Tech

Spider webs are one of nature's most fascinating manifestations. Many spiders extrude proteinaceous silk to weave sticky webs that ensnare unsuspecting prey who venture into their threads. Despite their elasticity, these webs possess incredible tensile strength. In recent years, scientists have expressed increased interest in the spider orb-web as a biological-mechanical system. The web's sensory mechanisms are especially fascinating, given that most web-weaving spiders--regardless of their vision level--use generated vibrations to effectively locate ensnared prey.

"The spider orb-web is a natural, lightweight, elegant structure with an extreme strength-to-weight ratio that is rarely observed among other structures, either natural or manmade," Antonino Morassi said. "Its primary functions are catching prey and gathering sensory information, and study of the mechanisms that guide these processes through web vibration has been one of the main research goals in the field."

To understand the mechanics of orb-webs, researchers have previously utilized simplified patterns of wave propagation or relied upon numerical models that reproduce a spider web's exact geometry via one-dimensional elements. While these numerical models adequately handle wind, prey movement, and other sources of vibration, they fall short of providing insight into the physical phenomena responsible for web dynamics. In an article publishing this week in the SIAM Journal on Applied Mathematics, Morassi and Alexandre Kawano present a theoretical mechanical model to study the inverse problem of source identification and localize a prey in a spider orb-web.

Due to structural interconnectivity between the circumferential and radial threads, vibrations in an orb-web spread laterally and move beyond the stimulated radius. This observation led Kawano and Morassi towards realistic mechanical models that measure a fibred web's two-dimensionality, rather than more limiting one-dimensional models. "There was no mechanical model--even a simplified one--that described the web as it really is: a two-dimensional vibrating system," Morassi said. "We decided to use a continuous membrane model since theoretical models often permit a deeper insight in the physical phenomena through analysis of the underlying mathematical structure of the governing equations." These equations are also useful in identifying the most relevant parameters that dictate a web's response.

The authors classify their model as a network of two intersecting groups of circumferential and radial threads that form an uninterrupted, continuous elastic membrane with a specific fibrous structure. To set up the inverse problem, they consider the spider's dynamic response to the prey's induced vibrations from the center of the web (where the spider usually waits). For the sake of simplicity, Kawano and Morassi limit the model's breadth to circular webs. The geometry of their model allows for a specific fibrous structure, the radial threads of which are denser towards the web's center.

The researchers note that the minimal data set to ensure uniqueness in the prey's localization seems to accurately reproduce real data that the spider collects right after the prey makes contact with the web. "By continuously testing the web, the spider acquires the dynamical response of the web approximately on a circle centered at the web's origin, and with radius significantly small with respect to the web dimensions," Kawano said. "Numerical simulations show that identification of the prey's position is rather good, even when the observation is taken on the discrete set of points corresponding to the eight legs of the spider."

Ultimately, the authors hope that their novel mechanical model will encourage future research pertaining to nearly periodic signals and more general sources of vibration. They are already thinking about ways to further expand their model. "We believe that it may be of interest to generalize the approach to more realistic geometries -- for example, for spider webs that deviate a little from the circular axisymmetric shape and maintain only a single axis of symmetry," Morassi said. "Furthermore, here we considered the transversal dynamic response caused by orthogonal impact of a prey on the web. In real-world situations, impact can be inclined and cause in-plane vibrations to propagate throughout the web. The analysis of these aspects, among others, may provide novel and important insights, not only for the prey's catching problem but also for bioinspired fibrous networks for sensing applications involving smart multifunctional materials."

Monsoons can have a significant impact on human populations all around the world, bringing heavy rainfall associated with flooding and mudslides that can damage crops and pose a health and safety risk. In countries such as India, monsoons also provide a vital source of water needed for growing crops. Being able to accurately forecast monsoons, as well as predict climate changes that drive these events, is of great benefit to humanity as it can help communities to better prepare and plan, which can improve safety and reduce economic losses. A team of researchers from the Chinese Academy of Sciences have conducted a series of model perturbation experiments, producing datasets that can help improve these predictions.

The model design, experiments and datasets from the simulations are described in a data description paper recently published on December 10, 2019 in Advances in Atmospheric Sciences.

A monsoon is a seasonal change in atmospheric circulation or prevailing wind direction that is associated with corresponding changes in precipitation resulting from uneven heating of sea and land surfaces. Monsoons blow from cold regions to warm regions, and are responsible for wet and dry seasons in the tropics. However, because external factors such as the location of land masses and oceans can influence regional wind and rainfall patterns, the characteristics and behavior of monsoons vary from region to region. The South Asian monsoon, for example, is particularly strong as the Himalayas and Tibetan-Iranian Plateau prevent dry air from the north flowing to the humid monsoon region in India and southern Asia.

The Chinese Academy of Sciences (CAS) Flexible Global Ocean-Atmosphere-Land System (FGOALS-f3-L) model datasets prepared for the sixth phase of the Coupled Model Intercomparison Project (CMIP6) Global Monsoons Model Intercomparison Project (GMMIP) provide a valuable tool to assess sea surface temperature trends and its influence on monsoon circulation and precipitation patterns, while also providing a clearer understanding of how topography can affect the global monsoon system as it passes over landscapes with high altitudes.

"These datasets are useful especially for understanding the changes of sub-seasonal climate signals forced by the Tibetan-Iranian Plateau," said lead author, Bian He, a research scientist at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS), and College of Earth and Planetary Sciences, University of Chinese Academy of Sciences, in Beijing, China.

The global monsoon system is made up of several sub-monsoon systems, including the Asian, Australian, northern and southern African, North American and South American monsoons, each with their own unique characteristics and behaviors relative to when and where they occur. These differences have proved challenging for current climate models, primarily because we do not yet fully understand the complex atmosphere-ocean-land interactions that drive monsoon systems, which in turn are influenced by external forces and internal variabilities.

Topography can affect weather, for example, by forcing air upwards which can cause disturbances in the weather system. As the air rises, changes in pressure and temperature can result in precipitation -- a phenomenon known as the orographic effect or orographic precipitation. While it is acknowledged that topography can influence monsoons, there is still much debate regarding the direct impact that global highlands have on monsoon circulation and precipitation.

"We provided three ensemble simulations of long-term changes of the global monsoon under observed Sea Surface Temperature (SST) and Sea ice forcing to reduce uncertainty from the initial method," explained He, "We also provided high time frequency outputs in GMMIP Tier-3 experiments for better understanding the role of the Tibetan Plateau in the global monsoon system by transient processes."

This is one of two papers the authors contributed to the IPCC CMIP6 world climate research programme. The companion paper describes the outputs of the Chinese Academy of Sciences (CAS) Flexible Global Ocean-Atmosphere-Land System (FGOALS-f3-L) model for the baseline experiment of the Atmospheric Model Intercomparison Project simulation in the Diagnostic, Evaluation and Characterization of Klima common experiments of phase 6 of the Coupled Model Intercomparison Project (CMIP6).

"Our next step is to consider air-sea interactions in the simulation, as this is also an important factor in understanding global monsoons and associated topographical effects," said He. "Our ultimate goal is to improve model simulations on monsoon behavior in order to more accurately forecast monsoons."

According to the CDC, the suicide rate for individuals 10-24 years old has increased 56% between 2007 and 2017. In comparison to the general population, more than half of people experiencing homelessness have had thoughts of suicide or have attempted suicide, the National Health Care for the Homeless Council reported.

Phebe Vayanos, assistant professor of Industrial and Systems Engineering and Computer Science at the USC Viterbi School of Engineering has been enlisting the help of a powerful ally -artificial intelligence- to help mitigate the risk of suicide.

"In this research, we wanted to find ways to mitigate suicidal ideation and death among youth. Our idea was to leverage real-life social network information to build a support network of strategically positioned individuals that can 'watch-out' for their friends and refer them to help as needed," Vayanos said.

Vayanos, an associate director at USC's Center for Artificial Intelligence in Society (CAIS), and her team have been working over the last couple of years to design an algorithm capable of identifying who in a given real-life social group would be the best persons to be trained as "gatekeepers" capable of identifying warning signs of suicide and how to respond.

Vayanos and Ph.D. candidate Aida Rahmattalabi, the lead author of the study "Exploring Algorithmic Fairness in Robust Graph Covering Problems," investigated the potential of social connections such as friends, relatives, and acquaintances to help mitigate the risk of suicide. Their paper will be presented at the Thirty-third Conference on Neural Information Processing Systems (NeurIPS) this week.

"We want to ensure that a maximum number of people are being watched out for, taking into account resource limitations and uncertainties of open world deployment. For example, if some of the people in the network are not able to make it to the gatekeeper training, we still want to have a robust support network," Vayanos said.

For this study, Vayanos and Rahmattalabi looked at the web of social relationships of young people experiencing homelessness in Los Angeles, given that 1 in 2 youth who are homeless have considered suicide.

"Our algorithm can improve the efficiency of suicide prevention trainings for this particularly vulnerable population," Vayanos said.

For Vayanos, efficiency translates into developing a model and algorithm that can stretch limited resources as far as they can go. In this scenario, the limited resources are the human gatekeepers. This algorithm tries to plan how these individuals can be best positioned and trained in a network to watch out for others.

"If you are strategic," says Vayanos, "you can cover more people and you can have a more robust network of support."

"Through this study, we can also help inform policymakers who are making decisions regarding funding on suicide prevention initiatives; for example, by sharing with them the minimum number of people who need to receive the gatekeeper training to ensure that all youth have at least one trained friend who can watch out for them," Vayanos said.

"Our aim is to protect as many youth as possible," said lead author, Rahmattalabi.

An important goal when deploying this A.I. system is to ensure fairness and transparency.

"We often work in environments that have limited resources, and this tends to disproportionately affect historically marginalized and vulnerable populations," said co-author on the study Anthony Fulginiti, an assistant professor of social work at the University of Denver who received his Ph.D. from USC, having begun his research with Eric Rice, founding director of USC CAIS.

"This algorithm can help us find a subset of people in a social network that gives us the best chance that youth will be connected to someone who has been trained when dealing with resource constraints and other uncertainties," said Fulginiti.

This work is particularly important for vulnerable populations, say the researchers, particularly for youth who are experiencing homelessness.

"One of the surprising things we discovered in our experiments based on social networks of homeless youth is that existing A.I. algorithms, if deployed without customization, result in discriminatory outcomes by up to 68% difference in protection rate across races. The goal is to make this algorithm as fair as possible and adjust the algorithm to protect those groups that are worse off," Rahmattalabi said.

The USC CAIS researchers want to ensure that "gatekeeper" coverage of the more vulnerable groups is as high as possible. Their algorithm reduced the bias in coverage in real-life social networks of homeless youth by as much as 20%.

Said Rahmattalabi: "Not only does our solution advance the field of computer science by addressing a computationally hard problem, but also it pushes the boundaries of social work and risk management science by bringing in computational methods into design and deployment of prevention programs."

The transformation and degradation of natural landscapes due to human activities has been intensifying for several decades. This is especially true for forestland: its area decreases each year, especially in tropical regions. In Southeast Asia, tropical rainforests are cut down to make room for new plantations. Around 0.4 mln ha of forests are destroyed every year on Sumatra (Indonesia) only.

These actions affect the biodiversity of soil fauna that are key in nutrient cycling and other biological processes. Large-scale deforestation influences the activities and diets of soil animals, forcing them to adapt to new conditions. For example, instead of hunting rainforest dwellers, some predatory myriapods switch to less nutritious species that can be found on oil palm plantations.
The study, carried out by the Institute for Ecological and Agricultural Biology (X-BIO) of Tyumen State University in collaboration with foreign colleagues, was a part of an interdisciplinary project titled "Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems". The study focused on oribatid mites (Oribatida), one of the most widely-spread soil arthropods in the world. Eleven thousand species of these mites are currently known to scientists, but there are likely many more.

The authors suggest that oribatid mites may adapt to environmental change by altering their diet. To confirm this hypothesis, the scientists measured nitrogen and carbon isotope ratios in six species of mites. The specimens were obtained from the tropical rainforest, rubber tree jungle, rubber tree plantation, and oil palm plantation habitats. Mites were taken from soil samples that came from two different regions of Jambi Province, Indonesia. Afterwards, the mites were divided into groups or guilds based on their diet: lichenophages (feed on lichen), primary saprophages (leaf litter), secondary saprophages-mycophages (floccus), and predators/scavengers.
Subsequently, the scientists measured stable nitrogen and carbon isotopes in the ex?rements of the mites, calculated the average values for each geographical area, and calculated the deviations for each species.

According to the researchers, the levels of stable isotopes differed considerably in mites from different land-use systems. In particular, Rostrozetes sp. found on oil palm plantations had lower nitrogen isotope content than mites of the same species from any other environment. For S. praeincisus, the lowest nitrogen content was found in the tropical rainforest, while the highest - in the rubber tree jungle. This means that mites switch from one food source to another depending on the environment. The research showed that oribatid mites, which are usually saprophages, turn into predators or scavengers, changing their diet depending on the environmental circumstances. R. cf. shibai mites were found to be saprophageous in the plantation and rainforest environments, while in the rubber tree jungle they displayed predatory dietary patterns. However, B. mahunkai mites were predacious in all sampled environments, which points to the fact that not all mites adapt their dietary patterns to the environmental conditions.

According to the study, oribatid mites are able to change their diet depending on the fluctuations in the available food resources. The biggest shifts occur when mites transition from living in natural ecosystems (rainforest or rubber tree jungle) to intensive land use environments (rubber tree or oil palm plantations). Based on the results of this study, scientists may be able to monitor man-induced changes in natural habitats using oribatid mites.

Highlights

- Secure data backup of medical records based on secret sharing

- Restoration of medical records via a satellite link within 9 sec after searching a patient ID

- Cross reference of medical records between different organizations using standardized data format

Abstract

The National Institute of Information and Communications Technology (NICT, President: Hideyuki Tokuda, Ph.D.), Kochi Health Science Center (KHSC, Director: Yasuhiro Shimada) and collaborating teams have developed a secure data backup system in an 800 km network connecting the data servers in Kochi, Osaka, Nagoya, Otemachi and Koganei, Japan, using secret sharing and secure communications technologies, and demonstrated distributed storage of medical records and prompt restoration of important items, such as prescription records and allergy information, via a satellite link within a time as short as 9 sec.

This technology would be useful for medical support in disaster situations as well as sharing and cross referencing medical records between various hospitals in ordinary situations.

The results will be presented in the session of quantum communication on December 16 in the EU-USA-Japan International Symposium on Quantum Technology 2019 held in Kyoto, Japan.

Background

In the Great East Japan Earthquake in 2011, many medical institutions were destroyed and data servers storing medical records were washed away by tsunami waters. It was then recognized that medical records should be backed up in remote places safely for such contingencies. In the case of emergency care after a disaster, medical examinations and treatment should be given to many people in a short time. During these times, there is a need to promptly restore a minimum of necessary items to profile a patient, such as prescription records and allergy information.

Medical records are highly confidential personal information. Therefore, the backup of medical records should be protected by appropriate security techniques. Furthermore, if the backup conforms to a common standardized data format, they can be shared and cross referenced by many medical institutions to prevent duplicated examination and excessive medication as well as to develop new medical technologies.

So far, no techniques have been available which satisfy all these requirements at once.

Achievements

We combined secret sharing and secure communications technologies to realize a secure data backup system and demonstrated distributed storage of medical records and prompt restoration of important items, such as prescription records and allergy information, via a satellite link. This system is referred to as the Healthcare Long-term INtegrity and Confidentiality protection System (H-LINCOS).

This H-LINCOS has been implemented in an 800 km network connecting the data servers in KHSC, and the access points of a high-speed R&D network testbed called JGN operated by NICT, which are located in Osaka, Nagoya, Otemachi, and Koganei (see Figure 1). To realize highly secure access control to the H-LINCOS, authentication functions are also implemented, using next generation technologies of quantum-safe public-key cryptography, which is expected to be secure even against quantum computer attacks.

In this experiment, sample data of medical records of 10,000 patients were provided by KHSC, whose total data size was 90 GB, converted into the standardized data format for medical information exchange (SS-MIX), and stored in a distributed manner in the H-LINCOS. In the demonstration of data recovery, we assumed that the Kochi area was damaged by a disaster, and terrestrial communication links to the Kochi area were disconnected. Under this scenario, a satellite link provided by SKY Perfect JSAT was introduced to the H-LINCOS connecting the ground stations in Yokohama and KHSC. Upon a query for a patient data item from a terminal device in KHSC, the original data was first restored in the Koganei data server by combining data pieces from two data servers in Osaka, Nagoya or Otemachi. The restored data was then sent to the Yokohama ground station, relayed to the KHSC ground station via the satellite link, and finally delivered to the terminal device in KHSC.

We could successfully restore important items, such as prescription records and allergy information, and display them on a screen within a time as short as 9 sec after the query. An allowable time to wait for information acquisition in emergency medicine is typically 15 sec. Our result satisfied this criterion. Our technology enables prompt delivery of medical information in disaster situations. It also provides a means to share and cross reference medical records between various hospitals in ordinary situations.

Future Prospects

We will further improve the performance and the reliability of the H-LINCOS. In particular, we will analyze communication latencies and H-LINCOS congestion when the stored data size and the number of connected terminal devices to access increase. We will also investigate efficient healthcare support in disaster situations by jointly operating the H-LINCOS and the Disaster/Digital information system for Health and well-being (D24H).

The evolution of human dance has been studied by psychologists in chimpanzees

Researchers from the University of Warwick, Durham University and Free University of Brussels found two chimpanzees performed a duo dance-like behaviour, similar to a conga-line

Behaviours displayed by the chimpanzees forces an interest in the evolution of dance as humans are no longer the only ape species where it takes two individuals to tango.

Psychologist observing two chimpanzees in a zoo have discovered that they performed a behaviour hitherto never seen, they coordinated together in a rhythmic social ritual.

Two chimpanzees housed in a zoo in the US have sparked the question about how human dance evolved after being observed performing a duo dance-like behaviour, similar to a human conga-line.

In the paper 'Coupled whole-body rhythmic entrainment between two chimpanzees' published today, the 12th of December in the Journal Scientific Reports, researchers led by the University of Warwick found the levels of motoric co-ordination, synchrony and rhythm between the two female chimpanzees matched the levels shown by orchestra players performing the same musical piece.

Other species have been shown to be able to entertain by moving to the pace of a rhythmic tempo by an external stimulus and solo individuals, however this is the first time it hasn't been triggered by nonhuman partners or signals.

Although the newly described behaviour probably represents a new form a stereotypy in captivity in this great ape species, the behaviour forces scientists interested in the evolution of human dance to consider new conditions that may have catalysed the emergence of one of human's most exuberant and richest forms of expression.

Dr Adriano Lameira, from the Department of Psychology at the University of Warwick comments:

"Dance is an icon of human expression. Despite astounding diversity around the world's cultures and dazzling abundance of reminiscent animal systems, the evolution of dance in the human clade remains obscure.

"Dance requires individuals to interactively synchronize their whole-body tempo to their partner's, with near-perfect precision, this explains why no dance forms were present amongst nonhuman primates. Critically, this is evidence for conjoined full-body rhythmic entrainment in great apes that could help reconstruct possible proto-stages of human dance is still lacking."

The researchers report an endogenously-effected case of ritualized dance-like behaviour between two captive chimpanzees - synchronized bipedalism. By studying videos they revealed that synchronisation between individuals was non-random, predictable, phase concordant, maintained with instantaneous centi-second precision and jointly regulated, with individuals also taking turns as "pace-makers".

As sea levels rise and adverse weather events become more common, vulnerable coastal communities are at increasing risk of devastation from storm surges and tsunamis. The death toll from tsunamis, at 260,000 during the past century, was higher than that from any other natural hazard. An international research team led by the University of Göttingen has now compared the effects of man-made and ecosystem protection to propose a hybrid approach including mangroves and coral reefs in coastal protection plans for tropical biodiversity hotspots. The results were published in the journal Trends in Ecology and Evolution.

In this study, led by Dr Thomas Wanger at the Agroecology Group at the University of Göttingen, an international team of scientists from Germany, China, Indonesia, Australia, and Singapore evaluated the ways coastal communities can be protected against disaster. The scientists compared conventional engineering solutions such as giant sea walls, with ecological solutions such as mangroves and coral reefs. They evaluated the effectiveness, cost, and the capacity to sustain biodiversity and ecosystems. The research provides new insights about the implementation of improving ecosystem-based coastal protection.

Palu in Indonesia has long been home to collaborative research centres led by the University of Göttingen. In 2018, Palu was destroyed by a major tsunami and so the Indonesian government implemented a coastal protection plan. The international research team has worked to improve the existing plan by applying their new findings. In addition, the team proposed to use the city of Palu as a case study to further investigate how ecological factors can mitigate the dangers for coastal communities globally.

"In the future, ecosystem-based protection should form the basis to plan a coastal protection strategy. Improving this strategy through man-made and engineered solutions may make the entire endeavour more cost-efficient and may better protect valuable coastal biodiversity and related ecosystem services," says Wanger. "If the international research community can monitor such a hybrid 'ecosystem-based and engineered' approach in Palu, the 'Palu Model' could become an important learning opportunity for other high risk coastal hazard sites in tropical biodiversity hotspots." he adds.

Strong and tough yet as light as a feather - materials with this exceptional combination of properties are urgently needed in many industrial sectors and in medicine, as well as being of great interest for scientific research. A research team from the University of Bayreuth has now developed polymer fibres with precisely these properties. Together with partners in Germany, China and Switzerland, the polymer fibers were characterized. The scientists have published their results in the journal Science.

"The fibres we discovered can be produced easily using high-tech processes that are already established in the industry - and on the basis of polymers that are readily available worldwide. One individual fibre is as thin as a human hair, weighs less than a fruit fly, and yet is very strong: It can lift a weight of 30 grams without tearing. This corresponds to about 150,000 times the weight of a fruit fly. Experiments on the high tensile strength of these fibres have furthermore revealed their high toughness. This means that each individual fibre can absorb a lot of energy," explains Prof. Dr. Andreas Greiner, who is the head of the research group Macromolecular Chemistry II at the University of Bayreuth, and who guided the research work. Also involved were researchers at the Forschungszentrum Jülich, the Martin Luther University Halle-Wittenberg, the Fraunhofer-Institute for Microstructure of Materials and Systems (IMWS), the Rheinisch-Westfälische Technische Hochschule Aachen University, the Jiangxi Normal University, Nanchang, and the ETH Zürich.

Due to their unique properties, the polymer fibres are ideally suited for technical components that are exposed to high loads. They enable innovative applications in a wide variety of fields, for example in the textile industry or medical technology, in automotive engineering, or in the aerospace industry. In addition, the polymer fibres can be recycled well. "We are certain that our research results have opened the door to a new, forward-looking class of materials. Practical applications on the part of industry can be expected in the near future. In polymer science, our fibres will be able to provide valuable services in the further research and development of high-performance functional materials," says Greiner.

The chemical basis of these promising fibres is polyacrylonitrile. A single fibre with a diameter of about 40,000 nanometres consists of up to 4,000 ultra-thin fibrils. These fibrils are linked by small amounts of an additive. Three-dimensional X-ray images show that the fibrils within the fibre are almost always arranged in the same longitudinal direction. "We prepared these multifibrillar polyacrylonitrile fibers in a laboratory for electrospinning at the University of Bayreuth and extensively tested them for their properties and behaviour. Their unique strength in combination with high toughness never ceased to fascinate us," reports the Bayreuth polymer scientist Prof. Dr. Seema Agarwal.

The lead author of the study published in Science is Xiaojian Liao, a doctoral researcher in chemistry in Bayreuth. "I am very pleased that I was able to contribute to this research success in materials science as part of my doctoral thesis. The intensive interdisciplinary contact between chemistry, physics, and material sciences on the Bayreuth campus has provided some critical impetus in recent years," says Liao.

New findings published in the Journal of Clinical Investigation suggest that specific immune T cells from people with myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) show disruptions in the way they produce energy. The research was supported by the National Institutes of Health.

"This research gives us additional evidence for the role of the immune system in ME/CFS and may provide important clues to help us understand the mechanisms underlying this devastating disease," said Vicky Whittemore, Ph.D., program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS), which partially funded the study.

ME/CFS is a severe, chronic, and debilitating disease that can cause a range of symptoms including pain, severe exhaustion, cognitive impairment, and post-exertional malaise, the worsening of symptoms after physical or mental activity. Estimates suggest that between 836,000 and 2.5 million people in the United States may be affected by ME/CFS. It is unknown what causes the disease and there are no treatments.

Research by Alexandra Mandarano and collaborators in the laboratory of Maureen Hanson, Ph.D., professor of molecular biology and genetics at Cornell University in Ithaca, New York, examined biochemical reactions involved in energy production, or metabolism, in two specific types of immune cells obtained from 45 healthy controls and 53 people with ME/CFS. Investigators focused on CD4 T cells, which alert other immune cells about invading pathogens, and CD8 T cells, which attack infected cells. Dr. Hanson's team used state-of-the-art methods to look at energy production by the mitochondria within T cells, when the cells were in a resting state and after they had been activated. Mitochondria are biological powerhouses and create most of the energy that drives cells.

Dr. Hanson and her colleagues did not see significant differences in mitochondrial respiration, the cell's primary energy-producing method, between healthy and ME/CFS cells at rest or after activation. However, results suggest that glycolysis, a less efficient method of energy production, may be disrupted in ME/CFS. Compared to healthy cells, CD4 and CD8 cells from people with ME/CFS had decreased levels of glycolysis at rest. In addition, ME/CFS CD8 cells had lower levels of glycolysis after activation.

"Our work demonstrates the importance of looking at particular types of immune cells that have different jobs to do, rather than looking at them all mixed together, which can hide problems specific to particular cells," said Dr. Hanson. "Additional studies focusing on specific cell types will be important to unravel what's gone wrong with immune defenses in ME/CFS."

Dr. Hanson's group also looked at mitochondrial size and membrane potential, which can indicate the health of T cell mitochondria. CD4 cells from healthy controls and people with ME/CFS showed no significant differences in mitochondrial size nor function. CD8 cells from people with ME/CFS showed decreased membrane potential compared to healthy cells during both resting and activated states.

Dr. Hanson's team examined associations between cytokines, chemical messengers that send instructions from one cell to another, and T cell metabolism. The findings revealed different, and often opposite, patterns between healthy and ME/CFS cells, suggesting changes in the immune system. In addition, the presence of cytokines that cause inflammation unexpectedly correlated with decreased metabolism in T cells.

This study was supported in part by the NIH's ME/CFS Collaborative Research Network, a consortium supported by multiple institutes and centers at NIH, consisting of three collaborative research centers and a data management coordinating center. The research network was established in 2017 to help advance research on ME/CFS.

"In addition to providing valuable insights into the immunology of ME/CFS, we hope that the results coming out of the collaborative research network will inspire more researchers, particularly those in the early stages of their careers, to work on this disease," said Joseph Breen, Ph.D., section chief, Immunoregulation Section, Basic Immunology Branch, National Institute of Allergy and Infectious Diseases (NIAID), which partially funded the study.

Future research studies will examine metabolism in other subsets of immune cells. In addition, researchers will investigate ways in which changes in metabolism affect the activity of T cells.

CHAMPAIGN, Ill. -- A virus that afflicts cattle that was first discovered in Japan in 2003 has made its way to the U.S., researchers report in the journal Emerging Infectious Diseases.

Bovine kobuvirus is fairly new to science, so its ill effects are not fully understood. It belongs to a family of viruses known as Picornaviridae, which includes Rhinovirus, a source of head colds and sinus infections in humans; and Poliovirus, which causes polio.

Previous studies conducted elsewhere in the world have found bovine kobuvirus in fecal samples of cattle with diarrhea. The new study confirmed this association by sequencing the microbial DNA in samples from cattle in the U.S. and analyzing the intestines of two calves that died after infection.

"Only bovine kobuvirus was detected in both cases," said University of Illinois veterinary clinical medicine professor Dr. Leyi Wang, who led the new study. "This provides evidence that this virus is the causative agent for calf diarrhea."

So far, no other negative associations with bovine infection have been observed. However, since almost no one in North America is looking for the virus in cattle or other species, it remains to be seen how this emerging disease agent influences health, Wang said.

"Continued surveillance of bovine kobuvirus is urgently needed to determine how widespread it is," Wang said. "Scientists have access to only a few genetic sequences of this virus in public databases. We need to be sequencing these viruses to learn more about their genetic diversity and evolution."

Four of nine samples tested at the U. of I. Veterinary Diagnostic Laboratory were found to harbor bovine kobuvirus, the team reported. All of the infected cows were from the state of Illinois.

Elsewhere in the world, bovine kobuvirus has been detected in about 10 countries in Asia, Europe, South America and Africa.

Astrophysicists are redrawing the textbook image of pulsars, the dense, whirling remains of exploded stars, thanks to NASA's Neutron star Interior Composition Explorer (NICER), an X-ray telescope aboard the International Space Station. Using NICER data, scientists have obtained the first precise and dependable measurements of both a pulsar's size and its mass, as well as the first-ever map of hot spots on its surface.

The pulsar in question, J0030+0451 (J0030 for short), lies in an isolated region of space 1,100 light-years away in the constellation Pisces. While measuring the pulsar's heft and proportions, NICER revealed that the shapes and locations of million-degree "hot spots" on the pulsar's surface are much stranger than generally thought.

"From its perch on the space station, NICER is revolutionizing our understanding of pulsars," said Paul Hertz, astrophysics division director at NASA Headquarters in Washington. "Pulsars were discovered more than 50 years ago as beacons of stars that have collapsed into dense cores, behaving unlike anything we see on Earth. With NICER we can probe the nature of these dense remnants in ways that seemed impossible until now."

A series of papers analyzing NICER's observations of J0030 appears in a focus issue of The Astrophysical Journal Letters and is now available online.

When a massive star dies, it runs out of fuel, collapses under its own weight and explodes as a supernova. These stellar deaths can leave behind neutron stars, which pack more mass than our Sun into a sphere roughly as wide as the island of Manhattan is long. Pulsars, which are one class of neutron star, spin up to hundreds of times each second and sweep beams of energy toward us with every rotation. J0030 revolves 205 times per second.

For decades, scientists have been trying to figure out exactly how pulsars work. In the simplest model, a pulsar has a powerful magnetic field shaped much like a household bar magnet. The field is so strong it rips particles from the pulsar's surface and accelerates them. Some particles follow the magnetic field and strike the opposite side, heating the surface and creating hot spots at the magnetic poles. The whole pulsar glows faintly in X-rays, but the hot spots are brighter. As the object spins, these spots sweep in and out of view like the beams of a lighthouse, producing extremely regular variations in the object's X-ray brightness. But the new NICER studies of J0030 show pulsars aren't so simple.

Using NICER observations from July 2017 to December 2018, two groups of scientists mapped J0030's hot spots using independent methods and converged on similar results for its mass and size. A team led by Thomas Riley, a doctoral student in computational astrophysics, and his supervisor Anna Watts, a professor of astrophysics at the University of Amsterdam, determined the pulsar is around 1.3 times the Sun's mass and 15.8 miles (25.4 kilometers) across. Cole Miller, an astronomy professor at the University of Maryland (UMD) who led the second team, found J0030 is about 1.4 times the Sun's mass and slightly larger, about 16.2 miles (26 kilometers) wide.

"When we first started working on J0030, our understanding of how to simulate pulsars was incomplete, and it still is," Riley said. "But thanks to NICER's detailed data, open-source tools, high-performance computers and great teamwork, we now have a framework for developing more realistic models of these objects."

A pulsar is so dense its gravity warps nearby space-time -- the "fabric" of the universe as described by Einstein's general theory of relativity -- in much the same way as a bowling ball on a trampoline stretches the surface. Space-time is so distorted that light from the side of the pulsar facing away from us is "bent" and redirected into our view. This makes the star look bigger than it is. The effect also means the hot spots may never completely disappear as they rotate to the far side of the star. NICER measures the arrival of each X-ray from a pulsar to better than a hundred nanoseconds, a precision about 20 times greater than previously available, so scientists can take advantage of this effect for the first time.

"NICER's unparalleled X-ray measurements allowed us to make the most precise and reliable calculations of a pulsar's size to date, with an uncertainty of less than 10%," Miller said. "The whole NICER team has made an important contribution to fundamental physics that is impossible to probe in terrestrial laboratories."

Our view from Earth looks onto J0030's northern hemisphere. When the teams mapped the shapes and locations of J0030's spots, they expected to find one there based on the textbook image of pulsars, but didn't. Instead, the researchers identified up to three hot "spots," all in the southern hemisphere.

Riley and his colleagues ran rounds of simulations using overlapping circles of different sizes and temperatures to recreate the X-ray signals. Performing their analysis on the Dutch national supercomputer Cartesius took less than a month -- but would have required around 10 years on a modern desktop computer. Their solution identifies two hot spots, one small and circular and the other long and crescent-shaped.

Miller's group performed similar simulations, but with ovals of different sizes and temperatures, on UMD's Deepthought2 supercomputer. They found two possible and equally likely spot configurations. One has two ovals that closely match the pattern found by Riley's team. The second solution adds a third, cooler spot slightly askew of the pulsar's south rotational pole.

Previous theoretical predictions suggested that hot spot locations and shapes could vary, but the J0030 studies are the first to map these surface features. Scientists are still trying to determine why J0030's spots are arranged and shaped as they are, but for now it's clear that pulsar magnetic fields are more complicated than the traditional two-pole model.

NICER's main science goal is to precisely determine the masses and sizes of several pulsars. With this information scientists will finally be able to decipher the state of matter in the cores of neutron stars, matter crushed by tremendous pressures and densities that cannot be replicated on Earth.

"It's remarkable, and also very reassuring, that the two teams achieved such similar sizes, masses and hot spot patterns for J0030 using different modeling approaches," said Zaven Arzoumanian, NICER science lead at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "It tells us NICER is on the right path to help us answer an enduring question in astrophysics: What form does matter take in the ultra-dense cores of neutron stars?"

NICER is an Astrophysics Mission of Opportunity within NASA's Explorers program, which provides frequent flight opportunities for world-class scientific investigations from space utilizing innovative, streamlined and efficient management approaches within the heliophysics and astrophysics science areas. NASA's Space Technology Mission Directorate supports the SEXTANT component of the mission, demonstrating pulsar-based spacecraft navigation.

Colon cancer cells deficient in p53, one of the most important control proteins in cell growth, activate a particular metabolic pathway to adapt to the lack of oxygen and nutrients inside the tumor. Statins, which are often prescribed to lower cholesterol, block this metabolic pathway and cause the cancer cells to die, as scientists from the German Cancer Research Center (DKFZ) have now discovered. The researchers now intend to investigate this potential treatment strategy in more detail in cancer cells and animal experiments.

Once a tumor has reached a certain size, the cancer cells face a particular challenge: Growing in a disorganized way, tumors lack blood vessels, which leads to oxygen and nutrient deficiency inside the tumor. "Cancer cells have to completely reorganize their entire metabolism to adapt to this deficiency," Almut Schulze, an expert on metabolism at DKFZ, explained.

In her current work, Schulze investigated indications that the important control protein and tumor suppressor p53 plays a crucial role in adapting to deficiencies. Schulze and her team examined p53-deficient colon cancer cells to find out how p53 actually impacts on metabolic adaptation.

In order to mimic the deficient environment inside a cancerous tumor in a Petri dish, the researchers let the cancer cells grow into small spheroids. Colon cancer cells with intact p53 adapted to the deficient environment by restricting their growth. In contrast, the p53-deficient tumor cells inside the spheroids continued to grow as before, activating a metabolic pathway known as the mevalonate pathway, which supplied the cells with cholesterol, an important cell membrane component.

The mevalonate pathway can be inhibited using statins, which are common cholesterol-lowering agents. Treatment with statins did in fact induce apoptosis in the deficient environment inside the p53-deficient microtumors. In contrast, microtumors with intact p53 did not respond to the treatment.

Schulze and her team also found another way in which p53-deficient colon cancer cells adapted to the deficiencies: The activated mevalonate pathway also promoted the synthesis of ubiquinone, an important component in electron transport in the respiratory chain. In deficient environments, cancer cells are more heavily dependent on this substance - also called coenzyme Q10 - to synthesize new DNA.

"Cancer cells that are deficient in p53 use the mevalonate pathway to promote cell respiration and to access key cell components, hence ensuring their survival. From an oncologist's viewpoint, it is particularly interesting that this metabolic pathway is easy to inhibit with statins, allowing us to use a common drug to induce apoptosis in the cancer cells," Almut Schulze explained. "This only applies under the particular conditions of deficiency that prevail inside a tumor, however," she added. "That means that statins should be combined with agents that promote this metabolic stress, such as drugs that inhibit the formation of new blood vessels." Schulze hopes to test this new treatment strategy on tumor cells and in animal experiments as soon as possible.

DURHAM, N.C. -- Scientists from Duke University have developed a model that can predict the amount of mercury being released into a local ecosystem by deforestation and small-scale gold mining.

The research, which appears online on December 11 in the journal Environmental Science and Technology, could point toward ways to mitigate the worst effects of mercury poisoning in regions such as those that are already experiencing elevated mercury levels caused by gold mining.

"We've taken a lot of ground measurements in the Peruvian Amazon of mercury levels in the water, soil and fish," said Heileen Hsu-Kim, professor of civil and environmental engineering at Duke University. "But many areas in the Amazon aren't easily accessible, and the government often does not have the resources needed to test local sites."

"When you clear the land for mining, it leaves behind a landscape that basically went from lush greenery to barren desert," said Hsu-Kim. "You can easily see the effects in satellite images. If (governments) could use publicly available satellite imagery to identify areas that are likely to be contaminated, it could help them make informed policy decisions to protect public health."

The past two decades have seen a sharp increase in illegal and informal gold mining in Peru's southern Amazon region of Madre de Dios. These small-scale operations typically involve cutting down all of the trees in a particular area, digging a large pit and then using mercury to extract gold from the excavated soil.

After larger, coarse particles are separated, the remaining fine soil is combined with water and mercury inside a large drum much like an oil barrel, and shaken. The mercury binds to any gold in the soil, creating a large chunk that can be easily removed. This chunk is then burned, evaporating and releasing the mercury into the air while leaving behind pure gold.

Besides releasing mercury into the atmosphere, miners typically add three to four times more mercury to each barrel than is actually needed, says Hsu-Kim. While this ensures all of the gold is extracted, it also means there is a large amount of leftover mercury in the slurry that is inevitably dumped back into the excavated pit.

And because the whole process started with the clearing of trees, there's nothing to stop the mercury-laden soil from eroding into nearby rivers.

"While the local mercury levels might only double due to the mining itself, the effect of the erosion creates a four-fold increase in the amount of mercury being released into local rivers," said Hsu-Kim.

"This means mining practices can hit people three times with mercury -- once from direct contact, once from atmospheric transport and deposition, and once from soil mercury mobilization due to land clearing," said William Pan, the Elizabeth Brooks Reid and Whitelaw Reid Associate Professor of Population Studies at Duke. "The scenarios we run demonstrate that even if mining were to end today, since vegetation is unlikely to return for several decades, the cleared land will continue to release mercury."

Hsu-Kim and Pan worked with graduate students Sarah Diringer and Axel Berky to build a model to predict the amount of mercury and other contaminants being released into rivers. It combines data from a watershed erosion model, local variables such as annual rainfall, landscape and soil types, and data gathered about deforestation from satellite imagery.

When they analyzed mercury content in samples of soil and water from nine locations in the Colorado River watershed in Madre de Dios, they found that their model accurately predicted which areas were likely to have higher water concentrations of mercury.

The model suggests that over the last two decades, deforestation has doubled the amount of mercury entering local water sources in the Colorado River watershed, and increased it four-fold in the Puquiri subwatershed. Their model also suggests that if the current trends of deforestation continue, the amount of mercury being released into the local river systems may increase by 20 to 25 percent by 2030.

While the findings may sound bleak, the fact that the model works does offer some light at the end of the tunnel.

"We have shared our model with the Peruvian Ministry of Environment and Ministry of Health," Pan said. "We are working with them to evaluate whether our approach can be used as a tool for developing new policies regarding mining, environmental monitoring of mercury and human exposure."

HOUSTON - (Dec. 12, 2019) - When do cancer-prone cells turn into full-blown cancer? A Rice University scientist and his colleague believe there's a way to know.

It may become possible for biomarkers in blood to reveal whether mutated cells have turned a corner toward forming tumors, and how long the process -- depending on the type of cancer -- is likely to take. That could give patients a sense of the risk they face before they become ill.

Rice chemist Anatoly Kolomeisky, with postdoctoral research associate Hamid Teimouri and graduate alumna Maria Kochugaeva, directed their theoretical expertise in modeling random (stochastic) processes to the problem of why cancerous cells that are usually destroyed by the body's immune system sometimes overcome a gauntlet of defenses to become tumors.

The study in Scientific Reports is intended to clarify microscopic aspects of cancer initiation, the point at which random mutations become "fixed" in cells, which pass them on and eventually overwhelm tissue.

As part of their study, the researchers calculated fixation probabilities for 28 types of cancer to see how they correlate with available clinical data on cancer lifetime risks -- and found that correlation was anything but sure.

"The problem with cancer is that we're detecting it too late," said Kolomeisky, a professor of chemistry and chairman of the department in Rice's Wiess School of Natural Sciences. The researchers argue their "convenient, simple and versatile" method to evaluate cancer initiation dynamics should incorporate initiation dynamics for specific cancer types as well as established lifetime risks.

Kolomeisky has a long track record of discovery related to cellular mechanisms, especially related to motor proteins that transport cargo in cells and genome editing. Inspired by an off-hand comment from a colleague that his calculations looked like they could relate to cancer, Kolomeisky set off to find out if his mathematical approach could be applied to cancer initiation dynamics.

Based on their formulas, the researchers developed a chart correlating lifetime risks and initiation times for 28 types of cancer -- and found very little to connect the two. "It indicates that cancer lifetime risks alone cannot be utilized to evaluate the danger of getting cancer," the researchers wrote, suggesting fixation times that indicate tumor initiation are a more important metric.

For example, the chart shows that colorectal adenocarcinoma with FAP carries the highest lifetime risk, but its fixation time of 15 years is nearly three times that of duodenum adenocarcinoma with FAP, which is thought to have a much lower lifetime risk. At the other end of the fixation scale are hepatocellular carcinomas, at more than 31,000 years.

Their calculations compared the "fitness" of individual cells with cancer-related mutations to normal cells without, and how fast they divided. Tissue with mutant cells that divided at a 1-to-1 ratio with normal cells were the slowest to "fix" tumors.

The researchers assumed mutant cells with a speed advantage would fix tumors faster, and they were right. But they were surprised when their models showed cells with disadvantageous mutations (slower-than-normal division) were also occasionally faster than normal cells to fix.

"People assume, usually subconsciously, that something more probable will happen faster," Kolomeisky said. "But we found that is not the case for cancers. Doctors shouldn't make decisions simply on lifetime risk, as is typically done, but also on the dynamics we calculated as our main results.

"The main points are that we can calculate, with a lot of assumptions, the average time before cancer will start," he said. "We also argue that the probability of cancer does not typically correlate well with the time it starts. Something more probable is not necessarily fast."

Mutant cells that release biomarkers to the bloodstream may provide a better way to spot precancerous conditions.

"In the future, this could become part of personalized medicine," Kolomeisky said. "A doctor gives you a test and checks for the fraction of mutated cells in your tissues.

Then you can estimate how long it would take before the mutated cells will occupy the whole tissue. If it's 100 years, you probably should not worry too much. But if it's one year, then you might have to take drastic measures."

He said the model will certainly improve as more relevant parameters are incorporated. But anything it produces now and in the future should not deter one from a healthy lifestyle.

"We're not saying that you will or won't get cancer no matter what you do," Kolomeisky said. "Just that the probability is different. If you smoke, if you don't eat well or don't exercise, the probability will be higher."

UNIVERSITY PARK, Pa. -- Not getting enough water is enough to make you feel sluggish and give you a headache, but a new Penn State study suggests it may also relate to cognitive performance.

The researchers investigated whether hydration levels and water intake among older adults was related with their scores on several tests designed to measure cognitive function. They found that among women, lower hydration levels were associated with lower scores on a task designed to measure motor speed, sustained attention, and working memory. They did not find the same result for men.

The findings were recently published in the European Journal of Nutrition.

"The study gives us clues about how hydration and related drinking habits relate to cognition in older adults," said Hilary Bethancourt, a postdoctoral scholar in biobehavioral health and first author on the study. "This is important because older adults already face increased risk of cognitive decline with advancing age and are often less likely than younger adults to meet daily recommendations on water intake."

Asher Rosinger, Ann Atherton Hertzler Early Career Professor in Global Health, said the researchers found similar results when the participants were overhydrated.

"We found a trend suggesting overhydration may be just as detrimental to cognitive performance as dehydration for older adults," said Rosinger, who also directs the Water, Health, and Nutrition Laboratory and was senior author on the study. "Because of this, being in the 'sweet spot' of hydration seems to be best for cognitive function, especially for tasks requiring sustained attention."

According to the researchers, scientists have long suspected that dehydration may have an effect on cognitive performance. However, previous studies have largely focused on young, healthy people who are dehydrated after exercise and/or being in the heat.

Bethancourt said that because exercise and elevated ambient and body temperatures can have their own, independent effects on cognition, she and the other researchers were interested in the effects of day-to-day hydration status in the absence of exercise or heat stress, especially among older adults.

"As we age, our water reserves decline due to reductions in muscle mass, our kidneys become less effective at retaining water, and hormonal signals that trigger thirst and motivate water intake become blunted," Bethancourt said. "Therefore, we felt like it was particularly important to look at cognitive performance in relation to hydration status and water intake among older adults, who may be underhydrated on a regular basis."

For the study, the researchers used data from a nationally representative sample of 1271 women and 1235 men who were 60 years of age or older. Data were collected by the Nutrition and Health Examination Survey. Participants gave blood samples and were asked about all foods and drinks consumed the previous day. The researchers calculated hydration status based on concentrations of sodium, potassium, glucose, and urea nitrogen in participants' blood. Total water intake was measured as the combined liquid and moisture from all beverages and foods.

Participants also completed three tasks designed to measure different aspects of cognition, with the first two measuring verbal recall and verbal fluency, respectively.

A final task measured processing speed, sustained attention, and working memory. Participants were given a list of symbols, each matched with a number between one and nine. They were then given a list of numbers one through nine in random order and asked to draw the corresponding symbol for as many numbers as possible within two minutes.

Bethancourt said that when they first plotted the average test scores across different levels of hydration status and water intake, there appeared to be a distinct trend toward higher test scores in relation to adequate hydration and/or meeting recommended water intake. However, much of that was explained by other factors.

"Once we accounted for age, education, hours of sleep, physical activity level, and diabetes status and analyzed the data separately for men and women, the associations with hydration status and water intake were diminished," Bethancourt said. "A trend toward lower scores on the number-symbol test among women who were categorized as either underhydrated or overhydrated was the most prominent finding that remained after we accounted for other influential factors."

Bethancourt said that because the data was cross-sectional, they can't be sure whether suboptimal hydration levels are causing cognitive impairment or if people with impaired cognition are just more likely to be under- or overhydrated. The researchers were also unsure why they failed to see the same associations among men. Still, she said the results raise interesting questions.

"It was interesting that even though the test of attention, processing speed, and working memory took only a few minutes, it was the one most strongly associated with lower hydration levels," Bethancourt said. "Other research has similarly suggested that attention may be one of the cognitive domains most affected by hydration status. This left us wondering what the effects of inadequate hydration might be on more difficult tasks requiring longer periods of concentration and focus."

Rosinger said the findings suggest older adults may want to pay close attention to their hydration status, by both consuming enough liquids to avoid dehydration as well as ensuring adequate electrolyte balance to avoid overhydration.

"Because older adults may not necessarily feel thirsty when their body is reaching a state of underhydration and may be taking diuretics that can increase salt excretion, it is important for older adults and their physicians to better understand the symptoms of being both under- and overhydrated," said Rosinger.

W. Larry Kenney, Marie Underhill Noll Chair in Human Performance, and David M. Almeida, professor of human development and family studies, also participated in this work.