Tech

Someday, microbial cyborgs -- bacteria combined with electronic devices -- could be useful in fuel cells, biosensors and bioreactors. But first, scientists need to develop materials that not only nurture the microbes, but also efficiently and controllably harvest the electricity or other resources they make. Now, researchers reporting in ACS Applied Materials & Interfaces have developed one such material that enabled them to create a programmable "biohybrid" system that conducts electrons from electricity-producing (exoelectrogenic) bacteria.

Unlike other bacteria, exoelectrogens can move electrons across their outer membrane to the outside of their cell. Scientists have tried to harness this electricity by using various materials to conduct the electrons to an electrode. So far, however, conductive materials that support bacterial growth have been either inefficient, or not easily programmable to control the electrical current. Christof Niemeyer and colleagues wanted to develop a nanocomposite material that supports exoelectrogen growth while conducting electricity in a controlled way.

The researchers made a porous hydrogel composed of carbon nanotubes and silica nanoparticles, woven together by DNA strands. They added exoelectrogenic bacteria to this scaffold, along with liquid culture medium to supply the microbes with nutrients. The material efficiently conducted the electrons produced by the bacteria to an electrode. The bacteria grew well on the material, completely penetrating it. To cut off the electricity, the researchers added an enzyme that snipped DNA strands, causing the material to disassemble. The conductivity and other properties of the material could also be tailored by varying the size and sequence of the DNA fragments that hold the scaffold together, the researchers say.

A national modelling paper predicting the number of available ICU beds across Canada during the COVID-19 pandemic suggests that self-isolation will likely not be enough to keep demand from exceeding supply. It is published in CMAJ (Canadian Medical Association Journal).

Researchers modelled several scenarios:

Without self-isolation of mild cases, each province would need an average of 569 ICU bed days per 10,000 people, and the infection peak would occur in mid-June.

If 20% of people with mild symptoms and 80% of people with severe illness self-isolate within 24 hours of symptom onset, ICU bed utilization would decrease 23.6% to 435 bed days per 10,000 population.

If 40% of people with mild symptoms self-isolate, overall ICU bed days would decrease to 264, and the outbreak peak would be delayed by up to 8 weeks.

The authors project that at the outbreak's peak, the need for ICU beds per 10,000 population could be 2.6 times higher than the number of available beds.

"Our results show that higher rates of self-isolation are needed to mitigate the increased strain on the health care systems at the provincial level," writes Dr. Joanne Langley, Canadian Centre for Vaccinology, Dalhousie University and IWK Health Centre, Halifax, Nova Scotia, with coauthors. "Should resources allow for an increase in COVID-19 testing, a higher fraction of mildly symptomatic cases would be identified, which could lead to a higher percentage of the population practising self-isolation. If infection confers immunity, a testing strategy could also permit recovered people to return to normal activity."

The number of ICU beds in each province ranged from 0.63 to 1.85 per 10,000 people in the model.

"If the scenarios we describe are true, health care planning will move to crisis management in Canada, but at different times across the country," write the authors. "This may allow some redistribution of human or material resources across jurisdictions. While provinces and territories ramp up capacity for more ICU beds (human resources, ventilators, beds, personal protective equipment, infection prevention and control support), these estimates can inform the timing and quantity of the expected need."

A fast-acting anti-malarial compound discovered at St. Jude Children's Research Hospital was well tolerated and showed promising anti-malarial effects in the first study in humans. The findings appear online first this week in the journal Lancet Infectious Diseases.

"The results support further development of the compound SJ733 as a fast-acting component of combination anti-malarial therapy," said corresponding author Aditya Gaur, M.D., of the St. Jude Department of Infectious Diseases. "The drug was well tolerated and well absorbed with a rapid anti-parasitic effect." Gaur and James McCarthy, M.D., MBBS, of QIMR Berghofer Medical Research Institute, Australia, are the co-first authors.

Researchers are exploring ways to increase and/or extend blood levels of SJ733 to maximize its effectiveness in patients.

The challenge

Malaria is caused by a parasite that is transmitted by infected mosquitos and destroys red blood cells. The disease remains a leading cause of illness and death worldwide. Young children are among the most vulnerable. Artemisinin-based combination drug therapy is currently being used as first-line treatment for malaria. But its success is threatened by emerging drug resistance.

"Safe and effective anti-malarial drugs that work by new mechanisms are critically needed to combat drug-resistant disease," said senior author R. Kip Guy, Ph.D., dean of the University of Kentucky College of Pharmacy. Guy led the anti-malarial drug-discovery effort and preclinical development of SJ733 while chair of the St. Jude Department of Chemical Biology and Therapeutics. The preclinical trials showed that SJ733 worked against malaria parasites that are resistant to current frontline drugs.

The research effort reflects the global reach of this disease, Gaur said. He noted that the work involved scientists working collaboratively and seamlessly exchanging information on three continents and across multiple time zones.

SJ733

SJ733 is one of the first in a new class of anti-malarial compounds to reach clinical trials. It works by disrupting the malaria parasite's ability to remove excess sodium from red blood cells. As sodium builds up, infected cells become less flexible. The cells are removed by the immune system or get caught in small blood vessels.

A total of 38 healthy volunteers were recruited as part of the Phase 1a study in Memphis and Phase 1b study in Brisbane, Australia. The 23 healthy volunteers in Memphis received increasing doses of SJ733 as part of the first-in-human study to understand SJ733 dosing, safety profile and metabolism, including absorption.

Based on those results the 15 Australian volunteers received SJ733 after being infected with malaria to understand the anti-malarial effectiveness of this new drug. The participants later received a curative dose of conventional anti-malarial combination therapy.

No significant SJ733 treatment-related side-effects were identified in any of the volunteers.

Consuming foods high in vitamin D may have heart-protective effects, according to new research published in the Journal of Human Nutrition and Dietetics.

The study was conducted during 2001-2012 and included 1,514 men and 1,528 women from the greater Athens area, in Greece. In the lowest, middle, and highest categories of vitamin D intake, cardiovascular events (such as heart attacks and strokes) occurred in 24%, 17%, and 12% of men and 14%, 10%, and 11% of women.

In contrast with vitamin D supplementation trials that have shown modest to neutral beneficial effects on heart health, this study revealed that increased vitamin D intake from food sources may protect against heart-related problems, especially in men.

In most animals, females are larger than males, but in most mammals, males are larger than females. A new analysis published in Mammal Review examines the potential drivers of these differences.

In most animals, females are larger than males, but in most mammals, males are larger than females. A new analysis published in Mammal Review examines the potential drivers of these differences, calling into question the theory that only sexual selection is at play in mammals--that males compete to mate with females, and bigger males are more likely to win.

The analysis suggests that, alongside sexual selection, natural selection may be an evolutionary driver of sexual size differences in mammals. Males and females may have evolved to differ in size so that they could exploit resources such as food.

Beaches in or near England's Marine Protected Areas (MPAs) have the same levels of litter as those in unprotected areas, new research shows.

The study, by the University of Exeter, Natural England and the Marine Conservation Society, found "no difference" in the amount of anthropogenic (caused by humans) litter present inside and outside MPAs.

These MPAs include the 91 Marine Conservation Zones established from 2009 onwards, 256 Special Areas of Conservation (SACs) and 89 Special Protection Areas (for birds).

Plastic was the main form of litter found, and "public littering" the most common identifiable source.

The study, which used data from Marine Conservation Society beach cleans, found MPAs in the South East (Kent) and South West (Cornwall and Devon) had the highest levels of shore-based litter.

Regional differences in the items found - such as fishing materials in the South West and debris from sewage around large rivers - demonstrate the need for "locally appropriate management", the researchers say.

"Our work has found that MPAs, which often contain sensitive marine habitats and species, are exposed to litter much in the same way as non-protected sites," said Dr Sarah Nelms, of the University of Exeter.

"MPAs have no physical boundaries so, to protect them from any potential impacts of litter, we need to take a whole-system approach and reduce the overall amount of litter being released into the environment.

"We also need a coordinated approach that considers local nuances, tackling sources of litter that cause specific problems in certain areas."

The study used 25 years of beach clean data collected by Marine Conservation Society volunteers.

Dr Hazel Selley, Marine Specialist from Natural England who commissioned the work, said: "A clean, healthy and biologically diverse marine environment is immensely valuable, for the economy in coastal communities, for our charismatic wildlife and - once we can travel again - for the mental well-being benefits of spending time by the sea.

"This research sheds a light on how marine plastic pollution respects no boundaries.

"As we continue to research the impact of plastics on our marine life and move to eliminate avoidable plastic waste, it's also clear is that we all have a role to play keeping our beaches and ocean clean."

Lauren Eyles, from the Marine Conservation Society, said: "The types of litter that were found are typical of those regularly picked up and recorded by our dedicated volunteers.

"What this study highlights is how long-term data from Beachwatch can provide vital evidence in helping to understand the problem, and that MPAs don't necessarily protect important habitats and species; an even more powerful message to stop litter at source."

College students who listened to classical music by Beethoven and Chopin during a computer-interactive lecture on microeconomics -- and heard the music played again that night -- did better on a test the next day than did peers who were in the same lecture, but instead slept that evening with white noise in the background.

Over the long haul -- when students took a similar test nine months later -- the boost did not last. Scores dropped to floor levels, with everyone failing and performance averaging less than 25% percent for both groups. However, targeted memory reactivation (TMR) may aid during deep sleep, when memories are theorized to be reactivated and moved from temporary storage in one part of the brain to more permanent storage in other parts, researchers said.

The study, supported by the National Science Foundation and conducted by Baylor's Sleep Neuroscience and Cognition Laboratory (SNAC), is published in the journal Neurobiology of Learning and Memory.

"All educators want to teach students how to integrate concepts, not just memorize details, but that's notoriously difficult to do," said Michael K. Scullin, Ph.D., director of Baylor's sleep lab and assistant professor of psychology and neuroscience. "What we found was that by experimentally priming these concepts during sleep, we increased performance on integration questions by 18% on the test the next day. What student wouldn't want a boost or two to their letter grade? The effects were particularly enhanced in participants who showed heightened frontal lobe activity in the brain during slow wave sleep, which is deep sleep."

He noted that the effects emerged when using gold standard procedures: neither participants nor experimenters knew who received a particular treatment, sleep was measured using EEG in a laboratory setting, and the learning materials matched those that would actually be used in a college classroom, in this case an undergraduate microeconomics lecture.

Poor sleep is widespread in college students, with 60 percent habitually sleeping fewer than the recommended seven hours on 50 to 65 percent of nights. While students may be more concerned about immediate test results -- and TMR may help them cram for an exam -- learning by rote (item memory) does not normally benefit grasping and retaining a concept.

For the study, researchers recruited 50 college students ages 18 to 33 for a learning task with a self-paced, computer-interactive lecture; and for two overnight polysomnography sessions, with the first night an adaptation to the lab and screening for sleep disorders, and the second done the evening of the lecture.

During the lecture, soft background selections were played from a computer: the first movement of Beethoven's "Moonlight" Piano Sonata, the first movement of Vivaldi's "Spring" Violin Concerto and Chopin's Nocturne in E-flat major, Op. 9, No. 2.

That night in Baylor's sleep lab, research personnel applied electrodes and used computers to monitor sleep patterns of both test and control groups. Once technicians observed a person was in deep sleep, they played either the classical music or the white noise -- depending on whether the individual was in the test or control group -- for about 15 minutes.

"Deep slow wave sleep won't last super long before shifting back to light sleep, so we couldn't play them endlessly," Scullin said. "If we played it during light sleep, the music probably would have awoken participants. The first slow wave cycle is the deepest and longest."

The music choice was important, researchers said.

"We ruled out jazz because it's too sporadic and would probably cause people to wake," Scullin said. "We ruled out popular music because lyrical music disrupts initial studying. You can't read words and sing lyrics -- just try it. We also ruled out ocean waves and ambient music because it's very easy to ignore. You're going to have a heck of a time forming a strong association between some learning material and a bland song or ambient noise.

"That left us with classical music, which many students already listen to while studying," he said. "The songs can be very distinctive and therefore pair well with learning material."

In the microeconomics exam the next day, the TMR of classical music more than doubled the likelihood of passing the test when compared with the control condition of white noise.

Scullin cautioned against confusing the Baylor study's findings with the so-called "Mozart Effect" -- the finding that having students listen to Mozart pieces led to better scores on intelligence tests. Subsequent tests of the "Mozart Effect" found that it either did not replicate or that boosts were strictly due to increased arousal when listening to energetic music.

"Mozart doesn't make memories," Scullin said.

Previous researchers have found that memories associated with sensory cues -- such as an odor or song -- are re-activated when the same cue is received later. When that happens during deep sleep, the corresponding memories are activated and strengthened, said co-researcher Chenlu Gao, a doctoral candidate of psychology and neuroscience at Baylor.

Early experimenters also played audio tapes during sleep to test whether individuals can learn new knowledge while sleeping. But while those experiments failed to create new memories, "our study suggests it is possible to reactivate and strengthen existing memories of lecture materials during sleep," Gao said.

"Our next step is to implement this technique in classrooms -- or in online lectures while students complete their education at home due to COVID-19 social distancing measures -- so we can help college students 're-study' their class materials during sleep."

"We think it is possible there could be long-term benefits of using TMR but that you might have to repeat the music across multiple nights," Scullin added. "After all, you wouldn't just study material a single time and then expect to remember it months later for a final exam. The best learning is repeated at spaced-out intervals -- and, of course, while maintaining good sleep habits."

Researchers at the National Eye Institute (NEI) have defined a crucial window of time that mice need to key in on visual events. As the brain processes visual information, an evolutionarily conserved region known as the superior colliculus notifies other regions of the brain that an event has occurred. Inhibiting this brain region during a specific 100-millisecond window inhibited event perception in mice. Understanding these early visual processing steps could have implications for conditions that affect perception and visual attention, like schizophrenia and attention deficit hyperactivity disorder (ADHD). The study was published online in the Journal of Neuroscience. NEI is part of the National Institutes of Health.

"One of the most important aspects of vision is fast detection of important events, like detecting threats or the opportunity for a reward. Our result shows this depends on visual processing in the midbrain, not only the visual cortex", said Richard Krauzlis, Ph.D., chief of the Section on Eye Movements and Visual Selection at NEI and senior author of the study.

Visual perception - one's ability to know that one has seen something - depends on the eye and the brain working together. Signals generated in the retina travel via retinal ganglion cell nerve fibers to the brain. In mice, 85% of retinal ganglion cells connect to the superior colliculus. The superior colliculus provides the majority of early visual processing in these animals. In primates, a highly complex visual cortex takes over more of this visual processing load, but 10% of retinal ganglion cells still connect to the superior colliculus, which manages basic but necessary perceptual tasks.

One of these tasks is detecting that a visual event has occurred. The superior colliculus takes in information from the retina and cortex, and when there is sufficient evidence that an event has taken place in the visual field, neurons in the superior colliculus fire. Classical experiments into perceptual decision-making involve having a subject, like a person or a monkey, look at an image of vertical grating (a series of blurry vertical black and white lines) and decide if or when the grating rotates slightly. In 2018, Krauzlis and Wang adapted these classic experiments for mice, opening up new avenues for research.

"Although we have to be cautious translating data from mice to humans, because of the difference in visual systems, mice have many of the same basic mechanisms for event detection and visual attention as humans. The genetic tools available for mice allow us to study how specific genes and neurons are involved in controlling perception," said Lupeng Wang, Ph.D., first author of the study.

In this study, Wang and colleagues used a technique called optogenetics to tightly control the activity of the superior colliculus over time. They used genetically modified mice so that they could turn neurons in the superior colliculus on or off using a beam of light. This on-off switch could be timed precisely, enabling the researchers to determine exactly when the neurons of the superior colliculus were required for detecting visual events. The researchers trained their mice to lick a spout when they'd seen a visual event (a rotation in the vertical grating), and to avoid licking the spout otherwise.

Inhibiting the cells of the superior colliculus made the mice less likely to report that they'd seen an event, and when they did, their decision took longer. The inhibition had to occur within a 100 millisecond (one-tenth of a second) interval after the visual event. If the inhibition was outside that 100-millisecond timeframe, the mouse's decisions were mostly unaffected. The inhibition was side-specific: because the retinal cells cross over and connect to the superior colliculus on the opposite side of the head (the left eye is connected to the right superior colliculus and vice versa), inhibiting the right side of the superior colliculus depressed responses to stimuli on the left side, but not on the right.

"The ability to temporarily block the transmission of neural signals with such precise timing is one of the great advantages of using optogenetics in mice and reveals exactly when the crucial signals pass through the circuit," said Wang.

Interestingly, the researchers found that the deficits with superior colliculus inhibition were much more pronounced when the mice were forced to ignore things happening elsewhere in their visual field. Essentially, without the activity of the superior colliculus, the mice were unable to ignore distracting visual events. This ability to ignore visual events, called visual attention, is critical for navigating the complex visual environments of the real world.

"The superior colliculus is a good target for probing these functions because it has a neatly organized map of the visual world. And it is connected to less neatly organized regions, like the basal ganglia, which are directly implicated in a wide range of neuropsychiatric disorders in humans," said Krauzlis. "It's sort of like holding the hand of a friend as you reach into the unknown."

Naturally occurring (geogenic) groundwater arsenic contamination is a problem of global significance, with noteworthy occurrences in large parts of the alluvial and deltaic aquifers in South and Southeast Asia. To address this problem tremendous research efforts have been dedicated over the last two decades to better understand the sources and distribution of arsenic-polluted groundwater. Now, an Australian team of scientists from Flinders University, CSIRO and the University of Western Australia, together with their colleagues at the Swiss Federal Institute of Aquatic Science and Technology (Eawag), have used computer modelling to integrate much of what has been learned over the years into computer simulations that mimic the complex interactions between groundwater flow, solute transport and geochemical reaction mechanisms. Such models are important to analyse field observations, to unravel which chemical and physical processes play a role, and to predict the behaviour of arsenic within aquifers – where and when pollution may occur in the future. The results of their study have now been published in the latest issue of Nature Geoscience.

Reconstructing the past to predict future arsenic behaviour

The research team selected a highly arsenic polluted site near Hanoi (Vietnam) to develop and test their computer model. In a first step they used the tiny concentrations of tritium that had entered the groundwater system from the atmosphere during the times of nuclear bomb testing, and its decay product helium, a noble gas, to reconstruct how fast and where the groundwater was moving over the last 5 decades. Once the model simulations were able to match the concentrations that were measured, additional complexity was added to the model in order to simulate how arsenic was mobilised and transported in the Holocene aquifer.

The river-groundwater interface acts as reaction hotspot

At the study site, changes in groundwater flow occurred over the past 50 years since the city of Hanoi markedly increased the extraction of groundwater to satisfy its steadily increasing water demand; this showed to be the main trigger for arsenic pollution in the aquifer. The computer modelling allowed the researchers to pinpoint the source of arsenic down to the river muds that are regularly deposited at the more slow-flowing zones of the Red River. The organic matter contained in those muds fuelled a biogeochemical reaction that led to the release of arsenic and its km-long transport into the aquifer underlying the Van Phuc village, a process that continues to this day. Employing their developed computer model in predictive mode the researchers were able to illustrate the interplay of four key factors on the evolution and longevity of arsenic release at surface water/groundwater interfaces, (i) the abundance of reactive organic matter; (ii) the abundance of iron oxides; (iii) the magnitude of groundwater flow; and (iv) river mud deposition rate.

Original publication: Ilka Wallis, Henning Prommer, Michael Berg, Adam Siade, Jing Sun, and Rolf Kipfer (2020). The river-groundwater interface as a hotspot for arsenic release. Nature Geoscience. https://doi.org/10.1038/s41561-020-0557-6

Further information: Dr Ilka Wallis, College of Science and Engineering, Flinders University, Adelaide, South Australia; ilka.wallis@flinders.edu.au

Journal

Nature Geoscience

DOI

10.1038/s41561-020-0557-6

Viruses that jump from animals to people, like the one responsible for COVID-19, will likely become more common as people continue to transform natural habitats into agricultural land, according to a new Stanford study.

The analysis, published in Landscape Ecology, reveals how the loss of tropical forests in Uganda puts people at greater risk of physical interactions with wild primates and the viruses they carry. The findings have implications for the emergence and spread of infectious animal-to-human diseases in other parts of the world, and suggest potential solutions for curbing the trend.

"At a time when COVID-19 is causing an unprecedented level of economic, social and health devastation, it is essential that we think critically about how human behaviors increase our interactions with disease-infected animals," said study lead author Laura Bloomfield, an MD student in the School of Medicine and a PhD candidate in the Emmett Interdisciplinary Program in Environment and Resources within Stanford's School of Earth, Energy & Environmental Sciences. "The combination of major environmental change, like deforestation, and poverty can spark the fire of a global pandemic."

A changing landscape

People have converted nearly half of the world's land into agriculture. Tropical forests have suffered the most, with some of the highest rates of agricultural conversion over the last few decades. In Africa, this has accounted for about three-quarters of recent forest loss. What remains, outside protected parks and preserves, are small islands of forest in a sea of farmland and areas where farmland intrudes into larger forested areas.

In Uganda, decades of migration and the creation of farmlands outside Kibale National Park have led to a high density of people trying to support their families at the edge of forested habitats. Ordinarily, people avoid wild primates because they are well-known carriers of disease, and many are protected by Uganda's Wildlife Authority. However, continued loss of forested habitat means wild primates and humans are increasingly sharing the same spaces and vying for the same food.

When people venture into forested areas for resources and when animals venture out of their habitats to raid crops, the chances increase for transmission of zoonotic - or animal-to-human - disease. A prime example is HIV, which is caused by a virus that jumped from wild primates to humans via infected bodily fluids.

"We humans go to these animals," study co-author Eric Lambin, the George and Setsuko Ishiyama Provostial Professor in Stanford's School of Earth, Energy & Environmental Sciences. "We are forcing the interaction through transformation of the land."

Predicting infection

Unlike previous studies that examined the issue from primarily an ecological standpoint, the Stanford study is the first to integrate landscape-level ecological factors with individual-level behavioral factors and weigh risks to human health.

The researchers began by collecting land use survey data from small-scale farmers living near forest fragments. They combined this information with high-resolution satellite imagery from the same time period to model how landscape patterns and individual behaviors together make certain people more likely to have contact with wild animals.

They found the strongest predictors of human-wild primate contact were the length of the forest boundary around people's homes and the frequency with which people ventured into these forested areas to collect small trees for construction material. Searching for these pole-like trees entails spending more time deep in primate habitats than other forest-based activities.

The researchers were surprised to find some of their assumptions turned upside down. For example, small fragments of residual forest – not larger expanses of habitat – were most likely to be the site of human-wild primate contacts due to their shared borders with agricultural landscapes.

Similarly, the researchers speculate that increasing intrusion of agriculture into forests and resulting human activities in these areas could lead to more spillover of infections from wild primates to humans worldwide.

Keeping disease at bay

The researchers suggest that relatively small buffer zones, such as tree farms or reforestation projects, around biodiversity-rich forests could dramatically lessen the likelihood of human-wild primate interaction. Using external resources, such as national or international aid, to provide fuel and construction material or monetary supplements could also reduce pressure on people to seek out wood in forested areas.

"At the end of the day, land conservation and the reduction of forest fragmentation is our best bet to reduce human-wild animal interactions," said study coauthor Tyler McIntosh, a former graduate student in the Stanford Earth Systems Program now working at the Center for Western Priorities.

The Russian side is represented by Structural Biology Lab (Kazan Federal University) and Institute of Proteins (Russian Academy of Sciences). This particular paper tackles the issue of stress resistance in Staphylococcus aureus. The results can help in finding new antibiotics.

Head of Structural Biology Lab Konstantin Usachev explains that this was the fruit of a five-year-long cooperation between KFU, Institute of Proteins, Stuttgart University, and Institute of Genetics and Molecular and Cellular Biology (Strasbourg, France). In 2016, the team was first to completely describe the structure of Staphylococcus aureus ribosome and compare it to other organisms.

"The ribosome is the largest ribonucleic complex in the cell, and it consists of two subunits: large and small. The small subunit is responsible for reading the genetic code, and the function of the large subunit is to ensure the formation of the peptide bond in the growing protein chain. In our article, using cryoelectron microscopy and X-ray diffraction methods, we were able to show the ribosome binding mechanism of the RsfS protein (Ribosome silencing factor S), which protects Staphylococcus aureus from stress (antibiotics, fever, or host immunity). Under stress, this protein binds to the large subunit of the ribosome and prevents the small subunit from joining, preventing the formation of functional ribosomes," says Usachev.

Research in this area began 5 years ago. For a long time, scientists were not able to obtain the structure of a complex of bacterial ribosomes with the RsfS protein in high resolution, which was necessary to understand the details of its mechanism of action.

"One of the problems was the high toxicity of this protein to the cells of the bacteria E. coli, the organism used to produce proteins in the laboratory. The fact is that the RsfS protein, which stops the synthesis of proteins in Staphylococcus aureus, is able to stop this process in other bacteria. This resulted in a very small amount of protein sample, insufficient for structural studies. In addition, the sample was extremely unstable and aggregated. Then the idea came to us - to isolate this protein simultaneously with its target in the structure of staphylococcus ribosome - protein L14, which is a part of the large subunit. It turned out that if you select both components at the same time, they will be stable in solution. We were able to obtain crystals of these proteins and solve the structure by X-ray diffraction analysis, first with medium resolution using the new single-crystal diffractometer available in our laboratory, and then with high resolution using the ESRF synchrotron in Grenoble, France," continues the interviewee.

Next, the scientists needed to study the details of the interaction of the RsfS protein with Staphylococcus aureus ribosome. This could be achieved with cryoelectron microscopy.

"Unfortunately, we did not have a microscope capable of solving high-resolution structures using this method, but NovAliX became interested in our studies and offered their microscope to test the initial samples. The obtained samples of the complexes had turned out so good that the company then contacted one of the world's leading manufacturers of FEI microscopes in the Netherlands and organized data collection on a Titan Krios microscope. As a result, combining the data of cryoelectron microscopy with the previously obtained data of X-ray diffraction analysis, we were able to show in detail the molecular mechanism of the action of the RsfS protein on Staphylococcus aureus ribosomes," concludes Usachev.

Currently, Structural Biology Lab is partnering up with the Chemoinformatics Lab to predict the structure of potential antibiotics disrupting the functioning of RsfS protein and thus effectively eliminating Staphylococcus.

According to Usachev, only combined efforts of biologists, chemists and physicists can advance the research in protein synthesis and new medications.

When a massive star in a distant galaxy collapses, forming a black hole, two giant jets of light-emitting plasma shoot from its core. These extremely bright gamma-ray bursts (GRBs) are the most powerful explosions in the universe, and when a jet points towards Earth, the afterglow can be detected from ground and space-borne telescopes. Material does not simply catapult from an exploding star, it accelerates to ultra-high speeds along the narrow beam of the gamma-ray jet, leaving astrophysics puzzled over the power source driving these extraordinary explosions. Now a new international study led by the University of Bath promises to shed light on this mysterious phenomenon.

Many astronomers favour an explanation for GRBs based on the baryonic jet model. This states that repeated violent collisions between material blasted out during the explosion and material surrounding the dying star produce the gamma-ray flash and the subsequent fading afterglow - the dying embers of the expanding fireball.

A second hypothesis, called the magnetic model, posits that a huge, primordial magnetic field in the star collapses within seconds of the initial explosion, releasing energy to power the prodigious blast.

Now, for the first time, an international team of researchers has found evidence backing this magnetic model. Working in collaboration with researchers from the UK, Italy, Slovenia, Russia, South Africa and Spain, Bath astrophysicists examined data from the collapse of a massive star in a galaxy 4.5 billion light-years away. They were alerted to the star's collapse after its gamma-ray flash (named GRB 190114C) was detected by NASA's space-borne Neil Gehrels Swift Observatory.

The researchers noted a startlingly low level of polarisation in the gamma-ray burst in the moments straight after the star's collapse, indicating the star's magnetic field had been destroyed during the explosion.

Nuria Jordana-Mitjans, lead author of the Astrophysical Journal paper, and holder of the Hiroko and Jim Sherwin Postgraduate Scholarship in Astrophysics, said: "From previous studies, we expected to detect polarisation as high as 30% during the first hundred seconds after the explosion. So we were surprised to measure just 7.7% less than a minute after the burst, followed by a sudden drop to 2% soon after."

She added: "This tells us that the magnetic fields collapsed catastrophically straight after the explosion, releasing their energy and powering the bright light detected across the electromagnetic spectrum."

GRBs are detected by dedicated satellites orbiting Earth, however no one can predict where or when a GRB will appear, so scientists rely on autonomous rapid-response robotic telescopes to catch the fast-fading light of the afterglow. Seconds after the NASA observatory identified GRB 190114C, robotic telescopes located in the Canary Islands and South Africa received NASA's discovery notification and repointed. Within one minute of the GRB discovery, the telescopes were gathering data about the emissions.

Professor Carole Mundell, head of Astrophysics at the University of Bath and co-author on the research, said: "Our innovative telescope systems are entirely autonomous, with no humans in the loop, so they slued very quickly and began taking observations of the GRB almost immediately after its discovery by the Swift satellite."

Prof Mundell continued: "It is remarkable that from the comfort of our own homes, we were able to discover the importance of primordial magnetic fields in powering a cosmic explosion in a distant galaxy."

Complex magnon bound states were predicted in 1931 by the theoretical physicist Hans Bethe in a one-dimensional quantum magnetic model. In 2018, physicist Dr Zhe Wang and his colleagues at the University of Cologne's Institute of Physics II confirmed this theory of a 'quantum string' for the first time. For his discovery, he was awarded the Walter Schottky Prize of the German Physical Society.

In his current work, Wang cooperated with scientists from Berlin, Cologne, Didcot, Dresden, Grenoble, Mumbai, Shanghai, and Vancouver to explore the dispersion relation - an important physical characteristic - of the complex quantum many-body states 'Bethe strings'. The team reported their results in the journal Nature Physics.

Magnons - particle-like magnetic excitations - exist not only independently in a quantum chain magnet, but can also be bound forming a 'string'-like excitation due to quantum many-body effects. Theoretical studies of quantum physics in one-dimensional systems have been way ahead of an experimental one. This is because a one-dimensional theoretical model can be more straightforwardly treated than higher-dimensional ones, but it is difficult to realize in a real-world solid-state material. After Bethe's seminal work, a systematic ansatz - the so-called Bethe ansatz - has been developed which is a very powerful tool in statistical physics to obtain exact solutions of the one-dimensional models. Using this method, previous theoretical studies showed that in certain one-dimensional models the Bethe strings are hardly detectable, e.g. by a spectroscopic method, because their contribution to quantum dynamics is negligibly small.

Two experimental breakthroughs have been achieved by the international research team. First evidence of Bethe strings was revealed in 2018 in a chain antiferromagnet, SrCo2V2O8, by high-resolution terahertz optical spectroscopy in applied external high magnetic fields. 'The external field plays a crucial role. Only in a field-induced gapless phase of the chain antiferromagnet we found the Bethe string states', said Dr Zhe Wang. 'This particular phase was rarely explored before, because neither a solid-state antiferromagnetic chain material nor the required strong magnetic field is easy to obtain.' The high-field terahertz spectroscopy allowed the team to identify the string states by precisely measuring characteristic field dependence of their eigenenergies. However, information on dispersion of the string states in momentum space cannot be provided by the optical spectroscopy. 'We need inelastic neutron scattering spectroscopy, for example', Zhe Wang added.

The team resolved the dispersion of Bethe strings for the first time by inelastic neutron scattering experiments. Dispersion relation - a relation between eigenenergy and momentum - is an important characteristic of the excitations. The successful measurements rely on high-quality single crystals and high magnetic fields at a neutron scattering facility, both of which were achieved recently by groups led by Professor Bella Lake from the Helmholtz-Zentrum and Technical University of Berlin. With her colleagues, in particular Dr Anup Kumar Bera, she measured dispersion of the Bethe strings in high fields at the neutron scattering facilities.

'Close collaboration between experimental and theoretical physicists is of particular importance for the achievements', said Zhe Wang. Precise calculations of the one-dimensional model were performed by the Tsung-Dao Lee Fellow Dr Jianda Wu from Tsung-Dao Lee Institute at Shanghai Jiao Tong University and Dr Wang Yang from the University of British Columbia in Vancouver using Bethe ansatz. Their results enabled a detailed comparison to the experimental data, and the identification of the string-states dispersion.

'Quantum many-body systems are in general challenging to study, while at the same time exotic and fascinating phenomena are realized in these systems. To explore these phenomena is an important goal of my research. In the long term, understanding these phenomena might lead to invention of new quantum technologies', Zhe Wang concluded.

In June 2018, large wildfires broke out on Saddleworth Moor and Winter Hill Saddleworth Moor in the northwest of England. The fires burned for roughly three weeks, 100 firefighters and the army attended and smoke from the fires spread widely across the northwest of England.

In a new study, published in Environmental Research Letters, researchers led by the University of Leeds used computer simulations to calculate the effect of the fires on air quality and the resulting impact on health.

Their findings include:

The fires caused poor air quality over a large region (including Bolton, Wigan and Southport).

4.5 million people were exposed to PM2.5 above the recommended level set by the World Health Organisation (24-hour guideline of 25 μg m-3) on at least one day, between 23rd and 30th June.

One of the measures of the impacts is 'deaths brought forward', this is a measure of unfulfilled life expectancy i.e. deaths which occurred earlier than they would have without the pollution from the fires. This can be calculated because exposure to PM2.5 pollution has been shown to be associated with increases in mortality from diseases such as heart disease and stroke.

The calculated health impact indicates that PM2.5 from the fires accounted for 9 deaths brought forward.

The PM2.5 pollution from the fires increased the number of deaths brought forward by up to 165% (Saddleworth Moor) and 95% (Winter Hill), compared to if there were no fires.

The authors estimate the economic impact of the fires to be £21.1 million

The authors said: "It's clear from this study that the pollution from wildfires can have a significant effect on public health. The smoke contains very high levels of toxic particulate matter aerosol, which can be transported long distances. When this smoke passes over urban areas it adds to an already polluted environment and can cause very poor air quality."

"We should be aware that the smoke from wildfires can travel long distances, and can damage people's health, even far from the fires."

"Although people may not have been able to smell smoke, particulate matter was very high in areas far away from the fires, such as Southport and Wigan."

"Particulate pollution from the fires substantially degraded air quality over the north-west of England, leading the pollution levels much above the recommended levels."

The study used a computer model of the atmosphere to investigate the impacts of particulate matter (PM2.5) air pollution from the fires on the population in the north-west of England. In the model two scenarios were considered: 1) a scenario with no wildfires and 2) a scenario in which pollutants from the fires are included.

The scenarios allowed researchers to investigate the difference in pollution that occurred as a result of the fires. From this, they calculated the effect of the fire on air quality and then attributed how many deaths were brought forward due to PM2.5 pollution from the fires directly.

Large wildfires are relatively rare in the UK, and few have occurred close to urban populations, so there is little knowledge of the potential impacts of wildfires on public health. However, climate change scenarios predict that UK summers will become both hotter and dryer, which means wildfires are likely to become both more common and thus the impact of wildfires on health is likely to become increasingly important.

A new genome editing system enhances the efficiency of an error-free DNA repair pathway, which could help improve agronomic traits in multiple crops.

Genome editing involves cutting DNA at very specific locations and utilizing cells' natural repair pathways to modify genes. Plant cells contain two repair pathways: nonhomologous end joining (NHEJ) and homology-directed repair (HDR).

"In plants, NHEJ is the dominant repair pathway at most cell stages," says KAUST postdoc Khalid Sedeek. "But it is prone to errors. For precise genetic modifications we need more control than provided by NHEJ. HDR is error-free but is inefficient in plants. We designed a genome editing system to enhance HDR efficiency."

The system uses Cas9 as its DNA scissor. Cas9 is fused to VirD2 a protein that comes from Agrobacterium tumefaciens, a soil bacterium that causes disease in plants by inserting part of its own DNA into the plant genome. VirD2 leads the bacterial DNA into the plant nucleus.

"We thought we could use VirD2 to bind to a wide range of repair templates to enhance the rate of HDR in plants by bringing the template close to the DNA break," says KAUST research scientist, Zahir Ali.

A guide RNA directs Cas9 to a specific location on the plant genome that is targeted for editing. Cas9 cuts the DNA strand, and then VirD2 holds the repair template close to the cut--the cell's natural HDR repair pathway uses it to conduct the repair with the corresponding genetic modifications encoded in the template.

"Our data showed that the binding of the repair template to the Cas9-VirD2 system improved the rate of HDR up to 5.5 fold in plant cells compared to Cas9 alone," says Ali.

The team tested their system in rice cells to show that the edits were precise and heritable. It successfully modified the gene that codes for the enzyme acetolactate synthase, a change that can help rice crops survive when herbicides are sprayed to kill surrounding weeds.

The system could also successfully attach a protein tag to the histone deacetylase gene in rice, which codes for an enzyme involved in plant development and reaction to stresses.

Finally, the system also successfully edited the gene that codes for the enzyme carotenoid cleavage dioxygenase 7. Precise editing of this gene results in dwarf rice plants with many grain-bearing branches.

"Our tests validated the use of this system for precise genome engineering in plants for the purpose of crop improvement," says KAUST molecular geneticist, Magdy Mahfouz, who led the study. "We expect our Cas9-VirD2 system could be adopted across most animal and plant species."

The researchers are testing their system for simultaneous edits in several genes and for multiple edits in a single gene. They are also testing it for improving various agronomic traits in multiple crops.