Tuesday, June 09, 2020

Virus DNA spread across surfaces in hospital ward over 10 hours

Virus DNA left on a hospital bed rail was found in nearly half of all sites sampled across a ward within 10 hours and persisted for at least five days, according to a new study by UCL and Great Ormond Street Hospital (GOSH).

The study, published as a letter in the Journal of Hospital Infection, aimed to safely simulate how SARS-CoV-2, the virus that causes Covid-19, may spread across surfaces in a hospital.

Instead of using the SARS-CoV-2 virus, researchers artificially replicated a section of DNA from a plant-infecting virus, which cannot infect humans, and added it to a milliliter of water at a similar concentration to SARS-CoV-2 copies found in infected patients' respiratory samples.

Researchers placed the water containing this DNA on the hand rail of a hospital bed in an isolation room—that is, a room for higher-risk or infected patients—and then sampled 44 sites across a hospital ward over the following five days.

They found that after 10 hours, the surrogate genetic material had spread to 41% of sites sampled across the hospital ward, from bed rails to door handles to arm rests in a waiting room to children's toys and books in a play area. This increased to 59% of sites after three days, falling to 41% on the fifth day.

Dr. Lena Ciric (UCL Civil, Environmental & Geomatic Engineering), a senior author of the study, said: "Our study shows the important role that surfaces play in the transmission of a virus and how critical it is to adhere to good hand hygiene and cleaning.

"Our surrogate was inoculated once to a single site, and was spread through the touching of surfaces by staff, patients and visitors. A person with SARS-CoV-2, though, will shed the virus on more than one site, through coughing, sneezing and touching surfaces."

The highest proportion of sites that tested positive for the surrogate came from the immediate bedspace area—including a nearby room with several other beds—and clinical areas such as treatment rooms. On day three, 86% of sampled sites in clinical areas tested positive, while on day four, 60% of sampled sites in the immediate bedspace area tested positive.

Co-author Dr. Elaine Cloutman-Green (UCL Civil, Environmental & Geomatic Engineering), Lead Healthcare Scientist at GOSH, said: "People can become infected with Covid-19 through respiratory droplets produced during coughing or sneezing. Equally, if these droplets land on a surface, a person may become infected after coming into contact with the surface and then touching their eyes, nose or mouth.

"Like SARS-CoV-2, the surrogate we used for the study could be removed with a disinfectant wipe or by washing hands with soap and water. Cleaning and handwashing represent our first line of defense against the virus and this study is a significant reminder that healthcare workers and all visitors to a clinical setting can help stop its spread through strict hand hygiene, cleaning of surfaces, and proper use of personal protective equipment (PPE)."

SARS-CoV-2 will likely be spread within bodily fluid such as cough droplets, whereas the study used virus DNA in water. More sticky fluid such as mucus would likely spread more easily.

One caveat to the study is that, while it shows how quickly a virus can spread if left on a surface, it cannot determine how likely it is that a person would be infectedFollow the latest news on the coronavirus (COVID-19) outbreak

More information: S. Rawlinson et al, COVID-19 pandemic – let's not forget surfaces, Journal of Hospital Infection (2020). DOI: 10.1016/j.jhin.2020.05.022

Provided by University College London

Psychedelic drug psilocybin tamps down brain's ego center

by Johns Hopkins University

Perhaps no region of the brain is more fittingly named than the claustrum, taken from the Latin word for "hidden or shut away." The claustrum is an extremely thin sheet of neurons deep within the cortex, yet it reaches out to every other region of the brain. Its true purpose remains "hidden away" as well, with researchers speculating about many functions. For example, Francis Crick of DNA-discovery fame believed that the claustrum is the seat of consciousness, responsible for awareness and sense of self.

What is known is that this region contains a large number of receptors targeted by psychedelic drugs such as LSD or psilocybin ¾ the hallucinogenic chemical found in certain mushrooms. To see what happens in the claustrum when people are on psychedelics, Johns Hopkins Medicine researchers compared the brain scans of people after they took psilocybin with their scans after taking a placebo.

Their findings were published online on May 23, 2020, in the journal NeuroImage.

The scans after psilocybin use showed that the claustrum was less active, meaning the area of the brain believed responsible for setting attention and switching tasks is turned down when on the drug. The researchers say that this ties in with what people report as typical effects of psychedelic drugs, including feelings of being connected to everything and reduced senses of self or ego.

"Our findings move us one step closer to understanding mechanisms underlying how psilocybin works in the brain," says Frederick Barrett, Ph.D., assistant professor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine and a member of the school's Center for Psychedelic and Consciousness Research. "This will hopefully enable us to better understand why it's an effective therapy for certain psychiatric disorders, which might help us tailor therapies to help people more."

Because of its deep-rooted location in the brain, the claustrum has been difficult to access and study. Last year, Barrett and his colleagues at the University of Maryland, Baltimore, developed a method to detect brain activity in the claustrum using functional magnetic resonance imaging (fMRI).

For this new study, the researchers used fMRI with 15 people and observed the claustrum brain region after the participants took either psilocybin or a placebo. They found that psilocybin reduced neural activity in the claustrum by 15% to 30%. This lowered activity also appeared to be associated with stronger subjective effects of the drug, such as emotional and mystical experiences. The researchers also found that psilocybin changed the way that the claustrum communicated with brain regions involved in hearing, attention, decision-making and remembering.

With the highly detailed imaging of the claustrum provided by fMRI, the researchers next hope to look at the mysterious brain region in people with certain psychiatric disorders such as depression and substance use disorder. The goal of these experiments will be to see what roles, if any, the claustrum plays in these conditions. The researchers also plan to observe the claustrum's activity when under the influence of other psychedelics, such as salvinorin A, a hallucinogen derived from a Mexican plant.

A 'consciousness conductor' synchronizes and connects mouse brain areas

More information: Frederick S. Barrett et al. Psilocybin acutely alters the functional connectivity of the claustrum with brain networks that support perception, memory, and attention, NeuroImage (2020). DOI: 10.1016/j.neuroimage.2020.116980

Journal information: NeuroImage

Provided by Johns Hopkins University

Exploring the nature of anomalous psychedelic experiences

by Ingrid Fadelli , Medical Xpress

JUNE 4, 2020 FEATURE

Exploring the nature of anomalous psychedelic experiences — Credit: Credit: Emma Miller / Unsplash

Psychedelics are among the most intriguing and mysterious psychoactive substances, as they can radically alter people's perceptions, cognitive processes and emotions. Their unique qualities and their effects on the human brain have made these substances an appealing subject of study for several researchers worldwide.\

While psychedelics have been extensively studied throughout history, many governments effectively banned research involving the use of these substances both outside and inside laboratory settings, which hindered close investigations into their effects on the brain and on human behavior. In recent years, however, there has been a renewed academic interest in these substances and their singular properties.

David Luke, a researcher at the University of Greenwich, recently carried out a study investigating the nature of anomalous experiences induced by psychedelic substances from a humanistic, neuroscientific and parapsychological standpoint. His most recent paper on this subject was published in a special issue of the Journal of Humanistic Psychology called "Anomalous Lifeworlds: Mysticism, Magic and Expanded Consciousness."

The key goal of Luke's study was to closely examine anomalous experiences often reported by people under the influence of psychedelics or after a psychedelic trip. The researcher wished to offer an overview of the prevalence and effects of these substances, summarizing past research findings while also introducing insight about the neurobiology of similar experiences that can occur spontaneously (i.e., without psychedelics), such as near-death experiences.

"I have always been intrigued by the extraordinary experiences people report during their psychedelic journeys, which have festooned the literature since the first 'developed world' discoveries of these substances, such as the original naming of the main ayahuasca alkaloid 'telepathine' in the 1920s, or the demonstration of apparent clairvoyance in the first-ever observed use of psilocybin, or the chemist Albert Hofmann's out-of-body experience on the world's seminal LSD trip," Luke told Medical Xpress. "These anomalous experiences are still commonly reported by people under the influence of psychedelics, but they have been woefully neglected academically in the last 100 years."

Luke has been conducting research exploring anomalous psychedelic experiences for over 20 years now, approaching the subject from an anthropological, psychological and neuroscientific perspective. In his work, he often adopts an interdisciplinary approach, merging ideas from cognitive and behavioural psychology with experimental, lab-based methods, while also conducting surveys, interviews, literature reviews and ethnographical studies with indigenous tribes known to use these substances.

"Much of the available research in this area is extremely nascent, despite these substances having been studied for over 100 years in some cases," Luke said. "Prohibition stalled nearly all human psychedelic research for about 50 years, which unavoidably slowed things down."

Past interviews with people who took psychedelics revealed patterns in anomalous experiences that are far more common in people under the influence of these substances than under that of other psychoactive drugs. Interestingly, some interviewees also said that psychedelic substances had profound and long-lasting positive effects on their life and overall perceptions of the world.

"A recent survey, for instance, found that more than half of all prior atheists reported no longer being atheist after having an entity encounter experience with the potent endogenous chemical DMT," Luke said. "Furthermore, the experiences were rated as among the most meaningful, spiritual, and psychologically insightful lifetime experiences, with persisting positive changes in life satisfaction, purpose and meaning attributed to them."

In his paper, Luke reviews and examines 10 anomalous experiences reported by many people who used psychedelics. These include synaesthesia (e.g., seeing sounds as colourful patterns), extradimensional perceptions, out-of-body experiences, near-death experiences, encounters with seemingly sentient entities, alien abduction experiences, sleep paralysis, interspecies communication, possession, and psychic experiences (e.g., telepathy, precognition, clairvoyance, or psychokinesis).

Luke investigated these experiences in relation with results gathered in past neuroscientific and neurobiological studies, which were carried out on people who were having psychedelic trips and in naturally occurring states of consciousness. In his paper, he concludes that anomalous experiences, such as the ones reported by psychedelic users, appear to be induced by altered states of consciousness rather than by psychedelic chemicals per se, as all the experiences examined in his work were also reported by some individuals who had not taken psychedelics or any other psychoactive drug.

Moreover, the temporary effects of psychedelics on the brain have been found to resemble those observed during naturally occurring altered states of consciousness, for instance, while dreaming, drumming or during a 'creative trance'. According to Luke, while psychedelic-induced and naturally occurring anomalous experiences might be similar in nature and produce analogous patterns in brain activity, each will ultimately have their own 'flavour' depending on how it is induced or how it arises.

"I believe that anomalous experiences with psychedelics have far-reaching implications for the study of consciousness and its applications, including neuroscience, psychiatry, psychology and even philosophy, as regards the mind, and the branches of metaphysics dealing with ontology and epistemology," Luke said.

Overall, Luke's recent study provides a detailed summary and analysis of past research findings associated with 10 of the most common anomalous psychedelic experiences. In the future, his work could inspire new research examining the effects and neurobiological underpinnings of psychedelic use or further investigating the nature of altered states of consciousness reported by individuals under the influence of psychedelics.

"I have several new projects underway, such as mapping some of the psychological correlates of a range of psychedelic and non-drug altered states, to discover commonalities, and exploring the nature of precognitive and shared visionary experiences with DMT under controlled conditions," Luke said.New research confirms lingering mood benefit of psychedelics

More information: David Luke. Anomalous Psychedelic Experiences: At the Neurochemical Juncture of the Humanistic and Parapsychological, Journal of Humanistic Psychology (2020). DOI: 10.1177/0022167820917767

Scientists warn against 'greenwashing' of global coastal developments

by Alan Williams, University of Plymouth

The world's waterfront cities should not be deluged with apparently green developments because they still carry the potential to cause damage to the marine and coastal environment, scientists have warned.

Coastal urban areas all over the world have expanded at an increasingly fast pace in recent years, with developers innovating a variety of ways to try and minimise their impact on natural habitats.

However, an international team of scientists has said the artificial structures and reclaimed land that have resulted are often poor surrogates for the natural environment they replace.

They say that where societal and economic demand makes development inevitable, more attention must be paid to claims over biodiversity gain because a 'greened' development will always impinge on natural systems.

The calls are made in a commentary article, accepted for publication in the Journal of Applied Ecology and written by eco-engineers, ecologists and marine biologists from the UK, Italy and Malaysia.

Led by researchers from the University of Plymouth, it particularly focuses on the application of so-called integrated greening of grey infrastructure (IGGI).

Despite it already being implemented in many places, they believe there is considerable scope for it to be misused, leading to the 'greenwashing' of new developments including seawalls, breakwaters and artificial islands.

Instead, the scientists say it can undoubtedly be used to enhance previously-developed or degraded environments, and those projects should act as a testbed for where IGGI can have a positive—and, just as importantly, a negative—impact.

Dr. Louise Firth, Lecturer in Marine Ecology at the University of Plymouth, is the article's lead author. She said: "The artificialisation of the global coastline is driving humanity to develop novel solutions to halt biodiversity loss and enhance the marine built environment. While IGGI has demonstrated real promise in experimental trials and redevelopment projects, there are many limitations and unknowns and now is the time to have an open discussion about its risks and benefits.

"It is certainly true that when incorporated in redevelopment or regeneration, it can represent something of a laurel wreath with measureable benefits for humans and nature. However, in new developments, it could be viewed as a fig leaf covering up environmental damage or even worse, a Trojan horse deliberately causing harm."

In the article, the researchers do highlight a number of projects where existing structures or developments are being regenerated for environmental benefit. These include the Billion Oyster Project in New York, which is using artificial structures to install oysters with widespread success.

They also highlight areas which could be at risk of greenwashing, including disused oil platforms in the Gulf of Mexico, which may be supporting marine life now but may not continue to do so as their structures degrade.

Their article adds that over the last 30 years, Asia and the Middle East have experienced the greatest population and urban growth while constructing some of the most ambitious and iconic land reclamation projects. However, of the top 50 countries expected to experience the fastest population growth from 2020-2100, 86% are African and 72% of them are coastal.

These countries have some of the largest remaining stretches of 'unaltered' coastlines, but limited environmental protection policies, and as such are potentially the most vulnerable to future habitat loss and megadevelopment.Artificial coastal defences could be used to enhance marine biodiversity, study shows

More information: L.B. Firth et al, Greening of grey infrastructure should not be used as a Trojan horse to facilitate coastal development, Journal of Applied Ecology (2020). DOI: 10.1111/1365-2664.13683

Journal information: Journal of Applied Ecology Provided by University of Plymouth

Boys' poor reading skills might help explain higher education gender gap

by Eric Stann, University of Missouri

Researchers at the University of Missouri and the University of Essex in the United Kingdom found boys' poor reading skills in adolescence, combined with the social attitudes about women attending college, can help explain why fewer men than women enroll in higher education or other types of post-high school education.

Their findings were published in the Proceedings of the National Academy of Sciences.

"Reading scores are important for both boys and girls, and we know that girls, on average, score better on reading tests," said co-author David Geary, a Curators Distinguished Professor of Psychological Sciences in the College of Arts and Science.

Geary said adolescent reading scores and social attitudes toward women attending college can predict the ratio of men and women attending college or other post-secondary education.

"Here, we studied a snapshot of reading achievements for boys and girls when they were 15 years old," he said. "And with an understanding of how social attitudes are in various countries about girls going to college, we can predict the ratio of men and women attending college five years later."

Geary and his co-author Gijsbert Stoet, a professor of psychology at University of Essex, analyzed three international databases: post-secondary education enrollment data between 2011-2017 from the Organization for Economic Co-operation and Development; national reading scores for 15- and 16-year-olds from the Program for International Student Assessment; and social attitudes toward women pursuing university education from the World Values Survey. Specifically, the researchers looked at one question in the World Values Survey that read, "A university education is more important for a boy than for a girl." In total, the data represents over 400,000 boys and girls in 18 countries.

Stoet explains why social attitudes should be considered along with reading scores.

"An important factor to consider is the degree to which people across the world believe that a college education is equally important for girls as it is for boys," Stoet said. "Although more and more girls have been going to college, girls are still more likely than boys to be at a disadvantage in terms of social attitudes; this is a bigger problem in some countries than in others."

Geary said the study paints a bleak picture for reducing this gender gap—unless reading skills are improved.

"The practical implication is that equity in college enrollment is well out of reach at this time," Geary said. "There is no good reason to expect that national reading levels for either gender will be sufficiently raised in the coming decade to change enrollment patterns. The way to counter that is to improve reading skills, but that improvement will have to start early in life. The reading gap between boys and girls is there from the very beginning of schooling, even in preschool."

The study, "Gender differences in the pathways to higher education," was published in the Proceedings of the National Academy of Sciences.

Girls lead boys in academic achievement globally

More information: Gijsbert Stoet et al, Gender differences in the pathways to higher education, Proceedings of the National Academy of Sciences (2020). DOI: 10.1073/pnas.2002861117

Journal information: Proceedings of the National Academy of Sciences

Provided by University of Missouri

Entire Roman city revealed without any digging

by University of Cambridge

For the first time, archeologists have succeeded in mapping a complete Roman city, Falerii Novi in Italy, using advanced ground penetrating radar (GPR), allowing them to reveal astonishing details while it remains deep underground. The technology could revolutionize our understanding of ancient settlements.

The team, from the University of Cambridge and Ghent University, has discovered a bath complex, market, temple, a public monument unlike anything seen before, and even the city's sprawling network of water pipes. By looking at different depths, the archeologists can now study how the town evolved over hundreds of years.

The research, published today in Antiquity, harnessed recent advances in GPR technology which make it possible to explore larger areas in higher resolution than ever before. This is likely to have major implications for the study of ancient cities because many cannot be excavated either because they are too large, or because they are trapped under modern structures.

GPR works like regular radar, bouncing radio waves off objects and using the 'echo' to build up a picture at different depths.* By towing their GPR instruments behind a quad bike, the archeologists surveyed all 30.5 hectares within the city's walls—Falerii Novi was just under half the size of Pompeii—taking a reading every 12.5cm.

Located 50 km north of Rome and first occupied in 241 BC, Falerii Novi survived into the medieval period (until around AD 700). The team's GPR data can now start to reveal some of the physical changes experienced by the city in this time. They have already found evidence of stone robbing.

The study also challenges certain assumptions about Roman urban design, showing that Falerii Novi's layout was less standardized than many other well-studied towns, like Pompeii. The temple, market building and bath complex discovered by the team are also more architecturally elaborate than would usually be expected in a small city.

In a southern district, just within the city's walls, GPR revealed a large rectangular building connected to a series of water pipes which lead to the aqueduct. Remarkably, these pipes can be traced across much of Falerii Novi, running beneath its insulae (city blocks), and not just along its streets, as might normally be expected. The team believes that this structure was an open-air natatio or pool, forming part of a substantial public bathing complex.

Even more unexpectedly, near the city's north gate, the team identified a pair of large structures facing each other within a porticus duplex (a covered passageway with central row of columns). They know of no direct parallel but believe these were part of an impressive public monument, and contributed to an intriguing sacred landscape on the city's edge.

Corresponding author, Professor Martin Millett from the University of Cambridge's Faculty of Classics, said:

"The astonishing level of detail which we have achieved at Falerii Novi, and the surprising features that GPR has revealed, suggest that this type of survey could transform the way archeologists investigate urban sites, as total entities."

Millett and his colleagues have already used GPR to survey Interamna Lirenas in Italy, and on a lesser scale, Alborough in North Yorkshire, but they now hope to see it deployed on far bigger sites.

"It is exciting and now realistic to imagine GPR being used to survey a major city such as Miletus in Turkey, Nicopolis in Greece or Cyrene in Libya", Millett said. "We still have so much to learn about Roman urban life and this technology should open up unprecedented opportunities for decades to come."

The sheer wealth of data produced by such high-resolution mapping does, however, pose significant challenges. Traditional methods of manual data analysis are too time consuming, requiring around 20 hours to fully document a single hectare. It will be some time before the researchers finish examining Falerii Novi but to speed the process up they are developing new automated techniques.

Falerii Novi is well documented in the historical record, is not covered by modern buildings and has been the subject of decades of analysis using other non-invasive techniques, such as magnetometry, but GPR has now revealed a far more complete picture.

Facebook wallet for Libra digital coins renamed 'Novi'

More information: L. Verdonck, A. Launaro, F. Vermeulen & M. Millett, 'Ground-penetrating radar survey at Falerii Novi: a new approach to the study of Roman cities', 9 June 2020. DOI: 10.15184/aqy.2020.82

*GPR is so effective because it relies on the reflection of radio waves off items in the ground. Different materials reflect waves differently, which can be used to create maps of underground features. Although this principle has been employed since the 1910s, over the past few years technological advances have made the equipment faster and higher resolution.

Journal information: Antiquity

Provided by University of Cambridge

Deadly superbug could get a vigorous foe in repurposed antibiotic

by University of Southern California JUNE 9, 2020

USC researchers have discovered that an old antibiotic may be a powerful new tool against a deadly superbug, thanks to an innovative screening method that better mimics conditions inside the human body.

The antibiotic, rifabutin, is "highly active" in fighting multidrug-resistant Acinetobacter baumannii, a significant cause of life-threatening infections in medical facilities, researchers found.

The study appears today in Nature Microbiology.

"Rifabutin has been around for more than 35 years, and no one has ever studied it for Acinetobacter infections before," said first author Brian Luna, assistant professor of molecular microbiology and immunology at Keck School of Medicine of USC. "Going forward, we may find many new antibiotics that have been missed over the last 80 years because the screening tests used to discover them were suboptimal."

Rifabutin is used to treat TB, especially in people with HIV/AIDS who can't tolerate a similar drug, rifampin. It is on the World Health Organization's List of Essential Medicines, the safest and most effective medicines needed in a health system.

Until now, it hadn't been tried against Acinetobacter baumannii, which emerged during the Iraq War as a troop-killing superbug in military treatment facilities. Acinetobacter causes pneumonia, meningitis and bloodstream infections; it tends to strike patients requiring lengthy hospital stays and invasive devices like catheters and ventilators.

Each year, Acinetobacter baumannii is responsible for about 2% of the 99,000 U.S. deaths from hospital-acquired infections, according to the Centers for Disease Control and Prevention.

One reason rifabutin's superpower against superbugs was overlooked is because of current screening techniques, researchers said. Since the 1940s, new or existing antibiotics have been tested against bacteria grown in "rich culture media," a nutrient-packed broth or gel which speeds up the process by making the bacteria to grow rapidly.

"But bacteria grow very differently inside the human body," said Brad Spellberg, chief medical officer at the Los Angeles County-University of Southern California Medical Center and senior author of the study. So, the team designed a new type of "nutrient-limited" media that better mimics conditions inside the body. They hypothesized that the more realistic media might unmask antibiotics with hidden strengths.

They found that rifabutin was vigorously active against Acinetobacter baumannii grown in the nutrient-limited media (as well as in animal tissue) but not effective against bacteria grown in the more commonly used media.

The scientists discovered that rifabutin uses a unique, Trojan-horse strategy to trick the bacteria into actively importing the drug inside itself, bypassing the bacterial outer cell defenses. This "pump" that imports the drug is only active in the more human-like media. In traditional rich culture media, high levels of iron and amino acids suppress the pump's activity, researchers found.

"Rifabutin can be used immediately to treat such infections because it is already FDA-approved, cheap and generic, and on the market," Spellberg said. "But we would like to see randomized controlled human trials to prove its efficacy, so we know for sure one way or the other."Researchers immunize mice against antibiotic-resistant bacteria, report potential for future vaccine

More information: B. Luna et al, A nutrient-limited screen unmasks rifabutin hyperactivity for extensively drug-resistant Acinetobacter baumannii, Nature Microbiology (2020). DOI: 10.1038/s41564-020-0737-6

Journal information: Nature Microbiology

Provided by University of Southern California

Scientists lament 'Humpty Dumpty' effect on world's spectacular, rare wildlife

by Colorado State University

Some of the world's largest, most spectacular and unheralded mammals are silently slipping away, species like Tibetan wild yaks and Patagonia's huemul, Bhutan's takin and Vietnam's saola. Even Africa's three species of zebras and wildebeest have suffered massive reductions over the last several decades.

The reasons for these losses are more than disease and habitat fragmentation, deforestation or wildlife trade, according to researchers. Ultimately, the cause is rampant human population growth. And unless human behavior changes in unprecedented ways, these scientists warn that future communities of these mammals will never resemble those of the recent past or even today.

The findings are based on a new study, "Disassembled food webs and messy projections: modern ungulate communities in the face of unabating human population growth," published June 9 in Frontiers in Ecology and Evolution.

Joel Berger, lead author of the study and a professor at Colorado State University, said that the time for action is now, and that touting past conservation achievements does little to better humanity's future.

"We all must realize we're members of a broad, beautiful and living planet, and we must find ways to subsist in this together or suffer more severe consequences than what we already see," said Berger, also a senior scientist at the Wildlife Conservation Society (WCS). "For many assemblages of animals, we are nearing a moment in time, when, like Humpty Dumpty, we will not be able to put things back together again." Berger is also the Barbara Cox Anthony University Chair of Wildlife Conservation at CSU.

Analyzing ecological, human disruptors

In this study, the research team—which also included Alejandro Vila, the director for Science for WCS's Patagonia Program; Cristobal Briceno, a professor and veterinarian at University of Chile; and Joanna Lambert, a professor at the University of Colorado Boulder—analyzed direct and indirect disruptions that lead to the changing roles of mammals in global ecosystems and noted how the nature of ecological interactions has changed and will do so, on an even larger scale, in coming decades.

More specifically, they looked at what has transpired with the huemul in Patagonia, takin in Bhutan, wild horses in deserts, wolves and coyotes in North America, and the inevitability of change in big ecosystems as large carnivores are extirpated.

Scientists said this is happening as the human population increases it footprint on land.

"Even in the remote reaches of the Himalayas, stray and feral dogs, a direct result of human intrusions, wreak havoc on wild and domestic species of high economic value and cultural importance," said Tshewang Wangchuk, a study co-author, conservation biologist and president of the Bhutan Foundation.

"I try to be a voice for these species that are unknown," said CSU Professor Joel Berger. He carries photos of rare species, including the takin, a member of the camel family, in his wallet. Credit: Joel Berger/ Colorado State University
Humans only recently colonized parts of the Himalayas, areas where ice has receded due to warming temperatures. Yet, the authors also point to human population change at a global scale. In 1830 when Vice-Admiral Robert Fitzroy captained his ship, the Beagle, through the Magellan Straits of South America, fewer than 1.2 billion people inhabited Earth. By Earth Day in 1970, there were more than 3.5 billion.

Today, only 50 years later the world's population approaches eight billion. Livestock and humans now constitute a staggering 97 percent of the planet's mammal biomass.

Food webs irretrievably altered

The research team said worldwide food webs have become irretrievably altered by humans, with little hope to reconstitute even recent past conditions or to put back the ecological functions once created by native species.

Feral pigs, for instance, exist today on every continent except Antarctica, and in 70 percent of the states in the United States. These animals disrupt fish, reptiles, birds and other small mammals, plants and soils. In addition, climate change warms the oceans, which in turn foments marine algal blooms, reducing fishery catches. With less demand for fish, a consequent uptick in wildlife poaching on land occurs.

The scientists also documented how an appetite for fashion like cashmere increases imports to the west from Mongolia, India and China, resulting in economic incentives for desert pastoralists to produce more domestic goats in central Asia. These goats compete for food with native species and are in danger due to increasing numbers of dogs in these areas. The dogs are not only predators but also carry diseases, which jeopardizes endangered species like snow leopards, kiang and Przewalksi's gazelle.

Use 'ecological grief' to implement action

Berger and the study authors suggest that despite the grim findings, all is not yet lost.

The world has remarkable protected areas including: Serengeti and Kruger National Park in Africa, Yellowstone and Wrangell-St. Elias National Park & Preserve in North America, Madidi National Park in Bolivia, the Patagonia Ice Fields of Chile and Argentina, Chang Tang Nature Reserve in China, and Northeast Greenland National Park, the world's largest national park.

And although food webs with large mammals will be different from those of the past and operate differently today, there are options to shape the future.

"It is not too late and we simply do not have the luxury of time to mourn what we have lost," said Lambert. "We need to use our ecological grief to implement action and honor the exceptional biodiversity that remains. This can be done by protecting large tracts of the planet's wild places."

New study reveals dangers to biological diversity from global cashmere garment industry

More information: Joel Berger et al, Disassembled Food Webs and Messy Projections: Modern Ungulate Communities in the Face of Unabating Human Population Growth, Frontiers in Ecology and Evolution (2020). DOI: 10.3389/fevo.2020.00128

Provided by Colorado State University

Titan is migrating away from Saturn 100 times faster than previously predicted

by Lori Dajose

Artwork of Saturn, Titan, and the Cassini spacecraft. Credit: Francesco Fiori, Radio Science and Planetary Exploration Lab

By Earthly standards, Saturn's moon Titan is a strange place. Larger than the planet Mercury, Titan is swaddled in a thick atmosphere (it is the only moon in the solar system to have one) and covered in rivers and seas of liquid hydrocarbons like methane and ethane. Beneath these is a thick crust of water ice, and beneath that may be a liquid water ocean that could potentially harbor life.

Now, decades of measurements and calculations have revealed that Titan's orbit around Saturn is expanding—meaning, the moon is getting farther and farther away from the planet—at a rate about 100 times faster than expected. The research suggests that Titan was born much closer to Saturn and migrated out to its current distance of 1.2 million kilometers (about 746,000 miles) over 4.5 billion years.

The findings are described in a paper that appears in the journal Nature Astronomy on June 8.

"Most prior work had predicted that moons like Titan or Jupiter's moon Callisto were formed at an orbital distance similar to where we see them now," says Caltech's Jim Fuller, assistant professor of theoretical astrophysics and co-author on the new paper. "This implies that the Saturnian moon system, and potentially its rings, have formed and evolved more dynamically than previously believed."

To understand the basics of orbital migration, we can look to our own moon. Earth's moon exerts a small gravitational pull on the planet as it orbits. This is what causes tides: the moon's rhythmic tugs cause Earth's oceans to bulge from side to side. Frictional processes inside the earth convert some of this energy into heat, distorting the earth's gravitational field so that it pulls the moon forward in its orbit. This causes the moon to gain energy and gradually move farther away from the earth, at a rate of about 3.8 centimeters per year. This process truly is gradual, though; Earth will not "lose" the moon until both the earth and moon are engulfed by the sun in roughly six billion years.

Titan exerts a similar pull on Saturn, but the frictional processes inside Saturn are usually thought to be weaker than those within Earth because of Saturn's gaseous composition. Standard theories predict that, because of its distance from Saturn, Titan should be migrating away at a sluggish rate of at most 0.1 centimeters per year. But the new results contradict this prediction.

In the work detailed in the Nature Astronomy paper, two teams of researchers each used a different technique to measure Titan's orbit over a period of 10 years. One technique, called astrometry, produced precise measurements of Titan's position relative to background stars in images taken by the Cassini spacecraft. The other technique, radiometry, measured Cassini's velocity as it was affected by the gravitational influence of Titan.

"By using two completely independent data sets—astrometric and radiometric—and two different methods of analysis, we obtained results that are in full agreement," says the study's first author, Valéry Lainey formerly of JPL (which Caltech manages for NASA), now of Paris Observatory, PSL University. Lainey worked with the astrometry team.

The results are also in agreement with a theory proposed in 2016 by Fuller, who predicted that Titan's migration rate would be much faster than standard tidal theories estimated. His theory notes that Titan is expected to gravitationally squeeze Saturn with a particular frequency that makes the planet oscillate strongly, similarly to how swinging your legs on a swing with the right timing can drive you higher and higher. This process of tidal forcing is called resonance locking. Fuller proposed that the high amplitude of Saturn's oscillation would dissipate a lot of energy, which in turn would cause Titan to migrate outward away from the planet at a faster rate than previously thought. Indeed, the observations both found that Titan is migrating away from Saturn at a rate of 11 centimeters per year, more than 100 times faster than previous theories predicted.

"The resonance locking theory can apply to many astrophysical systems. I'm now doing some theoretical work to see if the same physics can happen in binary star systems, or exoplanet systems," says Fuller.

The paper is titled "Resonance locking in giant planets indicated by the rapid orbital expansion of Titan."

A study of Saturn's largest moon may offer insights for Earth

More information: Valéry Lainey et al. Resonance locking in giant planets indicated by the rapid orbital expansion of Titan, Nature Astronomy (2020). DOI: 10.1038/s41550-020-1120-5
Journal information: Nature Astronomy

Part of China's Great Wall not built for war: study

JUNE 9, 2020

Israeli, Mongolian and US researchers have mapped the Northern Line of the Great Wall of China, in the Mongolian steppe, for the first time

The northern segment of the Great Wall of China was built not to block invading armies but rather to monitor civilian movement, an Israeli archaeologist said Tuesday.

When researchers fully mapped the Great Wall's 740-kilometre (460-mile) Northern Line for the first time, their findings challenged previous assumptions.

"Prior to our research, most people thought the wall's purpose was to stop Genghis Khan's army," said Gideon Shelach-Lavi from Jerusalem's Hebrew University, who led the two-year study.

But the Northern Line, lying mostly in Mongolia, winds through valleys, is relatively low in height and close to paths, pointing to non-military functions.

"Our conclusion is that it was more about monitoring or blocking the movement of people and livestock, maybe to tax them," Shelach-Lavi said.

He suggested people may have been seeking warmer southern pastures during a medieval cold spell.

Construction of the Great Wall, which is split into sections that in total stretch for thousands of kilometres, first began in the third century BC and continued for centuries.

The Northern Line, also known as "Genghis Khan's Wall" in reference to the legendary Mongolian conqueror, was built between the 11th and 13th centuries with pounded earth and dotted with 72 structures in small clusters.

Shelach-Lavi and his team of Israeli, Mongolian and American researchers used drones, high-resolution satellite images and traditional archaeological tools to map out the wall and find artefacts that helped pin down dates.

According to Shelach-Lavi, whose findings from the ongoing study were published in the journal Antiquity, the Northern Line has been largely overlooked by contemporary scientists.

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Journal information: Antiquity

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