Culture

In the aurora borealis on Earth, electrically charged particles of the solar wind move along the Earth's magnetic field. At high latitudes, these strike nitrogen and oxygen atoms and molecules in the upper Earth's atmosphere and cause them to glow. These kinds of or similar aurora phenomena have also been discovered on other planets and their moons. As an international team reported today in the Nature Astronomy journal, the phenomenon has now been discovered at comet Chury. The solar wind's particles are responsible for the aurora at Chury as they strike the gas around the comet, also known as the coma. "The resulting glow is one of a kind," says Marina Galand of Imperial College London, lead author of the study. "It's caused by a mix of processes, some seen at Jupiter's moons Ganymede and Europa and others at Earth and Mars."

Aurora observed in far ultraviolet light at a comet for the first time

Thanks to the analysis of data from the European Space Agency ESA's Rosetta mission, the researchers were able to prove that in the case of Chury solar wind electrons are accelerated towards the comet and strike the gas in the coma there. "Since this process is very high energy, the resulting glow is also highly energized and therefore in the ultraviolet range, which is invisible to the human eye," explains Martin Rubin, co-author of the study from the University of Bern Physics Institute.

These UV emissions had in fact been observed earlier at Chury. At that time though it was wrongly assumed that these emissions were caused by particles of sunlight, known as photons, similar to the so-called "nightglow" on Earth. "By analyzing the Rosetta data though, it was revealed that solar wind electrons are the reason for the glow and not in fact photons, as previously assumed," continues Galand.

"Rosetta is the first mission to observe an ultraviolet aurora at a comet," says Matt Taylor, ESA project scientist. "Auroras are inherently exciting - and this excitement is even greater when we see one somewhere new, or with new characteristics".

Data on gas composition from Bern

"The analysis was complicated and required data from various instruments," explains Kathrin Altwegg, head of ROSINA, the mass spectrometer at the University of Bern, which had collected data from comet Chury on board ESA's Rosetta space probe, providing information on the composition and density of the coma, among other things. According to Kathrin Altwegg, the study is evidence that our understanding can be deepened and new insights gained by using data from different teams, instruments and computer models. "And this even years after the official end of the mission in 2016 with the controlled crash of the Rosetta probe onto comet Chury's surface," continues Altwegg.

For the current study, Marina Galand and her team analyzed data from the Rosetta Orbiter Spectrometer for Ion and Neutral Gas Analysis (ROSINA) and the Alice UV spectrograph, Rosetta Plasma Consortium (RPC) Ion and Electron Spectrometer (IES) and the Langmuir Probe (LAP), the Microwave Instrument for the Rosetta Orbiter (MIRO) and the Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS).

Aurora as a tool for observing the solar wind

Aurora phenomena are observed in the most diverse environments in our solar system and beyond. "A magnetic field like the one on Earth is not needed for this, as comet Chury does not have one itself," explains Martin Rubin. The aurora phenomenon at Chury is therefore more diffuse than on Earth. "The observation of cometary aurora phenomena definitely has an aesthetic value. Beyond that the UV observations from Earth could one day also provide information about the solar wind at these comets - even without a space probe like Rosetta being on site," explains Martin Rubin.

Is the heat still bearable, or should I take my hand off the hotplate? Before the brain can react appropriately to pain, it must evaluate and integrate sensory, cognitive and emotional factors that modulate the perception and processing of the sensation itself. This task requires the exchange of information between different regions of the brain. New studies have confirmed that there is a link between the subjective experience of pain and the relative levels of neural activity in functional structures in various sectors of the brain. However, these investigations have been carried out primarily in contexts in which the perception of pain was intensified either by emotional factors or by consciously focusing attention on the painful stimulus. Now, LMU neuroscientist Enrico Schulz, in collaboration with colleagues at the University of Oxford, has asked how cognitive strategies that affect one's subjective perception of pain influence the patterns of neural activity in the brain.

In the study, 20 experimental subjects were exposed to a painful cold stimulus. They were asked to adopt one of three approaches to attenuating the pain: (a) counting down from 1000 in steps of 7, (b) thinking of something pleasant or beautiful, and (c) persuading themselves - by means of autosuggestion - that the stimulus was not really that bad. During the experimental sessions, the subjects were hooked up to a 7T magnetic resonance imaging (MRI) scanner to visualise the patterns of neural activity in the brain, which were later analysed in detail.

In order to assess the efficacy of the different coping strategies, participants were also asked to evaluate the subjective intensity of the pain on a scale of 0 to 100. The results revealed that the countdown strategy was the most effective of the three methods. "This task obviously requires such a high level of concentration that it distracts the subject's attention significantly from the sensation of pain. In fact some of our subjects managed to reduce the perceived intensity of pain by 50%," says Schulz. "One participant later reported that she had successfully adopted the strategy during the most painful phase of childbirth."

In a previous paper published in the journal Cortex in 2019, the same team had already shown that all three strategies help to attenuate the perception of pain, and that each strategy evoked a different pattern of neural activity. In the new study, Schulz and his collaborators carried out a more detailed analysis of the MRI scans, for which they divided the brain into 360 regions. "Our aim was to determine which areas in the brain must work together in order to successfully reduce the perceived intensity of the pain," Schulz explains. "Interestingly, no single region or network that is activated by all three strategies could be identified. Instead, under each experimental condition, neural circuits in different brain regions act in concert to varying extents."

The attenuation of pain is clearly a highly complex process, which requires a cooperative response that involves many regions distributed throughout the brain. Analysis of the response to the countdown technique revealed close coordination between different parts of the insular cortex, among other patterns. The imaginal distraction method, i.e. calling something picturesque or otherwise pleasing to mind, works only when it evokes intensive flows of information between the frontal lobes. Since these structures are known to be important control centres in the brain, the authors believe that engagement of the imaginative faculty may require a greater degree of control, because the brain needs to search through more 'compartments' - to find the right memory traces, for instance. Comparatively speaking, counting backwards stepwise - even in such awkward steps - is likely to be a more highly constrained task. "To cope with pain, the brain makes use of a recipe that also works well in other contexts," says Anne Stankewitz, a co-author of the new paper: "success depends on effective teamwork." Her team now plans to test whether their latest results can be usefully applied to patients with chronic pain.

Klebsiella pneumoniae is a nosocomial pathogen in outbreaks of hospital infections. It is one of the major factors for morbidity and mortality in hospitalized patients especially those infected with colistin resistant pathogens. Many plant essential oils have antimicrobial activities and have been investigated as natural sources to combat multiple antibiotic resistances. Moreover; recent advances in phytonanotechnology have created exciting opportunities for the management of many infections.

This study aims at investigating the antimicrobial and antibiofilm effect of rosemary and ginger essential oil-based nano-sized formulations on colistin resistant K. pneumonia clinical isolates.

Isolation and identification of 30 K. pneumonia isolates from different human samples was done followed by antibiotic susceptibility testing and detection of biofilm gene (mrkD). Examination of the activity of the tested essential oils and their chitosan nanoparticle formulations against the selected isolates was made by determination of their MICs using broth microdilution method followed by biofilm inhibition test and quantitative real-time PCR for the expression of mrkD gene in the presence of the oils and nanoparticles formulations compared to untreated bacterial isolates.

Our results showed that the minimum inhibitory concentrations of rosemary and ginger oils were found to be 1250 μg/ml, nanostructured lipid carrier-rosemary oil and nanostructured lipid carrier-ginger oil were 625 μg/ml and rosemary oil loaded chitosan nanoparticles and ginger oil loaded chitosan nanoparticles were 156 μg/ml. Results also revealed complete (100%) inhibition for mrkD gene expression when compared to untreated K. pneumonia.

We can conclude that oil loaded chitosan nanoparticles show a high antimicrobial and antibiofilm activity.

The concept of sustainable nature tourism plays a key role in mediating conflicts between tourism and nature conservation, a new study from the University of Eastern Finland shows.

The study takes a geo-historical approach to analysing the environmental conflict surrounding the founding of Koli National Park in Finland, where the idea of sustainable nature tourism was used as a way out of the conflict. In Koli National Park, sustainable nature tourism has proven to be useful concept for conflict resolution.

"Adopting the principles of sustainable nature tourism helped the national park's management to reach nature conservation goals. Moreover, the hopes and wishes of local residents and companies on how to develop tourism and the economy were also taken into consideration as part of sustainability, and this fostered a positive attitude towards the national park among locals," Researcher Jani Karhu from the University of Eastern Finland says.

The study was published in Tourism Geographies. The researchers interviewed managers and designers of Koli National Park, and they also analysed local newspaper articles.

National parks are a key instrument of nature conservation, and one of the most recognised institutions in nature tourism worldwide. Koli National Park was founded in 1991. The founding of the park was preceded by heated debate over whether the area should be developed into a modern resort for mass tourism, or whether its unique national landscape and nature should be protected. In Koli, the approach to solving the conflict was through sustainable nature tourism.

"Creating more jobs, preventing environmental harm, guaranteeing the satisfaction of tourists, and operating within the local cultural and social frameworks all constitute part of sustainable tourism. All of these aspects should be developed equally."

Emphasis on economy fuels new conflicts

In the early 2000s, the concept of sustainable nature tourism was largely accepted as a principle that guided the planning and management of Finnish national parks. Nowadays, this principle is widely accepted also among tourism developers. However, there are also indications that the concept of sustainable nature tourism is used for green washing extensive tourism projects. In Koli, too, the past few years have witnessed the revival of large projects that have failed in the past.

"These economy-driven ideas of sustainability push the idea of sustainable nature tourism away from nature itself, and serve as fuel for new conflicts," Karhu points out.

History awareness and cultural heritage are becoming part of nature tourism

Funded by Kone Foundation, the study constitutes part of the geo-historical research project Lively Border: The Nature Tourism and History Politics in the Finnish-Russian-Norwegian Border Region, focused on the historical sites and conservation areas within the Finnish-Russian-Norwegian border region. In the Fennoscandian Green Belt, history awareness and cultural heritage are only now becoming part of an eco-friendly tourism concept that is based on natural heritage.

"In the future we may have large Green Parks, a new type of conservation area, which doesn't push people away but rather highlights coexistence with nature, interaction with other people, and well-being," says Professor Maria Lähteenmäki, the project's Principal Investigator.

Homicides near schools negatively impact on the educational attainment of children, a new study in the Journal of Labor Economics reports.

During this unique study, researchers from the University of Surrey and University of Birmingham investigated if exposure to homicides had an impact on the educational outcomes of children in schools close by.

According to statistics from the World Bank, Brazil has one of the highest homicide rates in the world. The rate of homicides in the country is more than 29 per 100,000 people, which is approximately 6 times the US rate and 29 times the UK rate. To estimate the effect of these homicides on educational outcomes, researchers used georeferenced data from 2,470 homicides in Sao Paulo and linked these to nearby schools, comparing test scores, attendance of students and school progression.

Researchers found that when a homicide occurred within the close vicinity of a school (25 metre radius), children's math test scores decreased by 5 per cent of a standard deviation and similar-sized effects on Portuguese language test scores were found. This effect is of a similar magnitude to reducing the quality of teachers by one standard deviation. Interestingly, it was found that boys' attainment levels were more affected by exposure to violence than girls', both for math and language test scores.

Exposure to violence also negatively impacted attendance of students. Researchers found that for each additional homicide in the vicinity of a school, attendance was reduced by 1 per cent in the school year. Similarly to attainment scores, exposure to homicide impacted attendance rates of boys more than girls. However, an in-depth analysis of the data indicated that the reduction in attendance is unlikely to be the main reason for the decline in student achievement.

Researchers also investigated the impact of violence in the vicinity of a school on the aspirations and attitudes towards education. It was found that when exposed to homicides, boys changed their attitude towards education and generally displayed less interest in further education, had a more negative perception about their performance at school, and demonstrated lower effort towards education, whereas for girls no negative effect on this area was identified.

Dr Martin Foureaux Koppensteiner, Senior Lecturer in the School of Economics at the University of Surrey, said: "Violence has a negative effect on the education of exposed children and has the potential to damage their and their communities' futures. Boys, more so than girls, are affected by violence close to their schools, which may contribute to the reversed gender gap in education observed in Brazil and other Latin American countries."

Dr Livia Menezes from the University of Birmingham added: "In middle-income countries like Brazil, individuals from a lower socioeconomic background are disproportionally more exposed to violence. If this exposure also has an impact on their human capital accumulation, violence can be an important mechanism resulting in the persistence of poverty."

Confuciusornis was a crow-like fossil bird that lived in the Cretaceous ~120 million years ago. It was one of the first birds to evolve a beak (Fig. 1). Early beak evolution remains understudied. Using an imaging technique called Laser-Stimulated Fluorescence, researchers at the University of Hong Kong (HKU) address this by revealing just how different the beak and jaw of Confuciusornis were compared to birds we see today.

Laser-Stimulated Fluorescence (LSF) is an imaging technique co-developed at HKU that involves shining a laser onto a target. It is well-known in palaeontology for making fossil bones and the soft tissues preserved alongside them glow-in-the-dark. LSF has revealed fine skin details and other previously-invisible soft tissue in a wide range of fossils, especially those of early birds and other feathered dinosaurs (see notes).

HKU PhD student Case Vincent Miller and his supervisor Research Assistant Professor Dr. Michael Pittman (Vertebrate Palaeontology Laboratory, Division of Earth and Planetary Science & Department of Earth Sciences) led this study with Thomas G. Kaye of the Foundation for Scientific Advancement (Arizona, USA) and colleagues at the Shandong Tianyu Museum of Nature (Pingyi, China). Under LSF, which was co-developed by Dr. Pittman and Mr. Kaye, the team revealed the fingernail-like 'soft beak' of Confuciusornis, a feature that covers the beak of every bird and is called the rhamphotheca. The example the team found in Confuciusornis was preserved detached from the bony part of the beak (Fig. 2). "Fossilised rhamphothecae have been reported in fossil birds before," said Dr. Pittman, "but no one has really asked what they tell us about the earliest beaked birds."

The international research team reconstructed what the beak looked like in life (Fig. 3), and used this to consolidate knowledge of the beak of Confucusornis across all known specimens. In highlighting that the rhamphotheca was easily-detachable and by performing the first test of jaw strength in a dinosaur-era bird, the team suggested that this early beaked bird was suited to eating soft foods (Fig. 4). Finally, the team highlight differences in how the beak is assembled to show that despite looking like living birds, the early beaks of Confuciusornis and its close relatives are fundamentally different structures to those seen in modern birds.

Regarding future plans, Mr. Miller said, "Our research has raised a lot of interesting questions going forward. We know so little about fossil rhamphothecae and plan on using LSF to study even more fossils to find more of these hidden gems. I am particularly interested in seeing whether beak attachment strength in living birds has any correlation with the overall strength of their jaw. This might help us to better understand fossil birds. This study is only the first glimpse into this interesting and new line of study into early beaks, so I am very excited."

Some of the genetic differences that have arisen between domesticated chickens and their wild ancestors, the red junglefowl, are linked to epigenetic changes, according to a new study published in Nature Ecology & Evolution. Scientists at Linköping University in Sweden have discovered a small number of "hotspots" in the DNA that control epigenetic changes at hundreds of other locations throughout the genome.

Humans started to domesticate certain wild animals, including chickens, several thousand years ago, and change their characteristics through breeding. Domestication led to considerable differences between the domesticated variant and their wild counterpart with respect to behaviour, anatomy and physiology. The largest differences, however, have often arisen relatively recently, during the past few hundred years. Controlled breeding of chickens in the 20th century has led to two different types: laying hens for egg production and broilers that give more meat. A broiler chicken, for example, weighs 6-7 times more than its wild ancestor, the red junglefowl.

Not only do modern domesticated chickens differ in their properties from the junglefowl, they also have differences in their genetic material, in a part of the material known as the "epigenetic code". Epigenetic changes can be thought of as small flags that sit on the DNA. They can regulate how the genes are expressed and in this way affect the properties of the organism.

The scientists who conducted the new study wondered whether the epigenetic differences between modern domesticated chickens and their wild relatives play a role in driving the rapid change associated with domestication. They investigated this in an advanced cross-breed between the junglefowl and a certain type of domesticated chicken. By crossing these with each other through eight generations, the researchers bred chickens whose genetic material is a random mixture of very short fragments of "domesticated DNA" and "wild DNA". They identified markers in the genetic material to make it possible to see which small fragments came from the junglefowl and which came from the domesticated chicken. They could then study the genetic material at very high resolution.

The research group has previously investigated how the expression of certain genes regulates fear behaviour in chickens, which is one of the properties that differ significantly between domesticated chickens and their wild ancestors. The scientists could now measure the most common type of epigenetic marker, DNA methylation, in specimens from exactly the same area of the brain, the hypothalamus. They could then use advanced calculations to see the relationships between the methylation pattern, gene expression, mutations in the genome, and the behavioural properties of the individual animal.

"We found long, continuous parts of the genetic material where it seemed that the domestication process has caused lower levels of methylation in domesticated chickens than in the wild junglefowl. We also found several 'hotspots' - parts of the genetic material that regulate the methylation at hundreds of other locations separated by long distances. This is extremely exciting", says Dominic Wright, professor in the Department of Physics, Chemistry and Biology (IFM) at Linköping University. He has led the study, which has now been published in Nature Ecology & Evolution.

It was initially believed that the methylation of DNA always reduces gene expression, leading to changed properties, but it is now necessary to modify this as research has shown that the true picture is not quite as simple, with methylation both increasing and reducing gene expression. This study shows that, while it is true that methylation influences the expression of certain genes, the inverse can also happen: a mutation in the DNA may influence gene expression, which in turn can regulate methylation.

"It's extremely interesting that the methylation of specific parts of the genetic material seems to be so carefully controlled. The study shows that the regulation of methylation during the domestication of chickens has been extremely complex", says Dominic Wright.

This study has looked at the regulation of methylation in the cross-breeds between wild and domesticated chickens. The scientists are now planning the next step. They are curious about what happens to the methylation pattern when domesticated chickens become feral, and slowly but surely adapt to life in the wild. They have already started to investigate fowl populations on Hawaii, where feral chickens are found that are cross-breeds between junglefowl and domestic chickens without human interference. This will allow them to see how DNA methylation is regulated in wild chickens in natural environments.

Capecitabine is a chemotherapy drug used for breast and colorectal Cancer cancer. It can extend survival rate by nearly 10%. However, recent studies revealed that almost 50% of patients develop palmar-plantar erythrodysesthesia, a skin reaction also called hand-foot syndrome with mild to serious symptoms. Up to 17% of these patients can have a burning pain in their hands or feet that can prevent them from doing their usual activities. This adverse reaction is the main cause of dose reductions or therapy delays, with dangerous consequences for cancer patients.

There is, therefore, a pressing need to find predictive markers to identify those patients that are more likely to have this toxic reaction before the treatment starts. Patients might be classified according to their genetic risk and get personalised treatment accordingly.

Recently, a team of researchers led by Anna González-Neira, Head of the Human Genotyping-CEGEN Unit at the Spanish National Cancer Research Centre (CNIO), identified genetic markers associated with a higher risk to develop capecitabine-induced hand-foot syndrome. The study is being published in Clinical Pharmacology & Therapeutics.

The team carried out a genome-wide association study (GWAS) analysing more than 600,000 genetic variants across the genome in 166 patients treated with capecitabine in three major hospitals: Gregorio Marañón University Hospital, Virgen de la Victoria Hospital and San Carlos Clinical Hospital.

"Our study identified regulatory variants that affect the levels of CDH4 mRNA and the protein it encode (R-cadherin), which is key to maintaining the normal structure of the skin," explains Anna González Neira, corresponding author of the study. "The association of the genetic variants with the risk of developing the above-mentioned skin condition was replicated in a independent cohort of 85 new patients and validated in several functional studies," she adds.

The CDH4 gene encodes R-cadherin, a protein in the epidermis that plays a relevant role in maintaining the good condition of the skin. The CNIO researchers found that patients who developed hand-foot syndrome during chemotherapy with capecitabine carried these regulatory variants that resulted in the reduced expression of CDH4, as compared to other patients.

"In addition, in human cell cultures, CDH4 down-regulation resulted in the reduced expression of involucrin, another skin protein that is essential for the skin barrier function," González-Neira remarks.

In their observation of the normal skin of cancer patients before starting the treatment, the scientists at CNIO found that the patients with the alleles associated with a risk to develop the hand-foot syndrome had low levels of R-cadherin and involucrin before chemotherapy with capecitabine. The study results indicate that low levels of these two proteins could contribute to increase the cytotoxic effects of the drug. "This effect can be extremely severe in the palms of the hands and the soles of the feet for a number of reasons: epidermal cells divide at a high rate, there is a pressure and temperature effect on the palms and soles, and the numerous sweat glands on these parts of the body have a high drug concentration."

To conclude, the authors of the study detected genetic markers that, together with the levels of R-cadherin and involucrin, could be useful biomarkers to identify patients with a higher risk to develop hand-foot syndrome. "Oncologists could then decide to take preventive measures for these patients, like dose reduction or treatments with alternative drugs."

(Boston)-- Responding to the COVID-19 pandemic caused by the novel coronavirus, SARS-CoV-2, requires models that can duplicate disease development in humans, identify potential targets and enable drug testing. Specifically, access to primary human lung in vitro model systems is a priority since a variety of respiratory epithelial cells are the proposed targets of viral entry.

Now, a team of infectious disease, pulmonary and regenerative medicine researchers at Boston University, studying human stem cell-derived lung cells called type 2 pneumocytes, infected with SARS-CoV-2, have shown that the virus initially suppresses the lung cells' ability to call in the help of the immune system with interferons to fight off the viral invaders and instead activates an inflammatory pathway called NFkB. "The infected lung cells pour out inflammatory proteins. In the body of an infected person, those proteins drive up levels of inflammation in the lungs," explains corresponding author Darrell Kotton, MD, the David C. Seldin Professor of Medicine at BUSM and Director of the BU/BMC Center for Regenerative Medicine (CReM).

According to the researchers, the inflammatory signals initiated by the infected pneumocytes attract an army of immune cells into lung tissue laden with infected and already dead and dying cells. "Our data confirms that SARS-CoV-2 blocks cells from activating one of the anti-viral branches of the immune system early on after infection has set in. The signal the cells would typically send out, a tiny protein called interferon that they exude under threat of disease, are instead delayed for several days, giving SARS-CoV-2 plenty of time to spread and kill cells, triggering a buildup of dead cell debris and other inflammation," added Kotton.

The data is based on experiments the research team performed in the laboratory of co-senior author Elke Mühlberger, PhD, associate professor of microbiology at BUSM and a researcher at BU's National Emerging Infectious Diseases Laboratories (NEIDL). Kotton and other members of the CReM have developed sophisticated models of human lung tissue--three-dimensional structures of lung cells, called "lung organoids," grown from human stem cells--which they've used at BU and with collaborators elsewhere to study a range of chronic and acute lung diseases.

The research team, led by co-first authors, Jessie Huang, PhD, Kristy Abo, BA, Rhiannon Werder, PhD and Adam Hume, PhD, adapted an experimental model previously used to study the effects of smoking cigarettes to study the coronavirus in lung tissue. Droplets of live coronavirus were then added on top of the lung cells, infecting them from the air the way the virus infects cells lining the inside of the lungs when air containing the virus is breathed into the body. "This adaptation of human stem cell-derived pneumocytes to air, known as an 'air-liquid interface' cell culture was a key advance that allowed us to simulate how SARS-CoV-2 enters cells deep in the lungs of the most severely affected patients," said co-senior author Andrew Wilson, MD, associate professor of medicine at BUSM. "Type 2 pneumocytes are also infected and injured in patients with COVID-19, making this a clinically meaningful system to understand how the disease injures patient lungs."

Wilson and Kotton, are also pulmonary and critical care physicians taking care of patients with COVID-19 pneumonia at Boston Medical Center, while also leading their laboratories to produce the human lung cells that were then transported into the NEIDL. There Hume, a senior research scientist in the Mühlberger's lab, worked in a BSL-4 suit to perform the infections of the cells that the three collaborating teams then analyzed together through weekly zoom calls.

"These cells are an amazing platform to study SARS-CoV-2 infection," adds Mühlberger. "They likely reflect what is going on in the lung cells of COVID-19 patients. If you look at the damage SARS-CoV-2 inflicts on these cells, you definitely don't want to get the disease."

An international team of astrophysicists has found distinctive signatures of black hole event horizon, unmistakably separating them from neutron stars -- objects, comparable to black holes in mass and size but confined within a hard surface. This is by far the strongest steady signature of stellar-mass black holes to date. The team consisting of Mr. Srimanta Banerjee and Professor Sudip Bhattacharyya from the Tata Institute of Fundamental Research, India, and Professor Marat Gilfanov and Professor Rashid Sunyaev from Max Planck Institute for Astrophysics, Germany and Space Research Institute of Russian Academy of Sciences, Russia is publishing this research in a paper that has been accepted for publication in Monthly Notices of the Royal Astronomical Society.

A black hole is an exotic cosmic object without a hard surface predicted by Einstein's theory of General Relativity. Although it does not have a surface, it is confined within an invisible boundary, called an event horizon, from within which nothing, not even light, can escape. Definitive proof of the existence of such objects is a holy grail of modern physics and astronomy.

Only one supermassive black hole -- with the mass more than 6 billion times the mass of the Sun -- has so far been imaged using the surrounding radiation in radio wavelengths. But stellar-mass black holes -- with masses of about ten times the mass of the Sun -- should bend the spacetime around them at least ten thousand trillion times more than such a supermassive black hole does. Such smaller black holes are therefore indispensable to probe some extreme aspects of nature. When these smaller black holes merge with each other, they could be inferred from gravitational waves. Such waves are transient events, lasting for a fraction of a second and it is of immense interest to have a definitive proof of the existence of a stable stellar-mass black hole, which shine mainly in X-rays by devouring material from a companion star.

A neutron star, the densest known object in the universe with a hard surface, can also shine in X-rays by accreting matter from a companion star in a similar way, characterized by extremely high efficiency of conversion of the rest-mass energy mc2 to radiation, of the order of 20%. In order to prove the existence of stellar-mass black holes, one needs to distinguish them from such neutron stars. The authors of this research have done exactly that. Using the archival X-ray data from the now decommissioned astronomy satellite Rossi X-Ray Timing Explorer, they have identified the effect of the lack of hard surface on the observed X-ray emission, and thus have found an extremely strong signature of accreting stellar-mass black holes.

Scientists from the University of Bristol and the Royal Veterinary College (RVC) used three-dimensional computer modelling to investigate the hindlimb of Euparkeria capensis-a small reptile that lived in the Triassic Period 245 million years ago-and inferred that it had a "mosaic" of functions in locomotion.

The study, which was published today in Scientific Reports, was led by researcher Oliver Demuth, joined by Professors Emily Rayfield (Bristol) and John Hutchinson (RVC). Their new micro-computed tomography scans of multiple specimens revealed unprecedented information about the previously hidden shape of the hip bones and structure of the foot and ankle joint.

Euparkeria has been known from numerous fossil specimens since the early 1900s and was found to be a close relative of the last common ancestor of both crocodiles and birds. While birds and crocodiles show different locomotion strategies, two-legged birds with an upright (erect) posture, shared with two and four-legged dinosaurs, and crocodiles having a four-legged (quadrupedal) sprawling posture, their ancestor once shared a common mode of locomotion and Euparkeria can provide vital insight into how these differences came to be.

The authors' new reconstruction of the hip structure showed that Euparkeria had a distinctive bony rim on the pelvis, called a supra-acetabular rim, covering the top of the hip joint. This feature was previously known only from later archosaurs on the line to crocodiles and often was used to infer a more erect posture for these animals; reversed in crocodiles as they became more amphibious. The hooded rim allowed the pelvis to cover the top of the thigh bone and support the body with the limbs in a columnar arrangement; hence this type of joint is called 'pillar-erect'. Euparkeria is so far the earliest reptile with this structure preserved. Could it therefore have assumed a more erect, rather than more sprawling, posture as well?

To test how the hindlimb could or could not have moved in life, the team estimated how far the thigh bone could have rotated until it collided with the hip bones, and their models addressed how the ankle joint could have been posed, too. The computer simulations suggested that while the thigh bone could have been held in an erect posture, the foot could not have been placed steadily on the ground due to the way the foot rotates around the ankle joint, implying a more sprawling posture. However, the bony rim covering the hip joint restricted the movement of the thigh bone in a way that is unknown in any living animal capable of a more sprawling gait, hinting at a more upright posture.

The team's simulations thus revealed seemingly contradictory patterns in the hip and ankle joint. While Euparkeria is so far the earliest reptile with this peculiar hip structure, an ankle joint allowing a more erect posture appeared later on in Triassic archosaurs. Dr John Hutchinson, Professor of Evolutionary Biomechanics at the RVC, commented:

"The mosaic of structures present in Euparkeria, then, can be seen as a central stepping-stone in the evolution of locomotion in archosaurs."

First author Oliver Demuth, research technician at the RVC and former Masters student at the University of Bristol, commented:

"The hip structure of Euparkeria was extremely surprising, especially as it functionally contradicts the ankle joint. Previously it was thought that both were linked and evolved synchronously. However, we were able to demonstrate that these traits were in fact decoupled and evolved in a step-wise fashion."

Dr Emily Rayfield, Professor of Palaeobiology at the University of Bristol commented:

"This approach is exciting because Using CT scan datasets and computer models of how the bones and joints fitted together has allowed us to test long-standing ideas of how these ancient animals moved and how the limbs of the earliest ancestors of birds, crocodiles and dinosaurs may have evolved"

Doctors like to remind patients not to monkey around with their health, suggesting that a good diet and regular exercise improve longevity.

A new study on health in chimpanzees, which are the closest species to humans genetically, showed the benefits in what they eat and how they can travel and climb.

When chimpanzees have a plant-based diet and substantial opportunities to exercise, they fall into "healthy" human ranges. Lab chimpanzees, whose diet and exercise were limited, showed conditions indicative of cardiovascular disease risk, more like sedentary people.

Chimpanzees are critical for understanding the evolution of human health and longevity. Cardiovascular disease--a major source of mortality during aging in humans--is a key issue for comparative medicine.

Prior data indicated that compared to humans, chimpanzees have high levels of blood lipids that can promote cardiovascular disease in humans. However, most work on chimpanzee heart health comes from the animals living in laboratories where lifestyles diverge from a wild context.

Researchers from the University of Michigan and University of New Mexico partnered with wildlife veterinarians in Uganda and Congo to examine cardiovascular profiles in chimpanzees living in African sanctuaries. These chimpanzees occupy large rainforest enclosures, consume a diet of fruits and vegetables, and generally experience conditions more similar to a wild chimpanzee lifestyle.

They measured blood lipids, body weight and body fat in 75 sanctuary chimpanzees during annual veterinary health check-ups, and then compared them to published data from laboratory-living chimpanzees.

Free-ranging chimpanzees in sanctuaries exhibited lower body weight and lower levels of lipids, both risk factors for human cardiovascular disease. Some of these disparities increased with age, indicating that the free-ranging chimpanzees stayed healthy as they got older.

"Our findings support the hypothesis that lifestyle shapes health in chimpanzees, similar to effects in humans, and contribute to an emerging understanding of cardiovascular health in evolutionary context," said Alexandra Rosati, U-M assistant professor of psychology and anthropology.

This is the first evidence that chimpanzees show differences in blood lipids related to their lifestyle, such as diet and ranging opportunities, and indicates that these health effects in humans are rooted in our evolutionary past, said Megan Cole, a researcher at the University of New Mexico and the study's lead author.

Prior work suggested that chimpanzees have very high levels of blood lipids that are cardiovascular risk factors--higher than humans in post-industrial societies in some cases. The work also showed that chimpanzees living a naturalistic life have much lower levels even as they age, providing a new reference for understanding human health. In biomedical research labs, chimpanzees have more limited space and often consume a processed diet (food such as primate chow), unlike wild chimpanzees.

"These results show how the high-quality, natural conditions that chimpanzees experience in African sanctuaries fosters their long-term health," Rosati said.

PITTSBURGH, Sept. 21. 2020 - Researchers at the University of Pittsburgh School of Medicine and Carnegie Mellon University College of Engineering have created a machine-learning algorithm that can detect subtle signs of osteoarthritis--too abstract to register in the eye of a trained radiologist--on an MRI scan taken years before symptoms even begin. These results will publish this week in PNAS.

With this predictive approach, patients could one day be treated with preventative drugs rather than undergoing joint replacement surgery.

"The gold standard for diagnosing arthritis is x-ray. As the cartilage deteriorates, the space between the bones decreases," said study co-author Kenneth Urish, M.D., Ph.D., associate professor of orthopaedic surgery at Pitt and associate medical director of the bone and joint center at UPMC Magee-Womens Hospital. "The problem is, when you see arthritis on x-rays, the damage has already been done. It's much easier to prevent cartilage from falling apart than trying to get it to grow again."

Right now, the primary treatment for osteoarthritis is joint replacement. And the condition is so prevalent that knee replacement is the most common surgery in the U.S. for people over age 45.

For this study, the researchers looked at knee MRIs from the Osteoarthritis Initiative, which followed thousands of people for seven years to see how osteoarthritis of the knee develops. They focused on a subset of patients who had little evidence of cartilage damage at the beginning of the study.

In retrospect, we now know which of these participants went on to develop arthritis and which didn't, and the computer can use that information to learn subtle patterns on the MRI scans of presymptomatic people that are predictive of their future osteoarthritis risk.

"When doctors look at these images of the cartilage, there isn't a pattern that jumps out to the naked eye, but that doesn't mean there's not a pattern there. It just means you can't see it using conventional tools," said lead author Shinjini Kundu, M.D., Ph.D., who completed this project as part of her graduate training in the Pitt Medical Scientist Training Program and Carnegie Mellon Department of Biomedical Engineering.

To validate this approach, Kundu, who now is a resident physician and medical researcher at the Johns Hopkins Department of Radiology, trained the model on a subset of the knee MRI data and then tested it on patients it had never seen before. Kundu did this dozens of times, with different participants withheld each time, to test the algorithm on all the data.

Overall, the algorithm predicted osteoarthritis with 78% accuracy from MRIs performed three years before symptom onset.

Currently, there are no drugs that prevent presymptomatic osteoarthritis from developing into full-blown joint deterioration, though there are a few highly effective drugs that can prevent patients from developing a related condition--rheumatoid arthritis.

The goal is to develop the same types of drugs for osteoarthritis. Several candidates already are in the preclinical pipeline.

"Instead of recruiting 10,000 people and following them for 10 years, we can just enroll 50 people who we know are going to be getting osteoarthritis in two or five years," Urish said. "Then we can give them the experimental drug and see whether it stops the disease from developing."

September 21, 2020 - The amount Medicare reimburses for orthopaedic trauma surgery has fallen by nearly one-third over the past two decades, reports a study in the Journal of Orthopaedic Trauma. The journal is published in the Lippincott portfolio by Wolters Kluwer.

"When adjusted for inflation, [Medicare] reimbursement for common procedures in orthopaedic trauma surgery has steadily decreased from 2000 and 2020," according to the new research by Kenneth A. Egol and colleagues in the Department of Orthopedic Surgery at NYU Langone Health, New York City. They add: "Given increasing volumes and costs associated with medical practice in the United States, continued change may be necessary to ensure the financial health and success of physicians and hospitals caring for victims of orthopedic trauma."

'Steady Annual Decline' in Orthopaedic Trauma Surgery Reimbursements

Using publicly available data from the Centers for Medicare & Medicaid Reimbursement (CMS), the researchers examined reimbursement trends for the 20 most commonly billed surgical procedure codes in orthopaedic trauma from 2000 to 2020 - the majority of which are traumatic bone fractures requiring surgical repair with some type of hardware (internal fixation). Costs were adjusted for inflation to 2020 dollars, based on the Consumer Price Index (CPI).

During the study period, the CPI - a widely used measure of inflation - increased by 52.8 percent. Meanwhile, average Medicare reimbursement for the 20 orthopaedic trauma surgery procedures rose by only 4.9 percent, demonstrating the Government failing to keep up with increases in the cost of living.

After correction to 2020 dollars, average reimbursement for health care procedures for orthopaedic trauma decreased by 30 percent. Annual data showed a steady decline of 1.5 percent per year.

The trends varied by procedure type, with foot and ankle procedures demonstrating the sharpest drop in reimbursement: 42.6 percent. Decreases were 31.9 percent for hip fracture surgery (often a lifesaving procedure), 30.9 percent for lower extremity long bone procedures, and 23.7 percent for shoulder and upper extremity procedures.

Medicare reimbursements are calculated using "Relative Value Units" (RVUs) for individual procedures, an arbitrary multiplier that is supposed to reflect the value of the physician's work, practice expenses, and malpractice coverage. Average total RVUs for the 20 procedures increased 4.4 percent from 2000 to 2020. The majority of the increase was in malpractice RVUs, with a small decrease in practice expense RVUs - despite evidence showing that practice costs have increased in recent years.

The US healthcare system has seen major changes in policies and payment structures throughout the last several decades, including Medicare. With the aging of the population, there will be increased demand on the Medicare system to fund orthopaedic trauma surgery and fracture care in older Americans.

Orthopaedic surgery has been a major focus of Medicare payment reforms, with experiments including "bundled" payment programs for joint replacement surgery. "[T]he decisions made by the Centers for Medicare and Medicaid Services (CMS) have had a large-scale impact on reimbursement, influencing both the public and private healthcare sectors," according to the authors.

They review some of the policy actions that have led to declining Medicare reimbursements, as well as the possible impact of new initiatives designed to incentivize quality and value of care rather than quantity of care. "Despite this uncertainty regarding the future, the evidence demonstrates a clear trend of decreasing Medicare reimbursement in orthopedic trauma surgery," Dr. Egol and colleagues write.

They conclude: "Increased awareness and consideration of these trends will be important for policy-makers, hospitals, and surgeons in order to assure continued access to high quality surgical orthopedic trauma care in the United States." The authors hope their findings will serve as a "springboard" for efforts to develop sustainable policies to provide fair reimbursement for essential trauma surgery for the growing population of older adults covered by Medicare.

A discovery of more than a thousand dinosaur teeth, by a team of researchers from the University of Portsmouth, proves beyond reasonable doubt that Spinosaurus, the giant predator made famous by the movie Jurassic Park III as well as the BBC documentary Planet Dinosaur was an enormous river-monster.

Research published today in the journal Cretaceous Research proves that Spinosaurus aegyptiacus, a 15 metre long, six-tonne beast was in fact the most commonly found creature in the Kem Kem river system, which flowed through the Sahara Desert 100 million years ago.

Until recently it was believed that dinosaurs lived exclusively on land. However, research published earlier this year showed that Spinosaurus was well adapted to an aquatic lifestyle, due to its newly discovered tail. This latest research of 1,200 teeth found in the same region further supports this theory.

Scientists from the University of Portsmouth collected the fossilised remains from the site of an ancient river bed in Morocco. After analysing all of them it was discovered there was an abundance of Spinosaurus teeth, which are distinct and easily identifiable.

David Martill, Professor of Palaeobiology at the University of Portsmouth, said:

"The huge number of teeth we collected in the prehistoric river bed reveals that Spinosaurus was there in huge numbers, accounting for 45 per cent of the total dental remains. We know of no other location where such a mass of dinosaur teeth have been found in bone-bearing rock.

"The enhanced abundance of Spinosaurus teeth, relative to other dinosaurs, is a reflection of their aquatic lifestyle. An animal living much of its life in water is much more likely to contribute teeth to the river deposit than those dinosaurs that perhaps only visited the river for drinking and feeding along its banks.

"From this research we are able to confirm this location as the place where this gigantic dinosaur not only lived but also died. The results are fully consistent with the idea of a truly water-dwelling, "river monster"."

Professor Martill worked alongside two students studying for their Masters Degree in Paleontology at the University of Portsmouth.

Thomas Beevor said: "The Kem Kem river beds are an amazing source of Spinosaurus remains. They also preserve the remains of many other Cretaceous creatures including sawfish, coelacanths, crocodiles, flying reptiles and other land-living dinosaurs. With such an abundance of Spinosaurus teeth, it is highly likely that this animal was living mostly within the river rather than along its banks."

Aaron Quigley, explained the process of sorting through the teeth: "After preparing all the fossils, we then assessed each one in turn. The teeth of Spinosaurus have a distinct surface. They have a smooth round cross section which glints when held up to the light. We sorted all 1200 teeth into species and then literally counted them all up. Forty-five per cent of our total find were Spinosaurus teeth."