Culture

Charismatic, iconic and Instagram-friendly, the weedy seadragon is a favourite with divers and snorkellers. The first genomic study of east coast Australian seadragon populations can now reveal "weedies" from NSW, Victoria and Tasmania are significantly different.

The study, published in PLOS ONE, also reveals that Victorian weedy seadragons may form a subspecies which has implications for conservation management. The researchers recommend that, as a precautionary approach, these distinct populations be managed separately by each state.

Lead investigator Dr Selma Klanten, from the University of Technology Sydney (UTS) Fish Ecology Laboratory, said that despite the public popularity of these fish few scientific studies exist.

"The research aimed to understand the genetic structure and diversity of weedy seadragon populations along Australia's east coast," Dr Klanten said.

"This is important because like all sygnathids, seadragons are endemic to temperate Australia. As adults they might only move 50-500 metres away from where they were born. This can make them susceptible to loss of habitat and changing environmental conditions.

"Although 'weedies' aren't listed as endangered, there is concern that populations are in decline and recent surveys confirm this. If numbers continue to fall this might lead to further loss of genetic diversity which could have an impact on future generations of weedy seadragons," she said.

Using the latest genomics (NGS, or next generation sequencing), the researchers identified four distinct genetic clusters - central NSW, southern NSW, Victoria and Tasmania. High-resolution images were also used to measure seadragon length and shape, revealing NSW individuals differed in a few measurements to those from Mornington Peninsula in Victoria.

The combined results suggest that not only are weedy seadragon populations significantly different along the east coast of Australia but that the Victorian weedy seadragons may form a subspecies.

"They are highly distinct to NSW and Tasmania and do not interbreed with any of the other populations. Biologists refer to this as being reproductively isolated.

"Because Victorian 'weedies' are the only animals used in the aquarium trade, worldwide, a bias towards this population exists in captivity. This has implications for conservation management," Dr Klanten said.

Co-author Professor David Booth, also of UTS Fish Ecology Lab, noted "as an ecologist it was clear to me that weedies from the populations were shaped differently and occupied different habitat types, but we were surprised how different they were genetically.

"Most global aquariums that exhibit weedies have sourced them from the Melbourne area, and this was quite distinct in our study, so we recommend extra care in managing the wild populations there," Professor Booth said.

The study sites were located in Sydney, Jervis Bay and Eden in NSW; Mornington Peninsula in Victoria; and Tasmania, and were surveyed over three years between 2016 and 2019. Sampling these masters of camouflage involved removing a small piece of tissue from their leaf-like appendages. Tissue samples were also taken from dead individuals washed up onshore and collected by citizen scientists.

An international research team led by the University of British Columbia (UBC) has uncovered for the first time the importance of a small gland tucked behind the sternum that works to prevent miscarriage and diabetes in pregnant women.

The organ in question is the thymus, identified in a study published today in the journal Nature as playing a significant role in both metabolic control and immunity in pregnancy.

How the immune system adapts to support mother and fetus has puzzled researchers for decades. The study--conducted by an international research team, including UBC's Dr. Josef Penninger--reveals an answer. The researchers have found that female sex hormones instruct important changes in the thymus, a central organ of the immune system, to produce specialized cells called Tregs to deal with physiological changes that arise in pregnancy.

The researchers also identified RANK, a receptor expressed in a part of the thymus called the epithelium, as the key molecule behind this mechanism.

"We knew RANK was expressed in the thymus, but its role in pregnancy was unknown," says the study's senior author Dr. Penninger, professor in the department of medical genetics and director of the Life Sciences Institute at UBC.

To get a better understanding, the authors studied mice where RANK had been deleted from the thymus.

"The absence of RANK prevented the production of Tregs in the thymus during pregnancy. That resulted in less Tregs in the placentas, leading to elevated rates of miscarriage," says the study's lead author Dr. Magdalena Paolino, assistant professor in the department of medicine at the Karolinska Institutet.

The findings also offer new molecular insights into the development of diabetes during pregnancy, known as gestational diabetes, a disease that affects approximately 15 percent of women in pregnancy worldwide, and about which scientists still know little.

In healthy pregnancies, the researchers found that Tregs migrated to the mother's fat tissue to prevent inflammation and help control glucose levels in the body. Pregnant mice lacking RANK had high levels of glucose and insulin in their blood and many other indicators of gestational diabetes, including larger-than-average young.

"Similar to babies of women with diabetes in pregnancy, the newborn pups were much heavier than average," says Dr. Paolino.

The deficiency of Tregs during pregnancy also resulted in long-lasting, transgenerational effects on the offspring. The pups remained prone to diabetes and overweight throughout their life spans. Giving the RANK-deficient mice thymus-derived Tregs isolated from normal pregnancies reversed all their health issues, including miscarriage and maternal glucose levels, and also normalized the body weights of the pups.

The researchers also analyzed women with diabetes in pregnancy, revealing a reduced number of Tregs in their placentas, similar to the study on mice.

"The discovery of this new mechanism underlying gestational diabetes potentially offers new therapeutic targets for mother and fetus in the future," says co-author Dr. Alexandra Kautzky-Willer, a clinician-researcher based at the Medical University of Vienna.

"The thymus changes massively during pregnancy and how such rewiring of an entire tissue contributes to a healthy pregnancy has been one of the remaining mysteries of immunology," adds Dr. Penninger. "Our work over many years has now not only solved this puzzle - pregnancy hormones rewire the thymus via RANK - but uncovered a new paradigm for its function: the thymus not only changes the immune system of the mother so it does not reject the fetus, but the thymus also controls metabolic health of the mother.

"This research changes our view of the thymus as an active and dynamic organ required to safeguard pregnancies," says Dr. Penninger.

Female sex hormones instruct the thymus, a central organ of the immune system, to produce specialized cells called "Tregs" to deal with physiological changes to arise during pregnancy, the study revealed. The researchers also found that RANK, a receptor expressed in a part of the thymus called the epithelium, is the key molecule behind this mechanism. The study is an international research effort including scientists from IMBA, the University of British Columbia, the Karolinska Institutet and the Medical University of Vienna.

"We knew RANK was expressed in the thymus, but its role in pregnancy was unknown," says the study's senior author Josef Penninger, IMBA group leader and founding director, who is now director of the Life Sciences Institute of the University of British Columbia. To gain deeper insights, the authors studied mice where RANK had been deleted from the thymus. "The absence of RANK prevented the production of Tregs in the thymus during pregnancy. That resulted in less Tregs in the placentas, leading to elevated rates of miscarriage," says the study's lead author Magdalena Paolino, former postdoctoral fellow at IMBA, who now heads, since 2017, her own laboratory at the renowned Karolinska Institutet in Sweden.

The findings also offer new molecular insights into the development of gestational diabetes, a disease that affects approximately 15 percent of women in pregnancy worldwide, and yet still puzzles scientists to this day.

In healthy pregnancies, the researchers found that Tregs migrated to the mother's fat tissue to prevent inflammation and help control glucose levels in the body. Pregnant mice lacking RANK had high levels of glucose and insulin in their blood and many other indicators of gestational diabetes, including larger-than-average young. "Similar to babies of women with gestational diabetes, the newborn pups were much heavier than average," says Paolino.

The deficiency of Tregs during pregnancy in mothers also resulted in long-lasting transgenerational effects on the offspring, which remained prone to diabetes and overweight throughout their life spans. Interestingly, administering thymus-derived Tregs isolated from normal pregnancies to the RANK-deficient mice reversed all the mice's health issues, including miscarriage and maternal glucose levels, and also normalised the body weights of the pups.

The researchers also analysed women with gestational diabetes, revealing a reduced number of Tregs in their placentas, similar to the study on mice. "The discovery of this new mechanism underlying gestational diabetes potentially offers new therapeutic targets for mother and fetus in the future," says co-author Dr. Alexandra Kautzky-Willer, a clinician researcher based at the Medical University of Vienna.

"The thymus changes massively during pregnancy and how such rewiring of an entire tissue contributes to a healthy pregnancy has been one of the remaining mysteries of immunology," adds Dr. Penninger. "Our work over many years has now not only solved this puzzle - pregnancy hormones rewire the thymus via RANK - but uncovered a new paradigm for its function: the thymus not only changes the immune system of the mother so it does not reject the fetus, but the thymus also controls metabolic health of the mother." "This research changes our view of the thymus as an active and dynamic organ required to safeguard pregnancies," says Penninger.

The study was made possible thanks to a close collaboration between the Institute of Molecular Biotechnology of the Austrian Academy of Sciences in Vienna, the Life Sciences Institute in Vancouver, and the Karolinska Institutet. Researchers from the CeMM Institute and the Medical University in Vienna, as well as from the University of Birmingham and Oxford in the United Kingdom also participated.

PHILADELPHIA -- (Dec. 23, 2020) -- Wistar Institute scientists have discovered a new class of compounds that uniquely combine direct antibiotic killing of pan drug-resistant bacterial pathogens with a simultaneous rapid immune response for combatting antimicrobial resistance (AMR). These finding were published today in Nature.

The World Health Organization (WHO) has declared AMR as one of the top 10 global public health threats against humanity. It is estimated that by 2050, antibiotic-resistant infections could claim 10 million lives each year and impose a cumulative $100 trillion burden on the global economy. The list of bacteria that are becoming resistant to treatment with all available antibiotic options is growing and few new drugs are in the pipeline, creating a pressing need for new classes of antibiotics to prevent public health crises.

"We took a creative, double-pronged strategy to develop new molecules that can kill difficult-to-treat infections while enhancing the natural host immune response," said Farokh Dotiwala, M.B.B.S., Ph.D., assistant professor in the Vaccine & Immunotherapy Center and lead author of the effort to identify a new generation of antimicrobials named dual-acting immuno-antibiotics (DAIAs).

Existing antibiotics target essential bacterial functions, including nucleic acid and protein synthesis, building of the cell membrane, and metabolic pathways. However, bacteria can acquire drug resistance by mutating the bacterial target the antibiotic is directed against, inactivating the drugs or pumping them out.

"We reasoned that harnessing the immune system to simultaneously attack bacteria on two different fronts makes it hard for them to develop resistance," said Dotiwala.

He and colleagues focused on a metabolic pathway that is essential for most bacteria but absent in humans, making it an ideal target for antibiotic development. This pathway, called methyl-D-erythritol phosphate (MEP) or non-mevalonate pathway, is responsible for biosynthesis of isoprenoids -- molecules required for cell survival in most pathogenic bacteria. The lab targeted the IspH enzyme, an essential enzyme in isoprenoid biosynthesis, as a way to block this pathway and kill the microbes. Given the broad presence of IspH in the bacterial world, this approach may target a wide range of bacteria.

Researchers used computer modeling to screen several million commercially available compounds for their ability to bind with the enzyme, and selected the most potent ones that inhibited IspH function as starting points for drug discovery.

Since previously available IspH inhibitors could not penetrate the bacterial cell wall, Dotiwala collaborated with Wistar's medicinal chemist Joseph Salvino, Ph.D., professor in The Wistar Institute Cancer Center and a co-senior author on the study, to identify and synthesize novel IspH inhibitor molecules that were able to get inside the bacteria.

The team demonstrated that the IspH inhibitors stimulated the immune system with more potent bacterial killing activity and specificity than current best-in-class antibiotics when tested in vitro on clinical isolates of antibiotic-resistant bacteria, including a wide range of pathogenic gram negative and gram positive bacteria. In preclinical models of gram negative bacterial infection, the bactericidal effects of the IspH inhibitors outperformed traditional pan antibiotics. All compounds tested were shown to be nontoxic to human cells.

"Immune activation represents the second line of attack of the DAIA strategy," said Kumar Singh, Ph.D., Dotiwala lab postdoctoral fellow and first author of the study.

"We believe this innovative DAIA strategy may represent a potential landmark in the world's fight against AMR, creating a synergy between the direct killing ability of antibiotics and the natural power of the immune system," echoed Dotiwala.

As COVID cases rise, physically distancing yourself from other people has never been more important. Now a new UCLA study reveals how your brain navigates places and monitors someone else in the same location.

Published Dec. 23 in Nature, the findings suggest that our brains generate a common code to mark where other people are in relation to ourselves.

"We studied how our brain reacts when we navigate a physical space - first alone and then with others," said senior author Nanthia Suthana, the Ruth and Raymond Stotter Chair in Neurosurgery and an assistant professor of neurosurgery and psychiatry at the David Geffen School of Medicine at UCLA and Jane and Terry Semel Institute for Neuroscience and Human Behavior.

"Our results imply that our brains create a universal signature to put ourselves in someone else's shoes," added Suthana, whose laboratory studies how the brain forms and recalls memories.

Suthana and her colleagues observed epilepsy patients whose brains had been surgically implanted earlier with electrodes to control their seizures. The electrodes resided in the medial temporal lobe, the brain center linked to memory and suspected to regulate navigation, much like a GPS device.

"Earlier studies have shown that low-frequency brain waves by neurons in the medial temporal lobe help rodents keep track of where they are as they navigate a new place," said first author Matthias Stangl, a postdoctoral scholar in Suthana's lab. "We wanted to investigate this idea in people--and test whether they could also monitor others near them--but were hampered by existing technology."

Using a $3.3 million award from the National Institutes of Health's BRAIN Initiative, Suthana's lab invented a special backpack containing a computer that wirelessly connects to brain electrodes. This enabled her to study research subjects as they moved freely instead of lying still in a brain scanner or hooked up to a recording device.

In this experiment, each patient wore the backpack and was instructed to explore an empty room, find a hidden spot and remember it for future searches. While they walked, the backpack recorded their brain waves, eye movements and paths through the room in real time.

As the participants searched the room, their brain waves flowed in a distinctive pattern, suggesting that each person's brain had mapped out the walls and other boundaries. Interestingly, the patients' brain waves also flowed in a similar manner when they sat in a corner of the room and watched someone else approach the location of the hidden spot.

The finding implies that our brains produce the same pattern to track where we and other people are in a shared environment.

Why is this important?

"Everyday activities require us to constantly navigate around other people in the same place," said Suthana, who is also an assistant professor of psychology at UCLA's College of Letters and Science and of bioengineering at the Henry Samueli School of Engineering. "Consider choosing the shortest airport security line, searching for a space in a crowded parking lot or avoiding bumping into someone on the dance floor."

In a secondary finding, the UCLA team discovered that what we pay attention to may influence how our brains map out a location. For example, the patients' brain waves flowed stronger when they searched for the hidden spot - or witnessed another person approach the location - than when they simply explored the room.

"Our results support the idea that, under certain mental states, this pattern of brain waves may help us recognize boundaries," said Stangl. "In this case, it was when people were focused on a goal and hunting for something."

Future studies will explore how people's brain patterns react in more complex social situations, including outside the laboratory. The UCLA team has made the backpack available to other researchers to accelerate discoveries about the brain and brain disorders.

GAINESVILLE, Fla. --- The history of the Caribbean's original islanders comes into sharper focus in a new Nature study that combines decades of archaeological work with advancements in genetic technology.

An international team led by Harvard Medical School's David Reich analyzed the genomes of 263 individuals in the largest study of ancient human DNA in the Americas to date. The genetics trace two major migratory waves in the Caribbean by two distinct groups, thousands of years apart, revealing an archipelago settled by highly mobile people, with distant relatives often living on different islands.

Reich's lab also developed a new genetic technique for estimating past population size, showing the number of people living in the Caribbean when Europeans arrived was far smaller than previously thought - likely in the tens of thousands, rather than the million or more reported by Columbus and his successors.

For archaeologist William Keegan, whose work in the Caribbean spans more than 40 years, ancient DNA offers a powerful new tool to help resolve longstanding debates, confirm hypotheses and spotlight remaining mysteries.

This "moves our understanding of the Caribbean forward dramatically in one fell swoop," said Keegan, curator at the Florida Museum of Natural History and co-senior author of the study. "The methods David's team developed helped address questions I didn't even know we could address."

Archaeologists often rely on the remnants of domestic life - pottery, tools, bone and shell discards - to piece together the past. Now, technological breakthroughs in the study of ancient DNA are shedding new light on the movement of animals and humans, particularly in the Caribbean where each island can be a unique microcosm of life.

While the heat and humidity of the tropics can quickly break down organic matter, the human body contains a lockbox of genetic material: a small, unusually dense part of the bone protecting the inner ear. Primarily using this structure, researchers extracted and analyzed DNA from 174 people who lived in the Caribbean and Venezuela between 400 and 3,100 years ago, combining the data with 89 previously sequenced individuals.

The team, which includes Caribbean-based scholars, received permission to carry out the genetic analysis from local governments and cultural institutions that acted as caretakers for the human remains. The authors also engaged representatives of Caribbean Indigenous communities in a discussion of their findings.

The genetic evidence offers new insights into the peopling of the Caribbean. The islands' first inhabitants, a group of stone tool-users, boated to Cuba about 6,000 years ago, gradually expanding eastward to other islands during the region's Archaic Age. Where they came from remains unclear - while they are more closely related to Central and South Americans than to North Americans, their genetics do not match any particular Indigenous group. However, similar artifacts found in Belize and Cuba may suggest a Central American origin, Keegan said.

About 2,500-3,000 years ago, farmers and potters related to the Arawak-speakers of northeast South America established a second pathway into the Caribbean. Using the fingers of South America's Orinoco River Basin like highways, they travelled from the interior to coastal Venezuela and pushed north into the Caribbean Sea, settling Puerto Rico and eventually moving westward. Their arrival ushered in the region's Ceramic Age, marked by agriculture and the widespread production and use of pottery.

Over time, nearly all genetic traces of Archaic Age people vanished, except for a holdout community in western Cuba that persisted as late as European arrival. Intermarriage between the two groups was rare, with only three individuals in the study showing mixed ancestry.

Many present-day Cubans, Dominicans and Puerto Ricans are the descendants of Ceramic Age people, as well as European immigrants and enslaved Africans. But researchers noted only marginal evidence of Archaic Age ancestry in modern individuals.

"That's a big mystery," Keegan said. "For Cuba, it's especially curious that we don't see more Archaic ancestry."

During the Ceramic Age, Caribbean pottery underwent at least five marked shifts in style over 2,000 years. Ornate red pottery decorated with white painted designs gave way to simple, buff-colored vessels, while other pots were punctuated with tiny dots and incisions or bore sculpted animal faces that likely doubled as handles. Some archaeologists pointed to these transitions as evidence for new migrations to the islands. But DNA tells a different story, suggesting all of the styles were developed by descendants of the people who arrived in the Caribbean 2,500-3,000 years ago, though they may have interacted with and took inspiration from outsiders.

"That was a question we might not have known to ask had we not had an archaeological expert on our team," said co-first author Kendra Sirak, a postdoctoral fellow in the Reich Lab. "We document this remarkable genetic continuity across changes in ceramic style. We talk about 'pots vs. people,' and to our knowledge, it's just pots."

Highlighting the region's interconnectivity, a study of male X chromosomes uncovered 19 pairs of "genetic cousins" living on different islands - people who share the same amount of DNA as biological cousins but may be separated by generations. In the most striking example, one man was buried in the Bahamas while his relative was laid to rest about 600 miles away in the Dominican Republic.

"Showing relationships across different islands is really an amazing step forward," said Keegan, who added that shifting winds and currents can make passage between islands difficult. "I was really surprised to see these cousin pairings between islands."

Uncovering such a high proportion of genetic cousins in a sample of fewer than 100 men is another indicator that the region's total population size was small, said Reich, professor of genetics in the Blavatnik Institute at HMS and professor of human evolutionary biology at Harvard.

"When you sample two modern individuals, you don't often find that they're close relatives," he said. "Here, we're finding relatives all over the place."

A technique developed by study co-author Harald Ringbauer, a postdoctoral fellow in the Reich Lab, used shared segments of DNA to estimate past population size, a method that could also be applied to future studies of ancient people. Ringbauer's technique showed about 10,000 to 50,000 people were living on two of the Caribbean's largest islands, Hispaniola and Puerto Rico, shortly before European arrival. This falls far short of the million inhabitants Columbus described to his patrons, likely to impress them, Keegan said.

Later, 16th-century historian Bartolomé de las Casas claimed the region had been home to 3 million people before being decimated by European enslavement and disease. While this, too, was an exaggeration, the number of people who died as a result of colonization remains an atrocity, Reich said.

"This was a systematic program of cultural erasure. The fact that the number was not 1 million or millions of people, but rather tens of thousands, does not make that erasure any less significant," he said.

For Keegan, collaborating with geneticists gave him the ability to prove some hypotheses he had argued for years - while upending others.

"At this point, I don't care if I'm wrong or right," he said. "It's just exciting to have a firmer basis for reevaluating how we look at the past in the Caribbean. One of the most significant outcomes of this study is that it demonstrates just how important culture is in understanding human societies. Genes may be discrete, measurable units, but the human genome is culturally created."

CHAMPAIGN, Ill. -- Researcher Ryan Corey recently heard from a friend who teaches at a school where some of the students have hearing loss. The friend wanted to know if he had any ideas to help her communicate with these students while wearing a mask to slow the spread of COVID-19. Corey, who also has hearing loss, did not know what to tell her. So, he headed to the Illinois Augmented Listening Laboratory to look for solutions.

Corey, an electrical and computer engineering postdoctoral researcher under professor Andrew Singer at the University of Illinois Urbana-Champaign, leads a team that studies audio signal processing, especially for listening devices like hearing aids. The results of the team's new study evaluating the acoustic effects of face masks on speech are published in The Journal of the Acoustical Society of America.

To see a video explaining this research, click here.

"Previous research performed on this subject has focused on medical masks worn in health care settings," Corey said, "But no one has looked at the acoustic effects caused by different kinds of fabric masks, so that's where I focused our study."

The team tested medical masks, disposable surgical masks, masks with clear plastic windows around the mouth, and homemade and store-bought cloth masks made of different fabric types and numbers of layers.

The researchers used a special loudspeaker, custom built by School of Art and Design graduate Uriah Jones and shaped like a human head so that sound radiates as it would coming from a human mouth.

"We put the different masks onto the head-shaped loudspeaker and played the same sound for every test," Corey said. "We also placed the speaker onto a turntable to add a directional component to our data."

The team collected data from a mask-wearing human speaker, as well.

"Using a real person makes the sounds less repeatable because we can't say the same thing the same way every time. However, it does let us account for the real shape of the head and real movements of lips," Corey said. "Even though these two data sets are a bit different, they both show which sound frequencies are most affected by mask-wearing and which masks have the strongest effects."

Their data showed that all masks muffle the quiet, high-frequency sound generated when a person pronounces consonants. "Those sounds are already a challenge for those with hearing loss, with or without masks, and even become a challenge for those without hearing loss when you throw a mask into the mix."

Masks also block visual cues like facial expression and lip motion, so speech reading is no longer an option when wearing most masks. Almost everyone uses speech reading to some extent, with or without hearing loss, Corey said.

"That's why we tested the clear-window masks that have become very popular," he said. "Unfortunately, the trade-off is that you can see through them, but they block the most sound of all the masks we tested."

The study found that disposable surgical masks offer the best acoustic performance among all tested, Corey said. Loosely woven 100% cotton masks also perform well but, as shown in a study by other Illinois researchers, they may not be as effective as surgical masks at blocking respiratory droplets. That study showed that tightly woven cotton and blended fabrics may block more droplets, but Corey's team found that they also block more sound. Based on the droplet study, Corey suggested that multilayer masks made of loosely woven cotton may offer a reasonable compromise between droplet-blocking efficiency and acoustic performance.

The good news is that most masks do not completely block sound, they simply deflect it away from the mouth. This detail means that simple amplification devices can make masked speech more accessible to everyone. In particular, the lapel microphones that are already used in many classrooms and lecture halls are only mildly affected by face masks. Many hearing aids support remote microphone accessories that are also worn near the lapel.

"Most people do not walk around with lapel mics and amplification systems while wearing a mask, but it can help in settings where it does make sense, like classrooms and meetings," Corey said.

The perfect transmission of sound through a barrier is difficult to achieve, if not impossible based on our existing knowledge. This is also true with other energy forms such as light and heat.

A research team led by Professor Xiang Zhang, President of the University of Hong Kong (HKU) when he was a professor at the University of California, Berkeley, (UC Berkeley) has for the first time experimentally proved a century old quantum theory that relativistic particles can pass through a barrier with 100% transmission. The research findings have been published in the top academic journal Science.

Just as it would be difficult for us to jump over a thick high wall without enough energy accumulated. In contrast, it is predicted that a microscopic particle in the quantum world can pass through a barrier well beyond its energy regardless of the height or width of the barrier, as if it is "transparent".

As early as 1929, theoretical physicist Oscar Klein proposed that a relativistic particle can penetrate a potential barrier with 100% transmission upon normal incidence on the barrier. Scientists called this exotic and counterintuitive phenomenon the "Klein tunneling" theory. In the following 100 odd years, scientists tried various approaches to experimentally test Klein tunneling, but the attempts were unsuccessful and direct experimental evidence is still lacking.

Professor Zhang's team conducted the experiment in artificially designed phononic crystals with triangular lattice. The lattice's linear dispersion properties make it possible to mimic the relativistic Dirac quasiparticle by sound excitation, which led to the successful experimental observation of Klein tunneling.

"This is an exciting discovery. Quantum physicists have always tried to observe Klein tunneling in elementary particle experiments, but it is a very difficult task. We designed a phononic crystal similar to graphene that can excite the relativistic quasiparticles, but unlike natural material of graphene, the geometry of the man-made phononic crystal can be adjusted freely to precisely achieve the ideal conditions that made it possible to the first direct observation of Klein tunneling," said Professor Zhang.

The achievement not only represents a breakthrough in fundamental physics, but also presents a new platform for exploring emerging macroscale systems to be used in applications such as on-chip logic devices for sound manipulation, acoustic signal processing, and sound energy harvesting.

"In current acoustic communications, the transmission loss of acoustic energy on the interface is unavoidable. If the transmittance on the interface can be increased to nearly 100%, the efficiency of acoustic communications can be greatly improved, thus opening up cutting-edge applications. This is especially important when the surface or the interface play a role in hindering the accuracy acoustic detection such as underwater exploration. The experimental measurement is also conducive to the future development of studying quasiparticles with topological property in phononic crystals which might be difficult to perform in other systems," said Dr. Xue Jiang, a former member of Zhang's team and currently an Associate Researcher at the Department of Electronic Engineering at Fudan University.

Dr. Jiang pointed out that the research findings might also benefit the biomedical devices. It may help to improve the accuracy of ultrasound penetration through obstacles and reach designated targets such as tissues or organs, which could improve the ultrasound precision for better diagnosis and treatment.

On the basis of the current experiments, researchers can control the mass and dispersion of the quasiparticle by exciting the phononic crystals with different frequencies, thus achieving flexible experimental configuration and on/off control of Klein tunneling. This approach can be extended to other artificial structure for the study of optics and thermotics. It allows the unprecedent control of quasiparticle or wavefront, and contributes to the exploration on other complex quantum physical phenomena.

Almost four decades of research have led scientists at Japan's Institute for Integrated Cell-Material Sciences (iCeMS) to propose that a family of transporter proteins has played an important role in species evolution. One protein in particular, called ABCA1, was likely crucial for vertebrate evolution by helping regulate when signals involved in cell proliferation, differentiation and migration enter a cell. This process was necessary for vertebrates to develop into more complex organisms with sophisticated body structures.

The ATP-binding cassette proteins (ABC) are very similar across species, including in bacteria, plants and animals. There are different types of ABC proteins with different transportation roles, importing nutrients into cells, exporting toxic compounds outside them, and regulating lipid concentrations within cell membranes.

iCeMS cellular biochemist Kazumitsu Ueda has studied human ABC proteins for 35 years, ever since he and his colleagues identified the first eukaryote ABC protein gene.

"We believe ABC proteins must have played important roles in evolution," Ueda says. "By transporting lipids, they enabled plants and animals to thrive on land by protecting them from water loss and pathogen infection. They are also assumed to have accelerated vertebrate evolution by allowing cholesterol to function as an intra-membrane signalling molecule."

Organisms that existed early in Earth's history were probably formed of DNA and proteins surrounded by a leaky lipid membrane. As the organisms evolved, their membranes were fortified to protect them from the external environment. But this meant only organisms that evolved special ABC transporters capable of carrying nutrients across the membrane survived. The ABC proteins also played important roles in generating an outer membrane that protected cells from external stresses and in removing harmful substances from inside.

Recently, Ueda and his team studied the roles of ABCA1, gaining deeper insight into how it regulates cholesterol. Specifically, they found that ABCA1 exports cellular phospholipids and cholesterol outside the cell for generating high-density lipoproteins, popularly called good cholesterol.

They also found that ABCA1 constantly flops cholesterol from the cell membrane's inner leaflet to its outer leaflet, maintaining a lower concentration on the inner side. This flopping is temporarily suppressed when the cell is exposed to an external stimulus, like growth hormone. The resultant accumulation of cholesterol in the inner leaflet triggers the recruitment of proteins to the membrane and modulates the signal transduction. Ueda and his team suggest that ABCA1 allowed vertebrates to evolve complicated biological processes and sophisticated bodies.

"ABCA1 is very unique and its functions surprised us," says Ueda. "Cholesterol's role was thought to focus mainly on physically strengthening the cell membrane and reducing its permeability to ions. Our research suggests it played a more important role in vertebrates, accelerating their evolution."

A researcher from MIPT has proposed a new explanation for the Arctic's rapid warming. In his recent paper in Geosciences, he suggests that the warming could have been triggered by a series of great earthquakes.

Global warming is one of the pressing issues faced by civilization. It is widely believed to be caused by human activity, which increases the concentration of greenhouse gases in the atmosphere. However, this view does not explain why temperatures sometimes rise fairly abruptly.

In the Arctic, one of the factors driving climate warming is the release of methane from permafrost and metastable gas hydrates in the shelf zone. Since researchers began to monitor temperatures in the Arctic, the region has seen two periods of abrupt warming: first in the 1920s and '30s, and then beginning in 1980 and continuing to this day.

Leopold Lobkovsky, who authored the study reported in this story, is a member of the Russian Academy of Sciences and the head of the MIPT Laboratory for Geophysical Research of the Arctic and Continental Margins of the World Ocean. In his paper, the scientist hypothesized that the unexplained abrupt temperature changes could have been triggered by geodynamic factors. Specifically, he pointed to a series of great earthquakes in the Aleutian Arc, which is the closest seismically active area to the Arctic.

To test his hypothesis, Lobkovsky had to answer three questions. First, did the dates of the great earthquakes coincide with temperature jumps? Second, what is the mechanism that enables the lithospheric disturbances to propagate over more than 2,000 kilometers from the Aleutian Islands to the Arctic shelf region? Third, how do these disturbances intensify methane emissions?

The answer to the first question came from historical data analysis. It turned out that the Aleutian Arc was indeed the site of two series of great earthquakes in the 20th century (more details below the text). Each of them preceded an abrupt rise in temperature by about 15 to 20 years.

It took a model of lithospheric excitation dynamics to answer the second question. The model used by the researcher describes the propagation of so-called tectonic waves and predicts that they should travel at about 100 kilometers per year. This agrees with the delay between each of the great earthquake series and the subsequent temperature hike, as it took the disturbances 15 to 20 years to get transmitted over 2,000 kilometers.

To answer the third question, the researcher proposed the following explanation: The deformation waves arriving in the shelf zone cause minor additional stresses in the lithosphere, which are sufficient to disrupt the internal structure of the metastable gas hydrates and permafrost storing captured methane. This releases methane into the water of the shelf and atmosphere, leading to climate warming in the region due to the greenhouse effect.

"There is a clear correlation between the great earthquakes in the Aleutian Arc and the phases of climate warming. A mechanism exists for physically transmitting the stresses in the lithosphere at the appropriate velocities. And these added stresses are capable of destroying metastable gas hydrates and permafrost, releasing methane. Each of the three components in this scheme is logical and lends itself to mathematical and physical explanation. Importantly, it explains a known fact -- the abrupt rise in temperature anomalies in the Arctic -- which remained unaccounted for by the previous models," Lobkovsky commented.

According to the researcher, his model will benefit from discussion and will likely be improved, and there is much to be done in order to confirm or rule out the proposed mechanism.

Scientists of Tomsk Polytechnic University proposed a method to create a sorbent for imidacloprid insecticide removal from water. The sorbent belongs to metal-organic frameworks, a class of non-conventional materials. The TPU chemists grew such a framework right on polyethylene terephthalate (PET) used to produce regular plastic bottles. The method is quite simple and allows converting used materials into a useful product. The research findings are published in Applied Materials Today academic journal (IF: 8,352; Q1).

Metal-organic frameworks are substances with a three-dimensional structure, where clusters or metal ions are bridged by organic ligands. The result is a porous material with the properties of both metals and organic compounds.

"Due to their porous structure and a number of other properties, metal-organic frameworks have a high potential as sorbents. We are particularly interested in the problem of insecticide sorption, which are extensively used in modern agriculture and accumulated in soil and water.

We have proposed a new method to synthesize a metal-organic framework named UiO-66 with zirconium ions. The source material is what interests us first of all," Pavel Postnikov, the research supervisor and Associate Professor of TPU Research School of Chemistry and Applied Biomedical Sciences, says.

The researchers experimented with imidacloprid. This is one of the most widespread insecticides used in agriculture, including against Colorado potato beetles.

"Imidacloprid accumulates in natural water bodies penetrating from soil. According to Canadian researchers, imidacloprid was detected in waters around the world at concentrations ranging from 0.001 to 320 micrograms per litre. UiO-66 is usually derived at high temperatures and pressure using commercial terephthalic acid. However, we used PET consisting of ethylene glycol with terephthalic acid. This acid is a structural material for organic linkers in frameworks and plastic bottle material already contains it," Oleg Semyonov, one of the article authors and Junior Research Fellow at TPU Research School of Chemistry and Applied Biomedical Sciences, explains.

To create a framework, the chemists cut the plastic into small squares and partially destroyed them in an acidic solution. Then, zirconium salts were added to the solution.

"Terephthalic acid is partially released from PET forming small "anchors" on the surface of the plastic pieces while a part of the acid remains in the solution. Zirconium ions attach to the "anchors" and then, the process of self-assembly inherent to metal-organic frameworks occurs and further results in a framework formed on the plastic surface. This framework is sensitive to imidacloprid and due to its porosity and physicochemical properties, it attracts insecticide molecules removing them from water," the researcher says.

"During the experiments, we ran the insecticide solution through the sorbent. The effective water purification took 15 grams of sorbent per 1 liter, which is a very good indicator. Besides, the sorbent may be reused several times. We reached up to five cycles during our experiments. However, we expect that the sorbent will retain its properties much longer," the scientist says.

In the long run, in practice, this sorbent can be used in filtration systems, for instance, at agricultural enterprises.

"Our sorbent also has one more advantage. Usually, metal-organic frameworks are powder-like. They choke filters so that filtration systems should be designed considering this feature. The particles of our sorbent are larger and they do not choke a filter.

In addition, due to larger particles, the throughput of the sorbent is higher and liquids penetrate easier. According to our calculations, in this case water passage requires one hundred times less pressure as compared to powders. Ultimately, it is important for the technology development and use of this sorbent in a real technological process," Oleg Semyonov adds.

The scientists are currently conducting experiments using other metal-organic frameworks derived from PET.

ANN ARBOR, Michigan -- Income level, employment, housing location, medical insurance, education, tobacco and alcohol use, diet and obesity, access to medical care. These are some of the factors causing worse cancer outcomes in people who are Black.

The same factors are also causing worse outcomes from COVID-19 in this population.

"The similarities between COVID-19 issues and cancer disparities is uncanny," says John M. Carethers, M.D., John G. Searle Professor and Chair of Internal Medicine at Michigan Medicine.

"In cancer we are seeing in slow motion what has been observed rapidly with COVID - that the same conditions in our society put specific groups at risk for both. If we can fundamentally change socioeconomic inequality, we theoretically could reduce disparities in both diseases," says Carethers, who is a member of the University of Michigan Rogel Cancer Center.

Carethers collaborated with Lisa A. Newman, M.D., MPH, from Weill Cornell Medicine and Robert A. Winn, M.D., from Virginia Commonwealth University on a paper published in Clinical Cancer Research that outlines the similar disparities occurring in cancer and COVID-19 and recommends potential policy changes and strategies to help improve outcomes.

Racial disparities in cancer outcomes are well-documented, with lower five-year survival rates for Blacks than whites within most cancer types. With COVID-19, about 20% of cases in the U.S. have occurred in people who are Black, even though that population represents only 13% of the population. Similarly, Latinos comprise 32% of COVID-19 infections but are only 17% of the population.

On the surface these seem like very different diseases - cancer is often caused by genetic defects, COVID-19 is an infectious disease. But, the researchers point out, issues including socioeconomic disadvantages, education, lifestyle factors, other medical conditions and limited access to medical care are fueling risk for both cancer and COVID-19 - and contributing to worse outcomes.

"Eliminating these disparities should be a public health imperative," the authors write.

The major battles for health disparities are insurance coverage and use of preventive health services that could help eliminate co-morbidities such as obesity and diabetes, Carethers notes. The authors offer several suggestions that would impact both cancer and COVID-19 outcomes:

Ensure diversity in clinical trial participants.

Support public hospitals to meet the health care needs of those who are medically underserved.

Improve access to technology so all populations can access telehealth services.

"These strategies are feasible, but will take political will, and in some cases, funding. It relies on what people are willing to do to make it work," Carethers says. "We have much to do at all levels."

The innovation performance of firms depends on their ability to innovate in cooperation with external partners. In a study, HSE researchers found that most of innovation in Russian manufacturing happens in a sort of open processes, but extensive cooperation networks are barely detectable. The study was published in the December issue of Foresight and STI Governance.

Using data collected in 2015 and 2018 from a specialized survey measuring the innovation activity of manufacturing enterprises, researchers from the Institute for Statistical Studies and Economics of Knowledge (ISSEK) of HSE University for the first time confirmed the widespread, but not unambiguously proven, hypothesis that the openness of innovation strategy contributes to better innovation performance.

The survey included manufacturing enterprises located in at least 40 regions of Russia. In 2015, the sample included 1,206 enterprises, of which 805 were innovation-active, meaning that they had innovation activities during the past three years, regardless of whether the activity resulted in the implementation of an innovation. In 2018, 545 enterprises of high- and medium-tech manufacturing industries (422 of which were innovation-active) were surveyed.

'With Russian data we have shown that firms able to create innovation of high degree of novelty usually interact with a wide range of partners, and, most importantly, closely cooperate with R&D organizations and universities in innovation.' says Valeriya Vlasova, study co-author and Research Fellow of the Laboratory for Economics of Innovation at HSE University.

In the innovation development process, firms may cooperate with different types of partners: with value chain members (clients and suppliers), competitors, public authorities, consulting firms, and institutional R&D performing organizations (universities and research organisations). The published paper examines 9 types of different partners with which businesses can work in a wide variety of combinations.

To identify patterns in the configuration of cooperation networks, the researchers investigated three aspects of network interaction: the choice of partners, the role of spatial distance, and the duration of joint projects. The analysis made it possible to demonstrate a positive relationship between the openness of an innovation strategy and enterprises' innovation performance, in terms of innovation novelty and export capacity.

The results of the study indicate that in Russian manufacturing, almost all innovation-active enterprises cooperate with external counterparties in the process of innovation creation (98.5%), but only a few firms are integrated into extensive networks.

The most common cooperative strategy is vertical cooperation that is the involvement of clients and suppliers in the innovation process. The geography of cooperation rarely extends beyond the region's borders and is mostly of an irregular (short-term) nature. More than 40% of the surveyed enterprises follow this model.

Integration into international networks is weak (less than 5% of surveyed enterprises following this model). A small number of enterprises that engage in international cooperation tend to rely on long-term linkages with academia, which is a distinctive feature of the most innovative Russian companies.

'Despite the stereotypes about the unreadiness of Russian science to provide quality applied results, it is the active cooperation with universities and research organizations that turns out to be a characteristic feature of enterprises capable to create highly innovative products that are competitive in global markets,' says Vitaliy Roud, study co-author and Deputy Head of the HSE Laboratory for Economics of Innovation.

Innovation-active high-tech and medium high-tech enterprises that are engaged in industry-science cooperation are more often focused on the creation of new and significantly improved products or business processes; their strategic focuses also include searching for new client groups and expanding their product lines.

Announcing a new publication for BIO Integration journal. In this commentary the authors Phei Er Saw and Sangyong Jon from Sun Yat-Sen University, Guangzhou, China and the Korea Advanced Institute of Science and Technology, Daejeon, Korea, consider how the entry mechanism of nanoparticles into tumors determines the future direction of nanomedicine development.

Enhanced permeability and retention (EPR) allows nanoparticles to passively accumulate at tumor sites via gaps between endothelial cells (inter-endothelial gaps) in tumor-associated blood vessels that have abnormal structural integrity with pores ranging in size from submicron to micron. The authors review future directions of nanomedicine development, focusing on the mechanism of nanoparticle entry into tumors instead of clinical transformation itself. Designing better nanoparticles to achieve efficient clinical transformation can be informed by a deep understanding of the mechanism of nanoparticle entry or the mode of action.

The rhesus macaque is the most widely studied nonhuman primate in biomedical research. A genome sequencing project for this species, led by researchers at Baylor College of Medicine, the University of Missouri and the University of Washington, has created a new framework for study of this important primate. Research published in the journal Science has established a new reference genome assembly and identified more than 85 million genetic variants in the rhesus macaque, the largest database of genetic variation for any one nonhuman primate species to date.

"This is a major step forward in the amount of information we have about genetic variation in the rhesus macaque," said Dr. Jeffrey Rogers, associate professor at the Human Genome Sequencing Center and Department of Molecular and Human Genetics at Baylor and one of the corresponding authors of the study. "We have actually identified thousands of new mutations in the population of research animals. Now colleagues all over the country who are investigating various aspects of health and disease using rhesus macaques can begin to make use of that information."

Dr. Wesley C. Warren at the University of Missouri and Dr. Evan Eichler at the University of Washington, both corresponding authors of the study, used a combination of several advanced technologies to substantially improve the rhesus macaque reference genome assembly first created in 2007. The new reference genome published today provides a more complete and accurate picture of the rhesus macaque DNA sequence. This improvement can support more sophisticated and more detailed analyses of fundamental questions in molecular genetics, cell biology and physiology.

"When we coupled this higher quality genome reference with a broader sequencing of expressed genes, our team discovered gene structures unique to macaque as well as specific repeat sequences undergoing deletions that suggest evolutionary competition to suppress these elements from expanding continues today," said Warren, professor at the University of Missouri's Bond Life Sciences Center.

Researchers at Baylor's Human Genome Sequencing Center sequenced the genomes of 853 rhesus macaque from research institutions around the country and compared them to the new reference genome. The genome analysis showed that rhesus macaque have more genetic variants per individual than humans. Among the millions of genetic variants identified, researchers found several damaging mutations in genes known to cause genetic disorders in humans, including autism, inherited blindness and several others.

"We can find naturally occurring models of genetic disorders by surveying the rhesus macaque population," Rogers said. "We will find animals that naturally carry interesting and useful genetic mutations that can help us understand genetic variation and susceptibility to disease in humans. Rhesus macaques are also widely studied by primatologists and evolutionary biologists, so this new reference genome will also provide new insight into the evolution of the nonhuman primate and human genomes."