The end of the Permian period 252 million years ago, just before the age of the <a href="https://www.earth.com/news/most-of-the-dinosaurs-were-warm-blooded/">dinosaurs</a> starting in the Mesozoic era was a tumultuous time. This was when the greatest mass extinction to date occurred, killing the majority of Earth’s species. New research published in the journal <a href="https://pubs.geoscienceworld.org/palaios">Palaios</a> sheds new light on this extinction and the role of fires.&nbsp;



An increase in wildfires is often thought of as a mere symptom of climate change, which we are already seeing. Fires in California and Australia have shown how dangerous to wildlife such conflagrations can be.&nbsp;



Fires have happened recently in the Pantanal - a typically swampy region of South America that has been historically unaffected by fires. Now, they researchers see that the same pattern played out at the end of the Permian. They propose that wildfire was not only a symptom of climate change and extinction, but possibly contributed to it significantly.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;



“Sifting through the fossil plant records of eastern Australia and Antarctica, we found high abundances of burnt, or charcoalified, plants throughout the late Permian Period. From this high baseline, charcoal abundances reached a prominent peak right at the top of the last Permian coal beds, indicating a major but short-lived increase in wildfires. This was followed by low charcoal for the next three million years of the Early Triassic Period. It was an end-Permian burnout, followed by an Early Triassic depression," said Dr. Chris Mays, lecturer of Palaeontology at <a href="https://www.ucc.ie/">University College Cork</a> (UCC) and lead author of the study.



Wildfires in wetlands and forests destroy carbon sinks, thus acting as a feedback loop. Increased temperatures cause wildfires that release carbon into the atmosphere and cause an increase in temperatures.&nbsp;



“The potential for wildfires as a direct extinction driver during hyperthermal events, rather than a symptom of climatic changes deserves further examination," said Dr. Mays. "Unlike the species that suffered the mass extinctions of the past, we have the opportunity to prevent the burning of the world’s carbon sinks and help avoid the worst effects of modern warming."



---



By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Wildfires likely contributed to Earth's largest mass extinction

The end of the Permian period 252 million years ago,...

Climate change is bringing more frequent extremes in heat and this is a threat to human health, especially for the elderly. However, a new study from researchers at USC has found that the risks to human mortality increase dramatically when extreme heat events coincide with days on which air pollution is at its worst. This scenario is associated with <a href="https://www.earth.com/news/wildfires-will-release-massive-amounts-of-carbon-by-mid-century/">wildfires</a>, for example, which often involve extreme heat and pollution that last for days or weeks. Such wildfires are&nbsp;expected to increase&nbsp;in frequency by up to 50 percent before the end of the century,&nbsp;



The researchers used data from death certificates filed with California’s Department of Public Health to study all deaths in the state between 2014 and 2019. This totaled more than 1.5 million people who had passed away. They also obtained data on air temperatures and levels of fine particulate matter (PM2.5) in the air for different areas of California.&nbsp;



They then linked deaths with local environmental conditions, based on the location of the individual’s home address, in order to quantify the effects of exposure to these two environmental risks. Using data on temperature and air pollution levels, the researchers classified each day as one with no extreme exposure, with extreme heat only, with extreme air pollution only or with both extreme heat and air pollution.&nbsp;



The results of the analysis, published in the <a href="https://www.atsjournals.org/journal/ajrccm">American Journal of Respiratory and Critical Care Medicine</a>, showed that the risk of dying on extremely hot days was 6.1 percent higher than on days when no extreme conditions existed. On extreme air pollution days, deaths were 5 percent more likely. Strikingly though, on days with both extreme heat and air pollution, deaths were 21 percent more likely. These results indicate a synergistic effect where the combined effect of the two risk factors is more than the sum of their individual effects.&nbsp;



Study lead author Dr. Mostafijur Rahman is a postdoctoral fellow in the Department of Population and Public Health Sciences at the <a href="https://keck.usc.edu/">Keck School of Medicine of USC</a>. “We found that the mortality effect of exposure to both extreme temperatures and extreme pollution is greater than the sum of their individual effects."



Although previous studies had examined how extreme heat and air pollution separately affect mortality risk, the current study is the first to use a new approach to study what happens when extreme heat and air pollution coincide.&nbsp;



Along with overall mortality, this study also examined deaths due to cardiovascular and respiratory conditions. On days with both extreme heat and air pollution, the risk of death due to cardiovascular problems increased by 29.9 percent, while the risk of death due to respiratory problems was 38 percent higher.



Although the researchers did not study specific causes of death in this study, these problems typically include conditions such as heart failure and pneumonia. On days when both heat and air pollution reach extreme levels, people may have more inflammation and oxidative stress, as well as problems with regulating the body’s internal temperature, said Dr. Rahman.



People who were over the age of 75 also faced greater risks of death (increase of 36.2 percent) under these extreme conditions, than people who were 75 or younger (risk increased by 8.5 percent).&nbsp;



“Understanding the risks associated with these exposures is really important, because we know that they will increase with climate change in many different parts of the United States and the world,” said study senior author Dr.&nbsp;<a href="https://keck.usc.edu/faculty-search/erika-garcia/">Erika Garcia</a>.&nbsp;



The findings of the study highlight the need to protect vulnerable people as environments continue to change, Garcia said. Protective measures and interventions would help to prepare health care systems for extreme weather events and minimize harm to individuals and communities.&nbsp;



The authors suggest that local governments might combine heat and air pollution alert systems to stress that both types of exposures carry risks. They could also notify people to exercise increased caution when the two extremes conditions coincide. To help people stay safe, communities could provide air-conditioned cooling centers for older adults and other sensitive groups. Long-term investments could include adding more green space, as well as pavement and rooftops built from reflective materials, to help reduce temperatures in urban heat islands.&nbsp;



The research team is now exploring ways to translate the findings into changes that will benefit communities, both in California and beyond. Future studies will explore how extreme heat and air pollution may impact mortality related to mental health, including suicide and homicide. The research team is also studying whether disparities in mortality risk are linked to measures of neighborhood deprivation.



“If certain communities face an increased risk when these exposures occur, that will highlight an important target for interventions,” said Dr. Garcia.



---



By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

When heat and pollution coincide, mortality risk doubles

Climate change is bringing more frequent extremes in heat and...

Bees are amazing creatures who deserve to exist in their own right. They are also a significant economic driver, providing a no-cost <a href="https://www.earth.com/news/cacao-tree-pollination-remains-a-mystery/">pollination</a> service to the agriculture industry and allowing many of us the ability to have better access to food.&nbsp;



However, one of the primary causes of honey bee decline is larval nutritional stress caused by the very industry that depends on them.



"We've changed the way we use our land in the U.S. Now we have tons of monoculture crops like corn, which are wind pollinated and therefore no use to bees, covering acres and acres of land. Other crops that bees do pollinate are grown in monoculture as well, limiting the options for bees," explained study lead author Irene Newton, a professor in the Department of Biology at <a href="https://www.indiana.edu/">Indiana University</a>.



"If you limit yourself to only eating one thing, that's not healthy for you. You have to have a broad diet that will help fulfill all of your nutritional needs. Bees are the same way."



Sister bees feed larva various foods, including pollen, nectar, and a substance called royal jelly, a nutrient-rich glandular secretion. Although future queens will eat this mixture their entire lives, future workers will stop receiving royal jelly after a few days.



Royal jelly is a thick acetic substance, meaning most microbes die when exposed to it. Newton and her team discovered that Bombella apis is the only larva-associated bacterium that thrives in royal jelly. Moreover, it increases amino acids in royal jelly, making it more nutritious.&nbsp;



"We have identified a nutritional symbiont of honey bees - a microbe that can help bolster the bees against nutrient scarcity and stress," said Newton. "When we limited bee nutrition during development, we saw a drop in mass for the bees; bees were much smaller than their control counterparts.”



"When B. apis was added to these same bees, although they had poor nutrition, they reached the same mass as control bees given full nutrition. The microbe was able to make up for the poor diet. This suggests that B. apis could be added to colonies as a probiotic to protect from nutritional stress."



This means beekeepers can use B. apis as a supplement to help their hives flourish. The researchers, who have been studying B. apis-bee interaction for years, are excited to see what else this microbe has to offer.



The study is <a href="https://www.nature.com/articles/s41396-022-01268-x">published in the International Society for Microbial Ecology Journal</a>.



---



By <a href="mailto:nire518@gmail.com">Erin Moody </a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Honey bees are suffering from nutritional stress

Bees are amazing creatures who deserve to exist in their...

For a long time, artificial intelligence (AI) was something that we looked forward to; now, it is a reality. In a paper published in the journal <a href="https://www.nature.com/articles/s41558-022-01377-7">Nature Climate Change</a>, a group of experts in artificial intelligence, <a href="https://www.earth.com/news/how-will-climate-change-affect-extreme-weather-events/">climate change</a>, and public policy have explored the complicated relationship AI shares with emissions and climate change.&nbsp;



Study co-author David Rolnick is an assistant professor of Computer Science at <a href="https://www.mcgill.ca/">McGill University</a> and a core academic member of Mila – Quebec AI Institute.



"AI affects the climate in many ways, both positive and negative, and most of these effects are poorly quantified. For example, AI is being used to track and reduce deforestation, but AI-based advertising systems are likely making climate change worse by increasing the amount that people buy," explained Professor Rolnick.



The multi-disciplinary group also wants to make sure that all potential emission impacts of artificial intelligence are considered. To do this, they have divided the impacts into three categories: impacts from the energy used to build, train, and run programs; the immediate impacts, such as making buildings more efficient or supporting fossil fuel expansion; and the influence of artificial intelligence on human behavior, such as increasing consumption through advertising.



Study lead author Lynn Kaack, an assistant professor of Computer Science and Public Policy at the Hertie School, explained why we need to look at multiple impacts. “Climate change should be a key consideration when developing and assessing AI technologies.&nbsp; We find that those impacts that are easiest to measure are not necessarily those with the largest impacts. So, evaluating the effect of AI on the climate holistically is important.”



Overall, the researchers say the impacts of AI will depend on how society decides to use it. The paper uses autonomous vehicle technology as a specific example. We could choose to improve public transportation, which would help with emissions, but AI could also be used to encourage people to drive more, which would increase emissions.&nbsp;



Professor Rolnick believes that, ideally, we wouldn’t use AI to benefit large companies such as Amazon or Google. We should be using AI technology to influence positive environmental changes.&nbsp;



---



By <a href="mailto:nire518@gmail.com">Erin Moody </a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Environmental impacts of AI will be determined by society

For a long time, artificial intelligence (AI) was something that...

Although scientists have investigated extensively the <a href="https://www.earth.com/news/lager-beer-is-beneficial-for-mens-gut-microbiome/">microbiomes</a> of dogs, until recently most studies have been limited to domestic dogs. In a new study led by the <a href="https://illinois.edu/">University of Illinois, Urbana–Champaign</a>, experts have sampled the fecal microbiomes of dogs across diverse geographical populations to better understand their diversity around the world. Surprisingly, they discovered that, although the microbiomes across different populations differed in certain aspects, they were functionally similar.



“A lot of the studies look at how different diets affect dog microbiomes. Although they are extensive, they work with dogs in veterinary centers, which lead a very different life from dogs that don’t live as pets,” said study lead author Karthik Yarlagadda, a doctoral student in Biological Anthropology at the University of Illinois. “It’s similar to how studies on the microbiomes of humans have been focused on people who live in cities and eat processed foods.”



Together with his colleagues, Yarlagadda collected fecal matter from three different dog populations: pets from South Africa, stray and shelter dogs in India, and dogs from a rural village in Laos. In each of these locations, dogs had different diets. While the shelter dogs were fed rice, lentils, yoghurt, and dog food, village dogs consumed local agricultural products, such as maize, bamboo, sticky rice, and fish, and stray dogs likely scavenged on human leftovers.



Interestingly, although the scientists found several differences between the microbiomes of these populations, functionally they appeared to be quite similar. “It was cool to see that you can have different microbiomes, but they all fulfil the same metabolic function. For example, dogs that were consuming dairy in the South African and Indian populations had different&nbsp;Lactobacillus&nbsp;species that were probably involved in the same pathway,” Yarlagadda explained.



Besides comparing the microbiomes of dogs from different geographical locations, the researchers also contrasted samples from ancient microbiomes, obtained from fossilized dog feces. These microbiomes were more similar to those of dogs that lived in an outdoor environment and had mixed diets and more environmental exposures.



In future research, the scientists aim to find more data on ancient microbiomes in various dog species, and investigate how different diets influenced the composition of their microbiomes.



The study is published in the journal <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2022.0052">Proceedings of the Royal Society B: Biological Sciences</a>.



---



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Dog microbiomes around the world are functionally similar

Although scientists have investigated extensively the microbiomes of dogs, until...

While it is assumed that living in a large group offers protection for <a href="https://www.earth.com/news/ancient-squid-had-suckers-for-actively-hunting-prey/">prey</a> species, it is a challenge for scientists to test this hypothesis with many animals. Ocean-dwelling fish like salmon, for example, are hard to keep track of - except during their brief visit to fresh water.&nbsp;



“With salmon, most people think of them spawning in freshwater streams, but there’s also this huge amount of time they spend in the ocean feeding and growing,” said lead author <a href="https://annepolyakov.weebly.com/">Anne Polyakov</a>, a doctoral student in the interdisciplinary Quantitative Ecology and Resource Management Program and the School of Aquatic and Fishery Sciences at the <a href="https://www.washington.edu/">University of Washington</a>.&nbsp;



“One of the reasons why this study is so unique is that we essentially can’t observe these fish at all in their natural ocean environment, and yet we’re able to pull out these really strong results on how grouping affects predation risk and foraging success for individual fish using this incredibly valuable dataset.”



Since monitoring salmon directly through the salt water portion of their lives is highly impractical, the researchers used fishing data instead. The study drew on historical purse seine net data for sockeye, coho, chum and pink salmon from 1956 to 1991.



The scientists estimated the populations of different salmon groups based on the amount of fish caught in each net. They then looked at the number of salmon with wounds and found that a smaller number of fish were wounded within large groups compared to smaller groups. Lastly, the experts found that in some larger groups of salmon, many of the fish had empty stomachs.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;



“It was serendipitous that these data were available. They suggest that salmon are social during the ocean stage of their life and reveal the benefits and costs of this sociality,” said senior author <a href="https://fish.uw.edu/faculty/andrew-berdahl/">Andrew Berdahl</a>, an assistant professor in the UW School of Aquatic and Fishery Sciences. “Grouping is very common in marine fish and we think this is largely to help them evade predators, yet there’s actually not much empirical support showing this, especially from wild populations. I think this study is a piece of the foundation that many didn’t realize was missing.”



The scientists hope that this study may better inform fisheries management in the future as well as show the importance of fisheries data we might already have.&nbsp;&nbsp;



“Many of these data sets came at great cost and I think there’s a lot in them still ready to be uncovered,” said Berdahl. “I would hope it also motivates people to think about the ecological implications of collective behavior - in this case, how grouping impacts the food web, both by changing the rate a species is being eaten as well as the rate at which it is consuming others.”



The study is published in the journal <a href="https://www.science.org/journal/sciadv">Science Advances</a>.



---



By <a href="mailto:zachfitzner@yahoo.com">Zach Fitzner</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Schooling is a safe but costly bet for salmon

While it is assumed that living in a large group...

Cute,Panda,Bear,Climbing,Tree

Modern giant pandas&nbsp;have an unusual structure on their forepaws – an apparent sixth digit that acts as an opposable thumb. This structure is used by pandas when they tear and manipulate bamboo, the major component of their <a href="https://www.earth.com/news/most-people-overestimate-the-healthiness-of-their-diet/">diet</a>. Closer examination of the “fake thumb” reveals that it is not a digit at all, but a modified wrist bone that is elongated and somewhat hooked, making it a perfect tool for gripping and handling bamboo on the way to the mouth.&nbsp;&nbsp;



Previous research has dated the origin of this specialized adaptation, a modified carpal bone or radial sesamoid, to between 100,000 and 150,000 years ago. However, new research has challenged this timeline and indicated that ancestral pandas possessed this adaptation as well, at least six million years ago.&nbsp;



A team led by Xiaoming Wang from the Natural History Museum of Los Angeles County examined a wrist bone from a fossil panda that was discovered at Shuitangba, a site near the city of Zhaotong in Yunnan Province, China. The individual was identified as belonging to the genus Ailurarctos, which is ancestral to the modern giant panda, and the fossil was dated to the late Miocene Period, around six to seven million years ago.&nbsp;



The researchers compared the shape and size of this bone to previously published data on the wrist bones of modern giant pandas. In addition, they compared the fossil wrist bone to samples from the extinct species Indarctos arctoides, which is an ancient species of bear that lived nine million years ago and is thought to share a common ancestor with giant pandas.&nbsp;



The researchers found that the new specimen (Ailurarctos) from Shuitangba had an elongated, hooked wrist bone similar to that found in modern pandas. In contrast, I. arctoides fossils do not show this feature. The results, published today in the journal <a href="https://www.nature.com/srep/">Scientific Reports</a>, indicate that, while the thumb-like wrist bone was not present in&nbsp;I. arctoides&nbsp;or the common ancestor it shares with pandas, it has been present within the panda lineage for at least six million years. This suggests that pandas have indeed been bamboo specialists for at least that length of time.&nbsp;



There are some differences, however, in the structure of the false thumbs present in the new fossil Ailurarctos and in modern pandas. In pandas, the false thumb is significantly shorter in relation to body size than the thumb found in Ailurarctos from the Miocene. In addition, it is more hooked and has a flattened outer surface in pandas, features that are not present in the wrist bone of Ailurarctos.&nbsp;



The authors propose that the hook may help modern pandas to grasp bamboo better, while the shorter length and flattened outer surface may assist with weight distribution when walking, similar to the function of a heel bone in humans. These weight-bearing constraints could be the main reason that the giant panda’s thumb-like structure never evolved into a full digit, they add.



---



By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Pandas have “fake thumbs” to manipulate bamboo

Modern giant pandas&nbsp;have an unusual structure on their forepaws –...

Terrestrial and marine habitats have been considered the ecosystems with the highest levels of conversion of inorganic to organic carbon – a phenomenon called “primary production.” For instance, microscopic algae in the upper layers of seas and oceans and plants on land bind atmospheric carbon and produce plant material driven by <a href="https://www.earth.com/news/artificial-photosynthesis-could-help-grow-food-more-efficiently/">photosynthesis</a>. Since sunlight does not penetrate under the surface of the Earth, scientists have long thought that there is hardly any such primary production taking place there.&nbsp;



However, a new study led by the <a href="https://www.uni-jena.de/en">University of Jena</a> has found that many microorganisms in groundwater are capable of primary production. In the absence of light, these microbes must obtain energy from oxidizing inorganic compounds, such as from reduced sulfur of the surrounding rocks.



“The rates we measured were much higher than we anticipated,” said study lead author Will Overholt, a postdoctoral researcher in Environmental Microbial Ecology at the University of Jena. “They equal carbon fixation rates measured in nutrient-poor marine surface waters and are up to six-fold greater than those observed in the lower zones of the sunlit open ocean, where there is just enough light for photosynthesis.”



According to the scientists, global primary production in carbonate groundwater is estimated to be 110 million metric tons of carbon per year, while the net primary productivity of approximately 66 percent of the planet’s groundwater reservoirs would total up to 260 million metric tons of carbon per year - which is about 0.5 percent that of marine ecosystems, and 0.25 percent of the total global production.



“This may sound small but these measurements represent only our first estimate of what the true global value may be,” said study senior author Kirsten Küsel, an expert in Microbial Ecology at the University of Jena. “Since there is very little energy available in these nutrient-poor and permanently dark habitats, even a small percentage of the global primary production is a surprise.”&nbsp;&nbsp;



By using metagenomic analyses, Professor Küsel and her team have also identified the main microorganisms responsible for fixing carbon and generating new biomass in the aquifer: a highly abundant microbe unrelated to previously studied bacteria, belonging to an uncharacterized order of Nitrospiria.&nbsp;



“As food, these organisms are thought to form the basis of life for the entire groundwater ecosystem with all of its thousands of microbial species, similar to the role algae play in the oceans or plants on land,” Dr. Overholt concluded.



The study is published in the journal <a href="http://dx.doi.org/10.1038/s41561-022-00968-5">Nature Geoscience</a>.



---



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Life in Earth’s interior is highly productive

Terrestrial and marine habitats have been considered the ecosystems with...

Sperm,Whale,,Physeter,Macrocephalus,,Tooth,Whale

By investigating seven million-year-old fossilized sperm whale skulls discovered in Peru, a team of researchers led by the <a href="https://www.uzh.ch/de.html">University of Zurich</a> (UZH) has found that prehistoric sharks fed upon these whales. The predators included <a href="https://www.earth.com/news/megalodons-grew-larger-in-cold-water/">megalodons</a> – some of the largest and most ferocious marine predators in our planet’s history.



According to the experts, the whales’ enormous snouts – measuring up to a third of their bodies – were particularly appealing to these sharks, since they were packed with highly nourishing oily saturated fats.



During the Miocene period (from about 23 million to 2.5 million years ago), warmer oceanic water temperatures combined with several protected coastal environments greatly benefited marine biodiversity. Among the various species of aquatic creatures, sperm whales and sharks were some of the most abundant ones. For decades, paleontologists struggled to understand the connections between these groups of large animals.



Now, scientists discovered half a dozen sperm whale skulls unearthed at the Pisco Formation in the Ica Desert in southern Peru, which contained a series of bite marks indicating that sharks consistently fed on them. “These are concentrated along the nose, mouth, and face. In sperm whales, these regions receive most of their greatly enlarged nasal organs that are responsible for the sound production and emission system,” explained study lead author Aldo Benites-Palomino, a paleontologist at UZH.



“The main organs of this complex are the spermaceti and the melon, structures rich in fats and oils, but also heavily regulated by the facial muscles. Most of the bite marks have been found on the bones that would be adjacent to these soft tissue structures, such as the jaws, or around the eye, thus indicating that sharks actively targeted this region.”



Since the overall shape, size, and arrangement of the bite marks were quite variable, most probably it was more than one species of sharks preying upon the sperm whales, including not only the ferocious megalodon, but also species that are still around today, such as mako sharks, sand sharks, or great white sharks. Today, most of these shark species seek the carcasses of baleen whales with high concentration of fats, such as the blubber.



“During the Miocene baleen whales were small, but sperm whales would have constituted a perfect fat repository due to their greatly enlarged and lipid-rich nasal organs,”&nbsp;Benites-Palomino&nbsp;concluded.



The study is published in the journal <a href="https://royalsocietypublishing.org/doi/10.1098/rspb.2022.0774">Proceedings of the Royal Society B: Biological Sciences</a>.



---



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Megalodons feasted on sperm whales' enormous noses

By investigating seven million-year-old fossilized sperm whale skulls discovered in...

Adorable,Dog,Diligently,Studying,Road,While,Walking,Along,Old,Structure

Dogs have a much more powerful sense of <a href="https://www.earth.com/news/do-we-bond-more-with-people-that-smell-like-us/">smell</a> than humans: while we have roughly five to six million scent receptors in the nose, dogs have about 300 million. Due to this amazing capacity, dogs have been used to detect various diseases, ranging from Parkinson’s, cancer, and diabetes to Covid-19. 



Now, a research team from the <a href="https://www.tiho-hannover.de/">University of Veterinary Medicine</a> in Hannover, Germany has found that dogs trained to detect Covid-19 infections are also able to reliably identify <a href="https://www.earth.com/news/most-long-covid-cases-started-out-as-mild-infections/">long Covid</a> cases, which are characterized by a constellation of lingering or new post-infection symptoms that can last for several months, including fatigue, shortness of breath, heart palpitations, musculoskeletal pain, or brain fog.



Since April 2020, scientists have trained a group of dogs to detect by smell Covid-19 infections. “Dog odor detection is far better than the general public can imagine,” said study co-author Dr. Esther Schalke, a veterinary behaviorist at the <a href="https://www.bundeswehr.de/en/organization/bundeswehr-medical-service-">Bundeswehr Medical Service</a> in Koblenz, Germany. “We were amazed at how quickly our dogs could be trained to recognize samples from SARS-CoV-2 infected individuals.”&nbsp;



In the new study, the scientists had nine dogs dip their noses into scent holes containing samples of long Covid patients’ saliva, as well as Covid-19 positive and negative samples of saliva, sweat, and urine. Overall, the dogs managed to correctly identify 85 percent of long Covid samples.&nbsp;



When long Covid cases were presented next to negative Covid-19 samples, the dogs could more accurately detect them (94 percent) than when these cases were presented next to positive virus samples (86 percent). According to the researchers, this indicates that the “disease-specific odor” of Covid-19 was still detectable by the dogs in the long Covid samples, although not to the same extent as in samples of patients with acute Covid-19.



“These results suggest that the disease-specific odor of acute Covid-19 is still present in the majority of long Covid samples,”&nbsp;the authors explained. “The study should be regarded as a pilot study due to inclusion of a limited number of patients. Further research with more patients and samples acquired from the same patient at different time points is needed, to evaluate to what extent the sensitivity of medical detection dogs may vary throughout the course of the infection,” they concluded.



The research is published in the journal <a href="https://www.frontiersin.org/articles/10.3389/fmed.2022.877259/full">Frontiers in Medicine</a>.



---



By <a href="mailto:andrei.ionescu5891@gmail.com">Andrei Ionescu</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer&nbsp;&nbsp;

Dogs can reliably detect long Covid cases

Dogs have a much more powerful sense of smell than...

Plant,Leaf,With,Water,Drops

Heat waves are not good for people, but they can be just as bad for certain plants. Hot conditions can affect the <a href="https://www.earth.com/news/plants-activate-immune-defenses-against-pathogens-in-rain/">immune</a> systems of plants such that they no longer function efficiently. This means that plants are more susceptible to infection by pathogens after heatwaves, even when the extreme temperatures do not last for long.&nbsp;



Scientists have known for decades that above-normal temperatures suppress a plant’s ability to make salicylic acid, a defense hormone that has an important role in the plant’s immune system, stopping pathogens and pests before they get established. The exact mechanism by which this immune system failure occurs, however, was not fully understood.&nbsp;



In new research, published in the journal <a href="https://www.nature.com/">Nature</a>, scientists now say that they understand why a plant’s immune system becomes compromised when the temperatures rise too high. They have also proposed a way to reverse the effect and to boost plant defenses against heat. This would help plants to survive better in conditions of global warming, and keep food on tables around the world.&nbsp;



The scientists worked on a small species of cress, Arabidopsis thaliana, which is a flowering plant native to Eurasia and Africa. It is considered a weed and is commonly used in laboratory experiments involving plants. In earlier research, Sheng-Yang He from Duke University, and his graduate student Bethany Huot, found that even brief heat waves had a dramatic effect on the immune system functioning of Arabidopsis plants. The heat left them more prone to infection by a bacterium known as Pseudomonas syringae.



Under normal circumstances, when this pathogen infects a plant, the levels of salicylic acid in the leaves increase up to seven-fold, preventing the bacterium from taking hold or spreading. But when the temperature rises above 86oF, the plant cannot make enough of this defense hormone to keep the pathogen in check.&nbsp;



“Plants get a lot more infections at warm temperatures because their level of basal immunity is down,” said Sheng-Yang He. “So we wanted to know, how do plants feel the heat? And can we actually fix it to make plants heat-resilient?”



Around the same time, a different team of scientists had found that, in plant cells, molecules called phytochromes function as internal thermometers, helping plants sense warmer temperatures in the spring and activate growth and flowering. He and his colleagues wondered whether these same heat-sensing molecules could be involved in compromising the immune system when the heat is on.&nbsp;



To answer this question, the researchers looked at normal plants and mutant plants in which the phytochrome photoreceptors were always active, irrespective of the temperature. The plants were all infected with P. syringae&nbsp;bacteria, and then grown at temperatures of 73oF and 82oF.&nbsp; The researchers found that the phytochrome mutants fared exactly like normal plants: they still couldn’t make enough salicylic acid to fend off infections when temperatures were high.



The scientists continued to search for the molecular mechanism behind failed immunity in Arabidopsis plants that were exposed to excess heat. Co-first authors&nbsp;<a href="https://www.wlu.ca/academics/faculties/faculty-of-science/faculty-profiles/christian-danve-m-castroverde/index.html">Danve Castroverde</a>&nbsp;and&nbsp;<a href="https://sites.google.com/yonsei.ac.kr/jonghumkim/home">Jonghum Kim</a>&nbsp;spent several years doing similar experiments involving various plant genes that could potentially have been involved, but those mutant plants also became more vulnerable to infections during warm spells.&nbsp;



A new approach had to be adopted. Using next-generation sequencing, the researchers compared gene readouts in infected&nbsp;Arabidopsis&nbsp;plants at normal and elevated temperatures. They found that many of the genes that were suppressed at the higher temperatures were regulated by the same molecule, a gene called CBP60g.



The CBP60g gene acts like a master switch that controls the activity of many other genes, so anything that downregulates or “turns off” CBP60g will also affect the functioning of those other genes. In fact, the end result is that the plant cells simply don’t make the proteins needed in order to produce salicylic acid, a key substance in the immune response.&nbsp;



Further experiments revealed that the cellular machinery needed to start reading out the genetic instructions in the CBP60g gene doesn’t assemble properly when it gets too hot, and that’s why the plant’s immune system can’t do its job anymore. When the researchers used mutant Arabidopsis plants in which the CBP60g gene was constantly “switched on," the plants were able to produce high levels of salicylic acid and keep bacteria under control, even when they were heat stressed.&nbsp;



The team also found that elevated temperatures didn’t just impair salicylic acid defenses in&nbsp;Arabidopsis&nbsp;plants, but had a similar effect on crop plants such as tomato, rapeseed and rice.&nbsp;



The implications of this are that crop plants might be engineered in the same way to have functional immune systems even under conditions of extreme heat. In fact, the researchers found a way to produce heat-resilient plants in which the CBP60g master switch was turned on only when under attack from pathogens, and this helped to protect the plant’s immune response. In addition, there was no stunting of growth, which is critical if crop are to produce maximum yields.&nbsp;



Extreme heat events are becoming more common and more severe as global warming takes hold. Under these conditions, plants’ natural defenses are set to become less effective, which could lead to worldwide food shortages. Already, up to 40 percent of food crops are lost to pests and diseases each year, costing the global economy around $300 million. Heat waves can only make this situation worse.&nbsp;



At the same time, population growth is driving up the world’s demand for food. To feed the estimated 10 billion people expected on Earth by 2050, forecasts suggest that food production will need to increase by&nbsp;60 percent. The findings of the current study could therefore be good news for food security in the future.&nbsp;



Follow-up experiments to restore CBP60g gene activity in rapeseed thus far are showing the same promising results. In fact, genes with similar DNA sequences are found across plants, He says.



In&nbsp;Arabidopsis, keeping the CPB60g master switch from feeling the heat not only restored genes involved in making salicylic acid, but also protected other defense-related genes against warmer temperatures too.



“We were able to make the whole plant immune system more robust at warm temperatures,” said Sheng-Yang He. “If this is true for crop plants as well, that's a really big deal because then we have a very powerful weapon.”



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By <a href="mailto:bosman@truewan.co.za">Alison Bosman</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Plant immune defenses are weakened by rising temperatures

Heat waves are not good for people, but they can...

If global warming could be limited to 1.5 degrees Celsius, the risks to humans would be reduced by up to 85 percent. This is the conclusion of a study led by the <a href="https://www.uea.ac.uk/">University of East Anglia</a> (UEA), which also identified hotspot regions for climate change risks.



The researchers investigated how limiting global warming could simultaneously reduce the risk of human exposure to heat stress, water scarcity, coastal and river flooding, and disease. The experts compared the extent of these threats at various levels of warming (1.5°C compared to 2°C or 3.66°C).&nbsp;



The researchers also measured the impacts of global warming on agricultural yields and the economy. The study shows that overall, human exposure to these risks would be reduced by 10-44 percent if warming is reduced to 1.5°C rather than 2°C. Compared to 3.66 degrees Celsius of warming, a 1.5°C limit would reduce human risks by 32–85 percent.



The threats that were reduced the most were river flooding, drought, and heat stress, but the risk reduction was greatest for drought. Furthermore, West Africa, India and North America were identified as regions where the risks are projected to increase the most by the end of this century.



“Our findings are important because the Paris Agreement target is to limit global warming to ‘well below’ 2°C and to ‘pursue efforts’ to limit it to 1.5°C. This means that decision makers need to understand the benefits of aiming for the lower figure," said study lead author Professor Rachel Warren.



“In addition, at COP26 last year, the commitments made by countries in terms of greenhouse gas emission reductions are not sufficient to achieve the Paris goals. At present, current policies would result in average warming of 2.7°C, while the Nationally Determined Contributions for 2030 would limit warming to 2.1°C."



“While there are a number of planned additional actions to reduce emissions further, potentially limiting warming to 1.8°C in the most optimistic case, these still need to be delivered and further additional action is needed to limit warming to 1.5°C.”



The findings are published today in the journal <a href="https://www.springer.com/journal/10584">Climatic Change</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

Limiting global warming could reduce human risk by 85%

If global warming could be limited to 1.5 degrees Celsius,...