Genome of a Drought Tolerant Plant: Many Genes Are Involved in Resurrection

From:  University of Bonn

March 23, 2023

Some plants can survive months without water, only to turn green again after a brief downpour. A recent study by the Universities of Bonn and Michigan shows that this is not due to a "miracle gene." Rather, this ability is a consequence of a whole network of genes, almost all of which are also present in more vulnerable varieties. The results have already appeared online in advance in the journal "The Plant Journal." The print edition will be published soon.

In their study, the researchers took a close look at a species that has long been studied at the University of Bonn -- the resurrection plant Craterostigma plantagineum. It bears its name quite rightly: In times of drought, one might think it is dead. But even after months of drought, a little water is enough to revive it. "At our institute, we have been studying how the plant does this for many years," explains Prof. Dr. Dorothea Bartels from the Institute of Molecular Physiology and Biotechnology of Plants (IMBIO) at the University of Bonn.

Her interests include the genes that are responsible for drought tolerance. It became increasingly clear that this ability is not the result of a single "miracle gene." Instead, a great many genes are involved, most of which are also found in species that do not cope so well with drought.

The plant has eight copies of each chromosome

In the current study, Bartel's team, together with researchers from the University of Michigan (USA), analyzed the complete genome of Craterostigma plantagineum. And this is built quite complex: While most animals have two copies of each chromosome -- one from the mother, one from the father -- Craterostigma has eight. Such an "eightfold" genome is also called octoploid. We humans, in contrast, are diploid.

"Such a multiplication of genetic information can be observed in many plants that have evolved under extreme conditions," Bartels says. But why is that? A probable reason: If a gene is present in eight copies instead of two, it can in principle be read four times as fast. An octoploid genome can therefore enable large quantities of a required protein to be produced very quickly. This ability also appears to be important for the development of drought tolerance.

In Craterostigma, some genes associated with greater tolerance to drought are even further replicated. These include the so-called ELIPs -- the acronym stands for "early light inducible proteins," as they are rapidly switched on by light and protect against oxidative stress. They occur in high copy numbers in all drought-tolerant species. "Craterostigma has close to 200-ELIP genes that are nearly identical and are located in large clusters of ten or twenty copies on different chromosomes," Bartels explains. Drought-tolerant plants can therefore presumably draw on an extensive network of genes that they can rapidly upregulate in the event of drought.

Drought-sensitive species usually have the same genes -- albeit in lower copy numbers. This is also not surprising: The seeds and pollen of most plants are often still able to germinate after long periods without water. So they also have a genetic program to protect against drought. "However, this program is normally switched off at germination and cannot be reactivated afterwards," the botanist explains. "In resurrection plants, in contrast, it remains active."

Most species "can do" drought tolerance

Drought tolerance, then, is something that the vast majority of plants "can do." The genes that confer this ability probably emerged very early in the course of evolution. However, these networks are more efficient in drought-tolerant species and, moreover, are not active only at certain stages of the life cycle.

That said, not every cell in Craterostigma plantagineum has the same "drought program" either. This was shown by researchers from the University of Düsseldorf, who were also involved in the study. For instance, different drought network genes are active in roots during desiccation than in leaves. This finding is not unexpected: Leaves, for instance, need to protect themselves against the damaging effects of the sun. They are helped in this by ELIPs, for example. With sufficient moisture, the plant forms photosynthetic pigments that at least partially absorb radiation. This natural protection largely fails during drought. Roots, in contrast, do not have to worry about sunburn.

The study improves understanding of why some species suffer so little from drought. In the long term, it could therefore contribute to the breeding of crops such as wheat or corn that cope better with drought. In times of climate change, these are likely to be in greater demand than ever in the future.

Participating institutions and funding:

In addition to the University of Bonn, Michigan State University (USA) and Heinrich Heine University Düsseldorf were involved in the study. The work was funded by the US National Science Foundation (NSF) and the German Research Foundation (DFG).

Genome of a drought-tolerant plant: Many genes are involved in 'resurrection' -- ScienceDaily

  

Artificial Intelligence Discovers Secret Equation for Weighing Galaxy Clusters

From:  Flatiron Institute Center for Computational Astrophysics

March 23, 2023 -- Astrophysicists at the Institute for Advanced Study, the Flatiron Institute and their colleagues have leveraged artificial intelligence to uncover a better way to estimate the mass of colossal clusters of galaxies. The AI discovered that by just adding a simple term to an existing equation, scientists can produce far better mass estimates than they previously had.

The improved estimates will enable scientists to calculate the fundamental properties of the universe more accurately, the astrophysicists reported March 17, 2023, in the Proceedings of the National Academy of Sciences.

“It’s such a simple thing; that’s the beauty of this,” says study co-author Francisco Villaescusa-Navarro, a research scientist at the Flatiron Institute’s Center for Computational Astrophysics (CCA) in New York City. “Even though it’s so simple, nobody before found this term. People have been working on this for decades, and still they were not able to find this.”

The work was led by Digvijay Wadekar of the Institute for Advanced Study in Princeton, New Jersey, along with researchers from the CCA, Princeton University, Cornell University and the Center for Astrophysics | Harvard & Smithsonian.

Understanding the universe requires knowing where and how much stuff there is. Galaxy clusters are the most massive objects in the universe: A single cluster can contain anything from hundreds to thousands of galaxies, along with plasma, hot gas and dark matter. The cluster’s gravity holds these components together. Understanding such galaxy clusters is crucial to pinning down the origin and continuing evolution of the universe.

Perhaps the most crucial quantity determining the properties of a galaxy cluster is its total mass. But measuring this quantity is difficult — galaxies cannot be ‘weighed’ by placing them on a scale. The problem is further complicated because the dark matter that makes up much of a cluster’s mass is invisible. Instead, scientists deduce the mass of a cluster from other observable quantities.

In the early 1970s, Rashid Sunyaev, current distinguished visiting professor at the Institute for Advanced Study’s School of Natural Sciences, and his collaborator Yakov B. Zel’dovich developed a new way to estimate galaxy cluster masses. Their method relies on the fact that as gravity squashes matter together, the matter’s electrons push back. That electron pressure alters how the electrons interact with particles of light called photons. As photons left over from the Big Bang’s afterglow hit the squeezed material, the interaction creates new photons. The properties of those photons depend on how strongly gravity is compressing the material, which in turn depends on the galaxy cluster’s heft. By measuring the photons, astrophysicists can estimate the cluster’s mass.

However, this ‘integrated electron pressure’ is not a perfect proxy for mass, because the changes in the photon properties vary depending on the galaxy cluster. Wadekar and his colleagues thought an artificial intelligence tool called ‘symbolic regression’ might find a better approach. The tool essentially tries out different combinations of mathematical operators — such as addition and subtraction — with various variables, to see what equation best matches the data.

Wadekar and his collaborators ‘fed’ their AI program a state-of-the-art universe simulation containing many galaxy clusters. Next, their program, written by CCA research fellow Miles Cranmer, searched for and identified additional variables that might make the mass estimates more accurate.

AI is useful for identifying new parameter combinations that human analysts might overlook. For example, while it is easy for human analysts to identify two significant parameters in a dataset, AI can better parse through high volumes, often revealing unexpected influencing factors.

“Right now, a lot of the machine-learning community focuses on deep neural networks,” Wadekar explained. “These are very powerful, but the drawback is that they are almost like a black box. We cannot understand what goes on in them. In physics, if something is giving good results, we want to know why it is doing so. Symbolic regression is beneficial because it searches a given dataset and generates simple mathematical expressions in the form of simple equations that you can understand. It provides an easily interpretable model.”

The researchers’ symbolic regression program handed them a new equation, which was able to better predict the mass of the galaxy cluster by adding a single new term to the existing equation. Wadekar and his collaborators then worked backward from this AI-generated equation and found a physical explanation. They realized that gas concentration correlates with the regions of galaxy clusters where mass inferences are less reliable, such as the cores of galaxies where supermassive black holes lurk. Their new equation improved mass inferences by downplaying the importance of those complex cores in the calculations. In a sense, the galaxy cluster is like a spherical doughnut. The new equation extracts the jelly at the center of the doughnut that can introduce larger errors, and instead concentrates on the doughy outskirts for more reliable mass inferences.

The researchers tested the AI-discovered equation on thousands of simulated universes from the CCA’s CAMELS suite. They found that the equation reduced the variability in galaxy cluster mass estimates by around 20 to 30 percent for large clusters compared with the currently used equation.

The new equation can provide observational astronomers engaged in upcoming galaxy cluster surveys with better insights into the mass of the objects they observe. “There are quite a few surveys targeting galaxy clusters [that] are planned in the near future,” Wadekar noted. “Examples include the Simons Observatory, the Stage 4 CMB experiment and an X-ray survey called eROSITA. The new equations can help us in maximizing the scientific return from these surveys.”

Wadekar also hopes that this publication will be just the tip of the iceberg when it comes to using symbolic regression in astrophysics. “We think that symbolic regression is highly applicable to answering many astrophysical questions,” he said. “In a lot of cases in astronomy, people make a linear fit between two parameters and ignore everything else. But nowadays, with these tools, you can go further. Symbolic regression and other artificial intelligence tools can help us go beyond existing two-parameter power laws in a variety of different ways, ranging from investigating small astrophysical systems like exoplanets, to galaxy clusters, the biggest things in the universe.”

Artificial Intelligence Discovers Secret Equation for ‘Weighing’ Galaxy Clusters (simonsfoundation.org) 

Road Noise Makes Your Blood Pressure Rise – Literally

Study shows the sound of traffic is associated with increased risk of hypertension, calls for public health measures to reduce noise exposure.

From:  American College of Cardiology

Mar 22, 2023 -- If you live near a busy road you might feel like the constant sound of roaring engines, honking horns and wailing sirens makes your blood pressure rise. Now a new study published today in JACC: Advances confirms it can do exactly that.

Previous studies have shown a  connection between noisy road traffic and increased risk of hypertension. However, strong evidence was lacking, and it was unclear whether noise or air pollution played a bigger role. The new research shows that it is exposure to road traffic noise itself that can elevate hypertension risk.

“We were a little surprised that the association between road traffic noise and hypertension was robust even after adjustment for air pollution,” said Jing Huang, assistant professor in the Department of Occupational and Environmental Health Sciences in the School of Public Health at Peking University in Beijing, China, and lead author of the study.

Previous studies of the issue were cross-sectional, meaning they showed that traffic noise and hypertension were linked, but failed to show a causal relationship. For the new paper, researchers conducted a prospective study using UK Biobank data that looked at health outcomes over time.

Researchers analyzed data from more than 240,000 people (aged 40 to 69 years) who started out without hypertension. They estimated road traffic noise based on residential address and the Common Noise Assessment Method, a European modeling tool.

Using follow-up data over a median 8.1 years, they looked at how many people developed hypertension. Not only did they find that people living near road traffic noise were more likely to develop hypertension, they also found that risk increased in tandem with the noise “dose.”

These associations held true even when researchers adjusted for exposure to fine particles and nitrogen dioxide. However, people who had high exposure to both traffic noise and air pollution had the highest hypertension risk, showing that air pollution plays a role as well.

“Road traffic noise and traffic-related air pollution coexist around us,” Huang said. “It is essential to explore the independent effects of road traffic noise, rather than the total environment.”

The findings can support public health measures because they confirm that exposure to road traffic noise is harmful to our blood pressure, she said. Policymaking may alleviate the adverse impacts of road traffic noise as a societal effort, such as setting stricter noise guideline and enforcement, improving road conditions and urban design, and investing advanced technology on quieter vehicles.

“To date, this is the first large-sized prospective study directly addressing the effect of road traffic noise on the incidence of newly-diagnosed hypertension,” said Jiandong Zhang, cardiovascular disease fellow in the division of cardiology at the University of North Carolina at Chapel Hill, and author of the accompanying editorial comment. “The data demonstrated in this article provides a higher quality of evidence to justify the potential to modify road traffic noise and air pollution from both individual and societal levels in improving cardiovascular health.”

As a follow-up, Huang said field studies are underway to better understand the pathophysiological mechanisms through which road noise affects hypertension.

The study was supervised by Kazem Rahimi, lead of the Deep Medicine program at the Nuffield Department of Women’s and Reproductive Health at the University of Oxford, and Samuel Cai, lecturer in environmental epidemiology at the Centre for Environmental Health and Sustainability at the University of Leicester.

Road Noise Makes Your Blood Pressure Rise – Literally - American College of Cardiology (acc.org)

 

Yes You Can Be Too Tired to Sleep

Like toddlers, adults can also get "overtired."

From:  Big Think.com

March 22, 2023 -- KEY TAKEAWAYS

• "Overtiredness" is often blamed when infants are unable to fall asleep at night because they are stuck in an alert, emotional state. 
• Adults can become overtired as well. Fatigue makes it harder for us to regulate emotions and process thoughts rationally, making it difficult to wind down at night. 
• Giving your brain breaks during the day from our "always-on" existence can help prevent your brain from becoming overtired.

An “overtired” toddler is the bane of many parents’ existences. Your child hasn’t slept in a while and is clearly fatigued. Yet laying in the crib, they are restless and agitated, unable to gently drift off to dreamland and noisily demand your attention.

When overtired, toddlers are likely stuck in an emotional state, such as excitement, anxiety, or fear, wrote Helen L. Ball, a professor of anthropology and director of the Durham Infancy & Sleep Centre at Durham University.

“This is a survival response that helps us to stay awake when in danger, no matter how tired we are.”

Too emotional to sleep

But the crib tends to be a cozy, quiet, and safe place, so why is this survival response engaged? It’s because the longer humans go without sleep, the harder it is for us to regulate our emotions. A notable 2007 study showed that the emotion centers of sleep-deprived brains are more reactive to stimuli compared to rested brains.

“It’s almost as though, without sleep, the brain had reverted back to more primitive patterns of activity, in that it was unable to put emotional experiences into context and produce controlled, appropriate responses,” study author Matthew Walker, a professor of neuroscience and psychology at the University of California-Berkeley, and founder and director of the Center for Human Sleep Science, said of the findings.

An “overtired” toddler is the bane of many parents’ existences. Your child hasn’t slept in a while and is clearly fatigued. Yet laying in the crib, they are restless and agitated, unable to gently drift off to dreamland and noisily demand your attention.

When overtired, toddlers are likely stuck in an emotional state, such as excitement, anxiety, or fear, wrote Helen L. Ball, a professor of anthropology and director of the Durham Infancy & Sleep Centre at Durham University.

“This is a survival response that helps us to stay awake when in danger, no matter how tired we are.”

Too emotional to sleep

But the crib tends to be a cozy, quiet, and safe place, so why is this survival response engaged? It’s because the longer humans go without sleep, the harder it is for us to regulate our emotions. A notable 2007 study showed that the emotion centers of sleep-deprived brains are more reactive to stimuli compared to rested brains.

“It’s almost as though, without sleep, the brain had reverted back to more primitive patterns of activity, in that it was unable to put emotional experiences into context and produce controlled, appropriate responses,” study author Matthew Walker, a professor of neuroscience and psychology at the University of California-Berkeley, and founder and director of the Center for Human Sleep Science, said of the findings.

Since infants need more sleep than adults — anywhere from 12 to 16 hours each day broken into numerous naps in addition to a longer nighttime bout — it’s easy for them to reach that overtired state, but adults are susceptible as well. Have you ever laid awake at night, dwelling on decisions you made earlier that day or planning for the chores you face tomorrow? You’re more likely to find yourself locked in this insidious cycle of rumination if you’re overtired.

“Rested brains are good at ignoring things that happen all the time but have no real consequence,” Matt Jones, a professor of neuroscience at the University of Bristol, told BBC Science Focus. But when overtired or experiencing insomnia, “you’re less able to let go — consciously or unconsciously — of irrelevant information,” he further explained.

Coincidentally, parents of young, potentially overtired kids are themselves more at risk of being overtired themselves. Balancing work and childcare, along with personal physical hygiene, while hopefully attempting to maintain a semblance of a social life, can be mentally and physically exhausting. Our incessantly “on,” hyper-connected existence can also make us overtired. Work emails at all hours, rapid-fire news reports, and social media notifications leave our brains little chance to relax during the day.

How to avoid being overtired

Allotting time for peace and quiet can help. A study published last fall found that a peaceful one-hour walk in nature free from other distractions soothes activity in the amygdala, the primary brain area that processes emotions, including fear and anxiety.

Also helpful is adopting good sleep hygiene. After all, poor sleep also makes us overtired, a brutal feedback loop. If possible, reduce the distractions you face at least an our before bedtime, particularly from technological sources. Importantly, this winding down process should not occur in bed.

“It’s all about managing what’s called ‘stimulus control,’ Dr. Alex Scott, a lecturer in psychology at Keele University told BBC Science Focus. “This basically means it’s a good idea not to associate your bed with too much worrying — that can lead to more sleep problems.”

The rumination that occasionally creates a sleepless night is often a product of your actions earlier in the day. Preventing your brain from getting overtired will make it easier to find peaceful repose at night.

                Yes, you can be too tired to sleep - Big Think

 

Science Fiction Books That Predicted the Future with Terrifying Accuracy

Jules Verne wrote about gasoline-powered vehicles, weapons of mass destruction, and global warming more than a century ago.

By Tim Brinkhof

March 21, 2023 -- When the American financier J.P. Morgan hired the inventor of the lightbulb, Thomas Edison, to wire his mansion in New York, his father Junius Morgan warned him that electric light was only a passing craze. In 1903, Horace Rackham, the personal lawyer of automobile manufacturer Henry Ford, was told that cars would never replace horse-drawn carriages. And in his 1961 book The Wonderland of Tomorrow, Brendan Matthews announced that, soon, technology would allow us to eliminate aging and bad weather.

Predicting the future with any degree of accuracy is difficult, but certainly not impossible. As Czech writer Karel Čapek, whose 1920 play RUR is believed to have coined the term “robots,” once said, “Some of the future can always be read in the palms of the present.” The greater your understanding of science, society, and human nature, the more you can read. While some are more well-known than others, there is no shortage of books with shockingly accurate predictions of the future.   

Science vs science fiction

Classic literature anticipated a variety of modern inventions. Mary Shelley’s Frankenstein, one of the first true science fiction stories, foreshadowed the development of bioelectronics, organ transplants, genetic engineering, and artificial intelligence, to name just a few things. On a deeper level, Shelley’s 1818 novel also predicted the inevitable confrontation between science, religion, and ethics – a confrontation that carries on today with no clear end in sight.  

The book with the largest number of accurate predictions might be Jules Verne’s Paris in the Twentieth Century. Verne, the author of Journey to the Center of the Earth and Twenty Thousand Leagues Under the Sea, is one of the most influential sci-fi writers of all time. But Paris in the Twentieth Century proved to be particularly prophetic. In a single narrative, written during the 1860s, Verne mentions gasoline-powered vehicles, weapons of mass destruction, global warming, and changing gender norms.

Some predictions of mankind can be traced back to ancient times. In her book, Gods and Robots: Myths, Machines, and Ancient Dreams of Technology, the historian Adrienne Mayor points to the myth of Talos, an automaton constructed by Hephaestus, as an example of Greeks using their imagination to exceed the limitations of their technology. “Ideas about creating artificial life,” she writes, “were thinkable long before technology made such enterprises possible.”

From utopias to dystopias

Before there was dystopian fiction – a subgenre of science fiction we are all too familiar with nowadays – there was utopian fiction. Writers and thinkers from Plato to Thomas Moore drew on the latest in political, philosophical, and scientific thinking to build blueprints for an ideal civilization. In the 19^th century, authors like H.G. Wells and Jack London started to flip the age-old formula on its head, exploring how human development could lead to a distinctly undesirable future.

Every dystopian novel contains at least some echo of reality. Buzz Windrip, the demagogue politician who is elected president of the United States in Sinclair Lewis’ book It Can’t Happen Here (1935), was originally meant to be an allegory for Adolf Hitler and Benito Mussolini. Today, his brand of populism foils that of Donald Trump as well. In The Minority Report (1956) by Philip K. Dick, cops use algorithms to arrest criminals before they commit the crime — a long-standing objective in real-life AI research.

Yevgeny Zamyatin’s We, a major influence on George Orwell’s 1984, Ayn Rand’s Anthem, and Kurt Vonnegut’s Player Piano, takes place in an ultra-rational totalitarian state where people have numbers for names and follow instructions from an all-powerful dictator called The Benefactor. Released in 1924, the book satirizes an urge shared by capitalist businessmen and communist dictators alike: to turn people into obedient, indistinguishable machines.

Zamyatin’s characters insist on the right to be imperfect, make mistakes, and act of their own free will. It’s a moving sentiment, but Zamyatin was not the first writer to put it into words. As literary critics have noted, We stands on the shoulders of Fyodor Dostoevsky’s 1864 novella Notes from Underground, in which the Russian author effectively predicted the rise of 20th-century totalitarian regimes that sought to control every aspect of their subjects’ lives.

Books that shaped the future

Unlike We, which takes issue with parties on both sides of the political spectrum, Notes From Underground was written specifically in response to the rise of socialist movements in 19th-century Russia. As a Christian, Dostoevsky sympathized with the desire to end injustice and uplift the poor. At the same time, he believed all utopias – socialist or otherwise – are doomed to fail because people value freedom above all else. Like John Milton’s Lucifer, they would rather rule in hell than serve in heaven.

Dostoevsky was particularly upset by What is to be Done?, a social problem novel by Nikolay Chernyshevsky that, while awkwardly written, imparts a clear impression of what socialist utopias could look like and how socialist revolutionaries are supposed to act. Defying expectations, What is to be Done?became immensely popular upon its 1863 release. Today, it is a rare example of a book that didn’t just predict the future but also shaped it in its own image.

Imitating Chernyshevsky’s characters, young Russians slept on beds of nails to become tougher and took up work in communal sewing cooperatives. Revolutionaries Nikolai Ishutin and Dmitry Karakozov were so enamored by the book they plotted to assassinate Czar Alexander II on the anniversary of its publication, and Vladimir Lenin read What is to be Done? five times after his brother was executed for plotting his own assassination attempt. Would the future have unfolded the way it did without Chernyshevsky?

This excerpt was reprinted with permission of Big Think, where it was originally published.

            https://www.freethink.com/culture/science-fiction-predictions

 

CDC Warns of Deadly Fungus Spreading at Alarming Rate in U.S. Healthcare Facilities

CENTERS FOR DISEASE CONTROL AND PREVENTION MARCH 21, 2023

Candida auris (C. auris), an emerging fungus considered an urgent antimicrobial resistance (AR) threat, spread at an alarming rate in U.S. healthcare facilities in 2020-2021, according to data from the Centers for Disease Control and Prevention (CDC) published in the Annals of Internal Medicine. Equally concerning was a tripling in 2021 of the number of cases that were resistant to echinocandins, the antifungal medicine most recommended for treatment of C. auris infections. In general, C. auris is not a threat to healthy people. People who are very sick, have invasive medical devices, or have long or frequent stays in healthcare facilities are at increased risk for acquiring C. auris. CDC has deemed C. auris as an urgent AR threat, because it is often resistant to multiple antifungal drugs, spreads easily in healthcare facilities, and can cause severe infections with high death rates.

“The rapid rise and geographic spread of cases is concerning and emphasizes the need for continued surveillance, expanded lab capacity, quicker diagnostic tests, and adherence to proven infection prevention and control,” said CDC epidemiologist Dr. Meghan Lyman, lead author of the paper.

Candida auris is an emerging fungus that presents a serious global health threat. CDC is concerned about C. auris for three main reasons:

1. It is often multidrug-resistant, meaning that it is resistant to multiple antifungal drugs commonly used to treat Candida infections. Some strains are resistant to all three available classes of antifungals.
2. It is difficult to identify with standard laboratory methods, and it can be misidentified in labs without specific technology. Misidentification may lead to inappropriate management.
3. It has caused outbreaks in healthcare settings. For this reason, it is important to quickly identify C. auris in a hospitalized patient so that healthcare facilities can take special precautions to stop its spread.

As further explained in the article, C. auris has spread in the United States since it was first reported in 2016, with a total of 3,270 clinical cases (in which infection is present) and 7,413 screening cases (in which the fungus is detected but not causing infection) reported through December 31, 2021. Clinical cases have increased each year since 2016, with the most rapid rise occurring during 2020-2021. CDC has continued to see an increase in case counts for 2022. During 2019-2021, 17 states identified their first C. auris case ever. Nationwide, clinical cases rose from 476 in 2019 to 1,471 in 2021. Screening cases tripled from 2020 to 2021, for a total of 4,041. Screening is important to prevent spread by identifying patients carrying the fungus so that infection prevention controls can be used.

C. auris case counts have increased for many reasons, including poor general infection prevention and control (IPC) practices in healthcare facilities. Case counts may also have increased because of enhanced efforts to detect cases, including increased colonization screening, a test to see if someone has the fungus somewhere on their body but does not have an infection or symptoms of infection. The timing of this increase and findings from public health investigations suggest C. auris spread may have worsened due to strain on healthcare and public health systems during the COVID-19 pandemic.

The CDC’s Antimicrobial Resistance Laboratory Network, which provides nationwide lab capacity to rapidly detect antimicrobial resistance and inform local responses to prevent spread and protect people, provided some of the data for this report. CDC worked to significantly strengthen laboratory capacity, including in state, territorial, and local health departments, through supplemental funding supported by the American Rescue Plan Act. These efforts include increasing susceptibility testing capacity for C. auris from seven Regional Labs to more than 26 labs nationwide.

CDC continues to work with state, local, and territorial health departments and other partners to address this emerging threat to public health. Review more information on C. auris, the Antimicrobial Resistance Threats Report that identified C. auris as an urgent threat in the United States, or the WHO fungal priority pathogen list that identifies C. auris as a priority globally.

Reference: “Worsening Spread of Candida auris in the United States, 2019 to 2021” by Meghan Lyman, MD, Kaitlin Forsberg, MPH, D. Joseph Sexton, PhD, Nancy A. Chow, PhD, MS, Shawn R. Lockhart, PhD, Brendan R. Jackson, MD, MPH and Tom Chiller, MD, MPHTM, 21 March 2023, Annals of Internal Medicine.

CDC Warns of Deadly Fungus Spreading at Alarming Rate in U.S. Healthcare Facilities (scitechdaily.com)

 

Where Did Earth's Water Come From? Not Melted Meteorites, According to Scientists

A new insight into the extraterrestrial origins of our lakes, rivers and oceans

From:  University of Maryland

March 15, 2023 -- A new study brings scientists one step closer to answering the question of where Earth's water came from.

Water makes up 71% of Earth's surface, but no one knows how or when such massive quantities of water arrived on Earth.

A new study published in the journal Nature brings scientists one step closer to answering that question. Led by University of Maryland Assistant Professor of Geology Megan Newcombe, researchers analyzed melted meteorites that had been floating around in space since the solar system's formation 4 1/2 billion years ago. They found that these meteorites had extremely low water content -- in fact, they were among the driest extraterrestrial materials ever measured.

These results, which let researchers rule them out as the primary source of Earth's water, could have important implications for the search for water -- and life -- on other planets. It also helps researchers understand the unlikely conditions that aligned to make Earth a habitable planet.

"We wanted to understand how our planet managed to get water because it's not completely obvious," Newcombe said. "Getting water and having surface oceans on a planet that is small and relatively near the sun is a challenge."

The team of researchers analyzed seven melted, or achondrite, meteorites that crashed into Earth billions of years after splintering from at least five planetesimals -- objects that collided to form the planets in our solar system. In a process known as melting, many of these planetesimals were heated up by the decay of radioactive elements in the early solar system's history, causing them to separate into layers with a crust, mantle and core.

Because these meteorites fell to Earth only recently, this experiment was the first time anyone had ever measured their volatiles. UMD geology graduate student Liam Peterson used an electron microprobe to measure their levels of magnesium, iron, calcium and silicon, then joined Newcombe at the Carnegie Institution for Science's Earth and Planets Laboratory to measure their water contents with a secondary ion mass spectrometry instrument.

"The challenge of analyzing water in extremely dry materials is that any terrestrial water on the sample's surface or inside the measuring instrument can easily be detected, tainting the results," said study co-author Conel Alexander, a scientist at the Carnegie Institution for Science.

To reduce contamination, researchers first baked their samples in a low-temperature vacuum oven to remove any surface water. Before the samples could be analyzed in the secondary ion mass spectrometer, the samples had to be dried out once again.

"I had to leave the samples under a turbo pump -- a really high-quality vacuum -- for more than a month to draw down the terrestrial water enough," Newcombe said.

Some of their meteorite samples came from the inner solar system, where Earth is located and where conditions are generally assumed to have been warm and dry. Other rarer samples came from the colder, icier outer reaches of our planetary system. While it was generally thought that water came to Earth from the outer solar system, it has yet to be determined what types of objects could have carried that water across the solar system.

"We knew that plenty of outer solar system objects were differentiated, but it was sort of implicitly assumed that because they were from the outer solar system, they must also contain a lot of water," said Sune Nielsen, a study co-author and geologist at the Woods Hole Oceanographic Institution. "Our paper shows this is definitely not the case. As soon as meteorites melt, there is no remaining water."

After analyzing the achondrite meteorite samples, researchers discovered that water comprised less than two millionths of their mass. For comparison, the wettest meteorites -- a group called carbonaceous chondrites -- contain up to about 20% of water by weight, or 100,000 times more than the meteorite samples studied by Newcombe and her co-authors.

This means that the heating and melting of planetesimals leads to near-total water loss, regardless of where these planetesimals originated in the solar system and how much water they started out with. Newcombe and her co-authors discovered that, contrary to popular belief, not all outer solar system objects are rich in water. This led them to conclude that water was likely delivered to Earth via unmelted, or chondritic, meteorites.

Newcombe said their findings have applications beyond geology. Scientists of many disciplines -- and especially exoplanet researchers -- are interested in the origin of Earth's water because of its deep connections with life.

"Water is considered to be an ingredient for life to be able to flourish, so as we're looking out into the universe and finding all of these exoplanets, we're starting to work out which of those planetary systems could be potential hosts for life," Newcombe said. "In order to be able to understand these other solar systems, we want to understand our own."

            https://www.sciencedaily.com/releases/2023/03/230315132425.htm#