Culture

In a ground-breaking first, researchers have fabricated 3D scaffold implants containing antibiotics at high temperatures. These scaffolds not only support bone regeneration but manage the bone infections that can arise as a result of injury or surgery.

Each year, around 4 million people worldwide develop bone infection following an open fracture or surgery. The gold standard treatment consists of a lengthy antibiotic therapy, usually delivered orally or Intravenously, and the removal of infected bone tissue, which often leaves behind a hole too large for the body to fill via normal bone regeneration. In a study published in the KeAi journal Bioactive Materials, a group of researchers from the Netherlands, Italy and Spain, outline a new treatment approach they have developed - novel antibiotic-releasing and biodegradable 3D printed scaffolds, capable of supporting bone regeneration and delivering antibiotics at the same time.

"Every person has their own individual body anatomy, which certainly requires a specific intervention in the event of bone injury," explains one of the study's authors, Lorenzo Moroni, professor in biofabrication for regenerative medicine at Maastricht University's MERLN institute. "3D printed polymeric scaffolds possess several unique properties for bone regeneration: their shape can be tailored to fit the specific patient's anatomy, they are porous to allow cell infiltration, but at the same time mechanically strong, and they can degrade over time to make space for the newly-formed bone. However, incorporating antibiotics in these scaffolds is not straightforward, since the 3D printing process consists of melting the material at high temperatures and antibiotics are heat sensitive."

The study's multidisciplinary team of scientists found that covering the antibiotics with lamellar inorganic protectors, prior to mixing them with the polymer and placing them in the 3D scaffolds, not only protected the antibacterial agents, it also enabled a more controlled release. This extended the period the antimicrobial were active and helped to keep local antibiotic concentrations under potentially toxic levels. At the same time, the cells in contact with these scaffolds maintained their viability and could perform normal cell functions, including bone formation - the ultimate goal of the implant.

According to Maria Camara-Torres, the investigator who led the study, this is a great breakthrough in the field of bone regeneration. "Until now, the direct incorporation of antibiotics and other bioactive molecules within 3D printed scaffolds has been limited to the few polymers that can be processed at low temperatures. Our novel approach shows that the library of polymers can be expanded to include many more." She adds: "We hope that our results encourage scientists to continue investigating the use of lamellar inorganic fillers in combination with biomolecules to increase the functionality of 3D printed scaffolds in clinical applications."

A genetic variation that regulates iron metabolism may enhance athletes' endurance performance, researchers at the University of Toronto have shown.

The findings could help explain studies that show an association between the genetic variation and elite athletes across many sports, and may help competitive athletes fine-tune their iron intake to boost performance.

The variation, found in the homeostatic iron regulator (HFE) gene, is a known cause of iron overload, a condition called hemochromatosis in which the body absorbs too much iron leading to organ and joint damage.

Athletes at risk for hemochromatosis but with iron stores below potentially toxic levels could have a competitive edge, but most athletes are unsure if boosting their intake of iron from supplements or diet is likely to be beneficial or harmful.

"Increasing iron intake might not be ideal for athletes who already have the elevated risk genotype, but athletes with the low-risk genotypes could potentially benefit from increasing their iron stores," said Ahmed El-Sohemy, a professor of nutritional sciences in U of T's Temerty Faculty of Medicine.

"Genetic testing and supervision by a health-care professional to monitor iron status could be an effective way for athletes to optimize endurance performance," El-Sohemy said.

The findings were published online in Medicine & Science in Sport & Exercise recently and will appear in the journal's July 2021 print issue. The study is the first to look at the association between HFE genotype and endurance performance in competitive male athletes.

El-Sohemy and his colleagues studied 100 athletes from a variety of sports, tracking how quickly they cycled 10 kilometers while measuring their aerobic capacity through VO2 peak, a measure of oxygen used during exercise.

The researchers found that those genetically at risk for iron overload performed 8 per cent better than those with a low risk, cycling 1.3 minutes faster on average. They also showed that athletes with higher risk for iron overload had a 17 per cent greater oxygen carrying capacity, which could explain why they cycled faster.

The higher-risk group was small (11 males), but the findings are consistent with studies on iron in endurance performance, which show that iron facilitates oxygen transport and that athletes with levels on the higher end of normal can circulate oxygen in their muscles more efficiently.

Athletes with the elevated genetic risk variation may be less likely to feel fatigued and more likely to recover quicker after high-intensity exercise, El-Sohemy said.

Nanci Guest is a postdoctoral fellow at U of T and sport dietitian who conducted the trial. She said she hopes the study raises awareness about the importance of genetics in optimizing nutritional status among athletes, trainers and their coaches.

"Despite our vigilance toward addressing low-iron status, these findings suggest that we may need to direct our attention to achieving optimal iron status by aiming toward mid- or higher ends of normal," Guest said.

El-Sohemy and his colleagues are now looking at whether iron status is associated with other measures of athletic performance such as power and strength. They plan to examine whether HFE and additional genes could be important, and they hope to broaden the work further to include females and recreational athletes.

Drishti Thakkar is a graduate student in the Faculty of Information at U of T, who analyzed the trial data and compiled the results as part of an undergraduate project in nutritional sciences. "I'm excited to see more athletes consider genetic testing to obtain precise information for more personalized nutrition and training regimens," said Thakkar. "I think this is definitely part of the future in sports nutrition."

Ahmed El-Sohemy is the founder and chief science officer of Nutrigenomix Inc. and Nanci Guest is on the company's scientific advisory board, which provides genetic testing for personalized nutrition including the HFE gene and iron metabolism.

Usually scaled, the skin of fish can also be naked or made up of bony plates that form an armour, sometimes even covered with teeth. But how has this skin evolved over the ages? To answer this question, researchers at the University of Geneva (UNIGE), Switzerland, have reconstructed the evolution of the protective skin structures in fish, going back to the common ancestor of ray-finned fish, more than 420 million years ago. They found that only fish that had lost their scales were able to develop a bony armour, and that the protective state of their skin influenced their choice of open water or sea floor habitats. This study, published in the journal Evolution Letters, provides a new explanation for the incredible diversity of this lineage of fish, which includes more than 25,000 species.

Ray-finned fish, such as catfish or goldfish, constitute the most diverse lineage of vertebrates on Earth, with no less than 25 000 species, i.e. half of the planet's vertebrates. "Far from being limited to scales, these fish species can also have completely naked skin or a bony armour, sometimes covered with teeth, as is the case with certain catfish", notes Juan Montoya, a researcher in the Department of Genetics and Evolution at the UNIGE Faculty of Science. But how did the protective structure of the skin evolve in these fish?

A family tree that goes back 420 million years

The researchers used an evolutionary tree of fish that lists 11,600 species. "In order to reconstruct the ancestral characteristics of the species, we worked in parallel with a second tree of 304 species, which precisely establishes the links of relationship", explains Alexandre Lemopoulos, a researcher in the Department of Genetics and Evolution at the Faculty of Science of the UNIGE. They asked themselves two questions: What type of protection do the fish have on their skin? And do they live in the open water or on the seabed?

Using mathematical models, they reconstructed the most likely ancestral state and, as they went up the family tree, they reconstructed the transitions between the three skin types and observed whether these had conditioned their habitat. "We were able to go back to the first ancestor of ray-finned fish, more than 420 million years ago, who had scales", enthuses Juan Montoya.

Only naked fish can develop armour

By analysing the transitional stages, the Geneva researchers found several lineages of fish that lost their scales, but at different positions in the tree. "There is therefore no temporal coincidence in this evolution", emphasises Alexandre Lemopoulos. Moreover, once a lineage of fish has lost its scales, it cannot find them again. "On the other hand, some of these naked fish subsequently developed bony plates covering part or all of their body, forming a solid armour", points out Juan Montoya. "We now need to discover the underlying genetic mechanism, which probably no longer allows a return to the scale stage, but makes it possible to build a compensatory external skeleton." Thus, only naked fish were able to build up this armour. "It does not seem possible to go directly from a scaly skin to a cuirassed skin, nor to have a mixture of these two structures", he says.

Skin conditions the place of residence

The researchers also observed that the change in skin condition conditioned the place of habitation. "Several species of fish that have lost their scales have left the open waters in which they lived for the seabed, certainly finding an advantage in this new environment", explains Alexandre Lemopoulos. This is a pre-adaptation: the fish lose their scales, change environment and find advantages. As this sequence was repeated independently in several groups of fish, the researchers deduce that a skin without scales offers a real advantage for living on the bottom. "It should be noted that once a lineage of fish establishes itself on the seabed, it no longer returns to the open water, even if it subsequently develops a bony armour", he continues.

Two hypotheses seem to explain this 'move': respiration and immune defence. "Fish breathe through their gills, but also through their skin. Bare skin improves gas exchange in poorly oxygenated water by increasing the respiratory surface", suggests Alexandre Lemopoulos. Furthermore, recent studies have shown that the immune defence against viruses and bacteria, which are very present in the seabed, was more effective when the skin had no scales.

It is therefore thanks to the evolution of the protective structures of the skin that several families of fish have migrated to the seabed and opened up new ecological niches, colonising more and more different environments, whether in fresh or salt water. "This has contributed to the establishment of this enormous diversity, which makes ray-finned fish the largest group of vertebrates on the planet", concludes Juan Montoya.

The tiger shark is one of the largest predatory sharks known today. This shark is a cosmopolitan species occurring in all oceans worldwide. It is characterized by a striped pattern on its back, which is well marked in juveniles but usually fades in adults.

The fossil history of modern sharks reaches back to the Permian, about 295 million years ago. Complete fossil shark skeletons are very rare - the skeleton, which consists almost entirely of cartilage, is only preserved under very special circumstances during the fossilization processes. Due to the lifelong continuous tooth replacement, most extinct sharks are therefore only known by their well-mineralized teeth, which, nonetheless, can provide deep insights into their evolutionary history.

The teeth of the modern tiger shark are unique: they have a broad, double-serrated cutting edge which even allows them to cut through sea turtle shells with ease. Tiger shark teeth are known in the fossil record since about 56 million years. Based on these fossil teeth, over 22 extinct tiger shark species have been described.

An international team of researchers led by Julia Türtscher from the University of Vienna has now examined the fossil history of the tiger shark and its extinct relatives. With the help of geometric morphometrics, the scientists were able to show that only 5 of the 22 known fossil tiger sharks actually represent valid species. Nevertheless, tiger sharks were more diverse in the past and only a single species survived until today.

Another intriguing detail in the tiger shark fossil record emerged during this study. Up to now, it was assumed that the modern tiger shark originated ca. 5.3 million years ago. The team, however, was able to identify several 13.8 million year old fossil teeth as belonging to this shark demonstrating that it originated much earlier than previously assumed.

Nonalcoholic fatty liver disease (NAFLD) is a pathological condition characterized by excessive fat stored in the liver that is not attributed to heavy alcohol consumption, which can lead to liver failure and even cancer. Obesity, type 2 diabetes, and high cholesterol levels are all risk factors for this disease, and like the global prevalence of obesity, the prevalence of NAFLD is coincidently expected to rise as well.

It is therefore critical for clinicians to handle effective tools for diagnosing NAFLD. The current standard method for diagnosis is analysis of liver biopsy samples. However, this approach has shortcomings such as invasiveness and the potential for sampling errors, so there is a pressing need for reliable noninvasive methods. In a new study published in the journal Biomedical Optics Express, a team of researchers, led by Professor Kohei Soga of Tokyo University of Science including Assistant Professor Kyohei Okubo of Tokyo University of Science and Professor Naoko Ohtani of Osaka City University, reports the successful use of near-infrared hyperspectral imaging to quantitatively analyze the distributions of lipids (a class of lipids commonly found in fat) in mouse liver. Dr. Okubo says, "Lipid distribution in the liver provides crucial information for diagnosing fatty liver-associated liver diseases including cancer, and therefore, a noninvasive, label-free, quantitative modality is needed."

In describing the inspiration for this project, Dr. Okubo collaborated with Professor Ohtani, who studies the relationship between obesity and liver disease. Given the success of other research groups in using near-infrared hyperspectral imaging to visualize plaques in rabbit blood vessels and fatty acids in pork meats, Prof. Soga's team decided to try using it to visualize the distribution of lipids in mouse liver.

The study focused on mice that were either on a normal diet or one of three kinds of high-fat diets rich in various types of lipids. The objective of these varied diets was to generate a set of livers with diverse lipid profiles. After extracting the livers, the scientists used a reference test to generate convincing results for comparing their hyperspectral imaging results. They used the Folch extraction method to isolate lipids from small pieces of the livers and then weighed the isolated lipid samples to calculate the total weight of lipids within the livers. The scientists next performed near-infrared hyperspectral imaging and used two candidate data analysis methods--partial least-square regression and support vector regression--to quantitatively visualize lipid distributions within the liver to identify the better analytical method.

When the scientists examined their data, they found that it enabled them to image the livers in gradient colors according to the lipid levels contained in the livers and to generate maps of the local lipid densities within the livers. The lipid levels as measured with hyperspectral imaging closely correlated with the actual lipid levels as quantified based on Folch extraction method, and this correlation was stronger in the lipid levels calculated using support vector regression than for the lipid levels calculated using partial least square regression.

In articulating the significance of his team's research, Dr. Okubo notes, "We have developed a method to visualize the distribution of lipids in the liver using a near-infrared spectral imaging technique that incorporates machine learning." This is important because near-infrared spectral imaging technologies could be used for the noninvasive evaluation of the liver status, thus providing a diagnostic option for clinicians when investigating NAFLD cases. Near-infrared spectral imaging can also be used to detect specific lipid compound types, and Dr. Okubo is quick to emphasize that "the ultimate goal of this collaborative research is to differentiate and identify fatty acids in the liver." Achieving this future goal would represent a major advancement in research in fatty liver diseases.

Researchers led by TMDU fabricate a material that will aid bone healing, help medical practitioners clearly assess the full damage to bones after an injury, and clarify probable patient outcomes

Tokyo, Japan - Bone repair wasn't generally successful until the late 1800s. Until then, there were few options to repair major bone damage. Most materials don't have the functionality of bone and don't support blood vessels growing through them. Repair materials such as clay were commonly used yet often failed. In 1892, medical practitioners started using gypsum--calcium sulfate--as the first effective bone substitute material. Bone repair is much more straightforward and less risky these days, but repairing large-scale bone damage remains challenging.

Medical practitioners today use octacalcium phosphate--OCP--as a substitute bone material. It's a precursor of bone tissue and a logical choice for bone repair. However, medical practitioners may not be able to unambiguously assess the complete extent of bone damage by X-ray analysis. This may hinder their ability to accurately predict recovery timelines and other prognoses for patients.

In a study recently published in Communications Chemistry, a team led by researchers at Tokyo Medical and Dental University (TMDU) incorporated a fluorescent molecule--pyromellitic acid--into OCP. When used in clinical practice, this advanced modification to OCP will improve diagnostic analyses and predictions of therapeutic outcomes.

"We incorporated pyromellitic acid by a hydrolysis reaction with dicalcium phosphate dihydrate," explains Taishi Yokoi, lead author. "Analytical characterization and computational analyses confirmed that we prepared our target material."

Their synthetic approach avoided formation of undesired salts--calcium carboxylates--that would otherwise hinder the full functionality of pyromellitic acid. By carefully tailoring the pH and pyromellitic acid concentrations during synthesis, the researchers were able to optimize incorporation of pyromellitic acid into OCP.

"We found that 81% of the monohydrogen phosphate in OCP was replaced by pyromellitic acid," says senior author Masakazu Kawashita. "This is important for pyromellitic acid to help connect different inorganic layers into an intact whole, and facilitate complete repair."

The researchers' improved bone replacement material was bright blue, much brighter than pyromellitic acid is when it is not mixed with bone precursors. This opens up obvious possibilities for real-time visual analysis, and will help medical practitioners predict the time course of patient recovery and other diagnostic outcomes.

"Our improved OCP has distinct advantages over conventional bone repair materials," explains Yokoi. "We're optimistic that our material can quickly overcome regulatory hurdles and find use in dental implants, bone fractures, and other challenging surgical applications in the coming years."

Floating solar farms could help to protect lakes and reservoirs from some of the harms of climate change, a new study suggests.

However, given the complex nature of water bodies and differing designs of solar technologies, there could also be detrimental ecosystem impacts of deploying floating solar arrays.

Conventional solar farms are controversial due to the amount of land they take up. This is leading to increasing interest in floating solar farms - making use of the additional space that bodies of water provide.

So far, there are three commercial-size floating solar arrays in the UK, and hundreds more across the world. The number of installations is likely to grow significantly in coming decades as demand rises for renewable energy sources with more countries committing to net zero carbon targets.

However, little is known about the impacts - both positive and negative - these floating solar farms are having on the lakes and reservoirs they are installed on - until now.

Scientists from Lancaster University and the University of Stirling have completed the first detailed modelling of the environmental effects of floating solar installations on bodies of water.

"As demand for land increases, water bodies are increasingly being targeted for renewable energy. Deployment of solar on water increases electricity production, but it is critical to know if there will be any positive or negative environmental consequences," said Mr Giles Exley, PhD researcher and lead author from Lancaster University.

"Given the relative immaturity of floating solar farms, it is important to further scientific evidence of the impacts. Our results provide initial insight of the key effects that will help inform water body manager and policy maker decisions."

The research team undertook computer modelling using the MyLake simulation programme and data collected by the UK's Centre for Ecology and Hydrology from England's largest lake, Windermere. Although the researchers believe it is unlikely floating solar farms will be deployed on Windermere, it presents a rich data-set as it is one of the most comprehensively studied lakes in the world.

Their results show that floating solar arrays can cool water temperatures by shading the water from the sun. At scale, this could help to mitigate against harmful effects caused by global warming, such as blooms of toxic blue green algae, and increased water evaporation, which could threaten water supply in some regions.

The scientists found that floating solar installations also reduce the duration of 'stratification' - this is where the sun heats the water, forming distinct layers of water at different temperatures. This tends to happen more in the warmer summer months and can result in the bottom layer of water becoming deoxygenated, which deteriorates water quality - an obvious issue for supplies of drinking water. However, the picture is complex and there are also conditions under which stratification, and therefore detrimental water quality impacts, could increase if floating solar farms are deployed.

Mr Exley said: "The effects of floating solar on the temperature of the water body and stratification, both of which are major drivers of biological and chemical processes, could be comparable in magnitude to the changes lakes will experience with climate change. Floating solar could help to mitigate against the negative effects global warming will have on these bodies of water."

"However, there are also real risks of detrimental impacts, such as deoxygenation causing undesirable increases in nutrient concentrations and killing fish. We need to do more research to understand the likelihood of both positive and negative impacts."

The effects on water temperature increased the larger the solar installation, with small arrays of less than ten per cent of the lake surface generally having minimal impacts. However, this model concentrated on one lake. Further studies will be needed to determine the optimum size array, and design, and their effects for individual lakes and reservoirs - all of which have unique characteristics. Different designs of solar installations also have different shading and sheltering effects for the sun and wind.

Arrays covering more than 90 per cent of a lake could increase the chances of the lake freezing over in winter, the study found - though these effects would also be specific to the body of water and design of the installation and require further studying.

Field studies and further modelling work to build on these initial findings is ongoing.

A new study from the University of Bergen (UiB) shows that the way young people view their bodies have a great impact on their BMI.

In a two-year follow up study among 1225 Norwegian adolescents in their early teens, professor Eivind Meland and his team examined how body mass index, self-esteem and self-rated health were mutually impacted and influenced by body dissatisfaction.

"We revealed that positive self-image and self-esteem protected against weight gain", professor emeritus Meland says.

The girls had in general lower body confidence than boys, the study shows.

Body dissatisfaction

The eager to be thinner, dieting, and wanting to change something with the body all impaired self-rated health and self-esteem after and during the two years' observation. The eager to be fatter was associated with getting thinner, and the eager to lose weight was associated with body mass gain as compared with peers who were content with their body.

"We conclude that health promotive efforts in adolescence should be based on self- and body-acceptance", says Meland.

A new study shows that when people replace their old couch with a new one that has no added flame retardants, levels of the harmful chemicals in household dust drop significantly. Replacing the foam inside the couch cushions is also just as effective. The findings confirm that choosing healthier furniture without flame retardants can make a big difference in people's--especially children's--everyday exposures to these toxic chemicals.

"We've long suspected that couches are a major source of toxic chemicals in dust. Now, for the first time, we have evidence demonstrating the positive impacts of replacing old furniture containing flame retardants," says lead author Kathryn Rodgers, a research scientist at Silent Spring Institute.

The findings appear in the journal Environment International.

Flame retardants can migrate out of furniture into air and dust, and end up in people's bodies. Exposure to the chemicals has been associated with cancer, thyroid disease, decreased fertility, lower IQ, and other harmful health effects. Infants and young children are particularly at risk since they crawl and play on the floor, where contaminated dust settles, and frequently put their hands in their mouths.

Until recently, the use of flame retardants in upholstered furniture across the United States and Canada was driven by a California flammability standard called TB117. Amid a public outcry over the toxicity of these chemicals and their lack of fire safety benefits, California updated TB117 to a new standard called TB117-2013. The new standard is designed to stop smoldering fires in the furniture's fabric before they reach the flammable foam inside, eliminating the need to add flame retardants to the foam. It went into effect in 2014 and allows manufacturers to make furniture without flame retardants.

A Healthy Exchange

To evaluate the impact of the new standard, Rodgers teamed up with researchers at the University of California, Davis; Environmental Working Group; the California Department of Toxic Substances Control; and Green Science Policy Institute. The researchers recruited participants from 33 homes in Northern California who were willing to swap out their old furniture for flame retardant-free options. About two-thirds of the participants replaced their entire upholstered couch. The rest replaced their couch's foam.

The team collected dust samples from each home before the swap out, and then several times afterward over a period of 18 months. Concentrations of flame retardants dropped significantly after the first six months, and most remained lower a year after the furniture was replaced. The same drops were also seen in homes that replaced just the foam.

Of the seven types of flame retardants the researchers tested for in dust, two in particular--PBDEs and TPHP--decreased the most. The drop in PBDE levels was not unexpected due to their widespread use in furniture that met the old standard, says Rodgers. The researchers also observed decreases in a group of flame retardants called chlorinated OPFRs. However, the declines were not as sustained over time likely because the chemicals are used in other products including textiles, plastics, adhesives, and rubber.

Up to Standard

"For decades, our population has been needlessly exposed to harmful flame retardants from their furniture as a result of an outdated flammability standard that provided no fire safety benefit," says co-author Arlene Blum, executive director of Green Science Policy Institute. "This study confirms that the new standard reduces exposure to toxic flame retardants in our homes. This is a win-win for public health and also fire safety."

Beginning June 25, under a new federal bill recently signed into law, all upholstered furniture imported or sold in the United States will have to comply with California's TB117-2013 flammability standard for upholstered furniture.

"With the new national flammability standard, manufacturers are now assured they can continue to make furniture that is fire-safe without the need for toxic flame retardants," says Andy Counts, CEO of American Home Furnishing Alliance. "This is good for our business, and even more important, for the health of our workers and the public."

Despite recent successes at removing flame retardants from furniture, the global market for flame retardants continues to grow as the chemicals are increasingly used in other types of consumer products. "The findings from the new study should spur state and federal policymakers to reduce other harmful and ineffective uses of flame retardants in other items such as television cases and building insulation," says Blum.

What Can Consumers Do?

Because furniture can last a long time, many homes still have furniture that meets the old standard and contains flame retardants. "Replacing old furniture can be costly and may not be an option for everyone," says Rodgers. "The good news is our study shows that replacing your couch's foam can be just as effective." People can replace the foam in their couch by contacting a local foam supplier and asking for new foam that does not contain added flame retardants.

It's also important to keep dust levels low, says Rodgers, since the chemicals like to hang out in dust. She recommends vacuuming using a strong vacuum with a motorized brush and HEPA filter and wiping surfaces with a wet cloth or mop. Fixing rips in the furniture's fabric to make sure the foam is not exposed and washing hands regularly are also important, she says.

For more tips on keeping harmful chemicals out of the home, download Silent Spring's Detox Me app.

Copepods are tiny crustaceans about the size of a grain of rice, but they are one of the most important parts of the Earth's aquatic ecosystems. Their behavior and interaction with the environment, however, remains a relative mystery. Now, a recent paper published in the Journal of Experimental Biology sheds new light on how these miniature marvels move and cluster in the ocean.

Researchers from Bigelow Laboratory of Ocean Sciences and the Georgia Institute of Technology found that the copepods gather around small vortexes in the ocean, a finding which could have significant implications for the food web.

"We're getting at a mechanism that helps us understand how the ecosystem works," said Bigelow Laboratory Senior Research Scientist David Fields, a co-author on the paper. "These vortexes influence the behavior of copepods in a way that allows other animals in the food web to survive."

Copepods can be found in almost every freshwater and saltwater body in the world. If you were to take all copepods and put them together, their weight would be equivalent to about a trillion humans. Their abundance makes them critical to ocean health, where they serve as a cornerstone of the ocean food web and play an important role in global cycles.

"That many organisms breathing oxygen, eating phytoplankton, and producing waste is a major driver in how the ocean carbon cycle works," Fields said. "Despite their tiny individual size, they have a huge impact on the ecosystem."

Abundance alone, however, is not enough to make them such a vital food source for marine life from baby fish to right whales. Although plentiful, they are dispersed in the mind-bogglingly vast ocean. Fortunately for predators, copepods group together. Exactly where and why they do so has been a challenge for scientists to identify.

The newly published study suggests one gathering place is swirling ocean currents less than an inch in diameter. The scientists teamed up with engineers and developed a new type of instrument that can replicate these vortexes and allow for control over their size and speed.

The researchers discovered that the copepods could not only detect the vortexes but actually aggregate around them. The finding could be significant for understanding copepods, and the new ability to create these tiny vortexes in a laboratory may enable scientists to study ocean food webs in a new light.

"We've come up with an explanation for why these animals aggregate in what we like to think of as this, well-mixed, homogeneous ocean," Fields said.

These small vortexes have always been difficult to study in the field because of their scale, ephemeral nature, and how much other turbulence exists in the ocean. However, previous research using mathematical models has suggested these processes could explain a number of phenomena such as the behavior of marine organisms and nutrients mixing up from the deep ocean.

"People use this kind of concept to explain a lot about how ocean processes work, but nobody's really ever seen it," Fields said. "Until recently, you couldn't hold onto them long enough to study because they just pop up and disappear within seconds to minutes."

Researchers have previously observed some interactions between copepods and turbulent water. However, this study was the first to examine the interaction of individual copepods with a single vortex, which opens up new possibilities for understanding these vital organisms.

"These tiny vortexes are happening everywhere in the ocean, but we've never gotten the chance to really look at them," Fields said. "Now, we can create one of those little vortexes that live out in nature and hold it in the laboratory so we can analyze it in detail."

Chemists from RUDN University found out that fluorine and fluoroalkyl groups increase the efficiency of catalysts in metathesis reactions that are used in the pharmaceutical industry and polymer chemistry. The team also identified fluorine-containing compounds that can simplify the purification of the catalyst from the reaction product, making it reusable. The results of the study were published in the Russian Chemical Reviews journal.

Many medicinal drugs and polymers are based on olefins, organic compounds with a double bond between carbon atoms. To obtain useful substances from them, scientists used the metathesis reaction. In the course of metathesis, double bonds in the molecules are broken, and groups of different molecules attached to them are redistributed. However, this reaction requires powerful catalysts called ruthenium-carbene complexes. A team of chemists from RUDN University found a way to increase their catalytic activity with fluorine. The results of their work could be used in the pharmaceutical industry and industrial chemistry.

"We studied the scientific literature and summarized the data on the methods of adding fluorine atoms and fluoroalkyl groups into different ligands. This technology is used to create ruthenium-carbene complexes that would be active in the metathesis reaction. We have also analyzed the catalytic activity of complexes with different additives," said Sergey Osipov, PhD, researcher at the Joint Institute for Chemical Research, RUDN University.

Ruthenium-based complexes consist of the transition metal ruthenium and different types of ligands, including carbene ligands (unstable bivalent carbon compounds). When donor ligands react with the electrophilic atom of ruthenium, they bring the parts of the complex together. Electrophilicity is the ability to receive electrons, and it is this quality of the atom of ruthenium in the middle of a complex that determines the activity of a catalyst. The team summarized the data from other studies and found out that electrophilicity could be increased by adding fluorine to the ligands. This method works because both fluorine and fluoroalkyl groups that contain it have a high accepting ability.

By changing the types and structures of fluoroalkyl groups, one can create a catalyst with desired qualities. For example, when the team added fluorine to asymmetrical ligands, an additional reaction between ruthenium and the atom of fluorine was observed. It added stability to the whole complex and increased its catalytic activity. By adding polyfloroalkyl groups to ligands, one can simplify the purification of the catalyst from reaction products and make it reusable.

The results of the study can help chemists improve ruthenium-based catalysts by choosing specific floroalkyl additives for particular requirements.

"Fluorine in ligands speeds up the beginning of catalysis because the bond between ruthenium and the atom of ligand weakens in the course of metathesis. Moreover, adding polyfloroalkyl groups to ligands solves the issue of purification of the catalyst from reaction products. This way, an expensive catalyst can be reused several times," added Sergey Osipov from RUDN University.

Skoltech researchers examined the antibiotic compounds that employ a 'Trojan horse' strategy to get into a bacterial cell unrecognized and prevent the synthesis of proteins, ultimately killing the cell. They were able to identify new gene clusters that look like those of known 'Trojan horses' - these likely guide the biosynthesis of new antimicrobials that require further investigation. The review paper was published in the journal RSC Chemical Biology.

When it comes to antimicrobial attacks, the most difficult thing is breaching the formidable outer defenses: getting inside a target cell to deploy the deadly weapon can be tricky. A number of antimicrobial compounds employ the well-known 'Trojan horse' strategy: they present themselves to a cell as a valuable compound and, once inside, unleash the "acheans" that can, for instance, inhibit aminoacyl-tRNA synthetases, key enzymes needed for the translation of genetic information into proteins.

Skoltech PhD student Dmitrii Travin, Professor Konstantin Severinov and Svetlana Dubiley, head of Biomedical Teaching Laboratory, explored the three known "stables" of Trojan-horse inhibitors: albomycin, microcin C-related compounds, and agrocin 84. These three biological weapons mimic a siderophore (an iron-carrying compound), a variety of peptides, and an opine (a bacterial energy source).

As the authors note, the only real way bacteria can protect themselves against these antimicrobials is by disabling their transporters that take the seemingly harmless compound inside the cell. Even though that can happen quite often, it may not undermine the potential of Trojan horse inhibitors to be developed into drugs, as various pathogenic bacteria "disabled" in this way are also rendered less harmful.

By running a bioinformatics search, the team was able to find other gene clusters that were similar to the clusters encoding known Trojan-horse antimicrobials. "The results of our limited bioinformatics analyses show that the diversity of the three classes of molecules reviewed here is not yet completely tapped. When validated experimentally, these compounds may become viable antibiotics," the authors conclude in the paper.

A new study from the University of Kent's School of Anthropology and Conservation has found that Oldowan and Acheulean stone tool technologies are likely to be tens of thousands of years older than current evidence suggests.

They are currently the two oldest, well-documented stone tool technologies known to archaeologists.

These findings, published by the Journal of Human Evolution, provide a new chronological foundation from which to understand the production of stone tool technologies by our early ancestors. They also widen the time frame within which to discuss the evolution of human technological capabilities and associated dietary and behavioural shifts.

For the study, a team led by Kent's Dr Alastair Key and Dr David Roberts, alongside Dr Ivan Jaric from the Biology Centre of the Czech Academy of Sciences, used statistical modelling techniques only recently introduced to archaeological science. The models estimated that Oldowan stone tools originated 2.617-2.644 million years ago, 36,000 to 63,000 years earlier than current evidence. The Acheulean's origin was pushed back further by at least 55,000 years to 1.815-1.823 million years ago.

Early stone tool technologies, such as the Oldowan and Acheulean, allowed early human ancestors to access new food types, and increased the ease of producing wooden tools or processing animal carcasses.

Dr Key, a Palaeolithic Archaeologist and the lead author of the study, said: 'Our research provides the best possible estimates for understanding when hominins first produced these stone tool types. This is important for multiple reasons, but for me at least, it is most exciting because it highlights that there are likely to be substantial portions of the artifact record waiting to be discovered.'

Dr Roberts, a conservation scientist and co-author of the study, said: 'The optimal linear estimation (OLE) modelling technique was originally developed by myself and a colleague to date extinctions. It has proved to be a reliable method of inferring the timing of species extinction and is based on the timings of last sightings, and so to apply it to the first sightings of archaeological artifacts was another exciting breakthrough. It is our hope that the technique will be used more widely within archaeology.'

Although it is widely assumed that older stone tool sites do exist and are waiting to be discovered, this study provides the first quantitative data predicting just how old these yet-to-be-discovered sites may be.

A new view of the region closest to the supermassive black hole at the center of the galaxy Messier 87 (M87) has shown important details of the magnetic fields close to the black hole and hints about how powerful jets of material can originate in that region.

A worldwide team of astronomers using the Event Horizon Telescope, a collection of eight telescopes, including the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, measured a signature of magnetic fields -- called polarization -- around the black hole. Polarization is the orientation of the electric fields in light and radio waves and it can indicate the presence and alignment of magnetic fields.

"We are now seeing the next crucial piece of evidence to understand how magnetic fields behave around black holes, and how activity in this very compact region of space can drive powerful jets," said Monika Mo?cibrodzka, Coordinator of the EHT Polarimetry Working Group and Assistant Professor at Radboud University in the Netherlands.

New images with the EHT and ALMA allowed scientists to map magnetic field lines near the edge of M87's black hole. That same black hole is the first ever to be imaged -- by the EHT in 2019. That image revealed a bright ring-like structure with a dark central region -- the black hole's shadow. The newest images are a key to explaining how M87, 50 million light-years from Earth, can launch energetic jets from its core.

The black hole at M87's center is more than 6 billion times more massive than the Sun. Material drawn inward forms a rotating disk -- called an accretion disk -- closely orbiting the black hole. Most of the material in the disk falls into the black hole, but some surrounding particles escape and are ejected far out into space in jets moving at nearly the speed of light.

"The newly published polarized images are key to understanding how the magnetic field allows the black hole to 'eat' matter and launch powerful jets," said Andrew Chael, a NASA Hubble Fellow at the Princeton Center for Theoretical Science and the Princeton Gravity Initiative in the U.S.

The scientists compared the new images that showed the magnetic field structure just outside the black hole with computer simulations based on different theoretical models. They found that only models featuring strongly magnetized gas can explain what they are seeing at the event horizon.

"The observations suggest that the magnetic fields at the black hole's edge are strong enough to push back on the hot gas and help it resist gravity's pull. Only the gas that slips through the field can spiral inwards to the event horizon," explained Jason Dexter, Assistant Professor at the University of Colorado Boulder and Coordinator of the EHT Theory Working Group.

To make the new observations, the scientists linked eight telescopes around the world -- including ALMA -- to create a virtual Earth-sized telescope, the EHT. The impressive resolution obtained with the EHT is equivalent to that needed to measure the length of a credit card on the surface of the Moon.

This resolution allowed the team to directly observe the black hole shadow and the ring of light around it, with the new image clearly showing that the ring is magnetized. The results are published in two papers in the Astrophysical Journal Letters by the EHT collaboration. The research involved more than 300 researchers from multiple organizations and universities worldwide.

A third paper also was published in the same volume of the Astrophysical Journal Letters, based on data from ALMA, lead by Ciriaco Goddi, a scientist at Radboud University and Leiden Observatory, the Netherlands.

"The combined information from the EHT and ALMA allowed scientists to investigate the role of magnetic fields from the vicinity of the event horizon to far beyond the core of the galaxy, along its powerful jets extending thousands of light-years," Goddi said.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

The EHT collaboration involves more than 300 researchers from Africa, Asia, Europe, North and South America. The international collaboration is working to capture the most detailed black hole images ever obtained by creating a virtual Earth-sized telescope. Supported by considerable international investment, the EHT links existing telescopes using novel systems -- creating a fundamentally new instrument with the highest angular resolving power that has yet been achieved.

The individual telescopes involved are: ALMA, APEX, the Institut de Radioastronomie Millimetrique (IRAM) 30-meter Telescope, the IRAM NOEMA Observatory, the James Clerk Maxwell Telescope (JCMT), the Large Millimeter Telescope (LMT), the Submillimeter Array (SMA), the Submillimeter Telescope (SMT), the South Pole Telescope (SPT), the Kitt Peak Telescope, and the Greenland Telescope (GLT).

The EHT consortium consists of 13 stakeholder institutes: the Academia Sinica Institute of Astronomy and Astrophysics, the University of Arizona, the University of Chicago, the East Asian Observatory, Goethe-Universitaet Frankfurt, Institut de Radioastronomie Millimétrique, Large Millimeter Telescope, Max Planck Institute for Radio Astronomy, MIT Haystack Observatory, National Astronomical Observatory of Japan, Perimeter Institute for Theoretical Physics, Radboud University and the Smithsonian Astrophysical Observatory.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of ESO, the U.S. National Science Foundation (NSF) and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the Ministry of Science and Technology (MOST) and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI). ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of the construction, commissioning and operation of ALMA.

The unprecedented rainfall from Hurricane Harvey in 2017 brought more than flood damage to southeast Texas. For people living in environmental justice communities such as the Manchester neighborhood near the Houston Ship Channel, heavy rainfall and flooding may have increased risks of exposure to harmful chemicals from nearby industry.

To gain a better understanding of how flooding mobilized pollution in the area, a research team led by Garett Sansom, DrPH, research assistant professor in the Department of Environmental and Occupational Health at the Texas A&M University School of Public Health, analyzed samples of soil from the Manchester neighborhood collected immediately after Hurricane Harvey. Findings were just published in the Journal of Health and Pollution. Student and faculty researchers along with staff from Texas Environmental Justice Advocacy Services and residents of Manchester collected soil samples at 40 locations throughout Manchester one week after Harvey. The samples were then processed and analyzed to measure concentrations of pollutants known as polycyclic aromatic hydrocarbons (PAHs), which are linked with poor health outcomes, including different types of cancer.

PAHs come from incomplete burning of hydrocarbons like wood and fossil fuels. They are found in high concentrations near oil refineries and other industrial facilities as well as major highways and other transportation hubs like shipyards and railways. PAHs also attach themselves to particles in the air, meaning once they settle, they can be moved around by flood waters. The high baseline levels of PAHs in Manchester have thus fueled resident concerns that floods such as those caused by Hurricane Harvey could increase exposure risks.

Manchester is close to the Houston Ship Channel, a major interstate highway, a large railyard and several oil refineries. Previous studies have found that this neighborhood has a disproportionately high level of PAH pollution and associated health risks. Because of this it is important to understand how flooding and other disasters impact the area. Flooding is becoming a greater concern for residents in Manchester as well as in other locations in the Houston area as the frequency of heavy rainfall events appears to be increasing. Between 1981 and 2000, the odds of a rainfall event of more than 20 inches increased by one percent, and this frequency is expected to grow by 18 percent between 2018 and 2100.

The analysis found differences in PAH concentrations across all 40 sample sites, with nearly half of Manchester contaminated to some degree and nine of the sites having a higher PAH concentration than the minimum standard for increased cancer risk. The highest concentrations were found at sites closest to the highway and the Houston Ship Channel, and the lowest concentrations were in farther away locations. The distribution of PAHs in Manchester may have been controlled in part by the way flood waters moved through the area. However, the researchers did not have data on street-level differences in surfaces for their analysis. Thus, it is unclear how much surfaces that do not absorb water, such as streets and sidewalks, contributed to the distribution pattern.

The findings of this study build on prior research showing that people in areas that flood may have a greater risk of PAH exposure. This study also points to the need for a better understanding of how PAHs are dispersed during flood events. More data on baseline pollutant concentrations and improved analysis methods will help researchers, policy makers and community leaders assess the risks people living in environmental justice communities face, and possibly find ways to limit the health risks residents of neighborhoods like Manchester face in the future.