Culture

New estimates highlight global economic and environmental impacts of COVID-19

The COVID-19 pandemic has resulted in an estimated global consumption loss of $3.8 trillion, as well as significant job and income loss. However, these socioeconomic effects are accompanied by notable estimated reductions in air pollution. Manfred Lenzen of the University of Sydney, Australia, and colleagues present these findings in the open-access journal PLOS ONE on July 9, 2020.

Beyond its health effects, the COVID-19 pandemic and associated lockdowns have resulted in major social and economic losses worldwide. While some regions, such as China and the U.S., have experienced greater direct economic effects than others, the entire world economy has been impacted through international trade links.

To help clarify the global socioeconomic impact of COVID-19, Lenzen and colleagues applied an economic modeling approach known as multi-region input-output (MRIO) analysis to data on losses experienced by global businesses as a direct consequence of the pandemic. The MRIO approach enabled the researchers to account for how losses in individual countries impact the entire global economy through international supply chains.

The analysis revealed that the pandemic has resulted in an estimated global consumption loss of $3.8 trillion, accompanied by job losses equivalent to 147 million full-time positions, as well as a loss of $2.1 trillion in wages and salaries.

As a silver lining, however, decreases in production and air travel have resulted in environmental benefits. The MRIO analysis estimates a 2.5 metric gigaton reduction in greenhouse gasses, as well as significant reductions for other air pollutants, including PM2.5, sulfur dioxide, and NOx gases.

The authors note that decisions made in response to the ongoing pandemic could shape the future of humanity. They outline a choice between returning to "business as usual," which could leave humanity vulnerable to additional crises, or altering the global economy with an eye towards sustainability and resiliency.

Co-author Arunima Malik summarizes: "Our study highlights the interconnected nature of international supply chains, with observable global spillover effects across a range of industry sectors, such as manufacturing, tourism and transport."

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PLOS

Oil spill clean- up gets doggone hairy

Oil spill disasters on land cause long-term damage for communities and the natural environment, polluting soils and sediments and contaminating groundwater.

Current methods using synthetic sorbent materials can be effective for cleaning up oil spills, but these materials are often expensive and generate large volumes of non-biodegradable plastic wastes. Now the first comparison of natural-origin sorbent materials for land-based oil spills, including peat moss, recycled human hair, and dog fur, shows that sustainable, cheaper and biodegradable options can be developed.

The University of Technology Sydney (UTS) project found that dog fur and human hair products - recycled from salon wastes and dog groomers - can be just as good as synthetic fabrics at cleaning up crude oil spills on hard land surfaces like highway roads, pavement, and sealed concrete floors. Polypropylene, a plastic, is a widely-used fabric used to clean up oil spills in aquatic environments.

"Dog fur in particular was surprisingly good at oil spill clean-up, and felted mats from human hair and fur were very easy to apply and remove from the spills." lead author of the study, UTS Environmental Scientist Dr Megan Murray, said. Dr Murray investigates environmentally-friendly solutions for contamination and leads The Phyto Lab research group at UTS School of Life Sciences.

"This is a very exciting finding for land managers who respond to spilled oil from trucks, storage tanks, or leaking oil pipelines. All of these land scenarios can be treated effectively with sustainable-origin sorbents," she said.

The sorbents tested included two commercially-available products, propylene and loose peat moss, as well as sustainable-origin prototypes including felted mats made of dog fur and human hair. Prototype oil-spill sorbent booms filled with dog fur and human hair were also tested. Crude oil was used to replicate an oil spill. The results of the study are published in Environments.

The research team simulated three types of land surfaces; non-porous hard surfaces, semi-porous surfaces, and sand, to recreate common oil-spill scenarios.

"We found that loose peat moss is not as effective at cleaning up oil spills on land compared to dog fur and hair products, and it is not useful at all for sandy environments." Dr Murray said.

"Based on this research, we recommend peat moss is no longer used for this purpose. Given that peat moss is a limited resource and harvesting it requires degrading wetland ecosystems, we think this is a very important finding." she said.

The research concluded that, for now, sandy environments like coastal beaches can still benefit from the use of polypropylene sorbents, but further exploration of sustainable-origin sorbents is planned.

The researchers say that future applications from the research include investigating felted mats of sustainable-origin sorbents for river bank stabilisation, as well as the removal of pollutants from flowing polluted waters, similar to existing membrane technology.

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University of Technology Sydney

UQ researchers solve a 50-year-old enzyme mystery

image: 'This information provides new insights into an important enzyme -- acetohydroxyacid synthase -- a target for more than 50 commercial herbicides.'

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The University of Queensland

Advanced herbicides and treatments for infection may result from the unravelling of a 50-year-old mystery by University of Queensland researchers.

The research team, led by UQ's Professor Luke Guddat, revealed the complete three-dimensional structure of an enzyme, providing the first step in the biosynthesis of three essential amino acids - leucine, valine and isoleucine.

"This is a major scientific advance, which has been pursued globally by chemists for half a century," Professor Guddat said.

"This information provides new insights into an important enzyme - acetohydroxyacid synthase - a target for more than 50 commercial herbicides.

"It's also a potential target for new drugs to treat infections such as tuberculosis and invasive Candida infections."

Using advanced techniques such as cryo-electron microscopy and X-ray crystallography, the team deciphered the structure of the plant and fungal versions of the enzyme.

"We identified how this highly complex structure is assembled, which is the highly unusual shape of a Maltese Cross," Professor Guddat said.

"Coincidently, the Maltese Cross also features as a part of UQ's logo."

Professor Guddat said the discovery could have big implications for global agriculture.

"Sulfometuron is a herbicide that targets this enzyme, and was widely used in the 1990s for wheat crop protection throughout Australia," he said.

"But today it is completely ineffective due to the development of resistance.

"With this new insight, we will be able to make changes to existing herbicides, restoring options for future herbicide application."

Professor Guddat said the enzyme was only found in plants and microbes, not in humans.

"For this reason, the herbicides and drugs that it targets are likely to be safe and non-toxic to all mammals," he said.

"And another surprising finding of the research was the role that the molecule known as ATP plays in the regulation of the enzyme.

"Normally ATP plays a role in providing energy to all living cells," Professor Guddat said.

"However, here it is acting like a piece of glue to hold the structure together."

"They're fascinating findings for us, and we're excited for new opportunities for targeted design of next-gen herbicides and antimicrobial agents."

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University of Queensland

Magnetic memory states go exponential

image: Researchers from Bar-Ilan University have shown that relatively simple magnetic thin film structures of N crossing ellipses can support two to the power of 2N magnetic states - much greater than previously thought - and demonstrated switching between the states with spin currents. The ability to stabilize and control exponential number of discrete magnetic states in a relatively simple structure constitutes a major contribution to spintronics and may pave the way to multi-level magnetic memory with extremely large number of states per cell, be used for neuromorphic computing, and more. The image shows examples of simulated magnetic states supported by the structures, and pictures of the devices themselves that were taken with a scanning electron microscope.

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Shubhankar Das, Ariel Zaig, Moty Schultz and Lior Klein

Spintronics is a thriving branch of nano-electronics which utilizes the spin of the electron and its associated magnetic moment in addition to the electron charge used in traditional electronics. The main current practical contributions of spintronics are in magnetic sensing and non-volatile magnetic data storage, and additional breakthroughs in developing magnetic based processing and novel types of magnetic memory are expected.

Spintronics devices commonly consist of magnetic elements manipulated by spin-polarized currents between stable magnetic states. When spintronic devices are used for storing data, the number of stable states sets an upper limit on memory capacity. While current commercial magnetic memory cells have two stable magnetic states corresponding to two memory states, there are clear advantages to increasing this number, as it will potentially allow increasing the memory density and enable the design of novel types of memory.

Now, a group of researchers led by Prof. Lior Klein, from the physics department and the Institute of Nanotechnology and Advanced Materials at Bar-Ilan University, has shown that relatively simple structures can support exponential number of magnetic states - much greater than previously thought. The studied structures are magnetic thin films patterned in the form of N crossing ellipses which have two to the power of 2N magnetization states. Furthermore, the researchers demonstrated switching between the states by generating spin currents. Their research appears as a featured article on the cover of a June issue of Applied Physics Letters.

The ability to stabilize and control exponential number of discrete magnetic states in a relatively simple structure constitutes a major contribution to spintronics. "This finding may pave the way to multi-level magnetic memory with extremely large number of states per cell (e.g., 256 states when N=4), be used for neuromorphic computing, and more," says Prof. Klein, whose research group includes Dr. Shubhankar Das, Ariel Zaig, and Dr. Moty Schultz.

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Bar-Ilan University

A memory game could help us understand brain injury

After a traumatic brain injury, why do some people quickly regain their skills while others face long-lasting setbacks? Boston University neuroscientist Jerry Chen and his colleagues have been trying to answer this question by understanding which parts of the brain are used to process sensory information and remember different skills.

"From a biomedical standpoint, the question is whether certain parts of the brain are [solely responsible for] certain types of function," says Chen, a College of Arts & Sciences assistant professor of biology and faculty member of BU's Center for Systems Neuroscience. The latest research from his lab, published in Neuron, could eventually help us determine which abilities are particularly difficult to recover after a traumatic brain injury--likely because these skills are represented in only one area of the brain--and which are more resilient.

Chen's team created a memory game for mice in order to examine the function of two brain areas that process information about the sensation of touch and the memory of previous events--areas of the brain they called S1 and S2. Chen wanted to see whether S1 and S2 both processed the same information (distributed processing), or if the areas each had specialized, independent roles (localized processing).

Mice were presented with a memory game that gently stimulated their whiskers with a moving device. For the mice, the goal of the game was to recognize whisker movement patterns to receive a reward. First, each mouse felt the device move its whiskers either forward or backward. Then, after a two-second pause, the device moved their whiskers again. If their whiskers were moved in opposite directions during both rounds--for example, if the device moved the whiskers forward first, paused, and then moved the whiskers backward--the mice learned they could lick a straw to receive a thirst-quenching drink. On the other hand, if the device moved their whiskers in the same direction during both rounds, the mice were supposed to refrain from licking. If the mice got it wrong, they instead received a small puff of air and a timeout before they could resume the game.

Meanwhile, the researchers were observing the mice's brain activity throughout the game and seeing how the S1 and S2 areas impacted the mice's skills. They used a technique called optogenetics, a genetic engineering method that allowed them to selectively activate groups of brain cells in the S1 or S2 areas of the mice's brains using light.

The researchers found that the S1 and S2 areas of the mice's brains do a lot of the same processing, frequently sending information back and forth to each other. But they also observed that the two brain areas carried out some specialized roles while the mice played the memory game. S1 seems to be more involved in processing immediate sensory information, making sense of how the mice's whiskers move in real time. In contrast, S2 seems to be particularly involved in helping the mice recall past events, with the mice relying on this brain area to remember what happened in the first round of the game.

Chen says the findings suggest that S1 and S2 are wired differently, as the brain cells in S2 are more strongly connected with each other than the brain cells inside S1. Chen speculates that these stronger connections relate to S2's role in recalling the past. When brain cells are more connected, it may be easier for a cue to set off a chain of cells and trigger a memory--a "domino effect" of neural activity. Together, the localized and distributed processing roles of S1 and S2 both contributed to the mice being able to correctly play the game and earn a sugary snack.

Although humans don't have whiskers, the team's experimental observations could represent the same kind of sensory information processed by human hands.

"We have just as much sensitivity and dexterity to process tactile information with our fingers as a mouse has with its whiskers," Chen says. "So, if we were to study how we process tactile information in our hand and fingers, we might expect to see just as much distributed power as we would [in a mouse], because that's what we've evolved to use as one of our main senses."

Before these findings can help humans suffering from long-lasting loss of motor skills or other abilities after traumatic brain injury, Chen says there's still a lot of research to be done.

"One factor to keep in mind is that a mouse has a smaller brain [than a human], and some of these areas are much more intermingled, so the processing in a mouse brain might be more distributed," he says.

The volume of a human brain is so much greater than that of a mouse, Chen says, humans might have more regions that carry out localized processing. Or, the opposite could also be true, he says: "Because [we have] a larger brain, there are a lot more connections, so we might have just as much distributed power as a mouse--or more."

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Boston University

A new role for a tiny linker in transmembrane ion channels

image: Jianhan Chen at UMass Amherst reports new results on calcium-gated ion channels. Besides advancing knowledge, an important part of the discovery relates to the many other domain-to-domain linkers in membrane proteins that must now be considered part of the sensing apparatus. It is more important than some people thought, he says.

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UMass Amherst

AMHERST, Mass. - In the molecular-level world of ion channels - passageways through membranes that carry signals in a cell's environment and allow it to respond - researchers have debated about the role of a small piece of the channel called a linker, says computational biophysicist Jianhan Chen at the University of Massachusetts Amherst.

The linker communicates between the pore and its environment-sensing apparatus, and knowing its function - whether it's inert or plays an active sensing role - has been unclear. But it might lead to a new target for drugs and treatment in conditions such as hypertension, autism, epilepsy, stroke and asthma, he adds. Now, Chen and colleagues at Washington University report in eLife that their experiments have revealed "the first direct example of how non-specific membrane interactions of a covalent linker can regulate the activation of a biological ion channel."

Specifically, Chen and co-first authors Mahdieh Yazdani and Zhiguang Jia at UMass Amherst, with co-first author Guohui Zhang, Jingyi Shi and Jianmin Cui at Washington University, studied a pore called the large-conductance potassium (BK) channel. It is important in muscle and neuron function and is controlled by calcium concentration via a calcium-sensing domain. It is also controlled by electrical potential through a voltage-sensing domain. Either way, it opens and closes like a gate - "a really common architecture in transmembrane receptors and channels," Chen says.

A single, tiny "C-linker" connects the BK calcium sensor and pore and until now was believed to be largely an inert connection. To study it, Chen says, "The traditional approach, if you suspect a specific position of the protein is important, is to mutate it and see what happens. You replace one amino acid with another. But with this method, you could end up perturbing many things; it's hard to tell what you've done."

Instead, the researchers scrambled the C-linker amino acid sequence many times. "If you do enough scrambles, you create so many different effects that you can average them. If the function isn't changed and all the repetitions look basically the same, nothing will stand out," Chen notes. "This will also give you a clean background so that next you can test some specific force or type of interaction that the linker might be involved in."

They discovered that scrambling the linker dramatically affected BK activation, supporting the notion that the linker is more than an inert connection, he adds. Surprisingly, computational analysis predicted that it was nonspecific linker-membrane interactions, not the sensor or pore, that led to different channel properties.

To test this new mode of channel regulation, Zhang at Washington University conducted "two really elegant experiments," Chen says. He built a shorter version of the channel without the calcium sensor but leaving its voltage-sensing function intact. "If our hypothesis is correct, in this construct the linker scramble would affect this truncated channel in a similar fashion as in the full-length channel. And if the linker does react without the calcium domain there, the linker is interacting with something else," he adds.

That proved to be the case. Further, they took one of the scrambling mutants and removed the "membrane-anchoring" segment that interacted with the membrane, he says. "We show that this single change completely reverses the linker scrambling effect. This one particular anchoring piece is responsible for the functional differences we observed."

Besides advancing knowledge, Chen explains, an important part of the discovery relates to the many other domain-to-domain linkers in membrane proteins. "Now we must really consider that the linker itself is part of the sensing apparatus, rather than just a connection. It's a new way to think about it. Our study is a really strong argument that the linker is a lot more important than some people thought."

He adds, "We don't discuss a direct application to disease, but this paper offers an important insight. We think it's going to spark others to do more. It could offer a new way to design drugs because now you can also think about also targeting the linker, not only the sensing domain or the pore itself. It gives you one more possibility."

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University of Massachusetts Amherst

New study outlines best practices for delivering care via telehealth

(Boston)--The COVID-19 pandemic has prompted a rapid expansion of telehealth use in the U.S. While articles have been published on telehealth and best practices for patient-centered communication during the crisis, none have focused on applying principles of trauma-informed care until now.

COVID-19 is traumatizing for many and has a disproportionate impact on those who have prior trauma exposure and mental health conditions. Catastrophic events, such as natural disasters and pandemics, may serve as both newly traumatic and as potential triggers for survivors who have endured prior trauma. Social distancing serves to protect communities, but may amplify isolation and danger in abusive relationships or exacerbate underlying mental illness.

The Substance Abuse and Mental Health Services Administration (SAMHSA) has developed six principles of trauma-informed care: safety, trustworthiness and transparency, peer support, collaboration and mutuality, empowerment, voice and choice, and sensitivity to cultural, historical and gender issues. Researchers from Boston University School of Medicine (BUSM) describe ways in which these concepts can be used during telehealth encounters in primary care and other specialties to help mitigate the isolating, traumatic effects of COVID-19.

The researchers, experienced primary care and mental health clinicians at the Veteran's Health Administration, share their experience with telehealth and discuss the case for applying the principles of trauma-informed care to all telehealth encounters. Their article takes a practical, skills-based approach including a case study.

"Trauma-informed care is a global, "universal precautions" approach to providing quality care that can be applied to all aspects of healthcare and to all patients," explained corresponding author Megan R. Gerber, MD, MPH, medical director of women's health at VA Boston Healthcare System.

According to the researchers, trauma-informed virtual care during the COVID-19 pandemic has the potential to ensure and even expand continuity of medical care, offer connection and support to trauma survivors, and enhance patient and clinician resilience in this time of need. "Clinicians have a unique opportunity during this pandemic to apply trauma-informed care principles early on and to envision how telehealth may contribute to a more meaningful care experience for all and a more equitable future for those we care for," said Gerber, associate professor of medicine at BUSM.

The researchers believe it is critical for clinicians to be mindful that the public health approach to the pandemic may actually result in trauma and retraumatization for patients, which in turn can impact both access and response to care. "Because trauma may be unseen, unmeasured and unnamed, it is important to deliver all medical care with sensitivity to its potential presence. All clinicians have a unique opportunity in the setting of COVID-19 to apply a trauma-informed lens to our telehealth encounters which may promote connection, equity and healing-centered engagement in care."

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Boston University School of Medicine

CT of coronavirus disease (COVID-19) versus CT of influenza virus pneumonia

image: Artificial intelligence (AI)-assisted software was used to identify inflammatory tissues in lung and automatically segment inflammatory lesions. Three-dimensional image shows regions of COVID-19 pneumonia in lung through AI postprocessing.

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American Journal of Roentgenology (AJR)

Leesburg, VA, July 9, 2020--An open-access American Journal of Roentgenology (AJR) article investigating the differences in CT findings between coronavirus disease (COVID-19) pneumonia and influenza virus pneumonia found that most lesions from COVID-19 were located in the peripheral zone and close to the pleura, whereas influenza virus was more prone to show mucoid impaction and pleural effusion.

"However," lead author Liaoyi Lin of China's First Affiliated Hospital of Wenzhou Medical University cautioned, "differentiating between COVID-19 pneumonia and influenza virus pneumonia in clinical practice remains difficult."

A total of 97 patients (49 women, 48 men) were enrolled in this study. Of them, 52 patients (29 men, 23 women; age range, 21-73 years) had COVID-19 pneumonia; 45 patients (26 women, 19 men; age range, 15-76 years) had influenza virus pneumonia (28, influenza A; 17, influenza B). All patients had positive nucleic acid testing results for the respective viruses, as well as complete clinical data and CT images.

According to Lin and colleagues: "Between the group of patients with COVID-19 pneumonia and the group of patients with influenza virus pneumonia, the largest lesion close to the pleura (i.e., no pulmonary parenchyma between the lesion and the pleura), mucoid impaction, presence of pleural effusion, and axial distribution showed statistical difference (p

Meanwhile, Lin et al. noted that the properties of the largest lesion, presence of ground-glass opacities, consolidation, mosaic attenuation, bronchial wall thickening, centrilobular nodules, interlobular septal thickening, crazy paving pattern, air bronchogram, unilateral or bilateral distribution, and longitudinal distribution did not show significant differences (p > 0.05).

Additionally, the authors observed no significant difference (p > 0.05) in CT score, length of the largest lesion, mean density, volume, or mass of the lesions between the two groups.

Because the CT manifestations of COVID-19 and influenza virus so often overlap, "even with the characteristics evaluated using AI software," Lin et al. wrote, "no significant differences were detected."

Thus, the authors of this AJR article concluded that the more important role of CT during the present pandemic is in finding lesions and evaluating the effects of treatment.

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American Roentgen Ray Society

Lung cancer in non-smokers likely to respond differently to treatment

Lung cancer in non-smokers is a diverse and distinct disease from that in smokers, and is likely to respond differently to targeted treatments, a major new study shows.

Scientists studied a population in Taiwan with high rates of lung cancer among non-smokers - and found a range of genetic changes which varied depending on a patient's age or sex.

Many non-smokers with lung cancer had signs of DNA damage from environmental carcinogens, with young women in particular having particular genetic changes which are known to drive cancer to evolve aggressively.

The study - which was co-led by scientists at The Institute of Cancer Research, London, alongside colleagues in Taiwan - could lead to new treatments for non-smokers with lung cancer tailored to the newly identified genetic changes.

The research, published in the prestigious journal Cell today (Thursday), is the most comprehensive ever study of the biology of lung cancer in non-smokers. It was funded by Cancer Research UK and various institutions in Taiwan including the Ministry of Science and Technology.

Scientists at The Institute of Cancer Research (ICR) worked with colleagues at the Academia Sinica and the National Taiwan University to analyse tumour samples from 103 lung cancer patients from Taiwan - the majority of whom were non-smokers.

Around 10-15 per cent of lung cancers in the UK occur in people who have never smoked - but in East Asia, the proportion of lung cancers that occur in non-smokers is much higher, especially among women.

The researchers conducted a detailed analysis of genetic changes, gene activation, protein activity and cellular 'switches' in lung cancer to develop the most comprehensive overview of the biology of disease in non-smokers to date.

Looking at the genetics and the related proteins produced by cancer cells in the tumour samples, scientists found that some early-stage lung tumours in non-smokers were biologically similar to more advanced disease in smokers.

Tumours in women often had a particular fault in the well-known lung cancer gene EGFR, whereas in men the most common faults were in the KRAS and APC genes. These differences could affect the response to targeted drugs in men and women.

Picking out people with 'late-like' early-stage lung tumours could help guide treatment decisions, and patients could be monitored more closely for signs of their disease progressing.

The study found a pattern of genetic changes involving the APOBEC gene family in three-quarters of tumours of female patients under the age of 60, and in all women without faults in the EGFR gene.

APOBEC proteins play an important role in the function of the immune system - but they can be hijacked by cancers, speeding up evolution and the emergence of drug resistance, a key area of study in the ICR's new Centre for Cancer Drug Discovery.

Patients without EGFR faults tend to do better on immunotherapy, and so testing for APOBEC could help pick out women more likely to respond to this form of treatment.

The team also picked out groups of patients - particularly among older women - whose cancers had mutation patterns linked to cancer-causing substances in their environment such as pollutants.

Finally, the team identified 65 proteins that were overactive in lung tumours that matched with existing candidate drugs. They found that one protein that cuts away at the surrounding tissue, called MMP11, was linked to poorer survival - and could be explored as a marker for early detection.

While the new study looked at patients treated in Taiwan, the researchers believe that many of their findings could be applicable to UK patients. Next, they will be validating their findings in larger studies and beyond Asia.

Dr Jyoti Choudhary, Team Leader in Functional Proteomics at The Institute of Cancer Research, London, said:

"We carried out the most comprehensive study ever conducted into the biology of lung cancers in an East-Asian population with a high proportion of non-smokers, and found that their disease is molecularly diverse, and distinct from what we classically see in smokers.

"We found distinct patterns of genetic faults in non-smokers and between women and men, which suggest that a woman who has never smoked, for example, is likely to respond differently to treatment than a male smoker.

"Some early-stage lung tumours had molecular features that are much more like that typically seen in later-stage disease - which could help us more accurately diagnose patients with aggressive disease, and inform treatment strategies."

Professor Paul Workman, Chief Executive of The Institute of Cancer Research, London, said:

"This new study offers a deep dive into the biology of lung cancer in people who have never smoked. It reveals new ways of telling apart patients with different tumour characteristics that could be exploited with tailored treatment strategies.

"Lung cancer is the biggest cancer killer in the UK, and much of what we know about the disease comes from studies in smokers. I'm hopeful that the new insights gleaned in this new study will really step up precision medicine in lung cancer for non-smokers, so they can be offered smarter, kinder treatment options."

Dr Emily Armstrong, research information manager at Cancer Research UK, said:

"In order to beat cancer, we need to understand all the ways it can develop. This research highlights just how much cancers can vary between people depending on their lifestyle and environment. Understanding the difference between lung cancers in smokers and non-smokers could be vital for providing patients with the most appropriate treatment."

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Institute of Cancer Research

Global wildlife surveillance could provide early warning for next pandemic

image: A juvenile saddleback tamarin is measured as part of an annual health check of a population of three primate species in southeastern Peru. In a perspective article published July 9 in Science, a team of wildlife biologists, infectious disease experts, and others propose a decentralized, global wildlife biosurveillance system to identify - before the next pandemic emerges - animal viruses that have the potential to cause human disease.

Image: 
Ishaan Raghunandan

The virus that causes COVID-19 probably originated in wild bats that live in caves around Wuhan, China, and may have been passed to a second animal species before infecting people, according to the World Health Organization. Many of the most devastating epidemics of recent decades - including Ebola, avian influenza and HIV/AIDS - were triggered by animal viruses that spilled over into people. Despite the ever-present danger of a new virus emerging and sparking a worldwide pandemic, there is no global system to screen for viruses in wild animals that eventually may jump to humans.

In a perspective article published July 9 in Science, a diverse group of infectious disease experts, ecologists, wildlife biologists and other experts argue that a decentralized global system of wildlife surveillance could - and must ­- be established to identify viruses in wild animals that have the potential to infect and sicken people before another pandemic begins.

"It's impossible to know how often animal viruses spill over into the human population, but coronaviruses alone have caused outbreaks in people three times in the last 20 years," said co-author Jennifer A. Philips, MD, PhD, referring to the SARS, MERS and COVID-19 epidemics. Philips is an associate professor of medicine and co-director of the Division of Infectious Diseases at Washington University School of Medicine in St. Louis. "Even a decade ago it would have been difficult to conduct worldwide surveillance at the human-wildlife interface. But because of technological advances, it is now feasible and affordable, and it has never been more obvious how necessary it is."

Every animal has its own set of viruses, with some overlap across species. Often, an animal species and its viruses have lived together for so long that they've adapted to one another, and the viruses cause either no symptoms or only mild to moderate disease. But when different animal species that don't normally have much contact are brought together, viruses have the opportunity to jump from one species to another. Most viruses don't have the genetic tools to infect another species. But viruses with such tools can be lethal to a newly infected species with no natural immunity.

Human activity is making such spillover events more and more likely. As the population of the world continues to grow, the demand for natural resources skyrockets. People push into wild areas to make space for new homes and businesses, and to access resources to fuel their economies and lifestyles. Wild animals are caught and sold for consumption, or as exotic pets at wildlife markets, where diverse species are jumbled together under crowded and unsanitary conditions. Wild-animal parts are shipped around the world as trinkets or ingredients for traditional or alternative medicines.

And yet there is no international system set up to screen for disease-causing viruses associated with the movement of wildlife or wildlife products.

"In the lead up to this article, I spoke with friends and colleagues around the world who do wildlife research in Madagascar, Indonesia, Peru, Ecuador and asked them, 'Where do you take your samples for screening?'" said co-author Gideon Erkenswick, PhD, a postdoctoral research associate in Philips' lab. Erkenswick is also the director of Field Projects International, a nonprofit organization dedicated to the study and conservation of tropical ecosystems. "In almost every situation, the answer was 'Nowhere.' Locally, there is nobody with dedicated time and resources to do this work. To find new disease-causing viruses, we have to find willing foreign collaborators, then get samples out of the country, which is difficult and expensive."

Philips, Erkenswick, and colleagues in the Wildlife Disease Surveillance Focus Group that authored the Science paper, suggest the establishment of a global surveillance network to screen wild animals and their products at hotspots such as wildlife markets. The idea would be to have local teams of researchers and technicians extract viral genomes from animal samples, rapidly sequence them on site and upload the sequences to a central database in the cloud. The cost and size of the necessary scientific equipment has dropped in recent years, making such screening affordable even in resource-limited settings where most such hotspots are located.

"There's now a genetic sequencer available that is literally the size of a USB stick," Erkenswick said. "You could bring that and a few other supplies into a rainforest and analyze a sample for sequences associated with disease-causing viruses on site in a matter of hours. I mean, if you do chance upon something like the virus that causes COVID-19, do you really want to be collecting it, storing it, transporting it, risking further exposure, sample degradation, and adding months or years of delay, before you figure out what you've got? There are people with the expertise and skills to do this kind of work safely pretty much everywhere in the world, they just haven't been given the tools."

Once viral sequences are uploaded, researchers around the world could help analyze them to identify animal viruses that may be a threat to people and to develop a better understanding of the universe of viruses that thrive in different environments. By comparing genomic sequence data, researchers can identify what family an unknown virus belongs to and how closely it is related to any disease-causing viruses. They can also identify whether a virus carries genes associated with the ability to cause disease in people.

"By knowing the diversity out there, and tracking its evolution, we can ensure that we stay ahead of what's in wildlife populations and at the wildlife-human interface," Philips said. "In the past, before modern transportation, spillover events would have been local and spread slowly, giving people elsewhere time to respond. But now the world is so small that an event in one place puts the whole world at risk. This is not someone else's problem. It's everyone's problem."

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Washington University School of Medicine

Arctic Ocean 'regime shift'

Scientists at Stanford University have discovered a surprising shift in the Arctic Ocean. Exploding blooms of phytoplankton, the tiny algae at the base of a food web topped by whales and polar bears, have drastically altered the Arctic's ability to transform atmospheric carbon into living matter. Over the past decade, the surge has replaced sea ice loss as the biggest driver of changes in uptake of carbon dioxide by phytoplankton.

The research appears July 10 in Science. Senior author Kevin Arrigo, a professor in Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth), said the growing influence of phytoplankton biomass may represent a "significant regime shift" for the Arctic, a region that is warming faster than anywhere else on Earth.

The study centers on net primary production (NPP), a measure of how quickly plants and algae convert sunlight and carbon dioxide into sugars that other creatures can eat. "The rates are really important in terms of how much food there is for the rest of the ecosystem," Arrigo said. "It's also important because this is one of the main ways that CO2 is pulled out of the atmosphere and into the ocean."

A thickening soup

Arrigo and colleagues found that NPP in the Arctic increased 57 percent between 1998 and 2018. That's an unprecedented jump in productivity for an entire ocean basin. More surprising is the discovery that while NPP increases were initially linked to retreating sea ice, productivity continued to climb even after melting slowed down around 2009. "The increase in NPP over the past decade is due almost exclusively to a recent increase in phytoplankton biomass," Arrigo said.

Put another way, these microscopic algae were once metabolizing more carbon across the Arctic simply because they were gaining more open water over longer growing seasons, thanks to climate-driven changes in ice cover. Now, they are growing more concentrated, like a thickening algae soup.

"In a given volume of water, more phytoplankton were able to grow each year," said lead study author Kate Lewis, who worked on the research as a PhD student in Stanford's Department of Earth System Science. "This is the first time this has been reported in the Arctic Ocean."

New food supplies

Phytoplankton require light and nutrients to grow. But the availability and intermingling of these ingredients throughout the water column depend on complex factors. As a result, although Arctic researchers have observed phytoplankton blooms going into overdrive in recent decades, they have debated how long the boom might last and how high it may climb.

By assembling a massive new collection of ocean color measurements for the Arctic Ocean and building new algorithms to estimate phytoplankton concentrations from them, the Stanford team uncovered evidence that continued increases in production may no longer be as limited by scarce nutrients as once suspected. "It's still early days, but it looks like now there is a shift to greater nutrient supply," said Arrigo, the Donald and Donald M. Steel Professor in Earth Sciences.

The researchers hypothesize that a new influx of nutrients is flowing in from other oceans and sweeping up from the Arctic's depths. "We knew the Arctic had increased production in the last few years, but it seemed possible the system was just recycling the same store of nutrients," Lewis said. "Our study shows that's not the case. Phytoplankton are absorbing more carbon year after year as new nutrients come into this ocean. That was unexpected, and it has big ecological impacts."

Decoding the Arctic

The researchers were able to extract these insights from measures of the green plant pigment chlorophyll taken by satellite sensors and research cruises. But because of the unusual interplay of light, color and life in the Arctic, the work required new algorithms. "The Arctic Ocean is the most difficult place in the world to do satellite remote sensing," Arrigo explained. "Algorithms that work everywhere else in the world - that look at the color of the ocean to judge how much phytoplankton are there - do not work in the Arctic at all."

The difficulty stems in part from a huge volume of incoming tea-colored river water, which carries dissolved organic matter that remote sensors mistake for chlorophyll. Additional complexity comes from the unusual ways in which phytoplankton have adapted to the Arctic's extremely low light. "When you use global satellite remote sensing algorithms in the Arctic Ocean, you end up with serious errors in your estimates," said Lewis.

Yet these remote-sensing data are essential for understanding long-term trends across an ocean basin in one of the world's most extreme environments, where a single direct measurement of NPP may require 24 hours of round-the-clock work by a team of scientists aboard an icebreaker, Lewis said. She painstakingly curated sets of ocean color and NPP measurements, then used the compiled database to build algorithms tuned to the Arctic's unique conditions. Both the database and the algorithms are now available for public use.

The work helps to illuminate how climate change will shape the Arctic Ocean's future productivity, food supply and capacity to absorb carbon. "There's going to be winners and losers," Arrigo said. "A more productive Arctic means more food for lots of animals. But many animals that have adapted to live in a polar environment are finding life more difficult as the ice retreats."

Phytoplankton growth may also peak out of sync with the rest of the food web because ice is melting earlier in the year. Add to that the likelihood of more shipping traffic as Arctic waters open up, and the fact that the Arctic is simply too small to take much of a bite out of the world's greenhouse gas emissions. "It's taking in a lot more carbon than it used to take in," Arrigo said, "but it's not something we're going to be able to rely on to help us out of our climate problem."

Credit: 
Stanford's School of Earth, Energy & Environmental Sciences

Movement ecology bears fruits: ATLAS supports map-based navigation of wild bats

image: Researcher attaches ATLAS tracking collar to bat

Image: 
Courtesy of David Shohami

(Jerusalem, July 10, 2020) -- When wild Egyptian fruit bats set out at night to forage in Israel's Hula Valley, they do so using advanced spatial memory and a flexible cognitive mapping of the fruit trees and other goals scattered in their foraging area. They seldom search randomly and their foraging patterns cannot be explained by simpler navigation mechanisms, a research team headed by Hebrew University of Jerusalem's Professor Ran Nathan has found.

The groundbreaking study, co-authored with Tel Aviv University Prof. Sivan Toledo, Hebrew U doctoral candidate David Shohami and other members of Nathan's group, is featured as the cover story for the current issue of Science magazine. It details the bats' cognitive map - the animals' mental representation of their own position relative to the surrounding environment - that helps them to move efficiently from any location to any of the many goals within their foraging area, even if the goal is out of their sight or smell range.

The existence of a cognitive map allows the bats to remember and return to favorable fruit trees, roosting caves and other goals. They use mapping and memory skills, rather than relying on path "directions" following numerous landmarks, specific cues originating from these goals, or simply finding these targets by chance.

To track the animals, the researchers had to overcome the limitations of GPS and other available wildlife tracking technologies. Although scientists have achieved key insights into animals' navigational capabilities from experiments on rats and other laboratory animals, limited battery size and the need to remotely retrieve data from GPS trackers prevented researchers from collecting large sets of data on wild animals in their natural habitats.

Alternative tracking methods such as radio telemetry have been used to track small wild animals, but they do not provide sufficiently detailed, long-term information on the movements, leaving researchers at an impasse.

"Up to now the technologies we had could not be used to track small wild animals in their natural habitats with enough detail required to test the existence of a cognitive map," says Prof. Nathan.

To solve the dilemma, Nathan teamed up with Toledo to develop an advanced "reverse-GPS" tracking system they called ATLAS. After a few years of development and refinement, Shohami used the system to collect a large dataset of 172 foraging Egyptian fruit bats comprising more than 18 million localizations collected over 3449 bat-nights across 4 years.

ATLAS movement data provided the means for detailed track analysis combined with translocation experiments and mapping of all fruit trees in the study area, spanning 88,200 hectares. The system provided researchers with detailed, accurate information from many individuals for relatively long periods at relatively low cost, showing that wild bats seldom search for food randomly, but instead repeatedly forage in goal-directed, long, and straight flights that include frequent shortcuts.

The team also ruled out alternative, non-map-based strategies by analyzing simulated tracks, time-lag embedding, and other analyses of the trajectory data.

The results present the most comprehensive evidence for a cognitive map from any wild animal studied since scientists first hypothesized the existence of a human-style cognitive map in 1948, says Nathan. Furthermore, the study marks a landmark for movement ecology, the academic discipline that Nathan pioneered in 2008 to study life on the move.

"Movement ecology has benefited from advances in tracking technology, but new ideas and novel insights have lagged behind. ATLAS has given us the keys to unlock previously unanswerable questions and will continue to shed light on a range of enigmatic natural phenomena," he says.

Credit: 
The Hebrew University of Jerusalem

Fine-tuning excited state of Ru(II)-photosensitizers for boosting CO2-to-CO conversion

image: Photocatalytic CO2 reduction with Ru-1-Ru-4 PSs and their photocatalytic mechanism.

Image: 
©Science China Press

Solar-driven reduction of CO2 into energy-rich fuels, such as CO, HCOOH, and CH3OH, has been conceived as a highly promising approach to solve energy crisis and environmental pollution. Throughout the molecular photocatalytic systems, numerous catalysts, such as complexes of Re, Ru, Fe, Co and Ni, have been developed with detail study of their catalytic mechanism. In light of their relative mature study, more and more attention has begun to shift to accelerate electron transfer between catalyst and antenna molecules to promote CO2 reduction. At present, the research in this field focuses on the formation of composite systems between photosensitizers and catalysts through chemical bonds, hydrogen bonds, etc. This system shortens the distance between photosensitizers and catalysts, thus improving the electron transport capability between them. However, these studies still have many disadvantages, such as lack of flexibility and great influence from external factors. Accordingly, it's highly necessary yet remains great challenging to develop alternative strategy for dramatically boosting photocatalytic CO2 reduction.

At present, improving photosensitization ability of PSs for enhancing photocatalytic performance for CO2 reduction is still in its infancy. In this field, the frequently used PSs are confined to prototypical MLCT (metal-to-ligand charge transfer) complexes, such as Ru(bpy)32+ and Ru(phen)32+ (Phen = 1,10-phenanthroline), where their excited state lifetime was usually less than 1 μs (τ= 600 ns for Ru(bpy)32+ and 360 ns for Ru(phen)32+ in CH3CN). It will be a promising way to boost CO2 reduction via adjusting excited state population and lifetime of these PSs to improve their sensitizing ability.

In the present work, researchers put forward a new strategy to greatly boost photocatalytic CO2 reduction by improving photosensitization ability of PSs. A family of Ru(II)-based PSs Ru-2, Ru-3, and Ru-4 were prepared by selective addition of pyrene / pyrenyl ethynylene to 3- and 5-positions of Phen in Ru(Phen)32+ (Ru-1) (Fig. 1). As the triplet state energy level gradually decreased from Ru-1 with 3MLCT state to Ru-4 with 3IL state, the triplet lifetimes of these complexes were gradually prolonged and their excited state oxidation potentials became less negative, providing a platform to compare the effect of PSs with different sensitizing ability on photocatalytic CO2 reduction.

The photocatalytic process was dominated by oxidation mechanism for Ru-1 - Ru-4-containing system (Fig. 2). From the view of kinetics, long-lived triplet state of PSs greatly contributed to intermolecular electron transfer / energy transfer. Thus stern-volmer quenching constants of PSs by C-1 were in the order of 4.4 × 103 M-1 for Ru-4 > 3.2 × 103 M-1 for Ru-3 > 9.6 × 102 M-1 for Ru-2 > 3.8 × 102 M-1 for Ru-1, which was proportional to their excited state lifetimes (Fig. 2D). From the thermodynamics viewpoint, excited state oxidation potentials of PSs determine the driven force of electron transfer from excited PSs to C-1. As shown in Fig. 2F, the absolute value of excited state oxidation potential was in the order of Ru-4

This work provides a new insight for dramatically boosting photocatalytic CO2 reduction via improving photosensitization.

Credit: 
Science China Press

How vaping companies are use Instagram to market to young people

image: Samples of the images scraped from Instagram.

Image: 
Aqdas Malik, Aalto University

E-cigarettes are highly addictive nicotine products with unclear health impacts, particularly on young people. Instagram is a visual social media platform which is wildly popular, particularly with young people. Researchers interested in public health at Aalto university in Finland studied how vaping is represented on the platform. By using artificial intelligence, they were able to analyse hundreds of thousands of posts from a 6-month period last year, and found that a large portion of posts are promoting controversial flavoured e-liquids to young audiences.

The research worked by downloading every image on Instagram that had a caption including "#vaping" on the network for June to November 2019. 'We knew this would be predominantly promotional material,' said Dr Aqdas Malik from the department of computer science who studies public health and the internet, 'but we were interested in what types of images these would be, and who was posting them.' In the end, they generated a database of over half a million pictures, which they then sorted using a neural network, which grouped the images into categories of pictures with similar features.

What the neural network showed was that 40% of the images - the largest proportion out of the 6 categories - were of vaping e-liquids. These were predominantly posted by Instagram profiles listed as business accounts. The prominence of posts about e-liquids is interesting from a public health perspective because, although many e-cigarette brands market themselves as "smoking cessation" devices, it has been shown by other studies that flavoured liquids are strongly linked to adolescent users taking up vaping in the first place. The USA banned the sale of flavoured liquids at the beginning of this year specifically to help tackle the huge growth of teenage vaping, and other countries are looking to do the same.

'While print and broadcast media has clear rules and regulations about what can and cannot be advertised, and what constitutes advertising, we don't see this on social media,' said Dr Malik. 'I think we need stricter laws and rules on how we allow these products to be seen on these networks. Any 12-year-old with a phone can get an account and bypass the age-rules for seeing what's posted here, and the potential health implications are significant.' 60% of all the posts using the #vaping hashtag were from business accounts. Over 70% of Instagram users are under 35, and over 35% of its users are under 24 years old. 'It's a huge grey area in terms of advertising regulations, especially regarding promotion towards younger audiences' Dr Malik said.

Credit: 
Aalto University

Structural analysis of COVID-19 spike protein provides insight into its evolution

Researchers at the Francis Crick Institute have characterised the structure of the SARS-CoV-2 spike protein as well as its most similar relative in a bat coronavirus. The structures provide clues about how the spike evolved and could help inform vaccine design.

A characterising feature of SARS-CoV-2, the virus that causes COVID-19, is the protein spikes which cover the surface, which the virus uses to bind with and enter human cells.

Analysing the structure of these spikes could provide clues about the virus' evolution. It is not yet known how SARS-CoV-2 evolved to infect humans and whether this happened directly from coronaviruses in bats or via an intermediary species.

In their study, published in Nature Structural & Molecular Biology, the researchers characterised the spike protein in high resolution using a technique called cryo-electron microscopy, which allowed them to achieve a greater level of detail than previously reported structures. They then compared this structure to the spike protein of a bat coronavirus, RaTG13, which has the most similar spike to that of SARS-CoV-2.

While the spikes as a whole were over 97% similar, the researchers found a number of significant differences at the location where SARS-CoV-2 binds with a receptor on human cells, called ACE2, and at the surfaces that keep the subunits of the spike together.

These differences mean the spike of SARS-CoV-2 is more stable and is able to bind around 1,000 times more tightly to a human cell than this bat virus.

Based on their findings, the researchers suggest it is unlikely that a bat virus similar to RaTG13 could infect human cells. This supports the theory that SARS-CoV-2 is the result of different coronaviruses coming together and evolving over time, potentially also through several host species.

Antoni Wrobel, co-lead author and postdoctoral training fellow in the Structural Biology of Disease Processes Laboratory at the Crick, says: "The spike is the entry key that allows SARS-CoV-2 into human cells. Changes in the virus' genome, which affect the spike's structure, therefore have potential to make the virus either more or less able to enter the host's cell."

"At some point in the evolution of this virus, it seems to have picked up changes, like the differences we found, which made it able to infect humans."

Donald Benton, co-lead author and postdoctoral training fellow in the Structural Biology of Disease Processes Laboratory at the Crick, says: "The exact process of how SARS-CoV-2 evolved remains unclear and is something many researchers are trying to piece together. Our work provides a piece of this puzzle, as it suggests that the virus did not come straight from the bat coronaviruses currently known."

Steve Gamblin, group leader of the Structural Biology of Disease Processes Laboratory at the Crick says: "The world was caught off guard by SARS-CoV-2. Examining the structure of this virus, and its likely precursor, helps us understand where it came from, and how it interacts with human cells."

The Crick researchers will continue to study the structure of the virus, with a view to finding further clues as to its evolutionary path.

The spike protein structures are open-access, so other researchers can use these in their work and to aid with drug discovery and vaccine design.

Credit: 
The Francis Crick Institute