Earth

In a hard-hitting new paper leading ecologists and climate change specialists argue that current nature conservation practices are not sufficiently flexible and dynamic to weather the impacts of climate change.

Rather than only trying to conserve or restore nature to an original historical state, as is the case with static protected areas, a more flexible approach will reduce the adverse impacts of climate change by allowing species to migrate naturally, or even be moved to more suitable habitats, for example. Another approach would be identifying species at greater risk of extinction from climate change for proactive conservation of their genetic material in the hope of one day re-establishing them under more suitable conditions.

The paper, titled "Post-2020 biodiversity targets need to embrace climate change" was published in the high-impact journal PNAS this week. The paper refers to documented research indicating that species home ranges have already been shifting polewards, to cooler areas, with an estimated decadal average shift of 17 kilometers for terrestrial and 72 kilometers for marine taxa.

Prof Bob Scholes, editor of the paper and an ecologist in the Global Change Institute at the University of the Witwatersrand, says the question of whether to intervene to protect species or not is a heated debate in conservation circles: "Interestingly, the animal people are much happier in moving things around than the plant people, who are rather conservative, so to speak. This paper, in a way, was intended to shock the conservationists out of the state of just continuing doing things as they have always done".

The authors argue that nature conservation strategies need to become more flexible and dynamic in how it addresses the impact of climate change on natural habitats, genetic resources of plants, the composition of species, and the functioning of ecosystems. If not, any apparent short-term gains in reversing biodiversity loss could be lost in the decades to follow, due to climate change.

At present, none of the 2020 Aichi Biodiversity Targets of the Convention on Biodiversity Diversity explicitly addresses the urgency of climate change mitigation and adaptation as a critical component of biodiversity conservation. For example, they refer to Aichi Target 12, which aims to prevent the extinction of all known threatened species and improve their conservation status. A static or traditional approach to conservation would therefore seem unrealistic given the evidence that climate change has already resulted in significant range shifts: "Even very low levels of future climate change are projected to reduce the range size of a substantial fraction of species and put many species at high risk of extinction," they write.

Prof Guy Midgley, a global change and biodiversity specialist in the Department of Botany and Zoology at Stellenbosch University and one of the co-authors, says furthermore that several prominent measures to slow the rate of rising CO2, such as planting more trees, can conflict directly with the aims of biodiversity conservation in Africa.

"Large-scale afforestation of rich grassland ecosystems in Africa will not only threaten their unique shade-averse biodiversity, but also limit livelihoods options and reduce vital ecosystem services, like the delivery of freshwater, from these ecosystems," he argues.

Several unknowns still plague our ability to estimate risks, mainly because we still do not know what the impact of climate change could be on the delivery of multiple ecosystem services such as clean air and water, and food security, if pollination networks are at risk of disruption.

The authors argue that there are complex interactions between ecosystem processes, atmospheric composition and climate which we do not yet understand. Combined with continued human population growth and the concomitant increase in per capita consumption, which more often than not leads to the over-exploitation and pollution of ecosystems, it becomes clear that there is cause for serious concern.

The authors warn that recent assessment reports by the Intergovernmental Panel on Climate Change (IPCC) and the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES) have both highlighted the twinned risks to humanity arising from climate change and the "unprecedented and unsustainable use of natural resources".

Biodiversity directly supports the achievement of at least 13 of the Sustainable Development Goals (SDG), while climate change has the potential to undermine all 16 of the SDGs. It is obvious we cannot do without considering both.

"Nature is clearly resilient to shocks like climate change, given enough time, and the earth's biological diversity has shifted and changed in response to global crises in the deep geological past, like meteorite strikes. It is therefore crucial for us to work with the natural forces that provide resilience rather than limiting conservation thinking to achieving fixed ideals based on our limited historical perspectives of natural ecosystems," concludes Prof Midgley.

The paper is the result of a multi-year assessment process by the authors for the IPBES, which resulted in chapter 4 of the IPBES global report "Plausible futures of nature, its contributions to people and their good quality of life", available at https://ipbes.net/global-assessment; https://ipbes.net/sites/default/files/ipbes_global_assessment_chapter_4_unedited_31may.pdf

Weight loss appears as a holy grail in our modern societies. DNP (2,4-dinitrophenol), a molecule decreasing the efficiency at which food is converted to cellular energy, was discovered in the early 1930s to be an efficient chemical treatment to promote weight loss in humans. Due to acute toxic effects and the death of several users, DNP was rapidly withdrawn from the market and not used for decades. Yet, DNP has re-emerged over the last decade for human usage through its illegal selling on Internet, leading to several death cases and the recent conviction of an online seller. A global alert was issued by INTERPOL in 2015.

Despite its acute toxicity, the US FDA granted DNP an open Investigation New Drug (IND) approval to begin clinical testing linked to its potential to prevent 'metabesity' (i.e. global comorbidities associated with the over-nutritional phenotype). While DNP had a known acute toxicity in humans, it was still used by scientists at low doses in animal models to test hypotheses related to ageing. In 2008, it was for instance discovered that DNP can have beneficial effects on lifespan in laboratory mice. Dr Antoine Stier, who is currently working as Collegium Researcher at the University of Turku in Finland, suspected that the beneficial effects of DNP in mice could be attributable to obesity prevention and could mask the chronic toxicity of DNP for non-obese animals and humans.

A new study led by Dr Stier at the CNRS/University of Strasbourg, France, used captive zebra finches to investigate the impact of a long-term (> 4 years) DNP treatment on key hallmarks of cellular ageing and lifespan.

"The birds, which are a widely used avian model not displaying age-related obesity, were treated with a dose of DNP per kilo which was well within the range of what is used illegally by humans. The dose had no short-term deleterious effects and only mildly increased the metabolism of these birds," says Dr François Criscuolo, who is a CNRS researcher in Strasbourg.

"While DNP-treated birds were looking healthy, demonstrated similar physical performances than control animals, and were not displaying physiological signs of premature ageing, this new study reveals that the lifespan of the birds was actually reduced by 20% (~ 1 year). This would be equivalent to a reduction of approximately 15 years in human life, which should provide a serious warning signal to both current and prospective users, as well as to scientists investigating its use as a medicine," adds Dr Stier.

Having data from other long-term studies of DNP in animal models seems imperative to enable the scientific community and stakeholders to have a broader and more realistic picture of the long-term effects of DNP treatment before its potential therapeutic usage in humans.

CHAMPAIGN, Ill. -- Climate change contributes to gradually warming Aprils in southern Illinois, and at least one migratory bird species, the prothonotary warbler, is taking advantage of the heat. A new study analyzing 20 years of data found that the warblers start their egg-laying in southern Illinois significantly earlier in warmer springs. This increases the chances that the birds can raise two broods of offspring during the nesting season, researchers found.

They report their findings in the journal Frontiers in Ecology and Evolution.

"Warmer springs in temperate regions of the planet can create a mismatch between when food is available to breeding birds and when their energy demands are highest - when they are feeding nestlings," said Illinois Natural History Survey avian ecologist Jeffrey Hoover, who conducted the study with INHS principal scientist Wendy Schelsky. If climate change diminishes insect populations at critical moments in the birds' nesting season, food shortages may cause some chicks and even adults to die. Other long-distance migratory birds suffer ill consequences from warmer springs on their breeding grounds.

But this mismatch seems not to occur in prothonotary warblers, the researchers found.

In the Cache River watershed, where the study was conducted, the warblers nest in swamps and forested wetlands, which are abundant sources of insects throughout the spring and summer. The warblers eat caterpillars, flies, midges, spiders, mayflies and dragonflies. As long as it does not dry up, the wetland habitat provides a steady supply of food to sustain the birds.

"We studied populations of prothonotary warblers nesting in nest boxes in these areas from 1994-2013," Schelsky said. The researchers captured and color-banded the birds, studying 2,017 nesting female warblers in all. They visited the nests every three to five days from mid-April to early August, keeping track of when each bird laid its first egg and the birds' overall reproductive output for each nesting season.

They also compared local April temperature trends with those of the Annual Global Land Temperature Anomaly data, a federal record compiled by the National Oceanic and Atmospheric Administration. They found that local conditions reflected global temperature changes.

When local temperatures were warmer in April, the birds tended to lay their first eggs earlier in the spring and, on average, produced a greater number of offspring over the course of the breeding season.

"It was exciting to see that the birds could be flexible and adjust their timing of breeding to be earlier in warmer years and benefit by doing so," Schelsky said. Starting earlier meant more of the birds could raise additional broods of offspring.

As the warming trend continues, conditions may change in ways that harm the birds' reproductive capacity, Hoover said.

"Even though these warblers currently produce more offspring in warmer years, continued global warming may eventually upset the balance between arrival dates, food resources and the commencement of nesting," he said. For example, warmer temperatures could cause local wetlands to dry up during the nesting season, cutting off the steady supply of insects the birds rely on to raise their young and increasing the exposure of nests to predators.

Nutrient contamination of groundwater as a result of nitrogen-based fertilisers is a problem in many places in Europe. Calculations by a team of scientists led by the UFZ have shown that over a period of at least four months per year, nitrate can leach into the groundwater and surface water on about three-quarters of Europe's agricultural land. The proportion of areas at risk from nitrate leaching is thus almost twice as large as previously assumed.

In agriculture, nitrogen-based fertilisers are often not applied in a way that is appropriate to the location and use. If the level is too high, the plants do not fully take up the nitrogen. As a result, the excess nitrogen is leached into the groundwater and surface water as nitrate - a problem that occurs in several EU countries. For example, in 2018, the European Court of Justice (ECJ) condemned EU countries including Germany for breaching the EU Nitrates Directive. Last year, the EU Commission reminded Germany to implement the ECJ ruling.

How much of the nitrogen applied through fertilisation can enter the groundwater and surface water as nitrate or is denitrified (i.e. converted to molecular nitrogen and nitrogen oxides and released into the air) depends, among other things, on complex processes in the soil. A team of UFZ researchers and U.S. partners led by hydrologist Dr Rohini Kumar have now analysed in more detail which processes determine the fate of excess nitrogen. The focus is on hydrological and biogeochemical processes in the root zone (i.e. the area that extends from the surface of the soil down to a depth of one meter). "The root zone is the most dynamic and active part of the subsoil, where soil moisture, evaporation and dry/wet phases prominently take effect", says Kumar. It acts as both a hydroclimatic and biogeochemical filter between the surface and the deeper subsurface layers.

The vulnerability of agricultural land to nitrate leaching has so far been described using static information on land use, soils, and the topography of the landscape, combined with mean precipitation and groundwater levels - without taking into account of their temporal variability. "However, precipitation and temperatures change daily. This affects evaporation and soil water and ultimately the retention time and water transport to deeper layers. Mean values, as used to describe the static condition, are therefore less appropriate from today's perspective", explains Kumar. The researchers therefore use a dynamic approach to calculate how long the dissolved nitrate could remain in the root zone before it leach down to deeper levels. They combine the mHM (mesoscale hydrologic model) developed at the UFZ with calculations of the daily change of water retention and nitrate in the root zone as well as denitrification. With the help of the mHM, scientists can simulate the spatio-temporal distribution of hydrological dynamics as well as transport dynamics occurring in the root zone throughout Europe to the day for the past 65 years.

With the new approach, the UFZ researchers conclude that for at least four months per year, almost 75% of Europe's agricultural land is vulnerable to nitrate leaching into groundwater and surface waters. If the static approach is used, this proportion is only 42%. "Because the spatial-temporal dynamics of water transport have not been taken into account in the vulnerability assessment of delimiting nitrate vulnerable zones, the spatial extent of nitrate vulnerable areas is grossly underestimated", concludes co-author and UFZ hydrogeologist Dr Andreas Musolff. This concerns, among others, areas in the east and north-east of Germany, the Iberian Peninsula, and some Eastern European countries.

According to the UFZ researchers, the new findings could better aid to risk management of nitrogen in agriculture. "Farmers could use the more precise information to more precisely adjust their fertiliser regimes, thereby ensuring that as little nitrate as possible is present in the soil during the particularly critical months", says Musolff. This would prevent additional nitrate from entering the groundwater and surface waters. "This study focussing on the soil zone is a starting point for a comprehensive risk assessment of nitrate loads in the groundwater and surface water. It will be followed by further research on transport and denitrification in the subsoil, groundwater and the surface-waters", says Kumar.

Over the past 50 years, declining biodiversity has put many of nature s contributions to people at risk. This is the conclusion reached by fifteen leading international experts, including a French ethnoecologist* at the CNRS (French National Centre for Scientific Research). Based on the IPBES (Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services) Global Assessment, their work is the subject of an article, published this week in the journal PNAS, which discusses the risks to human well-being and prosperity resulting from the continuing degradation of the environment.

The authors looked at the many ways in which nature provides benefits, such as the production of material goods (food, wood, medicines, etc) and non-material goods (leisure activities, learning, experience, etc), as well as the ecological processes that regulate environmental conditions (water filtration, carbon sequestration, storm protection, etc). They point out that the well-being of people is already being affected, in particular by declining crop yields and soil productivity, as well as by increased exposure to floods and storms caused by degradation of coastal ecosystems.

*- Currently working at the Centre d Ecologie Fonctionnelle et evolutive (CNRS/Universite de Montpellier/EPHE/IRD/UniversitePaul Valery Montpellier).

A study of weakly electric fishes from a remote area of the Brazilian Amazon Basin has not only offered a unique window into how an incredibly rare fish has adapted to life in caves over tens of thousands of years, it has also revealed for the first time that electric fish are able to interact with each other over longer distances than known possible in a way similar to AM radio.

In findings published in the journal Frontiers, researchers have shown how a cave-adapted glass knifefish species of roughly 300 living members (Eigenmannia vicentespelea) has evolved from surface-dwelling relatives (Eigenmannia trilineata) that still live just outside their cave door -- by sacrificing their eyes and pigmentation, but gaining slightly more powerful electric organs that enhance the way they sense prey and communicate in absolute darkness.

The study, which analyzed the fishes' electric-based communication and behavior, has detailed the discovery that weakly electric fishes tap into a special channel for long-distance messaging via changes in the amplitude of electrical signals sent to one another. Researchers have adapted Einstein's famous quote on the theory of quantum entanglement -- "spooky interaction at a distance" -- to describe how the weakly electric fishes perceive these social messages, altering each other's behavior at distances up to several meters apart.

Of the nearly 80 species of cavefish known today to have evolved from surface-dwelling fish, all have developed sensory enhancements of some kind for enduring cave life, commonly adapting over millions of years while losing sensory organs they no longer need in the process.

However, biologists have questioned how weakly electric fishes, which use their electrical senses for navigating the dark and murky conditions of the Amazon River, might also adapt -- either evolving heightened electric senses to see and communicate in absolute darkness, or by powering down their electric fields to save on energetic cost when most caves have few food resources.

"One of the big questions about fish that successfully adapt to living in caves is how they adapt to life without light," said Eric Fortune, lead author of the study and biologist at New Jersey Institute of Technology (NJIT). "My colleagues were split between two groups ... one group that predicted that the electric fields of the cavefish would be weaker due to limited food supplies, and another that bet that the electric fields would be stronger, allowing the fish to use their electric signals to see and talk more clearly in the complete darkness of the cave.

"It seems that using their electric sense to detect prey and communicate with each other is quite valuable to these animals; they have greater electric field strengths. Interestingly, our analysis of their electric fields and movement shows that they can communicate at distances of meters, which is quite a long way for fish that are around 10cm in length."

"Nearly all research of cavefish species until now has been limited to behavioral experiments in labs, and that is why this study is special," said Daphne Soares, NJIT associate professor of biology and co-author on the study. "This is the first time we've been able to continuously monitor the behavior of any cavefish in their natural setting over days. We've gained great insight into their nervous system and specialized adaptations for cave life, but it's just as exciting to learn how sociable and chatty they are with each other ... it's like middle school."

Spooky Interactions & Shocking Adaptations

For the investigation, NJIT and Johns Hopkins researchers teamed with biologist Maria Elina Bichuette from the Federal University of São Carlos, who began studying the two groups of fish nearly two decades ago in the remote São Vicente II Cave system of Central Brazil's Upper Tocantins river basin.

Over several days, the team applied a customized electric fish-tracking technique involving placing electrode grids throughout the fishes' water habitats to record and measure the electric fields generated by each fish, allowing the team to analyze the fishes' movements and electricity-based social interactions.

The researchers were able to track more than 1,000 electrical-based social interactions over 20-minute-long recordings taken from both surface and cavefish populations, discovering hundreds of specialized long-distance exchanges.

"When I began studying these fishes, we could watch behavior associated with these fishes' unique and specialized morphology, but in this project, it was fascinating to apply these new technical approaches to reveal just how complex and refined their communication could be," said Bichuette.

"Basically, our evidence shows that the fishes are talking to each other at distance through electricity using a secret hidden channel, amplitude modulations that emerge through the summation of their electric signals. It is not unlike how an AM radio works, which relies on amplitude modulations of a radio signal." said Fortune.

The recordings also showed that strengths of electric discharges in the cavefish were about 1.5 times greater than those of surface fish despite coming at a cost of up to a quarter of their overall energy budget. The team conducted CT scans of both species, showing that the cavefish also possess relatively larger electric organs than their stream-mates, which could explain the source of the cavefishes' extra electrical power.

Another consequence of trading their eyes and surface life for heightened electrosensory perception is that the cavefish were more social and territorial at all hours. Unlike their freely-foraging surface relatives that sleep during the day and forage at night, the cavefish lacked a day-night cycle.

For now, the discovery of the fishes' AM radio-style distant interactions is noted by Fortune as the first of its kind reported among electric cavefish, though he says similar phenomena is now being reported in some other species as well, recently by researchers in Germany who have observed a form of long-distance electrical communication among a group of fish known as Apteronotus. Fortune says the finding could have implications for the field of neurobiology, where weakly electric fish is a unique and powerful model for exploring the nature of the brain-body connection in other animals including humans.

"Electric fish are great systems for understanding the neural basis of behavior, so we have been studying their brains for decades," said Fortune. "These new data are forcing a reexamination of the neural circuits used for the control of behavior of these fishes."

Fishing behavior of Nebraska anglers may be more predictable than previously thought, says a new paper published in the Ecological Society of America's journal Ecological Applications. Seven fishing spots across the state were visited by loyal communities of anglers throughout the year, with little variation from spring to fall in the home ZIP codes of visitors.

"Our original conceptual model was that anglers are highly mobile and dynamic in their behavior," said Mark Kaemingk, an assistant professor of aquatic ecology at the University of North Dakota and the paper's first author. "Our new conceptual model is that anglers, as a whole, could be more predictable than previously thought."

In Nebraska, fishing has an annual economic impact of over one billion dollars, but keeping track of who is fishing where - and how often - is critical for preventing overexploitation of lakes and reservoirs.

The authors had expected that the yearly summertime fishing spike would draw in vacationing families who were willing to travel farther during summer - but were surprised to find that summer anglers were traveling from the same places as those who visited during spring and fall.

The team also found that the pattern held true over the course of the whole four-year study period, with little year-to-year variation in the ZIP codes of angler parties' home residences.

Kaemingk and his colleagues are not sure whether the lakes were being visited by the same anglers repeatedly, or by different groups from the same ZIP codes - say, families with school-aged children during the summer, and retirees from the same town during autumn. But, Kaemingk says, having a big-picture view of anglers' traveling patterns can help natural resource agencies make more well-informed management decisions.

"Our previous research has also highlighted that where anglers reside on the landscape can be used to predict on-site behavior at the waterbody, such as harvest propensity," Kaemingk said.

Changes in participation patterns at a given lake could lead to higher or lower rates of fish harvest over time. This means that data about angler behavior can empower natural resource managers to set regulations that optimize the ecological conditions of a lake as well as creating sustainable fishing experiences for anglers.

The study surveyed anglers at Branched Oak Lake, Calamus Reservoir, Harlan County Reservoir, Lake McConaughy, Merritt Reservoir, Pawnee Lake, and Sherman Reservoir.

Exposure to toxic pollutants associated with human activities may be influencing the spread of infectious diseases in wildlife, according to a new study from the University of Georgia. The findings, just published in the Royal Society journal Biology Letters, have implications for both human health and wildlife conservation.

Researchers led by Cecilia Sánchez, a postdoctoral associate in the Odum School of Ecology, built a mathematical model to explore how toxic substances affect wildlife health and mobility, and how those effects in turn influence wildlife populations and the risk of disease spillover to humans.

"We found that while exposure to infectious agents or contaminants on their own might not have large effects on wildlife populations, the combination of the two can be greater than the sum of the parts," said senior author Richard Hall, a faculty member in the Odum School and College of Veterinary Medicine. "And further, when we start to see wildlife population declines under landscape modification, that could actually be a precursor to increased risk of zoonotic spillover, the chance that these pathogens transmit from wildlife into domestic animals and people."

Human activities like urban, industrial and agricultural development are increasingly altering landscapes across the globe. Among their impacts is the introduction of toxic pollutants including heavy metals and pesticides.

At the same time, these human-altered landscapes often attract wildlife--think of food sources like bird feeders, unsecured dumpsters and farm fields. This not only exposes wildlife to toxic substances, it also exposes people to wildlife and any diseases they may be carrying.

To understand how all these factors interact, the researchers created a mathematical model based on flying foxes infected by a virus. In Australia, several species of these fruit-eating bats have moved into urban areas in growing numbers, attracted by fruiting and flowering trees planted in gardens and parks and in response to the loss of native forest habitat. They are also known to carry viruses harmful to domesticated animals and humans.

For their model, Sánchez and her colleagues simulated a series of landscapes with varying proportions of contaminated versus pristine habitat.

They assumed that in all cases exposure to toxicants reduced both survival and mobility of wildlife, but because these substances can have very different effects on hosts and pathogens, they explored three scenarios for transmission. In one, toxicants reduced pathogen transmission through mechanisms like killing off parasites. In another, toxicants increased pathogen transmission, for instance by suppressing host immune systems. The final scenario assumed that toxicants had no effect on transmission.

For each of the landscapes and scenarios, they started off with a population of 50,000 animals, of which 100 were infected, and ran the model for the equivalent of 50 years. They then noted the resulting wildlife population size, level of infection and risk of spillover to humans.

The results were sometimes surprising.

One unexpected finding was that when there was only little contaminated habitat, the overall wildlife population size remained robust and even increased.

Sánchez explained that in this situation, the contaminated habitat could be acting as a trap for the pathogen. Sick animals that move in to those locations might die there because of the combined effects of contaminants and infection.

"We found that if toxicant-contaminated habitats trap animals in those areas by reducing movement capacity, that can help reduce infection prevalence in the overall population by not allowing sick animals to return to pristine habitats to seed infections there," she said.

When contaminated habitats predominated the landscape, however, the combination of toxicants and infection impacted a much larger number of animals, leading to wildlife population declines.

Increasing the percentage of contaminated habitat also affected spillover risk, which reached its peak when roughly half the landscape was contaminated.

"When wildlife comes into areas where there are lots of domestic animals and humans, that sets the stage for the potential for cross-species transmission," said Hall. "And that can be exacerbated where those areas are toxicant-contaminated. So if we want to reduce spillover risk and reduce negative effects on wildlife, this really points to the importance of restoring pristine or native habitats for these species."

An interdisciplinary team led by Senior Researcher Dr. Christoph Rupprecht (FEAST Project, RIHN) has revealed a new definition of sustainability that expands the concept to non-human species and their needs. With this new definition, published in the journal Global Sustainability, the researchers addressed a critical flaw in the original concept of sustainability that was hindering global transformation efforts. Examples from landscape planning and the Healthy Urban Microbiome Initiative (HUMI) suggest the new multispecies sustainability concept will have wide-ranging applications.

The team of nineteen researchers identified a contradiction at the core of sustainability: its resource management approach ignores that the well-being and needs of all living beings is interdependent in ecologically complex ways. To overcome this critical flaw, they combined recent advances in multispecies ethnography with research by Indigenous scholars and insights from cybernetics. Based on this work, the team formulated a set of six principles and a new concept of multispecies sustainability, defined as meeting the interdependent needs of all species while enhancing the ability of future generations of all species to meet their own needs. The researchers then showcased potential applications that help enable human-wildlife coexistence and radically rethink urban greenspace design based on recent microbiome and public health insights.

"Whether you look at climate change, biodiversity decline or microplastic pollution, sustainability efforts are failing across the board. Researchers pointing to capitalism and arguing for degrowth are not wrong. But radical transformation requires the right tools. Only a concept that understands and fosters complex multispecies relationships can help sustain the well-being of species depending on another, today and tomorrow," argues Christoph Rupprecht, lead author of the study.

An analysis of how the sustainability concept has been visualized in the literature underscores the team's findings. In the sustainability concept, environment, society and economy are given equal weight (Figure 1), despite the latter two depending entirely on the former. In contrast, in the new study, the conceptual models developed by the researchers involve taking a nested approach focused on the interdependence of human, animal, plant and microbial societies (Figure 2). Another model emphasizes how the earth system including landscapes, cities and the bodies of living things is shaped by shared agency (Figure 3).

Rupprecht adds, "Our work would not have been possible without building on Indigenous knowledge. Many best practices have been developed by Indigenous people and are part of traditional ecological knowledge systems. Think about it. Which societies and cultures have the best track records in co-existing with other species?"

The team hopes their findings will be a starting point for exploration and discussion. From questions about what multispecies cities might look like to the implications of a multispecies inspired concept of public health, there may be only few areas where a multispecies approach to sustainability will not bring fundamental changes.

Lead author biography: Dr. Christoph Rupprecht is a geographer with the FEAST Project at the Research Institute for Humanity and Nature, specializing in research on cities from the perspectives of food, agriculture, green space, degrowth and multispecies/more-than-human thinking.

WASHINGTON, December 8, 2020 -- Researchers routinely measure magnetic fields to better understand a vast array of natural phenomena including geological movements, solar flares, neuronal communication in the brain, and molecular-scale chemical processes.

Many state-of-the-art magnetic field measurements are performed in shielded environments with carefully controlled conditions. Yet significant advances in magnetometer sensitivity have also been accompanied by serious attempts to bring these magnetometers into challenging working environments.

In AVS Quantum Science, by AIP Publishing, researchers from the University of Washington, Johannes Gutenberg-Universitat, and the University of California, Berkeley provide an overview of how the research community has achieved these sensitive measurements in extreme environments as well as outside of highly controlled environments. The researchers discuss ways in which various predominantly optically pumped magnetometer technologies have been adapted for use in a wide range of noisy and physically demanding environments.

"You will see some images and discussion of magnetometer deployments that are not commonly seen in standard scientific journal articles," said author Kai-Mei Fu. "We wanted to highlight all the things that can go 'wrong' in order to motivate the deployment of the tools and tricks the community has developed to mitigate these challenges."

While magnetometers with high sensitivity are attractive for measuring minute signals, experimenters must also contend with the environment in which the measurement will be made.

The researchers explore relevant magnetic noise sources that are ubiquitous in the laboratory, field, and urban environments, such as a car passing or an elevator moving. The researchers explore the common techniques to enhance the signal and reduce the noise, shedding light on emerging hybrid sensors in which correlating different sensor modalities may be particularly useful when dealing with challenging environments.

The researchers examine the physical challenges presented in practical, high-sensitivity magnetometry, particularly in one of the major areas of magnetometry, the study of materials. For these studies, sensors must be able to operate in extreme temperatures, from extreme heat to cryogenic cold, and in pressures ranging from very high to very low.

They also explore magnetometry at the cellular level, because significant interest has arisen in the use of magnetometry to study biological processes and biomolecular structures of living organisms, including magnetometry of the brain, nerves, and muscle.

"The current breadth of applications in optically pumped magnetometers is truly vast -- from monitoring magnetic disturbances in near space to detecting neural activity," said Fu. "We hope that this review would provide the reader with a set of general and specific ideas of how to meet various diverse challenges arising in the way of real-life precision magnetic or other measurements."

Most autism spectrum disorders have a complex, multifactorial genetic component, making it difficult to find specific treatments. Rett syndrome is an exception. Babies born with this form of the disorder have mutations specifically in the MECP2 gene, causing a severe impairment in brain development that primarily affects females. Yet there is still no treatment -- current therapies are aimed at alleviating symptoms, but don't address the root cause.

Researchers at University of California San Diego School of Medicine and Sanford Consortium for Regenerative Medicine recently used stem cell-derived brain organoids -- also called "mini-brains" -- that lack the functional MECP2 gene to better study the disease.

In a study publishing December 8, 2020 in EMBO Molecular Medicine, the team identified two drug candidates that counteract the deficiencies caused by lack of the MECP2 gene. These compounds restored calcium levels, neurotransmitter production and electrical impulse activity, returning the Rett syndrome brain organoids to near-normal.

"The gene mutation that causes Rett syndrome was discovered decades ago, but progress on treating it has lagged, at least in part because mouse model studies haven't translated to humans," said senior author Alysson R. Muotri, PhD, professor of pediatrics and cellular and molecular medicine at UC San Diego School of Medicine. "This study was driven by the need for a model that better mimics the human brain."

Brain organoids are 3D cellular models that represent aspects of the human brain in the laboratory. These organoids help researchers track human development, unravel the molecular events that lead to disease and test new treatments. At UC San Diego, brain organoids have been used to produce the first direct experimental proof that the Brazilian Zika virus can cause severe birth defects and to repurpose existing HIV drugs to treat another rare, inherited neurological disorder. Muotri and team also sent their brain organoids to the International Space Station to test microgravity's effect on brain development -- and maybe prospects for human life beyond Earth.

They aren't perfect replicas, of course. Organoids lack connections to other organ systems, like blood vessels. Drugs tested on brain organoids are added directly -- they don't need to get across the blood-brain barrier, specialized blood vessels that keep the brain largely free of bacteria, viruses and toxins.

But researchers find organoids very useful for checking changes in physical structure or gene expression over time or as a result of a gene mutation, virus or drug. What's more, Muotri's team recently optimized the brain organoid-building process to match the electrical impulse pattern of premature babies, making them resemble real human brains more than ever.

In the latest study, the researchers applied this new protocol for functional brain organoids, using induced pluripotent stem cells (iPSCs) derived from patients with Rett syndrome. In short, they collected a skin sample, treated the cells in such a way that converted them to iPSCs, then in a way that coaxed them into becoming brain cells, preserving each patient's unique genetic background. To verify their findings, the team also engineered brain organoids that artificially lack the MECP2 gene, and even mixed mutated and control cells to mimic the mosaic pattern typically seen in female patients.

Lack of the MECP2 gene changed many things about the organoids: shape, neuron subtypes present, gene expression patterns, neurotransmitter production and synapse formation. Calcium activity and electrical impulses were also decreased. These changes led to major defects in the emergence of cortical neural oscillatory waves, aka "brainwaves."

In an attempt to compensate for the missing MECP2 gene, the team treated the brain organoids with 14 drug candidates that are known to affect various brain cell functions. Nearly all of the molecular and cellular symptoms were resolved when the researchers treated the Rett syndrome brain organoids with the two best drug candidates, Nefiracetam and PHA 543613. For example, the number of active neurons in Rett syndrome organoids roughly doubled following treatment. Nefiracetam and PHA 543613 were previously tested in Phase I and II clinical trials for the treatment of other conditions, meaning they are already known to cross the blood-brain barrier and to be safe for human consumption.

According to Muotri, these lab-based results provide a compelling argument for advancing Nefiracetam and PHA 543613 into clinical trials for patients with MECP2-deficient neurodevelopmental disorders.

But in the end, the best treatment for Rett syndrome may not be one "super" drug, he said.

"There's a tendency in the neuroscience field to look for highly specific drugs that hit exact targets, and to use a single drug for a complex disease," said Muotri, who is also director of the UC San Diego Stem Cell Program and a member of the Sanford Consortium for Regenerative Medicine. "But we don't do that for many other complex disorders, where multi-pronged treatments are used. Likewise, here no one target fixed all the problems. We need to start thinking in terms of drug cocktails, as have been successful in treating HIV and cancers."

Is gravity a quantum phenomenon? That has been one of the big outstanding questions in physics for decades. Together with colleagues from the UK, Anupam Mazumdar, a physicist from the University of Groningen, proposed an experiment that could settle the issue. However, it requires studying two very large entangled quantum systems in freefall. In a new paper, which has a third-year Bachelor's student as the first author, Mazumdar presents a way to reduce background noise to make this experiment more manageable.

Three of the four fundamental forces in physics can be described in terms of quantum theory. This is not the case for the fourth force (gravity), which is described by Einstein's theory of general relativity. The experiment that Mazumdar and his colleagues previously designed (1) could prove or disprove the quantum nature of gravity.

Superposition

A well-known consequence of the quantum theory is the phenomenon called quantum superposition: in certain situations, quantum states can have two different values at the same time. Take an electron that is irradiated with laser light. Quantum theory says that it can either absorb or not absorb the photon energy from the light. Absorbing the energy would alter the electron's spin, a magnetic moment that can be either up or down. The result of quantum superposition is that the spin is both up and down.

These quantum effects take place in tiny objects, such as electrons. By targeting an electron in a specially constructed miniature diamond, it is possible to create superposition in a much larger object. The diamond is small enough to sustain this superposition, but also large enough to feel the pull of gravity. This characteristic is what the experiment exploits: placing two of these diamonds next to each other in freefall and, therefore, cancelling out external gravity. This means that they only interact through the gravity between them.

Challenging

And that is where another quantum phenomenon comes in. Quantum entanglement means that when two or more particles are generated in close proximity, their quantum states are linked. In the case of the diamonds, if one is spin up, the other, entangled diamond should be spin down. So, the experiment is designed to determine whether quantum entanglement occurs in the pair during freefall, when the force of the gravity between the diamonds is the only way that they interact.

'However, this experiment is very challenging,' explains Mazumdar. When two objects are very close together, another possible mechanism for interaction is present, the Casimir effect. In a vacuum, two objects can attract each other through this effect. 'The size of the effect is relatively large and to overcome the noise it creates, we would have to use relatively large diamonds.' It was clear from the outset that this noise should be reduced to make the experiment more manageable. Therefore, Mazumdar wanted to know if shielding for the Casimir effect was possible.

Lockdown

He handed the problem to Thomas van de Kamp, a third-year Bachelor's student of Physics. 'He came to me because he was interested in quantum gravity and wanted to do a research project for his Bachelor's thesis,' says Mazumdar. During the spring lockdown, when most normal classes were suspended, Van de Kamp started working on the problem. 'Within a remarkably short time, he presented his solution, which is described in our paper.'

This solution is based on placing a conducting plate of copper, around one millimetre thick, between the two diamonds. The plate shields the Casimir potential between them. Without the plate, this potential would draw the diamonds closer to each other. But with the plate, the diamonds are no longer attracted to each other, but to the plate between them. Mazumdar: 'This removes the interaction between the diamonds through the Casimir effect, and therefore removes a lot of noise from the experiment.'

Remarkable

The calculations performed by Van de Kamp show that the masses of the two diamonds can be reduced by two orders of magnitude. 'It may seem like a small step, but it does make the experiment less demanding.' Furthermore, other parameters such as the level of vacuum needed during the experiment also become less demanding due to the shielding of the Casimir effect. Mazumdar says that a further update on the experiment, which also includes a contribution from Bachelor's student Thomas van de Kamp, will probably appear in the near future. 'So, his six-month project has brought him co-authorship on two papers, quite a remarkable feat.'

In recent years, hydrogen (H2) has emerged as the best option for clean energy in our pursuit of an alternative fuel for mitigating environmental problems such as global warming. Hailed as "batteries of the future," H2 fuel cells are touted as the fuel for the future generation. While this is all well and good, there is one major problem with H2: like every other gas fuel, it is highly explosive. A minor spark can set off an explosion in the presence of as low as 4% of H2 leaked into the air, as had happened in May 2019 in Gangneung, Korea, and June of the same year at the Uno-X fueling station in Norway. Therefore, safety is a major concern with handling of H2 gas; this warrants the sensing of even the smallest H2 leaks to avoid accidents.

While detectors for H2 leaks are available, they require high temperatures to operate (such as the metal-oxide semiconductor-based gas sensors) making them expensive, short-lived, and dangerous to use for detection of an explosive or flammable gas. They also suffer from low sensitivity due to a lack of enough active sites for gas detection (such as zinc oxide [ZnO] "nanosheets"). Scientists, therefore, have been busy developing sensors that can overcome these limitations.

In a new study published in Sensors and Actuators: B. Chemical, a team of scientists from Incheon National University, Korea, have come up with a novel room temperature H2 sensor design that makes use of nanometer-thin "2D" sheets of zinc oxide filled with nanometer-size holes and is aptly named "Holey 2D nanosheets". "Ordinary ZnO nanosheets have low sensitivity due to self-restacking that blocks the active sites for gas detection. Holey 2D nanosheets get around this problem with the holes opening up blocked active surfaces," explains Dr. Manjeet Kumar, who led the study.

The scientists thermally "treated" ZnO nanosheets at three different temperatures (400°C, 600°C, & 800°C) to tune their hole density, fabricated H2 sensor devices from these samples, and recorded their response to different levels of H2 and other gases at 100 ppm (parts per million) gas concentration at room temperature. The team also investigated the validity of the "metallization theory," which suggests that the underlying sensing mechanism is due to a semiconductor-to-metal transition, in which ZnO gets "reduced" to Zn metal under exposure to H2 gas.

They found that the ZnO nanosheet treated at 400°C (ZnO@400), with the maximum number of holes, showed the highest response towards 100 ppm of H2, along with the fastest response time of ~9 s. Furthermore, ZnO@400 also displayed high repeatability and stability of approximately 97-99% after 45 days. Finally, they found the experimental evidence to be in support of the metallization theory.

These results strongly suggest that 2D holey ZnO nanosheets possess remarkable physical/chemical properties that can potentially revolutionize gas sensing performance in the future. Dr. Kumar surmises, "Room temperature H2 sensors will play a key role in future technology, especially with the emergence of Internet of Things. Our holey 2D ZnO-based sensors will enable implementation of innovative H2 detection devices that can detect gas leakage at an early stage and can be integrated with smartphones and smartwatches,"

With a vision of a bright H2-powered future ahead of us, this technology goes a long way in ensuring a "safe" path to materializing this vision!

The first lockdown led to a significant increase in symptoms of depression among children, highlighting the unintended consequences of school closures, according to a new study from the University of Cambridge.

In response to the COVID-19 pandemic, the UK Government implemented a national "lockdown" involving school closures and social distancing. There has been widespread concern that these measures would negatively impact child and adolescent mental health. To date, however, there is relatively little direct evidence of this.

The most direct way of measuring the association between the onset of lockdown and children's mental health is to follow the same individuals over a length of time and look for changes - so-called 'longitudinal' changes.

To test whether changes in emotional wellbeing, anxiety and depression symptoms occurred during lockdown since their initial assessment, a team at the Medical Research Council (MRC) Cognition and Brain Sciences Unit, University of Cambridge, examined data from mental health assessments on 168 children (aged 8-12 years) before and during the UK lockdown. These assessments included self-reports, caregiver-reports, and teacher-reports.

The results of their study are published today in Archives of Disease in Childhood.

Relative to their own pre-pandemic scores, children tended to show more symptoms of depression during lockdown. Even though these symptoms are variable across children, the impact of lockdown can still be seen because the effect size is large. The researchers used the variability in scores to estimate how big an increase this is.

"To give an indication of how large this effect is, imagine ranking the children into 100 'centiles' depending on their scores," explained Dr Duncan Astle from the MRC Cognition and Brain Sciences Unit and senior author of the study. "A child in the 50th centile would be exactly at the middle of the distribution. But a child at this position before the pandemic, could expect to be at the equivalent of the 77th centile during the lockdown.

"Put differently, if you randomly selected a child from the sample there is a 70% chance that their depression symptoms were worse during lockdown than before the pandemic."

"National lockdowns with mass school closures are unprecedented, so going into this crisis, no one could say definitively what impact it would have on children," said Giacomo Bignardi, a PhD student at the MRC Cognition and Brain Sciences Unit.

"Our study is one of the first to follow the same children over time during lockdown and suggests that symptoms of depression among children got much worse during this period. This effect was independent of children's age, gender and family socio-economic status."

The team found only very small and not statistically significant changes in children's scores for emotional problems and anxiety during lockdown.

Dr Astle added: "Childhood is a period where mental health may be particularly vulnerable to reduced peer interaction and loneliness. Now that children have returned to school, their wellbeing, socialisation and enjoyment are crucial. Teachers may need additional resources and training to help them support children with low mood.

"Even before lockdown resources for Child and Adolescent Mental Health Services were stretched thin - and that was against a backdrop of worsening mental health among children. Our findings suggest that lockdown measures will likely exacerbate this. The education sector will bear the initial brunt of this."

The researchers say that how the lockdown measures impact children's mental health may depend on a variety of factors. A recent study found that loneliness in children was associated with subsequent mental health problems, particularly depression. Also, during lockdown children had fewer opportunities to engage in play and other fun activities that help improve mood.

Johns Hopkins researchers have found that more is not always better in the case of vitamin D consumption and seniors' fall risk.

In a study published in the Annals of Internal Medicine on Dec. 8, Lawrence Appel, M.D., M.P.H., director of the Johns Hopkins Welch Center for Prevention, Epidemiology and Clinical Research, and his team determined that large doses of vitamin D supplements were no better at preventing falls in people age 70 and older than a low dose.

The study, funded by the National Institute on Aging, showed that 1,000 or more international units per day (IU/day), equivalent to 25 micrograms/day of vitamin D, were no better than 200 IU/day at preventing falls, a dose about half of the typical amount in multivitamins.

"There's no benefit of higher doses but several signals of potential harm," says Appel, the C. David Molina, M.D., M.P.H. Professor of Medicine with joint appointments in epidemiology, international health and nursing. "A lot of people think if a little bit is helpful, a lot will be better. But for some vitamins, high-dose supplements pose more risks than benefits. There's a real possibility that higher doses of vitamin D increase the risk and severity of falls."

Preliminary studies show that vitamin D may increase muscle strength and improve balance. Appel says in his study, called STURDY [Study To Understand Fall Reduction and Vitamin D in You], vitamin D supplement doses of 2,000 and 4,000 IU/day appeared to increase the risk of falls compared with 1,000 IU/day, a relatively common dose for a pure vitamin D supplement. In addition, serious falls and falls with hospitalization occurred more frequently in persons assigned to 1,000 or more IU/day compared with those assigned to 200 IU/day.

The trial had two phases. During the first phase, known as the dose-finding phase, participants were assigned to one of four doses of supplemental vitamin D: 200 IU/day (the control dose), 1,000 IU/day, 2,000 IU/day and 4,000 IU/day.

In the first phase, the fall rates in the three higher-dose groups were compared to see which of the higher doses had the lowest fall rate. The 1,000 IU/day dose group had a lower fall rate than the 2,000 IU/day and 4,000 IU/day groups, so it was identified in the first phase as the dose to test in the second phase, also called the confirmatory phase.

In the confirmatory phase, the fall rate in the higher-dose group (1,000 IU/day) was compared with the fall rate in the control group (200 IU/day). The team found that 1,000 IU/day of vitamin D was no better than 200 IU/day at preventing falls.

Appel recommends that seniors discuss their fall risk and vitamin D level with their doctors and decide whether or not to continue vitamin D supplements. Appel, along with co-authors Erin Michos, M.D., M.H.S.; Edgar Miller III, M.D., Ph.D; and David Roth, Ph.D., are available for interviews.