Earth

ITHACA, N.Y. - As offices nationwide spring back to life, interior space designers and architects will soon have an easy-to-use planning tool to place indoor workplace furniture, staff, partitions and ventilation in a manner that maximizes fresh air flow and reduces the risk of airborne pathogens.

The Cornell Environmental Systems Lab in the College of Architecture, Art and Planning will introduce a new indoor module for their existing Eddy3D software, a professional-level airflow and microclimate simulator that can help improve ventilation.

The new indoor module will be released this summer, while the research supporting it will be presented at the International Building Performance Association conference this September in Belgium.

Based on computational fluid dynamics, the tool features a simple user interface, a validated simulation engine and streamlined simulation setup for a fast analysis. It shows the eddies of air flow and can indicate regions in rooms where air is stagnant and pathogens begin to concentrate.

The lab's research show that furniture - and people - have a large influence on virus diffusion throughout the floor plan. Plastic partitions can block the virus diffusion, but direct air allows a higher virus dissipation rate.

"As a designer or an architect, it's very difficult to develop an intuition for airflow," said Timur Dogan, assistant professor in the Department of Architecture, who directs Environmental Systems Lab. "With this, you are getting a good synchronization of airflow everywhere, so that you're not mixing or transporting bad air from one location to another, or from one desk to another."

A preprint of the September research presentation work is available on ResearchGate.

"Architects and designers are not necessarily experts in computational fluid dynamics," Dogan said. "The goal is to help professionals make decisions about workplace and classroom environments."

The Cornell Atkinson Center for Sustainability funded the research.

Eddy3D - currently without the new module - is available now for free. The new module will be available July 30.

HOUSTON - (July 6, 2021) - A small fungal enzyme could play a significant role in simplifying the development and manufacture of drugs, according to Rice University scientists.

The Rice lab of chemical and biomolecular engineer Xue Sherry Gao and collaborators isolated a biocatalyst known as CtdE after identifying it as the natural mechanism that controls the chirality -- the left- or right-handedness -- of compounds produced by the native fungal host.

The open-access study appears in Nature Communications.

Two chiral things are, like hands, alike in structure but cannot perfectly overlap. Because the property is important in designing drugs that bind correctly to their targets, the ability to achieve 100% correct chirality is highly desired, Gao said.

"It's important because if a pharmaceutical drug has the wrong stereochemistry (chirality in three dimensions), it could become a poison to humans, even if the planar chemical structure is the same," she said.

Like "left" or "right" orientation in chiral objects, what's known as a 3S or 3R orientation is determined by a molecule's stereocenter, a one-atom connection between parts of a molecule, Gao said.

But while nature handles the process with ease, selectively synthesizing stereocenters has been a challenge for chemists. The entire mechanism behind nature's ability to control whether a molecule has a 3S or 3R orientation has been hidden from view until now.

Understanding how it works in fungi and analyzing its structure could give scientists, particularly those who design drugs, a new chemical synthesis tool.

The focus of the study, a bioactive natural product known as 21R-citrinadin A, discovered in 2004 in a marine-derived fungal strain of Penicillium citrinum, is toxic to leukemia in mice and human lung cancer cells.

"21R-citrinadin A is a very complicated molecule, with eight stereocenters," Gao said. "In a way, the paper emphasizes how nature uses enzymes to synthesize a complex molecule with such a precision. Eight different stereocenters are a lot to control."

She said the molecule incorporates a "very intriguing" 3S spirooxindole ring. "Nature produces several other chemicals with a similar spirooxindole pharmacophore," Gao said. "However, we became very curious that some of them contain a 3R spirooxindole ring, the opposite of 3S in citrinadins.

"All the genes responsible for expressing this small molecule are clustered together in these fungi, so first we found the gene cluster and looked at each gene individually to see which one could be the most important to catalyze the specific chemical transformations," she said.

"Once we find it, we can take that gene outside of the fungus, put it back into a user-friendly host, E. coli, and then use protein purification technology to isolate and test its function in a test tube," Gao said. "By doing everything outside of the fungus, we can be sure there's only one enzyme that performs this one function."

The modified E. coli express CtdE protein in bulk. When subsequently used in chemical transformations, CtdE catalyzed the desired 3S stereoselectivity across the board. "A spirooxindole is hard to synthesize already," she said. "Our goal was to understand the mechanism of how the enzyme controls this specific 3S stereochemistry."

Bioinformatic analysis, X-ray crystallography and experiments confirmed that CtdE is solely responsible for catalyzing 3S stereoselectivity, Gao said. (Another enzyme, PhqK, was already known to catalyze 3R orientation.) "Having a set of two enzymes that give precise control over stereochemistry will eventually improve the synthesis in pharmaceutical production," she said.

Gao noted that because CtdE works at room temperature, it will help keep chemistry "green" as well. "Hopefully, these biocatalysts will catalyze chemical reactions in a more environmentally friendly way," she said.

Postdoctoral researchers Zhiwen Liu and Fanglong Zhao of Rice and graduate student Boyang Zhao of Baylor College of Medicine are co-lead authors of the paper.

Bioenergy crops are an alternative energy source that, unlike fossil fuels, could positively impact the environment by reducing greenhouse gases, soil erosion, and carbon dioxide levels. They can be produced even more sustainably if they are grown on poor quality land unsuitable for food. To make up for the poor land quality, these crops can rely on soil microbes like bacteria and fungi to help them access nutrients and water and store more carbon.

Switchgrass, a native prairie species, is championed as a promising bioenergy crop due to its ability to grow across many climates. It is also known to associate with beneficial microbes. To better understand the relationship between switchgrass and soil microbes, researchers at Michigan State University and Washington State University examined soil microbial communities and root traits among 12 switchgrass cultivars that had been planted in the same plot over nine years.

"This common garden design allowed us to determine how each cultivar affects their soil microbiome while controlling for difference in soil type and climate," explained Tayler Ulbrich, one of the researchers involved in the study. And unlike most studies that look at young switchgrass roots, their focus on a wide range of different cultivars and on mature switchgrass gave them a more representative understanding of the plant's long-life span and dense root systems.

"We learned that, even within one region, there is not one standard switchgrass microbiome but that each cultivar harbored a unique community of soil bacteria and fungi. We also found evidence that root characteristics, like length and diameter, differed among the cultivars and may influence the structure of these microbiomes."

Their study emphasizes the need to identify how plant traits affect soil microbiomes and their function. Ulbrich acknowledges that studying root traits is a tedious task, especially on plants growing in nature, but it is important to research because root systems are crucial for resource uptake and healthy soils as well as the plant's ability to communicate with other plants and microbes.

Producing profitable and sustainable bioenergy crops will require crops that can tolerate stressful growing conditions, such as poor soil nutrients or drought, with fewer inputs. Understanding that switchgrass cultivars differ in their abilities to tolerate these conditions and that microbiomes may play a role, future research should investigate cultivar-specific differences in microbiomes and use this information to select and breed cultivars with optimal microbiome-mediated traits such as high nitrogen-fixation or carbon-sequestration.

For more information about this research, read "Intraspecific Variability in Root Traits and Edaphic Conditions Influence Soil Microbiomes Across 12 Switchgrass Cultivars," published in the May issue of Phytobiomes Journal, which focuses on the phytobiomes of bioenergy crops and agroecosystems.

Amid calls for racial and social justice nationwide, businesses and educational institutions are grappling with how to adopt more inclusive organizational practices, including more diversified hiring. However, recruitment teams and strategic leaders often blame their lack of a diverse workforce on a lack of diverse applicants. A large study of recruitment data suggests a simple and efficient way of increasing diversity in applicant pools: have more diverse recruitment committees and leadership teams.

The study, led by researchers at the University of Houston's Center for ADVANCING Faculty Success and published online in the Journal of Applied Psychology, found that when the search committee chair for a job is a woman, 23% more women apply for the job than when the search committee is led by a man. What is more, over 100% more underrepresented minorities (URM), such as Hispanics and Blacks, apply for the job when the recruitment is led by a URM chair as opposed to a non-URM. 
  

In the context of workplace diversity, the concept of homophily - an affinity for similar others - has developed a bad reputation for furthering systemic barriers to opportunity for minority groups. In fact, homophily, if utilized wisely, can be leveraged to increase the representation of women and underrepresented minorities, according to Maryam A. Kazmi, a Ph.D. candidate at UH and the study's first author. 
  

"There is something that women and URM recruiters are doing differently than men and majority group members that encourages more women and URM applicants to apply for a job," she said. 

The study, an analysis of three years of recruitment data for tenure-track faculty jobs at a large, public research university, shows that one of the ways in which women and URM recruitment leaders are affecting applicant pools is by appointing more women and URM to participate on the search committees they lead. These women and URM search committee members, together with the leads of recruitment teams, disseminate job ads more widely, specifically to more women and URM potential applicants who then apply in greater numbers. But what motivates them to do so? 

Christiane Spitzmueller, professor of psychology at UH and a study co-author, said that women and URM recruitment leads and team members rely on their own experiences in developing applicant pools. 

"Women and underrepresented minority recruiters have likely experienced the same structural barriers to entry and career progress that the potential applicants may face. Their own experiences of inequity may make them likely to have a soft spot for similar others facing similar issues. This might motivate women and minority recruiters to work harder to ensure that they do what they can to ensure that more women and URM are made aware of the job opening and are encouraged to apply," she said. 

The researchers make a number of policy recommendations for human resource professionals, supervisors and other company executives to ensure more diverse applicant pools, which include: 

Posting the job ad on women/minority-specific websites

Cooperating with the organization/institution's diversity and inclusion offices to develop a diverse list of candidates to contact

Posting the position ad through department chair listservs

Calling women or colleagues from historically underrepresented backgrounds to get possible candidate names/recommendations on who to recruit

Using personal networks to recruit

Including language in the job ads promoting the diversity of the department and university to prospective candidates

The study found that women and URM recruiters tend to use different strategies to affect applicant pool diversity, says Juan Madera, study co-author and professor at the Conrad N. Hilton College of Hotel and Restaurant Management at UH. 

"We found preliminary evidence that women recruiters are more likely to use personal networks to identify and target women/URM applicants, whereas URM recruiters are more likely to use more formal strategies of increasing applicant pool diversity. For example, cooperating with the institution's diversity and inclusion offices to develop a diverse list of candidates to contact and posting the job ad on women and minority-specific websites," he said.   

"Women and URM continue to be underrepresented in workplaces. The diversification of applicant pools constitutes an important step for broadening the participation of women and URM in the workforce," says Paula Paula Myrick Short, senior vice president for academic affairs and provost at the University of Houston. "This study provides evidence of practical steps that organizations can take to increase their applicant pool diversity."

An unknown methane-producing process is likely at work in the hidden ocean beneath the icy shell of Saturn's moon Enceladus, suggests a new study published in Nature Astronomy by scientists at the University of Arizona and Paris Sciences & Lettres University.

Giant water plumes erupting from Enceladus have long fascinated scientists and the public alike, inspiring research and speculation about the vast ocean that is believed to be sandwiched between the moon's rocky core and its icy shell. Flying through the plumes and sampling their chemical makeup, the Cassini spacecraft detected a relatively high concentration of certain molecules associated with hydrothermal vents on the bottom of Earth's oceans, specifically dihydrogen, methane and carbon dioxide. The amount of methane found in the plumes was particularly unexpected.

"We wanted to know: Could Earthlike microbes that 'eat' the dihydrogen and produce methane explain the surprisingly large amount of methane detected by Cassini?" said Regis Ferriere, an associate professor in the University of Arizona Department of Ecology and Evolutionary Biology and one of the study's two lead authors. "Searching for such microbes, known as methanogens, at Enceladus' seafloor would require extremely challenging deep-dive missions that are not in sight for several decades."

Ferriere and his team took a different, easier route: They constructed mathematical models to calculate the probability that different processes, including biological methanogenesis, might explain the Cassini data.

The authors applied new mathematical models that combine geochemistry and microbial ecology to analyze Cassini plume data and model the possible processes that would best explain the observations. They conclude that Cassini's data are consistent either with microbial hydrothermal vent activity, or with processes that don't involve life forms but are different from the ones known to occur on Earth.

On Earth, hydrothermal activity occurs when cold seawater seeps into the ocean floor, circulates through the underlying rock and passes close by a heat source, such as a magma chamber, before spewing out into the water again through hydrothermal vents. On Earth, methane can be produced through hydrothermal activity, but at a slow rate. Most of the production is due to microorganisms that harness the chemical disequilibrium of hydrothermally produced dihydrogen as a source of energy, and produce methane from carbon dioxide in a process called methanogenesis.

The team looked at Enceladus' plume composition as the end result of several chemical and physical processes taking place in the moon's interior. First, the researchers assessed what hydrothermal production of dihydrogen would best fit Cassini's observations, and whether this production could provide enough "food" to sustain a population of Earthlike hydrogenotrophic methanogens. To do that, they developed a model for the population dynamics of a hypothetical hydrogenotrophic methanogen, whose thermal and energetic niche was modeled after known strains from Earth.

The authors then ran the model to see whether a given set of chemical conditions, such as the dihydrogen concentration in the hydrothermal fluid, and temperature would provide a suitable environment for these microbes to grow. They also looked at what effect a hypothetical microbe population would have on its environment - for example, on the escape rates of dihydrogen and methane in the plume.

"In summary, not only could we evaluate whether Cassini's observations are compatible with an environment habitable for life, but we could also make quantitative predictions about observations to be expected, should methanogenesis actually occur at Enceladus' seafloor," Ferriere explained.

The results suggest that even the highest possible estimate of abiotic methane production - or methane production without biological aid - based on known hydrothermal chemistry is far from sufficient to explain the methane concentration measured in the plumes. Adding biological methanogenesis to the mix, however, could produce enough methane to match Cassini's observations.

"Obviously, we are not concluding that life exists in Enceladus' ocean," Ferriere said. "Rather, we wanted to understand how likely it would be that Enceladus' hydrothermal vents could be habitable to Earthlike microorganisms. Very likely, the Cassini data tell us, according to our models.

"And biological methanogenesis appears to be compatible with the data. In other words, we can't discard the 'life hypothesis' as highly improbable. To reject the life hypothesis, we need more data from future missions," he added.

The authors hope their paper provides guidance for studies aimed at better understanding the observations made by Cassini and that it encourages research to elucidate the abiotic processes that could produce enough methane to explain the data.

For example, methane could come from the chemical breakdown of primordial organic matter that may be present in Enceladus' core and that could be partially turned into dihydrogen, methane and carbon dioxide through the hydrothermal process. This hypothesis is very plausible if it turns out that Enceladus formed through the accretion of organic-rich material supplied by comets, Ferriere explained.

"It partly boils down to how probable we believe different hypotheses are to begin with," he said. "For example, if we deem the probability of life in Enceladus to be extremely low, then such alternative abiotic mechanisms become much more likely, even if they are very alien compared to what we know here on Earth."

According to the authors, a very promising advance of the paper lies in its methodology, as it is not limited to specific systems such as interior oceans of icy moons and paves the way to deal with chemical data from planets outside the solar system as they become available in the coming decades.

A study published the week of July 5 in the Proceedings of the National Academy of Sciences led by Michael Moore at Washington University in St. Louis finds that dragonfly males have consistently evolved less breeding coloration in regions with hotter climates.

"Our study shows that the wing pigmentation of dragonfly males evolves so consistently in response to the climate that it's among the most predictable evolutionary responses ever observed for a mating-related trait," said Moore, who is a postdoctoral fellow with the Living Earth Collaborative at Washington University.

"This work reveals that mating-related traits can be just as important to how organisms adapt to their climates as survival-related traits," he said.

Many dragonflies have patches of dark black pigmentation on their wings that they use to court potential mates and intimidate rivals.

"Beyond its function in reproduction, having a lot of dark pigmentation on the wings can heat dragonflies up by as much as 2 degrees Celsius, quite a big shift!" Moore said, noting that would roughly equal a 3.5 degrees Fahrenheit change. "While this pigmentation can help dragonflies find mates, extra heating could also cause them to overheat in places that are already hot."

The researchers were interested in whether this additional heating might force dragonflies to evolve different amounts of wing pigmentation in different climates.

For this study, the scientists created a database of 319 dragonfly species using field guides and citizen-scientist observations. They examined the wing ornamentation shown in photographs submitted to iNaturalist and gathered information about climate variables in the locations where the dragonflies were observed. The researchers also directly measured the amount of wing pigmentation on individual dragonflies from almost 3,000 iNaturalist observations in a focused group of 10 selected species. For dragonflies in each of these 10 species, the scientists evaluated how populations differed in the warm and cool parts of their geographic ranges.

Whether they compared species with hotter versus cooler geographic ranges, or compared populations of the same species that live in warmer areas versus cooler areas, the researchers saw the same thing: male dragonflies nearly always responded to warmer temperatures by evolving less wing pigmentation.

Sorting the observations another way, the researchers determined that male dragonflies spotted in warmer years tended to have less wing pigmentation than male dragonflies of the same species in cooler years (the database included observations recorded during the time period from 2005-19).

"Given that our planet is expected to continue warming, our results suggest that dragonfly males may eventually need to adapt to global climate change by evolving less wing coloration," Moore said.

The study includes projections, based on climate warming scenarios, that indicate it will be beneficial for male wing pigmentation to shrink further as the Earth warms over the next 50 years.

But the changes are not happening the same way for both sexes.

"Unlike the males, dragonfly females are not showing any major shifts in how their wing coloration is changing with the current climate. We don't yet know why males and females are so different, but this does show that we shouldn't assume that the sexes will adapt to climate change in the same way," Moore said.

Dragonflies have different amounts of pigment on their wings that help males and females of the same species identify each other. One of the interesting implications of this research is that if the male wing pigmentation evolves in response to rapid changes in climate and the female pigmentation evolves in response to something else, females may no longer recognize males of their own species.

This could cause them to mate with males of the wrong species.

"Rapid changes in mating-related traits might hinder a species' ability to identify the correct mate," Moore said. "Even though our research suggests these changes in pigmentation seem likely to happen as the world warms, the consequences are something we still really don't know all that much about yet."

A huge global network of researchers is working together to take the pulse of our global tropical forests.

ForestPlots.net, which is co-ordinated from the University of Leeds, brings together more than 2,500 scientists who have examined millions of trees to explore the effect of climate change on forests and biodiversity.

A new research paper published in Biological Conservation explains the origins of the network, and how the power of collaboration is transforming forest research in Africa, South America and Asia.

The paper includes 551 researchers and outlines 25 years of discovery in the carbon, biodiversity and dynamics of tropical forests.

Professor Oliver Phillips, of Leeds' School of Geography, said "Our new paper shows how we are linking students, botanists, foresters and policy-makers with the ForestPlots.net technology developed at Leeds.

"This drives a new model of collective research. This is helping to transform scientific understanding of how tropical forests work - and how they are helping to slow climate change.

"In this new synthesis we outline how this collaboration has been built, and trace the exciting potential of collaborative science that reaches across the world's tropical forests to embrace colleagues from all countries and backgrounds."

ForestPlots.net provides a unique place to measure, monitor, and understand the world's forests, and especially the tropical forests.

Established in 2009, it has grown fast to track 5,138 plots in 59 countries, with a network of 2,512 people.

The collaboration, funded by UK NERC and the Royal Society, aims to promote cooperation across countries and continents, and enable partners to access, analyse and manage the information from their long-term plots.

Professor Phillips said: "Our core approach links long-term, grassroots researchers to generate robust large-scale results.

"This global, diverse community is measuring thousands of forests tree-by-tree in long-term plots.

"By connecting tropical researchers together and valuing the key role of the data originator in scientific discovery, our Social Research Network model of research seeks to support the key workers who make 21st century big data science possible."

ForestPlots.net hosts data from many individual researchers and networks including AfriTRON, ECOFOR, PPBio, RAINFOR, TROBIT and T-FORCES.

Working together equitably, the network has shown that long-term monitoring of forests on-the-ground is irreplaceable, making scientific discoveries across the globe.

Through large scale analysis, ForestPlots.net researchers discover where and why forest carbon and biodiversity respond to climate change, and how they help control it with a billion tonne annual carbon sink.

The new research paper, Taking the pulse of Earth's tropical forests using networks of highly distributed plots, provides a vision for more integrated and equitable monitoring of Earth's most precious ecosystems.

The collaborative paper is particularly timely as it also highlights the impact Leeds and research partners have made to the understanding of carbon dynamics in tropical forests ahead of the global climate conference COP26, which takes place in Glasgow in November.

Neuroscientists at the University of Massachusetts Amherst have demonstrated in new research that dopamine plays a key role in how songbirds learn complex new sounds.

Published in the Journal of Neuroscience, the finding that dopamine drives plasticity in the auditory pallium of zebra finches lays new groundwork for advancing the understanding of the functions of this neurotransmitter in an area of the brain that encodes complex stimuli.

"People associate dopamine with reward and pleasure," says lead author Matheus Macedo-Lima, who performed the research in the lab of senior author Luke Remage-Healey as a Ph.D. student in UMass Amherst's Neuroscience and Behavior graduate program. "It's a very well-known concept that dopamine is involved in learning. But the knowledge about dopamine in areas related to sensory processing in the brain is limited. We wanted to understand whether dopamine was playing a role in how this brain region learns new sounds or changes with sounds."

Studying vocal learning in songbirds provides insight into how spoken language is learned, adds behavioral neuroscientist Remage-Healey, professor of psychological and brain sciences. "It's not just the songbird that comes up with this strategy of binding sounds and meaning using dopamine. There's something parallel here that we ¬- as humans - are interested in."

The research team conducted a range of experiments in vitro and in vivo, poking neurons under the microscope and in the brains of live birds that were watching videos and hearing sounds. Ultimately, the scientists obtained anatomical, behavioral and physiological evidence to support their hypothesis about the role of dopamine.

Using antibodies, the researchers showed that dopamine receptors are present in many types of neurons in the songbird auditory brain ¬- they can be inhibitory or excitatory and may also contain an enzyme that produces estrogens. "Dr. Remage-Healey's research has shown that in the auditory brain of songbirds of both sexes, neurons produce estrogen in social situations, like when listening to birdsong or seeing another bird. We think that dopamine and estrogens might be working together in the sound learning process, but this work focused on dopamine because there was still so much we didn't know about how dopamine affected the songbird brain," explains Macedo-Lima, now a postdoctoral associate at the University of Maryland.

Macedo-Lima developed a test, similar to the well-known Pavlov's dog experiment, in which the birds sat alone in a chamber and were presented with a random sound followed immediately by a silent video of other birds. "We wanted to focus on the association between a meaningless sound - a tone - and the behaviorally relevant thing, which is another bird on video," he says.

The researchers looked at the birds' auditory brain regions after this sound-video pairing, using a gene marker known to be expressed when a neuron goes through change or plasticity. "We found this very interesting increase in this gene expression in the left hemisphere, the ventral part of the auditory region, in dopamine receptor-expressing neurons, reflecting the learning process, and paralleling human brain lateralization for speech learning," Macedo-Lima says.

To show the effect of dopamine on the basic signaling of neurons, the researchers used a whole cell patch clamp technique, controlling and measuring the currents the neurons received. They found in a dish that dopamine activation decreases inhibition and increases excitation.

"This one modulator is tuning the system in a way that ramps down the stop signals and ramps up the go signals," Remage-Healey explains. "That's a simple yet powerful control mechanism for how animals are potentially encoding sound. It's a neurochemical lever that can change how stimuli are registered and passed on in this part of the brain."

The team then painlessly probed the brain cells of live birds. "What happened when we delivered dopamine was exactly as we were predicting from the whole cell data," Macedo-Lima says. "We saw that inhibitory neurons fired less when we delivered the dopamine agonist, while the excitatory neurons fired more."

The same effect occurred when the birds were played birdsong from other songbirds - the excitatory neurons responded more and the inhibitory neurons responded less when dopamine activation occurred. "We were happy to replicate what we saw in a dish in a live animal listening to actual relevant sounds," Macedo-Lima says.

Dopamine activation also made these neurons unable to adapt to new songs presented to the animal, which strongly corroborates the hypothesis of dopamine's role in sensory learning. "We currently don't know how dopamine affects sensory learning in most animals," Macedo-Lima says, "but this research gives many clues about how this mechanism could work across vertebrates that need to learn complex sounds, such as humans."

For decades, people have wondered why pelagic red crabs--also called tuna crabs--sometimes wash ashore in the millions on the West Coast of the United States. New research shows that atypical currents, rather than abnormal temperatures, likely bring them up from their home range off Baja California.

Alongside the discovery, the scientists also created a seawater flow index that could help researchers and managers detect abnormal current years.

The new study, published July 1 in Limnology and Oceanography, began after lead author Megan Cimino biked past a pelagic red crab stranding on her way to her office in Monterey in 2018. Cimino, a biological oceanographer at the National Oceanic and Atmospheric Administration (NOAA) and UC Santa Cruz through the Institute of Marine Sciences Fisheries Collaborative Program, had witnessed a different stranding near where she grew up in Southern California a few years prior.

"At that time, I had no clue what a red crab was, what was going on, why they would be there," she said. "But it was very clear something different was going on in the ocean--something unusual."

She brought the question to her colleagues, and the lab decided to dive into the mechanism behind the seemingly random appearances.

The group spent months compiling data about the crabs and their recorded range. They scoured oceanographic research surveys, video data from remotely operated vehicles, citizen science programs, and even online media, such as Twitter.

Integrating the different data types proved challenging, but eventually the team had a clear idea of the species' range and strandings from 1950 to 2019.

Comparing these data with ocean conditions like temperature and current movements, the scientists found that the appearance of red crabs outside of their normal range correlated with the amount of seawater flowing from Baja California to central California. The finding supports strong currents as the key indicator for the presence of the crabs over the other major hypothesis--that warm water brought by marine heatwaves and El Niño events causes the appearances.

To study the currents, the researchers used a regional ocean model of the California Current System, developed by researchers in the UC Santa Cruz ocean modeling group.

"What you're doing is putting a tracer--you could think of it like a dye--into a particular part of the ocean and then running the model backwards in time to see where that came from," said Michael Jacox, a physical oceanographer with dual affiliation with NOAA and UC Santa Cruz.

Based on those tracer experiments, the team created the "southern source water index" (SSWI), which shows how much water off the central California coast comes from south of the U.S.-Mexico border.

"It's that pathway of water that brings up some of these unusual species," said Ryan Rykaczewski, a fisheries oceanographer at NOAA and the University of Hawai'i at Mānoa. "It's not just the pelagic red crabs, even though those might be the most conspicuous species that we see on the coast."

The red crabs draw the public's interest and serve as an important food source for lots of other species. These factors made them a good study subject, but they're not the only thing brought up by currents. They represent a larger phenomenon that researchers can use the SSWI to better understand.

"The index could be used as a kind of early warning system about what the ocean state is that year and whether we're going to expect southern species in northern regions," said Cimino. "That can help us plan and manage and give expectations for bycatch or different fisheries."

As climate change increases variability in ocean conditions, the locations of species will begin to shift. Knowing where to look for particular organisms helps researchers make more accurate observations and population estimates.

"We can go back and look at that source water index and use that perhaps as a predictive tool of how the composition of coastal species is going to change," said Rykaczewski. "And that might help us with ecosystem management."

The way currents shift is an often-overlooked piece of the puzzle when it comes to understanding climate change. Scientists are now in the process of testing whether the southern source water index is sensitive to it.

"We think a lot about the changes in things like temperature and oxygen, but changes in the contribution of waters from different locations in the broader North Pacific is also really important for understanding climate change," said Rykaczewski.

The movement of pelagic red crabs provides just one example of the practical applications of such studies.

"I think it's really, really important that when we think about climate change, we don't just think about 'warm temperature equals some response', and we really try to dig into the mechanisms," said Jacox.

With the case study of red crabs and the creation of the southern source water index, researchers now have another tool for doing just that.

In cancer research, it's a common goal to find something about cancer cells -- some sort of molecule -- that drives their ability to survive, and determine if that molecule could be inhibited with a drug, halting tumor growth. Even better: The molecule isn't present in healthy cells, so they remain untouched by the new therapy.

Plenty of progress has been made in this approach, known as molecular targeted cancer therapy. Some current cancer therapeutics inhibit enzymes that become overactive, allowing cells to proliferate, spread and survive beyond their norm. The challenge is that many known cancer-driving molecules are "undruggable," meaning their type, shape or location prohibit drugs from binding to them.

University of California San Diego School of Medicine researchers are now exploring the therapeutic potential of RNA-binding proteins, a relatively untapped family of cancer-driving molecules. After genes (DNA) are transcribed into RNA, these proteins provide an extra layer of cellular control, determining which RNA copies get translated into other proteins and which don't. Like many molecular systems that govern cell growth, RNA-binding proteins can contribute to tumor development when they malfunction.

In their latest study, publishing July 2, 2021 in Molecular Cell, the UC San Diego School of Medicine team discovered in human cells and mouse models that RNA-binding proteins represent a new class of drug targets for cancers, including triple-negative breast cancer, a particularly difficult-to-treat cancer because it lacks most other molecular drug targets.

One RNA-binding protein in particular stood out: YTHDF2. When the researchers genetically removed YTHDF2 from human triple-negative breast tumors transplanted into mice, the tumors shrank approximately 10-fold in volume.

"We're excited that RNA-binding proteins look like they could be new class of drug targets for cancer," said senior author Gene Yeo, PhD, professor of cellular and molecular medicine at UC San Diego School of Medicine. "We're not yet sure how easily druggable they are in this context, but we've built a solid framework to begin exploring them."

Yeo led the study with Jaclyn Einstein, PhD, a graduate student in his lab. Einstein will join a startup company spun out from the lab to explore YTHDF2's druggability.

Yeo's team has long studied the role of RNA-binding proteins in a number of other diseases. In 2016, for example, they discovered that mutations in one such protein contribute to ALS by scrambling crucial cellular messaging systems.

To begin exploring RNA-binding proteins as cancer drug targets, the researchers turned to an old philosophy known as synthetic lethality. In this one-two punch approach, they started with human breast cells engineered to over-produce another well-known cancer-driving molecule, and looked for additional vulnerabilities specific to those cells.

The researchers systematically silenced RNA-binding proteins in these cancer cells one-by-one using the CRISPR gene editing technique. They found 57 RNA-binding proteins that, when inhibited, kill cancer cells with the known hyperactive cancer-driver. The advantage of the synthetic lethal approach is that normal cells, which don't produce that cancer-driving molecule, should be left untouched by the treatment. Of these 57 RNA-binding proteins, YTHDF2 appeared most promising.

Yeo's team also recently developed a new laboratory technique called Surveying Targets by APOBEC-Mediated Profiling (STAMP), which allows them to measure what had previously been largely invisible: how RNA-binding proteins interact with RNA molecules within individual cells.

The researchers used STAMP in this study to get a detailed look at how the various cells that make up a breast tumor behave without YTHDF2. The approach revealed that YTHDF2-deficient cancer cells die by stress-induced apoptosis, a carefully controlled mechanism cells use to destroy themselves. Apoptosis is supposed to shut down malfunctioning cells so tumors don't arise, but it doesn't always work. By removing YTHDF2, they managed to re-activate this cell death signal.

To test how safe it might be to treat cancer by inhibiting YTHDF2, the researchers engineered mice that lack YTHDF2 in every cell of the adult body, not just transplanted breast cancer cells. The mice appeared completely normal -- not only did they not have tumors, there were no changes in body weight or behavior.

"Those otherwise healthy mice tell us that we might expect minimal adverse side effects of potential therapies that work by targeting YTHDF2," Einstein said.

Small children learn language at a pace far faster than teenagers or adults. One explanation for this learning advantage comes not from differences between children and adults, but from the differences in the way that people talk to children and adults.

For the first time, a team of researchers developed a method to experimentally evaluate how parents use what they know about their children's language when they talk to them. They found that parents have extremely precise models of their children's language knowledge, and use these models to tune the language they use when speaking to them. The results are available in an advance online publication of the journal of Psychological Science.

"We have known for years that parents talk to children differently than to other adults in a lot of ways, for example simplifying their speech, reduplicating words and stretching out vowel sounds," said Daniel Yurovsky, assistant professor in psychology at Carnegie Mellon University. "This stuff helps young kids get a toehold into language, but we didn't whether parents change the way they talk as children are acquiring language, giving children language input that is 'just right' for learning the next thing."

Adults tend to speak to children more slowly and at a higher pitch. They also use more exaggerated enunciation, repetition and simplified language structure. Adults also pepper their communication with questions to gauge the child's comprehension. As the child's language fluency increases, the sentence structure and complexity used by adults increases.

Yurovsky likens this to the progression a student follows when learning math in school.

"When you go to school, you start with algebra and then take plane geometry before moving onto calculus," said Yurovsky. "People talk to kids using same kind of structure without thinking about it. They are tracking how much their child knows about language and modifying how they speak so that for children understand them."

Yurovsky and his team sought to understand exactly how caregivers tune their interactions to match their child's speech development. The team developed a game where parents helped their children to pick a specific animal from a set of three, a game that toddlers (aged 15 to 23 months) and their parents play routinely in their daily lives. Half of the animals in the matching game were animals that children typically learn before age 2 (e.g. cat, cow), and the other half were animals that are typically learned later (e.g. peacock, leopard).

The researchers asked 41 child-adult pairs to play the game in a naturalistic setting in the laboratory. They measured the differences in how parents talked about animals they thought their children knew as compared to those they thought their children did not know.

"Parents have an incredibly precise knowledge of their child's language because they have witnessed them grow and learn," said Yurovsky. "These results show that parents leverage their knowledge of their children's language development to fine-tune the linguistic information they provide."

The researchers found that the caregiver used a variety of techniques to convey the 'unknown' animal to the child. The most common approach was to use additional descriptors familiar to the child.

"This [research] approach lets us confirm experimentally ideas that we have developed based on observations of how children and parents engage in the home," said Yurovsky. "We found that parents not only used what they already knew about their children's language knowledge before the study, but also that if they found out they wrong--their child didn't actually know 'leopard' for example-- they changed the way they talked about that animal the next time around."

The study consisted of 36 experimental trials where each animal appeared as a target at least twice in the game. The participants represented a racial composition similar to the United States (56% white, 27% Black and 8% Hispanic).

The results reflect a western parenting perspective as well as caregivers with a higher educational background than is representative in the country. The researchers did not independently measure the children's knowledge of each animal. The results of this study cannot differentiate whether the children learned any new animals while playing the game.

Yurovsky believes the results may have some relevance for researchers working in the field of machine learning.

"These results could help us understand how to think about machine learning language systems," he said. "Right now we train language models by giving them all of the language data we can get our hands on all at once. But we might do better if we could give them the right data at the right time, keeping it at just the right level of complexity that they are ready for."

The muskrat, a stocky brown rodent the size of a Chihuahua - with a tail like a mouse, teeth like a beaver and an exceptional ability to bounce back from rapid die-offs - has lived for thousands of years in one of Earth's largest freshwater deltas, in northeastern Alberta, Canada.

Today, this delta lies within one of the largest swaths of protected land in North America: a national park five times the size of Yellowstone that's home to the planet's biggest herd of free-roaming bison and the last natural nesting ground for the endangered whooping crane. It's also central to the culture and livelihoods of Indigenous peoples, including the Mikisew Cree First Nation, Athabasca Chipewyan First Nation and Métis Local 125.

New research focused on muskrat population dynamics in the Peace-Athabasca Delta, published June 24 in Communications Biology, demonstrates the vulnerability of even this most protected landscape to human-driven changes to water systems and the global climate.

"A little muskrat in the middle of this northern part of Canada is an indicator of human impacts at the local, regional and global level," said Stanford University environmental biologist Elizabeth Hadly, co-principal investigator of the study. "Climate change and dams have changed the ability of this exemplar species - and many plants, animals and people who depend on the same ecosystem - to thrive in this large area."

The research comes on the heels of a draft finding from the United Nations that Canada's Wood Buffalo National Park - the park and World Heritage Site that contains the Peace-Athabasca Delta - is likely in danger from threats related to governance as well as hydropower and oil sands development upstream of the delta. Previous research has implicated climate change as a driver of long-term drying in the delta and hydroelectric dams on the Peace River as a cause of reduced flooding.

"Our results speak to the impacts on the biotic environment of long-term drying - whatever the cause - and this has implications for science and environmental policy," said Stanford hydrologist Steve Gorelick, co-principal investigator of the study and a senior fellow at Stanford Woods Institute for the Environment.

Eruption and die-off

Muskrat (Ondatra zibethicus) populations have always followed a boom-and-bust cycle, with their numbers crashing in dry years and peaking after major floods. But in recent decades the booms - and the area of the delta inhabited by muskrats during wet years - have been shrinking. The authors found the most recent year of net population increase after flooding, 2014, was less productive than any such growth year going back to the 1970s.

While many creatures rely on the dynamic nature of wetlands to survive, muskrats depend heavily on floodwaters, rivers and streams to travel and disperse beyond their natal ponds. "During a big flood, a lot of muskrats will drown. Some will get swept up into trees and stay put," said lead study author Ellen Ward, who worked on the research as a PhD student in Earth system science at Stanford. "But some will stay in the water, either floating or clinging to debris, and get swept along quite far."

As floodwaters recede, the dispersed muskrats enjoy habitat gains that support larger populations. They graze intensively on plants near the shore, strongly influencing plant life in the area and providing prey for fox, lynx, mink and other predators.

Canary in a coal mine

Because muskrat behavior and dispersal are so closely linked to freshwater distribution and abundance, their genetic data offers hard evidence for how changes in the aquatic environment have affected a real population over time. "They're a bit of a canary in a coal mine," said Hadly, the Paul S. and Billie Achilles Professor in Environmental Biology and a senior fellow at Stanford Woods Institute for the Environment.

In one flood year, DNA from a pair of closely related muskrats turned up nearly 25 miles apart, suggesting that the animals can roam or be carried far in search of suitable habitat beyond their place of birth. During dry years, the authors found population size and density decreased while the number of individuals migrating through a given location increased, suggesting overcrowding in remaining patches of habitat drives long and perilous migrations in search of viable territory.

"Our work shows they can travel great distances - far longer than their home range - and that they breed so prolifically that their population bounces back, just not to anything like it was beforehand," said Gorelick, the Cyrus Fisher Tolman Professor in Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth).

Computer simulations and tail tissue

The new estimates derive from a collaborative effort combining computer simulations of freshwater habitat in the delta and muskrat behaviors, along with genetic analysis of 288 muskrat tail tissue samples collected and donated by Indigenous trappers who captured the animals for fur and meat. "Our modeling accounts for all stages of muskrat life: their travels, their diet, their reproduction and the many ways they can and do perish. They can freeze, drown, starve, be eaten or eat each other," Gorelick said.

Both the modeling and the genetic analysis suggest muskrats in the delta today are likely grouped into many smaller populations that, taken as a whole, show a long history of rapid die-offs and what scientists call genetic bottlenecks. "Even when the population increases to the huge sizes that we see in peak years, there is not as much genetic diversity in the population as we would expect," explained co-lead study author Katherine Solari, a postdoctoral research fellow in biology.

According to the authors, no single portion of the delta is most important for muskrat persistence. "You can't just go to one lake and say, 'We're going to protect all the fish and muskrats here,' because it will be completely different next year," Hadly said. "It challenges us to think of how we preserve the dynamism in this landscape in the face of an altered hydrology and climate."

Gorelick also directs the Global Freshwater Initiative at Stanford Woods Institute for the Environment. Hadly is a faculty director of Stanford's Jasper Ridge Biological Preserve, a member of Bio-X and a professor, by courtesy, of Geological Sciences. Co-author Amruta Varudkar worked on this project as a postdoctoral scholar in Stanford's Department of Biology.

New research published in The Journal of Physiology shows that researchers have successfully repurposed two existing medications to reduce the severity of sleep apnoea in people by at least 30 per cent.

Affecting around 1.5 million adults in the UK, sleep apnoea is a condition where the upper airway from the back of the nose to the throat closes repetitively during sleep, restricting oxygen intake and causing people to wake as often as 100 times or more per hour (1).

Those with untreated sleep apnoea are more likely to develop cardiovascular disease, dementia and depression, and are two to four times more likely to crash a car than the general population (2).

Despite almost thirty years of research, there are no approved drug therapies to treat the condition.

Professor Danny Eckert, Principal Research Scientist at NeuRA and Professor and Director of Adelaide Institute for Sleep Health at Flinders University, has brought scientists one step closer by repurposing two existing medications to test their efficacy in people in sleep apnoea.

Previous research showed two classes of medication, reboxetine and butylbromide, were able to keep muscles active during sleep in people without sleep apnoea, and assist their ability to breathe.

By repurposing the medications, researchers used a multitude of recording instruments to measure whether reboxetine and butylbromide could successfully target the main causes of sleep apnoea.

This included balancing the electrical activity of muscles around the airway, preventing the throat from collapsing while people were sleeping, and improving the regulation of carbon dioxide and breathing during sleep.

Results from the study showed these medications did in fact increase the muscle activity around participants' airways, with the drugs reducing the severity of participants' sleep apnoea by up to one third.

Almost everyone we studied had some improvement in sleep apnoea. People's oxygen intake improved, their number of breathing stoppages was a third or more less.

These new findings allow researchers to further refine these types of medications so that they have even greater benefit than what has currently been found.

Commenting on the study, Professor Eckert said:

"We were thrilled because the current treatment options for people with sleep apnoea are limited and can be a painful journey for many," he said. Next, we will look at the effects of these and similar medications over the longer term. We will assess whether we can harness the benefits of one drug without needing to use them both."

"Equally, we will test whether these treatments can be combined with other existing medications to see if we can improve their efficacy even more," he continued.

Until now, the main therapy for sleep apnoea involves wearing a mask to bed, or Continuous Positive Airway Pressure Therapy (CPAP), which benefits millions. However, many people find it uncomfortable and half the people that try it find it hard to tolerate.

Plus, the efficacy of second line therapies, such as mouthguards fitted by dentists, can be unpredictable and expensive.

A surprising study by UNSW on the behaviour of unrelated lizards in very different parts of the world has demonstrated how evolution can lead to different species learning the same skills.

The study in Ecology Letters documents how the Anolis lizard species in the Caribbean, and the Draco lizard species in Southeast Asia, have solved the challenge of communicating with one another to defend territories and attract mates.

It found males from both species perform elaborate head bob and push up displays, and rapidly extend and retract their often large and conspicuously coloured dewlap, or throat fan, specifically in habitats with lots of wind-blown vegetation or low light.

The lizards occupy the same range of rainforest and grassland habitats, and therefore face the same problems when it comes to communicating to a potential mate or enemy in visually 'noisy' environments.

Remarkably, they have evolved the same strategy to cope with the same selection problems, lead author Dr Terry Ord from the Evolution & Ecology Research Centre at the UNSW School of Biological, Earth and Environmental Sciences says.

According to his research, this scenario of two unrelated lizards displaying similar behaviour shows that natural selection directs evolution towards the same common set of adaptive outcomes over and over again.

"The surprise is that lizards in both groups have evolved remarkably similar displays for communication, but they also tailor the production of those displays according to the prevailing conditions experienced at the time of display," Dr Ord says.

"That is, increasing the speed or the length of time they spend displaying the movements as the viewing conditions deteriorate.

"Really there should be essentially innumerable ways these lizards could have adapted their displays to remain effective, and there is strong evolutionary predictions that would lead us to expect this as well."

Dr Ord says what this study shows is that natural selection driving similarities between different species.

Formally, this is known as convergent evolution -- the independent origin of similar adaptations, he says.

"It seemed that these types of convergent, common adaptations are outcomes that would only really occur among species that are closely-related in some capacity," he says.

"The reason for this is a bit complicated and it rests on the fact that adaptations build on characteristics that a species already possesses."

"So, the longer species have evolved independently of each other, the less likely they would evolve the same adaptive solutions if they were exposed to the same change in the environment."

But what this study highlights, he says, is what many evolutionary ecologists have argued - that natural selection is an extremely powerful process that can override the "baggage" of past history to produce the same adaptations.

"So if arm-waving is the most effective solution to some change in the environment, then natural selection would ultimately lead to its evolution rather than a more subtle (less effective) modification to an existing vocal call," he says.

"Evolutionary biologists are excited about convergent evolution because it gives us multiple examples of the same adaptation evolving time and time again in very different animals.?

"So it tells us what the challenges are faced by these animals and how they have solved it in terms of evolutionary adaptation."

The study documents this independent evolution of common communication strategies amongst groups that have evolved separately from each other for hundreds of millions of years.

Dr Ord says the striking similarities in communication strategies for maintaining an effective communication system in noisy conditions has evolved in various forms in many insects, fish, frogs, birds and mammals.

"For example, increasing the volume of calls when there's lots of acoustic background noise, or extending the length of those calls or even vibrational signals by spiders and such," Dr Ord says .

"The fact that many other groups of animals have also evolved thesesame adaptive strategies is even more extraordinary."

Read the study in Ecology Letters.

Researchers could not confirm that a feature that supposedly signals the presence of Majorana bound states - the unusual quasiparticles that may become the cornerstone of topological quantum computing - was in fact due to elusive Majorana particles, in full-shell semiconductor/superconductor nanowires. Rather, this feature, known as zero bias conductance peak, can arise from another quantum phenomenon in these hybrid nanowire structures, the authors say. In recent years, intense research has been conducted on nanowire-based semiconductor-superconductor hybrid systems because predictions suggest that a topological superconductor state with Majorana zero modes (MZMs) can be engineered from them. Even though several experiments in such platforms have reported on signatures compatible with MZMs, the interpretation that they demonstrate the presence of Majorana particles has been challenged; studies have shown that a quantum state known as the Andreev bound state - which can appear inside the superconducting gap of such structures - can mimic MZMs. A 2020 study in Science introduced an alternative platform for realizing topological superconductivity and thus for finding Majorana bound states. It proposed Majorana modes could be found in a semiconducting nanowire fully wrapped by a superconducting shell. Here, Marco Valentini and colleagues report experiments with such nanowire systems. Instead of confirming MZMs as they had hoped, however, the authors found that the zero-bias peaks they observed were a product of Andreev levels in their system. According to Valentini et al., the findings did help to constrain crucial experimental parameters for evaluating topological superconductivity in this system.