Culture

The findings published in eLife show that men with this unstable subtype of the Y chromosome have a significantly increased risk of genomic rearrangements. These rearrangements affect the sperm production process (spermatogenesis) and consequently, these men can be up to nine times more likely to have fertility issues. Molecular diagnostics of this genetic variant could help identify those at higher risk in their early adulthood, giving them the chance to make decisions about future family planning early on. Currently, the exact cause of infertility remains unknown in more than half of men with spermatogenic impairment.

In the large-scale study led by geneticist Pille Hallast and conducted in cooperation between the Human Genetics Research Group of the University of Tartu Institute of Biomedicine and Translational Medicine, the Andrology Centre of Tartu University Hospital and the Wellcome Sanger Institute, the Y chromosomes of more than 2,300 Estonian men were analysed. The men were involved in the study at the Andrology Centre of Tartu University Hospital by the team of Professor Margus Punab.

The Y-chromosomal region studied in this paper has been associated with male infertility before, but this is the first time the genetic variation of such a large clinical sample has been investigated. According to Hallast, this is the most sophisticated in-depth analysis of the genetic variation of Y chromosome in patients with spermatogenic impairment.

One of the senior co-authors of the study, Professor of Human Genetics of the University of Tartu Maris Laan said that the previously undescribed subtype of Y chromosome discovered in cooperation with colleagues from the UK causes a high risk of severe spermatogenic impairment. "At one point during evolution, the 'ancestor' of these Y chromosomes experienced the inversion of a long DNA segment, causing instability in this Y chromosome and predisposing to the deletion of surrounding DNA segments," explained Laan.

This inverted Y chromosome variant is relatively common and does not always lead to partial deletion of DNA or fertility issues. Therefore, it can be passed down in families and remain unnoticed until an offspring has infertility issues. According to estimates, in this Y lineage, the deletion of genetic material that harms spermatogenesis occurs in about one man in ten or even less often. This subtype is carried by a significant number of men of European descent, but it is not found as widely in other continents. In Estonia, it can be found in 5-6% of men, but in Poland and Czechia, the figure is nearly 20%.

The world's leading population geneticist Dr. Chris Tyler-Smith, collaborator working at the Wellcome Sanger Institute, underlined the need for more synergetic research between teams in population and reproductive genetics to map unfavourable Y-chromosomal variants linked to impaired spermatogenesis and understand how these have evolved and survived demographically.

Professor Maris Laan emphasised the potential practical value of molecular diagnostics of this research, as early identification of the genetic reason of male spermatogenic impairment could allow a more focused clinical management of infertile couples. "While the deletions in the studied Y chromosome region were previously known to interfere with sperm production, we now know that the deletion of DNA sequences leads to the genetic predisposition to infertility depending on the Y-chromosomal lineage," she added.

Infants born by cesarean section have a relatively meager array of bacteria in the gut. But by the age of three to five years they are broadly in line with their peers. This is shown by a study that also shows that it takes a remarkably long time for the mature intestinal microbiota to get established.

Fredrik Bäckhed, Professor of Molecular Medicine at Sahlgrenska Academy, University of Gothenburg, has been heading this research. The study, conducted in collaboration with Halland County Hospital in Halmstad, is now published in the journal Cell Host & Microbe.

Professor Bäckhed and his group have previously demonstrated that the composition of children's intestinal microbiota is affected by their mode of delivery and diet. In the current study, the researchers examined in detail how the composition of intestinal bacteria in 471 children born at the hospital in Halmstad had developed.

The first fecal sample was collected when each child was a newborn infant. Thereafter, sampling took place at 4 months, 12 months, 3 years and 5 years. The scientists were thus able to follow the successive incorporation of various bacteria into the children's gut microbiota.

At birth, the infant's intestine has already been colonized by bacteria and other microorganisms. During the first few years of life, the richness of species steadily increases. What is now emerging is a considerably more detailed picture of this developmental trajectory.

One key conclusion is that the intestinal microbiota forms an ecosystem that takes a long time to mature. Even at 5 years of age, the system is incomplete. The maturation process can look very different from one child to another, and take varying lengths of time.

At the age of 4 months, the gut microbiota in the cesarean-born infants was less diverse compared with vaginally born infants. However, when the children were 3 and 5 years the microbiota diversity and composition had caught up and were largely normalized intestinal microbiota.

"Our findings show that the gut microbota is a dynamic organ, and future studies will have to show whether the early differences can affect the cesarean children later in life," Bäckhed says.

"It's striking that even at the age of 5 years, several of the bacteria that are important components of the intestinal microbiota in adults are missing in the children," he continues.

This indicates that the intestine is a complex and dynamic environment where bacteria create conditions for one another's colonization.

According to the researchers, the current study has broadened our understanding of how humans interact with the trillions of bacteria contained in our bodies, and of how these bacteria become established.

Lisa Olsson, a researcher at the University of Gothenburg and one of the first authors, adds:

"Children learn skills like walking and talking at different rates, and it turns out that the same applies to the maturity of the gut microbiota."

Fredrik Bäckhed again:

"By investigating and understanding how the intestinal microbiota develops in healthy children, we may get a reference point to explorie if the microbiota may contribute to disease in future studies," he concludes.

Although beef is one of the most consumed foods around the world, eating it when it's past its prime is not only unsavory, but also poses some serious health risks. Unfortunately, available methods to check for beef freshness have various disadvantages that keep them from being useful to the public. For example, chemical analysis or microbial population evaluations take too much time and require the skills of a professional. On the other hand, non-destructive approaches based on near-infrared spectroscopy require expensive and sophisticated equipment. Could artificial intelligence be the key to a more cost-effective way to assess the freshness of beef?

At Gwangju Institute of Science and Technology (GIST), Korea, a team of scientists led by Associate Processors Kyoobin Lee and Jae Gwan Kim have developed a new strategy that combines deep learning with diffuse reflectance spectroscopy (DRS), a relatively inexpensive optical technique. "Unlike other types of spectroscopy, DRS does not require complex calibration; instead, it can be used to quantify part of the molecular composition of a sample using just an affordable and easily configurable spectrometer," explains Lee. The findings of their study are now published in Food Chemistry.

To determine the freshness of beef samples, they relied on DRS measurements to estimate the proportions of different forms of myoglobin in the meat. Myoglobin and its derivatives are the proteins mainly responsible for the color of meat and its changes during the decomposition process. However, manually converting DRS measurements into myoglobin concentrations to finally decide upon the freshness of a sample is not a very accurate strategy--and this is where deep learning comes into play.

Convolutional neural networks (CNN) are widely used artificial intelligence algorithms that can learn from a pre-classified dataset, referred to as 'training set,' and find hidden patterns in the data to classify new inputs. To train the CNN, the researchers gathered data on 78 beef samples during their spoilage process by regularly measuring their pH (acidity) alongside their DRS profiles. After manually classifying the DRS data based on the pH values as 'fresh,' 'normal,' or 'spoiled,' they fed the algorithm the labelled DRS dataset and also fused this information with myoglobin estimations. "By providing both myoglobin and spectral information, our trained deep learning algorithm could correctly classify the freshness of beef samples in a matter of seconds in about 92% of cases," highlights Kim.

Besides its accuracy, the strengths of this novel strategy lie in its speed, low cost, and non-destructive nature. The team believes it may be possible to develop small, portable spectroscopic devices so that everyone can easily assess the freshness of their beef, even at home. Moreover, similar spectroscopy and CNN-based techniques could also be extended to other products, such as fish or pork. In the future, with any luck, it will be easier and more accessible to identify and avoid questionable meat.

PROVIDENCE, R.I. [Brown University and Providence Veterans Affairs Medical Center] -- Brain-computer interfaces (BCIs) are an emerging assistive technology, enabling people with paralysis to type on computer screens or manipulate robotic prostheses just by thinking about moving their own bodies. For years, investigational BCIs used in clinical trials have required cables to connect the sensing array in the brain to computers that decode the signals and use them to drive external devices.

Now, for the first time, BrainGate clinical trial participants with tetraplegia have demonstrated use of an intracortical wireless BCI with an external wireless transmitter. The system is capable of transmitting brain signals at single-neuron resolution and in full broadband fidelity without physically tethering the user to a decoding system. The traditional cables are replaced by a small transmitter about 2 inches in its largest dimension and weighing a little over 1.5 ounces. The unit sits on top of a user's head and connects to an electrode array within the brain's motor cortex using the same port used by wired systems.

For a study published in IEEE Transactions on Biomedical Engineering, two clinical trial participants with paralysis used the BrainGate system with a wireless transmitter to point, click and type on a standard tablet computer. The study showed that the wireless system transmitted signals with virtually the same fidelity as wired systems, and participants achieved similar point-and-click accuracy and typing speeds.

"We've demonstrated that this wireless system is functionally equivalent to the wired systems that have been the gold standard in BCI performance for years," said John Simeral, an assistant professor of engineering (research) at Brown University, a member of the BrainGate research consortium and the study's lead author. "The signals are recorded and transmitted with appropriately similar fidelity, which means we can use the same decoding algorithms we used with wired equipment. The only difference is that people no longer need to be physically tethered to our equipment, which opens up new possibilities in terms of how the system can be used."

The researchers say the study represents an early but important step toward a major objective in BCI research: a fully implantable intracortical system that aids in restoring independence for people who have lost the ability to move. While wireless devices with lower bandwidth have been reported previously, this is the first device to transmit the full spectrum of signals recorded by an intracortical sensor. That high-broadband wireless signal enables clinical research and basic human neuroscience that is much more difficult to perform with wired BCIs.

The new study demonstrated some of those new possibilities. The trial participants -- a 35-year-old man and a 63-year-old man, both paralyzed by spinal cord injuries -- were able to use the system in their homes, as opposed to the lab setting where most BCI research takes place. Unencumbered by cables, the participants were able to use the BCI continuously for up to 24 hours, giving the researchers long-duration data including while participants slept.

"We want to understand how neural signals evolve over time," said Leigh Hochberg, an engineering professor at Brown, a researcher at Brown's Carney Institute for Brain Science and leader of the BrainGate clinical trial. "With this system, we're able to look at brain activity, at home, over long periods in a way that was nearly impossible before. This will help us to design decoding algorithms that provide for the seamless, intuitive, reliable restoration of communication and mobility for people with paralysis."

The device used in the study was first developed at Brown in the lab of Arto Nurmikko, a professor in Brown's School of Engineering. Dubbed the Brown Wireless Device (BWD), it was designed to transmit high-fidelity signals while drawing minimal power. In the current study, two devices used together recorded neural signals at 48 megabits per second from 200 electrodes with a battery life of over 36 hours.

While the BWD has been used successfully for several years in basic neuroscience research, additional testing and regulatory permission were required prior to using the system in the BrainGate trial. Nurmikko says the step to human use marks a key moment in the development of BCI technology.

"I am privileged to be part of a team pushing the frontiers of brain-machine interfaces for human use," Nurmikko said. "Importantly, the wireless technology described in our paper has helped us to gain crucial insight for the road ahead in pursuit of next generation of neurotechnologies, such as fully implanted high-density wireless electronic interfaces for the brain."

The new study marks another significant advance by researchers with the BrainGate consortium, an interdisciplinary group of researchers from Brown, Stanford and Case Western Reserve universities, as well as the Providence Veterans Affairs Medical Center and Massachusetts General Hospital. In 2012, the team published landmark research in which clinical trial participants were able, for the first time, to operate multidimensional robotic prosthetics using a BCI. That work has been followed by a steady stream of refinements to the system, as well as new clinical breakthroughs that have enabled people to type on computers, use tablet apps and even move their own paralyzed limbs.

"The evolution of intracortical BCIs from requiring a wire cable to instead using a miniature wireless transmitter is a major step toward functional use of fully implanted, high-performance neural interfaces," said study co-author Sharlene Flesher, who was a postdoctoral fellow at Stanford and is now a hardware engineer at Apple. "As the field heads toward reducing transmitted bandwidth while preserving the accuracy of assistive device control, this study may be one of few that captures the full breadth of cortical signals for extended periods of time, including during practical BCI use."

The new wireless technology is already paying dividends in unexpected ways, the researchers say. Because participants are able to use the wireless device in their homes without a technician on hand to maintain the wired connection, the BrainGate team has been able to continue their work during the COVID-19 pandemic.

"In March 2020, it became clear that we would not be able to visit our research participants' homes," said Hochberg, who is also a critical care neurologist at Massachusetts General Hospital and director of the V.A. Rehabilitation Research and Development Center for Neurorestoration and Neurotechnology. "But by training caregivers how to establish the wireless connection, a trial participant was able to use the BCI without members of our team physically being there. So not only were we able to continue our research, this technology allowed us to continue with the full bandwidth and fidelity that we had before."

Simeral noted that, "Multiple companies have wonderfully entered the BCI field, and some have already demonstrated human use of low-bandwidth wireless systems, including some that are fully implanted. In this report, we're excited to have used a high-bandwidth wireless system that advances the scientific and clinical capabilities for future systems."

The team led by Professor DU Jiangfeng and Professor WANG Ya from the Chinese Academy of Sciences (CAS) Key Laboratory of Microscale Magnetic Resonance of the University of Science and Technology of China put forward an innovative spin-to-charge conversion method to achieve high-fidelity readout of qubits, stepping closer towards fault-tolerant quantum computing.

Quantum supremacy over classical computers has been fully exhibited in some specific problems, yet the next milestone, fault-tolerant quantum computing, still requires the accumulated logic gate error and the spin readout fidelity to exceed the fault-tolerant threshold. DU's team has resolved the first requirement in the nitrogen-vacancy (NV) center system [Nat. Commun. 6, 8748 (2015)] previously and this work targeted at high-fidelity readout of qubits.

Qubit state, such as spin state, is fragile: a common readout approach may cause the flip between the 0 and 1 states for even a few photons resulting in a reading error. The readout fidelity of traditional resonance fluorescence method is strictly limited by such property. Since the spin state is difficult to measure, researchers blazed a trail to replace it with an easy-to-readout and measurable property: the charge state.

They first compared the optical readout lifetime of the charge state and spin state, finding that charge state is more stable than the spin state by five orders of magnitude. Experiment results showed that the average non-demolition charge readout fidelity reached 99.96%.

Then the team adopted near-infrared (NIR) light (1064 nm) to induce the ionization of the excited spin state, transforming the spin state 0 and 1 to the "electrically neutral" and "negatively charged" charge states respectively. This process converted the spin readout to the charge readout.

The results indicated that the error of traditional resonance fluorescence method reached 20.1%, while the error of this new method can be suppressed to 4.6%.

The article was published in Nature Communications.

This new method is compatible with tradition methods, provisioning a spin readout fidelity exceeding the fault-tolerant threshold in real applications. Thanks to the less damage of NIR light to biological tissues and other samples, this method will also effectively improve the detection efficiency of quantum sensors.

Pollen from trees, grasses and weeds are causing seasonal allergies for approximately one fifth of the Swiss population every year. A study now found that due to climate change, the pollen season has shifted substantially over the past 30 years in onset, duration and intensity. "For at least four allergenic species, the tree pollen season now starts earlier than 30 years ago - sometimes even before January," said Marloes Eeftens, Principal Investigator and Group Leader at Swiss TPH. "The duration and intensity of the pollen season have also increased for several species, meaning that allergic people not only suffer for a longer period of time but also react stronger to these higher concentrations."

The researchers analysed pollen data from 1990 to 2020 from all 14 pollen-monitoring stations in Switzerland, studying airborne pollen concentrations from 12 different plant species. "Previous studies have looked at single species or only a few locations, but this is the first time a study brings together comprehensive pollen data from across Switzerland," said Sarah Glick, first author of the study and scientific assistant at Swiss TPH.

Health impact beyond sneezing

Pollen allergies are the most common chronic disease in many European and North American countries. Today, an estimated 20% of the Swiss population suffers from pollen allergies, a dramatic increase from 100 years ago when less than 1% was affected. This increase is most likely related to changes in our environment, such as personal hygiene and increase in urban rather than rural living. Besides the typical itching eyes and nose and frequent sneezing, pollen allergies can also cause inflammation in the lungs, and result in negative impact on the cardiovascular system, decreased quality of life, and reduced school and work performance.

"Similar to man-made air pollutants like particulate matter or nitrogen dioxide, pollen may actually have numerous negative effects on our body much beyond just nuisance," explained Eeftens. "Given the extent of the population affected and the increasing burden, it is key that we further study the health effects of pollen both acute and more long-term." Swiss TPH just launched the EPOCHAL study to deepen the understanding of the multiple effects of pollen on health including blood pressure, lung function, ability to concentrate, mood and sleep.

"There is little we can do to prevent pollen release from plants, but we hope that the results of the study can help allergic people manage their allergies better," said to Eeftens. "A better understanding of allergenic species could also help guide urban planners in identifying suitable plants for parks. For example, we may think twice before planting highly allergenic trees like hazel and birch in densely populated areas."

The risk is low that scientists could pass coronavirus to North American bats during winter research, according to a new study led by the U.S. Geological Survey. Scientists find the overall risk to be 1 in 1,000 if no protective measures are taken, and the risk falls lower, to 1 in 3,333 or less, with proper use of personal protective equipment or if scientists test negative for COVID-19 before beginning research.

The research specifically looked at the potential transmission of SARS-CoV-2, which is the type of coronavirus that causes COVID-19, from people to bats. Scientists did not examine potential transmission from bats to people.

"This is a small number, but the consequences of human-to-bat transmission of coronavirus are potentially large," said USGS scientist Evan Grant, an author of the new rapid risk assessment. "The virus has not been identified in North American bats, but if it is introduced, it could lead to illness and mortality, which may imperil long-term bat conservation. It could also represent a source for new exposure and infection in humans."

"These are hard risks for wildlife managers and other decision makers to weigh as they consider whether and how to allow researchers to study bats in their winter colonies," continued Grant.

Bats provide natural services that people value; for example, previous USGS studies found that bats save the U.S. agriculture industry more than $3 billion per year by eating pests that damage crops, reducing the need for pesticides. Yet they are often erroneously portrayed as menacing creatures at Halloween and in horror movies. They are also under duress from white-nose syndrome, a disease that has killed millions of bats in North America.

The origin of SARS-CoV-2 is not confirmed, but studies indicate the virus likely originated from similar viruses found in bats in the Eastern Hemisphere.

The rapid risk assessment conducted by the USGS and U.S. Fish and Wildlife Service focused on the winter season, when some wildlife scientists conduct field work that may require close contact with or direct handling of the animals. This includes research on white-nose syndrome and population studies that support Endangered Species Act decisions.

"If scientists wear protective equipment, particularly properly fitted masks with high filtration efficiency, or test negative for COVID-19 before conducting the research, they greatly reduce the risk of transmission to North American bats," said USGS scientist Michael Runge, another author on the new assessment.

"The current assessment represents the best available information and is useful for informing time-sensitive management decisions, but there are still many unknowns about how susceptible North American bats are to SARS-CoV-2 and how future virus variants may affect transmission," said Grant.

"The potential for SARS-CoV-2 to infect wildlife is a real concern for state and federal wildlife management agencies and reflects the important connections between human health and healthy environments," said Jeremy Coleman, National White-nose Syndrome Coordinator for the USFWS and an author of the paper. "Natural resource managers need information from these kinds of analyses to make science-based decisions that advance conservation efforts while also protecting the health of people, bats, and other wildlife."

Three bat species - free-tailed bats, little brown bats and big brown bats - were included in the analysis. They were chosen because they have physical and behavioral differences and are typical of the kinds of bats studied in winter. Scientists considered different ways the virus could be transmitted between humans and bats, with airborne transmission as the main pathway.

This study estimates transmission risk to at least one bat during a typical winter survey, which includes a team of five scientists spending one hour in a cave colonized by 1,000 bats.

This research builds on a USGS-led study published last year that examined the likelihood of researchers transmitting SARS-CoV-2 to bats during summer research. Since that study, a substantial amount of new data and knowledge on the virus has been acquired and applied. Winter and summer research can involve different settings and activities.

The "Science for Disaster Risk Management 2020: acting today, protecting tomorrow", the second of its series, has been produced with the collaboration of more than 300 experts in disaster risk management. The participants come from different disciplines and sectors to provide the reader with accurate and updated information on the consequences that disasters have on key assets of society (population, economic sectors, critical infrastructures, environment and cultural heritage) and how these can be managed. Finally, the report provides a set of recommendations addressed to four target groups of society that can actively work to reduce disaster risk: policymakers, practitioners, scientists and citizens.?

The report aims to move from identifying problems to identifying solutions and approaches for action. The launch would be a good opportunity to engage with different stakeholders to identify what the community has learned up to now and to explore together how the proposed recommendations can be put in practice.

Jaroslav Mysiak, director of the CMCC research division 'Risk assessment and adaptation strategies' participated in the realization of the report as coordinating lead author (CLA).

In his contribution (Chapter 3 Assets at risks and potential impacts - 3.3. Economic Sectors), the authors reviewed the state-of-the-art knowledge, methodologies and practice of assessing damage and losses caused to residential building stock, agriculture, and industrial and energy assets.

Natural hazards are a major threat to sustainable development, economic stability and growth, territorial cohesion, and community resilience. According to the estimates of the European Environment Agency, the economic damage due to only natural hazard risks in the EU amounted to more than EUR 557 billion in 1980-2017, mostly triggered by extreme weather and climate-related events whose frequencies and/or intensities are expected to increase as a result of human-induced climate change.

"Over the past few decades, disaster risk assessment has improved thanks to the advancements in high performance computing, high-resolution topographic and other spatial data, a new generation of large-scale hazard and disaster loss/impact models, and high-resolution exposure datasets", Jaroslav Mysiak explains. "An accurate spatial representation of exposure features such as residential and industrial facilities and assets, infrastructure, population density and gross domestic product make it possible to improve the estimates and spatial distribution of disaster impacts. Advanced quality and accessibility of Earth observation products, including from the EU's Copernicus programme, have led the way to coherent exposure and vulnerability data at continental and global scales."

The authors concluded the chapter highlighting the lesson learnt from COVID-19 pandemic. "What we have lived through during the lockdown, and still will", they write, "is a mild foretaste of the systemic shocks that climate and global environmental changes may and will cause in the future. Future improvements of risk assessment need to be focused on a better understanding of indirect and spillover economic losses generated by slow-onset hazards, compound risks and cascading risks, as well as losses caused by disruption of social networks, economic flows and ecosystem services.

The EU Green Deal and the unprecedented post-COVID-19 recovery package will stimulate immense investments in green technologies and innovation, and lead the way to sustainable development and climate neutrality. Only with sound, evidence-based and multi-hazard risk assessments can we reconcile short-term 'building back better' recovery and medium- to long-term climate-resilient development."

What The Article Says: This JAMA Insights Clinical Update from the CDC's COVID-19 Response Team discusses the association of changes in COVID-19 case rates and death rates with implementation of state-issued mask mandates and allowance of any on-premises restaurant dining.

Authors: Gery P. Guy Jr, Ph.D., M.P.H., of the Centers for Disease Control and Prevention in Atlanta, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jama.2021.5455)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

The human body is an incredibly designed machine, and mechanical processes such as those in the lymphatic system play major roles in maintaining healthy tissue and organs.

Donny Hanjaya-Putra is an assistant professor whose work lies at the intersection of engineering and medicine. He studies the lymphatic system -- the part of the immune system that rids the body of toxins and other unwanted materials. He looks at how to restore dysfunctional lymphatic networks, which are associated with a wide range of diseases, including cancer, cardiovascular disease, diabetes, neurological conditions and metabolic syndromes.

Now Hanjaya-Putra and his team -- bioengineering doctoral student Laura Alderfer, along with Elizabeth Russo, a 2019 graduate; Adriana Archilla, a student from Syracuse University; and Brian Coe, class of '19 -- have demonstrated how extracellular matrix stiffness affects lymphatic vessel function.

The team is combining this knowledge with polymer science and mechanical engineering to build new lymphatic cord-like structures, which help restore normal behavior to dysfunctional lymphatic systems and allow the body to fight the disease.

"Cells can sense mechanical stimuli, such as matrix stiffness, and this activates certain genes to promote lymphatic formation," said Hanjaya-Putra. "We used hydrogels made from hyaluronic acid (a natural sugar molecule) to enhance the cell-binding motif with appropriate mechanical stimuli (matrix stiffness) in a 2D model of lymphatic vessels and successfully stimulated new lymphatic vessel formations."

The team has published its findings in The FASEB Journal of the Federation of American Societies for Experimental Biology.

This type of research is only possible, Hanjaya-Putra said, because of advances in imaging and stem cell biology.

"Traditionally, medical students spent hours studying the cardiovascular system, but not as much emphasis was placed on the lymphatic system," said Hanjaya-Putra. "The reason, in large part, was due to the difficulty in visualizing lymphatic vessels, which are transparent.

"Recent advances have allowed us to use specific cell markers to distinguish between blood endothelial cells and lymphatic endothelial cells, so we can now see and study these very important networks in vitro and in vivo."

Hanjaya-Putra and his team are now developing hydrogels that can be implanted under the skin to promote wound healing as well as gels that can be injected into the body at the site of injury.

Alderfer, the lead author on the FASEB article, was awarded a Fulbright U.S. Student Program Grant to study at the University of Helsinki. She will be studying lymphatic vessel formation in vivo in wound and cardiac injury models with Kari Alitalo, a global leader in the research of lymphatic vessels and translational cancer biology.

When we watch a mime seemingly pull rope, climb steps or try to escape that infernal box, we don't struggle to recognize the implied objects -- our minds automatically "see" them, a new study concludes.

To explore how the mind processes the objects mimes seem to interact with, Johns Hopkins University cognitive scientists brought the art of miming into the lab, concluding that invisible, implied surfaces are represented rapidly and automatically. The work appears today in the journal Psychological Science.

"Most of the time, we know which objects are around us because we can just see them directly. But what we explored here was how the mind automatically builds representations of objects that we can't see at all but that we know must be there because of how they are affecting the world," said senior author Chaz Firestone, an assistant professor who directs the university's Perception & Mind Laboratory. "That's basically what mimes do. They can make us feel like we're aware of some object just by seeming to interact with it."

In the experiments, 360 people were tested online. They watched clips where a character (Firestone himself) mimed colliding with a wall and stepping over a box in a way that suggested those objects were there, only invisible. Afterward, a black line appeared in the spot on the screen where the implied surface would have been. This line could be horizontal or vertical, so it either matched or didn't match the orientation of the surface that had just been mimed. Participants had to quickly answer if the line was vertical or horizontal. The team found people responded significantly faster when the line aligned with the mimed wall or box, suggesting that the implied surface was actively represented in the mind - so much so that it affected responses to the real surface participants saw immediately after.

Participants had been told not to pay attention to the miming, but they couldn't help but be influenced by those implied surfaces, said lead author Pat Little, who did the work as an undergraduate at Johns Hopkins, and is now a graduate student at New York University.

"Very quickly people realize that the mime is misleading them, and that there is no actual connection between what the person does and the type of line that appears," Little said. "They think, 'I should ignore this thing because it's getting in my way', but they can't. That's the key. It seems like our minds can't help but represent the surface that the mime is interacting with - even when we don't want to."

The work is partly inspired by a phenomenon in psychology called the Stroop Effect, where the name for one color is written in ink of a different color (e.g., the word "red" is written in blue ink); when a person is given the task of saying the color of the ink (blue), they can't help but read the mismatched text (red), which distracts them and slows them down. In this regard, miming is like reading: Just as you can't help but read the text you see (even when you're supposed to ignore it), you can't help but recognize the object being mimed, even when it's getting in the way of another task.

While it could seem that the findings diminish the work of mimes - since it suggests our brains are going to imagine these objects automatically - the researchers insist mimes still deserve credit.

"This suggests that miming might be different from other kinds of acting," Little said. "If the mime is skilled enough, understanding what's going on doesn't require any effort at all -- you just get it automatically."

The findings could also inform artificial intelligence related to vision.

"If you're trying to build a self-driving car that can see the world and steer around objects, you want to give it all the best tools and tricks," Firestone said. "This study suggests that, if you want a machine's vision to be as sophisticated as ours, it's not enough for it to identify objects that it can see directly -- it also needs the ability to infer the existence of objects that aren't even visible at all."

Space scientists at the University of Bath in the UK have found a new way to probe the internal structure of neutron stars, giving nuclear physicists a novel tool for studying the structures that make up matter at an atomic level.

Neutron stars are dead stars that have been compressed by gravity to the size of small cities. They contain the most extreme matter in the universe, meaning they are the densest objects in existence (for comparison, if Earth were compressed to the density of a neutron star, it would measure just a few hundred meters in diameter, and all humans would fit in a teaspoon). This makes neutron stars unique natural laboratories for nuclear physicists, whose understanding of the force that binds sub-atomic particles is limited to their work on Earth-bound atomic nuclei. Studying how this force behaves under more extreme conditions offers a way to deepen their knowledge.

Step in astrophysicists, who look to distant galaxies to unravel the mysteries of physics.

In a study described in the Monthly Notices of the Royal Astronomical Society, Bath astrophysicists have found that the action of two neutron stars moving ever faster as they spiral towards a violent collision gives a clue to the composition of neutron-star material. From this information, nuclear physicists will be in a stronger position to calculate the forces that determine the structure of all matter.

RESONANCE

It is through the phenomenon of resonance that the Bath team has made its discovery. Resonance occurs when force is applied to an object at its natural frequency, generating a large, often catastrophic, vibrational motion. A well-known example of resonance is found when an opera singer shatters a glass by singing loudly enough at a frequency that matches the oscillation modes of the glass.

When a pair of in-spiralling neutron stars reach a state of resonance, their solid crust - which is thought to be 10-billion times stronger than steel - shatters. This results in the release of a bright burst of gamma-rays (called a Resonant Shattering Flare) that can be seen by satellites. The in-spiralling stars also release gravitational waves that can be detected by instruments on Earth. The Bath researchers found that by measuring both the flare and the gravitational-wave signal, they can calculate the 'symmetry energy' of the neutron star.

Symmetry energy is one of the properties of nuclear matter. It controls the ratio of the sub-atomic particles (protons and neutrons) that make up a nucleus, and how this ratio changes when subjected to the extreme densities found in neutron stars. A reading for symmetry energy would therefore give a strong indication of the makeup of neutron stars, and by extension, the processes by which all protons and neutrons couple, and the forces that determine the structure of all matter.

The researchers stress that measurements obtained by studying the resonance of neutron stars using a combination of gamma-rays and gravitational-waves would be complementary to, rather than a replacement for, the lab experiments of nuclear physicists.

"By studying neutron stars, and the cataclysmic final motions of these massive objects, we're able to understand something about the tiny, tiny nuclei that make up extremely dense matter," said Bath astrophysicist Dr David Tsang. "The enormous difference in scale makes this fascinating."

Astrophysics PhD student Duncan Neill, who led the research, added: "I like that this work looks at the same thing being studied by nuclear physicists. They look at tiny particles and we astrophysicists look at objects and events from many millions of light years away. We are looking at the same thing in a completely different way."

Dr Will Newton, astrophysicist at the Texas A&M University-Commerce and project collaborator, said: "Though the force that binds quarks into neutrons and protons is known, how it actually works when large numbers of neutrons and protons come together is not well understood. The quest to improve this understanding is helped by experimental nuclear physics data, but all the nuclei we probe on Earth have similar numbers of neutrons and protons bound together at roughly the same density.

"In neutron stars, nature provides us with a vastly different environment to explore nuclear physics: matter made mostly of neutrons and spanning a wide range of densities, up to about ten times the density of atomic nuclei. In this paper, we show how we can measure a certain property of this matter - the symmetry energy - from distances of hundreds of millions of light years away. This can shed light on the fundamental workings of nuclei."

Recent research from the University of Vaasa and the University of Jyväskyla shows that speculation and lottery-like behavior is a fundamental factor for the pricing of cryptocurrencies. Speculation could explain the enormous increase in the market capitalizations of cryptocurrencies.

Nowadays more than 8000 cryptocurrencies have been launched. Unlike traditional assets like stocks, research has shown that investments in cryptocurrencies are associated with a considerably higher level of uncertainty. The price of Bitcoin, which is the first traded cryptocurrency, increased by from $7,200.17 to $29,374.15 in January 1, 2020 to January 1, 2021 period corresponding to a return of more than 300 percent in one year.

Interestingly, the sharp increase in the prices for cryptocurrencies happens in a period where the uncertainty in the market for traditional currencies has risen due to the enormous amounts of money that governments worldwide have decided to supply in an attempt to help economies that are on the edge of collapsing due to the ongoing worldwide COVID-19 crisis. The question arises what are the driving forces for pricing cryptocurrencies?

A recently published research article from Klaus Grobys, University of Vaasa and Juha Junttila, University of Jyväskylä in the well-known Journal of International Financial Markets, Institutions and Money explores this current issue.

In their study, the researchers examined the role of speculative behavior in cryptocurrency markets, that is, lottery-like demand. Their study makes use of a set of 20 cryptocurrencies to implement the analysis of the so-called MAX-effect over the January 2016-December 2019 period. These cryptocurrencies exhibited the highest market capitalizations. Their findings indicate that the portfolio of cryptocurrencies that exhibited the lowest daily log-return in the week preceding portfolio formation generates, on average, significantly higher returns than the portfolio of cryptocurrencies that exhibited the highest daily log-return in the week preceding portfolio formation. However, it is important to note that this result is based on portfolio analysis.

The authors also propose a new statistical methodology to compute risk-adjust the payoffs which is based on blocks bootstraps using different block lengths. They show that their new statistical methodology has some benefits because it ensures both (i) latent regimes in the first or second moment in that data generating process are preserved, and (ii) valuable information in the data is not lost.

Moreover, the authors explore the transition probabilities which answers the question of how likely is it that a single cryptocurrency will exhibit an extreme return in the time period that follows the portfolio formation. In this regard, their findings indicate that cryptocurrencies that have experienced extreme positive returns in the past are more likely to generate extreme positive returns in the future than generating extreme negative returns which in turn implies that investors' expectations appear to be rational.

The authors argue that their findings are also interesting from a theoretical point of view because they suggest that similar behavioral mechanisms of underlying investor behavior observed for stock markets are present even in digital financial markets.

- Earlier studies have shown that short-term return reversal and size are priced in the cross section of expected cryptocurrency returns. Another recent stream of research has shown that 50% of Bitcoin turnover is associated with criminal activities. Our study is the first that demonstrates that lottery-like behavior is also an important driving force that plays a role for pricing cryptocurrencies, says Dr. Klaus Grobys.

- Lottery-like behavior might actually explain part of the very recently observed rocket-wise rising valuation of some segments of cryptocurrency markets, too, emphasizes Professor Juha Junttila.

- A good example of this kind of betting behavior is the case of Wallstreetbets forum available from the social media site Reddit. There, the sudden increase in the number of micro level investors investing in some individual stocks has now caused a huge increase in the valuation of these stocks, and the fundamental pricing factors (like the expected future economic performance of the firm in question) have lost their role in the pricing behavior, at least for a short run. In cryptocurrency markets, this kind of behavior has been actually observed, too, so the MAX behavior in cryptocurrency markets can actually be also a reflection of these kinds of activities at the micro investor level. Obviously, our current results deserve much more scrutiny in the near future, says Junttila.

A team of researchers at the University of Alberta has uncovered a long-sought link in the battle to control cholesterol and heart disease.

The protein that interferes with low-density lipoprotein (LDL) receptors that clear "bad" cholesterol from the blood was identified in findings recently published in Nature Communications by Dawei Zhang, associate professor of pediatrics in the Faculty of Medicine & Dentistry. Excess LDL cholesterol can lead to atherosclerosis--a narrowing and hardening of arteries--and ultimately, heart attack.

"We have known for many years that these receptors could be cleaved, but nobody knew which protein was responsible," said Zhang. "There had been several attempts around the world but nobody else was successful."

Now that the culprit has been identified, Zhang's lab is already at work to find a drug to target the protein, allowing the receptors to clear more LDL.

A cholesterol-reducing class of drugs called statins--Lipitor and Crestor are two well-known brand names--has been shown to reduce cardiac events by 20 to 40 per cent, but they have side-effects that mean they can't be given in high enough doses to work for everyone. The new drug would be used in combination with statins to boost their effect, Zhang said.

Zhang's team stumbled upon the role of the protein--membrane type 1 matrix metalloproteinase--by accident while studying another protein involved in heart function. They then set out to repeat and confirm their findings in mouse, rat and human cells, working in collaboration with researchers in China and other faculty members at the U of A. Their study was funded by the Heart and Stroke Foundation of Canada and the Canadian Institutes of Health Research. Zhang is also a member of the Women and Children's Health Research Institute.

The protein has other critical physiological functions, Zhang explained, so his lab will work to identify and focus on the specific region within the protein that acts on the LDL receptor. They are also working with a new technique to further target their potential drug so it will work only within the liver, further reducing the likelihood of unwanted side-effects. Their early results are encouraging, Zhang said.

Zhang noted the protein is also critical for cancer tumour invasion, so the team will collaborate with U of A oncology experts to learn more.

"The one protein is a shared risk factor for the two most common diseases in humans--cancer and cardiovascular disease," he said. "We will explore whether we can target one protein to reduce the incidence of the two most common human diseases."

NASA's OSIRIS-REx mission is on the brink of discovering the extent of the mess it made on asteroid Bennu's surface during last fall's sample collection event. On Apr. 7, the OSIRIS-REx spacecraft will get one last close encounter with Bennu as it performs a final flyover to capture images of the asteroid's surface. While performing the flyover, the spacecraft will observe Bennu from a distance of about 2.3 miles (3.7 km) - the closest it's been since the Touch-and-Go Sample Collection event on Oct. 20, 2020.

The OSIRIS-REx team decided to add this last flyover after Bennu's surface was significantly disturbed by the sample collection event. During touchdown, the spacecraft's sampling head sunk 1.6 feet (48.8 centimeters) into the asteroid's surface and simultaneously fired a pressurized charge of nitrogen gas. The spacecraft's thrusters also mobilized a substantial amount of surface material during the back-away burn. Because Bennu's gravity is so weak, these various forces from the spacecraft had a dramatic effect on the sample site - launching many of the region's rocks and a lot of dust in the process. This final flyby of Bennu will provide the mission team an opportunity to learn how the spacecraft's contact with Bennu's surface altered the sample site and the region surrounding it.

The single flyby will mimic one of the observation sequences conducted during the mission's Detailed Survey phase in 2019. OSIRIS-REx will image Bennu for 5.9 hours, which is just over a full rotation period of the asteroid. Within this timeframe, the spacecraft's PolyCam imager will obtain high-resolution images of Bennu's northern and southern hemispheres and its equatorial region. The team will then compare these new images with the previous high-resolution imagery of the asteroid obtained during 2019.

Most of the spacecraft's other science instruments will also collect data during the flyover, including the MapCam imager, the OSIRIS-REx Thermal Emission Spectrometer (OTES), the OSIRIS-REx Visible and Infrared Spectrometer (OVIRS), and the OSIRIS-REx Laser Altimeter (OLA). Exercising these instruments will give the team a chance to assess the current state of each science instrument onboard the spacecraft, as dust coated the instruments during the sample collection event. Understanding the health of the instruments is also part of NASA's evaluation of possible extended mission opportunities after the sample is delivered to Earth.

After the Bennu flyby, it will take several days for the data from the flyover to be downlinked to Earth. Once the data are downlinked, the team will inspect the images to understand how OSIRIS-REx disturbed the asteroid's surface material. At this point, the team will also be able to evaluate the performance of the science instruments.

The spacecraft will remain in asteroid Bennu's vicinity until May 10, when the mission will enter its Return Cruise phase and begin its two-year journey back to Earth. As it approaches Earth, the spacecraft will jettison the Sample Return Capsule (SRC) that contains the rocks and dust collected from Bennu. The SRC will then travel through the Earth's atmosphere and land under parachutes at the Utah Test and Training Range on Sep. 24, 2023.

Once recovered, the capsule will be transported to the curation facility at the agency's Johnson Space Center in Houston, where the sample will be removed for distribution to laboratories worldwide, enabling scientists to study the formation of our solar system and Earth as a habitable planet.