Tech

Resistance to tangle formation may help preserve memory

SuperAgers have fewer tangles than normally aging individuals

Future research to see how SuperAgers are protected

CHICAGO - A new Northwestern Medicine study showed cognitive SuperAgers have resistance to the development of fibrous tangles in a brain region related to memory and which are known to be markers of Alzheimer's disease.

The tangles are made of the tau protein which forms structures that transport nutrients within the nerve cell. These tangles disrupt the cell's transport system, hampering communication within the neuron and preventing nutrients from performing their particular job within the cell. The end result of tangle formation is cell death.

"The results suggest resistance to age-related tau degeneration in the cortex may be one factor contributing to preserved memory in SuperAgers," said lead study author Tamar Gefen, an assistant professor of psychiatry and behavioral sciences at Northwestern University Feinberg School of Medicine.

"SuperAgers," a term coined by the Northwestern Mesulam Center for Cognitive Neurology and Alzheimer's Disease, are unique individuals over age 80 who show outstanding memory capacity at a level consistent with individuals 20 to 30 years younger. At the Center, SuperAgers are evaluated annually and may choose to donate their brains for post-mortem evaluation by Northwestern scientists.

This study quantified the amount of amyloid plaques and tau-containing neurofibrillary tangles in part of the brain that is heavily responsible for memory, known as the entorhinal cortex, in seven SuperAgers compared with six age-matched cognitively-healthy individuals. The findings showed significantly less tangles in the entorhinal cortex of SuperAgers than those of cognitively healthy controls by a difference of nearly three-fold.

"This finding helps us better identify the factors that may contribute to the preservation of memory in old age," Gefen said. "This research highlighted there are gradients of vulnerability to cell death in the brain."

"Individuals with significant memory impairment due to Alzheimer's disease showed nearly 100 times more tangles in the entorhinal cortex compared to SuperAgers," Gefen said. "There is a strong relationship between tau-tangles and memory loss, and these findings in a unique SuperAging cohort could guide research in a new direction."

The study, "Paucity of Entorhinal Cortex Pathology of the Alzheimer's Type in SuperAgers with Superior Memory Performance", was published in Cerebral Cortex on Feb. 17.

The seminal characteristics of Alzheimer's disease are amyloid plaques and tau-containing neurofibrillary tangles found in the brains of individuals at death after autopsy. While these plaques and tangles are most commonly found in the brains of those with memory impairment, they are also found in cognitively healthy elderly individuals but in a more limited distribution.

Because advancing age is typically associated with declining memory abilities and increased risk of developing Alzheimer's disease, the Center studies SuperAgers to better understand what is going right in their brains.

The study also found there were no significant differences in amyloid plaque density in SuperAgers compared to cognitively healthy older persons.

"Many investigators have long thought that amyloid plaques are drivers of memory loss, which isn't what we found," Gefen said.

Gefen wants to explore the interaction of genetics and environment/lifestyle, and their collective impact, on the cellular level in post-mortem brains of SuperAgers.

"Why are memory cells selectively vulnerable to tangles in the first place?" she asked. "What is it about the cellular environment in the brains of SuperAgers that seem to protect them from tangles? Are the behaviors of SuperAgers somehow building up resistance in the brain?"

"To address these questions, we can study the molecular, biochemical, and genetic components of these specific memory cells, in SuperAgers, that are typically targeted by Alzheimer's. And, certainly, we must take their personal narratives (history, proclivities, behaviors, cultures) into account when making conclusions about their unique neuroanatomic profiles."

Deprive a mountain range of its wolves, and soon the burgeoning deer population will strip its slopes bare. "I now suspect that just as a deer herd lives in mortal fear of its wolves, so does a mountain live in mortal fear of its deer," wrote ecologist Aldo Leopold in his landmark 1949 title "A Sand County Almanac."

Leopold proposed that predators keep herbivore populations in check to the benefit of an ecosystem's plant life. Remove one link in the food chain, and the effects cascade down its length. The idea of a trophic cascade has since become a mainstay in conservation ecology, with sea urchins as a prime example just off the California coast.

"Urchins play a key role in the kelp forest because they eat kelp," said Katrina Malakhoff(link is external), a doctoral student in UC Santa Barbara's Interdepartmental Graduate Program in Marine Science. "And there are times and places when urchins eat so much kelp that they actually end up removing it all and creating urchin barrens."

Scientists noticed that urchin populations seemed to explode after hunters decimated California's sea otters. The prickly critters went on to mow down entire kelp forests. Their conclusion: Predators like otters had kept the urchins in check. In Southern California, the otter's predatory role was thought to be filled by other species, particularly spiny lobster and sheephead fish.

But a new study by Malakhoff and her advisor, Robert Miller(link is external), suggests that the truth is much more nuanced. The researchers examined urchin populations inside and outside marine reserves, where protection from fishing should have enabled urchin predators to rebound and control their populations. But instead of finding fewer urchins, they found that one species was unaffected by the reserves, while the other flourished. Their work was supported by the National Science Foundation's Long-Term Ecological Research program, and results appear in the Proceedings of the Royal Society B [TK LINK].

Marine reserves cordon off areas of the ocean from fishing. They're often put in place to protect ecosystems by allowing species to recover, Malakhoff explained. In fact, California has a renowned network of marine protected areas along its coast, and many people hoped that the reserves could help control the region's two urchin species: the red sea urchin, which is fished for its roe, and the purple sea urchin, which isn't.

"We predicted that by protecting these areas we're increasing the number and density of urchin predators that will then control urchin populations and prevent them from overgrazing the kelp forest and turning it into an urchin barren," Malakhoff said. She sought to investigate this assumption, as well as the tendency of scientists and resource managers to lump the two species together and treat them as ecologically equivalent.

Malakhoff's project was made possible by the wealth of data ripe for analysis in the Channel Islands National Park Kelp Forest Monitoring Program, which has records stretching back to 1982. The data she used covers multiple sites from 13 years before, and roughly 15 years after, the establishment of marine reserves. As she examined figures on urchin populations, a peculiar trend began to emerge.

The reserves seemed to have no affect at all on unfished purple urchin populations. What's more, instead of decreasing in numbers, red urchins proliferated within the borders of some marine reserves. Their size, number and density increased once they no longer faced fishing pressures. Reserves also had no clear effect on giant kelp density.

"I was pretty surprised," Malakhoff said. "It contradicted what I expected to be happening in the kelp forest." If a rise in predation within the reserve influenced urchin populations, then both species should have decreased in number, and there ought to have been fewer small urchins, which provide an easier snack for predators.

"There's a simplistic picture that's been promulgated of kelp forests versus urchin barrens, and that predators are preventing this phase shift from happening," Miller said. The corollary is that, by restoring predator populations, reserves should allow the lush kelp forests to return.

Other studies have documented that the urchins' predators are thriving under the reserves' protection. The new results indicate that predation probably isn't the primary factor controlling urchin populations. For instance, larval dispersal and recruitment -- as well as the oceanographic regimes that affect them -- likely have greater effects on urchin populations, Miller said.

This study invites scientists to reconsider how common trophic cascades are, and whether marine reserves will always induce them. "Katrina's study adds to a growing body of evidence that suggests that trophic cascades are confined to a pretty narrow set of situations in the natural world," Miller said.

The two researchers acknowledge that some of their fellow scientists and resource managers might be reluctant to accept their conclusions. "The relationship between marine reserves and trophic cascades has approached paradigm status," Miller explained, "and it's always difficult to push back against a paradigm."

The study also calls into question the benefit to kelp forests of simply placing more area inside reserves. "One of the justifications that's been offered for expanding reserve coverage is saving kelp forests by increasing urchin predators," Miller said. "And this study suggests that this goal alone is not a good justification.

"I can see some controversy arising from this," he added, "but I think, as scientists, we have to maintain objectivity. We're fortunate that the Park Service and other monitoring programs collect the data we need to do this kind of analysis."

This doesn't mean that marine reserves are a bad idea, or that we should not expand them," he explained. "They clearly work very well for protecting fished species," Miller noted. "It's just that some of these popularly held ideas -- like that they'll cause trophic cascades to save the kelp -- might be less valid."

Marine protected areas may not be a panacea, but they do have their place. For one, they can serve as excellent natural experiments for scientists to investigate the effects of removing fishing from the equation. Stakeholders simply need to remember, the researchers said, that reserves are only one means of managing our oceans, and it's crucial to take advantage of all the strategies at their disposal.

Additionally, what scientists think will happen in a marine reserve may not always be what transpires, Malakhoff said, but that's not inherently a bad thing. "Just because we have more urchins inside the reserves doesn't necessarily mean we have less kelp," she pointed out, "because the story is complicated."

"These findings also highlight that we shouldn't necessarily adopt simplistic management approaches like smashing sea urchins to save kelp forests," Miller added.

Other factors influence how much kelp urchins eat, aside from their density. Urchin behavior also comes into play. Malakhoff is currently investigating how urchins digest different types of algae, and whether giant kelp truly is their preferred meal. This could shed light on the impact diet and other variables have on their grazing behavior.

"Sea urchins, they're sort of an enigma," said Miller. "Across the world, people are either trying to restore them or smash them based on a simple dichotomy: urchin good, urchin bad. But, like Katrina said, the truth may be somewhere in between."

Rapid global urbanization has dramatically changed the face of our planet, polluting our atmosphere with greenhouse gases and causing global warming. It is the need of the hour to control our activities and find more sustainable alternatives to preserve what remains of our planet for the generations to come.

Carbon dioxide (CO2) and carbon monoxide (CO) make up a large proportion of industrial flue gases. Recent research has shown that certain microorganisms are capable of metabolizing these gases into useful by-products. Thus, attempts are now being directed to using microbes to recycle these gases and convert them into useful chemicals in a process known as 'carbon capture and utilization' (CCU). This is a step beyond the current widespread practice of 'carbon capture and storage' (CCS). However, such CCU requires high energy input making the scaling up of this process difficult and expensive. How can this process then be optimized for maximum output?

A team of researchers from Korea, led by Prof. Jung Rae Kim from Pusan National University, have answered this question for a newer CCU system called the bioelectrochemical system (BES). Prof. Kim explains, "We have developed a 'bioelectrosynthetic process' in which electroactive bacteria convert CO/CO2 into useful metabolites like acetate and volatile fatty acids using electricity as the reducing power." The scientists were able to optimize BESs to increase their efficiency by 2 to 6 times that of current systems for CO gas. Their findings are published in Bioresource Technology since January 2021.

The two-chamber BES they used had several special features that achieved this. The cathode contained an electro-active biofilm, and the anode produced hydrogen ions via water electrolysis. These chambers were divided by an ion exchange membrane (IEM), which controlled the flow of protons and electrons between the chambers. Further, while the former contained microbial culture media, the latter contained mechanisms to control the initial pH of the system. In addition, a quinone electron mediator was used.

They found that, given the right IEM--one that allowed protons but not oxygen to pass through--an acidic pH in the anode chamber caused a higher proton concentration gradient across the membrane, which was key to enhancing acetate production and the synthesis of longer chain fatty acids in the cathode chamber. The quinone-dependent mediators improved electron transfer and increased product formation.

Prof. Kim states, "Since CO is a more reduced gas than CO2, perhaps unsurprisingly, the coulombic efficiency for CO was double that for CO2. CO is a major component in the industrial off-gas of most steel mill processes and biomass gasification. Via this BES conversion, it can be a valuable feedstock for various bioprocesses. This is the first study that makes the conversion of CO via BESs commercially viable." Highlighting the applications further, he continues: "The microbes self-replicate, making this BES an economical solution. That combined with the efficiency we've achieved and the optimal system we've created should make this of sufficient interest to industries such that this becomes commercial industrial machinery within 5 years."

This is one way in which the earth will be made cleaner, greener, and cooler!

Scientists from the Skoltech Center for Computational and Data-Intensive Science and Engineering (CDISE) and the Skoltech Digital Agriculture Laboratory and their collaborators from the German Aerospace Center (DLR) have developed an artificial intelligence (AI) system that enables processing images from autonomous greenhouses, monitoring plant growth and automating the cultivation process. Their research was published in the journal IEEE Sensors.

Modern technology has long become a fixture in all spheres of human life on Earth. Reaching out to other planets is a new challenge for humankind. Since greenhouses are likely to be the only source of fresh food for Mars space crews and settlers, development of artificial intelligence (AI) and computer vision based technologies for plant growth automation is perceived as a priority research target. A test site is already in place for developing and testing advanced life support systems: an autonomous plant cultivation module is operating at the Antarctic Neumayer Station III near the South Pole. Right now scientists focus on creating an AI system that could collect information about all the plant growth factors and seedling health and control greenhouses in autonomous mode without human involvement.

"One cannot maintain continuous communication with Neumayer III, while training computer vision models on board requires too many resources, so we had to find a way to send a stream of plant photographs to external servers for data processing and analysis," Skoltech PhD student Sergey Nesteruk explains.

As a conclusion to their research, the Skoltech team processed a collection of images from remote automated systems using their new approach based on convolutional neural networks and outperforming popular codecs by over 7 times in reducing the image size without apparent quality degradation. The researchers used the information from the reconstructed images to train a computer vision algorithm which, once trained, is capable of classifying 18 plant varieties according to species at different stages of development with an accuracy of 92%. This approach makes it possible to both visually monitor the system operation and continuously gather new ML model training data in order to enhance the models' functionality.

There are plans to deploy and test the new systems right on Neumayer III, which will mark an important step towards automation of plant growing modules, thus removing yet another roadblock on the way to Mars.

Robotic dogs, laughter therapy and mindfulness are some of the ways that might help people - particularly the elderly - cope with loneliness and social isolation while social distancing, say researchers at the University of Cambridge.

A team at Cambridge's School of Medicine carried out a systematic review looking at the existing evidence on different approaches to tackling loneliness and social isolation. While all the individual studies were carried out pre-pandemic, the team considered which approaches might be feasible when people are still required to socially distance. Their results are published today in PLOS ONE.

At the start of the pandemic in the UK, over 1.5 million people were told they must self-isolate or shield themselves for a period of at least 12 weeks. Strict social distancing guidance advised the public to stop all non-essential travel and stay at home. While these measures were initially eased, social distancing measures remain in place, cases and contacts are required to self-isolate, and further lockdown measures have been re-introduced.

One possible consequence of both the shielding of vulnerable people, and the social distancing restrictions for all, is for physical separation to lead to social isolation and loneliness. There is strong evidence that both social isolation and loneliness are linked to cardiovascular disease, depression and anxiety. This means there is an urgent need to identify effective interventions to combat this problem.

A team led by Dr Christopher Williams, at the time University of Cambridge medical student, identified 58 relevant studies of interventions to reduce social isolation, social support and loneliness that could potentially be adapted for people living in pandemic-related isolation. Most of the studies (51 out of 58) related to older people - a group that often face the strictest limitations imposed on their social contacts during the pandemic.

"Lockdown and social distancing measures have meant that many people have little or no contact with others, which can lead to loneliness and isolation," said Dr Williams, now a doctor in his first year of practice.

"We carried out our review to try and identify approaches that might help people cope with these challenging times. Although the individual studies themselves took place before the pandemic, we've identified several that would still be feasible even with social distancing measures in place."

Among some of the approaches identified in the studies are:

Robot dogs and robot seals (but not real budgies): Two studies indicated that robotic dogs could prove as effective as real dogs in reducing loneliness. They might also be more feasible for some groups living in pandemic conditions than real dogs. Similarly, weekly sessions with Paro, an interactive robotic seal that responds to contact and other stimuli by moving or imitating the noises of a baby harp seal, significantly improved loneliness scores.

The robotic animals gave better results than an 'avian companionship' scheme involving interacting with a live budgie, which did not report significant results.

Mindfulness and Tai Chi: Mindfulness-based therapies and Tai Chi Qigong meditation led to significant improvements in loneliness or social support outcomes.

Laughter therapy: Laughter exercises, deep breathing exercises, playing games, singing songs loudly and laughter meditation also helped reduce loneliness. Together with mindfulness and Tai Chi Qigong meditation, these represent potentially low-cost interventions that can be conducted in online groups on a large scale.

Talking about art: Visual art discussions - where participants were asked to describe a painting, to use their imagination to describe why, how and when it was made, and to describe associations that appear when looking at the painting such as feelings, memories and thoughts - demonstrated significant improvements in loneliness or social support outcomes.

Reminiscence therapy: Structured weekly sessions concentrated on a different topic each week, including sharing memories, increasing participant awareness/expression of their feelings, identifying past positive relationships, recalling family history and life stories, and identifying positive strengths and goals.

Lessons on friendship and social integration: Educational programme interventions varied, with some focusing on theories of loneliness and social integration while others sought to educate on health and well-being more generally. Lessons on friendship and social integration typically decreased loneliness, with three out of four studies showing improvement.

Wii gaming: Playing games such as Wii Sports and Cooking Mama on the Wii console were found to be effective at reducing loneliness. However, the studies involved group play, which would only be feasible in support bubbles during lockdown - it is not clear whether the same benefits would be seen from online play.

Indoor gardening: One study of an indoor gardening programme in a nursing home, where participants were given their own plants and taught how to look after them, reported decreased loneliness scores among participants of the programme and increased participants' social networks.

Get to know your neighbours: Group meetings between participants in the same neighbourhood, discussing the residential area, the role of retiree, social and medical services, and opportunities for leisure activities, reduced social isolation, though they did not significantly alter loneliness levels.

Video conferencing: Two studies looking at video calls found that weekly catch-ups with family members could help reduce feelings of loneliness.

The majority of the studies improved loneliness. The little evidence found by the team on tackling social isolation suggests that enabling or encouraging people to interact with their existing social circles was more effective than trying to enable them to make new friends.

"Many of these activities, such as mindfulness, meditation and talking therapies, could be delivered at a large scale in online groups, potentially at low cost," said Dr Adam Townson from School of Clinical Medicine at Cambridge.

"A significant problem, however, is that those who are most likely to be lonely or isolated - and most in need of support - may not own, or know how to use, electronic devices and might not have access to a high-speed internet connection. Any approach to help people suffering from loneliness or social isolation must take digital exclusion into consideration."

Several studies involved initiatives to combat loneliness and social isolation in nursing and care homes, which may have been hit particularly hard by lockdown measures. Effective interventions in these settings included weekly visits from an interactive robotic dog or seal, Wii gaming, gardening, videoconferencing, and cognitive/psychological interventions.

A pioneering study of U.S nitrogen use in agriculture has identified 20 places across the country where farmers, government, and citizens should target nitrogen reduction efforts.

Nitrogen from fertilizer and manure is essential for crop growth, but in high levels can cause a host of problems, including coastal "dead zones", freshwater pollution, poor air quality, biodiversity loss, and greenhouse gas emissions.

The 20 nitrogen "hotspots of opportunity" represent a whopping 63% of the total surplus nitrogen balance in U.S. croplands, but only 24% of U.S. cropland area. In total, they comprise 759 counties across more than 30 states, finds the study in Environmental Research Letters.

The top-ranked hotspot to target, based on total excess nitrogen, is a 61-county area across Illinois, Indiana, Missouri and Wisconsin. That's followed by a 55-county region in Kansas and Nebraska in second place, and 38 counties in Iowa, Minnesota and South Dakota in third. (Click for a full list of the 20 regions).

Several of the 20 hotspots--with high nitrogen balances per acre--surprised the researchers, particularly in the West--including a 32-county hotspot in Idaho, Montana, Wyoming and Utah--and the South (six hotspots across Texas, Louisiana, Mississippi, Alabama, Georgia, and Florida). Also on the list are chronic nitrogen problem areas, such as the Mississippi River Basin, Chesapeake Bay, and California's Central Valley.

"This study provides new perspective on where to focus efforts to tackle America's nitrogen problems," says lead author Eric Roy of the University of Vermont. "The U.S. has so many nitrogen trouble zones, and making progress will be easier in some locations than others. That's why this research is important. It reveals where programs aiming to increase the efficiency of farm nitrogen use are most likely to be successful."

First-of-its-kind study

Why these particular 20 hotspots? First, the study shows that nitrogen inputs are so high in many of these areas that farmers can most likely reduce nitrogen use without hurting crop yields. "This is a crucial finding because farmers naturally worry about lower crop yields when reducing nitrogen inputs," says UVM co-author Meredith Niles. "And we don't want to compromise food security goals."

Second--and perhaps most importantly--the study is the first to provide a robust, national analysis of underlying social, economic and agronomic factors linked to nitrogen balances on croplands at the county-level. That makes it one of the most comprehensive studies of U.S. nitrogen use to date.

Examples of these underlying factors include climate change beliefs, crop mix, precipitation, soil productivity, farm operating expenses, and more.

By examining these predictors, researchers were able to identify nitrogen hotspots where reductions in excess nitrogen are most achievable. Surplus nitrogen use was higher than expected in these regions based on the mix of underlying factors--suggesting less barriers to successful nitrogen reduction efforts.

"This suggests that nitrogen reduction programs--including those that offer farmers' financial incentives--have the highest potential for success in these 20 regions," says co-author Courtney Hammond Wagner of Stanford University, who recently completed a PhD at University of Vermont.

A new study, published in Bioscience, considers the future of ecology, where technological advancement towards a multidimensional science will continue to fundamentally shift the way we view, explore, and conceptualize the natural world.

The study, co-led by Greg Asner, Director of the Arizona State University Center for Global Discovery and Conservation Science, in collaboration with Auburn University, the Oxford Seascape Ecology Lab, and other partners, demonstrates how the integration of remotely sensed 3D information holds great potential to provide new ecological insights on land and in the oceans.

Scientific research into 3D digital applications in ecology has grown in the last decade. Landscape and seascape ecologists can now critically frame 3D ecological questions that have been challenging to answer across broad study areas--until recently. Advances in high-resolution remote sensing systems and data processing are allowing us to model the complex surface of the Earth, both above and below water, with greater detail and accuracy than ever before.

Future research applications in the marine environment should focus on addressing the challenges associated with integrating dynamic oceanographic information into maps capable of capturing 3D variability in the environment over time.

"3D-capable data sources have wide-ranging ecological applications and help in estimating carbon sequestration, quantifying habitat structure, mapping ecosystem services, and measuring and modeling consequences of climate change," said Asner.

As landscape and seascape ecology looks toward the future, the study notes a need for a continued progression toward a 3D science that will shift the way ecological patterns and processes are conceptualized. The paper provides key examples of 3D data application in terrestrial and marine environments to illustrate how state-of-the-art advances in ecology have been achieved through novel data fusion, spatial analysis, and visualization.

"This article highlights the unprecedented opportunity for understanding 3D ecological dynamics and human impacts on land and in the oceans, with a view to better inform management decisions," said Lisa Wedding, co-author and Associate Professor at the University of Oxford.

As a result of this 3D approach, natural resource management may support the development of conservation and management plans and shift the way that policymakers evaluate current and future regulations in a dynamic environment.

An engineered peptide given to ferrets two days before they were co-housed with SARS-CoV-2-infected animals prevented virus transmission to the treated ferrets, a new study shows. The peptides used are highly stable and thus have the potential to translate into effective intranasal prophylaxis to reduce infection and severe SARS-CoV-2 disease in humans, the study's authors say. The SARS-CoV-2 spike (S) protein binds to host cells to initiate infection. This stage in the virus life history is a target for drug inhibition. Here, researchers with past success designing lipopeptide fusion inhibitors that block this critical first step of infection for SARS-CoV-2 and other viruses sought to design a SARS-CoV-2-specific inhibitor that was highly potent. Testing various designs in cell culture, Rory D. de Vries and colleagues identified one particularly effective lipopeptide against SARS-CoV-2, which also inhibited binding by emerging SARS-CoV-2 variants, including B.1.1.7 and B.1.351. In further studies of this candidate in the lungs of humanized mice, it persisted in the respiratory tract, a sign that it can protect against virus replication. To test the ability of their leading inhibitor candidate to block viral transmission, the researchers turned to ferrets, a model for evaluating airborne virus spread (although ferrets do not display strong clinical symptoms after infection). Some ferrets in the authors' study were dosed with the peptide before being co-housed with SARS-CoV-2-infected ferrets for 24 hours; other ferrets weren't. After this 24-hour period, SARS-CoV-2 was not detected in the throats or noses of any treated ferrets, while infectious virus was detected in all untreated ferrets. In further experiments with ferrets, the authors show that administration of the peptide intranasally just two hours before exposure delayed infection. They say their intranasal peptide offers "successful prophylaxis that prevents SARS-CoV-2 transmission in a relevant animal model" and "should readily translate into a safe and effective nasal spray or inhalation administered fusion inhibitor for SARS-CoV-2 prophylaxis." They also note that a combination of drugs that target different aspects of the viral life cycle would likely be best-suited for SARS-CoV-2.

In ancient European settlements, livestock use was likely primarily determined by political structure and market demands, according to a study published February 17, 2021 in the open-access journal PLOS ONE by Ariadna Nieto-Espinet and colleagues of the Consejo Superior de Investigaciones Científicas, Barcelona.

Zooarchaeology - the study of animal remains from archaeological sites - has great potential to provide information on past human communities. Livestock preferences are known to have changed over time in Europe, but little is known about how much these changes are influenced by environmental, economic, or political conditions of ancient settlements.

In this study, Nieto-Espinet and colleagues gathered data from 101 archaeological sites across the northeastern Iberian Peninsula, ranging from the Late Bronze Age to Late Antiquity, a span of around 1700 years during which European cultural and agricultural practices underwent significant changes. At each site, they compared livestock remains with data on the local environment (including plant and climate data) and the economic and political conditions of the settlement.

These data show that political and economic factors were most important in determining the species distribution and body size of ancient livestock. During the Late Bronze Age and Late Antiquity, when political systems were more fragmented and food production was focused more on local markets, livestock choice was more dependent upon local environmental conditions. But during the later Iron Age and the time of the Roman Empire, the demands of a pan-Mediterranean market economy favored more changes in livestock use independent of environmental factors. Zooarchaeology is thus a vital source of information for understanding political and economic changes through time.

The authors add: "Archaeology reveals the influence of political systems on livestock practices over time."

The new method works without extremely high temperatures, is therefore more energy-efficient and has a significantly higher recovery rate (approx. 96 per cent of the starting material) than established processes. These findings will be published on 17 February 2021 in the scientific journal Nature.

Mechanical recycling vs. chemical recycling

"The direct re-utilization of plastics is often hampered by the fact that, in practice, mechanical recycling only functions to a limited degree - because the plastics are contaminated and mixed with additives, which impairs the properties of the recycled materials", Stefan Mecking explains.

"Chemical recycling" is an alternative: Via a chemical process, used plastic is broken down into its molecular building blocks, which can then be converted into new plastic.

Limitations of chemical recycling of polyethylene

Specifically in the case of polyethylene - the most widely used plastic - chemical recycling is difficult. On a molecular level, plastics are made up of long molecular chains. "Polymer chains of polyethylene are very stable and not easily reversed back into small molecules", Stefan Mecking explains. Temperatures exceeding 600° Celsius are required, making the procedure energy-consuming. At the same time, the recovery rate is limited (in some cases less than ten per cent of the starting material).

How chemical recycling of polyethylene can be made more sustainable

Stefan Mecking and his team report on a method that makes a more energy-efficient chemical recycling of polyethylene-like plastics possible, coupled with a very high recovery rate of around 96 per cent of the starting materials. To do so, the chemists used "breaking-points" on a molecular level enabling a deconstruction of the chain into smaller molecular building blocks. "Key for our method are polymers with a low density of predetermined breaking-points in the polyethylene chain, so that the crystalline structure and material properties are not compromised", Stefan Mecking explains and adds: "This type of materials is also very suitable for 3D printing."

Stefan Mecking´s research team demonstrated this chemical recycling on polyethylene-like plastics based on plant oil. The recycling stage requires temperatures of only about 120 degrees. Furthermore, the chemists also performed this recycling method on mixed plastics as they occur in waste streams. The properties of the recycled materials are on a par with those of the starting material. "Recyclability is an important aspect for future technologies based on plastics. Re-utilizing such valuable materials as efficiently as possible makes sense. With our research we want to contribute to making chemical recycling of plastics more sustainable and effective", Stefan Mecking resumes.

Engineers at the University of California San Diego have created a four-legged soft robot that doesn't need any electronics to work. The robot only needs a constant source of pressurized air for all its functions, including its controls and locomotion systems.

The team, led by Michael T. Tolley, a professor of mechanical engineering at the Jacobs School of Engineering at UC San Diego, details its findings in the Feb. 17, 2021 issue of the journal Science Robotics.

"This work represents a fundamental yet significant step towards fully-autonomous, electronics-free walking robots," said Dylan Drotman, a Ph.D. student in Tolley's research group and the paper's first author.

Applications include low-cost robotics for entertainment, such as toys, and robots that can operate in environments where electronics cannot function, such as MRI machines or mine shafts. Soft robots are of particular interest because they easily adapt to their environment and operate safely near humans.

Most soft robots are powered by pressurized air and are controlled by electronic circuits. But this approach requires complex components like circuit boards, valves and pumps--often outside the robot's body. These components, which constitute the robot's brains and nervous system, are typically bulky and expensive. By contrast, the UC San Diego robot is controlled by a light-weight, low-cost system of pneumatic circuits, made up of tubes and soft valves, onboard the robot itself. The robot can walk on command or in response to signals it senses from the environment.

"With our approach, you could make a very complex robotic brain," said Tolley, the study's senior author. "Our focus here was to make the simplest air-powered nervous system needed to control walking."

The robot's computational power roughly mimics mammalian reflexes that are driven by a neural response from the spine rather than the brain. The team was inspired by neural circuits found in animals, called central pattern generators, made of very simple elements that can generate rhythmic patterns to control motions like walking and running.

To mimic the generator's functions, engineers built a system of valves that act as oscillators, controlling the order in which pressurized air enters air-powered muscles in the robot's four limbs. Researchers built an innovative component that coordinates the robot's gait by delaying the injection of air into the robot's legs. The robot's gait was inspired by sideneck turtles.

The robot is also equipped with simple mechanical sensors--little soft bubbles filled with fluid placed at the end of booms protruding from the robot's body. When the bubbles are depressed, the fluid flips a valve in the robot that causes it to reverse direction.

The Science Robotics paper builds on previous work by other research groups that developed oscillators and sensors based on pneumatic valves, and adds the components necessary to achieve high-level functions like walking.

How it works

The robot is equipped with three valves acting as inverters that cause a high pressure state to spread around the air-powered circuit, with a delay at each inverter.

Each of the robot's four legs has three degrees of freedom powered by three muscles. The legs are angled downward at 45 degrees and composed of three parallel, connected pneumatic cylindrical chambers with bellows. When a chamber is pressurized, the limb bends in the opposite direction. As a result, the three chambers of each limb provide multi-axis bending required for walking. Researchers paired chambers from each leg diagonally across from one another, simplifying the control problem.

A soft valve switches the direction of rotation of the limbs between counterclockwise and clockwise. That valve acts as what's known as a latching double pole, double throw switch--a switch with two inputs and four outputs, so each input has two corresponding outputs it's connected to. That mechanism is a little like taking two nerves and swapping their connections in the brain.

Next steps

In the future, researchers want to improve the robot's gait so it can walk on natural terrains and uneven surfaces. This would allow the robot to navigate over a variety of obstacles. This would require a more sophisticated network of sensors and as a result a more complex pneumatic system.

The team will also look at how the technology could be used to create robots, which are in part controlled by pneumatic circuits for some functions, such as walking, while traditional electronic circuits handle higher functions.

More people than expected ended their own lives in 2020 in Japan, overturning a decadelong slow decline in the nation's annual number of suicides, according to a new analysis by public health experts at the University of Tokyo. The increase in suicides was especially pronounced among women younger than 30, potentially due to the COVID-19 pandemic's disproportionate effect on part-time and travel industry employees.

"This trend of increased suicides among young women and university and high school students is very different from before COVID-19. Before COVID-19, if suicides increased, we would expect more deaths of middle-aged men," said Dr. Haruka Sakamoto, an expert in public health at the University of Tokyo and first author of the research publication in the Journal of the American Medical Association (JAMA) Network Open.

The number of people who died by suicide in Japan peaked in 2003 with 34,427 total deaths, held relatively steady through 2009, and then slowly declined to 20,169 deaths in 2019, an all-time low since the government began compiling national suicide statistics in 1978.

In the late 2000s, suicides increased sharply among men in their 50s, many of whom were understood to be affected by the "Lehman shock" (the financial crisis following the bankruptcy of the Lehman Brothers company in 2008). Since then, depression and suicide in Japan have been widely viewed as diseases caused by overwork or work-related stress. In 2016, Japan's Basic Act on Suicide Prevention law required national and local governments to develop specific plans to reduce suicides.

"If they have a mental health problem, maybe they still feel some social shame, but now people know they can ask for rest from their employer," Sakamoto explained.

Sakamoto says that most suicide prevention policies are targeted to full-time employees of large companies. Anyone without a full-time job, especially young people who do not regularly visit medical clinics for physical health complaints, can be easily missed by current suicide prevention efforts.

In their recent analysis, Sakamoto and colleagues examined month-by-month differences in suicides from April to November of 2016-2019 versus April to November of 2020. This month-by-month analysis allowed researchers to account for the rapidly changing social conditions related to the pandemic.

Fewer suicides than expected occurred in April and May 2020 when Japan was under an official state of emergency.

"Our hypothesis to explain the decrease in suicides in April and May is that normally there is an increase in suicides because of people starting a new school year or a job change. The state of emergency delayed that normal time of change, so suicide rooted in school or working environment did not occur as usual," said Sakamoto.

The April-May decline in suicides is also expected based on the widely documented "pulling together phenomenon" in societies around the world as people support one another in the immediate aftermath of natural or national disasters. Eventually, this sense of community cohesion fades, the decline in suicides reverses to a brief spike, and then suicides return to their pre-disaster normal rate.

In July 2020, the number of women killing themselves in Japan started to increase, especially in those younger than 30, and remained higher than expected through November. Between 2016 to 2019, an average of 70 women under age 30 died by suicide each July, but 96 women did so in 2020. October was the deadliest month for women of all ages. An average of 486 total women took their own lives the previous four Octobers, but 826 total women did so in October 2020.

The total number of men taking their own lives did not rise significantly until October. An average of 1,096 men of all ages killed themselves each October from 2016 to 2019, but 1,246 total men did so in October 2020. Most of the increase was among men aged 30 to 49.

"If people feel the pandemic can finish soon, they can fight to maintain their business. But around October, globally we saw a resurgence of COVID-19, so maybe people felt like the situation will get worse soon in Japan too. Probably with this negative atmosphere in October, this is why there was such an increase in suicides that month," said Sakamoto.

Although the total number of suicides is higher in men, researchers say that the sudden and unexpected increase in younger women is especially concerning. Japan's current suicide prevention strategies are unlikely to catch this demographic, and the pandemic's effect on part-time, food service or restaurant workers, and tourism, travel and entertainment sector jobs -- where young women make up a significant portion of the workforce -- is unlikely to recover anytime soon.

"Now the government needs a new policy for women and university students added to the current overall suicide program," said Sakamoto.

The relationship between biology, external environments, depression and suicide have always been difficult for medical science to understand, but experts say the pandemic's environment of isolation, stress and general dread can create mental illness.

"Even now during COVID-19, not every part-time worker has a mental health problem and it is still very rare to kill yourself. Mental health problems are biological issues, but environment can strongly affect the biological part. Without COVID-19 pressures, I think most of these women who killed themselves in 2020 would not have had mental health problems," said Sakamoto.

Parts of Japan, including Tokyo and Osaka, re-entered a state of emergency at the start of January 2021. National suicide statistics are made rapidly available in Japan, so researchers are continuing to watch each month's data as it becomes available.

"No one knows when we can enjoy daily life again, so the pandemic's effects on mental health and suicide will not end soon," said Sakamoto.

Blockchain is a decentralized technology used to protect the security and privacy of online transactions and is usually associated with cryptocurrencies such as Bitcoin. However, it is a mechanism that can be applied to all kinds of digital exchanges. In a new study, researchers from the K-riptography and Information Security for Open Networks (KISON) group at the Internet Interdisciplinary Institute (IN3) Amna Qureshi and professor David Megías (who is also the director of the IN3) analysed existing blockchain-based multimedia content protection systems and established a taxonomy to classify them according to their technical features, the protection techniques they use and their performance. The study is the first detailed analysis of this type of application and looks at the technological and scientific challenges for their improvement and implementation.

The researchers said: "blockchain has an excellent potential to be broadly applied in copyright protection and management applications. However, there are still many open issues that need to be further researched and analysed in order to create workable copyright protection applications that can fully benefit from the use of the blockchain technology."

A gap in the research

Because of the growth in the distribution of audiovisual content through online platforms and peer-to-peer (P2P) file sharing, matters such as content security, copyright protection and piracy tracing are increasingly more pressing for the owners, producers and distributors of content. The researchers said that, faced with these problems, blockchain makes it possible to "upload copyrighted content, control licensing/copyright options, manage distribution, trace sources of piracy, and receive payments upon content usage."

However, despite the boom in the sector and the capabilities of this technology, the new study highlights the fact that there are still very few blockchain-based copyright protection systems: They said: "This points towards a research gap. To fill this gap, we propose a taxonomy that integrates technical aspects and application knowledge and can guide the researchers towards the development of blockchain-based multimedia copyright protection systems."

Comparing copyright protection systems

In order to address this shortcoming, the researchers reviewed the scientific literature, analysed 18 blockchain-based multimedia content protection systems and compared them systematically. They studied aspects such as whether they were public or private networks and which digital protection techniques were used, for example encryption or digital watermarking. They also looked at their performance in terms of scalability, their potential to resist cyberattacks, their response time and their data storage capacity.

Their findings made it possible to identify some of the gaps in the research that will need to be filled in order to implement blockchain in this area. They underlined general shortcomings such as poor interoperability due to the lack of universal standards and the lack of models for proof of concept validation or conflict resolution. And they also point out prevailing issues regarding the design of multimedia content protection systems that can support blockchain technology when incorporating distributed systems or technological advances and security guarantees that are accepted by all involved parties.

These are broad outlines designed to improve the usability of blockchain technology in an area with great growth potential, but for the researchers future success will depend on other factors related to the technology, such as "scalability, reliability or market adoption, that are difficult to foresee".

A secure digital accounting ledger

Blockchain gets its name from the fact that it works like a distributed, and therefore decentralized, digital accounting ledger, in which the records are blocks that are connected and encrypted cryptographically. Each block is linked cryptographically with the previous one after the distributed validation, in which the rest of the network users participate, thereby circumventing costly intermediaries. The addition of new blocks usually makes it impossible to modify or delete the older ones, thus preventing manipulation.

Research has found fidaxomicin, an antibiotic usually used to treat bowel infections, prevents growth of resistant strains of Mycobacterium tuberculosis (MTb) in the lab.

Published in the Journal of Medical Microbiology, the research found that fidaxomicin was more effective than existing tuberculosis (TB) medication at preventing growth of the bacterium that causes TB.

Researchers compared the activity of fidaxomicin and rifampicin, an antibiotic currently used to treat TB, against 72 different strains of MTb. Of these strains, 34 were resistant to multiple antibiotics. They found that fidaxomicin could prevent growth of all 72 strains at lower doses than rifampicin.

Both of the drugs tested work in a similar way and are in a group of antibiotics are known as RNAP inhibitors. These antibiotics target an enzyme called RNA polymerase, blocking it and preventing M. tuberculosis cells from reproducing.

Fidaxomicin is commonly used to treat Clostridium difficile (C. diff) infections. This is a bacterial infection of the bowel which usually causes diarrhoea. The researchers suggest that the antibiotic would need to be modified before use, to treat TB in vivo, as the drug in its current form targets the gastrointestinal tract instead of the lungs.

Rifampicin is a well-known frontline treatment for TB. There is increasing concern that antimicrobial resistance is becoming more common in MTb, with many strains resistant to several antibiotics. Over 90% of strains of multi-drug resistant MTb cannot be treated using rifampicin. Finding and developing affordable new antibiotics to treat MDR-TB is desperately needed.

An estimated 1.4 million people died of TB in 2019, and 10 million become unwell with the disease, including 1.2 million children. Very few antibiotics are effective against MTb, and as the bacteria become resistant to more and more antibiotics, TB is becoming harder and harder to treat.

The researchers hope to investigate the in vivo effects of fidaxomicin against TB using animal models.

Since Wilhelm Röntgen discovered them in 1895, X-rays have become a staple of medical imaging. In fact, barely a month after Röntgen's famous paper was published, doctors in Connecticut took the first ever radiograph of a boy's broken wrist.

There has been a lot of progress since. Aside from radiographs, which most people have taken at least once in their lives, today's X-ray medical uses includes fluoroscopy, radiotherapy for cancer, and computer tomography (CT), which takes multiple X-ray scans of the body from different angles and then combines them in a computer to generate virtual cross-sectional "slices" of a body.

Nonetheless, medical imaging often works with low-exposure conditions, and therefore requires cost-effective, high-resolution detectors that can operate at what is called a "low photon flux". Photon flux simply describes how many photons hit the detector at a given time and determines the number of electrons it generates in turn.

Now, scientists led by László Forró at the School of Basic Sciences have developed exactly such a device unit. By using used 3D aerosol jet-printing they developed a novel method for producing highly efficient X-ray detectors that can be easily integrated into standard microelectronics to considerably improve the performance of medical imaging devices.

The new detectors are made up by graphene and perovskites, which are materials made up of organic compounds bound to a metal. They are versatile, easy to synthesize, and are at the forefront of a wide range of applications, including in solar cells, LED lights, lasers, and photodetectors.

Aerosol jet-printing is fairly new, and is used to make 3D-printed electronic components like resistors, capacitors, antennas, sensors, and thin-film transistors or even print electronics on a particular substrate, like the case of cell phone.

Using the aerosol jet printing device at CSEM in Neuchatel, the researchers 3D-printed perovskite layers on a graphene substrate. The idea is that, in a device, the perovskite acts as the photon detector and electron discharger while the graphene amplifies the outgoing electrical signal.

The research team used the methylammonium lead iodide perovskite (MAPbI3), which has recently attracted a lot of attention because of its fascinating optoelectronic properties, which pair well with its low fabrication cost. "This perovskite has heavy atoms, which provide a high scattering cross-section for photons, and makes this material a perfect candidate for X-ray detection," says Endre Horváth, the research team's chemist.

The results were stunning. The method produced X-ray detectors with a record sensitivity and a four-fold improvement on the best-in-class medical imaging devices.

"By using photovoltaic perovskites with graphene, the response to X-rays has increased tremendously," says Forró. "This means that if we would use these modules in X-ray imaging, the required X-ray dose for forming an image could be decreased by more than a thousand times, decreasing the health hazard of this high-energy ionizing radiation to humans."

Another advantage of the perovskite-graphene detector is that it is simple to form images using it. "It doesn't need sophisticated photomultipliers or complex electronics," says Forró. "This could be a real advantage for developing countries."