Tech

CHAMPAIGN, Ill. -- Scientists built a computer model of a simple brain network based on that of a sea slug, taught it how to get food, gave it an appetite and the ability to experience reward, added a dash of something called homeostatic plasticity and then exposed it to a very intoxicating drug. To no one's surprise, the creature became addicted.

The research is part of a long-term project to create a working model of the brain, starting with the simplest of circuits and gradually adding complexity, said Rhanor Gillette, a University of Illinois at Urbana-Champaign professor emeritus of molecular and integrative physiology who led the research. Postdoctoral researcher and lead author Ekaterina Gribkova built the computer model based on previous work by co-author Marianne Catanho, now at the University of California, San Diego. They describe their work in the journal Scientific Reports.

"By watching how this brain makes sense of its environment, we expect to learn more about how real-world brains work," Gillette said. "We also think our model will make a great educational tool."

The researchers named their model slug ASIMOV after the well-known science fiction writer Isaac Asimov, who was among the first to think and write about the ethics of robotics. They set the creature loose in a confined area where it would randomly encounter pellets of food, some of which were delicious, others noxious.

Just like a real predator, ASIMOV learned to avoid the noxious prey items and gobble up the good ones - unless it was very hungry, in which case it would eat whatever crossed its path. Each type of pellet had its own characteristic odor that enabled ASIMOV to determine whether to turn toward it in pursuit or to avoid it.

In addition to eating to become satiated, ASIMOV was also able to experience reward. Maximizing its own satiation levels and reward experiences were the creature's two life goals.

After establishing that ASIMOV could discriminate between good and bad foods, the researchers then added a highly rewarding but nutritionally empty drug pellet to their model. The drug also had its own characteristic odor. Once ASIMOV consumed it and experienced the intoxicating reward, it began to pursue the drug to the exclusion of all else.

The drug also made ASIMOV feel satiated, satisfying both life goals. But these two "mental" states were temporary. Eating caused satiation, but that feeling of fullness waned over time. Furthermore, ASIMOV was designed to habituate to the drug, Gribkova said.

"Just like when you drink coffee every day, you get used to the effects, which lessen over time," she said. "And if you stop drinking coffee, you go into withdrawal."

This was the homeostatic plasticity feature kicking in, Gillette said.
"ASIMOV started going into withdrawal, which made it seek out the drug again as fast as it could because the periods during which a reward experience last were getting shorter and shorter," Gillette said.

Then the researchers took the drug away from ASIMOV. The creature experienced full-fledged withdrawal and, eventually, became resensitized to the drug.

ASIMOV's behavior followed the course of addiction seen in other organisms, including humans, the researchers said. Guided by desire for reward and satiation, but also attempting to avoid pain, the creature cycled between eating, not eating and chasing after the drug when it was available.

"If it's very intoxicated by the drug, what usually happens in our simulation is that it just ignores all the other options - for example, the option to eat," Gribkova said. "It ends up in this malnourished and intoxicated state. But if it goes into withdrawal because it can't find the drug, it loses its selectivity for different kinds of prey. It just eats everything in sight.

"We wanted to actually recreate addiction in this organism," she said. "And this is the simplest way we could do it."

"We expect that behavioral complexity in animals probably evolved from very simple beginnings like this, so we're trying to recreate that in a very evolutionarily plausible way," Gillette said.

The researchers say they aim to add more layers of complexity in future work, tackling attributes like social behavior and altruism.

How do you stop something that is faster than anything else, intangible and always in motion by nature? A team led by physicists Dr. Thorsten Peters and Professor Thomas Halfmann is doing the seemingly impossible: stopping light for tiny fractions of a second. They then end the stopover at the push of a button letting the light pulse continue its journey. The researchers are even stopping individual light particles.

What sounds like a physical gimmick, could be of use for future applications. So-called quantum technology attempts to use bizarre effects of quantum physics for faster computers, more precise sensors and bug-proof communications. Photons, which are used in quantum technology as information carriers, play a decisive role in this.

To this end, physicists, for example, require light sources that emit individual photons at the push of a button. To process the information stored on light particles, it would also be important for individual photons to interact, which they do not usually do. In future quantum computers, photons will for example have to transfer their information to atoms and vice versa. To this end too, the interaction between the two types of particles must be intensified, which the photons stopped by the group from the TU Darmstadt could make possible.

How does this emergency stop for light work? For some time now it has been possible to freeze photons and re-emit them on command. However, whilst they are stopped, the photons do not exist as such. They are swallowed by an atomic cloud, which then assumes a so-called excited state and stores the photon as information. Only upon receipt of a signal does the excitation change back into a photon, which then continues on. The researchers in Darmstadt are doing it in a similar manner, but with one crucial difference: their photons are actually preserved.

The light literally stands still. The team uses a special glass fibre with a hollow channel in the centre with a diameter of less than ten thousandths of a millimetre. The fibre has a porous structure round the core that keeps light at bay. This causes a laser beam to concentrate in the centre of the hollow channel. Its cross-section narrows to around one thousandth of a millimetre. The researchers use the light beam as a kind of trap for atoms. They introduce atoms of rubidium into the hollow fibre, which concentrate in the centre of the laser beam due to electromagnetic forces. The researchers then send the photons they want to stop into the channel. Roughly speaking, the photon is brought to a complete stop by two additional laser beams that are guided into the hollow fibre on both sides. Metaphorically speaking, these hold the photons between them like two footballers kicking the ball back and forth.

"It is also similar to a chamber in which light is thrown back and forth between two mirrors," as Thorsten Peters explains. "Just without a mirror." The TU-team is the first to succeed in slowing down photons in such a narrow capillary in this way and it was not easy. It is made extremely complicated by an optical property known as birefringence. The team was able to refine their method through a laborious birefringence analysis to the point where stopping individual photons became possible.

But simply stopping light itself they did not satisfy themselves. "Our objective," says Peters, "was to make photons interact with atoms more strongly than they normally do." In particular, it should be possible for two light particles to interact with an atom at the same time, which would produce a useful phenomenon known in physics as nonlinear optics in which photons penetrate a medium, such as a special crystal. When two photons simultaneously strike one of the atoms in the crystal, they interact with one another, which changes the frequency, i.e., the colour, of the light. The new frequency could, for example, be the sum of the frequencies of the photons that are sent in.

There are many technical applications for such effects, for example in laser pointers. The method does have one disadvantage: high intensity lasers are needed to guarantee that enough pairs of photons strike an atom within the medium simultaneously. "With our method, on the other hand," says Peters, "a weak light intensity may be sufficient." This is possible because the atoms are confined to the same narrow area as the laser beam within the hollow fibre, thus maximising the contact between the light and the atomic cloud. Therefore the probability of two photons hitting an atom simultaneously is relatively high even when the light intensity is low. So the same technical trick that makes it possible to stop the photons should also create a new method for nonlinear optics.

The Darmstadt-based team has more ideas for how to apply his new process. One of these involves a switchable source for single photons. Another is to create a crystal made of photons. Crystals usually consist of atoms arranged in an absolutely regular grid, comparable to layered spheres. A large number of stopped photons could also form an ordered grid. "We could use this to simulate a solid," says Peters. The physics of solid materials is an active field of research. Theoretical models are used in research to gain a better understanding of them - often through computer simulations. But the models are so complex that they quickly overwhelm the computers. Researchers are therefore looking for other ways to imitate crystals. A simulated solid made of photons would be one way of doing this.

"We are continuing to work intensively on this," says Peters. According to the physicist, collaboration with other research groups is crucial for success. The team achieved the current work in collaboration with groups from Taiwan and Bulgaria within the framework of an EU-funded project. Industrial partners are also involved in the research project, whose objective is to develop innovative technologies for the interaction of light with matter. "The exchange is very active," Peters is pleased to say. The next successes will not be long in coming.

How do animals adapt their behaviour during life in order to assure survival and reproduction? This is a question of great interest for behavioural biologists worldwide. An essential step is to examine hormonal mechanisms which have a fundamental impact on the animal's behaviour and thus make adaptations to various social situations possible.

It has been known for some time now - especially as a result of research in guinea pigs - that the social environment during adolescence, i.e. the period from late childhood through puberty into adulthood, has a considerable impact on how individuals behave in later life. Male guinea pigs, for example, which grew up only with a female during this period, are particularly aggressive towards unfamiliar males. Behavioural biologists at Münster University have now been able to demonstrate for the first time that males are still able to adapt their hormone systems to changes in their social environment in adulthood. The study has been published in the journal Proceedings of the Royal Society B.

Methodological approach:

The male guinea pigs used in the study grew up in different social housing conditions - either in large mixed-sex colonies with many other guinea pigs, or in pairs with a female. When the guinea pigs reached adulthood, the researchers transferred the males individually to pair housing with an unfamiliar female. This way in males stemming from colony housing a change of the social niche was induced. In contrast, in males which were previously housed in pairs the female partner was changed, but the social niche - i.e. pair living - remained the same. In order to assess immediate reactions of males to their new social environment, the researchers observed the behaviour of males and determined concentrations of the hormones testosterone and cortisol.

"We were able to demonstrate that one month after transfer to pair housing with an unfamiliar female, males which had previously been housed in colonies displayed a decrease in their testosterone levels and an increase in their cortisol responsiveness. Consequently, their hormone systems became similar to those of males in pair housing. This way, the animals were most likely also able to adapt their behaviour to the new situation," explains Alexandra Mutwill, first author of the study and PhD student being supervised by Prof. Dr Norbert Sachser at the Institute for Neuro- and Behavioural Biology at the University of Münster. "As in the case of males which had previously been housed in pairs, the female partner but not the social niche was altered, the hormone systems did not change: the low testosterone levels and the high cortisol responsiveness persisted."

When guinea pigs live in colonies with a large number of conspecifics, it is advantageous to have a hormonal status which favours a less aggressive behavioural tactic. However, after transfer to pair housing another hormonal status is beneficial which enables the male to adopt a more aggressive tactic in order to defend the female partner against unfamiliar males. In males from colony housing, the change in hormone systems built the basis for such a change in the behavioural tactic and probably reflects an evolutionary adaptation.

We know how important bacteria and fungi are for the health of plants. In marine environments and in our own gut, bacteriophages (viruses that infect bacteria) are important in regulating the microbiome. Yet, their effect on bacteria living around the roots of plants has hardly been studied. 'I cannot believe that they are not important,' says Joana Falcao Salles, Professor of Microbial Community Ecology at the University of Groningen. She is the lead author of a review paper in Trends in Microbiology, which argues for more research into the role of bacteriophages in plant health.

Bacteria play an important role in many ecosystems. The possibility of large-scale DNA identification of microorganisms has revealed this over the past decade. But bacteria themselves are affected by bacteriophages, viruses that infect them. These phages can lyse the bacteria, which releases nutrients into the environment. On the other hand, the phages can live inside bacterial cells and affect their function. Finally, bacteriophages stimulate DNA transfer between cells and are known to have given cells new functionalities through this horizontal gene transfer.

Rhizosphere

'We know that soil bacteria are important for plants as well,' says Salles. Soils are deserts with very little food, as most nutrients are present in complex forms that microorganisms cannot readily use. However, in the few millimetres of soil around plant roots, plants stimulate the growth of bacteria. Plants release carbon sources for the bacteria and the bacteria provide nutrients and protection for the roots. 'This creates an oasis called the rhizosphere,' explains Salles.

Salles wrote the review article with former University of Groningen PhD student Akbar Adjie Pratama (now working as a postdoc at Ohio State University, US), MSc student Jurre Terpstra (who's bachelor thesis inspired the review) and visiting scientist Andre Luiz Martinez de Oliveria from Universidade Estadual de Londrina, Brazil. In it, she describes the role of bacterial viruses in modifying the microbial community in seawater and in the gut. 'If viruses are important in these systems, why would they not be important in the rhizosphere?' she asks. Nevertheless, this was the conclusion of a paper published not too long ago. 'The scientists had counted viral particles in the soil and found very few of them. However, bacteriophages can even have effects when they are living inside cells,' Salles explains.

Overlooked

Technical problems may also have affected studies into soil viruses, she adds: 'We have the technology to identify viruses in ocean water and in our gut. Finding them in soil is quite a challenge.' It is relatively simple to filter virus particles from water but isolating them from a slurry is far more complicated. Salles suspects that this has led to bacteriophages being overlooked. 'There are just a handful of institutes where soil phages are being studied.'

Her own institute, the Groningen Institute for Evolutionary Life Sciences, has only recently appointed a virologist. Salles and her team will now start to look for evidence of the importance of bacteriophages. 'For instance, certain phages could stimulate microbes that will protect plants during droughts.' In another project, Salles wants to test the effect of viruses on the potato microbiome, using a large number of different potato breeds.

Forgotten

'Microbes were once considered to be unimportant,' Salles continues, 'until microbiome technologies showed otherwise. Sequencing viruses has become much easier now and I cannot imagine that they are not important. Bacteriophages are the forgotten sibling and, in my opinion, we underestimate their importance.'

Simple Science Summary

Even bacteria can catch viruses. These viruses play an important role in nature. For example, they can change the number of certain bacterial species by killing bacteria, thereby freeing lots of nutrients or they can transfer DNA between cells. Bacterial viruses (also called bacteriophages) can play an important role in maintaining a healthy community of bacteria in our gut and can do the same in seawater. However, their role in soils is unclear. In a review article, Joana Falcao Salles, Professor of Microbial Community Ecology at the University of Groningen, argues that it is very likely that they are important for plant health: plants need bacteria around their roots to provide them with all kinds of nutrients and other compounds. Viruses will have an impact on these bacterial communities. Therefore, viruses are likely to be important for the health of plants.

Announcing a new article publication for BIO Integration journal. In this mini review article the authors Yuhao Chen, Meng Du, Jinsui Yu, Lang Rao, Xiaoyuan Chen and Zhiyi Chen from The Third Affiliated Hospital of Guangzhou Medical University, Guangzhou, China and the National Institute of Biomedical Imaging and Bioengineering, Bethesda, MD, USA consider nanobiohybrids in cancer therapy.

Bacteria-based nanobiohybrids have the potential to provide a targeted and effective approach for cancer treatment. In this review, the authors summarize the development of nanomaterial-mediated cancer therapy. The mechanism and advantages of the bacteria in tumor therapy are described, focusing on different therapeutic strategies of nanobiohybrid systems which combine bacteria with nanomaterials in cancer therapy.

Cancer is a common cause of mortality in the world. For cancer treatment modalities such as chemotherapy, photothermal therapy and immunotherapy, the concentration of therapeutic agents in tumor tissue is the key factor which determines therapeutic efficiency. In view of this, developing targeted drug delivery systems are of great significance in selectively delivering drugs to tumor regions. Various types of nanomaterials have been widely used as drug carriers. However, the low tumor-targeting ability of nanomaterials limits their clinical application. It is difficult for nanomaterials to penetrate the tumor tissue through passive diffusion due to the elevated tumoral interstitial fluid pressure.

As a biological carrier, bacteria can specifically colonize and proliferate inside tumors and inhibit tumor growth, making it an ideal candidate as delivery vehicles. In addition, synthetic biology techniques have been applied to enable bacteria to controllably express various functional proteins and achieve targeted delivery of therapeutic agents. Nanobiohybrids constructed by the combination of bacteria and nanomaterials have an abundance of advantages, including tumor targeting ability, genetic modifiability, programmed product synthesis, and multimodal therapy. Nowadays, many different types of bacteria-based nanobiohybrids have been used in multiple targeted tumor therapies.

FAYETTEVILLE, Ark. - University of Arkansas physicists have documented a means of improving the magnetoelectric response of bismuth ferrite, a discovery that could lead to advances in data storage, sensors and actuators.

Bismuth ferrite, or BFO, has long been of interest to scientists because its functional properties can be controlled by applying external stimuli; its magnetic response can be controlled via electric field, and its electrical response can be controlled via magnetic field, hence the name magnetoelectric. BFO is of particular interest because it is one of few magnetoelectric materials functional at room temperature. A limiting factor, however, is the small magnetoelectric response. Enhancing that response would increase the material's usefulness.

U of A scientists devised a means of improving the response by simulating a situation in which a mix of three quasiparticles creates a new quasiparticle they called "electroacoustic magnons."

"This mechanism provides opportunities to engineer the size and shape of the material to reach strikingly larger magnetoelectric responses," said doctoral candidate Sayed Omid Sayedaghaee, first author of a paper published in the journal Nature Partner Journal Computational Materials. Physics researchers Charles Paillard and Bin Xu, along with research professor Sergey Prosandeev and Distinguished Professor Laurent Bellaiche contributed to the study.

The researchers used supercomputers at the Arkansas High Performance Computing Center to create a model that explains the electroacoustic magnons and also explains the dynamics of magnetoelectric effects. Their study was supported by grants from the Defense Advanced Research Projects Agency and the Army Research Office.

Using a first-of-its-class drug in a clinical trial, an international research effort headed by a scientist at University of California San Diego School of Medicine reports that inhibition of a key enzyme safely and effectively improved the health of persons with non-alcoholic fatty liver disease (NAFLD), a chronic metabolic disorder that affects hundreds of millions of people worldwide.

The gene silencing approach represents a novel way to reverse NAFLD. The findings are published in the June 15, 2020 online issue of The Lancet Gastroenterology and Hepatology.

NAFLD occurs when fat accumulates in liver cells due to causes other than excessive alcohol intake. The precise cause is not known, but diet and genetics are believed to play substantial roles. The condition is typically not noticed until the disease is well-advanced, and perhaps has transitioned to non-alcoholic steatohepatitis (NASH), a progressive form that can lead to cirrhosis, liver cancer and liver failure.

There is no cure. Treatment primarily consists of ameliorating contributory factors, such as losing weight, improving diet, exercising more and controlling for other conditions, such as diabetes and hypertension. No Food and Drug Administration-approved medications exist. In worst cases, a liver transplant may be required.

"NAFLD wasn't even recognized as a disease three decades ago; now it is alarmingly prevalent, affecting roughly one-quarter of all Americans and emerging as one of the leading causes for liver transplant in the United States," said the study's lead author Rohit Loomba, MD, professor of medicine in the Division of Gastroenterology at UC San Diego School of Medicine and director of the UC San Diego NAFLD Research Center. "Given its relative ubiquity and its potentially calamitous consequences, safe and effective treatments are absolutely needed."

In the double-blind, randomized, placebo-controlled Phase II trial, Loomba and colleagues enrolled 44 qualifying participants at 16 sites in Canada, Poland and Hungary. For 13 weeks, participants were injected with either an antisense inhibitor called IONIS-DGAT2 or a placebo. The inhibitor, produced by Carlsbad-based Ionis Pharmaceuticals, interferes with Diacylglycerol-O-acyltransferace or DGAT2, one of two enzyme forms required to catalyze or accelerate the production of triglycerides, a type of fat found in blood. High levels of triglycerides boost fat storage throughout the body, including the liver.

The researchers found that after 13 weeks of treatment, participants who received the enzyme inhibitor experienced measurable reductions in fatty liver levels compared to baseline, without elevated levels of fats, enzymes or sugars in the blood. There were six reported serious adverse events, including a cardiac arrest and deep vein thrombosis, but the researchers determined the events were unrelated to the study drug.

"These findings showed robust reduction in liver fat by MRI without corresponding increases in blood lipids," said Loomba. "Given significant proportion of patients achieving roughly a 30 percent reduction in MRI-PDFF, the threshold that corresponds with higher odds of histologic response when treated for a longer duration, it looks like after just 13 weeks of treatment, the drug was actually slowing progression of NAFLD to NASH.

"All of this is very encouraging and argues for the next step: longer term trials to further investigate the potential of this drug in improvement of liver histologic features associated with NASH, the progressive sub-type of NAFLD."

To an English scholar or avid reader, the Shakespeare Canon represents some of the greatest literary works of the English language. To a network scientist, Shakespeare's 37 plays and the 884,421 words they contain also represent a massively complex communication network. Network scientists, who employ math, physics, and computer science to study vast and interconnected systems, are tasked with using statistically rigorous approaches to understand how complex networks, like all of Shakespeare, convey information to the human brain.

New research published in Nature Physics uses tools from network science to explain how complex communication networks can efficiently convey large amounts of information to the human brain. Conducted by postdoc Christopher Lynn, graduate students Ari Kahn and Lia Papadopoulos, and professor Danielle S. Bassett, the study found that different types of networks, including those found in works of literature, musical pieces, and social connections, have a similar underlying structure that allows them to share information rapidly and efficiently.

Technically speaking, a network is simply a statistical and graphical representation of connections, known as edges, between different endpoints, called nodes. In pieces of literature, for example, a node can be a word, and an edge can connect words when they appear next to each other ("my"-- "kingdom"-- "for"-- "a"--"horse") or when they convey similar ideas or concepts ("yellow"--"orange"--"red").

The advantage of using network science to study things like languages, says Lynn, is that once relationships are defined on a small scale, researchers can use those connections to make inferences about a network's structure on a much larger scale. "Once you define the nodes and edges, you can zoom out and start to ask about what the structure of this whole object looks like and why it has that specific structure," says Lynn.

Building on the group's recent study that models how the brain processes complex information, the researchers developed a new analytical framework for determining how much information a network conveys and how efficient it is in conveying that information. "In order to calculate the efficiency of the communication, you need a model of how humans receive the information," he says.

With this analytical framework, the researchers evaluated 40 real-world communication networks to see what features were crucial for communicating information. They looked at works of English literature, including the canon of Shakespeare and Jane Austen's "Pride and Prejudice," along with musical pieces such as Mozart's Sonata No 11 and Queen's "Bohemian Rhapsody." They also studied networks of social relationships, including co-authorship networks in science and Facebook friend connections.

After looking at this diverse group of networks, the researchers found that the large-scale structure of a network was essential to that network's ability to convey information. What was surprising was just how similar this structure was across the different networks, whether the network was representing noun transitions in a work of literature or melodic progressions in a piece of music.

What makes these networks both information-rich and efficient is a balance between two key network features known as "community" structure and "heterogeneous" structure. Community structure occurs when nodes clump together and form clusters that evoke related concepts. Saying the word "dog" might bring to mind "ball," "Frisbee," or "bone," for example. Such community structure helps make networks more efficient because a person can anticipate what word or idea might come next.

But if a person can anticipate what comes next, there won't be much information conveyed because information is directly related to surprise. To provide information, networks have to have a "heterogeneous" mixture of both well-connected and sparsely connected nodes. Take the works of Shakespeare as an example. While "the" and "and" are used 28,944 and 27,317 times, respectively, there are also 12,493 word forms that only occur once. "At a hub like, 'the,' you can't anticipate where you are about to go," says Lynn. "It turns out that these hub nodes are really important for generating surprisal or, equivalently, information."

What's fascinating to Lynn is how the balance between heterogeneous and community structure is key for creating networks that are both information-rich but also easy to interpret. "People have studied these two structures for a long time; they are two of the foundational concepts of network science," he says. "This study gives an explanation for why some of these networks are structured the way they are: because they are trying to communicate information efficiently. That's what I think the coolest part is," he says.

The researchers will continue this work by expanding the types of communication networks they evaluate, with the goal of looking for trends across time and for differences and similarities between the works of other languages and cultures. "We are also particularly interested to delineate how efficient communication is related to error correction," says Bassett. "Our preliminary findings suggest that real world networks help humans automatically correct for their own mistakes."

Planting woody plant species alongside crops could double the number of insect pollinators helping farmers produce food, new research has demonstrated for the first time.

The study, led by the University of Reading and published in the journal Agriculture, Ecosystems and Environment, provides the first observed evidence that agroforestry increases wild insect pollinator numbers and increases pollination.

The team found agroforestry sites had double the number of solitary bees and hoverflies, and in arable agroforestry sites there were 2.4 times more bumblebees than in those with just one kind of crop. Solitary bee species richness also increased tenfold at some sites. These increases in wild insect pollinators resulted in more pollination, as potted flowers left out in the study fields had up to 4.5 times more seeds.

The findings support mooted plans to implement agroforestry in Europe in the near future, showing that agroforestry could help stop the global decline of pollinators, partly resulting from intensive farming methods.

Dr Alexa Varah, who led the study while completing her PhD at the University of Reading and now works at the Natural History Museum, said: "Insect pollination is globally important for ecosystems and for growing the food we need to feed rising populations.

"It is ironic that agriculture, which relies so heavily on pollinators, is actually one of the biggest contributors to their decline. Our study finally provides some proof that agroforestry is win-win for wild pollinators and for farmers growing crops that need pollinating."

Around 35% of the crop volume produced worldwide is estimated to be dependent on insect pollination, but efforts to improve wild plant diversity on agricultural land have not stopped pollinator decline. Agroforestry has long been suggested as a solution to halt the decline of pollinators, yet observational studies in temperate climates have been virtually non-existent.

The new study measured wild pollinator numbers in fields containing a mixture of crops and woody plants and in fields with only one type of crop, and compared pollinator numbers in the two systems.

Dr Varah said: "The next step is to look at yield in these mixed systems. If yield is also higher, agroforestry could be a great way to boost crop production as well as pollinator numbers, allowing us to produce more food in a more environmentally sustainable way."

In many regions of the world, populations of large mammalian herbivores have been displaced by cattle breeding, for example in Kenya the hippos by large herds of cattle. This can change aquatic ecosystems due to significant differences in the amount and type of dung input. Researchers from the University of Eldoret in Kenya, the University of Innsbruck and the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) have therefore taken a closer look at the dung of hippopotamus and cattle.

Animal dung can pollute water bodies with nutrients and impact water quality and the ecological functions of water bodies. For many aquatic ecosystems, however, the input of organic matter from the surrounding land is part of the natural matter cycling. In temperate latitudes, it is the leaf fall that brings nutrients into water bodies. In the rivers of the African savannah, it is the hippos with their dung. The increasing displacement of hippopotami by herds of cattle is changing the nutrient inputs into water bodies.

Professor Gabriel Singer, Dr. Frank O. Masese and their team investigated the effects of nutrient and carbon inputs from dung on aquatic ecosystems in experiments. The researchers also developed a mathematical model to compare dung inputs from cattle and hippos into the Mara River in Kenya. According to the mathematical simulation, despite lower manure introduction by the individual cattle compared to a hippopotamus, the large number of cattle gives this animal group overwhelming influence.

Cattle dung is more nutritious and stimulates the growth of plants, bacteria and algae

With cattle dung, higher amounts of nutrients such as nitrogen, phosphorus and dissolved organic carbon enter the Mara River. In the experiments, the researchers were able to show that, as a result, more plant biomass is formed with cattle dung. The biomass of bacteria and algae was also higher than with hippopotamus dung. This can change food webs in the river.

"Just the exchange of an animal species that lives on the edge of the river changes the ecological status of the river. Our results show the high species-specific importance of the various large herbivores; they also show how changes in land use or the composition of the species lead to unintended consequences that are not initially the focus of management measures, but which must always be taken into account. Especially with such crucial ecosystems as the waters of the savannah," Gabriel Singer explains the significance of the investigation.

A team of researchers led by Arizona State University (ASU) School of Earth and Space Exploration professor Lindy Elkins-Tanton has provided the first ever direct evidence that extensive coal burning in Siberia is a cause of the Permo-Triassic Extinction, the Earth's most severe extinction event. The results of their study have been recently published in the journal Geology.

For this study, the international team led by Elkins-Tanton focused on the volcaniclastic rocks (rocks created by explosive volcanic eruptions) of the Siberian Traps, a region of volcanic rock in Russia. The massive eruptive event that formed the traps is one of the largest known volcanic events in the last 500 million years. The eruptions continued for roughly two million years and spanned the Permian-Triassic boundary. Today, the area is covered by about three million square miles of basaltic rock.

This is ideal ground for researchers seeking an understanding of the Permo-Triassic extinction event, which affected all life on Earth approximately 252 million years ago. During this event, up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct.

Calculations of sea water temperature indicate that at the peak of the extinction, the Earth underwent lethally hot global warming, in which equatorial ocean temperatures exceeded 104 degrees Fahrenheit. It took millions of years for ecosystems to be re-established and for species to recover.

Among the possible causes of this extinction event, and one of the most long-hypothesized, is that massive burning coal led to catastrophic global warming, which in turn was devastating to life. To search for evidence to support this hypothesis, Elkins-Tanton and her team began looking at the Siberian Traps region, where it was known that the magmas and lavas from volcanic events burned a combination of vegetation and coal.

While samples of volcaniclastics in the region were initially difficult to find, the team eventually discovered a scientific paper describing outcrops near the Angara River. "We found towering river cliffs of nothing but volcaniclastics, lining the river for hundreds of miles. It was geologically astounding," says Elkins-Tanton.

Over six years, the team repeatedly returned to Siberia for field work. They flew to remote towns and were dropped by helicopter either to float down rivers collecting rocks, or to hike across the forests. They ultimately collected over 1,000 pounds of samples, which were shared with a team of 30 scientists from eight different countries.

As the samples were analyzed, the team began seeing strange fragments in the volcaniclastics that seemed like burnt wood, and in some cases, burnt coal. Further field work turned up even more sites with charcoal, coal, and even some sticky organic-rich blobs in the rocks.

Elkins-Tanton then collaborated with fellow researcher and co-author Steve Grasby of the Geological Survey of Canada, who had previously found microscopic remains of burnt coal on a Canadian arctic island. Those remains dated to the end-Permian and were thought to have wafted to Canada from Siberia as coal burned in Siberia. Grasby found that the Siberian Traps samples collected by Elkins-Tanton had the same evidence of burnt coal.

"Our study shows that Siberian Traps magmas intruded into and incorporated coal and organic material," says Elkins-Tanton. "That gives us direct evidence that the magmas also combusted large quantities of coal and organic matter during eruption."

And the changes at the end-Permian extinction bear remarkable parallels to what is happening on Earth today, including burning hydrocarbons and coal, acid rain from sulfur, and even ozone-destroying halocarbons.

"Seeing these similarities gives us extra impetus to take action now, and also to further understand how the Earth responds to changes like these in the longer term," says Elkins-Tanton.

The first city-wide health impact assessment of the estimated effects of a tree canopy initiative on premature mortality in Philadelphia suggests that increased tree canopy could prevent between 271 and 400 premature deaths per year. The study by Michelle Kondo, a Philadelphia-based research social scientist with the U.S. Department of Agriculture Forest Service, and her partners suggest that increased tree canopy or green space could decrease morbidity and mortality for urban populations - particularly in areas with lower socioeconomic status where existing tree canopies tend to be the lowest.

The study, "Health impact assessment of Philadelphia's 2025 tree canopy cover goals," examined the potential impact of Greenworks Philadelphia, a plan to increase tree canopy to 30 percent across the city by 2025, on human mortality. The analysis is one of the first to estimate the number of preventable deaths based on physical activity, air pollution, noise, heat, and exposure to greenspaces using a tool developed by public health researchers in Spain and Switzerland called the Greenspace-Health Impact Assessment

Recently published in the journal The Lancet Planetary Health, the study is available through the Forest Service's Northern Research Station at: https://www.nrs.fs.fed.us/pubs/59911

Kondo and her partners estimated the annual number of preventable deaths associated with projected changes in tree canopy cover in Philadelphia between 2014 and 2025 under three scenarios of increased urban green space. They found that increasing urban tree canopy to the Greenworks Philadelphia goal of 30 percent in all neighborhoods could prevent 400 deaths annually, but lesser increases in tree canopy still resulted in reduced mortality. A 5 percentage point increase in tree canopy only in areas without trees could result in an annual reduction of 302 deaths citywide, researchers found, and a 10 percentage point increase in tree canopy cover across the city was associated with an estimated reduction of 376 deaths

"This study supports the idea that increasing tree canopy and urban greening efforts are worthwhile, even at modest levels, as health-promoting and cost-saving measures," Kondo said.

Current tree canopy in Philadelphia ranges from 2 percent to 88 percent, with an average 20 percent urban tree canopy coverage based on 2014 data.

"In recent weeks, as residents of many cities experienced quarantine conditions, we experienced a heightened need for public green space," Kondo said. "While the COVID-19 pandemic has meant that we need to pay attention to our proximity to other people and take precautions to limit our contact, time outside in parks and forests has been critical to maintaining our mental and physical health."

Research partners included scientists from Universitat Pompeu Fabra, National Socio-Environmental Synthesis Center, Colorado State University, and Drexel University.

As the first pandemic in the digital era, COVID-19 has created an urgent need for coordinated mechanisms to respond to the outbreak across health sectors. While digital health solutions have been identified as promising approaches to address this challenge, their successful implementation depends on a series of socio-economic, ethical, legal and cultural factors and requires the appropriate enabling expertise, infrastructure and cohesion among all stakeholders concerned. Through the adoption of several digital health solutions, Luxembourg is positioning itself as a leader in this respect, both from a public health surveillance and a research perspective. Dr Guy Fagherazzi, Research Leader in "Digital Epidemiology and E-health" and colleagues from the Department of Population Health of the Luxembourg Institute of Health (LIH) released an editorial on June 16th reviewing international digital responses to the pandemic - including the "Predi-COVID study" - and providing recommendations and guidelines for future digital initiatives. Published in the prestigious Journal of Medical Internet Research, the paper was selected as a featured editorial for the launch of a dedicated article series on COVID-19.

Digital tools can effectively support institutions during a pandemic by allowing the deployment of novel digital healthcare models at different stakeholder levels -- from healthcare and research, to the government and general population. Telemedicine solutions, mobile applications, websites and "chatbots" are enabling the provision of virtual medical visits and primary care, electronic prescriptions, remote patient monitoring and screening in real time, risk assessment and triage prior to hospital admission, as well as the immediate widespread dissemination of information through digital communication campaigns. Moreover, digital tools, open search engines and social media platforms constitute useful resources to rapidly collect meaningful information on large samples and study the evolution of symptoms in real time, thereby increasing the understanding of the different clinical profiles of COVID-19 patients, the evolution of the pandemic and the long-term health consequences of the disease.

Leveraging on the interdisciplinary expertise of all national healthcare and biomedical research players, the prospective cohort study "Predi-COVID " was recently established to identify important risk factors and biomarkers associated with COVID-19 severity. The study boasts an innovative design, underpinned by a strong digital component relying on a series of tools collaboratively developed and implemented by the Predi-COVID consortium partners. Specifically, the recruitment of participants in Predi-COVID is made possible by the close collaboration between the LIH and the Health Directorate of the Luxembourg Ministry of Health, in charge of the national telemonitoring system "suivicovid.lu" for the remote surveillance of all patients who tested positive for COVID-19 and for the evaluation of the evolution of their symptoms and health condition. Clinical and epidemiological data is then combined with the collection of biological samples and associated data, electronic patient-reported outcomes and additional digital data gathered through the innovative "CoLive LIH" smartphone application. "CoLive LIH" was conceived by the LIH Department of Population Health (DoPH) to mainly capture vocal data to identify innovative digital vocal biomarkers to monitor patients with COVID-19.

"Voice recordings in particular will allow us to identify and study specific signatures in patients' voices - so-called vocal biomarkers - that can be associated with frequently observed COVID-19 symptoms, such as respiratory syndromes, fatigue, but also anxiety or negative emotions, and which could enable the easy remote monitoring of COVID-19 patients at home", explains Dr Guy Fagherazzi, corresponding author of the publication.

From a technological standpoint, the current pandemic has acted as an accelerator of new "e-Health" solutions. Nevertheless, there is a strong need for a concerted, streamlined action and better cohesion -- at the international level -- to ensure collected data is harmonised, reproducible and reliable. "The suddenness of the COVID-19 pandemic meant that new digital solutions had to be developed and rolled out rapidly. This reactivity stimulated creativity and innovation, but also raised new organisational challenges. Digital solutions should focus on easing the life of those who are at the forefront of the crisis and providing data to evaluate their effectiveness to support evidence-based public health decisions", underlines Prof Laetitia Huiart, head of the Department of Population Health at LIH and co-author of the paper. "Luxembourg has done very well on this aspect too", she adds.

Indeed, the Luxembourg Ministry of Health and its Health Directorate have been working in close cooperation with the main research institutes to build synergies in terms of COVID-19 surveillance and research, ensuring a smooth coordination between the country's healthcare and research activities. "To this end, the dual role of Prof Laetitia Huiart as both the Principal Investigator of Predi-COVID at LIH and as the leader of the 'Inspection Sanitaire' at the Ministry of Health has been crucial in fostering data sharing and ensuring that COVID-19 monitoring and research in Luxembourg go hand in hand through the effective implementation of novel 'e-Health' tools", Guy Fagherazzi concludes.

The original article was published on June 15th 2020 in the Journal of Medical Internet Research, with the full title "Digital Health Strategies to Fight COVID-19 Worldwide: Challenges and Recommendations". The article was selected as an editorial for the launch of a dedicated article series on COVID-19, with Dr Fagherazzi acting as a Guest Editor.

CORVALLIS, Ore. - The lives of honeybees are shortened - with evidence of physiological stress - when they are exposed to the suggested application rates of two commercially available and widely used pesticides, according to new Oregon State University research.

In a study published in the journal PLOS ONE, honeybee researchers in OSU's College of Agricultural Sciences found detrimental effects in bees exposed to Transform and Sivanto, which are both registered for use in the United States and were developed to be more compatible with bee health.

The western honeybee is the major pollinator of fruit, nut, vegetable and seed crops that depend on bee pollination for high quality and yield.

Coupled with other stressors such as varroa mites, viruses and poor nutrition, effects from these pesticides can render honeybees incapable of performing their tasks smoothly. Beekeepers and some environmental groups have raised concerns in recent years about these insecticides and potential negative effects on bees.

According to the researchers, this is the first study to investigate "sub-lethal" effects of sulfoxaflor, the active ingredient in Transform, and flupyradifurone, the active ingredient in Sivanto. Sub-lethal effects mean that the bees don't die immediately, but experience physiological stress resulting in shortened lifespan.

In the case of Transform, the bees' lives were severely shortened. A majority of the honeybees exposed to Transform died within six hours of being exposed, confirming the severe toxicity of the pesticide to bees when exposed directly to field application rates recommended on the label, the researchers said.

Study lead author Priyadarshini Chakrabarti Basu, a postdoctoral research associate in the Honey Bee Lab in OSU's College of Agricultural Sciences, emphasized that the researchers aren't calling for Sivanto or Transform to be taken off the market.

"We are suggesting that more information be put on the labels of these products, and that more studies need to be conducted to understand sublethal effects of chronic exposure," Basu said.

Sivanto and Transform are used on crops to kill aphids, leaf hoppers and whiteflies, among other pests. Many of these same crops attract bees for pollination. There are some restrictions on their use. For example, Transform can't be applied to crops in bloom, for example.

Honeybees might be exposed indirectly through pesticide drift, said study co-author Ramesh Sagili, associate professor of apiculture and honeybee Extension specialist in OSU's College of Agricultural Sciences.

"The average life span of a worker honeybee is five to six weeks in spring and summer, so if you are reducing its life span by five to 10 days, that's a huge problem," Sagili said. "Reduced longevity resulting from oxidative stress could negatively affect colony population and ultimately compromise colony fitness."

For the study, the researchers conducted two contact exposure experiments: a six-hour study and a 10-day study in May 2019. The honeybees were obtained from six healthy colonies at the OSU apiaries. In each experiment, groups of 150 bees were placed in three cages. One group was exposed to Transform, a second to Sivanto and the third was a control group that wasn't exposed to either pesticide.

Honeybee mortality, sugar syrup and water consumption, and physiological responses were assessed in bees exposed to Sivanto and Transform and compared to bees in a control group. Mortality in each cage was recorded every hour for the six-hour experiment and daily for the 10-day experiment.

While Sivanto was not directly lethal to honeybees following contact exposure, the 10-day survival results revealed that field-application rates of Sivanto reduced adult survival and caused increased oxidative stress and apoptosis in the honey bee tissues. This suggests that even though Sivanto is apparently less toxic than Transform, it might also reduce honeybee longevity and impart physiological stress, according to the study authors.

Johns Hopkins Kimmel Cancer Center researchers from the Department of Radiation Oncology and Molecular Radiation Sciences identified a lipid-regulating protein that conveys what the researchers describe as "superpowers" onto prostate cancer cells, causing them to aggressively spread.

In studies of human prostate cancer cell and stromal cell lines, when the lipid-regulating protein, called CAVIN1, was removed from stromal cells -- the connective tissue cells in and around tumors -- the cells no longer used the lipids. Instead, cancer cells feasted on lipids in the environment, using them as fuel, including to make hormones that feed the cancer.

The findings were reported June 3 in the journal Molecular Cancer Research.

"We know that aggressive behavior of tumors, such as rapid growth and metastasis, does not happen alone, so we wanted to find out the role of the tumor microenvironment, and specifically the interaction between prostate tumor cells and stromal cells, in increasing cancer growth," says Marikki Laiho, M.D., Ph.D., director of the Division of Molecular Radiation Sciences and professor of radiation oncology and molecular radiation sciences at the Johns Hopkins University School of Medicine, and senior author of the study.

In the human cell line experiments, when the researchers took CAVIN1 away from stromal cells called fibroblasts, the stromal cells no longer used the lipids, but the lipids remained in the environment, and to the researchers' surprise, they became a smorgasbord for the cancer cells. In every prostate cancer cell line tested, tumor cells universally had an appetite for the lipids, using them to fuel growth, strengthen the protective membrane around the cell, synthesize proteins and make testosterone to support the cancer's growth, says Jin-Yih Low, Ph.D., first author and a research fellow in the Department of Radiation Oncology and Molecular Radiation Sciences.

"As a consequence, the tumor cells behaved more aggressively, exhibiting invasive and metastatic behavior," says Low. "Just having access to the lipids gave the tumor cells more power. The tumor is the same tumor, but the behavior of the tumor changes."

In addition, when the stromal fibroblasts did not use the lipids, they changed, and started to secrete inflammatory molecules that altered the tumor microenvironment. Inflammation is a characteristic long known to promote cancer.

To confirm their findings, the researchers conducted similar experiments in mouse models, implanting the prostate cancer cells and stromal cells into the prostates of mice and comparing the behavior of tumors with and without CAVIN1 function in the stromal cells. Although the presence or loss of CAVIN1 did not impact the speed of tumor growth, lack of CAVIN1 caused the cancer to spread. All of the mice with tumors that did not express CAVIN1 had a twofold to fivefold increase in metastasis. The tumors also had a fortyfold to hundredfold increase in lipids and inflammatory cells.

Laiho calls the findings striking. "We suspected CAVIN1 was important but did not realize how important," she says. "Microenvironment matters, and the amount of lipids matters a lot. Just by converting the cells from a low level of lipids to a high level of lipids created a situation of rampant metastasis."

The researchers say the loss of CAVIN1 in tumor cells could potentially be used as a biomarker, alerting clinicians to a risk of metastasis. Interventions are being studied but are challenging because all cells need lipids. Any treatments aimed at inhibiting lipids would have to specifically target cancer cells. Ongoing studies are aimed at better understanding the inflammatory process and ways to stop its ability to fuel cancer spread. For example, the researchers want to understand why the inflammation draws cells, called macrophages, that further exacerbate the inflammatory process but does not attract beneficial T cells that could attack the cancer, and if lipid cells could be sending signals that affect immune checkpoints, which are the immune system's on and off switches.

CAVIN1 was first discovered in human lipodystrophy syndrome, a disorder that prevents the uptake of lipids and leaves those affected unable to make fat cells, placing them at risk of diseases including cardiovascular disease and diabetes.