Earth

Microorganisms are considered as dirty organism that threaten our health, decay food and cause inconvenience in our daily life. However, they are playing a critical role in making nutrients by metabolizing food, allowing all living creatures to live on. Especially, there are 2,000 kinds of microorganisms and several hundred trillions in figures living in our body. Most of these microorganisms live in digestive tracts but their effect is shown in our entire body. Recently, the research team of POSTECH (Pohang University of Science and Technology, President Moohwan Kim) discovered how microbiota transmit signals to entire body and control hematopoiesis in the bone marrow.

Professor Seung-Woo Lee, Research Professor Yunji Park, Master/PhD integrated program students, Seungwon Lee and Hyekang Kim of Division of Integrative Biosciences and Biotechnology from POSTECH described the mechanism how microbiota signals are sent to different organs. Also, they utilized imaging research to prove that CX3CR+ mononuclear cells contact hematopoietic progenitors for the first time in history. Their research is introduced as a featured content in the journal of the American Society of Hematology, Blood.

Recent researches on microorganism concluded that microbiota control biological phenomenon not only in digestive tracts but also in lung, liver, brain, bone marrow and other organs. But, none of them were able to define a mechanism for relaying microbiota signals to entire body or for producing immune cells by receiving microbiota signals.

Professor Lee and his research team focused on the fact that the microbiota regulate the immune system of our body by controlling hematopoiesis in the bone marrow to produce white blood cells. In this process, the team discovered that the microbiota signal including bacterial DNA is transferred to the bone marrow through bloodstream and CX3CR1+ mononuclear cells in the bone marrow recognize this signal.

They explained that when CX3CR1+ mononuclear cells recognize microbiota signals, they release signal substances called cytokines which control and stimulate body's defense system through the signal transduction. They also explained that cytokines control the number of hematopoietic progenitors or stimulate differentiation into myeloid lineages to make blood cells.

Furthermore, they verified that CX3CR1+ mononuclear cells contact hematopoietic progenitors at the perivascular region and they play as a signal receiving microbiota signals.

They discovered the hematopoiesis control mechanism which is controlled by cytokines produced when CX3CR1+ mononuclear cells recognize microbiota signals transferred to the bone marrow.

Professor Seung-Woo Lee commented, "For the first time, our research describes the mechanism that had not been explained how microbiota regulate not only digestive tracts but also entire body response. It might be possible to apply this study to control immune response in other parts of a body or to treat cancer and inflammatory disease via microbiota signal pathway.

This study was financially supported by National Research Foundation of Korea, Regional Leading Research Center, and Korea Ministry of Science and ICT under BK21 Plus project.

EAST LANSING, Mich. -- Salmonella is acting up in Michigan, and it could be a model for what's happening in other states, according to a new Michigan State University study.

The study, appearing in Frontiers in Medicine, documents a substantial uptick in antibiotic resistant strains, and consequently, longer hospital stays as doctors work to treat the increasing virulent pathogens.

"If you get a salmonella infection that is resistant to antibiotics today, you are more likely to be hospitalized longer, and it will take you longer to recover," said Shannon Manning, MSU Foundation professor in the Department of Microbiology and Molecular Genetics and senior author of the study. "We need better detection methods at the clinical level to identify resistant pathogens earlier so we can treat them with the right drugs the first time."

Losing a day or more to misdiagnosis or improper treatment allows symptoms to get worse. Doctors might kill off a subpopulation of bacteria that are susceptible, but the ones that are resistant grow stronger, she added.

Salmonella is a diverse group of bacterial pathogens that causes foodborne infections. Infected patients often develop diarrhea, nausea, vomiting and abdominal pain, though some infections are more severe and can be life threatening.

When it comes to treatments, each strain reacts differently to the range of antibiotics available for prescription by doctors. So getting it right the first time is crucial.

Specifically in Michigan, doctors are seeing more strains that are resistant to ampicillin, a common antibiotic prescribed to treat salmonella. Multidrug resistance, or resistance to more than three classes of antibiotics, has also increased in Michigan and could further complicate patient treatment plans.

"We're still uncertain as to why this is happening; it could be that these antibiotics have been overprescribed in human and veterinary medicine and that possessing genes for resistance has allowed these bacteria to grow and thrive in the presence of antibiotics," Manning said. "Each state has its own antibiotic-resistance issues. It's important that the medical profession remains vigilant to ever-changing patterns of resistance in salmonella and other foodborne pathogens, rather than look for a blanket national solution."

Historically, salmonella has affected young children and the elderly, but now there's been a rise in adult cases, suggesting that the epidemiology of the infections has changed in Michigan.

Diving into individual strains of salmonella, the team of scientists found that patients with Typhimurium were more likely to have resistant infections as were patients infected during the fall, winter or spring months.

Another distinction was revealed between the strains affecting people living in rural and urban areas. Enteritis infections tend to be higher in rural areas. This may be attributed to rural residents' exposure to farm animals or untreated sources of water.

Each state's salmonella population has its own personality; so every state's approach to identifying disease drivers and effective treatments should be modified to reflect these traits.

"Our results show the importance of surveillance, monitoring resistance frequencies and identifying risk factors specific to each state and region," Manning said. "The trends that are revealed can lead to new prevention strategies."

The study, which looks specifically at the behaviour of an endangered monkey species, reveals that even in national parks where human presence is reduced and regulated, the animals carry out careful calculations and modify their natural behaviour to balance the pros and cons of living in close proximity to humans.

It reveals the negative impact that consuming human foods can have on the physical health of the monkeys, and highlights the need for new and sustainable conservation programmes to save the growing number of endangered species in their natural habitats.

Barbary macaques are an endangered species of monkeys restricted to the forests of Morocco and Algeria, with an introduced population also living on the Rock of Gibraltar. The wild population in North Africa has dramatically declined in the last decades.

The new study, led by Dr Bonaventura Majolo from the University of Lincoln, UK, involved a detailed examination of the effects of human activity on wild Barbary macaques in Ifrane National Park in Morocco.

Dr Majolo said: "When we observe animals in the wild we often talk about a 'landscape of fear'. This term refers to the decisions that animals make when they choose whether or not to avoid an area where the risk of predation is highest; weighing up the risk of attack against the possible rewards to be found there.

"Our study shows that macaques make many behavioural adjustments in response to varying levels of risk and reward, and that the way the macaques respond to human activity is very similar to the way in which they respond to predation risk. We see evidence here that the macaques are capable of great behavioural flexibility as they navigate the problems and the opportunities that sharing space with humans presents."

The researchers followed five groups of Barbary macaques and observed their behaviour and habitat selection over the course of a year. Their findings reveal the true extent of human activity on the monkeys' habitats and choices.

The researchers observed the macaques making significant adjustments to their behaviour and navigating their environment strategically in relation to human activity. They appear to balance food acquisition and risk avoidance - for example they minimise risk by avoiding areas used by local shepherds and their dogs (which are now among the monkeys' most dangerous predators), and exploit opportunities to receive high-calorie human food by spending time close to roads.

Although being fed by humans may appear to be beneficial for the monkeys, food provisioning in fact has negative impacts on the macaques - increasing their stress levels, heightening the probability of road injury and death, and having a detrimental impact on their health.

The monkeys' behaviour also shows seasonal trends in correlation with human activities. The macaques avoid herding routes during summer months, when herding activity by the local shepherds is at its peak, and they are more likely to use areas close to roads in the autumn and winter months, when natural food sources are low and the benefits of receiving high calorie human food may exceed the risk of being injured or even killed by road traffic.

The study reveals that the 'home range' of each observed macaque group (the area where a group of monkeys spend most of their time) included some kind of human structure, from roads and paths to picnic areas and farms.
They also found that all of the study group's home ranges overlapped with at least one other, which the researchers conclude could be a result of declining availability of suitable habitats and food sources, or of direct competition over profitable areas close to roads and safe sleeping sites.

Their findings are published in the scientific journal Animal Conservation.

James Waterman, first author of the paper and a PhD student at Liverpool John Moores University, said: "Even in a national park, the effect of human disturbance on animal life can be considerable, and as our landscapes become increasingly human dominated, many wildlife species must cope with new ecological pressures. The impact of habitat loss and fragmentation, climate change, expanding human infrastructure, hunting and poaching quickly and dramatically alters habitats, forcing wildlife to adjust, move to more suitable areas (if these are available), or ultimately face the threat of extinction.

"This study highlights that it is more important than ever to develop conservation programs that take into account the requirements of all involved, including, but not limited to the wildlife that is ultimately at risk. Programs that fail to do so rarely produce lasting, positive change."

Dr Majolo concludes: "The good news is that we see certain species, like these monkeys, adapting in impressive and intelligent ways to increasing levels of human activity. The bad news is that this flexibility may only take them so far as habitats continue to shrink, and contact with humans becomes harder to avoid. We have a responsibility to try to understand the limits of this flexibility and find sustainable solutions for human-wildlife co-existence before that point is reached, and we risk losing them for good."

Climate change is reorganizing the life in our oceans in a big way: as waters warm, cold-loving species, from plankton to fish, leave the area and warm water species become more successful. So say an international group of scientists in the most comprehensive assessment of the effects of ocean warming on the distribution fish communities.

"We've known for a while that marine species tend to track ocean temperature, but this is the first time we've seen how entire communities respond, and that the redistribution of species is so predictable by temperature alone," said UC Santa Barbara marine ecologist Ben Halpern, an author on a paper in the journal Nature Climate Change. "The implications are very large for the ecology of the oceans and for the benefits -- like food from fishing -- people get from the oceans."

Halpern, who directs UCSB's National Center for Ecological Analysis and Synthesis and is a professor in the Bren School of Environmental Science & Management, joined researchers from the UK, Japan, Australia, the U.S., Germany, Canada, South Africa and New Zealand to analyze three million records of thousands of species from 200 ecological communities across the globe. Reviewing data from 1985-2014, the team, led by marine ecologist Michael Burrows of the Scottish Association for Marine Science (SAMS) in Oban, showed how subtle changes in the movement of species that prefer cold water or warm water, in response to rising temperatures, made a big impact on the global picture.

"For the period from 1985-2014 we created the equivalent of an electoral poll in the ocean, showing swings between types of fish and plankton normally associated with either cold or warm habitats," Burrows said. "As species increase in number and move into, or decline and leave a particular ecological community, the make-up of that community will change in a predictable way."

The truly global study looked at data from the North Atlantic, Western Europe, Newfoundland and the Labrador Sea, the U.S. east coast, the Gulf of Mexico and the North Pacific from California to Alaska.

While the global warming trend was widely seen, the North Atlantic showed the largest rise in average temperature during the time period. However, for fish communities in the Labrador Sea, where the temperature at 100 meters deep can be as much as five degrees Celsius cooler than the surface, moving deeper in the water column allowed the cold-water species to remain successful.

"Most of the data collected were targeted surveys of commercial fish stocks, so the changes seen reflect those likely to be seen in fish markets as cold-water fish like cod and haddock decline, while warm-water species like red mullet increase with warming," Burrows said, adding that there has been a temperature rise of almost one degree Celsius in some parts of the ocean since 1985.

While one degree Celsius may not seem like a big change, for those fish and other marine organisms already at their maximum temperature tolerance the shift is enough to alter their chances of success in a given area and impact the global ocean food web, according to the researchers.

"Given the complexity of the oceans and ocean life, it is really remarkable that a single factor -- ocean temperature -- is such a powerful predictor of change," Halpern said. "Few things in life can be explained by a single factor."

Boston, MA -- Obstructive sleep apnea (OSA) has been considered a predominantly male disease. While more women have been diagnosed with OSA in recent years, the numbers remain disproportionate, with 3-to-5 times more men than women receiving an OSA diagnosis. Investigators from Brigham and Women's Hospital and Yale School of Medicine set out to understand this disparity and its causes. They found that a high proportion of women experienced sleep apnea during dream sleep, which is associated with adverse outcomes including cardiovascular disease. Their findings have implications for the screening, diagnosis and treatment of OSA among women and men and are published in the journal SLEEP.

"Over the years, I've felt strongly that sleep apnea may be an exemplar of a chronic disease that may manifest differently in men and women, from how it presents to its underlying physiology, with implications for how it should be treated," said senior author Susan Redline, MD, MPH, a senior physician in the Division of Sleep and Circadian Disorders in the Departments of Medicine and Neurology at the Brigham. "Here, we begin to drill down to understand how sleep apnea may differ and how common scoring approaches may underestimate sleep apnea in women."

To conduct their study, the investigators analyzed participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Between 2010 and 2013, the team analyzed data from 2,057 MESA participants who underwent a comprehensive sleep study. The mean age of the study participants was 68.

Usually, home-based sleep studies only measure breathing activity, not brain activity and other criteria that can be measured in a sleep lab setting. But for this study, many parameters were measured, including brain activity and body movement.

The team compared a range of summary measures of sleep apnea severity based on the apnea-hyponea index (AHI), the number of breathing pauses per hour of sleep. An AHI greater than 15 is generally considered to indicate moderate to severe sleep apnea and is associated with increased risk of developing hypertension and mortality. The investigators calculated AHI numerous ways, some of which were more sensitive to capturing changes in breathing patterns during REM sleep (dream sleep) and non-REM sleep (other stages of sleep). The team extracted detailed measures from the overnight sleep study to also estimate some of the mechanisms that may cause sleep apnea, including measures of the collapsibility of the airway, the sensitivity of breathing patterns to changes in oxygen and changes in how quickly individuals woke up at night.

The team found that during non-REM sleep, twice as many men as women had an AHI score greater than 15. However, during REM sleep, the prevalence was the same in men and women. Among the study population, almost 60 percent of men and women met diagnostic criteria for moderately severe sleep apnea. The authors note that there is mounting evidence of an association between sleep apnea during REM sleep and adverse cardiovascular outcomes. The study also found that the physiological mechanisms that influence sleep apnea differ in men and women: women had lower loop gain (lower sensitivity to changes in ventilation), less airway collapsibility, and lower arousal threshold (more easily wake up after an apnea) in non-REM sleep. These specific aspects of sleep apnea are thought to be targets for new treatments for sleep apnea.

"We are more and more appreciating that sleep apnea is a heterogeneous disease," said corresponding author Christine Won, MD, MSc, the director of the Women's Sleep Health program at Yale School of Medicine. "It's important to understand how it affects men and women differently. Understanding sex-specific mechanisms allows us to target therapy and is expected to lead to better outcomes."

Medicare currently requires an oxygen desaturation level of 4 percent along with apnea events in order to consider someone to have OSA and receive coverage for treatment. Redline and colleagues compared this definition to other definitions in which the desaturation requirement was not as strict and took into consideration mini-awakenings -- events that are not measured in most at-home sleep studies. The team found OSA rates that were almost double in women when these definitions that counted events that resulted in milder desaturation or awakenings compared to events that were only counted when larger amount of desaturation occurred.

"This suggests that women may be preferentially underdiagnosed when we use the Medicare definition of sleep apnea," said Redline. "Women who have been evaluated using only home-based sleep studies should continue to speak to their doctor if they have not been diagnosed with sleep apnea but continue having symptoms."

Although the cilium has been known to scientists for more than 100 years, it is only recently that it has been acknowledged to play important roles in physiology. Virtually every cell has a primary cilium that functions to senses fluid flow, transmits chemical signals to other cells and controls cell growth. Defects in the function of cilia lead to a class of diseases called ciliopathies, which include polycystic kidney disease, primary ciliary dyskinesia and Bardet-Biedl syndrome.

Extracellular vesicles (EVs), membrane-bound carriers with complex cargos that include proteins, lipids and nucleic acids, function in long-distance cellular communication, but how cilia contribute to EV production was previously unclear to the scientific community. New work from researchers at the Medical University of South Carolina (MUSC), published online on Nov. 6 by the Journal of Biological Chemistry, shows that primary cilia generate approximately 60% of the small EVs produced by renal tubule cells and that manipulation of cilium length affects the production of EVs. Furthermore, the protein content of EVs is very different depending on the length of the cilia.

"For many years, people thought EVs represented a garbage disposal system - a way for the cell to get rid of things it didn't need. But I think it is pretty clear that small (50-150nm) EVs represent one of the main signaling mechanisms of the cell," says Joshua H. Lipschutz, M.D., the Arthur V. Williams Chair and director of the Division of Nephology at MUSC. "This is the first real demonstration in mammalian cells that ectosomes, EVs produced by primary cilia as opposed to exosomes, which are EVs that are similar in size but form in the multivesicular bodies of the cell, are so prominent."

One of the key components of ciliogenesis - the process of generating a cilium - is the exocyst, an eight-protein complex that is highly conserved and was first discovered in yeast. Previous work has shown that loss of exocyst complex component 5 (EXOC5), one of the eight proteins that make up the exocyst, causes very short or no cilia to be produced. Conversely, increased expression of EXOC5 causes the cilia to lengthen.

In their current work, Lipschutz and colleagues took these data one step further and examined the contribution of the exocyst to EV production. They compared three groups of cells: normal kidney cells, kidney cells that have lost EXOC5 and kidney cells that make more EXOC5 than normal. All three of these groups were significantly different from one another. The cells that lost EXOC5 had very short or absent cilia and also produced fewer EVs. On the other hand, cells that made more EXOC5 had longer cilia and produced significantly more EVs. Analysis of the protein content of the EVs that were made under these various conditions showed dramatic differences, which suggests that the capacity for these EVs to signal to other cells was different in each condition.

The researchers then expanded their work. They generated kidney cells that had lost expression of intraflagellar transport protein 88 (IFT88), a protein that is also required for proper cilium formation. These cells again showed a reduction in EV production like that seen under conditions where EXOC5 was reduced. Finally, the researchers made a mouse with EXOC5 depleted specifically in proximal tubule kidney cells and showed that EVs isolated from the urine of these mice had a different protein content than the EVs of normal mice, with many of the same changes observed in the cell lines.

"The exciting and surprising thing is that so many of the small EVs appear to be ectosomes because the cilia make up just 0.2% of the cell membrane yet are one of the main drivers of EV production," says Lipschutz.

In summary, Lipschutz and colleagues have linked the presence and length of mammalian primary cilia to EV production. Loss of EXOC5 or IFT88 resulted in shorter cilia that produced fewer EVs, while the presence of more EXOC5 resulted in longer cilia that produced more EVs. Importantly, the proteins that were found in these various EVs were very different. This has important implications for intercellular communication that is not limited to the kidney.

"These ectosomes are not only in the urine, but they're also likely in the blood and may play a role in the biology of many systems, including cancer," says Lipschutz.

Because most cells have a primary cilium, defects in cilia can affect many different tissue types. In the future, Lipschutz plans to work with other researchers at MUSC to examine EVs in other tissues with impaired cilia, including eye and heart tissues.

"These organelles, which 20 years ago people were writing were evolutionary holdovers, like the appendix of organelles, not only are mechano- and chemosensors but are also involved in making a significant portion of the EVs that are centrally involved in cell signaling," says Lipschutz. "I think we're finding out more and more things that cilia, which contain between 500 and 1000 proteins, do and how important they are."

'Origami robots' are state-of-the-art soft and flexible robots that are being tested for use in various applications including drug delivery in human bodies, search and rescue missions in disaster environments and humanoid robotic arms.

Because these robots need to be flexible, they are often made from soft materials such as paper, plastic and rubber. To be functional, sensors and electrical components are often added on top, but these add bulk to the devices.

Now, a team of NUS researchers has developed a novel method of creating a new metal-based material for use in these soft robots.

Combining metals such as platinum with burnt paper (ash), the new material has enhanced capabilities while maintaining the foldability and lightweight features of traditional paper and plastic. In fact, the new material is half as light as paper, which also makes it more power efficient.

These characteristics make this material a strong candidate for making flexible and light prosthetic limbs which can be as much as 60 per cent lighter than their conventional counterparts. Such prosthetics can provide real-time strain sensing to give feedback on how much they are flexing, giving users finer control and immediate information -- all without the need for external sensors which would otherwise add unwanted weight to the prosthetic.

This light-weight metallic backbone is at least three times lighter than conventional materials used to fabricate origami robots. It is also more power-efficient, enabling origami robots to work faster using 30 per cent less energy. Furthermore, the novel material is fire-resistant, making it suitable for fabricating robots that work in harsh environments as it can withstand burning at about 800°C for up to 5 minutes.

As an added advantage, the novel conductive material has geothermal heating capabilities on-demand -- sending a voltage through the material causes it to heat up, which helps to prevent icing damage when a robot works in a cold environment. These properties can be used in the creation of light, flexible search-and-rescue robots that can enter hazardous areas while providing real-time feedback and communication.

Research breakthrough published in prestigious Science Robotics journal

The metal-based material is produced through a new process developed by the team called 'graphene oxide-enabled templating synthesis'. Cellulose paper is first soaked into a graphene oxide solution, before dipping it into a solution made of metallic ions such as platinum. The material is then burned in an inert gas, argon, at 800°C and then at 500°C in air.

The final product is a thin layer of metal -- 90 micrometres (μm), or 0.09mm -- made up of 70 per cent platinum and 30 per cent amorphous carbon (ash) that is flexible enough to bend, fold, and stretch. This significant research breakthrough was published in the prestigious scientific journal Science Robotics on 28 August 2019. Other metals such as gold and silver can also be used.

Team leader Assistant Professor Chen Po-Yen used a cellulose template cut out in the shape of a phoenix for his research. "We are inspired by the mythical creature. Just like the phoenix, it can be burnt to ash and reborn to become more powerful than before," said Asst Prof Chen, from NUS Department of Chemical and Biomolecular Engineering.

Conductive backbone for smarter origami robots

The team's material can function as mechanically stable, soft, and conductive backbones that equips robots with strain sensing and communication capabilities without the need for external electronics. Being conductive means the material acts as its own wireless antenna, allowing it to communicate with a remote operator or other robots without the need for external communication modules. This expands the scope of origami robots, such as working in high-risk environments (e.g. chemical spills and fire disaster) as remote-control untethered robots or functioning as artificial muscles or humanoid robotic arms.

"We experimented with different electrically conductive materials to finally derive a unique combination that achieves optimal strain sensing and wireless communication capabilities. Our invention therefore expands the library of unconventional materials for the fabrication of advanced robots," said Mr Yang Haitao, doctoral student at the Department of Chemical and Biomolecular Engineering and the first author of the study.

In the next steps of their research, Asst Prof Chen and his team are looking at adding more functions to the metallic backbone. One promising direction is to incorporate electrochemically active materials to fabricate energy storage devices such that the material itself is its own battery, allowing for the creation of self-powered robots. The team is also experimenting with other metals such as copper, which will lower the cost of the material's production.

ASPB is pleased to announce the publication of research with significant implications for nitrogen nutrition in crop plants.

Researchers Karnelia Paul of the University of Calcutta (India), Chinmay Saha of the University of Kalyani (India), and Anindita Seal of the University of Calcutta (India) designed this research to study nitrogen nutrition in rice.

Nitrogen supply limits crop yields, but application of excess nitrogen fertilizer can pollute water and is expensive. Therefore, scientists are looking for beneficial microbes that could assist in providing plants with nitrogen by fixing nitrogen--converting atmospheric nitrogen to forms that plants can use. Such "green fertilizers" could improve grain yields without the need for application of chemical nitrogen fertilizers. Legumes such as soybeans have symbiotic bacteria that fix nitrogen, but most important grain crops, including rice, lack these bacteria. To address this problem, a study published in The Plant Cell used microbes that were discovered in an unusual and highly nutrient-limited environment, cattails growing in a pool of tailings from a uranium mine. The fungus Rhodotorula mucilaginosa JGTA-S1 (JGTA-S1 refers to the specific strain) was isolated from narrowleaf cattail (Typha angustifolia), and this pink-colored fungus improves growth in its host cattails. In their previous work, the authors sequenced the genome of this fungus and discovered that JGTA-S1 has several genes that support its role as a plant-associated fungus. Surprisingly, in the current study the researchers also discovered that this fungus contains nitrogen-fixing bacteria, which may allow it to fix nitrogen.

The authors of this study next set out to determine whether JGTA-S1 could use the important crop plant rice as a host and promote rice growth and nutrition, focusing on nitrogen in particular. Indeed, the authors showed that JGTA-S1 colonizes rice as a host and increases the nitrogen content in the plant. Furthermore, the authors studied the endosymbiotic bacteria and their role in fungal and plant growth. JGTA-S1 can grow in nitrogen-free media, with nitrogen fixation assisted by nitrogen-fixing bacteria, including Pseudomonas stutzeri. Nitrogen-fixing bacteria are key to JGTA-S1's viability and crucial for the increased biomass and ammonium in fungus-treated plants. The fungus associates with the plant to form filamentous structures, and the P. stutzeri bacteria then penetrate these structures. Therefore, this fascinating interaction among organisms from three kingdoms (plants, fungi, and bacteria) may hold the key to improving nitrogen nutrition in rice and perhaps other crop plants.

As next steps, corresponding author Anindita Seal said: "Improving nitrogen nutrition in crop plants is a challenge for scientists. It would be interesting to see whether this three-kingdom interaction can be used to improve nitrogen nutrition in plants other than rice or whether the beneficial role of the endofungal bacteria is plant specific."

Living beings, especially microorganisms, have a surprising ability to adapt to the most extreme environments on our planet, but there are still places where they cannot live. European researchers have confirmed the absence of microbial life in hot, saline, hyperacid ponds in the Dallol geothermal field in Ethiopia.

The infernal landscape of Dallol, located in the Ethiopian depression of Danakil, extends over a volcanic crater full of salt, where toxic gases emanate and water boils in the midst of intense hydrothermal activity. It is one of the most torrid environments on Earth. There, daily temperatures in winter can exceed 45° C and there are abundant hypersaline and hyperacid pools, with pH values that are even negative.

A recent study, published this year, pointed out that certain microorganisms can develop in this multi-extreme environment (simultaneously very hot, saline and acid), which has led its authors to present this place as an example of the limits that life can support, and even to propose it as a terrestrial analogue of early Mars.

However, now a French-Spanish team of scientists led by biologist Purificación Lopez Garcia of the French National Centre for Scientific Research (CNRS) has published an article in Nature Ecology & Evolution that concludes otherwise. According to these researchers, there is no life in Dallol's multi-extreme ponds.

"After analysing many more samples than in previous works, with adequate controls so as not to contaminate them and a well-calibrated methodology, we have verified that there's no microbial life in these salty, hot and hyperacid pools or in the adjacent magnesium-rich brine lakes," stresses López García.

"What does exist is a great diversity of halophilic archaea (a type of primitive salt-loving microorganisms) in the desert and the saline canyons around the hydrothermal site," the biologist explains, "but neither in the hyperacid and hypersaline pools themselves, nor in the so-called Black and Yellow lakes of Dallol, where magnesium abounds. And all this despite the fact that microbial dispersion in this area, due to the wind and to human visitors, is intense."

This is confirmed by the results of all the various methods used by the team, including the massive sequencing of genetic markers to detect and classify microorganisms, microbial culture attempts, fluorescent flow cytometry to identify individual cells, chemical analysis of brines and scanning electron microscopy combined with X-ray spectroscopy.

López García alerts that some silica-rich Dallol mineral precipitates may look like microbial cells under a microscope, so what is seen must be analysed well: "In other studies, apart from the possible contamination of samples with archaea from adjacent lands, these mineral particles may have been interpreted as fossilized cells, when in reality they form spontaneously in the brines even though there is no life."

According to the authors, this work "helps to circumscribe the limits of habitability and demands caution when interpreting morphological bio-signatures on Earth and beyond," that is, one should not rely on the apparently cellular or 'biological' aspect of a structure, because it could have an abiotic origin.

"In addition, our study presents evidence that there are places on the Earth's surface, such as the Dallol pools, which are sterile even though they contain liquid water," stresses Lopez Garcia. This means that the presence of liquid water on a planet, which is often used as a habitability criterion, does not directly imply that it has life.

In this case, the researchers have found two physical-chemical barriers that prevent the presence of living organisms in ponds: the abundance of chaotropic magnesium salts (an agent that breaks hydrogen bridges and denatures biomolecules) and the simultaneous confluence of hypersaline, hyperacid and high-temperature conditions.

"We would not expect to find life forms in similar environments on other planets, at least not based on a biochemistry similar to terrestrial biochemistry," points out Lopez Garcia, who insists on the need to have multiple indications, to analyse all types of alternatives and to be very prudent with interpretations before reaching any conclusions in astrobiology.

Both the French-Spanish group, in which researchers from the Geological and Mining Institute of Spain and the Autonomous University of Madrid participate, and other international teams continue to investigate the extreme environment of Dallol, where completely sterile pools could alternate with others with slightly better biophysical conditions that allow the presence of archaea and other extremophilic microorganisms. In any case, this is an exceptional environment to continue studying the limits of life.

Researchers of the Faculty of Science of the University of Malaga (UMA) have designed a low-cost T-shirt that generates electricity from the temperature difference between the human body and the surroundings. We are talking about the "e-textile" prototype, developed in collaboration with the Italian Institute of Technology in Genoa (IIT) based on sustainable methods and low-cost materials like tomato skin.

"So far, metals have been the chemical elements commonly used in the fabrication of electronic devices. This project took a step forward, and we have been able to generate electricity by using light and more affordable and less toxic materials", explains José Alejandro Heredia, one of the authors of this project.

The formula is very simple: water and ethanol -a type of ecological alcohol- derived from tomato skin and carbon nanoparticles. A solution that, according to experts, when heated, penetrates and adheres to cotton, thus obtaining electrical properties, like those generated by tellurium, germanium or lead, but from biodegradable materials.

"When someone walks or runs, warms up. If such person wore a T-shirt designed with these characteristics, the difference between his/her body and the colder temperature of the surroundings could generate electricity", says Susana Guzmán, another author from the UMA.

"Iron Man" made in UMA

The results of this project, in which the Italian researcher Pietro Cataldi has participated, were published in the journal Advanced Functional Materials. At present, this group of scientists continues their work on the development of devices that can be incorporated into textile to be able to, for example, generate light to make this T-shirt reflective or even charge a mobile phone without a charger.

Other possible applications include biomedicine, thanks to the monitoring of signals of each user, or robotics, because the use of these lighter and more flexible materials enables improvement of robot features.

"In a previous study, we were able to create a Wi-Fi antenna from tomato skin and graphene. We are also studying the possibility of incorporating this invention into the "e-textile" T-shirt, which would enable us to be like the superhero Iron Man, who wears a suit with all types of technological devices, and even fly", jokes Guzmán.

José Alejandro Heredia and Susana Guzmán are members of the Department of Molecular Biology and Biochemistry of the University of Málaga. They are part of the Institute for Mediterranean and Subtropical Horticulture (IHSM) and their main R+D+i lines include the fabrication of electronic devices with biodegradable materials.

José Alejandro Heredia and Susana Guzmán are members of the Department of Molecular Biology and Biochemistry of the University of Málaga. They are part of the Institute for Mediterranean and Subtropical Horticulture (IHSM) and their main R+D+i lines include the fabrication of electronic devices with biodegradable materials.

Bibliographic reference: Adv. Funct. Mater. 2019, 1907301

Journal

Advanced Functional Materials

DOI

10.1002/adfm.201907301

Digital coding and digital modulation technologies are important cornerstones of modern information science and technology, but they are limited in the digital world. In 2014, Prof. Tie Jun Cui at Southeast University and his coworkers proposed the concept of digital coding metamaterials, which combine the digital technologies with the electromagnetic wave manipulations, breaking the barrier between the digital world and physical world. However, manipulating confined electromagnetic waves in deep-subwavelength scale is still a significant challenge in this field.

Recently, Prof. Tie Jun Cui's group at Southeast University (SEU) has collaborated with Prof. Yu Luo at Nanyang Technological University (NTU), Singapore, and reported a breakthrough on this topic in National Science Review entitled "Active digital spoof plasmonics" (the first author is a graduate student, Hao Chi Zhang). In this work, a digital spoof surface plasmon polariton (SSPP) metamaterial is presented to achieve the combination of the tightly confined SSPP waves and the digital coding and modulation technologies.

Research on SSPPs has been a hotspot in the physical and microwave engineering communities since Prof. Tie Jun Cui's group proposed the first ultrathin corrugated metallic strip as the conformal SSPP waveguide in 2013. However, the existing SSPP metamaterials are not tunable after fabrication and cannot realize the real-time manipulations of SSPP waves in the subwavelenth scale. To solve the problem, the SEU-NTU joint group proposed discrete and dynamic controls of the SSPP waves by judiciously designing the surface metallic patterns and state-change medium. Two discrete dispersion states of the active digital spoof plasmonics are constructed, corresponding to "0" and "1" states in the digital world. Based the presented strategy, the joint group successfully designed a SSPP-based digital coding device which can implement both amplitude and phase modulations on a single SSPP platform. Hence, this work breaks the barrier between SSPPs and the digital world, and extends the scope of digital coding metamaterial in manipulating the confined electromagnetic waves, which opens a new avenue to novel system applications based on the digital coding metamaterials.

The semiconductor industry has been developed for more than 40 years following the Moore's Law. With the size of transistors being shrinking down to tenth of nanometer scale, the quantum effects start to dominate and cause problems such as operation stability and heat generations [Fig. 1a] [1]. An alternative route is to develop new functional materials and their architectures. Complex oxide is one of the most promising candidates. Recently, scientists have shown novel phenomena of complex oxide at nanometer length scale and its potential for applications.

In the article "Spatial confinement tuning of quenched disorder effects and enhanced magnetoresistance in manganite nanowires" published in SCIENCE CHINA Physics, Mechanics & Astronomy (First author: Yang Yu, Corresponding authors: Hangwen Guo, Lifeng Yin, Jian Shen), scientists has fabricated a series of complex oxide known as manganites nanowires ranging from 5 μm to 50 nm, by using state-of-the-art nanolithography techniques [Fig. 1b] [2]. From transport and magnetic imaging measurements, scientist reveals that when the nanowire size is smaller, the effect of quenched disorder becomes significantly enhanced----a new phenomenon that has not been identified before at nanometer scale [Fig. 1c].

Quenched disorder: In condensed matter physics, quenched disorder usually refers to the randomness in a material which is "frozen" or "quenched" at all times. The most common source of quenched disorder comes from impurities or chemical dopants. Quenched disorder plays significant roles in complex oxide systems.

Extensive theoretical treatments have shown the critical role of quenched disorder in complex oxide systems such as high-Tc cuprates and colossal magnetoresistive manganites. Experimental investigations, on the other hand, are rather complicated. The most common way to control quenched disorder is by chemical doping. However, chemical doping simultaneously alters material's chemical environments, structures, etc., clouding the impact of quenched disorder.

In this article, the scientist shows that spatial confinement is a clean and effective way to study quenched disorder effect without changing the chemical environments, structure and other physical parameters. The results reveal that enhanced quenched disorder not only can alter the nature of electronic and magnetic phase transition, but increase the magnetoreisistance up to 820000 %, a 200 times enhancement to its original values. These phenomena offer new routes on the understanding of complex materials at nanometer scales and their potential applications.

Digital innovations have the potential to bring people closer to nature, to help ensure there is the necessary strong public support for conservation measures. Examples below.

Author Professor Les Firbank, from the University of Leeds' School of Biology and Global Food and Environment Institute, said: "Our growing digital connection to wildlife, aided by broadcasters such as David Attenborough, may be crucial to securing broad public support for the protection of wildlife, which we are currently driving to extinction at record rates.

"In future, expertise in public engagement and digital innovation are likely to be as important as expertise in conservation biology, to ensure the values and culture of a community are placed at the heart of the protection of nature.

"Urbanisation is changing our cultural relationships with wildlife, and this has to be taken into account by nature conservation organisations if conservation is to be successful into the future."

"The growing popularity of rewilding may well be a reflection of humanity's changing view of ourselves, seeing humans as separate to nature, rather than as part of it.

"We need to defend and rebuild our connections with nature to help shape a culture that recognises the need to conserve wildlife.

Examples of digital innovation taking place today include:

Fitness apps that compare people to wild animals (such as snow leopards)

Live feeds for nests, birds, mammals, from urban through to wild nature (including peregrine falcons at the University of Leeds)

Gamification of simple experiments on habitat management in gardens (e.g. providing bird food)

Virtual reality experiences of climate change and wild lands (e.g. virtual planet)

Creating local wildlife hubs linked through social media, such as people tracking the number of birds killed by pet cats or sightings of foxes and other predators

Professor Firbank added: "Agriculture is the biggest driver of global biodiversity loss, and it has led us to the extinction crisis we face today.

"Increasing urbanization means that fewer people are experiencing nature through traditional, extensive farming, and instead they are experiencing a form of wild-nature through digital media."

St. Petersburg, Fla. (November 22, 2019)- University of South Florida geoscientists have successfully developed and tested a new high-tech shallow water buoy that can detect the small movements and changes in the Earth's seafloor that are often a precursor to deadly natural hazards, like earthquakes, volcanoes and tsunamis.

The buoy, created with the assistance of an $822,000 grant from the National Science Foundation's Ocean Technology and Interdisciplinary Coordination program, was installed off Egmont Key in the Gulf of Mexico last year and has been producing data on the three-dimensional motion of the sea floor. Ultimately the system will be able to detect small changes in the stress and strain the Earth's crust, said USF School of Geosciences Distinguished Professor Tim Dixon.

The patent-pending seafloor geodesy system is an anchored spar buoy topped by high precision Global Positioning System (GPS). The buoy' orientation is measured using a digital compass that provides heading, pitch, and roll information - helping to capture the crucial side-to-side motion of the Earth that can be diagnostic of major tsunami-producing earthquakes, Dixon said. He was joined in leading the project by USF Geoscience Phd student Surui Xie, Associate Professor Rocco Malservisi USF College of Marine Science's Center for Ocean Technology research faculty member Chad Lembke, and a number of USF ocean technology personnel.

Their findings were recently published in the Journal of Geophysical Research-Solid Earth.

While there are several techniques for seafloor monitoring currently available, that technology typically works best in the deeper ocean where there is less noise interference. Shallow coastal waters (less than a few hundred meters depth) are a more challenging environment but also an important one for many applications, including certain types of devastating earthquakes, the researchers said. Offshore strain accumulation and release processes are critical for understanding megathrust earthquakes and tsunamis, they noted.

The experimental buoy rests on the sea bottom using a heavy concrete ballast and has been able to withstand several storms, including Hurricane Michael's march up the Gulf of Mexico. The system is capable of detecting movements as small as one to two centimeters, said Dixon, an expert on natural hazards and author of the book Curbing Catastrophe.

"The technology has several potential applications in the offshore oil and gas industry and volcano monitoring in some places, but the big one is for improved forecasting of earthquakes and tsunamis in subduction zones," Dixon said. "The giant earthquakes and tsunamis in Sumatra in 2004 and in Japan in 2011 are examples of the kind of events we'd like to better understand and forecast in the future."

Dixon said the system is designed for subduction zone applications in the Pacific Ocean's "Ring of Fire" where offshore strain accumulation and release processes are currently poorly monitored. One example where the group hopes to deploy the new system is the shallow coastal waters of earthquake prone Central America.

The Egmont Key test location sits in just 23 meters depth. While Florida is not prone to earthquakes, the waters off Egmont Key proved an excellent test location for the system. It experiences strong tidal currents that tested the buoy's stability and orientation correction system. The next step in the testing is to deploy a similar system in deeper water of the Gulf of Mexico off Florida's west coast.

DURHAM, N.C. -- A new cancer-detecting tool uses tiny circuits made of DNA to identify cancer cells by the molecular signatures on their surface.

Duke University researchers fashioned the simple circuits from interacting strands of synthetic DNA that are tens of thousands of times finer than a human hair.

Unlike the circuits in a computer, these circuits work by attaching to the outside of a cell and analyzing it for proteins found in greater numbers on some cell types than others. If a circuit finds its targets, it labels the cell with a tiny light-up tag.

Because the devices distinguish cell types with higher specificity than previous methods, the researchers hope their work might improve diagnosis, and give cancer therapies better aim.

A team led by Duke computer scientist John Reif and his former Ph.D. student Tianqi Song described their approach in a recent issue of the Journal of the American Chemical Society.

Similar techniques have been used previously to detect cancer, but they're more prone to false alarms -- misidentifications that occur when mixtures of cells sport one or more of the proteins a DNA circuit is designed to screen for, but no single cell type has them all.

For every cancer cell that is correctly detected using current methods, some fraction of healthy cells also get mislabeled as possibly cancerous when they're not.

Each type of cancer cell has a characteristic set of cell membrane proteins on its cell surface. To cut down on cases of mistaken identity, the Duke team designed a DNA circuit that must latch onto that specific combination of proteins on the same cell to work.

As a result they're much less likely to flag the wrong cells, Reif said.

The technology could be used as a screening tool to help rule out cancer, which could mean fewer unnecessary follow-ups, or to develop more targeted cancer treatments with fewer side effects.

Each basic element of their DNA circuit consists of two DNA strands. The first DNA strand folds over and partially pairs up with itself to form a hairpin shape. One end of each hairpin is bound to a second strand of DNA that acts as a lock and tether, folding in such a way to fit a specific cell surface protein like a puzzle piece. Together these two strands act to verify that that particular protein is present on the cell surface.

To look for cancer, the circuit components are mixed with a person's cells in the lab. If any cells are studded with the right combination of proteins, the complete circuit will attach. Adding a strand of "initiator" DNA then causes one of the hairpins to open, which in turn triggers another in a chain reaction until the last hairpin in the circuit is opened and the cell lights up.

Test runs of the device in test tubes in Reif's lab showed it can be used to detect leukemia cells and to distinguish them from other types of cancer within a matter of hours, just by the strength of their glow.

The devices can be easily reconfigured to detect different cell surface proteins by replacing the tether strands, the researchers say. In the future, Reif plans to the DNA circuits to release a small molecule that alerts the body's immune system to attack the cancer cell.

The technology isn't ready for prime time yet. The researchers say their DNA circuits require testing in more realistic conditions to make sure they still flag the right cells.

But it's a promising step toward ensuring that cancer screens and therapies zero in on the right culprits.