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ALBUQUERQUE, N.M. -- Be grateful you're not on a dragonfly's diet. You might be a fruit fly or maybe a mosquito, but it really wouldn't matter the moment you look back and see four powerful wings pounding through the air after you. You fly for your life, weaving evasively, but the dragonfly somehow tracks you with seemingly instant reflexes. For a moment, you think you've gotten away, just as it closes in swiftly from below for the kill.

Then, as the dinosaur-era predator claws into you with its spiny legs and drags you into its jaws midair, you might wonder to yourself, "How did it catch me with such a tiny brain and no depth perception?"

Sandia National Laboratories is homing in on the answer with research showing how dragonfly brains might be wired to be extremely efficient at calculating complex trajectories.

In recent computer simulations, faux dragonflies in a simplified virtual environment successfully caught their prey using computer algorithms designed to mimic the way a dragonfly processes visual information while hunting. The positive test results show the programming is fundamentally a sound model.

The Sandia research is examining whether dragonfly-inspired computing could improve missile defense systems, which have the similar task of intercepting an object in flight, by making on-board computers smaller without sacrificing speed or accuracy. Dragonflies catch 95% of their prey, crowning them one of the top predators int he world.

Computational neuroscientist Frances Chance, who developed the algorithms, is presenting her research this week at the International Conference on Neuromorphic Systems in Knoxville, Tennessee. Earlier this month, she presented at the Annual Meeting of the Organization for Computational Neurosciences in Barcelona, Spain.

Research replicates dragonfly's highly efficient brain

Chance specializes in replicating biological neural networks -- brains, basically -- which require less energy and are better at learning and adapting than computers. Her studies focus on neurons, which are cells that send information through the nervous system.

"I try to predict how neurons are wired in the brain and understand what kinds of computations those neurons are doing, based on what we know about the behavior of the animal or what we know about the neural responses," she said.

For example, a dragonfly's reaction time to a maneuvering prey is a mere 50 milliseconds. A human blink takes about 300 milliseconds. Fifty milliseconds is only enough time for information to cross about three neurons. In other words, to keep up with a dragonfly, an artificial neural network needs to be done processing information after only three steps -- though, because brains fire lots of signals at once, each step may involve many calculations running at the same time.

Faster, lighter computing for missile defense

Missile defense systems rely on established intercept techniques that are, relatively speaking, computation-heavy. But rethinking those strategies using highly efficient dragonflies as a model could potentially:

Shrink the size, weight and power needs of onboard computers. This would allow interceptors to be smaller and lighter, and therefore more maneuverable.

Reveal new ways to intercept maneuvering targets such as hypersonic weapons, which follow less-predictable trajectories than ballistic missiles.

Reveal new ways to home in on a target with less sophisticated sensors than are currently used.

Dragonflies and missiles move at vastly different speeds, so it's unknown how well this research will ultimately translate to missile defense. But developing a computational model of a dragonfly brain also could have long-term benefits for machine learning and artificial intelligence.

AI is used throughout wide-ranging industries, from self-driving transportation to prescription drug development. These fields stand to gain from highly efficient methods for constructing fast solutions to complex problems. Ongoing research at Sandia is refining Chance's algorithms and determining where they're most applicable.

A drug-resistant fungus species called Candida auris, which was first identified ten years ago and has since caused hundreds of deadly outbreaks in hospitals around the world, may have become a human pathogen in part due to global warming, according to three scientists led by a researcher at the Johns Hopkins Bloomberg School of Public Health.

C. auris was first isolated from the infected ear of an elderly patient in Japan in 2009, and within a few years caused hospital outbreaks in many different parts of the world. Between 30 and 60 percent of patients diagnosed with invasive C. auris infection have died. C. auris's sudden emergence as a human-infecting pathogen is as mysterious as it is alarming, for it happened simultaneously among several distinct families or "clades" of this fungus that exist separately on different continents.

The scientists, in their paper published July 23 in the journal mBio, suggest that this global transformation of C. auris into a deadly pathogen may be due to global warming, which could have forced C. auris clades around the world to adapt to higher temperatures. That adaptation would have made it easier for this microbe to infect humans, whose relatively warm core temperature of 98.6 degrees Fahrenheit (37 degrees Celsius) normally serves as a "thermal barrier" against fungal invasion.

"We think that C. auris may be the first example of a fungal species that has jumped the thermal barrier due to adapting to global warming," says lead author Arturo Casadevall, MD, PhD, the Alfred and Jill Sommer Professor and Chair of the W. Harry Feinstone Department of Molecular Microbiology and Immunology at the Bloomberg School.

Microbiologists estimate there are more than a million fungal species. However, most known species are adapted for living in soils, on trees, and in other places in the natural environment, where temperatures on average are much cooler than mammalian core temperatures. Only a tiny proportion of fungal species can infect humans, and dangerous internal infections with fungi typically occur only in people with very weak immune systems.

Casadevall, a Bloomberg Distinguished Professor, warned in a paper in 2010 that global warming could trigger the emergence of many more fungal pathogens. In the new paper, he and his colleagues hypothesize that C. auris is the first of these.

Analyzing the temperature range for C. auris and a few dozen species that are its nearest fungal relatives, the scientists found that the new pathogen can grow at higher temperatures than most of these near-relatives, hinting that it may have acquired its thermal tolerance only recently. They also cited a previous finding from Casadevall's laboratory that some other fungal species in a large culture collection had begun to adapt to global warming by increasing their tolerance for higher temperatures.

Proving that global warming spurred the emergence of C. auris as a human pathogen will be difficult, but Casadevall and colleagues argue that this possibility--and the possibility that other new fungal pathogens will emerge--must be borne in mind as the global average temperature continues to rise.

"Right now fungal diseases are usually not reportable," Casadevall says. "So we need better surveillance of these infections in humans--and even in other mammals, where the first warnings of new fungal pathogens might occur."

C. auris strains usually have considerable resistance to antifungal drugs, and some resist all the usual treatments. How this resistance arose is another mystery--many scientists suspect that the widespread agricultural use of fungicides was the key factor. In any case, it underscores the need for better reporting of serious fungal infections and for new antifungal drugs, says Casadevall.

Experts are urging parents to brush up on national guidelines following a rapid rise in screen time on electronic devices for children under two.

A University of Queensland study found some young children might average 50 minutes per day, where the national guidelines called for zero screen time in children under the age of two.

UQ School of Public Health lead author Associate Professor Leigh Tooth said the guidelines were there to give children the best start in life.

"We were surprised to see the rapid increase in screen time from the first month of infancy," Dr Tooth said.

"Children are spending almost an hour per day in front of a screen before they turn one."

Dr Tooth's study showed screen time quickly increased with age before plateauing around three years, at an average of 94 minutes per weekday.

Screen time only fell into line with national guidelines when children moved into childcare and school, while weekends continued to spike well above the guidelines.

The Australian government, World Health Organization and other international bodies promote the same guidelines of zero screen time under two years.

"We need to let people know that young children should not be in front of a screen for long periods because there is emerging evidence this could be detrimental to their development and growth," she said.

"Screen time represents a missed opportunity where children could be practising and mastering a developmental skill, like skipping and jumping, over being sedentary and transfixed to a screen.

"This is particularly important in children under two who should not be spending any time in front of a screen."

The study showed mothers whose children exceeded the screen time guidelines experienced factors like financial stress, had high amounts of leisure time or allowed electronic devices in the bedroom.

"It's very easy to use screen time with children because there are so many child-friendly apps and games developed for young children and parents," Dr Tooth said.

"If you give a child an iPad for 30 minutes then they're going to be transfixed - you can understand why parents give their children access to screens."

Dr Tooth said the potential negative implications far outweighed any perceived benefits of the easy distraction tools.

"The fear is that it is these early years where the most negative impact on health and development can occur," she said.

"Parents need to be made aware of the national guidelines in their antenatal visits or during a follow-up appointment with their GP.

"The guidelines are there for a reason, and that is to protect your baby's health and development."

Homeowners who rely on private wells as their drinking water source can be vulnerable to bacteria, nitrates, and other contaminants that have known human health risks. Because they are not connected to a public drinking water supply, the homeowners are responsible for ensuring that their own drinking water is safe.

Similar to concerns that public drinking water treatment plants face, groundwater wells may be impacted by another group of contaminants -- and they might be part of your daily use!

Ingredients in personal care items, over-the-counter and prescription medicines, and even food and drink products are introduced into domestic wastewater streams and can persist through treatment technologies. "This causes trace-levels of these chemicals to be found in the environment," says Heather Gall. "Recently developed analytical technologies are now advanced enough for us to detect these compounds in water at increasingly low levels." Gall is an assistant professor at Pennsylvania State University who studies contaminants of emerging concern in surface and groundwater.

A fully-functioning septic system releases the effluent slowly into a septic field. The soil, roots, and soil microbes biodegrade pollutants in the water before it gets back into groundwater.

However, in the U.S., 10-20% of septic tanks function poorly. This can increase the chance of these contaminants getting to groundwater, especially those that biodegrade slowly in the environment. After that, they can enter a downgradient household's well water.

The presence of medicines in drinking water raise public health concerns. Impacted water may have harmful effects when consumed, but whether the levels present in private wells are high enough to pose a threat is an understudied area of research.

So, Gall partnered with the Pennsylvania Master Well Owner Network. Twenty-six homeowners volunteered to collect water samples from their private wells. "Since our project engaged private well owners, we wanted to focus on compounds they may be familiar with," says Gall.

Gall's team chose to test water samples for four common antibiotics, two over-the-counter anti-inflammatory drugs, and one common stimulant. Each reacts differently with soil in the septic field in different ways. These chemicals can bind physically to soil particles. They also can react with soil, soil microbes, and other compounds in the septic field. It's a virtual chemistry experiment when active pharmaceutical ingredients reach the septic tank.

Gall found that medicines' ability to get to groundwater was mostly controlled by two factors: sorption potential and biodegradability.

Sorption refers to the likelihood of the medicine attaching to another substance like soil or water. Medicines with low sorption are not likely to attach to soil in the septic field. That makes them more likely to move quickly through the soil profile and reach groundwater. The medicine most likely to reach groundwater was ofloxacin. This antibiotic was the most frequently detected medicine in the groundwater samples.

Naproxen, an anti-inflammatory drug, had the highest sorption, and was most likely to stay in the septic field. This could be the reason it was not detected in any of the groundwater samples of the study.

Biodegradability is the ability of the drug to break down in the soil. Medicines that break down quickly are unlikely to reach the groundwater. However, some medicines reach the groundwater before they begin breaking down. Scientists measure this factor using "half-life", which is how long it takes for half of the medicine to break down.

For example, ofloxacin, which was the most frequently detected, has a half-life of four years. However, acetaminophen, an anti-inflammatory drug, has a half-life shorter than one day. Luckily, so does your morning caffeine. Acetaminophen and caffeine were detected in less than half of the collected water samples.

Overall, the sorption potential and biodegradability of a medicine influences its ability to contaminate groundwater. Gall's results also show that septic tanks can impact a household's well water quality. But, the amount of medicines found in the samples suggest minimal risk to human health.

The issue of active pharmaceutical ingredients being present in drinking water sources is unfortunately something we have little control over from a use perspective. We can't control how much we excrete, and even when our septic tanks are working, it's clear that some compounds persist in the treated effluent. "We can do our best to be good environmental stewards by bringing expired and unused medicines to take-back locations, and of course, by maintaining septic tanks for many water quality reasons," says Gall.

For private well owners concerned about their water quality, she recommends getting a water quality test done for primary drinking water standards and ensuring all existing standards are being met. Then, additional treatment technologies that can be adopted on site to help reduce emerging contaminants.

The chemical interactions that give proteins their shape may be weaker and more numerous than previously recognized. These weak connections provide a new way for researchers to understand proteins that cause disease and help them gain insights into the fundamentals of chemistry.

Chemists at the University of Tokyo modeled the building blocks of the protein structure that causes Alzheimer's disease, amyloid beta sheets. Their calculations revealed that some atoms too far apart to bond were still in each other's "electron neighborhoods."

"This is so strange. It's outside the common sense of organic chemistry," said Professor Tomohiko Ohwada from the University of Tokyo

Atoms - the building blocks of life represented in the periodic table of the elements - connect together to build molecules by sharing or stealing electrons from other atoms. Those electrons fly around super-fast in a cloud of electrons.

The traditional understanding of chemical bonds is that in large molecules, atoms must be side by side to share electrons.

Ohwada's research team calculated that atoms located far apart do not share electrons, but their electron clouds can still influence each other. They call this influence "through-space bond path interactions." The through-space bond path interactions are extremely weak, but common enough to add up to a potentially significant influence on the overall structure of large molecules.

"We studied the amyloid beta structure because everyone knows it can cause disease, but nobody really knows how the problematic structure develops," said Ohwada.

Abnormal accumulation of amyloid beta sheets may cause Alzheimer's disease or cancers.

The beta sheet structure refers to long chains of protein folded at regular intervals and stacked one on top of another into a flat sheet. Through-space bond path interactions within and between the protein chains likely stabilize the structure and may help it clump together into disease-causing plaques.

Recognizing the location and nature of through-space bond path interactions may help researchers predict the true structure and behavior of a molecule based only on its chemical sequence.

The research team has so far only studied through-space bond path interactions in the water-repelling portions of synthetically built mini amyloid beta sheets. They plan to expand their computations to the water-attracting portions and to larger molecules.

"In theory, it might be possible to build an artificial molecule that could form through-space bond path interactions with natural proteins and change their activity," said Ohwada.

The computations in this research were performed at the Research Center for Computational Science in Okazaki, Japan.

A new study led by a researcher at Columbia University Mailman School of Public Health identifies a link between proximity to hydraulic fracking activities and mental health issues during pregnancy. Results appear in the journal Environmental Research.

The researchers looked at 7,715 mothers without anxiety or depression at the time of conception, who delivered at the Geisinger Health System in Pennsylvania between January 2009 and January 2013. They compared women who developed anxiety or depression during pregnancy with those who did not to see if the women's proximity to hydraulic fracturing activity played a role. Hydrofracking locations were available through public sources.

They found that for every 100 women, 4.3 additional women would experience anxiety or depression if they lived in the highest quartile of exposure compared to the other quartiles. The prevalence of anxiety or depression during pregnancy was 15 percent in the highest quartile, compared to just 11 percent in the lower three quartiles. The risk appeared greater among mothers receiving medical assistance (an indicator of low income) compared to those who did not: the authors observed 5.6 additional cases of anxiety or depression per 100 exposed women. They found no relationship between anxiety or depression during pregnancy and preterm birth and reduced term birth weight (an earlier study the research team found a link between proximity to hydrofracking and these adverse birth outcomes).

First author Joan Casey, PhD, assistant professor in the Department of Environmental Health Sciences, points to several possible reasons why living near fracking sites could lead to mental health problems in women. "Fracking activities may act as community-level stressors by degrading the quality of the natural environment, neighborhoods, such as by the production of toxic wastewater and increases in truck traffic, leading residents to feel a lack of control that harms their health," says Casey. "Another possibility is that air pollution from the sites could be directly contributing to mental health problems in this vulnerable population. Future research could examine other potential factors like air quality, noise, light pollution, psychosocial stress, and perception of activities."

BUFFALO, N.Y. - Introducing plant-based foods to a diet is a common-sense approach to healthy eating, but many people don't like the taste of vegetables, bitter greens, in particular.

But give that broccoli a chance.

Doing so won't just change your mind; it will actually change the taste of those foods, according to a new University at Buffalo study.

What sounds at first like a culinary parlor trick is actually a scientific matter based on specific proteins found in saliva. These proteins affect the sense of taste, and diet composition, at least in part, determines those proteins.

Saliva is a complex fluid containing around 1,000 specific proteins. Identifying all the players is a work in progress, but everything we eat is dissolved in saliva before it interacts with taste receptor cells and all these proteins are candidates for influencing stimuli before food is tasted.

"What you eat creates the signature in your salivary proteome, and those proteins modulate your sense of taste," says Ann-Marie Torregrossa, an assistant professor in UB's Department of Psychology and the associate director of the university's Center for Ingestive Behavior Research, a comprehensive research home for studying eating and drinking behavior, obesity and other factors contributing to the daily decisions people make related to food and fluid intake.

"We've shown in previous work with rats that changing your diet changes what proteins are in your saliva. Now we're showing that the proteins in your saliva change how you taste."

The findings, published in the journal Chemical Senses, have applications ranging from the obesity crisis to medical compliance.

"If we can convince people to try broccoli, greens and bitter foods, they should know that with repeated exposure, they'll taste better once they regulate these proteins," says Torregrossa.

How much repeated exposure? Give me a number.

"Our data doesn't provide a number, such as 12 servings of broccoli, however, for people who avoid these foods because of their bitterness, but would like to include them in their diet, they should know their taste will eventually change."

Bitterness is also a near-universal characteristic of many pediatric medicines, and getting infants to swallow a bitter liquid -- which by nature they want to reject -- can be a challenge.

"An additive to that medicine to make it less bitter would increase compliance," she says. "It's similar to liquid dietary supplements in the geriatric population, which often contain sugar to tame the bitterness. Achieving the same result without sweeteners has obvious benefits."

At a bare minimum, Torregrossa says health care and nutritional professionals can counsel people to explain the role of these salivary proteins.

"Trying to convince someone that a salad tastes great isn't going to work because to that person it doesn't taste great. Understanding with taste that we're dealing with something that's moveable is significant."

Think of this in an evolutionary context.

Bitter foods, for foragers, can serve as a sign of danger, but it's an unreliable predictor. Why look for another food source if there's something safe and abundant at hand?

"Instead of having the cognitive load of learning that a food is safe and having to maintain that memory, instead you know that eventually this bitter food will taste good," says Torregrossa. "It's an elegant physiological shift allowing you to put these foods into your diet."

For the study, Torregrossa trained to rats to choose from one of two water bottles after tasting a solution, to indicate whether it tasted bitter. Animal research in this case allows for tighter dietary control and the variation of specific proteins can be monitored in a way that's difficult to achieve with human participants.

"This is interesting because we're not asking, 'Do you like this?' we're looking only at 'Can you taste this as bitter?'" she says. "Animals with these bitter-induced salivary proteins turned on cannot taste the bitterness at higher concentrations than animals who do not have the same protein activated.

"Once these proteins are on board the bitter tastes like water. It's gone."

Torregrossa's work is an intriguing tactic in the obesity fight which sees many battles focusing on over-consumption of high-fat and high-sugar foods.

"The variation around sweets is very small," she says. "Nearly everyone likes a cupcake, but the variation around liking broccoli is enormous.

"This research helps explain why that variation with bitter food exists and how we can get more people to eat broccoli instead of cupcakes."

WEST LAFAYETTE, Ind. -- Nearly every atmospheric science textbook ever written will say that hurricanes are an inherently wet phenomenon - they use warm, moist air for fuel. But according to new simulations, the storms can also form in very cold, dry climates.

A climate as cold and dry as the one in the study is unlikely to ever become the norm on Earth, especially as climate change is making the world warmer and wetter. But the findings could have implications for storms on other planets and for the intrinsic properties of hurricanes that most scientists and educators currently believe to be true.

"We have theories for how hurricanes work at temperatures that we're used to experiencing on Earth, and theoretically, they should still apply if we move to a colder and drier climate," said Dan Chavas, an assistant professor of earth, atmospheric and planetary sciences at Purdue University. "We wanted to know if hurricanes really need water. And we've shown that they don't - but in a very different world."

In the world we live in now, hurricanes need water. When they reach land, they die because they run of out the water they evaporate for energy - but that doesn't have to be the case. The findings were published in the Journal of the Atmospheric Sciences.

"Just because there isn't something changing phase between liquid and vapor doesn't mean a hurricane can't form," Chavas said.

In collaboration with Timothy Cronin, an assistant professor of atmospheric science at MIT, he used a computer model that mimics a very basic atmosphere and constantly generates hurricanes. In a general hurricane scenario, this looks like a box with ocean at the bottom, but Chavas tweaked it to dry out the surface or cool it below temperatures that usually generate hurricanes.

The coldest simulations were run at 240 degrees Kelvin (-28 F) and produced a shocking number of cyclones. These cold, dry storms were generally smaller and weaker than the hurricanes on Earth, but they formed at a higher frequency.

As the temperature drops, the air can hold less water, which explains why cold temperatures and dry surfaces yield similar results in experiments. At 240 degrees K, air can hold roughly 100 times less water vapor than at temperatures typical of the modern tropics.

Interestingly, there is a range of moderate temperatures and moisture levels in which no cyclones formed at all. From 250 to 270 degrees Kelvin (-10 F to 26 F), no hurricanes formed, although the researchers aren't sure why. At 280 Kelvin (44 F), the atmosphere filled again with cyclones.

"Maybe that means there are ideal regimes for hurricanes to exist and the current world we live in is one," Chavas said. "Or you could be in another world where there's no water, but it's still capable of producing many hurricanes. When people are considering whether we could live on a dry, rocky planet like Mars, this could be something to consider."

Such a planet could have even more hurricanes than occur on Earth. Because it's difficult to study the atmospheres of other planets, scientists have to work with their knowledge of Earth and fundamental understanding of how atmospheres function.

Levels of atmospheric carbon dioxide (CO2) are rising, which experts predict could produce more droughts and hotter temperatures. Although these weather changes would negatively impact many plants' growth, the increased CO2 availability might actually be advantageous because plants use the greenhouse gas to make food by photosynthesis. Now, researchers reporting in ACS' Journal of Agricultural and Food Chemistry say that a much higher CO2 level could increase wheat yield but slightly reduce its nutritional quality.

Wheat is one of the world's most important crops; its flour is used as a major ingredient in a large variety of foods such as bread, pasta and pastries. Previously, scientists have shown that elevated CO2 can increase wheat yields at the expense of grain quality traits such as nitrogen and protein content. However, scientists don't yet know the full range of grain quality changes that can occur at different stages of wheat development or the biochemical mechanisms behind them. Iker Aranjuelo and colleagues wanted to examine the effects of elevated CO2 on wheat yield, quality and metabolism during grain formation and at maturity.

The researchers grew wheat in greenhouses at normal (400 parts per million; ppm) or elevated (700 ppm) CO2 concentrations. The team found that wheat grown under elevated CO2 levels showed a 104% higher yield of mature grain. However, the nitrogen content of the grain was 0.5% lower under these conditions, and there were also small declines in protein content and free amino acids. The researchers used gas chromatography-mass spectrometry to analyze metabolic changes in the grains at different developmental stages. Among other changes, elevated CO2 altered the levels of certain nitrogen-containing amino acids during grain formation and at maturity. Although the metabolic changes they detected had modest impacts on final grain quality, the effects could be amplified by other changes in a plant's environment, such as limited nitrogen availability or drought conditions, the researchers say.

ANN ARBOR--The fact that millions of North American monarch butterflies fly thousands of miles each fall and somehow manage to find the same overwintering sites in central Mexican forests and along the California coast, year after year, is pretty mind-blowing.

Once they get there, monarchs spend several months in diapause, a hormonally controlled state of dormancy that aids winter survival. Though diapause is not as obviously impressive as the celebrated annual migrations, it holds mysteries that have perplexed scientists who study biological timing.

Weeks before warming temperatures and longer days signal to the monarchs that it's time to mate and begin spring's northward migration, an internal timer goes off like an alarm clock to rouse the insects, telling them it's time to end diapause and prepare for the critical upcoming events.

Studies in other organisms have shown that cold temperatures can influence the diapause-termination timer, and University of Michigan biologist D. André Green suspected the same is true for monarchs. His study at monarch overwintering sites in central California confirmed it, and his gene expression analyses help explain how cold temperature speeds up that internal timer.

"These results are particularly interesting because they address a counterintuitive result: How does cold temperature, which normally slows down an organism's metabolism and development, speed up diapause? This work is one of the first to provide insights into this question," said Green, a President's Postdoctoral Fellow in the U-M Department of Ecology and Evolutionary Biology who began the work while at the University of Chicago.

The findings have important implications for North America's monarchs--whose populations have declined steadily for decades at the overwintering sites--as the climate changes, Green and co-author Marcus Kronforst of the University of Chicago wrote in a Molecular Ecology study scheduled for publication July 24.

"Understanding how diapause dynamics are affected by environmental and anthropogenic factors at their overwintering sites may be critical for understanding North American monarch population decline and guiding future conservation efforts, a point highlighted by the record low number of monarchs recorded in the western North American monarch population in 2018," Green and Kronforst wrote.

The findings also suggest that monarchs will act as an important sentinel species for monitoring environmental change and disturbance at overwintering sites. If diapause ends too early, monarchs may lose some of the protective time the dormancy period provides.

Green's study involved capturing female monarch butterflies at overwintering sites in central California in November 2015, after they entered diapause. The live insects were brought back to the Chicago lab.

In an environmental chamber there, the butterflies were exposed to temperatures and day lengths approximating November in central California: 10 hours of light at 63 degrees Fahrenheit, followed by 14 hours of darkness at 50 degrees.

In December and again in January, Green's team returned to the same overwintering sites, live-captured additional female monarchs and shipped them to the lab. In the wild, those winter-caught butterflies also experienced short days, along with nighttime temperatures that dipped below 50 degrees.

Green then compared the reproductive maturity of the different groups by counting the number of eggs in each female. An abundance of mature eggs is an indication that the female has terminated diapause, while a paucity of mature eggs indicates that she is still in diapause.

"The monarchs collected from the wild in December showed increased reproductive development compared to the monarchs that had been in the laboratory since November," Green said. "This indicated that an environmental condition in the wild--cold temperature--sped up the timer."

As part of the same study, Green also analyzed gene expression in the different groups of monarchs to understand how the internal timer works. Results suggest that transient markings on histones--proteins around which DNA winds and that control gene expression--may act as a timing mechanism.

The results also show that calcium signaling in the butterfly's head is key, potentially linking the accumulation of cryoprotectants during cold weather to the internal timer.

The research was supported by the National Science Foundation, U.S. Fish and Wildlife Service, and National Institutes of Health. Wild monarchs were collected on private property near Pismo Beach, California, with permission of the landowners.

Green is currently working on a separate study of monarch migration at a study site in U-M's Matthaei Botanical Gardens.

July 24, 2019 (Arlington, VA) -- Below is a summary of a study published online today in Infection Control and Hospital Epidemiology. This article will be freely available for a limited time. SHEA members have full access to all ICHE articles through the online portal.

Title: Attributable Costs and Length of Stay of Hospital-Acquired Clostridioides difficile: A population-based matched cohort study in Alberta, Canada

Conclusions: In this population-based, propensity score matched analysis using micro-costing data, researchers determined HA-CDI is associated with substantial attributable cost.

Background: Clostridioides difficile CDI places a significant economic burden on the healthcare system. In this study, we used a population-54 based dataset of over two million patients and a rigorous propensity score-based design and micro-costing data to determine the attributable cost and length of stay of HA-CDI among adult inpatients in Alberta, Canada.

Walk into a forest made of only native trees, and you probably notice many different tree species around you, with no one species dominating the ecosystem. Such biodiversity - the variety of life and species in the forest - ensures that each species gets a role to play in the ecosystem, boosting forest health and productivity. However, when non-native trees invade, they form dense groups of a single species of tree. This bucks conventional wisdom because, in theory, pathogens - microscopic disease-causing organisms - should prevent this from happening.

Trees have many natural enemies, such as herbivores and insects that nibble on their leaves. But their main foes are invisible to the naked eye. In older forests especially, fungal pathogens evolve to attack the seedlings of certain tree species and, over time, accumulate in the soils around the adults, hindering the growth of their seeds. Seeds that fall far away from their parent typically survive better. The pathogens thus help dictate where native trees can grow and prevent some species from dominating others.

This effect is part of the Janzen-Connell hypothesis, a widely accepted explanation for the promotion of biodiversity in forests. The theory was developed in the 1970s by ecologists Daniel Janzen and Joseph Connell, who said that species-specific herbivores, pathogens, or other natural enemies make the areas near a tree inhospitable for the survival of its seedlings. If one species becomes too abundant, there will be few safe places for its seedlings to survive, thus promoting the growth of other plant species within one area.

Why, then, do introduced tree species often invade, outcompete, and displace native trees, even those of the same genus? The subject is the focus of a new study published in the Ecological Society of America's journal Ecosphere.

Aleksandra Wróbel, a PhD candidate in the Department of Systematic Zoology at Adam Mickiewicz University in Poland, says that the relationship between native trees and their enemy pathogens is a tightly co-evolved one; so tight, in fact, that pathogens may not be able to recognize or attack even closely-related introduced tree species. "Enemy-release" theory states that because introduced species are new to the ecosystem, they do not have enemies yet in the soil, and their seeds can fall densely and thrive, becoming invasive. This relaxation of the Janzen-Connell effect, says Wróbel, "gives non-native species a big competitive advantage over native species."

To test how the intensity of the effect differs between tree species of a same genus, Wróbel and colleagues use greenhouse and field experiments to study two pairs of invasive and native tree species in Central Europe: boxelder (Acer negundo) vs. Norway maple (Acer platanoides), and Northern red oak (Quercus rubra) vs. pedunculate oak (Quercus robur). They also conduct surveys of natural forests containing populations of all four species to investigate their survival in an uncontrolled environment.

Under controlled conditions, the invasive species of both pairs fare better than their respective native cousins, avoiding attack by soil pathogens; they are released from the Janzen-Connell effect, giving them the survival advantage. However, under natural conditions, one genus pair (Acer) followed the expected pattern, with non-native seedlings escaping pathogen attack, while the other pair (Quercus) did not. Wróbel chalks this up to the complexity of interactions with other plants and animals that tree seedlings experience in the wild.

This study indicates that freedom from disease partially explains why non-native tree species dominate in areas where they are introduced. Improving understanding of the role that plant-soil interactions play in the establishment and spread of invasive plants is critical for developing effective management and control strategies.

"Figuring out why invasive species are able to proliferate so readily in new areas is one of the most important issues in ecology and nature protection," concludes Wróbel, "and the results of our research provide additional insight into the factors responsible for the success of certain non-native species."

Leesburg, VA, July 24, 2019--A new cosmetic product, magnetic eyelashes, should be of interest and concern to radiology professionals working in the MRI environment, according to an ahead-of-print article published in the November 2019 issue of the American Journal of Roentgenology (AJR).

With U.S. sales of false eyelashes having increased 31% since 2017 and magnetic eyelashes trending as the top beauty-related Google search of 2018, Einat Slonimsky and Alexander Mamourian at Penn State Health used a phantom to show that magnetic eyelashes worn during MRI can cause substantial artifact and that detachment of the eyelashes from the phantom can occur.

"Our purpose was to evaluate the magnitude of the susceptibility artifacts created by magnetic eyelashes on multiple standard imaging sequences and compare these artifacts with those created by aneurysm clips, which are a common source of image distortion," wrote Slonimsky and Mamourian. Using two sets of magnetic eyelashes from the same manufacturer that were randomly selected and purchased online, the phantom was created by drilling multiple 2-mm holes in a plastic container and then running monofilament line through these holes to create a grid. The two sets of eyelashes were attached to single nylon strings, placed diagonally within the phantom. The phantom was then submerged in a container filled with distilled water, covered with a layer of plastic film to prevent free movement of the lashes, should they detach.

MRI was performed using a 3-T scanner with T2-weighted images, FLAIR images, T1-weighted images, susceptibility-weighted images, DW images, T1-weighted magnetization-prepared rapid-acquisition gradient-echo images, and T2-weighted sampling perfection with application-optimized contrasts using different flip-angle evolutions.

Ultimately, the magnetic eyelashes evidenced an artifact much larger than that created by the aneurysm clips (two made of cobalt alloy, one made of titanium) using the same sequences--measuring 7 × 6 cm maximal on susceptibility-weighted images, obscuring the entire phantom. Although the eyelashes stayed attached to the strings during the scan, upon removal of the phantom from the bore, one set of eyelashes detached from its string. Restrained by the plastic covering, it became attracted to the other eyelashes still attached to the phantom.

"Although friction and adhesion may differ from patient to patient, depending on the width and character of the native eyelashes of an individual," Slonimsky and Mamourian wrote, "we strongly recommend inserting a line about magnetic eyelashes on the MRI safety questionnaire and adding stops in the screening system to prevent the entry of anyone with these lashes, including staff, into the MRI scanner room."

FOLSOM, Calif., July 24, 2019 - A new clinical trial found women who followed a Mediterranean-style diet during pregnancy, including a daily portion of tree nuts (half being walnuts) and extra virgin olive oil, had a 35 percent lower risk of gestational diabetes and on average, gained 2.75 pounds less, compared to women who received standard prenatal care.(1)

A Mediterranean-style diet rich in good, unsaturated fats, found in foods like walnuts and extra virgin olive oil, has been shown to reduce the risk of heart attack, stroke, and cardiovascular death in adults, according to the landmark PREDIMED study.(2) Walnuts, in particular, are a traditional food in the Mediterranean diet because of their omega-3 ALA content (2.5g/oz - the only nut significantly high in this essential fatty acid) and bioactive compounds. While there has been extensive research on the Mediterranean diet to date, the diet's potential to improve maternal and offspring outcomes has not been widely evaluated, making this study particularly valuable.

Conducted by researchers at Queen Mary University of London and the University of Warwick, this new study included 1,252 multi-ethnic inner-city pregnant women with metabolic risk factors, including obesity and chronic hypertension. In addition to receiving folic acid and vitamin D supplementation, the women were randomly assigned to either a Mediterranean-style diet or a control group that received dietary advice per UK national recommendations for prenatal care and weight management during pregnancy.

Those who followed the Mediterranean diet consumed a daily portion of nuts (30g/day; 15g walnuts, 7.5g almonds, 7.5g hazelnuts) and used extra virgin olive oil (0.5L/week) as their main source of cooking fat. In addition, the diet emphasized fruit, vegetables, non-refined grains and legumes; moderate to high consumption of fish; small to moderate intake of poultry and dairy products; low intake of red meat and processed meat; and avoidance of sugary drinks, fast food, and food rich in animal-based fat.

Participants received dietary advice at 18, 20, and 28 weeks' gestation to help improve compliance and make sure the diet was made culturally sensitive. Investigators measured dietary compliance using self-reported feedback from the participants, so it's important to note that there could have been human error in the reporting.

The investigators also assessed the effect of a Mediterranean diet on other pregnancy complications such as high blood pressure, preeclampsia, stillbirth, small for gestational age fetus, or admission to a neonatal care unit, but did not find any significant associations.

One in four mothers enter pregnancy with pre-existing obesity, chronic hypertension or raised lipid levels, which can lead to pregnancy complications, long-term risk of diabetes and cardiovascular complications for mothers and their children.(3,4,5) These findings provide additional support for following a Mediterranean-style diet which has been linked to additional health benefits such as improved cognitive function.

In a major step toward developing portable scanners that can rapidly measure molecules in pharmaceuticals or classify tissue in patients' skin, researchers have created an imaging system that uses lasers small and efficient enough to fit on a microchip.

The system emits and detects electromagnetic radiation at terahertz frequencies -- higher than radio waves but lower than the long-wave infrared light used for thermal imaging. Imaging using terahertz radiation has long been a goal for engineers, but the difficulty of creating practical systems that work in this frequency range has stymied most applications and resulted in what engineers call the "terahertz gap."

"Here, we have a revolutionary technology that doesn't have any moving parts and uses direct emission of terahertz radiation from semiconductor chips," said Gerard Wysocki, an associate professor of electrical engineering at Princeton University and one of the leaders of the research team.

Terahertz radiation can penetrate substances such as fabrics and plastics, is non-ionizing and therefore safe for medical use, and can be used to view materials difficult to image at other frequencies. The new system, described in a paper published in the June issue of the journal Optica, can quickly probe the identity and arrangement of molecules or expose structural damage to materials.

The device uses stable beams of radiation at precise frequencies. The setup is called a frequency comb because it contains multiple "teeth" that each emit a different, well-defined frequency of radiation. The radiation interacts with molecules in the sample material. A dual-comb structure allows the instrument to efficiently measure the reflected radiation. Unique patterns, or spectral signatures, in the reflected radiation allow researchers to identify the molecular makeup of the sample.

While current terahertz imaging technologies are expensive to produce and cumbersome to operate, the new system is based on a semiconductor design that costs less and can generate many images per second. This speed could make it useful for real-time quality control of pharmaceutical tablets on a production line and other fast-paced uses.

"Imagine that every 100 microseconds a tablet is passing by, and you can check if it has a consistent structure and there's enough of every ingredient you expect," said Wysocki.

As a proof of concept, the researchers created a tablet with three zones containing common inert ingredients in pharmaceuticals -- forms of glucose, lactose and histidine. The terahertz imaging system identified each ingredient and revealed the boundaries between them, as well as a few spots where one chemical had spilled over into a different zone. This type of "hot spot" represents a frequent problem in pharmaceutical production that occurs when the active ingredient is not properly mixed into a tablet.

The team also demonstrated the system's resolution by using it to image a U.S. quarter. Fine details like the eagle's wing feathers, as small as one-fifth of a millimeter wide, were clearly visible.

While the technology makes the industrial and medical use of terahertz imaging more feasible than before, it still requires cooling to a low temperature, a major hurdle for practical applications. Many researchers are now working on lasers that will potentially operate at room temperature. The Princeton team said its dual-comb hyperspectral imaging technique will work well with these new room-temperature laser sources, which could then open many more uses.

Because it is non-ionizing, terahertz radiation is safe for patients and could potentially be used as a diagnostic tool for skin cancer. In addition, the technology's ability to image metal could be applied to test airplane wings for damage after being struck by an object in flight.

In addition to Wysocki, the paper's Princeton authors are former visiting graduate student Lukasz Sterczewski (currently a postdoctoral scholar at NASA's Jet Propulsion Laboratory) and associate research scholar Jonas Westberg. Other co-authors are Yang Yang, David Burghoff and Qing Hu of the Massachusetts Institute of Technology; and John Reno of Sandia National Laboratories. Support for the research was provided in part by the Defense Advanced Research Projects Agency and the U.S. Department of Energy.