Culture

Climate signals detected in global weather

image: North American surface temperatures for Dec. 26, 2017-Jan. 2, 2018: even if it is extremely cold in a region, this does not mean that climate change has stopped.

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Source: NASA Earth Observatory

In October this year, weather researchers in Utah measured the lowest temperature ever recorded in the month of October in the US (excluding Alaska): -37.1°C. The previous low-temperature record for October was -35°C, and people wondered what had happened to climate change.

Until now, climate researchers have responded that climate is not the same thing as weather. Climate is what we expect in the long term, whereas weather is what we get in the short term - and since local weather conditions are highly variable, it can be very cold in one location for a short time despite long-term global warming. In short, the variability of local weather masks long-term trends in global climate.

A paradigm shift

Now, however, a group led by ETH professor Reto Knutti has conducted a new analysis of temperature measurements and models. The scientists concluded that the weather-is-not-climate paradigm is no longer applicable in that form. According to the researchers, the climate signal - that is, the long-term warming trend - can actually be discerned in daily weather data, such as surface air temperature and humidity, provided that global spatial patterns are taken into account.

In plain English, this means that - despite global warming - there may well be a record low temperature in October in the US. If it is simultaneously warmer than average in other regions, however, this deviation is almost completely eliminated. "Uncovering the climate change signal in daily weather conditions calls for a global perspective, not a regional one," says Sebastian Sippel, a postdoc working in Knutti's research group and lead author of a study recently published in Nature Climate Change.

Statistical learning techniques extract climate change signature

In order to detect the climate signal in daily weather records, Sippel and his colleagues used statistical learning techniques to combine simulations with climate models and data from measuring stations. Statistical learning techniques can extract a "fingerprint" of climate change from the combination of temperatures of various regions and the ratio of expected warming and variability. By systematically evaluating the model simulations, they can identify the climate fingerprint in the global measurement data on any single day since spring 2012.

A comparison of the variability of local and global daily mean temperatures shows why the global perspective is important. Whereas locally measured daily mean temperatures can fluctuate widely (even after the seasonal cycle is removed), global daily mean values show a very narrow range.

If the distribution of global daily mean values from 1951 to 1980 are then compared with those from 2009 to 2018, the two distributions (bell curves) barely overlap. The climate signal is thus prominent in the global values but obscured in the local values, since the distribution of daily mean values overlaps quite considerably in the two periods.

Application to the hydrological cycle

The findings could have broad implications for climate science. "Weather at the global level carries important information about climate," says Knutti. "This information could, for example, be used for further studies that quantify changes in the probability of extreme weather events, such as regional cold spells. These studies are based on model calculations, and our approach could then provide a global context of the climate change fingerprint in observations made during regional cold spells of this kind. This gives rise to new opportunities for the communication of regional weather events against the backdrop of global warming."

The study stems from a collaboration between ETH researchers and the Swiss Data Science Center (SDSC), which ETH Zurich operates jointly with its sister university EPFL. "The current study underlines how useful data science methods are in clarifying environmental questions, and the SDSC is of great use in this," says Knutti. Data science methods not only allow researchers to demonstrate the strength of the human "fingerprint", they also show where in the world climate change is particularly clear and recognisable at an early stage. This is very important in the hydrological cycle, where there are very large natural fluctuations from day to day and year to year. "In future, we should therefore be able to pick out human-induced patterns and trends in other more complex measurement parameters, such as precipitation, that are hard to detect using traditional statistics," says the ETH professor.

Credit: 
ETH Zurich

Study: Hearing develops in tandem with form and function

image: Electron microscopy images reveal the classic stair-stepping form of mature hair bundles in the inner ear of mice. New research provides important clues about how scientists might develop techniques to regenerate hair cells and reverse hearing loss.

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Oregon Health & Science University

New research reveals a key insight into the development of hair bundles, the intricately complex assemblies in the inner ear responsible for hearing.

Hair bundles are precisely arranged cellular structures deep within the spiral cavity of the inner ear. Together, they convert vibrational energy into electrical signals in the brain that translate into the sensation of hearing. Once they're lost - whether by loud noise, toxins, disease or aging - they do not naturally regenerate in people and other mammals.

The new research led by scientists at Oregon Health & Science University provides important clues that may help scientists develop new techniques to regenerate hair cells and reverse hearing loss.

In the study published in the journal Current Biology, researchers discovered the development of hair bundles occurs in a kind of feedback loop in which form follows function and function drives form.

Using mice, which closely model human hearing, the researchers found stereocilia, roughly 100 of which are assembled into a hair bundle, widened simultaneously with the onset of mechanotransduction - the action of converting mechanical signals in the form of sound into electrical signals measured within the brain. The stereocilia only elongated to their mature lengths after transduction had been established.

It turns out that form and function are mutually reinforcing.

"We've been looking at these as separate pathways," said lead author Jocelyn Krey, Ph.D., staff scientist in the Oregon Hearing Research Center and the Vollum Institute at OHSU. "But in the course of this research, we observed the change in form occurs at the same time as the conversion of mechanical to electrical signals. So we're seeing these happen together, and feeding each other in a way we hadn't seen before."

The researchers discovered when they examined mice lacking transduction or used a compound to block transduction, the animals did not develop the classic staircase-shaped form of mature hair bundles.

Researchers say the study suggests that new techniques to reverse hearing loss should focus on the critical importance of early development.

"In the future, with the rapid development of gene editing tools like CRISPR, we will be able to turn on genes at will," said senior author Peter Barr-Gillespie, Ph.D., professor in the Oregon Hearing Research Center and senior scientist in the Vollum Institute. "I have no doubt we will be there in 5 or 10 years."

Credit: 
Oregon Health & Science University

Some learning is a whole-brain affair, study shows

image: AMPA receptors in green on neurons in magenta at one time point in a live mouse.

Image: 
Richard Roth and Richard Huganir

Researchers at Johns Hopkins Medicine have successfully used a laser-assisted imaging tool to "see" what happens in brain cells of mice learning to reach out and grab a pellet of food. Their experiments, they say, add to evidence that such motor-based learning can occur in multiple areas of the brain, even ones not typically associated with motor control.

"Scientists should be looking at the entire brain to understand specific types of learning," says Richard Huganir, Ph.D., Bloomberg Distinguished Professor and Director of the Solomon H. Snyder Department of Neuroscience at the Johns Hopkins University School of Medicine. "Different parts of the brain contribute to learning in different ways, and studying brain cell receptors can help us decipher how this works."

The work, say the researchers, may ultimately inform efforts to develop treatments for learning-based and neurocognitive disorders.

In a report on the work, appearing online Dec. 31 in Neuron, Huganir and his research team say they focused on AMPA-type glutamate receptors, or AMPARs, key molecules that help send messages between brain cells called neurons. AMPARs function like antennas that form along the surface of a particular spot on neurons called a synapse, where it receives molecular signals from other neurons.

To monitor and measure AMPAR levels in mouse brains, scientists previously had to dissect the organ before and after a learning experiment and compare differences. Now, scientists have ways to directly view the brain during learning, recording thousands of synapses at a time.

In the new experiments, scientists injected DNA-encoding AMPARs carrying a fluorescent tag into the brains of mice, and used an electrical pulse to get neurons to absorb the AMPAR DNA. Next, with a tool called two-photon microscopy, the scientists used a laser -- essentially an intensely focused beam of light -- to detect and measure the amount of fluorescence coming from the tagged AMPARs.

More fluorescence is an indication of increased AMPAR activity and messaging between neurons, a good sign that learning and memory building is taking place in those neurons, Huganir says.

To "see" what learning looked like in the test animals' neurons, Huganir's team trained mice to reach for and grab a food pellet placed just outside their cage using their paws. Normally, mice get pellets with their mouths.

While the mice were learning how to reach for the pellet, the scientists found an approximately 20% increase in the activity of AMPARs in an area of the brain known as the motor cortex, which is known for controlling and precisely moving muscles. On neurons, the AMPARs look like lights on a Christmas tree and glow brighter with increasing activity.

But the experiments also showed the same increase in AMPAR activity levels in the visual cortex too.

"This made sense because vision is very important for motor control," says Richard Roth, Ph.D., currently a postdoctoral fellow at Stanford University, but who performed experiments for this study as a graduate student in Huganir's laboratory.

"So, we did the same experiment again, but with the lights switched off," says Roth.

Using infrared light, which the mice couldn't see, the mice eventually learned to successfully grab the food, but there was a smaller increase (10%) in the activity of AMPARs in the visual cortex.

"We believe the mice brains are using different sets of sensory cues in the dark to learn the motor task, including touch and smell, enabling these other senses to take over," says Roth.

Next, the research team repeated the experiments using specialized light-activated modulators to shut down neurons in either the motor or visual cortex.

If the mice were trained to get the pellet with the room lights on, the mice could not complete the task if their visual cortex was shut down. "Clearly, these mice relied on learning centralized in their visual cortex to reach the pellet," says Roth.

However, mice initially trained to grab the pellet in the dark could still complete the task, even if their visual cortex was shut down.

"We've traditionally thought that motor-based learning happens solely in the motor part of the brain, but our studies and others now show that it's not as specific as we had thought. There is more of a brainwide effect in learning," says Roth.

Huganir notes that among the genes that control neuronal receptors involved in learning is SYNGAP. His and others' research has shown that when the gene is mutated, it contributes to conditions including intellectual disability, autism and schizophrenia -- all conditions marked in part by disrupted thinking and learning.

Credit: 
Johns Hopkins Medicine

GMRT discovers a gigantic ring of hydrogen gas around a distant galaxy

image: The optical image from the CFHT telescope with the distribution of neutral hydrogen in the form of a large ring shown in red as observed by the GMRT. The other two red blobs show the distribution of neutral hydrogen around two other galaxies which are in the vicinity of the ring.

Image: 
O. Bait (NCRA-TIFR/GMRT), Duc (ObAS/CFHT)

A team of astronomers at the National Centre for Radio Astrophysics (NCRA) in Pune, India have discovered a mysterious ring of hydrogen gas around a distant galaxy, using the Giant Metrewave Radio Telescope (GMRT). The ring is much bigger than the galaxy it surrounds and has a diameter of about 380,000 light-years (about 4 times that of our Milky Way).

The galaxy (named AGC 203001), is located about 260 million light-years away from us. There is only one other such known system with such a large neutral hydrogen ring. The origin and formation of such rings is still a matter of debate among astrophysicists.

Neutral hydrogen emits radio waves at a wavelength of about 21cm. This radiation from neutral hydrogen atoms has allowed radio astronomers to map the amount and distribution of neutral hydrogen gas in our Milky Way galaxy and in other galaxies in the Universe. Typically, large reservoirs of neutral hydrogen gas are found in galaxies which are actively forming new stars. However, despite showing no signs of active star formation the galaxy AGC 203001 was known to have large amounts of hydrogen, although its exact distribution was not known. The unusual nature of this galaxy motivated astronomers in NCRA to use the GMRT to conduct high-resolution radio observation of this galaxy to find out where in the galaxy this gas lies.

The GMRT observations revealed that the neutral hydrogen is distributed in the form of a large off-centered ring extending much beyond the optical extent of this galaxy. More puzzlingly, the astronomers found that the existing optical images of the ring showed no sign of it containing stars. In collaboration with two French astronomers, Pierre-Alain Duc and Jean-Charles Cuillandre, the NCRA team obtained a very sensitive optical image of this system using the Canada-France-Hawaii-Telescope (CFHT) in Hawaii, USA. However, even these images do not show any sign of starlight associated with the hydrogen ring.

There is no clear answer today as to what could lead to the formation of such large, starless rings of hydrogen. Conventionally, galaxy-galaxy collisions were thought to lead to the formation of such off-centered rings around galaxies. However, such rings also generally contain stars. This is contrary to what is found in this ring. Figuring out how this ring was formed remains a challenge to astronomers.

Encouraged by this discovery, the team is now conducting a large survey to map the neutral hydrogen around several more similar galaxies. If some of them also show rings like this, it should help us to better understand the formation mechanism behind such rare rings.

This work was led by Omkar Bait, a doctoral student at NCRA working under the supervision of Yogesh Wadadekar. This work forms a part of Omkar's doctoral thesis. Sushma Kurapati, who is another doctoral student at NCRA also played a role in the radio observations. Other expert scientists who contributed include, Pierre-Alain Duc (Universite de Strasbourg, Strasbourg, France), Jean-Charles Cuillandre (PSL University, Paris, France), Peter Kamphuis (Ruhr University, Bochum, Germany) and Sudhanshu Barway (Indian Institute of Astrophysics, Bengaluru, India).

Credit: 
Tata Institute of Fundamental Research

Closer to identifying leukemic stem cells

image: Representative flow cytometric study of the alkaline phosphatase activity in a patient of the ALP ? 12% group. Alkaline phosphatase positive cells are represented in combination with CD34 staining at diagnosis (upper row) and after relapse (lower row). Reference contour plots for two bone marrow aspirates are compared in the same patient, displaying high levels of alkaline phosphatase activity in combination with CD34 staining. The statistics in the region represents percentage of the gate.

Image: 
Jordi Petriz

Acute myeloid leukemia is the most common type of leukemia in adults. It is characterized by the pathological expansion of immature cells (myeloblasts) that invade the bone marrow and expand into the blood, affecting the production of the rest of the healthy cells. Although patients usually respond well to chemotherapy-based treatments, a large proportion of them eventually relapse or show resistance to these procedures.

The cause of relapse or resistance to treatment is sometimes due to the existence of leukemic stem cells capable of starting cancer again, and in turn, for being resistant to chemotherapy. However, identifying them is a challenge since there are no specific markers to detect and isolate them.

The Functional Cytomics Research Group at the Josep Carreras Leukaemia Research Institute has developed innovative trials that allow the identification of these cells by testing the activity of a protein, alkaline phosphatase, present in myeloblasts.

To do this, they have used advanced cytomical methodologies that allow multiple functional characteristics to be analyzed cell by cell, individually, in a very few minutes.

The researchers identified a group of patients whose leukemic cells had high levels of alkaline phosphatase activity and another group of patients with lower levels of this activity. Both groups showed a differential response to chemotherapy treatment, with the most active phosphatase group showing the worst reaction to treatment and the shortest survival. Surprisingly, no significant association was detected between the results obtained through different cytogenetic analysis techniques and molecular studies, with the determination of prognostic factors of greater or lesser risk.

"These results represent a new approach to improve the prognosis in the diagnostic evaluation of acute myeloid leukemia and to estimate the probability of relapse and persistence of the disease. This will allow us to open new lines of research aimed at applying alternative strategies in terms of treatment," said Dr. Jordi Petriz, director of the study.

Credit: 
Josep Carreras Leukaemia Research Institute

MIPT physicists find ways to overcome signal loss in magnonic circuits

image: Study co-author Alexander Sadovnikov and the experimental setup for Brillouin spectroscopy.

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Image courtesy of Dmitry Kalyabin

Researchers from the Moscow Institute of Physics and Technology, Kotelnikov Institute of Radio Engineering and Electronics, and N.G. Chernyshevsky Saratov State University have demonstrated that the coupling elements in magnonic logic circuits are so crucial that a poorly selected waveguide can lead to signal loss. The physicists developed a parametric model for predicting the waveguide configuration that avoids signal loss, built a prototype waveguide, and tested the model in an experiment. Their paper was published in the Journal of Applied Physics.

The underlying goal of the research on magnonic logic is creating alternative circuit elements compatible with the existing electronics. This means developing completely new elements, including faster signal processors with low power consumption, that could be incorporated into present-day electronics.

In designing new devices, various components are integrated with each other. However, magnonic circuits rely on magnetic waveguides rather than wires for this. Researchers previously conjectured that waveguides could have an adverse effect on signal intensity in transmission from one component to another.

The recent study by the Russian physicists has shown the waveguides to have a greater effect than anticipated. In fact, it turns out that a poorly chosen waveguide geometry can result in complete signal loss. The reason for this is spin wave interference. Waveguides are extremely miniature components, measuring hundredths of a micrometer, and on this scale, the lateral quantization of the signal needs to be accounted for.

The researchers worked on an optimization problem: How does one design a waveguide for magnonic circuits to ensure maximum efficiency? The team developed a theory and a mathematical model to describe wave propagation in nanosized waveguides. To this end, senior researcher Dmitry Kalyabin of MIPT's Terahertz Spintronics Lab, adapted the team's previous results developed for acoustic systems to spin waves.

His colleagues in Saratov then created a prototype device and verified Kalyabin's calculations using a method known as Brillouin spectroscopy. This technique involves making a "snapshot" of the magnetization distribution in a sample following its exposure to laser light. The distribution observed in this way can then be compared with theoretical predictions.

"We initially aimed to build a model that enables calculating the throughput characteristics of a waveguide before it was actually made. Our expectation was that optimizing the shape of the waveguide would maximize signal transmission efficiency. But our research revealed the effects of interference to be greater than anticipated, with suboptimal parameters sometimes rendering the signal completely lost," said Sergey Nikitov, the head of the Terahertz Spintronics Lab and a corresponding member of the Russian Academy of Sciences.

Although the authors of the paper used the example of a tapering narrow ferromagnetic waveguide to demonstrate how their model works, it is applicable to the entire range of currently used waveguide types.

Credit: 
Moscow Institute of Physics and Technology

UNC expert helps treat astronaut's blood clot during NASA mission

image: Stephan Moll, M.D., at NASA.

Image: 
UNC School of Medicine

CHAPEL HILL, NC - "My first reaction when NASA reached out to me was to ask if I could visit the International Space Station (ISS) to examine the patient myself," said Stephan Moll, MD, UNC School of Medicine blood clot expert and long-time NASA enthusiast. "NASA told me they couldn't get me up to space quickly enough, so I proceeded with the evaluation and treatment process from here in Chapel Hill."

Moll was the only non-NASA physician NASA consulted when it was discovered that an astronaut aboard the ISS had a deep vein thrombosis (DVT) - or blood clot - in the jugular vein of their neck. The astronaut's identity is being kept anonymous for privacy reasons, so identifying information such as when this event happened is being omitted from the case study. We do know that the astronaut was two months into a six-month mission on the ISS when the DVT was discovered.

This was the first time a blood clot had been found in an astronaut in space, so there was no established method of treatment for DVT in zero gravity. Moll, a member of the UNC Blood Research Center, was called upon for his vast knowledge and treatment experience of DVT on Earth.

"Normally the protocol for treating a patient with DVT would be to start them on blood thinners for at least three months to prevent the clot from getting bigger and to lessen the harm it could cause if it moved to a different part of the body such as the lungs," Moll said. "There is some risk when taking blood thinners that if an injury occurs, it could cause internal bleeding that is difficult to stop. In either case, emergency medical attention could be needed. Knowing there are no emergency rooms in space, we had to weigh our options very carefully."

Moll and a team of NASA doctors decided blood thinners would be the best course of treatment for the astronaut. They were limited in their pharmaceutical options, however. The ISS keeps only a small supply of various medicines on board, and there was a limited amount of the blood thinner Enoxaparin (Lovenox®) available. Moll advised NASA on what dosage of Enoxaparin would effectively treat the DVT while also lasting long enough, until NASA could get a new shipment of drugs - which Moll helped select - to the ISS.

The course of treatment with Enoxaparin - a drug delivered by an injection into the skin - lasted for around 40 days. On day 43 of the astronaut's treatment, a supply of Apixaban (Eliquis®) - a pill taken orally- was delivered to the ISS by a supply spacecraft.

Throughout the treatment process, which lasted more than 90 days, the astronaut performed ultrasounds on their own neck with guidance from a radiology team on Earth in order to monitor the blood clot. Moll was also able to speak to the astronaut during this period through email and phone calls.

"When the astronaut called my home phone, my wife answered and then passed the phone to me with the comment, 'Stephan, a phone call for you from space.' That was pretty amazing," said Moll. "It was incredible to get a call from an astronaut in space. They just wanted to talk to me as if they were one of my other patients. And amazingly the call connection was better than when I call my family in Germany, even though the ISS zips around Earth at 17,000 miles per hour."

Four days before the astronaut's journey home to Earth, they stopped taking Apixaban. Moll and his NASA counterparts made that decision because of how physically demanding and potentially dangerous the re-entry process can be for astronauts, and they did not want an injury to be exacerbated by the use of blood thinners. The astronaut landed safely on Earth and the blood clot required no more treatment.

This astronaut's blood clot was asymptomatic - they didn't have any symptoms that would have otherwise made them aware of the clot. The DVT was discovered when the astronaut was taking ultrasounds of their neck for a research study on how body fluid is redistributed in zero gravity. If it wasn't for the study, there's no telling what the outcome could have been. That's why Moll continues to work with NASA and says there's a need for more research of how blood and blood clots behave in space.

"Is this something that is more common in space?" posed Moll. "How do you minimize risk for DVT? Should there be more medications for it kept on the ISS? All of these questions need answering, especially with the plan that astronauts will embark on longer missions to the moon and Mars."

Credit: 
University of North Carolina Health Care

Veterans report health as their No. 1 worry

(Boston)--Health concerns are the most important readjustment challenge facing veterans in the first year after they leave military service.

Every year, more than 200,000 U.S. service members transition out of military service. While many go on to have productive and fulfilling lives, researchers have called for greater attention to the military-to-civilian transition experience, suggesting that some military veterans may have difficulty securing meaningful employment, meeting health-care needs, and successfully integrating within civilian society.

In order to provide a descriptive picture of veterans' health and well-being in the first year after leaving military service based on their gender, military rank and deployment history, researchers studied more than 9,500 veterans.

The veterans were surveyed on their health, work, and social relationships within three months of leaving the military and then six months later. Among the findings: former enlisted personnel reported poorer outcomes on nearly all areas of well-being compared with officers, whereas deployed veterans reported poorer health and female veterans acknowledged more mental health concerns compared with their non-deployed and male peers.

"While many veterans indicated they had a chronic physical or mental health condition and were less satisfied with their health than other important aspects of their lives, many reported that they had found a job, were satisfied with their work and were well-integrated within their broader social communities," explained corresponding author Dawne S. Vogt, PhD, research psychologist in the Women's Health Sciences Division, National Center for PTSD at the VA Boston Healthcare System and associate professor of psychiatry at Boston University School of Medicine.

According to the researchers, the fact that veterans reported the poorest well-being in the health domain points to the importance of addressing veterans' health concerns at the time they leave military service, especially regarding chronic pain, sleep, anxiety and depression. "Given that some conditions may be in place prior to separation, it may also be necessary to bolster pre-separation health screening and intervention efforts," added Vogt.

Since health problems are known to erode broader well-being over time, the finding that many veterans reported chronic health concerns may have contributed to another key study result, which was that the proportion of veterans reporting good work functioning declined over the first year after leaving military service. "These findings point to the value of targeting intervention to at-risk veteran subgroups and implementing interventions before veterans' readjustment challenges worsen or have the chance to erode their broader well-being. This recommendation may require a fundamental re-thinking of how veteran programs prioritize efforts, as most transition support currently focuses on the needs of veterans with the most acute or chronic concerns."

These finding appear online in the American Journal of Preventive Medicine.

Credit: 
Boston University School of Medicine

Hearing through lip-reading

image: Speech entrainment during audio-only (top) and video-only (bottom).

Image: 
Bourguignon et al., <em>JNeurosci</em> 2019

Brain activity synchronizes with sound waves, even without audible sound, through lip-reading, according to new research published in JNeurosci.

Listening to speech activates our auditory cortex to synchronize with the rhythm of incoming sound waves. Lip-reading is a useful aid to comprehend unintelligible speech, but we still don't know how lip-reading helps the brain process sound.

Bourguignon et al. used magnetoencephalography to measure brain activity in healthy adults while they listened to a story or watched a silent video of a woman speaking. The participants' auditory cortices synchronized with sound waves produced by the woman in the video, even though they could not hear it. The synchronization resembled that in those who actually did listen to the story, indicating the brain can glean auditory information from the visual information available to them through lip-reading. The researchers suggest this ability arises from activity in the visual cortex synchronizing with lip movement. This signal is sent to other brain areas that translate the movement information into sound information, creating the sound wave synchronization.

Credit: 
Society for Neuroscience

A close look at thin ice

On frigid days, water vapor in the air can transform directly into solid ice, depositing a thin layer on surfaces such as a windowpane or car windshield. Though commonplace, this process is one that has kept physicists and chemists busy figuring out the details for decades.

In a new Nature paper, an international team of scientists describe the first-ever visualization of the atomic structure of two-dimensional ice as it formed. Insights from the findings, which were driven by computer simulations that inspired experimental work, may one day inform the design of materials that make ice removal a simpler and less costly process.

"One of the things that I find very exciting is that this challenges the traditional view of how ice grows," says Joseph S. Francisco, an atmospheric chemist at the University of Pennsylvania and an author on the paper.

"Knowing the structure is very important," adds coauthor Chongqin Zhu, a postdoctoral fellow in Francisco's group who led much of the computational work for the study. "Low-dimensional water is ubiquitous in nature and plays a critical role in an incredibly broad spectrum of sciences, including materials science, chemistry, biology, and atmospheric science.

"It also has practical significance. For example, removing ice is critical when it comes to things like wind turbines, which cannot function when they are covered in ice. If we understand the interaction between water and surfaces, then we might be able to develop new materials to make this ice removal easier."

In recent years, Francisco's lab has devoted considerable attention to studying the behavior of water, and specifically ice, at the interface of solid surfaces. What they've learned about ice's growth mechanisms and structures in this context helps them understand how ice behaves in more complex scenarios, like when interacting with other chemicals and water vapor in the atmosphere.

"We're interested in the chemistry of ice at the transition with the gas phase, as that's relevant to the reactions that are happening in our atmosphere," Francisco explains.

To understand basic principles of ice growth, researchers have entered this area of study by investigating two-dimensional structures: layers of ice that are only several water molecules thick.

In previous studies of two-dimensional ice, using computational methods and simulations, Francisco, Zhu, and colleagues showed that ice grows differently depending on whether a surface repels or attracts water, and the structure of that surface.

In the current work, they sought real-world verification of their simulations, reaching out to a team at Peking University to see if they could obtain images of two-dimensional ice.

The Peking team employed super-powerful atomic force microscopy, which uses a mechanical probe to "feel" the material being studied, translating the feedback into nanoscale-resolution images. Atomic force microscopy is capable of capturing structural information with a minimum of disruption to the material itself, allowing the scientists to identify even unstable intermediate structures that arose during the process of ice formation.

Virtually all naturally occurring ice on Earth is known as hexagonal ice for its six-sided structure. This is why snowflakes all have six-fold symmetry. One plane of hexagonal ice has a similar structure to that of two-dimensional ice and can terminate in two types of edges--"zigzag" or "armchair." Usually this plane of natural ice terminates with a zigzag edges.

However, when ice is grown in two dimensions, researchers find that the pattern of growth is different. The current work, for the first time, shows that the armchair edges can be stabilized and that their growth follows a novel reaction pathway.

"This is a totally different mechanism from what was known," Zhu says.

Although the zigzag growth patterns were previously believed to only have six-membered rings of water molecules, both Zhu's calculations and the atomic force microscopy revealed an intermediate stage where five-membered rings were present.

This result, the researchers say, may help explain the experimental observations reported in their 2017 PNAS paper, which found that ice could grow in two different ways on a surface, depending on the properties of that surface.

In addition to lending insight into future design of materials conducive to ice removal, the techniques used in the work are also applicable to probe the growth of a large family of two-dimensional materials beyond two-dimensional ices, thus opening a new avenue of visualizing the structure and dynamics of low-dimensional matter.

For chemist Jeffrey Saven, a professor in Penn Arts & Sciences who was not directly involved in the current work, the collaboration between the theorists in Francisco's group and their colleagues in China called to mind a parable he learned from a mentor during his training.

"An experimentalist is talking with theorists about data collected in the lab. The mediocre theorist says, 'I can't really explain your data.' The good theorist says, 'I have a theory that fits your data.' The great theorist says, 'That's interesting, but here is the experiment you should be doing and why.'"

To build on this successful partnership, Zhu, Francisco, and their colleagues are embarking on theoretical and experimental work to begin to fill in the gaps related to how two-dimensional ice builds into three dimensions.

"The two-dimensional work is fundamental to laying the background," says Francisco. "And having the calculations verified by experiments is so good, because that allows us to go back to the calculations and take the next bold step toward three dimensions."

"Looking for features of three-dimensional ice will be the next step," Zhu says, "and should be very important in looking for applications of this work."

Credit: 
University of Pennsylvania

Operating room reproductive hazards for female surgeons

What The Study Did: Researchers in this review article discuss occupational reproductive hazards for female surgeons in the operating room, including radiation exposure, surgical smoke, working conditions and physical demands, sharps injuries, anesthetic gases and the use of toxic agents.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

Authors: Matilda Anderson, M.B.B.S., M.P.H., of the Western Health Surgical Department, in Victoria, Australia, and Rose H. Goldman, M.D., M.P.H., of Harvard Medical School in Boston, are the authors.

(doi:10.1001/jamasurg.2019.5420)

Editor's Note: The article includes conflict of interest disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Credit: 
JAMA Network

Few people consider religious affiliation of hospital they choose

AURORA, Colo. (Jan. 2, 2020) - A small minority of Americans surveyed consider the religious affiliation of the hospitals that treat them, but a majority said they didn't want religious doctrine dictating their healthcare choices, according to a study by researchers at the University of Colorado Anschutz Medical Campus.

The study, published last week today in the journal JAMA Network Open, surveyed 1,446 adults and found that just 6.4% considered the religious affiliation of the hospitals they choose. Yet 71.4%, said that care should not be curtailed by religious dogma. This was especially true among women who are often denied certain reproductive healthcare at Catholic hospitals including birth control, tubal ligations and in vitro fertilization. Emerging health concerns related to transgender health and medical aid in dying have also highlighted conflicts in care for others.

"People may expect restrictions on abortions but they are surprised to find common services like birth control are also restricted," said the study's lead author Maryam Guiahi, MD, associate professor of obstetrics and gynecology at the University of Colorado School of Medicine. "They don't realize that they may not be getting care based on science but rather the care they get is based on religious dogma and doctrine."

Guiahi said religion-based hospitals, especially Catholic ones, are expanding rapidly across the country, particularly in the Midwest. Many have merged to create expansive healthcare systems that may not advertise their religious underpinnings.

A previous website analysis by Guiahi showed that less than a third of Catholic hospitals provided any description of the kinds of care restricted at their facilities.

In 2016, 18.5% of all hospitals were religiously-affiliated. Of those, 9.4% were Catholic non-profit hospitals, 5.1% were Catholic-affiliated, and 4% were affiliated with other religions. Between 2001 and 2016, the number of Catholic acute care hospitals grew by 22%. In 2016, ten of the top 25 healthcare systems were Catholic - nearly half of them located in the Midwest. In some places, they were the only hospitals available.

Providers at such facilities are expected to abide by the Ethical and Religious Directives for Catholic Health Care Services which limit reproductive and end-of-life care, the study said.

The researchers wanted to learn how much Americans actually care about the religious nature of the hospitals they choose and whether they believed such places had the right to override their medical desires based on religious dogma.

Prior surveys indicated that financial factors, travel distance and hospital size were the most important factors when choosing a hospital. But none had specifically asked about religious affiliation.

The researchers surveyed a cross-section of 1,446 adults - 51.5% men, 62.% white and the most common religion was Protestant. The majority didn't consider the religious affiliation of a hospital and didn't think it should impact their care. Only 193 respondents (13.4% of those surveyed) preferred a religious hospital.

The study revealed that 74.9% of women and 68.1% of men agreed with the statement that their healthcare should have priority over the doctrines of a religious hospital.

Guiahi noted a `discordance' between how most patients choose health facilities and their belief about how they should receive care.

"That suggests a general lack of understanding specific to the notion of `institutional conscience' and may cause conflicts in the delivery of care," she said.

The Trump Administration established the Conscience and Religious Freedom Division of the U.S. Dept. of Health and Human Services. The division broadens and enforces the right of religious health care institutions to deny care based on `institutional conscience.'

Guiahi said restricting care based on religious beliefs can be dangerous, especially for women.

"Given the growth in ownership by religious entities in the U.S. and increasing attention to conscientious objections," she said, "our findings point to a need for advocacy and legislation that effectively balance protections for religious institutions with protections for patients."

Credit: 
University of Colorado Anschutz Medical Campus

Rhythmicity of cluster headache

London, UK: A prospective study recently published in the journal Cephalalgia, the official journal of the International Headache Society, extends the idea behind cluster headache chronicity. The study, entitled "Temporal changes of circadian rhythmicity in cluster headache", was first-authored by Dr. Mi Ji Lee, from the Department of Neurology, Neuroscience Center, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.

Cluster headache (CH) is known in the medical literature as the most intense pain experienceable by humans and is popularly known as "suicidal headache". CH consists of a primary headache disorder, classed as a Trigeminal Autonomic Cephalalgia by the 3rd Version of the International Classification of Headaches Disorders - ICHD-3. It is characterized by severe or very severe unilateral orbital, supraorbital and/or temporal pain lasting 15-180 minutes, presenting with at least one of the following autonomic symptoms in the same side of the pain: conjunctival injection and/or lacrimation; nasal congestion and/or rhinorrhea; eyelid edema; forehead and facial sweating; miosis and/or ptosis; and a sense of restlessness or agitation.

Attacks occur with a frequency between one every other day and 8 per day. During part, but less than half, of the active time-course, attacks may be less severe and/or of shorter or longer duration. Attacks occur in series lasting for weeks or months (so-called cluster periods or bouts) separated by remission periods usually lasting months or years. Another hallmark feature of CH is its circadian, or even circannual pattern, with up to 82% of patients reporting CH attacks around the same time each day.

In this study, Dr. Lee's and colleagues investigated prospectively the pattern of circadian rhythmicity in relation to disease course in 175 patients in the active, within-bout period from 15 hospitals in Korea. The prevalence and characteristics of circadian rhythmicity were compared between- and within-patients with different numbers of total lifetime bouts. Patients with ≥ 2-lifetime bouts were categorized as stationary (no change between bouts), developing (becomes more prominent as disease progresses), decreasing (becomes less prominent as disease progresses), and variable (different from bout to bout), with regard the changes in the pattern of circadian rhythmicity during their disease progression.

Circadian rhythmicity was reported in 86 (49.1%) patients for the current bout. Seasonal rhythmicity was more prevalent in patients with circadian rhythmicity compared to patients with no seasonal rhythmicity (66.2 % vs 37.1 %, respectively). The prevalence of circadian rhythmicity was similar between groups (deciles groups) regarding the number of total lifetime bouts, while changes in circadian rhythmicity between bouts throughout the disease course were reported by 45.3% of patients. Patients without circadian rhythmicity showed a more variable pattern compared to patients with circadian rhythmicity (35.2% vs 8.8 %), whereas a stationary pattern was more common among patients with circadian rhythmicity in the current bout (64.7 % vs 40.9 %) compared to those without rhythmicity.

Regarding the time of CH attacks, 10 am and 3 pm, followed by 10 pm and 2 am, were the most common attack time recorded, and this was true either in the whole patients' sample as for patients with circadian rhythmicity. Concerning the time of day for cluster headache attacks in relation to the number of total lifetime bouts, with disease progression, a trend to a dichotomic distribution was observed for hypnic and midday occurrence in the current bout.

A greater variance was observed in the afternoon (1 pm to 6 pm) and hypnic (1 am to 6 am) groups, whereas the evening (7 pm to 12 am) group had the least variance, implicating that afternoon and hypnic attacks occur throughout the disease course, whereas evening attacks are prominent only during the earlier disease course.

The nighttime predilection was predominant in the earliest (1st to 2nd deciles) disease duration group, that is, those with ≤ 2 lifetime CH attacks, reduced as the disease progressed (up to the 7th decile), and increased again at the 8th and 10th deciles (mean of 44.1 total lifetime bouts in the 10th decile).

These data indicate that CH may not have fixed rhythmicity throughout the disease course, there is individual variability, and interpretations are as follows:

The suprachiasmatic nucleus may be additional, but not essential to in the pathophysiology of CH;

Internal/External homeostasis or treatment effects may influence as well;

Temporal evolution of CH rhythmicity should be further investigated;

Whether this circadian rhythmicity evolution is a marker of active disease progression merits additional research;

Many studies are needed indeed to clarify this new CH rhythmicity feature, as the authors conclude "This pattern may indicate a possible evolvement and regression of diurnal expression of CH, the biological implication of which has not yet been determined".

Credit: 
International Headache Society

Ten not-to-be-missed PPPL stories from 2019 -- plus a triple bonus!

image: Ten not-to-be-missed PPPL news stories.

Image: 
Elle Starkman / PPPL Office of Communications

Arms control robots, a new national facility, and accelerating the drive to bring the fusion energy that powers the sun and stars to Earth. These far-reaching achievements at the U.S. Department of Energy's (DOE) Princeton Plasma Physics Laboratory (PPPL) made 2019 another remarkable year. Research at the only national laboratory devoted to fusion and plasma physics -- the state of matter that makes up 99 percent of the visible universe -- broke new ground in varied fields as vast as astrophysics and as tiny as nanotechnology. Here in no particular order, in case you missed them, are 10 must-read stories that capture an example of the full range of research and development during the past year at the Laboratory -- plus three bonus stories highlighting a first-generation college student, an award-winning apprenticeship program, and creation of a supersonic plasma jet that could facilitate the study of stellar bodies light years away to help gain an understanding of our universe.

Find that nuclear warhead! PPPL develops and successfully tests the prototype for a swarm or robots that can detect neutrons, even when hidden, to help in arms control efforts.

High excitement for low-temperature plasma. The Laboratory teams with Princeton University to become home to a nationwide center to study a dynamic form of plasma in low temperatures, not the extremely high temperatures required for fusion reactions.

Artificial intelligence transforms scientific inquiry. The rapidly expanding branch of computer science speeds the development of fusion energy.

Spherical tokamaks as models for next-generation fusion facilities. A close look today at new options for tomorrow's power plants that will use fusion to provide energy.

Joining forces with private industry. The Laboratory houses a branch of a national program to enhance the harnessing of fusion energy, making a powerful public-private partnership.

A novel way to launch fusion reactions. PPPL scientists confirm a viable alternative to a widely used standard method.

All fired up and ready to go. The Laboratory powers up an upgrade of the Lithium Tokamak Experment (LTX) -- now called the LTX-β -- to test the ability of lithium metal to facilitate fusion reactions.

Streamlining designs of a different type of fusion device. PPPL physicist develops a technique to simplify development of complex stellarators -- the type of device created and envisioned by the Lab's founder, Lyman Spitzer -- to produce stable fusion plasmas.

Surprise! Researcher discovers turbulence is not all bad. Discovery demonstrates that eddies and currents that disturb the plasma that fuels fusion reactions may also be beneficial.

Smoothing the operation of fusion facilities. PPPL world-renowned expert is named co-leader of national program on the use of liquid metal components in future fusion devices.

Bonus 1. First-generation college student. Physics major Barbara Garcia pursues fresh ideas as a summer intern at PPPL.

Bonus 2. Apprentices alight. Award-winning program gives early career technicians the chance to learn high-tech skills.

Bonus 3. From the Lab to deep space. Development of plasma jets opens a new chapter in studying the stars.

Credit: 
DOE/Princeton Plasma Physics Laboratory

Mediterranean diet may help preserve the kidney health of transplant recipients

Highlight

In a study of kidney transplant recipients, those with higher adherence to the Mediterranean diet were less likely to experience kidney function loss.

Washington, DC (January 2, 2020) -- A new study indicates that following the Mediterranean diet may help kidney transplant recipients maintain transplant kidney function. The findings appear in an upcoming issue of CJASN.

Despite improvements in the survival of transplanted kidneys in the early years after transplantation, loss of kidney function within 10 years still occurs in more than one-third of recipients. António Gomes-Neto, MD (University of Groningen, in the Netherlands) and his colleagues investigated whether adhering to the Mediterranean diet--which focuses on high intake of fish, fruit, vegetables, legumes, nuts, and olive oil together with lower intake of dairy and meat products--might help protect transplant recipients' kidney health.

For the study, 632 adult kidney transplant recipients with a functioning donor kidney for at least one year completed a food-related questionnaire, and adherence to the Mediterranean diet was assessed using a 9-point score.

During an average follow-up of 5.2 years, 119 recipients experienced kidney function decline (76 of whom developed kidney failure). The Mediterranean Diet Score was inversely associated with kidney function decline and kidney failure. Each 2-point higher score was associated with a 29% lower risk of kidney function decline and a 32% lower risk of kidney failure.

"Increasing scientific evidence has demonstrated health benefits of the Mediterranean Diet on cardiovascular and kidney health. In this study, we show that kidney transplant recipients with higher adherence to the Mediterranean Diet are less likely to experience function loss of their kidney transplant," said Dr. Gomes-Neto.

Credit: 
American Society of Nephrology