Human societies often focus on dangers that exist here on Earth, but there are moments when the threats might come from much farther away.



Scientists have long wondered about cosmic events that can affect our planet’s biology. Some have been exploring whether powerful stellar explosions could be tied to catastrophic shifts in Earth’s distant past.



The idea that blasts from massive stars might have influenced global conditions is catching attention. 



Two large-scale losses of life have drawn renewed interest from researchers who see a pattern in the timing of star explosions and severe changes in Earth’s environment.



In a new study from <a href="https://www.keele.ac.uk/" target="_blank" rel="noreferrer noopener">Keele University</a>, lead author Dr. Alexis Quintana, formerly of Keele and now at the <a href="https://www.ua.es/en/" target="_blank" rel="noreferrer noopener">University of Alicante</a>, worked with Dr. Nick Wright from Keele to examine the distribution of massive stars in our region of the galaxy.



The study found that the rate of these stars going supernova near Earth appears to match two large ancient losses of life that happened 372 million years ago and 445 million years ago.



<h2 class="wp-block-heading" id="h-past-mass-extinctions">Past mass extinctions</h2>



Scientists refer to these moments in Earth’s past as the late <a href="https://www.earth.com/news/worlds-newest-oldest-forest-recently-discovered-is-full-of-calamophyton-trees/" target="_blank" rel="noreferrer noopener">Devonian</a> and <a href="https://www.earth.com/news/tiny-worms-sparked-explosive-evolutionary-period-of-life-on-earth/" target="_blank" rel="noreferrer noopener">Ordovician</a> events. 



The first occurred about 372 million years ago and led to the disappearance of around 70 percent of all species, shifting the balance of aquatic life.



The second happened 445 million years ago, removing 60 percent of marine invertebrates at a time when life mostly existed in the sea.



Researchers have struggled to nail down a clear spark for those events, though many have pointed to an erosion of the <a href="https://www.earth.com/news/the-ozone-layer-is-healing-will-the-hole-disappear-for-good/" target="_blank" rel="noreferrer noopener">ozone layer</a>. 



Some now propose that cosmic detonations may have stripped away that protective layer, allowing intense ultraviolet light to reach Earth’s surface.



<h2 class="wp-block-heading" id="h-supernovas-within-earth-s-reach">Supernovas within Earth's reach</h2>



The authors say it is "a great illustration for how massive stars can act as both creators and destructors of life". 



These stars generate heavy elements that make planets possible, but their demise can <a href="https://www.earth.com/news/t-coronae-borealis-nova-explosion-nearby-star-light-up-earths-skies/" target="_blank" rel="noreferrer noopener">produce bursts of radiation</a>.



The team embarked on what they call a “census” of nearby massive stars, known as OB stars, within around 3,260 light-years of the Sun.



OB stars are giants that can collapse under gravity when they run out of fuel, leading to an explosion that releases <a href="https://www.earth.com/news/star-collapse-black-hole-instead-of-supernova-vanish-from-sky/" target="_blank" rel="noreferrer noopener">intense waves of energy</a>.



The researchers then calculated how often these explosions might happen within 65 light-years of Earth, which is about 20 parsecs.



By comparing those estimates with the frequency of major losses of life linked to external triggers, they found a match that points to a nearby supernova as a likely suspect in the late Devonian and Ordovician events.



“We calculated the supernova rate close to Earth and found it to be consistent with the rate of mass extinction events on our planet that have been linked to external forces such as supernovae,” Dr Wright explained.



<h2 class="wp-block-heading" id="h-what-would-a-supernova-do-to-earth">What would a supernova do to Earth</h2>



The study suggests that a supernova near Earth might erode the ozone layer, spark chemical reactions that produce acid rain, and expose organisms to harmful solar radiation.



“Supernova explosions bring heavy chemical elements into the <a href="https://www.earth.com/news/astronomers-reveal-the-first-detailed-image-of-a-dying-star/" target="_blank" rel="noreferrer noopener">interstellar medium</a>, which are then used to form new stars and planets. Dr. Quintana explained. 



"But if a planet, including the Earth, is located too close to this kind of event, this can have devastating effects."



If enough shielding is lost, regions of the planet might become biologically hazardous. This could halt the growth of some organisms while allowing others to take over previously occupied niches.



Dr Wright added, “Supernova explosions are some of the <a href="https://www.earth.com/news/kilonova-explosion-light-years-away-would-devastate-earth/" target="_blank" rel="noreferrer noopener">most energetic explosions in the universe</a>. If a massive star were to explode as a supernova close to the Earth, the results would be devastating for life on Earth. This research suggests that this may have already happened.”



He and his colleagues see the new data as helpful for understanding how elements move around the galaxy and form the basis for new celestial objects.



<h2 class="wp-block-heading" id="h-why-does-any-of-this-matter">Why does any of this matter?</h2>



Supernova events are believed to happen at a rate of about one or two per century in galaxies such as the Milky Way. The chance of one erupting in our immediate neighborhood is low, though not impossible.



The researchers note that stars like Antares and <a href="https://www.earth.com/news/supergiant-star-betelgeuse-may-have-a-buddy-causing-it-to-flicker/" target="_blank" rel="noreferrer noopener">Betelgeuse</a> might run out of fuel in the next million years or so, yet they sit far enough away that the effects on Earth are likely limited.



The project’s census of massive stars also aids in studying black holes and neutron stars, which arise from the aftermath of stellar collapses.



The data can support improvements to gravitational wave detectors, which help scientists pinpoint the origins and structure of cosmic events.



By refining how often massive stars explode, astronomers can hone their forecasts for how often <a href="https://www.earth.com/news/matter-spacetime-gravitational-waves-fabric-of-the-universe/" target="_blank" rel="noreferrer noopener">gravitational waves</a> ripple through space.



<h2 class="wp-block-heading" id="h-earth-supernovas-and-future-study">Earth, supernovas, and future study</h2>



Plenty of questions remain about the ways in which these explosions can set off harmful changes in Earth’s environment.



Some experts wonder how quickly the atmosphere recovers if solar radiation spikes. Others are curious if life on land reacts differently from life at sea when <a href="https://www.earth.com/news/extreme-particle-acceleration-new-source-of-cosmic-rays-discovered/" target="_blank" rel="noreferrer noopener">cosmic rays</a> increase.



Although researchers highlight a connection between supernovae and serious biological upheavals, there could be additional processes at work.



These blasts may seed the universe with valuable ingredients while also posing potential dangers when they happen too close for comfort.



The evidence is still coming together, but it points to a story where Earth’s ancient tragedies may have a cosmic explanation. Scientists plan to keep tracking massive stars in our galaxy to see what more can be learned.



The full study was published in the journal <a href="https://academic.oup.com/mnras/article/537/4/3332/8038277" target="_blank" rel="noreferrer noopener">Monthly Notices of the Royal Astronomical Society</a>.



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Two of Earth's mass extinctions were caused by something much worse than asteroids

Human societies often focus on dangers that exist here on Earth, but there are moments when the threats might come from much farther away. Scientists have long wondered about cosmic events that can affect our planet’s biology. Some have been exploring whether powerful stellar explosions could be tied to catastrophic shifts in Earth’s distant past. The idea that blasts from massive stars might have influenced global conditions is catching attention. Two large-scale losses of life have drawn renewed interest from researchers who see a pattern in the...

Experts at <a href="https://www.osu.edu/">Ohio State University</a> have identified a type of gut bacteria that reduces the risk of heart disease. The heart health benefits of this bacteria, Eubacterium limosum, were previously unrecognized.

The activity of E. limosum reduces the production of a chemical within the intestines that is linked to clogging of the arteries in a condition known as atherosclerosis. After the chemical is produced, it travels through the bloodstream to the liver where it is converted into a more harmful form.

The researchers linked the beneficial behavior of E. limosum to a specific family of proteins, and this link helps to explain how good gut bacteria positively contribute to human health. 

In the gut, good bacteria compete with bad bacteria for the same nutrients. By helping to eliminate the bad microbes, the good bacteria may prevent health problems that can develop as a result of metabolic issues.

More research is needed, but the experts believe there is a lot of potential for E. limosum to be used for therapeutic purposes. Previous studies have already established that the bacteria calms gut inflammation.

"Over the last decade, it has become apparent that bacteria in the human gut influence our health in many ways," said study senior author Professor Joseph Krzycki. "The organism we studied affects health by preventing a problematic compound from becoming a worse one." 

"It's too soon to say whether this bacterium could have therapeutic value. But that's what we're working toward."

The chemical linked to clogged arteries is called trimethylamine (TMA). This is produced during metabolism when intestinal microbes - usually the bad type of gut bacteria - interact with certain nutrients from food. One such nutrient is L-carnitine, a chemical compound in meat and fish that is often used as a supplement to improve recovery after exercise.

The researchers discovered that E. limosum interacts with L-carnitine in a different way in the gut, eliminating L-carnitine's role in production of TMA.

The bacteria's beneficial behavior has been attributed to the protein MtcB, an enzyme involved in demethylation. By removing a methyl group, this process changes a compound's structure or function. 

The study revealed that when E. limosum is exposed to L-carnitine, the bacteria synthesizes the MtcB protein to specifically target and cut off L-carnitine's methyl group.

"The bacterium does this for its own benefit, but it has the downstream effect of reducing the toxicity of TMA," said Professor Krzycki. "Up until now, the only known gut microbial reactions with L-carnitine involved converting it into its bad form." 

"We've discovered that a bacterium known to be beneficial could remove a methyl group and send the resulting product down another pathway without making any other harmful compounds in the process."

According to Professor Krzycki, finding this significant health benefit in one species of gut bacteria suggests there is still a lot to learn about how gut bacteria can influence health outcomes associated with human metabolism.

"MtcB is part of a family of proteins with thousands of representatives that may use different compounds and change what nutrients bacteria consume in the gut," said Professor Krzycki. "These proteins may behave very similarly chemically, but using different compounds obviously can create big changes as far as biology goes."

The study is published in the <a href="https://www.jbc.org/">Journal of Biological Chemistry</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Experts find a gut bacteria that reduces the risk of heart disease

Experts at Ohio State University have identified a type of...

Native bee populations have been declining across the globe as a result of colony collapse disorder (CCD), a strange phenomenon where most of the healthy adult bees of a colony simply vanish. Scientists believe that the disorder affects the ability of the bees to navigate, which is why they never return, and the colony faces sudden death.

Colony collapse disorder is caused by pesticides, poor nutrition, pests, and <a href="http://www.earth.com/news/simple-leg-stretches-can-lower-your-risk-of-heart-disease/">disease</a>. A new study from <a href="https://www.colorado.edu/">UC Boulder</a> suggests that one particular pathogen, Nosema, has been playing a major role in the collapse of bee colonies worldwide.

The experts say there is growing evidence that Nosema has caused a "pandemic," infecting bees around the world for the past two decades. Various strains of Nosema have been recorded in Europe, Canada and Kenya, yet the European honeybee has taken by far the hardest hit. 

The researchers said that very little is known about the impact of Nosema on native bees. Study lead author Arthur Grupe II is a postdoctoral researcher in the Department of Ecology and Evolutionary Biology.

"More work needs to be done to understand Nosema infections in native bee species and the potential consequences to native ecosystems, and if native bees suffer a similar fate as honeybees when infected," said Grupe.

Native bees are critically important pollinators in their local ecosystems, where honeybees are often absent. According to Grupe, one out of every three bites of the food we eat can be attributed to a pollinator.

Nosema is a spore-forming single-celled parasite that survives by infecting the guts of bees. When the pathogen enters a host cell, it reproduces and ruptures the cell to release its spores. Other cells in the body become infected as the spores are passed through the digestive tract.

Once a bee is infected by Nosema, it can contaminate flowers, pollen, and the hive. There are some types of Nosema so destructive that they mutilate the male genitalia of bumblebees and lower their sperm count.

The study shows that different strains, such as Nosema apis, are now appearing in new places. One particular strain, Nosema ceranae, is even persisting year-round when it was previously seasonal.

Nosema bombi has arrived in Colorado, where it is infecting bumblebees. While this is the only strain documented in Colorado so far, Gripe said the more detrimental N. ceranae is probably not far behind.

The study authors emphasize that it is crucial for scientists to better understand how these Nosema strains are traveling the globe and affecting native, solitary bees, as they could lead to further bee pandemics and contribute to colony collapse.

"We know so little about the biology of what's happening," said study co-author Professor Alisha Quandt. "That's one of the reasons why we think it's so important for people to start doing this kind of surveillance work, going out there and sampling more native bees."

The study is published in the journal <a href="https://journals.plos.org/plospathogens/">PLOS Pathogens</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Bees have been enduring a pandemic for decades

Native bee populations have been declining across the globe as...

How does the <a href="http://www.earth.com/news/brain-pathway-activates-to-connect-memories-and-decisions/">brain</a> stay focused on a task while it is constantly bombarded with distractions? A new study from <a href="https://www.ucdavis.edu/">UC Davis</a> has pinpointed a specific region of the brain that blocks out distracting stimuli.

Using a mouse model, the researchers found that when stimuli are blocked, brain processing is disabled for concentration.

"When distracting stimuli are intentionally being ignored by the mice, we can now see where that distracting stimulus response is blocked. In the future, we would want to know how it is blocked," said study lead author Professor Zagha.

The experts trained mice to detect a particular target by responding to rapid stimuli on one side of their whiskers. They were also exposed to irrelevant stimuli on the whiskers opposite the target field. 

Using advanced brain imaging techniques, the team could see where the distractions were blocked, which resulted in no transmission to the cortex and no motor response.

"We observed responses to target stimuli in multiple sensory and motor cortical regions," said Professor Zagha. "In contrast, responses to distractor stimuli were abruptly suppressed beyond the sensory cortex."

The researchers were surprised by how abruptly the distractor information was blocked in the cortex. They observed that the distractor stimulus responses reached the part of the cerebral cortex responsible for early sensory processing, but were prevented from traveling any farther.

The cortex is the largest part of the brain and consists of folded gray matter with sensory and motor regions. Information processed in the cortex regulates functions such as sensation, perception, memory, attention, language, and motor functions.

"Our discovery may have important implications for the understanding and treatment of neuropsychiatric diseases such as attention deficit hyperactivity disorder and schizophrenia," said Professor Zagha. 

"By studying the mechanisms underlying the blocking of distracting stimuli we may be able to unravel the neural circuitry underlying attention and impulse control."

While scientists today know much about behavior and neurons, they only have a nascent understanding of how groups of neurons organize to mediate meaningful behaviors, explained Professor Zagha.

"A major challenge is recording neuronal activity at high spatiotemporal resolution in animals while they are performing goal-directed tasks. A second major challenge is using the correct computational methods to analyze that neuronal activity."

Professor Zagha emphasized that the findings do not fully explain what takes place in the brain that allows us to focus, such as how the distractions are actually blocked.

"But now we know exactly where to look in the brain, and we will be pursuing these questions in the future. We know that when someone is highly distractible, their cortex is not sufficiently deploying the intentional signals needed to prevent the distractor stimuli from propagating into working memory or triggering a behavioral response. 

"These processes - 'gatekeepers' of sensory signals - allow through only those signals that are task relevant. We believe this process is orchestrated by the prefrontal cortex; this is only one of the many possibilities we will be testing."

According to Professor Zagha, the neural circuits underlying sensory selection and impulse control are likely the same circuits impaired in attention deficit hyperactivity disorder and schizophrenia.

"The better we understand these circuits, the better we can design rational, targeted treatments to improve impulsivity in these disorders."

The study is published in the <a href="https://www.jneurosci.org/">Journal of Neuroscience</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Study reveals where distractions are blocked for the brain to focus

How does the brain stay focused on a task while...

The extreme rainfall patterns associated with climate change will disrupt food webs in the <a href="http://www.earth.com/news/urban-forests-store-co2/">rainforests</a> of Central and South America, according to a new study from the <a href="https://www.ubc.ca/">University of British Columbia</a>.

The research provides new insight into how climate change will impact forest ecosystems across the region, which is known as the Neotropics.

The team replicated future rainfall patterns that have been predicted by climate scientists throughout the Neotropics. 

The experts found that food webs became top-heavy with predators when there were large daily fluctuations in rainfall.

"This has knock-on effects for all parts of the rainforest system, because the larval insects in the bromeliads are destined to become winged adults that then are part of the forest ecosystem around them," said study co-author Professor Diane Srivastava.

For the investigation, the scientists performed identical experiments in Argentina, Brazil, Columbia, Costa Rica, French Guiana, and Puerto Rico. 

The experiments were focused on bromeliads, large flowering plants that trap water and provide a habitat for many insects. After covering bromeliads with rain shelters, the researchers were able to replicate 30 different rainfall patterns by watering them on strict schedules.

"This is the first study, to my knowledge, where we have a replicated study of how precipitation patterns affect an entire food web in multiple sites," said Professor Srivastava. "Every day we'd run around with a watering can with a list of how much water each bromeliad should get on each day. We had a customized rainfall schedule for each bromeliad in every field site."

While the extreme rainfall patterns resulted in top-heavy food webs, more consistent rainfall produced the opposite outcome. The researchers found that when similar amounts of rainwater was available to the plants each day, the larval communities consisted of fewer predators and more prey.

"We were actually expecting to see the opposite pattern," said Professor Srivastava. "We often think of predators being the most sensitive to environmental change, but we got the opposite result." 

"One reason may be that, when the water level in the bromeliad went down during drier days, there was less aquatic habitat, so the prey was condensed into a small amount of water together with their predators. This can really benefit predators and disadvantage prey."

The findings can be applied to other rainfall-dependent aquatic ecosystems, said Srivastava. "In any small pond or lake which is primarily determined by rainfall, we can expect to see a similar effect."

"We should be concerned about these findings, because we've shown that these extreme perturbations in rainfall really do affect the flow of energy through the food web."

The study is published in the journal <a href="https://www.nature.com/ncomms/">Nature Communications</a>.

&nbsp;

Extreme rainfall patterns disrupt rainforest food webs

The extreme rainfall patterns associated with climate change will disrupt...

The species that will thrive alongside <a href="http://www.earth.com/news/cold-climate-after-julius-caesars-death-linked-to-alaskan-volcano/">climate</a> change, as well as those that will struggle to survive, can be identified based on their adaptability to rising temperatures. 

A team of evolutionary biologists at <a href="https://www.flinders.edu.au/">Flinders University</a> has shown that vulnerability to future climate change is influenced by the thermal conditions of the region where a species evolved.

"Resilience or vulnerability to climate change is expected to be influenced by the thermal conditions where species are found, but we knew very little about this, and hardly anything about how this might vary across different climatic regions," said study co-author Dr Jonathan Sandoval-Castillo.

The investigation was focused on Australian rainbowfish living in different ecosystems. The researchers compared the thermal tolerance and gene expression of rainbowfish in desert, temperate, and subtropical conditions.

The analysis revealed that subtropical species have the highest capacity to adapt to climate change, while temperate species have the least adaptability.

According to study co-author Professor Luciano Beheregaray, subtropical species were found to be the winners in future climates because evolution suits their local conditions. He explained that subtropical fish have the ability to turn on and off a larger number of heat stress genes in hotter climates.

The researchers compared how genes are currently expressed and how they will be expressed in future temperatures projected for 2070. Based on the results, they produced a gene index that can be used to determine species adaptability.

"Our results suggest that the vulnerability of species to climate change will be highly influenced by geographic factors, emphasising the value of assessments of climate traits for more accurate estimates of population impacts and the way ecosystems will ultimately respond," said study co-author Katie Gates.

Professor Beheregaray noted that this information is important for identifying biodiversity at high risk of extinction, and for developing ways to help them adapt and survive. "This includes restoring lost habitat and actively moving populations to more favorable climatic locations, while we still have time."

The study is published in the journal <a href="https://www.pnas.org/">PNAS</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Subtropical species have the greatest climate adaptability

The species that will thrive alongside climate change, as well...

A new study from <a href="https://www.fau.edu/">Florida Atlantic University</a> has revealed that beluga whales form complex social networks that extend beyond <a href="http://www.earth.com/news/new-perching-bird-family-tree/">family</a> members. Using a combination of genetic tests and field studies, the researchers discovered that beluga whales not only interact with close relatives on a regular basis, but also with distant relatives and unrelated individuals.

The study is the first to analyze the dynamics of the relationships within groups of beluga whales, drawing from decades of research. 

The findings indicate that beluga communities resemble human societies in which social networks and support structures involve interactions between relatives and non-relatives. Furthermore, given their long lifespans of about 70 years, the relationships among belugas are likely to be long-term.

"This research will improve our understanding of why some species are social, how individuals learn from group members and how animal cultures emerge," explained study lead author Dr. Greg O'Corry-Crowe.

"It also has implications for traditional explanations based on matrilineal care for a very rare life-history trait in nature, menopause, which has only been documented in a handful of mammals, including beluga whales and humans."

The comprehensive study showed  that belugas form a limited number of group types that were consistent across sites in Arctic populations from Alaska to Canada and Russia to Norway. The group types observed include mother-calf dyads, adult male groups, mixed-age groups, and large herds. Like humans, there were certain behaviors associated with group type, and group membership was often dynamic.

"Unlike killer and pilot whales, and like some human societies, beluga whales don't solely or even primarily interact and associate with close kin. Across a wide variety of habitats and among both migratory and resident populations, they form communities of individuals of all ages and both sexes that regularly number in the hundreds and possibly the thousands," said Dr. O'Corry-Crowe.

"It may be that their highly developed vocal communication enables them to remain in regular acoustic contact with close relatives even when not associating together."

Contrary to previous assumptions, Beluga whale groups were not found to be centered around maternal or closely related females. DNA evidence showed that both smaller social groups and large herds included multiple maternal lines. In addition, many of the genetic links within a group involved paternal relatives instead of maternal relatives.

"Beluga whales exhibit a wide range of grouping patterns from small groups of two to 10 individuals to large herds of 2,000 or more, from apparently single sex and age-class pods to mixed-age and sex groupings, and from brief associations to multi-year affiliations," said Dr. O'Corry-Crowe.

"This variation suggests a fission-fusion society where group composition and size are context-specific, but it may also reflect a more rigid multi-level society comprised of stable social units that regularly coalesce and separate. The role kinship plays in these groupings has been largely unknown."

The study is published in the journal <a href="https://www.nature.com/srep/">Scientific Reports</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Beluga whales form complex social networks like humans

A new study from Florida Atlantic University has revealed that...

Among the healthcare workers in Tennessee who tested positive for <a href="http://www.earth.com/news/children-have-rarely-infected-others-with-covid-19/">COVID-19</a> by serology, nearly half had no symptoms. 

The results of the serology tests, which are designed to detect COVID-19 antibodies, suggested that the front-line medical staff members had contracted the disease during the first few weeks of caring for infected patients.   

Of those with positive serology results, 42 percent reported no symptoms of a respiratory illness in the prior two months. The research confirms that healthcare staff are at a high risk of COVID-19 infection and indicates that many of these workers do not exhibit the typical symptoms.

Dr. Wesley Self is an associate professor of Emergency Medicine at <a href="https://www.vumc.org/">Vanderbilt University Medical Center</a> and the lead investigator of the IVY Research Network.

"Our results suggest that screening health care workers for COVID-19 even when they don't have any symptoms could be important to prevent the spread of the virus within hospitals," said Dr. Self.

The IVY Network is a collaborative group of medical centers in the United States that is funded by the CDC to conduct research on severe respiratory infections, including COVID-19 and influenza.

In a separate study, experts with the IVY group studied 350 patients across 11 medical centers who tested positive for COVID-19. Among these patients, 54 percent reported having no close contact with any individual known to have COVID-19 in the two weeks prior to becoming sick.

"With over half of COVID-19 patients not identifying a clear source of their infection, this study reinforces the need for practical measures to reduce the spread of the virus, such as social distancing and the use of face coverings when out in public," said Dr. Self.

The researchers also found that 40 percent of COVID-19 patients exhibited symptoms for at least two weeks after testing positive, which shows that COVID-19 persists longer than other respiratory infections like the flu.

"We are continuing to study COVID-19 in front-line health care workers across the country to better understand what may be done to decrease their risk of infection, such as using specific types of personal protective equipment," said co-investigator Dr. Bo Stubblefield.

The study is published in the journal <a href="https://academic.oup.com/cid">Clinical Infectious Diseases</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Nearly half of healthcare staff had COVID-19 with no symptoms

Among the healthcare workers in Tennessee who tested positive for...

Around the time that Julius Caesar was assassinated in 44 BCE, ancient Rome and Egypt endured extreme climate change, characterized by unusually cold temperatures, failed harvests, famine, and <a href="http://www.earth.com/news/new-technique-tracks-the-spread-of-major-plant-disease/">disease</a>. A new study from the <a href="https://www.ku.dk/english/">University of Copenhagen</a> has linked this mysterious event to a massive volcano eruption on the other side of the world in Alaska.

The devastating effects of the climate change event were documented in written accounts, and these impacts ultimately contributed to the fall of the Roman Republic and Ptolemaic Kingdom. Scientists have long theorized that volcanic activity was to blame, but the site of the eruption has remained unclear.

To investigate, an international research team led by Dr. Joe McConnell of the Desert Research Institute analyzed volcanic ash in Arctic ice cores. The study suggests that the Mediterranean climate was impacted by a major eruption of Alaska's Okmok volcano in 43 BCE.

"To find evidence that a volcano on the other side of the Earth erupted and effectively contributed to the demise of the Romans and the Egyptians and the rise of the Roman Empire is fascinating," said Dr. McConnell. "It certainly shows how interconnected the world was even 2,000 years ago."

According to the ice core analysis, the Okmok volcano experienced a two-year mega-eruption that began in early 43 BCE, filling the atmosphere with massive amounts of smoke and ash that blocked out most sunlight.

"The eruption is regarded as one of the largest volcanic eruptions of the past 2,500 years. Using the ice core samples, climate models and historical records, we are quite certain that the eruption is linked to the violent climatic changes noted around the Mediterranean and in Rome," explained Professor Jørgen Peder Steffensen.

The researchers collaborated with historians and collected prehistoric climate data to confirm the theory that the Okmok volcano was powerful enough to cause widespread climate change.

An extensive amount of climate data showed that the Okmok eruption was followed by some of the coldest years in the northern hemisphere of the past 2,500 years. 

"Historical accounts describe how wet and extremely cold weather led to poorer harvests, as well as how the Nile overflowed its banks - destroying crops and leading to famine - all of which correlates with our results," said Professor Steffensen.

The study is published in the journal <a href="https://www.pnas.org/">Proceedings of the National Academy of Sciences</a>.

---

By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Cold climate after Julius Caesar's death linked to Alaskan volcano

Around the time that Julius Caesar was assassinated in 44...

Researchers at <a href="https://wsu.edu/">Washington State University</a> have identified a fatty acid that can kill <a href="http://www.earth.com/news/sedentary-behavior-linked-to-higher-risk-of-cancer-mortality/">cancer</a> cells. The experts demonstrated that dihomo-gamma-linolenic acid (DGLA) triggers a type of cell death known as ferroptosis in actual human cancer cells.

Ferroptosis is a recently discovered cell death pattern that is dependent on iron. This mode of cell death has become an important focus for medical research because it is associated with many serious illnesses, including cancer and cardiovascular, neurodegenerative, and hepatic diseases.

The discovery that DLGA induces ferroptosis has many implications, including a step toward a potential treatment for cancer, said study co-author Professor Jennifer Watts.

"If you could deliver DGLA precisely to a cancer cell, it could promote ferroptosis and lead to tumor cell death," said Professor Watts. "Also, just knowing that this fat promotes ferroptosis might also affect how we think about conditions such as kidney disease and neurodegeneration where we want to prevent this type of cell death."

DGLA is a polyunsaturated fatty acid that is found in small amounts in the human body, yet rarely found in the human diet. For nearly 20 years, Professor Watts has been researching DGLA and other dietary fats using the microscopic worm C. elegans as an animal model.

In previous work, Professor Watts  and her team discovered that feeding nematodes a diet of DGLA-containing bacteria killed all of their germ cells, as well as the stem cells that make the germ cells. This cell death pattern resembled ferroptosis.

"Many of the mechanisms we saw in the nematodes were consistent with the hallmarks of ferroptosis in mammalian systems, including the presence of redox-active iron and the inability to repair oxidized lipids, which are like molecular executioners," explained study first author Marcos Perez.

To investigate further, the researchers collaborated with Scott Dixon of Stanford University, who studies ferroptosis and its potential for fighting cancer.

The team showed that DGLA could induce ferroptosis in human cancer cells. In addition, the experts found another fatty acid, an ether lipid, that worked against DGLA. When they took out the ether lipids, the cells exposed to DLGA died faster.

Professor Watts and her team recently received a $1.4 million grant from the National Institutes of Health to investigate what makes the nematode germ cells so susceptible to DGLA. The researchers will also explore the role of mitochondria in ferroptosis.

The study is published in the journal <a href="https://www.cell.com/developmental-cell/home">Developmental Cell</a>.

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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Experts identify a fatty acid that can kill cancer cells

Researchers at Washington State University have identified a fatty acid...

In a new commentary, doctors report that <a href="http://www.earth.com/news/sleep-deprivation-affects-emotional-well-being-in-children/">children</a> do not frequently transmit COVID-19 to each other or to adults. The experts say that reopening schools in a safe manner this fall is important for the healthy development of children.

The commentary authors, Dr  Benjamin Lee and Dr. William V. Raszka, are pediatric infectious disease specialists on the faculty of the <a href="https://www.uvm.edu/">University of Vermont</a>.

The doctors base their commentary on five recent studies that examined COVID-19 transmission among children, who account for less than two percent of all COVID cases.

In a study published in the journal Pediatrics, researchers led by Dr. Klara M. Posfay-Barbe investigated 40 pediatric cases of COVID-19. They found that only three of the children were the first in the family to show symptoms.

In China, experts analyzed cases of children who were admitted to Qingdao Women's and Children's Hospital from January 20 to February 27, 2020 with COVID-19. Among the children, 96 percent lived in a household with a previously infected adult.

A study in France revealed that a student with COVID-19 exposed over 80 classmates at three schools to the disease, yet none of the other students were infected. The transmission of other respiratory diseases, including the flu, was common at the three schools.

There were similar findings in New South Wales, where nine infected students and nine infected staff members across 15 schools exposed 735 students and 128 adult to COVID-19. There were only two secondary infections, and only one of the infections was transmitted by a child.

"The data are striking," said Dr. Raszka. "The key takeaway is that children are not driving the pandemic. After six months, we have a wealth of accumulated data showing that children are less likely to become infected and seem less infectious; it is congregating adults who aren't following safety protocols who are responsible for driving the upward curve."

The growing cases of COVID-19 among adults and children in Texas child care facilities have the potential to be misinterpreted, said Dr. Raszka. Across the state, there have been 894 infected staff members and 441 infected children in 883 child care facilities.

"There is widespread transmission of COVID-19 in Texas today, with many adults congregating without observing social distancing or wearing masks," said Dr. Raszka. "While we don't yet know the dynamics of the outbreak, it is unlikely that infants and children in daycare are driving the surge. Based on the evidence, it's more plausible that adults are passing the infection to the children in the vast majority of cases."

According to the experts, mathematical models show that community-wide social distancing and widespread adoption of facial cloth coverings are far better strategies for stopping the spread of the disease than closing schools. They noted that many schools have reopened in Western Europe and Japan without a rise in community transmissions.

The doctors concluded that opening schools is important for the well-being of children. "By doing so, we could minimize the potentially profound adverse social, developmental, and health costs that our children will continue to suffer until an effective treatment or vaccine can be developed and distributed, or failing that, until we reach herd immunity."

The commentary is published in the journal <a href="https://pediatrics.aappublications.org/">Pediatrics</a>.

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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Children have rarely infected others with COVID-19

In a new commentary, doctors report that children do not...

In a new study from <a href="https://ioppublishing.org/">IOP Publishing</a>, experts investigated how the 2019 - 2020 Australian bushfires affected local <a href="http://www.earth.com/news/cause-of-mysterious-air-pollution-in-eastern-china-identified/">air</a> quality. The research may ultimately improve preparation for a projected increase in the frequency and duration of bushfires.

The scientists monitored air temperature, relative humidity, barometric pressure, precipitation, wind speed, solar radiation, UV radiation, UV index, and a range of particulate matter pollution at a site in Sydney over a few weeks when hundreds of bushfires were burning nearby.

"Many studies have investigated and confirmed the health implications of bushfires, as biomass burning is a major source of ambient particulate matter (PM). But underexplored is the impact on local urban microclimates, concerning not just temperature, but factors including solar and UV radiation, relative humidity, wind patterns and gusts, and urban heat island intensity," explained study senior author Professor Gianluca Ranzi from the <a href="https://www.sydney.edu.au/">University of Sydney</a>.

"Our study aims to unveil the connection between weather anomalies and livability of urban areas, by using multi-parameter measurements and a multifocal approach."

During the monitoring period in December and January, extreme pollution, drought, and heat were recorded simultaneously. 

"We found that specific combinations of air temperature and relative humidity were conducive to higher/lower levels of pollutant accumulation, reflecting findings from previous studies. In general, higher PM concentration was recorded for night-time and early morning, especially after daytime overheating events (with temperatures above 35°C)," explained study lead author Dr. Giulia Ulpiani.

"We also found that long-transport mechanisms and complex interactions between prevailing and local winds could have played a major role, making it difficult to establish definite correlations between PMs and single environmental parameters."

"Intense rain splashing was also associated with the most intense concentration of dust. Our data confirm that, despite their acknowledged air-cleansing properties, heavy raindrops also trigger a mechanism that produces solid particles from soil, which can substantially raise local pollution levels."

The researchers found a link between ultraviolet index (UVI) and particulate pollution. The team pinpointed several levels of pollution that strongly blocked UV radiation. When particulate concentrations fell below these thresholds, UVI was likely to exceed moderate levels. 

"While quantitative evaluations should be interpreted with caution, our study offers a new holistic approach to environmental monitoring," said Dr. Ulpiani.

"The associations we discovered would be extremely valuable in building up a cohesive national health protection strategy, and encouraging better responsiveness from governments and city planners. We will continue this work, to hopefully identify general laws and climate dependencies."

The study is published in the journal <a href="https://iopscience.iop.org/journal/2515-7620">Environmental Research Communications</a>.

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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

Study reveals the impacts of bushfires on urban microclimates

In a new study from IOP Publishing, experts investigated how...

In a surprising new study, researchers have traced the origin of human teeth back more than 400 million years when armored <a href="http://www.earth.com/news/fish-worldwide-are-shockingly-vulnerable-to-climate-change/">fish</a> called acanthothoracids developed jaws for catching prey. Humans, birds, reptiles, sharks, mammals - all 60,000 species of jawed vertebrates - are descendants of these fish.

In collaboration with the <a href="https://www.esrf.eu/">European Synchrotron Radiation Facility</a>, an international team of scientists led by Uppsala University used the world's most advanced X-ray technology to digitally "dissect" the most primitive jawed fish fossils with teeth. 

The jaws of the fossilized fish, which were uncovered near Prague more than 100 years ago, were found to contain remarkably modern features.

Prior to this study, researchers theorized that teeth first emerged in a group of ancient fish that lived about 430 to 360 million years ago, called the arthrodires. However, arthrodire teeth seem to be too different in position and mode of tooth addition to have given rise to the teeth of modern vertebrates.

To investigate, the scientists turned their attention to acanthothoracids. These fish are believed to have emerged before arthrodires and are thought to be closely related to the very first jawed vertebrates. The teeth of acanthothoracids had never been analyzed in detail.

The researchers used the most advanced techniques available to visualise the internal structure of the fossils in 3D without damaging them. 

"The results were truly remarkable, including well-preserved dentitions that nobody expected to be there," said study lead author Valéria Vaškaninová.

The researchers were able to visualize growth patterns and perfectly preserved cell spaces inside the dentine of these ancient teeth.

Despite some similarities, the acanthothoracid dentitions we found to be fundamentally different from those of arthrodires. Acanthothoracids only added new teeth on the inside, just like sharks, bony fish, and land animals, and the oldest teeth were located right at the jaw margin. For this reason, the acanthothoracid dentitions appeared surprisingly modern.

"To our surprise, the teeth perfectly matched our expectations of a common ancestral dentition for cartilaginous and bony vertebrates," explained Vaškaninová.

"These findings change our whole understanding of the origin of teeth," said study co-author Professor Per Ahlberg. "Even though acanthothoracids are among the most primitive of all jawed vertebrates, their teeth are in some ways far more like modern ones than arthrodire dentitions." 

"Their jawbones resemble those of bony fish and seem to be directly ancestral to our own. When you grin at the bathroom mirror in the morning, the teeth that grin back at you can trace their origins right back to the first jawed vertebrates."

The study is published in the journal <a href="https://www.sciencemag.org/">Science</a>.

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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

&nbsp;

The origin of human teeth dates back 400 million years

In a surprising new study, researchers have traced the origin...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Flu viruses are more flexible than expected

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Detecting mercury contamination with the tap of a finger

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Kainji Lake, a reservoir on the Niger River.



In 1968, Kainji Lake was created by the construction of the Kainji Dam. The Niger River, the third longest in Africa, enters the lake in the north.&nbsp;



According to <a href="https://www.earth.com/news/rivers-in-the-american-west-are-a-lifesaving-resource-for-birds/">ESA</a>, the creation of the lake submerged Foge Island and the town of Bussa and permanently flooded other riverine settlements, leaving around 50,000 people displaced.&nbsp;



Large parts of Foge Island are temporarily exposed during low water tides, and the land is often used by migrating fishermen. Kainji Dam is a dam across the Niger River in Niger State of Central Nigeria. 



Wild mammals occur at relatively low densities due to illegal hunting. Lake Kainji has suffered a dramatic decline as a fishery due to the high numbers of artisanal and subsistence fisherfolk using the lake. It has been suggested that a period of closure, together with controlled fishing rights may help improve fish stocks.



Kainji Lake National Park is the oldest of its kind in Nigeria. The park contains three distinct areas: a part of the Kainji Lake, the Borgu Game Reserve to the west of the lake, and the Zugurma Game Reserve to the southeast. The park is home to around 65 mammal species, 350 bird species, and 30 species of reptiles and amphibians. 



Video/ Image Credit: European Space Agency&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Kainji Lake in north central Nigeria

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Today’s Video of the Day from <a href="https://www.igb.illinois.edu/">Carl R. Woese Institute for Genomic Biology</a> reveals how scientists can modify common crops like soybean, rice, and wheat to protect them from heat stress.



“We need to double crop production by 2050 to feed a growing global population, and not only are we not on track to do that, but climate change is further complicating things,” said Amanda Cavanagh, a lecturer at the University of Essex. 



The study is part of Realizing Increased Photosynthetic Efficiency (RIPE), an international research project that aims to develop food crops that turn the sun’s energy into food more efficiently.



“Using an engineering approach we designed multiple alternative metabolic pathways to photorespiration. Testing them in the field showed increases in productivity which led Amanda to significantly move the project forward by showing our engineered plants can withstand pretty extreme temperature stress,” said study co-author and RIPE researcher Paul South.&nbsp;



“As the climate changes and temperature stresses increase the pressure on our global food supply, farmers will need every tool available including engineering approaches like the synthetic biology used here to maintain safe and productive harvests.”



The experts tested plants modified to have more efficient photorespiration to see if they were better adapted to warmer temperatures.&nbsp;



The team found that the engineered plants produced 26 percent more biomass than the wild-type plants exposed to the same temperatures, and had 15 percent less yield loss under the higher temperatures.



Video Credit: Amanda Nguyen/University of Illinois



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Designing crops that can beat the heat

[sendtonews key="QGPzYnXEtN-1712599-12187" type="single"] Today’s Video of the Day from Carl...

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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How does salt makes things taste better?

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Santiago, Chile in South America

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Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Interactive map of the universe includes 200,000 galaxies

[sendtonews key="e4ZG0Jawp3-2374785-12187" type="single"] Astronomers at Johns Hopkins University have created...

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes the first comprehensive estimate of carbon density in the Saharan, Sahel, and Sudanian zones of Africa. In an effort to measure the amount of carbon stored across these drylands, a team of scientists used high-resolution satellite images and artificial intelligence to map nearly 10 billion individual trees. 



"The high spatial resolution (50 cm) combined with AI and field measurements used in this study is key to improving tree inventories in drylands," said Pierre Hiernaux, a French researcher working for NASA. "The ever-increasing availability of very high-resolution satellite imagery will make it possible to assess carbon pools and their dynamics at the individual tree level on a global scale."



"This study is exceptional because it is pioneering a type of approach that will revolutionize the monitoring of trees and forests on a global scale: in the short term, it will be possible to map the world's trees from the centre of the Amazon to our schoolyards," said <a href="https://www.inrae.fr/en">INRAE</a> researcher Jean-Pierre Wigneron.



"Many fields of application will become much more efficient and accurate, such as tracking carbon stocks, biodiversity, monitoring logging and protection against illegal forest degradation, in near real time.”



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Remote sensing will revolutionize the way we monitor trees

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The province of Zaragoza in northeast Spain

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> features a visual dataset of.methane emissions from wetlands across the globe. Atmospheric methane levels have reached record highs in recent years, and wetlands are a major source of these emissions.&nbsp;



"Methane is an important greenhouse gas that contributes substantially to global warming. On a molecule by molecule basis, methane is much more efficient at trapping heat than carbon dioxide, the main driver of warming," says NASA.



"Though human activities, including agriculture, oil and natural gas production and use, and waste disposal, collectively contribute the majority of methane to the atmosphere, about a third of total methane emissions comes from wetlands."&nbsp;



According to NASA, understanding methane emissions from wetlands and other natural sources is critically important for scientists and policymakers who are working to combat climate change by reducing emissions from human activities.



Video Credit: NASA Goddard



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Wetlands are a major source of methane emissions

[sendtonews key="f8fukm28Vz-2491833-12187" type="single"] Today's Video of the Day from NASA...

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The rapid retreat of the Columbia Glacier

[sendtonews key="0879czfG3k-1785905-12187" type="single"] Today’s Video of the Day from NASA...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The Pyrenees Mountains in southwest Europe

[sendtonews key="6HyfrAJTBI-1831843-12187" type="single"] Today’s Video of the Day from the...

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Today’s Video of the Day from <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes why experts are studying zebrafish to gain a better understanding of how the immune system responds to injury. Zebrafish have the ability to repair and regenerate organs.



“Organ regeneration offers an exciting opportunity for studying the immune system and to inquire why some species can regenerate organs like the heart or missing limbs while others like humans cannot,” explained Dr. Tatjana Piotrowski.



Zebrafish sensory organ hair cells are an ideal system to investigate the pathways and cell types involved in regeneration since they are easily destroyed with antibiotics and begin regenerating within five hours. This enabled the researchers to identify the exact timing and genetic programs for each anti-inflammatory macrophage activation state.&nbsp;



“Our hypothesis is that human macrophages do not receive the proper chemical activation 'cocktail' to instruct pro-regenerative processes,” said Dr. Nicolas Denans. “Identifying the molecular recipe of macrophage activation in zebrafish may one day enable us to design regenerative immunotherapies in humans.”&nbsp;&nbsp;&nbsp;



“The new evidence is a valuable resource for comparative studies on the genetic programs involved in macrophage-mediated repair and regeneration. In other words, different types of injuries may induce different kinds of inflammatory responses. We want to decipher whether this 'language' is universal or if there are a variety of dialects."



Video Credit: Stowers Institute for Medical Research&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

How the immune system responds to injury

[sendtonews key="0dEcERCq61-2283382-12187" type="single"] Today’s Video of the Day from Stowers...

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes how record-breaking heat expressed itself around the world in 2022.



Scientists have determined that 2022 was the 5th warmest year since 1880. Furthermore, the last nine consecutive years have been the warmest on record.



From devastating floods and wildfires to natural disasters like Hurricane Ian, 2022 showed us yet again how a warming climate affects people across the globe.&nbsp;



"As we look back at 20:22 and years past, we see that each year we better understand the challenges we face and how important it is to meet them," says NASA.



Video/ Image Credit: NASA Goddard



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

2022 illustrated the consequences of a warming climate

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Earth,Like,Exoplanet,3d,Render

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Two distant planets may be "water worlds"

[sendtonews key="QIoVYJqRBi-2434608-12187" type="single"] Today's Video of the Day from NASA...

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites reveal how Earth's systems are interconnected

[sendtonews key="JbW4VsY53O-1632195-12187" type="single"] Satellites reveal how Earth's systems are interconnected...

Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...

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