Tech

RESEARCH TRIANGLE PARK, N.C. -- In northern Chile's Atacama Desert, one of the driest places on Earth, microorganisms are able to eke out an existence by extracting water from the rocks they colonize.

An Army-funded project by researchers at the University of California, Irvine, Johns Hopkins University and University of California, Riverside gained an in-depth understanding of the mechanisms by which some cyanobacteria, an ancient group of photosynthetic microbes, survive in harsh environments.

The new insights, published in Proceedings of the National Academy of Sciences, demonstrate how life can flourish in places without much water in evidence - including Mars - and how people living in arid regions may someday be able to procure hydration from available minerals.

"The Army has a strong interest in how microorganisms well-adapted to extreme environments can be exploited for novel applications such as material synthesis and power generation within these harsh fielded environments," said Dr. Robert Kokoska, program manager, Army Research Office, an element of U.S. Army Combat Capabilities Development Command's Army Research Laboratory. "This study provides valuable clues for uncovering the evolved design strategies used by these native desert-dwelling microbes to maintain their viability in the face of multiple environmental challenges."

Through work in the field and laboratory experiments, the research team focused on the interactions of Chroococcidiospsis, a desiccation-resistant species of cyanobacteria that is found in deserts around the world, and gypsum, a water containing calcium sulfate-based mineral. The colonizing lifeforms exist beneath a thin layer of rock that gives them a measure of protection against the Atacama's extreme temperature, high solar irradiance and battering winds.

Co-author Jocelyne DiRuggiero, JHU associate professor of biology, traveled to the remote desert to collect gypsum samples and brought them back to her labs in the United States. She cut small pieces, where microorganisms could be found, and sent them to UCI for materials analysis.

In one of the most striking findings of the study, the researchers learned that the microorganisms change the very nature of the rock they occupy. By extracting water, they cause a phase transformation of the material - from gypsum to anhydrite, a dehydrated mineral.

According to DiRuggiero, the impetus for the published work came when Wei Huang, a UCI post-doctoral scholar in materials science & engineering, spotted data showing an overlap in concentrations of anhydrite and cyanobacteria in the gypsum samples collected in the Atacama.

"Our analysis of the regions of rock where microbes were colonized revealed a dehydrated phase of calcium sulfate, suggesting that they extract water from the rock to survive," said David Kisailus, lead author and UCI professor of materials science & engineering. "We wanted to do some more controlled experiments to validate that hypothesis."

DiRuggiero's team then allowed the organisms to colonize half-millimeter cubes of rocks, called coupons, under two different conditions, one in the presence of water, to mimic a high-humidity environment, and the other completely dry. In the midst of moisture, the gypsum did not transform to the anhydrite phase.

"They didn't need water from the rock, they got it from their surroundings," Kisailus said. "But when they were put under stressed conditions, the microbes had no alternative but to extract water from the gypsum, inducing this phase transformation in the material."

Kisailus' team used a combination of advanced microscopy and spectroscopy to examine the interactions between the biological and geological counterparts, finding that the organisms bore into the material like tiny miners by excreting a biofilm containing organic acids, Kisailus said.

Huang used a modified electron microscope equipped with a Raman spectrometer to discover that the organisms used the acid to penetrate the rock in specific crystallographic directions - only along certain planes where they could more easily access water existing between faces of calcium and sulfate ions.

Kisailus said the project was a great demonstration of interdisciplinary research between microbiologists and materials scientists that may, one day, open doors to other forms of scientific discovery.

"Scientists have suspected for a long time that microorganisms might be able to extract water from minerals, but this is the first demonstration of it," DiRuggiero said. "This is an amazing survival strategy for microorganisms living at the dry limit for life, and it provides constraints to guide our search for life elsewhere."

Researchers said this study can benefit the Army Research Lab's efforts in synthetic biology.

"These findings have drawn the interest of our lab as microbial survival mechanisms can be leveraged for biomanufacturing or sensing platforms in harsh military environments," said Dr. Matthew Perisin of the lab's biotechnology branch.

Through a meta-analysis of biotrophs, hemibiotrophs, and necrotophs, four scientists set out to find if the latent period of leaf fungal pathogens reflects their trophic types. The answer? Yes, there is a strong relationship between the trophic type and the latent period, an important functional trait of pathogenic fungi.

"There are three major trophic types of plant pathogens that correspond with strategies for host exploitation," explains plant pathologist Pierre-Antoine Précigout. "Biotrophic pathogens colonize and reproduce in living tissues. Necrotrophic pathogens kill their host soon after infection and complete their whole infectious cycle on dead tissue. Hemibiotrophic pathogens have a rather intermediate life cycle: they infect and develop while the tissue is alive, and then kill it to reproduce."

Précigout and his colleagues believed that the trophic type of a fungi is related to its latent period, which is the duration of the host colonization phase before reproduction. To test this hypothesis, they analyzed 2,542 latent periods covering 53 pathogen species and found a significant link between latent period and trophic type. On average, necrotrophs have the shortest latent period at about 100 degree-days (DD), followed by biotrophs at about 170 DD, and then by hemibiotrophs that have the longest latent periods at about 270 DD.

When considering why hemibiotrophs have such a long latent period, Précigout and his colleagues propose an eco-evolutionary hypothesis based on the milker versus killer theory (van Baalen and Sabelis, 1995). They hypothesize that the long biotrophic phase corresponds to a milker strategy by delaying the virulence related to the switch to necrotrophy.

Their research also shows that host resistance, which results in an increase in the latent period, may be due to an increase in the incubation period alone (for hemibiotrophs), the symptom development period alone, or both periods simultaneously. For biotrophs and necrotophs, resistance also increased the period of symptom development.

"The link between the manifestation of host resistance and the trophic type of the pathogen, through an increase of the incubation period or via an increase of the period of symptom development (or both) may be of interest for crop protection," says Précigout. "More specifically, it can offer guidance for selecting resistant varieties by taking trophic type into account in plant breeding strategy."

Surprisingly, the environment in which the studies were conducted seemingly had little impact on the latent period. Also of note, the effect of the trophic type on the latent period was quantitatively as important as the effect of host resistance.

"Our article proposes an ecological vision of the latent period of pathogenic fungi, which may be of interest to the world of plant pathology. In particular, if pathogens are to adapt to environmental changes through their latent period, then the different trophic types shall have different adaptive capabilities," says Précigout. Read more about this research in "Does the Latent Period of Leaf Fungal Pathogens Reflect Their Trophic Type? A Meta-Analysis of Biotrophs, Hemibiotrophs, and Necrotrophs," published in the February issue of Phytopathology.

Spinels are oxides with chemical formulas of the type AB2O4, where A is a divalent metal cation (positive ion), B is a trivalent metal cation, and O is oxygen. Spinels are valued for their beauty, which derives from the molecules' spatial configurations, but spinels in which the trivalent cation B consists of the element chrome (Cr) have aroused strong interest for a reason that has nothing to do with aesthetics: they have magnetic properties with an abundance of potential technological applications, from gas sensors to drug carriers, and from data storage media to components of telecommunications systems.

A study by Brazilian and Indian researchers investigated a peculiar kind of spinel: zinc-doped manganese chromite. Nanoparticles of this material, described by the formula Mn0.5Zn0.5Cr2O4 [where manganese (Mn) and zinc (Zn) compose the A-site divalent cation], were synthesized in the laboratory and characterized by calculations based on density functional theory (DFT), a method derived from quantum mechanics that is used in solid-state physics and chemistry to resolve complex crystal structures.

The material's structural, electronic, vibrational and magnetic properties were determined by X-ray diffraction, neutron diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. A report of the study has been published in the Journal of Magnetism and Magnetic Materials with the title "Structural, electronic, vibrational and magnetic properties of Zn2+ substituted MnCr2O4 nanoparticles".

The Brazilian scientists who participated in the study are affiliated with the Center for Research and Development of Functional Materials (CDMF), one of the Research, Innovation and Dissemination Centers (RIDCs) supported by São Paulo Research Foundation - FAPESP.

A paramagnetic-to-antiferromagnetic phase transition was established at 19 kelvin (-254.15 Celsius). Paramagnetic materials are attracted by an external magnetic field because their atoms or molecules each have one electron with an unpaired spin. Magnetic materials have several organized unpaired electrons, and the cumulative effect of these electrons produces magnetic attraction. In antimagnetic or antiferromagnetic materials, the spins of all the electrons are paired, so that for every spin-up electron, there is a spin-down electron. As a result, they do not respond perceptibly to the presence of a moderate external magnetic field.

"Our interest in this material is due to its magnetic properties," Elson Longo, one of the authors of the study, told. Longo is a Professor Emeritus in the Chemistry Department of the Federal University of São Carlos (UFSCar) in the state of São Paulo, Brazil, and CDMF's principal investigator.

"Conventional studies consider magnetic properties generically, from the standpoint of the system as a whole, whereas we've developed a quantum mechanical method to determine magnetic properties on the basis of the morphologies of the surfaces of a material's crystal structure," Longo said. "Even before synthesizing any material, we're able to predict its magnetic properties theoretically. In this specific case, we expected the zinc to promote an increase in the surface with magnetic properties, and this did indeed happen."

According to Longo, to be properly understood, a crystal should be considered on three different scales. "At a long distance, we have the entire crystal. At a short distance, we have the smallest possible cluster of atoms. At a medium distance, we have two or more clusters interacting. If a cluster is perfectly ordered, it won't display paramagnetic behavior, let alone magnetic behavior, because for every spin-up electron, there will be an offsetting spin-down electron. However, if any change is made - if the chemical bond angles are altered, for example - then unpaired electrons may appear, and the material may become paramagnetic or even magnetic," he said.

This disturbance can also occur as a result of medium-distance interactions. Magnetism, therefore, can be produced by changes at both short and medium distances.

The same material can display different properties depending on variations in certain parameters, which has to do with how the material is synthesized.

"CDMF is conducting studies concentrating on identifying very cheap materials with bactericidal and fungicidal properties. One of the applications would be the production of packaging to extend the shelf life of food products.

Another focus is the identification of inorganic materials with anticancer properties. A third line of research aims to find photodegradation materials capable of breaking down organic molecules and converting them into carbon gas and water. These materials could be used to clean up rivers contaminated by pollutants," Longo said.

LANCASTER, England -- Researchers working on molecular-level responses in crops have taken a step closer to their goal of producing heat-tolerant wheat.

Smart thermostats tell air conditioners to switch on when the sun is bearing down in the summer and when to shut down to conserve energy. Similarly, plants have Rubisco activase, or Rca for short, that tells the plant's energy-producing enzyme (Rubisco) to kick on when the sun is shining and signals it to stop when the leaf is deprived of light to conserve energy.

Today, a team from Lancaster University reports in The Plant Journal that swapping just one molecular building block out of 380 that make up an Rca in wheat enables it to activate Rubisco faster in hotter temperatures, suggesting an opportunity to help protect crops from rising temperatures.

"We took a wheat Rca (2β) that was already pretty good at activating Rubisco in lower temperatures and swapped out just one of its amino acids with one found in another wheat Rca (1β) that works pretty well in higher temperatures but is rubbish at activating Rubisco -- and the result is a new form of 2β Rca that is the best of both worlds," said Elizabete Carmo-Silva, a senior lecturer at the Lancaster Environment Centre who oversaw this work for a research project called Realizing Increased Photosynthetic Efficiency (RIPE).

RIPE is engineering crops to be more productive by improving photosynthesis, the natural process all plants use to convert sunlight into energy 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).

Here's the breakdown: naturally occurring wheat Rca 1β has an isoleucine amino acid, works up to 39 degrees Celcius, but isn't great at activating Rubisco, whereas the naturally occurring 2β has a methionine amino acid, works up to about 30 degrees Celcius, and is good at activating Rubisco. Here the team has created a new version of 2β with an isoleucine amino acid that works up to 35 degrees Celcius and is quite good at activating Rubisco.

"Essentially, 1β is a rubbish enzyme and 2β is sensitive to higher temperatures," Carmo-Silva said. "The cool thing here is that we have shown how this one amino acid swap can make Rca active at higher temperatures without really affecting its efficiency to activate Rubisco, which could help crops kickstart photosynthesis under temperature stress to churn out higher yields."

This work was carried out in vitro in E. coli, supported by a Ph.D. studentship by the Lancaster Environment Centre to first author Gustaf Degen. Importantly, these findings will support RIPE's efforts to characterise and improve the Rca of other food crops such as cowpea and soybean, each with multiple different forms of Rca.

"When looking at cowpea growing regions in Africa, it goes all the way from South Africa with an average around 22 degrees Celcius to Nigeria at about 30, and areas further north get to 38," Carmo-Silva said. "If we can help Rubisco activate more efficiently across these temperatures, that is really powerful and could help us close the gap between yield potential and the reality for farmers who depend on these crops for their sustenance and livelihoods."

While public discussion during and after the 2016 presidential campaign between Donald Trump and Hillary Clinton largely focused on emails and email servers, a team of political science scholars zeroed in on email communications distributed by the campaigns and found that email is still an important campaign tool despite its mundane nature.

In their new research titled "The (surprisingly interesting) story of email in the 2016 presidential election" published in the Journal of Information Technology and Politics, Dr. Jeff Broxmeyer, assistant professor of political science at The University of Toledo, and Dr. Ben Epstein, associate professor of political science at DePaul University, explored 10 months of emails leading up to Election Day and analyzed ways that emails sent by campaigns reveal varied strategies and goals of campaigns.

Notably, Trump campaign e-mails were more participatory, fitting the populist theme of the campaign, and the Clinton campaign made the surprising strategic decision to stop direct e-mail communication to passive e-mail subscribers more than two months before Election Day.

"Trump's campaign was oddly silent with emails through the primary and the general up until October. When it revved up, turns out his campaign had fewer appeals to donate and more appeals to do something - show up to an event or make phone calls," Broxmeyer said. "That was a big outlier because we found that most of the top-tier candidates - the serious ones - ran sophisticated, full-gauge operations and used email extensively and almost entirely as an ATM to ply supporters with appeals for small donations, including Bernie Sanders despite his mobilizing rhetoric."

A window into campaign intensity, the researchers found that Clinton was sending eight emails a week to her supporters at peak; U.S. Senator Ted Cruz stopped campaign emails long before the Republican National Convention; Jim Gilmore, former governor of Virginia and chair of the Republican National Committee, didn't send a single email to supporters; and Lincoln Chaffee sent a total of eight campaign emails to his supporters.

The emails showed the degree to which campaigns existed on paper, but were not actively being run.

"Some candidates - also-rans - claimed they weren't getting enough attention from the press, but they didn't really try to communicate at all with their own supporters, people who went on the website and actually signed up to be on the email list," Broxmeyer said.

The researchers were surprised by the Clinton campaign's decision to stop sending emails to accounts that had not engaged with the campaign since signing up for emails.

"The Clinton campaign made that move in August, nearly three months before the end of the election and just as the Trump campaign started ramping up its email campaign," Epstein said. "Overall this study demonstrates how some strategies, such as the frequency of emailing, focus on fundraising, and consistent forms of interactions have become widely accepted norms. It is clear that e-mail remains valuable for campaigns and an important subject for scholarship, despite its mundane nature."

A Korean research team found a method to inhibit the fouling of membranes, which are used in the desalination process that removes salt and dissolved substances from seawater to obtain drinking, domestic, and industrial water.

The Korea Institute of Science and Technology (KIST) announced that a research team led by Dr. Seongpil Jeong and Dr. Seockheon Lee at KIST's Water Cycle Research Center developed a *membrane distillation pretreatment process that adds magnesium to inhibit the fouling and wetting of membranes during desalination.

*Membrane distillation (MD): A technology used to produce fresh water from seawater in which the seawater is heated to produce a vapor, which is then passed through a hydrophobic membrane that traps the salt and other particles to produce fresh water.

The membrane distillation process is a desalination technology used to produce fresh water in which seawater is heated to generate a vapor, which is then passed through a hydrophobic membrane before condensing into fresh water. The phenomena of **fouling and ***wetting can often occur during the membrane distillation process. If fouling occurs, it can cause the production of fresh water to take much longer or shorten the lifespan of the membrane used in the distillation process, thereby increasing the costs associated with freshwater production.

**Fouling: A phenomenon in which contaminants (particles, organic/inorganic matters) attach to or penetrate the membrane, resulting in membrane scaling

***Wetting: A phenomenon in which seawater directly passes through a hydrophobic membrane, which theoretically only lets vapor pass through

The KIST research team monitored the membrane distillation process and found that the formation of calcium carbonate (CaCO3) and calcium sulfate (CaSO4) crystals on the membrane surface was the main cause of fouling. They also found that the formation of CaCO3 crystals occurred at the beginning of the membrane distillation process, causing partial membrane wetting, while the formation of CaSO4 crystals caused a complete membrane wetting, halting membrane operation.

****Anti-scalants are often applied to prevent fouling caused by calcium-based crystal growth in the desalination process. There have been some reports in the industry about a chemical *****softening technology that can be applied as a pretreatment process for membrane distillation. However, it has also been reported that organic anti-scalants can reduce the surface tension of the feed solution and cause wetting. The application of chemical softeners, however, requires additional large-scale sedimentation and filtering processes to remove the crystals formed during the softening process.

****Anti-scalants: Chemicals that remove ions (calcium, magnesium) that can lead to the formation of crystals (scales)

*****Softening: Process of turning hard water into soft water by removing the calcium and/or magnesium found in the water.

KIST's research team, led by Dr. Seongpil Jeong, is the first research team to ever develop a pretreatment process that adds magnesium to seawater. The team found that magnesium inhibits the formation of CaCO3 and CaSO4 and effectively prevents membrane fouling since the magnesium readily combines with the carbonate and sulfate ions in the seawater The team also found that the added magnesium chloride (MgCl2) increased the stability of the hydrophobic membrane, thereby increasing wetting resistance.

"Increasing the stability of the hydrophobic membrane is expected to help improve desalination efficiency and lengthen the lifespan of the membrane," said Hye-won Kim (first author of Water Research (Vol. 175 (2020) 115677)) at KIST. "The mineral-based, environmentally-friendly pretreatment is applicable not only to the membrane distillation process but also to various other desalination processes."

Molecules are some of life's most basic building blocks. When they work together in the right way, they become molecular machines that can solve
the most amazing tasks. They are essential for all organisms by, for example, maintaining a wide range of cellular functions and mechanisms.

What if you could create and control an artificial molecular machine? And make it perform tasks that serve us humans?

Many researchers are looking for ways to create and control such molecular machines, and research is going on in labs all over the world.

At University of Southern Denmark, Ph.D. Rikke Kristensen and colleagues from Professor Jan O. Jeppesen's research group at the Department of Physics, Chemistry, and Pharmacy have published a scientific study on molecular machines that have attracted attention.

The study is published in the journal Chemistry -- A European Journal and has been published both as a so-called Hot Paper and as a Cover Feature.

Before a research result can be published in a scientific journal, it must be evaluated by a number of scientific peers, and in this case the reviewers have considered the study to be of great significance.

What attracts attention is that the researchers have succeeded to obtain control of the molecular machines, which in the future may enable them to perform controlled movements.

- In principle, this means that you can send the machine off to the place, where you want it to perform its function, says Rikke Kristensen.

One example could be to pack a molecular machine into a tablet of medicine and use it to control when the drug gets released.

The challenge of medicine today is that the active components must be well protected while being transported through the body, so they don't get degraded or released before they reach their destination in the body - but they also need to be released when they do reach their destination.

- If a molecular machine is built into the tablet, it can help when the active components in the tablet reaches their destination; then the molecular machine can help open the tablet and allow the active components to be released so they can do their job where needed, says Rikke Kristensen.

Optimal delivery of active components to destinations in the body is a huge challenge for anyone developing new drugs, and it is particularly difficult to deliver active components to the brain.

The so-called blood/brain barrier is one of the most impenetrable barriers in the human organism.

Another example is to include molecular machines in coating products that are added to surfaces: Activating the motions of the molecular machines will change the properties of the surface and thereby remove the dirt from the surface.

And then there are the small computers: Molecular machines have the potential to give us organic computers that are a hundred times smaller than the computers we know today.

- Future applications are fascinating, but it is important to remember that for now, this is basic and not applied science, says Professor and Principle Investigator Jan O. Jeppesen.

- Right now, we approach this field with curiosity and a desire to understand what happens, when we begin to tamper with nature's smallest building blocks. Where it all ends and what use our descendants can find for this in the future, we cannot predict, says Jan O. Jeppesen.

He continues:

- When electricity was invented, nobody could predict how it would affect the world. In a way, it is the same here; we are faced with something new that we may not fully understand today. Maybe people will laugh at our ideas in 50 years. Maybe the ideas will be surpassed. I can't tell you.

In short, the researchers' breakthrough is that they have succeeded in controlling the molecular machines so that they can be controlled to move only in one direction.

- It's a big step forward. So far, we have been able to move a molecular machine - but only between two points. Now, in principle, we can send the machine off in a desired direction for as long as we want to, explains Rikke Kristensen and continues:

- It is like having a car wheel that can only rotate back and forth for half a turn (between two points). That does not give the car momentum. If you want the car to move forward, the wheels must rotate in a certain direction as long as you want them to do so. Similarly, it is important that a molecular machine can move in the same direction for the desired period of time.

In a comprehensive ecological study, a team of scientists at the Max Planck Institute for Chemical Ecology in Jena examined three different species of the genus Drosophila and their interactions with their natural food resources, in particular the yeasts associated with these substrates. They found that vinegar flies do not necessarily prefer yeasts they know from their natural environments, but were also attracted by yeasts found in a foreign habitat. Female flies sometimes even decided to lay their eggs in presence of previously unknown yeast communities, although their offspring had less chance of survival there. Such processes in nature could be a key factor that leads to the flies populating new habitats and, provided that the larvae also survive there, the formation of niches and, ultimately, the evolution of new species (OIKOS, doi: 10.1111/oik.07180).

Everyone knows the common vinegar fly (Drosophila melanogaster), which - often not quite correctly called a "fruit fly" - is naturally found in swarms on fruit during the hot season, especially when bananas, apples, pears and other fruits are overripe and fermentation processes start. This is because the flies are attracted primarily by the odor of the yeasts involved in fermentation, rather than by the fruits themselves. Not only do the flies feed on these yeasts; the microorganisms also provide a first-class breeding substrate on which they lay their eggs and on which their larvae thrive. More than 1500 different species of the genus Drosophila are known. Many of the fly species are specialized for specific habitats; they feed, for example, exclusively on certain fruits and lay their eggs there.

Researchers at the Max Planck Institute for Chemical Ecology wanted to know more about the role of the yeasts that grow on the respective hosts play in the host selection of the flies, and whether a partnership or mutual dependency between flies and these yeasts had developed in the process of co-evolution. "We asked ourselves: Would the fly species remain faithful to their yeasts, or would they also be attracted towards other yeasts, and would that influence the reproductive success of their species?" Sarah Koerte, first author and doctoral researcher in the Department of Evolutionary Neuroethology, summarizes the initial question.

In addition to Drosophila melanogaster, the team took a closer look at two other species of the genus Drosophila, their host substrates and the associated yeasts: Drosophila mojavensis, a species first described in the Mojave Desert in the southwest of the USA, which thrives on cacti, especially necrotic cactus tissue, and Drosophila putrida, a species found in the Midwestern USA, which reproduces exclusively on fungi.

Female flies make decisions with negative consequences for their offspring

In behavioral experiments, the scientists tested the preferences of adult flies of all three species for yeasts, which grow either on fruit (the baker's or brewer's yeast Saccharomyces cerevisiae), on cacti (Pichia cactophila) or on fungi (Vanrija humicola), and are thus part of the naturally associated microbial communities for each of the fly species. In addition, the influence of different yeast species on the egg laying behavior of mated female flies was observed.

Surprisingly, the flies did not necessarily prefer yeasts from their familiar habitat, but were also attracted towards the other yeasts. Females of the vinegar fly Drosophila melanogaster preferred to lay their eggs on a substrate with yeasts found on cacti, while female flies of the fungus specialist Drosophila putrida preferred fruit-specific yeasts for egg deposition. A real surprise was that female flies laid their eggs in the presence of yeasts which even had a negative effect on the development of their offspring, as experiments with Drosophila larvae on different brood substrates showed: Larvae of the Drosophila species that had specialized in cacti or fungi actually thrived best on yeasts associated with the familiar habitat, while yeasts from unknown environments tended to cause poor larval development and high mortality. In contrast to the two species with a limited host spectrum, Drosophila melanogaster larvae developed equally well on all tested yeasts, as this species is a generalist with a more flexible lifestyle.

The yeasts help the flies to decompose the plant or fungal substrate. The flies, on the other hand, excrete the yeasts undigested with their frass, and as a consequence the yeasts can spread further. The researchers suspected that the yeasts might be involved to different degrees in the decomposition of the respective substrates. Analyses of the sugar contents and the degradation rates showed that flies and yeasts together accelerated the decomposition. However, there was no evidence that the interaction of a specific fly species with its associated yeast was beneficial.

"Our results show that flies with a broad host spectrum were also more tolerant to different yeasts in food sources and at oviposition sites. Interestingly, the flies did not care much which yeasts were present when laying their eggs, while the hatching larvae were often only able to grow on the yeasts they would have encountered in nature," said Markus Knaden, head of the study. However, if larvae survive on a new host and the host-specific yeasts, this might enable the flies to adapt to new environments, which might lead to the evolution of new species.

"The evolutionary success of Drosophila might be linked to the ability to adapt rapidly to new habitats. Insect-associated microbial communities could be the evolutionary keys to unlock new doors and pathways towards conquering unknown environments and establishing new ecological niches," says Sarah Koerte.

Biological clocks are an organism's innate timing device. It is composed of specific proteins called clock proteins, which interact in cells throughout the body. Biological clocks produce and regulate circadian rhythms - the physical, mental, and behavioural changes that follow a daily cycle. Understanding the molecular mechanisms of the circadian clock provides a huge potential to identify therapeutic interventions to mitigate circadian disruption, and its long-term consequences such as diabetes, obesity and cancer among shift workers, who undergo frequent circadian disruption and are more prone to these diseases.

The Duke-NUS scientists had previously discovered that mutations in a specific protein (called casein kinase 1) alters the core clock protein (called PERIOD or PER), and this changes the timing of the biological clock. In this study, preclinical models were used to investigate the role of PER2 (a type of PER protein) in clock regulation to further understand and strengthen the model.

"The study findings clearly demonstrated that targeted mutations in the PER2 protein can alter the balance of biological clock and can significantly lengthen the circadian period in preclinical models," said Dr Rajesh Narasimamurthy, Principal Research Scientist at the Duke-NUS' Cancer and Stem Cell Biology (CSCB) programme.

"People's sleep/wake patterns play a significant role in determining their cognitive skills, social behavior and their responses to drug," said Professor David Virshup, Director of the Duke-NUS' CSCB programme and corresponding author of this study.

"Our study helps us understand and validate the genetic and biochemical regulation of our circadian sleep/wake cycles, which can produce a morning lark or night owl effect. Understanding how the clock works can help in the development of new therapeutic interventions for treating people with sleep disorders," Prof Virshup added.

"Sleep disorders are increasingly recognised as a major public health concern. This important study by our researchers could open new possibilities and strategies to treat sleep disorders, and improve the quality of life among affected individuals in Singapore and beyond," said Professor Patrick Casey, Senior Vice Dean for Research at Duke-NUS.

The team is currently investigating other factors that can cause mutation in PER2 protein and regulate the clock speed.

The Video Enabled Justice (VEJ) Independent Evaluation was led by academics from the University of Surrey's Department of Sociology and the Centre for Translation Studies in the School of Literature and Languages. Sponsored by the Sussex Police and Crime Commissioner Katy Bourne, the report investigated the impact of a new booking tool used in the organisation of first appearance remand hearings in video court. Drawing on data from observation of over 600 video-enabled and traditional in-person hearings in magistrates' courts, and semi-structured telephone interviews with court users and stakeholders, the study provides new insights into the performance of the booking software used in the court listing process, as well as other pertinent features of video courts when compared to traditional in-person courts.

The evaluation found that the impact of the introduction of the booking tool on court processes was benign but relatively modest. Positive effects were identified, such as improved oversight of the court's list. However, resource and infrastructure constraints across the court and police estates inhibited the tool's optimal functioning. Booking software is closely integrated with the audio-visual infrastructure of the courts, and its optimal functionality is only achieved with high quality courtroom AV and suitably trained court staff.

Comprehensive planning across all criminal justice agencies whose staff have a role in the court process was found to be essential in order to reduce disruption to live hearings. An expansion in the number of end-points from which parties at remote locations can join a hearing, as well as improved internet access, was required to enable secure and reliable access to online hearings. The research also suggests that investment in audio-video equipment, as well as attention to the audio-visual environment in both the courtroom and remote video booths (such as those in remand centres and police custody suites), are required to improve the experience of participating in video hearings.

Since the parties involved in video court hearings are at different locations, such hearings pose additional challenges not found in traditional in-person contexts, highlighting the importance of enhanced digital working. These challenges are aggravated when the complexity of hearings increases, e.g. due to the involvement of an interpreter. For interventions such as the booking tool to realise their full potential within the court listing process there is a need to ensure that such investments are developed hand-in-hand with more comprehensive solutions for electronic protocols in court.

Professor Nigel Fielding, lead author and a long-standing researcher in criminology and the justice system, said: "Our report provides valuable insights on video-enabled justice for the court service and court users just as the Covid-19 pandemic seems poised to lead to a dramatic rise in the use of technology and other innovations to ensure the effective continued administration of justice. They will be using existing AV equipment on a 'whatever is to hand' basis, with many courts having relatively basic AV equipment and very few courts being equipped with booking software. We are delighted to be able to offer an evaluation that will help equip those who will deliver and experience this expansion of video-enabled justice with insights that should help ensure benefits are secured and challenges mitigated."

Here's a new chapter in the story of the miniaturisation of machines: researchers in a laboratory in Singapore have shown that a single atom can function as either an engine or a fridge. Such a device could be engineered into future computers and fuel cells to control energy flows.

"Think about how your computer or laptop has a lot of things inside it that heat up. Today you cool that with a fan that blows air. In nanomachines or quantum computers, small devices that do cooling could be something useful," says Dario Poletti from the Singapore University of Technology and Design (SUTD).

This work gives new insight into the mechanics of such devices. The work is a collaboration involving researchers at the Centre for Quantum Technologies (CQT) and Department of Physics at the National University of Singapore (NUS), SUTD and at the University of Augsburg in Germany. The results were published in the peer-reviewed journal npj Quantum Information on 1 May.

Engines and refrigerators are both machines described by thermodynamics, a branch of science that tells us how energy moves within a system and how we can extract useful work. A classical engine turns energy into useful work. A refrigerator does work to transfer heat, reducing the local temperature. They are, in some sense, opposites.

People have made small heat engines before using a single atom, a single molecule and defects in diamond. A key difference about this device is that it shows quantumness in its action. "We want to understand how we can build thermodynamic devices with just a few atoms. The physics is not well understood so our work is important to know what is possible," says Manas Mukherjee, a Principal Investigator at CQT, NUS, who led the experimental work.

The researchers studied the thermodynamics of a single barium atom. They devised a scheme in which lasers move one of the atom's electrons between two energy levels as part of a cycle, causing some energy to be pushed into the atom's vibrations. Like a car engine consumes petrol to both move pistons and charge up its battery, the atom uses energy from lasers as fuel to increase its vibrating motion. The atom's vibrations act like a battery, storing energy that can be extracted later. Rearrange the cycle and the atom acts like a fridge, removing energy from the vibrations.

In either mode of operation, quantum effects show up in correlations between the atom's electronic states and vibrations. "At this scale, the energy transfer between the engine and the load is a bit fuzzy. It is no longer possible to simply do work on the load, you are bound to transfer some heat," says Poletti. He worked out the theory with collaborators Jiangbin Gong at NUS Physics and Peter Hänggi in Augsburg. The fuzziness makes the process less efficient, but the experimentalists could still make it work.

Mukherjee and colleagues Noah Van Horne, Dahyun Yum and Tarun Dutta used a barium atom from which an electron (a negative charge) is removed. This makes the atom positively charged, so it can be more easily held still inside a metal chamber by electrical fields. All other air is removed from around it. The atom is then zapped with lasers to move it through a four-stage cycle.

The researchers measured the atom's vibration after applying 2 to 15 cycles. They repeated a given number of cycles up to 150 times, measuring on average how much vibrational energy was present at the end. They could see the vibrational energy increasing when the atom was zapped with an engine cycle, and decreasing when the zaps followed the fridge cycle.

Understanding the atom-sized machine involved both complicated calculations and observations. The team needed to track two thermodynamic quantities known as ergotropy, which is the energy that can be converted to useful work, and entropy, which is related to disorder in the system. Both ergotropy and entropy increase as the atom-machine runs. There's still a simple way of looking at it, says first author and PhD student Van Horne, "Loosely speaking, we've designed a little machine that creates entropy as it is filled up with free energy, much like kids when they are given too much sugar."

RICHLAND, Wash. -- Software vulnerabilities are more likely to be discussed on social media before they're revealed on a government reporting site, a practice that could pose a national security threat, according to computer scientists at the U.S. Department of Energy's Pacific Northwest National Laboratory.

At the same time, those vulnerabilities present a cybersecurity opportunity for governments to more closely monitor social media discussions about software gaps, the researchers assert. Their findings were published recently in the journal PLOS One.

"Some of these software vulnerabilities have been targeted and exploited by adversaries of the United States. We wanted to see how discussions around these vulnerabilities evolved," said lead author Svitlana Volkova, senior research scientist in the Data Sciences and Analytics Group at PNNL. "Social cybersecurity is a huge threat. Being able to measure how different types of vulnerabilities spread across platforms is really needed."

Social media - especially GitHub - leads the way

Their research showed that a quarter of social media discussions about software vulnerabilities from 2015 through 2017 appeared on social media sites before landing in the National Vulnerability Database, the official U.S. repository for such information. Further, for this segment of vulnerabilities, it took an average of nearly 90 days for the gap discussed on social media to show up in the national database.

The research focused on three social platforms--GitHub, Twitter and Reddit--and evaluated how discussions about software vulnerabilities spread on each of them. The analysis showed that GitHub, a popular networking and development site for programmers, was by far the most likely of the three sites to be the starting point for discussion about software vulnerabilities.

It makes sense that GitHub would be the launching point for discussions about software vulnerabilities, the researchers wrote, because GitHub is a platform geared towards software development. The researchers found that for nearly 47 percent of the vulnerabilities, the discussions started on GitHub before moving to Twitter and Reddit. For about 16 percent of the vulnerabilities, these discussions started on GitHub even before they are published to official sites.

Codebase vulnerabilities are common

The research points at the scope of the issue, noting that nearly all commercial software codebases contain open-source sharing and that nearly 80 percent of codebases include at least one vulnerability. Further, each commercial software codebase contains an average of 64 vulnerabilities. The National Vulnerability Database, which curates and publicly releases vulnerabilities known as Common Vulnerabilities and Exposures "is drastically growing," the study says, "and includes more than 100,000 known vulnerabilities to date."

In their paper, the researchers discuss which U.S. adversaries might take note of such vulnerabilities. They mention Russia, China and others and noted that there are differences in usage of the three platforms within those countries when exploiting software vulnerabilities.

According to the study, cyberattacks in 2017 later linked to Russia involved more than 200,000 victims, affected more than 300,000 computers, and caused about $4 billion in damages.

"These attacks happened because there were known vulnerabilities present in modern software," the study says, "and some Advanced Persistent Threat groups effectively exploited them to execute a cyberattack."

Bots or human: Both pose a threat

The researchers also distinguished between social media traffic generated by humans and automated messages from bots. A social media message crafted by an actual person and not generated by a machine will likely be more effective at raising awareness of a software vulnerability, the researchers found, emphasizing that it was important to differentiate the two.

"We categorized users as likely bots or humans, by using the Botometer tool," the study says, "which uses a wide variety of user-based, friend, social network, temporal, and content-based features to perform bot vs. human classification."

The tool is especially useful in separating bots from human discussions on Twitter, a platform that the researchers noted can be helpful for accounts seeking to spread an agenda. Also regarding Twitter, the researchers found a subset of its users--for example FireEye, The Best Linux Blog In the Unixverse, The Hacker News and individual accounts belonging to cybersecurity experts--focused on news about software vulnerabilities.

Ultimately, awareness of social media's ability to spread information about software vulnerabilities provides a heads-up for institutions, the study says.

"Social media signals preceding official sources could potentially allow institutions to anticipate and prioritize which vulnerabilities to address first," it says. "Furthermore, quantification of the awareness of vulnerabilities and patches spreading in online social environments can provide an additional signal for institutions to utilize in their open source risk-reward decision making."

Dark matter has so far defied every type of detector designed to find it. Because of its huge gravitational footprint in space, we know dark matter must make up about 85 percent of the total mass of the universe, but we don't yet know what it's made of.

Several large experiments that hunt for dark matter have searched for signs of dark matter particles knocking into atomic nuclei via a process known as scattering, which can produce tiny flashes of light and other signals in these interactions.

Now a new study, led by researchers at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley, suggests new paths for catching the signals of dark matter particles that have their energy absorbed by these nuclei.

The absorption process could give an affected atom a kick that causes it to eject a lighter, energized particle such as an electron, and it might produce other types of signals, too, depending on the nature of the dark matter particle.

The study focuses mostly on those cases where an electron or neutrino is ejected as the dark matter particle strikes an atom's nucleus.

Published May 4 in Physical Review Letters, the study proposes that some existing experiments, including ones that search for dark matter particles and processes related to neutrinos - ghostly, detectable particles that can pass through most matter and have the ability to change into different forms - can easily be broadened to also look for these absorption-related types of telltale dark matter signals.

Also, the researchers propose that new searches in previously collected particle detector data could possibly turn up these overlooked dark matter signals.

"In this field, we've had a certain idea in mind about well-motivated candidates for dark matter, such as the WIMP," or weakly interacting massive particle, said Jeff Dror, the lead author of the study who is a postdoctoral researcher in Berkeley Lab's Theory Group and UC Berkeley's Berkeley Center for Theoretical Physics.

Dark matter pushes at the boundaries of the known fundamental laws of physics, encapsulated in the Standard Model of particle physics, and "The WIMP paradigm is very easy to build into the Standard Model, but we haven't found it for a long time," Dror noted.

So, physicists are now considering other places that dark matter particles may be hiding, and other particle possibilities such as theorized "sterile neutrinos" that could also be brought into the family of particles known as fermions - which includes electrons, protons, and neutrinos.

"It's easy, with small modifications to the WIMP paradigm, to accommodate a whole different type of signal," Dror said. "You can make a huge amount of progress with very little cost if you step back a little bit in the way we've been thinking about dark matter."

Robert McGehee, a UC Berkeley graduate student, and Gilly Elor of the University of Washington were study co-authors.

The researchers note that the range of new signals they are focusing on opens up an "ocean" of dark matter particle possibilities: namely as-yet-undiscovered fermions with masses lighter than the typical range considered for WIMPs. They could be close cousins of sterile neutrinos, for example.

The study team considered absorption processes known as "neutral current," in which nuclei in the detector material recoil, or get jolted by their collision with dark matter particles, producing distinct energy signatures that can be picked up by the detector; and also those known as "charged current," which can produce multiple signals as a dark matter particle strikes a nucleus, causing a recoil and the ejection of an electron.

The charge current process can also involve nuclear decay, in which other particles are ejected from a nucleus as a sort of domino effect triggered by the dark matter absorption.

Looking for the study's suggested signatures of both the neutral current and charge current processes could open up "orders of magnitude of unexplored parameter space," the researchers note. They focus on energy signals in the MeV, which means millions of electron volts. An electron volt is a measure of energy that physicists use to describe the masses of particles. Meanwhile, typical WIMP searches are now sensitive to particle interactions with energies in the keV range, or thousands of electron volts.

For the various particle interactions the researchers explored in the study, "You can predict what is the energy spectrum of the particle coming out or the nucleon that's getting the 'kick,'" Dror said. Nucleon refers to the positively charged proton or uncharged neutron that resides in an atom's nucleus and that could absorb energy when struck by a dark matter particle. These absorption signals could possibly be more common than the other types of signals that dark matter detectors are typically designed to find, he added - we just don't know yet.

Experiments that have large volumes of detector material, with high sensitivity and very low background "noise," or unwanted interference from other types of particle signals, are particularly suited for this expanded search for different types of dark matter signals, Dror said.

LUX-ZEPLIN (LZ), for example, an ultrasensitive Berkeley Lab-led dark matter search project under construction in a former South Dakota mine, is a possible candidate as it will use about 10 metric tons of liquid xenon as its detector medium and is designed to be heavily shielded from other types of particle noise.

Already, the team of researches participating in the study has worked with the team operating the Enriched Xenon Observatory (EXO), an underground experiment searching for a theorized process known as neutrino-less double beta decay using liquid xenon, to open up its search to these other types of dark matter signals.

And for similar types of experiments that are up and running, "The data is already basically sitting there. It's just a matter of looking at it," Dror said.

The researchers name a laundry list of candidate experiments around the world that could have relevant data and search capabilities that could be used to find their target signals, including: CUORE, LZ predecessor LUX, PandaX-II, XENON1T, KamLAND-Zen, SuperKamiokande, CDMS-II, DarkSide-50, and Borexino among them.

As a next step, the research team is hoping to work with experiment collaborations to analyze existing data, and to find out whether search parameters of active experiments can be adjusted to search for other signals.

"I think the community is starting to become fairly aware of this," Dror said, adding, "One of the biggest questions in the field is the nature of dark matter. We don't know what it is made out of, but answering these questions could be within our reach in the near future. For me, that's a huge motivation to keep pushing - there is new physics out there."

The next time you get the urge to lapse into English while conversing in your other language, try not to and your brain will thank you for it.

Researchers from the Singapore University of Technology and Design (SUTD) examined and found that active bilingualism - the regular balanced use of two languages and language switching - will offer protection against the brain's aging process. The paper was published in the Journals of Gerontology: Psychological Sciences.

Current literature on the effects of bilingualism on the adult brain were inconsistent and lacking in clear trends - some reported that second language proficiency meant greater neural efficiency, whereas others concluded that it made no difference whatsoever. So the researchers from SUTD set out to explore the executive control mechanisms and context under which bilingualism can be a protective source against cognitive decline in the normal aging process.

Executive functions are complex, higher order processes that the brain performs. These functions mainly allow people to maintain their attention by focusing on relevant information and ignoring distractors, maintain information until execution as well as motor planning.

In the study that was conducted in Singapore, cognitively healthy seniors aged between 60 to 84 years old who were bilingual in Chinese and English were tasked to complete an array of computerized executive control tasks.

Tasks selected were commonly used in previous studies and identified with reference to well-established theories involving older adults that showed decreased performance with aging. For a more holistic examination, the researchers measured six different domains of executive control using four different tasks, all of which had been previously associated with bilingualism, while controlling for individual variables such as age, processing speed and fluid intelligence.

It was found that active usage of two languages with less frequent language switching predicted better performance in the goal maintenance and conflict monitoring aspects of executive control. This suggests that bilingualism can be a protective source against cognitive decline in the normal aging process. Importantly, active bilingualism can be seen as a lifestyle factor that could buffer against cognitive declines that are associated with normal aging.

"The effort involved in not switching between languages and "staying" in the target language is more cognitively demanding than switching between languages while actively using both languages. Our study shows that the seniors developed more efficient neural organization at brain regions related to language control, which also overlap with areas involved in executive control," explained lead principal investigator and corresponding author Associate Professor Yow Wei Quin from SUTD.

Researchers from University of Pennsylvania published a new paper in the Journal of Marketing that explains that the device people use to communicate can affect the extent to which they are willing to disclose intimate or personal information about themselves.

The study forthcoming in the Journal of Marketing is titled "Full Disclosure: How Smartphones Enhance Consumer Self-disclosure" and is authored by Shiri Melumad and Robert Meyer.

Do smartphones alter what people are willing to disclose about themselves to others? A new study in the Journal of Marketing suggests that they might. The research indicates that people are more willing to reveal personal information about themselves online using their smartphones compared to desktop computers. For example, Tweets and reviews composed on smartphones are more likely to be written from the perspective of the first person, to disclose negative emotions, and to discuss the writer's private family and personal friends. Likewise, when consumers receive an online ad that requests personal information (such as phone number and income), they are more likely to provide it when the request is received on their smartphone compared to their desktop or laptop computer.

Why do smartphones have this effect on behavior? Melumad explains that "Writing on one's smartphone often lowers the barriers to revealing certain types of sensitive information for two reasons; one stemming from the unique form characteristics of phones and the second from the emotional associations that consumers tend to hold with their device." First, one of the most distinguishing features of phones is the small size; something that makes viewing and creating content generally more difficult compared with desktop computers. Because of this difficulty, when writing or responding on a smartphone, a person tends to narrowly focus on completing the task and become less cognizant of external factors that would normally inhibit self-disclosure, such as concerns about what others would do with the information.?Smartphone users know this effect well--when using their phones in public places, they often fixate so intently on its content that they become oblivious to what is going on around them.

The second reason people tend to be more self-disclosing on their phones lies in the feelings of comfort and familiarity people associate with their phones. Melumad adds, "Because our smartphones are with us all of the time and perform so many vital functions in our lives, they often serve as 'adult pacifiers' that bring feelings of comfort to their owners." The downstream effect of those feelings shows itself when people are more willing to disclose feelings to a close friend compared to a stranger or open up to a therapist in a comfortable rather than uncomfortable setting. As Meyer says, "Similarly, when writing on our phones, we tend to feel that we are in a comfortable 'safe zone.' As a consequence, we are more willing to open up about ourselves."

The data to support these ideas is far-ranging and includes analyses of thousands of social media posts and online reviews, responses to web ads, and controlled laboratory studies.?For example, initial evidence comes from analyses of the depth of self-disclosure?revealed in 369,161 Tweets and 10,185 restaurant reviews posted on TripAdvisor.com, with some posted on PCs and some on smartphones.? Using both automated natural-language processing tools and human judgements of self-disclosure, the researchers find robust evidence that smartphone-generated content is indeed more self-disclosing. Perhaps even more compelling is evidence from an analysis of 19,962 "call to action" web ads, where consumers are asked to provide private information.

Consistent with the tendency for smartphones to facilitate greater self-disclosure, compliance was systematically higher for ads targeted at smartphones versus PCs.

The findings have clear and significant implications for firms and consumers.?One is that if a firm wishes to gain a deeper understanding of the real preferences and needs of consumers, it may obtain better insights by tracking what they say and do on their smartphones than on their desktops.?Likewise, because more self-disclosing content is often perceived to be more honest, firms might encourage consumers to post reviews from their personal devices.?But therein lies a potential caution for consumers--these findings suggest that the device people use to communicate can affect what they communicate. This should be kept in mind when thinking about the device one is using when interacting with firms and others.