Culture

March 27, 2020-- In a new study, researchers found that half of the patients they treated for mild COVID-19 infection still had coronavirus for up to eight days after symptoms disappeared. The research letter was published online in the American Thoracic Society's American Journal of Respiratory and Critical Care Medicine.

In "Time Kinetics of Viral Clearance and Resolution of Symptoms in Novel Coronavirus Infection," Lixin Xie, MD, Lokesh Sharma, PhD, and co-authors report on a study of 16 patients with COVID-19, who were treated and released from the Treatment Center of PLA General Hospital in Beijing between January 28 and Feb. 9, 2020. Patients studied had a median age of 35.5 years.

Researchers collected samples from throat swabs taken from all patients on alternate days and analyzed. Patients were discharged after their recovery and confirmation of negative viral status by at least two consecutive polymerase chain reaction (PCR) tests.

"The most significant finding from our study is that half of the patients kept shedding the virus even after resolution of their symptoms," said co-lead author Dr. Sharma, instructor of medicine, Section of Pulmonary, Critical Care & Sleep Medicine, Department of Medicine, Yale School of Medicine. "More severe infections may have even longer shedding times."

The primary symptoms in these patients included fever, cough, pain in the pharynx (pharyngalgia) and difficult or labored breathing (dyspnea). Patients were treated with a range of medications.

The time from infection to onset of symptoms (incubation period) was five days among all but one patient. The average duration of symptoms was eight days, while the length of time patients remained contagious after the end of their symptoms ranged from one to eight days. Two patients had diabetes and one had tuberculosis, neither of which affected the timing of the course of COVID-19 infection.

"If you had mild respiratory symptoms from COVID-19 and were staying at home so as not to infect people, extend your quarantine for another two weeks after recovery to ensure that you don't infect other people," recommended corresponding author Lixin Xie, MD, professor, College of Pulmonary and Critical Care Medicine, Chinese PLA General Hospital, Beijing.

The authors had a special message for the medical community: "COVID-19 patients can be infectious even after their symptomatic recovery, so treat the asymptomatic/recently recovered patients as carefully as symptomatic patients."

The researchers emphasized that all of these patients had milder infections and recovered from the disease, and that the study looked at a small number of patients. They noted that it is unclear whether similar results would hold true for more vulnerable patients such as the elderly, those with suppressed immune systems and patients on immunosuppressive therapies.

"Further studies are needed to investigate if the real-time PCR-detected virus is capable of transmission in the later stages of COVID-19 infection," Dr. Xie added.

A new technique allows researchers to test how the deformation of tiny train track-like cell proteins affects their function. The findings could help clarify the roles of deformed "microtubules" in traumatic brain injuries and in neurological diseases like Parkinson's.

Microtubules are tube-like proteins that act like train tracks for other cellular proteins to move along as they transport molecular cargo. In certain diseases, they become deformed, affecting this transport process. But scientists hadn't developed an experimental set-up that allows them to properly study this.

In the study published in ACS Applied Bio Materials, biophysicist Akira Kakugo of Hokkaido University and colleagues developed a novel technique that allowed them to control microtubular deformation and observe its effects on their transportation function.

Microtubules were anchored by proteins to an elastic "microstretcher." When the microstretcher is pulled taut, the microtubules lie parallel to the surface undeformed. Gradually relaxing the microstretcher causes the microtubules to buckle.

The scientists attached motor proteins called dyneins to the microtubules. Inside cells, dyneins appear as if they are walking along microtubules while carrying cargo. In the experiment, the dyneins were conjugated to a fluorescent cargo. The scientists then observed how stretching and relaxing the microstretcher affected dynein-cargo movement along the microtubules.

They found the dynein-cargo moved faster as the microtubules began to buckle, but only up to a certain point. Once the buckling strain reached 25%, the moving proteins and their cargo began to slow down. When the microtubules were bent further, they showed complete stops. The scientists also noticed the speed of movement varied along different sections of the buckled microtubules.

The researchers theorize these altered microtubular dynamics could form the basis of their roles in regulating numerous cellular activities. They next hope to study how microtubular deformation affects the movement of another motor protein, called kinesin, over its surface.

"Our experimental set-up enables us to study the relationship between the deformation of microtubules and their biological functions," says Kakugo. "The more we understand this process, the closer we might get to designing new nature-inspired materials that can act in a similar way."

"The findings are also expected to help explain the pathology of traumatic brain injury, which mechanically stresses cells, and neurological conditions like Huntington's and Parkinson's diseases, in which microtubules are known to malfunction," Syeda Rubaiya Nasrin of the research team added.

An international collaboration led by veterinary scientists at Tokyo University of Agriculture and Technology (TUAT), Japan, has found that size of a dog heart affects both vortex flow and pressure difference in the heart, which both are promising as an index of diastolic function. Their findings mean that size correction of vorticity and pressure difference allows us to use these indexes in the field of pediatric and veterinary medicine.

Their findings were published in Scientific Reports on January 24th, 2020.

The heart works through 2 steps, contraction (medical term: systole, systolic) and expansion (medical term: diastole, diastolic), to circulate blood to the whole body. Diagnosis of its systolic dysfunction is relatively simple by using echocardiographic examination. In contrast, its diastolic function is far complex despite the fact that patient numbers of the systolic dysfunction are about the same as those of the diastolic dysfunction. "We have to measure the diastolic function precisely by a catheter inserted in the heart," said Ryou Tanaka, Professor in the Department of Veterinary Surgery, Faculty of Veterinary Medicine, TUAT, and corresponding author of the paper. "So, we need to develop a noninvasive technique for measuring the diastolic function, which should be simple and reliable."

The heart expands using energy and acquires blood by creating a negative pressure in the heart. Blood entering the heart in response to the pressure difference creates a vortex in the left chamber. Currently, a method called Vector flow mapping (VFM) using echocardiography allows us to visualize and quantify the vortex flow in the heart. Their previous study found that the vortex flow in the left lower chamber (called the left ventricle) was stronger if the pressure was more different. Hence, both the vortex flow and the pressure difference in the left lower chamber when the heart expands could be markers for the diastolic function. It is noted that if the diastolic function becomes weaker, blood congestion tends to lead symptoms of heart failure such as shortness of breath.

"We started wondering wether or not the diastolic function of children hearts, which is much smaller than adults' hearts, could be evaluated by these 2 indexes, that is, the vorticity and the pressure difference," said Katsuhiro Matsuura, D.V.M., Ph.D, the first author of the paper and a postdoctoral fellow in the Department of Veterinary Surgery of TUAT. "We then hypothesized that an additional index must be required when the heat sizes are so different. To test this hypothesis, we chose "adult dogs" instead of observing hearts of healthy children and adults," adds Matsuura. It is because the function of the heart itself changes during the growth. Dogs are very different in body size within the same species and the body weight of adult dogs is very different, for example, from 1 kg to 80 kg.

"We examined flow dynamics in the heart of 58 healthy adult dogs (1.3 to 42.3 kg in weight) by VFM. We then found that the heart size is positively correlated with the pressure difference and inversely correlated with the vortex flow," Matsuura explained. "Our findings indicate that to non-invasively diagnose cardiac function using indexes of flow dynamics the heart size should be taken into account. Now that we can extend this non-invasive method to human pediatrics and veterinary medicine, and our next step is to study fluid dynamics in diseased cases," according to Tanaka.

Aichi, Japan -- How much we value an item is often related to what other people have. You might want the newest fashion, but not once everybody has it. Or, winning a free lunch at your favorite restaurant might not seem as great if the other person won a million dollars. Now, researchers in Japan have discovered a region of the brain that controls these kinds of behaviors in monkeys.

In their study published in Proceedings of the National Academy of Sciences, USA, a team of researchers from the National Institutes of Natural Sciences in Okazaki, Japan show that when monkeys think other monkeys will be rewarded, their own rewards become less appealing. This was evident in the amount that monkeys licked their lips while waiting for their reward. The team found that licking increased the more monkeys anticipated receiving a reward and decreased as they anticipated the other monkey would receive it instead.

This behavior was reflected in the brain. As first author Atsushi Noritake explains, "We found a clear link between brain activity in the lateral hypothalamus and the licking behavior that represented subjective value of the reward." The team recorded activity from neurons as monkeys saw pictures that indicated the chance that they or another monkey would receive a reward. The scientists found that for some cells, firing rates increased with the probability of receiving the reward and decreased with the probability that the other monkey would get the reward.

A second experiment showed that the same brain region was necessary for the social observations to affect how much the monkeys valued the reward. When the scientists temporarily shut down the lateral hypothalamus using an inhibitory drug, the monkeys' licking behavior was unchanged when they anticipated receiving the reward themselves--it still increased with the chance of reward. However, the amount of licking was now unrelated to the chance of reward when they were cued that the other monkey was likely to get it.

This behavior was similar to what happened when the other monkey was prevented from getting the reward or when it was absent altogether.

"Without a functioning lateral hypothalamus, it was as if the monkeys no longer processed what they were seeing as a social situation," says team leader Masaki Isoda. "Thus, we believe that the lateral hypothalamus is necessary for shaping socially motivated behavior, perhaps in coordination with other brain areas such as the medial prefrontal cortex."

Astronomers obtained the first resolved image of disturbed gaseous clouds in a galaxy 11 billion light-years away by using the Atacama Large Millimeter/submillimeter Array (ALMA). The team found that the disruption is caused by young powerful jets ejected from a supermassive black hole residing at the center of the host galaxy. This result will cast light on the mystery of the evolutionary process of galaxies in the early Universe.

It is commonly known that black holes exert strong gravitational attraction on surrounding matter. However, it is less well known that some black holes have fast-moving streams of ionized matter, called jets. In some nearby galaxies, evolved jets blow off galactic gaseous clouds, resulting in suppressed star formation. Therefore, to understand the evolution of galaxies, it is crucial to observe the interaction between black hole jets and gaseous clouds throughout cosmic history. However, it had been difficult to obtain clear evidence of such interaction, especially in the early Universe.

In order to obtain such clear evidence, the team used ALMA to observe an interesting object known as MG J0414+0534. A distinctive feature of MG J0414+0534 is that the paths of light traveling from it to Earth are significantly distorted by the gravity of another 'lensing' galaxy between MG J0414+0534 and us, causing significant magnification.

"This distortion works as a 'natural telescope' to enable a detailed view of distant objects," says Takeo Minezaki, an associate professor at the University of Tokyo.

Another feature is that MG J0414+0534 has a supermassive black hole with bipolar jets at the center of the host galaxy. The team was able to reconstruct the 'true' image of gaseous clouds as well as the jets in MG J0414+0534 by carefully accounting for the gravitational effects exerted by the intervening lensing galaxy.

"Combining this cosmic telescope and ALMA's high-resolution observations, we obtained exceptionally sharp vision, that is 9,000 times better than human eyesight," adds Kouichiro Nakanishi, a project associate professor at the National Astronomical Observatory of Japan/SOKENDAI. "With this extremely high resolution, we were able to obtain the distribution and motion of gaseous clouds around jets ejected from a supermassive black hole."

Thanks to such a superior resolution, the team found that gaseous clouds along the jets have violent motion with speeds as high as 600 km/s, showing clear evidence of impacted gas. Moreover, it turned out that the size of the impacted gaseous clouds and the jets are much smaller than the typical size of a galaxy at this age.

"We are perhaps witnessing the very early phase of jet evolution in the galaxy," says Satoki Matsushita, a research fellow at Academia Sinica Institute of Astronomy and Astrophysics. "It could be as early as several tens of thousands of years after the launch of the jets."

"MG J0414+0534 is an excellent example because of the youth of the jets," summarizes Kaiki Inoue, a professor at Kindai University, Japan, and the lead author of the research paper which appeared in the Astrophysical Journal Letters. "We found telltale evidence of significant interaction between jets and gaseous clouds even in the very early evolutionary phase of jets. I think that our discovery will pave the way for a better understanding of the evolutionary process of galaxies in the early Universe."

Researchers from the Centre for Genomic Regulation (CRG) have launched a new database to advance the international research efforts studying COVID-19.

The publicly-available, free-to-use resource (https://covid.crg.eu) can be used by researchers from around the world to study how different variations of the virus grow, mutate and make proteins.

"Scientists are working round the clock to understand SARS-CoV-2, the virus causing COVID-19, so that we can find its weak spots and beat it. A huge amount of scientific data is being published around the world," says Eva Novoa, a researcher at the CRG in Barcelona.

"However, some of the technologies we use to study SARS-CoV-2, such as nanopore RNA sequencing, are so new that the results of one paper aren't comparable to another due to the patchwork of different standards and methodologies used. We are taking all this data and analyzing it so that it meets a more universally comparable standard. This will help researchers more quickly and accurately spot the strengths and weaknesses of the coronavirus."

To understand how the coronavirus grows, mutates and replicates, scientists have to sequence the RNA of COVID-19. The RNA sequence reveals crucial information about the proteins the virus makes to invade human cells and replicate, which in turn informs governments on the infectiousness and severity of the pandemic.

Traditional sequencing tools can take a long time to provide results. In recent years, sequencing data in real time has become a reality thanks to the use of nanopore sequencing technologies, revolutionizing genomics research and disease outbreak monitoring. Nanopore sequencing provides scientists and clinicians with immediate access to the DNA and RNA sequence information of any living cell in real-time, enabling a rapid response against the threat of a pandemic.

However, the raw data produced by nanopore sequencing is highly complex. Scientists and clinicians currently lack systematic guidelines for the reproducible analysis of the data, limiting the vast potential of the nascent technology.

To standardize the analysis of publicly available SARS-CoV-2 nanopore sequencing data, researchers at the Centre for Genomic Regulation (CRG) in Barcelona are using MasterOfPores, a computer program developed by the group of Eva Novoa and CRG Bioinformatics Unit. The software was first described last week in Frontiers in Genetics.

"The internet and an increasing culture of open science, data sharing and preprints have transformed the research landscape. Infrastructure that would take months to set up to research an emerging virus can now be done in just a few days owing to novel scientific computing approaches," says Julia Ponomarenko, Head of the Bioinformatics Unit at the CRG.

MasterOfPores can be executed on any Unix-compatible OS on a computer, cluster or cloud without the need of installing any additional software or dependencies, and is freely available in Github. The publicly-available, free-to-use resource has currently analysed 3TB of SARS-CoV-2 nanopore RNA sequencing data. The CRG researchers will continue to update the resource with new data as soon as it becomes available.

Researchers from North Carolina State University and the Army Research Office have demonstrated a new model of how competing pieces of information spread in online social networks and the Internet of Things (IoT). The findings could be used to disseminate accurate information more quickly, displacing false information about anything from computer security to public health.

"Whether in the IoT or on social networks, there are many circumstances where old information is circulating and could cause problems - whether it's old security data or a misleading rumor," says Wenye Wang, co-author of a paper on the work and a professor of electrical and computer engineering at NC State. "Our work here includes a new model and related analysis of how new data can displace old data in these networks."

"Ultimately, our work can be used to determine the best places to inject new data into a network so that the old data can be eliminated faster," says Jie Wang, a postdoctoral researcher at NC State and first author of the paper.

In their paper, the researchers show that a network's size plays a significant role in how quickly "good" information can displace "bad" information. However, a large network is not necessarily better or worse than a small one. Instead, the speed at which good data travels is primarily affected by the network's structure.

A highly interconnected network can disseminate new data very quickly. And the larger the network, the faster the new data will travel.

However, in networks that are connected primarily by a limited number of key nodes, those nodes serve as bottlenecks. As a result, the larger this type of network is, the slower the new data will travel.

The researchers also identified an algorithm that can be used to assess which point in a network would allow you to spread new data throughout the network most quickly.

"Practically speaking, this could be used to ensure that an IoT network purges old data as quickly as possible and is operating with new, accurate data," Wenye Wang says.

"But these findings are also applicable to online social networks, and could be used to facilitate the spread of accurate information regarding subjects that affect the public," says Jie Wang. "For example, we think it could be used to combat misinformation online."

The discovery of a new species of dromaeosaurid -- a family of generally small to medium-sized feathered carnivores that lived during the Cretaceous Period -- is reported in Scientific Reports this week. The fossil furthers our understanding of dinosaur evolution during the Late Cretaceous (70-68 million years ago).

Steven Jasinski and colleagues discovered 20 identifiable skeletal elements of the new dromaeosaurid in deposits of the Ojo Alamo Formation in the San Juan Basin, New Mexico, USA. The dinosaur has been named Dineobellator notohesperus from the Navajo word Diné (Navajo people) and the Latin word bellator (warrior). The authors report a number of unique features, including vertebrae near the base of the tail that curved inwards, which could have increased Dineobellator's agility and improved its predation success. A gouge mark on the fossil's large sickle-shaped claw may have been inflicted during an altercation with another Dineobellator or other theropod such as Tyrannosaurus rex, they speculate.

Phylogenetic analyses of relationships between species suggest that Dineobellator may be part of the Velociraptorinae subfamily, which also includes velociraptors. Ancestors of Dineobellator are thought to have migrated from Asia to North America where multiple lineages may have evolved, potentially accounting for differences in morphology between Dineobellator and other dromaeosaurids.

The findings, which contribute to the sparse fossil record of dromaeosaurids, indicate that this family was still diversifying at the end of the Cretaceous period prior to the mass extinction that wiped out non-avian dinosaurs 65.5 million years ago.

Neanderthals slurping seashells by the seashore? This scene may startle those accustomed to imagining Homo neanderthalensis as a people of cold climes who hunted large herbivores. Yet an international team including scientists from three laboratories affiliated with the CNRS and partner institutions* have just demonstrated that Neanderthals hunted, fished, and gathered prodigious volumes of seafood and other marine animals: they discovered remains of molluscs, crustaceans, fish, birds, and mammals in a Portuguese cave (Figueira Brava) occupied by Neanderthals between 106,000 and 86,000 BCE. The diversity of marine food resources found there even exceeds that observed at other, much more recent Portuguese sites, dated to 9,000-7,500 BCE. The team's findings, published in Science (27 March 2020), suggest that many Neanderthal groups--living in Mediterranean climates far from the mammoth hunts of the frigid steppes--shared these dietary habitats.

The first significant evidence of marine resource use among Europe's Neanderthals is detailed in a new report, demonstrating a level of marine adaptation previously only seen in their contemporary modern humans living in southern Africa. The results further close the behavioral gap once thought to separate modern humans from their closest evolutionary cousins. For modern humans, coastal adaptations are widely recognized as having roots in southern Africa and dating as far back as ~160 thousand years ago (kya). Whether Neanderthals shared a similar interest in the sea's cuisine is debated. Some suggest that the consumption of the seafood and the brain-boosting fatty acids seafood contains enhanced cognitive development in early modern humans, allowing for the wide variety of technological and cultural innovations that blossomed during the Middle Stone Age (MSA), a period spanning 200-25 kya. This in turn allowed our species to expand out of Africa and outcompete coeval hominins. Archaeological evidence of Neanderthal coastal adaptation, meanwhile, is virtually unknown. João Zilhão and colleagues report on recent excavations at the Figueira Brava site on Portugal's coast, which revealed a uniquely preserved record of intense, systematic and long-term coastal resource use by Neanderthals during the Last Interglacial. The seaside site was dated to roughly 106-86 kya and contained middens rich in marine and terrestrial food remains. According to Zilhão et al., Figueira Brava's occupants relied on the sea in a scale comparable to the modern humans of MSA Africa. The results suggest that fisher-hunter-gatherers were widespread and likely relied on the sea earlier than previously thought. The lack of supporting evidence on this to date, they say, is likely a result of Pleistocene sea level-rise, which inundated similar sites across coastal Europe. Manuel Will discusses the study further in a related Perspective.

Addressing a fundamental limitation in CRISPR-Cas genome editing, researchers have developed new engineered Cas9 variants that nearly eliminate the need for a protospacer adjacent motif known as PAM. This motif is otherwise required for DNA-targeting CRISPR enzymes. According to the report, the novel Cas9 enzymes open up virtually the entire genome for targeting, with unprecedented accuracy. This drastically expands the potential of CRISPR-Cas systems, the authors say, something they showed by using their approach to correct mutations associated with human diseases located in previously "un-editable" regions of the genome. DNA-targeting CRISPR-associated enzymes find their targets by recognizing protospacer adjacent motif (PAM) sequences - short bits of genetic code that flag editable sections of DNA and serve as a binding signal for specific CRISPR-Cas nucleases. Without an adjacent, recognizable PAM sequence, a Cas enzyme will not recognize nor successfully attach to and cleave a desired section of DNA. While different Cas enzymes, including variants of the canonical Streptococcus pyogenes Cas9 (SpCas9), recognize different PAM sequences, much of the genome remains un-targetable for editing or more prone to generating off-target mutations. Thus, the PAM requirement represents a significant limiting barrier for applications that require high-resolution genome targeting. To address this limitation, Russell Walton and colleagues engineered new variants of the SpCas9 enzyme capable of targeting and editing sequences bearing a wider array of PAMs. Here, Walton et al. report on two significant variants: SpG, which is capable of targeting an expanded set of NGN PAMs, and a near-PAMless variant called SpRY. Collectively, SpG and SpRY enable unconstrained targeting using CRISPR-Cas9 nucleases across nearly the entire genome and with single base pair precision. Using SpRY, the authors were able to correct mutations associated with human diseases located in previously "un-editable" regions of the genome.

The journal Science has published a study led by the ICREA researcher João Zilhão, from the University of Barcelona, which presents the results of the excavation in Cueva de Figueira Brava, Portugal, which was used as shelter by Neanderthal populations about between 86 and 106 thousand years ago. The study reveals fishing and shellfish-gathering contributed significantly to the subsistence economy of the inhabitants of Figueira Brava. The relevance of this discovery lies in the fact that so far, there were not many signs of these practices as common among Neanderthals.

Regarding the consequences of this study, João Zilhão notes that "an influent model on our origins suggests the common consumption of water resources -rich in Omega3 and other fatty acids that favour the development of brain tissues- would have increased the cognitive skills of modern anatomy humans. That is, those humans who, in Africa, were contemporaries of Neanderthals and are usually regarded as the only ancestors of the current Homo sapiens". But the results of the excavation of Figueira Brava state that, if this common consumption of marine resources played an important role in the development of cognitive skills, it did so on the entire humanity, including Neanderthals, and not only the African population that spread later".

Zilhão member of the Prehistoric Studies and Research Seminar (SERP-UB), lists the research study in the line of "proof that accumulated over the last decade to show Neanderthals had a symbolic material culture". Two years ago, in 2018, the journals Science and Science Advances published two studies co-led by João Zilhão which showed that more than 65,000 years ago, Neanderthals made cave paintings in at least three caves in the Iberian Peninsula: La Pasiega, Maltravieso and Ardales (Science). Furthermore, more than 115,000 years ago, they used perforated marine shells and with ocher remains, such as the ones from Cueva de los Aviones (Murcia, Spain), as pendants and shell containers with residues of complex mixes of pigment (Science Advances). These findings, the most recent one being the one in Figueira Brava, "support a view on human evolution in which the known fossil variants, such as Neanderthals' in Europe and its African anatomy contemporaries -more similar to ours-, should be understood as remains from our ancestors, not as different higher-lower species", notes Zilhão.

A 50% of the diet of the inhabitants in Figueira Brava was built by coastal resources: molluscs (limpet, mussel and clams; crustaceans (brown crab and spider crab); fish (shark, eel, sea bream, mullet); birds (mallard, common scoter, goose, cormorant, gannet, shag, auk, egret, loon), and mammals (dolphin, seal). This was completed with the hunt of deer, goats, horses, aurochs and other small preys such as tortoises. Among the other carbonised plants were olive trees, vines, fig trees and other Mediterranean climate typical species, among which the most abundant was the stone pine -its wood was used as combustible. Pine forests were exploited as fruit tree gardens: mature pines, albeit closed, were taken from the branches and stored in the cave, where the fire could open them so as to take the pines.

The study also provides other results, such as the idea of the concept of Neanderthals as cold and tundra peoples, experts on hunting mammoths, rhinos, buffalos and reindeers, is biased. "Most Neanderthals would have lived in southern regions, specially in Italy and in the Iberian Peninsula, and its lifestyle would have been very similar to those in Figueira Brava", notes Zilhão.

Another important affirmation in the study is the familiarity of humans with the sea and its resources as something older and wider than what was thought. "This could probably help explain how, between 45,000 and 50,000 years ago, humans could cross the Timor Sea to colonize Australia and New Guinea, and then, about 30,000 years ago, the closest islands to the western Pacific", says Zilhão.

Over 80,000 years ago, Neanderthals were already feeding themselves regularly on mussels, fish and other marine life. The first robust evidence of this has been found by an international research team with the participation of the University of Göttingen during an excavation in the cave of Figueira Brava in Portugal. Dr Dirk Hoffmann at the Göttingen Isotope Geology Department dated flowstone layers - calcite deposits that form like stalagmites from dripping water - using the uranium-thorium method, and was thus able to determine the age of the excavation layers to between 86,000 and 106,000 years. This means that the layers date from the period in which the Neanderthals settled in Europe. The use of the sea as a source of food at that time has so far only been attributed to anatomically modern humans (Homo sapiens) in Africa. The results of the study were published in the journal Science.

The cave of Figueira Brava is located 30 kilometres south of Lisbon on the slopes of the Serra da Arrábida. Today it is located directly on the waterfront, but at that time it was up to two kilometres from the coast. The research team, coordinated by the first author of the study, Professor João Zilhão from the University of Barcelona, found that the Neanderthals living there were able to routinely harvest mussels and fish, and to hunt seals. Their diet included mussels, crustaceans and fish as well as waterfowl and marine mammals such as dolphins and seals. Food from the sea is rich in omega-3 fatty acids and other fatty acids that promote the development of brain tissue.

Until now, it has always been suspected that this consumption increased the cognitive abilities of the human populations in Africa. "Among other influences, this could explain the early appearance of a culture of modern people that used symbolic artefacts, such as body painting with ochre, the use of ornaments or the decoration of containers made of ostrich eggs with geometric motifs," explains Hoffmann. "Such behaviour reflects human's capacity for abstract thought and communication through symbols, which also contributed to the emergence of more organised and complex societies of modern humans".

The recent results of the excavation of Figueira Brava now confirm that if the habitual consumption of marine life played an important role in the development of cognitive abilities, this is as true for Neanderthals as it is for anatomically modern humans. Hoffmann and his co-authors previously found that Neanderthals made cave paintings in three caves on the Iberian Peninsula more than 65,000 years ago and that perforated and painted shells must also be attributed to the Neanderthals.

A new feathered dinosaur that lived in New Mexico 67 million years ago is one of the last known surviving raptor species, according to a new publication in the journal Scientific Reports.

Dineobellator notohesperus adds to scientists' understanding of the paleo-biodiversity of the American Southwest, offering a clearer picture of what life was like in this region near the end of the reign of the dinosaurs.

Steven Jasinski, who recently completed his Ph.D. in Penn's Department of Earth and Environmental Sciences in the School of Arts and Sciences, led the work to describe the new species, collaborating with doctoral advisor Peter Dodson of the School of Veterinary Medicine and Penn Arts and Sciences and as well as Robert Sullivan of the New Mexico Museum of Natural History and Science in Albuquerque.

In 2008, Sullivan found fossils of the new species in Cretaceous rocks of the San Juan Basin, New Mexico. He, along with his field team of Jasinski and James Nikas, collected the specimen on U.S. federal land under a permit issued by the Bureau of Land Management. The entire specimen was recovered over four field seasons. Jasinski and his coauthors gave the species its official name, Dineobellator notohesperus, which means "Navajo warrior from the Southwest," in honor of the people who today live in the same region where this dinosaur once dwelled.

Dineobellator, as well as its Asian cousin Velociraptor, belong to a group of dinosaurs known as the dromaeosaurids. Members of this group are commonly referred to as "raptor" dinosaurs, thanks to movies such as "Jurassic Park" and "Jurassic World." But unlike the terrifying beasts depicted in film, Dineobellator stood only about 3.5 feet (about 1 meter) at the hip and was 6 to 7 feet (about 2 meters) long--much smaller than its Hollywood counterparts.

Raptor dinosaurs are generally small, lightly built predators. Consequently, their remains are rare, particularly from the southwestern United States and Mexico. "While dromaeosaurids are better known from places like the northern United States, Canada, and Asia, little is known of the group farther south in North America," says Jasinski.

While not all of the bones of this dinosaur were recovered, bones from the forearm have quill nobs--small bumps on the surface where feathers would be anchored by ligaments--an indication that Dineobellator bore feathers in life, similar to those inferred for Velociraptor.

Features of the animal's forelimbs, including enlarged areas of the claws, suggest this dinosaur could strongly flex its arms and hands. This ability may have been useful for holding on to prey--using its hands for smaller animals such as birds and lizards, or perhaps its arms and feet for larger species such as other dinosaurs.

Its tail also possessed unique characteristics. While most raptors' tails were straight and stiffened with rod-like structures, Dineobellator's tail was rather flexible at its base, allowing the rest of the tail to remain stiff and act like a rudder.

"Think of what happens with a cat's tail as it is running," says Jasinski. "While the tail itself remains straight, it is also whipping around constantly as the animal is changing direction. A stiff tail that is highly mobile at its base allows for increased agility and changes in direction, and potentially aided Dineobellator in pursuing prey, especially in more open habitats."

This new dinosaur provides a clearer picture of the biology of North American dromaeosaurid dinosaurs, especially concerning the distribution of feathers among its members.

"As we find evidence of more members possessing feathers, we believe it is likely that all the dromaeosaurids had feathers," says Jasinski. The discovery also hints at some of the predatory habits of a group of iconic meat-eating dinosaurs that lived just before the extinction event that killed off all the dinosaurs that weren't birds.

Jasinski plans to continue his field research in New Mexico with the hope of finding more fossils.

"It was with a lot of searching and a bit of luck that this dinosaur was found weathering out of a small hillside," he says. "We do so much hiking and it is easy to overlook something or simply walk on the wrong side of a hill and miss something. We hope that the more we search, the better chance we have of finding more of Dineobellator or the other dinosaurs it lived alongside."

So far, the only direct evidence we have for the existence of dark matter is through gravity-based effects on the matter we can see. And these gravitational effects are so pronounced that we know it must make up about 85 percent of all matter in the universe.

But we know little else about dark matter, including whether it is made up of as-yet-undiscovered particles.

There are many competing theories for the composition and properties of dark matter, and for whether dark matter has any visible markers to at last unmask it.

Among the theorized dark matter particle candidates are WIMPs (weakly interactive massive particles), axions, and sterile neutrinos - and physicists have searched for each type using a variety of Earth and space-based instruments and methods.

Nearly 20 years ago, physicists suggested that the theorized sterile neutrino form of dark matter could be responsible for emitting light at a specific energy as its particles decay away in space, and in 2014 a study detailed a light signature, called the "3.5 keV line," found in very large galaxy clusters - keV is a measure of energy that represents a thousand electron volts or kilo electron volts.

The study theorized that this line, which had no confirmed source, could be the smoking gun for dark matter decay that scientists had been searching for.

But a new study by scientists at the U.S. Department of Energy's (DOE's) Lawrence Berkeley National Laboratory (Berkeley Lab), UC Berkeley, and the University of Michigan - publishing this week in the journal Science (see an arXiv.org preprint: https://arxiv.org/abs/1812.06976) - concludes that this explanation of sterile neutrino decay is now essentially ruled out as the source of this line.

"Our finding does not mean that the dark matter is not a sterile neutrino, but it means that ... there is no experimental evidence to-date that points towards its existence," said Benjamin Safdi, a study co-author and an assistant professor of physics at the University of Michigan.

The researchers' approach, which analyzed X-ray telescope observations of dark places within our own galaxy where dark matter was expected, did not find evidence of the 3.5 keV line.

"Our limits are so strong that they are likely to cause difficulty for any simple models of dark matter," said Nicholas Rodd, study co-author and a physicist affiliated with the Berkeley Lab theory group and the Berkeley Center for Theoretical Physics, which has faculty members from UC Berkeley and Berkeley Lab. Rodd has been working with Safdi for several years in researching possible visible manifestations of dark matter in space.

The technique the researchers developed, which is detailed in the latest study, also has the potential to analyze, with extreme sensitivity, other possible dark matter signatures in space.

"While this work does, unfortunately, throw cold water on what looked like might have been the first evidence for the microscopic nature of dark matter, it does open up a whole new approach to looking for dark matter which could lead to a discovery in the near future," Safdi said.

Instead of looking at other galaxies and galaxy clusters - places expected to be especially rich in dark matter - for signs of this 3.5 keV line, the researchers analyzed data from more than 20 years' worth of X-ray telescope images of "empty" space within our own Milky Way galaxy where you might expect the presence of dark matter but nothing else.

Based on observed gravitational effects associated with dark matter, galaxies including our own Milky Way galaxy are expected to be surrounded by so-called halos of dark matter. Such halos would explain observations showing that objects nearer to a galaxy's center orbit as the same speed as objects at the outskirts, which defies explanation if you only take into account visible matter.

"Everywhere we look, there should be some flux of dark matter from the Milky Way halo," Rodd said, owing to our solar system's location in the galaxy. "We exploited the fact that we live in a halo of dark matter" in the study.

Christopher Dessert, a study co-author who is a physics researcher and Ph.D. student at the University of Michigan, said galaxy clusters where the 3.5 keV line has been observed also have large background signals, which serve as noise in observations and can make it difficult to pinpoint specific signals that may be associated with dark matter.

"The reason why we're looking through the galactic dark matter halo of our Milky Way galaxy is that the background is much lower," Dessert said.

The researchers used data from the XMM-Newton (X-ray Multi-Mirror) mission, a space-based X-ray telescope launched in 1999 by the European Space Agency. They restricted the data they used to a collection of images from about 800 so-called "blank sky" regions in space that were sampled within 5 to 45 degrees of the Milky Way's galactic center - areas expected to have higher concentrations of dark matter.

They compared their own analysis to others' analyses that were based on observations of regions in space thought to be rich in dark matter, such as the Perseus Cluster of galaxies and the Andromeda Galaxy.

Rodd said the team's analysis technique could be used to reanalyze data taken from other X-ray telescopes' observations to scan in high detail for other light signals emitted across a far broader range of energies.

"How can we extend this technique to look at more cases?" Rodd said. "There are tons of other datasets out there that we don't say anything about in this study. If you are looking generically for dark-matter decay and you want to have more sensitivity, this is the way. This is a general tool that anyone searching for dark matter can use."