The group headed by Hongyu Yu – first at RUB, later at the Canadian Geological Survey of Canada – and RUB Professor Rebecca Harrington describes the results in the journal Nature Communications, published online on 25 November 2021.

Several theories on the origins of earthquakes

To date, researchers have explained the occurrence of earthquakes in the hydraulic-fracturing process with two processes. The first says that the fluid pumped into the rock generates a pressure increase substantial enough to generate a new network of fractures in the subsurface rocks near the well. As a result, the pressure increase can be large enough to unclamp existing faults and trigger an earthquake. According to the second process, the fluid pressure increase from injection in the subsurface also exerts elastic stress changes on the surrounding rocks that can be transmitted over longer distances. If the stress changes occur in rocks where faults exist, it can also lead to changes that cause the fault to slip and cause an earthquake.

Recently, numerical models and lab analyses have predicted a process on faults near injection wells that has been observed elsewhere on tectonic faults. The process, termed aseismic slip, starts out as slow slip that does not release any seismic energy. The slow slip can also cause a stress change on nearby faults that causes them slip rapidly and lead to an earthquake. The lack of seismic energy from aseismic slip and the size of the faults involved make it difficult to observe in nature. Researchers have therefore not yet been able to document aseismic slip broadly with any association to induced earthquakes. The work of the current study, provides indirect evidence of aseismic loading, and a transition from aseismic to seismic slip.

Modifying the hydraulic fracturing process

The German-Canadian research team interpret the recently discovered slow earthquakes as an intermediate form of conventional earthquake and aseismic slip – and thus as indirect evidence that aseismic slip can also occur in the vicinity of wells. The researchers therefore dubbed the events hybrid-frequency waveform earthquakes (EHW).

“If we understand at which point the subsurface reacts to the hydraulic-fracturing process with movements that don’t result in an earthquake and, consequently, cause no damage to the surface, ideally we could use that information to adjust the injection procedure accordingly,” as Rebecca Harrington, Head of the Hydrogeomechanics Group at RUB, describes one implication of the study.

Not all quakes spread at the same rate

“We’d assumed that induced earthquakes behave like most other earthquakes and have roughly the same rupture speed of two to three kilometres per second,” explains Rebecca Harrington. But that doesn’t always seem to be the case. While the shaking from a conventional earthquake of magnitude 1.5 in the researchers’ data set had died down after about seven seconds, an EHW earthquake of the same magnitude continued to shake for more than ten seconds.

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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.