Researchers: Let crop residues rot in the field -- it's a climate win

Plant material that lies to rot in soil isn't just valuable as compost. In fact, agricultural crop residue plays a crucial role in sequestering carbon, which is vital for reducing global CO2 emissions.

UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE

Research News

 

For quite some time, farmers and researchers have been focusing on how to bind carbon to soil. Doing so makes food crops more nutritious and increases yields.

However, because carbon is converted into CO2 when it enters the atmosphere, there is a significant climate benefit to capturing carbon in soil as well.

Too much carbon finds its way into the atmosphere. Should we fail to reverse this unfortunate trend, we will fail to achieve the Paris Agreement's goal of reducing greenhouse gas emissions by 40 percent by 2030, according to CONCITO, Denmark's Green Think Tank.

As such, it is important to find new ways of sequestering carbon in soil. This is where a team of researchers from the University of Copenhagen and the Technical University of Munich enter the picture.

In their new study, they argue for the potential of simply allowing agricultural crop residues to rot in fields.

"Fragments of dead plants in soil are often considered as fast food for microbes and fungi. But our study demonstrates that plant residues actually play a more significant role in forming and sequestering carbon in soil than what was once thought," explains Kristina Witzgall, a PhD Candidate at the Technical University of Munich and the study's lead author.

In the past, researchers mainly focused on carbon storage in the surfaces of minerals like clay. However, the new results demonstrate that plant residues themselves have the ability to store carbon, and perhaps for longer than once supposed.

This is because a number of important processes take place directly upon the surface of these plant remains.

"We demonstrate that agricultural crop residues are absolutely central to carbon storage and that we should use them in a much more calculated way in the future. Plant residues make it possible for carbon, in all likelihood, to be stored in soil for roughly four times longer than if they aren't added," states Carsten Müller, the study's co-author and an associate professor at the University of Copenhagen's Department of Geosciences and Natural Resource Management.

Fungi and soil clumps store carbon

To understand how plant residue sequesters carbon, it is important to know that plant tissue already contains carbon absorbed by plants from the atmosphere via photosynthesis. As plant matter rots, carbon can be transferred into the soil in a number of ways.

"Our analysis shows that plant residues, as they interact with fungi, play a surprisingly large role in carbon storage. As fungi fling their white strands around plant fragments, they 'glue' them together with the soil. The fungi then consume the carbon found in the plant matter. In doing so, they store carbon in the soil," explains Carsten Müller.

In addition to fungi, the researchers' analyses also show that the soil structure itself determines the amount of carbon that can be stored.

"When soil is glued together in large hard lumps by the stickiness of bacteria and fungi, plant residues are shielded from being consumed by bacteria and fungi, which would otherwise eat and then emit some of the carbon as CO2 into the atmosphere," says Kristina Witzgall.

She goes on to say that while carbon can be stored in soil from weeks to a thousand years, the usual duration is about 50 years.

Reducing CO2 in the future

The method of leaving crop residues like stalks, stubble and leaves to rot is not unheard of when it comes to enhancing agricultural land.

However, deploying rotten plants as a tool to store carbon should be taken more seriously and considered as a strategy to be expanded, according to the researchers behind the new study.

"The fertile and climate-friendly agricultural lands of the future should use crop residue as a way of sequestering carbon. We will also be conducting experiments where we add rotten plant matter deeper into the soil, which will allow carbon to be stored for even longer periods of time," says Carsten Müller.

If we work to create better conditions for carbon sequestration in soil, we could store between 0.8 and 1.5 gigatonnes of carbon annually. By comparison, the world's population has emitted 4.9 gigatonnes of carbon per year over the past 10 years.

All in all, the researchers' findings can be used to understand the important role and promise of crop residues for carbon storage in the future.

However, Kristina Witzgall goes on to say that a variety of initiatives are needed to increase carbon sequestration, such as crops that can absorb atmospheric carbon and the restoration of lost forests.

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Human environmental genome recovered in the absence of skeletal remains

UNIVERSITY OF VIENNA

Research News

IMAGE: OVERVIEW OF THE EXCAVATION WORKS OF SATSURBLIA CAVE IN 2017. view more 

CREDIT: © ANNA BELFER-COHEN

The cave of Satsurblia was inhabited by humans in different periods of the Paleolithic: Up to date a single human individual dated from 15,000 years ago has been sequenced from that site. No other human remains have been discovered in the older layers of the cave.

The innovative approach used by the international team led by Prof. Ron Pinhasi and Pere Gelabert with Susanna Sawyer of the University of Vienna in collaboration with Pontus Skoglund and Anders Bergström of the Francis Crick Institute in London permits the identification of DNA in samples of environmental material, by applying extensive sequencing and huge data analysis resources. This technique has allowed the recovery of an environmental human genome from the BIII layer of the cave, which is dated before the Ice Age, about 25,000 years ago.

This new approach has evidenced the feasibility of recovering human environmental genomes in the absence of skeletal remains. The analysis of the genetic material has revealed that the SAT29 human environmental genome represents a human extinct lineage that contributed to the present day West-Eurasian populations. To validate the results, the researchers compared the recovered genome with the genetic sequences obtained from bone remains of the nearby cave of Dzudzuana, obtaining definitive evidence of genetic similarities. This fact validate the results and excludes the possibility of modern contamination of the samples.

Along with the identified human genome, other genomes such as wolf and bison have also been recovered from the environmental samples. The sequences have been used to reconstruct the wolf and bison Caucasian population history and will help better understand the population dynamics of these species.

The team now plans to perform further analyses of soil samples from the cave of Satsurbia with the objective of revealing interactions between extinct fauna and humans and the effect of climatic changes on mammalian populations. The ability to recover DNA from soil samples allows us the reconstruction of the evolution of whole past ecosystems .

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Publication in Current Biology: Gelabert et al. 2021. Genome-scale sequencing and analysis of human, wolf and bison DNA from 25,000 year-old sediment. Current Biology. DOI: 10.1016/j.cub.2021.06.023

RUDN University mathematicians calculate the density of 5G stations for any network requirements

RUDN UNIVERSITY

Research News

IMAGE: RUDN UNIVERSITY MATHEMATICIANS HAVE DEVELOPED A MODEL FOR CALCULATING THE DENSITY OF 5G STATIONS NEEDED TO ACHIEVE THE REQUIRED NETWORK PARAMETERS. view more 

CREDIT: RUDN UNVIERSITY

RUDN University mathematicians have developed a model for calculating the density of 5G stations needed to achieve the required network parameters. The results are published in Computer Communications.

Network slicing (NS) is one of the key technologies that the new 5G communication standard relies on. Several virtual networks, or layers, are deployed on the same physical infrastructure (the same base stations). Each layer is allocated to a separate group of users, devices, or applications. To slice the network, one need the NR (New Radio) technology, which operates on millimetre waves. Most of the research in this area is aimed at creating an infrastructure of NR stations that would provide network slicing in each specific case. RUDN University mathematicians have developed a first general theoretical approach that helps to calculate the density of NR base stations needed to slice the network with the specified parameters of the quality of service.

"The concept of network slicing will drastically simplify the market entrance for mobile virtual network operators as well as provisioning of differentiated quality to network services. This functionality is a major paradigm shift in the cellular world enabling multi-layer network structures similar to that of the modern Internet and allowing resource sharing with logical isolation among multiple tenants and/or services in multi-domain context", said Ekaterina Lisovskaya, PhD, junior Researcher at the Research Center for Applied Probability & Stochastic Analysis at RUDN University.

When constructing the algorithm, the RUDN mathematicians used a model city. NR base stations were distributed with some density. The stations had three antennas, each of which covered 120 degrees. Users of devices with 5G cellular communication network operating in the millimetre frequency range (30-100 GHz) were randomly distributed around the city. They moved and could block each other's line-of-sight with the base station. Each antenna had an effective range, where the connection doesn't break even if the line-of-sight is blocked. The RUDN University mathematicians constructed the dependence of the network characteristics on the density of the station location.

To check the accuracy of the constructed model, mathematicians used a computer simulation. The results of theoretical and experimental calculations agreed. The model shows, for example, how the density of the stations affects the regime of network splitting from full isolation to full mixing. The first one assumes that each layer has its own frequency range of a fixed width. In the second regime, the frequencies of the layers are mixed with each other. The second option is more difficult from a technical point of view, but it increases the efficiency of using physical network resources. RUDN University mathematicians have studied these regimes as two boundary versions of the network implementation -- in real life, some intermediate implementation is usually required. It turned out that the difference in the density of stations between these bounds is small -- one station per 10,000 square meters.

"Our numerical evaluation campaign reveals that the full isolation and full mixing systems' operational regime changes rather abruptly with respect to the density of NR BSs. However, the system parameters may drastically affect the required density. Practically, it implies that at the initial market penetration phase, the full isolation strategy can be utilized without compromising the network performance. However, at mature deployment phases, more sophisticated schemes may reduce the capital expenditures of network operators" said Ekaterina Lisovskaya, PhD, junior Researcher at the Research Center for Applied Probability & Stochastic Analysis at RUDN University.

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Humans can learn from animals and insects about impact of climate change

Crucial that we continuously improve our ability to predict and mitigate the effects of climate change

STELLENBOSCH UNIVERSITY

Research News

If we pay closer attention to how birds, rabbits and termites transform their local living spaces in response to varying climate conditions, we could become much better at predicting what impact climate change will have on them in future.

This is according to a group of researchers* from the Universities of Montana and Wyoming in the United States, the University of Tours in France and Stellenbosch University (SU) in South Africa. They examined how animals' ability to respond to climate change likely depends on how well they modify their habitats, such as the way they build nests and burrows.

The findings of their study were published recently in the high-impact journal Trends in Ecology and Evolution.

"It's crucial that we continuously improve our ability to predict and mitigate the effects of climate change. One of the ways we can do this is by gaining a better understanding of how animals influence their own small-scale experience of climate at the level of individual members in a population," says one of the researchers, Prof John Terblanche from SU's Department of Conservation Ecology and Entomology.

Terblanche and his co-authors mention that in order to enhance the predictive power of typical contemporary climate change models, it will be important for biologists to understand how animals transform their living space locally in response to climate variability.

"Improving such models will be key to forecasting the effects of climate change on species, and to predict future effects, including how species ranges may shift and what the relative risks of extinction are for different animal species with high levels of precision."

They add that knowing which species will proliferate with climate change is central to understanding pest outbreaks on crops, or disease vectors changing risks for humans.

"Climate change will impact the spread of disease vectors, the health of marine and terrestrial biomes around the world and will influence whether agriculture and fishing will be able to continue supporting human populations, as they have in the past."

In their study, the researchers point out how some animals have found unique ways to protect themselves against extreme climate conditions.

"Many animals dig burrows, construct nests for themselves or their offspring, build homes for entire colonies (ants and termites), induce plants to produce galls, build leaf mines, or simply modify the structure or texture of their local environments.

"For example, birds build nests to keep eggs and chicks warm during cool weather, but also make adjustments in nest insulation to keep the little ones cool in very hot conditions. Mammals, such as rabbits or mice, sleep or hibernate in underground burrows that provide stable, moderate temperatures and avoid above-ground conditions that often are far more extreme outside the burrow.

"We've also seen how termites and ants build mounds that capture wind and solar energy to drive airflow through the colony, which stabilizes temperature, relative humidity, and oxygen level experienced by the colony."

The researchers say these modifications, known as extended phenotypes, filter climate into local sets of conditions immediately around the organism - 'the microclimate', which is key for a better understanding of the impact of climate change.

"Two features of microclimates are important. First, microclimates typically differ strongly from nearby climates, which means that the climate in an area may provide little information about what animals experience in their microhabitats. Second, because extended phenotypes are built structures, they often are modified in response to local climate variation, and potentially in response to climate change."

The researchers call for a renewed effort to understand how extended phenotypes mediate how organisms experience climate change. "We need a much better understanding of how much animals can adjust these structures in response to varying climate conditions," says Terblanche.

"Another key challenge is to understand how much flexibility there is in extended phenotypes, and how rapidly they can evolve. At this point, we pretty much have no idea whether these processes can keep up with climate change," adds lead author Art Woods from the University of Montana.

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* Source: Woods, HA; Pincebourde, S; Dillon, ME; & Terblanche, JS 2021. Extended phenotypes: buffers or amplifiers of climate change? Trends in Ecology and Evolution: doi.org/10.1016/j.tree.2021.05.010 1

*Art Woods (University of Montana), Sylvain Pincebourde (University of Tours), Michael Dillon (University of Wyoming) and John Terblanche (Stellenbosch University).

 

How more than 30 years of China's 

meteorological satellite data is used

 by the world

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

Research News

IMAGE: THE FENGYUN (FY) METEOROLOGICAL SATELLITES CONTRIBUTE TO EARTH SCIENCE STUDIES, PRODUCING HIGH QUALITY, STABLE DATA THROUGH AN OPEN DATA POLICY. THE COVER SHOWS BOTH GEOSTATIONARY AND POLAR ORBITING FY SATELLITES,... view more 

CREDIT: ADVANCES IN ATMOSPHERIC SCIENCES

China's first meteorological satellite launched in 1988. It was named Fengyun, which roughly translates to "wind and cloud". Since then, 17 more Fengyun meteorological satellites were launched, with seven still in operation, to monitor Earth's wind, clouds and, more recently, extreme weather events such as hurricanes and wildfires. With more than 30 years of Earth observational data freely available to international partners, the Fengyun Meteorological Satellite program works as part of Earth's operational observation system, along with the United States' National Oceanic and Atmospheric Administration satellites and Europe's polar orbiting meteorological satellite series to provide a more complete picture weather events and their global impacts

To highlight the Fengyun satellites' data applications and to encourage further research among domestic and international collaborators, Advances in Atmospheric Sciences published a special issue titled, "Fengyun Meteorological Satellites: Data, Application and Assessment," on 10 July, 2021. It's the first time international communities' evaluation and application of Fengyun satellites are collectively published in a journal.

The special issue is a culmination of research initiated at a 2019 conference for international users to develop a comprehensive, integrated approach for exchanging ideas and promoting global applications of the satellite data, according to the Peng Zhang, the deputy director of the National Satellite Meteorological Center of the China Meteorological Administration. More than 200 people representing more than 30 countries attended. Since then, international users have applied the data in various research projects, and Zhang said the intention is for collaborations to grow as the data capabilities expand.

"In the last decade, great efforts have been made to improve the performance of the satellites and their on-board instrumentation," said Zhang, who organized the special issue. "With extensive, multi-modal observational capabilities on Fengyun satellites, international communities have and will continue to make use of this data."

Such capabilities include image navigation, radiometric calibration, multiband optical imaging, atmospheric sounding, microwave imaging, hyperspectral trace gas detection, full-band radiation budget measuring and more -- in short, an extensive list of ways to monitor weather events and atmospheric changes of Earth. Zhang also co-authored a data description paper, which summarizes not only the data available, but how international users can access it.

The critical factor, Zhang said, is in how these data can be applied. The rest of the special issue features work undertaken in each of the 2019 conference's sections: retrieval algorithms, used to interpret raw data; products validation, which cross-references satellite data with earth-based observations; numerical weather predictions, or how to predict future weather using models of current atmospheric conditions; and climate and environmental predictions, which involves using satellite data to estimate surface effects of atmospheric changes.

On 5 July, Fengyun 3E, the world's first early morning orbit weather satellite was launched, and it will improve global weather forecast by filling in the data gap in a certain time of a day and assist in achieving 100 percent global data coverage every six hours.

"Fengyun satellites will continue to play an important role in Earth sciences in the future, especially as the international community continues to collaborate and apply this data to research that benefits us all," Zhang said. "The new epoch for comprehensive Earth observations has begun."

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Species of algae with three sexes that all mate in pairs identified in Japanese river

Researchers on quest to understand how different sexes first evolved

UNIVERSITY OF TOKYO

 VIDEO: THIS TYPE OF GREEN, FRESHWATER ALGAE LIVE IN COLONIES OF 32 OR 64 CELLS AND CAN REPRODUCE ASEXUALLY OR IN PAIRS SEXUALLY. EXPERTS AT THE UNIVERSITY OF TOKYO STUDYING THE... view more 

CREDIT: VIDEO BY HISAYOSHI NOZAKI, CC BY 4.0

For 30 years, University of Tokyo Associate Professor Hisayoshi Nozaki has traveled an hour west of Tokyo to visit the Sagami River and collect algal samples to understand how living things evolved different sexes. Through new analysis of samples collected in 2007 and 2013 from dam lakes along the river, Lake Sagami and Lake Tsukui, researchers identified a species of freshwater algae that evolved three different sexes, all of which can breed in pairs with each other.

This phenomenon of three sexes is slightly different from hermaphroditism. In species that normally have two sexes, a hermaphroditic individual who can produce both the male and female sex cells usually exists due to unusual gene expression. Many plants and some invertebrate species have three sexes due to normal gene expression, but this is the first time a species of algae or fungi has been identified with three sexes.

The threes sexes of the Pleodorina starrii algae are male, female, and a third sex that researchers call bisexual in reference to the fact that it can produce both male and female sex cells in a single genotype and exists due to normal expression of the species' genes. These algae are 32- or 64-celled organisms and have small mobile (male) and large immobile (female) sex cells.

"It seems very uncommon to find a species with three sexes, but in natural conditions, I think it may not be so rare," said Nozaki, the last author of the research paper published in Evolution.

Evoluntionarily ancient living things have sex cells that are similar in appearance and known as plus or minus, rather than male or female. More recently evolved species usually have dramatic differences between the sex cells, like the large egg and small spermatozoa of humans.

Nozaki and his colleagues are interested in Pleodorina starrii because it and its close evolutionary cousins use different sex systems, so they are useful models to study the genetics of how sex evolved. P. starrii had been identified decades prior, but had not been studied in detail.

In the lab, researchers can watch green P. starrii cells grow in spherical colonies with other individuals of their sex. Male colonies are recognizable by the clear packets of sperm they release into the water. The sperm packets swim until they hit a female colony, then split up into individual sperm cells that enter individual female cells and combine to produce a new generation.

Researchers separate colonies and then deprive them of nutrients to force them to reproduce sexually. In isolation, colonies reproduce asexually, forming cloned colonies of their same genotype. Isolated colonies of one sex can be mixed with isolated colonies of another sex and the ratio of their offsprings' sexes can be useful clues for researchers to understand the genetics of sex determination.

In 2006, Nozaki and other University of Tokyo experts were the first to find a male-specific gene in P. starrii, which they named OTOKOGI, a Japanese word meaning "manly." In 2010, they found a group of female-only genes and named them HIBOTAN, or "scarlet peony," after a 1960s film franchise where the lead female character had a red flower tattoo.

CAPTION

Research students working with Associate Professor Hisayoshi Nozaki collect algae samples in 2013 from the water Lake Sagami on Sagami River, about one hour west of Tokyo.

CREDIT

Image by Hisayoshi Nozaki, CC BY 4.0

After genetic analysis and more mating trials, researchers eventually concluded that P. starrii has a "bisexual-factor" gene that is likely located on a chromosome separate from the OTOKOGI and HIBOTAN sex genes. Cells in genetically bisexual P. starrii possess both OTOKOGI and bisexual-factor genes, but they can produce normal male or female colonies when they reproduce sexually with other P. starrii colonies.

Genetically male P. starrii have only the OTOKOGI male-type gene and genetically female can have either only the female-type HIBOTAN genes or both HIBOTAN and the bisexual-factor genes.

More experiments are needed to understand genes in more detail, but researchers suspect that the bisexual factor may only be active in the presence of the "manly" OTOKOGI.

"This finding was possible because of our very long-term experience of going on field collection trips and our practice growing and studying algae. Continued, long-term studies are very important to unveil the true nature of species in the natural world," Nozaki commented.

CAPTION

Left: Sexually induced male colony of algae. Center: Pleodorina starrii female colony with male sperm packet (arrowhead). Right: Pleodorina starrii female colony with dissociated male gametes (arrowheads). Scale bar = 50 micrometers.

CREDIT

Image by Kohei Takahashi, first published in Evolution DOI: 10.1111/evo.14306

Research Publication

Kohei Takahashi, Hiroko Kawai-Toyooka, Ryo Ootsuki, Takashi Hamaji, Yuki Tsuchikane, Hiroyuki Sekimoto, Tetsuya Higashiyama, and Hisayoshi Nozaki. 12 July 2021. Three sex phenotypes in a haploid algal species give insights into the evolutionary transition to a self-compatible mating system. Evolution. DOI: 10.1111/evo.14306

https://doi.org/10.1111/evo.14306

Related Links

Laboratory of Origin of Eukaryote Biodiversity (Japanese only): http://www.bs.s.u-tokyo.ac.jp/~tayousei/index.html

Department of Biological Sciences: http://www.bs.s.u-tokyo.ac.jp/english/

Graduate School of Science: https://www.s.u-tokyo.ac.jp/en/

About the University of Tokyo

The University of Tokyo is Japan's leading university and one of the world's top research universities. The vast research output of some 6,000 researchers is published in the world's top journals across the arts and sciences. Our vibrant student body of around 15,000 undergraduate and 15,000 graduate students includes over 4,000 international students. Find out more at http://www.u-tokyo.ac.jp/en/ or follow us on Twitter at @UTokyo_News_en.

Funders

Ministry of Education, Culture, Sports, Science and Technology and Japan Society for the Promotion of Science

 

Urban areas with high levels of air pollution may increase risk of childhood obesity

A study of more than 2,000 children in Sabadell (Barcelona, Spain) associates these three environmental factors with higher body mass index

BARCELONA INSTITUTE FOR GLOBAL HEALTH (ISGLOBAL)

Research News

Children living in urban areas with high levels of air pollution, noise and traffic may be at higher risk of childhood obesity, according to a study by the Barcelona Institute for Global Health (ISGlobal)--a centre supported by the "la Caixa" Foundation--and the University Institute for Primary Care Research Jordi Gol (IDIAP Jordi Gol). The study was funded by the La Marató de TV3 Foundation.

Published in Environment International, the study analysed data on 2,213 children aged 9 to 12 years in the city of Sabadell (Barcelona) who were participating in the ECHOCAT and INMA projects. Forty percent of the children were overweight or obese. The researchers investigated the association between urban factors that the children were exposed to between October 2017 and January 2019 (ambient air pollution, green spaces, built environment, density of unhealthy food establishments, road traffic and road traffic noise) and various measures of childhood obesity (body mass index, waist circumference and body fat) and weight-related behaviours (fast food and sugar-sweetened beverage consumption, physical activity, sedentary behaviour, sleep duration and well-being).

To date, few studies have assessed whether the urban environment influences children's behaviours in order to better understand the relationship between this environment and the risk of childhood obesity. An understanding of the mechanisms of this relationship will facilitate the development of community-level health promotion programmes to encourage healthier behaviours in the city. Another novel aspect of this study is that it assessed multiple urban exposures together, in accordance with the concept of exposome or the study of multiple simultaneous environmental factors.

Possible Mechanisms

"Higher levels of air pollution, traffic and noise were associated with higher body mass index and a higher likelihood of the child being overweight or obese," explained lead author Jeroen de Bont, a researcher at ISGlobal and IDIAP Jordi Gol. Although the mechanisms that could explain this association remain unknown, the scientific team proposed various hypotheses. Air pollution could disrupt the molecular mechanisms that cause obesity by inducing inflammation or oxidative stress, hormone disruption and visceral adiposity (although the studies published to date have been performed in mice). Noise could influence sleep deprivation and increase stress hormones, which are associated with physical development in childhood and could increase the risk of becoming overweight.

The findings were consistent with those obtained in the same study when some environmental exposures were analysed separately. In particular, the number of unhealthy food establishments in an area was also found to be associated with childhood obesity, probably because such an environment may favour higher fast food consumption and higher caloric intake.

The study did not, however, find an association between the urban environment and the level of physical activity, sedentary behaviour and other weight-related behaviours in children, although it is thought that such factors could play a role. (For example, in areas with a good public transport network and nearby facilities and shops, journeys tend to be made on foot or by bicycle, which increases children's physical activity.) The fact that the study did not find an association between these factors could be attributed to "the difficulty of determining to what extent obesity itself influences weight-related behaviours," explained de Bont. Moreover, information on children's physical activity was collected using a questionnaire that did not take into account where the activities took place. "We were able to find out if the children played basketball or football, but not if they cycled in nearby green spaces, for example," he added.

Finally, "socioeconomic status plays an important role in the association between the urban environment and childhood obesity that is not yet clear," commented last author Martine Vrijheid, a researcher at ISGlobal. In this study, children living in more deprived areas on the outskirts of the city had higher rates of overweight and obesity even though they were exposed to lower levels of air pollution, road traffic and noise and had access to more green spaces. Further research is needed to shed light on this issue.

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Reference

Jeroen de Bont, Sandra Márquez, Sílvia Fernández-Barrés, Charline Warembourg, Sarah Koch, Cecilia Persavento, Silvia Fochs, Núria Pey, Montserrat de Castro, Serena Fossati, Mark Nieuwenhuijsen, Xavier Basagaña, Maribel Casas, Talita Duarte-Salles, Martine Vrijheid. Urban environment and obesity and weight-related behaviours in primary school children. Environment International. Volume 155, 2021. https://doi.org/10.1016/j.envint.2021.106700.

 

India national school meal program linked to improved growth in children of beneficiaries

Benefits for next generation demonstrate long term positives of nutrition programs

INTERNATIONAL FOOD POLICY RESEARCH INSTITUTE

Research News

July 12, New Delhi - Women who received free meals in primary school have children with improved linear growth, according to a new study by researchers at the International Food Policy Research Institute (IFPRI).

India is home to the highest number of undernourished children and the largest school feeding program in the world--the Mid-Day Meal (MDM) scheme--yet long-term program benefits on nutrition are unknown. As school feeding programs target children outside the highest-return "first 1000-days" window spanning from conception until a child's second birthday, they have not been a focal point in the global agenda to address stunting. School meals benefit education and nutrition in participants, but no studies have examined whether benefits carry over to their children.

"Findings from previous evaluations of India's MDM scheme have shown a positive association with beneficiaries' school attendance, learning achievement, hunger and protein-energy malnutrition, and resilience to health shocks such as drought--all of which may have carryover benefits to children born to mothers who participated in the program," says study co-author, Harold Alderman.

The study, "Intergenerational nutrition benefits of India's national school feeding program", co-authored by University of Washington's Suman Chakrabarti and IFPRI's Samuel Scott, Harold Alderman, Purnima Menon and Daniel Gilligan, was published in Nature Communications. The authors used nationally representative data on mothers and their children spanning 1993 to 2016 to assess whether MDM supports intergenerational improvements in child linear growth. Further, they suggest a potential pathway through which school feeding programs may have intergenerational effects on child nutrition outcomes.

The study found that investments made in school meals in previous decades were associated with improvements in future child linear growth. "Our findings suggest that intervening during the primary school years can make important contributions to reducing future child stunting, particularly given the cumulative exposure that is possible through school feeding programs," explains study co-author Suman Chakrabarti.

Study results also show that school meals may contribute to education, later fertility decisions, and access to health care, reducing the risk of undernutrition in the next generation. "School feeding programs such as India's MDM scheme have the potential for stimulating population-level stunting reduction as they are implemented at scale and target multiple underlying determinants of undernutrition in vulnerable groups," explains study co-author Samuel Scott. Importantly, further research is required to understand whether improving the quality or quantity of meals provided and extending the program beyond primary school might further enhance its benefits.

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The International Food Policy Research Institute (IFPRI) seeks sustainable solutions for ending hunger and poverty. IFPRI was established in 1975 to identify and analyze alternative national and international strategies and policies for meeting the food needs of the developing world, with particular emphasis on low-income countries and on the poorer groups in those countries Visit: http://www.ifpri.org

New research reveals how the impact of ENSO on Asian-Western Pacific climate would change under global warming

INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

Research News

IMAGE: SCHEMATIC ILLUSTRATES THE RELATIVE CONTRIBUTIONS OF CHANGE IN DIFFERENT EL NINO CHARACTERISTICS (I.E. AMPLITUDE AND DECAYING PACE) TO THE TOTAL UNCERTAINTIES OF THE WESTERN NORTH PACIFIC ANOMALOUS ANTICYCLONE (WNPAC) PROJECTION.... view more 

CREDIT: MINGNA WU

The impact of El Nino on East Asian climate under a warmer climate will be dominated by the change in El Nino decaying pace, according to a new paper published by a research team based in the Institute of Atmospheric Physics, Chinese Academy of Sciences, China.

The western North Pacific anomalous anticyclone (WNPAC) is a low-level atmospheric circulation system, linking up El Nino events with East Asian -western Pacific summer climate. The WNPAC can persist from El Nino mature phase in boreal winter to the upcoming summer, bringing abundant moisture to enhance the precipitation over East Asia. How the WNPAC will change in the future concerns millions of people living in the East Asian -western Pacific region, but the future change in the WNPAC under global warming is highly uncertain across climate models.

The study, which appears in Journal of Climate online on 5th June, found that about 23% of the uncertainty in WNPAC projection is attributed to the El Nino amplitude change while the rest 77% is from non-amplitude change which is mainly related to the change in El Nino decaying pace, according to Tianjun Zhou, the corresponding author of the paper.

Zhou is a senior scientist at the Institute of Atmospheric Physics in the Chinese Academy of Sciences. He is also a professor at the University of Chinese Academy of Sciences (UCAS).

"To separately quantify the contributions of El Nino amplitude change and non-amplitude change from the total uncertainties, we have developed a new decomposition method. This decomposition method is based on large ensemble climate simulation. We have used the output of 40-member large ensemble from the Community Earth System Model Large Ensemble project", said Mingna Wu, the first author of the study, who is a Ph. D student from the UCAS.

"A larger El Nino amplitude can enhance the WNPAC through a stronger tropical Indian Ocean capacitor effect under a warmer climate, while a faster El Nino decaying pace can also enhance the WNPAC through descending Rossby waves in response to colder than normal sea surface temperature over the tropical central-eastern Pacific, and vice versa", explained Dr. Xiaolong Chen, co-author of the study, and an associated professor at the Institute of Atmospheric Physics, Chinese Academy of Sciences.

"In addition to El Nino amplitude, more attention should be paid to the influence of other El Nino characteristics (i.e. El Nino decaying pace) in climate system. Our decomposition method can be used to diagnose the origin of uncertainty related to El Nino in climate projections, as well as the relevant mechanisms." Highlighted Wu.

SCIENCE FAIR PROJECT

Danish student solves how the Universe is reflected near black holes

UNIVERSITY OF COPENHAGEN - FACULTY OF SCIENCE

Research News

IMAGE: A DISK OF GLOWING GAS SWIRLS INTO THE BLACK HOLE "GARGANTUA " FROM THE MOVIE INTERSTELLAR. BECAUSE SPACE CURVES AROUND THE BLACK HOLE, IT IS POSSIBLE TO LOOK ROUND ITS FAR... view more 

CREDIT: CREDIT: INTERSTELLAR.WIKI/CC BY-NC LICENSE.

In the vicinity of black holes, space is so warped that even light rays may curve around them several times. This phenomenon may enable us to see multiple versions of the same thing. While this has been known for decades, only now do we have an exact, mathematical expression, thanks to Albert Sneppen, student at the Niels Bohr Institute. The result, which even is more useful in realistic black holes, has just been published in the journal Scientific Reports.

You have probably heard of black holes -- the marvelous lumps of gravity from which not even light can escape. You may also have heard that space itself and even time behave oddly near black holes; space is warped.

In the vicinity of a black hole, space curves so much that light rays are deflected, and very nearby light can be deflected so much that it travels several times around the black hole. Hence, when we observe a distant background galaxy (or some other celestial body), we may be lucky to see the same image of the galaxy multiple times, albeit more and more distorted.

Galaxies in multiple versions

The mechanism is shown on the figure below: A distant galaxy shines in all directions -- some of its light comes close to the black hole and is lightly deflected; some light comes even closer and circumvolves the hole a single time before escaping down to us, and so on. Looking near the black hole, we see more and more versions of the same galaxy, the closer to the edge of the hole we are looking.

How much closer to the black hole do you have to look from one image to see the next image? The result has been known for over 40 years, and is some 500 times (for the math aficionados, it is more accurately the "exponential function of two pi", written e2π).

Calculating this is so complicated that, until recently, we had not yet developed a mathematical and physical intuition as to why it happens to be this exact factor. But using some clever, mathematical tricks, master's student Albert Sneppen from the Cosmic Dawn Center -- a basic research center under both the Niels Bohr Institute and DTU Space -- has now succeeded in proving why.

"There is something fantastically beautiful in now understanding why the images repeat themselves in such an elegant way. On top of that, it provides new opportunities to test our understanding of gravity and black holes," Albert Sneppen clarifies.

Proving something mathematically is not only satisfying in itself; indeed, it brings us closer to an understanding of this marvelous phenomenon. The factor "500" follows directly from how black holes and gravity work, so the repetitions of the images now become a way to examine and test gravity.

CAPTION

Light from the background galaxy circles a black hole an increasing number of times, the closer it passes the hole, and we therefore see the same galaxy in several directions

CREDIT

credit: Peter Laursen.

Spinning black holes

As a completely new feature, Sneppen's method can also be generalized to apply not only to "trivial" black holes, but also to black holes that rotate. Which, in fact, they all do.

"It turns out that when the it rotates really fast, you no longer have to get closer to the black hole by a factor 500, but significantly less. In fact, each image is now only 50, or 5, or even down to just 2 times closer to the edge of the black hole", explains Albert Sneppen.

Having to look 500 times closer to the black hole for each new image, means that the images are quickly "squeezed" into one annular image, as seen in the figure on the right. In practice, the many images will be difficult to observe. But when black holes rotate, there is more room for the "extra" images, so we can hope to confirm the theory observationally in a not-too-distant future. In this way, we can learn about not just black holes, but also the galaxies behind them:

The travel time of the light increases, the more times it has to go around the black hole, so the images become increasingly "delayed". If, for example, a star explodes as a supernova in a background galaxy, one would be able to see this explosion again and again.

CAPTION

The situation seen "face-on", i.e. how we would actually observe it from Earth. The extra images of the galaxy become increasingly squeezed and distorted, the closer we look at the black hole.

CREDIT

credit: Peter Laursen.