Earth

It's important to communicate about hard-to-see and complex environmental topics and issues with young people. In an article published in People and Nature, an international team reflects on the group's creation of the Shout Trout Workout, a lyric poem, comic, and music video for children aged 8-14 years old designed to entertain, engage, and enrich learning about migratory fishes and aquatic environments.

The authors hope that sharing their experiences and reflections will be useful and inspiring for those who aim to create learning enrichment and engagement materials about ecological processes and environmental issues for young people.

"We wanted to share about fish migration in an educational and informative way and think we achieved this through our interdisciplinary collaboration with passionate creatives and academics," said lead author Merryn Thomas, PhD, of the Freshwater Interdisciplinary Research and Engagement (FIRE) Lab at Swansea University, in the UK. "We also learned a lot about co-creation along the way, which we hope will be useful for others who are interested in collaborating across boundaries to design inspiring engagement materials for young people about our natural environments."

Results from a study published in Ibis show that how close Golden Eagles will fly to wind turbines depends on habitat suitability inside and outside of a wind farm. Also, the largest impact of wind farms was a loss of Golden Eagle habitat, which could be mitigated by including the study's findings in wind farm planning.

The study included data from 59 GPS-tagged Golden Eagles before and after turbine operation at 80 wind farms across Scotland.

"Previous research on Golden Eagles, notably in the United States, has tended towards collision with turbine blades as the main consequence of their interaction with wind farms. Our study shows that across numerous wind farms in Scotland, this was not the case, but that deleterious habitat loss through avoidance of turbines was the main impact," said corresponding author D. Philip Whitfield, PhD, of Natural Research Ltd, in the UK.

A relaxing vacation on the beach frees us from many of the worries of everyday life. But the sand not only cleans the head and soul of vacationers - it also cleans the seawater.

Coastal sands are so-called biocatalytic filters. Hundreds of thousands of bacteria live on each grain of sand, and they process, for example, nitrogen and carbon from the seawater that flows through the sands. In this way, the sands act like giant, purifying filters. Much of what the seawater washes into the ground does not come out again.

A study by researchers at the Max Planck Institute for Marine Microbiology in Bremen, Germany, published in the journal ISME Communications, now shows that the bacteria living on the sand are very different from the ones in seawater. And while the bacterial community in the water is constantly changing and adapting with the changing seasons, the sand bacteria are rather indifferent to spring, summer, fall and winter.

Stable in number and type

The team led by Katrin Knittel and Sebastian Miksch from the Max Planck Institute in Bremen studied the sand bacteria in the North Sea off Helgoland and in the Arctic near Spitsbergen, where there is no primary production at all during the polar night. "Both the number and the type of bacteria were surprisingly stable," reports Miksch, who conducted the study as part of his doctoral thesis. "Actinobacteria of the orders Actinomarinales and Microtrichales were particularly numerous and also particularly active. They probably play a prominent role in the turnover of organic material in these coastal areas." While the respective proportions of these two groups differ significantly between the studied sites in Helgoland and Svalbard, in themselves they hardly change.

All booked on the sand grain

"We were very surprised to see such a different pattern in the seafloor than in the water where microbial communities show a pronounced seasonality," Katrin Knittel explains. The spots on the sand grains that are well-protected from friction and predators are densely populated with bacteria while exposed spots show a low population density. The researchers therefore suspect that there is simply no habitable space for new, different inhabitants. "All the apartments are already occupied, so to speak. New tenants who could change the community simply can't find a sheltered place - or at least not in large numbers," Knittel adds.

But do bacteria really not care about the season as well as polar night and day? "We now want to go a step further, and look inside the bacteria. The bacteria remain the same, but over the seasons, perhaps the activity of different enzymes changes because different food arrives at the bottom."

The remains of microscopic plankton blooms in near-shore ocean environments slowly sink to the seafloor, setting off processes that forever alter an important record of Earth's history, according to research from geoscientists, including David Fike at Washington University in St. Louis.

Fike is co-author of a new study published July 20 in Nature Communications.

"Our previous work identified the role that changing sedimentation rates had on local versus global controls on geochemical signatures that we use to reconstruct environmental change," said Fike, professor of earth and planetary sciences and director of environmental studies in Arts & Sciences.

"In this study, we investigated organic carbon loading, or how much organic matter -- which drives subsequent microbial activity in the sediments -- is delivered to the seafloor," Fike said. "We are able to show that this, too, plays a critical role in regulating the types of signals that get preserved in sediments.

"We need to be aware of this when trying to extract records of past 'global' environmental change," he said.

Scientists have long used information from sediments at the bottom of the ocean -- layers of rock and microbial muck -- to reconstruct the conditions in oceans of the past.

A critical challenge in understanding Earth's surface evolution is differentiating between signals preserved in the sedimentary record that reflect global processes, such as the evolution of ocean chemistry, and those that are local, representing the depositional environment and the burial history of the sediments.

The new study is based on analyses of a mineral called pyrite (FeS2) that is formed in marine sediments influenced by bacterial activity. The scientists examined concentrations of carbon, nitrogen and sulfur and stable isotopes of glacial-interglacial sediments on the seafloor along the continental margin off of modern-day Peru.

Varying rates of microbial metabolic activity, regulated by regional oceanographic variations in oxygen availability and the flux of sinking organic matter, appear to have driven the observed pyrite sulfur variability on the Peruvian margin, the scientists discovered.

The study was led by Virgil Pasquier, a postdoctoral fellow at the Weizmann Institute of Sciences in Israel, and co-authored by Itay Halevy, also of the Weizmann Institute. Pasquier previously worked with Fike at Washington University. Together, the collaborators have raised concerns about the common use of pyrite sulfur isotopes to reconstruct Earth's evolving oxidation state.

"We seek to understand how Earth's surface environment has changed over time," said Fike, who also serves as director of Washington University's International Center for Energy, Environment and Sustainability. "In order to do this, it's critical to understand the kinds of processes that can influence the records we use for these reconstructions."

"In this study, we have identified an important factor -- local organic carbon delivery to the seafloor -- that modifies the geochemical signatures preserved in sedimentary pyrite records," he said. "It overprints potential records of global biogeochemical cycling with information about changes in the local environment.

"This observation provides a new window to reconstruct past local environmental conditions, which is quite exciting," Fike said.

Metabolic bone diseases, including osteoporosis, when bones lose their mass and become so fragile that they could be damaged while sneezing or under little stress, are called the silent epidemic of the 21st century. A person does not even know about his illness before the first symptom - it can be a fracture of the spine or the neck of the hip. According to statistics, every third woman and every fifth man after 50 have osteoporosis. Thus, it is promising to search for and obtain substances and materials for implants that have osteoinductive properties and are capable of initiating the processes of transformation of stem cells into bone.

Certain trace elements, such as calcium and magnesium, influence the processes of bone regeneration and the maintenance of their normal structure. Organic molecules that can bind to them provide an improvement in the selectivity of their therapeutic action - the resulting complexes play a significant role in bone formation and development. From this point of view, salts of chelidonic acid have great potential, for example, from the Saussurea controversa known since ancient times for its healing properties.

The group of scientists from the Immanuel Kant Baltic Federal University, Siberian State Medical University, and Tomsk Polytechnic University has previously discovered that calcium chelidonate is promising for engineering as a drug for restoring lost bone volume. In their latest work, they obtained this substance in a semisynthetic way: extracts from Saussurea controversa were the source of the chelidonic acid, to which an alkali solution and calcium chloride were added.

"The content of this substance differs in the samples of raw material and, most likely, its biosynthesis depends on the amount of calcium in the soil. For pharmaceutical purposes, it is advisable to use calcium chelidonate obtained by a semisynthetic method," explains Elena Avdeeva, candidate of pharmaceutical sciences, a researcher at the Siberian State Medical University.

Scientists from the Institute of Organic Chemistry carried out an X-ray analysis and confirmed that the substance has a structure identical to a natural compound.

Researchers from the Center for Immunology and Cellular Biotechnologies of the IKBFU, together with scientists from the Siberian State Medical University, tested the effect of the substance in vitro and in vivo: it promoted the conversion of human stem cells derived from adipose tissue (hAMMSC) and mouse mesenchymal stromal cells into osteoblasts respectively. Calcium chelidonate is non-toxic and promotes bone regeneration: the results of in vitro studies have shown that a dose of only 10 mg / L statistically increases the number of viable stem cells compared to the control without this substance. The calcium phosphate-coated titanium implants bearing autologous bone marrow were introduced into mice. Calcium chelidonate stimulated the growth of new bone on the surface of the implant with daily administration of the drug for 35 days.

"The use of substances with osteoprotective properties, in particular, calcium chelidonate, is promising for the treatment of several diseases associated with bone defects or bone metabolism disorders. We are considering the development of a pharmaceutical form of the substance and its introduction into practical medicine," concludes Larisa Litvinova, Doctor of Medicine, professor, head of the laboratory of immunology and cellular biotechnology at the IKBFU.

Spider silk is said to be one of the strongest, toughest materials on the Earth. Now engineers at Washington University in St. Louis have designed amyloid silk hybrid proteins and produced them in engineered bacteria. The resulting fibers are stronger and tougher than some natural spider silks.

Their research was published in the journal ACS Nano.

To be precise, the artificial silk -- dubbed "polymeric amyloid" fiber -- was not technically produced by researchers, but by bacteria that were genetically engineered in the lab of Fuzhong Zhang, a professor in the Department of Energy, Environmental & Chemical Engineering in the McKelvey School of Engineering.

Zhang has worked with spider silk before. In 2018, his lab engineered bacteria that produced a recombinant spider silk with performance on par with its natural counterparts in all of the important mechanical properties.

"After our previous work, I wondered if we could create something better than spider silk using our synthetic biology platform," Zhang said.

The research team, which includes first author Jingyao Li, a PhD student in Zhang's lab, modified the amino acid sequence of spider silk proteins to introduce new properties, while keeping some of the attractive features of spider silk.

A problem associated with recombinant spider silk fiber -- without significant modification from natural spider silk sequence -- is the need to create β-nanocrystals, a main component of natural spider silk, which contributes to its strength. "Spiders have figured out how to spin fibers with a desirable amount of nanocrystals," Zhang said. "But when humans use artificial spinning processes, the amount of nanocrystals in a synthetic silk fiber is often lower than its natural counterpart."

To solve this problem, the team redesigned the silk sequence by introducing amyloid sequences that have high tendency to form β-nanocrystals. They created different polymeric amyloid proteins using three well-studied amyloid sequences as representatives. The resulting proteins had less repetitive amino acid sequences than spider silk, making them easier to be produced by engineered bacteria. Ultimately, the bacteria produced a hybrid polymeric amyloid protein with 128 repeating units. Recombinant expression of spider silk protein with similar repeating units has proven to be difficult.

The longer the protein, the stronger and tougher the resulting fiber. The 128-repeat proteins resulted in a fiber with gigapascal strength (a measure of how much force is needed to break a fiber of fixed diameter), which is stronger than common steel. The fibers' toughness (a measure of how much energy is needed to break a fiber) is higher than Kevlar and all previous recombinant silk fibers. Its strength and toughness are even higher than some reported natural spider silk fibers.

In collaboration with Young- Shin Jun, professor in the Department of Energy, Environmental & Chemical Engineering, and her PhD student Yaguang Zhu, the team confirmed that the high mechanical properties of the polymeric amyloid fibers indeed come from the enhanced amount of β-nanocrystals.

These new proteins and the resulting fibers are not the end of the story for high-performance synthetic fibers in the Zhang lab. They are just getting started. "This demonstrates that we can engineer biology to produce materials that beat the best material in nature," Zhang said.

In an article published in the American Journal of Kidney Diseases (AJKD), researchers found that among 176 studies on acute kidney injury, the Kidney Disease Improving Global Outcomes (KDIGO) definitions of kidney injury were inconsistently applied and 80% of studies did not define recovery of kidney function.

The KDIGO definition of AKI is used in both clinical practice and in research. This scoping review demonstrated that there is a wide variation of practice in how this definition is applied and also a lack of transparency about how researchers applied it. An international panel of experts in AKI was formed in an attempt to achieve consensus on how this definition should be applied. They participated in a Delphi process and while they were able to agree on some aspects of how the definition should be implemented, there were many areas in which no agreement could be reached. Dr Guthrie and his coauthors recommend that researchers clearly state how they applied the KDIGO definition for AKI when basing it absence or presence on healthcare data.

Millions of people in countries around the world could face an increased risk of malnutrition as climate change threatens their local fisheries.

New projections examining more than 800 fish species in more than 157 countries have revealed how two major, and growing, pressures - climate change and over-fishing - could impact the availability of vital micronutrients from our oceans.

As well as omega-3 fatty acids, fish are an important source of iron, zinc, calcium, and vitamin A. A lack of these vital micronutrients is linked to conditions such as maternal mortality, stunted growth, and pre-eclampsia.

Analyses by an international team from the UK and Canada and led by scientists from Lancaster University reveal that climate change is the most pervasive threat to the supply of essential micronutrients from marine fish catches, and threatens the supply of vital micronutrients from fisheries in 40 per cent of countries. Fisheries micronutrient supplies were found to be less vulnerable to overfishing.

Countries among those whose fisheries micronutrient sources are at risk from climate change tend to be tropical nations and include East Asian and Pacific countries such as Malaysia, Cambodia, Indonesia, and Timor Leste, as well as Sub-Saharan African countries such as Mozambique and Sierra Leone.

This vulnerability to climate change for these nations' fisheries is particularly acute given dietary deficiencies in calcium, iron, zinc, and vitamin A are particularly prevalent in the tropics. And these tropical countries are also less resilient to disruptions of their fisheries by climate change because they strongly rely on fisheries to support their national economies and their population's diets and have limited societal capacity to adapt.

The study, which is outlined in the paper 'Micronutrient supply from global marine fisheries under climate change and overfishing', is published today by Current Biology.

Previous studies, most notably research into the micronutrient content of fish, which was led by Professor Christina Hicks and published by Nature, showed that fish are unequal when it comes to their nutritional content. A range of factors, such as diet, sea water temperature and energetic expenditure influence the amount of micronutrients that fish contain. Tropical fish tend to be richer in micronutrients than cold water species.

When it comes to resilience to climate change and fishing, again not all fish are equal. Earlier studies by Professor William Cheung and colleagues have shown large fish species that have a small range tend to be more vulnerable to climate change. While species that take longer to reach maturity and grow slower, are more vulnerable to fishing - because it takes longer for their stocks to replenish.

Their findings show only a weak link between the micronutrient density of an individual fish species' and its vulnerability to climate change or overfishing.

However, when the scientists looked at countries' overall fisheries catches then their findings revealed a clear impact from climate change on the overall availability of micronutrients for around 40 per cent of nations - threatening the food security of millions of people living in these countries.

A key reason for why climate change is such a threat comes down to the species of fish that the countries are targeting as part of their catches.

Some tropical nations' fishers are targeting micronutrient-dense species that have an increased vulnerability to climate change, such as Indian and short mackerels (Rastrelliger kanagurta and Rastrelliger brachysoma), bonga and hilsa shads (Ethmalosa fimbriata and Tenualosa ilisha) and dolphinfish (Coryphaena hippurus).

However, there is a silver-lining to the study's findings which offers some hope for the future. Some countries may be able to adapt their fisheries to switch from vulnerable species and instead target alternative micronutrient-rich species that are also resilient to both climate change and overfishing, but which are currently under-represented within catches.

Dr Eva Maire, of Lancaster University and Lead author of the study, said: "As climate change and over-fishing are significant and growing pressures on global fish stocks, it is essential for the dietary requirements of millions of people to know the extent that these pressures will have on the availability of micronutrients in our seas in the future.

"We have shown that climate change is the most pervasive threat to the supply of vital micronutrients for many countries around the world, and in particular in the tropics.

This study draws on the 'FishNutrients' model, a recently released finfish nutrient composition database.

"These data open up a whole new area of research and are crucial to address global food security challenges" said co-author Aaron MacNeil, Associate Professor in the Ocean Frontier Institute at Dalhousie University. "Our research highlights that efforts to improve food security and to tackle malnutrition there is a need to integrate fisheries, climate and food policies to secure these micronutrients for existing and future generations."

Professor William Cheung, co-author from the University of British Columbia, said: "As well as highlighting the growing threat of climate change to the food security of millions of people, our study also offers hope for the future. Armed with nutritional information about different fish species, many countries have the capacity to adapt their fisheries policies to target different more resilient fish species. By doing this then these nations can ensure a more reliable supply of micronutrients for their people."

An international group of researchers representing thousands of coral scientists across the globe is calling for new commitments and actions by the world's policymakers to protect and restore coral reefs.

In a paper presented July 20 at the International Coral Reef Symposium, the scientists said that the coming decade will likely offer the last chance for policymakers at all levels to prevent coral reefs "from heading towards world-wide collapse."

The paper, developed by the International Coral Reef Society, pushes for three strategies to save the reefs: addressing climate change, improving local conditions and actively restoring coral.

"The model projections show that up to 30% of coral reefs will persist through this century if we limit global warming to 1.5 degrees Celsius," said Andréa Grottoli, distinguished professor of earth sciences at The Ohio State University, society president and a contributing author of the paper.

"But if we are to limit warming to 1.5 degrees, we have to do it now: The science and the models show that we have only a few years left to reduce carbon dioxide emissions that put us on that path. It has to happen this decade, or we won't make that target."

Coral reefs are at an inflection point, the researchers say. Stop climate change now - and start to reverse it - and some reefs might survive, with the possibility that they could be rebuilt in the future and provide the seeds to regrow damaged reefs elsewhere.

"From a coral reef perspective, we go from 30% of reefs surviving to only a few percent surviving if we don't act now," Grottoli said. "We are already faced with a grand challenge in trying to restore the reefs. Once we do eventually reduce carbon dioxide emissions and the planet is no longer warming at an accelerated rate, trying to restore from just a few percent is much more difficult."

This year, policymakers from around the world will create updated global frameworks for addressing both of those crises, via the upcoming Conference of the Parties to the United Nations Framework Convention on Climate Change (COP26) and the Conference of the Parties to the Convention on Biological Diversity (COP15). Grottoli said the society created its policy paper to influence those frameworks.

The society's paper makes three asks of policymakers:

Commit to addressing biodiversity loss and the effect climate change has had on coral reefs, ensure policies are ambitious enough to address those crises, and ensure that policies are implemented.

Build coordinated actions across related policy fields at all levels of governance, from local councils to international bodies. This includes efforts in conservation, management and restoration, as well as policies that address climate change adaptation, biodiversity and sustainable development.

Innovate new approaches to help coral adapt to climate change. Global warming is here, and adaptation is unavoidable. A small percentage of reefs and some coral species have been successfully managed. "Studies of these 'bright spots' provide important lessons to guide future actions, such as how local community participation can improve management outcomes," the scientists wrote.

"As bad as climate change has been for the last decades, we also have lost vast amounts of coral reefs through overfishing, pollution and other local actions, and we need to tackle both of those fronts simultaneously," said Nancy Knowlton, lead author of the paper and Sant Chair for Marine Science Emerita at the Smithsonian Institution's National Museum of Natural History.

"Climate change is important but it's important that these other things aren't neglected. There's no time for arguing about which is most important; we need to do all of them."

Coral reefs are crucial ecosystems, housing about a third of the known ocean species despite covering less than 0.1% of the world's oceans. They are also critical for local food supplies and economies. Reef-related tourism alone generates some $36 billion per year and the global economic value of reefs across all sectors approaches $10 trillion per year.

They are sources for important biochemical compounds, including drugs that treat cancer.

And they protect coasts from storm flooding: A healthy reef can break waves and buffer more than 90% of incoming wave height and energy. In the United States and its territories alone, according to the ICRS paper, the annual value of flood risk reduction provided by coral reefs is more than 18,000 lives affected by flooding and $1.8 billion. Without reefs, researchers have estimated that annual flood damage would more than double, and that flooding would increase by 69%.

But reefs are particularly susceptible to the negative effects of climate change, which causes ocean temperatures to increase and ocean waters to acidify. Those environmental changes can cause coral to bleach, stop growing and die.

"The window for opportunities to act both on coral reef adaptation and on climate change mitigation will soon close for good," said David Obura, contributing author to the paper and director of CORDIO East Africa, a nonprofit research organization focused on coral reefs and sustainability in Africa. "We need a massive increase in commitment now and even more in coming years, coherence across all scales and jurisdictions, and innovation - new mindsets, approaches and techniques. More than anything we need everyone to act, including us scientists by providing our approaches and knowledge, to do our part in saving coral reefs."

The female tsetse fly, which gives birth to adult-sized live young, produce weaker offspring as they get older, and when they feed on poor quality blood.

The study, carried out by researchers at the Universities of Bristol, Oxford and the Liverpool School of Tropical Medicine, was designed to measure how tsetse offspring health is influenced by their mothers' age, and how factors such as the mother's nutrition and mating experience might come into play.

In many animals, females show signs of reproductive ageing - where offspring health declines with maternal age - but there is huge variation within species in how rapidly this ageing occurs.

Scientists found that female tsetse that experience nutritional stress have lower fertility and produce smaller offspring that are less likely to survive starvation. However, the rate at which the female fly ages is not affected by the quality of her diet or how long she waited to mate. Thus, neither nutrition during pregnancy nor mating costs drive variation in reproductive ageing in this species.

Dr Sinead English of Bristol's School of Biological Sciences and senior author of the paper said: "Tsetse are remarkable flies. Mothers can produce offspring the same size they are. But, like many other animals (including humans), this huge reproductive investment comes at a cost: as females get older or when they have low quality food, they produce weaker offspring which do not survive as long. We still do not know, however, why some females age more rapidly than others."

Now researchers will look at new ways to test evolutionary predictions about ageing, using a new model system and innovative method of tracking reproduction of individual flies.

Dr English added: "We are also interested in understanding these patterns in tsetse as they spread deadly parasites, called trypanosomes, to humans and animals. By understanding how offspring survival depends on maternal nutritional stress and age, we can design better population dynamic and disease transmission models.

Imagine you're a CEO who wants to promote an innovative new product -- a time management app or a fitness program. Should you send the product to Kim Kardashian in the hope that she'll love it and spread the word to her legions of Instagram followers? The answer would be 'yes' if successfully transmitting new ideas or behavior patterns was as simple as showing them to as many people as possible.

However, a forthcoming study in the journal Nature Communications finds that as prominent and revered as social influencers seem to be, in fact, they are unlikely to change a person's behavior by example -- and might actually be detrimental to the cause.

Why?

"When social influencers present ideas that are dissonant with their followers' worldviews -- say, for example, that vaccination is safe and effective -- they can unintentionally antagonize the people they are seeking to persuade because people typically only follow influencers whose ideas confirm their beliefs about the world," says Damon Centola, Elihu Katz Professor of Communication, Sociology, and Engineering at Penn, and senior author on the paper.

So what strategy do we take if we want to use an online or real world neighborhood network to 'plant' a new idea? Is there anyone in a social network who is effective at transmitting new beliefs? The new study delivers a surprising answer: yes, and it's the people you'd least expect to have any pull. To stimulate a shift in thinking, target small groups of people in the "outer edge" or fringe of a network.

Centola and Douglas Guilbeault, Ph.D., a recent Annenberg graduate, studied over 400 public health networks to discover which people could spread new ideas and behaviors most effectively. They tested every possible person in every network to determine who would be most effective for spreading everything from celebrity gossip to vaccine acceptance.

"Dozens of algorithms that are currently used by enterprises seeking to spread new ideas are based on the fallacy that everything spreads virally," says Centola. "But this study shows that the ability for information to pass through a social network depends on what type of information it is."

So, if you want to spread gossip -- easily digestible, uncontroversial bits of information -- go ahead and tap an influencer. But if you want to transmit new ways of thinking that challenge an existing set of beliefs, seek out hidden locations in the periphery and plant the seed there.

"Our big discovery," Centola added, "is that every network has a hidden social cluster in the outer edges that is perfectly poised to increase the spread of a new idea by several hundred percent. These social clusters are ground zero for triggering tipping points in society."

Centola and Guilbeault applied their findings to predicting the spread of a new microfinance program across dozens of communities in India. By considering what was being spread through the networks, they were able to predict where it should originate from, and whether it would spread to the rest of the population. Their predictions identified the exact people who were most influential for increasing the adoption of the new program.

Guilbeault, now an assistant professor at the University of California, Berkeley, noted, "in a sense, we found that the center of the network changed depending on what was spreading. The more uncertain people were about a new idea, the more that social influence moved to the people who only had parochial connections, rather than people with many far-reaching social connections." Guilbeault added, "the people in the edges of the network suddenly had the greatest influence across the entire community."

The findings "turn our notions about social influence for marketing, sales, and social movements upside down," says Centola. "Not everything spreads through a network in the same way," he adds, "and we can use this knowledge to pinpoint hotspots in the social graph. This can allow us to accurately tailor our network strategies for effecting positive social change."

Centola is the author of the new book, Change: How to Make Big Things Happen (Little Brown, 2021).

As multicellular life relies on cell-cell interactions, it is not surprising that this is not always peaceful: cells with higher fitness eliminate cells with lower fitness through cell competition. Cell competition has emerged as a quality control mechanism and occurs when cells differ, genetically or otherwise, from each other. In mammals, the process of cell competition has been observed e.g., in cancer, during organ homeostasis, and during development as a process to select the fittest cells in the embryo and the adult. However, the features that distinguish "winner" from "loser" cells and whether there are key determinants for cell competition in various biological contexts remain elusive.

The recipe for elimination of "loser" cells

The research team found out that the cells losing the competition are characterized by defective mitochondria and, in mouse embryos, they are marked by sequence changes in their mitochondrial genome. Their work was published in the journal Nature Metabolism. "Our work suggests that differences in mitochondrial activity are key determinants of competitive cell fitness in a wide range of systems. In particular, we discovered that genetic defects in the mitochondria characterize 'loser' cells in mouse embryos," says Antonio Scialdone, co-corresponding author of the article.

In more detail: The mouse embryo uses cellular competition to get rid of unfit epiblast cells before the basic body plan is laid down during gastrulation. Using single-cell RNAseq (a specific sequencing technique), the researchers compared cells in embryos treated with a cell death inhibitor versus those in untreated mouse embryos. By applying machine learning algorithms, they could identify the gene expression signature of "loser" cells and discovered that these cells have defective mitochondria and are marked by sequence changes in their mitochondrial genome. "It was nice to see how with our computational pipeline we were able to extract such important information from the single-cell RNAseq datasets," says Gabriele Lubatti co-first author of the article.

The information on how "loser" cells look like in the mouse embryo allowed them to determine a "loser" cell identity. By analyzing the mitochondrial activity in other cell competition models, they could identify that mitochondrial dysfunction is a common characteristic in different "loser" cells and that small changes in the mitochondrial DNA are enough to drive cell competition.

Future work

This study suggests that mitochondrial activity may be a key determinant of cellular fitness in a variety of contexts where competition between cells occurs. Environmental changes can strongly influence metabolism and mitochondria play a central role in this process. Therefore, it is possible that cellular competition and associated defects in the mitochondrial genome in response to certain environmental factors leads to the emergence of a particular genotype ("winner" cells). This implies that cellular competition could be a direct link between environment and genotype, which will be interesting to explore further.

Tokyo, Japan - While researchers have known for years that immunoglobulin A (IgA) is important for gut health, it has remained unclear exactly what role it plays in preventing infection and disease. But now, researchers from Japan have found that eliminating IgA disrupts the balance of the intestinal ecosystem, making it susceptible to disease.

In a study published online in May in Gut, researchers from Tokyo Medical and Dental University (TMDU) have revealed that IgA deficiency results in substantial inflammation of the ileum, a specific part of the small intestine.

IgA is present in large quantities in the small intestine, where it helps protect the body against microorganisms that could potentially cross the lining of the gut to cause disease. People who do not produce IgA are more likely to develop inflammatory bowel disease, allergies, or autoimmune disease, or to get repeated infections. However, attempts to explore the connection between IgA and disease in the laboratory have been hampered by contradictory results, with some studies suggesting that IgA is not important for gut health, and others concluding it is crucial.

"We sought to resolve this apparent discrepancy by generating a definitive mouse model of IgA deficiency," says senior author of the study Takahiro Adachi. "To do this, we used a cutting-edge gene engineering technology called CRISPR/Cas9 to delete the gene encoding IgA."

The researchers then analyzed the IgA-deficient mice in detail to determine the effect on gut health, inflammation, and the gut microbiota (the microorganisms that live in our digestive tract).

"The results were striking," explains Adachi. "We found that the IgA-deficient mice had spontaneous inflammation in the ileal portion of the small intestine, with enhanced immune cell activation and the production of pro-inflammatory cytokines". In addition, the gut microbiota in these mice was unbalanced, especially in the ileum.

"Our findings suggest that IgA plays a protective role in the intestine by maintaining a healthy balance of microorganisms in the gut and preventing pathologic inflammation," says Adachi.

Given that IgA deficiency is a known risk factor for inflammatory bowel disease such as Crohn's disease and ulcerative colitis, this new mouse model could be helpful for investigating these inflammatory conditions in the future. According to Takashi Nagaishi, lead author of the paper, the specific inflammation observed in the ileum of these mice, instead of the colon, makes this especially promising as a model of Crohn's disease in humans.

CORVALLIS, Ore. - A 17-year study in Oregon, Washington and California found that removal of invasive barred owls arrested the population decline of the northern spotted owl, a native species threatened by invading barred owls and the loss of old-forest habitats.

The conservation and management of northern spotted owls became one of the largest and most visible wildlife conservation issues in United States history after the U.S. Fish and Wildlife Service listed the spotted owl as threatened under the Endangered Species Act in 1990 because of rapid declines in the owl's old-forest habitats. Four years later, the Northwest Forest Plan was adopted and reduced the rate of logging of old-growth forests on federal lands.

Despite more than 30 years of protection, spotted owl populations have continued to decline, with steepest declines observed in the past 10 years. Long-term monitoring of spotted owl populations across the species' range identified rapid increases in the population of invasive barred owls as a primary reason for those declines, the researchers said.

The study published this week in PNAS by scientists at the U.S. Geological Survey, Oregon State University, and several other entities is the first to look at the wide-scale impact of barred owls on populations of spotted owls in the Pacific Northwest.

The study focused on two sites in northern California, two in Oregon and one in Washington and found that spotted owl populations stabilized in all study areas where the researchers lethally removed barred owls (0.2% decline per year on average) but continued to decline sharply in areas without removals (12.1% decline per year on average.)

The findings in the new paper inform future management decisions about the spotted owl population.

"This study is a promising example of successful removal and suppression of an invasive and increasingly abundant competitor, with a positive demographic response from a threatened native species," said David Wiens, the lead author of the paper who is a wildlife biologist with the USGS Forest and Rangeland Ecosystem Science Center in Corvallis and a courtesy faculty member with Oregon State's Department of Fisheries, Wildlife, and Conservation Sciences.

As a species native to eastern North America, barred owls began expanding their populations westward in the early 1900s. The newly extended range now completely overlaps that of the northern spotted owl.

While barred owls look similar to spotted owls, they are larger, have a stronger ecological impact and outcompete spotted owls for habitat and food. This competition exacerbated spotted owl population declines, which were historically triggered by loss of old-forest habitat.

Mounting concerns about the threat of barred owls prompted a barred owl removal pilot project from 2009 to 2013 in California that concluded removal of barred owls, coupled with conservation of old forest, could slow or reverse population declines of spotted owls.

The research outlined in the PNAS paper expanded the pilot project to cover a much wider geographic range and a longer time period. The new research showed that barred owl removal had a strong, positive effect on survival and population trends of spotted owls that was consistent across all five study areas.

The conservation and restoration of old forests, which has been a chief focus of recovery strategies for the northern spotted owl, is a major source of controversy in the Pacific Northwest. The barred owl invasion has exacerbated this issue, placing an even higher premium on remaining old conifer forests.

"While suppression of barred owls can be difficult, costly, and ethically challenging, improvements in vital rates and population trends of spotted owls, and perhaps other threatened wildlife, can be expected when densities of barred owls are reduced from current levels," the researchers write in the paper. "Alien predators are considered to be more harmful to prey populations than native predators, and the dynamic interactions between invasive and native predators can lead to profound changes in ecosystems, often with considerable conservation and economic impacts."

Berkeley -- More than 700 imaging satellites are orbiting the earth, and every day they beam vast oceans of information -- including data that reflects climate change, health and poverty -- to databases on the ground. There's just one problem: While the geospatial data could help researchers and policymakers address critical challenges, only those with considerable wealth and expertise can access it.

Now, a team based at the University of California, Berkeley, has devised a machine learning system to tap the problem-solving potential of satellite imaging, using low-cost, easy-to-use technology that could bring access and analytical power to researchers and governments worldwide. The study, "A generalizable and accessible approach to machine learning with global satellite imagery," was published today (Tuesday, July 20) in the journal Nature Communications.

"Satellite images contain an incredible amount of data about the world, but the trick is how to translate the data into usable insights without having a human comb through every single image," said co-author Esther Rolf, a final-year Ph.D. student in computer science. "We designed our system for accessibility, so that one person should be able to run it on a laptop, without specialized training, to address their local problems."

"We're entering a regime in which our actions are having truly global impact," said co-author Solomon Hsiang, director of the Global Policy Lab at the Goldman School of Public Policy. "Things are moving faster than they've ever moved in the past. We're changing resource allocations faster than ever. We're transforming the planet. That requires a more responsive management system that is able to see these things happen, so that we can respond in a timely, effective way."

The project was a collaboration between the Global Policy Lab, which Hsiang directs, and Benjamin Recht's research team in the department of Electrical Engineering and Computer Sciences. Other co-authors are Berkeley Ph.D. graduates Tamma Carleton, now at University of California, Santa Barbara; Jonathan Proctor, now at Harvard's Center for the Environment and Data Science Initiative; Ian Bolliger, now at the Rhodium Group; and Vaishaal Shankar, now at Amazon; and Berkeley Ph.D. student Miyabi Ishihara.

All of them were at Berkeley when the project began. Their collaboration has been remarkable for bringing together disciplines that often look at the world in different ways and speak different languages: computer science, environmental and climate science, statistics, economics and public policy.

But they have been guided by a common interest in creating an open access tool that democratizes the power of technology, making it usable even by communities and countries that lack resources and advanced technical skill. "It's like Ford's Model T, but with machine learning and satellites," Hsiang said. "It's cheap enough that everyone can now access this new technology."

--MOSAIKS: Improving lives, protecting the planet--

The system that emerged from the Berkeley-based research is called MOSAIKS, short for Multi-Task Observation using Satellite Imagery & Kitchen Sinks. It ultimately could have the power to analyze hundreds of variables drawn from satellite data -- from soil and water conditions to housing, health and poverty -- at a global scale.

The research paper details how MOSAIKS was able to replicate with reasonable accuracy reports prepared at great cost by the U.S. Census Bureau. It also has enormous potential in addressing development challenges in low-income countries and to help scientists and policymakers understand big-picture environmental change.

"Climate change is diffuse and difficult to see at any one location, but when you step back and look at the broad scale, you really see what is going on around the planet," said Hsiang, who also serves as co-director of the multi-institution Climate Impact Lab.

For example, he said, the satellite data could give researchers deep new insights into expansive rangeland areas such as the Great Plains in the U.S. and the Sahel in Africa, or into areas such as Greenland or Antarctica that may be shedding icebergs as temperatures rise.

"These areas are so large, and to have people sitting there and looking at pictures and counting icebergs is really inefficient," Hsiang explained. But with MOSAIKS, he said, "you could automate that and track whether these glaciers are actually disintegrating faster, or whether this has been happening all along."

For a government in the developing world, the technology could help guide even routine decisions, such as where to build roads.

"A government wants to build roads where the most people are and the most economic activity is," Hsiang said. "You might want to know which community is underserved, or the condition of existing infrastructure in a community. But often it's very difficult to get that information."

--The challenge: Organizing trillions of bytes of raw satellite data--

The growing fleet of imaging satellites beam data back to Earth 24/7 -- some 80 terabytes every day, according to the research, a number certain to grow in coming years.

But often, imaging satellites are built to capture information on narrow topics -- supplies of fresh water, for example, or the condition of agricultural soils. And the data doesn't arrive as neat, orderly images, like a snapshots from a photo shop. It's raw data, a mass of binary information. Researchers who access the data have to know what they're looking for.

Merely storing so many terabytes of data requires a huge investment. Distilling the layers of data embedded in the images requires additional computing power and advanced human expertise to tease out strands of information that are coherent and useful to other researchers, policymakers or funding agencies.

Inevitably, exploiting satellite images is largely limited to scholars or agencies in wealthy nations, Rolf and Hsiang said.

"If you're an elite professor, you can get someone to build your satellite for you," said Hsiang. "But there's no way that a conservation agency in Kenya is going to be able to access the technology and the experts to do this work.

"We wanted to find a way to empower them. We decided to come up with a Swiss Army Knife -- a practical tool that everyone can access."

--Like Google for satellite imagery, sort of--

Especially in low-income countries, one dimension of poverty is a poverty of data. But even communities in the U.S. and other developed countries usually don't have ready access to geospatial data in a convenient, usable format for addressing local challenges.

Machine learning opens the door to solutions.

In a general sense, machine learning refers to computer systems that use algorithms and statistical modeling to learn on their own, without step-by-step human intervention. What the new research describes is a system that can assemble data delivered by many satellites and organize it in ways that are accessible and useful.

There are precedents for such systems: Google Earth Engine and Microsoft's Planetary Computer are both platforms for accessing and analyzing global geospatial data, with a focus on conservation. But, Rolf said, even with these technologies, considerable expertise is often required to convert the data into new insights.

The goal of MOSAIKS is not to develop more complex machine learning systems, Rolf said. Rather, its innovation is in making satellite data widely useable for addressing global challenges. The team did this by making the algorithms radically simpler and more efficient.

MOSAIKS starts with learning to recognize minuscule patterns in the images -- Hsiang compares it to a game of Scrabble, in which the algorithm learns to recognize each letter. In this case, however, the tiles are minuscule pieces of satellite image, 3 pixels by 3 pixels.

But MOSAIKS doesn't conclude "this is a tree" or "this is pavement." Instead, it recognizes patterns and groups them together, said Proctor. It learns to recognize similar patterns in different parts of the world.

When thousands of terabytes from hundreds of sources are analyzed and organized, researchers can choose a village or a country or a region and draw out organized data that can touch on themes as varied as soil moisture, health conditions, human migration and home values.

In a sense, Hsiang said, MOSAIKS could do for satellite databases what Google in the early days did for the Internet: map the data, make it accessible and user-friendly at low cost, and perhaps make it searchable. But Rolf, a machine learning scholar based in the Berkeley Electrical Engineering and Computer Sciences department, said the Google comparison goes only so far.

MOSAIKS "is about translating an unwieldy amount of data into usable information," she explained. "Maybe a better analogy would be that the system takes very dense information -- say, a very large article -- and produces a summary."

--Creating a living atlas of global data--

Both Hsiang and Rolf see the potential for MOSAIKS to evolve in powerful and elegant directions.

Hsiang imagines the data being collected into computer-based, continually evolving atlases. Turn to any given "page," and a user could access broad, deep data about conditions in a country or a region.

Rolf envisions a system that can take the stream of data from humanity's fleet of imaging satellites and remote sensors and transform it into a flowing, real-time portrait of Earth and its inhabitants, continually in a state of change. We could see the past and the present, and so discern emerging challenges and address them.

"We've sent so much stuff to space," Hsiang says. "It's an amazing achievement. But we can get a lot more bang for our buck for all of this data that we're already pulling down. Let's let the world use it in a useful way. Let's use it for good."