Friday, January 28, 2022

Extremely harsh volcanic lake shows how life might have existed on Mars

A few specialist microbes survive conditions analogous to those of Mars' early history, reports a new publication in Frontiers in Astronomy and Space Science—and this may be thanks to a broad range of adaptations. The hydrothermal crater lake of the Poás volcano in Costa Rica is one of the most hostile habitats on the planet.

The water is ultra-acidic, full of toxic metals and the temperatures range from comfortable to boiling. In addition, recurrent 'phreatic eruptions' cause sudden explosions of steam, ash and rock. Despite such deadly eruptions, hydrothermal environments may be where the earliest forms of life began on Earth—and potentially also on Mars, if there ever was life.

Beyond discovering how life can survive these harsh conditions, studying these microbes provides clues about if and how life might have existed on Mars. "One of our key findings is that, within this extreme volcanic lake, we detected only a few types of microorganisms, yet a potential multitude of ways for them to survive," says first author Justin Wang, a graduate student at the University of Colorado Boulder, in the United States. "We believe they do this by surviving on the fringes of the lake when eruptions are occurring. This is when having a relatively wide array of genes would be useful."

This current interdisciplinary collaboration follows up on prior work from 2013. At that time, the researchers found that there was just one microbial species coming from the Acidiphilium genus in the Poás volcanic lake. Unsurprisingly, this type of bacteria is commonly found in acid mine drainages and hydrothermal systems, and they are known to have multiple genes adapted to diverse surroundings.

In the following years, there was a series of eruptions and the team returned in 2017 to see whether there had been changes in the microbial diversity, as well as to study the organisms' biochemical processes more comprehensively. This latest work shows that there was a bit more biodiversity, but still a dominance of the Acidiphilium bacteria.

Through DNA sequencing of the organisms in the lake samples, the team confirmed that the bacteria had a wide variety of biochemical capabilities to potentially help them tolerate extreme and dynamic conditions. These included pathways to create energy using sulfur, iron, arsenic, carbon fixation (like plants), both simple and complex sugars and bioplastic granules (which microorganisms can create and use as energy and carbon reserves during stress or starvation) Extremely harsh volcanic lake shows how life might have existed on Mars

The crater and its extremely harsh lake, Laguna Caliente, dominated by a single genus of extremophile Acidiphilium b

"We expected a lot of the genes that we found, but we didn't expect this many given the lake's low biodiversity," says Wang. "This was quite a surprise, but it is absolutely elegant. It makes sense that this is how life would adapt to living in an active volcanic crater lake."

Despite the oftentimes lethal surroundings, hydrothermal systems provide most of the key ingredients for the evolution of life, including heat, water and energy. This is why leading theories for both Earth and Mars focus on these locations. So far, previous efforts in search of life on Mars have focused on streambeds or river deltas, but the authors suggest that more attention should be given to the sites of past hot springs (which were present on Mars for billions of years).

"Our research provides a framework for how 'Earth life' could have existed in hydrothermal environments on Mars," explains Wang. "But whether life ever existed on Mars and whether or not it resembles the microorganisms we have here is still a big question. We hope that our research steers the conversation to prioritize searching for signs of life in these environments, for example there are some good targets on the crater rim of Jezero Crater, which is where the Perseverance rover is right now."Microbes living in a toxic volcanic lake could hold clues to life on Mars

More information: Microbial Survival in an Extreme Martian Analog Ecosystem: Poás Volcano, Costa Rica, Frontiers in Astronomy and Space Science (2022). DOI: 10.3389/fspas.2022.817900 , www.frontiersin.org/articles/1 … pas.2022.817900/full

Provided by Frontiers

A link between early maturation and better aerobic performance identified in juvenile salmon

by University of Helsinki

A study conducted at the University of Helsinki indicates that early sexual maturation and high aerobic performance in salmon have a genetic link that is already evident in juvenile salmon.

Salmon are born in rivers, migrate to the sea to reach maturity and return to spawn in their native river. While the salmon that reach their maturity at an early age return from the sea after a single year, the individuals that are slower to develop can spend two years or an even longer time at sea.

Genomic regions have been identified in the salmon genome that heavily regulate the number of years spent at sea. Under the direction of Academy of Finland Research Fellow Tutku Aykanat, researchers from the University of Helsinki bred a large number of young salmon that differed on the basis of two such regions.

The researchers measured the basal metabolism and aerobic performance of the juvenile salmon before the onset of their maturation process. Carriers of gene variants associated with early sexual maturation were found to have better aerobic performance than those whose variants were associated with the late onset of sexual maturity. Aerobic performance denotes the metabolic capacity to produce energy through aerobic cellular respiration, for example, in muscles.

"Greater aerobic performance can promote early maturation, since growth, food supply and reproduction require energy produced through aerobic metabolism," says Postdoctoral Researcher Jenni Prokkola from the Faculty of Biological and Environmental Sciences, University of Helsinki.

The genetic coupling of age-at-maturity and performance did not depend on the amount of food available to the salmon, which indicates that the finding could be generalisable to both wild salmon populations and fish farming conditions.

"Salmon that have spent several years at sea and mature at a later date are considerably larger and produce a larger number of offspring when they return to spawn compared to salmon that spawn after only one year at sea. Now, it would be important to determine whether these salmon are more susceptible to global warming due to their poorer aerobic performance. Higher water temperatures increase the energy needs of fish, but the limitations of aerobic performance make adaptation to high temperatures challenging. Aerobic performance can become an increasingly important factor for salmon in warming habitats," Prokkola says.

Investigating the genetic and physiological factors that affect age at sexual maturity is important for understanding changes taking place in salmon populations.

The research was published in Proceedings of the Royal Society B: Biological Sciences.Farmed fish breeding with wild fish is changing the life cycle of wild fish

More information: Jenni M. Prokkola et al, Genetic coupling of life-history and aerobic performance in Atlantic salmon, Proceedings of the Royal Society B: Biological Sciences (2022). DOI: 10.1098/rspb.2021.2500

Journal information: Proceedings of the Royal Society B

Provided by University of Helsinki

Peruvian gold rush turns pristine rainforests into heavily polluted mercury sinks

by Duke University

If you had to guess which part of the world has the highest levels of atmospheric mercury pollution, you probably wouldn't pick a patch of pristine Amazonian rainforest. Yet, that's exactly where they are.

In a new study appearing Jan. 26 in the journal Nature Communications, an international team of researchers show that illegal gold mining in the Peruvian Amazon is causing exceptionally high levels of atmospheric mercury pollution in the nearby Los Amigos Biological Station.

One stand of old-growth pristine forest was found to harbor the highest levels of mercury ever recorded, rivaling industrial areas where mercury is mined. Birds from this area have up to twelve times more mercury in their systems than birds from less polluted areas.

The impact and spread of mercury pollution have primarily been studied in aquatic systems. In this study, a team of researchers led by Jacqueline Gerson, who completed this research as part of her Ph.D. at Duke, and Emily Bernhardt, professor of Biology, provide the first measurements of terrestrial deposits of atmospheric methylmercury, the most toxic form of mercury.

Illegal miners separate gold particles from river sediments using mercury, which binds to gold, forming pellets large enough to be caught in a sieve. Atmospheric mercury is released when these pellets are burned in open fire ovens. The high temperature separates the gold, which melts, from the mercury, which goes up in smoke. This mercury smoke ends up being washed into the soil by rainfall, deposited onto the surface of leaves, or absorbed directly into the leaves' tissues.

To measure this mercury, Gerson and her team collected samples of air, leaf litter, soil and green leaves from the top of trees, which were obtained with the help of a huge slingshot. They focused their collection on four types of environments: forested and deforested, near mining activity or far from mining activity. Two of the forested areas near mining activity are patches with small, scraggly trees, and the third is Los Amigos Biological Station, a pristine old-growth forest that has never been touched.

Deforested areas, that would have received mercury solely through rainfall, had low levels of mercury regardless of their distance to the mining activity. Forested areas, which accumulate mercury both on their leaves and into their leaves, weren't all the same. The four areas with scraggly trees, two near mining activity and two further away, had levels of mercury in keeping with world-wide averages.

"We found that mature Amazonian forests near gold mining are capturing huge volumes of atmospheric mercury, more than any other ecosystem previously studied in the entire world," said Gerson, who is currently a postdoctoral researcher at the University of California, Berkeley.

For all forested areas, Gerson and her team measured a parameter called leaf area index, which represents how dense the canopy is.

They found that mercury levels were directly related to leaf area index: the denser the canopy, the more mercury it holds. The canopy acts like a catch-all for the gases and particulates originating from the nearby burning of gold-mercury pellets.

To estimate how much of the mercury caught in the forest canopy was making its way through the food web, the team measured the mercury accumulated in feathers of three songbird species, in reserve stations near and far from mining activity.

Birds from Los Amigos had on average three times, and up to 12 times more mercury in their feathers than those from a more remote biological station. Such high concentrations of mercury could provoke a decline of up to 30% in these birds' reproductive success.

"These forests are doing an enormous service by capturing a huge fraction of this mercury and preventing it from getting to the global atmospheric pool," Bernhardt said. "It makes it even more important that they not be burned or deforested, because that would release all that mercury back to the atmosphere."

Small-scale artisanal gold mining is an important livelihood for local communities. Akin to the American gold-rush that ravaged California in the 1850s, it is driven by economic necessity, and disproportionally impacts indigenous communities.

"This is not something new or exclusive to this area," Bernhardt said. "A very similar thing, with very similar methods, has already been done throughout many of the wealthy countries of the world where gold was available. The demand is just pushing mining further into new areas."

"There's a reason why people are mining," Gerson said. "It's an important livelihood, so the goal is not to get rid of mining completely, nor is it for people like us coming in from the United States to be the ones imposing solutions or determining what should happen."

"The goal is to highlight that the issues are far vaster than water pollution, and that we need to work with local communities to come up with ways for miners to have a sustainable livelihood and protect indigenous communities from being poisoned through air and water," Gerson said.

Mine ponds amplify mercury risks in Peru's Amazon

More information: Amazon Forests Capture High Levels of Atmospheric Mercury Pollution From Artisanal Gold Mining, Nature Communications (2022). DOI: 10.1038/s41467-022-27997-3

Journal information: Nature Communications

Provided by Duke University

Peruvian gold rush turns pristine rainforests into heavily polluted mercury sinks

Scientists record the highest levels of atmospheric mercury pollution in the world in a pristine patch of the Peruvian Amazon

Peer-Reviewed Publication

DUKE UNIVERSITY

Mercury Smoke in the Amazon — IMAGE: ARTISINAL GOLD MINERS IN THE PERUVIAN AMAZON USE OPEN PIT FIRES TO EXTRACT GOLD, SENDING METHYLMERCURY INTO THE ATMOSPHERE. NEW DATA SHOWS HOW THAT MERCURY IS ABSORBED BY NEARBY ECOSYSTEMS. view more
CREDIT: MELISSA MARCHESE

DURHAM, N.C. – If you had to guess which part of the world has the highest levels of atmospheric mercury pollution, you probably wouldn’t pick a patch of pristine Amazonian rainforest. Yet, that’s exactly where they are.

Deforested areas, that would have received mercury solely through rainfall, had low levels of mercury regardless of their distance to the mining activity. Forested areas, which accumulate mercury both on their leaves and into their leaves, weren’t all the same. The four areas with scraggly trees, two near mining activity and two further away, had levels of mercury in keeping with world-wide averages.

“We found that mature Amazonian forests near gold mining are capturing huge volumes of atmospheric mercury, more than any other ecosystem previously studied in the entire world,” said Gerson, who is currently a postdoctoral researcher at the University of California, Berkeley.

For all forested areas, Gerson and her team measured a parameter called leaf area index, which represents how dense the canopy is.

“These forests are doing an enormous service by capturing a huge fraction of this mercury and preventing it from getting to the global atmospheric pool,” Bernhardt said. “It makes it even more important that they not be burned or deforested, because that would release all that mercury back to the atmosphere.”

“This is not something new or exclusive to this area,” Bernhardt said. “A very similar thing, with very similar methods, has already been done throughout many of the wealthy countries of the world where gold was available. The demand is just pushing mining further into new areas.”

“There's a reason why people are mining,” Gerson said. “It's an important livelihood, so the goal is not to get rid of mining completely, nor is it for people like us coming in from the United States to be the ones imposing solutions or determining what should happen.”

“The goal is to highlight that the issues are far vaster than water pollution, and that we need to work with local communities to come up with ways for miners to have a sustainable livelihood and protect indigenous communities from being poisoned through air and water,” Gerson said.

Funding was provided to Jaqueline Gerson by Duke Global Health Institute Dissertation Fieldwork Grant, Duke Global Health Institute Doctoral Scholar Program, Duke University Bass Connections, Duke University Center for Latin American and Caribbean Studies Tinker Research Travel Grant Award, Duke University Center for International and Global Studies Research and Training Grant, Duke University Dissertation Research International Travel Award, Geological Society of America Grants in Aid of Research, Lewis and Clark Fund for Exploration and Field Research, and National Science Foundation Graduate Research Fellowship. Funding was provided to Emily Bernhardt by Josiah Charles Trent Memorial Foundation Endowment Fund Grant and the National Science Foundation, through the Graduate Research Fellowship Program.

CITATION: “Amazon Forests Capture High Levels of Atmospheric Mercury Pollution From Artisanal Gold Mining,” Jacqueline R Gerson, Natalie Szponar, Angelica Almeyda Zambrano, Bridget Bergquist, Eben Broadbent, Charles T Driscoll, Gideon Erkenswick, David C Evers, Luis E Fernandez, Heileen Hsu-Kim, Giancarlo Inga, Kelsey N Lansdale, Melissa J Marchese, Ari Martinez, Caroline Moore, William K Pan, Raúl Pérez Purizaca, Victor Sánchez, Miles Silman, Emily A Ury, Claudia Vega, Mrinalini Watsa, Emily S Bernhardt. Nature Communications, Jan. 28, 2022. DOI: 10.1038/s41467-022-27997-3

JOURNAL

Nature Communications

DOI

10.1038/s41467-022-27997-3

METHOD OF RESEARCH

Observational study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Amazon Forests Capture High Levels of Atmospheric Mercury Pollution From Artisanal Gold Mining

ARTICLE PUBLICATION DATE

28-Jan-2022

Magnetic navigation: Songbirds use the Earth's magnetic field as a stop sign during migration

by University of Oldenburg

A new study published today in Science has shed light on how birds navigate back to their breeding site after flying across two continents.

The study, part of an international collaboration led by researchers at the University of Oxford and including scientists from the University of Oldenburg, suggests that information extracted from the Earth's magnetic field tells birds where and when to stop migrating. This trick allows them to precisely target the same breeding site year-on-year from thousands of kilometers away.

How birds sense the Earth's magnetic field has been the subject of intense research. Birds might even 'see' magnetic field lines, and possibly use this ability to both determine the direction they're facing in and where they are.

Dr. Joe Wynn, formerly of the University of Oxford and now a researcher at the Institute for Avian Research, Germany, said that "whilst we know an increasing amount about how birds inherit migratory information from their parents, how they return to the same site year-on-year with pinpoint accuracy has remained elusive. It's quite exciting, therefore, that we've been able to find evidence that magnetic cues could be used by songbirds trying to re-locate their homes." He started developing the idea for the study during a stay as a guest scientist in the research group of biologist Prof. Dr. Henrik Mouritsen at the University of Oldenburg. Mouritsen was also involved in data analysis for the study.

You have arrived at your destination

The team analyzed data from nearly 18,000 reed warblers to investigate whether the birds used the Earth's magnetic field when finding their breeding site. Reed warblers are tiny songbirds that fly across the Sahara Desert each year to spend the summer in Europe.

They found that, as the magnetic field of Earth moved slightly, the sites to which birds returned moved with it, suggesting that birds homed to a moving magnetic target. Birds appeared to use magnetic information as a 'stop sign', with magnetic inclination in particular telling birds that they had arrived at their breeding location.

The work utilized 'ringing' data. For nearly a century, uniquely numbered metal rings have been attached to the legs of birds from across Europe.

Dr. Wynn added that "Ringing data are a fantastic way to answer questions about migration, simply because they've been gathered for so many years across a very large area…and when looking at where birds and ringed and then recovered, it seems that reed warblers use a single magnetic coordinate a bit like a 'stop sign'; when they reach the right magnetic field value, they stop migrating."

Why use the magnetic field to inform return migration?

Dr. Wynn explains that "Magnetic information seems to be pretty stable, meaning the magnetic field doesn't change very much in a given location year-on-year. Aiming for a specific magnetic value during migration might make sense then, and the cue we think birds are using, inclination, appears the most stable aspect of the magnetic field. We think this gives the birds the best chance of making it back to the breeding site."

In conclusion Dr. Wynn said that "the trans-continental migration of birds that weigh less than a teaspoon is remarkable for so many reasons, but the ability to precisely pinpoint the breeding site from half the world away is perhaps the most extraordinary aspect of all. That we can investigate this using data gathered by scientists and bird-watchers alike is extremely exciting, and we hope that this use of citizen science data inspires others to go out, watch birds and get excited about science more generally."Nature's GPS: How animals use the natural world to perform extraordinary feats of navigation

More information: Joe Wynn et al, Magnetic stop signs signal a European songbird's arrival at the breeding site after migration, Science (2022). DOI: 10.1126/science.abj421

Journal information: Science

Provided by University of Oldenburg

Creating non-hallucinogenic analogs of LSD and psilocybin to treat mental illnesses

by Bob Yirka , Medical Xpress

A combined team of researchers from the Shanghai Institute of Biochemistry and Cell Biology and ShanghaiTech University's, iHuman Institute has created non-hallucinogenic analogs of LSD and psilocybin for possible treatment of mental illnesses. In their paper published in the journal Science, the group describe the analogs they created and how they performed in mice.

In recent years, scientists have found that some hallucinogens, such as LSD and psilocybin, can provide relief for patients suffering from chronic depression and other mental illnesses like PTSD. And while many patients may enjoy the hallucinogenic experience, many do not. Scientists have therefore been taking a closer look at hallucinogens to find the mechanisms that provide relief to those suffering from depression—and if possible, to determine if the hallucinogenic effects of such drugs are necessary for treatment.

In this new effort, the researchers took a close look at both LSD and psilocybin using X-ray crystallography, and were able to determine their conformations when they become bound to the neural receptor 5-HT2AR. They found that both molecules could bind to 5-HT2AR in two ways, resulting in unique conformations. They then created compounds that would bind to 5-HT2AR in the secondary type of binding they discovered.

The researchers administered the compounds to mice that were stressed to the point of depression by being hung from their tails or forced to swim for extended periods. To test whether the mice were experiencing hallucinogenic effects, they used the twitch test. Prior research has shown that when mice are given hallucinogens, their heads twitch in a unique way. And to test whether symptoms of depression eased, they observed whether the test mice engaged in activities they had stopped doing when depression set in. The researchers found no head twitching and a renewed interest in normal activities. They suggest their work represents a good starting point for the development of non-hallucinogenic analogs of common hallucinogenic drugs.Active ingredient in magic mushrooms reduces anxiety and depression in cancer patients

More information: Dongmei Cao et al, Structure-based discovery of nonhallucinogenic psychedelic analogs, Science (2022). DOI: 10.1126/science.abl8615

Journal information: Science

Scientists develop novel non-hallucinogenic rapid-acting antidepressant compounds

Peer-Reviewed Publication

CHINESE ACADEMY OF SCIENCES HEADQUARTERS

According to the World Health Organization, approximately 280 million people worldwide live with depression. About two-thirds of those with depression have suicidal ideation, and 25% attempt suicide. Suicide is also one of the leading causes of death in 15-29-year-olds, with nearly 50% of suicides occurring in people with depression. However, conventional antidepressants produce effects only after weeks of daily dosing and do not alleviate all disease symptoms. Furthermore, 30% of patients with depression don’t respond to current antidepressant therapy.

In a study published in the journal Science, the labs led by Dr. WANG Sheng at the Center for Excellence in Molecular Cell Science, Shanghai Institute of Biochemistry and Cell Biology of the Chinese Academy of Sciences, and Dr. CHENG Jianjun at the iHuman Institute, ShanghaiTech University reported for the first time a structure-based strategy to design novel rapid-acting antidepressant compounds, a discovery that could accelerate the discovery of non-hallucinogenic psychedelic analogs.

Over the past ten years, many researchers and clinicians have come to believe that psychedelic pharmacology may represent a new era in psychiatric therapeutics. Most clinical studies described during this time have focused on psilocybin, a compound found in the Psilocybe genus of mushrooms, some of which were used for healing and spiritual purposes by the Mayan and Aztec cultures of Mesoamerica.

The US Food and Drug Administration granted psilocybin “breakthrough therapy” status for the treatment of major depressive disorder and drug-resistant depression in 2019. The results of a phase II clinical trial showed that psilocybin can greatly improve the symptoms of patients with depression within one day after dosing, and the effect can last for more than three months. However, the hallucinogenic effects of these drugs remain a concern, and scientists have been unsure whether hallucinations are therapeutically important or just a side effect.

Psilocybin is converted in the liver to pharmacologically active psilocin, which then acts on serotonin 2A receptors (5-HT2AR) in the brain. In this study, scientists produced six new crystal structures of 5-HT2AR that bound to compounds including psilocin, lysergic acid diethylamide (i.e., LSD, one of the most potent psychedelics), serotonin, and non-hallucinogenic psychedelic analogues. They found that psilocin displayed an unexpected binding mode known as the extended binding pocket (EBP) mode, which is regulated by lipids. They also found that compounds that occupied more EBP than orthosteric binding pocket (i.e., OBP, the usual site for receptor binding) were associated with anti-depressive activity in test animals without triggering hallucinations. Thus, scientists designed several new psychedelic analogues they thought would favor EBP binding over OBP binding.

Scientists then repeated the behavioral tests on mice receiving these compounds and found that two compounds, dubbed IHCH-7079 and IHCH-7806, did not trigger head twitch behavior, which has long been seen as indicative of hallucinations. However, the mice displayed standard behavioral measures suggesting the compounds were effective antidepressants.

These findings provide a solid foundation for the structure-based design of safe and effective non-hallucinogenic, rapid-acting antidepressants. It should be pointed out that the compounds reported in this work are not approved drugs, and further preclinical and clinical studies are needed to verify their safety and antidepressant effects in humans.

JOURNAL

Science

DOI

10.1126/science.abl8615

ARTICLE TITLE

Structure-based discovery of nonhallucinogenic psychedelic analogs

ARTICLE PUBLICATION DATE

27-Jan-2022

An electrically charged thin film patch used to promote wound healing

by Bob Yirka , Medical Xpress

A team of researchers working at the University of Electronic Science and Technology of China has developed an electrically charged thin film patch for promoting faster wound healing. In their paper published in the journal Science Advances, the group describes their patch, how it works, and how well it performed when tested on rats.

Humans have been looking for ways to promote faster healing of wounds for thousands of years in order to reduce both the length of time a patient experiences pain and the chances of infection. In this new effort, the researchers created an electrically charged thin film patch that helps wounds heal faster.

Prior research has shown that applying electricity to wounds induces faster healing. Unfortunately, this approach has been limited by bulky and complicated machinery. In this new effort, the researchers created a small, flexible patch that takes advantage of electricity's healing powers without the need for such equipment.

The patch is four-layered: the top and bottom layers are made of a type of electrically charged plastic and they get their charge through contact with the skin. One of the middle layers is made of a silicone rubber gel that helps the patch conform to the contours of the skin. The other middle layer is made of a shape-memory alloy material; its purpose is to pull the sides of the wound closer. The resulting thin-film patch is just 0.2 millimeters thick.

The researchers applied the patch to two kinds of wounds on test rats—straight and circular. They compared healing rates against other types of dressings and against undressed wounds. They found that circular wounds treated with the patch were 96.8% healed after eight days, compared to 76.4 to 79.9% for other dressings. Those that went untreated were only 45.9% healed. They found similar results in straight-line wound healing, though all of them healed faster than the circular wounds—such wounds require far less new skin development to heal.

The researchers suggest their patch is a viable wound treatment option and plan to continue upgrading its features, such as allowing for differently shaped wounds.

Printing technique creates effective skin equivalent, heals wounds

More information: Guang Yao et al, A programmable and skin temperature–activated electromechanical synergistic dressing for effective wound healing, Science Advances (2022). DOI: 10.1126/sciadv.abl8379

Journal information: Science Advances

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Friday, January 28, 2022

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Magnetic navigation: Songbirds use the Earth's magnetic field as a stop sign during migration

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An electrically charged thin film patch used to promote wound healing

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