Earth

Young children from dog-owning households have better social and emotional wellbeing than children from households who do not own a dog, suggests research published in the journal Pediatric Research.

A team of researchers at the University of Western Australia and Telethon Kids Institute utilised questionnaire data from 1,646 households that included children aged two to five years. The researchers found that, after taking into account children's age, biological sex, sleep habits, screen time and parents' education levels, children from dog-owning households were 23% less likely to have overall difficulties with their emotions and social interactions than children who did not own a dog. Children from dog-owning households were 30% less likely to engage in antisocial behaviours, 40% less likely to have problems interacting with other children, and were 34% more likely to engage in considerate behaviours, such as sharing.

Associate Professor Hayley Christian, the corresponding author said: "While we expected that dog ownership would provide some benefits for young children's wellbeing, we were surprised that the mere presence of a family dog was associated with many positive behaviours and emotions."

Among children from dog-owning households, those who joined their family on dog walks at least once per week were 36% less likely to have poor social and emotional development than those who walked with their family dog less than once per week. Children who played with their family dog three or more times per week were 74% more likely to regularly engage in considerate behaviours than those who played with their dog less than three times per week.

Associate Professor Hayley Christian said: "Our findings indicate that dog ownership may benefit children's development and wellbeing and we speculate that this could be attributed to the attachment between children and their dogs. Stronger attachments between children and their pets may be reflected in the amount of time spent playing and walking together and this may promote social and emotional development."

To examine children's social and emotional development and its possible association with family dog ownership, the authors analysed data collected between 2015 and 2018 as part of the Play Spaces and Environments for Children's Physical Activity (PLAYCE) study. During the study, parents of children aged between two and five years completed a questionnaire assessing their child's physical activity and social-emotional development. . Out of the 1,646 households included in the study, 686 (42%) owned a dog.

The authors caution that due to the observational nature of the study they were not able to determine the exact mechanism by which dog ownership may benefit social and emotional development in young children, or to establish cause and effect. Further research should assess the potential influence of owning different types of pets or the influence that children's attachment to their pets may have on child development.

Teenagers who prefer to stay up late and wake later in the morning are more likely to suffer with asthma and allergies compared to those who sleep and wake earlier, according to a study published in ERJ Open Research. [1]

Asthma symptoms are known to be strongly linked to the body's internal clock, but this is the first study to look at how individual sleep preferences influence asthma risk in teenagers.

Researchers say the study reinforces the importance of sleep timing for teenagers and opens up a new channel of research in to how sleep affects teenagers' respiratory health.

The study was led by Dr Subhabrata Moitra from the division of pulmonary medicine at the University of Alberta, Canada, who carried out the research while at the Barcelona Institute for Global Health, Spain. He said: "Asthma and allergic diseases are common in children and adolescents across the world and the prevalence is increasing. We know some of the reasons for this increase, such as exposure to pollution and tobacco smoke, but we still need to find out more.

"Sleep and the 'sleep hormone' melatonin are known to influence asthma, so we wanted to see if adolescents' preference for staying up late or going to bed early could be involved in their asthma risk."

The study involved 1,684 adolescents living in West Bengal, India, aged 13 or 14 years, who were taking part in the Prevalence and Risk Factors of Asthma and Allergy-Related Diseases among Adolescents (PERFORMANCE) study.

Each participant was asked about any wheezing, asthma, or symptoms of allergic rhinitis, such as a runny nose and sneezing. They were asked a series of questions to judge whether they were 'evening types', 'morning types' or in between, such as what time of the evening or night they tend to feel tired, when they would choose to wake up, and how tired they feel first thing in the morning.

Researchers compared the teenagers' symptoms with their sleep preferences, taking into account other factors that are known to affects asthma and allergies, such as where the participants live and whether their family members smoke.

They found that the chance of having asthma was around three times higher in teens who prefer to sleep later compared to those who preferred to sleep earlier. They also found the risk of suffering allergic rhinitis was twice as high in late-sleepers compared to early-sleepers.

Dr Moitra adds: "Our results suggest there's a link between preferred sleep time, and asthma and allergies in teenagers. We can't be certain that staying up late is causing asthma, but we know that the sleep hormone melatonin is often out of sync in late-sleepers and that could, in turn, be influencing teenagers allergic response.

"We also know that children and young people are increasingly exposed to the light from mobile phone, tablets, and other devices, and staying up later at night. It could be that encouraging teenagers to put down their devices and get to bed a little earlier would help decrease the risk of asthma and allergies. That's something that we need to study more."

A second phase of the PERFORMANCE study is scheduled in 2028-29, which means it will be possible to repeat the study with a new group of teenagers to see if there has been any change in teenagers sleeping habits and their respiratory health. Dr Moitra and his team also hope to quantify their findings by taking objective measurements of participants' lung function and sleep time.

Professor Thierry Troosters is President of the European Respiratory Society and was not involved in the research. He said: "We need to know much more about why asthma and allergies are rising in children and teenager and, hopefully, find ways to reduce these conditions.

"This is the first study to examine the possible role of different sleep preferences in teenagers' risk of asthma and allergies, and it opens up an interesting and important new line of research. We already know that sleeping well is important for physical and mental health, so we should continue to encourage teenagers to get a good night's sleep."

The New Siberian Islands were the birthplace of the MOSAiC floe: the sea ice in which the research vessel Polarstern is now drifting through the Arctic was formed off the coast of the archipelago, which separates the East Siberian Sea and the Laptev Sea to the north of Siberia, in December 2018. Sediments, and even small pebbles and bivalves, were incorporated into the ice during the freezing process, which the on-going melting process has brought to light on the surface of the MOSAiC floe. This is an increasingly rare phenomenon as nowadays most of the "dirty ice" melts before it even arrives in the Central Arctic. These are among the main findings of a study that MOSAiC experts have published now in the journal The Cryosphere, and which will provide the basis for numerous upcoming scientific assessments.

At first glance, it looks like a group of people with dirty shoes had left tracks all over the snow. But in reality, they are sediments, and even small pebbles and bivalves, which the on-going melting process has brought to light on the surface of the MOSAiC floe. When the sea ice formed, they were frozen inside; accordingly, they hail from the nursery of sea ice along the Siberian Shelf, which the experts have now used a combination of model simulations and satellite data to describe in detail.

The MOSAiC floe had already drifted over 1200 nautical miles in a meandering course when the research icebreaker Polarstern moored to it on 4 October 2019, at the coordinates 85° North and 137° East, and began to drift with it through the Arctic Ocean. While the current expedition team is busy taking readings in the Arctic, their colleagues back at home are analysing the data gathered. The precise analysis confirms the first impressions from the beginning of the expedition: "Our assessment shows that the entire region in which the two ships looked for suitable floes was characterised by unusually thin ice," reports Dr Thomas Krumpen, a sea-ice physicist at the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI). Last autumn, the first author of The Cryosphere study coordinated research activities on the Russian icebreaker Akademik Fedorov, which accompanied the flagship of the MOSAiC expedition, the Polarstern, for the first few weeks. The Akademik Fedorov was also instrumental in deploying monitoring stations at various locations across the MOSAiC floe - collectively referred to as the 'Distributed Network'.

"Our study shows that the floe we ultimately chose was formed in the shallow waters of the Russian shelf seas in December 2018," Krumpen explains. Off the coast of Siberia, strong offshore winds drive the young ice out to sea after it forms. In the shallow water, sediments are churned up from the seafloor and become trapped in the ice. Ice formation can also produce pressure ridges, the undersides of which sometimes scrape along the seafloor. As a result, stones can also become embedded in the sea ice. Now that the summertime melting has begun, all of this material is being revealed at the ice's surface: "At several points we've found entire mounds of pebbles measuring several centimetres in diameter, plus a number of bivalves," reports MOSAiC expedition leader Prof Markus Rex directly from the Arctic.

Meanwhile, back home in Bremerhaven, Germany, Thomas Krumpen is thrilled to see that the now emerging 'bivalve ice with pebbles', as he has affectionately dubbed it, so clearly confirms the study's findings. The team of authors led by the AWI expert used a combination of satellite imagery, reanalysis data and a newly developed coupled thermodynamics backtracking model to reconstruct the floe's origins. Now Krumpen and his colleagues are devising a strategy for gathering samples of the sediments. The extent to which these 'dirty' and therefore darker patches accelerate melting on the floe is an important question, and answering it could enhance our understanding of the interactions between the ocean, ice and atmosphere, of biogeochemical cycles, and of life in the Arctic in general.

In addition to mineral components, the sea ice also transports a range of other biogeochemical substances and gases from the coast to the central Arctic Ocean. They are an important aspect of MOSAiC research on biogeochemical cycles, i.e., on the formation or release of methane and other climate-relevant trace gases throughout the year. However, as a result of the substantial loss of sea ice observed in the Arctic over the past several years, precisely this ice, which comes from the shallow shelves and contains sediments and gases, is now melting more intensively in the summer, causing this material transport flow to break down. In the 1990s, the Polarstern was often in the same waters where the MOSAiC expedition began its drift. Back then the ice was still ca. 1.6 metres thick at the beginning of winter, whereas it had shrunk to ca. 50 centimetres last year - which made the search for a sufficiently thick floe in the autumn of 2019 all the more difficult.

"We were fortunate enough to find a floe that had survived the summer and formed in the Russian shelf seas. This allows us to investigate transport processes from the 'old Arctic', which now only partly function, if at all," says Krumpen. Particularly in the higher latitudes, global warming is causing temperatures to climb rapidly: in the summer of 2019, the last summer before the expedition, Russian meteorological stations reported record temperatures. These high temperatures sparked rapid melting and significantly warmed Russia's marginal seas. As a result, many parts of the Northeast Passage were ice-free for a 93-day period (the longest duration since the beginning of satellite observation). The experts predict that if CO2 emissions remain unchecked - as they have in the past several years -the Central Arctic could be ice-free in summer by 2030.

To testify the "iron hypothesis" in the North Greenland Eemian Ice Drilling (NEEM) ice core, Cunde Xiao and his colleagues firstly reconstructed the bioavailable Fe data in this deep ice core from the northern Hemisphere over the past 110 kyr B.P., which suggested that the dissolved Fe (DFe) records in NEEM ice core were significantly anti-correlated with the carbon oxide (CO2) concentrations during the cold periods. The pattern of Fe concentration was extremely similar to that of the number of dust particles. The results also emphasized that the changes of Fe fertilization effect could not be explained by a simple linear relationship with the glacial-interglacial changes in the CO2 concentration in the atmosphere.

This study focused on the linkages between NEEM ice core and Chinese loess record over the past 110 kyr B.P. The changes of Fe fluxes in the NEEM ice core were in phase with that archived in Chinese loess, where the mineral dust distribution was controlled by the vast Asian deserts and large-scale wind pattern. They suggest that the dust input on a hemispheric scale were most likely driven by the changes in solar radiation during the last glacial-interglacial cycle, as a response to Earth's orbital changes.

In the last glacial-interglacial cycle, the ratios between dissolved Fe and total dissolved Fe (DFe/TDFe) were higher during the warm periods (i.e., post-Industrial Revolution, the Holocene and the Last Interglacial period) than during the main cold period (i.e. the Last Glacial Maximum), indicating that the Fe fertilization effect was more complex during the Holocene, due to the presence of different composition of dust associated, with various grain sizes and other factors.

Although the burning of biomass has released large amounts of Fe-contained aerosols since the Industrial era, no significant responses were observed in Fe variations during the same time period.

Optogenetics is a recently developed technique that can control cellular functions by illuminating lights to the cells in which light-sensitive proteins are expressed by gene transfer. Optogenetics enabled us to activate or inhibit a specific population of neuronal cells and revolutionized stimulation methods. It has now become an indispensable tool for investigating brain functions. So far, most studies using this technique have been performed in rodents, whereas trials to modify behaviors in monkeys have ended up in failure, except for a few studies targeting eye movements.

The research group lead by Professor Atsushi Nambu at National Institute for Physiological Sciences and Professor Hajime Mushiake at Tohoku University, has succeeded in inducing arm movements in Japanese macaque monkeys by using optogenetics. This study will be published in Nature Communications.

First, the research team developed an adeno-associated viral vector that effectively expresses a light-sensitive protein, channelrhodopsin. The team injected the viral vector exactly into the arm region of the motor cortex in which electrical stimulation can induce clear arm movements. The team also developed an optrode that can record neuronal activity and apply light and electrical stimulation separately. The optrode was inserted into the motor cortex, and light stimulation was applied (Figure). Light stimulation through the optrode effectively activated neuronal cells expressing channelrhodopsin, and induced muscle activity and clear arm movements, which are comparable to those induced by electrical stimulation through the same optrode.

This study has opened the door to optogenetic studies in non-human primates and toward clinical application in human patients, such as optical deep brain stimulation (DBS).

A raster expression of a region or one of its eco-environmental properties can be abstracted to a mathematical surface. The mathematical surface is uniquely defined by the intrinsic and extrinsic properties in terms of the fundamental theorem of surfaces. The intrinsic properties can be gathered from local information, which might come from detailed ground observations and spatial sampling. The extrinsic properties can be gathered from satellite observations and the simulation results of spatial models on large scales. The urgency and necessity of integrating the extrinsic and intrinsic properties have been discussed at various scales

Surface modelling is a process of constructing a surface model for dynamically describing an Earth's surface system or a specific component of the Earth's surface environment. Various methods have been developed for surface modelling since the 1950s. They include the Kriging suite of geostatistical methods, spline function, irregular triangular network and inverse distance weighting, for which error and scale issues are long-term challenges.

To find solutions for the error and multi-scale problems, a method for high accuracy surface modeling (HASM) has been developed since 1986, which integrates the extrinsic and intrinsic properties. The need to combine extrinsic information with intrinsic information is a frequently discussed topic in eco-environmental surface modelling. For instance, ground observation can obtain high accuracy data at observation points, but the observations at ?xed positions are con?ned within some limited dispersal points. Satellite remote sensing can frequently supply surface information of eco-environmental processes, but remote sensing description is not able to directly obtain process parameters. Satellite and ground observations provide two different types of information about the Earth's surface. Global models and ground observations provide abundant information, but neither provides the complete picture. A global model, to be as accurate as possible, must supplement information from the currently available ground observations.

Although HASM solved the error and multi-scale problems, it could only be used with small areas because it must use the master equation set for simulating each lattice of a surface, which incurs a huge computation cost. To speed up the computation of HASM, the authors developed a multi-grid method of HASM (HASM-MG), an adaptive method of HASM (HASM-AM), an adjustment computation of HASM (HASM-AC), and a preconditioned conjugate gradient algorithm of HASM (HASM-PCG). These algorithms solved the low computational speed and large memory requirement problems.

HASM was successfully applied for constructing digital elevation models, filling voids in the Shuttle Radar Topography Mission (SRTM) dataset, simulating climate change, estimating carbon stocks, fusing satellite observations and the Total Carbon Column Observing Network (TCCON) measurements of the column-averaged dry air mole fraction of CO2 (XCO2), filling voids on remotely sensed XCO2 surfaces, modeling surface soil properties and soil pollution, and analyzing ecosystem responses to climatic change. In all of these applications, HASM produced more accurate results than the classical methods.

The fundamental theorem for earth surface system modeling (FTESM) was proposed on the basis of developing the HASM methods and their successful applications. FTESM is based on a combination of surface theory, system theory, and optimal control theory. The FTESM corollaries of spatial interpolation and data fusion were used in the Methodological Assessment Report on Scenarios and Models of Biodiversity and Ecosystem Services (IPBES, 2016). The role of this methodological assessment is defined by the Plenary of Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) as "guiding the use of scenario analysis and modelling in all work under IPBES to ensure the policy relevance of its deliverables" [Annex I, IPBES-2/5] (https://ipbes.net/). The FTESM was, in turn, referenced by The Global Assessment Report on Biodiversity and Ecosystem Services (IPBES, 2019).

However, the terminology used by the FTESM does not match the conceptual system of IPBES. Thus, a fundamental theorem for eco-environmental surface modelling (FTEEM) has been developed for eco-environmental surface modeling, from which several corollaries have been deduced, corresponding to spatial interpolation, spatial upscaling, spatial downscaling, data fusion and model-data assimilation, respectively. The eco-environmental surfaces include surfaces of nature, surfaces of nature's contributions to people, and surfaces of the driving forces of natural changes. Nature includes biodiversity and ecosystems as well as earth system. Nature's contribution to people consists of ecosystem services and nature's gifts. Driving forces of nature change was classified into direct driving forces and indirect driving forces. The FTEEM and FTESM have the same meaning with respect to the underlying theory but the terms mean this can be easily understood by different research fields.

Former president of The International Society for Ecological Modelling (ISEM), Perof. Sven Erik Jörgensen, stated: "Error problems and slow-computational-speed problems are the two critical challenges currently faced by Geographical Information Systems (GIS) and Computer-Aided Design Systems (CADS). High-accuracy and high-speed methods for surface modeling (HASM) provide solutions to these problems that have long troubled GIS and CADS." (Jörgensen, 2011)

Former President of the International Association of Ecology, Prof. Wolfgang Haber, pointed out that "All of the findings above described the essential significance of both extrinsic and intrinsic information, but the challenge is how to combine these two kinds of information. FTESM and FTEEM provide a solution to this challenge. FTEEM and FTESM as well as their corollaries for interpolation, upscaling, downscaling, data fusion and model-data assimilation together form the theoretical basis of eco-environmental informatics. I am convinced that the publication of "a fundamental theorem for eco-environmental surface modelling and its applications" (Yue et al., 2020) will serve as a landmark paper in the development of the theoretical underpinnings for a science of eco-environmental informatics moving forward." (Haber, 2020)

"To the best of our knowledge," wrote the 39 researchers, "this work first represents the fundamental theorem for eco-environmental surface modelling, which is serving as a landmark paper in the development of the theoretical underpinnings for a science of eco-environmental informatics moving forward. "

In higher organisms, cells and organelles are surrounded by a membrane, which plays a crucial role in not just creating a barrier from the external environment but also mediating exchange of fluids, electrolytes, proteins, and other useful material. Usually, these membranes are composed of water-repelling layers formed by lipid molecules, with various "transmembrane" proteins embedded in this double-layered sheet. These proteins are assembled in a way such that they create unique "gates" or "channels" that open and close in response to selective molecules or ions under specific conditions. These properties of "selectivity" and "sensing capacity" of a biological membrane come from its sophisticated structure, and together they make these membranes an attractive model for the synthesis of novel materials used to develop advanced sensing and separation devices. However, artificially developing such molecular assemblies--that can assemble itself in a membrane in a functionally active orientation--has remained challenging until now.

Advancing the research on artificial molecules, in a study published in Nature Communications, scientists from Tokyo Tech developed a synthetic channel that can mimic the ion-transporting activity of natural ion channels. Prof Kazushi Kinbara and Prof Takahiro Muraoka, the co-authors of the study, explain, "A major obstacle that limits the application of artificial transmembrane molecules is achieving the functionally active orientation. We tried to create a transmembrane molecule that would overcome this difficulty."

To achieve this goal, the scientists focused on the structure of a biological ion channel that spans the membrane multiple times, and used it as the basis to design two artificial molecules. These molecules were composed of both water-repelling structural blocks, called BPO unit, and water-soluble parts called oligoethylene glycol chains. These structural features lend these artificial molecules the capacity to self-aggregate when embedded in membranes. The molecules also contained phosphate groups that further helped them to achieve the correct orientation across the membranes.

Next, the scientists focused on one of the two molecules, to analyze its structural properties. They observed that when suitable bait-like "ligand" molecules were added to a solution containing the artificial molecule, they successfully bound to the structure--confirming that the structure was indeed functionally active. Moreover, when these molecules were introduced to a preformed membrane, they could insert and orient themselves in the membrane on their own. In the presence of the specific ligands, the membrane-embedded macromolecules changed their structures and transported ions, including lithium, potassium, and sodium ions. Because the synthetic molecule showed promising results with artificial membranes, the scientists then tested it in living cells. Using a technique called fluorescence microscopy, they observed that the macromolecule showed the same functional properties, including differential ligand binding and regulated ion transport activities, in biological membranes too!

Taken together, the study shows how an artificially designed molecule can self-assemble, localize, orient, and mimic the biological ion transport process. These findings can potentially spur advances in the field of biomimetic regulation. The authors optimistically conclude, "The promising results of our study addressed a persistent limitation that blocked the way of using artificial biomimetic membrane proteins in applied fields."

Skoltech researchers together with their industrial colleagues and academic partners have cracked a 1960s puzzle about the crystal structure of a superhard tungsten boride that can be extremely useful in various industrial applications, including drilling technology.

Tungsten borides first captured the imagination of scientists in mid-twentieth century due to their hardness and other fascinating mechanical properties. One long-standing puzzle has been the crystal structure of the highest W-B phases, the so-called "WB4", which varied wildly between experimental models and theoretical predictions.

"Experimentally, the crystal structure is determined by X-ray structure analysis. But the large difference in atomic scattering cross sections (heavy tungsten compared to light boron) renders positions of boron atoms in transition metal borides hardly discernable by X-ray diffraction. This can be resolved by neutron diffraction, but any diffraction method can only give the average structure. If the material is disordered, the complete knowledge of its crystal structure (including local arrangement of the atoms) can be obtained only using a combination of experimental techniques (X-ray, neutron diffraction) and computational methods of materials science," Alexander Kvashnin, Skoltech senior research scientist and first author of the study, explained.

In 2017, Andrei Osiptsov and Artem R. Oganov at Skoltech proposed an idea to search for superhard materials to be used for producing composite cutters installed on bits, which are used for drilling oil and gas wells. The idea was well received by Gazpromneft STC LLC, and the collaboration began between the company, Skoltech, and the Vereshchagin Institute for High Pressure Physics of the RAS. Researchers led by Artem R. Oganov of Skoltech and MIPT predicted the existence of WB5, tungsten pentaboride, which was expected to be harder than the widely used tungsten carbide and having comparable fracture toughness. The compound was successfully synthesized in the lab at Vereshchagin Institute to complete the research loop. In the new paper, Oganov and his colleagues show that the long-debated "WB4" and the newly predicted WB5 are actually the same material.

"We studied the W-B system in order to predict stable structure of higher tungsten borides as we had already known about this long-standing puzzle. Predicting a new WB5 structure was a surprise, especially as it has exciting properties as high Vickers hardness and fracture toughness and remains stable at very high temperatures. Then we thought this material should find application in the industry. Our colleagues from the Vereshchagin Institute successfully synthesized it. The diffraction patterns matched theoretical prediction very well, except a few weak peaks that were present in theory, but not in the experiment. Our predicted WB5 has perfect single crystal structure, but as we showed, experiments produced a closely related disordered WB5-x material," Kvashnin explained.

The researchers synthesized this new material, measured its properties, and revealed an unexpected connection between the two compounds: the new material has a crystal structure derived from the WB5 structure, with some amount of disorder and nonstoichiometry (this means that proportions of its elemental composition cannot be represented by a ratio of small integer numbers). Thus, the new material was denoted not as WB4 but as WB5?x. Its crystal structure was utlimately predicted by USPEX, an evolutionary algorithm developed by Oganov and his students, and elaborated by a microscopic lattice model.

Since WB5-x is relatively easy to synthesize, its excellent mechanical properties and stability at high temperatures make it a very promising material for many technologies where tungsten carbide-based composites dominated in the last 90 years.

"This puzzle is solved in full detail. We have a detailed microscopic description of this material and its structure, we know the range of chemical compositions it can adopt, and its properties. Other exciting puzzles are waiting for theorists' attention," said Artem R. Oganov.

The human brain has evolved over eons of time to develop the most complex and unique network to support the strong brain functions. So far, it is well known that the brain network has characteristic features such as small world, scale-free, community, and rich-club etc. However, we know little about how these features ensure strong brain functions or what are the mechanisms of brain functions. Recently, a team from East China Normal University and Hong Kong Baptist University (S. Huo, C. Tian, M. Zheng, S. Guan, C.S. Zhou, and Z. Liu) published a paper in National Science Review, which revealed that the real brain network has a new chimera state----spatial multi-scaled chimera state, and its formation is closely related the local symmetry of connections (see figure 1).

Different from artificial complex networks, the team considered a real network of cerebral cortex and let each node be represented by a neural mass model describing the mean field activity of a neuronal population. They paid attention to the collective behaviors of two brain networks with different sizes (one has 989 nodes and the other has 64 nodes) and found that the brain network may have a surprising behavior, i.e. global trivial but with local chimera state, depending on coupling strengths and time-delays. Further, the authors revealed that it is possible to have chimera states on both global and local levels, and thus call it spatial multi-scaled chimera state (see figure 2).

To understand the mechanism of spatial multi-scaled chimera state, the team further studied the topological symmetry of each cortical region and found that there is a positive correlation between the degree of symmetry and synchronization, i.e. the regions with higher symmetry take the role of relay nodes. Moreover, the team also studied both the structural and functional bifurcation trees of clusters and discovered the close relationship between network structure and functions. That is, for different network status, no matter it is normal or abnormal, the activation of different clusters or their combinations can result in different dynamical brain modes and thus implement the different rhythms such as the δ, θ, α, β and γ waves.

The discovery of spatial multi-scaled chimera state may be used to explain the experiments of brain rhythms and the diversity of chimera states may be used to explain the cognitive patterns of brain network. Thus, the new idea to study the formation of dynamical patterns from symmetry may provide a new approach to understand the mechanism of brain functions.

Humans have manipulated and managed rivers with dams for millennia. The number of river dam projects is predicted to rise sharply in the future, especially in the tropics where demand for hydroelectricity and water is accelerating. What are the long-term impacts of dams on highly biodiverse tropical forests? Scientists at the Smithsonian Tropical Research Institute (STRI) and collaborating institutions turned to one of the oldest tropical dams in the world to answer this question: The Panama Canal.

Over a century ago, the Chagres River was dammed to form Gatun Lake, the principal waterway of the canal and at the time the largest man-made lake in the world. Jorge Salgado, STRI fellow and postdoctoral researcher at the University of Nottingham, led a team that retrieved sediment cores from a basin in the lake and, with paleoecological techniques and historical records from the Panama Canal Authority, built a chronological sequence of biological and environmental changes. Their findings were recently published in the journal Science of the Total Environment.

"The unique historical data available from the Panama Canal makes it one of a kind," Salgado said. "When combined with paleoecological data, we have an unrivalled opportunity to explore the impacts of damming on a tropical river over a period of more than 100 years."

The data reveal the narrative of biological and environmental events that took place in Lake Gatun, ranging from enhanced pollution caused by canal construction, regional climate changes and shifts in land-use to the introduction of invasive species and salt-water intrusions.

"In most cases, the local impacts of dams would begin to dominate, but we found that in the Panama Canal, natural river processes continue to be very important today," Salgado said.

The researchers' findings emphasize the need to understand both long-term drivers of natural change, such as precipitation and river flow dynamics, and the human-driven changes that affect water bodies in order to effectively manage and preserve the lake basin's ecological functioning.

"Coring lake sediments gives us the chance to travel back in time and chronicle ecosystem change," said Aaron O'Dea, STRI staff scientist and co-author of the study. "It's a really powerful way to uncover past events and reveal ecological and environmental processes that would otherwise be undetectable. This is especially important in highly biodiverse tropical ecosystems where long-term monitoring data may be limited."

Salgado has plans to continue time-traveling. He and his team will collect more cores and reconstruct historical changes in other areas of the Panama Canal.

"Since its construction, the Panama Canal has protected a wide-swathe of biodiverse lowland tropical terrestrial and aquatic ecosystems," Salgado said. "Reconstructing the past can help us predict the future responses of both protected and non-protected areas to further global and local changes. This is paramount to the biological health of the canal."

Some of the most fundamental questions in evolution remain unanswered, such as when and how extremely diverse groups of animals - for example reptiles - first evolved. For 75 years, adaptive radiations - the relatively fast evolution of many species from a single common ancestor - have been considered as the major cause of biological diversity, including the origins of major body plans (structural and developmental characteristics that identify a group of animals) and new lineages. However, past research examining these rapid rates of evolution was largely constrained by the methods used and the amount of data available.

In a paper out today in Nature Communications, a research team led by Harvard University examined the largest available data set of living and extinct major reptile groups (such as marine reptiles, turtles, lizards, and the ancestors of dinosaurs and crocodiles) to tackle the longstanding question of how adaptive radiations have shaped reptile evolution. Using DNA information from modern species and hundreds of anatomical features from both modern and fossil species for statistical analysis, the study detected that periods of fast anatomical change during the origin of reptile groups often predate when those groups diversified into hundreds or thousands of species. This contradicts long-held ideas of adaptive radiation in evolution biology.

"Our findings suggest that the origin of the major reptile groups, both living and extinct, was marked by very fast rates of anatomical change, but that high rates of evolution do not necessarily align with taxonomic diversification" said first author Dr. Tiago Simões, Postdoctoral Fellow in in the lab of Stephanie Pierce, Associate Professor in the Department of Organismic and Evolutionary Biology at Harvard University.

Simões and Pierce revealed that rates of evolution and morphological variety in reptiles prior to the Permian-Triassic Mass Extinction - the biggest mass extinction of all time - were equally high, or even higher, than after the event. As reptile species diversity was much lower during the Permian compared to Triassic, these results indicate that fast rates of evolution do not need to coincide with rapid taxonomic diversification as predicted by the classical theory of adaptive radiation. The two can be decoupled.

The team, which also included PhD student Oksana Vernygora and Professor Michael Caldwell at the University of Alberta, further discovered that accelerated rates of evolution correspond to the origin of unique reptile body plans, but that very similar functional adaptations in reptiles can arise through varying rates of evolution.

"Surprisingly," Pierce said, "reptiles that evolved similar protective armour like turtles or serpentine bodies like snakes, show radically different rates of evolution, indicating the origin and evolution of unique body plans is heterogeneous through evolution."

"Our results also show that the origin of snakes is characterized by the fastest rates of anatomical change in the history of reptile evolution," said Simões. "But, that this does not coincide with increases in taxonomic diversity [as predicted by adaptive radiations] or high rates of molecular evolution."

The mismatch between morphological and molecular evolution supports the idea that protein coding DNA sequences do not seem to be correlated with broad-scale changes in anatomy. Although much more research is needed to understand how body plans evolve, the team hypothesizes that non-protein coding regions of the genome may be responsible for rapid morphological change, as these parts are more free to mutate and take on new functional roles.

"It is clear to us that to advance our understanding of the major patterns in evolution we need further studies capable of measuring phenotypic and molecular evolutionary rates, times of origin, and phenotypic diversity across large timescales" said Simões.

Simões and colleagues continue to develop new methods and are expanding their data set back in time to look at the origins of amniotes, the group that includes both reptiles
and mammals. Of particular interest is pinpointing when in geological time these two groups of animals diverged and how extinction, diversification, and adaptation have shaped their evolutionary history over the last 300+ million years.

"I'm excited to continue my research to unravel the early evolutionary dynamics of the two most successful groups of animals on the planet," Simões said. "I'm also focusing on improving available protocols to analyze morphological data and construct more robust evolutionary trees, including the timing of origin of major vertebrate lineages."

Toxic metallic air pollution nanoparticles are getting inside the crucial, energy-producing structures within the hearts of people living in polluted cities, causing cardiac stress - a new study confirms.

Using state-of-the-art electron microscopy, scientists are now able to show for the first time that tiny metal nanoparticles are getting inside the mitochondria of heart tissue - damaging these crucial 'powerhouses' that provide energy for the heart to pump.

The research team, led by Professors Barbara Maher of Lancaster University and Lilian Calderón-Garcidueñas of The University of Montana and the Universidad del Valle de Mexico, found the metallic nanoparticles, which included iron-rich nanoparticles and other pollution-derived metals such as titanium, inside the damaged heart cells of a 26-year-old and even a three-year-old toddler.

The hearts had belonged to people who had died in accidents and who had lived in highly-polluted Mexico City.

The findings shed new light on how air pollution can cause the development of heart disease, as the iron-rich particles were associated with damage to the cells, and increased cardiac oxidative stress, even in these very young hearts.

The repeated inhalation of these iron-rich nanoparticles, and their circulation by the bloodstream to the heart, may account for the well-established associations between exposure to particulate air pollution and increased cardiovascular disease, including heart attacks. The study indicates that heart disease can start in very early age, before progressing to full-blown cardiovascular illness later in life. This type of air pollution may thus be responsible for the 'silent epidemic' of heart disease, internationally. By causing pre-existing heart conditions, it may also account for some of the increased death rates from Covid-19 seen in areas with high levels of particulate air pollution.

Professor Maher said: "It's been known for a long time that people with high exposure to particulate air pollution experience increased levels and severity of heart disease. Our new work shows that iron-rich nanoparticles from air pollution can get right inside the millions of mitochondria inside our hearts...the structures which generate the energy needed for our hearts to pump properly.

"That we found these metal particles inside the heart of even a three-year old indicates that we're setting heart disease in train right from the earliest days, but only seeing its full, clinical effects in later life. It's really urgent to reduce emissions of ultrafine particles from our vehicles and from industry, before we give heart disease to the next generation too."

The researchers, using high-resolution transmission electron microscopy and energy-dispersive X-ray analysis, found that the mitochondria containing the iron-rich nanoparticles appeared to be damaged, with some cells showing deformities and others with ruptured membranes. Professor Calderón-Garcidueñas stated that increased levels of markers of cardiac oxidative stress are present in the very young cases examined.

The iron-rich nanoparticles found inside the heart cells are identical in size, shape and composition to those emitted from sources such as the exhausts, tyres and brakes of vehicles. These air pollution nanoparticles are also emitted by industrial sources as well as open fires in homes.

Some of the iron-rich nanoparticles are also strongly magnetic. This raises concerns about what might happen when people with millions of these nanoparticles in their hearts are using appliances with associated magnetic fields, such as hair dryers and mobile phones. People who work in industries that mean they are exposed to magnetic fields such as welders and power line engineers may also be at risk. This kind of exposure could potentially lead to heart electrical dysfunction and cell damage.

The findings builds on the researchers' previous findings that show that the hearts of city dwellers contain billions of these nanoparticles and can be up to ten times more polluted than the hearts of people living in less polluted places.

The researchers say their study underlines the need for governments across the world to tackle ultrafine particulate pollution in their cities.

Professor Calderón-Garcidueñas said: "Exposure to such air pollution is a modifiable risk factor for cardiovascular disease, on a global scale, reinforcing the urgent need for individual and government actions not just to reduce PM2.5 but to monitor, regulate and reduce emissions of these specific, ultrafine components of the urban air pollution 'cocktail'."

Even today, nobody can reliably predict when and where an earthquake will occur. However, eyewitnesses have repeatedly reported that animals behave unusually before an earthquake. In an international cooperation project, researchers from the Max Planck Institute of Animal Behavior in Konstanz/Radolfzell and the Cluster of Excellence Centre for the Advanced Study of Collective Behaviour at the University of Konstanz, have investigated whether cows, sheep, and dogs can actually detect early signs of earthquakes. To do so, they attached sensors to the animals in an earthquake-prone area in Northern Italy and recorded their movements over several months. The movement data show that the animals were unusually restless in the hours before the earthquakes. The closer the animals were to the epicentre of the impending quake, the earlier they started behaving unusually. The movement profiles of different animal species in different regions could therefore provide clues with respect to the place and time of an impending earthquake.

Experts disagree about whether earthquakes can be exactly predicted. Nevertheless, animals seem to sense the impending danger hours in advance. For example, there are reports that wild animals leave their sleeping and nesting places immediately before strong quakes and that pets become restless. However, these anecdotal accounts often do not stand up to scientific scrutiny because the definition of unusual behaviour is often too unclear and the observation period too short. Other factors could also explain the behaviour of the animals.

In order to be able to use animal activity patterns as a kind of early warning system for earthquakes, the animals would have to show measurable behavioural changes. Moreover, if they do indeed react to weak physical changes immediately before an earthquake, they should react more strongly the closer they are to the epicentre of the quake.

In an international cooperation project, researchers from the Max Planck Institute of Animal Behavior in Radolfzell/Konstanz and the Centre for the Advanced Study of Collective Behaviour, a Cluster of Excellence at the University of Konstanz, have investigated whether animals really do this. On an Italian farm in an earthquake-prone area, they attached accelerometers to the collars of six cows, five sheep, and two dogs that had already displayed unusual behaviour before earthquakes. The researchers then recorded their movements continuously over several months. During this period, official authorities reported about 18,000 earthquakes in the region. In addition to many small and hardly noticeable quakes, there were also 12 earthquakes with a strength of 4 or higher on the Richter scale.

The researchers then selected the quakes that triggered statistically relevant earth movements on the farm. These included strong quakes up to 28 km away as well as weaker quakes, the epicentres of which were very close to the farm. However, instead of explicitly looking for abnormal behaviours in the period before these events, the researchers chose a more cautious approach. They first marked all behavioural changes of the animals that were unusual according to objective, statistical criteria. "In this way, we ensure that we not only establish correlations retrospectively but also that we really do have a model that can be used for predictions," says Martin Wikelski, director at the Max Planck Institute of Animal Behavior and Principal Investigator at the Centre for the Advanced Study of Collective Behaviour.

The data--measured as body acceleration of each farm animal (indicating activity level)--were evaluated using statistical models drawn from financial econometrics. "Because every animal reacts differently in size, speed and according to species, the animal data resemble data on heterogenous financial investors," explains co-author Winfried Pohlmeier, Professor of Econometrics at the University of Konstanz and Principal Investigator at the Centre for the Advanced Study of Collective Behaviour. The scientists also considered other disturbance factors such as natural changes in animal activity patterns over the day.

In this way, the researchers discovered unusual behavioural patterns up to 20 hours before an earthquake. "The closer the animals were to the epicentre of the impending shock, the earlier they changed their behaviour. This is exactly what you would expect when physical changes occur more frequently at the epicentre of the impending earthquake and become weaker with increasing distance," explains Wikelski. However, this effect was clear only when the researchers looked at all animals together. "Collectively, the animals seem to show abilities that are not so easily recognized on an individual level," says Wikelski.

It is still unclear how animals can sense impending earthquakes. Animals may sense the ionization of the air caused by the large rock pressures in earthquake zones with their fur. It is also conceivable that animals can smell gases released from quartz crystals before an earthquake.

Real-time data measured by the researchers and recorded since December 2019 show what an animal earthquake early warning system could look like: a chip on the collar sends the movement data to a central computer every three minutes. This triggers a warning signal if it registers a significantly increased activity of the animals for at least 45 minutes.

The researchers have once received such a warning. "Three hours later, a small quake shook the region," says Wikelski. "The epicentre was directly below the stables of the animals."

However, before the behaviour of animals can be used to predict earthquakes, researchers need to observe a larger number of animals over longer periods of time in different earthquake zones around the world. For this, they want to use the global animal observation system Icarus on the International Space Station ISS, which will start its scientific operation in a few weeks.

Icarus, a scientific project directed by Martin Wikelski, is a joint project funded and carried out by the German Aerospace Center (DLR) and the Russian space agency Roskosmos and is supported by the European Space Agency (ESA).

When we think of engineering in nature, we tend to think of beavers -- the tree-felling, dam-building rodents whose machinations can shape the landscape by creating lakes and changing the path of rivers. But beavers are far from the only organisms to reshape their environment. A squirrel who inadvertently plants oak trees is also an "ecosystem engineer" -- roughly speaking, any organism whose impact on the environment outlasts its own lifetime. The coolest of these biological builders, according to Justin Yeakel, might be the shipworm, which eats through rocks in streams, creating cozy abodes for future invertebrate inhabitants.

Yeakel, an ecologist at the University of California, Merced, and a former Santa Fe Institute Omidyar Fellow is the lead author of a new paper that models the long term impact of ecosystem engineers. Researchers have long considered the role of ecosystem engineers in natural histories, but this study is among the first to quantitatively assess them in an ecological network model.

"We wanted to understand how food webs and interaction networks were established from a mechanistic perspective," he says. "To do that, you have to include things like engineering because species influence their environment and there's this feedback between the environment to the species."

In particular, the model uses simple rules to show how food webs can be assembled, how species interactions can change over time, and when species go extinct. One striking result: Few ecosystem engineers led to many extinctions and instability while many ecosystem engineers led to stability and few extinctions.

"As you increase the number of engineers, that also increases the redundancy of the engineers and this tends to stabilize the system," Yeakel says.

So, how do you create an ecological network model? It's highly abstracted -- there are no specific species like beavers or concrete environmental features like rivers. Everything is reduced to interactions: species can eat, need, or make. In this sense, nature becomes a network of interactions. For example, bees eat nectar from flowers; flowers need bees to be pollinated; trees make shade which flowers need.

The researchers gave the model a small number of rules, the main one being: Species have to eat only one thing to survive but they have to obtain all of the things they need. In less abstract terms, even if one flower species goes extinct, bees could survive on nectar from other flowers. But if either bees or trees fail to provide pollination or shade, which flowers need, then the flowers will go extinct.

Using these rules, the models were able to produce ecological networks similar to those in the real world, with a characteristic hourglass shape in species diversity -- more diversity at the top and the bottom of the web, less in the middle. To expand the model for future research, Yeakel plans on incorporating evolutionary dynamics so that species can change what they eat and need and make.

Two and a half billion years before humans showed up, cyanobacteria were a planetary-scale engineer that slowly changed the composition of the entire atmosphere by oxygenating it. But unlike our photosynthetic predecessors, "we're making changes on ecological timescales rather than evolutionary timescales," Yeakel says. "Is an organism that becomes a planetary-scale engineer doomed to extinction if it changes the environment too quickly?"

Study of more than 400 Syrian refugee children in Lebanon identified significant development and learning difficulties when children are above the regular age for their grade.

NYU researchers drew insights into potential impacts as children around the world return to school following COVID-19.

Abu Dhabi, July 2, 2020: Researchers at Global TIES for Children, an international research center based at NYU Abu Dhabi and NYU New York, examined a variety of post-migration risks faced by Syrian refugee children enrolled in Lebanese public schools and found that students being older than expected for the grade in which they were placed was most consistently and strongly associated with developmental and learning difficulties. As many schools around the world prepare to reopen in 2020 and beyond, the study provides critical insights that can help inform efforts to reintegrate children into schools after significant disruption and time away.

The findings of the study are detailed in a paper published in the Journal for Applied Developmental Psychology and corresponding policy brief released on July 1, 2020. The study collected and analyzed assessment data from 448 Syrian refugee children in November 2016 through March 2017. Researchers found that children who were older than expected for their grade level - so-called "age-for-grade" - had poorer cognitive executive functioning and behavioral regulation skills than children who were placed in a typical grade level for their age. Being overage-for-grade also forecasted decrements in literacy and math skills.

"We embarked on one of the first comprehensive and rigorous studies to look at the interaction between adversities that refugee children face living in middle-income host-countries and learning outcomes, including academic, cognitive, emotional, and behavioral skills and processes," said co-author of the paper and Deputy Director of Global TIES for Children Carly Tubbs Dolan. "As of today, over a billion children worldwide have faced numerous personal and academic adversities and disruptions. This type of research can help inform the design, implementation, and funding of evidence-based programs and policies to ensure children's holistic learning during crisis situations."

School closures due to the COVID-19 pandemic have left nearly 1.6 billion children and youth out of school around the world, while the cascading economic impacts are anticipated to force millions more to drop out. Recent research indicates that even short-term, 14-week school closures can have significant long-term repercussions on children's academic outcomes.

"Our research suggests that such cumulative experiences of adversity can have repercussions for both children's academic performance and their social and emotional skills," said lead author of the study and a Senior Research Scientist at Global TIES for Children Ha Yeon Kim. "To best support children in returning to school, we recommend that practitioners use differentiated instructional and pedagogical strategies appropriate for children's varying ages, and incorporate evidence-based strategies - such as social and emotional learning (SEL) practices and curricula--into education programming."

In this study, grade level may be associated with cognitive, behavioral, and academic difficulties for several possible reasons. First, being older than expected for a grade can be a marker that a child has faced numerous and cumulative risks earlier in childhood that interrupted schooling or impaired learning. Second, studying in a classroom without same-age peers or developmentally appropriate teaching practices, routines, and learning materials may itself result in cognitive and behavioral challenges. Third, and conversely, there may be a tendency to place older children with lower cognitive, behavioral, and socio-emotional skills in lower grades.