Culture

Potassium is an essential nutrient for all living things. Plants need it in large quantities, especially for growth and in order to withstand stress better. For this reason, they absorb large quantities of potassium from the soil. In agriculture, this leads to a lack of available potassium in the soil - which is why the mineral is an important component in fertilizers. A team of German and Chinese researchers has now shown, for the first time, where and how plants detect potassium deficiency in their roots, and which signalling pathways coordinate the adaptation of root growth and potassium absorption to to uphold the plants potassium supply.

The background: The absorption and transportation of potassium at the level of individual cells have been relatively well characterized, and many of the molecular structures and mechanisms which play a role in these processes are known. Also, researchers demonstrated decades ago that plants adapt very specifically to potassium deficiency. One puzzle that still remains, however, is how plants detect the availability of potassium in the soil and which mechanisms are behind the adaptational reactions in the plant's organism. The new study sheds light on these questions. The results have been published in the journal Developmental Cell

Observations contradict the textbooks

The researchers examined thale cress plants (Arabidopsis thaliana) which were transformed with the newly developed potassium reporter protein GEPII. This reporter protein enables the microscopic detection of the concentration and distribution of potassium ions in cells and tissues. Even when there was no potassium deficiency, the research team made a very surprising discovery: the concentration of this nutrient in the cytoplasm of the cells increased with each cell layer within the root, from the outside to the inside.

"These observations were really surprising," says Prof. Jörg Kudla from the Institute of Plant Biology and Biotechnology at the University of Münster (Germany). "They contradict the textbooks, which say that the nutrients are passed on evenly, from the outside to the inside, towards the root's vascular tissue - not only from cell to cell but also through the intercellular spaces."

"Potassium-sensitive niche" reacts to potassium deficiency

The team of researchers subsequently examined how roots react to potassium deficiency. In doing so, they demonstrated for the first time that if plants are subjected to potassium deficiency, the concentration of potassium is reduced only within certain cells in the root tip. These "postmeristematic cells" directly above the viable stem cells in the root tip react extremely rapidly to potassium deficiency; the concentration of potassium inside the cell (in the cytoplasm) decreases within seconds. It had not previously been known that a certain group of cells located centrally inside the root tip reacts to a potassium deficiency in its surroundings. The researchers named this group of cells "potassium-sensitive niche".

"These observations, too, were very surprising," says Kudla. "If plants are deprived of potassium, only the cells in the potassium-sensitive niche show a reaction; the concentration of potassium in the other root cells remains unchanged. Previously it was assumed that naturally the cells in the outermost cell layer, the epidermis, would react first to a reduction in the concentration of potassium in the soil."

Visualizing the path of potassium

Simultaneously with the decrease in the potassium concentration in the potassium-sensitive niche, calcium signals occur in these cells and spread out in the root. As a messenger substance, calcium controls many processes in living organisms - just as it does here: the calcium signals start off a complex molecular signalling cascade. This chain of signals, which the researchers were the first to define in detail, ultimately causes not only an increased formation of potassium transport proteins, but also brings about changes in tissue differentiation in the root. This facilitates a more efficient absorption of potassium ions and maintains its distribution in the plant. "For the first time," says Kudla, "using imaging methods, we have visualized the path of potassium in a living organism."

The results provide fundamental insights into where plants detect the availability of the essential nutrient potassium and how they adapt to it. Understanding these processes could in future help to breed better plants for agricultural purposes and deploy fertilizers in a more tailor-made way.

The methodology

To visualize the distribution of potassium in the plant's roots, the researchers used special microscopic methods (for example, Förster resonance energy transfer, FRET), in combination with sensor proteins for potassium, calcium and hydrogen peroxide. In order to examine the molecular mechanisms, the researchers produced and compared transgenic Arabidopsis plants which, due to different genetic mutations, showed symptoms of potassium deficiency. They used a variety of genetic, molecular-biological and biochemical methods to identify and characterize the proteins and mechanisms involved in the transmission of the potassium and calcium signals.

A number of studies have shown that human coronaviruses, including SARS-CoV-2 which causes COVID-19, appear to attack neurons and the nervous system in vulnerable populations. This neuroinvasion through the nasal cavity leads to the risk of neurological disorders in affected individuals. Research conducted at the Institut national de la recherche scientifique (INRS) has identified ways to prevent the spread of infection within the central nervous system (CNS). The study, led by Professor Pierre Talbot and his research associate Marc Desforges, now at CHU-Sainte-Justine, was published in the Journal of Virology.

Antiviral immunity to human coronaviruses

The research team is the first to make the demonstration of a direct link between neurovirulence, protein S cleavage by cellular proteases and innate immunity. This antiviral immunity arises from the production of interferons, frontline proteins that help to detect early the presence of the virus.

"Using a common cold coronavirus, similar to SARS-CoV-2, we were able to show that cleavage of the S protein and interferon could prevent its spread to the brain and spinal cord in mice," says Talbot, who has been studying coronaviruses for nearly 40 years.

Two therapeutic approaches

According to Marc Desforges, currently a clinical specialist in medical biology at the CHU-Sainte-Justine virology laboratory, the cleavage of the S protein by various cellular proteases is essential for these viruses to effectively infect cells and spread to various organs and systems in the body, including the central nervous system (CNS).

"Our results demonstrate that interferon produced by different cells, including olfactory receptors and cerebrospinal fluid (CSF) producing cells in the brain, could modulate this cleavage. Thus, it could and does significantly limit the viral spread in the CNS and the severity of the associated disease," says the specialist who worked for 16 years as a research associate at the Armand-Frappier Health Biotechnology Centre of the IRNS.

Taken together, these results point to two potential antiviral targets: protein S cleavage and effective interferon-related innate immunity. "Understanding the mechanisms of infection and viral propagation in neuronal cells is essential to better design therapeutic approaches," says Talbot. This is especially important for vulnerable populations such as the elderly and immunocompromised.?" This discovery opens the door to new therapeutic strategies.

According to a recent Finnish study, accumulating more brisk and vigorous physical activity can curb adiposity-induced low-grade inflammation. The study also reported that diet quality had no independent association with low-grade inflammation. The findings, based on the ongoing Physical Activity and Nutrition in Children (PANIC) Study conducted at the University of Eastern Finland, were published in the European Journal of Sport Science.

The study was made in collaboration among researchers from the University of Jyväskylä, the University of Eastern Finland, the Norwegian School of Sport Sciences, and the University of Cambridge.

Low-grade inflammation is linked to many chronic diseases, but exercise can curb it

Long-lasting low-grade inflammation increases the risk for type 2 diabetes and cardiovascular diseases. Being overweight and obese contribute to low-grade inflammation, but little is still known about the role of lifestyle in curbing low-grade inflammation since childhood.

"Our study showed that children who were physically more active and less sedentary had a healthier inflammatory profile than children who were physically less active," explains Dr. Eero Haapala from the Faculty of Sport and Health Sciences at the University of Jyväskylä. "However, our results suggest that the positive effects of high levels of vigorous physical activity and low levels of sedentary time on low-grade inflammation are partly explained by their positive effects on body composition."

Low physical activity, unhealthy diet quality, and being overweight is the most unfavourable combination

Researchers found unhealthier inflammatory profile particularly in children with the lowest levels of physical activity, poorest diet quality and the highest body fat percentage.

"The key message of our results is that increasing physical activity and reducing sedentary time are key in preventing low-grade inflammation since childhood," says Haapala. "They would be particularly important for overweight children."

The study looked at the associations between physical activity, sedentary time, diet quality, body fat content, and low-grade inflammation in 390 children aged 6 to 8 years. Physical activity and sedentary time were measured by a combined heart rate and movement sensor and body composition with a DXA device. Low-grade inflammation was assessed using biomarkers measured from blood samples.

Casual sex is on the decline for both young men and women, according to a Rutgers University-New Brunswick study that found less alcohol consumption among both genders is a major reason while playing video games and living at home with parents are another--but only for men.

The study, published in the journal Socius, found that between 2007 and 2017, the percentage of 18-to 23-year-old men who had casual sex in the past month dropped from 38 percent to 24 percent. The percentage dropped from 31 percent to 22 percent for young women of the same age.

The most important factor driving the decline among young men is the decrease in drinking, which alone explains more than 33 percent of the drop. The increase in computer video gaming explains about 25 percent of the change in sexual behavior among young men, while the increase in living with parents explains a little more than 10 percent. No other factor explained a significant portion of the decline.

"The recent cohorts of young people adopt adult roles later in their lives and depend on their parents for longer periods," said the study's co-author Lei Lei, an assistant professor of sociology at Rutgers. "The declining engagement in casual sex among this age group could be another sign of delayed transition into adulthood."

For young women, about 25 percent is attributable to a decline in drinking, which was the only factor that explained a significant portion of the decline. Increased internet usage among young women suppressed what would have been a larger 11 percent decline in casual sex. The study said that while both young women and men play computer games more frequently now than in the past, gaming inhibits only young men's casual sexual activity.

Researchers say the odds that young men who live with their parents engage in casual sex are only 63 percent of those who live independently. The odds that young men who play computer games daily have casual sex are less than half the odds for those who never game. And the odds that young men who report drinking daily have casual sex are about 5.5 times the odds for those who don't drink.

"The new generation of young adults became more individualistic and less social in real life, but more involved in social media and online gaming networks," said Lei. "The changes in how young people socialize affect their opportunity to have casual sex, which often serves as a trial or rehearsal for long-term romantic relationships."

Trends in young adults' financial insecurity, including their student debt loan, do not appear to underlie their change in casual sexual activity. Nor does an increase in time spent watching television.

Researchers analyzed survey data from the 2007-2017 Panel Study of Income Dynamics Transition to Adulthood Supplement, which interviewed about 2,000 young adults ages 18 to 23 and focused on sexual activity outside of committed relationships. They examined whether changes in young adults' economic status, living arrangement, technology use and drinking behavior helped explain the decline in casual sex.

As the pandemic's economic effects drive more people to enroll in Medicaid as safety-net health insurance, a new study suggests that the program's dental coverage can improve their oral health in ways that help them seek a new job or do better at the one they have.

The study focuses on the impact of dental coverage offered through Michigan's Medicaid expansion, called the Healthy Michigan Plan. The researchers, from the University of Michigan, used a survey and interviews to assess the impact of this coverage on the health and lives of low-income people who enrolled.

In all, 60% of the 4,090 enrollees surveyed for the new study had visited a dentist at least once since enrolling in the Healthy Michigan Plan a year or two earlier, which the researchers verified with state records.

Among those who saw a dentist in that time, 57% said their oral health had improved since enrolling. The percentage who reported better oral health was even higher among Black respondents and those who said they'd been uninsured for a year or more before getting covered.

The findings are published in the Journal of Public Health Dentistry by a team from the U-M Institute for Healthcare Policy and Innovation that evaluates the impacts of the Healthy Michigan Plan. The authors hope their findings will inform policy decisions about dental coverage for Medicaid plans in Michigan and other states.

Impact on work lives

Half of the respondents had jobs or were self-employed, though their incomes were low enough to qualify for the Healthy Michigan Plan - about $15,600 for an individual in the year studied.

Just over 39% of all survey respondents, with jobs or without, said their oral health had improved since they enrolled.

Of those who had jobs and reported improved oral health, 76% said that their Healthy Michigan Plan coverage had helped them do a better job at work compared to 65% of those who had jobs but hadn't experienced improvements in oral health.

Meanwhile, 60% of the unemployed people who said their oral health had improved credited their coverage with helping them look for a job, compared with 51% of those who hadn't experienced improvement in oral health.

Although the data were collected before the COVID-19 pandemic began, the findings have implications for the hundreds of thousands of Michiganders who have enrolled in the Healthy Michigan Plan in the past year when they lost jobs or income.

The Healthy Michigan Plan includes basic dental care coverage such as cleanings, fillings, X-rays and dentures, and is open to people making up to 133% of the federal poverty level. Enrollment has grown to more than 895,000.

Voices of Healthy Michigan Plan enrollees

Most respondents had no health insurance coverage in the year before enrolling in Michigan's program.

"The Healthy Michigan Plan's dental coverage enabled many to get the dental care they needed," says Edie Kieffer, Ph.D., M.P.H., lead author of the paper and a professor emeritus in the U-M School of Social Work. "In our interviews with enrollees, people talked about the great impact of having this dental coverage. People told us that, without dental coverage, they had to have their teeth pulled. They used their new coverage to get dentures, which improved their appearance, employment options and ability to eat. Dental coverage helped people address dental infections and get preventive dental care."

Some enrollees mentioned that previously they had turned to hospital emergency departments for urgent dental care needs, for instance to get an antibiotic to treat an oral infection, but not to address the underlying problem that led to the infection. One interviewee said their first dental visit uncovered a tumor.

As one of the middle-aged male participants interviewed by the researchers and quoted in the paper says:

"My teeth were pretty bad...and they fixed it up fine, and now...I feel better when I am looking for a job...I feel better because my appearance has changed a lot. That has helped me a lot, physically and mentally."

Practice and policy implications

The authors note that Medicaid coverage in Michigan improves patients' access to primary health care as well as basic dental care. In both settings, providers can identify patients at risk of oral health problems, and suggest treatments for problems so they can be addressed before they worsen.

Nearly half of all survey respondents said their access to dental care had improved thanks to their dental coverage. That percentage was even higher among the 60% of respondents who had been uninsured for at least a year before getting covered under the Healthy Michigan Plan.

The findings about Michigan Medicaid expansion coverage's impact on dental health are similar to other findings on health outcomes made by the IHPI team, says John Z. Ayanian, M.D., M.P.P., the study's senior author.

"We can clearly see the positive impact of Medicaid coverage of dental care," he says. "These findings have implications for states that have yet to expand Medicaid at all, or to include dental coverage in their Medicaid expansion programs."

Ayanian heads the IHPI team that is evaluating the Healthy Michigan Plan through a collaboration with the Michigan Department of Health and Human Services. He also serves as IHPI's director and a primary care physician and professor of internal medicine at Michigan Medicine, U-M's academic medical center.

Access to dental care for Medicaid enrollees depends not just on the availability of coverage, which can vary by state, but also on the number of dental practices that accept Medicaid plans. Low reimbursement rates are a major factor in Michigan, says Romesh Nalliah, D.D.S., M.H.C.M., a co-author of the paper and professor at the U-M School of Dentistry.

Dental disparities

Nalliah notes that the inclusion of adult dental coverage in Medicaid and other plans could help reduce the disparities in oral health that he and others have documented.

In 2019, he and colleagues published data showing that while the oral health gap between Black and white Americans had narrowed between 1999 and 2014 (the year before Medicaid expansion took effect under the Affordable Care Act), there were still disparities in dental visits and tooth loss due to cavities and gum disease. More than 22% of Black Americans over age 65 had lost all their natural teeth by 2014, compared with 14% of whites.

The National Poll on Healthy Aging, also based at IHPI, has also studied dental health among adults aged 50 to 64 and adults over 65, finding disparities by income, race/ethnicity and education level in both age groups.

Oral health has important influences on people's overall health, Kieffer explains, and poor oral health is very common among low-income adults.

Because dental coverage is an optional benefit under state Medicaid and Medicaid expansion plans, she and her colleagues hope policymakers will consider the potential for Medicaid dental coverage to both reduce oral health disparities, and improve the health and socioeconomic well-being of low-income adults.

All viruses mutate as they make copies of themselves to spread and thrive. SARS-CoV-2, the virus the causes COVID-19, is proving to be no different. There are currently more than 4,000 variants of COVID-19, which has already killed more than 2.7 million people worldwide during the pandemic.

The UK variant, also known as B.1.1.7, was first detected in September 2020, and is now causing 98 percent of all COVID-19 cases in the United Kingdom. And it appears to be gaining a firm grip in about 100 other countries it has spread to in the past several months, including France, Denmark, and the United States.

The World Health Organization says B.1.1.7 is one of several variants of concern along with others that have emerged in South Africa and Brazil.

"The UK, South Africa, and Brazil variants are more contagious and escape immunity easier than the original virus," said Victor Padilla-Sanchez, a research scientist at The Catholic University of America. "We need to understand why they are more infectious and, in many cases, more deadly."

All three variants have undergone changes to their spike protein -- the part of the virus which attaches to human cells. As a result, they are better at infecting cells and spreading.

In a research paper published in January 2021 in Research Ideas and Outcomes, Padilla-Sanchez discusses the UK and South African variants in detail. He presents a computational analysis of the structure of the spike glycoprotein bound to the ACE2 receptor where the mutations have been introduced. His paper outlines the reason why these variants bind better to human cells.

"I've been analyzing a recently published structure of the SARS-CoV-2 spike bound to the ACE2 receptor and found why the new variants are more transmissible," he said. "These findings have been obtained using UC San Francisco Chimera software and molecular dynamics simulations using the Frontera supercomputer of the Texas Advanced Computing Center (TACC)."

Padilla-Sanchez found that the UK variant has many mutations in the spike glycoprotein, but most important is one mutation, N501Y, in the receptor binding domain that interacts with the ACE2 receptor.

"This N501Y mutation provides a much higher efficiency of binding, which in turn makes the virus more infectious. This variant is replacing the previous virus In the United Kingdom and is spreading in many other places in the world," he said.

The South Africa variant emerged in October 2020, and has more important changes in the spike protein, making it more dangerous than the UK variant. It involves a key mutation -- called E484K -- that helps the virus evade antibodies and parts of the immune system that can fight coronavirus based on experience from prior infection or a vaccine. Since the variant escapes immunity the body will not be able to fight the virus. "We're starting to see the South Africa variant here in the U.S.," he said.

Padilla-Sanchez performed structural analysis, which studied the virus's crystal structure; and molecular dynamics to obtain these findings.

"The main computational challenge while doing this research was to find a computer powerful enough to do the molecular dynamics task, which generates very big files, and requires a great amount of memory. This research would not have been possible without the Frontera supercomputer," Padilla-Sanchez said.

According to Padilla-Sanchez, the current vaccines will not necessarily treat the variants. "The variants will require their own specific vaccines. We'll need as many vaccines for variants that appear."

Going forward, Padilla-Sanchez will continue to research the changes taking place with SARS-CoV-2.

"This was a very fast project -- the computational study lasted one month," he said. "There are many other labs doing wet lab experiments, but there aren't many computational studies. That's why I decided to do this important work now."

DALLAS - March 23, 2021 - It's not just your legs and heart that get a workout when you walk briskly; exercise affects your brain as well. A new study by researchers at UT Southwestern shows that when older adults with mild memory loss followed an exercise program for a year, the blood flow to their brains increased. The results were published online today in the Journal of Alzheimer's Disease.

"This is part of a growing body of evidence linking exercise with brain health," says study leader Rong Zhang, Ph.D., professor of neurology at UTSW. "We've shown for the first time in a randomized trial in these older adults that exercise gets more blood flowing to your brain."

As many as one-fifth of people age 65 and older have some level of mild cognitive impairment (MCI) - slight changes to the brain that affect memory, decision-making, or reasoning skills. In many cases, MCI progresses to dementia, including Alzheimer's disease.

Scientists have previously shown that lower-than-usual levels of blood flow to the brain, and stiffer blood vessels leading to the brain, are associated with MCI and dementia. Studies have also suggested that regular aerobic exercise may help improve cognition and memory in healthy older adults. However, scientists have not established whether there is a direct link between exercise, stiffer blood vessels, and brain blood flow.

"There is still a lot we don't know about the effects of exercise on cognitive decline later in life," says C. Munro Cullum, Ph.D., professor of psychiatry at UTSW and co-senior author of the study. "MCI and dementia are likely to be influenced by a complex interplay of many factors, and we think that, at least for some people, exercise is one of those factors."

In the study, Zhang, Cullum, and their colleagues followed 70 men and women aged 55 to 80 who had been diagnosed with MCI. Participants underwent cognitive exams, fitness tests, and brain magnetic resonance imaging (MRI) scans. Then they were randomly assigned to either follow a moderate aerobic exercise program or a stretching program for one year. The exercise program involved three to five exercise sessions a week, each with 30-40 minutes of moderate exercise such as a brisk walk.

In both programs, exercise physiologists supervised participants for the first four to six weeks, then had the patients record their exercises and wear a heart rate monitor during exercise.

Forty-eight study participants - 29 in the stretching group and 19 in the aerobic exercise group - completed the full year of training and returned for follow-up tests. Among them, those who performed aerobic exercise showed decreased stiffness of blood vessels in their neck and increased overall blood flow to the brain. The more their oxygen consumption (one marker of aerobic fitness) increased, the greater the changes to the blood vessel stiffness and brain blood flow. Changes in these measurements were not found among people who followed the stretching program.

While the study didn't find any significant changes in memory or other cognitive function, the researchers say that may be because of the small size or short length of the trial. Changes to blood flow could precede changes to cognition, they say. They're already carrying out a larger two-year study, Risk Reduction for Alzheimer's Disease (rrAD), that further investigates the link between exercise and cognitive decline.

"There are likely some people who benefit more from exercise than others," says Cullum. "But with the sample size in this study, it was hard to analyze subgroups of people to make those conclusions."

Still, the data are important to help explain the effects of exercise on the brain and why it can be beneficial, say Zhang and Cullum, who are members of the Peter O'Donnell Jr. Brain Institute.

"Having physiological findings like this can also be useful for physicians when they talk to their patients about the benefits of exercise," says Zhang. "We now know, based on a randomized, controlled trial, that exercise can increase blood flow to the brain, which is a good thing."

A study of ancient bones shows that Early Neolithic sheep-breeders were faced with high levels of mortality among young animals in their herds. A statistical model, partly developed at Ludwig-Maximilians-Universitaet (LMU) in Munich, allowed the age distribution of the bones to be precisely determined.

In the 8th millennium BCE, early sheep-herders were already aware that the conditions under which their animals were housed had an impact on mortality rates among the lambs. This one result of a study researchers led by Nadja Pöllath (a curator at the State Collection for Anthropology and Palaeoanatomy in Munich), LMU zooarchaeologist Joris Peters (who is also the Director of the state collection) and LMU statistician Sevag Kevork have now taken a closer look at the bones of unborn and neonatal lambs, which form part of the collections studied by them. The material comes from the Early Neolithic site A??kl? Höyük, one of the largest and best investigated settlements from this period in Central Anatolia. The site was occupied from 8350 to around 7300 BCE, and the study reveals that the life expectancy of newborn lambs gradually increased over this timespan. The researchers attribute this finding to improvements in husbandry of the herds, which enabled a larger proportion of neonates to survive the nursing period, and be let out to graze the nearby pastures.

The archaeological remains that have come to light at A??kl? Höyük provide valuable information, not only on its domestic architecture and cultural practices, but also on the surrounding vegetation and the diets of the people and animals living in the area. Moreover, it sheds light on the development of agriculture and animal husbandry during the Early Neolithic period. The finds indicate that, in the settlement's earliest phase, its inhabitants still obtained their meat mainly from hunting. Later on, however, domesticated animals - primarily sheep - supplied much of the animal protein consumed. The discovery of compacted dung layers within the settlement indicates that sheep were kept for longer periods within the boundaries of the settlement.

A new analysis of the age distribution of the animal bones found at A??kl? Höyük illustrates the problems with which early sheep-herders were confronted - and on how they learned to mitigate them. Most of the conventional approaches used to determine the exact age at which the animals died focus on teeth. However, such methods are not sufficiently sensitive to enable researchers to reliably differentiate between developmental stages in very young animals - in this case, sheep covering the age range from the fetus to newborns and juveniles.

In order to determine the ages of fetuses and lambs as accurately as possible, the researchers developed a new statistical model. They first analyzed the morphology of the humerus or upper-arm bone in a sample of modern sheep breeds, based on material kept in anatomical reference collections in the US, the UK, Spain, Portugal and Germany, and used the results to construct a comparative model for Neolithic sheep. In this way, the age at death of the bones of lambs from A??kl? Höyük could be precisely determined. "Our analyses were of great value in enabling us to narrow down the range of possible ages of death in fetuses and lambs," says Nadja Pöllath. "We now have a better understanding of the difficulties that early herders faced in the early phases of sheep domestication in A??kl? Höyük." Infections were the primary causes of early mortality, together with malnutrition and dietary deficiencies. In addition, the animals were kept under overcrowded conditions. When they were subsequently let out to grass their health improved. The zooarchaeological data also suggest that, towards the end of the occupation of A??kl? Höyük, fetal mortality fell and more lambs survived. Prof. Peters concludes: "Our research thus proves for the first time that learning by doing determined the early phase of livestock farming in the 9th and 8th millennia BCE."

A study co-authored by researchers at the Johns Hopkins Bloomberg School of Public Health found that telehealth consults among privately insured working-age patients accounted for almost 24 percent of outpatient consults with health care providers during the early phase of the pandemic, March to June 2020, up from less than 0.3 percent during the same period in 2019.

The dramatic shift occurred as many medical practices halted or curtailed in-person office hours and patients stayed away from doctor's offices out of fear of transmission during the early months of the pandemic. At the same time, insurance companies and the federal government relaxed policies around telehealth to meet demand for remote medical consults via internet video or telephone.

The study was published online March 23 in JAMA Network Open.

For their study, researchers from Johns Hopkins Bloomberg School of Public Health and Blue Health Intelligence®, an independent licensee of the Blue Cross Blue Shield Association, analyzed anonymized claims data drawn from 36.6 million private insurance plan members who were of working age and continuously enrolled during the study period. The claims data for the study were provided by Blue Health Intelligence.

A total of 15 million telehealth claims were submitted during the March to June 2020 study period, with nearly three-quarters involving video support (74.4 percent) and fewer than one in ten occurring via phone (9.2 percent). Just over 3 percent (3.3 percent) were conducted either by email or chat while 13.1 percent were unspecified.

Mental health consults were far more likely to take place virtually--with 46.1 percent taking place via telehealth. By comparison, 22.1 percent of medical consults were virtual. In COVID-19 "hot spot" states--those with a COVID-19 prevalence at least 1.5 times the national average--36 percent of all consults were telehealth versus 21.6 percent in areas with lower COVID-19 prevalence. The study also found that the greater the COVID-19 prevalence in a specific ZIP code, the higher the use of telehealth.

"Telehealth has been around for a long time, but the recent increase has been enormous," says the study's lead author, Jonathan Weiner, DrPH, co-director of the Center for Population Health Information Technology and professor in the Department of Health Policy and Management at the Bloomberg School. "These findings will not only help doctors and other clinicians plan for the future, they will also guide policymakers and technology companies, especially as we learn more about the challenges of accessing telehealth among older patients, the uninsured, and low-income patients."

About a quarter of consults, 24.2 percent, in urban areas were via telehealth. This compared to only 14.2 percent of visits for members who lived in more rural settings. Age and number of chronic diseases were associated with more frequent telehealth consults, with individuals age 18 to 49 and those with more than two chronic conditions using telehealth the most.

The study also found that overall total medical care costs, including hospitalizations, dropped 15 percent, from $358 to $306 per person per month, from 2019 to 2020. Persons with at least one COVID-19-related consult in 2020 had more than three times the medical costs compared to those with no COVID-19-related services--$1,701 per member per month versus $544, a difference of $1,157.

Overall, the researchers found that in-person, outpatient visits decreased by 37 percent, from an average of 1.63 visits per enrollee during the three-month 2019 study period to an average of 1.02 visits per enrollee in 2020. However, since telehealth visits filled much of the gap, the total combined in-person and virtual encounter rate dropped only 18 percent between 2019 and 2020.

For persons with at least one COVID-19-related insurance claim, including screening and care, the average number of in-person and telehealth consults were about 30 percent higher than the average number of claims for persons with no COVID-19-related visit. One-quarter of COVID-19-related consults were via telehealth versus 23.5 percent for non-COVID-19-related consults.

"Even though some of our findings are unique to the COVID-19 era, we need to consider what telehealth will look like beyond the pandemic," says Weiner. "We will need to continue to assess and modify telehealth strategies to maximize value during this digital age, particularly given the challenges of the digital divide across social and geographic lines."

HOUSTON - (March 23, 2021) - Fish that dine on corals may pay it forward with poop.

It's an unexpected twist on coral reef symbiosis, said Rice University marine biologist Adrienne Correa, whose lab discovered coral predator feces are jam-packed with living symbiotic algae that corals depend on for survival. The discovery confirms that poop from coral-eating fish is an important environmental source of symbiotic dinoflagellate algae on coral reefs.

Correa said coral-eating predators are typically thought of as biting and weakening reef structures, thereby generating hiding spaces for other organisms and, ultimately, beach sand. In contrast, grazing fish that crop down bushy algae get the limelight for helping reefs maintain healthy coral cover.

"The message is, 'Move over grazers, it's not just you helping maintain coral dominance. These coral-eating fishes are probably helping too by spreading beneficial coral symbionts,'" she said.

Rice doctoral student Carsten Grupstra, lead author of the study in Animal Microbiome, said, "This tells us we don't really know all of the interactions that are happening on coral reefs, and some species may be important for coral reef conservation in ways that we haven't imagined."

In exchange for a sheltered life, dinoflagellates nourish their hosts by sharing the food they photosynthesize. Millions of symbionts live in each coral, but some corals aren't born with dinoflagellates. They acquire them as babies.

"When many baby corals settle on the reef bottom, they have to get their symbionts from the environment," Correa said. "We've seen symbionts in the water and sediments and on big bushy algae on reefs, but we haven't really looked at how those microorganisms get to all those places."

In thinking about ways symbionts might be distributed on reefs, Grupstra, Correa, graduate student Lauren Howe-Kerr and undergraduate Kristen Rabbitt were inspired by studies of pollinating insects and birds that pass beneficial bacteria between flowering plants. Like pollinating bees that visit many flowers in a single flight, coral-eating fish constantly crisscross reefs and interact with many corals each day.

"Most of them take small bites of adult corals and don't kill the colonies they're eating," Grupstra explained.

During an expedition to the Mo'orea Coral Reef Long-term Ecological Research station in French Polynesia, Grupstra, Howe-Kerr, Rabbitt and Correa followed fish that ate different amounts of coral and algae. Using underwater clipboards, they made note of what the fish ate and where and how often they defecated. Grupstra also gathered samples of predator and grazer poop to examine in the lab.

"I left some samples in the window sill for a couple of weeks in Mo'orea" he said. "Later, when I started looking at them (under a microscope), I found tons of symbionts. A lot of them were swimming around and some were dividing."

The sheer number of live symbionts was both unexpected and potentially important in the larger picture of reef ecology, Correa said. While symbionts had previously been reported in feces from a limited number of coral predators, it was unclear how many of them were alive and potentially useful to corals. Her group found high concentrations of live symbionts in the feces of a diverse group of coral predators. For example, the Rice team estimated that two species at the Mo'orea research station, Chaetodon ornatissimus and Chaetodon reticulatus, each spread about 100 million live symbionts per day over an area of reef approximately the size of six parking spaces.

"This expands how we can think about the roles of coral-eating fishes on reefs," Correa said. "They don't just break up reef frameworks. They also disperse symbionts that corals and other organisms need."

The knowledge that predator poop creates "hotspots" of live symbiotic dinoflagellates on reefs raises questions about whether and how coral use them. Correa's team has planned a series of experiments on both juvenile and stressed adult corals to determine how readily they absorb beneficial symbionts from the poop.

She said many questions remain about how and how frequently corals take up symbionts from the environment. For example, marine biologists widely agree that many coral babies get their symbionts from the environment, but it is unclear how often adults do this and under what conditions. Better understanding symbiont uptake could lead to new methods to help reefs recover from stress-induced "bleaching."

Bleaching occurs when stressed corals expel their symbionts en masse, frequently leaving corals colorless, as the name implies. Bleaching events are increasingly common due to climate change. While some corals never recover from bleaching, others do, which raises the question of how bleached corals repopulate their symbiont communities. Grupstra and Correa are conducting research to find out whether contact with coral predator feces can improve bleaching recovery rates and long-term coral health.

Hummingbird hawkmoths are small insects that hover in the air like hummingbirds when drinking nectar from flowers. Dr. Anna Stöckl from the Biocentre of the Julius-Maximilians-Universität (JMU) Würzburg in Bavaria, Germany, is studying the visual performance of these insects. Dr. Stöckl and her doctoral student Ronja Bigge now present their latest findings in the journal Current Biology.

"To control their flight, hummingbird hawkmoths rely on optic flow in the lower half of their visual field," Ronja Bigge explains. Optic flow is the relative motion that the surrounding image casts on the animals' retinas when they fly. We experience this phenomenon ourselves when travelling by train - the landscape passing by the train windows allows us to estimate our speed, for example.

For hawkmoths, the optic flow also provides information about their own movement. It helps them to control the straightness and speed of their flight. The JMU researchers have now shown with outdoor measurements that the optic flow components parallel to the direction of flight are always strongest below the hawkmoths' body. This is where the insects see meadows, gardens and streets that provide a varied texture. For flight control, what happens in the lower visual field is therefore the most reliable parameter.

Previously unknown behaviour discovered

"Surprisingly, we were able to show that the hawkmoths displayed a completely different and novel behaviour when we presented them with visual textures in the upper half of their visual field," says Anna Stöckl.

The animals then oriented themselves along prominent contours in the patterns. Thus, they did not use the visual information for flight control, but for orientation - although the visual patterns were exactly the same as the ones that were previously presented in the lower half of their visual field.

"Our optical measurements in natural habitats showed a comparable relationship: high-contrast structures that can be used for orientation occur primarily in the upper half of the visual field," says the JMU researcher. These are, for example, the silhouettes of treetops or bushes that form a strong contrast with the sky.

Visual field is divided in two

The conclusion of the Würzburg biologists: "The flight control system and the orientation system of the hummingbird hawkmoth divide the visual field among themselves and focus on the respective area that provides the most reliable information in their natural habitats."

In other words, it is not only important what the animals see, but also where they see it.

Amsterdam, NL, March 22, 2021 - The COVID-19 pandemic has had a profound impact on our world, with disequilibrium, uncertainty, and human suffering making it difficult to envision a human, societal and individual future. Milan Zeleny, PhD, Professor Emeritus of Management Systems, Fordham University, New York, NY, USA, and world-recognized authority on decision making, productivity, knowledge management, and more recently the corporation as a living organism, says that "COVID-19 is rapidly changing from a cause to one of the symptoms of an increasingly unhinged world."

Writing in the journal Human Systems Management, published by IOS Press, Prof. Zeleny discusses the consequences of disequilibrium across business, political, and other systems and proposes new models that may help systems evolve to succeed in the future.

'Accelerating speed of change is a natural evolutionary phenomenon, originally noticeable over many generations and now emerging within a single generation. It is the most important causal factor of our disequilibrium, yet it is virtually ignored or misunderstood by science and philosophy," notes Prof. Zeleny. "The faster the new emerges, the more of the old that must be abandoned. This leads to resistance, political disruptions, and populist defense of the status quo. New and reliable Evolutionary Economics [a name coined by Prof. Zeleny for this new science] must be recognized."

Economic differences between nations are fast disappearing, while inequalities in terms of local and reginal economies are widening even faster. "Well balanced regional and local economies are the only assurance of a well-balanced country or nation as a whole. New and lasting improvements can emerge by not ignoring, but by respecting and enhancing natural evolutionary tendencies," explains Prof. Zeleny.

Other pressures Prof. Zeleny explores include conflicts between state intervention and self-organized natural response; an imbalance between rates of accepting the new and abandoning old; conflicts between the man-made and the naturally occurring world; and emerging needs for multidisciplinary education thinking, research, and action.

The most significant challenges to overcome include the protection of old paradigms, overcoming tendencies towards preserving status quo, or returning to the old "normal," especially for political reasons.

Prof. Zeleny reviews the management system concept he developed, known as the Zeleny ZIPF, or Rotary. It rotates and revolves around customer satisfaction to drive innovation, improve processes, and achieve financial success. He also draws on the experience of the Bata Management System, now celebrating (as BSO in India) its 126th anniversary, which was organized to behave as a living organism: learning, adjusting, and self-organizing.

Prof. Zeleny asserts that in a rapidly evolving environment, additional cultural traits should be acquired within a properly run ZIPF or a similar rotary management system. For example, rapid change does not allow for a traditional strategy; you have to handle the future. He calls this the Strategy of the first step. You take the first step, evaluate the impacts, and then take the next first step. It is like every day is the Day 1!

To achieve equilibrium in human systems, Prof. Zeleny introduces the idea of Integrated Productive Environments (IPE), in which regions, localities, and communities are allowed their economic independence, self-sufficiency, entrepreneurship, and innovative originality. Such independence and self-determination, he says, will lead to cooperation, coordination, and local exchanges of specific knowledge products and services, in the interest of continued self-enhancement.

The highest IPE would be a complete town: productive, flexible, modular, fully equipped to provide food, products, and services, all in the closest proximity to regional or local customers. The first such IPE town was the Bata-Zlín in Moravia, which was "exported" all over the world, and is still functional even today.

"Such orientation requires competent cooperation of many individuals, companies, and institutions at multilayered cultural, professional and knowledge levels," says Prof. Zeleny. "It is this kind of deep cooperation that is needed to restore regional and local equilibrium."

IPEs are also needed in education, government, healthcare, defense, and environmental protection. "As we are abandoning the old to embrace the new, we cannot remain the narrow specialists or 'experts.' We have to become multidisciplinary polymaths," he concludes.

Prof. Zeleny is the Founding Editor of Human Systems Management, which is celebrating its 40th anniversary in 2021. His article is the first in a new section of the journal, "Strategic revival of Human Systems Management." Editor-in-Chief Nada Trunk Širca, PhD, International School for Social and Business Studies, Euro-Mediterranean University, University of Primorska, Slovenia, explains that articles in the new section will address how the concepts raised by Prof. Zeleny can be woven into human systems management research and applications. "The journal will continue as a self-renewing, evolving entity, open to new paradigms, new technologies, timely adaptations, and trailblazing new authors from around the world," she says.

A University of New Mexico research team conducted a data analysis that has found that as a larger portion of the population gets vaccinated against COVID-19, it becomes economically advantageous to start relaxing social distancing measures and open businesses.

Francesco Sorrentino, associate professor of mechanical engineering, is lead author of "Data-driven Optimized Control of the COVID-19 Epidemics," published March 22 in Scientific Reports.

Co-authors of the study are Afroza Shirin of the Department of Mechanical Engineering and the Department of Electrical and Computer Engineering, and Yen Ting Lin, a staff scientist of the Information Science Group in the Computer, Computational and Statistical Sciences Division at Los Alamos National Laboratory.

The study looked at data from four metropolitan statistical areas (MSAs) within the United States: Seattle, New York City, Los Angeles and Houston from January 21 to July 8, 2020. The four cities were chosen because they have had divergent trends with the virus (Seattle and New York City were early hotspots, while Los Angeles and Houston peaked in the summer).

Sorrentino said that while the findings perhaps may seem obvious, they are significant because the model is inferred and parametrized by regional new case reports and could potentially help guide policy decisions as more businesses, schools and other organizations ponder when and how to reopen during the pandemic.

"Our work is quantitative, so it can hopefully offer some evidence that shows the vaccines are going to allow us to loosen social distancing measures, including opening businesses," he said. "It provides a measure of hope as we go forward and increase the percentage of citizens who are vaccinated."

He points out that the study was looking at just the numbers, what he calls an "optimization problem," to determine the economic cost of keeping many businesses closed or at reduced capacity. Sorrentino said the study defined economic impact by the extent that a city's economy was closed -- businesses like restaurants, gyms, salons and airports that would lose business without people's physical presence. The study took into account both the costs associated with quarantining (which requires supervision costs as well as costs due to lowered productivity) as well as social distancing (which incurs costs only due to productivity).

"We did not look at this mainly from a public health standpoint. We were looking at the economic impact of the pandemic, which we attempted to minimize while in the presence of constraints relevant to the public health domain, such as suppressing the number of infected individuals below a threshold over the course of a few months" he said. "But our model shows that even before we achieve herd immunity, we can relax social distancing compared to the situation prior to immunization."

Sorrentino said there are several other caveats to the study. For instance, the analysis took place before the virus variants were a factor in the United States, so that variable is not taken into account.

The analysis looked at Seattle, beginning on December 14, 2020, when the vaccine was first being administered. Even with this limited data, the effect of vaccinations was dramatic, impacting the so-called "optimal control solution." The study computed these optimal solutions under many different conditions.

"While the optimal interventions would vary depending on a number of factors, we always saw that a gradual relaxation of social distancing was possible after roughly 10% of the population got vaccinated," he said.

After just 20 days, the trend was becoming clear when comparing with the case in which the effects of vaccinations were not incorporated in the model.

"With even just a small percentage of the population being vaccinated, much less social distancing was optimal, so it can be assumed that the effect from increased vaccination efforts will be even more robust," he said.

Sorrentino emphasizes also that everyone should continue to follow the current policy and health guidelines, and that the relaxing of social distancing should adhere to these guidelines and be gradual. And of course, that guidance may change, based on the rates of spread of the virus and the variants.

Sorrentino has conducted extensive research in the area of control theory and synchronization using mathematical models. Last year, he was awarded the National Institutes of Health Trailblazer Award from the National Institute of Biomedical Imaging and Bioengineering for a research project that could improve the way drugs for diseases are timed and delivered to patients.

A cast of so-called 'nurse cells' surrounds and supports the growing fruit fly egg during development, supplying the egg -- or 'oocyte' -- with all the nutrients and molecules it needs to thrive. Long viewed as passive in this process, the Drosophila egg actually plays an active role not only in its own growth, but also in the growth of the surrounding nurse cells, Princeton University researchers report on March 21 in Developmental Cell.

"Here we show an example of bidirectional communication -- a dialogue -- between different cells. The egg is taking an active hand in controlling its own feeding by these supporting cells," says Stanislav Shvartsman, head of the developmental dynamics group within the Flatiron Institute's Center for Computational Biology and professor of molecular biology at Princeton. The discovery of bidirectional communication in fruit flies has implications for understanding development in mammals, in which the egg is also nursed by surrounding cells.

The research was led by Shvartsman and Elizabeth Gavis, also professor of molecular biology; Caroline Doherty was lead author, and Rocky Diegmiller and Manisha Kapasiawala contributed to the study.

In early development, four cell divisions give rise to the 16 connected cells that make up the Drosophila germline cyst, the first structure formed during gamete development. One of these becomes the egg; the other 15 cells support the egg's dramatic growth by supplying it with vast quantities of nutrients that travel via intricate microtubule networks, and through cytoplasmic connections between the egg and nurse cells. Until now, scientists have viewed the oocyte as merely a passive recipient. The observation of groups of nurse cells that vary in size according to their distance from the oocyte led the researchers to suspect that some type of cell-cell communication occurs, says Shvartsman. Since cell size and cell cycle are tightly correlated, investigating the factors influencing the nurse cell cycle was the clear next step, says Doherty.

Researchers honed in on a protein called Dap (short for 'Da capo', meaning 'from the top'), which is known to influence cell cycle progression. Nurse cells supply the oocyte with RNA molecules needed to make the Dap protein. Doherty noticed that oocyte-manufactured Dap protein appeared in the nurse cells, at a rate suggesting that it diffused from the oocyte. After fusing a tiny Dap-recognizing antibody (called a nanobody) to a protein that could trap Dap within the egg, Doherty saw a decrease of the Dap level in the nurse cells. Together, these experiments showed that once the egg makes Dap, it diffuses to the very nurse cells that donated Dap RNA, providing the first evidence for two-way oocyte-nurse cell communication in fruit flies. "It was so exciting to see the oocyte is communicating with the nurse cells -- this is something scientists hadn't considered," says Gavis. Further, the egg communicates via Dap, which controls the nurse cell cycles, which in turn influence the egg's growth. So, in a feedback loop, "the egg is controlling the growth of the cells that load it with nutrients and information" says Doherty.

To better understand the logic of this bidirectional communication, researchers modeled the system as a network of coupled oscillators: models based on the biochemical clocks that drive cell cycles. The model underscored the role of a diffusible cell cycle inhibitor (like Dap) in creating a hierarchy of cell sizes similar to what is observed in Drosophila. Importantly, it also showed the oscillators must be tuned within a specific range to establish a feedback loop that gives the egg the right amount of sustenance for proper growth and viability. "These 16 cells make up one of the simplest systems in which we can dissect this sophisticated feedback loop," says Shvartsman.

As a next step, Doherty plans to investigate signaling between the oocyte-nurse cells cyst and the sheet of follicle cells that surrounds it. "These two tissue types need to grow together, and later, the follicle cells that stay over the nurse cells stretch out. Is this positioning necessary to properly stretch the follicle cells?" Doherty asks. "We might move from a dialogue to a conversation between these three cell types," adds Shvartsman.

The discovery of bidirectional communication in fruit fly development points to the notion of universal mechanisms at play in biology, as back-and-forth communication between the oocyte and supporting cells is also seen in mammals. "This study opens up the possibility to discover many more instances of this kind of cellular crosstalk in development," says Yukiko Yamashita, professor of biology at the Massachusetts Institute of Technology. Although previous work on mammals focused on the egg's control of the metabolism of surrounding cells, this study may spur researchers to investigate the egg's impact on cell cycle regulation in mammals, says Francesca Duncan, co-director of the Center for Reproductive Science at the Feinberg School of Medicine at Northwestern University. "This work solidifies the parallels between fruit flies and mammals," adds Gavis.

Scientists from the Department of Physiology of the University of Granada (UGR) have shown that caffeine (about 3 mg/kg, the equivalent of a strong coffee) ingested half an hour before aerobic exercise significantly increases the rate of fat-burning. They also found that if the exercise is performed in the afternoon, the effects of the caffeine are more marked than in the morning.

In their study, published in the Journal of the International Society of Sports Nutrition, the researchers aimed to determine whether caffeine--one of the most commonly-consumed ergogenic substances in the world to improve sports performance--actually does increase oxidation or "burning" of fat during exercise. Despite the fact that its consumption in the form of supplements is very common, the scientific evidence for its beneficial claims is scarce.

"The recommendation to exercise on an empty stomach in the morning to increase fat oxidation is commonplace. However, this recommendation may be lacking a scientific basis, as it is unknown whether this increase is due to exercising in the morning or due to going without food for a longer period of time," explains the lead author of this research, Francisco José Amaro-Gahete of the UGR's Department of Physiology.

A total of 15 men (mean age, 32) participated in the research, completing an exercise test four times at seven-day intervals. Subjects ingested 3 mg/kg of caffeine or a placebo at 8am and 5pm (each subject completed the tests in all four conditions in a random order). The conditions prior to each exercise test (hours elapsed since last meal, physical exercise, or consumption of stimulant substances) were strictly standardized, and fat oxidation during exercise was calculated accordingly.

Maximum fat oxidation

"The results of our study showed that acute caffeine ingestion 30 minutes before performing an aerobic exercise test increased maximum fat oxidation during exercise regardless of the time of day," explains Francisco J. Amaro. The existence of a diurnal variation in fat oxidation during exercise was confirmed, the values ??being higher in the afternoon than in the morning for equal hours of fasting.

These results also show that caffeine increases fat oxidation during morning exercise in a similar way to that observed without caffeine intake in the afternoon.

In summary, the findings of this study suggest that the combination of acute caffeine intake and aerobic exercise performed at moderate intensity in the afternoon provides the optimal scenario for people seeking to increase fat-burning during physical exercise.