Culture

Scientists at the University of Kent have developed a new method of determining gene function in a breakthrough that could have major implications for our understanding of the processes of life.

A team at the University's School of Biosciences developed a novel computational approach which enabled them to assign functions to genes which hitherto had unknown function.

One approach to improve understanding of the basic features and requirements of life is to generate organisms with a minimal genome, i.e. the smallest number of genes that enable life.

Dr Mark Wass, Professor Martin Michaelis and Magdalena Antczak studied the organism with the smallest genome generated so far, based on a bacterium (Mycoplasma mycoides) that is cultivated in a nutrient-rich environment. It contains 473 genes, nearly one-third (149) of which have an unknown function, illustrating the limitations of our current understanding of how life works.

The Kent researchers developed a novel computational approach which enabled them to assign functions to 66 of the genes of unknown function. They found that many of the encoded functions have a role in substance transport into and out of the cell.

Dr Wass said: 'This seems to reflect the requirements of an organism with a minimal genome in a nutrient-rich environment. If nutrition is available in abundance, many genes performing metabolic functions are not needed, but transporters that enable nutrient transport into the cell and the excretion of (toxic) metabolites out of the cell become critical.

'This indicates that there is not one minimal genome but that the nature of a minimal genome will always be shaped by the environment. Consequently, a minimal genome consists of a set of essential genes, which are indispensable for all forms of life, and a second set of facilitator genes, which enable life in a certain environment.'

The team say that their findings should pave the way to more focused research on the identification of essential and facilitator gene sets to advance the understanding of the fundamental processes of life.

Researchers from the National Museums of Kenya, University of Arkansas, University of Missouri and Duke University have announced the discovery of a tiny monkey that lived in Kenya 4.2 million years ago.

Nanopithecus browni was the same size as a modern talapoin monkey, the smallest living Old World monkey species that weighs only 2 to 3 pounds, about the size of a cottontail rabbit. Talapoins are part of a large group of monkeys called guenons, which are commonplace and widespread across Africa today. Most species are several times larger in size than Nanopithecus browni.

Guenon evolution is poorly understood but thought to be driven by changes in forest habitats, with the distribution of modern species reflecting the breakup and re-convergence of ancient forests. Talapoins live only in West Central Africa, are confined to tropical forests, and are thought to be dwarfed from a larger ancestor in response to life in woody, swampy habitats.

Nanopithecus browni, though, was found in Kenya on the eastern side of the continent, at a site called Kanapoi. The Kanapoi habitat was dry and covered with grasslands and open forests - a very different place from the tropical forests of Cameroon and Gabon in West Central Africa. It is also at Kanapoi where remains of some of the earliest human ancestors, Australopithecus anamensis, have been found and would have lived alongside Nanopithecus browni.

Nanopithecus browni is the second oldest guenon found so far, just younger than the guenon single tooth found 10 years ago on the Arabian Peninsula. The ancient date, combined with a habitat so different and so far away from that of modern talapoins, reveals a much more complex evolution of guenon monkeys than previously thought. This new enigmatic member of the primate family reveals that dwarfing occurred far longer ago than scientists suspected and may have happened more than once, and in very different habitats perhaps for different reasons.

Nanopithecus browni was discovered by the West Turkana Paleo Project, led by Fredrick Kyalo Manthi of the National Museums of Kenya, with project co-leaders Carol Ward of the University of Missouri and Michael Plavcan of the University of Arkansas. The fossils were analyzed in collaboration with Richard Kay of Duke University.

The fossil is housed at the National Museums of Kenya. The researchers published their findings in the Journal of Human Evolution.

"The discovery of Nanopithecus browni reaffirms Kenya's contribution to understanding the evolution and diversity of Pliocene fauna and the environmental contexts in which they lived," said Manthi. "Environmental changes during the Plio-Pleistocene may have influenced the present-day distribution of guenons."

Nanopithecus browni is named after the late Francis Brown of the University of Utah for his contribution to understanding the geological history of the Omo-Turkana Basin within which the Kanapoi site is located.

For the first time, the bivalve mollusc Guyanella clenchi has been reported from Abrolhos Bank, Brazil. This almost unknown bivalve had previously been reported solely from the Caribbean region. Apart from being the southernmost record for the species, its presence also helps the experts to determine the way the marine fauna from the Caribbean interacts with its South American relatives.

The bivalve, which is a minute mollusc of only a few millimetres, had been known from Suriname, Guadeloupe, Colombia and French Guiana for nearly half a century. However, it is almost absent from the bibliographical registers and zoological collections.

Then, unexpectedly, during recent cruises to Abrolhos Bank (Bahia, Brazil), carried out as part of the Pro-Abrolhos project at Instituto Oceanografico da Universidade de Sao Paulo (IO-USP), enough specimens were retrieved to document the mysterious species from the Brazilian site.

The resulting study is published in the open-access journal Check List by Dr Barbara Louise Valentas-Romera, Museu de Zoologia da Universidade de Sao Paulo (MZSP), together with MSc Flavia Maria Pereira Costa and Dr Ana Maria Setubal Pires-Vanin, both affiliated to Instituto Oceanografico da Universidade de Sao Paulo (IO-USP).

According to the scientists, the discovery is very important for the understanding of the interaction between the mollusc faunas from the Caribbean and Southern Atlantic regions. While a mixture of these had long been known at both localities, serving as evidence that many species are indeed capable of crossing the geographical barriers between the two oceanic areas, it seems that no one had managed to answer how exactly this is happening. Now, the discovery of the tiny species shows that even small-sized molluscs have the ability to disperse so widely.

Additionally, the discovery of fresh specimens, complete with the body inside the shell, brings to light new information about the anatomy of the species itself, since the existing knowledge had only been derived from dry shells. Now, the secretive bivalve is to finally undergo molecular analyses.

"Despite its small size, the new occurrence of Guyanella clenchi brings new key data needed to understand the biogeography of the Caribbean and Southern Atlantic regions and improve our knowledge of the molluscs inhabiting the Brazilian coast, specifically the Abrolhos Bank, which is an important South Atlantic biodiversity hotspot," explain the researchers behind the study.

Abrolhos Bank is the largest and most species-rich coral reef in the Southern Atlantic. It is located in the Abrolhos Archipelago area and is part of the Abrolhos Marine National Park. Its most notable peculiarity is the giant coral structures shaped like mushrooms, locally known as "Chapeiroes". A "chapeirao" can reach up to 25 metres in height and 50 metres in diameter. The region is considered the most biodiverse spot in the Southern Atlantic Ocean, providing home to several species that occur nowhere else.

For the first time, a study has measured antioxidant levels in commercially available edible insects.

Sure, most of them don't have six legs - and scorpions, spiders, and centipedes aren't even insects. But for open-minded health freaks, it's good news: crickets pack 75% the antioxidant power of fresh OJ, and silkworm fat twice that of olive oil.

And while even ladybugs fart, insects have a tiny land, water and carbon footprint compared with livestock - so anything that encourages insect eating is good news for the planet, too.

Look who's come crawling back

Faced with eating ourselves and the planet to death, the West has begun reluctantly to consider creepy crawlies as a more sustainable alternative to meat and animal products.

"At least 2 billion people - a quarter of the world's population - regularly eat insects," says Prof. Mauro Serafini, lead author of the study published in Frontiers in Nutrition. "The rest of us will need a bit more encouragement."

Providing selfish and immediate incentives could help consumers to make the environmentally friendly choice, says Serafini. Taste and image are key - but for many, health is also an incentive.

"Edible insects are an excellent source of protein, polyunsaturated fatty acids, minerals, vitamins and fiber. But until now, nobody had compared them with classical functional foods such as olive oil or orange juice in terms of antioxidant activity."

Antioxidant activity is that free-radical scavenging ability that typically designates a 'superfood' - although this poorly defined term is eschewed by researchers, says Serafini.

The study

The researchers tested a range of commercially available edible insects and invertebrates, using various measures of antioxidant activity.

Inedible parts like wings and stings were removed, then the insects were ground and two parts extracted for each species: the fat, and whatever would dissolve in water.

Each extract was then tested for its antioxidant content and activity.

"For perspective, using the same setup we tested the antioxidant capacity of fresh orange juice and olive oil - functional foods that are known to exert antioxidant effects in humans," Serafini explains.

The first insect antioxidant rankings

Water-soluble extracts of grasshoppers, silkworms and crickets displayed the highest values of antioxidant capacity - fivefold higher than fresh orange juice - while giant cicada, giant water bugs, black tarantula and black scorpions showed negligible values.

"There's a clear trend: the vegetarians have markedly higher antioxidant capacity," notes Serafini.

Note that these comparisons are for the dry, fat-free insect dust - a tad tougher to swallow than fresh OJ. Even so, some quick math shows that at the same dilution (88% water), grasshoppers and silkworms would have about 75% the antioxidant activity of OJ.

Interestingly, the total content of polyphenols - the major source of plant-derived antioxidant activity - followed a similar pattern across species, but was far lower in all insects compared to OJ.

"These results suggest that besides polyphenols, the antioxidant capacity of insects also depends on other, as yet unknown compounds," Serafini adds.

The results for the insect fat were similarly impressive.

"Fat from giant cicadas and silkworms showed twice the antioxidant activity of olive oil, while black tarantula, palm worm and black ants are placed in the bottom of the ranking."

Bioavailability

The group's key message is: edible insects like grasshoppers and silkworms are a rich source of antioxidants.

"A high content of antioxidant in the food matrix is a primary requisite for a first screening of antioxidant potentiality of novel foods, so these are promising results."

But the questions remains: what are these antioxidants, and do they work in humans?

"The in vivo efficiency of antioxidant-rich food is highly dependent on bioavailability and the presence of an ongoing oxidative stress. So as well as identifying other antioxidant compounds in insects, we need tailored intervention studies to clarify their antioxidant effects in humans.

"In the future, we might also adapt dietary regimens for insect rearing in order to increase their antioxidant content for animal or human consumption."

WASHINGTON-(July 15, 2019)-States with stricter firearms laws had lower firearm-related deaths among children and adolescents, finds research led by faculty at Children's National in Washington, D.C. Furthermore, state laws that had been in place for more than five years requiring universal background checks for firearm purchases were associated with a 35% lower firearm-related death rate among children. The findings underscore the need for robust research to understand the interplay between legislation type and pediatric deaths due to firearm injuries, according to research published online July 15, 2019, in Pediatrics.

The cross-sectional study examined 2011 to 2015 firearm fatality data from the Web-based Injury Statistics Query and Reporting System (WISQARS), de-identified data collected by the Centers for Disease Control and Prevention about fatal injuries in the U.S. The team used the Brady Campaign to Prevent Gun Violence's gun law scorecards which measure the strength or weakness of state laws, with higher scores designating states with consistently strong firearm laws.

Some 21,241 children aged 21 years and younger died from firearm-related injuries over the five-year study period, or about 4,250 deaths per year.

"Firearm injuries represent the second-leading cause of death for U.S. children. That's about 10* funerals a day for kids whose untimely deaths could have been prevented," says Monika K. Goyal, M.D., MSCE, director of research in the Division of Emergency Medicine and Trauma Services at Children's National and the study's lead author. "For every 10-point increase in the strictness of firearm legislation, there was a 4% drop in firearm-related mortality rates among children and youth."

States that had laws in effect for five years or longer requiring universal background checks for firearm purchase had 35% lower rates of death due to firearms in children.

"Our findings demonstrate a powerful association between the strength of firearm legislation and pediatric firearm-related mortality, Dr. Goyal adds. "This association remains strong even after we adjust for rates of firearm ownership and other population variables, such as education level, race/ethnicity and household income."

Just as a combination of evidence-based public health approaches - including legislation mandating seatbelt use - reduced mortality from motor vehicle crashes (6.1 deaths per 100,000 children in 2015 compared with 9.8 deaths per 100,000 in 2007), the authors contend that a similar strategy could help to inform decision-making to reduce childhood injuries and deaths due to firearms.

Young Australian eastern blue-tongue lizards (Tiliqua scincoides) are every bit as clever as adults, researchers have found.

Life is hard for baby blue-tongues. As soon as they are born, they are on their own, with neither parental support nor protection. Adults of the species can grow to 600 millimetres long and enjoy the benefits of thick scales and a powerful bite, but the young are much smaller and thus more vulnerable to predation.

And that means they have to box clever if they are to survive.

To establish just how smart baby blueys are, researchers Birgit Szabo and Martin Whiting from Australia's Macquarie University, together with colleagues from the Australian National University, the University of New South Wales, and St Andrews University in Scotland, put wild-caught adult and juvenile lizards through a series of tasks designed to test their cognitive abilities.

A dozen adults, all over two years old, took part in the tests, along with 16 captive-born juveniles, all aged between 23 and 56 days.

"In all the tests, the young lizards performed every bit as well as the adults," said Szabo. "This indicates that the young learn at adult levels from a very early age."

MONDAY 15TH JULY - The most complete skull of a duck-billed dinosaur from Big Bend National Park, Texas, is revealed in the Journal of Systematic Palaeontology as a new genus and species, Aquilarhinus palimentus. This dinosaur has been named for its aquiline nose and wide lower jaw, shaped like two trowels laid side by side.

In the 1980s, Texas Tech University Professor Tom Lehman (then a Master's student) was conducting research on rock layers at Rattle Snake Mountain and discovered badly-weathered bones. He and two others from the University of Texas at Austin collected them, but some were stuck together making them impossible to study. Research in the 1990s revealed an arched nasal crest thought to be distinctive of the hadrosaurid Gryposaurus. At the same time, the peculiar lower jaw was recognized. However, the specimen spent additional years waiting for a full description and it was not until recent analysis that the researchers came to realize that the specimen was more primitive than Gryposaurus and the two major groups of duck-billed dinosaurs.

"This new animal is one of the more primitive hadrosaurids known and can therefore help us to understand how and why the ornamentation on their heads evolved, as well as where the group initially evolved and migrated from," says lead author Dr Albert Prieto-Márquez from the Institut Català de Paleontologia Miquel Crusafont, near Barcelona. "Its existence adds another piece of evidence to the growing hypothesis, still up in the air, that the group began in the southeastern area of the US."

Duck-billed dinosaurs, also known as hadrosaurids, were the most common herbivorous dinosaurs at the end of the Mesozoic Era, and all had a similar-looking snout. The front of the jaws meet in a U-shape to support a cupped beak used for cropping plants. The beak of some species is broader than in others, but there was no evidence of a significantly different shape and therefore likely also different feeding style in duckbills until Aquilarhinus was discovered. The lower jaws of Aquilarhinus meet in a peculiar W-shape, creating a wide, flattened scoop.

Around 80 million years ago, this particular dinosaur would have been shovelling through loose, wet sediment to scoop loosely-rooted aquatic plants from the tidal marshes of an ancient delta, where today lies the Chihuahuan desert. When the dinosaur died, some of its bones were transported downstream by the tide and became lodged in vegetation. The twice-daily flow of the tide dropped silt that built up the bank of the channel around its body, fossilising the bones in thick ironstone.

The jaw and other characteristics of the specimen show that it does not fit with the main group of duck-billed dinosaurs known as Saurolophidae. It is more primitive than this group, suggesting there might have been a greater number of lineages than previously recognised that evolved before the great radiation that gave rise to the bewildering array of unadorned, solid and hollow-crested forms. Most saurolophids had bony cranial crests of many different shapes and sizes. Aquilarhinus also sported a bony crest, albeit a simple one shaped like a humped nose. The discovery of a solid crest outside the major radiation of hadrosaurids supports the hypothesis that all crests derived from a common ancestor that had a simple humped nose.

Headgear worn during women's lacrosse practice and games can reduce the rate of head and face injuries as well as concussions, according to research presented by researchers in the Department of Orthopedics at the New York University Langone Health. The research was presented today at the American Orthopedics Society of Sports Medicine Annual Meeting.

"There has been continued controversy regarding whether or not headgear use in women's lacrosse will increase or decrease the rate of head injuries," said Dr. Samuel L. Baron, the lead researcher. In 2017, the Public Schools Athletic of New York City became the first high school organization in the country to mandate ASTM standard F3137 headgear for all women's lacrosse players.

The researchers set up a prospective cohort that included eight varsity and junior varsity women's lacrosse teams, as well as their game opponents, who were mandated to wear F3137 headgear for all practice and game events over the course of the 2017 and 2018 seasons. Certified athletic trainers assessed and documented all injuries that occurred as a result of participation on the lacrosse teams and athlete exposures were estimated based on the number of team practice and game events. Injury rates were compared with those from the High School RIO (Reporting Information Online) injury data reports from the 2009 to 2016 seasons.

Over the study period, 17 total injuries were reported during 22,397 exposures for an injury rate of 0.76 injuries per 1,000 athlete-exposures. Two head/face injuries, both of which were classified as concussions, were reported during the study for a head/face injury rate and concussion rate of 0.09 per 1,000 athlete-exposures. The headgear cohort demonstrated significant decreases in rates of head/face injury in-game concussion and practice non-head/face injury when compared to the control cohort.

Baron and his team concluded that mandated use of F3137 headgear was shown to be effective at lowering the rate of head or face injury and concussions in women's lacrosse. Additionally, mandated headgear use was also shown to lower the rate of injury to body locations other than the head or face during practice.

In previous studies, males have been found to kill when females will not mate with them if they are still caring for an offspring sired by their previous partner. Dieter Lukas and Elise Huchard have now looked into infanticide by female mammals. "Across mammals, females are more likely to commit infanticide when conditions are harsh and when having offspring is particularly costly to females", says Huchard. "The potential triggers and likely benefits of infanticide however appear to differ according to the specific circumstances."

Infanticide can remove potential competitors

The researchers found that when females are territorial and need access to breeding space or burrows, infanticide can cause neighbouring females to leave, so that killers may expand their territory. When females come together on breeding grounds, females might commit infanticide to prevent other offspring from stealing their milk. When females live in groups with others who care for offspring that are not their own, infanticide increases the help that their own surviving offspring receive. And when females live in stable social groups, infanticide can remove potential competitors for access to status or resources. "All these circumstances have in common that infanticide occurs when the proximity of offspring born to other females directly threatens the killer's reproductive success by limiting access to the resources that are most critical for her own offspring: access to breeding space, milk, offspring care, or social status", says Huchard.

Many female mammals live with related groupmates, suggesting that the threat of within-group infanticide might be lower in these species. However, this study found that infanticide was more likely to occur when females live in groups rather than solitary, with opportunities to commit and to observe infanticides potentially greater when females live together. "Among group-living species, females were equally likely to kill offspring when they lived with close relatives than with unrelated females", says Lukas. "There are several instances of grandmothers killing their grandchildren or aunts killing their nieces. This observation indicates that the benefits gained by the killer and her offspring even outweigh the costs of harming a relative."

Bottom Line: This observational study looked at whether a healthy lifestyle was associated with a lower risk of dementia regardless of genetic risk. Genetic factors are associated with increased risk of dementia but to what extent these might be offset by lifestyle factors is unknown. Genetic information from the UK Biobank was available for the 196,383 adults in this study who were of European ancestry, at least 60 years old and without dementia at the study baseline. Scores reflecting genetic risk and lifestyle were compiled based on genetic variants associated with Alzheimer disease and dementia and questionnaires about smoking, physical activity, diet and alcohol consumption. Over eight years of follow-up, there were 1,769 new cases of dementia. Both an unfavorable (the least healthy) lifestyle and high genetic risk were associated with higher dementia risk compared with low genetic risk and a favorable (the most healthy) lifestyle score. A favorable lifestyle was associated with lower dementia risk regardless of genetic risk, indicating that genetic risk and healthy lifestyle are independently associated with risk of dementia. The study has a number of limitations including that it cannot show causality, lifestyle factors were self-reported and the study was restricted to adults of European ancestry so it may not be generalizable to other populations.

Authors: David J. Llewellyn, Ph.D., University of Exeter Medical School, Exeter, United Kingdom, and coauthors

(doi:10.1001/jama.2019.9879)

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

Most non-traumatic fatalities among high school and college football athletes do not occur while playing the game of football, but rather during conditioning sessions which are often associated with overexertion or punishment drills required by coaches and team staff, according to research presented today at the American Orthopedic Society for Sports Medicine Annual Meeting. The research was presented by Dr. Barry P. Boden of The Orthopaedic Center, Rockville, Md.

Football is associated with the highest number of fatalities of any high school or college sport, but the number of traumatic injuries incurred while playing football have declined significantly since the 1960s.

However, the annual number of non-traumatic fatalities has stayed constant with current rates that are two to three times higher than traumatic fatalities.

Heat and sickle cell trait fatality rates were compared pre- and post-implementation of the NCAA football acclimatization model in 2003 and sickle cell screening policies implemented in 2010, respectively.

Boden and his team reviewed 187 non-traumatic football fatalities that occurred between 1998 and 2018. The researchers obtained information from extensive internet searches, as well as depositions, investigations, autopsies, media and freedom of information reports.

Of the 187 fatalities, more than half (52 percent) were due to cardiac issues; 24 percent were caused by heat; and five percent from asthma.

"The majority of deaths occurred outside of the regular season months of September through December, with the most common month for fatalities being August," Boden reported.

Boden said many of the fatalities had three issues in common: the conditioning sessions were supervised by the football coach or strength and conditioning coach; irrationally intense workouts and/or punishment drills were scheduled; and an inadequate medical response was implemented.

The average annual rate of heat-related fatalities remained unchanged at the collegiate level pre- and post-implementation of the NCAA football acclimatization model in 2003. The average annual number of sickle cell trait deaths in collegiate football declined 58 percent after the 2010 NCAA sickle cell screening policies were implemented. At the high school level, where there are no sickle cell guidelines, the number of sickle cell fatalities increased 400 percent since 2010.

The football acclimatization model implemented by the NCAA in 2003 has failed at reducing exertional heat-related fatalities at the collegiate level. Sickle cell trait screening policies adopted by the NCAA in 2010 have been effective at reducing fatalities in college athletes and similar guidelines should be mandated at the high school level.

"Conditioning-related fatalities are preventable by establishing standards in workout design, holding coaches and strength and conditioning coaches accountable, ensuring compliance with current policies, and allowing athletic health care providers complete authority over medical decisions," Boden reported.

Professional baseball players with a low-grade elbow injury that occurs on the humeral side of the elbow have a better chance of returning to throw and returning to play, and a lower risk of ulnar collateral ligament surgery than players who suffered more severe injuries on the ulnar side of the elbow. The research was presented at the Annual Meeting of the American Orthopedic Society of Sports Medicine.

Led by Dr. AaKash Chauhan from DuPage Medical Group, Downers Grove, Ill., the team of researchers conducted a study of 544 professional baseball players, average age 22.5 years with 90 percent playing in the Major League Baseball level and 84 percent identified as pitchers.

Chauhan and his team of researchers sought to evaluate the relationship of MRI tear grade and injury location with outcomes for nonoperatively treated elbow ulnar collateral ligament (UCL) injuries in professional baseball players.

There were no statistically significant differences in return to throw, return to pitch and ulnar collateral ligament repair by grade or tear location. However, objectively, ulnar-sided tears had the lowest return to throw rate at 81 percent and return to pitch rate at 42 percent, respectively. Players with ulnar and both-sided tears also had a higher rate of elbow repair surgery compared to players with humeral-side tears.

Chauhan's analysis found that older players were less likely to return to play compared with younger players, and major league players were more likely to suffer re-injury or ulnar collateral ligament surgery than minor league players.

The researchers found that lower MRI grade and humeral location were objectively associated with a higher return to throw, higher return to pitch, lower rate of elbow surgery, and higher survival rates compared to higher grade, and ulnar or both-sided tears. Players who were older than 25 had a significantly higher likelihood of not returning to play after non-operative treatment. Competing at the Major League Baseball level had a higher likelihood of re-injury or having ulnar surgery.

"Based on this study, non-operative treatment of ulnar collateral ligament injuries will likely be more successful in younger players, lower grade tears, and humeral-sided injuries," Chauhan said.

BUFFALO, N.Y. -- New research from the University at Buffalo provides pathophysiologic evidence of the effect of air pollution on cardiovascular disease in China. The findings also suggests that China may need to revise its standard for one type of pollutant.

Researchers found that long-term exposure to particulate matter and nitrogen dioxide, as well as proximity to vehicular traffic, were associated with severity of coronary artery calcium, or the buildup of plaque in the artery walls. The study was conducted on 8,867 Chinese adults aged 25 to 92.

The findings, published in JAMA Network Open, are significant because, while similar studies have been conducted in the U.S. and Europe, this one is the first to investigate the connection between air pollution and coronary artery calcium in China. The country has focused more recently on reducing the extremely high levels of air pollution that exist in some regions, particularly northern China.

"This study may provide evidence that coronary atherosclerosis is a pathological pathway through which air pollution exposure increases risk of death from coronary heart disease," said the paper's first author, Meng Wang, assistant professor of epidemiology and environmental health in UB's School of Public Health and Health Professions.

"This finding should contribute to an understanding of air pollutant effects worldwide, providing both much-needed, locally generated data and supportive evidence to inform the air pollution standard setting process on a global scale," added Wang, PhD, who is also a faculty member in the UB RENEW (Research and Education in eNergy, Environment and Water) Institute.

Atherosclerosis refers to the build-up of plaque, or fatty deposits, in the artery walls, which, over time, restricts blood flow through the arteries. This can cause a blood clot resulting in a heart attack or stroke.

"Atherosclerosis is a lifelong process. As such, the effects of air pollution exposure on atherosclerosis are likely to be chronic," Wang explained.

If an association between this condition and air pollution were established, Wang added, it could provide an opportunity for local-level efforts to control people's exposure to pollution before it becomes harmful to health.

The study centered on levels of nitrogen dioxide and PM2.5, or fine particulate matter. PM2.5 are super tiny particles that can easily be inhaled, causing serious health problems, according to the U.S. Environmental Protection Agency.

The study also looked at proximity to traffic and used nitrogen dioxide as a more precise indicator of vehicular emissions. It showed that the risk of a higher coronary artery calcium score increased by 24.5 percent for every 20 micrograms per cubic meter of air increase in nitrogen dioxide.

Air pollution remains a significant issue in China. In 2015, more than 95 percent of the Chinese population was exposed to concentrations of PM2.5 and nitrogen dioxide greater than the minimum level of the study, according to Wang.

"Since more than 40 percent of all deaths are attributable to cardiovascular disease, the potential contribution of air pollutants to cardiovascular disease in China is very large," he said.

Improving air quality to the Chinese national standards of 35 and 40 micrograms per cubic meter of air for PM2.5 and nitrogen dioxide, respectively, may help people live longer, Wang said.

Still, the effect of nitrogen dioxide exposure on coronary artery calcium persisted even when researchers restricted their analysis to concentrations below 40 micrograms per cubic meter of air.

"This suggests that the current air pollution standard may need to be re-evaluated," Wang said.

Scientists at the Basque research centre BCBL conclude that the voice is fundamental for mentally presenting the meaning of words in the brain. This finding implies a greater knowledge about how sound waves bring additional information to words.

For years, neuroscientists have been trying to find out whether the voice influences the processing of information or whether we understand a word in one way or another depending on who pronounces it.

Now, a study by the Basque Center on Cognition, Brain and Language (BCBL) in San Sebastian concludes that sound waves effectively transmit information beyond the lexical meaning of words.

This research, published online in the Journal of Memory and Language, has proven that words carry information indexed through the voice.

Led by Efthymia Kapnoula, the paper determines that the meaning we give to words is conditioned by factors that are not simply limited to lexical information. People, and more specifically their voices, have much to say in the mental representation of words.

A decade ago another study concluded that the speaker is influential when it comes to listening to a sentence. "This experiment showed that if we hear a child saying something like 'every night I drink a little wine before going to sleep,' our brain is surprised. However, it's not the same if this is said by an adult," Kapnoula says.

However, the BCBL team sought to go further and determine whether the additional information provided by the speaker's voice is stored in the interlocutor's brain as part of the lexical representation of the speaker's voice.

The learning of new words

"All the words a person knows make up what we call mental lexicon, and each of them is thought to be abstract in the sense that it only carries linguistic information. The identity of the person who pronounces the word is non-linguistic information and, until now, it was thought that it was not kept in the mental lexicon," explains the researcher.

The study has paid particular attention to whether the cognitive representations of words carry information about the voice of the speaker who pronounces them. Thus, the experiment consisted in participants learning a series of words they did not know, emitted by different voices.

"At those sessions we manipulated the frequency at which a spoken word in a specific voice was used to refer to an image. The results showed that the new words were activated faster when the voice matched the image," Kapnoula says.

The discovery involves understanding what mental lexicon consists in. "Understanding the nature of lexical representations is a prerequisite for all research related to words, as well as for discovering how people learn and process them," he claims.

Kapnoula acknowledges that there is still much to study in this area. "One possible direction lies in investigating whether this effect of the voice is even stronger in children, in whom mental lexicon is still developing more drastically," she concludes.

Lobachevsky University scientists together with their colleagues from the National Research Center "Kurchatov Institute" (Moscow) and the National Research Center "Demokritos" (Athens) are working on the hardware implementation of a spiking neural network based on memristors. The key elements of such a network, along with pulsed neurons, are artificial synaptic connections that can change the strength (weight) of connection between neurons during the learning.

For this purpose, memristive devices based on metal-oxide-metal nanostructures developed at the UNN Physics and Technology Research Institute (PTRI) are suitable, but their use in specific spiking neural network architectures developed at the Kurchatov Institute requires demonstration of biologically plausible learning principles.

The biological mechanism of learning of neural systems is described by Hebb's rule, according to which learning occurs as a result of an increase in the strength of connection (synaptic weight) between simultaneously active neurons, which indicates the presence of a causal relationship in their excitation. One of the clarifying forms of this fundamental rule is plasticity, which depends on the time of arrival of pulses (Spike-Timing Dependent Plasticity - STDP).

In accordance with STDP, synaptic weight increases if the postsynaptic neuron generates a pulse (spike) immediately after the presynaptic one, and vice versa, the synaptic weight decreases if the postsynaptic neuron generates a spike right before the presynaptic one. Moreover, the smaller the time difference Δt between the pre- and postsynaptic spikes, the more pronounced the weight change will be.

According to one of the researchers, Head of the UNN PTRI laboratory Alexei Mikhailov, in order to demonstrate the STDP principle, memristive nanostructures based on yttria-stabilized zirconia (YSZ) thin films were used. YSZ is a well-known solid-state electrolyte with high oxygen ion mobility.

"Due to a specified concentration of oxygen vacancies, which is determined by the controlled concentration of yttrium impurities, and the heterogeneous structure of the films obtained by magnetron sputtering, such memristive structures demonstrate controlled bipolar switching between different resistive states in a wide resistance range. The switching is associated with the formation and destruction of conductive channels along grain boundaries in the polycrystalline ZrO2 (Y) film," notes Alexei Mikhailov.

An array of memristive devices for research was implemented in the form of a microchip mounted in a standard cermet casing, which facilitates the integration of the array into a neural network's analog circuit. The full technological cycle for creating memristive microchips is currently implemented at the UNN PTRI. In the future, it is possible to scale the devices down to the minimum size of about 50 nm, as was established by Greek partners.

Our studies of the dynamic plasticity of the memoristive devices, continues Alexey Mikhailov, have shown that the form of the conductance change depending on Δt is in good agreement with the STDP learning rules. It should be also noted that if the initial value of the memristor conductance is close to the maximum, it is easy to reduce the corresponding weight while it is difficult to enhance it, and in the case of a memristor with a minimum conductance in the initial state, it is difficult to reduce its weight, but it is easy to enhance it.

According to Vyacheslav Demin, director-coordinator in the area of nature-like technologies of the Kurchatov Institute, who is one of the ideologues of this work, the established pattern of change in the memristor conductance clearly demonstrates the possibility of hardware implementation of the so-called local learning rules. Such rules for changing the strength of synaptic connections depend only on the values of variables that are present locally at each time point (neuron activities and current weights).

"This essentially distinguishes such principle from the traditional learning algorithm, which is based on global rules for changing weights, using information on the error values at the current time point for each neuron of the output neural network layer (in a widely popular group of error back propagation methods). The traditional principle is not biosimilar, it requires "external" (expert) knowledge of the correct answers for each example presented to the network (that is, they do not have the property of self-learning). This principle is difficult to implement on the basis of memristors, since it requires controlled precise changes of memristor conductances, as opposed to local rules. Such precise control is not always possible due to the natural variability (a wide range of parameters) of memristors as analog elements," says Vyacheslav Demin.

Local learning rules of the STDP type implemented in hardware on memristors provide the basis for autonomous ("unsupervised") learning of a spiking neural network. In this case, the final state of the network does not depend on its initial state, but depends only on the learning conditions (a specific sequence of pulses). According to Vyacheslav Demin, this opens up prospects for the application of local learning rules based on memristors when solving artificial intelligence problems with the use of complex spiking neural network architectures.