Sep 17, 2023

Genetically modified bacteria break down plastics in saltwater

Researchers have genetically engineered a marine microorganism to break down plastic in salt water. Specifically, the modified organism can break down polyethylene terephthalate (PET), a plastic used in everything from water bottles to clothing that is a significant contributor to microplastic pollution in oceans.

"This is exciting because we need to address plastic pollution in marine environments," says Nathan Crook, corresponding author of a paper on the work and an assistant professor of chemical and biomolecular engineering at North Carolina State University.

"One option is to pull the plastic out of the water and put it in a landfill, but that poses challenges of its own. It would be better if we could break these plastics down into products that can be re-used. For that to work, you need an inexpensive way to break the plastic down. Our work here is a big step in that direction."

To address this challenge, the researchers worked with two species of bacteria. The first bacterium, Vibrio natriegens, thrives in saltwater and is remarkable -- in part -- because it reproduces very quickly. The second bacterium, Ideonella sakaiensis, is remarkable because it produces enzymes that allow it to break down PET and eat it.

The researchers took the DNA from I. sakaiensis that is responsible for producing the enzymes that break down plastic, and incorporated that genetic sequence into a plasmid. Plasmids are genetic sequences that can replicate in a cell, independent of the cell's own chromosome. In other words, you can sneak a plasmid into a foreign cell, and that cell will carry out the instructions in the plasmid's DNA. And that's exactly what the researchers did here.

By introducing the plasmid containing the I. sakaiensis genes into V. natriegens bacteria, the researchers were able to get V. natriegens to produce the desired enzymes on the surface of their cells. The researchers then demonstrated that V. natriegens was able to break down PET in a saltwater environment at room temperature.

"This is scientifically exciting because this is the first time anyone has reported successfully getting V. natriegens to express foreign enzymes on the surface of its cells," Crook says.

"From a practical standpoint, this is also the first genetically engineered organism that we know of that is capable of breaking down PET microplastics in saltwater," says Tianyu Li, first author of the paper and a Ph.D. student at NC State. "That's important, because it is not economically feasible to remove plastics from the ocean and rinse high concentration salts off before beginning any processes related to breaking the plastic down."

"However, while this is an important first step, there are still three significant hurdles," Crook says. "First, we'd like to incorporate the DNA from I. sakaiensis directly into the genome of V. natriegens, which would make the production of plastic-degrading enzymes a more stable feature of the modified organisms. Second, we need to further modify V. natriegens so that it is capable of feeding on the byproducts it produces when it breaks down the PET. Lastly, we need to modify the V. natriegens to produce a desirable end product from the PET -- such as a molecule that is a useful feedstock for the chemical industry.

"Honestly, that third challenge is the easiest of the three," says Crook. "Breaking down the PET in saltwater was the most challenging part.

"We are also open to talking with industry groups to learn more about which molecules would be most desirable for us to engineer the V. natriegens into producing," Crook says. "Given the range of molecules we can induce the bacteria to produce, and the potentially vast scale of production, which molecules could industry provide a market for?"

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Making hydrogen from waste plastic could pay for itself

Hydrogen is viewed as a promising alternative to fossil fuel, but the methods used to make it either generate too much carbon dioxide or are too expensive. Rice University researchers have found a way to harvest hydrogen from plastic waste using a low-emissions method that could more than pay for itself.

"In this work, we converted waste plastics -- including mixed waste plastics that don't have to be sorted by type or washed -- into high-yield hydrogen gas and high-value graphene," said Kevin Wyss, a Rice doctoral alumnus and lead author on a study published in Advanced Materials. "If the produced graphene is sold at only 5% of current market value -- a 95% off sale! -- clean hydrogen could be produced for free."

By comparison, 'green' hydrogen -- produced using renewable energy sources to split water into its two component elements -- costs roughly $5 for just over two pounds. Though cheaper, most of the nearly 100 million tons of hydrogen used globally in 2022 was derived from fossil fuels, its production generating roughly 12 tons of carbon dioxide per ton of hydrogen.

"The main form of hydrogen used today is 'gray' hydrogen, which is produced through steam-methane reforming, a method that generates a lot of carbon dioxide" said James Tour, Rice's T. T. and W. F. Chao Professor of Chemistry and a professor of materials science and nanoengineering. "Demand for hydrogen will likely skyrocket over the next few decades, so we can't keep making it the same way we have up until now if we're serious about reaching net zero emissions by 2050."

The researchers exposed plastic waste samples to rapid flash Joule heating for about four seconds, bringing their temperature up to 3100 degrees Kelvin. The process vaporizes the hydrogen present in plastics, leaving behind graphene -- an extremely light, durable material made up of a single layer of carbon atoms.

"When we first discovered flash Joule heating and applied it to upcycle waste plastic into graphene, we observed a lot of volatile gases being produced and shooting out of the reactor," Wyss said. "We wondered what they were, suspecting a mix of small hydrocarbons and hydrogen, but lacked the instrumentation to study their exact composition."

Using funding from the United States Army Corps of Engineers, the Tour lab acquired the necessary equipment to characterize the vaporized contents.

"We know that polyethylene, for example, is made of 86% carbon and 14% hydrogen, and we demonstrated that we are able to recover up to 68% of that atomic hydrogen as gas with a 94% purity," Wyss said. "Developing the methods and expertise to characterize and quantify all the gases, including hydrogen, produced by this method was a difficult but rewarding process for me.

"I am glad that techniques I learned and used in this work -- specifically life-cycle assessment and gas chromatography -- can be applied to other projects in our group. I hope that this work will allow for the production of clean hydrogen from waste plastics, possibly solving major environmental problems like plastic pollution and the greenhouse gas-intensive production of hydrogen by steam methane reforming."

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Sep 16, 2023

Electrons from Earth may be forming water on the Moon

A team of researchers, led by a University of Hawai'i (UH) at Manoa planetary scientist, discovered that high energy electrons in Earth's plasma sheet are contributing to weathering processes on the Moon's surface and, importantly, the electrons may have aided the formation of water on the lunar surface. The study was published today in Nature Astronomy.

Understanding the concentrations and distributions of water on the Moon is critical to understanding its formation and evolution, and to providing water resources for future human exploration. The new discovery may also help explain the origin of the water ice previously discovered in the lunar permanently shaded regions.

Due to Earth's magnetism, there is a force field surrounding the planet, referred to as the magnetosphere, that protects Earth from space weathering and damaging radiation from the Sun. Solar wind pushes the magnetosphere and reshapes it, making a long tail on the night side. The plasma sheet within this magnetotail is a region consisting of high energy electrons and ions that may be sourced from Earth and the solar wind.

Previously, scientists mostly focused on the role of high energy ions on the space weathering of the Moon and other airless bodies. Solar wind, which is composed of high energy particles such as protons, bombards the lunar surface and is thought to be one of the primary ways in which water has been formed on the Moon.

Building on his previous work that showed oxygen in Earth's magnetotail is rusting iron in the Moon's polar regions, Shuai Li, assistant researcher in the UH Manoa School of Ocean and Earth Science and Technology (SOEST), was interested in investigating the changes in surface weathering as the Moon passes through Earth's magnetotail, an area that almost completely shields the Moon from solar wind but not the Sun's light photons.

"This provides a natural laboratory for studying the formation processes of lunar surface water," said Li. "When the Moon is outside of the magnetotail, the lunar surface is bombarded with solar wind. Inside the magnetotail, there are almost no solar wind protons and water formation was expected to drop to nearly zero."

Li and co-authors analyzed the remote sensing data that were collected by the Moon Mineralogy Mapper instrument onboard India's Chandrayaan 1 mission between 2008 and 2009. Specifically they assessed the changes in water formation as the Moon traversed through Earth's magnetotail, which includes the plasma sheet.

"To my surprise, the remote sensing observations showed that the water formation in Earth's magnetotail is almost identical to the time when the Moon was outside of the Earth's magnetotail," said Li. "This indicates that, in the magnetotail, there may be additional formation processes or new sources of water not directly associated with the implantation of solar wind protons. In particular, radiation by high energy electrons exhibits similar effects as the solar wind protons."

"Altogether, this finding and my previous findings of rusty lunar poles indicate that the mother Earth is strongly tied with its Moon in many unrecognized aspects," said Li.

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Earth's stability and ability to support civilization at risk: Six of nine planetary boundaries exceeded

A new study updates the planetary boundary framework and shows human activities are increasingly impacting the planet and, thereby, increasing the risk of triggering dramatic changes in overall Earth conditions.

For over 3 billion years, the interaction between life (represented by the planetary boundary, Biosphere Integrity) and climate have controlled the overall environmental conditions on Earth. Human activities, for example replacing nature with other land uses, changing the amount of water in rivers and in soil, the introduction of synthetic chemicals to the open environment, and the emission of greenhouse gases to the atmosphere all influence these interactions.

Respecting and maintaining interactions in the Earth system so that they remain similar to those that have controlled Earth conditions over the past ~12,000 years are critical for ensuring human activities do not trigger dramatic changes in Earth condition -- changes that likely would decrease the Earth's ability to support modern civilizations.

The nine "planetary boundaries" represent components of the global environment that regulate that stability and liveability of the planet for people. The degree of breaching of the safe boundary levels is caused by human-driven activities impacting the components. The planetary boundaries framework applies the newest scientific understanding of the functioning of the Earth system to identify a "safe operating space" for humanity by proposing limits for the extent to which human activities can be allowed to impact critical processes without risk of potentially triggering irreversible changes in the Earth conditions that support us.

For the first time, metrics for all boundaries are presented. Six of the boundaries are found to be transgressed, and transgression is increasing for all boundaries except the degradation of the Earth's ozone layer. A global focus on climate is not enough. Development of Earth system models that accurately reproduce interactions between boundaries, especially Climate and Biosphere Integrity, is an urgent priority.

The study, published in Science Advances, represents the third update of the framework carried out by twenty-nine scientists from eight different countries.

The Earth's "blood pressure" is too high

The trend of increasing transgression of the boundaries is worrying explains Katherine Richardson, professor at Globe Institute, Leader of the Sustainability Science Centre at the University of Copenhagen, and leader of the study:

"Crossing six boundaries in itself does not necessarily imply a disaster will ensue but it is a clear warning signal. We can regard it as we do our own blood pressure. A BP over 120/80 is not a guarantee of a heart attack but it increases the risk of one. Therefore, we try to bring it down. For our own -- and our children's -- sakes we need to reduce the pressure on these six planetary boundaries."

An important conclusion of the study is that more focus is needed on interactions between the boundaries:

"Focus on human-caused climate change is not enough if we want to protect the earth system from irreversible harm," says Johan Rockström, Director of the Potsdam Institute for Climate Impact Research (PIK), and original proposer of the framework in 2009.

"Next to climate change, integrity of the biosphere is the second pillar of stability of our planet. Our research shows that mitigating global warming and saving a functional biosphere for the future have to go hand in hand," co-author Wolfgang Lucht, Head of PIK's department of Earth System Analysis, stresses.

Use of biomass affects biodiversity

The need to respect the Land Use Change boundary puts focus on the increasing global use of biomass as an alternative for coal, oil, and gas. Biomass is the product of photosynthesis, the process where plants convert the sun's energy to energy that can be used by other living organisms and, thus, supplies the energy that supports biodiversity.

"Our study shows that humans are appropriating the equivalent of ~30 % of the energy that was available to support biodiversity before the Industrial Revolution," says Richardson.

"Surely, the removal of so much of the energy that otherwise would have been available to nature must be a driver of biodiversity loss. Therefore, we propose the adoption of Human Appropriation of Net Primary Production (HANPP), i.e., biomass use, as one of two metrics when assessing human impacts on biodiversity."

Better Earth system models needed

"A world that develops within science defined boundaries is the only way to navigate our current situation with rising, potentially catastrophic risks, at the planetary scale. We already recognise this on Climate, where the Paris agreement has adopted the climate planetary boundary of holding the 1.5°C limit. Similarly, the world has accepted the planetary boundary on biodiversity, when decided at the 2022 Montreal-Kunming COP15, to halt and reverse biodiversity loss on land and in the ocean," says Johan Rockström and continues:

"Our study shows, however, that this is by far not enough. The Planetary Boundaries science provides a 'guide for action' if we truly want to secure prosperity and equity for all on Earth, and this goes well beyond climate only, requiring novel Earth system modelling and analysis, and systematic efforts to protect, recover and rebuild planetary resilience."

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'Night owls' more likely than 'early birds' to develop diabetes

Investigators found evening 'chronotype,' or going to bed late and waking up late, was associated with a 19 percent increased risk of diabetes after accounting for lifestyle factors

A new study has an important message for people who consider themselves night owls. Investigators from Brigham and Women's Hospital, a founding member of the Mass General Brigham healthcare system, found that people with later sleep and wake times had less healthy lifestyles and were at greater risk of developing diabetes than those with early-bird sleep habits. Their results are published in the Annals of Internal Medicine.

"Chronotype, or circadian preference, refers to a person's preferred timing of sleep and waking and is partly genetically determined so it may be difficult to change," said corresponding author Tianyi Huang, MSc, ScD, an associate epidemiologist in the Brigham's Channing Division of Network Medicine. "People who think they are 'night owls' may need to pay more attention to their lifestyle because their evening chronotype may add increased risk for type 2 diabetes."

The researchers previously found that people with more irregular sleep schedules are at higher risk of developing diabetes and cardiovascular disease and that people with evening chronotypes are more likely to have irregular sleep patterns. For this study, they wanted to understand the relationship between chronotype and diabetes risk and looked at the role of lifestyle factors as well.

The team analyzed data from 63,676 female nurses from the Nurses' Health Study II collected from 2009-2017 and included self-reported chronotype (the extent to which participants perceived themselves to be an evening person or a morning person), diet quality, weight and body mass index, sleep timing, smoking behaviors, alcohol use, physical activity, and family history of diabetes. The team determined diabetes status from the participants' self-reports and medical records.

The Nurses' Health Study II, a joint effort between the Brigham's Channing Division of Network Medicine and Harvard T.H. Chan School of Public Health, is among the largest investigations into risk factors for major chronic diseases in women. One of the study's strengths is its regular follow-up of study participants and repeated assessment of health and lifestyle factors.

Approximately 11 percent of participants reported having a 'definite evening' chronotype and about 35 percent reported having 'definite morning' chronotype. The remaining population, around half, were labeled as 'intermediate,' meaning they either identified as being neither a morning nor evening type or as being only slightly more one than the other.

The evening chronotype was associated with a 72 percent increased risk for diabetes before accounting for lifestyle factors. After accounting for lifestyle factors, evening chronotype was associated with a 19 percent increased risk of diabetes. Among those in the study with the healthiest lifestyles, only 6 percent had evening chronotypes. Among those with the unhealthiest lifestyles 25 percent were evening chronotypes.

Those with evening chronotypes were found to be more likely to drink alcohol in higher quantities, have a low-quality food diet, get less hours of sleep per night, currently smoke, and have weight, BMI, and physical activity rates in the unhealthy range.

"When we controlled for unhealthy lifestyle behaviors, the strong association between chronotype and diabetes risk was reduced but still remained, which means that lifestyle factors explain a notable proportion of this association," said first author Sina Kianersi, DVM, PhD, a postdoctoral research fellow in the Brigham's Channing Division of Network Medicine.

They also found the association between evening chronotype and diabetes risk only in those nurses who worked day shifts and not those who worked overnight shifts.

"When chronotype was not matched with work hours we saw an increase in type 2 diabetes risk," said Huang. "That was another very interesting finding suggesting that more personalized work scheduling could be beneficial."

The Nurses' Health Study is comprised mainly of white female nurses -- future investigations will be needed to determine if the patterns detected here are consistent across populations. The study's results point to associations but cannot determine causality -- it's possible that other factors may contribute to a person's chronotype, propensity for unhealthy habits and risk of diabetes.

Next, the researchers plan to investigate genetic determinants of chronotype and its association with cardiovascular disease, in addition to diabetes, in larger, more diverse populations.

Read more at Science Daily

Sep 15, 2023

Snaps supersonic outflow of young star

Herbig-Haro (HH) objects are luminous regions surrounding newborn stars, formed when stellar winds or jets of gas spewing from these newborn stars form shock waves colliding with nearby gas and dust at high speeds. This image of HH 211 from NASA's James Webb Space Telescope reveals an outflow from a Class 0 protostar, an infantile analog of our Sun when it was no more than a few tens of thousands of years old and with a mass only 8% of the present-day Sun (it will eventually grow into a star like the Sun).

Infrared imaging is powerful in studying newborn stars and their outflows, because such stars are invariably still embedded within the gas from the molecular cloud in which they formed. The infrared emission of the star's outflows penetrates the obscuring gas and dust, making a Herbig-Haro object like HH 211 ideal for observation with Webb's sensitive infrared instruments. Molecules excited by the turbulent conditions, including molecular hydrogen, carbon monoxide, and silicon monoxide, emit infrared light that Webb can collect to map out the structure of the outflows.

The image showcases a series of bow shocks to the southeast (lower-left) and northwest (upper-right) as well as the narrow bipolar jet that powers them. Webb reveals this scene in unprecedented detail -- roughly 5 to 10 times higher spatial resolution than any previous images of HH 211. The inner jet is seen to "wiggle" with mirror symmetry on either side of the central protostar. This is in agreement with observations on smaller scales and suggests that the protostar may in fact be an unresolved binary star.

Earlier observations of HH 211 with ground-based telescopes revealed giant bow shocks moving away from us (northwest) and moving towards us (southeast) and cavity-like structures in shocked hydrogen and carbon monoxide respectively, as well as a knotty and wiggling bipolar jet in silicon monoxide. Researchers have used Webb's new observations to determine that the object's outflow is relatively slow in comparison to more evolved protostars with similar types of outflows.

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Freshwater connectivity can transport environmental DNA through the landscape

A new paper published in the journal Proceedings of the Royal Society B used environmental DNA (eDNA) metabarcoding to analyze fish and zooplankton communities. The study found that the movement of water between freshwater bodies, or freshwater connectivity, can transport eDNA. This highlights the potential of eDNA to provide a comprehensive view of freshwater biodiversity.

Aquatic ecosystems are connected by waterways, which allow fish, plants, and other organisms to move from one place to another. This connectivity is important for the resilience of aquatic populations, but it can also make it difficult to track the DNA of these organisms.

The study, led by Dr Joanne Littlefair, a lecturer in biological sciences at Queen Mary University of London, looked at three lake networks containing 21 lakes in Canada's Boreal Forest at IISD Experimental Lakes Area. The researchers found that within-lake eDNA generally reflected the habitat preferences of the species, but that some eDNA was also transported into downstream lakes. Lakes with a higher degree of connectivity had more eDNA detections that could not be explained by conventional monitoring techniques.

The findings have implications for the use of eDNA to monitor biodiversity in freshwater ecosystems. eDNA is a promising tool for biodiversity monitoring, but data must be interpreted in light of connectivity in the landscape.

"eDNA can be used to detect the presence of species that are not easily monitored using conventional methods, including invasive species, or for monitoring the presence of rare or endangered species," said Dr Littlefair." "Our study showed that eDNA surveys can be carefully designed to consider the connectivity of the freshwater system being studied. In systems with high levels of connectivity, it is important to collect samples from multiple locations, which will allow us to build a complete picture of the biodiversity present."

The study also highlights the need for more research on the factors, such as effects of water movement, influencing the spatial resolution of eDNA detection. For example, if the water in an ecosystem is moving quickly, then it may be necessary to collect more samples to increase the chances of detecting eDNA. This research will help to improve scientists' understanding of how eDNA can be used to monitor and conserve aquatic biodiversity.

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How just one set of animal tracks can provide a wealth of information

Rock faces in Namibia are decorated with hundreds of stone-age images not only of animals and human footprints, but also of animal tracks. These have been largely neglected to date as researchers lacked the knowledge required to interpret them. Archaeologists from Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) and the University of Cologne have now worked together with animal tracking experts from the Nyae Nyae Conservancy in Tsumkwe, Namibia, to investigate the engraved animal tracks on six rock faces in more detail, and were able to determine detailed information on the species, age, sex, limbs, side of the body, trackway and relative direction of the tracks.

In the Doro !nawas mountains in the Namib desert in northwest Central Namibia, vegetation is sparse, trees and bushes generally only grow along small dry river beds. Thanks to various permanent waterholes, however, there is an unusually high occurrence of different animals: springboks, giraffes, elephants, lions and leopards all cross the area. The area remains untouched by humans at the current time. It is not inhabited or exploited in any other way. It was a different story in the past, however. Numerous instances of rock art representing animals as well as human footprints and animal tracks show that stone age hunters and gatherers lived here in the past.

Until now, archaeologists have only been able to interpret the species of the animals depicted in the rock art. Animal tracks tended to be classified together with the abstract symbols. "Researchers have until now completely neglected the fact that traces and tracks are also a valuable source of information," explains PD Dr. Andreas Pastoors from the Institute for Prehistory and Protohistory at FAU. Together with his FAU colleagues Prof. Dr. Thorsten Uthmeier and Dr. Tilman Lenssen-Erz from the African Research Institute at the University of Cologne, Pastoors has therefore taken a new approach, merging western archaeological science with indigenous knowledge in an innovative research project. The project began in 2013, when San tracking experts from Namibia read human footprints on the floor of caves in France decorated with rock art from the Ice Age. Now together with the Namibian tracking experts Tsamgao Ciqae, Ui Kxunta and Thui Thao from the Nyae Nyae Conservancy in Namibia, the three researchers set up camp for approximately one week in the Doro !nawas mountains, and investigated six rock faces depicting a particularly large number of human footprints and animal tracks.

The investigated rock faces are at the edge of an area resembling a crater with a diameter of approximately one kilometer in the Doro !nawas mountains. "At the upper edge there are large boulders with flat surfaces which people in the Stone Age decorated with rock art," explains Pastoors. The rock art shows various different motifs, ranging from human footprints to people and animals such as elephants, giraffes, rhinoceroses and ostriches. "These images are easily recognizable by western archaeologists," says Pastoors. However, they also depict animal tracks that have until now only been classified together with the abstract symbols. "Seen from the perspective of western art history, researchers are unable to recognize anything in these images, as they are lacking the relevant expertise. For this reason, the tracks have not yet been assessed as a legible source of information, which has in turn led to misleading hierarchies being created with regard to the value of the various images."

Stone age illustrations of animal tracks prove to be a valuable source of information

The study that has now been published counteracts this trend. Tsamgao Ciqae, Ui Kxunta und Thui Thao have discovered surprising details in the rock art. In more than 90 percent of the analyzed 513 images they were able to determine the species, age range, sex, specific limbs, side of the body and the direction of the animal tracks or human footprints. Interestingly, the animal tracks indicated a larger variety of species than those in the pictures of animals illustrated in profile in rock art in neighboring regions. The team of researchers was able to identify 20 further animal species in the animal tracks, ranging from bushpig, buffalo, monkey and caracal to various different types of antelopes (duiker, bushbuck, roan antelope, ibex), to bird species such as red-crested korhaan and marabou. One rather surprising aspect is that some of these species require damper conditions than those found in this part of Namibia, at least at the current time. But then why did the stone-age artists draw them? How did they know about them? "We cannot answer these questions with the state of research as it stands at present," admits Pastoors. However, it is plausible that the artists knew other regions with damper environmental conditions, as the Doro !nawas mountains were similarly dry as they are today."

In addition, the analyses show patterns that are obviously the result of cultural preferences. This includes, for example, the relative direction of the individual animal tracks that the tracking experts were able to decipher from the images. "We beamed a virtual clock onto the rock face and then noted the direction of the tracks according to the hours on the clock face." The result: Most tracks pointed upwards towards 12 o'clock, only a few pointed down towards 6 o'clock. The one exception were the zebra tracks. They were depicted traveling in all directions. "It's really exciting to see that the animal tracks can give us far more information that we originally thought," summarizes Pastoors.

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New evidence indicates patients recall death experiences after cardiac arrest

Up to an hour after their hearts had stopped, some patients revived by cardiopulmonary resuscitation (CPR) had clear memories afterward of experiencing death and had brain patterns while unconscious linked to thought and memory, report investigators in the journal Resuscitation, published by Elsevier.

In a study led by researchers at NYU Grossman School of Medicine, in cooperation with 25 mostly US and British hospitals, some survivors of cardiac arrest described lucid death experiences that occurred while they were seemingly unconscious. Despite immediate treatment, fewer than 10% of the 567 patients studied, who received CPR in the hospital, recovered sufficiently to be discharged. Four in 10 of patients who survived, however, recalled some degree of consciousness during CPR not captured by standard measures.

The study also found that in a subset of these patients, who received brain monitoring, nearly 40% had brain activity that returned to normal, or nearly normal, from a "flatline" state, at points even an hour into CPR. As captured by EEG, a technology that records brain activity with electrodes, the patients saw spikes in the gamma, delta, theta, alpha, and beta waves associated with higher mental function.

Survivors have long reported having heightened awareness and powerful, lucid experiences, say the study authors. These have included a perception of separation from the body, observing events without pain or distress, and a meaningful evaluation of their actions and relationships. This new work found these experiences of death to be different from hallucinations, delusions, illusions, dreams, or CPR-induced consciousness.

The study authors hypothesize that the "flatlined," dying brain removes natural inhibitory (braking) systems. These processes, known collectively as disinhibition, may open access to "new dimensions of reality," they say, including lucid recall of all stored memories from early childhood to death, evaluated from the perspective of morality. While no one knows the evolutionary purpose of this phenomenon, it "opens the door to a systematic exploration of what happens when a person dies."

Senior study author Sam Parnia, MD, PhD, associate professor in the Department of Medicine at NYU Langone Health and director of critical care and resuscitation research at NYU Langone, says, "Although doctors have long thought that the brain suffers permanent damage about 10 minutes after the heart stops supplying it with oxygen, our work found that the brain can show signs of electrical recovery long into ongoing CPR. This is the first large study to show that these recollections and brain wave changes may be signs of universal, shared elements of so-called near-death experiences."

Dr. Parnia adds, "These experiences provide a glimpse into a real, yet little understood dimension of human consciousness that becomes uncovered with death. The findings may also guide the design of new ways to restart the heart or prevent brain injuries and hold implications for transplantation."

Called the AWAreness during REsuscitation (AWARE)-II study -- it followed 567 men and women who suffered cardiac arrest during hospital stays between May 2017 and March 2020 in the United States and United Kingdom. Only hospitalized patients were enrolled to standardize the CPR and resuscitation methods used, as well as recording methods for brain activity. A subset of 85 patients received brain monitoring during CPR. Additional testimony from 126 community survivors of cardiac arrest with self-reported memories was also examined to provide greater understanding of the themes related to the recalled experience of death.

Read more at Science Daily

Sep 14, 2023

Discovery of two potential Polar Ring galaxies suggests these stunning rare clusters might be more common than previously believed

A group of international astronomers, including researchers from Queen's University, has identified two potential polar ring galaxies, according to results published today in the Monthly Notices of the Royal Astronomical Society.

Queen's researchers Nathan Deg and Kristine Spekkens (Physics, Engineering Physics & Astronomy) led the analysis of data obtained using a telescope owned and operated by CSIRO, Australia's national science agency. Looking at sky maps of hydrogen gas in over 600 galaxies as part of CSIRO's ASKAP radio telescope's WALLABY survey, they identified two potential polar ring galaxies, a type of galaxy that exhibits a ring of stars and gas perpendicular to its main spiral disk.

Although this is not the first time that astronomers have observed polar ring galaxies, they are the first observed using the ASKAP telescope located at Inyarrimanha Ilgari Bundara, CSIRO's Murchison radio astronomy observatory on Wajarri Yamaji Country in Western Australia.

These new detections in gas alone suggest polar ring galaxies might be more common than previously believed.

Understanding how galaxies evolve

Further investigation of polar ring structures can help us better understand how galaxies evolve. For example, one of the main hypotheses to explain the origin of polar rings is a merger where a larger galaxy 'swallows' a smaller one. If polar ring galaxies are more common than previously thought, this could mean that these mergers are more frequent.

In the future, polar ring galaxies can also be used to deepen our understanding of the universe, with potential applications in dark matter research. It is possible to use polar rings to probe the shape of dark matter of the host galaxy, which could lead to new clues about the mysterious properties of the elusive substance.

Visualizing polar ring galaxies

Jayanne English, a member of the WALLABY research team and also an expert in astronomy image-making at the University of Manitoba, developed the first images of these gaseous polar ring galaxies using a combination of optical and radio data from the different telescopes. First, optical and infrared data from the Subaru telescope in Hawaii provided the image for the spiral disk of the galaxy. Then, the gaseous ring was added based on data obtained from the WALLABY survey, an international project using CSIRO's ASKAP radio telescope to detect atomic hydrogen emission from about half a million galaxies.

The creation of this and other astronomical images are all composite because they include information that our eyes can't capture. In this particular case, the cold hydrogen gas component, invisible to the human eye, is seen in radio "light" using CSIRO's ASKAP. The subtle colour gradient of this ring represents the orbital motions of the gas, with purple-ish tints at the bottom tracing gas that moves towards the viewer while the top portion moves away. The emission from the ring was separated from the radio emission emanating from the disk of the galaxy using virtual reality tools, in collaboration with Professor Tom Jarrett (University of Cape Town, South Africa).

Over 25 global collaborators from Canada, Australia, South Africa, Ecuador, Burkina Faso, Germany, China, and beyond worked together to analyze the data from the first public data release of the WALLABY survey, resulting in the newly published paper.

The next step for the team is to confirm the polar ring galaxies finding through additional observations using different telescopes, including the MeerKAT radio telescope in South Africa.

Read more at Science Daily