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Hanging out with bats to discover the secrets of their biology

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by Emanuela Barbiroglio

By turns admired and reviled, bats are one of the most mysterious mammals alive. Their nocturnal habits and unique adaptations mean that bats’ biology still holds many secrets. It is possible that bats may hold the key to understanding diabetes.

When the pandemic started in 2020 and speculation began that a notorious zoonotic “spillover” appeared to have triggered it all, one specific animal was identified almost immediately as a threat to humans – the bat. People feared and, in some cases, even killed them in a futile attempt to stop the virus from spreading.

Then, the perception of nature’s only flying mammal reversed again and scientists’ understanding of ecosystems moved forward precisely as a consequence of covid-19.

‘The pandemic highlighted the importance of better understanding bat species as well as their habitats,’ said Elise Sivault, ‘And, more generally, of avoiding any kind of process which brings wildlife into closer contact with humans.’ She has been catching bats in Papua New Guinea for the BABE project led by Dr Katerina Sam, from the Biology Centre of Czech Academy of Sciences.

The BABE project analyses how bats and other predators help keep the world green. And with over 1 450 species and making up 20% of the mammals on our planet, bats constitute one of the most diverse and geographically dispersed species. As such, they play a valuable role in the global ecosystem by pollinating crops and maintaining plant diversity.

‘They are also one of the most misunderstood mammals, due to their cryptic and nocturnal life-style,’ added Sivault.

While they are widely accepted as arthropod (insects, spiders and other invertebrates) predators, bats are often absent from insect studies compared to birds. ’We don’t know much about their impact on arthropod populations nor on their indirect consequences on plants,’ said Sivault. 

What we do know is that bats are great at gobbling up insects and other arthropods. Sivault and her team look at what and how much the individual species eat. For now, findings have indicated the difference in the strength of arthropod control by bats along different latitudes.

‘In Europe, most of the bat species have legal protection but elsewhere, many don’t,’ said Sivault. ‘Much more needs to be done to understand their needs, habitats and behaviours in order to find an effective way to protect them.’

Sweet nectar

Not many people know it but, bats are helping us to study and prevent human diseases such as diabetes. Some species of the winged mammalian possess genes that allow them to survive on a super-sweet diet of nectar. What this teaches us about diabetes in humans is part of the research being conducted by the Chiroglu project.

As fruit bats subsist on either fruits or nectar, the researchers sequenced over 1 000 genes in a wide range of fruit bat species. They identified a suite of molecular adaptations in genes involved in carbohydrate metabolism. To analyse the gene sequences of over 100 fruit bat species, they used a technique called ‘sequence capture’.

The findings show that several distantly related fruit bat species, having independently evolved to feed on nectar, have undergone identical molecular adaptations in the genes responsible for their sugar metabolism. This indicates that evolution appears to have followed the same path more than once to solve a particular problem.

‘Our research is curiosity-driven, but it has potentially important implications for humans,’ said Stephen Rossiter, professor of Molecular Ecology and Evolution at Queen Mary University of London. ‘We, like lab animals, develop diabetes if we live on sugar rich diets. Nectar-feeding bats appear to have evolved unique changes in the metabolic enzymes that might allow them to avoid diabetes and other metabolic diseases.’

Tough life

On the other hand, a bat’s life is not an easy one. They are put at risk by human encroachment and hunting, climate change and habitat loss. Some bat species in North America are also being impacted by white-nose syndrome (WNS), a disease caused by a fungal pathogen that infects bats during their hibernation. Researchers from the EVOL-WNS project are trying to understand why the WNS pathogen is not lethal to European bats but kills their American counterparts.

Back in 2015, Thomas Lilley, then a Marie Skłodowska–Curie Actions (MSCA) fellow at the University of Liverpool, discovered that the fungus causing the disease originated from Europe, where bats were actually being infected but not dying. ‘This meant they must have evolved resistance or tolerance at some point in their history,’ said Lilley.

He was keen to see if this process towards tolerance had already begun in North America after 10 years of exposure to the fungus. This would be evidenced by looking at differences in the genomes of bats sampled before the arrival of the fungus and bats coexisting with it. Compared to the genomes of bats sampled prior to the arrival of the fungus, Lilley would have expected to see reduced genetic diversity in the bats sampled 10 years after. This would have indicated some sort of selection towards resistance or tolerance. However, he found no evidence for this, meaning that the populations of bats were using other mechanisms besides genetic immunity to survive infection.

‘I thought I would find a signal for emerging selection in the bats in North America, because this is what should be happening in theory,’ said Lilley. ‘But in reality, there are so many factors at play that it is difficult to pinpoint causality.’ This discovery helped Lilley to view the ecosystem in a much more holistic fashion. ‘Everything is connected and that is a super-interesting thought,’ he said.

Lilley is now working on project at the Finnish Museum of Natural History (Luomus). He is researching how bats in Europe cope with fungal infection. To better protect bats, Lilley says that the first thing we need to do is to learn more about them. Work undertaken so far demonstrates that they are rather difficult to study. This means there are many aspects of their lifecycle even scientists know very little about.

‘For instance, here in Finland, we don’t really know where the bats hibernate during the winter,’ said Lilley. ‘And the winter is long here in the North, so not knowing where these protected species reside for most of the year is a huge problem for conservation.’

To successfully protect bats also means getting the public on board. Bats often reside in and breed in buildings during the summer, so they are often seen as pests although in fact they keep the mosquitoes at bay in the surroundings. ‘It is important to make sure the public understands that coexistence, and more importantly, even cohabitation is possible with bats and facilitates the protection of these animals,’ said Lilley.

Research in this article was funded via the EU’s European Research Council and the Marie Skłodowska-Curie Actions (MSCA). This article was originally published in Horizon, the EU Research and Innovation Magazine.  

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Why more heatwaves endanger our health and ability to work

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As the Earth warms, heatwaves are expected to occur more often, with sharper intensity and for longer periods. Rising temperatures adversely affect worker productivity and human health, but for policymakers to take substantive action for heat adaptation, and meet what researchers see as a life-saving Paris climate agreement, making an economic case is key.

BY NATALIE GROVER

As the Earth warms, heatwaves are expected to occur more often, with sharper intensity and for longer periods. Rising temperatures adversely affect worker productivity and human health, but for policymakers to take substantive action for heat adaptation, and meet what researchers see as a life-saving Paris climate agreement, making an economic case is key. This article first appeared in Horizon Magazine in August 2020.

It’s actually quite easy for us to point out the problem — we have increasing temperatures, increasing frequency of heatwaves…it affects our physical and cognitive performance,’ said Lars Nybo, a professor of integrative physiology from the University of Copenhagen, Denmark. He worked on a project called HEAT-SHIELD designed to examine the effects of heat exposure on worker productivity in industrial sectors that employ half of Europe’s workforce: manufacturing, construction, transportation, tourism, and agriculture. The project ran from January 2016 until December 2021.

Globally, 2021 was among the seven hottest on record, with Europe experiencing its hottest summer to date. In the Mediterranean region, an intense and prolonged heatwave in July and August lead to new temperature records and devastating wildfires, a poignant reminder that the achievement of the Paris climate agreement to keep global mean temperature increases well below 2°C is as important as ever.

Data from HEAT-SHIELD project suggest that exposure to external heat in combination with physical activity, which elevates the body’s production of heat, can result in physiological changes that can diminish occupational performance, via reduced working endurance, vision, motor coordination and concentration. This can lead to more mistakes as well as injuries.

‘Roughly 70% of all European workers, at some time during the working day, are not optimally hydrated,’ Prof. Nybo said. The solution to the problem, he added, is intuitive: drink water, replace electrolytes and reduce physical activity, but implementing these measures whilst maintaining productivity is where things get tricky. 

‘You could just say to the worker stay at home and drink cold margaritas in the shadow to prevent heat stress,’ he joked. ‘But that will not help productivity.’

Productivity

As coordinator of HEAT-SHIELD, Prof. Nybo and his team were tasked with not just assessing the extent of the problem — modelling the expected rise in temperature in Europe in the coming years and its impact on worker productivity ­— but also devising and implementing solutions that are location and vocation specific to adjust to the inevitable increases in temperature.

A construction worker wears a safety helmet, which impairs the body’s ability to purge heat, but the worker thinks this problem cannot be solved because it is intrinsic to their work, Prof. Nybo noted.

Surmounting challenges like this was one of the key objectives of the project — conceiving ways to weave in heat mitigation strategies alongside the practicalities of the job.

For instance, outdoor workers should be vigilant of weather patterns and plan work earlier in the day during periods of extreme heat, take a short break every hour and secure easy access to water. Similar remedies for workers in enclosed settings could mean a combination of air conditioning, working in shade and improving ventilation — keeping in mind the ecological footprint of such measures.

But on a macro level, for climate change policymakers to take concrete action here and now ­— the numbers are key, Prof. Nybo said.

In Europe, agricultural and construction workers for instance, lose some 15% of effective working time when the temperature goes beyond 30°C, which works out to almost one working day per week, he noted, citing HEAT-SHIELD analyses.

If you are a policymaker, he says, the numbers show that there’s an incentive to act now: if you mitigate the problem the cost will stabilise at a lower level in the long run than if you don’t.

Excessive heat

Diminished worker productivity and the downstream economic damage are prominent impacts of rising temperatures caused by climate change. But to get a full picture of the consequences, it’s necessary to understand what excessive heat does to the human body.

It can damage organs such as the heart and the lungs, exacerbate a range of diseases, and increase the risk of death.

Extreme heat can increase the occurrence of heart attacks and strokes in susceptible patients due to increased blood viscosity, and raise the risk of cardiovascular death in vulnerable patients. Hot, humid days can also trigger asthma symptoms and have been shown to increase airway resistance, while warmer climates tend to extend the pollen season.

Another side effect of rising temperatures is the association with air pollution — the largest environmental killer in Europe, causing roughly 500,000 premature deaths annually.

Observational data and modelling suggest that as it gets warmer, air pollution levels — particularly surface ozone gas (O3) and fine particulate matter (PM2.5) — increase in some populated regions, even when emissions of air pollutants have not risen, as well as create conditions favourable for forest fires.

Both extreme heat and air pollution raise the risk of cardiovascular and respiratory disease, which currently costs the European Union an estimated €600bn a year. If these environmental stressors continue to accumulate unabated, these costs could jump.

Projections

But the synergistic relationship between air pollutants and rising temperatures is not well understood and existing health-risk projections in Europe do not properly account for adaptive measures that can be taken to ameliorate associated health risks, according to Dr Kristin Aunan, a senior researcher at the Norway-based Center for International Climate Research.  

‘There’s quite a lot of literature on short-term impact — in terms of the day-to-day variation on the impact of heat stress on mortality — but when it comes to long-term impact, there is not a lot of information,’ she said.

As part of a project called EXHAUSTION that kicked off in 2019 and is due to run until May 2023, researchers including project coordinator Dr Aunan, are focused on quantifying the risks of cardiopulmonary disease in different temperatures.

The project is also working on identifying interventions to minimise the risks to health sparked by environmental stressors and demystifying the link between air pollution and temperature hikes.

Quantifying the cascading effect of cardiopulmonary diseases on the economy is key to affecting action on climate change, she suggests.

EXHAUSTION researchers, for instance, are devising a macro-economic model that tracks increased hospitalisation and mortality in different age groups to measure the impact on the broader economy in different European countries. ‘We also have a bottom-up model — where you put a price on every premature death or hospital admission and add up to estimate the economic cost.’

One of the main questions the researchers hope to answer is the magnitude of impact limiting temperature spikes to 1.5°C — the aim of the Paris climate agreement — will have on health. 

‘I have no answer to that today — but the reason why we’re doing this project…is that we think there are reasons to believe that being able to comply with a Paris agreement will save very many lives and reduce human suffering,’ Dr Aunan said.

‘When you discuss climate policy and discuss the costs of it — it’s very expensive to reduce emissions of greenhouse gases, etc. But you also need to consider the benefits and that’s what we are doing with this project — hoping that we can contribute to the other side of the coin.’

This article first appeared in Horizon Magazine in August 2020.

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Children at risk of new ‘unexplained acute hepatitis’ outbreak

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The world is currently facing a new outbreak of “unexplained acute hepatitis infections” affecting children, the World Health Organization (WHO) warned on Thursday, World Hepatitis Day.

The current uptick focuses attention on the thousands of acute viral hepatitis infections that occur every year among children, adolescents, and adults.

Treat hepatitis

WHO, together with scientists and policymakers in affected countries, are working to understand the cause of this infection that does not appear to belong to any of the known five types of hepatitis viruses: A, B, C, D, and E.

While the world has the guidance and tools to diagnose, treat, and prevent chronic viral hepatitis, these services are often out of reach for communities and are sometimes only available at centralized or specialized hospitals.

“To be most effective, hepatitis care must be delivered in communities through strong primary healthcare and integrated with other health services that address the full range of health needs,” WHO chief Tedros Adhanom Gebreyesus said in his message for World Hepatitis Day.

At risk

Although most acute infections cause mild disease and even go undetected, some can lead to complications and turn fatal.

In 2019 alone, complications of acute hepatitis A to E infections caused an estimated 78,000 deaths worldwide.

Global efforts prioritize the elimination of hepatitis B, C and D infections.

Unlike acute viral hepatitis, B, C and D cause chronic disease, which lasts for several decades, culminating in over one million deaths per year from cirrhosis and liver cancer. And they are responsible for over 95 per cent of hepatitis deaths.

Death every 30 seconds

“Every 30 seconds, someone dies from hepatitis-related diseases, including liver failure, cirrhosis and cancer,” said the WHO chief.

Moreover, some 80 per cent of people living with the disease are unable to access or afford care.

With the goal of eliminating hepatitis by 2030, the UN health agency has called on countries to reach four specific targets.

It aims to reduce new infections of hepatitis B and C by 90 per cent; reduce hepatitis-related deaths from liver cirrhosis and cancer by 65 per cent; ensure that at least 90 per cent of people with hepatitis B and C virus are diagnosed; and at least 80 per cent of those eligible, receive appropriate treatment.

Low coverage of testing and treatment is the most important gap to be addressed, in order to achieve the global elimination goals by 2030,” according to WHO.

Call to action

WHO is calling on all governments and partners to “scale up the use of effective tools” against the potentially deadly disease.

Tedros drew attention to a new WHO report that shows how Brazil, Egypt, Georgia, Mongolia, Rwanda, Thailand and the United Kingdom, are making progress towards the elimination of hepatitis B and C by applying the UN health agency’s tools and guidelines.

“With political commitment and investment, the elimination of viral hepatitis is within our reach,” he stated.

July spotlight

The day aims to raise awareness of viral hepatitis, which causes inflammation of the liver that leads to severe disease and liver cancer.

It also offers an opportunity to step up national and international efforts on the infection, encourage individuals, partners and the public to act, and highlights the need for a greater global response, as outlined in the WHO’s Global hepatitis report of 2017.

This year, WHO is highlighting the importance of bringing hepatitis care closer to primary health facilities and communities for better access treatment, no matter the type of hepatitis.

The 28 July date was chosen because it is the birthday of Nobel-prize winning scientist Baruch Blumberg, who discovered hepatitis B virus (HBV) and developed a diagnostic test and vaccine for the virus. 

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Tone as important as truth to counter vaccine fake news

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By ALEX WHITING

Lack of trust in health authorities, combined with the fear and uncertainty about the disease, created fertile ground for false rumours to spread about Covid-19 vaccines. Countering the rumours may be about attitude as well as facts.

False assertions about Covid-19 vaccines have had a deadly impact – they are one reason why some people delayed being inoculated until it was too late. Some still refuse to be vaccinated.

More than two years after the start of the pandemic, false rumours continue to circulate that the vaccines do not work, cause illness and death, have not been properly tested and even contain microchips or toxic metals.

Now a study raises hopes of deflecting such falsehoods in future by changing the tone of official health messaging and building people’s trust.

In many countries, public confidence in government, media, the pharmaceutical industry and health experts was already on the wane before the pandemic. And in some cases, it deteriorated further during the rollout of Covid vaccines.

This was partly because some national campaigns said the jabs would protect people from falling ill.

Friends over facts

‘There was a lot of overpromising around the vaccine without really knowing what would happen,’ said Prof Dimitra Dimitrakopoulou, research scientist and Marie Curie Global Fellow at the Massachusetts Institute of Technology and the University of Zurich.

‘Then people started getting sick, even though they were vaccinated. That created a lack of trust in the government issuing these policies, and in the scientific community.’

Prof Dimitrakopoulou studied public perceptions of Covid vaccines and obstacles to acceptance of reliable information as part of a project called FAKEOLOGY.

She found that, when people lose faith in institutional sources, they end up relying only on themselves, close friends and family.

‘They trust their instincts, they trust what resonates with them,’ Prof Dimitrakopoulou said. That means they will search the internet, social media and other sources until they find information that reinforces the beliefs they already hold.

‘We have lived with fake news and misinformation long enough to understand that it cannot be debunked with facts,’ she said. ‘People just raise these emotional blocks.’

For example, a story about a mother whose child fell sick after getting a Covid vaccination would likely be more influential than a message containing scientific facts.

Building trust

Prof Dimitrakopoulou surveyed 3 200 parents of children under 11 years old in the United States, and conducted focus groups with 54 of them, to discuss their views about Covid vaccines for kids.

Many parents felt confused by conflicting information about the shots and had a lot of questions about their effectiveness.

She gave the parents a selection of messages to assess. They were put off by the ones that were largely factual, rigid and prescriptive – the tone of many public health campaigns.

They were more persuaded by messages that addressed their concerns about the vaccines with empathy and compassion while acknowledging that they face a difficult decision.

‘We need to be ready to answer any questions they may have and be ready to have a conversation – without expecting the conversation to end with someone getting vaccinated,’ said Prof Dimitrakopoulou.

Those exchanges will ultimately help bolster public faith in health bodies and government institutions. ‘Covid is a great opportunity for us to start building this trust,’ she said.

While a lengthy process, building these bridges could enlighten people’s perceptions for the rest of their lives, she said.

Fake news filter

It is also important for journalists, researchers and the general public to be able to spot and filter out fake news.

Researchers on a project called SocialTruth have developed a tool to flag fake news content on the internet and social media.
 
The software, called a Digital Companion, can check the reliability of a piece of information. It analyses the text, images, source and author and, within two minutes, produces a credibility score – a rating of between one and five stars.

‘This is a computer-generated score that can give a red-flag warning if the content is very similar to other types of content that have been found to be false,’ said Dr Konstantinos Demestichas, researcher at the Institute of Communication and Computer Systems in Athens and coordinator of SocialTruth.

The Digital Companion uses computer algorithms that draw on a wide variety of verification services. These include non-governmental organisations, businesses and academic institutions – all with different interests, opinions and intentions.

Because of the diversity of verification-service providers, ‘We need to establish their trustworthiness by continuously evaluating their results,’ said Dr Demestichas.

To do this, the project uses blockchain to record all the scores and results produced by the verifiers. If the verifiers perform poorly, they lose their status – ensuring the Digital Companion can offer a quality assurance, he said.

Digital and human fact checkers

For now, the technology has been developed to scan health science and political content. In future, it could be developed for almost all areas.

Initially it will be for institutions that monitor fake news and disinformation, but the aim is to enable journalists and the general public to take advantage of the resource too.

The technology ‘could really make a difference in the daily use of the internet and social media,’ said Dr Demestichas.

Still, because it will never be able to spot all fake news, ‘We need journalists, fact checkers, and citizens to be well-trained to exercise their critical thinking,’ he said.

Manipulated feelings

The fight against misinformation is about more than protecting people’s health, important as that is. The well-being of democratic societies themselves is also at stake, said Dr Demestichas.

‘Fake news tries to manipulate our feelings and fears to get our “clicks” to read their content,’ he said.

Curbing it is critical ‘to defend our democracies and allow our societies to function better.’

The research in this article was funded by the EU. This article was originally published in Horizon, the EU Research and Innovation Magazine

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