite being nonessential. They are maintained in populations by mechanisms of "drive" that make them inherited at higher than typical Mendelian rates. Key properties such as its origin, evolution, and the molecular mechanism for its accumulation in maize have remained unclear even though such chromosomes have been a potent tool for studying maize genetics.

The researchers used a well-established set of sequencing and mapping tools, including chromosome flow-sorting, Illumina sequencing, Bionano optical mapping, and chromatin conformation capture (Hi-C).

The rich availability of deletion derivatives ensured strong scaffolding and vetting of assembly. In addition, 758 protein-coding genes were identified from the 125.9-Mb of chromosome sequence, of which at least 88 are expressed.

The scientists discovered that the current gene content is a result of continuous transfer from the A chromosomal complement over an extended evolutionary period. This process has been accompanied by subsequent degradation even though selection for maintenance of this nonvital chromosome has also continued.

The annotation results demonstrate that transposable elements in the B chromosome are shared with the standard A chromosome set. However, the failure of multiple lines of evidence to reveal a syntenic region in the B chromosome with any A chromosome indicates that this chromosome has been present in the evolutionary lineage for millions of years since any such synteny has disintegrated.

Sequence and deletion analysis reveals that a specific DNA repeat is located in and around the centromere that is involved with its drive mechanism, consisting of nondisjunction at the second pollen mitosis and preferential fertilization of the egg by the B-containing sperm.

This analysis cleverly combines comparisons among a variety of translocation and B-deletion stocks along with many years of genetic analysis. This approach provides a unique view of the sequence of this chromosome, as well as characterization of potentially functional elements within it.

UCLA HEALTH RESEARCH BRIEF

FINDINGS

A new study shows that tai chi mirrors the beneficial effects of conventional exercise by reducing waist circumference in middle-aged and older adults with central obesity. The study was done by investigators at the University of Hong Kong, The Chinese University of Hong Kong; Chinese Academy of Sciences; and UCLA.

BACKGROUND

Central obesity is a major manifestation of metabolic syndrome, broadly defined as a cluster of cardiometabolic risk factors, including central obesity, dyslipidemia, hyperglycemia, low high-density lipoprotein cholesterol (HDL-C) level, and high blood pressure, that all increase risk for type 2 diabetes and cardiovascular disease.

METHOD

543 participants were randomly assigned in a 1:1:1 ratio to a control group with no exercise intervention (n= 181), conventional exercise consisting of aerobic exercise and strength training (EX group) (n= 181), and a tai chi group (TC group) (n= 181). Interventions lasted 12 weeks.

The primary outcome was waist circumference. Secondary outcomes were body weight; body mass index; high-density lipoprotein cholesterol (HDL-C), triglyceride, and fasting plasma glucose levels.

IMPACT

The findings suggest that tai chi is an effective approach for management of central obesity. This study has great translational significance because our findings support the notion of incorporating tai chi into global physical activity guidelines for middle-aged and older adults with central obesity.

By including multi-ethnic participants, a largescale genetic study has identified more regions of the genome linked to type 2 diabetes-related traits than if the research had been conducted in Europeans alone.

The international MAGIC collaboration, made up of more than 400 global academics, conducted a genome-wide association meta-analysis led by the University of Exeter. Now published in Nature Genetics, their findings demonstrate that expanding research into different ancestries yields more and better results, as well as ultimately benefitting global patient care.

Up to now, nearly 87 per cent of genomic research of this type has been conducted in Europeans. This means that the way these findings are implemented may not optimally benefit people from non-European ancestries.

The team analysed data across a wide range of cohorts, encompassing more than 280,000 people without diabetes. Researchers looked at glycaemic traits, which are used to diagnose diabetes and monitor sugar and insulin levels in the blood.

The researchers incorporated 30 percent of the overall cohort with individuals of East Asian, Hispanic, African-American, South Asian and sub-Saharan African origin. By doing so, they discovered 24 more loci - or regions of the genome -linked to glycaemic traits than if they had conducted the research in Europeans alone.

Professor Inês Barroso, of the University of Exeter, who led the research, said: "Type 2 diabetes is an increasingly huge global health challenge- with most of the biggest increases occurring outside of Europe. While there are a lot of shared genetic factors between different countries and cultures, our research tells us that they do differ, in ways that we need to understand. It's critical to ensuring we can deliver a precision diabetes medicine approach that optimises treatment and care for everyone."

First author Dr Ji Chen, of the University of Exeter, said: "We discovered 24 additional regions of the genome by including cohorts which were more ethnically diverse than we would have done if we'd restricted our work to Europeans. Beyond the moral arguments for ensuring research is reflective of global populations, our work demonstrates that this approach generates better results."

The team found that though some loci were not detected in all ancestries, they were still useful to capture information about the glycaemic trait in that ancestry. Co-author Cassandra Spracklen, Assistant Professor at the University of Massachusetts-Amherst, said: "Our findings matter because we're moving towards using genetic scores to weigh up a person's risk of diabetes. We know that scores developed exclusively in individuals of one ancestry don't work well in people of a different ancestry. This is important as increasingly healthcare is moving towards a more precise approach. Failing to account for genetic variation according to ancestry will impact our ability to accurately diagnose diabetes."

Between 1991 and 2018, more than a third of all deaths in which heat played a role were attributable to human-induced global warming, according to a new article in Nature Climate Change.

The study, the largest of its kind, was led by the London School of Hygiene & Tropical Medicine (LSHTM) and the University of Bern within the Multi-Country Multi-City (MCC) Collaborative Research Network. Using data from 732 locations in 43 countries around the world it shows for the first time the actual contribution of man-made climate change in increasing mortality risks due to heat.

Overall, the estimates show that 37% of all heat-related deaths in the recent summer periods were attributable to the warming of the planet due to anthropogenic activities. This percentage of heat-related deaths attributed to human-induced climate change was highest in Central and South America (up to 76% in Ecuador or Colombia, for example) and South-East Asia (between 48% to 61%).

Estimates also show the number of deaths from human-induced climate change that occurred in specific cities; 136 additional deaths per year in Santiago de Chile (44.3% of total heat-related deaths in the city), 189 in Athens (26.1%), 172 in Rome (32%), 156 in Tokyo (35.6%), 177 in Madrid (31.9%), 146 in Bangkok (53.4%), 82 in London (33.6%), 141 in New York (44.2%), and 137 in Ho Chi Minh City (48.5%).
The authors say their findings are further evidence of the need to adopt strong mitigation policies to reduce future warming, and to implement interventions to protect populations from the adverse consequences of heat exposure.

Dr Ana M. Vicedo-Cabrera, from the University of Bern and first author of the study, said: "We expect the proportion of heat-related deaths to continue to grow if we don't do something about climate change or adapt. So far, the average global temperature has only increased by about 1°C, which is a fraction of what we could face if emissions continue to grow unchecked."

Global warming is affecting our health in several ways, from direct impacts linked to wildfires and extreme weather, to changes in the spread of vector-borne diseases, among others. Perhaps most strikingly is the increase in mortality and morbidity associated with heat. Scenarios of future climate conditions predict a substantial rise in average temperatures, with extreme events such as heatwaves leading to future increases in the related health burden. However, no research has been conducted into what extent these impacts have already occurred in recent decades until now.

This new study focused on man-made global warming through a 'detection & attribution' study that identifies and attributes observed phenomena to changes in climate and weather. Specifically, the team examined past weather conditions simulated under scenarios with and without anthropogenic emissions. This enabled the researchers to separate the warming and related health impact linked with human activities from natural trends. Heat-related mortality was defined as the number of deaths attributed to heat, occurring at exposures higher than the optimum temperature for human health, which varies across locations.

While on average over a third of heat-related deaths are due to human-induced climate change, impact varies substantially across regions. Climate-related heat casualties range from a few dozen to several hundred deaths each year per city, as shown above, depending on the local changes in climate in each area and the vulnerability of its population. Interestingly, populations living in low and middle-income countries, which were responsible for a minor part of anthropogenic emissions in the past, are those most affected.

In the UK, 35% of heat-related deaths could be attributed to human-induced climate change, which corresponds to approximately 82 deaths in London, 16 deaths in Manchester, 20 in West Midlands or 4 in Bristol and Liverpool every summer season.

Professor Antonio Gasparrini from LSHTM, senior author of the study and coordinator of the MCC Network, said: "This is the largest detection & attribution study on current health risks of climate change. The message is clear: climate change will not just have devastating impacts in the future, but every continent is already experiencing the dire consequences of human activities on our planet. We must act now."

The authors acknowledge limitations of the study including being unable to include locations in all world regions--for example, large parts of Africa and South Asia--due to a lack of empirical data.