Culture

Tokyo, Japan - The development and progression of cancer is a complicated process that occurs when cells in the body grow out of control. Many different mechanisms and pathways that directly affect cell proliferation have been uncovered. Researchers from Tokyo Medical and Dental University (TMDU) have made an additional discovery; a unique anti-cancer function for an enzyme previously believed to only influence RNA molecule structure.

In a report published in The EMBO Journal, a group of researchers from TMDU detail the identification of the protein TruB1 as a regulator of the microRNA (miRNA) let-7, which has significant implications for the fight against various cancers.

MiRNAs are small RNA molecules that serve as a sort of molecular brakes. They work by blocking certain gene expression messages from being formed into proteins. Let-7 was one of the first of over 1,500 miRNAs to be discovered and is present in the cells of many species, including humans. Previous work has shown that many tumor cells have fewer let-7 molecules than normal cells, and therefore this miRNA may be important in cancer development. Because of this, the researchers at TMDU were curious if there were any cellular proteins that could help increase the amount of let-7 present in cells.

"Let-7 is a very important miRNA in human cells that can affect many processes from development to tumor suppression," says lead author of the study Ryota Kurimoto. "However, it is still unclear how levels of let-7 in cells are controlled, so we wanted to investigate this further."

To do this, the researchers performed a cell-based screening of proteins that can bind to RNA molecules. They did this with a system called a luciferase assay, which helped them identify proteins that could assist with increasing let-7 levels.

"Our main finding was quite unexpected," describes Hiroshi Asahara, senior author. "The protein TruB1 significantly promoted maturation of let-7 in our experiments."

The results were mainly surprising because TruB1 had previously only been characterized as a protein that participates in a process called RNA modification.

"When binding to let-7, TruB1 didn't perform the modification it had always been known for," says Kurimoto. "In fact, TruB1 helped other proteins bind to let-7, which enhanced expression levels of this miRNA."

Additionally, through regulation of let-7, TruB1 could suppress growth and division of cells. This is quite significant because it implies that TruB1 has an anti-cancer role in cells. This study provides crucial information that will be critical for the development of novel cancer therapeutics.

Scientists around the world have been working to grow arbuscular mycorrhizal fungi without their host plants because they can be used as organic fertilizer in agriculture and forestry. AM fungi help plants receive nutrients from the soil through a network that is efficient and far more reaching than their own roots can provide. A group led by graduate students Yuta Sugiura, Rei Akiyama and Associate Professor Katsuharu Saito of Shinshu University successfully demonstrated that AM fungi can be grown asymbiotically when given myristate as a carbon and energy source.

The history of the relationship between AM fungi and plants growing on land goes back 460 million years. For the first time in its 460 million year history, arbuscular mycorrhizal is about to gain independence from plants, so that it can be used to help plants grow in less fertile soil. Corresponding author Professor Saito states "although it was considered difficult, AM fungi has been successfully grown in a culture medium. With advancements, microbial materials for agricultural use can be produced."

"The growth speed and efficiency is still low and we are working on spore formation so the next generation can be grown. We hope to work on a collection of cultures that can be grown independently and be applied for use in agriculture." Currently, the only way for AM fungi to be used in agriculture is with their host plants, making its use as fertilizer expensive and hard to implement. With the advancement in asymbiotic culture, the hope is that less chemical fertilizer will be needed for use in agriculture.

Among the most damaging natural hazards, earthquakes are still today one of the least understood phenomena in Earth Sciences. Earthquakes happen when rocks on either side of a tectonic fault slide. The sliding, however, does not occur along the whole fault at once but starts at one point, the hypocenter, and then spreads over the entire fault at a speed known as the "rupture speed" of the earthquake. Geophysicists are particularly interested in rupture speeds because the faster they are, the stronger the seismic waves and therefore the greater the damage caused.

Seismic models developed so far concluded that earthquakes could not propagate in a stable and sustainable way at arbitrary speeds. Scientists had therefore determined a "forbidden speed" range situated between the speed of P and S waves, the two main seismic waves that propagate through the Earth. However, progress in the seismological observation of earthquakes has made it possible to demonstrate that recent earthquakes had actually propagated within the forbidden range. Such was the case for the 2018 earthquake in Palu, Indonesia, for example, which caused a destructive tsunami.

Uninterrupted rupture speeds due to oblique sliding

To resolve this puzzling inconsistency between earthquake theory and observations, researchers of Université Côte d'Azur and the IRD developed a new model to predict the propagation speed of earthquakes. This feat was accomplished using the high-performance computer of the Côte d'Azur Observatory, one of the participants in OPAL, a shared platform that provides access to all the computational resources of the region.

The researchers managed to overcome two crucial limitations of the previous models. The first was to rely on 2-dimensional models, while the Earth is 3-dimensional. The second was to assume either a horizontal or a vertical direction of sliding, while earthquake sliding can be oblique. By overcoming these two limitations, they were able to explain why the "forbidden speeds" are actually admissible.

"One of the main challenges in the prevention of earthquakes is to predict their impact. We need to seize this opportunity to introduce more physics in the evaluation of seismic hazards, which has been very empirical so far," points out Huihui Weng, researcher at Université Côte d'Azur. "The new model provides validated theoretical elements which could ultimately be used to improve the way seismic risk is evaluated," adds Jean-Paul Ampuero, seismologist at the IRD.

A researcher at University of Limerick in Ireland has played a key role in examining some of the secrets behind Game of Thrones.

What are the secrets behind one of the most successful fantasy series of all time? How has a story as complex as the one in George R.R. Martin's novels enthralled the world and how does it compare to other narratives?

Researchers from five universities across the UK and Ireland - including UL's Dr Padraig MacCarron - came together to unravel 'A Song of Ice and Fire', the books on which the TV series is based.

In a paper that has just been published by the Proceedings of the National Academy of Sciences of the USA, the team of physicists, mathematicians and psychologists from Coventry, Warwick, Limerick, Cambridge and Oxford universities used data science and network theory to analyse the acclaimed book series by George R.R. Martin.

The study shows the way the interactions between the characters are arranged is similar to how humans maintain relationships and interact in the real world. Moreover, although important characters are famously killed off at random as the story is told, the underlying chronology is not at all so unpredictable, the research shows.

The team found that, despite over 2,000 named characters in 'A Song of Ice and Fire' and over 41,000 interactions between them, at chapter-by-chapter level these numbers average out to match what we can handle in real life.
Even the most predominant characters - those who tell the story - average out to have only 150 others to keep track of. This is the same number that the average human brain has evolved to deal with.

While matching mathematical motifs might have been expected to lead to a rather narrow script, George R. R. Martin keeps the tale bubbling by making deaths appear random as the story unfolds. But, as the team show, when the chronological sequence is reconstructed the deaths are not random at all: rather, they reflect how common events are spread out for non-violent human activities in the real world.

"These books are known for unexpected twists, often in terms of the death of a major character, it is interesting to see how the author arranges the chapters in an order that makes this appear even more random than it would be if told chronologically," explained Dr Padraig MacCarron, a postdoctoral researcher at the Centre for Social Issues Research and Mathematics Applications Consortium for Science and Industry (MACSI) at UL.

"Social networks of the most connected characters, while seemingly extensive, mirrored the typical range of social networks that humans maintain. Furthermore, characters' social networks did not extend beyond the cognitive limit of social connections that humans are able to sustain.

"Although the time intervals between significant deaths in relation to the story's timeline may appear random, they are not told in chronological order. Re-arranging them in order of which they occur, they follow a pattern more commonly observed in reality," added Dr MacCarron.

'Game of Thrones' has invited all sorts of comparison to history and myth and the marriage of science and humanities in this paper opens new avenues to comparative literary studies. It shows, for example, that it is more akin to the Icelandic sagas than to mythological stories such as the Tain Bo Cuailnge or Beowulf. The trick in Game of Thrones, it seems, is to mix realism and unpredictability in a cognitively engaging manner.

"People largely make sense of the world through narratives, but we have no scientific understanding of what makes complex narratives relatable and comprehensible. The ideas underpinning this paper are steps towards answering this question," explained Professor Colm Connaughton, from the University of Warwick.

Fellow researcher Professor Robin Dunbar, from the University of Oxford, observed: "This study offers convincing evidence that good writers work very carefully within the psychological limits of the reader."

COLUMBUS, Ohio - African Americans who attend Historically Black Colleges or Universities (HBCUs) may be at lower risk for health problems later in adulthood compared to African Americans who attend predominantly white institutions, a new study suggests.

The research showed that Black adults who had enrolled in an HBCUs had a 35% lower probability of developing metabolic syndrome by midlife compared to Black adults who enrolled in predominantly white schools. Additionally, the benefit of attending an HBCU was more pronounced in African Americans who grew up in more segregated environments.

Metabolic syndrome is defined as the presence of at least three of five factors that increase the risk for heart disease, diabetes and stroke - excess belly fat, elevated blood pressure, low "good" cholesterol, and high levels of blood glucose and triglycerides.

"We've known for a very long time that the more years of completed schooling someone has, the better their health is likely to be across the life course, but there's been very little research looking at the different contexts in which education occurs and their impact on subsequent health outcomes," said Cynthia Colen, lead author of the study and associate professor of sociology at The Ohio State University.

"This study really points to a strength of HBCUs that people don't normally think about: Not only can they be health protective, but they can be health protective for years to come, not just while people are in school."

Colen conducted the study with Nicolo Pinchak, an Ohio State graduate student in sociology, and Kierra Barnett, a postdoctoral researcher in Ohio State's Kirwan Institute for the Study of Race and Ethnicity. The research is published online in the American Journal of Epidemiology.

The team used data from the National Longitudinal Survey of Adolescent to Adult Health (Add Health), which consists of periodic interviews with people who were middle- and high-school students in grades 7-12 in 1994-95. Colen specifically used information collected during follow-up interviews that were conducted in 1996, 2001 and 2008.

The 727 Black respondents in the final study sample attended a total of 319 institutions of higher learning - 273 predominantly white institutions and 46 HBCUs. The National Center for Education Statistics describes Historically Black Colleges and Universities as "institutions that were established prior to 1964 with the principal mission of educating Black Americans."

This national survey (Add Health) collected detailed health data during all interview waves, providing the Ohio State researchers with the specific measures they used to assess whether the Add Health respondents had developed metabolic syndrome by 2008 when they were in their late 20 and early 30s.

Colen and colleagues constructed statistical models to determine the extent to which HBCU attendance was associated with metabolic syndrome in midlife. These models controlled for a number of characteristics that could influence both HBCU enrollment and adult health, such as age, sex and region of the country, as well as a series of family, school and neighborhood conditions they experienced during their childhoods.

The analysis showed that 31% of the respondents who had attended predominantly white institutions had metabolic syndrome by midlife, compared to 23% of those who had attended HBCUs, and that HBCU attendance was associated with a 35% reduction in the odds of having metabolic syndrome among college-educated African Americans. The researchers noted that this kind of health benefit mirrors the risk reduction that scientific studies suggest people can achieve through change in diet or exercise.

Overall, almost 30% of college-educated Black adults in the study sample developed metabolic syndrome by the time of their interviews in 2008, when they were still relatively young.

"That is the time period of the life course, when people are in their 30s and 40s, when we see the fastest growth in Black/white health disparities. This is largely driven by the emergence of chronic diseases, such as hypertension, diabetes and obesity," Colen said.

What is notable about this particular study is that college-educated African Americans were not being compared to whites - which was a strength of this research, she said: "Here, we are looking at how health is unequally distributed among African Americans. And we identify HBCUs as an opportunity not only for upward mobility, but as a potential driver of better health over the life course for individuals who spent their formative years at these types of institutions of higher learning."

Though the available data can't explain why or how former HBCU students' risk for metabolic syndrome is lower than those who attended predominantly white schools, Colen has some possible theories: At HBCUs, Black students regularly interact with African American faculty, staff and students who can serve as mentors, and they are less likely to be chronically exposed to the racial discrimination that has been shown to erode both mental and physical health years after people first encounter this type of unfair treatment.

Similarly, the researchers can only speculate about why the health-protective benefits of HBCUs are stronger for Black adults who grew up in more segregated environments.

"Our findings suggest that HBCUs are likely to be health protective for the segment of society who needs it most - those growing up in the most racially isolated environments," the researchers noted. "Moreover, this finding underscores the important role that place, in general, and segregation, specifically, plays in the unequal distribution of health."

DURHAM, N.C. - Biomedical engineers at Duke University have developed a new way of modeling how potentially beneficial packages of DNA called plasmids can circulate and accumulate through a complex environment that includes many bacterial species. The work has also allowed the team to develop a new factor dubbed the "persistence potential" that, once measured and computed, can predict whether or not a plasmid will continue to thrive in a given population or gradually fade into oblivion.

The researchers hope that their new model will lay the groundwork for others to better model and predict how important traits such as antibiotic resistance in pathogens or metabolic abilities in bacteria bred to clean environmental pollution will spread and grow in a given environment.

The results appear online on November 4 in the journal Nature Communications.

In addition to the Darwinian process of handing down genes important for survival from parents to offspring, bacteria also engage in a process called horizontal gene transfer. Bacteria are constantly sharing genetic recipes for new abilities across species by swapping different packages of genetic material called plasmids with one another.

"In an examination of just a single bottle of seawater, there were 160 bacterial species swapping 180 different plasmids," said Lingchong You, professor of biomedical engineering at Duke. "Even in a single bottle of water, using current methods to model plasmid mobility would far exceed the collective computing power of the entire world. We've developed a system that simplifies the model while maintaining its ability to accurately predict the eventual results."

The potential of any one of these genetic packages to become common throughout a given population or environment, however, is far from certain. It depends on a wide range of variables, such as how quickly the packages are shared, how long the bacteria survive, how beneficial the new DNA is, what the trade-offs are for those benefits and much more.

Being able to predict the fate of such a genetic package could help many fields -- perhaps most notably the spread of antibiotic resistance and how to combat it. But the models required to do so in a lifelike scenario are too complicated to solve.

"The most complex system we've ever been able to model mathematically is three species of bacteria sharing three plasmids," said You. "And even then, we had to use a computer program just to generate the equations, because otherwise we'd get too confused with the number of terms that were needed."

In the new study, You and his graduate student, Teng Wang, created a new framework that greatly reduces the complexity of the model as more species and plasmids are added. In the traditional approach, each population is divided into multiple subpopulations based on which plasmids they're carrying. But in the new system, these subpopulations are instead averaged into a single one. This drastically cuts down on the number of variables, which increases in a linear fashion as new bacteria and plasmids are added rather than exponentially.

This new approach enabled the researchers to derive a single governing criterion that allows the prediction of whether or not a plasmid will persist in a given population. It's based on five important variables: the cost to the bacteria of having the new DNA, how often the DNA is lost, how quickly the population is diluted by the flux through the population, how quickly the DNA is swapped between bacteria, and how fast the population as a whole is growing.

With measurements for these variables in hand, researchers can calculate the population's "plasmid persistence." If that number is greater than one, the genetic package will survive and spread, with higher numbers leading to greater abundance. If less than one, it will fade away into oblivion.

"Even though the model is simplified, we've found that it's reasonably accurate under certain constraints," said Wang. "As long as the new DNA doesn't place too great of a burden on the bacteria, our new framework will succeed."

You and Wang tested their new modeling approach by engineering a handful of different synthetic communities, each with different strains of bacteria and genetic packages for swapping. After running the experiments, they found that the results fit quite well within the expectations of their theoretical framework. And to go the extra mile, the researchers also took data from 13 previously published papers and ran their numbers as well. Those results also supported their new model.

"The plasmid persistence criterion gives us the hope of using it to guide new applications," said You. "It could help researchers engineer a microbiome by controlling the genetic flow to achieve a certain function. Or it can give us guidance on what factors we can control to eliminate or suppress certain plasmids from bacterial populations, such as those responsible for antibiotic resistance."

When and how did the first animals appear? Science has long sought an answer. Uppsala University researchers and colleagues in Denmark have now jointly found, in Greenland, embryo-like microfossils up to 570 million years old, revealing that organisms of this type were dispersed throughout the world. The study is published in Communications Biology.

"We believe this discovery of ours improves our scope for understanding the period in Earth's history when animals first appeared - and is likely to prompt many interesting discussions," says Sebastian Willman, the study's first author and a palaeontologist at Uppsala University.

The existence of animals on Earth around 540 million years ago (mya) is well substantiated. This was when the event in evolution known as the "Cambrian Explosion" took place. Fossils from a huge number of creatures from the Cambrian period, many of them shelled, exist. The first animals must have evolved earlier still; but there are divergent views in the research community on whether the extant fossils dating back to the Precambrian Era are genuinely classifiable as animals.

The new finds from the Portfjeld Formation in the north of Greenland may help to enhance understanding of the origin of animals. In rocks that are 570-560 mya, scientists from Uppsala University, the University of Copenhagen and the Geological Survey of Denmark and Greenland have found microfossils of what might be eggs and animal embryos. These are so well preserved that individual cells, and even intracellular structures, can be studied. The organisms concerned lived in the shallow coastal seas around Greenland during the Ediacaran period, 635-541 mya. The immense variability of microfossils has convinced the researchers that the complexity of life in that period must have been greater than has hitherto been known.

Similar finds were uncovered in southern China's Doushantuo Formation, which is nearly 600 million years old, over three decades ago. Since then, researchers have been discussing what kinds of life form the microfossils represented, and some think they are eggs and embryos from primeval animals. The Greenland fossils are somewhat younger than, but largely identical to, those from China.

The new discovery means that the researchers can also say that these organisms were spread throughout the world. When they were alive, most continents were spaced out south of the Equator. Greenland lay where the expanse of the Southern Ocean (surrounding Antarctica) is now, and China was roughly at the same latitude as present-day Florida.

"The vast bedrock, essentially unexplored to date, of the north of Greenland offers opportunities to understand the evolution of the first multicellular organisms, which in turn developed into the first animals that, in their turn, led to us," Sebastian Willman says.

Bacteria are considered to be true experts in survival. Their rapid adaptive response to changing environmental conditions is based, among other things, on two competing signaling molecules. As the "Yin and Yang" of metabolic control they decide on the lifestyle of bacteria, as reported by researchers from the University of Basel. The new findings also play a role in the context of bacterial infections.

Whether they are pathogens, deep-sea microbes or soil-dwelling organisms, in order to survive, microorganisms must be able to adapt rapidly to diverse changes in their environment, including nutrient depletion. Bacteria owe their extraordinary ability to quickly adjust to adverse living conditions to small signaling molecules.

Scientists headed by Professor Urs Jenal and Professor Tilman Schirmer from the Biozentrum, University of Basel, have now discovered that bacteria use two chemically related signaling molecules to adapt their lifestyle to the prevailing living conditions. The researchers present their results in the latest issue of "Nature Microbiology". Like Yin and Yang, the two molecules embody two forces that control bacterial growth and metabolism reciprocally.

Bacterium with two different lifestyles

The researchers investigated the antagonistic nature of the two signaling molecules ppGpp and c-di-GMP in the cell using Caulobacter crescentus as a model organism. This bacterium can slip into two different roles: It can be found in a free-swimming form that is unable divide and in a surface-attached, reproductive state.

Both the lifestyle and the environmental conditions are reflected in the concentration of the two signaling molecules. This information is detected by a protein that binds both signaling molecules and acts a molecular switch, controlling growth, metabolism and lifestyle of the bacterium.

Signaling molecules determine bacterial way of life

The signaling molecules ppGpp und c-di-GMP compete for binding to the master switch. "In swarming bacteria with high levels of ppGpp, the protein is switched on; it is active," explains Urs Jenal. "In this state, glucose consumption is in full swing. Simultaneously, the resulting harmful oxygen radicals are efficiently neutralized." This ensures, that metabolic reactions adapt to the high energy demand of the motile swimmer cells and cell damage is averted.

Under favorable living conditions, providing sufficient nutrients, the level of c-di-GMP increases constantly, forcing the swimmer to develop into a sessile form. "In this case, c-di-GMP displaces ppGpp from the protein's binding pocket, it changes its structure and turns itself off," says Jenal. "This redirects metabolic reactions allowing bacteria to settle, grow and reproduce. The production of building blocks for the cell is boosted along with adhesive substances for surface attachment."

Important role also in pathogens

With the molecular master switch, the scientists have discovered the link between two large regulatory networks, which until now have been thought to operate independently. Although Caulobacter is a harmless environmental bacterium, the newly uncovered "Yin and Yang" mechanism could also play an important role in pathogens.

This may prove to be of key importance: Both ppGpp and c-di-GMP influence bacterial virulence and persistence as well as antibiotic resistance in different ways, thus influencing the course of many infections.

URBANA, Ill. - The transition to middle school is undeniably tough for many sixth-graders, even in the best of times. Mounting academic demands, along with changes in peer dynamics and the onset of puberty, result in a predictable and sometimes irreversible slump in academic performance.

A new University of Illinois study suggests an unexpected but potentially potent remedy: trees.

"Hundreds of studies show a positive link between contact with nature and learning outcomes, but the studies on nature near schools focus on young children or older learners. We wanted to make sure the same pattern was true in this vulnerable and overlooked population," says Ming Kuo, associate professor in the Department of Natural Resources and Environmental Sciences at Illinois.

It was. Even after taking a whopping 17 variables into account including student demographics, school resources, and neighborhood characteristics, Kuo and her co-authors found that the more tree cover around a school, the better its standardized test scores in both math and reading. The study included 450 middle schools and nearly 50,000 students in urban, suburban, and rural communities in Washington State.

But why would trees boost test scores? Kuo's previous work points to a cause-and-effect relationship between nature and learning, with more exposure to nature resulting in improved concentration, greater classroom engagement, and less disruptive behavior. No surprise, then, that greener schools perform better.

Samantha Klein, a master's student who worked with Kuo on the study, made a point to compare different kinds of vegetation at different distances from schools.

"We wanted to offer concrete guidance to landscape architects, principals, and school boards interested in putting the greenness-achievement link to work, giving them clues as to what should be planted, and where," Klein says.

Kuo, Klein, and their team were able to differentiate tree cover from grass and shrubs using satellite imagery. "From a practical standpoint, trees cost more to install than grass. So if school districts could get away with just putting grass everywhere, that would be really helpful to know," Klein explains.

Unfortunately, that wasn't the case. Trees were far and away more impactful for test scores than other types of vegetation. Still, Kuo emphasizes that compared with other school resource investments planting trees around a schoolyard is still an incredibly cheap and effective intervention. But it could take a sea change before school districts accept school greening when other demands seem so much more pressing.

"I think school boards have always been faced with distributing very limited funds, especially in the poorest areas. They might think that, with all the other pressing needs for funding, school landscaping is the least of their concerns. Little do they suspect that a treeless schoolyard may actually be contributing to poor school performance," Kuo says.

The satellite images also helped Kuo's team pinpoint where tree cover mattered most. They compared the importance of greenness in different buffer zones around schools, within 250 meters (around two blocks) and 1000 meters. It turned out trees closer to the schools made all the difference, even when controlling for greenness at farther distances. In other words, even if the larger neighborhood was leafy, students were no better off if the schoolyard wasn't.

These findings extend previous discoveries in Chicago public schools. Kuo's work there showed the importance of tree cover near schools in low-income urban districts. But since her current study includes 450 schools across a wide spectrum of populations, she's confident her results apply more broadly.

"One of the nice things about this study is not only the sheer number of schools and students we're looking at, but the huge range in Washington State. We've captured everything from extremely urban to totally rural areas; rich schools and poor schools; schools with predominately white, Hispanic, Black, or American Indian student bodies; and every level of greenness represented within each of those samples," Kuo says. "The fact that the greenness-achievement link is true here is encouraging to me. It gives us some confidence that our recommendations apply to a whole variety of schools."

How does all this apply against the backdrop of remote learning during the COVID-19 pandemic? School greenness won't make much of a difference if kids aren't leaving the house. But whether they are physically in school or not, Kuo thinks contact with nature could be critical right now.

"I think the need for trees is more acute at this time. One of the big benefits of greenery, and one of the reasons we think it affects academic achievement, is it's a really potent stress reliever. Kids are aware that things are weird and that a lot of adults are kind of freaked out. And so having access to nature might be even more important than usual."

November 9, 2020 - Most young athletes don't get enough sleep - and that may significantly affect their sports performance, according to a paper in the November issue of Current Sports Medicine Reports, official journal of the American College of Sports Medicine (ACSM). The journal is published in the Lippincott portfolio by Wolters Kluwer.

"There's growing evidence to suggest that youth athletes don't get required amount of sleep, and that this negatively affects their performance," comments Mark F. Riederer, MD, of C.S. Mott Children's Hospital, University of Michigan, Ann Arbor, author of the new review. He believes that the trend toward more-intensive training might contribute to a lack of adequate sleep in in young athletes.

Rested and ready? Youth athletes need more sleep to do their best

Faced with competing demands including school, sports, and social life, young athletes tend to put off sleep in favor of other activities. Generally, the evidence suggests that they don't meet recommended guidelines for sleep duration: 9 to 12 hours for children aged 6 to 12 years and 8 to 10 hours for adolescents aged 13 to 18 years. For example, one study found that more than 90 percent of teen gymnasts get less than 8 hours of sleep per night.

Most studies find that young athletes get less sleep than non-athletes; they may sleep longer on the weekends, trying to make up their "sleep debt." The evidence suggests that young female athletes sleep less than their male counterparts. However, elite-level teen athletes of both sexes seem to get more sleep - possibly related to higher sleep need due to higher training loads.

Although studies vary, the evidence suggests that getting less-than-recommended sleep leads to decreased performance on the playing field. Some papers report that inadequate sleep has significant effects on reaction time, strength, speed, cognitive learning, and decision-making.

"[S]tudies consistently demonstrate that lack of recommended sleep results in poor sense of well-being, increased perceived training load, and poor placement in competitions," Dr. Riederer writes. Sleep deficits may also place young athletes at risk for injury and illness.

Other recent findings include:

Studies of napping and other sleep interventions show inconsistent effects on athletic performance.
Young athletes with symptoms of insomnia may be at increased risk of burnout, along with a higher risk of dropping out of their sport due to injury.
Levels of the stress hormone cortisol are increased after competitive matches, leading to reduced sleep time and quality.
Poor sleep may be linked to obstructive sleep apnea among college football linemen.
Inadequate sleep might be a risk factor for bony stress injuries (such as stress fractures).
Although it has been suggested that using smartphones or other electronic devices before bed can lead to impairments of sleep or athletic performance, one recent study found no such effects.

"The message for young athletes is, getting recommended sleep can improve your performance," Dr. Riederer comments. He notes that an emphasis on increasing training workload to improve skill and performance may adversely affect young athletes in other ways.

"Trends like early-morning training schedules, two-a-day practices, and late night practices and competitions come at the expense of good sleep habits - as well as leaving kids less time to socialize and do homework," Dr. Riederer adds. "We need to ensure our youth athletes are getting adequate amounts of sleep, and there is evidence to support this claim."

A biologist from RUDN University studied the development of the immune response in prepubertal male and female animals. According to her, the severity and mortality of infectious and inflammatory diseases at this age depend not on the sex hormones, but mainly on the chromosome set or karyotype. The results of the study were published in the Scientific Reports journal.

The amount of sex hormones in an animal's body changes during its life along with the state of its immune system. The correlation between these two processes hasn't been fully understood yet. It is yet unknown how sex hormones affect the immune systems of animals in the prepubertal period (in humans, this term refers to the age from 6-7 to 11-12 years). A biologist from RUDN University was the first to describe the differences in the immune response in prepubertal male and female rats. The results of the study can help find more effective treatment methods for children's diseases and increase the safety of vaccines.

"Understanding the peculiarities of the immune response in prepubertal animals can lead to the development of more effective immunotherapeutic approaches and help minimize the side effects of vaccination in children. That is why we decided to focus on the sex differences in the inflammatory response in prepubertal rats," said Anna Kosyreva, a Ph.D. in Biology, and an Assistant Professor at the Department of Histology, Cytology, and Embryology, RUDN University.

The team used 51 10-day-old rats (21 females and 30 males) in their experiment. 35 of them (12 females and 23 males) were injected with lipopolysaccharide (LPS), a toxic structural component of bacterial cell walls, to imitate septic shock--a common complication of severe infectious diseases. The administered dose (15 mg per one kg of weight) is deadly for adult animals but in the pups, the mortality rate amounted to 17% (2 out of 12) in females and 56% (13 out of 23) for males. 24 hours after the injection the team conducted a histological analysis of the lungs, livers, and thymuses of the survivors as well as the pups from the control group that hadn't received an injection. Before and after the injection the biologists measured the levels of the sex hormones estradiol and testosterone, as well as corticosteroids (hormones produced only by the adrenal cortex, not the genital glands) in all animals.

According to the team, the sex differences in the immune response to LPS in female and male rats did not depend on sex hormones. However, the progress of the inflammation in males was more severe: the area of liver necrosis in them was seven times larger than in females. Almost all injected pups developed pulmonary edema, but the number of neutrophils (inflammation-targeting cells) in males was 1.5 times higher. This more active inflammatory reaction is likely to be the cause of higher mortality among male rats. This difference could not have been explained by sex hormones. Therefore, the team assumed that the X chromosome could be the case.

The X chromosome contains immune response genes, including the regulators of NF-κB--a factor in charge of the synthesis of inflammation mediators. Females have two X chromosomes, one from each parent. If the genes responsible for NF-κB turn out to be dominant in one of the chromosomes, it takes over the other, and the dominant genes start to determine the production of inflammation mediators. In such a case, an animal has more chances to effectively fight infections. However, the males don't have this advantage because they only have one X chromosome with a single group of immune response genes.

A randomized clinical trial of Greek High Phenolic Early Harvest Extra Virgin Olive Oil in mild cognitive impairment: the MICOIL pilot study

Thessaloniki, Greece, November 9, 2020 - Greek researchers and clinicians investigated for the first time the effect of High Phenolic Early Harvest Extra Virgin Olive Oil (HP-EH-EVOO) versus Moderate Phenolic (MP-EVOO) and Mediterranean Diet (MeDi) as a therapeutic pharmaceutical natural compound for older adults with amnestic Mild Cognitive Impairment (aMCI). Amnestic MCI is usually a prodromal condition of Alzheimer's disease (AD) and is characterized by memory loss and inability to execute very complex Activities of Daily Living. While there is no treatment for MCI and symptomatic only treatment for AD, the global effort against cognitive disorders is focused on early detection and management of AD at the stage of aMCI.

Scientists from the Aristotle University of Thessaloniki (AUTH) and the Greek Association of Alzheimer's Disease and Related Disorders (GAADRD) have succeeded in making the shift to MCI therapy via robust natural remedies that can be used in order to forestall cognitive deterioration. In an article published in the Journal of Alzheimer's Disease, the researchers conducted a randomized prospective study so as to examine the HP-EH-EVOO and MP-EVOO versus MeDi. Moreover, genetic predisposition (APOE ε4) to Alzheimer's Disease (AD) was tested and an extensive neuropsychological battery was administered at baseline and after 12 months. Each participant was randomized and assigned to one of three groups i) Group 1 received the HP-EH-EVOO (50 mL/day) plus MeDi, ii) Group 2 received the MP-EVOO (50 mL/day) plus MeDi, and iii) Group 3 received only the MeDi instructions.

Recent literature paves the way to investigate natural compounds as alternative treatments of MCI due to AD. The MeDi is not a single prescribed diet, but rather a general food-based eating pattern, which is characterized by local and cultural differences throughout the Mediterranean region. Recent studies have proposed that more adherence to MeDi improved cognitive functions, decreased the possibility to develop MCI, and lessened the risk of MCI progression to AD. A Spanish longitudinal study showed that EVOO keeps the cognitive function better than nuts. A recent study suggests that intake of EVOO might offer a protective effect and/or slow AD pathology in transgenic mice. The results of this study suggest that the long-term consumption of an EVOO-containing diet starting at early age provides a protective effect against AD and its related disorder cerebral amyloid angiopathy (CAA), while a long-term intervention with an EVOO-rich MedDiet in 285 participants with high vascular risk resulted in better cognitive functioning when compared to a control diet.

The MICOIL study revealed better follow-up performance in Group 1 compared to Group 2 and Group 3 in almost all cognitive domains. Moreover, Group 2 showed also significant improvement compared to Group 3 in ADAS-cog (p=0.001) and MMSE (p=0.05), whereas Group 3 exhibited worse or similar to baseline performance in almost all domains. In particular, Group 1 and Group 2 had better outcomes with regards to ADAS-cog (p=0.003), Digit Span (p=0.006) and letter fluency (p=0.003). Moreover, there was a significant difference (p=0.001) in the presence of APOΕ ε4 between the Groups 1 and 2 vs. Group 3. Therefore, MICOIL showed that long-term intervention with HP-EH-EVOO or MP-EVOO was associated with significant improvement in cognitive function compared to MeDi, independent of the presence of APOE ε4.

Our study revealed in all measures we used better performance of treatment group compared with control group in the second assessment after 12 months of follow-up. Until today there is no other study which has examined in such detailed manner the effects of Greek EVOO in elders with MCI as an effective solution for cognitive impairment.

Gender discrimination continues to plague organizations, and "gig economy" businesses, which have thrived over the last decade, are not immune, according to new research from the University of Notre Dame.

Gig economy businesses, including Uber and Airbnb, offer temporary positions to independent workers while relying on consumer ratings and reviews as part of their advertising and marketing strategies.

But the system has its flaws. While digital brokerages provide a more efficient method for the exchange of goods and services and an improved way for consumers to voice their opinions about the quality of work they receive, bias and discrimination can emerge as part of the review process, according to "How unbecoming of you: Online experiments uncovering gender biases in perceptions of ridesharing performance," forthcoming in the Journal of Business Ethics from Nathan Meikle, postdoctoral research and teaching associate, and Corey Angst, professor of information technology, analytics and operations at Notre Dame's Mendoza College of Business.

For the study, the team created an ostensibly new ride-sharing service called Agile Rides with a publicly available mock website to reinforce its legitimacy. The team asked 919 participants from the crowdsourcing website Amazon MTurk to help them understand what makes a good rider experience and to imagine going through a detailed experience based on a recent customer experience with a driver. The vignette varied by gender and whether the rider had a good or bad experience. Participants then rated driver performance.

"In the online experiment, we examined participants' perceptions of the drivers," said Meikle, who specializes in social perception and its implications for organizations. "When driver performance was high-quality, participants rated female and male drivers equally. However, when driver performance was low-quality, participants rated female drivers significantly lower than male drivers."

In the gig economy, the traditional manager-subordinate relationship is absent and drivers receive their "performance evaluations" from customers.

The team points out that because digital platforms represent new, rapidly growing work environments capable of subjecting workers to bias and discrimination from a wide number of evaluators, companies should -- for moral, strategic and legal reasons -- consider algorithmic weightings based on gender to combat discrimination.

"If customers discriminate against female drivers, the female drivers may be dismissed from the platform, or at least punished financially, for performing equal quality work as men," Meikle said. "When employees' compensation and job security depend on the ratings of customers rather than on the ratings of managers, companies should examine whether customers are rating employees fairly and adjust the ratings accordingly."

Found in more than 60 countries, cruciferous clubroot disease is one of the most destructive plant diseases, causing so-called tumors on the roots of Brassicaceae crops and resulting in huge yield losses annually. The causal agent of this disease, Plasmodiophora brassicae, was first discovered by Russian biologist M. S. Woronin in 1878. Despite this early discovery, the life history of the pathogen remains a mystery.

"Although P. brassicae has been identified as the causal agent of cruciferous clubroot disease for 142 years, much earlier than the discovery of most plant pathogens, we were astonished that the full life cycle of this pathogen remained unclear when we started our investigation on this plant disease in 2015," said Lijang Liu, a scientist based at the University of Saskatchewan and the Chinese Academy of Agricultural Sciences. "The limited knowledge of P. brassicae biology greatly hinders the progress of studies on the cruciferous clubroot disease, which drove us to conduct this research."

The life history of the pathogen is very complex, comprising many different life forms. Liu and colleagues clarified the life history of P. brassicae in the root tissues of host Arabidopsis in a recently published article.

"Using confocal and electron microscopic imaging, we provide compelling evidence to support the proposed life cycle of P. brassicae, making it more convincing and acceptable to the community," explained Liu. "Notably, and most surprisingly, we discovered the existence of a sexual life stage of P. brassicae, starting from the fusion of two secondary zoospores within the infected epidermal cells."

Their other major findings include defining the development of zoosporangia and secondary zoospores and the sexual behavior between secondary zoospores in root epidermal cells and elucidating the growth and development of secondary plasmodia in root cortical cells, as well as the resultant physiological disturbances to host cortical cells.

"This research provides a fundamental understanding of the pathogen's biology as well as its cellular interactions with host plants. The knowledge gained from this investigation may further illuminate cellular mechanisms underlying host resistance and susceptibility and offers insights into the management practices against clubroot disease," said Liu. "Our article will help readers understand how such a lower eukaryotic microorganism performs a complex and sophisticated life history, giving a rise to a 'tumor' disease on plant roots."

Their article also highlights microscopic techniques coupled with live microbial fluorescence staining, which can be widely used in studying host-pathogen interactions. For more information, read "Refining the Life Cycle of Plasmodiophora brassicae" published in the October issue of Phytopathology.

A new study from researchers at Columbia University Vagelos College of Physicians and Surgeons has found evidence of a potential neurobiological mechanism for hallucinations and delusions that fits within the hierarchical model of psychosis and can explain their clinical presentation.

The study was published in eLife.

Columbia researchers Kenneth Wengler, PhD, a Postdoctoral Research Fellow and Guillermo Horga, MD, PhD, Florence Irving Associate Professor of Psychiatry, investigated the neurobiological mechanisms of two symptoms of schizophrenia: hallucinations and delusions. These two symptoms form the syndrome of psychosis, an immensely disabling psychiatric condition where patients lose their ability for reality testing.

"Typically, patients with more severe hallucinations also have more severe delusions, and these two symptoms respond similarly to antipsychotic medications. But this is not always the case; some patients have very prominent hallucinations but less severe delusions and vice versa," says Wengler. "This suggests that these symptoms may share a common neurobiological mechanism while simultaneously depending on symptom-specific pathways."

Some experts in the field believe that a hierarchical perceptual-inference model can explain the mechanisms behind psychosis. Wengler explains, "In its simplest form, the hierarchical model has two levels to the hierarchy: low and high. The low level makes inferences about basic features of stimuli and the high level makes inferences about their causes. An intuitive example of this is inferring the weather. In this scenario, you must decide if you are going to take an umbrella with you when you leave the house. The stimulus in this scenario is what you see when you look out the window; let's say it's cloudy. The context in this scenario is what you expect the weather to be like on a given day in the city you are in; let's say you are in Seattle. Although it is not currently raining, because it's cloudy and you are in a city where it often rains, you may decide to take an umbrella with you. The hierarchical model of psychosis frames hallucinations as resulting from dysfunction at the lower levels of the hierarchy and delusions as resulting from dysfunction at the higher levels of the hierarchy. Critically, these levels of inference are distinct but interconnected, so a dysfunction at one level would likely propagate upwards or downwards to other levels, therefore explaining why these symptoms tend to co-occur."

To investigate the neurobiological mechanisms of hallucinations and delusions within the framework of the hierarchical model, the researchers used functional magnetic resonance imaging to measure intrinsic neural timescales throughout the brain. These neural timescales reflect how long information is integrated in a given brain region. Most importantly, these neural timescales are organized hierarchically, making it a fitting measure to test the hierarchical model of psychosis.

The researchers collected data from 127 patients with schizophrenia from various online databases and determined how an individual's neural timescales related to their hallucination and delusion severities together. They found that neural timescales in the lower levels of the hierarchy tended to be longer in patients with more severe hallucinations, while neural timescales in the higher levels tended to be longer in patients with more severe delusions. These results provide the first direct evidence of a potential neurobiological mechanism for hallucinations and delusions that fits within the hierarchical model of psychosis and can explain their clinical presentation. The common neurobiological mechanism for both symptoms could result in increased neural timescales, but the symptom-specific pathways are the level of the hierarchy at which the neural timescales are increased. "Our findings open the door for the development of treatments to target specific symptoms of psychosis depending on an individual subject's symptom profile, in line with the current push for individualized medicine," says Horga.

The paper is titled "Distinct Hierarchical Alterations of Intrinsic Neural Timescales Account for Different Manifestations of Psychosis."