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An international research collaboration including Northwestern University astronomers has produced the most detailed family portrait of black holes to date, offering new clues as to how black holes form. An intense analysis of the most recent gravitational-wave data available led to the rich portrait as well as multiple tests of Einstein's theory of general relativity. (The theory passed each test.)

The team of scientists who make up the LIGO Scientific Collaboration (LSC) and the Virgo Collaboration is now sharing the full details of its discoveries. This includes new gravitational-wave detection candidates which held up to scrutiny -- a whopping total of 39, representing a variety of black holes and neutron stars -- and new discoveries as a result of combining all the observations. The 39 events averaged more than one per week of observing.

The observations could be a key piece in solving the many mysteries of exactly how binary stars interact. A better understanding of how binary stars evolve has consequences across astronomy, from exoplanets to galaxy formation.

Details are reported in a trio of related papers which will be available in pre-print on Oct. 28 at arxiv.org. The studies also are being submitted to peer-reviewed journals.

The gravitational-wave signals on which the studies are based were detected during the first half of the third observing run, called O3a, of the National Science Foundation's Laser Interferometry Gravitational-wave Observatory (LIGO), a pair of identical, 4-kilometer-long interferometers in the United States, and Virgo, a 3-kilometer-long detector in Italy. The instruments can detect gravitational-wave signals from many sources, including colliding black holes and colliding neutron stars.

"Gravitational-wave astronomy is revolutionary -- revealing to us the hidden lives of black holes and neutron stars," said Christopher Berry, an LSC member and author of the papers. "In just five years we have gone from not knowing that binary black holes exist to having a catalog of over 40. The third observing run has yielded more discoveries than ever before. Combining them with earlier discoveries paints a beautiful picture of the universe's rich variety of binaries."

Berry is the CIERA Board of Visitors Research Professor in Northwestern's CIERA (Center for Interdisciplinary Exploration and Research in Astrophysics) and a lecturer at the University of Glasgow. Other Northwestern authors include CIERA members Maya Fishbach and Chase Kimball. CIERA is home to a broad group of researchers in theory, simulation and observation who study black holes, neutron stars, white dwarfs and more.

As a member of the collaboration, Northwestern researchers analyzed data from the gravitational-wave detectors to infer the properties of detected black hole and neutron star binaries and to provide an astrophysical interpretation of these discoveries.

The papers are summarized as follows:

The "catalog paper" details the detections of black holes and neutron stars from the first half of O3a, bringing the total number of detection candidates for that period to 39. This number vastly exceeds detections from the first two observing runs. (The first run had three gravitational-wave detections, and the second had eight.) Previously announced detections from O3a include a mystery object in the mass gap (GW190814) and the first-of-its-kind intermediate mass black hole (GW190521).

In the "populations paper," the researchers reconstructed the distribution of masses and spins of the black hole population and estimated the merger rate for binary neutron stars. The results will help scientists understand the detailed astrophysical processes which shape how these systems form. This improved understanding of the mass distribution of black holes and knowing that black hole spins can be misaligned suggests there could be multiple ways for binary black holes to form.

Using the set of detections reported in the catalog paper, the researchers conducted detailed analysis by combining everything together. In what they call the "testing general relativity paper," the authors placed constraints on Einstein's theory of general relativity. The theory passed with flying colors, and they updated their best measurements on potential modifications.

"So far, LIGO and Virgo's third observing run has yielded many surprises," said Fishbach, a NASA Einstein Postdoctoral Fellow and LSC member. "After the second observing run, I thought we'd seen the whole spectrum of binary black holes, but the landscape of black holes is much richer and more varied than I imagined. I'm excited to see what future observations will teach us."

Fishbach coordinated writing of the populations paper which outlines what the collaboration has learned about the properties of the family of merging black holes and neutron stars.

Berry helped coordinate analysis as part of a global team to infer the properties of the detections, and he served as an LSC Editorial Board reviewer for the catalog and testing general relativity papers.

Graduate student Chase Kimball, an LSC member, contributed calculations of the rates of mergers to the populations paper. Kimball is co-advised by Berry and Vicky Kalogera, the principal investigator of Northwestern's LSC group, director of CIERA and the Daniel I. Linzer Distinguished University Professor of Physics and Astronomy in the Weinberg College of Arts and Sciences.

The LIGO and Virgo detectors finished their latest observing run this past March. The data analyzed in these three papers were collected from April 1, 2019, to Oct. 1, 2019. Researchers are in the process of analyzing data from the second half of the observing run, O3b.

The detectors are scheduled to resume observing next year after work is done to increase their detection range.

"Merging black hole and neutron star binaries are a unique laboratory," Berry said. "We can use them to study both gravity -- so far Einstein's general relativity has passed every test --and the astrophysics of how massive stars live their lives. LIGO and Virgo have transformed our ability to observe these binaries, and, as our detectors improve, the rate of discovery is only going to accelerate."

Centaurs are minor planets believed to have originated in the Kuiper Belt in the outer solar system. They sometimes have comet-like features such as tails and comae--clouds of dust particles and gas--even though they orbit in a region between Jupiter and Neptune where it is too cold for water to readily sublimate, or transition, directly from a solid to a gas.

Only 18 active Centaurs have been discovered since 1927, and much about them is still poorly understood. Discovering activity on Centaurs is also observationally challenging because they are faint, telescope time-intensive and because they are rare.

A team of astronomers, led by doctoral student and Presidential Fellow Colin Chandler in Northern Arizona University's Astronomy and Planetary Science PhD program, earlier this year announced their discovery of activity emanating from Centaur 2014 OG392, a planetary object first found in 2014. They published their findings in a paper in The Astrophysical Journal Letters, "Cometary Activity Discovered on a Distant Centaur: A Nonaqueous Sublimation Mechanism." Chandler is the lead author, working with four NAU co-authors, graduate student Jay Kueny, associate professor Chad Trujillo, professor David Trilling and PhD student William Oldroyd.

The team's research involved developing a database search algorithm to locate archival images of the Centaur as well as a follow-up observational campaign.

"Our paper reports the discovery of activity emanating from Centaur 2014 OG392, based on archival images we uncovered," Chandler said, "plus our own new observational evidence acquired with the Dark Energy Camera at the Inter-American Observatory in Cerro Tololo, Chile, the Walter Baade Telescope at the Las Campanas Observatory in Chile and the Large Monolithic Imager at Lowell Observatory's Discovery Channel Telescope in Happy Jack, Ariz."

"We detected a coma as far as 400,000 km from 2014 OG392," he said, "and our analysis of sublimation processes and dynamical lifetime suggest carbon dioxide and/or ammonia are the most likely candidates for causing activity on this and other active Centaurs."

"We developed a novel technique," Chandler said, "that combines observational measurements, for example, color and dust mass, with modeling efforts to estimate such characteristics as the object's volatile sublimation and orbital dynamics."

As a result of the team's discovery, the Centaur has recently been reclassified as a comet, and will be known as "C/2014 OG392 (PANSTARRS)."

"I'm very excited that the Minor Planet Center awarded a new comet designation befitting the activity we discovered on this unusual object," he said.

This week, Chandler has been invited to present the results at the 52nd Division for Planetary Sciences (DPS) of the American Astronomical Society (AAS) 2020 meeting.

Menstrual dysfunction is more prevalent in young Finnish athletes than it is among non-athletes of a similar age, but athletes experience less body weight dissatisfaction than non-athletes do. These findings are from a recent study at the Faculty of Sport and Health Sciences at the University of Jyväskylä, Finland. The study was conducted among members of sports clubs who exercised at least four times a week (athletes) and non-members (non-athletes).

The current study used data from the Finnish Health Promoting Sports Club (FHPSC) study, in which a cohort of athletes and non-athletes in adolescence (14-16 years) and subsequently in young adulthood (18-20 years) were investigated.

The findings of the study showed that in adolescence, 18% of both athletes and non-athletes reported menstrual dysfunction. However, 8% of the athletes reported primary amenorrhea (absence of menses by the age of 15) in contrast to the non-athletes group, where the prevalence of primary amenorrhea was 0%. In young adulthood, the prevalence of menstrual dysfunction in athletes was 39%, while 6% of the non-athletes reported menstrual dysfunction. In this study, menstrual dysfunction was defined as follows: primary amenorrhea, prolonged menstrual cycle (>35 days) or absence of menses for at least three consecutive months (secondary amenorrhea).

"We did not investigate the reasons for menstrual dysfunction, but we know from previous studies that one of the most common reasons for menstrual dysfunction is low energy availability (i.e., inadequate energy intake relative to exercise energy expenditure)," explains Suvi Ravi, the corresponding author and a PhD student at the Faculty of Sport and Health Sciences.

"The human body is wise, and in this kind of situation it allocates energy to the functions essential for survival and reduces energy allocation for the systems that are not so essential for life, such as reproductive function."

The present study also assessed body weight dissatisfaction among the participants. The results showed that athletes were more satisfied with their weight and had less desire to lose weight than non-athletes did. Despite this, in both age groups about 20% of the athletes and about 40% of the non-athletes reported body weight dissatisfaction.

"This is concerning since we know that body weight dissatisfaction can result in disordered eating," Ravi says.

"Attention should be paid to young people's body weight dissatisfaction as well as menstrual dysfunction in order to prevent future health problems, such as disordered eating and impaired bone mineral density, which can result from low energy availability and menstrual dysfunction."

The study, in which six Wits researchers were involved, show that these newly discovered variants were found mostly among newly sampled ethnolinguistic groups.

Researchers identified new evidence for natural selection in and around 62 previously unreported genes associated with viral immunity, DNA repair and metabolism.

They observed complex patterns of ancestral mixing within and between populations, alongside evidence that populations from Zambia was a likely intermediate site along the routes of expansion of Bantu-speaking populations.

These findings improve the current understanding of migration across the continent, and identify responses to human disease and gene flow as strong determinants of population variation.

The study contributes a new major source of African genomic data, which showcases the complex and vast diversity of African genetic variation and which will support research for decades to come.

"Africa is the continent with greatest genetic diversity and this study shows the importance of African genomic data for taking science and health research forward. It is an important step in redressing existing biases in available data for research, which hamper the study of African health problems and narrows global research," says Zané Lombard, a senior author of the study and an Associate Professor in the Division of Human Genetics in the Faculty of Health Sciences at Wits and at the National Health Laboratory Service.

Lombard led the study under the auspices of the Human Heredity and Health in Africa (H3Africa) Consortium in association with Dr Neil Hanchard, Baylor College of Medicine, Texas, U.S.A, and Dr Adebowale Adeyemo, National Human Genome Research Institute, Maryland, U.S.A.

Members of the H3Africa Consortium who contributed to this work comprise people from 24 institutions across Africa, including the Sydney Brenner Institute for Molecular Bioscience (SBIMB) in the Faculty of Health Sciences at Wits University.

The SBIMB's Dr Ananyo Choudhury, Dr Dhriti Sengupta, Professor Scott Hazelhurst and Mr Shaun Aron led analyses and writing the paper, while Professor Michèle Ramsay, director of the SBIMB, participated in developing the study design and was a principal investigator who contributed samples towards this large-scale sequencing effort.

426 INDIVIDUALS, 13 AFRICAN COUNTRIES, 50 ETHONLINGUISTIC GROUPS

The study found a vast breadth of genomic diversity among these genomes, with each ethnolinguistic group harbouring thousands of unique genetic variants.

Not only populations from the same geographic region but even those from the same country showed a great deal of variation among themselves, reflecting the deep history and rich genomic diversity across Africa.

"We used a wide variety of computational techniques to gain insights into population history, environmental adaptation, and susceptibility to diseases from these genomes", says Choudhury, first author of the study and a senior scientist at the SBIMB.

"We were able to discover over 3 million novel variants within these genomes. This was after comparison with more than 1000 African genomes in public repositories, suggesting that the potential for discovering novel genetic variants by sequencing African populations is still far from saturation."

First evidence of East Africa to Nigeria migration 50+ generations ago

In addition to contributing to the vast amount of novel variation observed in African populations, the inclusion of previously unstudied population groups in the study enabled scientists to add puzzle pieces to the jigsaw of established historical interactions and migration events on the continent.

"Inclusion of novel African genomes in our study strongly supported Zambia as an intermediate site in the Bantu-migration route to the South and East of the continent," said Mr Shaun Aron, lead analyst on the population genetics component of the study and a lecturer in the SBIMB.

Evidence supporting movement from East Africa to central Nigeria between 1500 and 2000 years ago was revealed through the identification of a substantial amount of East African ancestry, particularly Nilo-Saharan from Chad, in a central Nigerian ethnolinguistic group, the Berom.

"This highlights the complex historical movement of people on the continent and diversity of even proximally close African groups," says Aron.

VIRAL INFECTIONS MIGHT SHAPE GENOMIC DIFFERENCES

The researchers found more than 100 areas of the genome that had probably been under natural selection; a sizable proportion of which were associated with immunity related genes.

Natural selection - "selected by nature" - comes from Charles Darwin's work into survival of the fittest. It means that when individuals are exposed to certain environmental factors (diet, viral infection, etc.) some gene variants may give the humans that bear them in their genome an added advantage to survive.

"While genes involved in resistance to insect-transmitted diseases like malaria and sleeping sickness have long been known to be positively selected, our study shows that other viral infections could have also helped to shape genomic differences between people and groups by altering the frequency of genes that affect individuals' disease susceptibility," says Dr Dhriti Sengupta of the SBIMB and one of the lead analysts.

Also, the selection signals were not homogenous across the continent. Sengupta says, "There were noticeable variations in selection signals between different parts of the continent, indicating that large-scale local-adaptations might have accompanied the migration of populations to new geographies, and consequent exposure to new diets and pathogens."

Selection signals are parts of the genome that give us a signature (signal) that the specific part of the genome was under selection pressure at some point.

AFRICAN ACCESS TO PRECISION MEDICINE

Lombard, a senior author on the paper and an Associate Professor in the Division of Human Genetics at Wits, says: "The findings have broad relevance, from population genetics research into human history and migration, to clinical research into the impact of specific variants on health outcomes".

Immediate next steps include further examination of the initial findings and leveraging the data to represent more African populations.

The researchers hope their work will lead to wider recognition of the extent of uncatalogued genomic variation across the African continent and the need for continued inclusion of the many diverse populations in Africa in genomics research.

"Adding genomic data from all global populations - including Africa - is essential to ensure that everyone can benefit from the advances in health that precision medicine offers," says Lombard. Precision medicine - or 'personalised' medicine - refers to disease treatment and prevention that takes into account individual variability in genes, environment, and lifestyle for each person.

AFRICAN GENOMIC RESEARCH IN AFRICA, BY AFRICANS

The study represents a major milestone in advancing African genomics research capacity. Instead of African data being analysed elsewhere - as has been the general trend over the last decade - this research was conducted predominantly by local African researchers using local computational facilities.

Studies like this one highlight the importance of computing infrastructure and storage capacity for large data projects at Wits and in South Africa.

Infrastructure such as the computing cluster at Wits, established and managed by Professor Scott Hazelhurst, director of Wits Bioinformatics, is essential to support genomics research and growing African datasets. He says: "Initiatives such as the H3Africa Consortium have laid the foundation to foster and encourage collaborative research in Africa, which has made studies like these possible."

Professor Michèle Ramsay, director of the SBIMB, says: "This study, in a sense, announces the availability of both infrastructure and analytic skills for large-scale genomics research on the continent."

According to the Job Stress Index 2020 compiled by Stiftung Gesundheitsförderung Schweiz, a Swiss health foundation, almost one-third of the Swiss workforce experience work-related stress. Should this stress become chronic, it can lead to states of exhaustion that have a negative impact on public health and carry a significant economic cost.

The goal: a digital early warning system

At the Mobiliar Lab for Analytics at ETH Zurich, an interdisciplinary team is working to pre-empt such states of exhaustion by developing a digital early warning system that uses machine learning to detect stress in the workplace in real time. "Our first step was to find out how to measure the effects of social pressure and interruptions - two of the most common causes of stress in the workplace," says psychologist Jasmine Kerr. Kerr is driving the project forward together with mathematician Mara Nägelin and computer scientist Raphael Weibel.

The three doctoral students are all lead authors on a recent study, details of which appeared in the journal Psychoneuroendocrinology. They used a university platform to recruit 90 participants, who agreed to take part in an experiment lasting just under two hours. To conduct their experiment, Kerr, Nägelin and Weibel transformed the Decision Science Laboratory at ETH Zurich into three group office environments. Each workstation was equipped with a chair, a computer with monitor and kits for collecting samples of saliva.

Playing the parts of employees at a fictional insurance company, the participants were asked to perform typical office tasks, such as typing up information from hand-written forms and arranging appointments with clients. While they did so, the researchers observed their psychobiological responses. At a total of six points during the experiment, the participants rated their mood on questionnaires, while a portable ECG device continuously measured their heartbeat. The researchers used the saliva samples to measure the concentration of the stress hormone cortisol.

In line for a promotion

For their experiment, the researchers divided the participants into three groups and exposed each group to a different level of stress. All groups were given the same workload. In the middle of the experiment, all participants were visited by two actors masquerading as representatives of the insurance company's HR department. For participants in the control group, the actors staged a sales pitch dialogue, while in the two stress groups they pretended to be looking for the most suitable candidates for a promotion.

The difference between the two stress groups was that participants in the first group stopped work only to have samples of their saliva taken. But the participants in the second stress group had to contend with additional interruptions in the form of chat messages from their superiors urgently requesting information.

Almost twice the level of cortisol

Upon evaluation, the data indicated that asking participants to compete for a fictional promotion was enough to raise their heart rate and trigger the release of cortisol. "Participants in the second stress group released almost twice the level of cortisol as those in the first stress group," Nägelin says. Weibel adds: "Most research into workplace interruptions carried out to date focused only on their effect on performance and productivity. Our study shows for the first time that they also affect the level of cortisol a person releases, in other words they actually influence a person's biological stress response."

What surprised the researchers were participants' subjective responses in terms of how they perceived psychological stress. They observed that participants in the second stress group, who were interrupted by chat messages, reported being less stressed and in a better mood than the participants in the first stress group, who didn't have these interruptions. Interestingly, although the two groups rated the situation as equally challenging, the second group found it less threatening. The researchers inferred that the release of cortisol triggered by the additional interruptions mobilised more physical resources, which in turn led to a better emotional and cognitive response to stress. It is also possible that the interruptions distracted the participants from the impending social stress situation, meaning that they felt less threatened and thus less stressed.

Enzymes enable biochemical reactions that would otherwise not take place on their own. In nature, it is mostly proteins that function as enzymes. However, other molecules can also perform enzymatic reactions - for example ribonucleic acids, RNAs. These are then called ribozymes.

In this field, the research group of chemistry professor Claudia Höbartner is now reporting a scientific breakthrough: Her team at Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, has developed a ribozyme that can attach a very specific small chemical change at a very specific location in a target RNA.

More precisely: the ribozyme transfers a single methyl group to an exactly defined nitrogen atom of the target RNA. This makes it the first known methyl transferase ribozyme in the world. Accordingly, Höbartner's group has given it the short name MTR1.

In the journal Nature the group presents details about the new ribozyme. In the target RNA, it produces the methylated nucleoside 1-methyladenosine (m1A). The methyl group is transferred from a free methylated guanine nucleobase (O6-methylguanine, m6G) in a binding pocket of the ribozyme.

Ribozymes in evolution

The ribozyme discovered at the JMU Institute of Organic Chemistry sheds light on an interesting aspect of evolution. According to the "RNA world hypothesis", RNA was one of the first information-storing and enzymatically active molecules. Ribozymes similar to those developed by Claudia Höbartner and her team may have produced methylated RNAs in the course of evolution. This in turn may have led to a greater structural and thus functional diversity of RNA molecules.

In nature, methyl groups are installed on RNAs by specialised protein enzymes. These proteins use cofactors that contain RNA-like components. "It is reasonable to assume that these cofactors could be evolutionary 'leftovers' of earlier enzymatically active RNAs. Our discovery may therefore mimic a ribozyme that has possibly been lost in nature a long time ago," says Claudia Höbartner.

In the laboratory, new or naturally extinct ribozymes can be found by a method called in vitro evolution. "It starts from many different sequences of synthetic RNA, and is analogous to finding a needle in the haystack", says co-author Mohammad Ghaem Maghami, a postdoctoral researcher in the Höbartner group.

New ribozyme also acts on natural RNA

The authors have also been able to show that MTR1 can install a single methyl group not only on synthetic RNA structures but also on natural RNA strands found in cells.

This news is likely to attract great attention from cell biologists, among others. The reason for this is that the methylation of RNA can be considered as a biochemical on or off switch. It has a key role in the functioning of RNA structures and can control many life processes in the cell.

The newly developed ribozyme MTR1 is expected to be a useful tool for a wide range of research areas in the future. "For example, it could help to better understand the interaction of methylation, structure, and function of RNA," explains JMU PhD student Carolin Scheitl, the first author of the publication in Nature.

The next steps of the researchers

Many new projects will build on these results. Höbartner's group intends to solve the structure of their new ribozyme and reveal the detailed chemical mechanism of the RNA-catalyzed methylation. With the methods now established, her team will also be able to develop ribozymes for a variety of other reactions.

According to the JMU professor, these ribozymes also offer an excellent possibility to control Watson-Crick base pairing and to install fluorescent labels for RNA imaging.

BUFFALO, N.Y. - A University at Buffalo-led research team has discovered a technique that could help increase the effectiveness of vaccines against the novel coronavirus, the virus that causes COVID-19.

Jonathan F. Lovell, PhD, associate professor in the Department of Biomedical Engineering at UB, is the primary investigator on the research, titled "SARS-CoV-2 RBD Neutralizing Antibody Induction is Enhanced by Particulate Vaccination," which was published online in Advanced Materials today, Oct. 28.

COVID-19 has caused a disruptive global pandemic, infecting at least 40 million worldwide and causing more than 220,000 deaths in the United States alone. Since it began spreading in early 2020, biomedical researchers have been in active pursuit of an effective vaccine.

According to Lovell, one answer might lie in designing vaccines that partially mimic the structure of the virus. One of the proteins on the virus - located on the characteristic COVID spike - has a component called the receptor-binding domain, or RBD, which is its "Achilles heel." That is, he said, antibodies against this part of the virus have the potential to the neutralize the virus.

It would be "appealing if a vaccine could induce high-levels of antibodies against the RBD," Lovell said. "One way to achieve this goal is to use the RBD protein itself as an antigen, that is, the component of the vaccine that the immune response will be directed against."

The team hypothesized that by converting the RBD into a nanoparticle (similar in size to the virus itself) instead of letting it remain in its natural form as a small protein, it would generate higher levels of neutralizing antibodies and its ability to generate an immune response would increase.

Lovell's team had previously developed a technology that makes it easy to convert small, purified proteins into particles through the use of liposomes, or small nanoparticles formed from naturally-occurring fatty components. In the new study, the researchers included within the liposomes a special lipid called cobalt-porphyrin-phospholipid, or CoPoP. That special lipid enables the RBD protein to rapidly bind to the liposomes, forming more nanoparticles that generate an immune response, Lovell said.

The team observed that when the RBD was converted into nanoparticles, it maintained its correct, three-dimensional shape and the particles were stable in incubation conditions similar to those in the human body. When laboratory mice and rabbits were immunized with the RBD particles, high antibody levels were induced. Compared to other materials that are combined with the RBD to enhance the immune response, only the approach with particles containing CoPoP gave strong responses.

Other vaccine adjuvant technology does not have the capacity to convert the RBD into particle-form, Lovell said.

"We think these results provide evidence to the vaccine-development community that the RBD antigen benefits a lot from being in particle format," Lovell said. "This could help inform future vaccine design that targets this specific antigen."

In a new international cross disciplinary study, researchers have used artificial intelligence to analyse large amounts of historical photos from WW2. Among other things, the study shows that artificial intelligence can recognise the identity of photographers based on the content of photos taken by them.

Artificial Intelligence (AI) is now able to identify photographers based on the content of images they've taken.

This is the conclusion of a new study at AU Engineering, Aarhus University, where, in collaboration with Tampere University and the Finnish Environment Institute, researchers have used state-of-the-art artificial intelligence to trawl through photographs taken by 23 well-known Finnish photographers during the Second World War.

The photographs used in the study are part of the publicly available Finnish Wartime Photograph Archive containing around 160,000 photographs from Finnish Winter, Continuation, and Lapland Wars captured in 1939-1945.

The study was published in the scientific journal IEEE Access, and the researchers wanted to demonstrate the advantages of using modern neural networks to analyse images to such an extent that the machine could automatically detect people and objects in a variety of scenes and even distinguish photographers on the basis of characteristics in the image - all much faster than any manual reviewing process.

Such an automatic analysis can serve as a tool for providing content-based textual descriptions of public photographic archives like the Photo Archives of the Museum of Danish Resistance, as it is now required at the European Union level.

The EU Accessibility Directive (DIRECTIVE (EU) 2016/2102) came into effect in September 2020 and requires textual descriptions of image contents to be added to all public images on the Web.

"We were quite surprised by the accuracy with which the AI can recognise photographers based on characteristics in the photos, such as content and framing," says Alexandros Iosifidis, an associate professor and expert in artificial intelligence at Aarhus University.

The photographs analysed in the study show that some photographers have very distinct and easily recognisable characteristics, while others are more difficult for the AI to recognise. On average, the AI model achieved a classification accuracy of 41.1 per cent. (20.1 - 69.7 per cent).

The most recognisable photographer was Heikki Roivainen, a Finnish professor of botany who worked as an official war photographer during the Continuation War; the second of two wars fought between Finland and the Soviet Union during WW2.

"Big data analysis of the contents of photograph collections has been a long-time dream for me and I am very fascinated about the results in this project. That an AI can recognize eg. the framing and various aspects of contents in photographs has many applications in a wide range of fields within humanities and social sciences," says university lecturer at Tampere University Anssi Männistö, who has been researching photographs in journalism for more than 25 years.

The name of the study is 'Machine-Learning-Based Analysis of Finnish World War II Photographers', and it was initiated to facilitate public access to the Finnish war photography archive by using intelligent image search, among other things.

AI also provides the opportunity to link photo archives of this kind to war-related research in social sciences, as the AI can make observations that would otherwise not be possible at a large-scale.

The research results have now been made publicly available to introduce and facilitate this modern approach to research into historical and social studies via photo archives.

Climate change is leaving its mark on the bog complexes of the German Black Forest. Due to rising temperatures and longer dry periods, two plant species have already gone extinct over the last 40 years. The populations of many others have decreased by one third. In the next couple of decades ten more species could become extinct, researchers from Martin Luther University Halle-Wittenberg (MLU) and the German Centre for Integrative Biodiversity Research (iDiv) write in Diversity and Distributions.

There are only a few healthy ombrotrophic bogs, raised bogs and spring mires left in Germany. They used to cover large swathes of north-western Germany. Today they are still found in the foothills of the Alps and on low mountain ranges, for example in the Black Forest. They are very sensitive ecosystems that are highly dependent on certain climatic conditions. “These bogs and spring mires are seismographs of climate change. They react very sensitively to small changes in precipitation and temperature,” says professor Helge Bruelheide, a geobotanist at MLU and a member of iDiv. Bog complexes also have a very high proportion of endangered plant and animal species.

Bruelheide joined forces with Thomas Sperle, a biologist and wetlands expert, to investigate the trends in biodiversity in bogs and spring mires in the southern region of the Black Forest. The two scientists drew on data from the 1970s about the vegetation of 124 complete bogs. Sperle completely re-surveyed nearly all of the areas over a period of four years. "It is really tricky to prove the extinction of a species for an entire bog. I had to carefully scan the whole area to ensure that specific individuals were not overlooked," says Sperle. Bruelheide then used the data to analyse the 88 plant species. Two species have already become extinct. The population size of another 37 have decreased by about one third since the 1970s. This has disproportionately affected so-called specialist species that are adapted to specific climatic conditions and make up a large portion of the biodiversity in Germany. However, there were also 46 so-called generalist species that have coped better with the changes and whose numbers have increased over time.

The researchers also checked whether their observations could be explained by other factors, such as the size of the bogs, the distance from one bog to another and whether adjacent areas were used for agriculture. However, no factor could explain the data better than climate change. "Our analyses clearly show that species are declining and dying out in places where it is drier and warmer for longer periods of time in the summer. This is the first indication that climate change has already arrived in our latitudes," concludes Bruelheide. "It is getting noticeably drier and hotter in the Black Forest, which is why this change is evident there. Presumably, the same thing will happen in other low mountain ranges such as the Harz. Our study can serve as an example for other regions in Germany, but also for other habitats and groups of species."

In their study, the biologists predict that ten more specialist species will disappear by 2045 if conditions progress as expected. This is an alarming sign as there is no way to counteract this extinction in raised bogs and spring moors. "You cannot really replace missing rain in those bogs," says Bruelheide.

A team of biophysics from leading Russian research and educational institutions (MSU, RUDN University, and the Federal Research and Clinical Center of the Federal Medical-Biological Agency of Russia) developed a computer model that shows the effect of antiseptics on bacterial membranes. The common concepts regarding the mode of action of antiseptics turned out to be incorrect: instead of destroying bacterial membranes, they cause changes in their structure. These changes make the bacteria weaker and more susceptible to adverse external factors. The results of the study were published in The Journal of Physical Chemistry.

Antiseptics are chemical agents that affect the internal processes or external structures of harmful microorganisms causing them to die. For example, alcohols break down important building and regulation blocks of bacteria and viruses. Other antiseptics target the integrity of bacterial membranes. They are effectively used against a wide range of pathogens, but their mode of action remains elusive. Scientists are aware of some general patterns, such as the presence of electrically charged particles in the molecules of antiseptic agents. The team developed a computer model of a bacterial membrane and found out the mechanism of the antiseptic activity. The results of the study can help to combat bacterial resistance.

"Some pathogens, especially those associated with hospital infections, show resistance to antiseptics. It is important to understand the physics behind the interaction of antiseptics and microorganisms to use antiseptics more efficiently and to develop new agents," said professor Ilya Kovalenko, Ph.D., Doctor of Science in Physics and Mathematics, working under Project 5-100 at RUDN University.

The scientists developed a model of a bacterial membrane and put the molecules of four antiseptics (miramistin, chlorhexidine, picloxydine, and octenidine) on it. All these substances are cationic antiseptics, i.e. their molecules are positively charged. However, to the researchers' surprise, the antiseptics failed to damage the membrane and just slightly changed its structure. Even when the ratio of antiseptics to membrane lipids was increased from 1/24 to 1/4, the membrane was not destroyed.

The destruction of the membrane took place only when an external electric field (with the intensity of 150 mV/nm) was added to the model. The membrane started to restructure, and pores began to form around the molecules of the antiseptics. Then, water got into them and made them bigger; and eventually, the membrane was torn apart. This was because the membrane became thinner around positively charged molecules: the molecules of the membrane had no charge and therefore were pushed away. An uneven membrane became more susceptible to adverse external factors, which led to the death of the cell.

"We studied the reaction of the model membrane to several cationic antiseptics and found out that structural changes in the membrane in the presence of an electrical field play a key role in the formation of pores. We plan to use this model to predict the effect of existing and new antiseptics on different microorganisms," added professor Ilya Kovalenko, Ph.D., Doctor of Science in Physics and Mathematics, working under Project 5-100 at RUDN University.

Knee replacement surgery, also known as total knee arthroplasty (TKA), is increasing among patients 65 and younger. One study projects a potential 183% increase in the number of TKA and revision TKA surgeries by the year 2030 in that age group, raising concerns about poorer clinical outcomes, lower patient satisfaction and diminished joint survival compared to an older patient population.

Researchers from the University of Missouri School of Medicine and MU Health Care compared past TKA and revision TKA cases in older and younger patient populations. They found younger patients had early reoperation and component revision surgery nearly twice as often as older patients.

"Advances in the field of joint replacement along with newer implant designs have encouraged surgeons to expand TKA to a younger age group," said senior author James Keeney, MD, associate professor of orthopaedic surgery. "Most of our younger patients who have had knee replacement surgery are doing very well, but this patient group has a higher likelihood of needing an additional surgery during their lifetime. A small percentage of these patients may undergo a revision surgery during the first five years after their knee replacement. We wanted to know more about the potential causes of poor outcomes."

Keeney's team completed its own detailed medical record review of 147 patients age 55 and younger and compared them to 276 patients between 60 and 75 years old at the time of surgery. They documented reoperation rates, the timing of reoperation, complications, patient demographics and chronic conditions. They found younger patients were twice as likely to undergo revision surgery within two years of their primary procedure and had higher incidence of infection, mechanism complications and five-year failure of the joint.

"A combination of factors may contribute to the risk of failure, but the general observation of higher tobacco use among the younger patients suggests a possible primary culprit," Keeney said. "Smokers have been noted in previous studies to experience increased joint infection risk after primary hip and knee replacement surgery and higher rates of wound complications."

While younger age is thought to be associated with better physical health, previous studies also have suggested that younger TKA patients potentially have poorer health characteristics, including increased obesity, higher body mass index and lower activity levels. However, Keeney's team found no significant differences in comorbidities between the younger and older patient groups, with the exception of a history of tobacco use.

"Based on our findings, smoking cessation efforts should be part of the treatment plan following initial surgery, and may be even more important for patients undergoing revision surgery," Keeney said. "Efforts should also be made to decrease the risk of infection, mechanism failure, stiffness and instability, which are the common reasons for reoperation."

Researchers worldwide have been surprised to see that individuals can be infected with the SARS-CoV-2 virus - the virus that produces COVID-19 - without showing symptoms. Since these individuals expose others to infection without knowing it, it is important to find an explanation and hopefully a solution to this.

On the inside of our lungs are specialised immune cells, called alveolar macrophages, which help maintain a healthy environment in the lungs. The lungs contain a large number of alveolar macrophages, so they are probably also the first cell type an invading virus encounters.

When the body recognises a viral infection, our immune system initiate the production of interferons. Interferons are a group of cytokines that help shape the immune response and are therefore essential in the fight against a viral infection. Alveolar macrophages have previously been shown to produce large amounts of interferons upon infection with respiratory viruses, such as influenza.

SARS-CoV-2 is a respiratory virus that typically infects the outermost cell layer of the lungs, the epithelial layer. New research has shown that interferon production in the infected epithelial cells can be inhibited by the SARS-CoV-2 virus. This results in low interferon production and therefore also a limited activation of the immune system to fight against the virus. Although the epithelial layer is the target of the virus, it must be assumed that the first cell type the virus encounters is the alveolar macrophages, and therefore these cells are important for how quickly an immune response to a SARS-CoV-2 infection can be initiated.

Therefore, a team of researchers from Aarhus University and Aarhus University Hospital in Denmark set out to investigate how these important cells react to the SARS-CoV-2 virus. To answer this, they isolated the alveolar macrophages from lung lavage and examined the activation of the immune system in these cells when they encounter the SARS-CoV-2 virus.

The SARS-CoV-2 virus can hide its genome from being recognised

The results of their research show that alveolar macrophages effectively produce interferons when infected with known viruses, such as influenza. They have thereby confirmed that they have the potential to produce large amounts of interferons during a viral infection. Contrary to their expectations, the researchers saw no interferon production in the cells when the alveolar macrophages were exposed to the SARS-CoV-2 virus.

These results therefore suggest that the SARS-CoV-2 virus may hide its genomic material from being recognised in the alveolar macrophages, thereby not inducing the production of interferons. This is why there will be no activation of the immune system in the early stages of a SARS-CoV-2 infection, allowing the virus to spread further in the community before symptoms occur. However, more research is needed to understand how SARS-CoV-2 can avoid being recognised by the immune system.

Hurricanes and other tropical cyclones can severely impact human health in communities across the country, but data for these events is limited, especially in a format that is easy to link with human health outcomes.

Scientists have looked at death certificates to see if the cause could be linked up clearly to a storm, but it is easy to miss something in this type of data review. A person could have a heart attack brought on by stress from clearing tree limbs in a yard, following a storm.

An interdisciplinary team - including epidemiologists, engineers, an atmospheric scientist and software developer - led by Colorado State University (CSU) has created an open source data set that can be used for epidemiological research on tropical cyclones. The new tool also provides insights that can guide the design and analysis of this type of research.

The paper describing the new data set, "Assessing United States County-Level Exposure for Research on Tropical Cyclones and Human Health," is published Oct. 28 in Environmental Health Perspectives.

Interdisciplinary team tackles lack of data

Brooke Anderson, lead author of the paper and an associate professor in the Department of Environmental and Radiological Health Sciences at CSU, teamed up on this project with scientists including Andrea Schumacher, research associate with the Cooperative Institute for Research in the Atmosphere (CIRA) at CSU.

"For heatwaves, there has already been a lot of research on what the risks are for human health," said Anderson. Scientists can estimate community-wide deaths and illnesses associated with several types of climate-related disasters, including heat waves, floods and wildfires, she added.

Anderson said that with this new data set, scientists can now analyze multiple storms in different places and time periods, and drill down to see what happens in different health outcomes for people. Prior to the release of this new tool, most research has focused on data related to a single storm.

Schumacher said she's always been interested in looking at how counties across the country are affected by hurricane winds on a broad scale. And she found the perfect research partner in Anderson.

"Brooke and I found that we had a similar interest in characterizing hurricane winds," said Schumacher, who helps develop satellite-based products for hurricane forecasters.

Data set designed for others to build upon
The team used what's known as the R programming language to create the data set, which will allow scientists from around the world to add new facets and enrich what the team has started.

Anderson said the concept is similar to when a child gets a toy train set, and it just comes with an oval. "Next, the grandparents come along, and you get a bridge or you get new roads that head off in different directions," she said.

The new tool - maintained by an international group of volunteers on the Comprehensive R Archive Network, CRAN - also provides very precise data. A scientist can look at rainfall during Hurricane Floyd from several days before (or after) the storm came, Anderson said.

CSU scientists are already using the new data set to look at Medicare hospitalizations following storms over a decade in the Eastern United States. Anderson said the team found that the number of people being hospitalized for respiratory conditions tended to increase when the storm hit, and a week after.

Another team she's part of used the dataset to look at how tropical cyclones affect different birth outcomes, including pre-term birth and pregnancy outcomes.

Schumacher said she sees lots of possibilities for where this research tool can go.

"From my end, there's still plenty of work to do," she said. "What we've created is a really good start. I can see all kinds of ways that we can improve on it, especially as we get better and better observations."

Since the famous discovery of dinosaur eggs in the Gobi Desert in the early 1920s, the fossilized remains have captured the imaginations of paleontologists and the public, alike. Although dinosaur eggs have now been found on every continent, it's not always clear to scientists which species laid them. Now, researchers reporting in ACS Omega have narrowed down the list for an unknown eggshell from Mexico by comparing its microstructure and composition with four known samples.

Because many dinosaur eggs are similar in size and shape, it can be difficult to determine what type of dinosaur laid them. Clues can come from fossilized embryos (which are rare), hatchlings in the same nest or nearby adult remains. Scientists also have identified microscopic features of eggshells that differ among groups of dinosaurs. In addition, researchers have studied the elemental composition of fossil eggshells to learn more about the paleoenvironment and conditions that led to the eggs' fossilization. Abel Moreno and colleagues wanted to compare the microstructure and composition of five dinosaur eggshells from nests in the El Gallo Formation of Baja California, Mexico. Based on the eggs' shapes and sizes and the fossil record of the area, the researchers had concluded that three of the eggs were laid by ornithopods (bipedal herbivores) of the hadrosaur family (duck-billed dinosaurs) and one by a theropod (bipedal carnivores) of the troodontidae family (small, bird-like dinosaurs). The remaining sample was too damaged to classify by the naked eye.

Using scanning electron microscopy, the team examined the external and internal surfaces and a cross-section of each eggshell. In contrast to the smooth outer surface of the theropod shell, the shells from the ornithopods and the unknown sample had nodes at different distances across the shell. Images of shell cross-sections from the ornithopods revealed that mammillary cones -- calcite crystals on the inner surface of the shell -- formed thin, elongated columns arranged in parallel, with irregular pores. In contrast, the eggshell from the theropod showed thicker, shorter cones arranged in a bilayer, with wider pores. The unknown sample more closely resembled the ornithopod eggshells, leading the researchers to hypothesize that it was probably also from the hadrosaur family. In addition, the researchers conducted an elemental composition analysis, which they say is the first such analysis on dinosaur eggshells collected in Mexico. They say the findings might help reveal how the fossilization process varied among species and locales.

If you've ever had a cold, you know that too much mucus can be an annoyance, but mucus plays a very important role in the body. The respiratory system creates mucus as part of the immune system, meant to trap inhaled bacteria, viruses, and dirt so they can be removed before causing infection. However, for people with the genetic disorder cystic fibrosis (CF), the mucus that their bodies produce is thicker and stickier, leading to an increased risk from infection and decreased ability to breathe over time.

New research led by the University of Pittsburgh's Swanson School of Engineering examines the properties of the mucus of CF patients and the role it plays in a pathogens' ability to survive. The new information could have important implications for CF treatment.

The researchers examined nonmucoid (PANT) and mucoid (PASL) strains of P. aeruginosa, a common pathogen that infects the lungs. P. aeruginosa adapts to the host environment mutating from a non-mucoid phenotype (PANT) to a mucoid phenotype (PASL). This mutation in P. aeruginosa creates a protective film of mucus around the bacteria thereby forming a more hydrated and slimy biofilm in the mucus.

"Think of the cells like grains of rice. PANT cells are like basmati rice, while PASL cells are like sushi rice: coated in such a way that they stick together when they're compressed," explained Tagbo Niepa, assistant professor of chemical and petroleum engineering, whose lab led the study. Niepa also has appointments in the Departments of Bioengineering, Civil and Environmental Engineering, and Mechanical Engineering and Materials Science. "We can measure how investigational drugs can alter the sticky nature of the coating that pathogens such as P. aeruginosa create upon mutation."

This mutation gives the mucus unique properties that contribute to increased antibiotic resistance. It also shields them against phagocytic cells, which help the immune system clear out dead or harmful cells by ingesting them.

In order to study these properties, the researchers used pendant drop elastometry to compress and expand the biofilm that the cells formed. They also assessed the transcriptional profile of the cells to correlate the film's mechanics to cell physiology.

"This is the first time that the pendant drop elastometry technique has been used to study the mechanics of these cells. We demonstrate that these techniques can be used to investigate the efficacy of mucolytic drugs--drugs that are used to break down the film of mucus that the cells are making," noted Niepa. "This technique could be powerful for investigating those agents, to see if they have the anticipated effect."