Culture

What The Article Says: Researchers review evidence on the risks of aerosolization and transmission of SARS-CoV-2 from patients to health care workers during endoscopy of the upper aerodigestive tract.

Authors: Josh K. Kay, M.D., of Tulane University in New Orleans, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamaoto.2020.1973)

Editor's Note: Please see the article for additional information, including other authors, author contributions and affiliations, conflicts of interest and financial disclosures, and funding and support.

#  #  #

Media advisory: The full article is linked to this news release.

Embed this link to provide your readers free access to the full-text article This link will be live at the embargo time https://jamanetwork.com/journals/jamaotolaryngology/fullarticle/10.1001/jamaoto.2020.1973?guestAccessKey=3c9c67ea-9627-4f43-a910-9af79f270c2b&utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_content=tfl&utm_term=073020

What The Study Did: Age-related differences in nasopharyngeal SARS-CoV-2 levels in patients with mild to moderate COVID-19 were investigated in this observational study.

Authors: Taylor Heald-Sargent, M.D., Ph.D., of the Ann & Robert H. Lurie Children's Hospital in Chicago, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamapediatrics.2020.3651)

Editor's Note: The article contains conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

#  #  #

Media advisory: The full study is linked to this news release.

Embed this link to provide your readers free access to the full-text article This link will be live at the embargo time https://jamanetwork.com/journals/jamapediatrics/fullarticle/10.1001/jamapediatrics.2020.3651?guestAccessKey=df327a0d-b3d8-49ee-a482-76dc3116e6e6&utm_source=For_The_Media&utm_medium=referral&utm_campaign=ftm_links&utm_content=tfl&utm_term=073020

Melbourne researchers have revealed the multiple, intertwined cell death systems that prevent the spread of the 'intracellular' bacterium Salmonella, an important cause of typhoid fever which kills more than 100,000 people annually.

The team revealed that the spread of Salmonella is curtailed by the death of infected cells, but surprisingly cells can die in several distinct ways. Although Salmonella continuously seeks to outsmart infected cells by blocking their suicide, cells have evolved impressive 'back-up' strategies to ensure that the infected cell can still die and thus protect the body from Salmonella infection and consequent typhoid fever.

The research, published in the journal Immunity, was led by a collaborative team including Walter and Eliza Hall Institute researchers Dr Marcel Doerflinger, Ms Yexuan Deng, Dr Ranja Salvamoser, Associate Professor Marco Herold and Professor Andreas Strasser, and University of Melbourne Professor Sammy Bedoui and Dr Paul Whitney, researchers from the Peter Doherty Institute for Infection and Immunity (Doherty Institute).

**At a glance

- Some disease-causing bacteria, including Salmonella, can grow within cells - a tactic that helps them avoid the body's immune defences.

- Melbourne researchers have revealed that cells infected with Salmonella can die - helping to clear the infection - this death can occur in surprisingly different ways, a system that has evolved fail-safe backups.

- The research also revealed unexpected connections between different members of a family of cell death proteins called caspases in helping Salmonella-infected cells to die.

**Fighting the enemy within

Many disease-causing bacteria invade cells, surviving and reproducing within the cells and hiding from the body's immune system. Salmonella, a cause of serious food-borne infections, is one such 'intracellular' bacterium. Cells have developed a range of defences against intracellular bacteria, Professor Bedoui said.

"The rapid death of infected cells is an important protective strategy against intracellular bacteria. This stops the reproduction and spread of the bacteria, and can trigger protective immune defences at the site of the infection, which further control the infection," he said.

"Many proteins have been thought to be important for driving the death of bacteria-infected cells, which signal within cells and also degrade key components of the cell to bring about its death. However, there has been uncertainty about precisely how bacteria-infected cells die, the key molecules involved, and what this means for controlling an infection," Professor Bedoui said.

**Backup cell death pathways

The team used laboratory models lacking different combinations of cell death proteins to understand their contribution to the control of Salmonella infections, Associate Professor Herold said.

"We investigated the roles of proteins involved in three key types of cell death: apoptosis, pyroptosis and necroptosis," he said. "While these processes all result in cell death, each occurs differently at the molecular level, and has different consequences for triggering immunity and inflammation."

When only one of the three forms of cell death were disabled, there was only a minor impact on how effectively Salmonella infections were controlled - this showed that cells were not reliant on one specific system, Dr Doerflinger said.

"When we disabled two or all three forms of cell death, we saw that Salmonella infections were not controlled and the bacteria rapidly spread. This suggested that cells have developed several 'backups' to ensure cell death happens if there is a fault in one cell death pathway. While we only studied Salmonella, we speculate that our findings might be relevant to other intracellular pathogens such as the bacterium that causes tuberculosis," he said.

The team also revealed unexpected roles for cell death proteins called caspases, Professor Strasser said. "Until now, certain caspases including two known as 'caspase 1' and 'caspase 8' had very well-defined roles as early triggers of two distinct types of cell death. Our results showed that contrary to current perceptions these caspases can act within the 'other pathway' and even at later, critical stages of cell death when the cell is being dismantled.

"This is an example of another fail-safe process in the overall cell death machinery that ensures protection against pathogens like Salmonella," he said.

The flexibility in how cells can die can be explained by the ongoing battle between animals and disease-causing bacteria.

"Throughout evolution, both sides have developed new tactics in an 'arms race' for supremacy. Living and multiplying inside cells - rather than outside - helped the bacteria avoid immune detection, but animals responded by developing ways for infected cells to undergo altruistic suicide - which we have revealed is a highly coordinated but flexible system that has several fail-safe mechanisms," Professor Strasser said.

To determine immunity to Sars-Cov-2 and the effectiveness of potential vaccines, the amount of neutralising antibodies in the blood of recovered or vaccinated individuals must be determined. A traditional neutralisation test usually takes two to three days and must be carried out with infectious coronaviruses in a laboratory complying to biosafety level 3. A Swiss-German research team from Bern and Bochum has launched a test that takes only 18 hours and doesn't have high biosafety requirements. The researchers have published their report in the journal Vaccines on 15 July 2020.

The test was developed at the Institute of Virology and Immunology (IVI) of the University of Bern and the Swiss Federal Office for Food Safety and Animal Health, and evaluated in cooperation with colleagues from the Ruhr-Universität Bochum (RUB) using serum samples from Covid-19 patients.

Disguising a harmless virus as Sars-Cov-2

In order to detect antibodies against Sars-Cov-2, the researchers used another virus that doesn't propagate. They exchanged the envelope protein of this virus for the spike protein of the novel coronavirus, which mediates virus entry and infection. "As a result, the viruses can be identified by antibodies against Sars-Cov-2," explains lead author Toni-Luise Meister from the Department of Molecular and Medical Virology at Ruhr-Universität Bochum. "The antibodies bind to the viruses that have been altered in this way and neutralise them so that no longer can penetrate the host cells."

Luminescence helps determine immunity

Since the virus pseudotyped in this way can't propagate in host cells, no elaborate biosafety precautions are necessary for the test. In order to determine the amount of antibodies, the researchers genetically modified the virus so that green fluorescent protein and a luciferase, an enzyme from fireflies, will be produced by infected cells. "After a single round of infection, we can then determine how many cells show green fluorescence," says lead author Ferdinand Zettl from the Institute of Virology and Immunology in Bern. The green fluorescence is an indicator of infection with the pseudotyped virus. The less green cells the researchers are finding, the more neutralizing antibodies are present which blocked the virus. In addition, a luminometer may be used to read the luminescence signal produced by the luciferase enzyme - another way of evaluating the test.

Quick and reliable

In order to check the reliability and comparability with the conventional neutralisation test, the researchers applied it to blood samples from Covid-19 patients. "The direct comparison showed a good correlation between the two test systems," explains corresponding author Professor Stephanie Pfänder from the Department of Molecular and Medical Virology at RUB. Compared to 56 hours for the conventional test, the new test is much faster, with only 18 hours to the test result. "Another great advantage is that it can be carried out in almost all medical labs, because no sophisticated safety precautions are necessary," points out Dr. Gert Zimmer from the Institute of Virology and Immunology in Bern, corresponding author of the study.

Sitting back and watching your toddler explore their world is good for parent mental health, a new study has found.

As part of her PhD at Edith Cowan University in Western Australia, Mandy Richardson conducted the world's first data-driven study of parenting classes based on the Respectful Approach intervention.

The Respectful Approach, modelled on Resources for Infant Educators (RIE)TM, guides parents to treat young children as capable and independent humans who can flourish if given safe space and freedom from too much adult direction.

Parents were invited to take part in a class for infants or toddlers over six weeks where they observed their children in uninterrupted play in a room with age appropriate toys.

The infants and toddlers were free to investigate their environment and interact with other children while parents sat in the room and watched with a facilitator. After an observation period, each class introduced and discussed a topic related to the Respectful Approach.

At the end of the program, parents reported significantly lower stress levels, with more confidence and a better understanding of their children's capabilities.

Children make progress when given space and time

Ms Richardson said the Respectful Approach is ultimately about building a trusting, lasting bond with positive communication between parents and children. There is less focus on checklists and achieving milestones, with acknowledgement that each child is different.

"Participants in the study reported worrying less about performance pressure after attending the classes, which let them refocus on their relationship with their children," she said.

"As parents we tend to go and 'save' our children when they start to struggle with something, instead of letting them try to resolve their own challenges. But if the children aren't looking for help, perhaps they can be left to do their own thing and work it out themselves."

Ms Richardson explained the Respectful Approach helps to establish good patterns in early years so children learn to build confidence in their abilities and to deal with conflict in emotionally intelligent ways.

"Traditionally early behavioural interventions have predominantly focused on modifying undesirable child behaviours," Ms Richardson said.

"By building good communication and a close parent-child bond, we can potentially prevent problems occurring in the long term."

Ms Richardson and her research supervisor Associate Professor Therese O'Sullivan are now expanding the pilot study to track parents and children over three years to determine whether the decline in parental stress levels has a lasting impact and investigate long term outcomes in child development.

Boston, Mass. - The development of a safe and effective vaccine will likely be required to end the COVID-19 pandemic. A group of scientists, led by Beth Israel Deaconess Medical Center (BIDMC) immunologist Dan H. Barouch, MD, PhD, now report that a leading candidate COVID-19 vaccine developed at BIDMC in collaboration with Johnson & Johnson raised neutralizing antibodies and robustly protected non-human primates (NHPs) against SARS-CoV-2, the virus that causes COVID-19. This study builds on the team's previous results and is published in the journal Nature.

"This vaccine led to robust protection against SARS-CoV-2 in rhesus macaques and is now being evaluated in humans," said Barouch, who is Director of BIDMC's Center for Virology and Vaccine Research.

The vaccine uses a common cold virus, called adenovirus serotype 26 (Ad26), to deliver the SARS-CoV-2 spike protein into host cells, where it stimulates the body to raise immune responses against the coronavirus. Barouch has been working on the development of a COVID-19 vaccine since January, when Chinese scientists released the SARS-CoV-2 genome. Barouch's group, in collaboration with Johnson & Johnson, developed a series of vaccine candidates designed to express different variants of the SARS-CoV-2 spike protein, which is the major target for neutralizing antibodies.

Barouch and colleagues conducted a study in 52 NHPs, immunizing 32 adult rhesus macaques with a single dose of one of seven different versions of the Ad26-based vaccine, and giving 20 animals sham vaccines as placebo controls. All vaccinated animals developed neutralizing antibodies following immunization. Six weeks after the immunization, all animals were exposed to SARS-CoV-2. All 20 animals that received the sham vaccine became infected and showed high levels of virus in their lungs and nasal swabs. Of the six animals that received the optimal vaccine candidate, Ad26.COV2.S, none showed virus in their lungs, and only one animal showed low levels of virus in nasal swabs.

Moreover, neutralizing antibody responses correlated with protection, suggesting that this biomarker will be useful in the clinical development of COVID-19 vaccines for use in humans.

"Our data show that a single immunization with Ad26.COV2.S robustly protected rhesus macaques against SARS-CoV-2 challenge," said Barouch, who is also the William Bosworth Castle Professor of Medicine at Harvard Medical School, a member of the Ragon Institute of MGH, MIT, and Harvard, and a co-leader of the vaccine working group of the Massachusetts Consortium on Pathogen Readiness. "A single-shot immunization has practical and logistical advantages over a two-shot regimen for global deployment and pandemic control, but a two-shot vaccine will likely be more immunogenic, and thus both regimens are being evaluated in clinical trials. We look forward to the results of the clinical trials that will determine the safety and immunogenicity, and ultimately the efficacy, of the Ad26.COV2.S vaccine in humans."

Investigators at Beth Israel Deaconess Medical Center (BIDMC) and other institutions have initiated a first-in-human Phase 1/2 clinical trial of the Ad26.COV2.S vaccine in healthy volunteers. Kathryn E. Stephenson, MD, MPH, is the principal investigator for the trial at BIDMC, which is funded by Janssen Vaccines & Prevention, B.V., a pharmaceutical research arm of Johnson & Johnson.

Pending clinical trial outcomes, the Ad26.COV2.S vaccine is on track to start a phase 3 efficacy trial in 30,000 participants in September.

To fight viruses, cells can deploy defence enzymes that progressively destroy viral genome strands starting from one of the two strand ends. However, this degradation mechanism is not effective against epidemic viruses such as Zika. In fact, the defence enzyme jams at precise points of the viral genome, which put up a strenuous resistance by assuming "defensive" conformation. This is how the virus succeeds at protecting important pieces of its RNA inside infected cells, as demonstrated by a recent study coordinated by SISSA of Trieste and published in the journal Nature Communications. Although the capability of some viruses, such as those responsible for Zika infection, dengue or yellow fever, to generate RNAs resistant to the attack from the cellular machinery was already known, the scientists have discovered and explained in this study the mechanistic rationale behind the phenomenon using computer simulations. Some parts of the viral RNA strand react to the progressive enzymatic degradation, which starts from one particular end of the strand, by assuming an extremely compact form. The degradation process is thus blocked and eluded. At the same time, if the same RNA strand is approached from the other end, the one engaged by the enzymes that copy it, the molecule does not oppose as strongly, allowing the virus to replicate itself efficiently. The defence mechanism, in short, starts where the attack begins.

The new study opens new perspectives for the use of computer simulations to discover heretofore unimagined properties of viral RNAs and thus providing, in perspective, possible mechanistic clues for novel therapeutic approaches.

Furthermore, the unusual properties found in Zika RNA, which are the product of the long evolutionary race between the virus and the infected organisms, could be exploitable for designing new meta-materials endowed with directional mechanical resistance.

Virtual experiments to study viral genome resistance

"Lab experiments had already discovered that sizeable portions of the Zika genome could successfully resist to the attack of degrading enzymes. How exactly this occurred, however, was unclear and beyond reach of direct probing with current experimental techniques", explains Cristian Micheletti of SISSA, who coordinated the study. To shed light on the issue, the scientists have used computer simulations, reproducing in a sort of virtual experiment what happens inside the cell when the viral RNA is engaged at its two ends. "The research has allowed us to understand how the degradation resistance of these viral RNA is encoded in their intricate structure and how the latter, in turn, causes the mechanical resistance to be so different at the two ends. The uncovered mechanical rationale is as simple as it is elegant and at the same time very efficient."

Like an automatic umbrella

Micheletti explains it using the metaphor of an automatic umbrella: "if we put our automatic umbrella into the holder and we inadvertently press the button, the umbrella will get stuck and will resist our attempts to pull it out. This is more or less what happens when the defence enzymes interact with special spots of the viral RNA strand: they trigger a tightening process of the strand which prevents them from proceeding any further". By contrast, the enzymes that read or copy the same viral RNA work from the opposite end of the strand, and do not trigger a significant resistance, allowing the pathogen to replicate and spread the infection. In short, by taking the umbrella from the other end, there is no risk of triggering the switch.

From biology to nanotechnology: new research perspectives

Antonio Suma, lead author of the study, explains: "By using modelling and simulations we have shed light on the unusual mechanical properties of Zika genome and complemented experiments by providing a detailed description of the underpinning atomistic processes."

"It will be very interesting" continues Micheletti, "to investigate whether these surprising mechanical properties can be found in other viral and non-viral RNA. We also hope our findings will inspire the realization of new types of meta-materials, for example supra-molecular strands that, thanks to a judicious design of their conformation, might acquire the same directional mechanical strength found in Zika RNA."

A new study has revealed that tumours can evade the immune system by telling immune cells to produce immunosuppressive steroids. Researchers from the Wellcome Sanger Institute, Department of Pathology, University of Cambridge, and MRC Cancer Unit, discovered that immune T cells from mouse skin and breast tumours secrete steroids, and that preventing this steroid production reduced growth of tumours in mice. The study found that either removing a key steroid-producing gene, or switching it off with a drug, dramatically slowed the formation or progression of cancers.

Reported in Nature Communications, the mouse study revealed this steroid signalling pathway contained potential drug targets for developing new types of cancer immunotherapy, although further human studies are needed.

The immune system is extremely complex. While immune cells protect the body from tumours and infections, some chemicals produced in the body can dampen down the immune system. This makes it much harder for the body to fight against cancer, and cancer immunotherapies that restore the activity of the immune system are urgently needed.

A previous study* had revealed that some immune cells, known as T cells, produced steroids after an infection had passed, to reduce their activity back to low levels again. The researchers wanted to find out if tumour T cells could behave in the same way.

The team tested T cells from melanoma and breast tumours in mice, using single cell RNA sequencing to see exactly which genes were switched on in each individual cell. The researchers discovered that T cells from tumours did produce steroids, which could potentially reduce their effectiveness at battling the tumour.

Dr Bidesh Mahata, the lead author from the University of Cambridge and the Wellcome Sanger Institute, said: "For the first time, we could see that mouse tumour T cells were producing immunosuppressive steroids, even though T cells from healthy mice didn't. It appears that tumours could be instructing their T cells to produce steroids, which would then allow the tumours to evade the immune system and continue growing. This is a really exciting discovery as it means there might be a way of switching the steroid production off again to treat cancer. This is a new hope in cancer, particularly for those tumours that use this trick to suppress anti-tumour immunity."

To test switching off the steroid production, the researchers worked with mice that were missing a key steroid-synthesis gene - Cyp11a1 - from their T cells. They discovered that whereas tumours developed rapidly in normal, wild-type mice, tumour growth was inhibited in these knockout mice with any tumours being much smaller and slower to grow. They also showed that a drug that inactivates the Cyp11a1 protein, aminoglutethimide, also reduced the tumours in normal mice.

Dr Jacqui Shields from the MRC Cancer Unit Cambridge, said: "Using mouse models, we showed that preventing T cells from producing steroids made a huge difference to tumour growth, reducing it dramatically. We found that either removing the key gene, or preventing it from functioning with drugs, stimulated anti-tumour immunity. This suggests the steroid-production pathway could be a real contender in the search for drug targets for designing cancer immunotherapies, to help treat cancer patients."

Dr Sarah Teichmann, a senior author from the Wellcome Sanger Institute, said: "This study may pave the way for new hope in cancer immunotherapy. While these results are from mice, preliminary data from human tissues suggests that the same tumour defence may happen in people and we now need further research to show direct evidence in human cancer. If this is confirmed, in the future, it might be possible to target this immunosuppressive pathway, to create new treatments to switch the immune system back on, and help save lives."

Resembling a butterfly with its symmetrical structure, beautiful colours, and intricate patterns, this striking bubble of gas — known as NGC 2899 — appears to float and flutter across the sky in this new picture from ESO’s Very Large Telescope (VLT). This object has never before been imaged in such striking detail, with even the faint outer edges of the planetary nebula glowing over the background stars.

NGC 2899’s vast swathes of gas extend up to a maximum of two light-years from its centre, glowing brightly in front of the stars of the Milky Way as the gas reaches temperatures upwards of ten thousand degrees. The high temperatures are due to the large amount of radiation from the nebula’s parent star, which causes the hydrogen gas in the nebula to glow in a reddish halo around the oxygen gas, in blue.

This object, located between 3000 and 6500 light-years away in the Southern constellation of Vela (The Sails), has two central stars, which are believed to give it its nearly symmetric appearance. After one star reached the end of its life and cast off its outer layers, the other star now interferes with the flow of gas, forming the two-lobed shape seen here. Only about 10–20% of planetary nebulae [1] display this type of bipolar shape.

Astronomers were able to capture this highly detailed image of NGC 2899 using the FORS instrument installed on UT1 (Antu), one of the four 8.2-metre telescopes that make up ESO’s VLT in Chile. Standing for FOcal Reducer and low dispersion Spectrograph, this high-resolution instrument was one of the first to be installed on ESO’s VLT and is behind numerous beautiful images and discoveries from ESO. FORS has contributed to observations of light from a gravitational wave source, has researched the first known interstellar asteroid, and has been used to study in depth the physics behind the formation of complex planetary nebulae.

This image was created under the ESO Cosmic Gems programme, an outreach initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.

Irvine, Calif., July 30, 2020 -- The first landmark study using next-generation technology to comprehensively examine contaminants in oysters in Myanmar reveals alarming findings: the widespread presence of human bacterial pathogens and human-derived microdebris materials, including plastics, kerosene, paint, talc and milk supplement powders.

The study -- led by scientists from the University of California, Irvine, in collaboration with Environmental Defense Fund, Cornell University and the University of Queensland -- was conducted in the eastern Andaman Sea through partnerships with local researchers in Myanmar in the densely populated but still rural Tanintharyi region. The study concludes that coastal urbanization and lack of sewage treatment increases contamination in seafood and can cause potential health risks to humans, even large distances from pollution sources.

Study results appear in Science of the Total Environment. (Link to study: https://doi.org/10.1016/j.scitotenv.2020.139081)

The area covered by the study spanned nine coral reefs off Myanmar's Mergui Archipelago, situated roughly 40 miles from Myeik, a city with a population of over 250,000 people. The study examined contaminants in seawater and in oysters using next-generation DNA sequencing to reveal 5,459 potential human pathogens belonging to 87 species of bacteria. More than half of these pathogens are considered detrimental to human health. In addition, the scientists used infrared spectroscopy to examine individual microdebris particles found in the oysters. Of the 1,225 individual microdebris particles examined, 78 different types of contaminant materials were found.

"While 48 percent of the microparticles were microplastics - a finding representative across numerous ocean ecosystems - many other particles were not plastic and originated from a variety of human-derived materials that are constituents of fuels, paints and cosmetics," said senior author Joleah Lamb, assistant professor of ecology & evolutionary biology at UCI. "We were particularly surprised to find three different brands of milk powder formula, which comprised 14 percent of the microdebris contaminants."

Both types of contaminants - pathogens and microparticles - reflect the pervasive presence of sewage and runoff from human and animal sources. The implications for other coastal regions are significant, since coastal marine environments worldwide are being increasingly subjected to reduced water quality from urbanization that could be leading to the contamination of important fishery species on a global scale.

Implications for human health are also significant. Oysters in this region and elsewhere are part of the local diet and typically consumed raw and whole. The contaminants found in this study indicate that even the Mergui Archipelago in largely rural Myanmar has significant and widespread pollution from runoff of agricultural and human waste that can affect downstream food sources over a wide area far from urban centers.

Today more than half of seafood exports by value originate in developing countries, raising more general concerns about local food safety and food security worldwide.

"It's important to keep in mind that much of our seafood is imported from overseas, from places that may be contaminated, emphasizing the importance of both adequate testing and improvements to coastal water quality worldwide," said lead author Raechel Littman, a postdoctoral scholar in ecology & evolutionary biology at UCI.

Apart from human bacterial pathogens, the predominance of microplastics and other types of microparticles present in seafood could have implications for both the environment and human health.

"Scientists are only beginning to explore the human health consequences from consuming microplastics," said Lamb.

Many plastic particles can carry toxins, such as persistent organic pollutants, or POPs, like dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs) and bisphenol A (BPA), that subsequently enter the ocean and marine food webs, and can eventually be transferred to people through food. Therefore, the uptake of microplastics in the marine environment could have far-reaching consequences for human consumption of seafood and can be an emerging risk to public health globally.

Also concerning is that over half of the microdebris contaminants detected in the Myanmar oyster tissues were composed of non-polymer materials that can be harmful to human health if ingested, such as kerosene, saponin and talc. Moreover, the prominence of milk supplement detected suggests a direct fecal-oral link between human waste and sewage making its way back into the food chain, thereby elevating the risk of contamination or disease transmission.

"This study in important in its global implications. There is strong evidence of transferability of the findings from Myanmar to other seafood sources around the world," said Douglas Rader, chief scientist for the EDF Oceans program and collaborator on this study. "These findings highlight both the risks of coastal urbanization and the importance of adequate wastewater and stormwater management. It also shows clearly the need for better science related to the potential impacts of these contaminants, and the need for better testing programs so that seafood consumers can rely on its wholesomeness.

COVID-19 has changed the lives of millions and even billions of people around the world. The disease is caused by SARS coronavirus 2 (SARS-CoV-2), an RNA virus, i.e. a virus that uses RNA to store its genetic information. In order to confront it, we must have a detailed understanding of the structure and function of its individual proteins.

One of the mechanisms that the coronavirus uses to try and outsmart our immunity and convince our cells that the viral RNA is harmless is the installation of so-called caps, special structures at the beginning of the RNA, thanks to which the viral RNA imitates human RNA, allowing the virus to infect the human body and multiply within it.

The cap installation process catalyzes the Nsp16 coronavirus protein with involvement from another viral protein, Nsp10. Headed by Dr. Evžen Bou?a and Dr. Radim Nencka, a group of researchers at the Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences used X-ray crystallography to determine and analyze the precise structure of the complex of these two proteins.

This allowed the researchers to identify several fundamental characteristics of the Nsp16 and Nsp10 protein complex, namely a deep canyon on the surface of the protein complex where binding of the viral RNA occurs and a cap is installed. This canyon can be targeted by inhibitors that suppress the activity of the Nsp16 and Nsp10 protein complex and thus of the entire cap installation process and may, in the future, serve as drugs to combat many coronaviruses.

"Hundreds of research teams tried to shed light on how the COVID-19 virus is able to hide its RNA from cellular immunity. In the end, two American teams and we here in Prague were the ones who succeeded," explains Evzen Boura, head of the Structural Membrane Biology group. "We used X-ray analysis to determine the structure of the responsible viral enzyme with inhibitor."

Two teams of astronomers have made a compelling case in the 33-year-old mystery surrounding Supernova 1987A. Based on observations of the Atacama Large Millimeter/submillimeter Array (ALMA) and a theoretical follow-up study, the scientists provide new insight for the argument that a neutron star is hiding deep inside the remains of the exploded star. This would be the youngest neutron star known to date.

Ever since astronomers witnessed one of the brightest explosions of a star in the night sky, creating Supernova 1987A (SN 1987A), they have been searching for a compact object that should have formed in the leftovers from the blast.

Because particles known as neutrinos were detected on Earth on the day of the explosion (23 February 1987), astronomers expected that a neutron star had formed in the collapsed center of the star. But when scientists could not find any evidence for that star, they started to wonder whether it subsequently collapsed into a black hole instead. For decades the scientific community has been eagerly awaiting a signal from this object that has been hiding behind a very thick cloud of dust.

The "blob"

Recently, observations from the ALMA radio telescope provided the first indication of the missing neutron star after the explosion. Extremely high-resolution images revealed a hot "blob" in the dusty core of SN 1987A, which is brighter than its surroundings and matches the suspected location of the neutron star.

"We were very surprised to see this warm blob made by a thick cloud of dust in the supernova remnant," said Mikako Matsuura from Cardiff University and a member of the team that found the blob with ALMA. "There has to be something in the cloud that has heated up the dust and which makes it shine. That's why we suggested that there is a neutron star hiding inside the dust cloud."

Even though Matsuura and her team were excited about this result, they wondered about the brightness of the blob. "We thought that the neutron star might be too bright to exist, but then Dany Page and his team published a study that indicated that the neutron star can indeed be this bright because it is so very young," said Matsuura.

Dany Page is an astrophysicist at the National Autonomous University of Mexico, who has been studying SN 1987A from the start. "I was halfway through my PhD when the supernova happened," he said, "it was one of the biggest events in my life that made me change the course of my career to try to solve this mystery. It was like a modern holy grail."

The theoretical study by Page and his team, published today in The Astrophysical Journal, strongly supports the suggestion made by the ALMA team that a neutron star is powering the dust blob. "In spite of the supreme complexity of a supernova explosion and the extreme conditions reigning in the interior of a neutron star, the detection of a warm blob of dust is a confirmation of several predictions," Page explained.

These predictions were the location and the temperature of the neutron star. According to supernova computer models, the explosion has "kicked away" the neutron star from its birthplace with a speed of hundreds of kilometers per second (tens of times faster than the fastest rocket). The blob is exactly at the place where astronomers think the neutron star would be today. And the temperature of the neutron star, which was predicted to be around 5 million degrees Celsius, provides enough energy to explain the brightness of the blob.

Not a pulsar or a black hole

Contrary to common expectations, the neutron star is likely not a pulsar. "A pulsar's power depends on how fast it spins and on its magnetic field strength, both of which would need to have very finely tuned values to match the observations," said Page, "while the thermal energy emitted by the hot surface of the young neutron star naturally fits the data."

"The neutron star behaves exactly like we expected," added James Lattimer of Stony Brook University in New York, and a member of Page's research team. Lattimer has also followed SN 1987A closely, having published prior to SN 1987A predictions of a supernova's neutrino signal that subsequently matched the observations. "Those neutrinos suggested that a black hole never formed, and moreover it seems difficult for a black hole to explain the observed brightness of the blob. We compared all possibilities and concluded that a hot neutron star is the most likely explanation."

This neutron star is a 25 km wide, extremely hot ball of ultra-dense matter. A teaspoon of its material would weigh more than all the buildings within New York City combined. Because it can only be 33 years old, it would be the youngest neutron star ever found. The second youngest neutron star that we know of is located in the supernova remnant Cassiopeia A and is 330 years old.

Only a direct picture of the neutron star would give definite proof that it exists, but for that astronomers may need to wait a few more decades until the dust and gas in the supernova remnant become more transparent.

Detailed ALMA images

Even though many telescopes have made images of SN 1987A, none of them have been able to observe its core with such high precision as ALMA. Earlier (3-D) observations with ALMA already showed the types of molecules found in the supernova remnant and confirmed that it produced massive amounts of dust.

"This discovery builds upon years of ALMA observations, showing the core of the supernova in more and more detail thanks to the continuing improvements to the telescope and data processing," said Remy Indebetouw of the National Radio Astronomy Observatory and the University of Virginia, who has been a part of the ALMA imaging team.

Global warming will modify the distribution and abundance of fish worldwide, with effects on the structure and dynamics of food networks. However, making precise predictions on the consequences of this global phenomenon is hard without having a wide historical perspective.

A study carried out at the University of Barcelona and the Southern Centre for Scientific Research (CADIC-CONICET, Argentina), analysed the potential implications in the distribution of the Argentinian hake (Merluccius hubbsi), caused by the warming of marine waters. The study is based on the analysis of the structure of the marine ecosystems from 6,000 to 500 years ago, when temperatures were warmer than now. The results show this species could expand towards south and reach the coast of the South America extreme southern area, like it happened in the past. According to the researchers, this approach allows researchers to make predictions on the transformations to be caused by the climate change in the marine environment with important ecogical and economic implications.

The study, published in the journal Oecologia, is part of the doctoral thesis by the researcher Maria Bas, member of CADIC-CONICET and the Biodiversity Research Institute (IRBio) of the University of Barcelona, co-supervised by the tenure-track 2 lecturer Lluís Cardona, from the Research Groups on Large Marine Vertebrates at the Department of Evolutionary Biology, Ecology and Environmental Sciences of the Faculty of Biology and IRBio, and by the expert Ivan Briz i Godino, from CADIC-CONICET. York University (United Kingdom) and British Columbia University (Canada) have also taken part in the study.

The Middle Holocene, a plausible view of the future

Researchers focused on the Atlantic coast of Isla Grande in Tierra del Fuego, in the extreme south of Argentina, where the hake is a key species for industrial fisheries. They collected samples from two archaeological sites dating from the Middle Holocene, that is, between 6,000 and 500 years ago, a period when temperatures would be analogous to those we are heading to in the future -according to climate models. "Remains from fish that lived in the warmest periods of the Holocene are specially interesting since they offer a plausible view of the future in the context of global warming. At the moment, the average annual temperature of the sea surface in Tierra del Fuego is about 7ºC, but during the Middle Holocene it reached 11 and 12ºC. Therefore, data on the biology of the hake during this period can provide information on the distribution of this species in a near future", note the authors.

The presence of remains from other models of hake in the archaeological site Río Chico 1, in the north of Tierra del Fuego (Argentina), show the existence of a large population of hake in the northern east of Tierra del Fuego during the Middle Holocene. Since then, this population disappeared due to the cooling temperatures and their habitat was unknown.

Changes in the distribution of the Argentinian hake

In order to discover the habitat of these fish, the first step in the study was to identify the remains through the mitochondrial DNA analysis and make a reconstruction of the size of old models. Then, researchers used the technique of carbon and nitrogen stable isotope analysis to study changes in the trophic position and the use of the habitat over time. This technique enables researchers to get information on the food intake, and the environment of the species that lived in a recent past, since the information is registered in the bone isotopic signal.

Results show that Argentinian hake that lived in the Atlantic coast of Tierra del Fuego during the Middle Holocene had a broader isotopic niche and fed in more coastal habitats compared to those in current times. "This information, combined with strong winds and currents of the region, together with the lack of sailing technology during the Middle Holocene suggest that groups of aboriginal hunter-fisher-gatherers were likely to fish in the shore", note the authors. If the environmental conditions of a warmer world coincide with what prevails in the Middle Holocene, the Argentinian hake could be more abundant in the continental Argentinian platform of Tierra del Fuego. "From a fishing perspective, this situation suggests a potential increase of resources in shallow waters regarding Tierra del Fuego with important changes in the fishing industry in this region", highlights Lluís Cardona.

According to the researchers, this methodology can be used with other species and in other areas of the planet. "In the future, we would like to know the changes that have taken place in the distribution and ecological niche of the hake and the cod in European waters", concludes the researcher.

RESEARCH TRIANGLE PARK, N.C. -- An Army-funded project marks a turning point in the field of scalable quantum processors, producing the largest quantum chip of its type using diamond-based qubits and quantum photonics.

Millions of quantum processors will be needed to build quantum computers, and new research at MIT and Sandia National Laboratories, funded and managed in part by the U.S. Army Combat Capability Development's Command's Army Research Laboratory's Center for Distributed Quantum Information, demonstrates a viable way to scale-up processor production.

"Building large scale quantum devices will entail both the assembly of large numbers of high-quality qubits and the creation of reliable circuits for transmitting and manipulating quantum information between them," said Dr. Fredrik Fatemi, Army researcher and CDQI co-manager. "Here, the research team has demonstrated exceptional progress toward reliably manufacturing complex quantum chips with both critical elements."

Unlike classical computers, which process and store information using bits represented by either 0s and 1s, quantum computers operate using quantum bits, or qubits, which can represent 0, 1, or both at the same time. This strange property allows quantum computers to simultaneously perform multiple calculations, solving problems that would be intractable for classical computers.

The qubits in the new chip are artificial atoms made from defects in the diamond, which can be prodded with visible light and microwaves to emit photons that carry quantum information. The process, which the researchers describe in the peer-reviewed journal Nature, is a hybrid approach, in which carefully selected quantum micro-chiplets containing multiple diamond-based qubits are placed on an aluminum nitride photonic integrated circuit.

"In the past 20 years of quantum engineering, it has been the ultimate vision to manufacture such artificial qubit systems at volumes comparable to integrated electronics," said Dirk Englund, an associate professor in MIT's Department of Electrical Engineering and Computer Science. "Although there has been remarkable progress in this very active area of research, fabrication and materials complications have thus far yielded just two to three emitters per photonic system."

Using their hybrid method, the researchers were able to build a 128-qubit system -- the largest integrated artificial atom-photonics chip yet.

The artificial atoms in the chiplets consist of color centers in diamonds, defects in diamond's carbon lattice where adjacent carbon atoms are missing, with their spaces either filled by a different element or left vacant. In the chiplets, the replacement elements are germanium and silicon. Each center functions as an atom-like emitter whose spin states can form a qubit. The artificial atoms emit colored particles of light, or photons, that carry the quantum information represented by the qubit.

Diamond color centers make good solid-state qubits, but "the bottleneck with this platform is actually building a system and device architecture that can scale to thousands and millions of qubits," said Noel Wan, MIT research and the paper's coauthor. "Artificial atoms are in a solid crystal, and unwanted contamination can affect important quantum properties such as coherence times. Furthermore, variations within the crystal can cause the qubits to be different from one another, and that makes it difficult to scale these systems."

Instead of trying to build a large quantum chip entirely in diamond, the researchers decided to take a modular and hybrid approach.

"We use semiconductor fabrication techniques to make these small chiplets of diamond, from which we select only the highest quality qubit modules," Wan said. "Then we integrate those chiplets piece-by-piece into another chip that wires the chiplets together into a larger device."

The integration takes place on a photonic integrated circuit, which is analogous to an electronic integrated circuit but uses photons rather than electrons to carry information. Photonics provides the underlying architecture to route and switch photons between modules in the circuit with low loss. The circuit platform is aluminum nitride, rather than the traditional silicon of some integrated circuits.

Using this hybrid approach of photonic circuits and diamond chiplets, the researchers were able to connect 128 qubits on one platform. The qubits are stable and long-lived, and their emissions can be tuned within the circuit to produce spectrally indistinguishable photons, according to the researchers.

While the platform offers a scalable process to produce artificial atom-photonics chips, the next step will be to test its processing skills.

"This is a proof of concept that solid-state qubit emitters are very scalable quantum technologies," Wan said. "In order to process quantum information, the next step would be to control these large numbers of qubits and also induce interactions between them."

The qubits in this type of chip design wouldn't necessarily have to be these particular diamond color centers. Other chip designers might choose other types of diamond color centers, atomic defects in other semiconductor crystals like silicon carbide, certain semiconductor quantum dots, or rare-earth ions in crystals.

"Because the integration technique is hybrid and modular, we can choose the best material suitable for each component, rather than relying on natural properties of only one material, thus allowing us to combine the best properties of each disparate material into one system," said Tsung-Ju Lu, MIT researcher and the paper's co-author.

Finding a way to automate the process and demonstrate further integration with optoelectronic components such as modulators and detectors will be necessary to build even bigger chips necessary for modular quantum computers and multichannel quantum repeaters that transport qubits over long distances, the researchers said.

"The team has made an incredible advance toward the large-scale integration of artificial atoms and photonics and, looking forward, we are very excited for increasingly complex testing of the devices," said Dr. Sara Gamble, program manager at the Army Research Office, an element of CCDC ARL, and CDQI co-manager. "The modular approach so far successfully demonstrated by the team has enormous promise for the future quantum computers and quantum networks of high interest to the Army."

Washington, DC - Before the era of COVID-19, research suggested that premature deaths among white Americans were rising. Even before the era of COVID-19, these findings were surprising. As Dr. Cooley explains, "These trends were puzzling to us because white people, on average, have more wealth than other racial groups and are generally privileged in our society." As a result, Cooley and colleagues questioned whether factors other than income and education, known as objective indicators of status, may not buy happiness for white people. Instead, they investigated the role of social comparisons - or the desire to "keep up with the Joneses."

Their research indicates that white Americans tend to compare their own status to other white Americans--people they perceive as much wealthier than their selves; and, the greater the perceived disparity, the worse they feel--psychologically and physically--regardless of their objective status.

In one study, white and Black Americans (490 white people and 519 Black people) were asked to rank their own status on a ladder--selecting higher ladder rungs if they felt high status and lower rungs if they felt low status. Next, participants were asked to rank "the majority of their racial group" (i.e., white or Black people) on the same scale. The researchers followed with questions about participants' health, emotions, and wellbeing. A second study replicated their findings.

"Results revealed that white Americans tended to make upward status comparisons - in other words, they most often compared their status to other white people--people who they perceived as having higher status than the self" says Erin Cooley, one of the study's co-lead authors. "In contrast, Black Americans most often compared their status to other Black people--people who they perceived as doing worse than the self." And, among white Americans, larger upward comparisons were associated with feeling fewer positive emotions and having worse physical health.

Interestingly, these data suggest that it is exactly because of this belief that white = wealth, that many white people feel as if they are falling behind.

Although their work illuminates psychological processes that may harm the health of white Americans, the authors also urge readers to consider two points: (1) these data were collected before the worldwide COVID-19 pandemic, and (2) as clearly revealed by the pandemic, minority racial/ethnic groups - particularly African Americans and Latinx Americans - are disproportionately impacted by poor health outcomes and economic downturns.

"Due to racism and persistent racial inequities, there are many health disparities experienced by people of color in the United States including rates of heart disease and diabetes," says Jazmin Brown-Iannuzzi, also a co-lead author of the research. Thus, while the authors think the current work represents an interesting psychological mechanism for white Americans, this work should not detract from the fact that structural racism in this country creates health and wealth inequalities along racial lines.