Prolonged sunny or rainy conditions lead to extreme events

To prove this, the scientists analysed the persistence of specific weather conditions. They applied established image comparison methods on atmospheric data, comparing millions of successive weather circulation patterns worldwide over the last 40 years. They especially looked at two individual extreme events, the 2010 heat wave over Russia and the extraordinary dry summer over Europe in 2018. “We found that weather patterns in general are more persistent now than some decades ago,” says Hoffmann. “Especially in summer, heat waves often last longer now, and also rainfall events tend to linger longer and to be more intense. The longer these weather conditions last, the more intense the extremes can become, both on the warm and dry side as well as on the steady rain side.”

The rise in persistent weather conditions is to a large extent due to dynamical changes in the atmosphere as the westerly winds tend to stop pushing forward weather systems which therefore become more persistent, turning some sunny days into heatwaves of several weeks as well as intensive rainfall into floods.

Climate models might underestimate rise in persistent weather patterns

Like the eye of a knowledgeable observer, the new image comparison method systematically scans atmospheric fields and helps to assess to which extent successive weather circulation patterns change over time or remain stable. Fred Hattermann, co-author of the study and also scientist at PIK, explains the potential of the new approach: “Our method crucially improves the interpretation of long-term climate impacts. When applying the same methodology to climate model output, we do not see a comparable increase in weather persistence, especially not over Europe. Climate models may have been a bit too conservative, underestimating the rise in weather persistence — thus underestimating weather extremes over Europe.” This becomes ever more important with ongoing climate change.

“Recent events and ongoing research have shown that the number and intensity of extreme events have increased due to the global rise in temperature,” concludes Hattermann. “To counteract this worrying trend, the goal has to be to reduce global greenhouse gas emissions and by doing so limit climate change.”

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Materials provided by Potsdam Institute for Climate Impact Research (PIK). Note: Content may be edited for style and length.

Glionitrin A and B are two molecules with properties that make them useful in drug development. However, researchers who want to use these molecules have faced an uphill battle for almost a decade.

Glionitrin A and B are natural products, and are produced a fungus found in extremely contaminated acidic wastewater from an abandoned South Korean mine. Since the fungus only creates the molecules when triggered by specific bacteria from the same sewage, it has proved difficult to produce .

“We have been working on this problem for four years. Every time we thought we had a solution, the molecules revealed unexpected properties that sent us back to the drawing board,” says Daniel Strand, chemistry researcher at Lund University.

Despite the complex nature of the problem, the solution proved to be both simpler and more effective than the researchers thought. By developing a new so-called asymmetric organocatalytic reaction, Daniel Strand and his colleagues succeeded in the most inaccessible parts of the molecules.

“we thought the problem was solved, the molecule had one last surprise. It turned out that the real structure was the mirror image of we initially thought was glionitrin A. So, all this time we had chased a molecule that ,” says Daniel Strand.

Complex natural products with unique properties such as glionitrin A and B are important tools in develop.

Glionitrin A has shown antibiotic properties against resistant bacteria, while glionitrin B makes cancer cells less to migrate. Being able to produce the molecules synthetically helps researchers not only understand how they work, but also improve their properties.

“There is a great need for new types of antibiotics, especially those that can contribute to the fight against resistant bacteria. We expect our results to inspire further development basic synthetic chemistry but also to be used in drug development,” concludes Daniel Strand.

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Materials provided by Lund University. Note: Content may be edited for style and length.

In a paper published in the Proceedings of the National Academies of Sciences, researchers from WSU and Brigham Young University warn that current efforts are overlooking huge swathes of diversity and opportunity.

The analysis found that nearly 3,300 animal species have had their genomes sequenced and assembled, a process that gives organizational context to an organism’s DNA. While the rate is picking up, the number is small in comparison to the world’s 1.66 million animal species, and vertebrates make up the lion’s share of current sequences. They account for 54% of all the assemblies, despite representing only 3.9% of animal species. In contrast, the invertebrates of the Arthropoda phylum, which includes insects and spiders, comprise only 34% of current datasets while representing 78.5% of all species.

“With genome assemblies accumulating rapidly, we want to think about where we are putting our efforts. It’s not being spread evenly across the animal tree of life,” said lead author Scott Hotaling, a WSU post-doctoral researcher. “Invertebrates are still very underrepresented, which makes sense given that people seem to care more about vertebrates, the so-called ‘charismatic megafauna.'”

The family Hominidae, which includes great apes and humans, had the most contiguous genome data assembled, but the human genome is not the longest: that title goes to the Australian lungfish. Of all the genomic data, only five arthropod groups were well represented: bees, butterflies, mosquitoes, fruit flies and ants — all notable for the utility, or problems, they pose to humans.

“We are interested in ourselves, and that’s not necessarily a bad thing,” said Paul Frandsen, a corresponding author on the paper and a BYU assistant professor. “But to begin to understand entire ecosystems, we have to start sampling more of the variety of life to gain a clearer picture. Vertebrates are important components of ecosystems, but arguably insects and many other small creatures probably play an even more important role because they’re down at the base of the food web.”

The authors, Hotaling, Frandsen and WSU associate professor Joanna Kelley, also noted that the vast majority of genetic sequencing work is happening in developed countries often called the Global North because most are located in the Northern Hemisphere. Three countries, the United States, China and Switzerland produce the most. There were even certain proclivities for different regions with North America doing the most sequencing of mammals and insects, Europe of fish and Asia of birds.

In recent years, several large genome sequencing efforts have been announced, including the Earth BioGenome Initiative, which set an ambitious goal to sequence all of eukaryotic life, which includes animals, bacteria and one-celled organisms, within the next 10 years.

The current number of about 3,300 animal genome assemblies as of June 2021 is a big jump in 25 years from when the first animal genome sequence was produced, the Caenorhabditis elegans roundworm in 1998. But the authors calculated that at the current rate of about four genome assemblies per day, the goal of sequencing all eukaryotic life would not be reached until the year 3130.

The researchers propose that one way to help spur more work in this area would be to develop infrastructure and involve more researchers from countries in the Global South, particularly in tropical regions where there also happens to be a lot of animal diversity.

“If we want to build a global discipline, we need to include a global people,” Hotaling said. “It’s just basic equity, and from a pure scientific standpoint, the people who live in areas where species are being sequenced have a lot of knowledge about those species and ecosystems. They have a lot to contribute.”

Since water is present in every known living organism, the splitting of the water molecule H₂O by radiation, called the photolysis of water, is often the starting point for radiation damage. “However, the chain of reactions that can be triggered in the body by high-energy radiation is still not fully understood,” explains Inhester. “For example, even just observing the formation of individual charged ions and reactive radicals in water when high-energy radiation is absorbed is already very difficult.”

To study this sequence of events, the researchers shot the intense pulses from the X-ray laser at the water vapour. Water molecules normally disintegrate on absorbing a single such high-energy X-ray photon. “Due to the particularly intense pulses from the X-ray laser, it was even possible to observe water molecules absorbing not just one, but two or even more X-ray photons before their debris flew apart,” Inhester reports. This gives the researchers a glimpse of what goes on inside the molecule after the first absorption of an X-ray photon.

“The movement of the molecule between two absorption events leaves a clear fingerprint, in other words, its fragments fly apart in a very specific, characteristic way,” says Piancastelli. “By carefully analysing this fingerprint, as well as using detailed simulations, we were able to draw conclusions about the ultra-fast dynamics of the water molecule after it had absorbed the first X-ray photon.” The team measured the directions in which the fragments travelled and their speeds using a so-called reaction microscope. This allowed the scientists to record the disintegration of the water molecule, which lasted only a few femtoseconds (quadrillionths of a second), in a kind of slow-motion movie.

It turns out that the disintegration of the water molecule is much more complicated than initially expected. The water molecule (H₂O) starts to stretch and expand before eventually breaking apart. After only ten femtoseconds, the two hydrogen atoms (H), which are normally attached to the oxygen atom (O) at an angle of 104 degrees, can build up so much momentum as to face each other at an angle of around 180 degrees. As a result, the oxygen atom is not in fact flung away hard when the molecule breaks up, because the momenta of the two hydrogen nuclei largely balance each other out as they fly off, leaving the oxygen virtually at rest in the middle. In an aqueous environment, this free oxygen radical can then easily lead to further potentially harmful chemical reactions.

“In our research, we succeeded for the first time in taking a closer look at the dynamics of a water molecule after it absorbs high-energy radiation,” says Inhester, who works at the Centre for Free-Electron Laser Science (CFEL), a collaboration between DESY, the University of Hamburg and the Max Planck Society. “In particular, we were able to characterise the formation of the oxygen radical and the hydrogen ions more precisely, as well as the way this process unfolds over time. This disintegration of the water molecule is an important first step in the further chain of reactions that ultimately lead to radiation damage.”

The analysis adds to the overall picture of radiation effects on water. A previous study involving some members of the same team had explored the detailed dynamics of the formation of so-called free radicals by less energetic radiation in water. The processes observed there have similar dynamics to the secondary processes in the absorption of high-energy radiation now under investigation. The newly gained insights address elementary questions about reaction dynamics in water, which are to be further investigated at the Centre for Molecular Water Science (CMWS) currently being set up with international partners at DESY.

The new experiments on single water molecules were among the first performed with the new COLTRIMS reaction microscope at the experimental station SQS of the European XFEL. “The results show that we will be also able to look at other solvents and molecules with more complex structure, such as ethanol or cyclic compounds, which are of great interest in chemistry and other disciplines,” says Jahnke.

Involved in the study were researchers from the universities of Frankfurt am Main, Freiburg, Hamburg and Kassel as well as Gothenburg, Lund and Uppsala in Sweden and Turku in Finland, from the Fritz Haber Institute of the Max Planck Society and the Max Planck Institute for Nuclear Physics, from Lawrence Berkeley National Laboratory and Kansas State University in the USA, the National Research Council and the Technical University of Milan in Italy, the Sorbonne in Paris, European XFEL and DESY.

According to scientists at Rice University’s George R. Brown School of Engineering, discarded polystyrene broken down into microplastics provides a cozy home not only for microbes and chemical contaminants but also for the free-floating genetic materials that deliver to bacteria the gift of resistance.

A study in the Journal of Hazardous Materials describes how the ultraviolet aging of microplastics in the environment make them apt platforms for antibiotic-resistant genes (ARGs). These genes are armored by bacterial chromosomes, phages and plasmids, all biological vectors that can spread antibiotic resistance to people, lowering their ability to fight infections.

The study led by Rice civil and environmental engineer Pedro Alvarez in collaboration with researchers in China and at the University of Houston also showed chemicals leaching from the plastic as it ages increase the susceptibility of vectors to horizontal gene transfer, through which resistance spreads.

“We were surprised to discover that microplastic aging enhances horizontal ARG,” said Alvarez, the George R. Brown Professor of Civil and Environmental Engineering and director of the Rice-based Nanotechnology Enabled Water Treatment Center. “Enhanced dissemination of antibiotic resistance is an overlooked potential impact of microplastics pollution.”

The researchers found that microplastics (100 nanometers to five micrometers in diameter) aged by the ultraviolet part of sunlight have high surface areas that trap microbes. As the plastics degrade, they also leach depolymerization chemicals that breach the microbes’ membranes, giving ARGs an opportunity to invade.

They noted that microplastic surfaces may serve as aggregation sites for susceptible bacteria, accelerating gene transfer by bringing the bacteria into contact with each other and with released chemicals. That synergy could enrich environmental conditions favorable to antibiotic resistance even in the absence of antibiotics, according to the study.

Co-authors of the paper are Rice graduate student Ruonan Sun; former Rice postdoctoral researcher Pingfeng Yu, now a faculty member at Zhejiang University; associate professor Qingbin Yuan, Yuan Cheng and lecturer Wenbin Wu of Nanjing Tech University, and Jiming Bao, a professor of electrical and computer engineering at the University of Houston.

The Natural Science Foundation of Jiangsu Province (BK20201367), National Natural Science Foundation of China (42177348) and National Science Foundation funding of NEWT (1449500) supported the research.

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Materials provided by Rice University. Original written by Mike Williams. Note: Content may be edited for style and length.

Gharials are some of the rarest crocodylians on Earth and members of a group of animals that once roamed the planet with the dinosaurs. Native to India, gharials resemble American alligators and crocodiles, but with bulging eyes and an extremely long and thin snout that allows them to cut through water when hunting prey. In males, this snout houses an even longer nose that ends in an enlarged bulb.

At first glance, these unusual animals appear to have little in common with humans. However, a new study led by Jason Bourke, Ph.D., assistant professor of basic sciences at the College of Osteopathic Medicine at Arkansas State University (NYITCOM-Arkansas), reports that — just like humans — gharials suffer from nasal septal deviation.

The Cleveland Clinic estimates that up to 80 percent of people have a deviated septum, a condition in which the nasal cartilage is “off-center.” While the condition is mild in most individuals, larger deviations can restrict nasal breathing and require reconstructive surgery.

Bourke and his colleagues are the first to document deviated nasal septa in crocodylians. Using medical imaging technology, they analyzed the heads of multiple gharial specimens, including that of a large female from the Fort Worth Zoo nicknamed “Louise,” which fueled their curiosity.

“This weird nasal septum was an unexpected discovery,” said study co-author Casey Holliday, Ph.D., associate professor of pathology and anatomical sciences at the University of Missouri, who initially scanned the specimen for a separate project on gharial anatomy. “I saw this roller coaster of a septum and wondered what this might mean for respiration.”

Holliday shared Louise’s extreme anatomy with Bourke, a vertebrate paleontologist whose lab specializes in modeling fluid dynamics in animal noses using sophisticated computer software that simulates air movement.

“We know remarkably little about normal gharial anatomy, much less their pathology. I couldn’t pass up such a unique opportunity,” said Bourke, who has also studied nasal airflow and thermoregulation in dinosaurs.

Intrigued, Bourke and the team began collecting samples from other gharial specimens housed in zoos around the country. While some specimens showed minor septal deviations, Louise had the most extreme case.

Like humans who experience severe nasal septum deviation, Louise had to work harder to achieve the same breathing rate as her peers. This produced high shearing stresses along the nasal walls, which may have made the animal more prone to nosebleeds. Despite the physiological challenges produced from this nasal pathology, Louise successfully made it to adulthood and lived to the ripe old age of 50.

“It’s a testament to crocodylian resiliency,” said Bourke. “A human with this pathology would need surgery to fix it, but these critters just keep on going.”

In contrast to humans, the researchers found that gharial septal deviation comes with a unique twist. “When the septum deviates in humans, a part or all of the septum bows into one of the airways,” said Nicole Fontenot, fourth-year NYITCOM student, and study co-author. “In our gharials, the septum is so long that it wiggles back and forth along the snout, creating a wavy pattern.”

While this pathology is not found in other modern crocodylians, in the distant past, many other animals showed similarly stretched-out noses, including crested, duck-billed dinosaurs like Parasaurolophus and strange crocodile-mimicking reptiles known as champsosaurs. Bourke suspects that at least a few of them would have also suffered from nasal septum deviations. As for why other crocodylians don’t seem to be as prone to these deviated noses, Bourke explains:

“Other crocodylians have wider snouts with much thicker nasal septa. Thinning out the snout places a premium on space inside the nose. Gharials’ long and very thin nasal septa probably don’t need much to make them start wobbling.

Next, the researchers will continue their investigation by examining the sound-producing abilities of gharials’ unique noses.