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LAWRENCE, KANSAS -- In a new study, Monarch Watch Director Chip Taylor and colleagues have shown that speculation regarding the declining monarch population, despite having received much attention, is unsupported.

Published Aug. 7 in the journal Frontiers in Ecology and Evolution, the researchers show that the decline in the monarchs' overwintering numbers is not due to an increase in the deaths of monarchs during the migration -- the "migration mortality hypothesis." The main determinant of yearly variation in overwintering population size, they found, is the size of the summer population.

Taylor, a University of Kansas professor emeritus of ecology & evolutionary biology, said the monarch butterfly populations have been declining for most of the last two decades. The numbers of monarchs measured at the monarch overwintering sites in Mexico in the winter of 2013-2014 were an all-time low.

The progressive decline in prior years, and these low numbers, led to the submission of a petition to the Department of the Interior to have the monarch declared a threatened species. These concerns also increased the search for an explanation for the decline.

The prevailing view was that the decline was due to habitat loss that followed increased use of glyphosate herbicide on corn and soybean fields in the Upper Midwest -- the "milkweed limitation hypothesis."

However, that view was challenged by a number of researchers who maintained that the decline was likely due to increasingly high levels of mortality during the butterflies' migration. This became known as the migration mortality hypothesis.

Taylor said the migration mortality hypothesis, though unsupported by data, has received substantial coverage in Science and Scientific American.

"Monarch Watch has been collecting recovery data for tagged monarchs since 1992, and we knew that those advocating the migration mortality hypothesis were on the wrong track from the outset and told them so," he said.

In this recently published study, Taylor and co-authors summarized the results of tagging almost 1.4 million monarchs that resulted in nearly 14,000 recoveries of tagged butterflies in Mexico.

"Showing the migration mortality hypothesis advocates their assumptions were wrong took awhile since that required a significant effort to vet our monarch tagging database for accuracy and to analyze the data," Taylor said. "Dealing with 1.4 million records is no simple task."

In contrast to the predictions of the migration mortality advocates, the tagging recoveries -- a measure of migration success -- did not decrease over time, the researchers found.

In addition, the number tagged each year was correlated with the size of the overwintering population in Mexico, consistent with the milkweed limitation hypothesis. The tagging also confirmed that the majority of monarchs reaching the overwintering sites originated from the Upper Midwest.

These findings support the conclusion reached by a team of experts that sustaining the monarch migration will require the restoration of over a billion milkweed stems in the Upper Midwest in the coming years.

Researchers at Harvard Medical School, Massachusetts Institute of Technology and Northwestern University have identified a subtype of autism arising from a cluster of genes that regulate cholesterol metabolism and brain development.

The researchers say their findings, published Aug. 10 in Nature Medicine, can inform both the design of precision-targeted therapies for this specific form of autism and enhance screening efforts to diagnose autism earlier.

The team identified the shared molecular roots between lipid dysfunction and autism through DNA analysis of brain samples--findings that they then confirmed by examining medical records of individuals with autism. Indeed, both children with autism and their parents had pronounced alterations in lipid blood, the analysis showed.

The results of the study, the researchers said, raise many questions; key among them are: Just how do lipid alterations drive neurodevelopmental dysfunction and could normalizing lipid metabolism affect disease outcomes?

The new findings set the stage for future studies to answer these questions and others.

"Our results are a striking illustration of the complexity of autism and the fact that autism encompasses many different conditions that each arise from different causes--genetic, environmental or both," said study senior investigator Isaac Kohane, chair of the Department of Biomedical Informatics in the Blavatnik Institute at Harvard Medical School. "Identifying the roots of dysfunction in each subtype is critical to designing both treatments and screening tools for correct and timely diagnosis--that is the essence of precision medicine."
A Google map of autism
Autism and autism-spectrum disorders, estimated to affect one in 54 children in the United States, are among the most complex heritable conditions. Thousands of gene variants, both rare and common, have been implicated in autism, likely through an intricate and not-well understood interplay between genetic and environmental factors--both before and after birth.

The new study findings not only underscore this complexity but also demonstrate the critical importance of defining the various subtypes of the condition and developing treatments that target subtype-specific anomalies.

Achieving a meaningful level of specificity in the study of a vastly complex disorder such as autism, however, is not easy. To do so, the researchers used a novel approach based on the interlacing of multiple layers of data, including whole exome sequencing, patterns of protein expression, medical records and health insurance claims.

"Think of a Google map and how it overlays various types of information on top of one another--cities, streets, parcels, land use, electrical grids, elevations--for a more detailed representation," said Yuan Luo, who co-led the study with Alal Eran, a Harvard Medical School lecturer on pediatrics at Boston Children's Hospital.

"This is what we did with our data to get a complete view of genes that have multiple regulatory functions and are implicated in autism," said Luo, who started working on the research while at MIT's Computer Science & Artificial Intelligence Lab and continued the work at Northwestern University, where he is now associate professor of preventive medicine at the Feinberg School of Medicine.

The team started out by analyzing patterns of gene expression from brain samples contained in two large national brain banks, focusing on genes that work in tandem during prenatal and postnatal brain development. Because autism is four times more common in males than females, they further focused on genes that had the largest male-to-female differences during development. Within those, they homed in on exons--the protein-coding parts of genes--to seek out mutations that occurred more often in patients with autism. Through this progressive zooming in, the researchers identified a previously unrecognize node of shared function--a cluster of exons regulating both neurodevelopment and fat metabolism.

Protein to person

To confirm whether the molecular link between autism and lipid metabolism was borne out in actual patients, the team turned to two vast clinical record repositories. In one that contained more than 2.7 million records of patients seen at Boston Children's, including more than 25, o00 children with autism, the researchers identified notable lipid alterations in children with autism, including changes in levels of their bad cholesterol (LDL), good cholesterol (HDL) and triglycerides.

The other dataset contained medical records of more than 34 million individuals seen at multiple U.S. medical institutions. Of those, more than 80,700 individuals had diagnoses of autism. Overall, 6.5 percent of those who had an autism diagnosis also had abnormal lipid levels. Individuals with autism were nearly twice as likely to have abnormal lipid tests results as those without autism. There was also a pronounced familial link. Mothers with lipid abnormalities were 16 percent more likely to have a child with autism than mothers without lipid abnormalities. The risk for having a child with autism among fathers with lipid abnormalities was 13 percent greater than in males with normal lipid levels. And within families with more than one child, children diagnosed with autism were 76 percent more likely to have abnormal lipid profiles than their siblings.

Among individuals with autism and abnormal lipid levels on their blood work, conditions such as epilepsy, sleep disorders and attention deficit hyperactivity disorder were markedly more common than among those without elevated lipid levels--a finding that suggests dyslipidemia may alter neurodevelopment in general, the researchers said. Individuals with autism and dyslipidemia were also more likely to have certain hormonal and metabolic conditions including anemia, hypothyroidism and vitamin D deficiency.

The autism-dyslipidemia link persisted even when the researchers accounted for the possible influence of drugs commonly used in people with autism, some of which are known to affect lipid levels. In fact, lipid abnormalities were more common among people with autism who were not taking such medications.

The newly found link offers a molecular explanation to the well-established observation that a mutation in a gene involved in cholesterol metabolism is also found in people with Rett syndrome, a neurodevelopmental disorder closely related to autism. Another striking observation that may be explained by the newly found link is that between 50 and 88 percent of children born with Smith-Lemli-Opitz syndrome, caused by a defect in cholesterol synthesis, also have autism.

The researchers say their approach--based on integrating multiple data modalities-- could be adapted to other similarly genetically complex conditions as a way to precision-profile subtypes of disease.

For example, the ability to identify disease subtypes in cancer in the past two decades has propelled the field of oncology forward and led to the development of many targeted cancer treatments, researchers said.

"Our findings can help design precision-targeted treatments that home in on the specific defect underlying the development of dyslipidemia-related autism," Kohane said. "Conceptually, this is the same framework that we can apply in complex inherited neurodevelopmental disorders like autism and beyond. Our multimodal approach combining multiple types of data demonstrates that this is not only possible but imminent."

WASHINGTON, Aug. 17, 2020 -- Milk chocolate is a consumer favorite worldwide, prized for its sweet flavor and creamy texture. This confection can be found in all types of treats, but it isn't exactly health food. In contrast, dark chocolate has high levels of phenolic compounds, which can provide antioxidant health benefits, but it is also a harder, more bitter chocolate. Today, researchers report a new way to combine milk chocolate with waste peanut skins and other wastes to boost its antioxidant properties.

The researchers will present their results today at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo. ACS is holding the meeting through Thursday. It features more than 6,000 presentations on a wide range of science topics.

"The idea for this project began with testing different types of agricultural waste for bioactivity, particularly peanut skins," says Lisa Dean, Ph.D., the project's principal investigator. "Our initial goal was to extract phenolics from the skins and find a way to mix them with food."

When manufacturers roast and process peanuts to make peanut butter, candy and other products, they toss aside the papery red skins that encase the legume inside its shell. Thousands of tons of peanut skins are discarded each year, but since they contain 15% phenolic compounds by weight, they're a potential goldmine of antioxidant bioactivity. Not only do antioxidants provide anti-inflammatory health benefits, they also help keep food products from spoiling.

"Phenolics are very bitter, so we had to find some way to mitigate that sensation," Dean says. In fact, the natural presence of phenolic compounds is what gives dark chocolate its bitterness, along with less fat and sugar compared to its cousin milk chocolate. Dark varieties are also more expensive than milk ones because of their higher cocoa content, so the addition of a waste like peanut skins provides similar benefits for a fraction of the price. And peanut skins are not the only food waste that can enhance milk chocolate in this way; the researchers are also exploring the extraction and incorporation of phenolic compounds from used coffee grounds, discarded tea leaves and other food scraps.

To create their antioxidant-boosted milk chocolate, Dean and her team of researchers at the U.S. Department of Agriculture's (USDA's) Agricultural Research Service worked with peanut companies to obtain the peanut skins. From there, they ground the skins into a powder, and extracted the phenolic compounds with 70% ethanol. The lignin and cellulose left behind can be used in animal feed as roughage. They also worked with local coffee roasters and tea producers to obtain used coffee grounds and tea leaves, using a similar methodology to extract the antioxidants from those materials. The phenolic powder is then combined with maltodextrin, a common food additive, to make it easier to incorporate into the final milk chocolate product.

To make sure their new confection would pass gastronomic muster, the researchers created individual squares of chocolate with concentrations of phenolics ranging from 0.1% to 8.1% and had a trained sensory panel taste each one. The goal was to have the phenolic powder be undetectable in the flavor of the milk chocolate. The taste-testers found that concentrations over 0.9% were detectable, but incorporating the phenolics at 0.8% resulted in a good compromise of a high level of bioactivity without sacrificing flavor or texture. In fact, more than half of the taste testers preferred the 0.8% phenolic milk chocolate over the undosed control milk chocolate. This sample had higher chemical antioxidant activity than most dark chocolates.

While these results are very promising, Dean and team also acknowledge that peanuts are a major food allergy concern. They tested the phenolic powder made from the skins for presence of allergens, and while none were detected, they say that a product containing peanut skins should still be labeled as containing peanuts.

Next, the researchers plan to further explore the use of peanut skins, coffee grounds and other waste products into additional foods. In particular, Dean is hoping to test whether the antioxidants in peanut skins extend the shelf life of nut butters, which can go rancid quickly because of their high fat content. While commercial availability of their boosted chocolate is still a ways off and subject to corporate patents, they hope that their efforts will eventually lead to a better milk chocolate on supermarket shelves.

WASHINGTON, Aug. 17, 2020 -- Like electronic devices, biological cells send and receive messages, but they communicate through very different mechanisms. Now, scientists report progress on tiny communication networks that overcome this language barrier, allowing electronics to eavesdrop on cells and alter their behavior -- and vice versa. These systems could enable applications including a wearable device that could diagnose and treat a bacterial infection or a capsule that could be swallowed to track blood sugar and make insulin when needed.

The researchers will present their results today at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo. ACS is holding the meeting through Thursday. It features more than 6,000 presentations on a wide range of science topics.

"We want to expand electronic information processing to include biology," says principal investigator William E. Bentley, Ph.D. "Our goal is to incorporate biological cells in the computational decision-making process."

The new technology Bentley's team developed relies on redox mediators, which move electrons around cells. These small molecules carry out cellular activities by accepting or giving up electrons through reduction or oxidation reactions. Because they can also exchange electrons with electrodes, thereby producing a current, redox mediators can bridge the gap between hardware and living tissue. In ongoing work, the team, which includes co-principal investigator Gregory F. Payne, Ph.D., is developing interfaces to enable this information exchange, opening the way for electronic control of cellular behavior, as well as cellular feedback that could operate electronics.

"In one project that we are reporting on at the meeting, we engineered cells to receive electronically generated information and transmit it as molecular cues," says Eric VanArsdale, a graduate student in Bentley's lab at the University of Maryland, who is presenting the latest results at the meeting. The cells were designed to detect and respond to hydrogen peroxide. When placed near a charged electrode that generated this redox mediator, the cells produced a corresponding amount of a quorum sensing molecule that bacteria use to signal to each other and modulate behavior by altering gene expression.

In another recent project, the team engineered two types of cells to receive molecular information from the pathogenic bacteria Pseudomonas aeruginosa and convert it into an electronic signal for diagnostic and other applications. One group of cells produced the amino acid tyrosine, and another group made tyrosinase, which converts tyrosine into a molecule called L-DOPA. The cells were engineered so this redox mediator would be produced only if the bacteria released both a quorum sensing molecule and a toxin associated with a virulent stage of P. aeruginosa growth. The size of the resulting current generated by L-DOPA indicated the amount of bacteria and toxin present in a sample. If used in a blood test, the technique could reveal an infection and also gauge its severity. Because this information would be in electronic form, it could be wirelessly transmitted to a doctor's office and a patient's cell phone to inform them about the infection, Bentley says. "Ultimately, we could engineer it so that a wearable device would be triggered to give the patient a therapeutic after an infection is detected."

The researchers envision eventually integrating the communication networks into autonomous systems in the body. For instance, a diabetes patient could swallow a capsule containing cells that monitor blood sugar. The device would store this blood sugar data and periodically send it to a cell phone, which would interpret the data and send back an electronic signal directing other cells in the capsule to make insulin as needed. As a step toward this goal, VanArsdale developed a biological analog of computer memory that uses the natural pigment melanin to store information and direct cellular signaling.

In other work, Bentley's team and collaborators including Reza Ghodssi, Ph.D., recently designed a system to monitor conditions inside industrial bioreactors that hold thousands of gallons of cell culture for drug production. Currently, manufacturers track oxygen levels, which are vital to cells' productivity, with a single probe in the side of each vessel. That probe can't confirm conditions are uniform everywhere in the bioreactor, so the researchers developed "smart marbles" that will circulate throughout the vessel measuring oxygen. The marbles transmit data via Bluetooth to a cell phone that could adjust operating conditions. In the future, these smart marbles could serve as a communication interface to detect chemical signals within a bioreactor, send that information to a computer, and then transmit electronic signals to direct the behavior of engineered cells in the bioreactor. The team is working with instrument makers interested in commercializing the design, which could be adapted for environmental monitoring and other uses.

WASHINGTON, Aug. 17, 2020 -- Oceans cover almost three-quarters of the globe, yet little is known about how gases and aerosols made by ocean microbes affect weather and climate, or how human-produced pollution could influence this process. Now, scientists report they've used an "ocean-in-a-lab" to show that air pollution can change the makeup of gases and aerosols that sea spray releases into the atmosphere and, in turn, potentially alter weather patterns.

The researchers will present their results today at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo. ACS is holding the meeting through Thursday. It features more than 6,000 presentations on a wide range of science topics.

"It's surprising that we don't know more about the central role of ocean microbes in controlling climate," says Kimberly Prather, Ph.D., the project's principal investigator. "They have the potential to influence atmospheric composition, cloud formation and weather. Humans can alter these natural processes in two ways: by changing the microbial community structure in the ocean, and by producing air pollutants that react with compounds that the microorganisms produce."

Through natural biological processes, ocean microbes -- including bacteria, phytoplankton and viruses -- produce compounds that enter the atmosphere as gases or aerosols (tiny water droplets or particles in air that form when waves crash). In addition, the microorganisms themselves can be ejected from the ocean in the form of aerosolized droplets. Some of these particles can seed clouds, absorb or reflect sunlight, or otherwise influence atmospheric conditions and weather.

“There’s a standard belief that one way the ocean can regulate the temperature of the planet is through emission of gases and particles,” says Prather, who holds a joint appointment at the University of California (UC) San Diego’s Scripps Institution of Oceanography and the department of chemistry and biochemistry. “Some scientists refer to the ocean as the ‘planetary thermostat.’”

Prather and colleagues wondered how humans might influence this thermostat. But first, they needed to learn how ocean microbes affect climate without humans. To find out, the researchers built a 108-foot-long wave channel and filled it with 3,400 gallons of seawater. They caused a phytoplankton bloom -- an overgrowth of microscopic algae that occurs naturally in oceans -- under certain conditions -- in this ocean-in-a-lab. They continuously monitored the gases and aerosols produced in the air above the water, measuring things such as aerosol size, composition, shape, enzymatic activity and pH. They also studied how natural changes in the microbial community, for example, introducing certain species of bacteria and phytoplankton, affected the cloud-forming potential of the aerosols. "The short answer is that the biology had very little effect on sea spray aerosol composition," Prather says. "Altering natural biological processes in seawater resulted in a very small change in the ability of the primary particles to form cloud droplets."

In contrast, adding a small amount of an atmospheric oxidant (hydroxyl radical, which can be generated naturally and can be enhanced in polluted atmospheres) caused an immediate shift in the composition and cloud-forming potential of marine aerosols. According to Prather, the oxidant reacted with microbe-produced gases in the air, transforming them into compounds that changed the composition of the primary sea spray aerosol and formed new types of particles. Although the researchers don't know yet how other individual pollutants affect sea spray aerosols, Prather says that it's important to study the complete gas phase mixture of pollutants to mimic and understand real-world chemical reactions.

The team is now also exploring how water pollution -- in particular, sewage discharge and pollution run-off that empty into coastal estuaries and oceans -- can restructure microbial communities and affect human health, climate and air quality. Previous studies have examined how human pollution impacts water quality; however, Prather's are the first studies focusing on how waterborne pollution that enters the surf zone impacts air quality and human health. Her research group is making measurements in the ocean and atmosphere in a region known to be impacted by pollution flowing in from a heavily polluted estuary. This project aims to understand which viruses, bacteria and other pollutants become airborne in the surf zone.

A press conference on this topic will be held Monday, Aug. 17, at 1 p.m. Eastern time online at http://www.acs.org/fall2020pressconferences.

The researchers acknowledge support and funding from the National Science Foundation (NSF) through the NSF Center for Aerosol Impacts on Chemistry of the Environment.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS' mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people. The Society is a global leader in providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a specialist in scientific information solutions (including SciFinder® and STN®), its CAS division powers global research, discovery and innovation. ACS' main offices are in Washington, D.C., and Columbus, Ohio.

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Title
Impact of ocean microbes on the composition of the marine atmosphere, clouds, and climate

Abstract
Covering 71% of the Earth, the oceans represent a significant source of gases and aerosol particles to our atmosphere. Biological processes in the ocean produce chemical species which can profoundly alter the composition of the atmosphere. Once in the atmosphere, these species can undergo photochemical and chemical reactions which modify their ability to form clouds and impact climate. In the summer of 2019, the NSF Center for Aerosol Impacts on Chemistry of the Environment (CAICE) conducted the Sea Spray Chemistry And Particle Evolution project, or SeaSCAPE, a unique ocean-in-the laboratory experiment which focused on unraveling complex ocean-atmosphere interactions. The focus of the project involves developing a better understanding of how human pollution interacts and reacts with ocean emissions of gases and aerosols - and ultimately affects cloud formation, air quality, and climate. In a 33 m long wave channel filled with 3,400 gallons of seawater, sea spray aerosols and volatile organic carbon gases (VOCs) were continuously measured over the lifecycle of a phytoplankton bloom. Oxidative flow reactors were utilized to simulate different amounts of atmospheric aging of both nascent sea spray aerosols (SSA) and VOCs. The resulting aged SSA and newly formed secondary marine aerosol (SMA) were investigated using a broad suite of complementary on-line and off-line measurements of aerosol number, size, and composition. In addition, other properties including morphology, hygroscopicity, IN activity, phase state, enzymatic activity, and pH were measured. To link changes in the chemistry of the airborne species with seawater biological processes, seawater measurements were made to track the progression of the microbial communities to account for and explain the turnover of organic and inorganic species. As a whole, the SeaSCAPE experiment focuses on capturing how much and how rapidly atmospheric reactions transform ocean-derived biogenic emissions in an effort to unravel the impact of humans on the ocean's ability to control climate.

WASHINGTON, Aug. 17, 2020 -- Sour beer, the tart and tangy outcome of a brewing process that's been used in Europe for centuries, has recently surged in popularity in the U.S. Today, scientists report progress on a study of how acids and other flavor components evolve while the beverage ages. Their aim is to help brewers understand and gain more control over sour beer's taste.

The researchers will present their results at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo. ACS is holding the meeting through Thursday. It features more than 6,000 presentations on a wide range of science topics.

A brand-new video about the ongoing research is available at http://www.acs.org/fall2020-sour-beer.

Sour beer is an ancient type of beer in which wild yeast and bacteria are allowed to grow in freshly brewed beer (wort), which then ferments. After this stage, the wort is often transferred to wooden barrels where it matures for months or years. During that time, the microbes produce numerous metabolic products -- including ethanol, acids and esters -- that provide much of the unique flavor of sour beers. The barrels themselves can infuse trace components, such as vanillin and catechin, that contribute to the flavor profile.

"Scientists are very interested in beer and especially sours because they are such complicated systems," says Teresa L. Longin, Ph.D., one of the project's principal investigators. "There have been several prior studies of the components in finished sour beers. What makes our study different is that we've been able to get samples of beer in progress from many different batches." Their findings could help brewers make better products.

Longin was drawn into the study by her husband and co-PI, David P. Soulsby, Ph.D., and both are at the University of Redlands. When Soulsby began the project a couple of years ago, he reached out to Bryan Doty, a master brewer at nearby Sour Cellars. Doty was eager to learn what was going on in his beer and has provided a series of samples from the same barrels as the beer has aged.

Soulsby and undergraduate student Alexis Cooper examined each sample using NMR spectroscopy coupled with a new analysis method for quantitating the data. They used this approach to track the levels of acetic acid, the main component of vinegar; lactic acid, which gives sourdough bread its distinctive taste; and succinic acid, which is found in broccoli, rhubarb and meat extracts. They found that each acid stabilized at similar concentrations in the different batches, though some batches had greater variability. "These organic acids give sour beers a lot of their flavor, and the balance of organic acids produces very different types of sour beer," Longin says. "It can be more like balsamic vinegar, which has a sweet/sour flavor, or it can be 'puckery' sour. So the mix of organic acids is really important for understanding the flavor profile."

Working with Emily Santa Ana, one of the undergraduates in her lab, Longin drew on expertise in liquid chromatography/time-of-flight mass spectrometry to search for other compounds that contribute subtly to flavor but are present at levels too low to detect with NMR.

"This is a work in progress, but I'm definitely seeing some trace compounds that are changing over time," Longin says. Some compounds start off at high concentrations and then disappear; they might be sugars that are being consumed by yeast as they produce ethanol and carbon dioxide, and by bacteria as they form organic acids. Others "grow in" over time. They could be additional organic acids, health-promoting antioxidants known as phenolics, or vanillin, which lends a hint of vanilla to beer.

The researchers will use the mass spectrometry data to identify the trace compounds and determine whether they come from the barrels or from byproducts of yeast or bacteria metabolism. "In addition, if a brewer knows a particular combination of yeast and bacteria produces a desirable flavor profile, they can culture more of it," Longin says. "Or if they know that a beer with a specific combination of acids is especially pleasing, they'll know when to stop aging the beer so it doesn't lose that balance."

WASHINGTON, Aug. 17, 2020 -- Oral bacteria are ready to spring into action the moment a dental hygienist finishes scraping plaque off a patient's teeth. Eating sugar or other carbohydrates causes the bacteria to quickly rebuild this tough and sticky biofilm and to produce acids that corrode tooth enamel, leading to cavities. Scientists now report a treatment that could someday stop plaque and cavities from forming in the first place, using a new type of cerium nanoparticle formulation that would be applied to teeth at the dentist's office.

The researchers will present their progress toward this goal today at the American Chemical Society (ACS) Fall 2020 Virtual Meeting & Expo. ACS is holding the meeting through Thursday. It features more than 6,000 presentations on a wide range of science topics.

The mouth contains more than 700 species of bacteria, says Russell Pesavento, D.D.S., Ph.D., the project's principal investigator. They include beneficial bacteria that help digest food or keep other microbes in check. They also include harmful streptococcal species, including Streptococcus mutans. Soon after a cleaning, these bacteria stick to teeth and begin multiplying. With sugar as an energy source and building block, the microbes gradually form a tough film that can't easily be removed by brushing. As the bacteria continue metabolizing sugar, they make acid byproducts that dissolve tooth enamel, paving the way for cavities.

Dentists and consumers can fight back with products including stannous fluoride to inhibit plaque, and silver nitrate or silver diamine fluoride to stop existing tooth decay. Researchers have also studied nanoparticles made of zinc oxide, copper oxide or silver to treat dental infections. Although bactericidal agents such as these have their place in dentistry, repeated applications could lead to both stained teeth and bacterial resistance, according to Pesavento, who is at the University of Illinois at Chicago. "Also, these agents are not selective, so they kill many types of bacteria in your mouth, even good ones," he explains.

So, Pesavento wanted to find an alternative that wouldn't indiscriminately kill bacteria in the mouth and that would help prevent tooth decay, rather than treat cavities after the fact. He and his research group turned to cerium oxide nanoparticles. Other teams had examined the effects of various types of cerium oxide nanoparticles on microbes, though only a few had looked at their effects on clinically relevant bacteria under initial biofilm formation conditions. Those that did so prepared their nanoparticles via oxidation-reduction reactions or pH-driven precipitation reactions, or bought nanoparticles from commercial sources. Those prior formulations either had no effect or even promoted biofilm growth in lab tests, he says.

But Pesavento persevered because the properties and behavior of nanoparticles depend, at least partially, on how they're prepared. His team produced their nanoparticles by dissolving ceric ammonium nitrate or sulfate salts in water. Other researchers had previously made the particles this way but hadn't tested their effects on biofilms. When the researchers seeded polystyrene plates with S. mutans in growth media and fed the bacteria sugar in the presence of the cerium oxide nanoparticle solution, they found that the formulation reduced biofilm growth by 40% compared to plates without the nanoparticles, though they weren't able to dislodge existing biofilms. Under similar conditions, silver nitrate -- a known anti-cavity agent used by dentists -- showed no effect on biofilm growth.

"The advantage of our treatment is that it looks to be less harmful to oral bacteria, in many cases not killing them," Pesavento says. Instead, the nanoparticles merely prevented microbes from sticking to polystyrene surfaces and forming adherent biofilms. In addition, the nanoparticles' toxicity and metabolic effects in human oral cells in petri dishes were less than those of silver nitrate.

Pesavento, who was awarded a patent in July, would like to combine the nanoparticles with enamel-strengthening fluoride in a formulation that dentists could paint on a patient's teeth. But, he notes, much work must be done before that concept can be realized. For now, the team is experimenting with coatings to stabilize the nanoparticles at a neutral or slightly basic pH -- closer to the pH of saliva and healthier for teeth than the present acidic solution. His team has also begun working with bacteria linked to the development of gingivitis and has found one particular coated nanoparticle that outcompeted stannous fluoride in limiting the formation of adherent biofilms under similar conditions. Pesavento and his team will continue to test the treatment in the presence of other bacterial strains typically present in the mouth, as well as test its effects on human cells of the lower digestive tract to gain a better sense of overall safety for patients.

MADISON, Wis. -- University of Wisconsin-Madison scientists have discovered that a majority of back-pain patients they tested who were taking opioid painkillers produced anti-opioid antibodies.

These antibodies may contribute to some of the negative side effects of long-term opioid use. Existing antibodies may also limit the benefit a patient receives from an anti-opioid vaccine, the production of which is the ultimate goal of this line of work. A vaccine stimulating an immune response against opioids could reduce the harm of opioid abuse, but researchers must identify the population of patients that will respond well to that treatment.

Cody Wenthur, a professor in the UW-Madison School of Pharmacy, led the work with collaborators at the Scripps Research Institute and Scripps Health in San Diego. Wenthur lab postdoctoral researcher Jillian Kyzer announced the team's findings Aug. 17 at the American Chemical Society Fall 2020 virtual meeting.

The researchers discovered antibodies against protein-bound opioids in 10 of 19 patients who took opioids to treat chronic lower back pain. Those who took higher doses of opioids had a stronger antibody response. A control group of three patients who did not take opioids for their back pain had only very low levels of anti-opioid antibodies.

For this initial study, Wenthur's team could only identify three patients with chronic pain who had not previously taken opioids, even after a months-long radio and print recruiting campaign. This challenge was an indication of the ubiquity of these drugs, despite evidence that they are riskier options than non-opioid painkillers for treating chronic pain.

"Opioid use disorder and opioid overdoses continue to be a major epidemic in this country," says Wenthur. "A relatively new therapeutic approach entering clinical trials is what in shorthand we call an opioid vaccine, where the immune system generates a response against the drugs. But for this approach to be successful, we need to identify the people who would benefit from that approach."

For decades, researchers have understood that the immune system can produce antibodies against psychoactive drugs under the right conditions. While the chemicals themselves are too small for the immune system to recognize, they can permanently bind to large proteins in the blood, which can then trigger an immune response.

If a vaccine can produce antibodies capable of neutralizing the drugs, it could help people combat addiction by reducing the pleasurable feelings the drugs produce in the brain. Past trials of vaccines against nicotine or cocaine have had limited success, in part because of individual differences in how the immune system produces antibodies.

As part of their overall objective to improve the treatment of substance use disorders, the Wenthur lab is studying immune reactions to combat opioid abuse, which claims tens of thousands of lives each year in the U.S. Patients who take opioids for extended periods can develop serious side effects, including hyperalgesia, a sensitive, painful response to harmless touch. Wenthur's team thought that the immune system's response to the drugs might help explain these side effects.

To test that idea, they looked for antibodies against the drugs in people who took opioids. Kyzer worked with postdoctoral researchers Hyeri Park and Tyson Belz at the Scripps Research Institute to develop molecular traps for any potential antibodies. They linked the common opioids hydrocodone and oxycodone to a ubiquitous blood protein in the hopes that these drug-protein conjugates would bind to any opioid antibodies in patients' blood.

"When we looked, we did see a correlation between recent opioid dose exposure and the amount of antibodies that we saw," says Wenthur.

Counterintuitively, the patients who already produce a measurable antibody response to opioids may be the least likely to benefit from a potential anti-opioid vaccine. That's because they produce a relatively weak type of antibody, known as IgM, which may reduce their ability to generate stronger, neutralizing IgG antibodies against the same drug target in the future.

As researchers advance toward a potential opioid vaccine, tests like this one proposed by the Wenthur lab might help identify the patients who are likely to benefit.

"In order to confirm these results and help us understand who might be good vaccine candidates, we need to find a larger cohort of individuals, track their opiate use history, and figure out if this is a useful biomarker for subsequent vaccine protection against overdose and for clinical outcomes like hyperalgesia," says Wenthur.

Crops grow dense canopies that consist of several layers of leaves--the upper layers with younger sun leaves and the lower layers with older shaded leaves that may have difficulty intercepting sunlight trickling down from the top layers.

In a recent study published in Food and Energy Security, scientists from Realizing Increased Photosynthetic Efficiency (RIPE) aimed to understand how much variation exists within diverse cowpea lines in light absorption and carbon dioxide (CO2) assimilation throughout the canopy. This information can ultimately be used to design more efficient canopies--with greater CO2 assimilation and water-use efficiency--to increase yields.

RIPE, which is led by the University of Illinois, is engineering crops to be more productive by improving photosynthesis, the natural process all plants use to convert light energy to produce biomass and yields. RIPE is supported by the Bill & Melinda Gates Foundation, the U.S. Foundation for Food and Agriculture Research (FFAR), and the U.K. Government's Department for International Development (DFID). One of the target crops of the RIPE project is cowpea.

Cowpeas, commonly known as black-eyed peas in the U.S., are one of the oldest domesticated crops in the world, responsible for feeding more than 200 million people per day.

"They are a staple crop in Africa, providing a source of protein for humans and livestock, and restoration of soil nutrition through nitrogen fixation," said Lisa Ainsworth, a research plant physiologist with the U.S. Department of Agriculture, Agricultural Research Service (USDA-ARS).

The RIPE team screened 50 cowpea genotypes from a multi-parent advanced generation inter-cross (MAGIC) population for canopy architecture traits, canopy photosynthesis, and water-use efficiency by using a canopy gas exchange chamber. This chamber was used to measure the rate by which plants would convert CO2 in the atmosphere into carbohydrates as energy for growth.

"Since sub-Saharan Africa is the region where important yield gaps persist, it is crucial that we develop a high yielding crop that can be easily grown there," said first author Anthony Digrado, a USDA-ARS postdoctoral researcher in Ainsworth's lab based at Illinois. "That is to say that water-use efficiency should be taken into serious account when developing new varieties for sub-Saharan African countries that are challenged by access to water in several regions."

The team used Principal Component Analysis (PCA) models to first group the 50 MAGIC genotypes into five general canopy architectural types to study plant traits, including leaf area index, leaf greenness, and canopy height and width. This analysis gave researchers the ability to gather an overview of the traits, or combinations of traits, that could be modified to have the strongest impact on canopy photosynthesis to maximize growth.

Canopy architecture contributed to 38.6 percent of the variance observed in canopy photosynthesis. Results showed that in canopies with lower biomass, the major limitation to canopy photosynthesis was leaf area; however, in higher biomass canopies, the major limiting factor was, instead, the light environment. Canopies with high biomass have greater canopy photosynthesis when leaves at the top of the canopy have lower chlorophyll content.

Overall, canopy architecture significantly affected canopy photosynthetic efficiency and water-use efficiency, suggesting that optimizing canopy structures can contribute to yield enhancement in crops.

"Water-use efficiency refers to the amount of CO2 assimilated by a crop canopy relative to the amount of water that is lost by the canopy," said Digrado, who led this work at the Carl R. Woese Institute for Genomic Biology (IGB). "The ideal for a crop is to be able to have a lot of carbon intake without losing too much water."

The MAGIC cowpea population that the team used matches this criteria for an ideal crop, especially one to be grown in the drought conditions of Africa. However, research on how canopy architecture affects canopy CO2 assimilation and water-use efficiency in cowpea continues to be scarce.

"There is still a lot to do to improve cowpea yields and much more research is needed," Digrado said. "But this work has established that variation exists that can be used to improve productivity and efficiency of an important food security crop."

The RIPE project and its sponsors are committed to ensuring Global Access and making the project's technologies available to the farmers who need them the most.

A research team in Korea has developed a material that may potentially replace color shifting ink in prevention of forgery of bank notes, ID cards, and so on. A team headed by Dr. Sang-seok Lee from the Functional Composite Material Research Center of the Korea Institute of Science and Technology(KIST) announced that it has successfully developed a technology to fabricate liquid crystals* comprised of several layers with a thickness comparable to that of a hair strand using hydrophilic and hydrophobic properties through a joint study with a team led by Kim Shin-Hyun, Professor of Chemical and Biomolecular Engineering at the Korea Advanced Institute of Science and Technology(KAIST).

When a special additive called chiral dopant is mixed with the liquid crystal material commonly used in display devices, the liquid crystal molecules rotate spontaneously to form a spiral structure. This is referred to as "cholesteric liquid crystal*," an photonic crystal material that can exhibit color, without the addition of pigments, by selectively reflecting light of certain wavelengths due to its periodic nanostructure. Also, the light has a circular polarization* property in that it rotates in only one direction, and by using this property, it is possible to make colors appear and disappear by changing certain polarization conditions.

If this liquid crystal structure is repeated, it is possible to make a material that can exhibit two or more different characteristics at the same time. Liquid crystals with diverse optical characteristics from having multiple layers, for example, can be used as a material to prevent counterfeiting. However, to make such material consisting of several layers, there is a need to build each layer on top of the one before in a repeated fashion using a elaborately designed device, and there was a need to develop the technology for this complex process.

The KIST-KAIST research team added a cosolvent that dissolved in both oil and water as a way to mix organic alcohol, a hydrophilic moisturizing agent, and the hydrophobic liquid crystal material for all three substances to become evenly mixed together. Then, the mixture was emulsified* in water to form microemulsion drops. With the exchanges occurring among the cosolvent, moisturizing agent, and water molecules through the surfaces of the emulsion drops, this resulted in a separation of the hydrophobic and hydrophilic layers.

Depending on the initial mixing ratio of the substances, they separated into multiple layers ranging from one to five, and these layers could be freely controlled. Also, with the phase separation occurring continually within each emulsion drop, the concentration of the chiral dopant inside the liquid crystals changed, resulting in multiple structural colors. This is a new technology to fabricate liquid crystals of multiple layers through a simple process of emulsifying the mixture that has never before been reported.

Dr. Lee from KIST said, "What we've developed is a simple method of creating multi-layered liquid crystals and we expect it will serve as the basis for adding unique optical characteristics to materials," and added, "Based on this new technology, we plan on developing diverse functional particles to develop composite materials."

PITTSBURGH--People rarely use just one sense to understand the world, but robots usually only rely on vision and, increasingly, touch. Carnegie Mellon University researchers find that robot perception could improve markedly by adding another sense: hearing.

In what they say is the first large-scale study of the interactions between sound and robotic action, researchers at CMU's Robotics Institute found that sounds could help a robot differentiate between objects, such as a metal screwdriver and a metal wrench. Hearing also could help robots determine what type of action caused a sound and help them use sounds to predict the physical properties of new objects.

"A lot of preliminary work in other fields indicated that sound could be useful, but it wasn't clear how useful it would be in robotics," said Lerrel Pinto, who recently earned his Ph.D. in robotics at CMU and will join the faculty of New York University this fall. He and his colleagues found the performance rate was quite high, with robots that used sound successfully classifying objects 76 percent of the time.

The results were so encouraging, he added, that it might prove useful to equip future robots with instrumented canes, enabling them to tap on objects they want to identify.

The researchers presented their findings last month during the virtual Robotics Science and Systems conference. Other team members included Abhinav Gupta, associate professor of robotics, and Dhiraj Gandhi, a former master's student who is now a research scientist at Facebook Artificial Intelligence Research's Pittsburgh lab.

To perform their study, the researchers created a large dataset, simultaneously recording video and audio of 60 common objects -- such as toy blocks, hand tools, shoes, apples and tennis balls -- as they slid or rolled around a tray and crashed into its sides. They have since released this dataset, cataloging 15,000 interactions, for use by other researchers.

The team captured these interactions using an experimental apparatus they called Tilt-Bot -- a square tray attached to the arm of a Sawyer robot. It was an efficient way to build a large dataset; they could place an object in the tray and let Sawyer spend a few hours moving the tray in random directions with varying levels of tilt as cameras and microphones recorded each action.

They also collected some data beyond the tray, using Sawyer to push objects on a surface.

Though the size of this dataset is unprecedented, other researchers have also studied how intelligent agents can glean information from sound. For instance, Oliver Kroemer, assistant professor of robotics, led research into using sound to estimate the amount of granular materials, such as rice or pasta, by shaking a container, or estimating the flow of those materials from a scoop.

Pinto said the usefulness of sound for robots was therefore not surprising, though he and the others were surprised at just how useful it proved to be. They found, for instance, that a robot could use what it learned about the sound of one set of objects to make predictions about the physical properties of previously unseen objects.

"I think what was really exciting was that when it failed, it would fail on things you expect it to fail on," he said. For instance, a robot couldn't use sound to tell the difference between a red block or a green block. "But if it was a different object, such as a block versus a cup, it could figure that out."

The intensive implementation of currently available tools to fight malaria can achieve a drastic reduction in disease burden, but is not enough to interrupt its transmission. This is the main conclusion reached by the Mozambican Alliance Towards Elimination of Malaria (MALTEM), coordinated by the Barcelona Institute for Global Health (ISGlobal) and the Manhiça Health Research Center (CISM), with the support of the "la Caixa" and Bill & Melinda Gates Foundations, and in collaboration with the Ministry of Health of Mozambique. The MALTEM research team has just published in Plos Medicine the results from the Magude Project, a three-year intervention in southern Mozambique estimated to have averted almost 40,000 malaria cases and which provides valuable lessons to guide the roadmap towards malaria elimination.

The World Health Organisation (WHO) has set a long-term goal: eradicate malaria. To do so, the malaria community must start by generating evidence on the best way to use the available tools and identify new strategies and tools that accelerate the process: from disease control and its elimination, particularly in African countries where tackling transmission has been most challenging, to its total eradication (at a global level).

"The Magude project was designed to evaluate the feasibility of eliminating malaria with the available tools in a region of Mozambique with moderate disease transmission," explains Pedro Aide, last author of the study and researcher at CISM in Mozambique, one of the 10 countries with the highest malaria burden in the world. "This is critical to understand what can be achieved and what else needs to be done", he adds.

The five-year project took place in the Magude district in southern Mozambique, a rural setting where 48,448 people lived in 10,695 households, according to the census performed by the research team in 2015. The objective of the first phase of the project was to reduce disease transmission in order to reach zero cases, while the goal of the second phase was to sustain the gains achieved.

The strategy for the first phase included all prevention and treatment tools that are currently available and recommended by the WHO: continuous detection and treatment of cases, a strengthened epidemiological and entomological surveillance, and two rounds of mass administration of antimalarial drugs to the whole population, during two consecutive years. In parallel, insecticide-treated bednets were distributed and the houses were protected through indoor-residual spray, once a year, in order to fight the mosquito that transmits the disease. During the second phase, the interventions continued but the mass drug administration was replaced by the focal administration of drugs to people living within the households of malaria cases detected by health facilities or community health workers.

A high impact

"At the end of the three-year intervention, the percentage of people infected by the malaria parasite decreased from 9.1% to 1.4%, which means a reduction of almost 85%. This translates in an estimated 39,000 cases of malaria averted," says Beatriz Galatas, ISGlobal researcher and first author of the study. "The results show that, even if disease transmission was not interrupted, the impact of the first phase was very high and we managed to keep the number of cases at very low levels for at least one year after the last mass drug administration," explains Francisco Saúte, project director and deputy scientific director at CISM. The impact analysis of the second phase has not been published yet.
For Regina Rabinovich, study co-author and director of the Malaria Elimination Initiative at ISGlobal, "the question now is why, despite this drastic reduction, we are failing to interrupt disease transmission, and what are the strategies required to achieve this goal."

"This is an extremely valuable project for advancing the fight against malaria, and particularly relevant for the "la Caixa" Foundation, for whom global health remains a priority," says Ariadna Bardolet, director of the International Cooperation Programme at "la Caixa" Foundation.

Philip Welkhoff, Malaria Program Director at the Bill and Melinda Gates Foundation, points out that "these findings unequivocally show that we can increase the number of lives saved by optimally applying the tools we have today, while we develop new ones to address the gap between low and zero transmission. Through partnerships like this one with ISGlobal, CISM and "la Caixa" Foundation, we can turn the corner and ultimately achieve malaria eradication."

"We have proved that the combined use of interventions can considerably reduce the burden of disease, an essential step for its elimination," adds ISGlobal's general director, Antoni Plasència.

What The Study Did: The goal of this study was to compare International Statistical Classification of Diseases and Related Health Problems, Tenth Revision (ICD-10) codes with manual electronic medical records review in capturing symptoms of fever, cough and shortness of breath (dyspnea) among patients being tested for SARS-CoV-2 infection.

Authors: Rashmee U. Shah, M.D., M.S., of the University of Utah School of Medicine in Salt Lake City, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2020.17703)

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

A new design for light-emitting diodes (LEDs) developed by a team including scientists at the National Institute of Standards and Technology (NIST) may hold the key to overcoming a long-standing limitation in the light sources' efficiency. The concept, demonstrated with microscopic LEDs in the lab, achieves a dramatic increase in brightness as well as the ability to create laser light -- all characteristics that could make it valuable in a range of large-scale and miniaturized applications.

The team, which also includes scientists from the University of Maryland, Rensselaer Polytechnic Institute and the IBM Thomas J. Watson Research Center, detailed its work in a paper published today in the peer-reviewed journal Science Advances. Their device shows an increase in brightness of 100 to 1,000 times over conventional tiny, submicron-sized LED designs.

"It's a new architecture for making LEDs," said NIST's Babak Nikoobakht, who conceived the new design. "We use the same materials as in conventional LEDs. The difference in ours is their shape."

LEDs have existed for decades, but the development of bright LEDs won a Nobel prize and ushered in a new era of lighting. However, even modern LEDs have a limitation that frustrates their designers. Up to a point, feeding an LED more electricity makes it shine more brightly, but soon the brightness drops off, making the LED highly inefficient. Called "efficiency droop" by the industry, the issue stands in the way of LEDs being used in a number of promising applications, from communications technology to killing viruses.

While their novel LED design overcomes efficiency droop, the researchers did not initially set out to solve this problem. Their main goal was to create a microscopic LED for use in very small applications, such as the lab-on-a-chip technology that scientists at NIST and elsewhere are pursuing.

The team experimented with a whole new design for the part of the LED that shines: Unlike the flat, planar design used in conventional LEDs, the researchers built a light source out of long, thin zinc oxide strands they refer to as fins. (Long and thin are relative terms: Each fin is only about 5 micrometers in length, stretching about a tenth of the way across an average human hair's breadth.) Their fin array looks like a tiny comb that can extend to areas as large as 1 centimeter or more.

"We saw an opportunity in fins, as I thought their elongated shape and large side facets might be able to receive more electrical current," Nikoobakht said. "At first we just wanted to measure how much the new design could take. We started increasing the current and figured we'd drive it until it burned out, but it just kept getting brighter."

Their novel design shone brilliantly in wavelengths straddling the border between violet and ultraviolet, generating about 100 to 1,000 times as much power as typical tiny LEDs do. Nikoobakht characterizes the result as a significant fundamental discovery.

"A typical LED of less than a square micrometer in area shines with about 22 nanowatts of power, but this one can produce up to 20 microwatts," he said. "It suggests the design can overcome efficiency droop in LEDs for making brighter light sources."

"It's one of the most efficient solutions I have seen," said Grigory Simin, a professor of electrical engineering at the University of South Carolina who was not involved in the project. "The community has been working for years to improve LED efficiency, and other approaches often have technical issues when applied to submicrometer wavelength LEDs. This approach does the job well."

The team made another surprising discovery as they increased the current. While the LED shone in a range of wavelengths at first, its comparatively broad emission eventually narrowed to two wavelengths of intense violet color. The explanation grew clear: Their tiny LED had become a tiny laser.

"Converting an LED into a laser takes a large effort. It usually requires coupling a LED to a resonance cavity that lets the light bounce around to make a laser," Nikoobakht said. "It appears that the fin design can do the whole job on its own, without needing to add another cavity."

A tiny laser would be critical for chip-scale applications not only for chemical sensing, but also in next-generation hand-held communications products, high-definition displays and disinfection.

"It's got a lot of potential for being an important building block," Nikoobakht said. "While this isn't the smallest laser people have made, it's a very bright one. The absence of efficiency droop could make it useful."

The programme is funded by the German-Argentinean University Centre (DAHZ-CUAA). Dr. Regina Mencia from Argentina was the first doctoral student to complete her doctorate under this programme at the beginning of this year. The success of her German-Argentinean cooperation has now been crowned by a joint publication in the renowned journal "Plant Physiology".

Under the supervision of Professors Jutta Ludwig-Müller (TUD) and Elina Welchen (UNL), Regina Mencia researched a new method for increasing the resistance of plants to pathogens as part of her doctorate. Between 2017 and 2018 she was a guest at the Chair of Plant Physiology at TU Dresden for one year. Here she investigated the influence of the mitochondrial protein Arabidopsis thaliana Oxidation Resistance 2 (AtOXR2) on plant defence.

"At TU Dresden, I was able to carry out experiments for which we in Santa Fe do not have the appropriate laboratory equipment or the necessary expertise. I also had the opportunity here to exchange ideas with many other scientists, attended numerous courses and conferences. As a result, I have advanced not only scientifically, but also personally and culturally. I was warmly welcomed in the research group of Prof. Ludwig-Müller and very well supervised. I could well imagine returning to TU Dresden one day", Dr. Mencia describes her guest stay.

During her investigations, she found out that the protein AtOXR2 has an influence on the salicylic acid pathway of the plant, thereby increasing the plant's resistance to pathogen infections. Salicylic acid is a chemical substance that occurs as a plant hormone in the leaves, flowers and roots of various plants and plays an important role in the defence against pathogens. The overexpression of AtOXR2 leads to a general activation of the salicylic acid-signalling pathway, the plant boosts its defense and becomes resistant to the attack of pathogens.

Professor Ludwig-Müller explains the relevance of these investigations: "The results are very promising for applications. Whereas in previous studies, salicylic acid-based resistance led to a deterioration in plant growth, the plants from this project showed improved growth in addition to resistance".