Culture

Which political parties have the most ambitious climate and energy policies? The answer, according to a new study, is surprising. In Germany, France, Spain and Italy, parties across the political spectrum, from the Greens to the Liberals, show a similar level of ambition on this score. However, researchers have also identified a major impediment to the energy transition: none of the investigated parties has a convincing idea for a technology mix that would ensure grid stability despite weather-related fluctuations in wind and solar energy.

The researchers analysed climate policies in the EU's four largest electricity markets. In the case of Germany and Spain, representative citizen polls were also considered in the investigation. As lead author Richard Thonig from the IASS explains, the political parties were categorised according to three distinct energy transition strategies or pathways: "In the state-centred approach, the task of planning the energy transition is left to experts, who prescribe how exactly grid expansion or the nuclear and coal phaseout should proceed. In the market-centred strategy, market actors are trusted to determine the specifics of the future energy system and the government's role is limited to defining the boundary conditions of the transition. Grassroots-centred strategies, by contrast, aim for a decentralised, citizen-led energy transition." The study shows how the three approaches manifest in national climate targets, renewable electricity targets, and the flexibility preferences of government and opposition political parties.

Flexibility options are required to deal with the challenge of intermittent renewable electricity. To ensure an uninterrupted electricity supply, electricity generation and consumption need to be balanced. This can be achieved through cross-border electricity trading, the development of storage facilities, or the installation of additional generation capacities, based, for example, on biomass or concentrated solar power.

Strong goals, weak strategy

Across the political spectrum, researchers found a similar level of ambition with regard to decarbonisation and the expansion of renewables among parties and citizens alike. Thus, contrary to their expectations, the different political ideologies had hardly any effect on energy policy preferences. All three pathways foresee more stringent decarbonisation targets over time, ranging from 75% to 100% by 2050 (compared to 1990). While there is no significant ideologically motivated difference in overall ambition, the decarbonisation targets set by the market-centred strategy are somewhat lower (75% to 80% by 2050) than those of the grassroots-centred (85% to 95%) and state-centred (75% to 100%) pathways.

However, to have any chance of meeting these targets, governments now need to make up for lost time. "Regardless of the strategies they pursue - grassroots, state-centred or market-centred - none of the parties has a plan that is even remotely clear about how they intend to ensure a stable and reliable future supply of electricity in the absence of sunshine or wind," summarises co-author Johan Lilliestam. "Climate targets that are compatible with the Paris Agreement call for the decarbonisation of the European electricity system well before the year 2050. To allow for that possibility, governments now urgently need to adopt plausible policy pathways for achieving that goal." For the rapidly emerging renewable electricity system, flexibility is an issue that needs far more political attention.

The outbreak of coronavirus disease (COVID-19) caused by SARS-CoV-2 virus continues to cause human infection and mortality worldwide. Currently, there are no specific viral protein-targeted therapeutics available. Viral nucleocapsid protein is a potential antiviral drug target, serving multiple critical functions during the viral life cycle. However, the structural information of SARS-CoV-2 nucleocapsid protein remains unclear.

In this article, the authors have determined the 2.7 Å crystal structure of the N-terminal RNA binding domain of SARS-CoV-2 nucleocapsid protein. Although the overall structure is similar as other reported coronavirus nucleocapsid protein N-terminal domain, the surface electrostatic potential characteristics between them are distinct. Further comparison with mild virus type HCoV-OC43 equivalent domain demonstrates a unique potential RNA binding pocket alongside the β-sheet core. Complemented by in vitro binding studies, the authors data provides several atomic resolution features of SARS-CoV-2 nucleocapsid protein N-terminal domain, which could guide the design of novel antiviral agents specifically targeting to SARS-CoV-2.

The study by the Department of Political Science at Aarhus BSS shows that the growing trust crisis observed in many Western democracies in recent decades cannot merely be attributed to news criteria from the media and prioritisation of personal-interest stories. Citizens play a significant role in the rapid spread of these types of articles at the expense of positive stories.

"People are better at remembering information about selfish politicians and are better and more motivated to forward that type of information to other people compared to information that focuses on political substance," explains Troels Bøggild, associate professor in political science at Aarhus BSS, Aarhus University.

"This is because there is an inherent bias in human memory that affects the type of political information we pass on in our social network. This means that citizens are part of exaggerating the problem of selfish politicians," he continues.

Troels Bøggild, together with Associate Professor Lene Aarøe and Professor Michael Bang Petersen from the Department of Political Science at Aarhus BSS, Aarhus University, is behind the study titled "Citizens as Complicits: Distrust in Politicians and Biased Social Dissemination of Political Information ", which has just been published in the prestigious journal American Political Science Review.

Gossip lives on

The conclusions of the study are based on a number of internet-based experiments using a representative sample of 3,353 participants in the US. The experiments were carried out in the form of a telephone game. The participants in the first group read an entire news article, which they then recounted to the next group, who then recounted it to another group. Only the information considered important survives such treatment.

"We observed that people pick up and communicate more about strategy and the selfish behaviour of politicians than the political content itself," says Troels Bøggild. He continues:

"We can also see that mistrust spreads. When negative information about politicians is overrepresented, people who receive it second and third hand will also have less trust in those politicians and support their political decisions to a lesser extent. That's the crux of it," says Troels Bøggild.

It was once a survival mechanism

According to Aarhus BSS researchers, this innate psychological tendency stems from the history of human development, where it was an evolutionary advantage to pay particular attention to leaders who lined their own pockets at the expense of the community.

"At that time, there were no formal control bodies to keep leaders in check, so this was people's way of protecting themselves against authoritarian leaders and non-cooperative behaviour," says Troels Bøggild.

The researchers are now applying this to a political context, and linking it to possible negative consequences for political discourse. The behaviour of politicians, the news values of media, and the level of attention of citizens for politicians who abuse their position of power to promote their own interests, are all key ingredients in this dynamic.

However, the researchers stress that the attention people give to personal interest stories is not necessarily an issue. Together with the media, vigilant citizens can prevent corrupt politicians from coming to power.

The coronavirus SARS-CoV-2 is known to infect cells via the receptor ACE2. An international research team under German-Finnish coordination has now identified neuropilin-1 as a factor that can facilitate SARS-CoV-2 entry into the cells' interior. Neuropilin-1 is localized in the respiratory and olfactory epithelia, which could be a strategically important localization to contribute to SARS-CoV-2 infectivity and spreading. Experts from the German Center for Neurodegenerative Diseases (DZNE), Technical University of Munich, University Medical Center Goettingen, University of Helsinki and other research institutions now published their findings in the journal "Science".

The coronavirus SARS-CoV-2 can affect various organs such as the lung and kidneys and also trigger neurological symptoms, including a temporary loss of smell and taste. The spectrum of symptoms of the associated disease - known as COVID-19 - is therefore quite complex. A related virus, SARS-CoV, led to a much smaller outbreak in 2003, possibly because the infection was limited to the lower respiratory system, making the virus less transmissible. SARS-CoV-2, in contrast, additionally infects the upper respiratory system including the nasal mucosa and, in consequence, spreads rapidly through active viral shedding, e.g. when sneezing.

Door opener to the cell

Tissue tropism reflects the ability of a virus to infect specific cell types in different organs. It is determined by the availability of docking sites, so-called receptors, on the surface of cells. These allow docking to and penetration into the cells. "The starting point of our study was the question why SARS-CoV and SARS-CoV-2 that both use ACE2 as a receptor cause different diseases," explained Mikael Simons, a research group leader at the DZNE's Munich site and professor of molecular neurobiology at the Technical University of Munich, whose team was involved in the current studies, together with Giuseppe Balistreri's group at the University of Helsinki.

To understand how these differences in tissue tropisms can be explained, the researchers took a look at the viral "spike proteins" that are essential for virus entry. "The SARS-CoV-2 spike protein differs from its older relative by the insertion of a furin cleavage site," explained Simons. "Similar sequences are found in the spike proteins of many other highly pathogenic human viruses. When we realized that this furin cleavage site is present in the SARS-CoV-2 spike protein, we thought that this might lead us to the answer." When proteins are cleaved by furin, a specific amino acid sequence becomes exposed at its cleaved end. Such furin cleaved substrates have a characteristic pattern that are known to bind to neuropilins at the cell surface.

Experiments using cells cultured in the laboratory, in conjunction with artificial viruses that mimick SARS-CoV-2 as well as naturally occurring virus, indicate that neuropilin-1 is able to promote infection in the presence of ACE2. By specifically blocking neuropilin-1 with antibodies, infection was suppressed. "If you think of ACE2 as a door to enter the cell, then neuropilin-1 could be a factor that directs the virus to the door. ACE2 is expressed at very low levels in most cells. Thus, it is not easy for the virus to find doors to enter. Other factors such as neuropilin-1 might be necessary to help the virus," explained Simons.

A potential way into the nervous system

Since loss of smell is among the COVID-19 symptoms and neuropilin-1 is mainly found in the cell layer of the nasal cavity, the scientists examined tissue samples from deceased patients. "We wanted to find out whether cells equipped with neuropilin-1 are really infected by SARS-CoV-2, and found that this was the case," said Simons. Additional experiments in mice showed that neuropilin-1 enables transport of tiny, virus-sized particles from the nasal mucosa to the central nervous system. These nanoparticles were chemically engineered to bind to neuropilin-1. When the nanoparticles were administered to the nose of the animals, they reached neurons and capillary vessels of the brain within few hours - in contrast to control particles without affinity for neuropilin-1. "We could determine that neuropilin-1, at least under the conditions of our experiments, promotes transport into the brain, but we cannot make any conclusion on whether this is also true for SARS-CoV-2. It is very likely that this pathway is suppressed by the immune system in most patients," explained Simons.

A starting point for future therapies?

"SARS-CoV-2 requires the ACE2 receptor to enter the cells, but other factors such as neuropilin-1 may be required to support its function," said Simons. "However, at present we can only speculate about the molecular processes involved. Presumably, neuropilin-1 catches the virus and directs it to ACE2. Further investigations are needed to clarify this issue. It is currently too early to speculate whether blocking neuropilin could be a viable therapeutic approach. This will have to be addressed in future studies."

In a major breakthrough an international team of scientists, led by the University of Bristol, has potentially identified what makes SARS-CoV-2 highly infectious and able to spread rapidly in human cells. The findings, published in Science today [20 October] describe how the virus's ability to infect human cells can be reduced by inhibitors that block a newly discovered interaction between virus and host, demonstrating a potential anti-viral treatment.

Unlike other coronavirus, which cause common colds and mild respiratory symptoms, SARS-CoV-2, the causative agent of COVID-19, is highly infective and transmissive. Until now, major questions have remained unanswered as to why SARS-CoV-2 readily infects organs outside of the respiratory system, such as the brain and heart.

To infect humans, SARS-CoV-2 must first attach to the surface of human cells that line the respiratory or intestinal tracts. Once attached, the virus invades the cell then replicates multiple copies of itself. The replicated viruses are then released leading to the transmission of SARS-CoV-2.

The virus's process of attachment to and invasion of human cells is performed by a viral protein, called the 'Spike' protein. Understanding the process by which the 'Spike' protein recognises human cells is central to the development of antiviral therapies and vaccines to treat COVID-19.

In this breakthrough study, the research groups in Bristol's Faculty of Life Sciences, Professor Peter Cullen from the School of Biochemistry; Dr Yohei Yamauchi, Associate Professor and virologist from the School of Cellular and Molecular Medicine, and Dr Boris Simonetti, a senior researcher in the Cullen lab, used multiple approaches to discover that SARS-CoV-2 recognises a protein called neuropilin-1 on the surface of human cells to facilitate viral infection.

Yohei, Boris and Pete explained: "In looking at the sequence of the SARS-CoV-2 Spike protein we were struck by the presence of a small sequence of amino acids that appeared to mimic a protein sequence found in human proteins which interact with neuropilin-1. This led us to propose a simple hypothesis: could the Spike protein of SARS-CoV-2 associate with neuropilin-1 to aid viral infection of human cells? Excitingly, in applying a range of structural and biochemical approaches we have been able to establish that the Spike protein of SARS-CoV-2 does indeed bind to neuropilin-1.

"Once we had established that the Spike protein bound to neuropilin-1 we were able to show that the interaction serves to enhance SARS-CoV-2 invasion of human cells grown in cell culture. Importantly, by using monoclonal antibodies - lab-created proteins that resemble naturally occurring antibodies - or a selective drug that blocks the interaction we have been able to reduce SARS-CoV-2's ability to infect human cells. This serves to highlight the potential therapeutic value of our discovery in the fight against COVID-19."

Intriguingly, scientists at the Technical University of Munich, Germany and the University of Helsinki, Finland, have independently found that neuropilin-1 facilitates SARS-CoV-2 cell entry and infectivity.

Together the Bristol researchers concluded: "To defeat COVID-19 we will be relying on an effective vaccine and an arsenal of anti-viral therapeutics. Our discovery of the binding of the SARS-CoV-2 Spike to neuropilin-1 and its importance for viral infectivity provides a previously unrecognised avenue for anti-viral therapies to curb the current COVID-19 pandemic."

Helping to explain what makes SARS-CoV-2 so capable of infecting human cells, researchers in two independent studies discovered that the virus's spike protein recognizes and binds a protein on the human cell surface called neuropilin-1. This facilitates its ability to enter and infect cells, they suggest. Demonstrating a potential anti-viral treatment, the findings of both studies also describe how the virus's ability to infect human cells through neuropilin-1 can be reduced by inhibitors. Compared to SARS-CoV, which led to a much smaller outbreak in 2003, SARS-CoV-2 spreads rapidly through active pharyngeal viral shedding. Despite these differences, uptake of both viruses is mediated by the identical cellular receptor, ACE2. One hypothesis to explain the enhanced spreading of SARS-CoV-2 is the presence of a unique cleavage site in the SARS-CoV-2 spike protein, the presence of which could potentially create additional human cell surface receptor binding sites. In looking at the sequence of the SARS-CoV-2 spike protein, James Daly and colleagues identified the presence of a small sequence of amino acids that appeared to mimic a protein sequence found in human proteins that interacts with neuropilin-1. This led them to propose the spike protein of SARS-CoV-2 associates with neuropilin-1 to aid viral infection, a hypothesis they confirmed with a range of structural and biochemical approaches. As well, by knocking out neuropilin-1 in human cells, and, in another test, using a monoclonal antibody against neuropilin-1, they were able to reduce SARS-CoV-2's ability to infect cells in culture. A second study independently found that neuropilin-1 facilitates SARS-CoV-2 cell entry and infectivity. In this work Ludovico Cantuti-Castelvetri et al., seeking to inform the reported disturbance of olfaction in a large fraction of COVID-19 patients, analyzed a series of autopsies from six COVID-19 patients. They detected infection of the olfactory epithelium in five out of six. The infected olfactory epithelial cells showed high expression of neuropilin-1, the authors report. While the focus to date in SARS-CoV-2 entry has been almost entirely on the role of ACE2, Cantuti-Castelvetri et al. note, the expression pattern of ACE2 does not match tissue tropism of SARS-CoV-2. This raises the possibility that co-factors are required to facilitate virus-host cell interactions in cells with low ACE2 expression. "[Neuropilin-1] could represent such an ACE2 potentiating factor," Cantuti-Castelvetri et al. say.

During the first wave of COVID-19, which paralyzed the world in spring, it was initially thought that effective hand washing and 2-metre social distancing would help prevent the highly contagious virus. Scientists, however, have now come to the conclusion that proper indoor ventilation is even more effective. It was also found that SARS-CoV-2 is rather moderately infectious and a person would need to remain in a poorly ventilated room for a considerable amount of time to receive an infectious dose of SARS-CoV-2.

Since the first coronavirus SARS-CoV-1 that broke out in Hong-Kong has been proven to be transmitted across long distances in the air, there is a good reason for the scientists, after hearing the large droplets theory, to raise the question of whether there is a transmission risk of the current SARS-COV-2 virus (causing the coronavirus disease COVID-19) beyond 2 metres.

Head of the TalTech Nearly Zero Energy Buildings Research Group, Professor Jarek Kurnitski says, "Multiple studies provided quickly strong scientific evidence for successful indoor airborne transmission of COVID-19 in inadequately ventilated environments. The virus is transmitted via saliva droplets with a size from 0.5 micrometre up to a few thousand micrometres produced by a person by talking, sneezing, coughing, or even just breathing."

The point is that small and large droplets act completely differently. Tiny droplets below 5 micrometres do not settle on surfaces, they remain airborne and follow airflow streamlines for tens of meters. Large droplets above 100 micrometres in diameter fall down like rocks - they do not travel farther than 1.5 meters even by coughing. The air exhaled by humans contains mainly droplets with diameter in the range of 1-10 micrometres. Until this spring, it was held in the medical literature and guidelines that droplets larger than 5 micrometres fall down at the distance of up to 2 meters (which is why it was concluded that 2-metre social distancing would ensure complete safety). By now, however, scientists have found out that this was a misconception or even a long-persisting erroneous medical dogma. Aerosol physics shows convincingly that in reality only droplets larger than 50 micrometres fall down at a distance of 2 meters, while smaller ones remain suspended in the air and travel farther. Thus, acknowledging this tenfold error fundamentally changed the understanding of the spread of virus particles and it was realized that the largest number of exhaled droplets travel far and the virus can remain infectious in aerosol particles for up to 3 hours.

"By breaking this medical dogma, researchers also gave an important signal regarding the measures applied to prevent the spread of COVID-19 that led to the paralysis. Measures can and must be applied taking into account the known transmission routes, which is why it is important to know that the disease is transmitted by aerosols, i.e. tiny droplets suspended in air. This means that you can get the virus in two ways: in close contact, where the concentration of aerosols and larger droplets in close proximity of the infected person is very high, or farther away in inadequately ventilated rooms, where the concentration of aerosols remains so high that a person can get an infectious dose for example within an hour spent in the same room with an infected person," Professor Kurnitski says.

According to academician Kurnitski, the following engineering controls targeting airborne transmission should be applied as a preventive measure in indoor spaces:

sufficient outdoor air ventilation should be applied as the main control (in principle, it does not matter whether outdoor air enters through a ventilation supply duct or a window, the amount of air is important);

if the building does not have a functioning ventilation system, portable air cleaners with fine particle filters should be used to clean indoor air;

in addition, viral contamination can be deactivated by applying short-wavelength ultraviolet (UV-C) light, which is used for example in certain hospital settings.

Ventilation systems with recirculation air that circulate a part of the extract air from a room into the supply air duct, leaving virus particles recirculating in the ventilation system, pose a particular challenge. It is necessary to increase outdoor air supply in such systems. If a system cannot be switched to fully outdoor air, filtration of extract air must be improved by installing more effective filters.

According to the generally recognised infection control classification, the impact of engineering controls is considered to be greater than that of the second most important, currently however most widely applied administrative measures (closing of institutions, canceling of events, etc.). Wearing personal protective equipment (e.g. face masks) is considered to be the least effective measure in preventing the spread of the virus.

A total of 36 researchers from all over the world published the article on the topic titled "How can airborne transmission of COVID-19 indoors be minimised?". In this research group, Estonian researchers were represented by a civil engineer from TalTech, academician Jarek Kurnitski. Prior to publication of the article, a joint petition on the same topic was signed by 239 scientists and submitted to the World Health Organisation (WHO) with a request to acknowledge that the virus is transmitted by aerosols so that ventilation solutions could be implemented to prevent the spread of the virus. As a result, the WHO and other health authorities acknowledged that COVID-19 is spread not only by large droplets but also by tiny aerosol particles remaining in the air for hours and traveling tens of meters.

Cuscuta spp., also known as dodder, is a parasitic vine which grafts to the host plant using special suckers to obtain water, minerals and carbohydrates. The parasite also attacks and damages crops such as oilseed rape, sweetcorn, soy, flax or clover. Although the infection generally goes undetected by the host, some species of tomato actively defend themselves by forming wooden tissue which prevents the suckers from penetrating the plant. In earlier research, the biologists at FAU discovered that these tomatoes possess a special receptor, the Cuscuta receptor 1 (CuRe1), which triggers the defence mechanism. However, until now it was unclear how the receptor recognises the danger posed by the dodder.

The researchers have now succeeded in answering this question: the dodder possesses a specific marker in its cellular wall, a glycine-rich protein (GRP). Using its receptor CuRe1, the tomato is able to recognise the molecular pattern of the GRP and identify the dodder as a pathogen, and triggers the immune reaction as a result. The new findings concerning the molecular dialogue between the Cuscuta marker and the tomato receptor may help to increase the resistance of crop plants against parasitic plants.

If you think that the Sahara is covered only by golden dunes and scorched rocks, you aren't alone. Perhaps it's time to shelve that notion. In an area of West Africa 30 times larger than Denmark, an international team, led by University of Copenhagen and NASA researchers, has counted over 1.8 billion trees and shrubs. The 1.3 million km2 area covers the western-most portion of the Sahara Desert, the Sahel and what are known as sub-humid zones of West Africa.

"We were very surprised to see that quite a few trees actually grow in the Sahara Desert, because up until now, most people thought that virtually none existed. We counted hundreds of millions of trees in the desert alone. Doing so wouldn't have been possible without this technology. Indeed, I think it marks the beginning of a new scientific era," asserts Assistant Professor Martin Brandt of the University of Copenhagen's Department of Geosciences and Natural Resource Management, lead author of the study's scientific article, now published in Nature.

The work was achieved through a combination of detailed satellite imagery provided by NASA, and deep learning -- an advanced artificial intelligence method. Normal satellite imagery is unable to identify individual trees, they remain literally invisible. Moreover, a limited interest in counting trees outside of forested areas led to the prevailing view that there were almost no trees in this particular region. This is the first time that trees across a large dryland region have been counted.

The role of trees in the global carbon budget

New knowledge about trees in dryland areas like this is important for several reasons, according to Martin Brandt. For example, they represent an unknown factor when it comes to the global carbon budget:

"Trees outside of forested areas are usually not included in climate models, and we know very little about their carbon stocks. They are basically a white spot on maps and an unknown component in the global carbon cycle," explains Martin Brandt.

Furthermore, the new study can contribute to better understanding the importance of trees for biodiversity and ecosystems and for the people living in these areas. In particular, enhanced knowledge about trees is also important for developing programmes that promote agroforestry, which plays a major environmental and socio-economic role in arid regions.

"Thus, we are also interested in using satellites to determine tree species, as tree types are significant in relation to their value to local populations who use wood resources as part of their livelihoods. Trees and their fruit are consumed by both livestock and humans, and when preserved in the fields, trees have a positive effect on crop yields because they improve the balance of water and nutrients," explains Professor Rasmus Fensholt of the Department of Geosciences and Natural Resource Management.

Technology with a high potential

The research was conducted in collaboration with the University of Copenhagen's Department of Computer Science, where researchers developed the deep learning algorithm that made the counting of trees over such a large area possible.

The researchers show the deep learning model what a tree looks like: They do so by feeding it thousands of images of various trees. Based upon the recognition of tree shapes, the model can then automatically identify and map trees over large areas and thousands of images. The model needs only hours what would take thousands of humans several years to achieve.

"This technology has enormous potential when it comes to documenting changes on a global scale and ultimately, in contributing towards global climate goals. We are motivated to develop this type of beneficial artificial intelligence," says professor and co-author Christian Igel of the Department of Computer Science.

The next step is to expand the count to a much larger area in Africa. And in the longer term, the aim is to create a global database of all trees growing outside forest areas.

Wear a mask, keep your distance, avoid crowds - these are the common recommendations to contain the COVID-19 epidemic. However, the scientific foundations on which these recommendations are based are decades old and no longer reflect the current state of knowledge. To change this, several research groups from the field of fluid dynamics have now joined forces and developed a new, improved model of the propagation of infectious droplets. It has been shown that it makes sense to wear masks and maintain distances, but that this should not lull you into a false sense of security. Even with a mask, infectious droplets can be transmitted over several meters and remain in the air longer than previously thought.

TU Wien (Vienna), the University of Florida, the Sorbonne in Paris, Clarkson University (USA) and the MIT in Boston were involved in the research project. The new fluid dynamics model for infectious droplets was published in the "International Journal of Multiphase Flow".

A new look on old data

"Our understanding of droplet propagation that has been accepted worldwide is based on measurements from the 1930s and 1940s", says Prof. Alfredo Soldati from the Institute of Fluid Mechanics and Heat Transfer at TU Wien. "At that time, the measuring methods were not as good as today, we suspect that especially small droplets could not be measured reliably at that time".

In previous models, a strict distinction was made between large and small droplets: The large droplets are pulled downwards by gravity, the small ones move forward almost in a straight line, but evaporate very quickly. "This picture is oversimplified," says Alfredo Soldati. "Therefore, it is time to adapt the models to the latest research in order to better understand the propagation of COVID-19".

From a fluid mechanics point of view, the situation is complicated - after all, we are dealing with a so-called multiphase flow: The particles themselves are liquid, but they move in a gas. It is precisely such multiphase phenomena that are Soldati's specialty: "Small droplets were previously considered harmless, but this is clearly wrong," explains Soldati. "Even when the water droplet has evaporated, an aerosol particle remains, which can contain the virus. This allows viruses to spread over distances of several meters and remain airborne for long time."

In typical everyday situations, a particle with a diameter of 10 micrometers (the average size of emitted saliva droplets) takes almost 15 minutes to fall to the ground. So it is possible to come into contact with virus even when distancing rules are observed - for example in an elevator that was used by infected people shortly before. Particularly problematic are environments with high relative humidity, such as poorly ventilated meeting rooms. Special care is required in winter because the relative humidity is higher than in summer.

Protection rules: Useful, but not enough

"Masks are useful because they stop large droplets. And keeping a distance is useful as well. But our results show that neither of these measures can provide guaranteed protection," says Soldati. With the mathematical model that has now been presented, and the current simulations under way it is possible to calculate the concentration of virus-carrying droplets at different distances at different times. "Until now, political decisions on COVID-protection measures have mainly been based on studies from the fields of virology and epidemiology. We hope that in the future, findings from fluid mechanics will also be included," says Alfredo Soldati.

"For 30 weeks already, our study has been documenting how people assess what is happening around the coronavirus," says BfR President Professor Dr. Dr. Andreas Hensel. "This enables us to observe how people react to changes in the pandemic."

https://www.bfr.bund.de/cm/349/201013-bfr-corona-monitor-en.pdf

Further trends in the overview:

Classification of possible sources of infection

Since March, the survey has registered which sources the respondents consider as possible transmission pathways for the coronavirus. Over the entire course of the survey, a stable pattern has been observed: Proximity to other people is mostly associated with a high probability of infection (67 percent in the current survey). Relatively often, contact with door handles is also seen as a source of infection (44 percent). In contrast, the probability of transmission through food, pets or clothing is usually rated as low.

Personal protective measures

The regulations - including the mandatory use of masks and the mandatory distance - are continuously implemented by the vast majority. More attention is also paid to hygiene: In the current survey, respondents said that they protect themselves against an infection by washing their hands more thoroughly (92 percent) and using disinfectants more frequently (74 percent). Many also restrict their social contacts. However, a downward trend could be observed over the summer: While in June about 80 percent said that they met with others less often, this figure has dropped to 60 percent in recent months.

Information behaviour

Since the beginning of the epidemic in Germany, people have informed themselves through various information channels: Here, traditional media such as radio, print and particularly television play a role, as do conversations among acquaintances or the Internet. In this respect, the majority of respondents consider the media coverage surrounding the outbreak to be appropriate (65 percent in the current survey), while around a third (30 percent) rate it as exaggerated.

What happens next?

The BfR-Corona-Monitor will continue in November. The survey will continue to be carried out every two weeks and will comprise around 1,000 people at a time.

The BfR continually adapts its FAQs on the topic of coronavirus to the current state of science:

https://www.bfr.bund.de/en/can_the_new_type_of_coronavirus_be_transmitted_via_food_and_objects_-244090.html

Washington, October 20, 2020--A study of 33 public community college promise programs, or free-college programs, across the United States found that they are associated with large enrollment increases of first-time, full-time students--with the biggest boost in enrollment among Black, Hispanic, and female students. The results come as the economic impact of the Covid-19 pandemic is leading states to tighten higher education budgets, as low-income students are forgoing their postsecondary plans at higher rates this fall than their wealthier peers, and as community colleges are experiencing larger enrollment declines than four-year universities. The study was published today in Educational Evaluation and Policy Analysis, a peer-reviewed journal of the American Educational Research Association.

The research, conducted by Denisa Gándara at Southern Methodist University and Amy Li at Florida International University, is the first on this topic to examine the effects of multiple promise programs on enrollment at community colleges across the United States. For their study, the authors analyzed data from the U.S. Department of Education's Integrated Postsecondary Education Data System, for academic years 2000-01 to 2014-15, to examine the impact of 33 promise programs at 32 community colleges.

Gándara and Li found that, on average, overall enrollments at the community colleges with promise programs increased 23 percent more than at the seven geographically nearest public community colleges without promise programs. Compared to the nearest seven community colleges, promise colleges experienced a 47 percent greater enrollment increase of Black males, a 51 percent greater enrollment of Black females, a 40 percent greater enrollment of Hispanic males, and a 52 percent greater enrollment of Hispanic females. (These increases occurred at different times, depending on when each college had a promise program between 2000 and 2015.) The only groups that did not, on average, experience an enrollment boost associated with promise programs were Asian, Native Hawaiian, and Pacific Islander (API) males and females.

"Prior to the pandemic, promise programs were an increasingly popular mechanism for enhancing college entry and postsecondary attainment," said Gándara, an assistant professor of education policy and leadership at Southern Methodist University. "Our study offers compelling evidence, and reinforces evidence from prior research, of the benefits of such programs in achieving college enrollment goals."

"Our overall findings also offer encouraging evidence that promise programs can help more historically underserved students enroll in college," said Gándara.

In addition, Gándara and Li noted that the effects on enrollment for different demographic groups differed based on program design features and eligibility criteria. These included whether the programs were merit-based or need-based, whether they paid partial or full tuition, and whether the amount of the financial support provided was determined before ("first dollar in") or after ("last dollar in") students' other sources of aid were considered.

Programs with merit-based requirements yielded higher enrollments of White males and females as well as API females, compared to programs without merit-based requirements. Programs with need-based criteria were associated with smaller enrollment increases among all demographic groups, compared to programs without need-based criteria, with the exception of Black males, who showed no difference in effects.

Programs that were "first dollar in" had a significant positive effect on the enrollment of White students but not on other demographic groups. Programs that covered full tuition, as opposed to partial tuition, had a significant positive effect on the enrollment of API students.

"These findings suggest that programs that are more generous might be more likely to attract students categorized as White or API," said Li, an assistant professor of educational policy studies at Florida International University.

"Programs with income criteria have consistent negative effects on enrollment of all groups, except for Black male students," Gándara added. "This could be related to the higher administrative burdens for students, such as requiring proof of income. This potential burden for students should be weighed against the benefits of targeting promise aid to students who need it most."

Findings from the study also reinforced prior research that found promise programs had a greater effect on enrollment than reductions in tuition and fees.

"In addition to reducing price obstacles, promise programs can foster the college-going culture in schools and communities, and change students' perceptions of affordability," Gándara said. "The universal 'free college' and 'college for all' messages that generally accompany promise programs can be especially impactful for racial minority students, who are often subject to lower educational expectations from teachers and counselors and who are more likely to perceive college as unaffordable."

"The budget pressures facing states are very real, as is the developing crisis in college enrollment among the country's least advantaged students," said Li. "Given such encouraging evidence of the effectiveness of community college promise programs on initial college enrollment, working to protect them should be among the top priorities of policymakers."

In birds and other species alike, pairs can face considerable difficulties with reproduction. Scientists at the Max Planck Institute for Ornithology in Seewiesen have now shown in an extensive analysis of 23,000 zebra finch eggs that infertility is mainly due to males, while high embryo mortality is more a problem of the females. Inbreeding, age of the parents and conditions experienced when growing up had surprisingly little influence on reproductive failures.

Zebra finches are small songbirds that originate from Australia. As colony-living granivores, they are easy to keep in aviaries, and they reproduce all year round under favourable conditions. However, reproduction is remarkably unsuccessful: a quarter of the eggs remain unfertilised, and in another quarter of the eggs the embryo dies early during development. Researchers at the Max Planck Institute for Ornithology in Seewiesen have therefore carried out a study to investigate the potential causes of unsuccessful reproduction.

The scientists tracked the fate of more than 23,000 eggs. They measured longevity, productivity, infertility, offspring mortality and other fitness-related traits that covered most phases of reproduction for both sexes. Factors that were expected to influence reproductive failure, such as inbreeding, age of the parents and growing up under unfavourable conditions had negligible effects on the reproductive performance of the zebra finches. This suggests that individuals are remarkably robust to bad conditions and that the causes must lie elsewhere.

When partners are swapped to form new pairs, it becomes clear that problems with fertility typically remain with the male, while problems with embryo mortality typically remain with the female. "Of course, for both problems the pair combination also plays a role", says Yifan Pei, a doctoral student at Seewiesen, "because the formation of a viable embryo requires genes from both the mother and the father".

Although the specific causes of infertility and embryo mortality could not be identified, the researchers showed that reproductive failure has a measurable genetic basis. These results are somewhat surprising, because natural selection should favour genetic variants that optimise reproduction. However, some gene variants that are advantageous for one sex may be disadvantageous for the other. Indeed, the results also indicate that gene variants that reduce male fertility tend to have positive effects on female reproductive output - and vice versa. This effect is known by the technical term "sexually antagonistic pleiotropy" and might explain why such genetic variants can persist in the population.

Many genes influence the reproductive success of zebra finches. Despite the development of sophisticated genomic techniques, it remains difficult to identify and study all genetic components - not to mention the interaction between those genes and the interaction between the genes and the environment in which they are expressed. "If nothing else, the results of the study have shown us where it is not worth looking," says Bart Kempenaers, director of the Department. "Seemingly obvious genetic causes for unsuccessful reproduction, such as inbreeding, contribute far less than we initially thought".

Wolfgang Forstmeier, who supervised the study, adds: "Now we are concentrating our work on a somewhat mysterious chromosome that only exists in the germline (cells that form the egg and the sperm), but not in the body cells of birds. Because it is difficult to take samples from the reproductive organs of living animals, the investigation of the causes is complicated. But the chromosome is a hot candidate for the origin of the problems."

Lack of sleep significantly impairs our ability to stop unwanted and unpleasant thoughts from entering our mind, a new study reveals.

The authors of the study say the findings could have implications for people suffering from psychiatric conditions associated with unwanted thoughts - such as post-traumatic stress disorder, depression and schizophrenia.

The study, from the University of York, tested the ability of participants to suppress intrusive thoughts when they were either sleep deprived or well rested. Sleep deprived participants suffered an increase in unwanted thoughts of nearly 50% compared to those who had a good night's sleep.

Lead author of the study, Dr Marcus Harrington, from the Department of Psychology at the University of York, said: "In everyday life, mundane encounters can remind us of unpleasant experiences. For example, a car driving too fast on the motorway might cause us to retrieve unwanted memories from a car accident many years ago. For most people, thought intrusions pass quickly, but for those suffering with psychiatric conditions such as post-traumatic stress disorder, they can be repetitive, uncontrollable, and distressing.

"It is clear that the ability to suppress unwanted thoughts varies dramatically between individuals, but until now the factors that drive this variability have been mysterious. Our study suggests sleep loss has a considerable impact on our ability to keep unwanted thoughts out of our minds."

For the study, sixty healthy participants learnt to associate faces with photographs of emotionally negative scenes (such as an image from a war zone) or neutral scenes (such as an image of a cityscape).

The following morning, after a night of either sleep or total sleep deprivation, participants were shown the faces and asked to try to suppress thoughts related to the scenes with which they were paired.

Compared to the sleep group, the sleep deprived participants had much more difficulty keeping unwanted thoughts of the emotionally negative and neutral scenes from their minds. While the task became easier with practice for the rested participants, for those who had gone without sleep, thought intrusions remained consistently high.

The sleep group's success at suppressing unwanted thoughts caused them to view the negative scenes more positively after the suppression task, and they also showed a reduced sweat response when the negative scenes were presented. In contrast, the sleep deprivation group's failure to keep unwanted thoughts out of mind meant that they did not experience this positive change in their responses.

Senior author of the study, Dr Scott Cairney, from the Department of Psychology at the University of York, added: "This study offers an important insight into the impact of sleep on mental health. Besides post-traumatic stress disorder and depression, our findings might have implications for our understanding of other disorders linked to sleep disturbances, such as obsessive-compulsive disorder and schizophrenia".

"The study also suggests that the onset of intrusive thoughts and emotional disturbances following bouts of poor sleep could create a vicious cycle, whereby upsetting intrusions and emotional distress exacerbate sleep problems, inhibiting the sleep needed to support recovery".

NUST MISIS material scientists have presented antibacterial nano-coatings based on boron nitride, which are highly effective against microbial pathogens (up to 99.99%). They can become a safe alternative to the usual antibiotics in implantology since they do not have typical negative side effects. The results of the work are published in the international scientific journal ACS Applied Materials & Interfaces.

Nowadays, due to the significant increase in the number of surgical procedures around the world, scientists are solving the problem of microbial infections caused by implants. It is especially serious during orthopedic and dental operations. It is no secret that concomitant drug therapy for inflammation around implants often leads to side effects due to the characteristic properties of the antibiotics, as well as its high doses.

A group of young scientists from NUST MISIS has proposed a non-standard solution to the problem by investigating the interaction of antibiotic-resistant gram-negative bacteria Escherichia coli (E.coli) and a nanofilm consisting of a structured boron nitride surface. It turned out that such a coating inactivates 100% of bacterial cells after 24 hours.

"Hexagonal boron nitride has a complex of unique physicochemical and mechanical properties. As a result of the experiments, we have found out that the special specific structure of boron nitride nanoparticles provides a bactericidal effect comparable to that of an antibiotic: bacteria die as a result of direct physical contact with a special needle-shaped surface of the nano-film. At the same time, there are no side effects typical of an antibiotic on the tissues of the body, and boron nitride itself does not cause cytotoxicity," said Christina Gudz, co-author of the study, a researcher at the NUST MISIS Inorganic Nanomaterials Laboratory.

The researchers went further and filled the micro-pores of a thin coating of boron nitride with the gentamicin antibiotic. The result is an antibacterial effect due to the complete release of the drug in a short initial period. Moreover, its dose was an order of magnitude less than with a conventional injection.

"Taking into account an average patient weight of 60 kg, his daily antibiotic dose is approximately 180 mg; provided that the implant area is, say, 30 cm2 and given that 55 μg of antibiotic is released from the nano-coating under study on the first day, it turns out that the proposed method assumes 100 times less antibiotic than with a standard injection," added Christina Gudz.

According to the authors of the development, the application of an antibacterial film based on boron nitride nanoparticles to the implant can minimize the risk of bacterial contamination due to the physical properties of the surface itself, as well as, in the case of antibiotic modification, local delivery of a minimum amount of the bactericidal component without weighting the implant.

At present, the team is completing in vitro studies of the obtained coatings and is also working on optimizing the coating method for its future use.