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CORVALLIS, Ore. - Researchers using electronic tags were able to monitor blue and fin whales off the coast of Southern California over multiple weeks, providing new insight into the feeding behaviors of the two largest whale species. The researchers also found evidence of differences in the feeding intensity and habitat use of males and females of both species.

"The information collected with these tags gives us a good description of the scale of whales' feeding behavior over periods of hours, days and weeks, which is something we've not been able to do before," said Ladd Irvine, a senior faculty research assistant in Oregon State University's Marine Mammal Institute and the study's lead author.

The whales fed mostly during the day, usually in short bursts lasting one to two hours, but would also feed continuously throughout the daytime, and in rare circumstances for an entire day.

"We were able to quantify feeding bouts, which are periods of uninterrupted feeding, and found that the duration of feeding bouts correlated with another measure of feeding success - the number of prey capture events, known as feeding lunges," Irvine said. "That means the whales stayed longer in areas where they fed more. This allowed us to make inferences about the profitability of feeding patches, as whales should stay in an area and feed longer where prey is abundant and move on when prey becomes scarce."

The findings, which were published this week in the journal Frontiers in Ecology and Evolution, could have implications for managing populations of blue and fin whales, both of which are listed as endangered in the United States.

In 2014 and 2015, researchers tagged eight blue and five fin whales off the coast of Point Mugu and San Miguel Island in Southern California. Both species frequent the area, feasting on krill.

Prior whale monitoring efforts had relied solely on location tracking, which tells researchers where the whales travel, but not what happens along the way. The tags used in this study, developed at Oregon State in collaboration with Wildlife Computers Inc., included GPS for movement monitoring as well as the ability to record information about the whales' behavior every second while they were on the move. Accelerometers and other sensors on the tags measured lunge-feeding behavior as well as frequency and depth of dives.

"The hardest thing about studying whales is that you can't really follow them when they dive below the surface" said Irvine, who is also a doctoral student in the OSU College of Agricultural Sciences' Department of Fisheries and Wildlife. "The data collected from these tags give us unprecedented detail about what whales are doing over a longer time period than was previously possible."

Tags remained on the blue whales an average of 22 days and on the fin whales about 14 days. It's unclear why the tags came off the fin whales more quickly, but it could have to do with their movement and faster speed in the water, Irvine said.

The researchers found that both species of whales had similar feeding bout characteristics. During an average feeding bout, blue whales made 24 dives over a period of about 3.3 hours, while fin whales made 19 dives over 2.7 hours. The similarities are not surprising, the researchers said, as the two species are similar in size and feed in the same way. Slight differences observed may be due to preferences in terms of patch characteristics or prey type.

"This study represents a significant leap forward in our knowledge of whale foraging ecology," said Daniel Palacios, who holds the Endowed Faculty in Whale Habitats position at the Marine Mammal Institute and is a co-author of the paper.

"By collecting data from individual whales over multiple days and weeks, we were able to obtain large amounts of new information about how feeding intensity evolves and changes in time and space, at scales that are relevant to ecology as well as management," he said. "We were able to answer questions like how long does a whale feed? What is the size of a feeding patch? How far does a whale need to move before it finds the next patch? Do females and males feed at the same intensity? It may seem surprising, but studying whales is enormously challenging and we lacked much of this information."

But feeding might not be the only thing on the whales' minds, as the researchers also found differences in movements between tagged males and females of both species.

"The males made big loops offshore of Southern California, while the females stuck closer to shore. Those routes may be related somehow to breeding behavior, and could have implications in terms of exposure to human activities if whales of one sex are more likely to be encountered in specific parts of busy Southern California waters," Irvine said.

"While the results are exciting, our conclusions about the behaviors of whales from this initial set of data from 13 animals should be viewed as preliminary," he said. "These data are an incredibly rich description of the tagged whales' behavior, but they ultimately represent a relatively small number of individuals, occupying a portion of their overall range."

Ideally, similar data would be collected again from different locations or different whales to determine if the observed feeding and other behavior patterns are representative of the broader populations, he said.

"Nevertheless, this information is a huge addition to our understanding of blue and fin whale feeding ecology," Irvine said. "Does what we saw with these individuals hold up as we continue to study them in other places and seasons? That's a question still to be determined. We're still just scratching the surface of our understanding of whale behavior."

AUGUSTA, Ga. (Sept. 11, 2019) - In the face of obesity, the sex hormone progesterone that helps females get and stay pregnant appears to also put them at increased, early risk for cardiovascular disease, investigators report.

Premenopausal women are considered protected from cardiovascular disease, but evidence indicates obesity can negate those benefits, and in fact put them at even higher risk than men, but just how remains an unfolding mystery.

"The question we had is exactly what is happening with these young women," says Dr. Eric Belin de Chantemele, physiologist in the Vascular Biology Center and Department of Medicine at the Medical College of Georgia at Augusta University.

As they walk down the path to how their protection is lost, investigators have now documented high levels of a receptor for the hormone aldosterone, which can damage the vasculature, in the endothelial cells that line blood vessels, and that progesterone enables the high levels of receptor expression they found, says Belin de Chantemele.

The latest findings, published in the journal Hypertension, were consistent in both animal models and, for the first time, in human blood vessels as well.

Corresponding author Belin de Chantemele and his colleagues reasoned and have now confirmed that females just have higher expression of these mineralocorticoid receptors on endothelial cells. Females also have naturally higher levels of the hormone aldosterone, and in the face of obesity, produce even more of the hormone, which is bad for blood vessels at these now very high levels. At high levels, aldosterone, which has a direct effect on blood pressure by regulating salt-water balance in the body, prompts inflammation; stiff, scarred arteries; enlargement of the heart and more, but how the hormone levels get so high in obesity was among the unknowns.

An earlier starting point for this perfect storm appears to be the fact that fat produces the satiety hormone leptin, and women generally produce more leptin per ounce of fat than men. With obesity, men and women both obviously make more leptin because they have more fat tissue, but the brain stops listening to leptin's signal that we are full and the cardiovascular system starts paying more attention.

In males, leptin activates the sympathetic nervous system, the so-called fight or flight system that gets hearts beating faster and blood pressure up, but that system is not typically activated in younger females even in the face of obesity. In their search to find what was happening in these females, the MCG team found the "sky-high" aldosterone levels in their research models.

Belin de Chantemele and his colleagues reported in Circulation in 2015 that in females, higher leptin levels prompt the adrenal glands to make more of the hormone.

Their findings at that point already were pointing toward targeted intervention for premenopausal women with obesity and, in fact, there are already older drugs, like the diuretic spironolactone, that target aldosterone by blocking its receptor. The newest findings appear to strengthen the target.

They had reasoned that like naturally higher levels of aldosterone, females also have more receptors for that hormone on their endothelial cells.

They again found they were correct in their animal models and, for the first time, in human blood vessels as well, removed during the usual course of surgery by MCG cardiothoracic surgeon and coinvestigator Dr. Vijay Patel.

"As clinicians, we are always asking why patients develop this," says Patel, who has being doing cardiothoracic surgery for two decades. He notes more recent years have seen a shift toward more female patients generally, now about one third of the patients he operates on at AU Medical Center, and they are often relatively young and also have overweight or obesity. They also often have other compounding factors like diabetes and smoking.

To better understand sex differences in the disease process that can land patients in the operating room, the investigators deleted either the mineralocorticoid receptor or the progesterone receptor in female mice.

They found both deletions prevented the blood vessel dysfunction that usually followed, which illustrated a clear partnership between the two. But it was progesterone really driving the sex differences in the expression of mineralocorticoid receptors on endothelial cells. In fact, just knocking out the progesterone receptor also suppressed the aldosterone receptor, says postdoctoral fellow and first author Dr. Jessica Faulkner.

When Faulkner removed the ovaries -- which produce both estrogen and progesterone -- female mice had essentially equal numbers of mineralocorticoid receptors on endothelial cells as their male counterparts. Then she gave back the female sex hormones estrogen and progesterone, both separately and together, at levels similar to what is found in birth control pills.

She found it was progesterone, not estrogen, which restored the typically higher expression of these receptors in females. Adding progesterone to human endothelial cells invoked a similar response.

"Basically we think that progesterone is some sort of evolutionary mechanism for sustenance of an increased mineralocorticoid receptor expression in the vasculature of females," she says. That may tie back to reproduction and pregnancy because progesterone is high in pregnancy and vascular tone is very important to both baby and mother.

When obesity is not a factor, high levels of both are probably not a bad thing, she adds. The investigators don't know yet if progesterone also increases with obesity but there is evidence that generally obesity throws off the balance of hormones and they are looking specifically at progesterone now. They note that there may be other factors besides progesterone and obesity driving increased aldosterone receptors in the endothelial cells but at this point it looks like it's only happening in females. Another factor they are looking at is high blood sugar. They also want to know whether factors besides higher leptin levels can drive higher aldosterone levels in these females.

The strength of their newest study is, because of the cooperation of Patel and patients, they have been able to see that what they are finding in animals holds up in humans, Belin de Chantemele says.

Better care for patients with cardiovascular disease, the number one killer in Georgia and the United States, is definitely the bottom line, says Patel. "We know there are certain risk factors we can help modify but there is a lot more beyond the five predominant risk factors that we see," says Patel, of contributors like high cholesterol and smoking.

The heart surgeon would like to see studies on young women with obesity who are taking a mineralocorticoid receptor blocker, versus more commonly prescribed medications for problems like high blood pressure, and compare their impact on disease development. Pulling this kind of data out of large studies that already have been done likely would be a more rapid way to see if the promising work of his research colleagues continues to play out in human studies.

Researchers from Chalmers University of Technology have demonstrated a detector made from graphene that could revolutionize the sensors used in next-generation space telescopes. The findings were recently published in the scientific journal Nature Astronomy.

Beyond superconductors, there are few materials that can fulfill the requirements needed for making ultra-sensitive and fast terahertz (THz) detectors for astronomy. Chalmers researchers have shown that engineered graphene adds a new material paradigm for THz heterodyne detection.

"Graphene might be the only known material that remains an excellent conductor of electricity/heat even when having, effectively, no electrons. We have reached a near zero-electron scenario in graphene, also called Dirac point, by assembling electron-accepting molecules on its surface. Our results show that graphene is an exceptionally good material for THz heterodyne detection when doped to the Dirac point", says Samuel Lara-Avila, assistant professor at the Quantum Device Physics Laboratory and lead author of the paper.

In detail, the experimental demonstration involves heterodyne detection, in which two signals are combined, or mixed, using graphene. One signal is a high intensity wave at a known THz frequency, generated by a local source (i.e. a local oscillator). The second is a faint THz signal that mimics the waves coming from space. Graphene mixes these signals and then produces an output wave at a much lower gigahertz (GHz) frequency, called the intermediate frequency, that can be analyzed with standard low noise gigahertz electronics. The higher the intermediate frequency can be, the higher bandwidth the detector is said to have, required to accurately identify motions inside the celestial objects.

Sergey Cherednichenko, professor at the Terahertz and Millimetre Wave Laboratory and co-author of the paper, says:

"According to our theoretical model, this graphene THz detector has a potential to reach quantum-limited operation for the important 1-5 THz spectral range. Moreover, the bandwidth can exceed 20 GHz, larger than 5 GHz that the state of the artstate-of-the-art technology has to offer."

Another crucial aspect for the graphene THz detector is the extremely low power needed for the local oscillator to achieve a trustable detection of faint THz signals, few orders of magnitude lower than superconductors require. This could enable quantum-limited THz coherent detector arrays, hence opening the door to 3D imaging of the universe.

Elvire De Beck, astronomer at the Department of Space, Earth and Environment, who did not take part in the research, explains the possible implications for practical astronomy:

"This graphene-based technology has enormous potential for future space missions that aim at e.g. unveiling how water, carbon, oxygen and life itself came to earth. A lightweight, power effective 3D imager that is quantum-limited at terahertz frequencies is crucial for such ambitious tasks. But, at the moment, THz 3D imagers are simply not available".

Sergey Kubatkin, professor at the Quantum Device Physics Laboratory and co-author of the paper, explains:

"The core of the THz detector is the system of graphene and molecular assemblies. This is in itself a novel composite 2D material that deserves deeper investigation from a fundamental point of view, as it displays a whole new regime of charge/heat transport governed by quantum-mechanical effects."

New research shows that the presence of microplastics can stunt the growth of earthworms, and even cause them to lose weight - potentially having a serious impact on the soil ecosystem.

The study, to be published in the journal Environmental Science & Technology, is the first to measure the effects of microplastics on endogeic worms, which live in the top soil.

Academics from Anglia Ruskin University (ARU) examined the impact of biodegradable polylactic acid (PLA), high-density polyethylene (HDPE), and microplastic clothing fibres (acrylic and nylon) on earthworms living in the soil as well as ryegrass sown on top.

After a period of 30 days in the presence of HDPE, which is commonly used in the production of plastic bottles and carrier bags, they found that rosy-tipped earthworms (Aporrectodea rosea) lost on average 3.1% of their weight.

In comparison, the earthworms living in control conditions, without added microplastics, saw their weight increase by 5.1% over the 30-day period.

At the same time the study found that the presence of HDPE led to a decrease in the soil pH. And soil containing PLA, a biodegradable form of plastic, led to a reduction in the shoot height of the ryegrass (Lolium perenne), while both PLA and clothing fibres led to fewer ryegrass seeds germinating.

Lead author Dr Bas Boots, Lecturer in Biology at Anglia Ruskin University (ARU), said: "The earthworms lost weight overall when certain microplastics were present and grew significantly in weight in soil without added microplastics. However, the specific reasons for this weight loss needs unravelling.

"It may be that the response mechanisms to microplastics may be comparable in earthworms to that of the aquatic lugworms, which have been previously studied. These effects include the obstruction and irritation of the digestive tract, limiting the absorption of nutrients and reducing growth."

Connor Russell, a graduate of the MSc Applied Wildlife Conservation course at Anglia Ruskin University (ARU) and a co-author of the study, said: "Earthworms can be called 'ecosystem engineers' as they help maintain a healthy soil. They do this through ingesting dead organic matter, therefore contributing to the availability of nutrients.

"Their burrowing activity improves soil structure, helping with drainage and preventing erosion. It's therefore highly likely that any pollution that impacts the health of soil fauna, such as earthworms, may have cascading effects on other aspects of the soil ecosystem, such as plant growth."

UCSF Benioff Children's Hospitals have successfully treated a months-old infant with a rare childhood leukemia using a targeted therapy approved for adults with inoperable liver cancer and advanced kidney cancer.

The decision to use the drug, sorafenib, was made after pathologists identified a unique mutation in the form of two genes being fused together instead of on separate chromosomes -- according to a case study publishing in the journal Leukemia on Sept. 11, 2019.

The patient, now a thriving toddler, personifies a growing shift in cancer treatment: the genes fueling the cancer, rather than the type of cancer itself, may determine optimal therapy, say researchers, led by senior author Elliot Stieglitz, MD, a physician scientist in the UCSF Division of Pediatric Hematology/Oncology and the Helen Diller Family Comprehensive Cancer Center.

The authors report that the infant presented with the hallmarks of leukemia, including enlargement of the liver and spleen, and elevated white blood cell counts.

The child was believed to have JMML, or juvenile myelomonocytic leukemia, an aggressive type of blood cancer most commonly affecting infants and toddlers, and occurring in about 1.2 children per million, per year. JMML is treated with a stem cell transplant, in which intense chemotherapy is given to wipe out JMML cells, followed by a transplant of donated stem cells from a closely matched donor into the recipient's bone marrow, where they produce healthy blood cells. However, up to 50 percent of JMML patients relapse after transplantation.

Live-Saving Treatment Stalled When Infant's Condition Declined

Chemotherapy was initiated in an attempt to reduce the disease burden before stem cell transplant, said Stieglitz. "Unfortunately, the patient did not respond to chemotherapy and his symptoms worsened. The stem cell transplant was no longer an option."

Facing shrinking options, Stieglitz's team conducted molecular profiling of the child's cancer cells, in the hope that mutations could be identified and matched with targeted therapies. They used both UCSF 500, a cancer gene panel that sequences DNA from a patient's cancer cells and compares them to normal tissue, and a second tool that analyzes RNA, which offers a more sensitive measurement of gene expression and may identify novel features, including fusion genes. None of the mutations associated with JMML were found. However, the pathologists were surprised to discover a mutation known as an FLT3 fusion -- something that had never before been reported in a pediatric malignancy, the authors said.

"We know that fusions are more likely to respond to targeted therapies than other types of mutations," said Mignon Loh, MD, a co-author and Chair in Pediatric Molecular Oncology, who was involved in the patient's care. "Sorafenib, which was developed at UCSF, is a type of targeted therapy known as a kinase inhibitor that works by blocking the action of an abnormal protein that signals cancer cells to multiply."

After two weeks on sorafenib, the patient's white blood cell counts plummeted to within the normal range. After 10 weeks' treatment, the infant was well enough to undergo a stem cell transplant. Sorafenib was stopped after nearly two years. The patient remains in remission months later.

"The patient's history reveals that the one-size-fits-all treatment approach does not work well for all children with JMML," said Stieglitz. "The course of JMML is highly variable. In rare cases, children spontaneously go into remission with minimal treatment, while half of all patients suffer from a highly aggressive form of the disease that fails to respond to stem cell transplant."

Most JMML patients present with genes that hyperactivate the Ras pathway, said Stieglitz, referring to a chain of proteins within the cell that communicates a signal from a receptor to the DNA in the nucleus.

"Recently there have been reports of JMML patients who have lacked these Ras mutations, but have fusions like our patient," he said. "We recommend that all patients without Ras mutations undergo RNA sequencing to identify any fusions that might be treated with targeted therapies."

Fibrosis, the damaging build-up of hardened or scarred tissue in the body, is a hallmark of various diseases and can lead to the dysfunction and failure of organs such as the heart and kidney. Fibrosis-related diseases in various organs contribute to around 45 per cent of deaths in developed countries.

A Monash Biomedicine Discovery Institute (BDI) researcher leading a team investigating the promising anti-fibrotic effects of a drug version of the hormone, relaxin, has discovered that the receptor through which it mediates its therapeutic actions can communicate and/or interact with other receptors in cells that contribute to fibrosis progression. Receptors are protein structures that transmit signals to other parts of the body when triggered by a stimulus.

The study, led by Associate Professor Chrishan Samuel and published in the Journal of the American Society of Nephrology today, suggests the ability of receptors to 'talk' to each other may affect the way relaxin (and other drugs that act through the receptors) work. It may have implications for the design of clinical trials involving relaxin and its concomitant use with other drugs that act on these receptors.

Associate Professor Samuel said the paper describes for the first time the communication between three receptors that exist on myofibroblasts, the cellular basis of progressive fibrosis. The receptors investigated were: the relaxin family peptide receptor 1 (RXFP1, which relaxin acts through to reduce tissue fibrosis and related dysfunction); the angiotensin II type 1 (AT1) receptor, which is targeted by clinically-used angiotensin receptor blockers to treat high blood pressure-induced organ damage; and the angiotensin II type 2 (AT2) receptor, which can also facilitate the reduction of tissue fibrosis by compounds that stimulate its activity.

"We've shown that because these receptors have the ability to communicate, they have the ability to either promote or negate the actions of various drugs that act on each receptor. For example, our findings suggest that the effects of relaxin may be compromised as a treatment for heart failure when administered to patients who are already receiving angiotensin receptor blockers as frontline treatments."

The communication between the receptors resulted in the anti-fibrotic effects of relaxin being indirectly abolished by compounds that blocked the activity of the AT1 receptor or AT2 receptor. Likewise, the anti-fibrotic effects of a drug that acted through the AT2 receptor were indirectly abrogated by compounds that blocked the activity of RXFP1 or the AT1 receptor in myofibroblasts.

Relaxin, a hormone that is also naturally produced during pregnancy, plays several roles in facilitating childbirth by reducing the rigidity of the pelvic ligaments. It has been well studied for its organ-protective actions at the pre-clinical level, but has not yet been approved as an anti-fibrotic agent.

"What we need to do now is better understand how these receptors communicate, not just in myofibroblasts, but in other cells in which they are co-localised. With an improved understanding of how these receptors interact, they may represent a previously unrecognised target for treating organ fibrosis."

SALT LAKE CITY, September 11, 2019--John A. Moran Eye Center physician-researcher Paul S. Bernstein, MD, PhD, and his patients at the University of Utah played a key role in the recent discovery of the first genetic cause for a rare eye disease.

Macular telangiectasia type 2 (MacTel) affects about one in 5,000 people, causing a gradual loss of central vision, typically after age 40. As part of an international research effort directed by the Lowy Medical Research Institute (LMRI), Bernstein has spent 15 years working with MacTel patients, sifting through family genetic histories.

Among 250 patients enrolled in the Utah Center for MacTel Genetics, part of an LMRI network of more than 30 centers around the world, a Utah father and son gave Bernstein and LMRI researchers a breakthrough clue. Both had MacTel, along with a rare neurological condition called hereditary sensory neuropathy type 1 (HSAN1). HSAN1 damages the peripheral nerves, typically producing tingling, weakness, and a reduced ability to feel pain and sense hot and cold in the legs and feet. Some patients do not lose sensation but instead feel shooting pains.

Research published in The New England Journal of Medicine (NEJM) on September 11, 2019, "Serine and Lipid Metabolism in Macular Disease and Peripheral Neuropathy," confirms two of the genetic variants that cause HSAN1 also cause MacTel.

"We believe this will be the first of many genes linked to MacTel," said Bernstein, one of three senior authors on the NEJM paper and a retinal specialist who directs clinical research at Moran. "This discovery gives patients hope for new treatments, and our research has important implications for other retinal eye diseases."

HSAN1 is associated with rare coding mutations in SPT genes that lead to accumulation of toxic biomolecules in the body called deoxysphingolipids (deoxySLs). Presumably, these same toxic molecules cause damage to the macula, or center of the retina, in patients with HSAN1 and MacTel.

Working with LMRI and the Deater Foundation, a Pennsylvania-based non-profit dedicated to HSAN1 research, Bernstein and fellow clinicians on LMRI's MacTel Project conducted comprehensive eye exams on a group of 10 HSAN1 patients unrelated to the Utah family. They found the majority (7/10) of the patients had MacTel.

All HSAN1 patients who did not have clinical signs of MacTel were less than 46 years old and may have been too young to exhibit signs of this late-onset eye disease. Bernstein was able to examine several of these young HSAN1 patients who did not yet show definite signs of MacTel using fluorescence lifetime imaging ophthalmoscopy (FLIO)--an extremely sensitive, non-invasive imaging technology available in the U.S. only at the Moran Eye Center. FLIO images show a characteristic crescent or ring in the macula in all patients affected by MacTel. All of the young asymptomatic HSAN1 patients exhibited the "MacTel signature" in their FLIO images, suggesting that they are at high risk of developing MacTel in the future.

Further research, combining clinical and laboratory studies, showed that many other MacTel patients also had elevated deoxySL levels, presumably due to other genetic defects or low levels of serine, an amino acid that we make and consume in our diets. Elevated levels of deoxySL in the retina were shown to compromise visual function. Low serine and the deoxySLs were not previously known to affect the eye's macular health.

Laboratory experiments determined fenofibrate, a lipid-lowering medication used for high cholesterol, shows potential for protecting the retina from deoxySLs. Areas of future research include determining how widespread the role of deoxySLs is in causing eye disease; finding the pathways that lead to elevated deoxySLs in MacTel; and developing treatment plans based on a patient's unique genetic and metabolomic profile.

These findings offer potential new insights into other more common eye and systemic diseases, like diabetic retinopathy, liver disease, and metabolic syndrome that are also associated with elevated deoxySLs.

Moran study participant Tami Murphy, a Deater Foundation executive and board member with HSAN1 and possible early signs of MacTel, said she's grateful for the many collaborators who have worked so hard over the years.

"It's exciting to be a part of an international research community that is working so hard to shed light on rare diseases, advancing our knowledge of MacTel and HSAN1," she said.

ALBUQUERQUE, N.M. -- Experimenting at 4.1 million degrees Fahrenheit, physicists at Sandia National Laboratories' Z machine have found that an astronomical model -- used for 40 years to predict the sun's behavior as well as the life and death of stars -- underestimates the energy blockage caused by free-floating iron atoms, a major player in those processes.

The blockage effect, called opacity, is an element's natural resistance to energy passing through it, similar to an opaque window's resistance to the passage of light.

"By observing real-world discrepancies between theory and our experiments at Z, we were able to identify weaknesses in opacity figures inserted into solar models," said Taisuke Nagayama, lead author on the Sandia groups' latest publication in Physical Review Letters.

The good news is that Sandia's experimental opacity measurements can help bloodlessly resolve a major discrepancy in how the widely used Standard Solar Model uses the composition of the sun to predict the behavior of stars.

Until 2005, the SSM's multiplication of the amount of each element present by its opacity accounted for the observed temperature structure of the sun. But new astrophysical observations and more sophisticated physics then led astronomers to revise their estimates of the sun's composition. Unfortunately, these new estimates, inserted into the model and multiplied by their opacities, did not account for the sun's temperature. There were three possibilities: either the new composition observations were inaccurate, or the venerated SSM was wrong, or the theoretically derived opacities of elements were incorrect.

Experiments at the sun's temperature provide answers

The best resolution clearly would come from experiments performed at the same temperatures as those found in the sun's interior.

More than a decade ago, Sandia researchers began taking pieces of iron, each smaller than a dime, and inserting them into the target area of Z. When Z fired, the extreme heat changed the solid into plasma (a gas) as it exists in the sun, but only for nanoseconds. That was long enough, however, for researchers to send an energy wave through each sample and measure how much got through. The idea was to create, for the first time, laboratory-derived measures of the opacity of iron at the temperature of the sun to learn whether it agreed with the theoretical figures used in Standard Solar Model calculations.

Increasing the opacity of iron to the extent demonstrated by Z in multiple independent experiments removed about half the discrepancy between computed and actual solar temperature, Nagayama said.

The top graph in red shows greater opacity of iron as determined experimentally by Sandia National Laboratories' Z machine. The lower graph shows the earlier theoretical calculation. (Graphic provided by Sandia National Laboratories researcher Taisuke Nagayama). Click on thumbnail for a larger image.

"Astronomers are happy with us because we're saying it's the opacity figures that may be wrong," said paper author and Sandia researcher Jim Bailey. "Then they don't have to come up with a new model and redo all their calculations using the sun as a benchmark for predicting the evolution of stars."

That's because astronomers use the sun's composition as a reference for the universe.

"Decreasing the oxygen amount in the sun by 50% is equivalent to halving the amount of water (H2O) in the universe," said Bailey. "There are many exoplanets orbiting around sun-like stars; revising the understanding of our sun would also have significant impact on understanding those exoplanets.

"The astronomers liked the opacity supposition the best, and that's what we're finding so far."

A metallic surprise

On the same test, Sandia also measured the opacities of chromium and nickel under the same conditions used on iron. The idea was to use those elements -- respectively smaller and larger than iron, but adjacent to iron in the periodic table -- as though iron were being tested closer and farther from the sun's core. Surprisingly, those elements produced experimental opacity results basically in accord with model predictions at some photon energies. Still, they differed from opacity predictions at particular wavelengths -- further grist for model revision.

"Our work over the last five years has been focused on resolving the discrepancies," said Nagayama. "And yet the new results mean new science may be necessary to account for them."

To explain new experimental results, physicists are examining new models. One, called two-photon opacity, explores the idea that an element may absorb two photons at a time instead of the one thought standard.

"If this multi-photon absorption is considered in the model, it would enhance the calculated iron opacity and may resolve the discrepancy," he said.

If correct, the new physics model must calculate the opacity increase only for iron, since model and data already agree for chromium and nickel.

Other experimental limitations include the fact that little is known about the structure of the sun inside particular distances from the sun's center.

"Is the discrepancy worse if you go even deeper in the sun?" Nagayama asked. "We don't know. It all depends on what's causing the discrepancy. We may find that the discrepancy is even worse in the solar core, or the problem may be isolated to the region around 0.7 solar radii, the distance which matches the energies at which these experiments were performed."

Answering those questions should lead to a more accurate model, he said.

"Experiments of hot dense plasma are challenging enough that we should not rule out the possibility of error," Nagayama said. "And the science impact is enormous -- this obligates us to continue examining the experiment's validity."

EVANSTON, Ill. -- An international team of astronomers, including Northwestern University's Farhad Yusef-Zadeh, has discovered one of the largest structures ever observed in the Milky Way. A newly spotted pair of radio-emitting bubbles reach hundreds of light-years tall, dwarfing all other structures in the central region of the galaxy.

The team believes the enormous, hourglass-shaped structure likely is the result of a phenomenally energetic burst that erupted near the Milky Way's supermassive black hole several million years ago.

"The center of our galaxy is relatively calm when compared to other galaxies with very active central black holes," said Ian Heywood of the University of Oxford, first author of study. "Even so, the Milky Way's central black hole can -- from time to time -- become uncharacteristically active, flaring up as it periodically devours massive clumps of dust and gas. It's possible that one such feeding frenzy triggered powerful outbursts that inflated this previously unseen feature."

The paper will publish on Sept. 11 in the journal Nature. The study's co-authors represent 15 institutions, including Northwestern, Oxford, the South African Radio Astronomy Observatory in Cape Town and the National Radio Astronomy Observatory in Charlottesville, Virginia.

For this work, the team used the South African Radio Astronomy Observatory (SARAO) MeerKAT telescope, the largest science project in Africa. This is the first paper detailing research completed with MeerKAT's full 64-dish array since its launch in July 2018.

Mysteries of the Milky Way

More turbulent and unusually active compared to rest of the Milky Way, the environment surrounding our galaxy's central black hole holds many mysteries. Northwestern's Yusef Zadeh, a senior author of the paper, has dedicated his career to studying the physical processes that occur in the Milky Way's mystifying center.

In the early 1980s, Yusef-Zadeh discovered large-scale, highly organized magnetic filaments in the center of the Milky Way, 25,000 light-years from Earth. While their origin has remained an unsolved mystery ever since, the filaments are radio structures stretching tens of light-years long and one light-year wide.

"The radio bubbles discovered with MeerKAT now shed light on the origin of the filaments," Yusef-Zadeh said. "Almost all of the more than 100 filaments are confined by the radio bubbles."

Yusef-Zadeh is a professor of physics and astronomy at Northwestern's Weinberg College of Arts and Sciences and a member of CIERA (Center for Interdisciplinary Exploration and Research in Astrophysics), an endowed research center at Northwestern focused on advancing astrophysics studies with an emphasis on interdisciplinary connections.

The researchers believe that the close association of the filaments with the bubbles implies that the energetic event that created the radio bubbles also is responsible for accelerating the electrons required to produce the radio emission from the magnetized filaments.

Tracing energetic regions

Using MeerKAT, the research team mapped out broad regions in the center of the galaxy, conducting observations at wavelengths near 23 centimeters. Radio emission of this kind is generated in a process known as synchrotron radiation, in which electrons moving at close to lightspeed interact with magnetic fields. This produces a characteristic radio signal that can be used to trace energetic regions in space. The radio light seen by MeerKAT easily penetrates the dense clouds of dust that block visible light from the center of the galaxy.

By examining the nearly identical extent and morphology of the twin bubbles, the researchers think they have found convincing evidence that these features were formed from a violent eruption that over a short period of time punched through the interstellar medium in opposite directions.

"These enormous bubbles have until now been hidden by the glare of extremely bright radio emission from the center of the galaxy," said Fernando Camilo of SARAO in Cape Town and co-author on the paper. "Teasing out the bubbles from the background noise was a technical tour de force, only made possible by MeerKAT's unique characteristics and ideal location. With this unexpected discovery we're witnessing in the Milky Way a novel manifestation of galaxy-scale outflows of matter and energy, ultimately governed by the central black hole."

EPFL scientists are developing new approaches for improved control of robotic hands - in particular for amputees - that combines individual finger control and automation for improved grasping and manipulation. This interdisciplinary proof-of-concept between neuroengineering and robotics was successfully tested on three amputees and seven healthy subjects. The results are published in today's issue of Nature Machine Intelligence.

The technology merges two concepts from two different fields. Implementing them both together had never been done before for robotic hand control, and contributes to the emerging field of shared control in neuroprosthetics.

One concept, from neuroengineering, involves deciphering intended finger movement from muscular activity on the amputee's stump for individual finger control of the prosthetic hand which has never before been done. The other, from robotics, allows the robotic hand to help take hold of objects and maintain contact with them for robust grasping.

"When you hold an object in your hand, and it starts to slip, you only have a couple of milliseconds to react," explains Aude Billard who leads EPFL's Learning Algorithms and Systems Laboratory. "The robotic hand has the ability to react within 400 milliseconds. Equipped with pressure sensors all along the fingers, it can react and stabilize the object before the brain can actually perceive that the object is slipping. "

How shared control works

The algorithm first learns how to decode user intention and translates this into finger movement of the prosthetic hand. The amputee must perform a series of hand movements in order to train the algorithm that uses machine learning. Sensors placed on the amputee's stump detect muscular activity, and the algorithm learns which hand movements correspond to which patterns of muscular activity. Once the user's intended finger movements are understood, this information can be used to control individual fingers of the prosthetic hand.

"Because muscle signals can be noisy, we need a machine learning algorithm that extracts meaningful activity from those muscles and interprets them into movements," says Katie Zhuang first author of the publication.

Next, the scientists engineered the algorithm so that robotic automation kicks in when the user tries to grasp an object. The algorithm tells the prosthetic hand to close its fingers when an object is in contact with sensors on the surface of the prosthetic hand. This automatic grasping is an adaptation from a previous study for robotic arms designed to deduce the shape of objects and grasp them based on tactile information alone, without the help of visual signals.

Many challenges remain to engineer the algorithm before it can be implemented in a commercially available prosthetic hand for amputees. For now, the algorithm is still being tested on a robot provided by an external party.

"Our shared approach to control robotic hands could be used in several neuroprosthetic applications such as bionic hand prostheses and brain-to-machine interfaces, increasing the clinical impact and usability of these devices," Silvestro Micera, EPFL's Bertarelli Foundation Chair in Translational Neuroengineering, and Professor of Bioelectronics at Scuola Superiore Sant'Anna.

Modern atomic clocks are the most accurate measurement tools currently available. The best current instruments deviate by just one second in 30 billion years. However, even this extraordinary level of precision can be improved upon. Indeed, a clock based on an excited nuclear state of thorium-229 should make it possible to enhance timing accuracy by another order of magnitude. Now a research team led by Ludwig-Maximilians-Universitaet (LMU) in Munich physicist Peter Thirolf, in collaboration with colleagues at the Max Planck Institute for Nuclear Physics in Heidelberg, the GSI Helmholtzzentrum für Schwerionenforschung in Darmstadt, Mainz University, Helmholtz Institute Mainz, the University of Bonn and the Technical University of Vienna has taken an important step towards such a clock. Indeed, the new study is featured on the title page of the leading journal Nature. In the paper, the authors report that they have succeeded in quantifying the energy released by the decay of the excited thorium-229 nucleus, which is an essential prerequisite for the realization of a thorium-based nuclear clock.

Unlike current atomic clocks, which make use of oscillations in the outer electron shells of atoms, nuclear clocks employ oscillations within the nucleus as their timekeeper. In both cases, the oscillations are the product of transitions between defined energy levels, which can be excited by laser light of a specific wavelength. Typically, the energies required to excite oscillations in the vast majority of atomic nuclei are orders of magnitude higher than those required to stimulate transitions in the orbital shells of electrons - which precludes the use of conventional lasers for this purpose. However, there is only one viable candidate for the development of a nuclear clock - the thorium-229 nucleus. Its excited state is located at an energy that is by far the lowest of any state found in the approximately 3800 currently known atomic nuclei. Irradiation with UV light, which is within the capability of lasers now available, is sufficient to populate this excited state.

However, up to now, the precise energy required to generate the excited thorium-229 has remained unknown. "To induce the nuclear transition, the wavelength of the laser light must be tuned to match the transition energy exactly. We have now succeeded in measuring this precisely for the first time," says Benedict Seiferle, lead author of the new paper.

For these measurements, carried out at LMU, the authors of the study made use of the doubly charged thorium-229 cation. Sources providing this cation in the excited nuclear state were developed in Mainz and then placed inside of a dedicated ion trap developed at LMU. The excited state of the cation has a lifetime of hours. This is relatively long for an excited nuclear state and is crucial for the future development of the clock, but it hampers measurement of the decay energy. "This long lifetime means that decay to the ground state occurs only rarely. As measurement of this decay was the goal of our experiment, we exploited the fact that decay occurs rapidly when the cations are given the opportunity to collect the missing electrons," says Seiferle.

To provide electrons, Seiferle and colleagues guided the ions through a layer of graphene. On its way through this layer, each ion picks up two electrons and emerges as a neutral atom on the other side. Thanks to this controlled neutralization step, the excited state then decays to the ground state within a few microseconds. The neutralized atoms expel an electron from an outer atomic shell, thus generating a positively charged thorium-229 ion. The kinetic energy of the free electron depends on the excitation energy of the nuclear state and is determined using an electron spectrometer. However, this energy is only a fraction of the energy used to generate the excited nuclear state. The rest remains in the thorium-229, which renders the interpretation of the resulting spectra complex. To get around this problem, the authors based at the Max-Planck Institute for Theoretical Physics in Heidelberg calculated the spectra to be expected. With the aid of these predictions, and in collaboration with their colleagues in Vienna and Bonn, the team in Munich was then able to determine the energy actually associated with the decay of the excited nuclear state.

The result indicates that the thorium-229 nucleus can be excited to this level by irradiation with laser light at a wavelength of around 150 nanometers. Now lasers specifically designed to emit in this wavelength range can be constructed. This step will bring the first nuclear clock a great deal closer to practical realization. The researchers believe that a thorium-based nuclear clock will open up new avenues in the basic sciences, but will also find many applications, which only become possible on the basis of extremely precise measurements in the time domain.

Groundwater is essential for growing crops, but new research shows climate change is making it harder for soil to absorb rainfall.

While the idea that soil particles rearrange themselves in response to environmental conditions is not new, scientists once thought these shifts in the ground happened slowly. Not anymore.

A study published today in Science Advances shows increased rainfall reduces the rate at which water can move into the soil, and that this change happens fast -- it only takes a few years or decades, not centuries as scientists previously assumed.

UC Riverside soil scientist Daniel Hirmas, who participated in the study, said the repercussions of rainfall-induced changes to soil's ability to absorb water extend beyond agriculture.

"These findings mean that more water heads into streams or lakes instead of into the ground, potentially increasing susceptibility to flash floods," he said.

"The ability for soil to store carbon is also dependent on groundwater," he said. "Thus, carbon stores may be impacted via this change in soil properties. There is the potential for carbon to move into other places either in the environment or atmosphere if it isn't being retained in the ground as much."

Hirmas and a team of scientists examined the dirt from different plots of prairie land in Kansas, some subjected to 25 years of simulated extra rainfall from sprinklers, and some that were not.

The team, including scientists from Rutgers, Temple, University of Kansas, Kansas State and Colorado State universities, then examined samples of soil from both the sprinkler irrigated and nonirrigated sites.

They found that the architecture of the soils, meaning the organization of particles and large pores in the samples, were different.

In the irrigated soil, plant roots clogged the open pores more often, causing samples to retain slightly more water than the soil not affected by simulated rainfall. The roots respond to extra water either from rain or atmospheric humidity, taking up residence in and reducing the space available in soil pores.

The team also found irrigated soils were less able to expand or contract because of more constant soil moisture conditions. Soil expands when it gets wet and shrinks when it dries. If conditions are more consistently wet, the expansion and contraction isn't happening as much.

Given that rainfall and other environmental conditions are likely to continue shifting rapidly across the globe, it follows that soil conditions worldwide could also shift fairly rapidly.

The next step is to expand these investigations to a wider array of soil types and environmental conditions, so scientists can eventually apply what they've learned to other regions of the world.

In addition, these findings are likely to have implications for climate modeling work.

"Future climate models need to account for these dynamic soil changes to more accurately predict effects of climate change on groundwater, carbon storage, and food security."

Nocturnal and diurnal mammals see the same - but only for a brief time. When mice are born, the chromatin in the cells of their eyes has a diurnal structure. Day by day, the layout of this chromatin slowly inverts, allowing the mice to see at night. How this change happens was a mystery.

Sungrim Seirin-Lee, Associate Professor, and Hiroshi Ochiai, Lecturer, in the Graduate School of Integrated Sciences for Life at HU, suspected that the chromatin was making the shape of the nuclei change shape. "When we started this research, our hypothesis was based 100 percent on mathematics," Seirin-Lee said. "Because of our mathematical modeling, we found that nuclear deformation might be a key point in DNA's structure change."

If we could see inside of the nucleus, we would see that chromatin comes in different types and territories. Around the center of the nucleus is euchromatin, or DNA that is largely active. Heterochromatin, on another hand, is a kind of DNA that lies around the envelope or ceiling of the nucleus. Unlike euchromatin, the gene activation of heterochromatin is low.

Between nocturnal and diurnal animals, though, the differences in nuclear architecture get bigger - especially around the retina. The DNA is in the center of the nucleus in nocturnal mammals. Usually, heterochromatin stays put in the nuclear envelope. In the case of nocturnal animals, though, Seirin-Lee and Ochiai found it can be moved by the nucleus changing shape.

To describe the movement of chromatin, Seirin-Lee and her colleagues used a type of mathematical modeling called phase-field modeling. A method commonly used in physics; phase-field modeling can be used to do things like telling apart ice from water. However, according to Seirin-Lee, "it is not common in the biological sciences. In chromatin dynamics, it is the first trial in the world!" Using this function, the group could see the movement of chromatin and nucleus by determining and defining the inside and outside of the nucleus, as well as euchromatin versus heterochromatin.

When the group observed heterochromatin in the mouse's eyes, they found that conditional architecture triggered dynamic deformation, which resulted in an inverted nuclear architecture. In the inverted architecture case, two proteins are removed, which allows heterochromatin to move.

Then, with the assistance Ochiai, they put their model to the test on neural stem cells, which mimic retinal cells. After treating the cells with proteins that keep heterochromatin at the nuclear periphery, deformation stopped. Chromatin clustering increased, and nuclear architecture could not finish inverting. This finding was consistent with Lee's mathematical modeling.

Ultimately, Seirin-Lee and her colleagues want to see if their findings are universal to mammal cells. "At this stage, we think it is just mouse eyes," Seirin-Lee said, "but we don't know! Maybe humans could have such structures by dynamic nuclear deformation." Next, Seirin-Lee is looking to tackle the intermediate structure, or a sort of hybrid between conventional and inverted architecture of the nucleus.

The proportion of young people in Finland diagnosed with depression in specialised services is increasing, showed a study based on an extensive set of national data. An increasing number of adolescents seek and get help, but the increase in service use burdens specialised services. The study was conducted by the Research Centre for Child Psychiatry at the University of Turku in Finland.

The proportion of individuals who received a diagnosis by the age of 15 in specialised services increased 53% among boys and 65 % among girls born between 1994 and 2000 compared to young people born between 1987 and 1993.

According to the lead author, Dr Svetlana Filatova from the Research Centre for Child Psychiatry, the results do not imply an increase in depression among adolescents.

"The results can most probably be explained by an increase in service use. An increasing number of depressed adolescents get help at an early stage which is positive," says Filatova.

There has been an increase in the use of psychiatric services among adolescents in the past 20 years both in Finland and worldwide.

"The increase in service use can reflect better identification of depression and a more positive attitude to mental health," Filatova continues.

Examining Temporal Changes Identifies Challenges in Healthcare

Knowledge of time trends for depression is important for disease prevention and healthcare planning. However, few studies until now have examined these for the incidence and cumulative incidence of diagnosed depression from childhood to early adulthood.

According to Docent David Gyllenberg from the Research Centre for Child Psychiatry, it is important to monitor changes in the incidence of depression to timely address challenges faced by mental health services.

"The rapid increase in the number of children and adolescents diagnosed with depression poses a burden for specialised mental health services that need to provide evidence-based treatment for a growing patient population," Gyllenberg stresses.

The data consisted of 1,240,062 persons including 37,682 individuals with a depression diagnosis who had visited specialised care at least once. 10% of females and 5% of males who had been followed up to the age of 25 had been diagnosed with depression.

The frigid waters of the Antarctic may yield a treatment for a deadly disease that affects populations in some of the hottest places on earth. Current medications for that scourge -- malaria -- are becoming less effective as drug resistance spreads. But researchers report in ACS' Journal of Natural Products that a peptide they isolated from an Antarctic sponge shows promise as a lead for new therapies.

Some 219 million cases of malaria were reported worldwide in 2017, according to the World Health Organization, with 435,000 people having died from the disease in that year. Symptoms begin with fever and chills, which can be followed by severe anemia, respiratory distress and organ failure. The parasite responsible for malaria is transmitted to people through mosquito bites. It spends some of its lifecycle first in the liver, where it reproduces, and then it moves into the blood. Conventional treatments based on artemisinin and its derivatives hold the parasite in check when it is in patients' blood, but the parasites are increasingly becoming resistant to these medications. One solution is to attack the organism at an earlier stage in its lifecycle, when there are fewer parasites, and resistance might not have developed yet -- namely, when it's in the liver. In their search for a suitable pharmaceutical weapon, Bill J. Baker and colleagues turned to sponges, which rely on an array of chemical defenses to fight off predators.

The team screened a collection of natural products extracted from a Southern Ocean sponge known as Inflatella coelosphaeroides. One compound, which they dubbed friomaramide, blocked infection and development of the malaria parasite Plasmodium falciparum in liver cells in a culture dish as effectively as primaquine, one of the few existing liver-stage treatments. Friomaramide is also nontoxic to the liver cells themselves. The researchers determined that the compound is a linear peptide with a distinctive structure, which they say makes it a promising framework for producing new leads for malaria treatment.