Saturday, April 04, 2020

Alphabet's DeepMind masters Atari games

I MASTERED THEM TOO DIDN'T YOU

by Peter Grad , Tech Xplore

In order to better solve complex challenges at the dawn of the third decade of the 21st century, Alphabet Inc. has tapped into relics dating to the 1980s: video games.

The parent company of Google reported this week that its DeepMind Technologies Artificial Intelligence unit has successfully learned how to play 57 Atari video games. And the computer system plays better than any human.

Atari, creator of Pong, one of the first successful video games of the 1970s, went on to popularize many of the great early classic video games into the 1990s. Video games are commonly used with AI projects because they challenge algorithms to navigate increasingly complex paths and options, all while encountering changing scenarios, threats and rewards.

Dubbed AGENT57, Alphabet's AI system probed 57 leading Atari games covering a huge range of difficulty levels and varying strategies of success.

"Games are an excellent testing ground for building adaptive algorithms," the researchers said in a report on the DeepMind blog page. "They provide a rich suite of tasks which players must develop sophisticated behavioral strategies to master, but they also provide an easy progress metric —game score—to optimize against.

DeepMind's AlphaGo system earned wide recognition in 2016 when it beat world champion Lee Sedol in the strategic game of Go.

Among the current crop of 57 Atari games, four are considered especially difficult for AI projects to master: Montezuma's Revenge, Pitfall, Solaris and Skiing. The first two games pose what DeepMind calls the perplexing "exploration-exploitation problem."

The other two challenging games impose long waiting times between challenges and rewards, making it more difficult for AI systems to successful analyze.

Previous efforts to master the four games with AI all failed.

Ultimately, DeepMind researchers foresee a program that can apply human-like decision-making choices while encountering ever-changing and previously unseen challenges.

"True versatility, which comes so easily to a human infant, is still far beyond AIs' reach," the report concluded.

Atari master: New AI smashes Google DeepMind in video game challenge

"The ultima
te goal is not to develop systems that excel at games, but rather to use games as a stepping stone for developing systems that learn to excel at a broad set of challenges," the report said.DeepMind's AlphaGo system earned wide recognition in 2016 when it beat world champion Lee Sedol in the strategic game of Go.Among the current crop of 57 Atari games, four are considered especially difficult for AI projects to master: Montezuma's Revenge, Pitfall, Solaris and Skiing. The first two games pose what DeepMind calls the perplexing "exploration-exploitation problem."

"Should one keep performing behaviors one knows works (exploit), or should one try something new (explore) to discover new strategies that might be even more successful?" DeepMind asks. "For example, should one always order their same favorite dish at a local restaurant, or try something new that might surpass the old favorite? Exploration involves taking many suboptimal actions to gather the information necessary to discover an ultimately stronger behavior."The other two challenging games impose long waiting times between challenges and rewards, making it more difficult for AI systems to successful analyze.Previous efforts to master the four games with AI all failed.

The report says there is still room for improvement. For one, long computational times remain an issue. Also, while acknowledging that "the longer it trained, the higher its score got," DeepMind researchers want Agent57 to do better. They want it to master multiple games simultaneously; currently, it can learn only one game at a time and it must go through training each time it restarts a game.Ultimately, DeepMind researchers foresee a program that can apply human-like decision-making choices while encountering ever-changing and previously unseen challenges."True versatility, which comes so easily to a human infant, is still far beyond AIs' reach," the report concluded.Atari master: New AI smashes Google DeepMind in video game challenge

UPDATED
Coronavirus may spread through normal breathing:
US scientists

Issam AHMED,AFP•April 3, 2020

Washington (AFP) - The new coronavirus might spread through the air via normal breathing and speaking, a top US scientist said Friday as the government was poised to recommend the use of face masks for everyone.

Anthony Fauci, head of infectious diseases at the National Institutes of Health, told Fox News the guidance on masks would be changed "because of some recent information that the virus can actually be spread even when people just speak, as opposed to coughing and sneezing."

As it stands, the official advice is that only sick people need to cover their faces, as well as those caring for them at home.

Fauci's comments come after the National Academy of Sciences (NAS) sent a letter to the White House on April 1 that summarized recent research on the subject.

It said that though the research isn't yet conclusive, "the results of available studies are consistent with aerosolization of virus from normal breathing."

Until now, US health agencies have said that the primary pathway of transmission is respiratory droplets, about one millimeter in diameter, expelled by sick people when they sneeze or cough.

These quickly fall to the ground around a meter away.

But if the virus can be suspended in the ultrafine mist we expel when we exhale, in other words an aerosol, it becomes much harder to prevent its spread, which in turn is an argument in favor of everyone covering their faces.

- The aerosol debate -

A recent NIH funded study published in the New England Journal of Medicine found that the SARS-CoV-2 virus could become an aerosol and remain airborne for up to three hours.

This triggered a debate even as critics said the findings were overblown because the team behind the study used a medical device called a nebulizer to deliberately create a viral mist and argued this would not occur naturally.

The NAS letter pointed to preliminary research by the University of Nebraska Medical Center that found the genetic code of the SARS-CoV-2 virus, its RNA, were found in hard to reach areas of patients' isolation rooms.

The NAS scientists also pointed to two other studies -- both not yet peer reviewed -- from Hong Kong and from mainland China.

The Hong Kong researchers collected viral samples from patients with the coronavirus and other viral respiratory illnesses, and gave some of the patients face masks.

The masks reduced the detection of both droplets and aerosols for coronavirus patients.

The Chinese paper on the other hand raised concerns that personal protective gear used by health care workers could itself be a source of airborne virus.

The team studied hospitals in Wuhan and found that there were two major areas where the virus was aerosolized: the bathrooms of patients, and rooms where medical staff removed their protective gear.

This may be because doffing protective gear causes the particles to get re-suspended in the air. Even if these particles are not of breathable size, they could settle on people's hands and bodies, the NAS panel said.

So far, the World Health Organization (WHO) has been more cautious on the airborne threat.

In an analysis published on March 29, it wrote that aerosol transmission was only known to occur during particular medical treatments that required assisted breathing.

On the recent preliminary research, such as the University of Nebraska's paper, the WHO cautioned that the detection of the virus' genetic code in patient's rooms did not necessarily amount to viable amounts of the pathogen that could be transmitted onward.

Coronavirus may spread through normal breathing

US scientists

Credit: CC0 Public Domain

The new coronavirus might spread through the air via normal breathing and speaking, a top US scientist said Friday as the government was poised to recommend the use of face masks for everyone.

Anthony Fauci, head of infectious diseases at the National Institutes of Health, told Fox News the guidance on masks would be changed "because of some recent information that the virus can actually be spread even when people just speak, as opposed to coughing and sneezing."

As it stands, the official advice is that only sick people need to cover their faces, as well as those caring for them at home.

Fauci's comments come after the National Academy of Sciences (NAS) sent a letter to the White House on April 1 that summarized recent research on the subject.

It said that though the research isn't yet conclusive, "the results of available studies are consistent with aerosolization of virus from normal breathing."

Until now, US health agencies have said that the primary pathway of transmission is respiratory droplets, about one millimeter in diameter, expelled by sick people when they sneeze or cough.

These quickly fall to the ground around a meter away.

But if the virus can be suspended in the ultrafine mist we expel when we exhale, in other words an aerosol, it becomes much harder to prevent its spread, which in turn is an argument in favor of everyone covering their faces.

The aerosol debate

A recent NIH funded study published in the New England Journal of Medicine found that the SARS-CoV-2 virus could become an aerosol and remain airborne for up to three hours.

This triggered a debate even as critics said the findings were overblown because the team behind the study used a medical device called a nebulizer to deliberately create a viral mist and argued this would not occur naturally.

The NAS letter pointed to preliminary research by the University of Nebraska Medical Center that found the genetic code of the SARS-CoV-2 virus, its RNA, were found in hard to reach areas of patients' isolation rooms.

The NAS scientists also pointed to two other studies—both not yet peer reviewed—from Hong Kong and from mainland China.

The Hong Kong researchers collected viral samples from patients with the coronavirus and other viral respiratory illnesses, and gave some of the patients face masks.

The masks reduced the detection of both droplets and aerosols for coronavirus patients.

The Chinese paper on the other hand raised concerns that personal protective gear used by health care workers could itself be a source of airborne virus.

The team studied hospitals in Wuhan and found that there were two major areas where the virus was aerosolized: the bathrooms of patients, and rooms where medical staff removed their protective gear.

This may be because doffing protective gear causes the particles to get re-suspended in the air. Even if these particles are not of breathable size, they could settle on people's hands and bodies, the NAS panel said.

So far, the World Health Organization (WHO) has been more cautious on the airborne threat.

In an analysis published on March 29, it wrote that aerosol transmission was only known to occur during particular medical treatments that required assisted breathing.

On the recent preliminary research, such as the University of Nebraska's paper, the WHO cautioned that the detection of the virus' genetic code in patient's rooms did not necessarily amount to viable amounts of the pathogen that could be transmitted onward.Air samples from coronavirus patient rooms being analyzed

How important is speech in transmitting coronavirus?

by Andy Fell, UC Davis
covid

Credit: CC0 Public Domain

Normal speech by individuals who are asymptomatic but infected with coronavirus may produce enough aerosolized particles to transmit the infection, according to aerosol scientists at the University of California, Davis. Although it's not yet known how important this is to the spread of COVID-19, it underscores the need for strict social distancing measures—and for virologists, epidemiologists and engineers who study aerosols and droplets to work together on this and other respiratory diseases.

Aerosols are particles small enough to travel through the air. Ordinary speech creates significant quantities of aerosols from respiratory particles, said William Ristenpart, professor of chemical engineering at UC Davis. Ristenpart is co-author on an editorial about the problem published this week in the journal Aerosol Science and Technology.

These respiratory particles are about one micron, or one micrometer, in diameter. That's too small to see with the naked eye, but large enough to carry viruses such as influenza or SARS-CoV-2.

Some individuals superemitters

Last year, Ristenpart, graduate student Sima Asadi and colleagues published a paper showing that the louder one speaks, the more particles are emitted and that some individuals are "superemitters" who give off up to 10 times as many particles as others. The reasons for this are not yet clear. In a follow-up study published in January in PLOS One, they investigated which speech sounds are associated with the most particles.

Calculating just how easily a virus like SARS-CoV-2 spreads through droplets requires expertise from different fields. From virology, researchers need to know how many viruses are in lung fluids, how easily they form into droplets and how many viruses are needed to start an infection. Aerosol scientists can study how far droplets travel once expelled, how they are affected by air motion in a room and how fast they settle out due to gravity.

"The aerosol science community needs to step up and tackle the current challenge presented by COVID-19, and also help better prepare us for inevitable future pandemics," Ristenpart and colleagues conclude.

Hopes for pandemic respite this spring may depend upon what happens indoors

More information: Sima Asadi et al. Effect of voicing and articulation manner on aerosol particle emission during human speech, PLOS ONE (2020). DOI: 10.1371/journal.pone.0227699

Journal information: PLoS ONE

Wearing surgical masks in public could help slow COVID-19 pandemic's advance: study

by University of Maryland

Virus shedding by participants was measured using the Gesundheit II machine developed by the University of Maryalnd's Dr. Don Milton Credit: University of Maryland School of Public Health

Surgical masks may help prevent infected people from making others sick with seasonal viruses, including coronaviruses, according to new research that could help settle a fierce debate spanning clinical and cultural norms.

In laboratory experiments, the masks significantly reduced the amounts of various airborne viruses coming from infected patients, measured using the breath-capturing "Gesundheit II machine" developed by Dr. Don Milton, a professor of applied environmental health in the University of Maryland School of Public Health and a senior author of the study published April 3 in the journal Nature Medicine.

Milton has already conferred with federal and White House health officials on the findings, which closely follow statements this week from the head of the Centers for Disease Control and Prevention saying the agency was reconsidering oft-stated advice that surgical masks aren't a useful precaution outside of medical settings. (The debate takes place at a time when clinicians themselves face dangerously inadequate supplies of masks—a shortfall other UMD researchers are scrambling to help solve.)

The question of masks has roiled society as well, with some retailers refusing to let employees wear them for fear of sending negative signals to customers, and cases of slurs and even physical attacks in the United States and elsewhere against Asians or Asian Americans who were wearing masks, a measure some consider a necessity during a disease outbreak.

The study, conducted prior to the current pandemic with a student of Milton's colleagues on the Faculty of Medicine at the University of Hong Kong, does not address the question of whether surgical masks protect wearers from infection. It does suggest that masks may limit how much the infected—who in the case of the novel coronavirus often don't have symptoms—spread diseases including influenza, rhinoviruses and coronaviruses.

Milton, who runs the Public Health Aerobiology, Virology, and Exhaled Biomarker Laboratory in the School of Public Health, demonstrated in a 2013 study that surgical masks could help limit flu transmission. However, he cautions that the effect may not be as great outside of controlled settings.

Nevertheless, he said, the chance they could help justifies taking a new look at whether all people should be encouraged to wear them when they venture out of their houses to stores or other populated locations during the current COVID-19 lockdown.

"In normal times we'd say that if it wasn't shown statistically significant or the effective in real-world studies, we don't recommend it," he said. "But in the middle of a pandemic, we're desperate. The thinking is that even if it cuts down transmission a little bit, it's worth trying."

Previous studies have shown that coronavirus and other respiratory infections are mostly spread during close contact, which has been interpreted by some infectious disease specialists to mean that the disease could spread only through contact and large droplets, such as from a cough or sneeze—a message that has often been shared with the public.

"What they don't understand is that is merely a hypothesis," Milton said. The current study (along with earlier ones) shows, by contrast, that tiny, aerosolized droplets can indeed diffuse through the air. That means it may be possible to contract COVID-19 not only by being coughed on, but by simply inhaling the breath of someone nearby who has it, whether they have symptoms or not. Surgical masks, however, catch a lot of the aerosolized virus as it's exhaled, he said.

The study was conducted at the University of Hong Kong as part of the dissertation research of the lead author, Dr. Nancy Leung, who, under the supervision of the co-senior authors Drs. Cowling and Milton, recruited 246 people with suspected respiratory viral infections. Milton's Gesundheit machine compared how much virus they exhaled with and without a surgical mask.

"In 111 people infected by either coronavirus, influenza virus or rhinovirus, masks reduced detectable virus in respiratory droplets and aerosols for seasonal coronaviruses, and in respiratory droplets for influenza virus," Leung said. "In contrast, masks did not reduce the emission of rhinoviruses."

Although the experiment took place before the current pandemic, COVID-19 and seasonal coronaviruses are closely related and may be of similar particle size. The report's other senior author, Professor Benjamin Cowling, division head of epidemiology and biostatistics, School of Public Health, HKUMed, and co-director of the World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, said, "The ability of surgical masks to reduce seasonal coronavirus in respiratory droplets and aerosols implies that such masks can contribute to slowing the spread of (COVID-19) when worn by infected people."

Milton pointed to other measures his research has found is even more effective than masks, such as improving ventilation in public places like grocery stores, or installing UV-C lights near the ceiling that works in conjunction with ceiling fans to pull air upwards and destroy viruses and bacteria.

"Personal protective equipment like N95 masks are not our first line of defense," Milton said. "They are our last desperate thing that we do."

Explore further

Should we wear masks or not? An expert sorts through the confusion
More information: Nancy H. L. Leung et al, Respiratory virus shedding in exhaled breath and efficacy of face masks, Nature Medicine (2020). DOI: 10.1038/s41591-020-0843-2

Journal information: Nature Medicine

Unsustainable food systems:

Can we reverse current trends?

by International Center for Tropical Agriculture (CIAT)

As rural masses migrate to urban areas, populations grow, and people work toward better living standards, global food system sustainability is jeopardized, according to a new analysis spanning low- to high-income countries. The study, which was published April 3 in the scientific journal PLOS ONE, shows that only one major global driver—the increase in international trade flows—appears to have a net positive effect on global food systems sustainability. All other major drivers (population growth, urbanization, lifestyle change, and changes in land use) seem to have negative effects.

"Trade seems to be good for food systems—but only up to a point," said Steven Prager, a study co-author from the Alliance of Bioversity International and CIAT. "Beyond a certain level, the positive effect of trade tends to plateau. High-income countries simply don't continue to benefit."

In the context of the COVID-19 pandemic, the immediate focus of the research community is, correctly, on human health. But global disturbances sparked by the pandemic also reveal how fragile our global food systems are.

In those conditions, "Understanding what drives our food systems and how we can measure or monitor them becomes vital if we want to give policymakers better tools for making food systems more sustainable and more resilient to local or global shocks such as the extreme one we are experiencing today," said Christophe Béné, the study's lead author.

Helping policymakers "understand the dynamic of our food systems"

The study builds on a global map of food system sustainability published in November in Scientific Data. That study showed that high-income countries tend to have a higher level of food system sustainability (despite all the junk food they consume) than lower-income countries. Those findings were one of the motivations behind the new study. Its authors wanted to understand what drives those different levels of sustainability and what can be done to improve the situation.

"Local and global food systems are simply reflecting the ways the world is evolving," said Jessica Fanzo, a co-author and associate professor of global food and agricultural policy and ethics at the Johns Hopkins School of Advanced International Studies.

"Some of the key drivers of the global demographic transition that the world is experiencing right now are also heavily impacting our food systems," said Fanzo, who was also the team leader on the 2017 report by the High Level Panel of Experts on Food Security and Nutrition, an initiative of the Food and Agriculture Organization of the United Nations.

The problem is that all these drivers, so far, have had a negative impact on food systems and these drivers are very difficult to control.

"It would be very difficult to prevent people from migrating to cities or from embracing new lifestyles as their income rises," said Fanzo. "We need therefore to find very rapidly the way to reverse or mitigate the consequences of these trends."

Though the results of the study point to some serious challenges ahead, they also offer some initial indications for policymakers about where to direct effort and investment to improve the long-term sustainability of our food systems.A new world map rates food sustainability for countries across the globe

More information: PLOS ONE (2020). DOI: 10.1371/journal.pone.0231071

When what-if scenarios turn real: Pandemic modelers providing new COVID-19 insights

by Colorado State University

As a Yale University postdoctoral researcher, economist Jude Bayham studied the potential consequences of a global pandemic that could shutter schools, close businesses, and strain hospitals. That was back in 2013.

Now, as the world grapples with the coronavirus, the Colorado State University economist and a multi-institutional team are turning those prescient modeling exercises into real insights for policymakers.

"We're repurposing models we had done a while back that frankly at the time, people didn't really care about," said Bayham, assistant professor in the Department of Agricultural and Resource Economics. "It's an 'I told you so' moment. I'm not happy about it. It's unfortunate."

In the last several weeks, Bayham and Yale collaborator Eli Fenichel have run a series of analyses illustrating the toll that long-term school closures may have on U.S. health care providers. They're now fielding inquiries from all over the world, from state governments to child care needs assessment professionals, who think the economists' work could help them navigate the here and now. In the last two weeks, the researchers created an interactive dashboard for drilling down statistics on child care needs by state, city and industry sector. Their data were published in The Lancet Public Health April 3.

Bayham and Fenichel have also created another dashboard for viewing COVID-19 complication risk factors in the workforce.

A third of health workers care for young children

For their health care worker analysis, the researchers used data from the U.S. Current Population Survey to show that about a third of health care workers—doctors, nurses, hospital staff—care for children ages 3-12. Fifteen percent of those households don't have other adults or older children who can help with child care.

At the time they did their original analysis, a long-term school closure was a far-off hypothetical. Now, as school districts nationwide shutter for weeks or months, Bayham's work of yore takes on new significance, and the team is scrambling to update it with current figures.

School closures are intended to slow the transmission of the virus. But Bayham and Fenichel find that the toll school closures take on health care workers could potentially negate any mortality benefits from the closures. Their calculations indicate that if the health care workforce declines by 15 percent, due to the workers now having to care for their children, it could lead to an increase in coronavirus deaths, because the workers aren't there to care for sick people. Specifically, they report that assuming a 15 percent loss of the health care labor force, a coronavirus infection mortality rate increase of just 0.35 percentage points would net a greater number of deaths than would be prevented by the closures.

These calculations are just that—calculations, which don't take into account, for example, the potential rollout of state or federal programs to offer child care relief to workers. And the estimates aren't perfect; the researchers don't claim to know, down to a precise number, what one health care worker's absence portends.

"We don't know, in terms of a productivity measure, the estimate of one nurse saving this many lives or reducing mortality," Bayham said. "But we think it's not zero. So essentially we are getting at how productive they need to be for us to be concerned about how school closures would undermine the goal of saving lives."

The work is a sobering reminder of the societal and public-health tradeoffs of large-scale disruptions like long-term school closures.

Forming networks

As the pandemic continues to unfold, Bayham and colleagues at Yale, Northwestern University and other institutions have quickly formed a network of economists and epidemiologists to continue this and other lines of work. They hope to help inform decisionmakers on questions not only of tradeoffs of school closures, but also, strategies for peeling back such restrictive measures when the time is right.

As researchers all over the world converge their expertise around the pandemic, Bayham and colleagues are also jumping into other projects to help. For example, Bayham is serving on a U.S. Forest Service task force that will examine potential outcomes of coronavirus on firefighters as fire season returns.

And along with department colleagues Becca Jablonski and Dawn Thilmany, Rebecca Clary, Rebecca Hill and Alexandra Hill, he is also serving on a Colorado Department of Agriculture-focused task force looking at effects of social distancing measures on food supply chain issues. CSU's vice president for engagement and extension, Blake Naughton, established the CSU Task Force on Colorado Food Supply to conduct research on several key areas: food access and security; designating food retail establishments as "essential services;" food supply chain workforce readiness; and consumer expenditure and farm market access.

Should schools have to close, enlist childcare workers as nannies for health workers

More information: Link to interactive dashboard with child care needs by state: covid.yale.edu/resources/childcare/

Link to interactive dashboard with COVID-19 complication risk factors: foodsystems.colostate.edu/covi … ty-labor-force-risk/

Jude Bayham et al, Impact of school closures for COVID-19 on the US health-care workforce and net mortality: a modelling study, The Lancet Public Health (2020). DOI: 10.1016/S2468-2667(20)30082-7

Changes to drylands with future climate change

by Washington State University

Arid chaco. Credit: Valerio Pillar, CC BY-SA 2.0

A research team led by Washington State University has found that while drylands around the world will expand at an accelerated rate because of future climate change, their average productivity will likely be reduced.

The study, published in Nature Communications on April 3, is the first to quantify the impact of accelerated dryland expansion under future climate change on their gross primary production. Drylands, which primarily include savannas, grasslands and shrublands, are important for supporting grazing and non-irrigated croplands around the world. They are also an important player in the global carbon cycle and make up 41% of Earth's land surface and support 38% of its population.

"Our results highlight the vulnerability of drylands to more frequent and severe climate extremes," said Jingyu Yao, a research assistant in WSU's Department of Civil and Environmental Engineering and lead author on the paper.

Using satellite data of vegetation productivity, measurements of carbon cycling from 13 sites and datasets from global models of future climate change, the researchers found that productivity of drylands will increase overall by about 12% by 2100 compared to a baseline from about 10 years ago. However, as drylands replace more productive ecosystems, overall global productivity may not increase. Furthermore, due to expected changes in precipitation and temperatures, the amount of productivity in any one dryland area will decrease.

In addition, the researchers found that expansion among different types of drylands will lead to large changes in regional and subtype contributions to global dryland productivity.

Drylands will experience substantial expansion and degradation in the future due to climate change, wildfire and human activities, including changes to their ecosystem structures as well as to their productivity, said Heping Liu, professor in the Department of Civil and Environmental Engineering and corresponding author on the paper.

Because these regions are already water stressed, they are particularly sensitive to temperature or precipitation changes. Warming temperatures from climate change and more frequent and severe droughts threaten their biodiversity as well as their ability to take in and hold carbon.

Especially in developing countries, the degradation of dryland ecosystems could have strong societal and economic impacts, said Yao.

These changes have already started happening in the last few decades. In the U.S. Southwest, the introduction of invasive species has changed dryland regions from green to brown. Precipitation changes in Australia, which is composed almost entirely of drylands, have meant a dryer continent with dramatic impacts and Mongolia's grasslands have deteriorated because of warmer temperatures, less rainfall and overgrazing.

While the drylands' productivity is important for supporting people, these areas also play a critically important role in annual carbon cycling. They help the planet breathe, absorbing carbon dioxide every spring as plants grow and then breathing it out in the fall as they become dormant. Because the growth of dryland ecosystems is very sensitive to changes in rainfall and temperature, drylands show the most impact of any ecosystem in year-to-year changes in the carbon cycle.

Understanding their role in future carbon cycling can help researchers determine how to best preserve areas of high carbon uptake.

"In our society, we are not paying much attention to what's going on with dryland regions," Liu said. "Given their importance in global carbon cycling and ecosystem services, a global action plan involving stringent management and sustainable utilization of drylands is urgently needed to protect the fragile ecosystems and prevent further desertification for climate change mitigation."

Explore furtherNew research offers global drylands solution to climate change
More information: Nature Communications (2020). DOI: 10.1038/s41467-020-15515-2
Journal information: Nature Communications

Provided by Washington State University

Deep-sea worms and bacteria team up to harvest methane

by Robert Perkins, California Institute of Technology

Scientists at Caltech and Occidental College have discovered a methane-fueled symbiosis between worms and bacteria at the bottom of the sea, shedding new light on the ecology of deep-sea environments.

They found that bacteria belonging to the Methylococcaceae family have been hitching a ride on the feathery plumes that act as the respiratory organs of Laminatubus and Bispira worms. Methylococcaceae are methanotrophs, meaning that they harvest carbon and energy from methane, a molecule composed of carbon and hydrogen.

The worms, which are a few inches long, have been found in great numbers near deep-sea methane seeps, vents in the ocean floor where hydrocarbon-rich fluids ooze out into the ocean, although it was unclear why the worms favored the vents. As it turns out, the worms slowly digest the hitchhiking bacteria and thus absorb the carbon and energy that the bacteria harvest from the methane.

That is to say, with a little help and some extra steps, the worms have become methanotrophs themselves.

"These worms have long been associated with seeps, but everyone just assumed they were filter-feeding on bacteria. Instead, we find that they are teaming up with a microbe to use chemical energy to feed in a way we hadn't considered," says Victoria Orphan, James Irvine Professor of Environmental Science and Geobiology and co-corresponding author of a paper on the worms that was published by Science Advances on April 3.

Orphan and her colleagues made the discovery during research cruises to study methane vents off the coast of Southern California and Costa Rica.

"We had a colleague on board who was an expert on these worms and noticed that the morphology was unusual. The respiratory plumes were much frillier than anyone had ever seen before, which was the first clue. It was enough to make us say, 'That's interesting. We should investigate,'" says Shana Goffredi, visitor in geobiology at Caltech and lead author of the Science Advances paper. Goffredi is an associate professor of biology at Occidental College in Los Angeles.

To probe the nature of the relationship between the worms and the bacteria, the scientists had to first use robotic submarines to take samples from deep-sea methane vents, which, in this case, lie 1,800 meters below the ocean surface.

Once the worms were brought topside, the scientists analyzed their tissues, cataloging the carbon isotopes that they had consumed. Carbon exists in two stable isotopic forms—different "flavors" of carbon, so to speak. Around 99 percent of all carbon is carbon-12, which has six neutrons and six protons in each atomic nucleus, and about 1 percent is carbon-13 (six protons and seven neutrons). Carbon-14, a radioactive isotope, exists in trace amounts.

All organisms require carbon—in some form—to survive, and they absorb it through metabolic processes. Studying the ratio of carbon-13 to carbon-12 in an organism's tissues can give clues to where that carbon came from and the conditions under which it formed. In the case of the deep-sea worms, their tissues had an unusually low ratio of carbon-13 to carbon-12, meaning that the carbon in the worm's body probably came from methane. Orphan and her collaborators reasoned that because the worms are incapable of processing methane directly, they must be getting their carbon from methanotrophic bacteria.

"The fact that we found this specific isotope of carbon throughout the worms' bodies and not just in their respiratory plumes indicates that they are consuming methane carbon from these bacteria," Orphan says. The research team followed up on this hypothesis by using molecular techniques and microscopy as well as experiments to test the ability of these worms to incorporate a modified, traceable version of methane.

Their research findings change our understanding of seep ecosystems and have implications for deep-sea stewardship, as methane seeps and hydrothermal vents are sure to experience increasing pressure because of human exploitation of energy and minerals.

The paper is titled "Methanotrophic bacterial symbionts fuel dense populations of deep-sea feather duster worms (Sabellida, Annelida) and extend the spatial influence of methane seepage."New method converts carbon dioxide to methane at low temperatures

More information: Shana K. Goffredi et al. Methanotrophic bacterial symbionts fuel dense populations of deep-sea feather duster worms (Sabellida, Annelida) and extend the spatial influence of methane seepage, Science Advances (2020). DOI: 10.1126/sciadv.aay8562

SCIENTISTS IDENTIFY NEW SPECIES OF ANCIENT PORPOISE

A worm-like creature that lived more than half a billion years ago has been discovered which is the ancestor for almost all living creatures.

The creature, called Ikaria wariootia, lived around 555 million years ago

it is believed the animal measured between two and seven millimetres in length

First known example of a bilaterian which most modern life descended from

By JOE PINKSTONE FOR MAILONLINE 23 March 2020

A worm-like creature that lived more than half a billion years ago has been discovered which is the ancestor for almost all living creatures.

The creature, called Ikaria wariootia, lived around 555 million years ago and was found in Australia.

It is the earliest known bilaterian, a creature with both a front and back, two symmetrical sides and openings at either end connected by a gut.

This blueprint was a success and almost all life on Earth now follows this template.

The creatures were between two and seven millimetres long and up to 2.5mm wide, with the largest of the species being about the same size as a grain of rice.

Pictured, artist's rendering of Ikaria wariootia. The tiny worm-like creature lived more than 555 million years ago, according to geologists who made the find. They say it the first ancestor on the family tree that contains most familiar animals today, including humans

Researchers from the University of California Riverside believe the creature is the first ancestor on the family tree from which most existing animals, including humans, descended.

Older animals have previously been discovered but these creatures had variable shapes.

For example, Ediacaran Biota, which includes sponges and algal mats have previously been discovered that pre-date the latest find.

However, these creatures are not directly related to today's fauna.

Bilateral symmetry was a critical step in the evolution of animal life as it gave animal's the ability to move purposefully.

Scott Evans, a recent doctoral graduate from University of California, Riverside, and Professor Mary Droser studied ancient deposits from Australia.

The rock was dated to 555 million years ago and the burrows made by the worm-like creatures had been previously identified, but never the animal's themselves.

But the American academics noticed miniscule, oval impressions near some of the burrows.

With funding from NASA, they used a three-dimensional laser to see what was inside.

It revealed the regular, consistent shape of a cylindrical body with a distinct head and tail.

Dr Evans said: 'We thought these animals should have existed during this interval, but always understood they would be difficult to recognise.

'Once we had the 3D scans, we knew that we had made an important discovery.'

Professor Droser said: 'Burrows of Ikaria occur lower than anything else.

'It's the oldest fossil we get with this type of complexity.'

These are Ikaria wariootia impressions in stone. Older animals have previously been discovered but these complex creatures had variable shapes and are unrelated to most modern life

With funding from NASA, researchers used a three-dimensional laser to see what was inside. It revealed the regular, consistent shape of a cylindrical body with a distinct head and tail and faintly grooved musculature

'We knew that we also had lots of little things and thought these might have been the early bilaterians that we were looking for.'

In spite of its relatively simple shape, Professor Droser explainedthe creature burrowed in thin layers of well-oxygenated sand on the ocean floor in search of organic matter, indicating rudimentary sensory abilities.

The depth and curvature of Ikaria represent clearly distinct front and rear ends, supporting the directed movement found in the burrows.

Professor Droser said the burrows also preserve crosswise, 'V'-shaped ridges, suggesting Ikaria moved by contracting muscles across its body like a worm.

She explained that evidence of sediment displacement in the burrows indicates the organism fed on buried organic matter and probably had a mouth, anus, and gut.

Professor Droser added: 'This is what evolutionary biologists predicted.

'It's really exciting that what we have found lines up so neatly with their prediction.'

The findings were published in the journal Proceedings of the National Academy of Sciences.

Fish fingers: Prehistoric sea creature that swam in the oceans and walked on land 380 million years ago is a 'missing link' in the evolution of the human hand

The prehistoric creature is thought to be one path in the evolution of fingers

It was discovered in Quebec in 2010 but has recently been studied by scientists

It is 5ft long with powerful sharp fangs, flat head, long snout and round eyes

The fingered fish was unearthed in Miguasha National Park on the Quebec coast

By RYAN MORRISON FOR MAILONLINE18 March 2020
A prehistoric sea creature that swam in the oceans and walked on land 380 million years ago had 'fingers', making it a 'missing link' in the evolution of the human hand.

The fish 'fingers' on 'Elpistostege watsoni' enabled our primitive sea-dwelling 'relative' to make the transition from water to land, experts claim.

An international team of palaeontologists from Flinders University in Australia and Universite du Quebec studied the fossilised remains of our evolutionary cousin.

The 5ft long 'missing link' looked like a shark with powerful sharp fangs, a flat head, long snout and small round eyes - but it was the fins that fascinated scientists.

The unusual fins on all four limbs provide the first evidence in fossil form of skeletal digital appendages - finger-like bones that gave rise to hands.

An animation showing the 5ft Elpistostege fish as it may have looked millions of years ago. It is not our direct ancestor but is part of the evolutionary process that led to human hands

The evolution of fishes into tetrapods - four-legged vertebrates of which humans belong - was one of the most significant events in the history of life.

The creature had four limbs and each had the unusual 'finger' like bones - making it similar to a tetrapod - a group including humans and most modern animals.

Corresponding author Professor John Long, a palaeontologist at Flinders University in Adelaide, said it was an incredible discovery and important finding to able to study the complete fossil of a tetrapod-like fish.

'It revealed extraordinary new information about the evolution of the vertebrate hand,' Long said.

'This is the first time we have unequivocally discovered fingers locked in a fin with fin-rays in any known fish.

'The articulating digits in the fin are like the finger bones found in the hands of most animals.'

Professor John Long with Elpistostege fish fossil found in Miguasha, Canada which has revealed new insights into how the human hand evolved from fish fins

Tetrapods are four-footed animals that include todays amphibians, reptiles, birds and mammals - including humans.

The fish was unearthed in Miguasha National Park on the Quebec coast - a graveyard of animals from the Devonian Period known as the 'Age of Fishes'.

Using CT (computed tomography) scans, the international team found it had arms, wrists and fingers - hand bones or 'phalanges' organised in digits.

The discovery pushes back the origin date of digits in vertebrates to the fish level - rather than at the later land dwellers.

'It also tells us the patterning for the vertebrate hand was first developed deep in evolution - just before fishes left the water,' said Long.

The evolution of fishes into tetrapods - four-legged vertebrates of which humans belong - was one of the most significant events in the history of life.

These back-boned animals were then able to leave the water and conquer land. In order to complete this change they needed hands and feet.

To understand the evolution from a fish fin to a tetrapod limb, palaeontologists study the fossils of lobe-finned fish and tetrapods from 393 to 359 million years ago - known as the Middle and Upper Devonian.

These animals are called 'elpistostegalians' and include Tiktaalik from Arctic Canada.

This is a freshwater creature that reached ten feet long but only its partial skeleton have been unearthed by scientists so far.

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This is the evolutionary fish family tree showing significance of Elpistostege in understanding the origin of tetrapods. It was on the path towards most modern mammals, birds and reptiles

Over the past decade fossils informing the fish-to-tetrapod transition have shed light on anatomical changes including breathing, hearing and feeding.

This happened as Earth's habitat changed from water to land.

Co-author Richard Cloutier, of Quebec University, said the origin of digits coincides with the ability for the fish to support its own weight in shallow water or on land.

'The increased number of small bones in the fin allows more planes of flexibility to spread out its weight through the fin,' he said.

'The other features the study revealed concerning the structure of the upper arm bone or humerus, which also shows features present that are shared with early amphibians,' Cloutier said.

'Elpistostege is not necessarily our ancestor, but it is closest we can get to a true 'transitional fossil', an intermediate between fishes and tetrapods.'

It was the largest predator living in the shallow mudflats of Quebec at the time.

The ancient sea creature would have fed upon several of the larger extinct lobe-finned fishes found fossilised in the same deposits in Quebec.

The remarkable new complete specimen of Elpistostege was discovered in 2010. It has only now been described in detail for the first time.

The research has been published in the journal Nature.
Ancient fish with fingers solves missing link in evolution

WHAT IS CONVERGENT EVOLUTION?

Convergent evolution is the process by which two unrelated species independently evolve similar features to adapt to similar problems or habitats.

Modern-day examples of convergent evolution are the hedgehog and the tenrec - a Madagascan animal which closely resembles the hedgehog but is totally unrelated.

An example of convergent evolution is the similar nature of the flight/wings of insects, birds, pterosaurs, and bats.

All four serve the same function and are similar in structure, but each evolved independently.

The tenrec (TOP) and the hedgehog (BOTTOM) are the perfect example of convergent evolution. One is commonly found in UK gardens and the other is exclusive to the island of Madagascar. They are not related

Paintings are discovered inside the coffin of a 3,000-year-old Egyptian mummy after she was lifted out of it for the first time in more than a century

Paintings on the coffin of mummy 'Ta-Kr-Hb' depict Egyptian goddess Amentet

Amentet (Ament, Amentit, Imentet, Imentit) was the Egyptian goddess and friend of the dead, and the personification of the Land of the West, 'Amenti'. It was she who welcomed the deceased to their new dwelling place in the netherworld.

'Ta-Kr-Hb' is a 3,000-year-old believed to be a priestess or princess from Thebes

She is set to be displayed to the public at the Perth City Hall Museum from 2022

By JONATHAN CHADWICK FOR MAILONLINE PUBLISHED: 2 April 2020

Paintings have been discovered inside the coffin of an Egyptian mummy after she was lifted out of it for the first time in more than 100 years.

Scottish conservators made the discovery during work to conserve Ta-Kr-Hb – pronounced ‘takerheb' – believed to be a priestess or princess from Thebes.

The mummy, which is nearly 3,000 years old, was in fragile condition after being targeted by grave robbers throughout history.

Work has been required to ensure her condition did not deteriorate further before her remains are displayed in the new City Hall Museum in Perth, Scotland.

Conservators were surprised to find painted figures of an Egyptian goddess on both the internal and external bases of the coffin trough when Ta-Kr-Hb was lifted out.

Conservators at Perth Museum and Gallery cleaning the 3,000 old mummy Ta-Kr-Hb's coffin

Both figures are representations of the Egyptian goddess Amentet or Imentet, known as the 'She of the West' or sometimes 'Lady of the West'.

'It was a great surprise to see these paintings appear,' Dr Mark Hall, collections officer at Perth Museum and Art Gallery, told the PA news agency.

'We had never had a reason to lift the whole thing so high that we could see the underneath of the trough and had never lifted the mummy out before and didn't expect to see anything there.

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Photo issued by Perth Museum and Art Gallery showing paintings of the Egyptian goddess Amentet discovered inside the coffin. Amentet, meaning 'She of the West', was a goddess in Ancient Egyptian religion

'So to get a painting on both surfaces is a real bonus and gives us something extra special to share with visitors.'

Further research will be carried out on the paintings to find out more about the history of the mummy, believed to date from somewhere between 760 and 525 BC.

The painting on the interior base of the coffin trough was previously hidden by Ta-Kr-Hb and is the best preserved of the two.

The underside of the coffin, which is slightly less well preserved, also shows a portrait of Amentet

It shows Amentet in profile, looking right and wearing her typical red dress.

Her arms are slightly outstretched and she is standing on a platform, indicating the depiction is of a holy statue or processional figure.

Usually, the platform is supported by a pole or column and one of these can be seen on the underside of the coffin trough.

Conservators clean the front of the coffin in preparation for its presentation at the new Perth City Hall, which will open as a museum in 2022

The mummy was donated to Perth Museum by the Alloa Society of Natural Science and Archaeology in 1936.

It was presented to the society by a Mr William Bailey, who bought it from the curator of the Egyptian Museum in Cairo.

In 2013, Ta-Kr-Hb was transferred temporarily for a 'check-up' at Manchester Royal Children’s Hospital, which included a CT scan and X-rays of her coffin.

Amentet (right) greeting Pharaoh Horemheb in his tomb. According to some sources, Amentet was often depicted on tombs to welcome the deceased into the afterlife

Radiographic examinations revealed that her skeleton had suffered extensive damage to the chest and pelvis, sometime after the body had been mummified, according to SCBP Perth.

While the skull remains intact, radiography revealed that as part of the mummification process the brain mass was removed through the sinuses.

But the full removal of Ta-Kr-Hb's remains this year allow today's researchers to closely observe the paintings beneath.

Perth Museum and Art Gallery are now hoping to save 'Ta-Kr-Hb' – as written in hieroglyphics on the lid of her coffin – for future generations.

'The key thing we wanted to achieve was to stabilise the body so it didn't deteriorate any more so it has been rewrapped and then we wanted to stabilise the trough and upper part of the coffin which we've done,' said Dr Hall.

Remains of a hide beetle - which is associated with decomposing remains - that was taken from inside the coffin

'Doing this means everybody gets to find out a lot more about her.

'One of the key things is just physically doing the work so we have a better idea of the episodes Ta-Kr-Hb went through in terms of grave robbers and later collectors in the Victorian times so we can explore these matters more fully and we can share that with the public.'

Conservators Helena Jaeschke and Richard Jaeschke have been working closely with Culture Perth and Kinross on the project, which started work in late January.

Culture Perth and Kinross is campaigning to raise money for the conservation of Ta-Kr-Hb as she prepares to go on display at the Perth City Hall Museum, which is set to open in 2022.

HOW DID EGYPTIANS EMBALM THEIR DEAD?

It is thought a range of chemicals were used to embalm and preserve the bodies of the dead in ancient cultures.

Russian scientists believe a different balm was used to preserve hair fashions of the time than the concoctions deployed on the rest of the body.

Hair was treated with a balm made of a combination of beef fat, castor oil, beeswax and pine gum and with a drop of aromatic pistachio oil as an optional extra.

Mummification in ancient Egypt involved removing the corpse’s internal organs, desiccating the body with a mixture of salts, and then wrapping it in cloth soaked in a balm of plant extracts, oils, and resins.

Older mummies are believed to have been naturally preserved by burying them in dry desert sand and were not chemically treated.

Gas chromatography/mass spectrometry (GC/MS) techniques have been deployed in recent years in find out more about the ancient embalming process.

Studies have found bodies were embalmed with: a plant oil, such as sesame oil; phenolic acids, probably from an aromatic plant extract; and polysaccharide sugars from plants.

Thew recipe also featured dehydroabietic acid and other diterpenoids from conifer resin.

Amentet | Ancient Egypt Online

https://ancientegyptonline.co.uk › amentet

The ancient Egyptian Goddess Amentet (also known as Ament, Amentit, Imentet and Imentit) was the consort of Aken (the ferryman of the dead). Her name means “She of the west”. This was not just a geographical statement, although some scholars consider that she originated from Libya (west of Egypt).

IImentet - Wikipedia

https://en.wikipedia.org › wiki › Imentet

Imentet was a goddess in Ancient Egyptian religion representing the necropolises west of the ... Additionally, amenti (or amentet) was thought to be where the sun set, and where the entrance to the Underworld was located, although later the ...

Amentet, Ancient Egyptian Goddess of the Dead - thekeep.org

www.thekeep.org › ~kunoichi › kunoichi › themestream › amentet

Jun 25, 2002 - Amentet (Ament, Amentit, Imentet, Imentit) was the Egyptian goddess and friend of the dead, and the personification of the Land of the West, Amenty - imnty. It was she who welcomed the deceased to their new dwelling place in the netherworld.

LA REVUE GAUCHE - Left Comment