Culture

COVID-19: Viral shutdown of protein synthesis

Researchers from Munich and Ulm have determined how the pandemic coronavirus SARS-CoV-2 inhibits the synthesis of proteins in infected cells and shown that it effectively disarms the body's innate immune system. 

Although its name is relatively unspecific and indeed opaque, the Nonstructural Protein 1 (Nsp1) encoded by the coronavirus SARS-Cov-2, which is responsible for the current pandemic, has now been shown to have a devastating effect on host cells. Nsp1 is in fact one of the central weapons used by the virus to ensure its own replication and propagation in human hosts. Nsp1 was identified as a virulence factor following the outbreak of the related SARS coronavirus nearly 20 years ago, when it was shown to inhibit protein synthesis in infected cells. Now researchers based at Ludwig-Maximilians-Universitaet (LMU) in Munich and Ulm University Hospital have discovered what makes Nsp1 so potent. In a paper which appears in the journal Science, they describe the protein's mode of action in detail.

In all biological cells, the task of synthesizing proteins is performed by complex molecular machines known as ribosomes. Ribosomes interact with messenger RNAs (mRNAs), which serve as blueprints for protein synthesis, and translate the nucleotide sequence of each mRNA into the amino-acid sequence of the corresponding protein. The amino-acid sequence in turn determines the shape and biological function of each individual protein. Ribosomes consist of two distinct subunits, and Nsp1 binds to the smaller one - the 40S subunit. The mRNA initially binds to the small subunit, prior to the latter's interaction with the 60S subunit to form the cavity through which the mRNA is then threaded. The new study shows that one end of the Nsp1 protein interacts with the 40S subunit in such a way that it prevents binding of the mRNA. With the aid of high-resolution cryo-electron microscopy, Professor Roland Beckmann and his colleagues at the LMU Gene Center have shown in three-dimensional detail how Nsp1 binds tightly to a specific pocket in the small ribosomal subunit and inhibits the formation of functional ribosomes. Further experiments revealed that Nsp1 can also interact with specific configurational states of the fully assembled ribosome.

In addition, the team led by Konstantin Sparrer at Ulm University Hospital was able to show that the shutdown of protein synthesis leads to an almost complete collapse of one of the body's major lines of defense against the virus. Nsp1 inactivates the innate immune response by inhibiting a vital signaling cascade. The authors of the study hope that the insights gained will make it possible to find ways to neutralize the novel coronavirus, and thus mitigate the severity of the respiratory disease that it causes. One potential approach, they say, would be to develop a molecule that masks the viral protein's binding site. This should be feasible, since the Nsp1-binding pocket itself appears not to have an essential role in ribosomal function.

Credit: 
Ludwig-Maximilians-Universität München

Perspective: T cell responses to COVID-19 are a crucial target for research

While early research on the adaptive immune response to COVID-19 primarily looked at antibodies, more information is now emerging on how T cells react to the SARS-CoV-2 virus - addressing a crucial knowledge gap, say Daniel Altmann and Rosemary Boyton in a new Perspective. While antibody responses are generally much easier to study, T cells are known to play a more important role in protecting the body against viral infections. In the context of COVID-19, "antibody responses appear short-lived and T cell memory is potentially more durable," Altmann and Boyton say, leading them to argue that "it's time to admit that we really need the T cell data too." Seeking to assess the current state of knowledge on how T cells respond to the SARS-CoV-2 virus, the authors selected 9 studies - some published in peer-reviewed journals, while others are still under review and available as preprints - and summarized key takeaways and emerging points of consensus. "To fully understand population level immunity, screening for both antibody and T cell immunity using standardized testing methods would be beneficial," Altmann and Boyton conclude, noting that standardized tests to measure T cell immunity to SARS-CoV-2 could be designed using methods in common with established tests for T cell immunity to Mycobacterium tuberculosis.

Credit: 
American Association for the Advancement of Science (AAAS)

Coordination helps avoid continental COVID-19 resurgence, European modeling study shows

Coordinated lockdown strategies among countries is key to preventing resurgent COVID-19 outbreaks in continental Europe, a new modeling study shows. A continental epidemic could occur as many as five weeks earlier when well-connected countries with stringent existing interventions end their interventions prematurely, the study's authors say. As rates of new COVID-19 cases begin to decline in countries around the world, governments are considering how to ease restrictions without disease resurgence. This includes lifting non-pharmaceutical interventions such as social distancing policies and lockdown measures in a coordinated way that prevents international travel from causing resurgent epidemics. While such efforts are generally considered important, evidence informing how countries should implement them, and of their potential benefits, is lacking. To better quantify the value of coordinated exit strategies, Nick Ruktanonchai and colleagues took advantage of the way data from mobile phones can inform contact rates between people and the effect of interventions on human mobility. With data provided Vodafone and Google, they modelled the spread of COVID-19 under different coordinated and uncoordinated exit strategy scenarios using an openly available epidemiological model of COVID-19 transmission. Across 1200 simulations, they found that synchronized cycles of interventions were always more likely to end community transmission. In the most striking example, synchronizing four cycles of three-week long lockdowns led to local elimination of COVID-19 cases in 90% of simulations, while unsynchronized cycles only led to elimination 5% of the time. Importantly, say the authors, their simulations do not include any importation from other regions of the globe. "The implications of our study extend well beyond Europe and COVID-19," say Ruktanonchai and colleagues, "broadly demonstrating the importance of communities coordinating easing of various non-pharmaceutical interventions for any potential pandemic."

Credit: 
American Association for the Advancement of Science (AAAS)

A call to arms: Enlisting private land owners in conservation

image: People recreating in Yellowstone National Park, the world's first protected area. Protected areas like Yellowstone are invaluable, but they not enough to adequately conserve endangered species in the United States.

Image: 
Edward Hammill/Utah State University

In 1872 the United States created Yellowstone, the first National Park in the world. Since then many more parks, monuments, preserves, wildernesses and other protected areas have been created in the USA. Protected areas, like Yellowstone, are invaluable, but are they actually effective at preserving endangered species? And if not, how can future protected areas do better?

A team of ecologists at Utah State University published a study in Scientific Reports to answer these questions. They used computer models to determine if protected areas in the USA preserve enough land inhabited by endangered species to adequately ensure their future survival in the wild. As it is, the situation is problematic:

Of the 159 endangered mammal, bird, reptile and amphibian species in the continental USA only 21 are adequately preserved by existing protected areas.

Creating new protected areas on public land is fraught with obstacles. Many protected areas are designated based on scenic beauty or lack of agricultural value and these criteria don't necessarily benefit at-risk species.

Unfavorable political climates can also present problems. Trisha Atwood, Assistant Professor in the Department of Watershed Sciences and Ecology Center, and study co-author explained, "There has been a huge political push in the USA to reduce protected areas such as National Monuments. However, our results suggest that we not only need to increase the spatial coverage of protected areas in the USA, but we also need to ensure that we are protecting the places that contain critical habitat for endangered species."

Another obstacle is the limited availability of public land. For example, in the state of Texas 95% of the land is privately owned. And according to the study even if all federal and state public lands were given protected area status more than half of the at-risk species in the USA would still be in danger of extinction.

"We are not suggesting that protected areas are doing a bad job," said Edward Hammill, Assistant Professor in the Department of Watershed Sciences and Ecology Center and study co-author, "what we are suggesting is that there are many opportunities to increase protection."

One of those opportunities is the creation of conservation easements on private land. Conservation easements are voluntary, legal agreements that restrict future development on private land. In exchange for contributing to conservation efforts, land owners retain their property rights and can receive tax benefits. One of the most important findings from the study is that with the help of private land owners the USA has not lost the capacity to adequately protect 100% of its endangered species.

"It is unlikely that adequate conservation of endangered species will be achieved by increasing federal protected areas," said Hammill. "Our research highlights that private land owners represent an alternative route to achieving conservation goals."

Atwood concluded, "These findings give me hope that we can still make a change for the better. But, if we are going to win the fight against extinction we are going to need the help of private land owners."

Credit: 
S.J. & Jessie E. Quinney College of Natural Resources, Utah State University

UNH scientists find faster way to count animal sperm using DNA

DURHAM, N.H.-- Researchers at the University of New Hampshire have identified a quicker and less expensive way to count sperm in lobsters that could help scientists looking at any animal better understand mating, a key aspect of species survival.

"Scientists used to have to do this using a very tedious or expensive method so it was rarely attempted," said Win Watson, professor emeritus of marine biology. "Now that DNA technology has become so accessible and affordable, we decided to try it and it worked great."

The technique is described in their study which was recently featured in the Journal of Crustacean Biology. Researchers outlined how they were looking to better understand how climate change may alter lobster reproduction by influencing the amount of sperm a male lobster could produce. The challenge they encountered was counting the number of sperm contained in the lobster's spermatophore -- the package of sperm a male lobster transfers to females during mating. Each spermatophore contains about two million sperm cells, so counting them under a microscope is too time-consuming, especially when processing numerous samples. The new DNA method they developed allowed them to determine whether male lobsters experienced declining numbers of sperm when they mated successively, leading to sperm limitation within the population.

"Imagine if it took a week to produce a complete lobster spermatophore. That would mean that male lobsters might only be able to mate once a week," said Watson. "That, in turn, might mean that some female lobsters that might be ready to mate, would not get the chance. Females only mate after they molt, which they do only once per year, and they all tend to do it around the same time. So, limited availability of male sperm could significantly impact the population."

The absence of cost-effective ways to measure lobster sperm meant that testing the sperm limitation hypothesis were rarely attempted, despite concerns about the sustainability of the American lobster population.

"Beforehand, if we wanted to look at questions of reproductive output in lobsters, it took labor-intensive methods and an incredible amount of time," says Ben Gutzler, a recent PhD graduate from UNH in Marine Biology and lead author. "This new DNA method will hopefully make it possible for a broader group of scientists to ask more relevant questions about more animals."

Although the researchers did not find evidence of sperm limitation among male lobsters, they did uncover inconsistent sperm production among the individual lobsters studied. For example, they found that lobsters with severe shell disease, which is very common in southern New England, packaged fewer sperm cells in each spermatophore. This could have implications for population sustainability and prompt further study.

Credit: 
University of New Hampshire

Decadal predictability of North Atlantic blocking and the NAO

Climate in different parts of the world is undergoing a warming trend, but also significant interdecadal variations that compensate, or exacerbate the former. These variations are associated not only with changes in the radiative forcing, but also to natural variability in the atmospheric and oceanic circulation patterns. Can multi-annual variations in the frequency of North Atlantic atmospheric blocking and mid-latitude circulation regimes be skillfully predicted? Recent advances in seasonal forecasting have shown that mid-latitude climate variability does exhibit significant predictability. Decadal predictions fill the gap between assessing long-term climate trends (climate projections) and predicting short-term climatic anomalies (seasonal forecasting), thus targeting near-term regional climatic anomalies with multi-annual lead time and responding to an increasingly needed service to society.

A study recently published on the Nature Research Journal Climate and Atmospheric Science led by the CMCC Foundation (in particular, with the contribution of the CMCC scientists Panos Athanasiadis, lead author of the study, Alessio Bellucci and Stefano Tibaldi from CSP - Climate Simulations and Predictions Division) illustrates the latest breakthrough in the field of decadal predictions, with a special focus on the documented predictability for the North Atlantic Oscillation (NAO) and blocking in the North Atlantic.

The authors made use of a large ensemble of decadal predictions and found remarkable skill in reproducing the observed multi-annual variations of wintertime blocking frequency over the North Atlantic and of the North Atlantic Oscillation (NAO) itself. Therefore, skillfully predicting the decadal fluctuations of blocking frequency and the NAO may be used in statistical predictions of near-term climate anomalies, and it provides a strong indication that impactful climate anomalies may also be predictable with improved dynamical models.

Credit: 
CMCC Foundation - Euro-Mediterranean Center on Climate Change

Supplements with potential to prevent Alzheimer's affect blood, but less so the brain

image: ApoE4 reduces n-3 PUFA brain delivery

Image: 
USC

For years, a scientific puzzle has bedeviled researchers aiming to fight Alzheimer's disease, a common and incurable form of dementia.

The results of numerous lab investigations and population studies support the preventive potential of omega-3 fatty acids, "good fats" found abundantly in fish. However, to date the majority of studies evaluating omega-3s for averting or curtailing cognitive decline in human participants have failed to show benefits.

Now, a small clinical trial from USC provides important clues about this discrepancy, in the first Alzheimer's prevention study to compare levels of omega-3s in the blood with those in the central nervous system. The findings suggest that higher doses of omega-3 supplements may be needed in order to make a difference, because dramatic increases in blood levels of omega-3s are accompanied by far smaller increases within the brain. Among participants who carry a specific mutation that heightens risk for Alzheimer's, taking the supplements raised levels of a key fatty acid far less compared to those without the mutation.

"Trials have been built on the assumption that omega-3s get into the brain," said senior author Dr. Hussein Yassine, associate professor of medicine and neurology at the Keck School of Medicine of USC. "Our study was specifically designed to address this question."

The paper was published today in the journal EBioMedicine.

The researchers recruited 33 participants who had risk factors for Alzheimer's but were not cognitively impaired. All participants had a family history of the disease, a sedentary lifestyle and a diet low in fatty fish. Fifteen carried a gene variant called APOE4, which is linked to inflammation in the brain and increases Alzheimer's risk by a factor of four or more; the other 18 were noncarriers.

At random, participants were assigned to a treatment group or control group. Members of the treatment group were asked to take supplements containing more than 2 grams of an omega-3 called docosahexaenoic acid (DHA) daily for six months. Control group members took placebos each day over the same period. Participants in both groups also were asked to take daily B-complex vitamins, which help the body process omega-3s.

Dr. Yassine and his colleagues gathered samples of blood plasma and cerebrospinal fluid -- a gauge for whether the omega-3s reached the brain -- from participants at the outset, and again at the end of the study period. The scientists looked at levels of two omega-3 fatty acids: DHA and eicosapentaenoic acid (EPA), a potent anti-inflammatory that the body derives from a small portion of its DHA intake.

Higher doses for omega-3s to be effective?

The researchers found that at the end of the six months, participants who took omega-3 supplements had 200 percent more DHA in their blood compared to those who took placebos. In contrast, the DHA found in cerebrospinal fluid was only 28 percent higher in the treatment group than the control group. This result hints that measuring omega-3 levels in the blood may not indicate how much is reaching the brain.

Dr. Yassine and his co-authors also report that, within the treatment group, those without the risk-inflating APOE4 mutation showed an increase of EPA (anti-inflammatory omega-3 fatty acid) in their cerebrospinal fluid three times greater than what was seen in carriers of the gene.

"E4 carriers, despite having the same dose, had less omega-3s in the brain," he said. "This finding suggests that EPA is either getting consumed, getting lost or not getting absorbed into the brain as efficiently with the E4 gene."

Notably, the 2-gram dose of DHA in this study far exceeded what has been used in major clinical trials testing the preventive power of omega-3s, which typically administer 1 gram or less daily.

"If you use a lower dose, you can expect a less-than-10-percent increase in omega-3s in the brain, which may not be considered meaningful," Dr. Yassine said.

The sacrifice of study participants advances Alzheimer's research

The investigators worked for two years to recruit participants for the trial. The barrier to entry came from the only method capable of extracting cerebrospinal fluid: a lumbar puncture, also known as a spinal tap. It proved challenging to find people willing to undergo that procedure, which involves a hollow needle piercing the lower back, two times.

Dr. Yassine had high praise for the study participants.

"They were generous with their time, and they were courageous to do the lumbar punctures," he said. "The main reason they did this was their desire to advance science."

The participants' bravery may pay off in the creation of even more knowledge about omega-3s and Alzheimer's.

The preliminary data from the current study was intriguing enough that the scientists were able to attract funding for a larger trial for which recruitment is underway. Following 320 participants over two years, it will examine whether high doses of omega-3s can slow cognitive decline in carriers of the APOE4 gene.

Dr. Yassine believes that the progression from a small study to a bigger one is a good model for developing therapies and preventions targeting the brain.

"These pilot studies are so important as a step toward much larger, more complicated studies," he said. "The bottom line is, before you embark upon very expensive clinical trials, you need to show proof of concept, that your drug is getting into the brain and changing biomarkers of disease in the right direction."

Credit: 
Keck School of Medicine of USC

Researchers discover hybrid fungus involved in lung infections

image: The species is more drug-resistant than its two parents and highly dangerous for patients with respiratory diseases and compromised immune systems.

Image: 
Gustavo H. Goldman / USP

Aspergillus latus, a species of fungus previously found only in soil or plants, has been found for the first time in a hospital environment by an international group of researchers. The group sequenced its genome and discovered that it is actually a hybrid and is up to three times more drug-resistant than the two species from which it derives.

An article on the study is published in Current Biology and coauthored by researchers from Brazil, the United States, Portugal and Belgium. The research was supported by São Paulo Research Foundation - FAPESP .

Aspergillosis is a lung disease caused by fungi of this genus, especially A. fumigatus, which is widely found in plants and soil. All humans regularly inhale spores of Aspergillus, which do not usually cause symptoms in healthy subjects. In patients with weak immune systems, however, the mold can cause pneumonia, build up fungal balls (aspergillomas) in the lungs, and spread to become invasive pulmonary aspergillosis, the most severe form of the disease. A. fumigatus is the most frequent cause of aspergillosis, but other species also cause the condition, including A. flavus, A. niger, A. nidulans and A. terreus.

"In about 90% of cases, infection by Aspergillus is caused by A. fumigatus, but in some human genetic diseases, A. nidulans is a more frequent cause. We therefore started assembling clinical material from various parts of the world to see how often this species occurred in a hospital environment. To our surprise, six out of ten samples contained a fungus that had never before been found to infect people," said Gustavo Henrique Goldman , a professor in the University of São Paulo's Ribeirão Preto School of Pharmaceutical Sciences (FCFRP-USP) in Brazil and coprincipal investigator for the study with Antonis Rokas, a professor at Vanderbilt University in the United States.

Genetic sequencing also revealed that A. latus is a hybrid of two relatively distantly related species and contains complete copies of the DNA of both parental species. Tests performed by other groups have already shown that A. latus can be up to three times more resistant to anti-fungal drugs than its parental species, A. spinulosporus and an unknown relative of A. quadrilineatus. It also more effectively combats human immune cells.

"The fungus gains significant advantages from being a hybrid," Goldman said. "Accurate identification of the species that causes the infection is important in order to decide on the best treatment and avoid resistance to existing drugs."

However, he added, few Brazilian hospitals currently have the resources to perform genetic sequencing in order to identify the fungi that contaminate patients with greater than genus-level precision. Identification is typically achieved by morphological analysis under a microscope, which leaves room for misdiagnosis. The samples of A. latus used in the study, for example, had previously been labeled as A. nidulans by this method.

Fungi and COVID-19

The presence of fungi in hospital environments is a well-known factor in disease aggravation and even death. In collaboration with researchers in Germany, Goldman and his group are now assembling samples of fungi present in the lungs of COVID-19 patients with the aim of investigating how these organisms can aggravate their condition as a basis for developing strategies to avoid and combat infections.

"Several COVID-19 patients have died owing to concomitant infection by Aspergillus," Goldman said. "We currently have four strains that were isolated from patients who died of COVID-19 in Europe and will sequence their genomes to identify the species and see if they're favored by the disease."

He is looking for partners to help collect material in Brazil, but the sample isolation procedure entails a strict clinical protocol not yet in use in Brazil that ensures health workers and researchers are not infected by the novel coronavirus. In Europe, the experimental protocol was implemented in time for the pandemic.

Cases of concomitant COVID-19 and infection by fungi of the genus Aspergillus evidence the importance of knowing more about these microorganisms. For example, A. fumigatus is found worldwide and capable of surviving under extreme conditions, such as temperatures of up to 70 °C and a scarcity of nutrients. It can even extract food from water.

"We've now brought to light another feature of the genus, which is the formation of hybrids," Goldman said.

For the recently published study, the researchers assembled ten samples of fungi mainly found in material collected from patients with allergic bronchopulmonary aspergillosis and other disorders, such as chronic granulomatous disease, caused by a genetic dysfunction that impairs the immune system, and chronic obstructive pulmonary disease, including chronic bronchitis and emphysema.

The samples were collected in Portugal, Belgium, the US and Canada. Sequencing confirmed only three to be A. nidulans. One was identified as A. quadrilineatus, a soil fungus that also infects humans, and the other six as A. latus, hitherto found only in soil and plants.

Evolution

A. latus is the first hybrid filamentous fungus known to cause disease in humans, a relatively common property of yeasts such as those of the genus Candida, which causes candidiasis. Another curious feature of A. latus is that it is diploid; i.e., its cells contain two sets of chromosomes, similar to all human cells except egg and sperm cells. Most fungi are haploid, with only one set of chromosomes.

The hybrid also retains the DNA from both parental species, suggesting that the fusion is recent. Genes are recombined in ancient hybrids or species that diverged from a common ancestor eons ago, and some genes are lost or change position during the process of evolution.

Mules are a well-known example of a hybrid. They have 63 chromosomes, a mixture of the mare's 64 and the donkey's 62. In the case of A. latus, however, the genetic material of both parents is preserved in its entirety.

"Another curiosity is that the genetic distance between its two parental species is more or less the same as that between Homo sapiens and the lemur," Goldman said, referring to the 88 species of Lemuroidea primates native to Madagascar in Africa.

Credit: 
Fundação de Amparo à Pesquisa do Estado de São Paulo

COVID-19 news from Annals of Internal Medicine

Below please find a summary and link(s) of new coronavirus-related content published today in Annals of Internal Medicine. The summary below is not intended to substitute for the full article as a source of information. A collection of coronavirus-related content is free to the public at http://go.annals.org/coronavirus.

SARS-CoV-2 RNA found in a healthy blood donor 40 days after resolution of symptoms

Asymptomatic donors infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may pose a risk to the safety of the blood supply. Researchers from Stanford University School of Medicine report the case of a volunteer blood donor who was healthy on the day of donation but had detectable SARS-CoV-2 RNA levels in their blood at least 40 days after resolution of COVID-19-like symptoms. The donor had symptoms of upper respiratory infection in early March, including body aches and sore throat without fever. The donor did not seek medical attention and was not tested for SARS-CoV-2 at that time. After the donor was notified about the results, and 5 days after the donation date, RT-PCR assay of the donor's nasopharyngeal swab specimen showed no SARS-CoV-2 RNA.

According to the authors, the confirmation of SARS-CoV-2 RNA in donor blood more than 1 month after symptom resolution is concerning in light of current guidelines, which do not recommend screening in the general allogeneic donor population. Although this case is insufficient to recommend universal SARS-CoV-2 blood screening, the authors say their institution will continue to do so. Read the full text: https://www.acpjournals.org/doi/10.7326/L20-0725.

Media contacts: A PDF for this article is not yet available. Please click the link to read full text. The lead authors, Benjamin A. Pinsky, MD, PhD and Tho D. Pham, MD, can be reached through Julie Greicius at jgreicius@stanford.edu or Lisa Kim at LiKim@stanfordhealthcare.org.

Credit: 
American College of Physicians

Climate-friendly Cooling Could Cut Years of Greenhouse Gas Emissions and Save US$ Trillions: UN

image: An estimated 3.6 billion cooling appliances are in use worldwide and if cooling is provided to everybody who needs it - and not just those who can afford it - up to 14 billion cooling appliances would be required by 2050.

Doubling the energy efficiency of air conditioning by 2050 would reduce the need for 1,300 gigawatts of additional electricity generation capacity to meet peak demand - the equivalent of all the coal-fired power generation capacity in China and India in 2018. Worldwide, doubling the energy efficiency of air conditioners could save up to USD 2.9 trillion by 2050 in reduced electricity generation, transmission and distribution costs alone.

Image: 
UNEP / IEA

Coordinated international action on energy-efficient, climate-friendly cooling could avoid as much as 460 billion tonnes of greenhouse gas emissions - roughly equal to eight years of global emissions at 2018 levels - over the next four decades, according to the Cooling Emissions and Policy Synthesis Report from the United Nations Environment Programme (UNEP) and the International Energy Agency (IEA).

Reductions of between 210 and 460 billion tonnes of carbon dioxide-(CO2) equivalent emissions can be delivered over the next four decades through actions to improve the cooling industry’s energy efficiency together with the transition to climate-friendly refrigerants, according to the report.

The report says countries can institutionalize many of these actions by integrating them into their implementation of the Kigali Amendment to the Montreal Protocol. Signatories to the Kigali Amendment have agreed to reduce the production and use of climate-warming refrigerant gases known as hydrofluorocarbons (HFCs), which has the potential to avoid as much as 0.4°C of global warming by 2100 through this step alone.

Nations must deliver massive cuts in their greenhouse gas emissions to get on track to limit global temperature rise this century to 1.5°C. This is critical to minimizing the disastrous impacts of climate change. As nations invest in COVID-19 recovery, they have an opportunity to use their resources wisely to reduce climate change, protect nature and reduce risks of further pandemics. Efficient, climate-friendly cooling can help to achieve all of these goals," said Inger Andersen, UNEP Executive Director.

The report highlights the importance of cooling to maintaining healthy communities; fresh vaccines and food; a stable energy supply, and productive economies. The essential nature of cooling services is underlined by the COVID-19 pandemic, as temperature-sensitive vaccines will require quick deployment around the globe; lockdowns forcing people to stay at home for long periods of time are a health concern in many hot countries.

However, increasing demand for cooling is contributing significantly to climate change. This is the result of the emissions of HFCs, CO2, and black carbon from the mostly fossil fuel-based energy that powers air conditioners and other cooling equipment.

"As governments roll out massive economic stimulus packages to deal with the economic and social impacts of the COVID-19 crisis, they have a unique opportunity to accelerate progress in efficient, climate-friendly cooling.Higher efficiency standards are one of the most effective tools governments have to meet energy and environmental objectives. By improving cooling efficiency, they can reduce the need for new power plants, cut emissions and save consumers money. This new report gives policy makers valuable insights to help them address the global cooling challenge" said Dr Fatih Birol, IEA Executive Director.

Worldwide, an estimated 3.6 billion cooling appliances are in use. The report says that if cooling is provided to everybody who needs it - and not just those who can afford it - this would require as many as 14 billion cooling appliances by 2050.

The IEA estimates that doubling the energy efficiency of air conditioning by 2050 would reduce the need for 1,300 gigawatts of additional electricity generation capacity to meet peak demand - the equivalent of all the coal-fired power generation capacity in China and India in 2018. Worldwide, doubling the energy efficiency of air conditioners could save up to USD 2.9 trillion by 2050 in reduced electricity generation, transmission and distribution costs alone.

Action on energy efficiency would bring many other benefits, such as increased access to life-saving cooling, improved air quality and reduced food loss and waste, the report says.

The report lays out the available policy options available that can make cooling part of climate and sustainable development solutions, including:

International cooperation through universal ratification and implementation of the Kigali Amendment and initiatives such as the Cool Coalition and the Biarritz Pledge for Fast Action on Efficient Cooling

National Cooling Action Plans that accelerate the transition to climate friendly cooling, and identify opportunities to incorporate efficient cooling into stronger Nationally Determined Contributions under the Paris Agreement

Development and implementation of Minimum Energy Performance Standards and energy efficiency labelling to improve equipment efficiency

Promotion of building codes and other considerations to reduce demand for refrigerant and mechanical cooling, including integration of district and community cooling into urban planning, improved building design, green roofs, and tree shading

Campaigns to stop environmentally harmful product dumping to transform markets and avoid the burden of obsolete and inefficient cooling technologies

Sustainable cold-chains to both reduce food loss - a major contributor to greenhouse gas emissions - and reduce emissions from cold chains

The 48-page peer-reviewed report was authored by a range of experts under the guidance of a 15-member steering committee co-chaired by Nobel laureate Mario Molina, President, Centro Mario Molina, Mexico, and Durwood Zaelke, President, Institute for Governance & Sustainable Development, USA. The report is supported by the Kigali Cooling Efficiency Programme (K-CEP).

Credit: 
Terry Collins Assoc

Pigs turn to humans as dogs do, unless they have a problem to solve

image: Researchers of the MTA-ELTE 'Lendület' Neuroethology of Communication Research Group at the Department of Ethology at the Faculty of Science, Eötvös Loránd University, Budapest (ELTE) compared human-oriented communicative behaviours of young miniature pigs and dogs kept as companion animals.

Image: 
Eotvos Lorand University / Paula Perez

Researchers of the MTA-ELTE 'Lendület' Neuroethology of Communication Research Group at the Department of Ethology at the Faculty of Science, Eötvös Loránd University, Budapest (ELTE) compared human-oriented communicative behaviours of young miniature pigs and dogs kept as companion animals. They found that in a neutral situation pigs turn to humans, initiating interactions as much as dogs do. But in a problem solving situation the two species behave differently: whereas pigs keep trying to solve the task on their own, dogs often stop trying alone and display human-oriented communicative behaviours. Natural differences between pigs and dogs prevail despite similar socialization if an exciting challenge comes, the research suggests. The study is published in Animal Cognition.

Dogs are known to look at humans in a problem-solving context to establish joint attention and initiate communicative interactions, already from an early age. Is it really dogs' specialty, or would other companion animals do the same? "Similarly socialized wolves and cats communicate less with humans than dogs in the same problem-solving context, but maybe it is because wolves are not domesticated, and cats are not a social species. So we designed a study to compare dogs' behaviour with that of another domestic and social species, the pig" - explains PhD student Paula Pérez.

The miniature variant of the domestic pig is a popular companion animal occupying a similar "social niche" in the human families as the family dog. "We launched the Family Pig Project in 2017 at the Department of Ethology, Budapest. The animals are raised in a similar environment as family dogs, providing the basis for unique comparative investigations between the two species" - says Attila Andics, principal investigator of the MTA-ELTE 'Lendület' Neuroethology of Communication Research Group.

"We used the so called 'Unsolvable task paradigm', where the animal first faces a problem that he can solve, in our case an easy-to-open box with food inside. After some trials, the problem becomes unsolvable because the box is securely closed" - adds Pérez. "When the box was first in the room without food in it, pigs and dogs performed similar human-oriented behaviours" - says Linda Gerencsér, research fellow at the Research Group. "The differences appeared when we put food in the box and opening it became an exciting challenge. Pigs were faster than dogs already in solving the task and getting the reward, perhaps due to their better manipulative capacities. Then, when the task became unsolvable, dogs turned to the humans more than before. In contrast, pigs performed less human-oriented behaviours, but they were more persistent than dogs in trying to solve the task, which may reflect their predisposition to solve problems independently."

The study is the first to compare family dogs and pigs in a problem-solving situation. "The similarities that we found between the two species point to their similar capacities for engaging in communicative interactions with humans" - notes Pérez. "However, species-specific predispositions might be responsible for the found differences. Dogs are naturally more dependent on and cooperative with humans. This explains their unique success in interacting with us."

Credit: 
Eötvös Loránd University

Predicting the biodiversity of rivers

image: Stoneflies of the genus Isoperla and many other aquatic insect species have been determined using environmental DNA.

Image: 
Florian Altermatt, University of Zurich

Biodiversity is severely threatened both in Switzerland and worldwide, and numerous organisms are facing massive declines - particularly in freshwater ecosystems. All the species living in rivers - including fish, bacteria and many different aquatic invertebrates, such as mayflies, stoneflies and caddisflies - are crucial for the functioning of these ecosystems. But many species are under threat due to habitat homogenization, pollution by pesticides and nutrients, and the spread of non-native species. In order to understand and protect riverine ecosystems, assessing their biodiversity is essential.

Combining environmental DNA and hydrological models

In a new study, the research group of Florian Altermatt, professor at the Department of Evolutionary Biology and Environmental Studies of the University of Zurich (UZH) and the Swiss Federal Institute of Aquatic Science and Technology (Eawag), developed a novel approach to predict biodiversity patterns in river ecosystems. "For the first time, we combined the use of environmental DNA with hydrological models in order to make predictions on the state of biodiversity at a very fine resolution across catchments of hundreds of square kilometers," says Altermatt.

Biodiversity predictions with high accuracy

All organisms constantly shed their DNA into the environment. By collecting water samples and extracting and sequencing the so-called environmental DNA (eDNA), the biodiversity can be determined faster, less invasively and more comprehensively than by identifying the organisms themselves. Since the DNA in rivers can be transported downstream by stream flow for many kilometers, information on the occurrence of organisms in the upstream catchment is also received. Using mathematical models based on hydrological principles, the scientists were able to reconstruct biodiversity patterns for the whole 740 square kilometer basin of the Thur in north-eastern Switzerland with a resolution of stream sections of one kilometer. "Our model matches the direct observation of aquatic insects' local occurrence with an unprecedented accuracy of 57 to 100%," says Luca Carraro, first author of the study.

Identifying unseen biodiversity hotspots

The Thur catchment is representative of many land-use types, including forest, agriculture and settlements. It thus serves as a generalizable example for many riverine ecosystems. Furthermore, the new method can be used for large-scale and high-resolution assessments of biodiversity state and change even with minimal prior knowledge of the riverine ecosystem. "Specifically, the approach enables biodiversity hotspots to be identified that might be otherwise overlooked, thus enabling focused conservation strategies to be implemented," adds Altermatt.

Rapid application of research findings in Switzerland

Many countries are currently establishing aquatic biomonitoring using eDNA, and could profit from the novel method. According to Florian Altermatt, Switzerland has a leading role in this field: "The transfer from scientific findings to application is very rapid. We are now finalizing guidelines for the Federal Office for the Environment on how to use eDNA in standard biodiversity monitoring." This will make it easier to describe and monitor biodiversity for the whole network of Swiss rivers and streams, which is about 65,000 kilometers in total.

Credit: 
University of Zurich

N-doped carbon encapsulated transition metal catalysts to optimize performance of zinc-air batteries

In a report published in NANO, a team of researchers from Sichuan University of Science and Engineering, China have developed N-doped carbon encapsulated transition metal catalysts for oxygen reduction reactions (ORR) and oxygen evolution reactions (OER) to optimize performance of zinc-air batteries.

Three-dimensional porous graphene-like carbon layer encapsulated Fe/Fe3C (Fe@NCG) was prepared by pyrolysis of the mixture of Fe- chitosan chelate assembled without solvent and urea with small molecular nitrogen source. The space limiting effect of the chelate suppressed the agglomeration of Fe3+ ions, and the small molecular nitrogen source promoted the regulation of N configuration. The zinc-air battery assembled with Fe@NCG catalyst shows good performance.

The catalyst Fe@NCG shows remarkable ORR/OER bifunctional catalytic activity with a half wave potential of 0.86 V for ORR and a moderate potential difference of 0.85 V in alkaline medium. "The zinc-air battery assembled with Fe@NCG as positive and negative catalyst showed good discharge platform, high peak power density, high energy density, and high cycle stability." says Lei Ying, PhD, the corresponding author of the paper.

What is special about the study is that the Fe@NCG was prepared by pyrolyzing solvent-free formed fechitosan chelates and additional small molecule nitrogen source urea. The in-situ nitrogen doping and etching of self-nitrogen-doped carbonized chitosan by CN gas produced by g-C3N4 decomposition (such as C2N2+, C3N2+, C3N3+) is helpful to the regulation of electronic structure and the formation of pore structure in the carbon skeleton.

Moreover, the uniform distribution of Fe could be attributed to the molecular-level chelating space confinement effect of Fe-chitosan chelate compound precursor, wherein chitosan molecular served as a "fence" to effectively reduce excess aggregation of Fe3+ ions. The group then tested the product electrocatalytic performance.

The work of this team of researchers from Sichuan University of Science & Engineering has led to the exciting development of electrocatalytic materials. This work suggests that a simple and universal strategy can also be extended to the synthesis of other transition metal electrocatalysts coated with carbon.

One of the most fascinating frontiers in this research field might be combining chelating space confinement strategy and regulation of N configuration. Understanding these processes will improve the performance of materials and equipment, which will improve the lives of all of us. More recently, the group has been working on multifunctional conversions of electrocatalytic materials and assembly of devices.

Credit: 
World Scientific

The secret to renewable solar fuels is an off-and-on again relationship

image: These scanning electron microscopy images show the copper catalyst structure at different stages. (a) The catalyst prior to running any reactions. The cube structures on the surface are a result of the oxide. (b) What the catalyst looks like after running the CO reduction chemistry; all the oxygen is gone. (c) The catalyst after intentionally adding oxygen back to the metal as a way of recovering the performance of the catalyst. Copper oxide has formed in small nanoparticles on top of the smooth copper metal surface.

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Lee et al./ACS Catalysis

They say it's better to have had something special and lost it than to have never had it at all. Who would have thought that sentiment holds true for metal oxide catalysts? According to scientists at Lawrence Berkeley National Laboratory (Berkeley Lab) and Caltech, copper that was once bound with oxygen is better at converting carbon dioxide into renewable fuels than copper that was never bound to oxygen.

For their study, now published in the journal ACS Catalysis, the scientists performed X-ray spectroscopy on working solar fuel generator prototypes to demonstrate that catalysts made from copper oxide are superior to purely metallic-origin catalysts when it comes to producing ethylene, a two-carbon gas with a huge range of industrial applications - even after there are no detectable oxygen atoms left in the catalyst.

"Many researchers have shown that oxide-derived copper catalysts are better at making fuel products from CO2, however, there is debate about why this occurs," said research co-leader Walter Drisdell, a Berkeley Lab chemist and member of the Joint Center for Artificial Photosynthesis (JCAP). JCAP's mission is to develop efficient, solar-powered technologies that can convert atmospheric CO2 into petroleum alternative fuels. Drisdell and his colleagues say their discovery is an important advance towards that goal.

He explained that under operating conditions for fuel generation - which involves first converting the CO2 into carbon monoxide then building hydrocarbon chains - the copper-bound oxygen is naturally depleted in the catalyst. However, some researchers believe that small amounts of oxygen remain in the metal structure, and that this the source of the increased efficiency.

To resolve the debate, the team brought a gas chromatography (GC) system to the X-ray beamline so they could detect ethylene production in real time. "Our collaborators from Caltech drove the GC all the way from Pasadena and installed it at the X-ray facility in Palo Alto," said Soo Hong Lee, a postdoctoral researcher at Berkeley Lab and co-lead author of the study. "With it, we showed that there is no correlation between the amount of oxygen ('oxide') in the catalyst and the amount of ethylene produced. So, we think that oxide-derived catalysts are good, not because they have oxygen remaining while they reduce carbon monoxide, but because the process of removing the oxygen creates a metallic copper structure that is better at forming ethylene."

The team further showed that although oxide-derived catalysts' efficiency wanes over time, it can be regularly "reactivated" by re-adding and re-removing oxygen during a simple maintenance process. Their next step is to design a fuel-generating cell that can operate with X-ray scattering instruments, allowing them to directly map the changing structure of the catalyst while it converts carbon monoxide into ethylene.

The research team also included Ian Sullivan and Chengxiang Xiang at Caltech, and David Larson, Guiji Liu, and Francesca Toma at Berkeley Lab. This work was supported by the U.S. Department of Energy (DOE) Office of Science. JCAP is a DOE Energy Innovation Hub.

Credit: 
DOE/Lawrence Berkeley National Laboratory

River plants counter both flooding and drought to protect biodiversity

image: Inland waters are freshwater hotspots for biodiversity. Occupying just one percent of the planet's surface, they are home to ten percent of all species.

Image: 
Loreta Cornacchia

'Water plants are a nuisance in streams, blocking the flow. You should remove them'. This notion has for many years determined how streams were managed to prevent flooding during high rainfall events. Research by NIOZ scientist Loreta Cornacchia, published in the journal Proceedings of the Royal Society B, in cooperation with Utrecht University and British and Belgian partners, shows how vegetation in streams can actually buffer water levels, by adjusting vegetation cover. By adapting the patterning of plant clumps to changes in discharge, river plants can both counter flooding as well as prevent drying out, thereby protecting biodiversity. Cornacchia: 'They provide a natural buffer against hydrological changes.'

Huge implications for water management

'The implications for water management are huge', says Cornacchia. The current strategy of plant removal does not only threaten a naturally balanced water level, it also threatens a stream's biodiversity. Inland waters are freshwater hotspots for biodiversity and vegetation is its guardian. It provides habitats and food for invertebrate and fish, helps stabilize the river banks, and removes excess nutrients from the water.

Surprisingly, during extensive empirical research and sampling at two stream sites in the United Kingdom, the researchers observed that plant cover adjustments led to a more constant water level and flow regime. Cornacchia: 'We actually observed that the plants determined the water flow, rather than the other way around. In this way, submerged aquatic vegetation in rivers ensures that organisms that depend on the aquatic environment to persist can remain in the stream year-round.'

A nature-based solution

At high flows, the vegetation is pushed to the side or even dislodged, keeping an open lane in the middle for high-flow traffic. During periods of low flows, aquatic plants gradually clog up the stream, and thereby prevent the water from draining quickly. This so-called self-organization process counteracts the variation in waterflow that streams experience through the seasons. Geraldene Wharton, Professor at Queen Mary University of London in the UK and co-author of the study, adds: 'Our research shows the important buffering capacity of instream vegetation against both low flows and high flows which also maintains healthy ecosystems: a nature-based solution to flow regulation.'

Cornacchia: 'This more nature-based approach to the control of water levels harnesses natural processes rather than human control to maintain biodiversity hotspots.' An approach that is especially relevant in the light of a predicted increase in heavy rainfall and drought through climate change. The vegetation's ability to adapt through self-organization shows great potential to mitigate the effects of both floods and low water levels. Cornacchia: 'Insight in self-organizing plants and understanding their role in ecosystem resilience is essential in a future governed by global change.'

Credit: 
Royal Netherlands Institute for Sea Research