Culture

Many industrial and agriculture processes use chemicals that can be harmful for workers and the ecosystems where they accumulate. Researchers from Thailand have now developed a bioinspired method to detect and detoxify these chemicals in only one step. As they report in the journal Angewandte Chemie, a combination of two natural enzymatic reactions convert harmful chloro- and nitrophenols into the substance that causes the characteristic glowing of fireflies: luciferin.

Oxygenated benzene or phenol molecules are part of the chemical structure of many organic substances, from lignin and tar, to pharmaceuticals, dyes, and herbicides. Phenol-derived compounds are added to plastics as plasticizers. Although many of these chemicals are not harmful as such, pesticides, herbicides, or flame retardants may degrade to cancerous and stable nitrophenols and halogenated phenols that accumulate in the workplace or in fields.

Phenolic compounds are usually detected with techniques such as mass spectrometry. Biochemist Pimchai Chaiyen at the Vidyasirimedhi Institute of Science and Technology, Thailand, and colleagues, have now developed a more practical approach. They combined an established biodetoxification method with chemical and biochemical conversion schemes to detect and remove contaminants in one step. The key product is witnessed widely on summer nights in gardens and in the countryside: luciferin--the bioluminescent compound produced by fireflies.

Nature has developed several mechanisms to degrade and detoxify chemicals. Bacteria use specialized enzymes to dehalogenate phenols and convert them into oxidized compounds called benzoquinones, which can be metabolized by organisms. Enzymes called dehalogenases or mono-oxygenases have thus been used in industry for biological detoxification.

Chaiyen and colleagues went further than pure detoxification and coupled the enzymatic process with a method to convert the benzoquinone product into luciferin. "The developed chemoenzymatic cascade offers additional value: it provides biodetection technology for nitrophenols and halogenated phenols," they claim. The chemoenzymatic cascade entails conversion of the product from the first enzymatic conversion step, benzoquinone, into luciferin in a second step, but within the same reaction vessel.

To achieve conversion of benzoquinone into luciferin, the authors added the natural compound cysteine to the reaction mixture. They then included a third step in the reaction sequence and detected the luciferin product through the glowing reaction caused by an enzyme called luciferase, which is also present in fireflies. The authors also proved that their detoxification-luciferin production and detection scheme was robust and capable of quantitative conversion of hazardous phenols into luciferin.

Simultaneous detoxification and luciferin production may offer additional benefits. Luciferin is a highly valued compound in biomedicine. The authors point out that their approach is a remarkably straightforward and useful strategy for analysis and detoxification of the workplace in one step, and it can be used to synthesize luciferin from waste chemicals.

NOAA-NASA's Suomi NPP satellite captured this image using NASA's Earth Observing System Data and Information System (EOSDIS) Worldview application on Aug. 08, 2019 and it shows Supertyphoon Lekima heading towards the coast of China as Typhoon Krosa brings up the rear moving slowly towards Japan.

Typhoon Krosa is currently located 167 nautical miles southwest of Iwo To, Japan.  It is slowly tracking northeastward at one knot over the past six hours making it quasi-stationary as it intensified and maintained its 14 nautical mile eye.

Krosa's winds are steady at approximately 100 knots (115 mph) which on the Saffir-Simpson hurricane scale would make this storm just over the Category 3 designation.

Like Lekima, Krosa is able to intensify due to low vertical wind shear and warm sea surface temperatures in the area of 30 degrees C (86 degrees F) both of which are favorable to typhoon development and intensification.

For the time being, Krosa will remain quasi-stationary and continue to intensify for the next 12 hours.  Then the equatorial ridge nearby will steer the storm northeastward. The subtropical ridge will rebuild and steer north-northwestward toward Japan.  Krosa will gradually weaken over the next five days, still maintaining typhoon strength throughout that period.

Bees are in vast decline in the UK and across Europe, as are the wildflowers on which they rely. Bees have an essential role in our ecosystems and a third of all our food is dependent on their pollination; just in economic worth, pollination by bees is annually estimated at £265 billion, worldwide.

The main risks to bees include wide-spread pesticide use in agriculture, parasites, disease and climate change, and crucially - the loss of valuable biodiversity which poses a further threat to bees and other wild pollinators. One way to help boost their numbers is by planting the correct wildflowers, providing a better habitat for pollinators to disperse, nest and breed.

However, it is unclear which plant species are the most preferred between different pollinators, including bees, and how this might change over time and in different environmental conditions. In agriculture, farmers want to know that the pollinators are actually visiting the plants they need them to. Historically, scientists used light microscopy to identify individual bee-collected pollen grains, which was a time-consuming and impractical method.

To obtain a more accurate understanding without the need for laborious manual inspection of pollen, scientists have developed a rapid analysis method called 'Reverse Metagenomics' (RevMet) that can identify the plants that individual bees visit using the MinION, a portable DNA sequencer from Oxford Nanopore Technologies.

The portability of the equipment involved means that this type of analysis could be performed on-site where bees are collected and sampled - vastly increasing our understanding of where bees look for pollen on a national scale.

Ned Peel, the PhD student who carried out the research in the Leggett Group at EI: "Importantly, from a mixed sample of pollen, as well as being able to work out what species of plant bees have visited, we can also measure the relative quantities of each type of pollen. This type of analysis can be applied not only to conserving pollinators but to helping us to sustainably improve crop production that relies on pollinators."

Previous costly and inefficient manual methods to measure pollen and other genomics methods, such as metabarcoding, have been developed - but these can't accurately measure how much of each different type of pollen is found in a sample.

Ned goes on to explain the new genomics method further: "In standard metagenomics, short stretches of DNA from mixed samples are compared to whole genomes, which can be expensive to generate. In collaboration with UEA's School of Biological Sciences, who performed the ecological side of the research - collecting bees and plant samples - we discovered that we could conduct the analysis using 'reference skims' instead.

"To make a skim, we carry out really cheap sequencing that only partially covers the complete genome of the plants, but this is enough when compared with the long reads from the MinION to identify plants. In our work, we generated skims of 49 different wild UK plant species."

This technique can reliably differentiate species in a mixed sample according to the amount of DNA present of each. The results showed that honeybees, and two species of bumblebee, demonstrate a high preference for one plant species per foraging trip."

The reverse metagenomics pipeline can be applied to more questions than just what plants bees like to pollinate; we can also understand whether certain wildflowers compete with agricultural flowers for pollinators, or the behaviour of pollinators across large areas and land types.

The method could also be used to study other mixed samples, such as herbivore dung, for diet analysis; and air, to identify airborne allergenic pollen and crop pathogens.

Archaeologists have uncovered the earliest evidence of high-altitude prehistoric living in the form of a rock shelter in Ethiopia, though whether the site was inhabited permanently is unclear. According to the report - based on archeological, biogeochemical, glacial chronological and other analyses - more than 30,000 years ago, the Fincha Habera rock shelter, a site situated more than 11,000 feet above sea level in the Bale Mountains of Ethiopia, was home to Middle Stone Age foragers who made use of nearby resources and feasted upon plentiful giant mole-rats. Life at high-altitude imposes a number of limitations and stresses on the human body. Because of this, it has long been assumed that the peopling of high-elevation environments - those more than 2,500 meters above sea level (masl) - has only recently occurred in human history. However, from the Andean altiplano to the Tibetan Plateau, a growing number of new archaeological finds in high places across the globe has begun to show otherwise. Still, these sites are rare, and much remains to be discovered about the nature of human high-altitude settlements. Following excavations at Fincha Habera, which the team approached on foot or by pack horse , as well as based on archaeological surveys and paleoenvironmental analyses, Götz Ossendorf and colleagues present results that push back the antiquity of a human presence at high elevation. They report thousands of Middle Stone Age (MSA) artifacts, including locally collected stones, burnt animal bones, and the hearths of former fires. Radiocarbon dates from the site's earliest contexts suggest that occupation began during the Late Pleistocene, sometime between 47,000 and 31,000 years ago. While the environment enabled long-term stays at Fincha Habera repeatedly over several thousand years, the authors say, the permanence of these occupations cannot be proven nor refuted. In a related Perspective, Mark Aldenderfer discusses Ossendorf et al.'s findings in the context of recent high-altitude studies, some of which present conclusions largely unsupported by underlying data. "Words matter, and it's time for archaeologists working on the world's high plateaus to be more deliberate about the terms they use to describe and frame their findings," writes Aldenderfer. To that end, he describes the restraint applied in descriptions in the report by Ossendorf's team as "admirable."

St. Paul, MN (August 2019)--Soilborne pathogens are a major issue worldwide as they can infect a broad range of agricultural plants, resulting in serious crop losses devastating to farmers. These persistent pathogens are often resistant toward chemical fungicides, making them difficult to control, and have a broad host range, enabling them to damage a variety of important crops.

Some of these pathogens have the ability to form survival bodies called sclerotia that can survive for many years in the soil before they cause infection and disease in new plant generations. Other microorganisms often form stable associations with these sclerotia, resulting in a complex system teeming with fungal pathogens and non-pathogenic bacteria.

A team of scientists based in Austria and Germany analyzed the microorganisms within the sclerotia of soilborne fungal pathogens from genera Rhizoctonia and Sclerotinia in attempt to discover effective control methods. In these microorganisms, the team found specific bacterial communities different from both the surrounding soil and the host plants affected by the pathogens.

They extracted samples from these communities and through additional analysis discovered that several of the bacteria can produce volatile compounds (small chemicals that easily disperse) with the potential to reduce the viability of the pathogens. The team also found that specific combinations of these bacteria can even more effectively counteract the pathogens.

This study, published in the completely open access Phytobiomes Journal, introduces a new strategy for identifying antagonistic bacteria, which can then be used to control important plant pathogens. These findings suggest that biological control of pathogens might be improved by combining different beneficial microorganisms and highlight novel strategies used to control widespread phytopathogenic fungi.

Also of note, this study "shows how a multi-phasic approach combining different disciplines (microbiology, molecular biology and analytical chemistry) can be implemented to find new solutions for plant protection," according to co-author Tomislav Cernava.

People in Ethiopia did not live in low valleys during the last ice age. Instead they lived high up in the inhospitable Bale Mountains. There they had enough water, built tools out of obsidian and relied mainly on giant rodents for nourishment. This discovery was made by an international team of researchers led by Martin Luther University Halle-Wittenberg (MLU) in cooperation with the Universities of Cologne, Bern, Marburg, Addis Ababa and Rostock. In the current issue of "Science", the researchers provide the first evidence that our African ancestors had already settled in the mountains during the Palaeolithic period, about 45,000 years ago.

At around 4,000 metres above sea level, the Bale Mountains in southern Ethiopia are a rather inhospitable region. There is a low level of oxygen in the air, temperatures fluctuate sharply, and it rains a lot. "Because of these adverse living conditions, it was previously assumed that humans settled in the Afro-Alpine region only very lately and for short periods of time," says Professor Bruno Glaser, an expert in soil biogeochemistry at MLU. Together with an international team of archaeologists, soil scientists, palaeoecologists, and biologists, he has been able to show that this assumption is incorrect. People had already begun living for long periods of time on the ice-free plateaus of the Bale Mountains about 45,000 years ago during the Middle Pleistocene Epoch. By then the lower valleys were already too dry for survival.

For several years, the research team investigated a rocky outcrop near the settlement of Fincha Habera in the Bale Mountains in southern Ethiopia. During their field campaigns, the scientists found a number of stone artefacts, clay fragments and a glass bead. "We also extracted information from the soil as part of our subproject," says Glaser. Based on the sediment deposits in the soil, the researchers from Halle were able to carry out extensive biomarker and nutrient analyses as well as radiocarbon dating and thus draw conclusions as to how many people lived in the region and when they lived there. For this work, the scientists also developed a new type of palaeothermometer which could be used to roughly track the weather in the region - including temperature, humidity and precipitation. Such analyses can only be done in natural areas with little contamination, otherwise the soil profile will have changed too much by more recent influences. The inhospitable conditions of the Bale Mountains present ideal conditions for such research since the soil has only changed on the surface during the last millennia.

Using this data, the researchers were not only able to show that people have been there for a longer period of time. The analyses may also have uncovered the reasons for this: during the last ice age the settlement of Fincha Habera was located beyond the edge of the glaciers. According to Glaser, there was a sufficient amount of water available since the glaciers melted in phases. The researchers are even able to say what people ate: giant mole rats, endemic rodents in the region the researchers investigated. These were easy to hunt and provided enough meat, thereby providing the energy required to survive in the rough terrain. Humans probably also settled in the area because there was deposit of volcanic obsidian rock nearby from which they could mine obsidian and make tools out of it. "The settlement was therefore not only comparatively habitable, but also practical," concludes Glaser.

The soil samples also reveal a further detail about the history of the settlement. Starting around 10,000 years before the Common Era, the location was populated by humans for a second time. At this time, the site was increasingly used as a hearth. And: "For the first time, the soil layer dating from this period also contains the excrement of grazing animals," says Glaser.

According to the research team, the new study in "Science" not only provides new insights into the history of human settlement in Africa, it also imparts important information about the human potential to adapt physically, genetically and culturally to changing environmental conditions. For example, some groups of people living in the Ethiopian mountains today can easily contend with low levels of oxygen in the air.

Extreme wildfires in British Columbia, Canada, pumped so much smoke into the upper atmosphere in August 2017 that an enormous cloud circled most of the Northern Hemisphere - a finding in the journal Science that will help scientists model the climate impacts of nuclear war.

The pyrocumulonimbus (pyroCb) cloud - the largest of its kind ever observed - was quickly dubbed "the mother of all pyroCbs." When the smoke reached the lower stratosphere, it was heated by sunlight and "self-lofted" from 7 to 14 miles up within two months. The pivotal ingredient was black carbon (soot), which absorbed solar radiation, heating the air and fueling the smoke's rapid rise. The smoke lasted more than eight months because the stratosphere has no rain to wash it out.

"This process of injecting soot into the stratosphere and seeing it extend its lifetime by self-lofting, was previously modeled as a consequence of nuclear winter in the case of an all-out war between the United States and Russia, in which smoke from burning cities would change the global climate," said co-author Alan Robock, a distinguished professor in the Department of Environmental Sciences at Rutgers University-New Brunswick.

"Even a relatively small nuclear war between India and Pakistan could cause climate change unprecedented in recorded human history and global food crises," said Robock, who works in the School of Environmental and Biological Sciences.

The scientists used a state-of-the art climate model from the National Center for Atmospheric Research to model the lofting and movement of the colossal Canadian wildfire smoke cloud. The modeling considered smoke characteristics such as the ratio of soot to other ingredients and the rate at which ozone in the upper atmosphere broke down the smoke.

The smoke cloud contained only about 0.3 million tons of soot, while a nuclear war between India and Pakistan could produce 15 million tons and a U.S. vs. Russia war could generate 150 million tons. Still, the scientists validated their previous theories and the climate model they're using for ongoing research on nuclear war impacts by studying the wildfire, according to Robock.

The observed rapid rise of the smoke plume, its spread and photochemical reactions in the ozone layer provide new insights into the potential global climate impacts from nuclear war, the study says.

The next steps, as part of a Rutgers nuclear conflict climate modeling project, are to use refined nuclear war scenarios to determine the potential impact on the climate and food production on land and in the ocean, along with the potential for global famine. What the scientists learned from the wildfire modeling will make their new work more accurate and credible.

AURORA, Colo. (Aug. 8, 2019) - Researchers at the University of Colorado Anschutz Medical Campus have found that intense light amplifies a specific gene that bolsters blood vessels and offers protection against heart attacks.

"We already knew that intense light can protect against heart attacks, but now we have found the mechanism behind it," said the study's senior author Tobias Eckle, MD, PhD, professor of anesthesiology at the University of Colorado School of Medicine.

The study was published recently in the journal Cell Reports.

The scientists discovered that housing mice under intense light conditions for one week `robustly enhances cardio protection', which resulted in a dramatic reduction of cardiac tissue damage after a heart attack. They also found that humans could potentially benefit from a similar light exposure strategy.

In an effort to find out why, they developed a strategy to protect the heart using intense light to target and manipulate the function of the PER2 gene which is expressed in a circadian pattern in the part of the brain that controls circadian rhythms.

By amplifying this gene through light, they found that it protected cardiovascular tissues against low oxygen conditions like myocardial ischemia, caused by reduced oxygen flow to the heart.

They also discovered that the light increased cardiac adenosine, a chemical that plays a role in blood flow regulation.

Mice that were blind, however, enjoyed no cardio protection indicating a need for visual light perception.

Next, they investigated whether intense light had similar effects on healthy human volunteers. The subjects were exposed to 30 minutes of intense light measured in lumens. In this case, volunteers were exposed to 10,000 LUX, or lumens, on five consecutive days. Researchers also did serial blood draws.

The light therapy increased PER2 levels as it did in mice. Plasma triglycerides, a surrogate for insulin sensitivity and carbohydrate metabolism, significantly decreased. Overall, the therapy improved metabolism.

Eckle has long known that light plays a critical role in cardiovascular health and regulating biological processes. He pointed out that past studies have shown an increase in myocardial infarctions during darker winter months in all U.S. states, including sunnier places like Arizona, Hawaii and California. The duration of the light isn't as important as the intensity, he said.

"The most dramatic event in the history of earth was the arrival of sunlight," Eckle said. "Sunlight caused the great oxygen event. With sunlight, trillions of algae could now make oxygen, transforming the entire planet."

Eckle said the study shows, on a molecular level, that intensive light therapy offers a promising strategy in treating or preventing low oxygen conditions like myocardial ischemia.

He said if the therapy is given before high risk cardiac and non-cardiac surgery it could offer protection against injury to the heart muscle which can be fatal.

"Giving patients light therapy for a week before surgery could increase cardio protection," he said. "Drugs could also be developed that offer similar protections based on these findings. However, future studies in humans will be necessary to understand the impact of intense light therapy and its potential for cardio protection."

Researchers at North Carolina State University have shown that "sticky" hairlike structures on tobacco leaves can help attract beneficial insects that scavenge on other insects trapped on the leaves, increasing leaf yield and reducing pest damage to plant structures.

In a study examining pests of tobacco plants and opportunistic insects that eat the pests, researchers show that sticky glandular trichomes on tobacco leaves trap insects that aren't adapted to interacting with perilous plant surfaces. The trapped insects perish and then become food for the spined stilt bug (Jalysus wickhami) - a small but long-legged insect predator that has a beneficial relationship with tobacco plants.

Tobacco plants provide a trapped-insect buffet that spined stilt bugs are more than happy to feast upon, which helps protect the plant from pest infestation and damage. Better still, the spined stilt bug - which uses its long legs as leverage to navigate across the sticky parts of tobacco leaves to reach its bug banquet - isn't harmful to tobacco plants, researchers say, although it drinks some sap from tobacco plants to stay hydrated between pest meals.

"A sticky plant isn't a dead end for all insects; some actually prefer sticky plants and take advantage of the difficult plant surface," said Peter Nelson, an NC State Ph.D. graduate and lead author of a paper describing the study.

"By taking a closer look at how insects interact with plants, we might be able to take advantage of unique interactions for pest management," Nelson added. "Our review of the literature found that over 25 economically important plants have sticky surfaces that trap insects and might benefit from the same type of interaction with predatory arthropods."

"This is a mutualistic relationship previously unrecognized on domesticated tobacco plants," said Clyde Sorenson, Alumni Association Distinguished Undergraduate Professor of Entomology at NC State and corresponding author of the paper. "The academic literature shows a number of wild flowers with similar symbiotic relationships with predators to reduce damage to the plant, but tobacco is the first economically important plant to show this mutualistic relationship."

In the study, the abundance of spined stilt bugs grew when researchers added dead fruit flies (Drosophila melanogaster) to the leaves of tobacco plants in greenhouse and field settings. Increased leaf yield - the primary economic consideration for tobacco farmers - and less damage to tobacco plant structures resulted when additional fruit flies were added to leaves.

The study also showed that insecticide use did not affect pest entrapment by sticky glandular trichomes. Plants treated with imidacloprid, a common tobacco insecticide, had fewer spined stilt bugs than untreated plants, but that did not significantly affect pest densities or plant health.

Surprisingly, the study showed that densities of pests like the tobacco budworm on tobacco leaves did not decrease, even though more spined stilt bugs were present.

"We're not completely sure about why this counterintuitive finding occurred, although one hypothesis is that the increased number of predator stilt bugs may trigger a behavioral response in the tobacco budworm and other pests to feed less on tobacco plants," Sorenson said.

Sorenson said the results could lead to further improvement or manipulation of glandular trichomes.

"We don't expect farmers to throw dead fruit flies on 40 acres of a tobacco crop, but recognizing the effects of beneficial insects and how these mutually beneficial relationships work is important," he said. "Plus, these types of effects may occur in other economically important crops with glandular trichomes, like tomatoes."

A team of environmental scientists from the University of Massachusetts Amherst and China has for the first time used a dynamic, two-step process to completely degrade a common flame-retardant chemical, rendering the persistent global pollutant nontoxic.

This new process breaks down tetrabromobisphenol A (TBBPA) to harmless carbon dioxide and water. The discovery highlights the potential of using a special material, sulfidated nanoscale zerovalent iron (S-nZVI), in water treatment systems and in the natural environment to break down not only TBBPA but other organic refractory compounds that are difficult to degrade, says Jun Wu, a visiting Ph.D. student at UMass Amherst's Stockbridge College of Agriculture and lead author of the paper published in Environmental Science & Technology.

"This is the first research about this dynamic, oxic/anoxic process," Wu says. "Usually, reduction or oxidation alone is used to remove TBBPA, facilitated by S-nZVI. We combined reduction and oxidation together to degrade it completely."

Wu emphasizes that "the technique is technically simple and environmentally friendly. That is a key point to its application."

The research is featured on the cover of ES&T, which is widely respected for publishing papers in the environmental disciplines that are both significant and original.

"This research can lead to a decrease in the potential risk of TBBPA to the environment and human health," says Wu, who began the research at the University of Science and Technology of China in Hefei. At UMass Amherst, Wu works in the pioneering lab of Baoshan Xing, professor of environmental and soil chemistry, corresponding author of the new study and one of the world's most highly cited researchers.

"Our research shows a feasible and environmentally friendly process to completely degrade refractory brominated ?ame retardants in a combined oxic and anoxic system," Xing says. "This is important for getting rid of these harmful compounds from the environment, thus reducing the exposure and risk."

Among the most common flame retardants that hinder combustion and slow the spread of fire, TBBPA is added to manufactured materials, including computer circuit boards and other electrical devices, papers, textiles and plastics.

Associated with a variety of health concerns, including cancer and hormone disruption, TBBPA has been widely detected in the environment, as well as in animals and human milk and plasma.

Although Wu and Xing's research breaks new ground in the efforts to develop safe and effective processes to remediate groundwater and soil contaminated with TBBPA, they say more research is needed to learn how to best apply the process.

Their research was supported by grants from the National Natural Science Foundation of China and the USDA-National Institute of Food and Agriculture's Hatch Program.

CATONSVILLE, MD, August 8, 2019 - More than a trillion dollars was spent on healthcare in the United States in 2018, with Medicare and Medicaid accounting for some 37% of those expenditures. With healthcare costs expected to continue to rise by roughly 5% per year, a continued debate in healthcare policy is how to reduce costs without compromising quality.

As part of this effort, the Medicare Shared Savings Program was created to control escalating Medicare spending by giving healthcare providers incentives to deliver more efficient healthcare.

New research published in the INFORMS journal Operations Research offers a new approach that could substantially change the healthcare spending paradigm by utilizing performance-based incentives to drive down spending.

The researchers Anil Aswani and Zuo-Jun (Max) Shen of the University of California, Berkeley, and Auyon Siddiq of the University of California, Los Angeles found that redesigning the contract for the shared savings program to better align provider incentives with performance-based subsidies can both increase Medicare savings and increase providers' reimbursement payments.

"Introducing performance-based subsidies can boost Medicare savings by up to 40% without compromising provider participation in the shared savings program," said Aswani, a professor in the Industrial Engineering and Operations Research Department at UC Berkeley. "This contract can lead to improved outcomes for both Medicare and participating providers," he continued.

It is well known that tobacco, alcohol, and cannabis use during pregnancy are associated with poor birth outcomes, yet many women continue to use these substances during pregnancy.

Researchers at Western University and its affiliate Brescia University College have now shown that depression is the single largest driver of substance use during pregnancy, highlighting the need for greater supports for the mental health of pregnant mothers.

The research team analyzed health and geographical data gathered through Lawson Health Research Institute from more than 25,000 pregnant women in Southwestern Ontario.

"Pregnant women who were depressed were 2.6 times more likely to use cannabis and twice as likely to smoke cigarettes and use alcohol while pregnant," said Jamie Seabrook, PhD, and Associate Professor at Brescia and Western's Schulich School of Medicine & Dentistry, and Scientist at Children's Health Research Institute, a Lawson program. "We don't know when the substance use first began but we do know that it was continuing during pregnancy and that is a big risk factor for poor maternal and infant health outcomes."

The study, published in the Journal of Neonatal-Perinatal Medicine, is the first Canadian study with a sample size this large to show that depression during pregnancy is the primary risk factor for cannabis, tobacco and alcohol use, and is more important than education, income, or age.

"This really highlights the importance of programming for mental health, including mental health promotion strategies, psychotherapy and safe and proper medication for mental health during pregnancy," said Rachel Brown, an MSc candidate and first author on the paper. "The research shows that there is an effect later on in life as well with infants that are born preterm or low birth weight. To intervene or advocate for mental health programs for the mom, the idea is that it sets up the health of the infants later on in life."

The research team points out that this research is especially important in Canada with the recent legalization of recreational cannabis.

"Let's help women with their mental health to improve their overall health and in doing so, improve the health of their baby," said Seabrook.

Firearm retailers around Washington state are willing to learn about suicide prevention and to train their employees in how to spot and act on suicide warning signs, a new University of Washington study finds.

With firearms the commonly used and most lethal means of suicide nationwide, the findings from the survey of nearly 200 independent firearm retailers across the state demonstrate the potential for key community members to be proactive in helping to prevent people from taking their own lives, said Thomas Walton, a UW doctoral candidate of social work at Forefront Suicide Prevention and lead author of the paper.

The study, believed to be first to look at what influences firearm retailers in suicide prevention efforts, also finds that a lack of awareness of the role of firearms in suicide, as well as a reluctance to talk to customers about personal issues, likely inhibit greater progress in suicide prevention.

"Suicide prevention hasn't been an area of focus in the firearm community, and it shows," Walton said. "But there's a definite willingness to pass on firearm safety information, and they want to be able to see how to integrate suicide prevention into talking about firearm safety."

The study was published online July 29 in the journal Suicide and Life-Threatening Behavior.

According to the Centers for Disease Control and Prevention, about half of all suicides in the United States from 1999 to 2017 (the most recent statistics available) involved a firearm. The percentage is even higher in veteran suicides.

In Washington, the data is similar: From 2013 to 2017, almost half of all suicides, and 67% of veteran suicides, involved a firearm, according to the state Department of Health. Beginning in 2017, the state Legislature helped fund Forefront's Safer Homes, Suicide Aware campaign, which offers training, outreach and locking devices for firearms and medications in communities with high rates of firearms ownership.

As part of its mission, the Safer Homes program has identified gun retailers as a key potential stakeholder in distributing information about suicide prevention. Other states, such as New Hampshire and Colorado have been working to engage firearm retailers in the issue; the UW study is the first aimed at understanding what influences such engagement.

The first step for UW researchers was surveying firearm retailers about their knowledge of suicide prevention and willingness to participate. Using records from the state Department of Licensing and the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, Walton and Forefront director Jennifer Stuber were able to find email or mailing addresses for nearly 800 independent retailers around the state. The team created a 42-question survey that was available in print or online.

Big-box stores that sell guns were not included because of corporate policies governing store-level training and outreach.

The researchers also partnered with the Second Amendment Foundation and the owner of a Spokane gun shop, who together sent an introductory letter to the retailers explaining the survey.

In the end, 178 surveys were completed. Sixteen retailers contacted the researchers to refuse the survey, while 62 were minimally completed, and 33 were returned as undeliverable. The remaining 500 weren't returned.

"There are barriers to working with this population because of distrust and incomplete contact information," said Stuber, an associate professor in the UW School of Social Work. "But if you get the right messengers to get people to the table, there is clearly a willingness among retailers to be involved in the solutions."

The results can be grouped generally into three distinct types of questions: knowledge of suicide and how to prevent it; support for learning more; and a willingness to intervene directly with customers.

About half of the retailers who responded said they were familiar with warning signs of suicide, while nearly two-thirds of respondents said they wanted to know more about how firearm retailers can help prevent suicide. About 72% said they would provide free training to employees.

At the other end of the spectrum were beliefs about suicide and the retailer's role in talking with customers in crisis. Nearly three-quarters said asking customers about their mental health might offend them. About 45% said asking about personal issues is not their responsibility, and 66% agreed with the statement: "If a person wants to die by suicide, there is nothing I can do to stop them."

"It is critical to work on changing this common misperception that suicide is inevitable," Walton said. "For the vast majority of individuals, the desire to die by suicide is fleeting, so anything any of us can do to prevent or postpone a suicidal act is helping to save a life."

Survey results also indicated that the more a retailer knows about suicide, and the longer they have been in business, the more comfortable they are with ideas about training employees and talking with customers. For instance, retailers for whom a majority of sales come from firearms and ammunition were more likely to support education and outreach around suicide prevention. Those with longer tenure in the industry, the authors wrote, were also more supportive of suicide prevention efforts and thus could be tapped as leaders in any future effort among retailers.

"Notably, most firearm retailers lack awareness that suicide is the most common type of firearm fatality. Education about this fact is an important first step to increasing engagement in prevention efforts," Stuber said. "We are going to need out-of-the-box solutions to reach communities with high rates of firearm ownership to create compelling public health messages about suicide prevention."

What The Study Did: Giant cell arteritis is an inflammation of the blood vessels that typically occurs in adults over 50 and, if left untreated, can result in irreversible vision loss and death. This study examined whether occurrence of the disorder was associated with race.

Authors: Anna M. Gruener, B.M.B.S., M.Sc., F.R.C.Ophth, of the Nottingham University Hospitals National Health Service Trust in the United Kingdom, is the corresponding author.

(doi:10.1001/jamaophthalmol.2019.2919)

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

Identifying species among plants and animals has been a full-time occupation for some biologists, but the task is even more daunting for the myriad microbes that inhabit the planet. Now, MIT researchers have developed a simple measurement of gene flow that can define ecologically important populations among bacteria and archaea, including pinpointing populations associated with human diseases.

The gene flow metric separates co-existing microbes in genetically and ecologically distinct populations, Martin Polz, a professor of civil and environmental engineering at MIT, and colleagues write in the August 8 issue of Cell.

Polz and his colleagues also developed a method to identify parts of the genome in these populations that show different adaptations that can be mapped onto different environments. When they tested their approach on a gut bacterium, for instance, they were able to determine that different populations of the bacteria were associated with healthy individuals and patients with Crohn's disease.

Biologists often call a group of plants or animals a species if the group is reproductively isolated from others -- that is, individuals in the group can reproduce with each other, but they can't reproduce with others. As a result, members of a species share a set of genes that differs from other species. Much of evolutionary theory centers on species and populations, the representatives of a species in a particular area.

But microbes "defy the classic species concept for plants and animals," Polz explains. Microbes tend to reproduce asexually, simply splitting themselves in two rather than combining their genes with other individuals to produce offspring. Microbes are also notorious for "taking up DNA from environmental sources, such as viruses," he says. "Viruses can transfer DNA into microbial cells and that DNA can be incorporated into their genomes."

These processes make it difficult to sort coexisting microbes into distinct populations based on their genetic makeup. "If we can't identify those populations in microbes, we can't one-to-one apply all this rich ecological and evolutionary theory that has been developed for plants and animals to microbes," says Polz.

If researchers want to measure an ecosystem's resilience in the face of environmental change, for instance, they might look at how populations within species change over time. "If we don't know what a species is, it's very difficult to measure and assess these types of perturbations," he adds.

A yardstick for gene flow

Martin and his colleagues decided to look for another way to define ecologically meaningful populations in microbes. Led by microbiology graduate student Philip Arevalo, the researchers developed a metric of gene flow that they called PopCOGenT (Populations as Clusters Of Gene Transfer).

PopCOGenT measures recent gene flow or gene transfer between closely related genomes. In general, microbial genomes that have exchanged DNA recently should share longer and more frequent stretches of identical DNA than if individuals were just reproducing by splitting their DNA in two. Without this sort of recent exchange, the researchers suggested, the length of these shared stretches of identical DNA would shorten as mutations insert new "letters" into the stretch.

Two microbial strains that are not genetically identical to each other but share sizable "chunks" of identical DNA are probably exchanging more genetic material with each other than with other strains. This gene flow measurement can define distinct microbial populations, as the researchers discovered in their tests of three different kinds of bacteria.

In Vibrio bacteria, for instance, closely related populations may share some core gene sequences, but they appear completely isolated from each other when viewed through this measurement of recent gene flow, Polz and colleagues found.

Polz says that the PopCOGenT method may work better at defining microbial populations than previous studies because it focuses on recent gene flow among closely related organisms, rather than including gene flow events that may have happened thousands of years in the past.

The method also suggests that while microbes are constantly taking in different DNA from their environment that might obscure patterns of gene flow, "it may be that this divergent DNA is really removed by selection from populations very quickly," says Polz.

The reverse ecology approach

Microbiology graduate student David VanInsberghe then suggested a "reverse ecology" approach that could identify regions of the genome in these newly defined populations that show "selective sweeps" -- places where DNA variation is reduced or eliminated, likely as a result of strong natural selection for a particular beneficial genetic variant.

By identifying specific sweeps within populations, and mapping the distribution of these populations, the method can reveal possible adaptations that drive microbes to inhabit a particular environment or host -- without any prior knowledge of their environment. When the researchers tested this approach in the gut bacterium Ruminococcus gnavus, they uncovered separate populations of the microbe associated with healthy people and patients with Crohn's disease.

Polz says the reverse ecology method is likely to be applied in the near future to studying the full diversity of the bacteria that inhabit the human body. "There is a lot of interest in sequencing closely related organisms within the human microbiome and looking for health and disease associations, and the datasets are growing."

He hopes to use the approach to examine the "flexible genome" of microbes. Strains of E. coli bacteria, for instance, share about 40 percent of their genes in a "core genome," while the other 60 percent -- the flexible part -- varies between strains. "For me, it's one of the biggest questions in microbiology: Why are these genomes so diverse in gene content?" Polz explains. "Once we can define populations as evolutionary units, we can interpret gene frequencies in these populations in light of evolutionary processes."

Polz and colleagues' findings could increase estimates of microbe diversity, says Marx. "What I think is really cool about this approach from Martin's group is that they actually suggest that the complexity that we see is even more complex than we're giving it credit for. There may be even more types that are ecologically important out there, things that if they were plants and animals we would be calling them species."