Earth

Researchers at the University of Helsinki, Aarhus University and the University of Manchester have investigated the link between the socio-economic position of parents and the risk of children developing mental disorders later in life.

As research data, the project employed a cohort of roughly one million Danish children born between 1980 and 2000. The income of their parents was measured in the year of birth as well as when the children were 5, 10 and 15. Five income brackets were utilised in each measurement point, enabling the researchers also to measure income fluctuation during childhood.

The mental health of the children included in the dataset was monitored from the age of 15 until mental disorder diagnosis or the end of 2016, and thus the longest follow-up was until the age of 37. Data on mental disorder diagnoses were obtained from the Danish psychiatric register. In other words, the study subjects identified this way had ended up in treatment at a psychiatric hospital or outpatient clinic due to mental health problems. The overall follow-up period in the study was carried out from 1995 to 2016.

The results have been published in the BMC Medicine journal.

"Our study demonstrated that the longer children grew up in families with low-income parents, the greater their risk was of developing a mental disorder," says Christian Hakulinen, university lecturer in health psychology at the University of Helsinki.

One quarter of those born in the lowest parental income quintile developed a mental disorder

Based on the study findings, 25.2% of children born into the lowest parental income quintile developed a clinically diagnosed mental disorder by the time they turned 37. Correspondingly, 13.5% of children born in the top parental income quintile developed a mental disorder in the same period of time.

"From among the mental disorders studied, the only exception was eating disorders. In their case, low parental income was associated with a lower risk of developing an eating disorder," Hakulinen says.

The results show that the longer children lived in low-income families, the greater their risk was of developing a mental health disorder.

"We observed that a third of the children who lived in low-income families throughout their childhood were later diagnosed with a mental disorder. At the same time, 12% of the children who grew up in the top income quintile were later diagnosed with a mental disorder," Hakulinen says.

More measures in childhood to prevent mental disorders?

Although the study focused on Danish families, Hakulinen believes the findings can be used to draw conclusions also in the context of other Nordic countries, since our healthcare systems are fairly similar in the treatment of mental disorders.

"Mental disorders that reduce functional capacity are typically treated in secondary care in both Denmark and the rest of the Nordic countries, particularly if they appear in early adulthood," says Hakulinen.

The results indicate that the socioeconomic conditions in childhood are associated with the onset of mental disorders. In fact, Hakulinen would like attention to be paid to the prevention and treatment of such disorders already in childhood.

"Measures focused on childhood, such as interventions in support of parenthood, could benefit low-income families in particular. This would make it possible to tackle psycho-social risk factors, which financial challenges typically aggravate," Hakulinen notes.

Prevalent piezoelectric materials like barium titanate (BaTiO3) and lead zirconate titanate (PZT) possess high piezoelectric coefficients 20-800 pC/N, which are also ferroelectric. The Curie temperature of those ferroelectrics are mostly far above room temperature, so the change of polarization ΔP upon a strain at room temperature is approximately the same as ΔP0 at 0K.

Recently, scientists at Huazhong University of Science and Technology and at the Nanjing University in China proposed a new possibility of inducing ultra-high piezoelectric coefficient, which will be theoretically infinitely large if the Curie temperature is right at the working temperature and sensitive to strain. Well-known ferroelectric perovskites like BaTiO3 or PZT are not such candidates due to their high Curie temperature that is insensitive to strain. However, many hydrogen-bonded ferroelectrics with Curie temperature ranging from 200 to 400K can be ideal candidates, which are also soft, flexible and lead-free. For examples, the measured Curie temperature of organic PhMDA and [H-55DMBP][Hia] were respectively 363 and 268K. For hydrogen bonds like O-H...O, each proton will be covalently bonded to only one side of O atom due to the saturation of covalent bond. The O-H bond is on the verge of breaking at the hopping transition state where the proton locates at the midpoint. Due to the brittle nature of covalent bond, if the O-H...O bonds are prolonged upon a tensile strain, the hopping barrier as well as Curie temperature may be greatly enhanced with a much larger transfer distance. Meanwhile their hydrogen-bonded network can be easily compressed or stretched due to low bulk modulus.

The authors have shown first-principles evidence combined with Monte Carlo simulation, that the proton-transfer barriers as well as the Curie temperature of some hydrogen-bonded ferroelectrics can be approximately doubled upon a tensile strain of as low as 2 %. Their Curie temperature can be tuned exactly to room-temperature by applying a fixed strain in one direction, and the systems will exhibit ultra-high piezoelectricity in another direction. The unprecedented piezoelectric coefficient of 2058 pC/N obtained in PhMDA is more than 3 times higher than PZT, and an order of magnitude higher than the highest value obtained in current lead-free piezoelectrics. This value is even underestimated and can be greatly enhanced upon smaller strain. Since this proposed principle for such piezoelectricity can be applied to most hydrogen-bonded ferroelectrics, the large number of organic or inorganic candidates should facilitate its experimental realizations and optimizations in future, which will be a breakthrough for the long-sought lead-free high-coefficient piezoelectrics. This mechanism may also clarify the previously reported drastic rise in piezoelectric coefficient for SbSI when approaching its Curie temperature.

Abundant. Clean. Flexible. Alluring enough to explain why hydrogen, the most common molecule in the universe happens to have its name as part of an national Hydrogen and Fuel Cell Day. Chosen to signify hydrogen's atomic weight of 1.008, the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy celebrates advances in hydrogen-use technology every October 8 since 2015. When hydrogen is consumed in a fuel cell (which takes the water molecule H2O and seperates it into oxygen and hydrogen, a process called electrolysis), it only produces water, electricity, and heat. As a zero-carbon energy source, the range of its potential use is limitless: transportation, commercial, industrial, residential, and portable.

While traditional hydrogen production processes required fossil fuels or CO2, electrolysis produces "green hydrogen" from water molecules. Since water cannot be split into hydrogen and oxygen by itself, the electrochemical hydrogen-water conversion needs highly active electrocatalysts. The conventional water electrolysis, however, faces technological challenges to improve the efficiency of the water-splitting reaction for the sluggish oxygen evolution reaction. Noble metal-based ruthenium oxide (RuO2) and iridium oxide (IrO2) are used to enhance the oxygen generation rate. However, these noble metal catalysts are very expensive and show poor stability under long-term operation.

Led by Associate Director LEE Hyoyoung of the Center for Integrated Nanostructure Physics within the Institute for Basic Science (IBS) located at Sungkyunkwan University, the IBS research team developed a highly efficient and long-lasting electrocatalyst for water oxidation using cobalt, iron, and a minimal amount of ruthenium. "We used 'amphiphilic block copolymers' to control electrostatic attraction in our single ruthenium (Ru) atom-bimetallic alloy. The copolymers facilitate the synthesis of spherical clusters of hydrocarbon molecules whose soluble and insoluble segments form the core and shell. In this study, their tendency for a unique chemical structure allows the synthesis of the "high-performance" single atomic Ru alloy present atop the stable cobalt iron (Co-Fe) metallic composite surrounded by porous, defective and graphitic carbon shell," says LEE Jinsun and Kumar Ashwani, the co-first authors of the study.

"We were very excited to discover that pre-adsorbed surface oxygen on the Co-Fe alloy surface, absorbed during the synthesis process, stabilizes one of the important intermediates (OOH*) during the oxygen generation reaction, boosting the overall efficiency of the catalytic reaction. The pre-absorbed surface oxygen has been of little interest until our finding," notes Associate Director Lee, the corresponding author of the study. The researchers found that four hour-annealing at 750°C in an argon atmosphere is the best appropriate condition for the oxygen generating process. In addition to the reaction-friendly environment on the host metal surface, the single Ru atom, where oxygen generation takes place, also fulfills its role by lowering the energy barrier, synergistically enhancing the efficiency of oxygen evolution.

The research team evaluated the catalytic efficiency with the overvoltage metrics needed for the oxygen evolution reaction. The advanced noble electrocatalyst required only 180 mV (millivolt) overvoltage to attain a current density of 10 mA (milliampere) per cm2 of catalyst, while ruthenium oxide needed 298 mV. In addition, the single Ru atom-bimetallic alloy showed long-term stability for 100 hours without any change of structure. Furthermore, the cobalt and iron alloy with graphitic carbon also compensated electrical conductivity and enhanced the oxygen evolution rate.

Associate Director Lee explains, "This study takes us a step closer to a carbon-free, and green hydrogen economy. This highly efficient and inexpensive oxygen generation electro-catalyst will help us overcome long-term challenges of the fossil fuel refining process: to produce high-purity hydrogen for commercial applications at a low price and in an eco-friendly manner."

Although coastlines have widely been proposed as potential corridors of past migration, the occupation of Africa's tropical coasts during the Stone Age is poorly known, particularly in contrast to the temperate coasts of northern and southern Africa. Recent studies in eastern Africa have begun to resolve this, detailing dynamic behavioural changes near the coast of Kenya during the last glacial phase, but studies of Stone Age occupations along western Africa's coasts are still lacking.

In recent years, anthropological research has begun to investigate the relationship between demographic diversity and patterns of behavioural change. A range of genetic and palaeoanthropological studies have begun to highlight the considerable demographic diversity present in West Africa in the recent past, but archaeological studies of Stone Age sites are still needed to understand how this diversity relates to patterns of behaviour shown in the archaeological record.

"There are plenty of surface sites that have demonstrated the wealth of Stone Age archaeology in West Africa," says Jimbob Blinkhorn of MPI-SHH, "but to characterise patterns of changing behaviour, we need large, excavated stone tool assemblages that we can clearly date to specific periods."

Tiémassas is a Stone Age site with a notable history of research, including surface surveys and early excavations in the mid-20th century, but the lack of systematic study meant it was mired in controversy.

"In the past, Tiémassas has been described as a Middle Stone Age, Later Stone Age or Neolithic site, and resolving between these alternatives has important implications for our understanding of behaviour at the site," says lead author Khady Niang of Université Cheikh Anta Diop de Dakar. "We've reviewed previously collected material from the site, conducted new excavations and analysis of stone tools and combined this with dating studies that make Tiémassas a benchmark example of the Middle Stone Age of West Africa."

Previous research by the team dated a Middle Stone Age occupation at Tiémassas to 45 thousand years ago. The new research extends the timeframe of occupations at the site, with further stone tool assemblages recovered dating to 62 thousand and 25 thousand years ago. Critically, these stone tool assemblages contain technologically distinct types that help to characterise the nature of stone tool production during each occupation phase.

"The Middle Stone Age occupants of Tiémassas employed two distinct technologies - centripetal Levallois and discoidal reduction systems," says Niang. "What is really notable is that the stone tool assemblages are really consistent with one another and form a pattern we can match up with the results of earlier excavations too. Pulled together, the site tells a clear story of startling technological continuity for nearly 40 thousand years."

The results of this new research at Tiémassas consolidate the sparse record of Middle Stone Age occupations of West Africa. Yet, the site's location is distinct from others dated to the Middle Stone Age in the region as it is located close to the coast and at the interface of three ecozones: savannahs, forests and mangroves.

"Our new work at Tiémassas offers a neat comparison to recent work on coastal occupations in eastern Africa. They span roughly the same timeframe, have similar ecological characteristics, and are found along tropical coasts," says Blinkhorn. "But the continuity in behaviour we see at Tiémassas stands in stark contrast to the technological changes observed in eastern Africa, and this reflects a similar pattern seen in genetic and palaeoanthropological studies of enduring population structure in West Africa."

As director of fieldwork for the 'Lise Meitner' Pan-African Evolution research group's aWARE project, Blinkhorn is conducting research in Senegal, Ivory Coast, Benin, and Nigeria, looking for connections between the environments of the past and recent human evolution.

Between April and June of 2019, 10 research teams composed of 34 international and Nepali scientists journeyed toward the summit of Mount Everest as part of the 2019 National Geographic and Rolex Perpetual Planet Everest Expedition. Early results from this expedition, publishing November 20 in the journal One Earth, look at the impacts of climate change and human activity on Mount Everest, including glacier loss, precipitation changes, the presence of microplastics on the mountain, and more. Highlights from the findings include:

Six decades of glacier mass changes around Mt. Everest are revealed by historical and contemporary images

King et al. show that glaciers around Mt. Everest have thinned by more than 100m since the 1960s and that the rate of ice mass loss has consistently accelerated over the past six decades. To arrive at their findings, the researchers constructed time series of glacier mass-change measurements based on modern and historical satellite images of Mt. Everest and the surrounding glacial valleys stretching back 56 years. The work provides a baseline for future glacier loss and meltwater predictions, which are especially important because of the role that meltwater from Himalayan glaciers plays in providing water to the surrounding communities.

One Earth, King et al.: "Six decades of glacier mass changes around Mt. Everest revealed by historical and contemporary images" https://www.cell.com/one-earth/fulltext/S2590-3322(20)30549-2 DOI: 10.1016/j.oneear.2020.10.019

How climate change will increase the oxygen available to humans on Mount Everest

Not only is it currently possible for humans to climb to the summit of Mount Everest without supplemental oxygen, it's actually become easier since the beginning of the 20th century: increases in temperature have increased the air pressure on its summit and made more oxygen available for human climbers to breathe. Matthews et al. provide the highest resolution estimate to date of how close Mt. Everest summit oxygen availability encroaches upon human aerobic limits and the most detailed assessment yet of the potential shifts in the aerobic challenge of Mt. Everest due to climate change.

iScience, Matthews et al.: "Into Thick(er) Air? Oxygen Availability at Humans' Physiological Frontier on Mount Everest" https://www.cell.com/iscience/fulltext/S2589-0042(20)30915-9 DOI: 10.1016/j.isci.2020.101718

Behind the scenes of a comprehensive scientific expedition to Mt. Everest

In this Backstory, Elvin et al. describe the "symphony of logistics" it takes to conduct science on the world's tallest mountain. They calculate the supplemental oxygen needed to take the team to the summit, devise ways to lighten scientific equipment, design an inflatable catamaran raft to use for sample collection in alpine lakes, and map a route involving more than six different types of transportation. They also discuss the importance of receiving informed buy-in from local communities and the essential leadership, guidance, and support of the high-altitude climbing Sherpas who were key partners in the expedition.

One Earth, Elvin et al.: "Behind the scenes of a comprehensive scientific expedition to Mt. Everest" https://www.cell.com/one-earth/fulltext/S2590-3322(20)30536-4 DOI: 10.1016/j.oneear.2020.10.006

Scientists have identified the highest recorded microplastics ever found on Earth - at an altitude of more than 8,000metres, close to the summit of Mount Everest.

Samples collected on the mountain and in the valley below it revealed substantial quantities of polyester, acrylic, nylon, and polypropylene fibres.

The materials are increasingly being used to make the high performance outdoor clothing commonly used by climbers, as well as the tents and climbing ropes used in attempts to climb the mountain.

As a result, researchers have suggested the fibres - the highest of which were found in samples from the Balcony of Mount Everest, 8,440 metres above sea level - could have fragmented from larger items during expeditions to reach the summit.

However, they have also surmised the plastics could have been transported from lower altitudes by the extreme winds which regularly impact the mountain's higher slopes.

The research, published in One Earth, was led by researchers from the University of Plymouth's International Marine Litter Research Unit, working with colleagues from the UK, USA and Nepal. It was supported by the National Geographic Society and Rolex.

Research Fellow and National Geographic Explorer Dr Imogen Napper, the study's lead author, said: "Microplastics are generated by a range of sources and many aspects of our daily lives can lead to microplastics entering the environment. Over the past few years, we have found microplastics in samples collected all over the planet - from the Arctic to our rivers and the deep seas. With that in mind, finding microplastics near the summit of Mount Everest is timely reminder that we need to do more to protect our environment."

The samples were collected in April and May 2019, as part of National Geographic and Rolex's Perpetual Planet Everest Expedition, and then analysed in specialist facilities in Plymouth.

Of 19 high elevation samples collected from the Mount Everest region for microplastic analysis, 11 were snow and eight stream water. This included streams along the trekking routes close to the Khumbu Glacier, in the snow at Everest Base Camp, and high into the Death Zone near the mountain's summit.

The highest quantities (79 microplastic fibres per litre of snow) were found at Base Camp, where summit expeditions are based for periods of up to 40 days. However, evidence was also found at Camps 1 and 2 on the climbing route, with 12 microplastic fibres per litre of snow recorded from the Balcony.

There were lower quantities in streams leading down from the mountain to the Sagarmatha National Park, with scientists saying this could be due to the continuous flow of water created by the region's glaciers.

The first confirmed summiting of Mount Everest in 1953 coincided with the global rise to prominence of plastics and their use in society.

From a time in the 1950s when it had very few visitors, the Sagarmatha National Park (which includes the mountain) welcomed more than 45,000 visitors in 2016, while in 2019, climbing permits for Everest were issued in Nepal.

Over the same period, the versatility of plastic materials has resulted in a substantial increase in their use from five million tonnes globally in the 1950s to over 330 million tonnes in 2020.

Professor Richard Thompson OBE FRS, Head of the International Marine Litter Research Unit, said: "Since the 1950s, plastics have been increasingly used in all kinds of products because of their practicality and durability. However, it is those qualities which are, in large part, creating the global environmental crisis we are seeing today. There is now global recognition of the need to take action, with Nepal itself imposing regulations on climbing expeditions to try and curb the environmental problems created by waste. This study and our continued research only emphasises the importance of designing materials that have the benefits of plastics without the lasting and harmful legacy."

New York, NY--November 20, 2020--Forests can help mitigate climate change, by taking in carbon dioxide during photosynthesis and storing it in their biomass (tree trunks, roots, etc.). In fact, forests currently take in around 25-30% of our human-generated carbon dioxide (CO2) emissions. Certain rainforest regions, such as the Amazon, store more carbon in their biomass than any other ecosystem or forest but when forests become water-stressed (not enough water in the soil, and/or air is extremely dry), forests will slow down or stop photosynthesis. This leaves more CO2 in the atmosphere, and can also lead to tree mortality.

The current Earth system models used for climate predictions show that the Amazon rainforest is very sensitive to water stress. Since the air in the future is predicted to get warmer and drier with climate change, translating to increased water stress, this could have large implications not just for the forest's survival, but also for its storage of CO2. If the forest is not able to survive in its current capacity, climate change could greatly accelerate.

Columbia Engineering researchers decided to investigate whether this was true, whether these forests are really as sensitive to water stress as what the models have been showing. In a study published today in Science Advances, they report their discovery that these models have been largely over-estimating water stress in tropical forests.

The team found that, while models show that increases in air dryness greatly diminish photosynthesis rates in certain regions of the Amazon rainforest, the observational data results show the opposite: in certain very wet regions, the forests instead even increase photosynthesis rates in response to drier air.

"To our knowledge, this is the first basin-wide study to demonstrate how--contrary to what models are showing--photosynthesis is in fact increasing in some of the very wet regions of the Amazon rainforest during limited water stress," said Pierre Gentine, associate professor of earth and environmental engineering and of earth and environmental sciences and affiliated with the Earth Institute. "This increase is linked to atmospheric dryness in addition to radiation and can be largely explained by changes in the photosynthetic capacity of the canopy. As the trees become stressed, they generate more efficient leaves that can more than compensate for water stress."

Gentine and his former PhD student Julia Green used data from the Intergovernmental Panel on Climate Change's Coupled Model Intercomparison Project 5 (CMIP5) models and combined them with machine learning techniques to determine what the modeled sensitivity of photosynthesis in the tropical regions of the Americas was to both soil moisture and air dryness. They then performed a similar analysis, this time using observational remote sensing data from satellites in place of the model data, to see how the observational sensitivity compared. To relate their results to smaller-scale processes that could explain them, the team then used flux tower data to understand their results at the canopy and leaf level.

Earlier studies have shown that there are increases in greenness in the Amazon basin at the end of the dry season, when both the soil and air is drier, and some have linked this to increases in photosynthesis. "But before our study, it was still unclear whether these results translated to an effect over a larger region, and they had never been connected to air dryness in addition to light," Green, who is now a postdoctoral research associate at Le Laboratoire des Sciences du Climat et de l'Environnement in France, explained. "Our results mean that the current models are overestimating carbon losses in the Amazon rainforest due to climate change. Thus, in this particular region, these forests may in fact be able to sustain photosynthesis rates, or even increase it, with some warming and drying in the future."

Gentine and Green note, however, that this sensitivity was determined using only existing data and, if dryness levels were to increase to levels that are not currently being observed, this could in fact change. Indeed, the researchers found a tipping point for the most severe dryness stress episodes where the forest could not maintain its level of photosynthesis. So, say Gentine and Green, "our findings are certainly not an excuse to not reduce our carbon emissions."

Gentine and Green are continuing to look at themes related to vegetation water stress in the tropics. Green is currently focusing on developing a water stress indicator using remote sensing data (a dataset that can be used to identify when a forest is under stressful conditions), quantifying the effects of water stress on plant carbon uptake, and relating them to ecosystem traits.

"So much of the scientific research coming out these days is that with climate change, our current ecosystems might not be able to survive, potentially leading to the acceleration of global warming due to feedbacks," Green added. "It was nice to see that maybe some of our estimates of approaching mortality in the Amazon rainforest may not be quite as dire as we previously thought."

The impact of sea surface temperature variations in the tropical Pacific on global climate has long been recognized. For instance, the episodic warming of the tropical Pacific during El Niño events causes melt of sea ice in far-reaching parts of the Southern Ocean via its effect on the global atmospheric circulation. A new study, published this week in the journal Science Advances by an international team, demonstrates that the opposite pathway exists as well.

Using a hierarchy of climate model simulations, the authors demonstrate the physical pathways via which polar climate variations can affect the trade winds in the tropics.

"Climate signals can propagate from the polar regions to the tropics either via the atmosphere or the ocean," explained Malte Stuecker, co-author and assistant professor in the Department of Oceanography and International Pacific Research Center at the University of Hawai?i at Mānoa. "Our climate model simulations were designed to investigate the relative role of these pathways and whether their importance differs for perturbations originating from the North pole or the South pole."

The authors found that in the most complex model simulations, which include realistic representations of the ocean, atmosphere, land, and sea ice, an anomalous cooling in either hemisphere leads to a strengthening of the tropical trade winds.

Lead author Sarah Kang from the Ulsan National Institute of Science and Technology in South Korea explained the reasoning behind these experiments: "One of the largest sources of uncertainty in the current generation of climate models are biases in the representation of clouds over the cold Southern Ocean. We wanted to explore what effect too much reflection of solar radiation by these clouds to outer space might have on global climate. In addition, large emissions of aerosols in the late 20th century due to industrial activity in the Northern Hemisphere from North America, Europe, and Asia resulted in a slight, temporary reduction of the global warming rate that is due to increasing greenhouse gas emissions."

According to the authors' results, both of these effects could potentially explain why the Pacific trade winds were anomalously strong in recent decades.

"If the communication between the poles and the tropics would only occur via the atmosphere, we would see quite a distinct response in the tropics depending on whether an anomalous cooling arises from the Arctic or the Antarctic," Stuecker added. "This is because the Intertropical Convergence Zone - the largest rainband on Earth - is located to the north of the equator. It effectively blocks a communication from the Arctic to the equator via the atmosphere."

Contrasting experiments with and without a realistic ocean representation, the authors show that enhanced upwelling of cold subsurface water in the eastern tropical Pacific is able to communicate the Arctic cooling towards the tropics and thereby strengthening the trade winds.

An important implication of the results is that reducing uncertainty in simulated extratropical climate may also lead to improved simulation of climate in the tropics. The model hierarchy developed by the authors can be used to further explore two-way interactions between the tropics and polar regions both for future climate projections as well as for interpreting reconstructions of climate states in the geological past.

The research, carried out using a wearable cuff, provides a new method for monitoring movements in babies, and new insights into how babies' reflexes - like kicking - develop. These insights and the cuff could also be used to spot early signs of motor disorders such as cerebral palsy.

The research, published today in Science Advances, was done in collaboration with the Santa Lucia Foundation and Casilino Hospital in Rome.

Babies start kicking as foetuses in the womb and continue to kick instinctively until they are around four months old. The kicks mainly involve spinal neurons, as do protective reflexes found in adults like swiftly removing a hand from heat. However, not much is known about how the movement is generated on a neuronal level because detailed analysis of individual nerve cells has previously not been possible without surgery.

Now, Imperial and Santa Lucia Foundation researchers have developed a non-invasive cuff that slips onto freely kicking babies' legs to monitor neuronal activity without the need for surgery. The system decodes the electrical field potentials on the body surface and mathematically reverses their generation process, thus identifying the neural activity of the spinal cord.

Using the cuff the researchers found that, unlike fast leg movements in adults, babies' kicks are generated by the neurons in the spinal cord firing at the exact same time. This 'extreme synchronisation', the researchers say, increases the force generated by muscles attached to the nerves - which explains why babies' kicks can be relatively hard and fast even though their muscles are still weak and slow.

The researchers say these results, which are published today in Science Advances, are crucially important for our understanding of the development of spinal neural networks.

Lead author Professor Dario Farina of Imperial's Department of Bioengineering said: "This is a fundamental discovery of how foetuses and babies develop. The findings, and the new technology that helped us make the discovery, could help monitor development in babies and spot signs of motor disorders like cerebral palsy early on."

Co-senior author Professor Francesco Lacquaniti of the University of Rome Tor Vergata and Santa Lucia Foundation added: "The new monitoring cuff is an exciting technological achievement that could help us monitor babies for signs of motor problems so that we can diagnose and treat them early."

Fundamental discovery

The cuff attaches to the lower leg and contains a neuromuscular interface which records the electrical signals on the skin. It then decodes these signals and their timings to work out which spinal cord neurons are firing, and how quickly.

They tested the cuff on four freely kicking healthy babies aged two to 14 days old, and on twelve adult men doing various movements.

They found that in babies, all neurons fire closely in time to generate a kick, whereas there was significantly less synchronisation in the adult individuals.

Professor Farina said: "Generating fast movements is vital for human survival and health. Babies can already kick very fast just days after birth, and now we know that they do so using all spinal nerves at the same time."

Evolutionary advantage?

Baby kicks are thought to strengthen leg muscles and prepare the infant to roll over and eventually learn to walk. However, the researchers say their findings could suggest another advantage.

Dr Del Vecchio, the first author of the study from Professor Farina's research group, said: "The strength and speed of the kicking, as well as the synchronisation of nerve activity, could suggest that kicking has a more immediate protective advantage for babies. Perhaps babies developed such strong kicks through evolution to avoid potential dangers like predators."

The researchers are now looking into monitoring spinal neurons in babies with motor disorders like cerebral palsy. They hope their research could help to develop new clinical markers for the early diagnoses of these types of disorders.

The vision of the future of miniaturisation has produced a series of synthetic molecular motors that are driven by a range of energy sources and can carry out various movements. A research group at Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) has now managed to control a catalysis reaction using a light-controlled motor. This takes us one step closer to realising the vision of a nano factory in which combinations of various machines work together, as is the case in biological cells. The results have been published in the Journal of the American Chemical Society.

Laws of mechanics cannot always be applied

Per definition, a motor converts energy into a specific type of kinetic energy. On a molecular level, for example, the protein myosin can produce muscle contractions using chemical energy. Such nanomachines can now be synthetically produced. However, the molecules used are much smaller than proteins and significantly less complex.

'The laws of mechanical physics cannot simply be applied to the molecular level,' says Prof. Dr. Henry Dube, Chair of Organic Chemistry I at FAU. Inertia, for example, does not exist at this level, he explains. Triggered by Brownian motion, particles are constantly in motion. 'Activating a rotating motor is not enough, you need to incorporate a type of ratchet mechanism that prevents it from turning backwards,' he explains.

In 2015 while at LMU in Munich, Prof. Dube and his team developed a particularly fast molecular motor driven by visible light. In 2018, they developed the first molecular motor that is driven solely by light and functions regardless of the ambient temperature. A year later, they developed a variant capable not only of rotation but also of performing a figure of eight motion. All motors are based on the hemithioindigo molecule, an asymmetric variant of the naturally occurring dye indigo where a sulphur atom takes the place of the nitrogen atom. One part of the molecule rotates in several steps in the opposite direction to the other part of the molecule. The energy-driven steps are triggered by visible light and modify the molecules so that reverse reactions are blocked.

Standard catalysts in use

After coming to FAU, Henry Dube used the rotating motor developed in 2015 to control a separate chemical process for the first time. It moves in four steps around the carbon double bond of the hemithioindigo.  Two of the four steps triggered by a photo reaction can be used to control a catalysis reaction. 'Green light generates a molecular structure that binds a catalyst to the hemithioindigo and blue light releases the catalyst,' explains the chemist.

A standard catalyst is used that does not have any metal atoms. Using electrostatic forces, the catalyst docks via a hydrogen bond onto an oxygen atom in the 'motor molecule'. All catalysts that use a hydrogen bond could be used, in principle. 'The great advantage of hemithioindigo is that its innate structure has a bonding mechanism for catalysts,' explains Prof. Dube. It would otherwise have to be added using chemical synthesis.

The rotation of the hemithioindigo motor is controlled by visible light. At the same time, the system allows the targeted release and bonding of a catalyst that accelerates or decelerates desired chemical reactions. 'This project is an important step towards integrating molecular motors in chemical processes simply and in a variety of ways,' says Prof. Dube. 'This will let us synthesise complex medication at a high level of precision using molecular machines like a production line in future.'

The Indian subcontinent is a hotspot for wild felines. A new study headed by Uppsala University now shows that only 6-11 per cent of the areas where three rare cat species have their habitat are protected. Lack of knowledge about these species has been an obstacle to understanding their needs for reserves. The research is presented in the journal Scientific Reports.

Over a third of the world's cat species inhabit the Indian subcontinent. In the new study, the researchers have explored the situation of the Prionailurus genus. It includes the rusty-spotted cat (P. rubiginosus), found in this region alone, which seems to thrive best in broadleaved forests; the fishing cat (P. viverrinus), a species associated primarily with wetlands, mangrove swamps and coastal areas; and the leopard cat (P. bengalensis), which has been observed mainly in tropical and subtropical forest areas.

"This study is important because it shows that many small, rare and elusive cats in the Indian subcontinent don't get as much attention as the more spectacular big cats. Nevertheless, the need to protect them is just as pressing, so the number and size of the protected areas must be increased to include more biotopes containing these species," says Mats Björklund, Professor Emeritus of Zooecology at Uppsala University.

Using the geographic coordinates of sites where the various species have been seen over the years, and more recent information collected from camera-trap surveys, the scientists were able to develop ecological niche models. These could then be used to identify zones with environmental conditions that, to a high degree, suit these species individually. These models also enabled the researchers to gain a better understanding of ecological factors, such as climate, land cover and land use, that restrict or favour the occurrence of a species - information of the utmost importance for future conservation measures.

The scientists were also able to see that the most severe threats vary for the species included in the study. The leopard cat, for example, is most threatened by a warmer climate since parts of its range, such as the mountainous areas in the Western and Eastern Ghats, are clearly beginning to develop higher temperatures than this species can withstand. The rusty-spotted cat, on the other hand, is limited mainly by human cultivation of the land, especially in areas of intensive irrigation. This is of particular concern because the proportion of farmland in the region is rising. The fishing cat seems to be the Prionailurus species that, to date, has had the smallest proportion of its habitat protected.

Small, shy and rare cats have the greatest need for protection. The results of this study show that, although the species studied are closely interrelated, they respond differently to environmental change. Accordingly, to cover their main biotopes, future protection must cover larger areas and more habitats accessible to these species.

"Some of these species, like the fishing cat, are extremely rare and probably need protection for long-term survival. The fact that only a very small proportion of the most suitable habitat for this species is protected is a warning sign that the protected-area network in the Indian subcontinent needs to be reviewed. Species like the rusty-spotted cat exist only in this region, so to ensure we don't lose them it's essential to create more protected areas," says André P. Silva, a doctoral student at the Department of Ecology and Genetics at Uppsala University and the study's lead author.

ITHACA, N.Y. - Floods of unimaginable magnitude once washed through Gale Crater on Mars' equator around 4 billion years ago - a finding that hints at the possibility that life may have existed there, according to data collected by NASA's Curiosity rover and analyzed in joint project by scientists from Jackson State University, Cornell University, the Jet Propulsion Laboratory and the University of Hawaii.

The research, "Deposits from Giant Floods in Gale Crater and Their Implications for the Climate of Early Mars," was published Nov. 5 in Scientific Reports.

The raging megaflood - likely touched off by the heat of a meteoritic impact, which unleashed ice stored on the Martian surface - set up gigantic ripples that are tell-tale geologic structures familiar to scientists on Earth.

"We identified megafloods for the first time using detailed sedimentological data observed by the rover Curiosity," said co-author Alberto G. Fairén, a visiting astrobiologist in the College of Arts and Sciences. "Deposits left behind by megafloods had not been previously identified with orbiter data."

As is the case on Earth, geological features including the work of water and wind have been frozen in time on Mars for about 4 billion years. These features convey processes that shaped the surface of both planets in the past.

This case includes the occurrence of giant wave-shaped features in sedimentary layers of Gale crater, often called "megaripples" or antidunes that are about 30-feet high and spaced about 450 feet apart, according to lead author Ezat Heydari, a professor of physics at Jackson State University.

The antidunes are indicative of flowing megafloods at the bottom of Mars' Gale Crater about 4 billion years ago, which are identical to the features formed by melting ice on Earth about 2 million years ago, Heydari said.

The most likely cause of the Mars flooding was the melting of ice from heat generated by a large impact, which released carbon dioxide and methane from the planet's frozen reservoirs. The water vapor and release of gases combined to produce a short period of warm and wet conditions on the red planet.

Condensation formed water vapor clouds, which in turn created torrential rain, possibly planetwide. That water entered Gale Crater, then combined with water coming down from Mount Sharp (in Gale Crater) to produce gigantic flash floods that deposited the gravel ridges in the Hummocky Plains Unit and the ridge-and-trough band formations in the Striated Unit.

The Curiosity rover science team has already established that Gale Crater once had persistent lakes and streams in the ancient past. These long-lived bodies of water are good indicators that the crater, as well as Mount Sharp within it, were capable of supporting microbial life.

"Early Mars was an extremely active planet from a geological point of view," Fairén said. "The planet had the conditions needed to support the presence of liquid water on the surface - and on Earth, where there's water, there's life.

"So early Mars was a habitable planet," he said. "Was it inhabited? That's a question that the next rover Perseverance ... will help to answer."

Perseverance, which launched from Cape Canaveral on July 30, is scheduled to reach Mars on Feb. 18, 2021.

The cell membrane is impermeable to viruses: to get inside and infect a cell, they use a range of strategies to exploit the cellular and biochemical properties of the membranes. The thiol-mediated uptake of organic molecules similar to alcohols, where oxygen is replaced by a sulphur atom, is one of the entry mechanisms, with its use by Human Immunodeficiency Virus (HIV) demonstrated a few years ago. No effective inhibitor is currently available because of the robustness of the chemical reactions and bonds at work. A research group from the University of Geneva (UNIGE) has identified inhibitors that are up to 5,000 times more effective than the one most often used today. Preliminary tests - published and available free of charge in Chemical Science, the flagship journal of the Royal Society of Chemistry - demonstrate the blocking of the cellular entry of viruses expressing the SARS-CoV-2 proteins. The study paves the way for research into new antivirals.

Since 2011, the laboratory led by Professor Stefan Matile in UNIGE's Department of Organic Chemistry, member of the two National Centre of Competence in Research (NCCR) &laquo Chemical Biology » and &laquo Molecular Systems Engineering », has been investigating the way thiols react with other structures containing sulfur: sulfides, molecules where sulfur is combined with another chemical element. &laquoThese are very special chemical reactions because they can change state dynamically», begins Professor Matile. In fact, covalent bonds, based on sharing electrons between two atoms, freely oscillate between sulfur atoms, depending on conditions.

Passing the cell membrane

Sulfur compounds are present in nature, particularly on the membrane of eukaryotic cells and on the envelope of viruses, bacteria and toxins. Studies suggest that they play a role in one of the mechanisms - known as thiol-mediated uptake - that enables the very difficult passage from outside to inside the cell. This key step involves the dynamic bond between thiols and sulfides. &laquoEverything that approaches the cell can connect to these dynamic sulfur bonds», continues Professor Matile. &laquoThey cause the substrate to enter the cell either by fusion or endocytosis, or by direct translocation through the plasma membrane into the cytosol». Studies a few years ago showed that the entry of HIV and diphtheria toxin use a mechanism involving thiols.

&laquoThis chemistry is well known, but no one believes it was involved in cellular uptake,» says the professor, who explains that this scepticism on the part of the scientific community is probably due to the lack of inhibitor available to test it. &laquoThe involvement of membrane thiols in cellular uptake is usually tested by inhibition using Ellman's reagent. Unfortunately, this test isn't always reliable, partly because of the relatively low reactivity of Ellman's reagent faced with the high reactivity of thiols and sulfides».

The quest for an inhibitor

While Stefan Matile's laboratory was working on writing a bibliographic review on the subject during the first Swiss lockdown in the spring of 2020, it began looking for a potential inhibitor, thinking that it could prove useful as an antiviral against SARS-CoV-2. Professor Matile's coworkers reviewed potential inhibitors and carried out in vitro cellular uptake tests of sulfur molecules marked with fluorescent probes to assess their presence inside cells using fluorescence microscopy.

Molecules up to 5,000 times more effective than Ellman's reagent were identified. With these excellent inhibitors in hand, the laboratory threw itself into viral tests with the help of Neurix, a Geneva-based start-up. They modified laboratory viruses, called lentivectors, expressing the proteins of the SARS-CoV-2 viral envelope pandemic safely and harmlessly. One of the inhibitors was found to be effective at blocking the virus's entry into cells in vitro. &laquoThese results are at a very early stage and it would be entirely speculative to say we've discovered an antiviral drug against coronavirus. At the same time, this research shows that thiol-mediated uptake could be an interesting line of enquiry for developing future antivirals», concludes Professor Matile.

While the broad architecture and organization of the human brain is universal, new research shows how the differences between how people reimagine common scenarios can be observed in brain activity and quantified. These unique neurological signatures could ultimately be used to understand, study, and even improve treatment of disorders such as Alzheimer's disease.

"When people imagine similar types of events, each person does it differently because they have different experiences," said Feng (Vankee) Lin, Ph.D., R.N. "Our research demonstrates that we can decode the complex information in the human brain related to everyday life and identify neural 'fingerprints' that are unique to each individual's remembered experience." Lin is an associate professor in the University of Rochester Del Monte Institute for Neuroscience and co-author of the study which appears in the journal Nature Communications.

In the study, researchers asked 26 participants to recall common scenarios, such as driving, attending a wedding, or eating out at a restaurant. The scenarios were broad enough so that each participant would reimagine them differently. For example, when researchers asked volunteers to vividly remember and describe an occasion involving dancing, one person might recall watching their daughter participating in a dance recital, while another may imaging themselves dancing at a Bar Mitzvah.

The participant's verbal descriptions were mapped to a computational linguistic model that approximates the meaning of the words and creates numerical representation of the context of the description. They were also asked to rate aspects of the remembered experience, such as how strongly it was associated with sound, color, movement, and different emotions.

The study volunteers were then placed in a functional MRI (fMRI) and asked to reimagine the experience while researchers measured which areas of the brain were activated. Using the fMRI data and the subject's verbal descriptions and ratings, researchers were able to isolate brain activity patterns associated with that individual's experiences. For instance, if the participant imagined driving through a red light in the scenario, areas of the brain associated with recalling motion and color would be activated. Using this data, the researchers built a functional model of each participant's brain, essentially creating a unique signature of their neurological activity.

The researchers were able to identify several areas of the brain that served as hubs for processing information across brain networks that contribute to recalling information about people, objects, places, emotions, and sensations. The team was also able to observe how activation patterns within these networks differed on an individual level depending upon the details of each person's recollections and imagination.

"One of the goals of cognitive science is to understand how memories are represented and manipulated by the human brain," said Andrew Anderson, Ph.D., with the Del Monte Institute for Neuroscience and co-author of the study. "This study shows that fMRI can measure brain activity with sufficient signal to identify meaningful interpersonal differences in the neural representation of complex imagined events that reflect each individual's unique experience."

In addition to expanding our understanding of how the brain is networked, the authors point out that many of the key regions they identified tend to decline in function as we age and are vulnerable to the degeneration that occurs in disease like Alzheimer's. The findings could lead to new ways to diagnose and study disorders associated with irregular memory deficits, including dementia, schizophrenia, and depression, and perhaps even personalize treatments and predict which therapies will be more effective.

GRAND RAPIDS, Mich. (Nov. 20, 2020) -- For more than a decade, scientists studying epigenetics have used a powerful method called ChIP-seq to map changes in proteins and other critical regulatory factors across the genome. While ChIP-seq provides invaluable insights into the underpinnings of health and disease, it also faces a frustrating challenge: its results are often viewed as qualitative rather than quantitative, making interpretation difficult.

But, it turns out, ChIP-seq may have been quantitative all along, according to a recent report selected as an Editors' Pick by and featured on the cover of the Journal of Biological Chemistry.

"ChIP-seq is the backbone of epigenetics research. Our findings challenge the belief that additional steps are required to make it quantitative," said Brad Dickson, Ph.D., a staff scientist at Van Andel Institute and the study's corresponding author. "Our new approach provides a way to quantify results, thereby making ChIP-seq more precise, while leaving standard protocols untouched."

Previous attempts to quantify ChIP-seq results have led to additional steps being added to the protocol, including the use of "spike-ins," which are additives designed to normalize ChIP-seq results and reveal histone changes that otherwise may be obscured. These extra steps increase the complexity of experiments while also adding variables that could interfere with reproducibility. Importantly, the study also identifies a sensitivity issue in spike-in normalization that has not previously been discussed.

Using a predictive physical model, Dickson and his colleagues developed a novel approach called the sans-spike-in method for Quantitative ChIP-sequencing, or siQ-ChIP. It allows researchers to follow the standard ChIP-seq protocol, eliminating the need for spike-ins, and also outlines a set of common measurements that should be reported for all ChIP-seq experiments to ensure reproducibility as well as quantification.

By leveraging the binding reaction at the immunoprecipitation step, siQ-ChIP defines a physical scale for sequencing results that allows comparison between experiments. The quantitative scale is based on the binding isotherm of the immunoprecipitation products.