Tech

Municipal solid waste is trash -- such as plastic, food scraps and lawn clippings -- that goes into garbage bins and doesn't get recycled. Most of this waste is buried in landfills or is incinerated. Now, researchers reporting in ACS' Environmental Science & Technology have shown that when disposed of in this way, municipal solid waste can be an important source of antibiotic-resistance genes in the air.

Residual antibiotics from discarded medications and other products can end up in municipal solid waste. Some microbes in the garbage are resistant to those antibiotics, and they can spread resistance genes to other bacteria, allowing them to survive in the presence of these drugs. But scientists hadn't studied whether treating the garbage through incineration or landfilling releases these bacteria and genes into the air, where people or animals could breathe them in. So Yi Luo, Xiangdong Li and colleagues wanted to investigate the bacterial community and associated antibiotic-resistance genes in the municipal solid waste treatment system of Changzhou, a city in eastern China.

The researchers collected air samples surrounding a landfill site, a municipal solid waste incinerator and two transfer stations (where garbage is delivered and processed). Air from both the municipal incinerator and the landfill site had higher levels of particulate matter and bacteria than upwind locations. The team identified 16 antibiotic-resistance genes in the air samples and tracked their source to municipal solid waste and leachate in the system. The genes were much more abundant in air downwind from the facilities than upwind. These results suggest that municipal solid waste treatment systems could be a reservoir of antibiotic-resistance genes that can be transmitted to nearby residents who breathe the air, the researchers say.

Spilled coffee forms a ring as the liquid evaporates, depositing solids along the edge of the puddle. This "coffee ring effect" has fascinated scientists for decades, but now a team says they have uncovered the mechanism behind an even more striking, web-like pattern that forms when drops of American whiskey dry up. The results, reported in ACS Nano, suggest that these distinctive 'whiskey webs' could someday be used to identify counterfeit spirits.

When a drop of liquid evaporates, solids are left behind in a pattern that depends on what the liquid is, what solids are in it and the environmental conditions. Stuart Williams and colleagues previously found that drops of diluted American whiskeys -- but not their Scotch or Canadian counterparts -- formed webbed patterns when dried on a glass surface, and there were hints that the pattern was distinctive for different brands of whiskey. In the current study, the researchers wanted to see how the whiskey webs form in more detail, and whether they could serve as fingerprints of the spirits.

The team used time-lapse microscopy to examine droplets of diluted American whiskey as the liquid evaporated. Non-volatile organic compounds, such as phenols, aromatics and esters, clustered together and were driven to the surface of the droplet, where they formed monolayers. As the surface area of the droplet decreased, the monolayers collapsed, creating strands of the web. The researchers showed that different American whiskeys showed unique web patterns that could be correctly matched to unknown samples more than 90% of the time. The distinctive webs arise from the unique combination of solutes in each whiskey, the researchers say.

(Philadelphia, PA) - The immune system is like a carefully regulated machine, complete with its own built-in "brakes" that prevent it from overreacting and causing excess inflammation in otherwise healthy tissues. This preventative safety net, however, is highly vulnerable, particularly in cancer, where tumor cells step on the brakes constantly, because doing so allows the tumor cells to escape immune detection.

Several molecules that act as natural brakes on immune activity have been discovered, which has opened the door to immunotherapy - a potentially highly effective way of leveraging the immune system to attack cancer cells. For immunotherapy to reach its full potential in human patients, however, more must be learned about factors driving cancer immunity.

Now, researchers at the Lewis Katz School of Medicine at Temple University (LKSOM) and Fox Chase Cancer Center show for the first time that a molecule called EGR4 -known mainly for its role in male fertility - serves as a critical brake on immune activation. The new study, published online March 25 in the journal EMBO Reports, shows that taking EGR4 away - effectively releasing the brake - promotes the activation of so-called killer T cells, which infiltrate and attack tumors and thereby boost anticancer immunity.

"Other early growth response proteins, or EGRs, are important to T cell activity, but whether EGR4 also has a role in immunity has been largely overlooked," explained Jonathan Soboloff, PhD, Professor of Medical Genetics and Molecular Biochemistry at the Fels Institute for Cancer Research and Molecular Biology at LKSOM. "Our study reveals a new side to the importance of EGR4."

Dr. Soboloff's team examined the influence of EGR4 expression in immune cells in collaboration with Dietmar J. Kappes, PhD, Professor of Blood Cell Development and Cancer at Fox Chase Cancer Center.

In initial experiments, the researchers found that T cell activation is associated with EGR4 upregulation. They then showed that knocking-out, or eliminating, EGR4 from immune cells results in a dramatic increase in calcium signaling and expansion of T helper type 1 (Th1) cell populations. Th1 cells, in response to the presence of foreign entities, including tumor cells, activate cytotoxic, or killer, T cells, which then wipe out the invader.

"We know from our previous work that T cells control calcium signaling and that when intracellular calcium levels are elevated, calcium signaling can drive T cell activation," Dr. Soboloff said.

The Soboloff and Kappes labs next studied the functional importance of EGR4 in cancer immunity by utilizing an adoptive mouse model of melanoma in which some host animals lacked EGR4 expression. Compared to mice with typical EGR4 levels, EGR4 knockout animals showed evidence of expanded populations of Th1 cells and enhanced anticancer immunity. In particular, EGR4 knockout mice had reduced lung tumor burden and fewer metastases than mice with normal EGR4 expression.

In future work, the Soboloff and Kappes groups plan to further explore strategies for EGR4 targeting. The development of an agent to target EGR4 specifically may be difficult, due to the diverse actions of EGR pathways. "But eliminating EGR4 specifically from a patient's T cells, and then putting those cells back into the patient, may be a viable immunotherapeutic approach," Dr. Kappes said.

To understand what happens in the brain when Alzheimer's disease develops, researchers need to be able to study the molecular structures in the neurons affected by Alzheimer's disease. Researchers at Lund University in Sweden have tested a new imaging method for this purpose. The research is published in the journal Advanced Science.

In Alzheimer's disease, so-called beta-amyloid plaques are formed in the brain, and neurons in the brain die. When the plaque becomes visible in brain tissue, the disease is already in an advanced stage. As more and more nerve cells die, memory disruptions begin, something that eventually results in memory loss. But what happens in the nerve cells before amyloid plaques appear, and why do nerve cells die?

"This is a question that researchers have long struggled to find answers to. We have not had enough imaging techniques to study the structural changes in nerve cells. This is required to detect very early changes, and therefore potentially understand the triggers", says researcher Oxana Klementieva, group leader for medical microscopy at Lund University.

Using a new method, optical photothermal spectroscopy, O-PTIR, researchers at Lund University have collaborated with colleagues at Synchrotron SOLEIL in France to study protein structures within nerve cells - without using the chemical processing of nerve cells required for other imaging techniques, something that can affect the very structures that scientists want to study.

"We saw that the structure of the protein changes in different ways depending on where in the nerve cell it is. So far, there have been no methods that can produce these types of images, giving us insight into what the first molecular changes in neurons actually look like in Alzheimer's disease", says Oxana Klementieva.

Oxana Klementieva and her colleagues have previously shown that early structural changes of beta-amyloid, the protein believed to be at the root of Alzheimer's disease, happen before amyloid plaques appear. The goal now is to investigate further where in the cell the structures change happen, and whether it can help to explain the mechanisms behind Alzheimer's disease.

"If it depends on several different mechanisms, something I believe to be the case, we therefore, would need different types of treatments", says Oxana Klementieva.

The researchers have been able to use the new method to image neurons affected by early-stage Alzheimer's disease in mice before the death of the nerve cells, something that is important when mapping the disease mechanisms. Oxana Klementieva believes that the new technology can also be used to study protein structures related to other diseases that affect the brain, such as Parkinson's disease, Lewy Body dementia and frontal lobe dementia.

Gunnar Gouras, a professor of experimental neurology at Lund University who also participated in the study, believes that technology shifts like this are necessary for researchers to be able understand the complex diseases that affect the brain. He points out that Sweden is at the forefront of developing new ways of measuring biomarkers and diagnosing, but that we still do not understand how and what disease mechanisms break down the nerve cells.

"The reason why we do not yet have effective treatments for Alzheimer's disease have to do with the complexity of the brain", says Gunnar Gouras.

To put this complexity into perspective, he compares the brain to the heart.

"The heart itself is a complex muscle and, like all our other organs, is controlled by the brain - the brain's nerve cells thus extend throughout the body. It is extremely complex. This imaging method provides a unique opportunity to study complexity in a way we could not do before", concludes Gunnar Gouras.

Magnetic bacteria might soon be used for the production of novel biomaterials. A team of microbiologists at the University of Bayreuth led by Prof. Dr. Dirk Schüler developed a modular system for the genetic reprogramming of bacteria, thereby turning the organisms into cell factories for multifunctional magnetic nanoparticles that combine various useful functions and properties. Because of their exceptional magnetic properties and good biocompatibility, these nanoparticles might be a promising new material in the biomedical and biotechnological field. In the journal "Small" the scientists presented their findings.

From magnetosomes to versatile nanoparticles

Magnetic bacteria of the species Magnetospirillum gryphiswaldense align their swimming behaviour along the Earth's magnetic field. Within the cells, magnetic nanoparticles, the magnetosomes, are arranged in a chain-like manner, thereby forming an intracellular compass needle. Each magnetosome consists of a magnetic iron oxide core surrounded by a membrane. In addition to lipids, this membrane also contains a variety of different proteins. The microbiologists of the University of Bayreuth have now succeeded in the coupling of biochemically active functional groups, which originate from various foreign organisms, to these proteins. The method used here starts at the stage of the genes that are responsible for the biosynthesis of the membrane proteins. These bacterial genes are fused to foreign genes from other organisms that control the production of the respective functional proteins. As soon as the genes are re-integrated into the genome, the reprogrammed bacteria produce magnetosomes that display these foreign proteins permanently installed on the particle surface.

In the study, four different functional groups (i.e. foreign proteins) were coupled to the membrane proteins. These include the enzyme glucose oxidase from a mould fungus, which is already used biotechnologically, for example as a "sugar sensor" in diabetes diseases. In addition, a green fluorescent protein from a jellyfish and a dye-producing enzyme from the bacterium Escherichia coli, whose activity can be easily measured, were installed on the surface of the magnetosomes. The fourth functional group is an antibody fragment from a lama (Alpaca) that was used as a versatile connector. Thus, all these properties including the superb magnetization of the magnetosomes are genetically encoded in the bacteria.

"Using this genetic strategy, we reprogrammed the bacteria to produce magnetosomes that glow green when irradiated with UV light and at the same time display novel biocatalytic functions. Various biochemical functions can be precisely installed on their surfaces. Thereby, magnetosomes from living bacteria are transformed into multifunctional nanoparticles with fascinating functions and properties. Moreover, the particles remain fully functional when they are isolated from the bacteria - which can be easily performed by taking advantage of their inherent magnetic properties," says Professor Dirk Schüler, who led the research team.

A genetic toolkit for applications in biomedicine and biotechnology

Functionalization of the magnetosomes by no means is limited to the functional groups that were installed on the particle surface by the Bayreuth microbiologists. Instead, these proteins can easily be replaced by other functions, thus providing of a highly versatile platform. Genetic reprogramming therefore opens up a broad spectrum to design the magnetosome surface. It provides the basis for a "genetic toolkit" that allows the production of tailored magnetic nanoparticles, combining different useful functions and properties. Each of these particles is between three and five nanometres in size.

"Our genetic engineering approach is highly selective and precise, compared to, for instance, chemical coupling techniques which are not as efficient and lack this high degree of control", explains the Bayreuth microbiologist Dr. Frank Mickoleit, the first author of the study. He points to a decisive advantage of the new biomaterials: "Previous studies show that the magnetic nanoparticles are likely not harmful to cell cultures. Good biocompatibility is an important prerequisite for the future application of the particles in biomedicine, for instance as contrast agents in magnetic imaging techniques or as magnetic sensors in diagnostics. In the future, for example, similar particles might help to detect and destroy tumour cells. Bioreactor systems are another field of application. Magnetic nanoparticles equipped with tiny catalysts would be highly suitable for this purpose and enable complex biochemical processes.

"There is an enormous application potential for nanoparticles that display different functional groups on the surface, particularly in the fields biotechnology and biomedicine. The magnetic bacteria now may serve as a platform for a versatile nano-toolkit, inspiring scientific creativity in the field of Synthetic Biology. It will initiate further interesting research approaches", adds the microbiologist Clarissa Lanzloth B.Sc., who was involved in the new study as co-author during completion of her Master thesis in "Biochemistry and Molecular Biology" in Bayreuth.

Highlight

In an analysis of information on adults who began treatment for kidney failure at any Georgia, North Carolina, or South Carolina dialysis facility, the distance from a patient's residence to the nearest transplant center did not appear to affect the likelihood of transplant-related referrals and evaluations.

Washington, DC (March 24, 2020) -- In a study of Southeastern U.S. patients undergoing dialysis, the distance from a patient's residence to the nearest transplant center did not appear to affect access to early steps in the kidney transplantation process. The findings appear in an upcoming issue of CJASN.

To be considered for kidney transplantation, patients must be referred to a transplant center for medical evaluation, most often from a dialysis facility. Prior research suggests that the distance a person must travel to reach a transplant center might be a barrier to referral.

To investigate, Laura J. McPherson, MPH, Rachel E. Patzer, PhD, MPH (Emory University School of Medicine), and their colleagues examined whether a shorter distance from patients' residence to a transplant center increased the likelihood of referral and initiating a transplant evaluation once referred.

For the study, the investigators examined information on adults who began treatment for kidney failure at any Georgia, North Carolina, or South Carolina dialysis facility from 2012 through 2015.

Among 27,250 patients, 9,582 (35%) were referred to a transplant center within 1 year of dialysis initiation, and among those referred, 58% initiated evaluation within 6 months of referral. Although patients living the farthest (>90 miles) compared with the shortest (

"Our results indicate that distance from patient ZIP code to the nearest transplant center may not be the driving force in accessing the early steps in the kidney transplant process, referral, and evaluation initiation, among patients in the Southeastern U.S.," said McPherson. "Other unmeasured factors in the genre of distance, such as travel time or transportation options, may have a larger impact on these early steps and should be further examined. Future studies outside of the Southeastern U.S. should also be done to observe whether there are similar findings across geographic regions."

An accompanying editorial notes that the findings are likely to apply nationally across the United States, but should be confirmed in other geographic regions and in international settings.

An accompanying Patient Voice editorial provides the perspective of a working professional and patient advocate who lives in and serves fellow patients across a very rural part of America marked by a disproportionately high level of kidney disease.

DURHAM, N.C. - Contaminants that occur together naturally in groundwater under certain geological conditions may heighten health risks for millions of North Carolinians whose drinking water comes from private wells, and current safety regulations don't address the problem, a new Duke University study finds.

"Guidelines for safe drinking water are normally based on one element or contaminant," said Avner Vengosh, professor of geochemistry and water quality at Duke's Nicholas School of the Environment. "They tell us how much arsenic is okay to have in our water or the maximum amount of chromium that's safe. But what if arsenic and chromium occur together? That's something the guidelines aren't equipped to address, even though recent research suggests exposure to multiple contaminants may increase toxicity."

The Vengosh lab's new study of four naturally occurring elements - arsenic, chromium, vanadium and uranium - in North Carolina groundwater wells highlights this disconnect, Vengosh said.

"Around 84% of the wells sampled in the Kings Mountain Belt and the Charlotte and Milton Belts of the Piedmont region contained concentrations of vanadium and chromium, in its more toxic hexavalent form, that exceeded health recommendations from the North Carolina Department of Health and Human Services," said Rachel Coyte, a doctoral student at Duke University, who led the study. Of the four elements studied, vanadium and chromium were found to co-occur most frequently, she noted.

The Kings Mountain Belt and the adjacent Charlotte and Milton Belts are geological formations underlying the western Piedmont. They cover a combined area that extends northward from Charlotte and its suburbs to the Virginia border.

The fact that 84% of the nearly 1,500 wells sampled in this area contained levels of both vanadium and hexavalent chromium in excess of state health recommendations is reason for concern, Vengosh said, especially since these recommendations are based on epidemiological studies of risk factors. Yet none of the wells violate the Environmental Protection Agency's current maximum contaminant level (MCL) regulations. This sends a mixed message, he said.

"People with private wells - they don't know who to follow. The state says their water exceeds guidelines, but the EPA says they have no problem," Vengosh said.

The EPA has a maximum contaminant level for total chromium in drinking water of 100 micrograms per liter, but it has no separate MCL for hexavalent chromium, a known carcinogen, he noted. It likewise has no MCL for vanadium. By contrast, the NC Department of Health and Human Service has a much lower health advisory level for hexavalent chromium of 0.07 micrograms per liter to protect against a one-in-one-million risk of cancer over a 70-year life span. The state has a 0.3 microgram per liter health advisory level for vanadium, which some studies suggest may affect reproductive health and fetal development, though its risks are still not well-documented.

There are no guidelines, at either the federal or state levels, that address human safety of chromium and vanadium, or any other combination of elements, occur together.

Coyte and Vengosh published their peer-reviewed paper March 13 in the journal Environmental Science & Technology.

To conduct the research, they analyzed groundwater samples from 1494 private drinking water wells across North Carolina to determine the concentrations of arsenic, chromium, vanadium and uranium in each of the wells.

The highest concentrations of the four naturally occurring elements were found mostly in wells overlying fractured igneous and metamorphic geologic formations in the state's
Piedmont region. Similar geological conditions underlie the Piedmont regions in South Carolina, Georgia and Virginia, as well as other regions worldwide.

"As climate change and population growth continue to stress our water resources, North Carolina and many other communities all over the world are relying more and more on groundwater to meet their growing water needs," Coyte said. "It is important that we systematically, continually and comprehensively monitor this vital resource. We also need more research to better understand the health impacts of geogenic contaminants and mixtures of geogenic contaminants. Only then can we understand who is being exposed, and what increased health risks, if any, they may face. It's an answer we don't have now."

How do animals that help their brethren manage to prioritize those most in need? A study publishing March 24 in the open-access journal PLOS Biology by Karin Schneeberger and colleagues of the Universities of Bern in Switzerland and Potsdam in Germany, shows that rats can use odor cues alone to determine how urgently to provide food assistance to other rats in need.

Reciprocal cooperation among unrelated individuals is widespread in the animal kingdom. For example, Norway rats (Rattus norvegicus) exchange food reciprocally and take into account both the cost of helping and the potential benefit to the receiver. Rats show their need for food through solicitation, which increases the chances they will receive help. But communication through calls and gestures may not honestly reflect the actual need of the recipient, and might instead be used to trick a potential donor into helping. In the new study, Schneeberger and colleagues used Norway rats to investigate odor as a potentially "honest cue" by which prospective donors can assess others' need for food.

The researchers provided rats with odor cues from hungry or well-fed rats located in a different room. They found that the rats were quicker to provide help (by pulling a food tray within reaching distance of another rat) when they received odor cues from a hungry rat than from a well-fed one.

The authors then analyzed the air from around the rats, revealing seven different volatile organic chemicals that differed significantly in their abundance between hungry and satiated rats. According to the authors, the olfactory cues may result directly from recently ingested food sources, from metabolic processes involved in digestion, or from a putative pheromone that indicates hunger. This "smell of hunger" can serve as a reliable cue of need in reciprocal cooperation, supporting the hypothesis of honest signaling.

The authors add: "Rats donate food preferably to social partners in urgent need."

Transistors in computer chips work electrically, but data can be transmitted more quickly by using light. For this reason, researchers have long been looking for a way to integrate lasers directly in silicon chips. Scientists from Forschungszentrum Jülich have now come a step closer to achieving this. Together with researchers from Centre de Nanosciences et de Nanotechnologies (C2N) in Paris and the French company STMicroelectronics as well as CEA-LETI Grenoble, they have developed a compatible semiconductor laser made of germanium and tin, whose efficiency is comparable with conventional GaAs semiconductor lasers on Si. (Nature Photonics, DOI: 10.1038/s41566-020-0601-5)

Optical data transfer permits much higher data rates and ranges than current electronic processes while also using less energy. Computation and data centres, therefore, already default to optical fiber whenever cables exceed a length of about one metre. In future, optic solutions will be in demand for shorter and shorter distances due to increasing requirements, for example board to board or chip to chip data transfer. This applies particularly to artificial intelligence (AI) systems where large data volumes must be transferred within a large network in order to train the chip and the algorithms.

"The most crucial missing component is a cheap laser, which is necessary to achieve high data rates. An electrically pumped laser compatible with the silicon-based CMOS technology would be ideal," explains Prof. Detlev Grützmacher, director at Forschungszentrum Jülich's Peter Grünberg Institute (PGI-9). "Such a laser could then simply be shaped during the chip manufacturing process since the entire chip production is ultimately based on this technology".

But there is one problem: pure silicon is an "indirect semiconductor" and, therefore, unsuitable as a laser material. Different materials are currently used for manufacturing lasers. Generally, III-V compound semiconductors are used instead. "Their crystal lattice, however, has a completely different structure than that of silicon, which is a group IV element. Laser components are currently manufactured externally and must be integrated subsequently, which makes the technology expensive," explains Grützmacher.

In contrast, the new laser can be manufactured during the CMOS production process. It is based on germanium and tin, two group IV elements like silicon. Back in 2015, Jülich researchers showed that laser emission can be obtained in GeSn system. The decisive factor in this is the high tin content: back then, it amounted to 12 %, which is far above the solubility limit of 1 % .

"Pure germanium is, by its nature, an indirect semiconductor like silicon. The high concentration of tin is what turns it into a direct semiconductor for a laser source," explains Dr. Dan Buca, working group leader at Jülich's Peter Grünberg Institute (PGI-9).

The patented epitaxial growth process developed by Jülich is used by several research groups all over the world. By further increasing the tin concentration, lasers have already been made that work not only at low temperatures but also at 0°C.

"A high tin content, however, decreases the laser efficiency. The laser then requires a relatively high pumping power. At 12-14 % tin, we already need 100-300 kW/cm2," explains Nils von den Driesch. "We thus tried to reduce the concentration of tin and compensate this by additionally stressing the material, which considerably improves the optical properties."

For the new laser, the researchers reduced the tin content to approximately 5 % - and simultaneously decreased the necessary pumping power to 0.8 kW/cm2. This produces so little waste heat that this laser is the first group IV semiconductor laser that can be operated not only in a pulsed regime but also in a continuous working regime, i.e. as a "continuous-wave laser".

"These values demonstrate that a germanium-tin laser is technologically feasible and that its efficiency matches that of conventional III-V semiconductor lasers grown on Si. This also brings much closer to an electrical pumped laser for industrial-application that works at room temperature," explains institute head Grützmacher. The new laser is currently limited to optical excitation and low temperatures of about -140°C.

Such a laser would be interesting not only for optical data transfer but also for a variety of other applications since there are hardly any cheap alternatives for the corresponding wavelengths in the infrared range of 2-4 μm. Potential applications range from infrared and night-vision systems all the way to gas sensors for monitoring the environment in climate research or even breath gases analyses for medical diagnosis.

Researchers at the University of Notre Dame are using artificial intelligence to develop an early warning system that will identify manipulated images, deepfake videos and disinformation online. The project is an effort to combat the rise of coordinated social media campaigns to incite violence, sew discord and threaten the integrity of democratic elections.

The scalable, automated system uses content-based image retrieval and applies computer vision-based techniques to root out political memes from multiple social networks.

"Memes are easy to create and even easier to share," said Tim Weninger, associate professor in the Department of Computer Science and Engineering at Notre Dame. "When it comes to political memes, these can be used to help get out the vote, but they can also be used to spread inaccurate information and cause harm."

Weninger, along with Walter Scheirer, an assistant professor in the Department of Computer Science and Engineering at Notre Dame, and members of the research team collected more than two million images and content from various sources on Twitter and Instagram related to the 2019 general election in Indonesia. The results of that election, in which the left-leaning, centrist incumbent garnered a majority vote over the conservative, populist candidate, sparked a wave of violent protests that left eight people dead and hundreds injured. Their study found both spontaneous and coordinated campaigns with the intent to influence the election and incite violence.

Those campaigns consisted of manipulated images exhibiting false claims and misrepresentation of incidents, logos belonging to legitimate news sources being used on fabricated news stories and memes created with the intent to provoke citizens and supporters of both parties.

While the ramifications of such campaigns were evident in the case of the Indonesian general election, the threat to democratic elections in the West already exists. The research team at Notre Dame, comprised of digital forensics experts and specialists in peace studies, said they are developing the system to flag manipulated content to prevent violence, and to warn journalists or election monitors of potential threats in real time.

The system, which is in the research and development phase, would be scalable to provide users with tailored options for monitoring content. While many challenges remain, such as determining an optimal means of scaling up data ingestion and processing for quick turnaround, Scheirer said the system is currently being evaluated for transition to operational use.

Development is not too far behind when it comes to the possibility of monitoring the 2020 general election in the United States, he said, and their team is already collecting relevant data.

"The disinformation age is here," said Scheirer. "A deepfake replacing actors in a popular film might seem fun and lighthearted but imagine a video or a meme created for the sole purpose of pitting one world leader against another -- saying words they didn't actually say. Imagine how quickly that content could be shared and spread across platforms. Consider the consequences of those actions."

DURHAM, NC -- The stereotype of grumpy old people apparently doesn't hold up under closer inspection. A new study from Duke and Vanderbilt University psychologists finds that older people are generally more emotionally stable and better able to resist temptations in their daily lives.

"There is evidence here that emotional health and regulation improve with age," said Daisy Burr, a Duke PhD student who led the study with Gregory Samanez-Larkin, an assistant professor of psychology and neuroscience. Their work appeared March 23 in the journal Emotion.

The researchers pinged 123 study participants aged 20 to 80 on their cell phones three times a day for ten days. Participants were asked to indicate how they felt on a five-point scale for each of eight emotional states, including contentment, enthusiasm, relaxation and sluggishness. Then they were asked whether they were desiring anything right then, including food or alcohol, cigarettes, social media, shopping, talking to someone, sex, sleep or work. They could report up to three temptations at once.

Each participant had also been assessed on a standard measure of "global life satisfaction," which determined their general well-being, regardless of the moment-to-moment moods.

What the researchers were looking for is how positive or negative feelings and the ability to resist temptations might change as people get older.

What they found is that the older people in the study were more stable and "less volatile in their emotions," Samanez-Larkin said. And age, it turns out, is a stronger predictor of the ability to resist temptation than the emotional state.

Samenez-Larkin said a person's goals change with age. The older person may be more oriented toward the present and "trying to maximize well-being every day. You want to feel good as much as possible."

The researchers said their findings are a better reflection of real-world conditions because they surveyed participants in their own time and space, rather than having them respond to cues in a laboratory setting. Burr added that older people are better at regulating their emotional state when allowed to do what they want.

In the end, Burr's analysis of the data found people experiencing more negative affect are worse at resisting desires. Younger study participants who had higher levels of life satisfaction were better able to resist desires.

But older adults were better at resisting temptation, regardless of their life satisfaction.

In a new study, higher daily step counts were associated with lower mortality risk from all causes. The research team, which included investigators from the National Cancer Institute (NCI) and the National Institute on Aging (NIA), both parts of the National Institutes of Health, as well as from the Centers for Disease Control and Prevention (CDC), also found that the number of steps a person takes each day, but not the intensity of stepping, had a strong association with mortality.

The findings were published March 24, 2020, in the Journal of the American Medical Association.

"While we knew physical activity is good for you, we didn't know how many steps per day you need to take to lower your mortality risk or whether stepping at a higher intensity makes a difference," said Pedro Saint-Maurice, Ph.D., of NCI's Division of Cancer Epidemiology and Genetics, first author of the study. "We wanted to investigate this question to provide new insights that could help people better understand the health implications of the step counts they get from fitness trackers and phone apps."

Previous studies have been done on step counts and mortality. However, they were conducted primarily with older adults or among people with debilitating chronic conditions. This study tracked a representative sample of U.S. adults aged 40 and over; approximately 4,800 participants wore accelerometers for up to seven days between 2003 and 2006. The participants were then followed for mortality through 2015 via the National Death Index. The researchers calculated associations between mortality and step number and intensity after adjustment for demographic and behavioral risk factors, body mass index, and health status at the start of the study.

They found that, compared with taking 4,000 steps per day, a number considered to be low for adults, taking 8,000 steps per day was associated with a 51% lower risk for all-cause mortality (or death from all causes). Taking 12,000 steps per day was associated with a 65% lower risk compared with taking 4,000 steps. In contrast, the authors saw no association between step intensity and risk of death after accounting for the total number of steps taken per day.

"At NIA, we've long studied how exercise is important for older adults, and it's good to see further evidence from a large study with a broad sample that the main thing is to get moving for better overall health as we age," said Eric Shiroma, Ph.D., a co-author and NIA Intramural Research Program scientist.

In analyses by subgroups of participants, the authors found that higher step counts were associated with lower all-cause death rates among both men and women; among both younger and older adults; and among white, black, and Mexican-American adults. In secondary outcomes of the study, higher step counts were also associated with lower rates of death from cardiovascular disease and cancer.

Data collection was conducted through the CDC's National Health and Nutrition Examination Survey (NHANES), a program of studies designed to assess a nationally representative sample of the health and nutritional status of adults and children in the United States.

The researchers were surprised they didn't find an association between higher stepping intensity and all-cause mortality after adjusting for the total number of steps per day. Because few studies have investigated an association between mortality and intensity among adults going about their daily lives, the study authors wrote that future studies of walking intensity and mortality are warranted.

Although the study authors controlled for factors that could have affected the results, the study is observational and cannot prove causality. Nevertheless, their findings are consistent with current recommendations that adults should move more and sit less throughout the day. Adults who do any amount of physical activity gain some health benefits. For even greater health benefits, adults are recommended to get at least 150 minutes of moderate-intensity physical activity per week.

"Being physically active has many benefits, including reducing a person's risk of obesity, heart disease, type 2 diabetes, and some cancers. And on a daily basis, it can help people feel better and sleep better," said Janet Fulton, Ph.D., of CDC's Division of Nutrition, Physical Activity, and Obesity. "CDC is working with communities and partners across the country, as part of the Active People, Healthy Nation initiative, to make it easier, safer, and more convenient for people to be active in their own communities."

Researchers at Kyoto University's Institute for Integrated Cell-Material Sciences (iCeMS) have developed a device that moves fluids over corneal cells similarly to the movement of tears over a blinking eye. The scientists hope their findings, reported in the journal Lab on a Chip, will help improve ophthalmic drug development and testing, and advance understanding of how blinking affects the corneal surface.

The cornea is the transparent disc that covers the central surface of the eye. It acts as a protective barrier against dust, germs, and other potentially damaging objects.

One way scientists test ophthalmic drugs is to administer them into rabbit's eyes. But rabbits blink significantly less than humans, so drugs have more of a chance to permeate the rabbit's cornea and enter into the eye. Alternatively, scientists use tiny wells containing human corneal cells. But here also, the cells aren't exposed to the normal environment of a living human eye.

Kyoto University pharmaceutical scientist Rodi Abdalkader and micro-engineer Ken-ichiro Kamei collaborated to develop a device that overcomes these issues. They 3D-printed a device that contains four upper and four lower channels, separated by a clear polyester porous membrane. Corneal cells are incubated in each upper channel on top of the membrane. After seven days, they form a barrier of cells that separates the upper and lower channels. Fluid is then moved through the device to emulate the pressure exerted on one side of the cornea by a blinking eyelid and moving tears, and on the other side by the fluid of the inner eye.

Interestingly, they found that this movement changed the shape of the cells and increased the production of filaments, which are known for keeping corneal cells flexible and elastic.

"It was really interesting to find that an eye-blinking-like stimulus has a direct biological impact on these cells," says Abdalkader. "We blink frequently and unconsciously all the time. With each blink, a shear stress is applied on the corneal barrier that causes the cornea counter-defence system to secrete fibrous filaments, like keratins, to overcome the effects of the stress."

Not only does the device emulate human blinking while using human cells, but it also allows testing four different samples under similar conditions at the same time.

"We believe this platform will pave the way for improved ocular drug development, and further investigations into the effects of the shear stress caused by eye blinking on the eye's surface," says Abdalkader.

NIMS has developed a solid material capable of slowly releasing hydrogen sulfide (H2S) and nitric oxide (NO) when exposed to air. These gases can induce physiologically favorable effects at low concentrations (e.g., reducing inflammation and expanding blood vessels). However, their medical use has been limited due to difficulties in storing them and regulating their concentration. This material can release these gases safely and conveniently and will facilitate their medical use.

Although H2S and NO are toxic at high concentrations, they can generate beneficial physiological effects when used at low concentrations, such as anti-oxidation, reducing inflammation, expanding blood vessels and regulating insulin secretion. Human bodies produce these gases in small amounts to regulate various physiological functions. Medical use of these gases has been drawing a great deal of interest in recent years. For example, a low concentration of NO can be administered by inhalation to patients with severe respiratory failure (e.g., newborns with persistent pulmonary hypertension and acute respiratory distress syndrome) to expand their pulmonary vessels, thereby improving their symptoms. In addition, hot springs containing H2S have long been known to have positive effects on the skin and cardiovascular system, making H2S a potentially promising agent in the types of medicine dedicated to extending healthy life spans. However, the use of these gases has been accompanied by safety concerns and requires a large system equipped with high-pressure gas tanks. To address these issues, efforts have been made to develop solid materials capable of safely and easily storing medically useful gases and releasing them at regulated concentration in the hope of facilitating their medical use.

The NIMS research team recently developed a solid material using an inorganic compound called a layered double hydroxide which can slowly release H2S or NO at a desirable concentration when exposed to air. This material is primarily composed of layers of two-dimensional hydroxide nanosheets that contain magnesium (Mg) and aluminum (Al). This research team previously discovered that carbonate ions in the interlayer space of nanosheet layers are actively exchanged with atmospheric carbon dioxide. In this project, the team intercalated gas-source ions to the interlayer spaces and allowed them to interact with atmospheric carbon dioxide and water vapor, yielding H2S or NO gas. The team then adjusted the Mg/Al ratio in the nanosheets, thereby modifying the size of the gap between them. Different gap sizes enabled H2S or NO gas to be released stably at an intended concentration. The team also succeeded in fabricating a portable NO inhaler prototype capable of operating without a power source. This safe material composed of relatively inexpensive and nontoxic ingredients, including Mg and Al, can be kept in good condition by storing it in a gas impermeable bag. This material can be used easily by exposing it to air in a manner similar to using disposable hand warmers.

Through future study, the team is hoping to develop new drugs and medical devices incorporating this material. The use of such products may enable the provision of new health services and emergency medical services, such as making NO inhalation technologies available at home, at various destinations and in developing countries. Moreover, the material structure the team have developed may be applied to the synthesis of new materials capable of releasing other types of functional gases.

Scientists at University of Limerick's Bernal Institute have helped discover a molecule that could have a major impact on how data is stored and processed.

The UL researchers found that a simple metal-organic molecule can go beyond simple binary (0 - OFF, 1 - ON) computing logic and can in fact switch between three distinct, long-lived states.

This first demonstration of a ternary 'molecular traffic light' device could provide a low-energy means of storing and processing unstructured 'big data' required for the Internet of Things (IoT) and Artificial Intelligence (AI).

Damien Thompson, Associate Professor in Physics at UL who leads a research team in predictive materials design at the Bernal Institute, proved, using state of the art computer simulations performed on the Irish Centre for High-End Computing supercomputer, that the surprisingly stable third state is made possible by an unequal sharing of electrons between different sides of the molecule.

The research solves a 50-year-old puzzle in physics.

The work, published today in the world-leading journal Nature Nanotechnology, is a result of an international collaboration with National University of Singapore (NUS), Indian Association for the Cultivation of Science (IACS), and Texas A&M University (TAMU).

The device was conceptualized and developed at NUS by Professor T. Venkatesan and his post-doctoral researcher Dr. Sreetosh Goswami, based on a molecular complex discovered by Prof Sreebrata Goswami of IACS in Kolkata. Prof Stanley Williams, founding director of the Quantum Science Research Laboratory at Hewlett-Packard and now at TAMU, developed the new device paradigm based on the newly discovered electrical properties.

Science Foundation Ireland-supported scientist and theory lead on the project Professor Thompson explained that 'big data' is the Achilles heel of next-generation of computing, demanding ever-increasing higher computing density which means, with current binary devices, huge power requirements, impractically complex component manufacture and/or convoluted circuit designs.

"Here, we managed to push way beyond industry roadmaps by finding a ternary resistive memory device with three states that are well-separated from each other in terms of conductance and, just as importantly, stay working away perfectly for weeks on end," explained Professor Thompson.

"The trick to this first commercially viable multi-level computing device is a slightly arcane physical phenomenon called 'charge disproportionation' or symmetry breaking, which we proved using computer simulations," he added.

Professor Luuk van der Wielen, Director of Bernal Institute, said the research was "high impact and reinforces the ambition of the Bernal Institute to impact the world on the basis of top science in an increasingly international context.

"This is a continuation of Bernal scientists' world-leading contribution to the field of predictive materials modelling," he added.

Professor Sean Arkins, Dean of Science and Engineering at UL, said: "Researchers at UL's Department of Physics continue to pioneer the exploitation of organic materials for electrical applications, and this work places them at the forefront of molecular nanotechnology."

Professor Thompson outlined that scientists have long noticed that certain materials can "breathe" in an electric or magnetic field, and sometimes the electron cloud around the molecules can lose its symmetry.

"This has remained an academic curiosity until now lacking technological relevance because it has always been associated with a big change in temperature or pressure," he said.

"Whereas here the third asymmetric state is created simply by allowing current to flow through the device and it persists over a broad temperature range (-100 to +100 °C) so it is suitable for most conventional computing as well as future applications emerging from the symbiosis between physics, computing and biology.

"In this new material, ions pulse back and forth between different binding sites on the molecules, which opens up the third state, making it energetically accessible and technologically exploitable," he added.