Wednesday, April 01, 2020

Plant disease primarily spreads via roadsides

by Riitta-Leena Inki, University of Helsinki

To the naked eye, the infection appears as white fungal spore growth covering the plant. A powdery mildew fungus is a common parasite of the ribwort plantain. Credit: Elina Numminen

An analysis based on mathematical statistics more precise than those previously carried out uncovered the reason why powdery mildew fungi on Åland are most abundant in roadsides and crossings. The specific cause was the fact that traffic raises the spores found on roadsides efficiently into the air.

New statistical methods make it possible to identify complex mechanisms in nature that could potentially fundamentally alter our understanding of how diseases spread, among other things.

A recently published study utilised a comprehensive monitoring dataset on fungal diseases and the environmental variables affecting their distribution, collected over several years on Åland by Anna-Liisa Laine, professor of ecology at the University of Helsinki. The findings were published in the PLoS Computational Biology journal.

"Consolidating data collected on the road network, plants and the occurrence of plant diseases is no simple task. It required both new kinds of statistical models and computing power, which were not available only roughly ten years ago," says postdoctoral researcher Elina Numminen from the Department of Mathematics and Statistics, University of Helsinki.

With the adapted statistical model, the researchers were also able to demonstrate how epidemics caused by powdery mildew fungi were usually more extensive and persistent when originating in roadsides compared to epidemics originating in meadows or elsewhere further away from roads.

Plant diseases are common among both wild and cultivated plants, with many plants having a specific powdery mildew fungus of their own. For instance, in the autumn symptoms of such diseases are in evidence on the leaves of many trees.

Betweenness, for the considered host populations, computed based on their projection to the closest point in the road network. Credit: Elina Numminen

In this study, the researchers examined a powdery mildew fungus that is a common parasite of the ribwort plantain on the Åland Islands. The fungus is primarily dispersed by wind in the summer, as the small fungal spores fly from one plant to another. To the naked eye, the infection appears as white fungal spore growth covering the plant.

Rivers, ocean currents and forest paths also potential routes of transmission

The researchers are interested in disease transmission, as it helps explain the occurrence and biology of diseases. There are plant diseases that spread along riversides, bird migration routes, ocean currents or, for example, air traffic networks, much like human diseases that spread through social networks.

The transmission process determines the abundance and location of occurrence, while the method of transmission determines how the diversity of the disease branches off temporally and spatially, and, in the end, how the disease evolves through natural selection.

Typically, diseases that spread very efficiently and over long distances do not evolve to adapt well to local conditions. They make do in a range of environments and potentially are more harmful to their hosts. On the other hand, there are diseases that spread less efficiently and over shorter distances.

"New techniques in statistical ecology can significantly expand our previous understanding of not only plant diseases but also, say, the distribution of various invasive or threatened species," Numminen notes. What is more, this makes them essential to predicting future environmental change. According to Numminen, distribution and strain estimates may be based on very simple statistical analyses, whose reliability could be boosted by an injection of ecological realism.

The enemy within: How a killer hijacked one of nature's oldest relationships
More information: Elina Numminen et al, The spread of a wild plant pathogen is driven by the road network, PLOS Computational Biology (2020). DOI: 10.1371/journal.pcbi.1007703
Journal information: PLoS Computational Biology

Scientists take aim at the coronavirus toolkit

by Tom Rickey, Pacific Northwest National Laboratory

The novel coronavirus sweeping the globe packs 27 proteins, each adopting a unique, often incredibly complex 3-D structure.

Each protein is part of the molecular toolkit that the virus uses to infect, replicate, and spread.

That presents scientists with 27 targets—27 potential opportunities to stop the virus.

Even before the word "coronavirus" inserted itself into the nation's vernacular, a nationwide network of scientists jumped into the effort to start revealing those structures—structures that hold the keys to a vaccine or treatment.

Garry Buchko is part of the endeavor. A PNNL scientist in Richland, Buchko collaborates with scientists at the Seattle Structural Genomics Center for Infectious Disease (SSGCID) to look for any sign of weakness that scientists can use to muck up the virus's inner workings. Creating atomic-level pictures of the protein structures in the viral toolkit is a crucial first step.

A track record against infectious disease

The team has a powerful track record. In the 13 years since its creation, SSGCID has solved the structures of close to 1,300 proteins from over 70 organisms that cause human death and disease. The group has brought discovery to bear on diseases like tuberculosis, plague, Ebola and the flu. The structures help scientists develop better treatments or vaccines against a host of nasty agents that can cause ills ranging from fatigue and food poisoning to difficulty breathing, and sometimes even death.

"We work on well-known infectious disease organisms like malaria and tuberculosis, but we are also tackling lesser-known infectious agents as well. You never know what might become the next threat," Buchko said.

Now, Buchko and his SSGCID collaborators are looking carefully at the coronavirus proteins. Scientists get a lock on many proteins by using X-ray crystallography, which yields an extraordinary snapshot at the atomic level, but some proteins resist the process. That's where Buchko comes in, tackling some of the toughest proteins using nuclear magnetic resonance (NMR) spectroscopy—a cousin to magnetic resonance imaging used widely in medicine.

"A load of 27 different proteins is fairly large for a virus," said Buchko. "We need to understand the role that each one plays in allowing the virus to hijack human host cells to replicate."

A unique role for NMR in coronavirus research

Buchko does not work directly with the entire coronavirus, known as SARS-CoV-2. Rather, he and his Seattle colleagues use snippets of genetic code to study one protein at a time by growing the individual proteins in bacteria. The individual proteins are harmless.

From there, other scientists at SSGCID solve the bulk of the protein structures using X-rays, while Buchko turns his focus to the subset that resists crystallizing by using NMR. NMR has an added advantage: It allows scientists to watch a protein in action in a way other methods do not.

To do so, Buchko inserts a small glass tube containing the dissolved protein, itself just one ten-thousandth the width of a human hair, into a machine four times the weight of an Asian elephant. He does the protein prep work late at night, when laboratory staffing is minimal and social distancing is easy.

Then he heads home and, remotely, manipulates the experiments happening inside the NMR located in the Environmental Molecular Sciences Laboratory, a U.S. Department of Energy Office of Science user facility at PNNL. The protein in the spectrometer is surrounded by a very strong magnetic field, thousands of times stronger than the typical MRI, and then pumped with additional radiofrequency energy to watch how individual atomic nuclei respond.

In this way, he can look in incredible detail at not just a single protein but at tiny segments—for instance, specific amino acids in precise locations. Indeed, scientists can monitor the environment of almost every carbon, nitrogen, and hydrogen atom in the protein.

Ultimately, after weeks of data collection, Buchko is left with thousands of pieces of data. He feeds that into a computer program to calculate the position of every single atom, resulting in a complete 3-D reconstruction of the protein. That's crucial information for scientists around the globe who are working on ways to stop the virus, supplying them with a how-to guide to identify viral vulnerabilities.

"In our current work, our hope is that others can use our findings as blueprints for drug design. Perhaps they will be able to pluck out a specific site on the protein for targeting that will weaken the virus's virulence," said Buchko, who has a joint appointment at Washington State University's School of Molecular Biosciences.

His findings, like those of his SSGCID counterparts, will be deposited in a bank—the Protein Data Bank, a public database of protein structures that the group shares with the scientific community so that scientists worldwide can exploit the team's findings to make further discoveries.

Ready to meet the coronavirus challenge

Immediately when the coronavirus threat became known in January, the SSGCID team switched its work to focus on the problem. The SSGCID is a consortium funded in whole or in part with federal funds from the National Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of Health and Human Services, under contract no. HHSN272201700059C.

It seemed a natural shift, since the team, headed by Peter Myler of the Seattle Children's Research Institute, is funded to learn more about important infectious diseases. Within just a few weeks, participants at the University of Washington had solved the structure of the virus's spike protein, which allows the virus to bind to cells inside our lungs.

"This shows the value of basic research," Buchko said. "It's because we look at these fundamental questions constantly that we had everything in place to address key questions related to this coronavirus. Our colleagues were able to solve the structure of the spike protein so quickly because we had people in place, ready to work together and act very rapidly.

"In research, you never know what will lead to the 'ah-ha' moment. You never know what will become topical. Fifteen years ago, I determined structures of proteins that no one gave a hoot about, but every now and then I get calls from people very interested in some of these protein structures. What we do now increases the odds of someone else solving both current problems but also problems of which we're not yet aware."

Tackling infectious disease – one protein at a time

Provided by Pacific Northwest National Laboratory

Smaller than expected phytoplankton may mean less carbon sequestered at sea bottom

by Steve Lundeberg, Oregon State University

A study that included the first-ever winter sampling of phytoplankton in the North Atlantic revealed cells smaller than what scientists expected, meaning a key weapon in the fight against excess carbon dioxide in the atmosphere may not be as powerful as had been thought.

Thus, commonly used carbon sequestration models might be too optimistic.

The Oregon State University research into the microscopic algae, part of NASA's North Atlantic Aerosols and Marine Ecosystems Study, was published this week in the International Society for Microbial Ecology Journal.

The findings are significant because the spring phytoplankton bloom in the North Atlantic "is probably the largest biological carbon sequestration mechanism on the planet each year, and the size of cells determines how fast that carbon sinks," said the study's corresponding author, OSU College of Science microbiology researcher Steve Giovannoni.

OSU postdoctoral researcher Luis Bolaños is the lead author.

Phytoplankton are microscopic organisms at the base of the ocean's food chain and a key component of a critical biological carbon pump. Most float in the upper part of the ocean, where sunlight can easily reach them.

The tiny plants have a big effect on the levels of carbon dioxide in the atmosphere by sucking it up during photosynthesis. It's a natural sink and one of the largest ways that CO2, the most abundant greenhouse gas, is scrubbed from the atmosphere. Understanding how and why phytoplankton bloom every spring is critical to learning how the Earth's living systems could respond to global climate change.

As the ocean pulls in atmospheric carbon dioxide, phytoplankton use the CO2 and sunlight for photosynthesis: They convert them into sugars the cells can use for energy, producing oxygen in the process.

The phytoplankton cells absorb that CO2 eventually sinking to the bottom of the ocean as they die. The planet's ecological health depends on regular plankton blooms such as the spring event in the North Atlantic in which huge numbers of phytoplankton accumulate over thousands of square miles.

The larger project that Bolaños and Giovannoni were part of, the North Atlantic Aerosols and Marine Ecosystems Study, was led by Michael Behrenfeld of the OSU College of Agricultural Sciences. The team used ship- and aircraft-based measurements and satellite and ocean sensor data to help clarify the annual phytoplankton cycles and their relationship with atmospheric aerosols.

Aerosols are minute particles suspended in the atmosphere that can affect the Earth's climate and radiation budget—by bouncing sunlight back into space and, in the lower atmosphere, by modifying the size of cloud particles, which changes how clouds reflect and absorb sunlight.

Bolaños, Giovannoni and their collaborators sampled phytoplankton in the western North Atlantic in both early winter and spring to try to get a handle on how the phytoplankton community transitioned between those seasons.

In earlier research, Behrenfeld found that the increase in numbers of phytoplankton, shown by chlorophyll and carbon concentrations, begins in midwinter when growth conditions are at their worst rather than being started by the onset of spring weather.

"The surface layer of the North Atlantic is deeply mixed in winter by storms and temperature-dependent 'convective' mixing," Behrenfeld explained. "This causes phytoplankton to be spread more thinly in the water, making it tough for the tiny animals that eat phytoplankton to track their prey. The reduction in feeding enables the phytoplankton to get a head start in growth as an opening act to the massive bloom that occurs once the winter storms fade and conditions for growth get better. By spring's end, the grazers have made up the lost ground, eating the phytoplankton as it grows and bringing the bloom to an end."

About half of the organisms in the spring bloom that the researchers sampled could not be genetically traced to the winter samples, Bolaños said.

"This suggests that there are life history strategies by which phytoplankton that are undetectable in winter can rise to high numbers in the spring, or there is a quick community turnover due to the circulation of water masses," he said.

Bolaños added that diatoms, thought to dominate phytoplankton blooms in the North Atlantic, often were not a big part of the samples' genetic profiles, and when they were a big part, the cells were small—either of the nano-phytoplankton variety or at the smaller end of the micro-phytoplankton scale.

"Biogeochemical models are often influenced by the perception that North Atlantic phytoplankton blooms are composed of large cells," he said. "That perception has been perpetuated by models that assume that diatoms are uniformly large cells. But they're not."

Algorithms that predict carbon export from satellite-sensed chlorophyll tend to assign high export rates to phytoplankton blooms on the belief, based on observations from the eastern North Atlantic, that large diatoms dominate at their climax.

The findings of this study, Giovannoni said, suggest that extrapolating those observations to the western North Atlantic may not be a valid practice.

"We're not certain whether our new observations of small phytoplankton in the western North Atlantic are due to physical differences between the western and eastern North Atlantic, ocean warming and higher atmospheric CO2 concentrations, or constraints of earlier research methods," he said. "There's also a chance our observations were an anomaly, a coincidence. We don't know for sure."

Cells less than 20 micrometers in diameter made up most of the phytoplankton biomass in the study samples. Diatoms were important contributors but not the main component of biomass.

"We found that diverse, small phytoplankton taxa were unexpectedly common in the western North Atlantic and that regional influences play a large role in community transitions during the seasonal progression of blooms," Giovannoni said. "The profoundly contrasting composition of the winter community, and the domination by small taxa that we found in the spring, are system features that alter our perspective and are areas for future research. Our results could have major implications for understanding how the blooms affect regional carbon biogeochemistry—the multispecies blooms we describe can have lower carbon export efficiencies than the models typically allow for."

Phytoplankton bloom in the North Atlantic

More information: Luis M. Bolaños et al, Small phytoplankton dominate western North Atlantic biomass, The ISME Journal (2020). DOI: 10.1038/s41396-020-0636-0

Journal information: ISME Journal

Provided by Oregon State University

The young Brazilians fighting for the Amazon
by Vitoria Velez

Fishermen and children are seen in the river in Bauana, a village in the heart of the Brazilian Amazon, on March 14

Maria dreams of being the next Greta Thunberg. Kelita is studying in the first-ever university program in the Amazon. Fabio is helping his family do its part to fight climate change through sustainable agriculture.

A new generation of young Brazilians from the Amazon region are seeking to reshape the fight for the world's largest rainforest, which is shrinking before their eyes.

The first Youth of the Forest Conference recently brought together 287 of them to discuss what they can do to fight rampant wildfires, deforestation from logging, farming and mining, and apathy about the rapid loss of one of Earth's most important natural resources.

AFP profiles three of them.

Amazonian Greta

Maria Cunha, 26, is from Sao Raimundo, a small village in a protected reserve whose residents live off fishing and gathering.

A volunteer forest ranger with a degree in sustainable production techniques, she says saving the Amazon will require working with the people who know it best: its inhabitants.

"We are the guardians of the forest. We live here and depend on the rainforest for practically everything. If we don't protect our forests, how will we live?" she added.

She is already seeing the impact of climate change at home, she said: hotter weather, lower water levels on the rivers, fewer fish.

Maria Cunha, 26, is a volunteer forest ranger with a degree in sustainable production techniques

Animals are feeling the impact, too.

"They come into our yard looking for food because they can't find enough, because of fires and deforestation," she said.

She fears it could "all disappear in the near future" if others her age don't act.

She sees Thunberg, the 17-year-old Swedish climate activist, as a role model.

"I dream of being the next Greta, an empowered girl fighting for her rights," she said.

Prodigal daughter

Kelita do Carmo left the rainforest at 13 years old, moving to the city of Manaus, to work as a nanny.

Eight months later, she was back home in Bauana, a village of stilt houses on the banks of the Jurua River.

"I learned to appreciate things here," she said.

Now 22, she is studying to become a teacher, part of the first-ever degree program offered in the rainforest.

The program aims to supply teachers to far-flung rainforest villages. It is a joint project by the Amazonas Sustainable Foundation—which sponsored the Youth of the Forest Conference—and Amazonas State University in Manaus.

It includes coursework on sustainable agriculture and the environment.

Sixteen-year-old Fabio Gondim, who lives in the community of Bauana, picks acai fruit

A boat speeds down the Jurura River in the Brazilian Amazon

Kelita do Carmo (C) attends class as part of a program offered by the Amazonas Sustainable Foundation

Farmer, math whizz

Fabio Gondim dreams of becoming a math teacher one day.

At 16 years old, he is already an expert farmer.

He helps his family harvest acai, a fruit in high demand for its health properties, and cassava, which they use to make flour.

A natural athlete, he can scale a 10-meter (33-foot) acai palm in a flash.

"It never crossed my mind to leave" the rainforest, he said.

"I wouldn't want to live in the city. Everything is easier here. The forest provides our food and our income."

He is helping his family adopt more sustainable farming techniques, such as clearing fewer trees to farm cassava.

"We have to keep fighting for the Amazon," he said.

"It's what's sustaining the world."

Explore furtherSimulations show parts of Amazon could switch from carbon sink to carbon source by 2050

© 2020 AFP

Malaysia makes massive seizure of pangolin scales

Pangolin scales are used in traditional Chinese medicine, and the animal could have been a possible vector in the novel coronavirus making a leap to humans

Malaysian authorities seized about six tonnes of pangolin scales and smashed a smuggling syndicate, officials said Wednesday, as the country clamps down on rampant wildlife trafficking.

The pangolin, the world's most heavily trafficked mammal, is believed to have possibly been a vector in the leap of the novel coronavirus from animal to human at a market in China's Wuhan city last year.

Its body parts fetch a high price on the black market as they are commonly used in traditional Chinese medicine, although scientists say they have no therapeutic value.

The haul was found Tuesday at a port outside the capital Kuala Lumpur, hidden inside a container along with a shipment of cashew nuts, said customs department chief Paddy Abdul Halim.

Officials said they had detained two people for questioning, and the operation had put a smuggling syndicate out of operation.

They could be jailed for up to three years if convicted of breaking wildlife protection laws.

It was not immediately clear if the scales originally came from Malaysia or elsewhere. Malaysia is often used as a transit point for smuggling wildlife across the region.

Traffic, a group that monitors animal trafficking, praised authorities for "prioritising wildlife even while countries are focused on dealing with the coronavirus pandemic", spokeswoman Elizabeth John said.

Malaysia torches 2.8 tonnes of African pangolin scales

Landmark study concludes marine life can be rebuilt by 2050

by King Abdullah University of Science and Technology

An international study recently published in the journal Nature, led by KAUST Professors Carlos Duarte and Susana Agustí, lays out the essential roadmap of actions required for the planet's marine life to recover to full abundance by 2050.

The project brings together the world's leading marine scientists working across four continents, in 10 countries and from 16 universities, including KAUST, Aarhus University, Massachusetts Institute of Technology, Colorado State University, Boston University, Pontificia Universidad Catolica de Chile, Sorbonne Universite, James Cook University, The University of Queensland, Dalhousie University and the University of York.

"We are at a point where we can choose between a legacy of a resilient and vibrant ocean or an irreversibly disrupted ocean," said Carlos Duarte, KAUST professor of marine science and the Tarek Ahmed Juffali research chair in Red Sea ecology.

"Our study documents recovery of marine populations, habitats and ecosystems following past conservation interventions. It provides specific, evidence-based recommendations to scale proven solutions globally," Duarte added.

Although humans have greatly altered marine life to its detriment in the past, the researchers found evidence of the remarkable resilience of marine life and an emerging shift from steep losses of life throughout the 20th century to a slowing down of losses—and in some instances even recovery—over the first two decades of the 21st century.

The evidence—along with particularly spectacular cases of recovery, such as the example of humpback whales—highlights that the abundance of marine life can be restored, enabling a more sustainable, ocean-based economy.

The review states that the recovery rate of marine life can be accelerated to achieve substantial recovery within two to three decades for most components of marine ecosystems, provided that climate change is tackled and efficient interventions are deployed at large scale.

"Rebuilding marine life represents a doable grand challenge for humanity, an ethical obligation and a smart economic objective to achieve a sustainable future," said Susana Agusti, KAUST professor of marine science.

By studying the impact of previously successful ocean conservation interventions and recovery trends, the researchers identified nine components integral to rebuilding marine life, salt marshes, mangroves, seagrasses, coral reefs, kelp, oyster reefs, fisheries, megafauna and the deep sea.

By stacking a combination of six complementary interventions called "recovery wedges," the report identifies specific actions within the broad themes of protecting species, harvesting wisely, protecting spaces, restoring habitats, reducing pollution and the mitigation of climate change.

The actions recommended include opportunities, benefits, possible roadblocks and remedial actions, giving a tangible roadmap to deliver a healthy ocean that would provide huge benefits for people and the planet.

If all recovery wedges are activated at scale, recovery timescales of previously damaged marine life show that the abundance of marine life can be recovered within one human generation, or two to three decades, by 2050.

A key element identified for success is the mitigation of climate change by reducing global greenhouse gas emissions. Impacts from realized and unavoidable climate change already limit the scope for rebuilding tropical corals to a partial—rather than substantial—recovery. The goal of rebuilding the abundance of marine life can only succeed if the most ambitious goals within the Paris Agreement are reached.

Success largely depends on the support of a committed, resilient global partnership of governments and societies aligned with the goal. It will also require a substantial commitment of financial resources, but the new study reveals that the ecological, economic and social gains from rebuilding marine life will be far-reaching.

The review is timely, as nations consider their actions to conserve biodiversity beyond 2020 and as the Kingdom leads its G20 partners as the group's 2020 president into novel, pragmatic approaches to tackling the climate challenge and protecting coral reefs and other vulnerable marine ecosystems.

"We have a narrow window of opportunity to deliver a healthy ocean to our grandchildren's generation, and we have the knowledge and tools to do so. Failing to embrace this challenge—and in so doing condemning our grandchildren to a broken ocean unable to support high-quality livelihoods—is not an option," Duarte said.Scientists call on government to increase ambition to save our ocean

More information: Rebuilding marine life, Nature (2020). DOI: 10.1038/s41586-020-2146-7 , https://nature.com/articles/s41586-020-2146-7

Uncertain climate future could disrupt energy systems

by Julie Chao, Lawrence Berkeley National Laboratory

Extreme weather events—such as severe drought, storms, and heat waves—have been forecast to become more commonplace and are already starting to occur. What has been less studied is the impact on energy systems and how communities can avoid costly disruptions, such as partial or total blackouts.

Now an international team of scientists has published a new study proposing an optimization methodology for designing climate-resilient energy systems and to help ensure that communities will be able to meet future energy needs given weather and climate variability. Their findings were recently published in Nature Energy.

"On one side is energy demand—there are different types of building needs, such as heating, cooling, and lighting. Because of long-term climate change and short-term extreme weather events, the outdoor environment changes, which leads to changes in building energy demand," said Tianzhen Hong, a Berkeley Lab scientist who helped design the study. "On the other side, climate can also influence energy supply, such as power generation from hydro, solar and wind turbines. Those could also change because of weather conditions."

Working with collaborators from Switzerland, Sweden, and Australia, and led by a scientist at the Ecole Polytechnique Fédérale de Lausanne (EPFL), the team developed a stochastic-robust optimization method to quantify impacts and then use the data to design climate-resilient energy systems. Stochastic optimization methods are often used when variables are random or uncertain.

"Energy systems are built to operate for 30 or more years. Current practice is just to assume typical weather conditions today; urban planners and designers don't commonly factor in future uncertainties," said Hong, a computational scientist leading multi-scale energy modeling and simulation at Berkeley Lab. "There is a lot of uncertainty around future climate and weather."

"Energy systems," as defined in the study, provide energy needs, and sometimes energy storage, to a group of buildings. The energy supplied could include gas or electricity from conventional or renewable sources. Such community energy systems are not as common in the U.S. but may be found on some university campuses or in business parks.

The researchers investigated a wide range of scenarios for 30 Swedish cities. They found that under some scenarios the energy systems in some cities would not be able to generate enough energy. Notably, climate variability could create a 34% gap between total energy generation and demand and a 16% drop in power supply reliability—a situation that could lead to blackouts.

"We observed that current energy systems are designed in a way that makes them highly susceptible to extreme weather events such as storms and heat waves," said Dasun Perera, a scientist at EPFL's Solar Energy and Building Physics Laboratory and lead author of the study. "We also found that climate and weather variability will result in significant fluctuations in renewable power being fed into electric grids as well as energy demand. This will make it difficult to match the energy demand and power generation. Dealing with the effects of climate change is going to prove harder than we previously thought."

The authors note that 3.5 billion people live in urban areas, consuming two-thirds of global energy, and by 2050 urban areas are expected to hold more than two-thirds of the world's population. "Distributed energy systems that support the integration of renewable energy technologies will support the energy transition in the urban context and play a vital role in climate change adaptation and mitigation," they wrote.

Hong leads an urban science research group at Berkeley Lab that studies energy and environmental issues at the city scale. The group is part of Berkeley Lab's Building Technology and Urban Systems Division, which for decades has been at the forefront of research into advancing energy efficiency in the built environment.

Extreme weather to overload urban power grids, study shows

More information: A. T. D. Perera et al, Quantifying the impacts of climate change and extreme climate events on energy systems, Nature Energy (2020). DOI: 10.1038/s41560-020-0558-0

Coronavirus having little impact on climate: UN agency

*The coronavirus crisis has cleared the streets—and the air—in cities like New Delhi, but the UN warns the change is only temporary*

Though factories have shut, planes have been grounded and cars left in the garage, the coronavirus pandemic is having very little impact on climate change, the World Meteorological Organization said Wednesday.

Any reductions in pollution and carbon dioxide emissions are likely to be temporary, said Lars Peter Riishojgaard, from the infrastructure department of the WMO, a United Nations agency based in Geneva.

"It does not mean much for climate," he told a virtual press conference.

Riishojgaard said there was a lot of media speculation about what impact the global pandemic might have on the climate, greenhouse gas emissions and longer-term global warming.

"The answer to that is it probably does not mean very much," he said.

While in the short term, carbon dioxide emissions would go down as cars stay put and aircraft remain on the ground, "we expect the impact will be fairly short-lived," Riishojgaard said.

"The pandemic will be over at some point and the world will start going back to work and with that, the CO2 emissions will pick up again, maybe or maybe not to quite the same level."

He said visibility in cities such as New Delhi had improved because there were fewer traffic-emitting fumes, but cautioned that it was only down to an "artificial halt" to normal activity.

"You could see it as maybe science experiment: what happens if all of a sudden we turn the whole thing off?" said Riishojgaard.

"It will lead some people, and perhaps also some governments, to rethink."

He reflected on China shutting down much industrial production during the Beijing 2008 Olympics.

"They demonstrated very clearly that you can absolutely, if you have enough control over the situation, you can turn off the air pollution," he said.

"But I don't think we should claim victory here yet because things will pick up again eventually."COVID-19: Economic slowdown doesn't stop climate change

Elephant welfare can be assessed using two indicators

by University of Turku

Across the world, animals are kept in captivity for various reasons: in zoos for education and research, in research facilities for testing, on farms for meat and other products, and in people's homes as pets. Maintaining good animal welfare is not only important for ethical reasons; poor welfare can impact human wellbeing and the economy. But how do we assess how animals are feeling?

One way to assess animal wellbeing is to look at stress levels. Vets typically use two biological measures of stress: stress hormone levels and white blood cell ratios. In mammals—including humans—the most important stress hormone is cortisol. When animals are faced with danger, cortisol is produced to help prepare the body for a challenge. However, if high stress and cortisol are experienced constantly, they can impact an animal's health.

In addition to cortisol, scientists can also look at the ratio of two types of white blood cells, heterophils (or neutrophils) and lymphocytes. These cells play an important role in the immune system of mammals, and after animals have experienced a stressful event, their ratio is typically high.

Researchers at the University of Turku, Finland, wanted to find out if these two biological measures of stress were correlated and whether animals with high levels of cortisol also had a high heterophil to lymphocyte ratio. They measured cortisol and heterophil to lymphocyte ratios in 120 Asian elephants from a semi-captive population of working timber elephants in Myanmar. The researchers also weighed each elephant, as body weight is a good indicator of general health.

"Some previous studies have found a positive relationship between stress hormones and heterophil to lymphocyte ratios, while others have found no relationship at all. It was also unclear from previous studies whether these two measures of stress are comparable across individuals of different sex and age, as well as across the seasons. In this population, we found that elephants with higher levels of the stress hormone cortisol also had higher ratios of heterophils to lymphocytes. This was true regardless of sex and age," says Postdoctoral Researcher and the lead author on the first study, Martin Seltmann, from the Department of Biology at the University of Turku.

An additional aim of the study was to test if stress hormones and heterophil to lymphocyte ratios are related to body weight in Asian elephants.

"We did not find a link between the white blood cell ratios and body weight, but elephants with higher levels of stress hormone had a lower body weight, indicating that elevated stress is linked to weight loss. It is useful to see that both a biological marker (cortisol) and physical indicator (body weight) of welfare respond in the same way. This means that both markers can be used to assess the wellbeing of elephants," says researcher Susanna Ukonaho, who participated in the study.

Non-experts Can Identify Stress Behaviour

In the second study, the researchers investigated whether welfare can also be reliably assessed by observing an animal's behaviour. While elephant specialists may be able to quickly identify behavioural changes, expert knowledge is not always available, so the researchers wanted to test the reliability of behavioural assessments by non-experts. First, they filmed over 100 working Asian elephants undertaking tasks that were either familiar or new to them.

"The elephants were asked to pick up different types of objects, including objects they had never seen before. This included items such as a plastic bottle, which some elephants were clearly unsure about," says the lead author on the study, Jonathan Webb.

The researchers constructed a list of elephant behaviours, which was then used by three volunteers with no prior experience of Asian elephants to collect behavioural data from the films.

To assess the reliability of the behavioural data, the researchers looked at how similar the observers' scores were for each film. They also assessed observer consistency by getting the volunteers to score films twice. They found that all three volunteers consistently and reliably identified many elephant behaviours, indicating that even with limited experience, people can reliably monitor elephant behaviour in a way which could improve the quality and safety of working elephant-human relationships.

Behavioural markers could therefore be a simple but useful tool for elephant welfare assessment on a larger scale, although the researchers caution that we still need to know how different behaviours are linked to biological measures of stress.

The relationship between different measures of animal welfare is often complex, but the findings of these two studies show that, at least when working with elephants, caretakers have several options for assessing the wellbeing of their animals. These options will not only facilitate the caretakers' work, but also help elephants to live better and healthier lives.

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New welfare tool to help improve the lives of elephants in human care

More information: Martin W. Seltmann et al, Faecal Glucocorticoid Metabolites and H/L Ratio Are Related Markers of Stress in Semi-Captive Asian Timber Elephants, Animals (2020). DOI: 10.3390/ani10010094

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Models explain changes in cooking meat

by Springer

Meat is no ordinary solid. Made up of complex networks of moisture-saturated proteins, it displays some intriguing physical properties when it is cooked. Several studies in the past have attempted to recreate this behaviour in computer simulations, but because this demands so much computing power, they have only achieved simplified, one-dimensional recreations of the process, which aren't particularly accurate. In new research published in EPJ Plus, mathematicians led by Dr. Hala Nelson at James Madison University show that by modelling meat as a fluid-saturated matrix of elastic proteins, which are deformed as the fluid moves, cooking behaviours can be simulated more precisely.

The insights gathered by the team could have numerous advantages, such as improvements in the safety regulations which govern the meat we consume; optimisations of its quality and flavour; and new ways to maximise its shelf life to ensure minimal wastage. In the team's model, the cooking process heated the fluid unevenly, causing it to move around and deform the protein matrix. In turn, the movement of the fluid is itself altered by this distortion. The result demonstrates a fairly strong agreement with real observations—where moisture is partially evaporated but is also pushed inwards from the meat surface during heating, causing the middle to swell.

Nelson and colleagues based their model on fundamental principles of conservation of mass, energy and momentum. They derived equations describing how polymers will behave when mixed with molecules of liquid, then fine-tuned their model's parameters until it was as realistic as possible. They then compared the outcomes of their simulations with experimental measurements of how thin steak slices shrink when cooked in the oven. In future studies, the team hopes to extend their simulations to 3-D models. This would require far more computing power, but if achieved, could raise our level of understanding about the important food source.

New insights into juicy steak

More information: H. Nelson et al, A mathematical model for meat cooking, The European Physical Journal Plus (2020). DOI: 10.1140/epjp/s13360-020-00311-0

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