Culture

BOSTON - Studies with a popular laboratory model, the nematode Caenorhabditis elegans, have revealed a possible therapeutic avenue for a rare but deadly condition in which children are born without the ability to make molybdenum cofactor (Moco) on their own.

Though little known, Moco is essential for life and so far it has proven extremely difficult to stably isolate this compound in the laboratory, preventing its use as a therapeutic supplement. This new work, which appears in Genes & Development, reveals that nematodes genetically engineered to be Moco-deficient can take up Moco that is attached to several types of proteins. This suggests that such protein-Moco complexes could be used as a treatment for Moco deficiency in people.

Children born with mutations that make them unable to synthesize Moco suffer lethal neurological and developmental defects. Providing them supplemental Moco might reverse these devastating symptoms. This work suggests a potential new route for delivering this essential cofactor.

The researchers carried out studies in C. elegans that were engineered to be deficient in their ability to make Moco. Like humans, C. elegans deficient in Moco die very early in development. Nematodes, however, can also ingest Moco from their diet - a process that is similar to supplementation, as with vitamins. The researchers found that the worms could take in Moco as a range of purified Moco-protein complexes. These included complexes with proteins from bacteria, bread mold, green algae and cow's milk. Ingesting these complexes saved the Moco-deficient worms.

Further, they demonstrated that the Moco-protein complexes were very stable, suggesting it is possible to produce them as a supplement for children born with Moco deficiency.

"We tested four proteins and all four were restorative in our nematode model. That's very encouraging," says Kurt Warnhoff, PhD, an investigator in the Department of Molecular Biology at Massachusetts General Hospital (MGH) and the paper's co-lead author. "We do not want to overstate our findings, especially as they relate to patients, but we are extremely excited about the therapeutic and fundamental implications of this work."

Anthropologist Caleb Everett and former student Sihan Chen used a novel data analysis of thousands of languages, in addition to studying a unique subset of celebrities, to reveal how a soft food diet--contrasted with the diet of hunter-gatherers--is restructuring dentition and changing how people speak.

Their findings, published in Scientific Reports, counter the longstanding belief within the field that maintains that languages are susceptible to the same pressures and so are essentially immune to external factors.

"Our results represent the most compelling evidence to date that languages are very much affected by external factors that differ across populations," said Everett, professor and chair of the Department of Anthropology at the University of Miami.

"Languages change--we can see this in any language--but the thinking has long been that all languages have the same pressures, that there is no difference across populations that make some people more prone than others to use certain sounds," he noted.

Everett said that in the past decade, he and others have produced new evidence suggesting that there might be other factors that are likely to influence speech patterns. He highlighted a "highly publicized" paper published in Science Magazine two years ago, while noting that in addition to this new research, he has spent several years studying how environmental factors such as ambient aridity--extreme dryness--shift speech patterns by reducing vowel usage, which requires more effort to pronounce.

He credited the linguistic acumen and diligence of Chen, his former student now pursuing a doctorate in cognitive science, with advancing the dentition study.

"Sihan took a linguistics course and fell in love with the study of languages. An exceptionally bright student, he demonstrated an incredible aptitude for phonetics and transcribing precisely what's going on in people's mouths as they speak," said Everett, who holds a secondary appointment in psychology.

Yet changes in language take hundreds of years to emerge, Everett explained. So, to obtain a quicker accounting, the two examined the speech patterns of 10 celebrities--including British singing phenom Freddie Mercury and former Olympic swimmer Michael Phelps--a research subset that offered a spectrum of dentition variance.

Mercury's four additional teeth--a hereditary dental condition--caused a famously unusual overbite. (Mercury was embarrassed by the protrusion but resisted any oral surgery believing the anomaly contributed to his exceptional four-octave vocal range.) And Phelps also presented a unique alignment issue.

Everett recognized that, from a research standpoint, utilizing the data from the 10 celebrities was "a bit tricky."

"Freddie Mercury's bite isn't the way that it is because of his diet; there are obviously genetic factors here," he said. "Yet the data from the celebrities provides us insight in real time and contributes to understanding this story of human language that is changing over time."

Additionally, using the publicly accessible videos created a research trail that allowed others to check the data and transcriptions, Everett noted, adding, "the pattern was a lot clearer than I would have expected."

In meticulously transcribing the online videos of the celebrities, Chen focused on establishing the ratio of labiodental sounds such as "f" and "v"--sounds common today but that rarely existed until soft diets became pervasive. Mercury in particular was known to pronounce these particular sounds with abnormal frequency due to his dental abnormality.

"He was really an extreme because he produced these labiodental sounds all over the place even when they shouldn't be there," Everett said. "On the other end of the spectrum Michael Phelps is kind of doing the reverse."

In studying thousands of languages, the researchers established two linguistic camps--hunter-gatherers, whose diets have changed little and whose mouths get a lot more wear, and non-hunter-gatherers. Everett's extensive previous research on indigenous peoples in the Amazon--whose diets remain akin to those of hunter-gatherers--aided the study.

Previous research on the subject has examined whether languages have this sound, or they don't. Everett and Chen delved deeper, analyzing the ratios of frequency between the two research groups.

"We basically adopted a whole new series of methods to test this and we found extensive support for it," he said, yet emphasized that the findings show correlational, not causal, links between diet, dentition, and speech patterns.

"These pressures are subtle and operate over hundreds and thousands of years, so it's a hard thing to know for sure," he said. "But what we see are these probabilistic tendencies in the worlds 7,000 languages.

"These new findings provide a better understanding of why languages--which are a key distinguishing characteristic for anthropologists and a key aspect of being human--take the shape they do, how they diverge, and what factors impact their evolvement," Everett said.

DARIEN, IL - Editors of the Journal of Clinical Sleep Medicine have identified some of the most significant articles in the publication's history, publishing new commentaries on them in a special 15th anniversary collection. The 15 commentaries from associate editors and members of the journal's editorial board describe the impact of the selected articles both at the time of their publication and today.

"The collection highlights some of the most influential publications in clinical sleep research over the past 15 years," JCSM Editor-in-Chief Dr. Nany Collop said. "These studies underscore the remarkable breadth of our field and display the intellectual curiosity and scientific rigor of talented sleep researchers."

First published by the American Academy of Sleep Medicine in 2005, JCSM has grown significantly from its first year, when 22 original articles were published. In 2020 the monthly journal published more than 200 scientific investigations and case reports. The 15th anniversary collection highlights peer-reviewed, original research papers on sleep disorders such as obstructive sleep apnea, insomnia, narcolepsy, and restless legs syndrome. The selected papers also cover other wide-ranging topics including opioids, school start times, caffeine, melatonin, and the impact of binge-watching on sleep.

The most highly cited article is on sleep deprivation: "Behavioral and physiological consequences of sleep restriction," written by Banks and Dinges in 2007. In the commentary, AASM Past President Dr. Nathaniel Watson and sleep scientist Hans Van Dongen, who has a doctorate in chronobiology and sleep, write that this landmark review "crystallized the problem of short sleep from basic science to epidemiology."

Collop and the journal's founding editor, Dr. Stuart Quan, assessed the most-cited and viewed articles, which associate editors helped narrow to the final selection of 15 studies. An expert on each manuscript topic was invited to prepare a commentary on the paper, describing its impact and influence since its original publication.

A clinical trial involving COVID-19 patients hospitalized at UT Health San Antonio and University Health, among roughly 100 sites globally, found that a combination of the drugs baricitinib and remdesivir reduced time to recovery, according to results published Dec. 11 in the New England Journal of Medicine. Six researchers from UT Health San Antonio and University Health are coauthors of the publication because of the San Antonio site's sizable patient enrollment in the trial.

The Adaptive COVID-19 Treatment Trial 2 (ACTT-2), which compared the combination therapy versus remdesivir paired with an inactive placebo in hospitalized COVID-19 patients, was supported by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health.

Significantly, patients on high oxygen by nasal canula or receiving breathing assistance with a mask when they were enrolled in the study had a time to recovery of 10 days with combination treatment versus 18 days with remdesivir and placebo.

Investigators also saw a difference in patient survival. The 28-day death rate was 5.1% in the combination therapy group and 7.8% in the remdesivir placebo group.

"We are making progress in the treatment of COVID-19," said principal investigator Thomas Patterson, MD, professor and chief of infectious diseases in the Joe R. and Teresa Lozano Long School of Medicine at UT Health San Antonio. "Remdesivir markedly improved recovery of critically ill patients in the first ACTT study, and baricitinib further helped patients in this second study."

Remdesivir is a direct-acting antiviral drug, whereas baricitinib is an anti-inflammatory medicine.

"I think this combination is good for a couple of reasons," Dr. Patterson said. "Baricitinib, as opposed to other anti-inflammatory drugs, has activity itself against the virus. Second, it is a pretty specific inhibitor of the inflammation."

Baricitinib is approved for the treatment of patients with active rheumatoid arthritis. The U.S. Food and Drug Administration issued an emergency use authorization on Nov. 19, 2020, for baricitinib, in combination with remdesivir, for the treatment of suspected or laboratory-confirmed COVID-19 in hospitalized adults and pediatric patients 2 years of age or older requiring supplemental oxygen, invasive mechanical ventilation or extracorporeal membrane oxygenation.

"We do these clinical trials to accomplish a goal, and that is to save lives," Dr. Patterson said. "At the beginning of the pandemic, we were losing a lot of patients who we are now saving, so we are getting closer to our goal."

Certain snakes have evolved a unique genetic trick to avoid being eaten by venomous snakes, according to University of Queensland research.

Associate Professor Bryan Fry from UQ's Toxin Evolution Lab said the technique worked in a manner similar to the way two sides of a magnet repel each other.

"The target of snake venom neurotoxins is a strongly negatively charged nerve receptor," Dr Fry said.

"This has caused neurotoxins to evolve with positively charged surfaces, thereby guiding them to the neurological target to produce paralysis.

"But some snakes have evolved to replace a negatively charged amino acid on their receptor with a positively charged one, meaning the neurotoxin is repelled.

"It's an inventive genetic mutation and it's been completely missed until now.

"We've shown this trait has evolved at least 10 times in different species of snakes."

The researchers found that the Burmese python - a slow-moving terrestrial species vulnerable to predation by cobras - is extremely neurotoxin resistant.

"Similarly, the South African mole snake, another slow-moving snake vulnerable to cobras, is also extremely resistant," Dr Fry said.

"But Asian pythons which live in trees as babies, and Australian pythons which do not live alongside neurotoxic snake-eating snake, do not have this resistance.

"We've long known that some species - like the mongoose - are resistant to snake venom through a mutation that physically blocks neurotoxins by having a branch-like structure sticking out of the receptor, but this is the first time the magnet-like effect has been observed."

"It has also evolved in venomous snakes to be resistant to their own neurotoxins on at least two occasions."

The discovery was made after the establishment of UQ's new $2 million biomolecular interaction facility, the Australian Biomolecular Interaction Facility (ABIF).

"There's some incredible technology at the ABIF allowing us to screen thousands of samples a day," Dr Fry said.

"That facility means we can do the kinds of tests that would have just been science fiction before, they would have been completely impossible."

"The lotus roots may break, but the fiber remains joined" is an old Chinese saying that reflects the unique structure and mechanical properties of the lotus fiber. The outstanding mechanical properties of lotus fibers can be attributed to their unique spiral structure, which provides an attractive model for biomimetic design of artificial fibers.

In a new study published in Nano Letters, a team led by Prof. YU Shuhong from the University of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS) reported a bio-inspired lotus-fiber-mimetic spiral structure bacterial cellulose (BC) hydrogel fiber with high strength, high toughness, excellent biocompatibility, good stretchability, and high energy dissipation.

Unlike polymer-based hydrogel, the newly designed biomimetic hydrogel fiber (BHF) is based on the BC hydrogel with 3D cellulose nanofiber networks produced by bacteria. The cellulose nanofibers provide the reversible hydrogen bonding network that results in unique mechanical properties.

The researchers applied a constant tangential force to the pretreated BC hydrogel along the cross-sectional direction. Then, the two sides of the hydrogel were subjected to opposite tangential forces, and local plastic deformation occurred.

The hydrogen bonds in the 3D network of cellulose nanofibers were broken by the tangential force, causing the hydrogel strip to twist spirally and the network to slip and deform. When the tangential force was removed, the hydrogen bonds reformed between the nanofibers, and the spiral structure of the fiber was fixed.

Benefited from lotus-fiber-mimetic spiral structure, the toughness of BHF can reach ?116.3 MJ m-3, which is more than nine times higher than those of non-spiralized BC hydrogel fiber. Besides, once the BHF is stretched, it is nearly non-resilient.

Combining outstanding mechanical properties with excellent biocompatibility derived from BC, BHF is a promising hydrogel fiber for biomedical material, especially for surgical suture, a commonly used structural biomedical material for wound repair.

Compared with commercial surgical suture with higher modulus, the BHF has similar modulus and strength to soft tissue, like skin. The outstanding stretchability and energy dissipation of BHF allow it to absorb energy from the tissue deformation around a wound and effectively protect the wound from rupture, which makes BHF an ideal surgical suture.

What's more, the porous structure of BHF also allows it to adsorb functional small molecules, such as antibiotics or anti-inflammatory compounds, and sustainably release them on wounds. With an appropriate design, BHF would be a powerful platform for many medical applications.

URBANA, Ill. ¬- Illinois residents value efforts to reduce watershed pollution, and they are willing to pay for environmental improvements, according to a new study from agricultural economists at the University of Illinois.

Nutrient runoff from agricultural production is a major cause of pollution in the Mississippi River Basin and contributes to hypoxia - limited oxygen to support sea life in the Gulf of Mexico. The U.S. Environmental Protection Agency (EPA) set up action plans to reduce pollution in 12 midwestern states and reduce transmissions of nitrate-nitrogen and phosphorus by 45% in 2040.

Illinois agencies have established the Illinois Nutrient Loss Reduction Strategy (INLRS) to address those issues, relying on voluntary efforts as well as policy measures such as state subsidies. Understanding the level of support from local residents can help inform nutrient reduction initiatives.

"We know water quality is important and water pollution has costs in terms of both health and economic damages," says Bryan Parthum, lead author on the paper. Parthum was a graduate student in the Department of Agricultural and Consumer Economics at U of I when the study was conducted; he now works as an economist in the EPA Office of Policy.

"We wanted to find out how much people care about local water quality, fish populations, and algal blooms, and how much they care about meeting EPA targets which benefit the Gulf of Mexico," Parthum explains.

The researchers surveyed respondents in the Upper Sangamon River Watershed in Central Illinois, an INLRS priority watershed due to high levels of nitrate and phosphorus transmission.

Respondents completed a choice experiment survey containing different scenarios that described water quality improvements such as reducing algal bloom, increasing the overall fish population and number of fish species, and meeting EPA targets for reducing nutrient pollution.

The scenarios also included information about proximity to the respondent, and a range of potential costs associated with those measures.

The researchers could then estimate how much people were willing to pay for the various improvements. For example, a 50% reduction of algal blooms in the watershed would, on average, be worth $32 annually per household.

"And if you combine reduced algal blooms, improved fish population and diversity, and meeting the nutrient targets, that whole bundle is worth $85 per household," Parthum says.

Amy Ando, professor of agricultural and consumer economics at U of I and co-author of the paper, notes the Sangamon River isn't known as a tourist destination, yet still holds value for recreational purposes. Close to 50% of respondents indicated using the river for fishing, boating, or hiking at least once a year.

"The actions taken by the INLRS, if successful, will reduce hypoxia in the Gulf of Mexico, and people in Illinois care about doing that. But the strategies also have value for improvements in fish populations and reductions in algal blooms right here at home, so people get some local benefits as well," Ando notes.

The survey included 373 respondents, about evenly divided between urban and rural residents. The researchers observed no difference in attitudes towards water policy measures among the two groups.

"There may be a perception that urban residents care more about environmental improvements. But we found both urban and rural groups expressed value for improved fish populations and water quality in the rivers that run through where they live," Ando says.

Recently there has been a reemergence of interest in optical computing platforms for artificial intelligence-related applications. Optics/photonics is ideally suited for realizing neural network models because of the high speed, large bandwidth and high interconnectivity of optical information processing. Introduced by UCLA researchers, Diffractive Deep Neural Networks (D2NNs) constitute such an optical computing framework, comprising successive transmissive and/or reflective diffractive surfaces that can process input information through light-matter interaction. These surfaces are designed using standard deep learning techniques in a computer, which are then fabricated and assembled to build a physical optical network. Through experiments performed at terahertz wavelengths, the capability of D2NNs in classifying objects all-optically was demonstrated. In addition to object classification, the success of D2NNs in performing miscellaneous optical design and computation tasks, including e.g., spectral filtering, spectral information encoding, and optical pulse shaping have also been demonstrated.

In their latest paper published in Light: Science & Applications, UCLA team reports a leapfrog advance in D2NN-based image classification accuracy through ensemble learning. The key ingredient behind the success of their approach can be intuitively understood through the experiment of Sir Francis Galton (1822-1911), an English philosopher and statistician, who, while visiting a livestock fair, asked the participants to guess the weight of an ox. None of the hundreds of participants succeeded in guessing the weight. But to his astonishment, Galton found that the median of all the guesses came quite close - 1207 pounds, and was accurate within 1% of the true weight of 1198 pounds. This experiment reveals the power of combining many predictions in order to obtain a much more accurate prediction. Ensemble learning manifests this idea in machine learning, where an improved predictive performance is attained by combining multiple models.

In their scheme, UCLA researchers reported an ensemble formed by multiple D2NNs operating in parallel, each of which is individually trained and diversified by optically filtering their inputs using a variety of filters. 1252 D2NNs, uniquely designed in this manner, formed the initial pool of networks, which was then pruned using an iterative pruning algorithm, so that the resulting physical ensemble is not prohibitively large. The final prediction comes from a weighted average of the decisions from all the constituent D2NNs in an ensemble. The researchers evaluated the performance of the resulting D2NN ensembles on CIFAR-10 image dataset, which contains 60,000 natural images categorized in 10 classes and is an extensively used dataset for benchmarking various machine learning algorithms. Simulations of their designed ensemble systems revealed that diffractive optical networks can significantly benefit from the 'wisdom of the crowd'. For example, with an ensemble of 14 individually trained D2NNs, the researchers achieved 61.21% blind testing accuracy on CIFAR-10 dataset, which is ~16% higher than the average accuracy of the individual constituent D2NNs.

This research is led by Professor Aydogan Ozcan from the Electrical and Computer Engineering Department at UCLA, USA. This significantly improved inference and generalization performance achieved by D2NN ensembles marks a major advancement in closing the gap between optical neural networks and their digital counterparts. Together with the advances in the fabrication and assembly of nanoscale optical systems, the presented framework bears the promise for miniaturized, ultrafast machine learning solutions for a variety of applications, for example, all-optical object classification, diffraction-based optical computing hardware, and computational imaging tasks.

Astronomers using images from Kitt Peak National Observatory and Cerro Tololo Inter-American Observatory have created the largest ever map of the sky, comprising over a billion galaxies. The ninth and final data release from the ambitious DESI Legacy Imaging Surveys sets the stage for a ground-breaking 5-year survey with the Dark Energy Spectroscopic Instrument (DESI), which aims to provide new insights into the nature of dark energy. The map was released today at the January 2021 meeting of the American Astronomical Society.

For millennia humans have used maps to understand and navigate our world and put ourselves in context: we rely on maps to show us where we are, where we came from, and where we're going. Astronomical maps continue this tradition on a vast scale. They locate us within the cosmos and tell the story of the history and fate of the Universe: it will expand forever, the expansion currently accelerating because of an unknown quantity called dark energy. Astronomical maps may help explain what this dark energy is and why it exists.

Capitalizing on that possibility requires an unprecedented map -- one that charts faint galaxies more uniformly and over a larger area of sky than ever before. To meet that challenge, astronomers have now created a new two-dimensional map of the sky that is the largest ever made in terms of sky coverage, sensitivity, and the total number of galaxies mapped.

From among the more than 1 billion galaxies in the map, astronomers will select tens of millions of galaxies for further study with the Dark Energy Spectroscopic Instrument (DESI), in order to construct the largest 3D map ever attempted. The results from the DESI survey, which will be carried out at Kitt Peak National Observatory (KPNO), a Program of National Science Foundation's NOIRLab, will ultimately provide new insights into the nature of dark energy.

The new map is the result of the DESI Legacy Imaging Surveys, an ambitious 6-year effort involving 1405 observing nights at three telescopes, years of data from a space telescope, 150 observers and 50 other researchers from around the world, 1 petabyte of data (1000 trillion bytes), and 100 million CPU hours on one of the world's most powerful computers. The images were taken at KPNO and Cerro Tololo Inter-American Observatory (CTIO), also a Program of NOIRLab, and supplemented by images from NASA's Wide-field Infrared Survey Explorer (WISE) mission. The data were reduced at Berkeley Lab's National Energy Research Scientific Computing Center (NERSC).

The map covers half of the sky, digitally sprawling over 10 trillion pixels, which is equivalent to a mosaic of 833,000 high-resolution smartphone photos, and is one of the most uniform, deep surveys of the sky ever undertaken. "This is the biggest map by almost any measure," said David Schlegel, co-project scientist for DESI who also co-led the imaging project. Schlegel is an astrophysicist at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), the lead institution for the international DESI collaboration.

Arjun Dey, the DESI Project Scientist for NOIRLab, co-led two of the three imaging surveys, serving as the lead scientist for the Mayall z-band Legacy Survey (MzLS) observed by the Mosaic3 camera on the Nicholas U. Mayall 4-meter Telescope at KPNO, and as co-lead scientist with Schlegel for the Dark Energy Camera Legacy Survey (DECaLS) on DECam on the Víctor M. Blanco 4-meter Telescope at CTIO in Chile.

The third survey is the Beijing-Arizona Sky Survey (BASS) observed by the 90Prime camera on the Bok 2.3-meter Telescope, which is owned and operated by the University of Arizona and located at KPNO.

The collective effort of the three surveys, Dey said, "was one of the most uniform, deep surveys of the sky that has ever been undertaken. It was really exciting to participate."

The DESI collaboration will select 35 million galaxies and 2.4 million quasars in the map -- some as far away as 12 billion light-years -- as targets for the DESI survey. Over five years of operations, DESI will create a giant 3D map of the Universe by measuring the galaxies' distances and the rate at which they are moving away from us. To make these measurements, DESI will take the fingerprint of a galaxy by measuring its spectrum: the light from individual galaxies will be dispersed into fine bands of color.

Capturing the spectra of so many galaxies so quickly requires a high degree of automation. DESI -- equipped with an array of 5000 swiveling, automated robots, each toting a thin fiber-optic cable that can point at individual galaxies -- is designed to measure the spectra of 5000 galaxies at a time. The results will ultimately provide new insights into the mysterious dark energy that is driving the Universe's accelerating expansion.

The quest to understand the nature of dark energy has led to major opportunities for discovery in other areas of astronomy. Adam Bolton, Director of NOIRLab's Community Science and Data Center, explained: "To solve some of the biggest mysteries in fundamental physics today, we are driven to create huge digital databases of stars and galaxies, which in turn enable a new data-mining approach to making additional astronomical discoveries."

With the completion of the DESI Legacy Imaging Surveys, all data have been released to the scientific community and the public. This final data release, known as Data Release 9, has been preceded by eight other intermediate data releases.

NOIRLab will host these data products in the Astro Data Archive, from the original images taken at the telescopes to the catalogs that report the positions and other properties of stars and galaxies. Astro Data Lab also serves the catalogs as databases, which astronomers can easily analyze using the Astro Data Lab tools and services, and cross-match them with other datasets, giving more opportunities for discovery. In addition, Astro Data Lab provides astronomers with example scientific applications and tutorials to assist with their research. The DESI Legacy Imaging Surveys data have already been used for many other research projects [1] [2], including citizen science efforts that utilize the wisdom of crowds [3].

There are many components to aging, both mental and physical. When it comes to the infrastructure of the human body - the musculoskeletal system that includes muscles, bones, tendons and cartilage - age-associated decline is inevitable, and the rate of that decline increases the older we get. The loss of muscle function -- and often muscle mass -- is scientifically known as sarcopenia or dynapenia.

For adults in their 40s, sarcopenia is hardly noticeable -- about 3% muscle mass is lost each decade. For those aged 65 years and older, however, muscle decline can become much more rapid, with an average loss of 1% muscle mass each year. More importantly, sarcopenia is also marked by a decrease in strength, impaired gait, reduced physical activity, or difficulty completing everyday tasks.

The proportion of older adults aged 65+ is projected to more than double by the year 2060, driving research into the process of musculoskeletal decline. Researchers at Colorado State University's Columbine Health Systems Center for Healthy Aging believe they have found an animal model that will help them better understand it and find ways to curtail the symptoms.

The study, published in Frontiers in Physiology: Striated Muscle in October, is an example of using comparative medicine to understand human diseases and conditions.

Animal models

Scientists often rely on animal models to mimic disease progression and study the prevention, diagnosis and treatment of conditions. However, until now, no animal model has been able to fully capture all aspects of human musculoskeletal aging.

"Existing preclinical models either rely on unloading the muscle, meaning mimicking bedrest in an animal, or they must wait until the animals get really, really old, and even then they don't really get the same muscle aging phenotype as people do," said Karyn Hamilton, a professor in the CSU Department of Health and Exercise Science, an associate director at the Center for Healthy Aging, and a researcher on the study.

In their work, Hamiliton's team found that the Dunkin Hartley guinea pig was a good candidate for a muscle aging model due to the animal's tendency to develop osteoarthritis (OA) at a young age.

The two conditions -- OA and sarcopenia -- seem to be linked in humans: With advancing age, skeletal muscle dysfunction increases the risk for OA, and OA increases the risk for further muscle decline.

Hamilton teamed up with Dr. Kelly Santangelo -- an associate professor in the Department of Microbiology, Immunology, and Pathology at CSU, who has been studying primary OA in Hartley guinea pigs for many years -- and Associate Professor Raoul Reiser, also in Department of Health and Exercise Science, to understand how skeletal muscle changes as OA progresses in guinea pigs.

The team hypothesized that those muscle changes might mimic human musculoskeletal aging.

Classic signs

Muscle composition also changes with age: fast-twitch fibers, which are larger and capable of exerting stronger forces, decrease in number, and slow-twitch fibers, which are smaller and less metabolically efficient, tend to increase. Generally when people "lose muscle mass," it's the large, fast-twitch fibers that are affected. With decreasing muscle mass also tends to come an increase in fat mass, or adipose tissue, in the body.

As humans age, it may be that maintaining muscle function is more important than preventing loss of mass.

"What we've learned over the decades is that age-related loss of muscle mass and age-related loss of muscle function don't always go hand in hand," Hamilton said. "You can do things to improve muscle mass, and you might not get an improvement in muscle function; you can do things to improve muscle function and may not get an increase in muscle mass."

The researchers compared muscle changes observed in Hartley guinea pigs with those in Strain 13 guinea pigs, which tend to develop OA later in their lifespan and, therefore, might not exhibit the same classic signs of muscle aging.

They found some striking similarities to human muscle aging, such as a decrease in muscle density, likely due to an increase in fat mass. While a decrease in muscle mass was not noted, researchers did find a shift toward smaller, slow-twitch muscle fibers, as is expected in human muscle with advancing age.

"If you look at the overall picture, we think that some of the key things that always happen with human muscle aging -- that shift toward a less powerful, slower-twitch muscle phenotype -- are quite clearly modeled in the Hartley guinea pigs," Hamilton said. "And we believe that if we started looking at even older guinea pigs, we might see more of the things that people think of as classic sarcopenia."

Future directions

This study provides a baseline that allows the team to take multiple directions in future research. One direction will be to employ functional tests to study how muscle strength and gait or mobility change with age in the Hartley guinea pigs, and how these changes mimic the deterioration of muscle function in aging humans.

A priority will be to identify if Hartley guinea pigs can be a valuable translational model for identifying interventions that show promise for preventing or slowing the decline in overall musculoskeletal function with aging in humans.

In fact, Hamilton and Santangelo have already begun treating the guinea pigs with plant-based phytochemicals that target a protective suite of genes. The treatment seems to reverse some signs of musculoskeletal aging at the molecular level by improving mitochondrial function as well as preventing joint deterioration and preserving aspects of gait that normally deteriorate with advancing age.

Overall, Hamilton says she hopes this work can provide researchers with another animal model for studying human aging, one that can "successfully translate preclinical findings and basic science discoveries to encouraging interventions to increase human health span or improve healthy aging."

Researchers from MBARI, the University of Hawai'i at Mānoa (UH Mānoa), and Woods Hole Oceanographic Institution, after years of development and testing, have successfully demonstrated that a fleet of autonomous robots can track and study a moving microbial community in an open-ocean eddy. The results of this research effort were recently published in Science Robotics.

Autonomous robotic fleets enable researchers to observe complex systems in ways that are otherwise impossible with purely ship-based or remote sensing techniques. In a time when the COVID-19 pandemic is reducing opportunities for researchers to go to sea, autonomous fleets offer an effective way to maintain a persistent presence in features of interest.

Oceanic microbes are essential players in the global climate system, producing roughly half of the world's oxygen, removing carbon dioxide, and forming the base of the marine food web. Open-ocean eddies can be over 100 kilometers (62 miles) across and last for months. Phytoplankton (a kind of microscopic algae) thrive when these eddies spin counterclockwise in the Northern Hemisphere and bring nutrient-rich water from the depths up toward the surface.

"The research challenge facing our interdisciplinary team of scientists and engineers was to figure out a way to enable a team of robots--communicating with us and each other--to track and sample the DCM," said Brett Hobson, a senior mechanical engineer at MBARI and a coauthor of this study. Researchers have struggled to study the DCM because at depths of more than 100 meters (328 feet), it can't be tracked with remote sensing from satellites. Moreover, the position of the DCM can shift more than 30 meters (98 feet) vertically in just a few hours. This variability in time and space requires technology that can embed itself in and around the DCM and follow the microbial community as it drifts in the ocean currents.

Ed DeLong and David Karl, oceanography professors in the UH Mānoa School of Ocean and Earth Science and Technology (SOEST) and co-authors of the study, have been researching these microbes for decades. DeLong noted that these teams of coordinated robotic vehicles offer a vital step toward autonomous and adaptive sampling of oceanographic features. "Open-ocean eddies can have a huge impact on microbes, but until now we haven't been able to observe them in this moving frame of reference," he explained.

During the Simons Collaboration on Ocean Processes and Ecology (SCOPE) Eddy Experiment in March and April 2018, researchers used satellite imaging to locate an eddy north of the Hawaiian Islands. They deployed a hi-tech team of three robots--two long-range autonomous underwater vehicles (LRAUVs) and one Wave Glider surface vehicle--from the Schmidt Ocean Institute's (SOI) research vessel Falkor.

The first LRAUV (named Aku) acted as the primary sampling robot. It was programmed to locate, track, and sample the DCM. Using an onboard 3rd-Generation Environmental Sample Processor (3G-ESP), Aku filtered and preserved seawater samples, allowing researchers to capture a series of snapshots of the organisms' genetic material and proteins.

The second LRAUV (named Opah) acoustically tracked Aku and spiraled vertically around it to collect crucial information about the environment surrounding the DCM. LRAUVs Aku and Opah carried a suite of sensors to measure temperature, salinity, depth, dissolved oxygen, chlorophyll concentrations, optical backscatter, and photosynthetically active radiation. Aku remained submerged for several days at a time sampling the DCM, while Opah surfaced every few hours to relay information via satellite back to scientists on the ship. A Wave Glider surface robot (named Mola) also tracked Aku with sonar and communicated with the science team aboard the Falkor.

"This work is really the fulfillment of a decades-long vision," said MBARI President and CEO Chris Scholin. Scholin has been engaged in this effort since he was an MBARI postdoctoral researcher seeking to develop autonomous sampling technology for marine systems. "Coordinating a robotic fleet to show how microbial communities react to changing conditions is a game-changer when it comes to oceanographic research."

The researchers determined that Aku accurately and consistently tracked the DCM over the course of its multi-day sampling missions. By tracking the temperature corresponding to the peak of chlorophyll (an indicator of phytoplankton) in the DCM, the LRAUV maintained its position within the DCM even as this biological feature moved as much as 36 meters (118 feet) vertically in four hours.

"Building an LRAUV with an integrated ESP that could track this feature was a milestone. Combining that sampling power with the agility of three different robots autonomously working together over the course of the experiment is a significant engineering and operations achievement," said Yanwu Zhang, a senior research engineer at MBARI and the lead author of this study.

Beyond the extraordinary engineering feat of organizing this robot ballet, the study also offers key takeaways related to how the biological community behaves inside a swirling eddy. RNA measurements reveal that as the eddy weakened into the second leg of the experiment, the phytoplankton biomass in the DCM decreased. "Much like our own team of researchers, each of the robots in the fleet is a specialist contributing to the experiment," said John Ryan, a senior research specialist at MBARI and a coauthor of the study. "This adaptive approach gives us a new perspective on the environmental processes going on inside and around this plankton community."

These robotic fleets are now also being used to monitor other key disturbances to ocean health like harmful algal blooms and oil spills. "Given the rapid changes our ocean is undergoing as a result of human activities such as climate change, pollution and overfishing, this technology has the potential to transform our ability to understand and predict ocean health," said Scholin.

Rising temperatures could trigger Earth's terrestrial ecosystems to transition from carbon sinks to carbon sources in the next 20 to 30 years, according to data from the world's largest continuous carbon monitoring network. The researchers suggest that up to half of land ecosystems could reach this tipping point - when plants begin to release carbon into the atmosphere faster than they sequester it - by 2100 under a business-as-usual emissions scenario. However, biomes that store the most carbon, including rainforests and Taiga forests, may lose more than 45% of their carbon sink capabilities by midcentury. Research suggests that climate change may play out through a series of tipping points - thresholds beyond which the climate system undergoes dangerous and irreversible shifts. To avoid these tipping points, the Paris Agreement established a goal of keeping global temperature increases below 2°C above preindustrial levels. But while scientists know that temperature influences the rates of photosynthesis and respiration in terrestrial ecosystems, which currently absorb about 30% of carbon emissions from human activities each year, it has remained uncertain how these processes will be altered on a global scale as the climate warms. To investigate when global and regional temperatures might reach the critical threshold at which the land's carbon sink declines, Katharyn Duffy and colleagues analyzed records spanning from 1991 to 2015 from the global network FLUXNET, which accounts for the movement of carbon dioxide between ecosystems and the atmosphere. The researchers determined photosynthesis and respiration changes attributed solely to changes in temperature at each flux tower site, then aggregated these temperatures at the biome and global levels. While the data suggests global photosynthesis reaches a peak rate at temperatures of 18° Celsius for C3 plants and 28° Celsius for C4 plants, and declines at higher temperatures, respiration rates increased across the full range of observed temperatures without appearing to reach a maximum threshold. While less than 10% of land ecosystems currently experience temperatures beyond these photosynthesis thresholds (and only for a small fraction of the year), Duffy et al. caution that failure to implement agreements that meet or surpass the Paris Accord goals could dramatically alter carbon storage in terrestrial biomes around the world.

The build-up of calcium in a major artery outside of the heart could predict future heart attack or stroke, a new Edith Cowan University led study has demonstrated.

Published today in the Journal of the American Heart Association, the research could help doctors identify people at risk of cardiovascular disease years before symptoms arise.

Analysing 52 previous studies, the international team of researchers found that people who have abdominal aortic calcification (AAC) have a two to four times higher risk of a future cardiovascular event.

The study also found the more extensive the calcium in the blood vessel wall, the greater the risk of future cardiovascular events and people with AAC and chronic kidney disease were at even greater risk than those from the general population with AAC.

Calcium can build up in the blood vessel wall and harden the arteries, blocking blood supply or causing plaque rupture, which is a leading cause of heart attacks and strokes.

The factors contributing to artery calcification include poor diet, a sedentary lifestyle, smoking and genetics.

Predicting a 'silent killer'

Lead researcher Associate Professor Josh Lewis from ECU's School of Medical and Health Sciences, and Heart Foundation Future Leader Fellow, said the findings offer important clues for cardiovascular health.

"Heart disease is often a silent killer as many people don't know they are at risk or that they have the early warning signs, such as abdominal or coronary artery calcification," he said.

"The abdominal aorta is one of the first sites where the build-up of calcium in the arteries can occur - even before the heart. If we pick this up early, we can intervene and implement lifestyle and medication changes to help stop the condition progressing."

Saving lives

Associate Professor Lewis hopes this discovery will lead to more people understanding their own risk of having a heart attack or stroke.

"Abdominal aortic calcification is often picked up incidentally in many routine tests, such as lateral spine scans from bone density machines or x-rays, and now we have a much better idea of the prognosis in these people when it is seen," he said.

"This can signal an early warning for doctors that they need to investigate and assess their patient's risk of heart attack or stroke.

"Ultimately, if we can identify this condition sooner, people can make lifestyle changes and start preventative treatments earlier, which could potentially save many lives in the future."

The international study involved researchers from INSERM, the Hinda and Marcus Institute for Ageing Research, University of Sydney, University of Western Australia and University of Minnesota.

The study builds on Associate Professor Lewis's recent research on using bone density scans and artificial intelligence to identify and quantify abdominal aortic calcification.

A promising future

Associate Professor Josh Lewis is supported in his position at ECU by the National Heart Foundation of Australia Future Leader Fellowship.

The Heart Foundation's manager of clinical evidence, Amanda Buttery welcomed the study.

"The researchers found that evidence of abdominal aortic calcification in patients with no known cardiovascular disease may indicate that a more comprehensive cardiovascular risk assessment is required, including blood pressure and cholesterol testing or a Heart Health Check," Ms Buttery said.

"The findings are promising, and the Heart Foundation would like to see more research in this area."

DURHAM, N.C. - Most of the revenues extracted from use of the world's oceans is concentrated among 100 transnational corporations, which have been identified for the first time by researchers at Duke University and the Stockholm Resilience Centre at Stockholm University.

Dubbed the "Ocean 100," these "ocean economy" companies collectively generated $1.1 trillion in revenues in 2018, according to research published Wednesday in the journal Science Advances. If the group were a country, it would have the world's 16th-largest economy, roughly equivalent to the gross domestic product (GDP) of Mexico.

"Now that we know who some of the biggest beneficiaries from the ocean economy are, this can help improve transparency relating to sustainability and ocean stewardship," said lead author John Virdin, director of the Ocean and Coastal Policy Program at Duke's Nicholas Institute for Environmental Policy Solutions. "The small number of companies that dominate these industries likely reflects high barriers to entry in the ocean economy. A lot of expertise and capital are needed to operate in the sea, both for the established industries and emerging one such as deep-sea mining and marine biotechnology."

The researchers studied eight core industries in the ocean economy: offshore oil and gas, marine equipment and construction, seafood production and processing, container shipping, shipbuilding and repair, cruise tourism, port activities and offshore wind. The 100 largest companies took an estimated 60 percent of the $1.9 trillion in revenues generated by these industries in 2018, the most recent year analyzed.

Offshore oil and gas dominated the Ocean 100 list with a combined revenue of $830 billion. The only corporation from outside that industry to make the top 10 is the Danish shipping company A.P. Møller-Mærsk at No. 9.

The researchers found a consistent pattern across all eight industries of a small number of companies accounting for the bulk of revenues. On average, the 10 largest companies in each industry took 45 percent of that industry's total revenue. The highest concentrations were found in cruise tourism (93 percent), container shipping (85 percent) and port activities (82 percent).

The authors write that this concentration presents both risks and opportunities.

"Senior executives of these few, but large companies, are in a unique position to exercise global leadership in sustainability," said co-author Henrik Österblom, science director at the Stockholm Resilience Centre. "The fact that these companies are headquartered in a small number of countries also illustrates that concerted actions by some governments, could rapidly change how the private sector interacts with the ocean."

The Ocean 100 builds on the concept of "keystone actors" developed by Österblom and his colleagues at the centre in a 2015 paper published in the journal PLOS ONE. Using keystone species in ecosystems as an analogy, the researchers identified a handful of corporations that dominate the global seafood industry. The study led to the formation of the Seafood Business for Ocean Stewardship (SeaBOS) initiative as a way to connect scientists with industry leaders to work toward more sustainable seafood production.

Virdin became interested in whether the keystone actor concept could be applied more broadly while advising governments on integrated ocean development and management policies for the ocean economy, or sometimes called the blue economy. The Ocean 100 study expands interdisciplinary research conducted into the blue economy topic by Duke scholars across the university, including Virdin and co-author Daniel Vermeer.

"Oceans will be increasingly central to the global economy in the 21st century," said Vermeer, executive director of the Center for Energy, Development and the Global Environment (EDGE) at Duke's Fuqua School of Business. "One of our biggest challenges is to sustain healthy ocean ecosystems as economic use increases and climate impacts accelerate. This study confirms that a relatively small number of companies will be central to this challenge, and have a real opportunity for leadership."

BINGHAMTON, NY -- A new leader takes office and foreign rivals begin to test the waters. How tough is this new leader? Are they willing to risk war, or just full of bluster?

This testing can escalate crises, increasing the risk of war as international adversaries gauge the new leader's willingness to use force. A new paper co-written by faculty at Binghamton University, State University of New York shows that when this "turnover trap" occurs depends a good deal on the politics back home, and the nature of the leader's transition into office.

Binghamton University Associate Professor of Political Science Amanda Licht was among a trio of researchers behind "Same as the Old Boss? Domestic Politics and the Turnover Trap," recently published in International Studies Quarterly. The other authors are Assistant Professor of Political Science and International Studies Cathy Xuanxuan Wu of Old Dominion University and Professor of Government Scott Wolford at the University of Texas at Austin.

"What makes this a 'trap' is that both leaders would prefer to not actually go through the costly process of real military conflict. But for the foreign rival, the potential benefits of forcing a weak new leader into concessions are so tempting that they will behave in ways that risk a real conflict," Licht explained. "And, for the new leader, the risks of being 'outed' as lacking in resolve and consequently having to offer large concessions are so great that they also will act more aggressively than a more experienced leader of similar resolve would feel free to do."

The researchers analyzed international disputes between rival countries from 1918 to 2007, discovering patterns behind the turnover trap. International disputes were more likely to escalate under new democratic leaders from a different party than their predecessor, and among autocrats who are closely tied to their predecessor's regime.

In democratic societies, leaders typically serve for set terms, which means that new presidents and prime ministers are usually very secure in their jobs. "Democratic heirs" who are of the same party or coalition as their predecessor may be assumed to follow the same decision-making processes as the previous leader and face fewer challenges as a result.

The situation changes when there is a significant shift in the governing party: in other words, a "democratic challenger." Foreign adversaries are eager to learn more about this new leader; combined with the typical stability of democratic government style and term lengths, that may prompt a "turnover trap" situation soon after the leader takes power.

Authoritarian governments, on the other hand, have different domestic considerations. After a chaotic and violent overthrow, a new authoritarian leader often needs to secure their power and eliminate rivals at home. Foreign adversaries may also consider testing an "authoritarian challenger" to be a waste of time, since the new leader may not stay in power long.

"Authoritarian heirs" who come to power in a relatively secure regime are more likely to look beyond their borders and face international challenges.

"Rather than being constrained to serve the same constituencies, as a democratic heir to power would be, an autocratic heir is free to operate as they please," Licht said. "This means that they may be a target for probes from rivals, and that they know it."

The analysis also revealed something else: Whether democratic or authoritarian, leaders face fewer incidents of the turnover trap as they and their foreign opponents learn more about each other's resolve.

"As time goes on, escalation of a conflict is less likely because both sides know what the other is willing to do," Licht said.

Domestic politics matter

The research wasn't sparked by a particular leader or conflict, but as a general exploration of the workings of governmental power transitions. In another paper, Wu and Wolford establish turnover as opening up an information trap; Licht's work, on the other hand, suggests that the turnover type matters. This most recent publication integrates the two perspectives.

Examples of the principles in action, however, do exist. The paper offers one example of an autocratic heir: Syrian President Bashar al-Assad, who inherited the regime from his father in 2000. Initially considered a genteel, Western-educated physician, he has since proven his willingness to engage in war.

Or consider the 2017 Twitter exchanges between U.S. President Donald Trump, a democratic challenger, and North Korean Kim Jong-Un, another autocratic heir who inherited a regime from his father. Their initial interactions followed the path of probing and bluster at the center of the turnover trap.

While often ignored by theories that deal with war and conflict, domestic politics really do play a role in international affairs, often in complicated, nuanced ways, Licht pointed out.

The research also shows that the voting public has an important voice in a democratic country's trajectory. The stability and broad coalitions in democratic institutions often lead scholars to expect that a change in democratic leaders rarely matters when it comes to international issues such as trading patterns, willingness to uphold alliance commitments or the termination of economic sanctions.

"From the perspective of democratic citizens who want their vote to be able to affect what policies their government pursues, that's a pretty upsetting thing to think about," Licht said. "In contrast, our paper suggests that when democratic publics vote out an administration this creates real change, but this change comes with an increase in the danger of undesirable conflict."