Culture

A new study in the Review of Economic Studies finds that U.S. counties with more historical immigration have higher incomes, less poverty, and lower unemployment today.

An important issue in current American political discourse is the effect that immigrants have on the communities in which they settle. While this topic has received significant attention, the focus has generally been on the short-term effects of immigrants. We know much less about the long-run consequences of immigration.

Researchers studied the effects of immigration into the United States from 1850 to 1920, a period in which immigration to the country increased dramatically, and the immigration sources also changed. In 1850 over 90% of foreign-born people living in the United States were from Great Britain, Ireland, or Germany. By 1920, this figure was only 45%.

The authors found that immigration resulted in benefits that were felt soon after their arrival. Immigration resulted in more and larger manufacturing establishments, greater agricultural productivity, and higher rates of innovation. These findings are consistent with a long-standing narrative suggesting that immigrants contribute to economic growth by providing an ample supply of unskilled labor, as well as a smaller supply of skilled people, who bring with them knowledge and innovations that are important for development.

The size of the effects suggest that increasing the percentage of immigrants in a county by 4.9% results in a 13% increase in average per capita income today, a 44% increase in average manufacturing output per capita from 1860-1920 (and a 78% increase in 1930), a 37% increase in farm values, and a 152% increase in the number of patents per capita.

The researchers also found that these economic benefits did not have long-run social costs. Places with more historical immigrant settlement today have similar levels of social capital, civic participation, and crime rates.

"What is fascinating is that despite the exceptionalism of this period in US history," said the paper's lead author, Sandra Sequeira. "There are several important parallels that one could draw between then and now: the large influx of unskilled labor, the small but important inflow of highly skilled innovators, as well as the significant short-run social backlash against immigration. There is much to be learned from taking a longer perspective on the immigration debate."

WASHINGTON -- In late 2018, the Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) spacecraft arrived at Bennu, the asteroid it will be studying and sampling over the next several years.

Now, new research in the AGU journal Geophysical Research Letters shows Bennu is spinning faster over time - an observation that will help scientists understand the evolution of asteroids, their potential threat to Earth and if they could be mined for resources.

Bennu is 110 million kilometers (70 million miles) away from Earth. As it moves through space at about 101,000 kilometers per hour (63,000 miles per hour), it also spins, completing a full rotation every 4.3 hours.

The new research finds the asteroid's rotation is speeding up by about 1 second per century. In other words, Bennu's rotation period is getting shorter by about 1 second every 100 years.

While the increase in rotation might not seem like much, over a long period of time it can translate into dramatic changes in the space rock. As the asteroid spins faster and faster over millions of years, it could lose pieces of itself or blow itself apart, according to the study's authors.

Detecting the increase in rotation helps scientists understand the types of changes that could have happened on Bennu, like landslides or other long-term changes, that the OSIRIS-REx mission will look for.

"As it speeds up, things ought to change, and so we're going to be looking for those things and detecting this speed up gives us some clues as to the kinds of things we should be looking for," said Mike Nolan, a senior research scientist at the Lunar and Planetary Laboratory at the University of Arizona in Tucson, who is the lead author of the new paper and the head of the OSIRIS-REx mission's science team. "We should be looking for evidence that something was different in the fairly recent past and it's conceivable things may be changing as we go."

The OSIRIS-REx mission is scheduled to bring a sample of Bennu to Earth in 2023. Understanding Bennu's rotational change could help scientists figure out what asteroids can tell us about the origin of the solar system, how likely it is for asteroids to pose a threat to humans and if they could be mined for resources.

"If you want to do any of those things, you need to know what is affecting it," Nolan said.

Detecting a change

In order to understand Bennu's rotation, scientists studied data of the asteroid taken from Earth in 1999 and 2005, along with data taken by the Hubble Space Telescope in 2012. It was when they looked at the Hubble data that they noticed the rotation speed of the asteroid in 2012 didn't quite match their predictions based on the earlier data.

"You couldn't make all three of them fit quite right," Nolan said. "That was when we came up with this idea that it had to be accelerating."

The idea that the rotation of asteroids could speed up over time was first predicted around 2000 and first detected in 2007, according to Nolan. To date, this acceleration has only been detected in a handful of asteroids, he said.

The change in Bennu's rotation could be due to a change in its shape. Similar to how ice skaters speed up as they pull in their arms, an asteroid could speed up as it loses material.

Nolan and his co-authors suggest the reason for the increase in Bennu's rotation is more likely due to a phenomenon known the YORP effect. Sunlight hitting the asteroid is reflected back into space. The change in the direction of the light coming in and going out pushes on the asteroid and can cause it to spin faster or slower, depending on its shape and rotation.

The OSIRIS-REx mission will determine Bennu's rotation rate independently this year, which will help scientists nail down the reason for the increase in rotation. Since spacecraft will never visit the vast majority of asteroids, the measurements will also help scientists learn how well ground-based measurements are able to understand these far-away objects.

"By testing these predictions in a few cases, we will significantly improve our confidence in predictions made for other objects," the study's authors write.

The measurement of Bennu's acceleration rate combined with the arrival of OSIRIS-REx at the asteroid gives scientists a great opportunity to validate the new study's results and test theories about the YORP effect, said Desiree Cotto-Figueroa, an assistant professor of physics and electronics at the University of Puerto Rico at Humacao, who was not involved in the new study.

"This is a great opportunity, in general, having this measurement and having the spacecraft OSIRIS-REx there observing this asteroid to help us better understand this effect, which is a dominant mechanism in the evolution of asteroids," she said.

MISSOULA - New University of Montana research suggests climate change makes it increasingly difficult for tree seedlings to regenerate following wildfires in low-elevation forests, which could contribute to abrupt forest loss.

The study, "Wildfires and Climate Change Push Low-elevation Forests Across a Critical Climate Threshold for Tree Regeneration," was published March 11 in the Proceedings of the National Academy of Sciences and is available online at http://bit.ly/2HeZc8t.

Kimberley Davis, a postdoctoral research associate in the W.A. Franke College of Forestry and Conservation at UM, and her co-authors examined the relationship between annual climate and post-fire regeneration of ponderosa pine and Douglas fir in low-elevation forests of western North America.

"Forests in the western U.S. are increasingly affected by both climate change and wildfires," said Davis, the study's lead author. "The ability of forests to recover following wildfire depends on annual climate conditions, because tree seedlings are particularly vulnerable to hot and dry weather. We wanted to identify the specific conditions necessary for post-fire tree regeneration to better understand how climate change has been affecting forests through time."

The authors used tree rings to determine establishment dates of more than 2,800 trees that regenerated after fires in Arizona, California, Colorado, Idaho, Montana and New Mexico between 1988 and 2015. Annual tree regeneration rates were much lower when seasonal climate conditions, including temperature, humidity and soil moisture, crossed specific threshold values.

Over the past 20 years, climate conditions have crossed these thresholds at the majority of study sites, leading to abrupt declines in how often annual conditions are suitable for tree regeneration. The study results highlight how future fires in similar sites may catalyze transitions from forest to non-forest ecosystems.

"Adult trees can survive in warmer and drier conditions than seedlings, and our study found that some low-elevation areas that are currently forested no longer have climate conditions that are suitable for tree regeneration," Davis said. "In these areas, high-severity fire may lead to ecosystem transitions from forests to grasslands or shrublands.

"It is important to understand how climate change and wildfires will affect tree regeneration because forests are important economically, ecologically and culturally," she said. "Ponderosa pine and Douglas fir are two of the most dominant tree species in the western U.S., and they are critical for the regional forestry industry. Forests also contain high levels of biodiversity and provide a variety of ecosystem services, such as carbon sequestration and water regulation and supply. Additionally, people love to recreate in forests, which is an increasingly important part of the economy in western states."

ANN ARBOR--By slingshotting themselves forward, human cells can travel more than five times faster than previously documented.

University of Michigan researchers observed the movement in bioengineered 3D scaffolds that model stromal tissue--the connective tissue that surrounds organs.

The researchers say this method of cell movement, observed for the first time, could be involved in the spread of cancer. And in the future it could potentially be harnessed to direct the movement of healthy cells for tissue repair therapies.

The cells pull on and stretch the surrounding fibrous tissue, eventually using that tension to launch themselves forward. The motion looked familiar enough that researchers dubbed it "slingshot migration."

"We found that cells can move in this very distinct way that results in effective migration far faster than anything previously reported," said Brendon Baker, U-M assistant professor of biomedical engineering.

William Wang, a doctoral student in biomedical engineering, was the first to witness it. He was studying the properties of stromal tissue that either hinder or promote the spread of cells in diseases such as cancer.

"I was definitely shocked seeing a cell move so fast," Wang said. "What was even more surprising was then capturing this migration mode in multiple cell types and finding that their speed was so much faster than traditional modes of cell migration."

Research in this area typically involves observing cells under the microscope on a flat petri dish. But that doesn't provide a complete picture.

"These flat, two-dimensional surfaces really don't resemble the structure and mechanical behavior of real tissues, especially the ones where so much of the migration in our body is occurring," Wang said.

The researchers study cells in a 3D fibrous environment, which is closer to the real thing.

Most organs can be broken down into two parts: functional elements such as sacs, ducts or glands called the parenchyma, and the surrounding collagenous tissue that supports the blood vessel network, called the stroma or interstitia.

Baker's lab builds stromal tissue for two applications: to study how cells behave during disease progression, and to advance organ replacement therapies.

Cancer cells that remain within the parenchyma, where most originate, can typically be dealt with effectively by surgical removal. When they migrate into the stromal tissue, they pose a much greater threat.

"It's metastasis, or the spread of the cancer, that kills patients," Baker said. "For that to happen, the cells have to break out of the parenchyma and cross through the fibrous stroma to reach blood or lymphatic vessels or the lymphatic system."

Modern coal-fired power stations produce more ultrafine dust particles than road traffic and can even modify and redistribute rainfall patterns, a new 15-year international study shows.

The study indicates filtration systems on modern coal-fired power stations are the biggest source of ultrafine particles and can have considerable impacts on climate in several ways.

In urban areas, road traffic has long been considered the main source of small particle emissions which have the potential to adversely affect health and the environment.

However, long-term measurements carried out by two scientists, Professor Wolfgang Junkermann from the Karlsruhe Institute of Technology (KIT) in Germany and Professor Jorg Hacker from Airborne Research Australia - who are affiliated with Flinders University - have revealed a source that particularly affects regional climate: modern coal-fired power stations.

In the Bulletin of the American Meteorological Society, the researchers report how coal-fired power stations clearly emit large amounts of ultrafine particles (UFP) through filtering technology of exhaust gas. The key findings of the long-term study are:

Modern coal-fired power stations emit more UFP than urban road traffic

UFP can harm human health

UFP can affect rainfall distribution on local to regional scales by increasing the condensation nuclei count

UFP can be transported in layers with high concentrations for hundreds of kilometres and then lead to localised "particle events" (dramatic spikes in short-term particle concentrations on the ground) far away from their source.

The research also found UFP concentrations have increased continuously since modern coal-fired power stations were commissioned in many locations around the world.

For the measurement flights in Europe, Australia and even Mexico and Inner Mongolia, the research team used two rather unusual small research aircraft, the world's most comprehensively instrumented motorglider in Australia and a 'trike' developed in Germany - believed to be the smallest manned research aircraft worldwide.

The flying laboratories are equipped with highly sensitive instruments and sensors measuring dust particles, trace gases, temperature, humidity, wind and energy balances.

"Our two research aircraft are particularly suitable to follow the plumes from the smoke stacks downwind for hundreds of kilometres and study their behaviour in great detail," says Professor Hacker, who is based at Airborne Research Australia (ARA) in South Australia.

The scientists then linked these data with meteorological observations and used dispersion and transport models to trace back their origin.

"In this way, we found that fossil power stations have for many years become the strongest individual sources of ultrafine particles worldwide. They massively influence meteorological processes and may cause extreme weather events, including intensive rain events.

"By redistributing rainfall events, this can lead to drier than usual conditions in some places and to unusually heavy and persistent strong rainfall elsewhere," Professor Hacker says.

With a diameter of less than 100 nm, UFP have an enormous impact on environmental processes, capable of influencing the properties of clouds and precipitation, the paper says.

"The UFP offer surfaces for chemical reactions in the atmosphere or may influence the properties of clouds and precipitation," says Professor Junkermann.

In open nature, forest fires, dust storms or volcanic eruptions produce fine particles, but mostly not in the nanometer range.

To study the existence and distribution and transport processes of UFP, the researchers not only flew their instruments near to or downwind of coal-fired power stations but also over remote regions where very low UFP concentrations have been measured in the past at ground level.

Specifically, in regions with conspicuous precipitation trends such as inland Western Australia and Queensland, the researchers found that UFP concentrations have increased constandly and could be linked to emissions made by coal-fired power stations and refingeries.

"Exhaust gas cleaning takes place under conditions that are optimal for the new formation of particles. Ammonia is added to the exhaust gases in order to convert nitrogen oxides into harmless water and nitrogen," Professor Junkermann says.

At the same time ammonia is available at the right mixing ratio for particle formation, resulting in concentrations in the exhaust gas becoming high. After emission at 200-300 m height from smoke stacks, the very small particles typically spread over several hundreds of kilometres depending on weather and climate conditions in the atmosphere, the researchers found.

ITHACA, N.Y. - It's not whether you win or lose; it's how hard the robot is working.

A Cornell University-led team has found that when robots are beating humans in contests for cash prizes, people consider themselves less competent and expend slightly less effort - and they tend to dislike the robots.

The study, "Monetary-Incentive Competition Between Humans and Robots: Experimental Results," brought together behavioral economists and roboticists to explore, for the first time, how a robot's performance affects humans' behavior and reactions when they're competing against each other simultaneously.

Their findings validated behavioral economists' theories about loss aversion, which predicts that people won't try as hard when their competitors are doing better, and suggests how workplaces might optimize teams of people and robots working together.

"Humans and machines already share many workplaces, sometimes working on similar or even identical tasks," said Guy Hoffman, assistant professor in the Sibley School of Mechanical and Aerospace Engineering. Hoffman and Ori Heffetz, associate professor of economics in the Samuel Curtis Johnson Graduate School of Management, are senior authors of the study.

"Think about a cashier working side-by-side with an automatic check-out machine, or someone operating a forklift in a warehouse which also employs delivery robots driving right next to them," Hoffman said. "While it may be tempting to design such robots for optimal productivity, engineers and managers need to take into consideration how the robots' performance may affect the human workers' effort and attitudes toward the robot and even toward themselves. Our research is the first that specifically sheds light on these effects."

Alap Kshirsagar, a doctoral student in mechanical engineering, is the paper's first author. In the study, humans competed against a robot in a tedious task - counting the number of times the letter G appears in a string of characters, and then placing a block in the bin corresponding to the number of occurrences. The person's chance of winning each round was determined by a lottery based on the difference between the human's and robot's scores: If their scores were the same, the human had a 50 percent chance of winning the prize, and that likelihood rose or fell depending which participant was doing better.

To make sure competitors were aware of the stakes, the screen indicated their chance of winning at each moment.

After each round, participants filled out a questionnaire rating the robot's competence, their own competence and the robot's likability. The researchers found that as the robot performed better, people rated its competence higher, its likability lower and their own competence lower.

When men and women contract a disease, it is very different when this is discovered by the healthcare system. On average, women are diagnosed later in life than men. This issue has been studied and analysed by researchers from the Novo Nordisk Foundation's Center for Protein Research, the Faculty of Health and Medical Sciences, UCPH, in a comprehensive study where data from the entire Danish population have been in use. The new research results have been published in the scientific journal Nature Communications.

'When we look across all diseases, we see a tendency that women on average are diagnosed later than men. We have looked not just at diseases, but also at the course of the patient care. Our study zooms in on the areas where the differences are most pronounced - both for the individual diseases and for the course of the patient care. The message is that the national strategies that are established need to take a difference into account. We can no longer use the 'one size fits all' model. We are already heading in that direction with respect to personalised medicine,' says last author and Professor Søren Brunak, the Novo Nordisk Foundation Center for Protein Research.

The researchers analysed data from 6.9 million Danish people. The population was divided into two groups according to their sex. Over a 21-year period, from 1994 to 2015, the researchers have e.g. analysed the occurrence of all types of diseases, multimorbidity, where you suffer from more than one disease, and courses of patient care. They found that women on average are older when they are diagnosed compared to men. The entire sequence of the women's and men's patient care course was different and time-staggered.

In connection with ADHD, there was a difference of almost six years between the time when the two groups were diagnosed with the disease. The boys were about 14 years old, while the girls were about 20 years old. Here, according to the researchers, some studies point out that the reason for the difference is that women have a different subtype of ADHD, which manifests itself in a quiet and solitary manner as opposed to the externalising behaviour often seen in boys with ADHD.

Osteoporosis Was the Exception

Osteoporosis was one of the exceptions where women were diagnosed first. Here, women were typically diagnosed before they suffered a fracture caused by the disease, while the course for men was the opposite. They were typically not diagnosed until they turned up at the emergency room with a fracture.

Scientists do not yet know whether the differences are due to genetics, environment, diagnostic criteria or a mixture hereof. They are currently investigating this in their next step in collaboration with a research team from Finland. But they believe that there is a need to think about the sex right from the start of the research in tests with rats and mice.

'It has been surprising to see that there is such a big difference between the diseases that affect men and women and between their patient care courses in a society where otherwise, we have equal and uniform access to the healthcare system. Now we are trying to map out what really lies behind the differences we see. Can they e.g. be attributed to genetics or environment and culture?' asks first author and Postdoc David Westergaard, Novo Nordisk Foundation Center for Protein Research.

'But we need to think about the fact that there may be a sex difference right from the beginning at the hospitals and in the research. Traditionally, e.g. 50 men and women will be recruited for clinical trials. Afterwards you look at the overall effect for the test participants. But you forget to make a subanalysis, where you look at the groups separately to see if there are differences. This has only been done during recent years,' says David Westergaard.

In connection with 770 types of diseases, women were diagnosed later than men. There was an average difference of about four years.

In case of cancer, women were on average diagnosed 2.5 years later than men.

For metabolic diseases such as diabetes, women were on average diagnosed about 4.5 years later.

Aging affects every living organism, but the molecular processes that contribute to aging remain a subject of debate. While many things contribute to the aging process, one common theme in animal aging is inflammation--and this may be amplified by a class of selfish genetic elements.

The human genome is littered with selfish genetic elements--repetitive elements that do not seem to benefit their hosts, but instead seek only to propagate themselves by inserting new copies into their host genomes. A class of selfish genetic elements called LINE1 retrotransposons are the most prevalent retrotransposon selfish genetic elements found in humans; approximately 20 percent of both human and mice genomes are composed of LINE1s.

Researchers have long suspected that LINE1s contribute to cancer and genomic instability. However, the harm inflicted by these genomic parasites reaches much further than researchers had at first thought. In a paper in the journal Cell Metabolism, researchers from the University of Rochester, including Vera Gorbunova, the Doris Johns Cherry professor of biology, and Andrei Seluanov, professor of biology, show that LINE1 retrotransposons become more active with age and may cause age-related diseases by triggering inflammation. By understanding the impacts of retrotransposons, researchers can better recognize the processes by which cells age and how to combat the deleterious effects of aging.

Human cells have evolved multiple molecular mechanisms--such as gene silencing--to keep selfish genetic elements like LINE1s at bay. However, these mechanisms become less efficient during the aging process, allowing LINE1 elements to be reactivated.

As LINE1s become active, some of their copies leak outside the cell nucleus into the cytoplasm, Gorbunova says. "Any DNA in the cytoplasm is a signal for alarm, as it resembles viruses that are invading the cell." Cytoplasmic "guardians"--types of DNA sensors--typically recognize invaders and trigger immune responses like inflammation. This process, which normally functions to protect humans from viruses and foreign DNA, recognizes leaked LINE1 copies in the old cells and triggers a "false alarm" in the form of age-related inflammation.

The researchers found that they can reduce LINE1s using drugs that inhibit reverse transcriptase, an enzyme that catalyzes LINE 1 DNA formation. These drugs were originally developed to combate reverse transcriptase in HIV patients. Using these drugs to reduce LINE1s improves health in mice and reduces inflammation, in addition to improving lifespan, Seluanov says. "Sterile inflammation triggered by LINE1 elements is a new mechanism of aging. We can now develop strategies that target LINE1s and the pathways that lead to inflammation."

With these new insights into LINE1 and its effects on inflammation, researchers hope to develop interventions aimed at inhibiting LINE1s, Gorbunova says. "These interventions may serve as new forms of therapy for age-related diseases fueled by inflammation, such as neurodegeneration, cancer, diabetes, and autoimmune diseases."

EAST LANSING, Mich. - When it comes to advancing social status, it's not what you know, it's who you know - for humans and spotted hyenas alike.

In a new study published in the current issue of Proceedings of the National Academy of Sciences, Michigan State University scientists show that hyenas that form strong coalitions can gain social status, which can have lasting benefits over many generations.

"The high-ranked animals clearly benefit from this system," said Eli Strauss, MSU integrative biologist and the study's lead author. "But low-ranked animals have a strong incentive to challenge the established pecking order and attempt to improve their position in society. This work represents a first step in reconciling the advantages of high status with the appearance of 'arbitrary' conventions that structure inequality in animal and human societies."

Moving up the proverbial ladder can result in substantive differences in health, survival and reproductive success. So, with some animals, social rank is determined by individual fighting ability or physical attributes. Typically, low-ranked individuals are unable to defeat their larger or stronger, higher-ranked contemporaries. However, in other species, such as spotted hyenas, social rank is determined through a convention known as "maternal rank inheritance."

This structure can be compared to royal families. The queen sits at the top, and her offspring are the heirs to the throne. This explains what's been observed in hyena clans since Kay Holekamp, MSU University Distinguished Professor of integrative biology and co-author, started her study in Kenya's Masai Mara National Reserve 27 years - and five generations of spotted hyenas - ago.

Spotted hyenas live in large, mixed-sex groups, or clans. They have highly stable hierarchies, in which being a "queen" reaps many benefits. Sometimes, however, the crown is challenged, and "lesser" hyenas move up the ladder.

"We often see small individuals dominate larger individuals, and even severely wounded individuals can dominate their healthy group-mates," Strauss said. "Given that rank has a large effect on the fitness of these animals, what maintains the stability of a system where rank is determined in such an arbitrary manner?"

The answer, the study revealed, is strong alliances. First off, rank changes are rare among spotted hyenas.

When they do happen, though, upward changes are marked by the females armed with a strong coalition. Researchers measured rank reversals in the context of coalitionary aggression - where two or more individuals team up together in an aggression against another.

Females that form coalitions with other females harboring strong social bonds have the strongest chance of overthrowing their superiors. The results also suggest that as individual hyenas engage in more coalitions together, they become more willing to challenge dominant individuals as well as their underlings, for that matter.

"Eli developed a new method for studying dynamic changes in social rank over time and determined that coalitions of social allies can not only maintain stable rank relationships over many years by attacking lower-ranked individuals," Holekamp said, "but also can sometimes help one another improve their status by defeating higher-ranked opponents, and thus also increase their fitness."

Going to war, of course, is not without consequence. Subordinates risk injury or possibly death, which obviously can be detrimental to their lives, let alone their place in the social strata.

Future research will attempt to rate cost factors of these revolutionary interactions. In the meantime, this paper solves a long-standing mystery, said Holekamp, one of the world's leading behavioral ecologists.

"This resolves a perplexing issue regarding why low-ranking animals in hierarchical societies structured by seemingly arbitrary conventions, such as royalty, don't simply usurp power from the smaller, weaker group-mates who outrank them," she said. "Consider, for example, how easy it would be for a strong young man to overthrow Queen Elizabeth, who is now old and frail, yet maintains her high status in British society because she has loads of allies."

That's because it's good to be the queen - one with strong coalition forces at her disposal.

"It is known that there are important similarities between the visual system of primates and the artificial neural networks of the latest generation. Our study shows how these similarities exist also with the visual system of rats, whose architecture is undoubtedly more primitive, if compared with the brain of primates, but whose functions and potential still remain largely unexplored". This is the comment by Davide Zoccolan, professor of neuroscience at SISSA, on the research conducted by his group, the Visual Neuroscience Laboratory, and recently published in The Journal of Neuroscience.

The study, supervised by Professor Zoccolan and Dr. Federica B. Rosselli (a SISSA graduate and now postdoctoral researcher in the Caesar centre of the Max Plank Society in Bonn) and conducted together with Giulio Matteucci (first author), Rosilari Bellacosa Marotti and Margherita Riggi, provides new insights on the mechanisms used by neurons in rat visual cortex to encode the shape of visual objects. The results confirm the importance that rodents can have in the study of the neuronal basis of vision. They also suggest that the brain of these animals, in addition to that of the most evolved species, can inspire improvements to the so-called Artificial Deep Neural Networks, possibly helping them to "see" in a way that is increasingly more similar to their biological counterparties.

"By exploring a progression of cortical areas that, in the rat brain, runs across the occipital and temporal lobes, we have found trends that are similar to those observed in the monkey visual system, with respect to the ability of visual neurons to represent increasingly complex shapes". Zoccolan continues "these trends, which are considered to be at the root of the extraordinary object recognition abilities of primates (including humans), are very similar to those found in deep neural networks, as confirmed by the simulations run in our study. Thus, our work provides further evidence about the existence of a hierarchy of visual areas, which are responsible for processing the shape of visual objects and forming mental representations of the world in the rat brain".

The use of rodents to study high-level visual functions

The visual cortex of humans and, in general, of primates, is organised hierarchically: different areas exist, which are responsible for representing progressively more abstract information: from the identification of borders between light and shadow in localised regions of the visual field, to the identification of the objects contained in an image. It is not clear yet if an equally advanced specialisation exists in the cortex of rodents.

The study conducted at SISSA starts to clarify some of these doubts, confirming the existence of functional similarities between primates and rodents that open interesting prospects for future research. In fact, establishing how advanced the visual system of the rat is, compared to that of a superior mammal, is essential to understand if this species can be a good model to study the mechanisms at the root of high-level visual functions. On the other hand, understanding these mechanisms is a key step towards bridging the gap that still separates the perceptive skills of machines from our own.

Models to develop artificial intelligence

The research of Zoccolan's group lends itself to potential applications in the field of artificial intelligence.

"We are increasingly directing our efforts at the interface between biological and artificial vision, using approaches of machine learning and deep neural networks. The advent of deep networks, which, in recent years, have revolutionized the field of artificial intelligence and machine vision, has also been possible thanks to the inspiration provided by the understanding of biological vision. For this reason, several scholars in the field of AI are convinced that further developments will come from better understanding biological intelligence. "If the neuronal mechanisms that allow processing visual information in biological systems will be better clarified, this knowledge could be applied to develop increasingly advanced and efficient algorithms to process and understand images and videos in artificial systems" concludes Davide Zoccolan.

A new study has found that frequent visits to the bathroom at night could cost the US economy $44.4 billion a year. According to researchers at the not-for-profit research organisation RAND Europe, waking up more than twice a night due to nocturia, a health condition that affects the lower urinary tract, can have a detrimental effect on a person's wellbeing and productivity at work, which in turn has an impact on a country's GDP.

People who wake up at least twice a night to go to the toilet are more likely to be absent from work due to sickness or be less productive at work, as the disrupted night's sleep affects their ability to function during the day. The study's findings suggest that a person suffering with nocturia loses on average at least seven more working days a year due to absenteeism and presenteeism (being in suboptimal health while at work) than a person who does not have nocturia.

The number of people in the US workforce estimated to suffer with nocturia is 27.5 million, 12.5 per cent of the total working population. In the five other countries included in the economic analysis of the report - the UK, Germany, Spain, Japan and Australia - an additional 53.6 million people could have nocturia, ranging from 13 per cent to 17 per cent of the population of each country.

The economic losses (in GDP terms) associated with nocturia are estimated to be about $13.7 billion in Japan, followed by Germany at $8.4 billion, the UK at $5.9 billion, and Spain and Australia each at about $3 billion.

Researchers used a unique macroeconomic model to simulate the current economic situation of each of the six countries under consideration and then predicted how economic output would be affected, if the proportion of people suffering with nocturia in the economy were reduced.

People suffering with nocturia also reported lower life satisfaction and work engagement, according to data collected through two large, linked employer-employee surveys (see below). On average, a person with nocturia has a 2 per cent lower life satisfaction compared to a person not suffering with nocturia. This association is similar to if the individual suffered from other serious health conditions such as hypertension, cardiovascular disease or asthma.

Furthermore, people suffering with nocturia have a 1.3 per cent lower engagement at work compared to people not suffering from the condition. This is similar to people with chronic conditions like kidney disease or hypertension.

Marco Hafner, lead researcher and senior economist says: "Doctors and health practitioners often overlook nocturia as a potential health problem associated with sleep loss, and patients can delay reporting the condition until it becomes unbearable and substantially affects their wellbeing.

"Given the substantial economic implications of untreated nocturia, this should be a 'wake-up' call to diverse stakeholders, including patients, health-care providers and employers, of the importance of identifying and treating nocturia."

A variety of demographic, lifestyle and health factors are associated with nocturia and they differ by age and gender. The study found that chronic health conditions such as kidney disease, diabetes, cardiovascular disease, cancer and hypertension could all play a role.

Factors that influence the health of our blood vessels, such as smoking, high blood and pulse pressures, obesity and diabetes, are linked to less healthy brains, according to research published in the European Heart Journal [1] today (Monday).

The study examined the associations between seven vascular risk factors and differences in the structures of parts of the brain. The strongest links were with areas of the brain known to be responsible for our more complex thinking skills, and which deteriorate during the development of Alzheimer's disease and dementia.

The researchers, led by Dr Simon Cox, a senior research associate at the Centre for Cognitive Ageing and Cognitive Epidemiology at the University of Edinburgh (UK), examined MRI scans of the brains of 9,772 people, aged between 44 and 79, who were enrolled in the UK Biobank study - one of the largest groups of people from the general population to have data available on brain imaging as well as general health and medical information. All had been scanned by a single scanner in Cheadle, Manchester, and most of the participants were from the north-west of England. This is the world's largest single-scanner study of multiple vascular risk factors and structural brain imaging.

The researchers looked for associations between brain structure and one or more vascular risk factors, which included smoking, high blood pressure, high pulse pressure, diabetes, high cholesterol levels, and obesity as measured by body mass index (BMI) and waist-hip ratio. These have all been linked to complications with the blood supply to the brain, potentially leading to reduced blood flow and the abnormal changes seen in Alzheimer's disease.

They found that, with the exception of high cholesterol levels, all of the other vascular risk factors were linked to greater brain shrinkage, less grey matter (tissue found mainly on the surface of the brain) and less healthy white matter (tissue in deeper parts of the brain). The more vascular risk factors a person had, the poorer was their brain health.

Dr Cox said: "The large UK Biobank sample allowed us to take a comprehensive look at how each factor was related to many aspects of brain structure. We found that higher vascular risk is linked to worse brain structure, even in adults who were otherwise healthy. These links were just as strong for people in middle-age as they were for those in later life, and the addition of each risk factor increased the size of the association with worse brain health.

"Importantly, the associations between risk factors and brain health and structure were not evenly spread across the whole brain; rather, the areas affected were mainly those known to be linked to our more complex thinking skills and to those areas that show changes in dementia and 'typical' Alzheimer's disease. Although the differences in brain structure were generally quite small, these are only a few possible factors of a potentially huge number of things that might affect brain ageing."

Smoking, high blood pressure and diabetes were the three vascular risk factors that showed the most consistent associations across all types of brain tissue types measured. High cholesterol levels were not associated with any differences in the MRI scans.

To quantify the size of the differences they observed, Dr Cox explained: "We compared people with the most vascular risk factors with those who had none, matching them for head size, age and sex. We found that, on average, those with the highest vascular risk had around 18ml, or nearly 3%, less volume of grey matter, and one-and-a-half times the damage to their white matter - the brain's connective tissue - compared to people who had the lowest risk; 18ml is slightly more than a large tablespoon-full, or a bit less than a small, travel-sized toothpaste tube."

He said that the findings showed the potential of making lifestyle changes to improve brain and cognitive ageing.

"Lifestyle factors are much easier to change than things like your genetic code - both of which seem to affect susceptibility to worse brain and cognitive ageing. Because we found the associations were just as strong in mid-life as they were in later life, it suggests that addressing these factors early might mitigate future negative effects. These findings might provide an additional motivation to improve vascular health beyond respiratory and cardiovascular benefits."

Limitations of the study include the fact that it does not include people over the age of 79 and that UK Biobank participants tend to live in less deprived areas, which may restrict how the findings can be generalised to other populations. As the researchers were measuring brain structures only, and were not carrying out functional brain imaging or tests of thinking skills, they cannot show in this study how the changes in brain structure might impact cognitive function, but other studies have shown the relationship between increased numbers of vascular risk factors and worse or declining thinking skills, and dementia.

Now the researchers plan to measure the links between vascular risk factors and thinking skills in the UK Biobank participants and in other groups too. In addition, they are following older people, and carrying out multiple scans and tests of thinking skills. They hope this will tell them more about the role that vascular risk factors play in the decline of different types of thinking skills and which areas of the brain are implicated. They also hope that the findings will motivate future work to understand the biological mechanisms through which different sources of vascular risk might be related to different brain areas and tissues.

A study of university rugby players has shown that they are more likely to suffer sleep disordered breathing than an average middle-aged man.

The study also showed that the athletes who experience this problem are also more likely to have low levels of oxygen in their blood and higher pulse rates during the night, suggesting that athletes with sleep disordered breathing may be at risk of heart abnormalities.

The researchers say this study could indicate that sleep disordered breathing is a factor in the phenomenon of seemingly healthy young athletes dying from a sudden and unexplained heart attack.

Sleep disordered breathing (SDB) is characterised by abnormal respiratory patterns or pauses in breathing during sleep, ranging from snoring to sleep apnoea, where the airways close completely or partially many times during sleep. Having a high BMI, being over 40 years of age and having a large neck circumference are some of the common factors associated with SDB. If untreated, patients with SDB-related conditions face an increased risk of developing chronic diseases such as cardiovascular disease, heart failure and type 2 diabetes.

The study, published in ERJ Open Research [1], was led by Yoshitaka Iso, a cardiologist and Associate Professor at Showa University Research Institute for Sport and Exercise Sciences, Yokohama, Japan. He explained: "We wanted to investigate the prevalence of sleep disordered breathing in collision sport athletes, such as rugby or American-style football players, because we know that they usually have a higher BMI and larger neck circumference than athletes from other sports.

"We tend to assume that young, competitive athletes will not experience conditions like SDB, which are more common in people with a higher BMI and inactive lifestyles, but more research is needed to determine what may be contributing to sudden cardiac death in athletes, and SDB is a good candidate for this as it can affect the heart's normal functions."

The study included 42 male rugby players aged 18-19 years. A special device was used to monitor overnight changes in the athletes' breathing rhythm, heartbeats and heart rate, blood oxygen levels, the number of times they woke up, and how long they were awake for.

The data showed that 18 (43%) of the athletes met the criteria for SDB, which means they experienced five or more pauses in breathing that lasted for at least 10 seconds, over a total sleeping time of more than three hours.

The data also showed that athletes with SDB had higher average heart-rates and lower levels of oxygen in their blood than athletes who did not have SDB. They also experienced more periods of time when their blood oxygen levels were unusually low.

Professor Iso and his team then assessed the performance of each young man's heart and lungs at rest and during exercise, to check for cardiovascular abnormalities among athletes with and without SDB. These tests showed that resting heart-rate was higher among SDB athletes, and that SDB athletes experienced more incidences of extra or disruptive heartbeats than non-SDB athletes, further suggesting that SDB may be linked to heart abnormalities.

Professor Iso said: "Sleep disordered breathing was observed in 43% of the young athletes we assessed. This is a higher rate than we expected, and is higher still than the levels of SDB reported among middle-aged men from the general population of the US and Europe. Our data also showed that several potential warning signs, such as effects on the athletes' breathing and heart rates, occurred frequently among the athletes with SDB.

"Although none of the athletes in this study were found to have serious conditions yet, likely due to their young ages, we do not know how their conditions may worsen in the future due to associated cardiovascular consequences. Based on the link between SDB and abnormal heart functions that we observed in this group, we speculate that SDB could be a possible factor in the unexplained deaths of some young collision sport athletes, as it appears to be very prevalent but currently is not regularly screened for."

Professor Anita Simonds is a Consultant in Respiratory and Sleep Medicine at Royal Brompton and Harefield NHS Foundation Trust, UK and President Elect of the European Respiratory Society, and was not involved in the research. She said: "It is too early to conclude that sleep disordered breathing is a definite factor in sudden cardiac death of athletes, but these results provide food for thought on the ways that breathing disorders may affect the health of young, fit athletes.

"In this study the overall level of sleep disordered breathing was mild, but the results highlight that a sleep study to assess for the presence of sleep disordered breathing should be considered in the care of collision sport athletes, such as rugby or American-style football players, as it could help to identify those at risk of cardiovascular complications."

The researchers say that additional large studies are necessary to confirm their results and to determine the underlying mechanisms that lead to SDB, and note that a limitation of the study is that SDB assessment was only performed on a single night.

As if being picked on wasn't bad enough, victims of workplace mistreatment may also be seen as bullies themselves, even if they've never engaged in such behavior.

Adding insult to injury, victims may even be seen by supervisors as worse employees, despite exemplary performance. Bullies, on the other hand, may be given a pass if they are liked by their supervisor.

A study about this bias toward victim blaming was recently published in the Journal of Applied Psychology. The peer-reviewed article was co-authored by Shannon Taylor, an associate professor of management in the University of Central Florida's College of Business.

"The results are eye-opening," Taylor says. "I think they are useful because, given all of these accounts in the media of bad behavior happening, people are often left wondering how can we blame victims, and why do we let these perpetrators off the hook, why do they go unpunished?"

Taylor attributes the flawed decision making to cognitive biases, such as the halo effect, in which positive attributes mask negative traits, or the horns effect, in which one negative attribute casts a person in a completely negative light.

He recommends that supervisors receive bias training.

"The first step is really awareness of these biases," Taylor says. "We hope this study will at least bring awareness to people's potential for bias."

The researchers performed their work over the course of four studies. The first two studies showed through surveys of employees and supervisors that supervisors tend to view victims of bullying as being bullies themselves.

Studies three and four were experiments where participants evaluated employees based on descriptions of their work performance, as well as how they treated others and how they were treated.

They found that even when evaluators were clearly informed that a victim did not mistreat others, victims were still seen as bullies. In the fourth study, they found that not only are victims seen as bullies despite evidence to the contrary, but also that they receive lower job performance evaluations as a result of being victimized.

The researchers found support in all four studies that bullies were less likely to be seen as deviant when their supervisor considered them to be good performers.

"What I think is really interesting about this is, when you hear stories of high-profile people engaging in bad behavior at work, a lot of these people have gone unpunished for long periods of time," Taylor says. "And we have examples of victims of this bad behavior being called out and attacked on social media and by the media. Our studies show this is actually pretty common. We're all susceptible to these biases."

An example - the victim blaming that occurred during Christine Blasey Ford's testimony during and after Brett Kavanaugh's Supreme Court confirmation hearing, Taylor says.

MADISON, Wis. -- "Microbial communities run the world," says Jo Handelsman, director of the Wisconsin Institute for Discovery at the University of Wisconsin-Madison.

"People always laugh when I say that," she adds. "But it's true."

Our rich new understanding of microbial communities and their influence on human health or crop productivity has led to the dream of changing these communities to produce benefits. In pursuit of that dream, millions of Americans now take probiotics, beneficial microbes they hope will improve their gut.

But the immense complexity and resiliency of these microbiomes leave researchers unsure how to produce predictable and long-lasting changes for the better.

New research by Handelsman and her collaborators addresses that complexity head-on. The team developed a community they named THOR, three species of bacteria isolated from soybean roots and grown together. The complex community of microbes developed new behaviors together that couldn't be predicted from the individual members alone -- they grew tougher structures known as biofilms, changed how they moved across their environment, and controlled the release of a novel antibiotic.

Each of the three members of THOR has a sequenced genome, and an array of tools are available to easily study the bacteria in isolation and together, which opens up opportunities to start unraveling the complexity of microbial communities like THOR and others. A better understanding of these microbiomes could help scientists figure out how to improve them.

The work is published March 5 in the journal mBio. The work was led by Handelsman lab postdoctoral researcher Gabriel Lozano with collaborators at the UW-Madison Department of Plant Pathology, Yale University and other institutions.

The thunderous name THOR stems from the members of the community: The Hitchhikers Of the Rhizosphere. Years ago, Handelsman's lab noticed that several bacteria came along for the ride when members of common Bacillus bacteria were isolated from the microbiome of soybean roots, known as the rhizosphere. These hitchhikers only showed themselves when Bacillus bacteria were grown in the cold for several weeks.

Those tight associations between different species suggest they could serve as a model community to test how complex traits emerge when multiple species share the same space. The researchers settled on species from the Pseudomonas and Flavobacterium groups of bacteria to grow and study alongside Bacillus.

Combined, the members of THOR boasted some 15,000 genes and were capable of producing thousands of small molecules, creating "layers of complexity" over time and across space, says Handelsman.

When grown alone, the Pseudomonas member of THOR produces a biofilm, a hearty structure that protects the bacteria from its environment. Biofilms gum up implants used in medicine and make bacteria resistant to antibiotics. When all three members of THOR were grown together, the community produced two times as much biofilm and the biofilm lasted longer than when Pseudomonas was alone.

"Even when their populations are small, these other species are sparking larger biofilms," says Handelsman.

Other complex traits emerged in THOR as well. The Bacillus member reduced the production of antibiotics made by Pseudomonas, protecting Flavobacterium from their effects. And the other members of THOR induced Bacillus colonies to grow out like the branches of a tree, spreading over and around the other bacteria in complex patterns.

Many efforts to manipulate microbiomes are focused on improving human health, and model communities like THOR could help scientists understand how complex microbial relationships can be altered to benefit us.

But THOR's information about the microbiome of plant roots, the rhizosphere, is just as vital. The rhizosphere helps glue soil together, preventing erosion. And soil locks up three times more carbon than floats in the atmosphere, making it an important element in addressing climate change. Knowing how individual microbes come together to produce the rich, complex behavior of the soil microbiome may be a key to maximizing the benefit we derive from these unseen communities.

"It's one of the most critical relationships we have," says Handelsman.