Tuesday, June 09, 2020

Amazon risks combusting with twin fire, virus crises

by Joshua Howat Berger

Fire burning along the BR163 highway in the Amazon rainforest September 2019; experts fear the 2020 fire season could be worse

As tens of thousands of fires consumed the Amazon last year, it seemed the world's biggest rainforest could not be in greater peril.

But now fire season is here again, and the coronavirus pandemic risks making it even worse.

This year, experts say, the huge number of trees already felled in the rainforest could fuel more destructive fires.

Meanwhile, the smoke risks causing a new spike in respiratory emergencies in a region already overwhelmed with them because of coronavirus.

And there is a potentially vicious circle fueling these twin crises: the more the region is consumed by the pandemic, the less environmental authorities have staff and resources to protect the forest; but the more the forest burns, the worse the health crisis will get.

Last August, scenes of the Amazon burning triggered world outcry, as giant swathes of one of Earth's most vital resources sent a thick haze of black smoke all the way to Sao Paulo, thousands of kilometers away.

In a report published Monday, the Amazon Environmental Research Institute (IPAM) warned that this year, fire season, which typically starts in June with dryer weather, could be far more devastating.

Amazon fires are caused mainly by illegal farmers and ranchers who clear land and torch the trees.

But last year, international scrutiny and Brazil's decision to deploy its army to the region forced many of them to forego the "burn" part of the slash-and-burn method, experts say.

"A deforested area of at least 4,500 square kilometers (1,750 square miles) in the Amazon, three times larger than the city of Sao Paulo, Brazil, is ready to burn," IPAM said.

Meanwhile, slashing has increased.

Deforestation in the Brazilian Amazon hit a record high of 1,843 square kilometers in the first five months of 2020, according to satellite data.

IPAM said the figure of 4,500 square kilometers would probably double by August.

"If only 60 percent of this estimated area burns, we will have a fire season in the region similar to that of 2019," it said.

"If 100 percent of this area burns, we will be able to witness an unprecedented health calamity in the Amazon region, when adding the effects of COVID-19."

Fuel to the fire

Last year's fires triggered international criticism of Brazilian President Jair Bolsonaro, a far-right climate-change skeptic who wants to legalize logging, farming and mining on protected Amazon land.

Bolsonaro initially downplayed the fires as they ripped through the forest with the help of hot temperatures and a long dry season.

But eventually, he gave in to pressure and deployed the army to crack down on deforestation.

The strategy worked—in the short term.

"What I saw in lots of different areas where I work ... is that people just didn't burn. They left the forest on the ground. So then it brings another angle to the story, which is, when is this going to burn?" said Erika Berenguer, an Amazon ecologist at Oxford and Lancaster Universities.

"If it burns now ... we have respiratory illness due to smoke, and we have COVID," she told AFP.

Feedback loop

Brazil, which holds about 60 percent of the Amazon, is the latest epicenter of the pandemic, with the third-highest death toll worldwide.

The Amazon region has been hit hard, with overstretched hospitals and indigenous populations that are especially vulnerable to outside diseases.

Brazil's Amazonas state has just one intensive care unit to serve an area more than four times the size of Germany.

It has had to dig mass graves and store cadavers in refrigerator trucks to cope.

Meanwhile, coronavirus has reduced the authorities' capacity to stop record deforestation driven by illegal agriculture, logging and mining.

"The bad guys and land-grabbers aren't in quarantine while the good guys, police and government agents are fighting the virus," IPAM's director, Andre Guimaraes, told newspaper Globo.

The diversion may be deliberate.

Environment Minister Ricardo Salles was recorded in April saying the government should take advantage of the pandemic distraction to relax regulations.

Meanwhile, air pollution from fires could cause a critical new phase in Brazil's coronavirus crisis.

"This nefarious combination can result in an unprecedented burden on the already fragile and deficient health system in the Amazon," IPAM said.

Brazilian Amazon deforestation hits new Jan-Apr high

Seven factors contributing to American racism

by Sandra Feder, Stanford University JUNE 9, 2020

"American racism is alive and well," begins a new journal article led by Steven O. Roberts, a Stanford psychologist, that arrives during a time of heightened attention to racial injustice in the United States.

In the paper, which is available online and soon to appear in American Psychologist, the journal of the American Psychological Association, the scholars contend that racism is a deeply American problem and identify, based on a review of prior research published on the topic, seven factors contributing to racism in the U.S. today.

"People often define racism as disliking or mistreating others on the basis of race. That definition is wrong," said Roberts, who directs the Social Concepts Lab, part of the psychology department, in the School of Humanities and Sciences. "Racism is a system of advantage based on race. It is a hierarchy. It is a pandemic. Racism is so deeply embedded within U.S. minds and U.S. society that it is virtually impossible to escape."

Roberts, an assistant professor and co-author, Michael Rizzo, a postdoctoral fellow at New York University and the Beyond Conflict Innovation Lab, write that "just as citizens of capitalistic societies reinforce capitalism, whether they identify as capitalist or not, and whether they want to or not, citizens of racist societies reinforce racism, whether they identify as racist or not, and whether they want to or not."

After examining research on racism from psychology, the social sciences and the humanities, the researchers argue that American racism systematically advantages White Americans and disadvantages Americans of color—but that it does not have to. It all starts with awareness, they contend.

"Many people, especially White people, underestimate the depths of racism," Rizzo said. "A lot of attention is rightfully put on the recent murders of Breonna Taylor, Ahmaud Arbery, George Floyd and far too many others. But people need to understand that those horrific events are a consequence of a larger system. We want readers to walk away with a better understanding of how that system works."

Seven factors

The first three factors Roberts and Rizzo reviewed are: categories, which organize people into distinct groups; factions, which trigger ingroup loyalty and intergroup competition; and segregation, which hardens racist perceptions, preferences and beliefs. Simply put, the U.S. systematically constructs racial categories, places people inside of those categories and segregates people on the basis of those categories, the authors argue.

For example, there is a considerable body of research showing that people, adults and children alike, tend to feel and act more positively toward those they consider to be like them and in their "ingroup." This means that they are likely to treat people from outside of their social circles less favorably.

For many White Americans, their ingroups do not include Black Americans. Part of the reason for this has to do with America's fraught history of racial segregation, which kept White and Black communities separated. Roberts and Rizzo point to studies demonstrating that the amount of exposure a child has to other racial groups early in life affects how they will think about and act toward those groups when they are adults.

Research also shows that children are more attuned to faces of the racial majority group. That is, Black children are better at recognizing White faces than White children are at recognizing Black faces. This disparity can have tragic real-world consequences. In a criminal lineup, for instance, not being able to recognize Black faces, paired with biased preferences and beliefs, increase the odds that an innocent Black suspect will be misidentified as the perpetrator of a crime.

Roberts and Rizzo note that in cases where felony convictions were overturned because of DNA evidence, a significant number of the original convictions were due to incorrect eyewitness identifications.

The remaining four factors the researchers argue contribute to American racism include: hierarchy, which emboldens people to think, feel and behave in racist ways; power, which legislates racism on both micro and macro levels; media, which legitimizes overrepresented and idealized representations of White Americans while marginalizing and minimizing people of color; and passivism, such that overlooking or denying the existence of racism encourages others to do the same. In short, they argue that the U.S. positions and empowers some over others, reinforces those differences through biased media, and then leaves those disparities and media in place.

Of the seven factors they identified, perhaps the most insidious is passivism or passive racism, according to the scholars. This includes an apathy toward systems of racial advantage or denial that those systems even exist.

Discussions about passivism are particularly relevant now, Roberts said, as thousands take to the streets to protest against racism. "If people advantaged by the hierarchy remain passive, it is no surprise that those at the bottom cry out to be heard," he added. "People have been crying for centuries."

Anti-racism

At the end of the review, the scholars call for a move to anti-racism. Inspired by historian Ibram X. Kendi's work, Roberts and Rizzo contribute two new terms to the conversation—reactive anti-racism, defined as challenging racism whenever it appears, and proactive anti-racism, or challenging racism before it appears.

"One of the most important steps for future research will be to shift our attention away from how people become racist, and toward the contextual influences, psychological processes and developmental mechanisms that help people become anti-racist," Roberts and Rizzo wrote. "In a state of increasing racial inequality, we hope to find future students and scholars, both in the U.S. and beyond, well-versed and embedded within a psychology of anti-racism."

In a move that they hope becomes standard, the scholars included an author's statement in their paper indicating that one author, Roberts, identifies as Black American and the other, Rizzo, as White American.

"We [psychologists] often present ourselves as objective observers, but I think it's important to acknowledge our own positionality," Roberts said. "We put it in the author's note to normalize it and say good work can come when people from different identities work together for a common goal."

Blacks' views on racism affect likelihood of self-employment

More information: Steven Roberts et al. The Psychology of American Racism, (2020). DOI: 10.31219/osf.io/w2h73

Journal information: American Psychologist

Provided by Stanford University

UK pesticide standards could be slashed in new trade deals, threatening public health and the environment

by Neil Vowles, University of Sussex

UK consumers are likely to be exposed to larger amounts of more toxic chemicals in their food if trade negotiators from the US have their way, warns a new report out today.

The warning comes alongside new YouGov polling which reveals that almost three quarters (71%) of the British public want the UK Government to resist US attempts to overturn bans on pesticides, even if this means the "best" trade deal cannot be reached.

Authored by Pesticide Action Network UK (PAN UK), Sustain and University of Sussex trade expert Dr. Emily Lydgate, Toxic Trade highlights that a rise in exposure to hazardous chemicals could be unavoidable for UK consumers because pesticides are not mentioned on food labels.

While far from perfect, the UK currently has some of the most stringent pesticide regulations in the world, meaning that many agricultural products produced elsewhere cannot be sold here.

However, concern is mounting that in the wake of the UK's exit from the EU, trade deals currently under negotiation with the U.S., and planned imminently for Australia and India, will drive down UK pesticide standards.

This not only risks damaging public health but also the environment as trade negotiators push the UK government to allow currently banned hazardous pesticides to be used in UK farms and gardens.

The YouGov poll reveals high levels of concern among consumers, with 71% of those surveyed concerned that a US trade deal will mean larger amounts of pesticides in their food; 79% concerned about impacts to health if UK Government caves to US pressure to lower pesticide standards; and 77% worried about negative impacts on the environment.

Josie Cohen, Head of Policy and Campaigns at Pesticide Action Network, said: "Much attention has been paid to the dangers of 'chlorinated chicken', but the UK public is equally concerned about weakening pesticide protections. We know that US negotiators have our pesticide standards firmly in their sights, and with the talks happening behind closed doors the public has no way of knowing if health and environmental protections are being traded away."

If UK trade negotiators bow the demands of trade partners then the increased risk to human health could be significant:

Compared to UK grapes, American grapes are allowed to contain 1,000 times the amount of the insecticide propargite that can affect sexual function and fertility, and has been linked to cancer and miscarriages.
American apples are allowed to contain 400 times the level of the insecticide malathion than UK apples. Malathion has also been linked to cancer and can impair the respiratory system and cause confusion, headaches and weakness.

The pesticide chlorpyrifos has been shown to negatively affect the cognitive development of foetuses and young children and is banned from use in the UK but is used by farmers in the US and India.

The environmental impacts of a drop in UK pesticide standards could also be significant.

Huge declines in bee populations have been caused by highly toxic neonicotinoids which are currently banned in the UK, but which Australia, the US and India all permit. These countries also authorise pesticides known to contaminate groundwater and harm aquatic ecosystems, such as the herbicides atrazine and diuron.

The report paints an alarming picture of the tactics that overseas negotiators will try to use to water-down standards. US trade officials want the UK to commit to consulting with the US government and private sector before implementing any new pesticide regulations or bans.

Dr. Lydgate, Senior Lecturer in Environmental Law at the University of Sussex, said: "A clear and central objective of US negotiators is for the UK to lower its pesticide standards. The current picture in the UK of intense political pressure coupled with a lack of parliamentary and public scrutiny means the risk of this happening is very high."

The report also highlights the dual risk to UK farmers of reduced pesticide standards.

Vicki Hird, Farm Campaign Coordinator at Sustain, said: "In an already uncertain economic climate, the lowering of pesticide standards could be catastrophic for UK farming as well as the environment. If UK farmers are forced
into using pesticides in order to compete with a flood of cheap food imports then their exports will no longer meet EU standards and they'll lose one of their key markets. 60% of UK agricultural exports currently go to the EU so this could finish off many farming businesses."

The report calls on the UK government to prioritise human health and meet their stated commitment of "leaving the natural environment in a better state than we found it".

Key recommendations for the UK government:

Do not allow any weakening of UK pesticide standards via post-Brexit trade agreements.
Protect UK farmers from being disadvantaged by cheap food imports produced using pesticides, and maintain current pesticide standards so they can continue exporting to the European Union.
Preserve the power for the UK to exercise its right to continually strive for higher levels of consumer and environmental protection.
Ensure that trade agreements are developed in the open with the opportunity for full democratic scrutiny.

India weeds out 27 highly toxic pesticides

Provided by University of Sussex

Parasitic fungi keep harmful blue-green algae in check

When a lake is covered with green scum during a warm summer, cyanobacteria—often called blue-green algae—are usually involved. Mass development of such cyanobacteria is bad for water quality because they can deprive the water of oxygen and produce toxins. But cyanobacteria can become sick, when for instance infected by fungal parasites. Researchers from the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) found out that these infections do not only kill cyanobacteria, they also make them easier to consume for their natural predators. Fungal parasites thus help to slow down the growth of blue-green algae.

Blue-green algal blooms are an increasing problem in waterbodies worldwide: Higher temperatures and growing nutrient loads lead to excessive growth of cyanobacteria. These mass developments affect water quality because many cyanobacteria produce toxins and reduce the oxygen concentration in the water, sometimes leading to death of fish and other aquatic organisms.

The international team led by IGB found that algal growth can be controlled by parasitic fungi. "Many of these algae have long filamentous shapes or grow in colonies, which makes them difficult to be eaten by their natural predators," explains Dr. Thijs Frenken, first author of the study and researcher at IGB and the University of Windsor in Canada. Chytrids, a very common group of fungi, often infect cyanobacteria. The researchers have now shown that, in addition to infecting and killing algae, the fungi "chop" the algae into shorter pieces, making them easier to be eaten by small aquatic organisms. "We knew that fungal infections reduce the growth of cyanobacteria, but now we know that they also make them easier prey," says IGB researcher Dr. Ramsy Agha, head of the study.

Fungi as food supplements for zooplankton

The researchers showed that in addition to "chopping" infected cyanobacteria filaments and making them more vulnerable to predation by small organisms in the water, zooplankton, parasitic fungi themselves serve as a valuable food supplement. Chytrid fungi contain various fats and oils that are an important part of the diet of small freshwater organisms and are not present in blue-green algae. Parasitic fungi therefore serve as an important dietary connection between different levels of aquatic food webs.

"These results show how parasites, although usually perceived as something bad, also have important positive effects on the functioning of aquatic ecosystems," says Professor Justyna Wolinska, head of the IGB research group Disease Evolutionary Ecology.

Fungicides as an underestimated hazard for freshwater organisms

More information: Thijs Frenken et al. Infection of filamentous phytoplankton by fungal parasites enhances herbivory in pelagic food webs, Limnology and Oceanography (2020). DOI: 10.1002/lno.11474

Provided by Forschungsverbund Berlin e.V. (FVB)

5 shares

A new mechanism improves the efficiency of antibacterial surfaces

by Universitat Rovira i Virgili

Resistance to antibiotics has become a serious public health problem. Hospital infections, prostheses or surgical implants that become infected and do not respond to treatment are a real challenge to the research community, which has been seeking alternatives for effectively eliminating these bacteria for years. In 2012 the researchers from the Department of Chemical Engineering of the Universitat Rovira i Virgili, Vladimir Baulin and Sergey Pogodin, opened a line of research to develop antibacterial models that were inspired by insects. The wings of, for example, dragon flies are made up of complex structures of nanometric geometric shapes, which are highly efficient at killing bacteria. In their attempt to understand these forms and reproduce them as new anti-bacterial materials, a team consisting of Vladimir Baulin, Marc Werner, from the Leibniz-Institut für Polymerforschung (Dresden, Germany) and Elena Ivanova from the Australian university RMIT, discovered that the elasticity of nanopillars is a key factor because they can retain and release sufficient energy to kill the bacteria.

The line of research that had been initiated years before had already found that the wings of these insects are made up of a structure of nanopillars that eliminates bacteria mechanically, which is known as the biocide effect. These mechano-bactericidal properties—by which bacteria are killed almost instantly when they come into contact with the pillars without any need to use a chemical substance—raises numerous questions that researchers are attempting to answer by experimenting with different shapes and geometries that will help them to understand which has the most efficient bactericidal effect.

They investigated the bactericidal capacity on nanometric surfaces by varying the height of the pillars and keeping the other dimensions constant. The results, which have just been published in the journal PNAS, have shown that the flexibility of these pillars is closely connected to their appearance. "Even the solid and rigid materials become flexible if one of the dimensions is much longer than the others (for example, a guitar string or a long pillar)," says Vladimir Baulin. The researchers have developed a physical model that shows that when bacteria come into contact with these pillars they can accumulate elastic energy even at such a small scale. Thanks to this model it is now possible to calculate the elastic response of other structures and optimize their antibacterial properties.

The deformation forces of the pillar caused by the contact of the bacteria are so high that they can even break the bacteria's cell wall, thus providing a new mechanism for killing them. These forces are associated with surface tensions imposed on the bacterial cells. The pillars under the bacteria that approach stretch more at the edges, whereas the pillars located under the center of the bacteria practically do not change. The study shows, then, that the gradual variation in the height of the pillars of a nanometric surface can determine their bactericidal efficacy.

This discovery may lead to a completely new class of antibacterial materials, which could range from packaging for food to filters or masks. Unlike traditional filters, where the bacteria remain but are not deactivated, the new nanoscale elastic material can safely kill the bacteria in a matter of minutes, which means that they cannot activate any defense mechanisms or give any resistance at all," concluded Baulin

Insect wings hold antimicrobial clues for improved medical implants

More information: Elena P. Ivanova et al, The multi-faceted mechano-bactericidal mechanism of nanostructured surfaces, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.1916680117

Journal information: Proceedings of the National Academy of Sciences

Provided by Universitat Rovira i Virgili

Unexpected uncertainty can breed paranoia, researchers find

by Yale University

Pixabay/CC0 Public Domain

In times of unexpected uncertainty, such as the sudden appearance of a global pandemic, people may be more prone to paranoia, Yale University researchers suggest in a new study published in the journal eLife.

"When our world changes unexpectedly, we want to blame that volatility on somebody, to make sense of it, and perhaps neutralize it,'' said Yale's Philip Corlett, associate professor of psychiatry and senior author of the study. "Historically in times of upheaval, such as the great fire of ancient Rome in 64 C.E. or the 9/11 terrorist attacks, paranoia and conspiratorial thinking increased."

Paranoia is a key symptom of serious mental illness, marked by the belief that other people have malicious intentions. But it also manifests in varying degrees in the general population. For instance, one previous survey found that 20% of the population believed people were against them at some time during the past year; 8% believed that others were actively out to harm them.

The prevailing theory is that paranoia stems from an inability to accurately assess social threats. But Corlett and lead author Erin Reed of Yale hypothesized that paranoia is instead rooted in a more basic learning mechanism that is triggered by uncertainty, even in the absence of social threat.

"We think of the brain as a prediction machine; unexpected change, whether social or not, may constitute a type of threat—it limits the brain's ability to make predictions," Reed said. "Paranoia may be a response to uncertainty in general, and social interactions can be particularly complex and difficult to predict."

In a series of experiments, they asked subjects with different degrees of paranoia to play a card game in which the best choices for success were changed secretly. People with little or no paranoia were slow to assume that the best choice had changed. However, those with paranoia expected even more volatility in the game. They changed their choices capriciously—even after a win. The researchers then increased the levels of uncertainty by changing the chances of winning halfway through the game without telling the participants. This sudden change made even the low-paranoia participants behave like those with paranoia, learning less from the consequences of their choices.

In a related experiment, Yale collaborators Jane Taylor and Stephanie Groman trained rats, a relatively asocial species, to complete a similar task where best choices of success changed. Rats who were administered methamphetamine—known to induce paranoia in humans—behaved just like paranoid humans. They, too, anticipated high volatility and relied more on their expectations than learning from the task.

Reed, Corlett and their team then used a mathematical model to compare choices made by rats and humans while performing these similar tasks. The results from the rats that received methamphetamine resembled those of humans with paranoia, researchers found.

"Our hope is that this work will facilitate a mechanistic explanation of paranoia, a first step in the development of new treatments that target those underlying mechanisms," Corlett said.

"The benefit of seeing paranoia through a non-social lens is that we can study these mechanisms in simpler systems, without needing to recapitulate the richness of human social interaction," Reed said.

Explore further

London cyclists feel paranoid road users are out to get them
More information: Erin J Reed et al, Paranoia as a deficit in non-social belief updating, eLife (2020). DOI: 10.7554/eLife.56345
Journal information: eLife

Close-up view reveals binary proto-stars in the process of assemblage
JUNE 9, 2020

by Max Planck Society

]

Zoom into the Ophiuchus molecular cloud, highlighting the star forming system IRAS 16293-2422 with the proto-star B in the upper right corner and the now clearly identified binary proto-stars A1 and A2 on the bottom left. The binary system is shown also in a further zoom-in panel. Credit: MPE; background: ESO/Digitized Sky Survey 2; Davide De Martin

High-resolution observations of a young star forming system clearly unveil a pair of proto-stars at their earliest stages of evolution deeply embedded within the source IRAS 16293-2422 in the Ophiuchus molecular cloud. The team led by the Max Planck Institute for Extraterrestrial Physics used the ALMA interferometer not only to pin down the source configuration, but also to measure the gas and stellar kinematics, determining the mass of the young binary. The two close proto-stars are somewhat heavier than previously thought and they revolve around each other once in about 400 years.

The system called IRAS 16293-2422 is one of the brightest star-forming regions in our neighborhood. It is located in the Ophiuchus molecular cloud at a distance of about 460 light-years and has been widely studied, also because it shows strong emission of numerous complex organic molecules, building blocks of pre-biotic species. However, until now the detailed configuration of the region was unclear, with observations at different wavelengths showing multiple compact sources at slightly different locations. This confusion was due to the large amount of material in front of the nascent proto-stars, expected at these earliest stages of formation.

An international team of astronomers led by the Max Planck Institute for Extraterrestrial Physics (MPE) has now obtained high-resolution radio observations with the ALMA interferometer, which clearly reveals two compact sources A1 and A2 in addition to the well-known proto-star B (see Fig. 1). "Our observations confirm the location of the two close proto-stars and reveal that each is surrounded by a very small dust disk. Both, in turn, are in turn embedded in a large amount of material showing complex patterns" remarks María José Maureira from MPE, the lead author of the study.

Detailed view of the binary proto-star system with a size comparison to our solar system. The separation between the sources A1 and A2 is roughly the diameter of the Pluto orbit. The size of the disk around A1 (unresolved) is about the diameter of the asteroid belt. The size of the disk around A2 is about the diameter of the Saturn orbit. Credit: MPE

The source A1 has a mass of a bit less than 1 solar mass and is embedded in a small dust disk about the size of the asteroid belt; the source A2 has a mass of about 1.4 solar masses and is embedded in a somewhat larger disk (see Fig. 2). Interestingly, this disk around A2 also appears at an angle compared to the overall orientation of the larger cloud structure, while the disk around the source B—at a much larger distance—is seen face-on, indicating a rather chaotic formation history.

In addition to direct imaging of the dust emission, the team also obtained information on the motion of the gas around the stars through observations of spectral lines of organic molecules, which well trace the high-density region surrounding the discovered binary system. This allowed them to get an independent mass measurement and to confirm that A1 and A2 form a bound pair.

Relative motion of A1 (blue) with respect to A2 (red) overlaid on the ALMA continuum observation. The visual impression that A1 orbits around A2 is confirmed through a detailed analysis of the motion of the proto-stars over a 30-year period. Credit: MPE

Combining their latest observations with data collected over the past 30 years, the team found that the two stars orbit each other once every 360 years at a distance similar to the extent of Pluto's orbit, where the orbit is tilted by about 60° (see Fig. 3). "This is the first time that we were able to derive the full orbital parameters of a binary system at this early stage of star formation," points out Jaime Pineda from MPE, who contributed to the modelling.

"With these results we are finally able to dive into one of the most embedded and youngest proto-stellar systems, unveiling its dynamical structure and complex morphology, where we clearly see filamentary material connecting the circumstellar disks to the surrounding region and likely to the cirbumbinary disk. The small disks are probably still being fed and growing!" emphasizes Paola Caselli, director at MPE and head of the Center for Astrochemical Studies. "This was only possible thanks to the great sensitivity of ALMA and the observations of molecules which uniquely trace these dense regions. Molecules send us signals at very specific frequencies, and, following changes of such frequencies across the region (due to internal motions) one can reconstruct the complex kinematics of the system. This is the power of astrochemistry."

Explore furtherAstronomers observe how two suns collect matter in a binary system
More information: Orbital and mass constraints of the young binary system IRAS 16293-2422 A: arXiv:2005.11954 [astro-ph.SR] arxiv.org/abs/2005.11954
Provided by Max Planck Society
25 shares

Study reveals birth defects caused by flame retardant

by University of Georgia

Credit: Pixabay/CC0 Public Domain

A new study from the University of Georgia has shown that exposure to a now-banned flame retardant can alter the genetic code in sperm, leading to major health defects in children of exposed parents.

Published recently in Scientific Reports, the study is the first to investigate how polybrominated biphenyl-153 (PBB153), the primary chemical component of the flame retardant FireMaster, impacts paternal reproduction.

In 1973, an estimated 6.5 million Michigan residents were exposed to PBB153 when FireMaster was accidentally sent to state grain mills where it made its way into the food supply. In the decades since, a range of health problems including skin discoloration, headache, dizziness, joint pain and even some cancers have been linked to the exposure.

More striking, the children of those who were exposed seemed to experience a host of health issues as well, including reports of hernia or buildup in the scrotum for newborn sons and a higher chance of stillbirth or miscarriage among adult daughters.

Yet, little work has been done to understand how the chemical exposure could have impacted genes passed from an exposed father, said study author Katherine Greeson.

"It is still a relatively new idea that a man's exposures prior to conception can impact the health of his children," said Greeson, an environmental health science doctoral student in Charles Easley's lab at UGA's College of Public Health and Regenerative Bioscience Center.

"Most studies where a toxic effect is observed in children look only to the mothers and the same has been true of studies conducted on PBB153," she said.

Greeson and a team of researchers from UGA and Emory University used a unique combination of observational and laboratory approaches to demonstrate how PBB153 acted on sperm cells.

"Typically, scientific studies are either epidemiological in nature and inherently observational or focus on bench science, but in this study, we did both," said Greeson.

This approach allowed the researchers to mimic the known blood exposure levels of PBB153 in a lab environment.

"We were uniquely able to recreate this effect using our previously characterized human stem cell model for spermatogenesis," she said, "which allowed us to study the mechanism that causes this effect in humans."

The team looked at the expression of different genes in their human spermatogenesis model after dosing with PBB153 and found marked alterations in gene expression between dosed and undosed cells, specifically at genes important to development, such as embryonic organ, limb, muscle, and nervous system development.

"PBB153 causes changes to the DNA in sperm in a way that changes how the genes are turned on and off," said Greeson. "PBB153 seems to turn on these genes in sperm which should be turned off," said Greeson, which may explain some of the endocrine-related health issues observed in the children of exposed parents.

Though the study used this model to directly replicate exposure to PBB153, Greeson says this approach could be used to better understand the impact of other environmental exposures on reproduction, including large-scale accidental exposures to toxic chemicals or everyday exposures.

"Hopefully this work will lead to more studies combining epidemiology and bench science in the future, which will tell us more about why we're seeing an effect from an environmental exposure in human populations and encourage experimental studies to more closely mimic human exposures," she said.

The study, "Detrimental Effects of Flame Retardant, PBB153, Exposure on Sperm and Future Generations," published May 22.

Monitoring environmental exposures in dogs could be early warning system for human health

More information: Katherine Watkins Greeson et al, Detrimental effects of flame retardant, PBB153, exposure on sperm and future generations, Scientific Reports (2020). DOI: 10.1038/s41598-020-65593-x

Journal information: Scientific Reports

Provided by University of Georgia

Study finds another reason to wash hands: Flame retardants

by University of Toronto

Harmful flame retardants may be lurking on your hands and cell phone, according to a peer-reviewed study published today in Environmental Science & Technology Letters.

The researchers found that halogenated flame retardants added to plastic TV cases can move from the TV to indoor air and dust, to hands, and then to cell phones and other hand-held electronic devices. Once on your cell phone, that surface provides an ongoing source of exposure to these chemicals each time you touch your cell phone.

"It's well-known that viruses are transferred between surfaces and hands," said co-author Miriam Diamond, a Professor in the Department of Earth Sciences at the University of Toronto. "Our study shows that toxic chemicals like flame retardants do the same. That's another reason we should all wash our hands often and well."

Halogenated flame retardants, such as polybrominated diphenyl ethers, are known to pose a health risk to children. Previous studies have found that exposure to these chemicals can cause lower IQ in children and behavioral problems.

The authors were surprised to find higher levels of almost all halogenated flame retardants, all organophosphate flame retardants, and phthalate plasticizers on the surfaces of cell phones and other hand-held electronic devices like tablets, compared to non-hand-held devices like desktop computers. This included finding higher levels of long-banned polybrominated diphenyl ethers on new cell phones than on the surfaces of older desktop computers. The researchers suggest that these old chemicals got to the new phones by transfer from hands.

Why are TVs a source of flame retardants? The answer lies in the odd story of old "instant-on" cathode ray tube TVs manufactured in the 1970s. This technology, which involved warming the cathode ray tube so that the TV would immediately project an image when turned on, resulted in several hundred TV fires in the 1970s. The response was to recommend flammability standards that led to large amounts of flame retardants added to the outside casings of the TVs.

However, those same levels of flame retardants continued to be used —as much as a quarter of the weight of the plastic case— even after the industry moved to current TVs that pose a minimal fire risk. Thus, recently manufactured TVs contain high levels of unnecessary and harmful flame retardants. We are exposed because the flame retardants are not bonded to the cases, but escape over time to contaminate our indoor environments.

"If a flame retardant is used in the TVs, we then find it throughout the house, including on the hands of the resident," said co-author Lisa Melymuk, an Assistant Professor of Environmental Chemistry at Masaryk University.

The COVID-19 pandemic has taught us to wash our hands regularly and well to avoid getting ill. The results of this study suggest that frequent handwashing can also reduce our exposure to harmful flame retardants.

"However, to reduce health harm from flame retardants, the electronics industry should stop their unnecessary use," said Arlene Blum, Executive Director of the Green Science Policy Institute. "Fire safety can be achieved by innovative product design and materials instead of the use of toxic chemicals that can remain in our homes—and in us—for years to come."

New flame retardants, old problems

More information: Congqiao Yang et al, Are We Exposed to Halogenated Flame Retardants from both Primary and Secondary Sources?, Environmental Science & Technology Letters (2020). DOI: 10.1021/acs.estlett.0c00268

Journal information: Environmental Science & Technology Letters

Provided by University of Toronto

Renewable fuel from carbon dioxide with the aid of solar energy
by Linköping University

Researchers at Linköping University work with the growth reactor in which cubic silicon carbide is made. Credit: Thor Balkhed/Linköping University

Researchers at Linköping University, Sweden, are attempting to convert carbon dioxide, a greenhouse gas, to fuel using energy from sunlight. Recent results have shown that it is possible to use their technique to selectively produce methane, carbon monoxide or formic acid from carbon dioxide and water. The study has been published in ACS Nano.

Plants convert carbon dioxide and water to oxygen and high-energy sugars, which they use as "fuel" to grow. They obtain their energy from sunlight. Jianwu Sun and his colleagues at Linköping University are attempting to imitate this reaction, known as photosynthesis, used by plants to capture carbon dioxide from air and convert it to chemical fuels, such as methane, ethanol and methanol. The method is currently at a research stage, and the long-term objective of the scientists is to convert solar energy to fuel efficiently.

"By converting carbon dioxide to fuel with the aid of solar energy, this technique could contribute to the development of sources of renewable energy and reduce the impact on the climate of the combustion of fossil fuels," says Jianwu Sun, senior lecturer in the Department of Physics, Chemistry and Biology at Linköping University.

Graphene is one of the thinnest materials that exist, consisting of a single layer of carbon atoms. It is elastic, flexible, transparent to sunlight, and a good conductor of electricity. This combination of properties ensures that graphene has potential for use in applications such as electronics and biomedicine. But graphene alone is not suitable for the solar energy conversion application sought by the LiU researchers, and they have therefore combined the graphene with a semiconductor, cubic silicon carbide (3C-SiC). Scientists at Linköping University have previously developed a world-leading method to grow graphene on cubic silicon carbide, which consists of carbon and silicon. When the silicon carbide is heated, the silicon is vaporized, while the carbon atoms remain and re-construct in the form of a graphene layer. The researchers have previously shown that it is possible to place up to four layers of graphene on top of each other in a controlled manner.

Jianwu Sun, senior lecturer at Linköping University. Credit: Thor Balkhed/Linköping University

They have combined the graphene and cubic silicon carbide to develop a graphene-based photoelectrode that preserves the ability of cubic silicon carbide to capture the energy of sunlight and create charge carriers. The graphene functions as a conducting transparent layer while protecting the silicon carbide.

The performance of the graphene-based technique is controlled by several factors, an important one of which is the quality of the interface between the graphene and the semiconductor. The scientists have looked at the properties of this interface in detail. They show in the article that they can tailor the layers of graphene on the silicon carbide and control the properties of the graphene-based photoelectrode. The conversion of carbon dioxide is in this way made more efficient, while the stabilities of the components are at the same time improved.

The photoelectrode developed by the researchers can be combined with cathodes of various metals, such as copper, zinc or bismuth. Different chemical compounds, such as methane, carbon monoxide and formic acid, can be selectively formed from carbon dioxide and water by selecting suitable metal cathodes.

"Most importantly, we have demonstrated that we can use solar energy to control the conversion of carbon dioxide to methane, carbon monoxide or formic acid," says Jianwu Sun.

Methane is used as a fuel in vehicles adapted to use gaseous fuels. Carbon monoxide and formic acid can either be further processed such that they can function as fuels, or they can be used in industry."

Graphene takes a step toward renewable fuel
More information: Hao Li et al, Atomic-Scale Tuning of Graphene/Cubic SiC Schottky Junction for Stable Low-Bias Photoelectrochemical Solar-to-Fuel Conversion, ACS Nano (2020). DOI: 10.1021/acsnano.0c00986
Journal information: ACS Nano

Provided by Linköping University

LA REVUE GAUCHE - Left Comment