Tech

Twelve-foot metal poles with long outstretched arms dot a Midwestern soybean field to monitor an invisible array of light emitted by crops. This light can reveal the plants' photosynthetic performance throughout the growing season, according to newly published research by the University of Illinois.

"Photosynthetic performance is a key trait to monitor as it directly translates to yield potential," said Kaiyu Guan, an assistant professor in the College of Agriculture, Consumer, and Environmental Sciences (ACES) and the principal investigator of this research. "This method enables us to rapidly and nondestructively monitor how well plants perform in various conditions like never before."

Published in the Journal of Geophysical Research - Biogeosciences, the Illinois team led by Guofang Miao, a postdoctoral researcher in ACES and the lead author of the paper, report the first continuous field season to use sun-induced fluorescence (SIF) data to determine how soybeans respond to fluctuating light levels and environmental stresses.

"Since the recent discovery of using satellite SIF signals to measure photosynthesis, scientists have been exploring the potential to apply SIF technology to better agricultural ecosystems," said study collaborator Carl Bernacchi, an associate professor of plant science at the Carl R. Woese Institute for Genomic Biology (IGB). "This research advances our understanding of crop physiology and SIF at a local scale, which will pave the way for satellite observations to monitor plant health and yields over vast areas of cropland."

Photosynthesis is the process where plants convert light energy into sugars and other carbohydrates that eventually become our food or biofuel. However, one to two percent of the plant's absorbed light energy is emitted as fluorescent light that is proportional to the rate of photosynthesis.

Researchers capture this process using hyperspectral sensors to detect fluctuations in photosynthesis over the growing season. They designed this continuous study to better understand the relationship between absorbed light, emitted fluorescent light, and the rate of photosynthesis. "We want to find out whether this proportional relationship is consistent across various ecosystems, especially between crops and wild ecosystems such as forests and savannas," said Miao.

"We are also testing the applicability of this technology for crop phenotyping to link key traits with their underlying genes," said co-author Katherine Meacham, a postdoctoral researcher at the IGB.

"SIF technology can help us transform phenotyping from a manual endeavor requiring large teams of researchers and expensive equipment to an efficient, automated process," said co-author Caitlin Moore, also a postdoctoral researcher at the IGB.

A network of SIF sensors has been deployed across the U.S. to evaluate croplands and other natural ecosystems. Guan's lab has launched two other long-term SIF systems in Nebraska to compare rainfed and irrigated fields in corn-soybean rotations. "By applying this technology to different regions, we can ensure the efficacy of this tool in countless growing conditions for a myriad of plants," said Xi Yang, an assistant professor at the University of Virginia, who designed this study's SIF monitoring system.

"Our ability to link SIF data at the leaf, canopy and regional scales will facilitate the improvement of models that forecast crop yields," Guan said. "Our ultimate goal is to monitor the photosynthetic efficiency of any field across the world to evaluate crop conditions and forecast crop yields on a global scale in real time."

Writing in the February 27 online issue of Science Signaling, researchers at University of California San Diego School of Medicine and Moores Cancer Center describe how a signaling protein that normally suppresses tumors can be manipulated (or re-programmed) by growth factors, turning it into a driver of malignant growth and metastasis.

In the lives of cells, complex communications carrying proteins and other molecules along signaling pathways dictate cellular function and well-being. But in cancer cells, communications are often massively dysregulated. "Although the multiple signaling pathways in cells are typically conceptualized as independent entities, it is their complex crosstalk that shapes many aspects of cancer," said senior author Pradipta Ghosh, MD, professor of medicine and cellular and molecular medicine at UC San Diego School of Medicine.

Building upon earlier work published in 2015, Ghosh and colleagues investigated a protein called Disheveled-associating protein or Daple, which is produced by nearly all healthy cells in the body and is well-recognized for its role in helping cells in different tissues coordinate processes, such as development and maintenance of organs.

In their earlier work, the research team reported for the first time that Daple appeared to exert some control over the initiation and progression of colorectal cancer by suppressing tumor formation, but when cells escaped the main tumor and began circulating in the blood stream, the protein made cancer cells more invasive and more likely to spread.

At the time, however, it was not clear how the tumor suppressor could turn rogue. In their new work, the team found the culprit: an overabundance of growth factors in the tumor microenvironment.

The Wnt signaling pathway in cells is fundamental in embryonic development, helping direct the organization of cells, their functions and their fates. Later, it is essential for tissue homeostasis or equilibrium.

Normally Daple, which operates within the Wnt pathway, serves to prevent abnormal growth and stays bound to the protein Disheveled, which acts as a brake on Daple. But as normal tissue becomes cancerous, rising levels of different types of growth factors hijack this system, disengaging Disheveled from Daple, disabling the brake and unleashing Daple. Instead of suppressing tumors, Daple begins to promote tumor growth and spread. The researchers found that in colon cancers in which Daple is highly expressed with concomitant high growth factor signaling, there was a high risk for tumor recurrence compared to all other tumors.

"This work not only brings out the complexity of crosstalk between major signals that drive cancers, but also defines how such crosstalk triggers a Jekyll-to-Hyde transition in Daple at an atomic level, and what that means for patients," said Ghosh.

Because Daple is expressed in almost all normal tissues, the researchers are optimistic that future work will reveal its impact in other cancers. In fact, Daple's role in ovarian and gastric cancers has already been demonstrated.

"Going forward, we strive to understand what other factors trigger a Jekyll-to-Hyde transition in Daple and how we can anticipate, detect and prevent such a transition," Ghosh said. "For a protein that first goes away during normal-to-cancer transition only to return later during cancer spread, Daple plays a sophisticated game of hide-and-seek and exemplifies the complexity in cancers."

Times are tough for 31 of Michigan's 45 varieties of freshwater mussels. Sporting evocative names like wavy-rayed lampmussel and round pigtoe, these residents of the state's rivers are imperiled by habitat disruption and pollution and are also threatened by climate change.

Michigan State University (MSU) scientists' recommendation to figure out the best places to focus conservation efforts: Worry about fish.

In this month's journal Hydrobiologia, researchers say that if you care about those wavy-rayed lampmussels and round pigtoes, then you also must care about Michigan's johnny darters and rosyfaced shiners.

This research group for the first time creates models that acknowledge how tightly the fate of mussels and fish are entwined in the state's ecosystems and helps chart a path for conservation managers to save the mussels. Mussels filter water - a single one can clean up 20-30 gallons a day - as they eat, and excrete nutrients upon which other water organisms can feast. Their shells are important terrain for algae and insect larvae to attach, and mussels are an important food source for some aquatic critters.

"Mussels need host fishes to spawn, and some mussels are obligated to just a few species or even a single species for their hosts," said Dana Infante, associate professor of fisheries and wildlife in MSU's Aquatic Landscape Ecology Lab. "The big message for conservation is that to protect imperiled mussels, we must also protect their host fishes."

The research took a novel approach to understand the mussels - which live a long time, have limited mobility and because of that, are highly sensitive to different types of habitat and habitat disturbances. Physical habitat factors are commonly assessed in efforts to conserve mussels, but one of the most important parts of their early life, the paper notes, is rarely factored in.

Mussels start life as larvae that must, after being expelled by their mothers, hitch a ride on fish gills. They usually don't harm the fish and simply fall off when they develop into juvenile mussels. But it's not any fish - different varieties of mussels are particular about what species of fish they hang with.

So this group selected 11 of Michigan's imperiled mussels and created models that not only looked at prime habitat now and in the future for them, but also for their corresponding fish hosts.

"Due to the complexity of threats we have identified in this study, conservation efforts in Michigan should prioritize both protecting the highly suitable mussel habitats that are left, and identifying any additional populations in under-sampled areas of the state," said Wesley Daniel, a former research associate in Infante's Aquatic Landscape Ecology Lab, and now Cherokee Nation Technologies contractor for U.S. Geological Survey in Gainesville, FL.

The group notes that streams that have the optimal combination of several imperiled mussel species, low chance of a significant temperature swing with projected climate change and being in a protected area are few, but are a good bet to start conservation efforts.

SYRACUSE, N.Y. - Former Syracuse postdoctoral researcher Holly Root-Gutteridge has always been a good listener - a trait that has served her very well in her bioacoustic research of mammals, both aquatic and landlocked. Most recently her ears have tuned-in to vocal stylings of the North Atlantic right whale.

Through extensive listening and analysis of whale calls--which were recorded by a large collaboration of scientists over the past two decades--Root-Gutteridge was able to pick up the slow gradual changes in sound production in the marine giants as they age. Looking at spectrograms of the calls, which provide visual representations of the sound, the research team could see the progression of vocal characteristics of the animals from calf throughout adulthood.

The whales produced clearer, longer calls with age, a trend that did not end when they reached physical maturity, as had been predicted.

"We're learning that these right whales can have more control of their voices," explains the bioacoustics researcher. "That means they may be sending more complex information than we previously thought."

Through continued study, Root-Gutteridge believes that scientists will be able to better understand how whales communicate in the wild, which can lead to stronger worldwide conservation efforts of the sea mammals.

Root-Gutteridge's newest investigation "A lifetime of changing calls: North Atlantic right whales, Eubalaena Glacialis, refine call production as they age", a collaborative research project with researchers from Syracuse University, Cornell University, Duke University and the National Oceanic and Atmospheric Administration (NOAA) Northeast fisheries office, was recently published in the March edition of the journal Animal Behaviour. The paper is based on work that was done while she was a researcher in the lab of Associate Professor, Susan Parks.

While still at Syracuse, Root-Gutteridge turned heads around the world with her wolf dialect research back in 2016. Contrasting the recordings of over 2,000 howls from 13 different species and subspecies of wolves, the biologist discovered that wolves, much like people, have regional vocalization patterns, or dialects, depending on their locale.

"I learned a lot at Syracuse as I'd never studied marine mammals before. I know a lot more about whales and their songs and have developed some great skills in analyzing animal sound," says Root-Gutteridge. "I also have a much better understanding of how tough it is to study marine mammals as their home ranges are just so big. When I studied wolves, I thought 25 square miles was a lot of territory to cover, but the whales swim all the way up and down the East Coast!"

Since finishing at Syracuse, her work has literally gone to the dogs. Root-Gutteridge is currently at the University of Sussex in the United Kingdom where her next bioacoustics project, "How Dogs Hear Us: Human speech perception by domestic dogs," explores what animals of the canine persuasion hear when humans speak.

PITTSBURGH, Feb. 26, 2018 - Critically ill patients who experience long periods of hypoxic, septic or sedative-associated delirium, or a combination of the three, during an intensive care unit (ICU) stay are more likely to have long-term cognitive impairment one year after discharge from the hospital, according to a new study from the University of Pittsburgh and Vanderbilt University. This is the first study to show more than half of patients with acute respiratory failure or shock, or both, develop multiple sub-categories of delirium with lasting effects.

The results, published today in the journal Lancet Respiratory Medicine, indicate that clinicians should seek to minimize the duration of exposure of the three delirium groups.

"Our findings show patients who are exposed to sedative-associated delirium are at similar risk for long-term cognitive impairment as patients exposed to hypoxic or septic delirium," said lead author Timothy Girard, M.D., M.S.C.I., associate professor of critical care medicine, Pitt School of Medicine. "We were surprised by this because, previously, clinicians believed that sedatives had short-term effects, which were eliminated once the patient regained consciousness. But our results show that clinicians should see it as a red flag when ICU patients respond to sedatives in an adverse manner."

Sepsis is a condition that arises when the body's response to an infection injures its own tissues and organs, and hypoxia is a lack of oxygen reaching the body's tissues. Doctors often sedate ICU patients to help them relax and manage pain. All three conditions--sepsis, hypoxia and sedation--are common during critical illness and can cause delirium.

Delirium was common in the study, affecting 71 percent of participants. Sedative-associated delirium, the most common subcategory, is of particular interest since clinicians control patients' exposure to sedatives.

Researchers examined more than 1,000 adult medical/surgical patients across five centers with respiratory failure or shock, or both, for hypoxic, septic and sedative-associated delirium, as well as a fourth category, metabolic delirium, which can occur when patients have changes in metabolism due to kidney or liver failure. Researchers assessed 564 patients at a three-month follow-up, and 471 at a one-year follow-up.

The study found duration of delirium as a key indicator of cognitive decline, with longer periods of multiple delirium subcategories predicting worse cognitive decline after one year of hospital discharge.

Out of the four phenotypes, metabolic delirium was the only one that didn't affect long-term cognitive decline, after adjusting for age, severity of illness, doses of sedating medications and other factors.

"Clinicians should be careful not to underestimate the importance of delirium in sedated patients," Girard said. "We recommend that clinicians focus on reducing delirium risk factors, including sedation, in addition to treating the critical illness that brought the patient to the ICU."

Eating a diet that emphasizes vegetables, fruit and whole grains it may lead to a reduced risk of depression, according to a study by researchers at Rush University Medical Center.

Study author Dr. Laurel Cherian will present a preliminary study abstract with these conclusions during the American Academy of Neurology's 70th Annual Meeting in Los Angeles from April 21 to 27, 2018.

Study participants who closely adhered to a diet similar to the Dietary Approaches to Stop Hypertension (DASH) diet were less likely to develop depression than people who did not closely follow the diet. The DASH diet recommends fruits and vegetables and fat-free or low-fat dairy products and limits foods that are high in saturated fats and sugar.

"Depression is common in older adults and more frequent in people with memory problems, vascular risk factors such as high blood pressure or high cholesterol, or people who have had a stroke," said Cherian, a vascular neurologist and assistant professor in Rush's Department of Neurological Sciences. "There is evidence linking healthy lifestyle changes to lower rates of depression and this study sought to examine the role that diet plays in preventing depression."."

The National Institutes of Aging-funded study evaluated a total of 964 participants of the Rush Memory and Aging Project with an average age of 81 annually for approximately six-and-a-half years. Each participant was monitored for symptoms of depression and filled out questionnaires about how often they ate various foods. The researchers examined how closely the participants' reported diets adhered diets such as the DASH diet, Mediterranean diet and the traditional Western diet, which is high in saturated fats and red meats and low in fruits and vegetables.

The researchers categorized participants in three groups based on how closely they adhered to these diets. Those who were in the two groups that followed the DASH diet more closely were 11 percent less likely to develop depression than people in the group that did not follow the diet closely. Conversely, the researchers found that the more closely people followed a Western diet, the more likely they were to develop depression.

Cherian noted that the study does not prove that the DASH diet leads to a reduced risk of depression; it only shows an association.

"Future studies are now needed to confirm these results and to determine the best nutritional components of the DASH diet to prevent depression later in life and to best help people keep their brains healthy," said Cherian.

February 26, 2018 - Commonly used ICU risk scores can be "repurposed" as continuous markers of severity of illness in critically ill patients--providing ongoing updates on changes in the patient's condition and risk of death, according to a study in the March issue of Critical Care Medicine, official journal of the Society of Critical Care Medicine (SCCM). The journal is published by Wolters Kluwer.

Three ICU risk scores, designed for different purposes, "performed reasonably well as a marker of severity of illness at admission, as well as throughout the ICU stay, demonstrating that it is possible for risk models to perform well even when deployed for uses other than originally intended," write Omar Badawi, PharmD, MPH, FCCM, and colleagues of Philips Healthcare, Baltimore. The study illustrates how the use of "Big Data" can advance our understanding of critically ill patients, drawing on extensive data contributed by tele-ICU programs across the United States.

One of Three ICU Risk Models Performs Best in Predicting Mortality

The study used data from the Philips eICU Research Institute database, which assembles clinical data from a diverse mix of hospitals using tele-ICU software. The analysis included de-identified data on more than 560,000 ICU patient stays, contributed by 333 ICUs at 208 US hospitals. The data covered nearly 39 million patient-hours of ICU care.

The analysis transformed three widely used ICU risk scores--designed to be assessed for different clinical scenarios--into continuous risk markers:

Acute Physiology and Chronic Health Evaluation IV (APACHE): Perhaps the best-known ICU risk score, originally designed to estimate the risk of death on admission to the ICU.
Sequential Organ Failure Assessment (SOFA): Originally designed to assess organ failure risk in patients with sepsis, the SOFA score was later validated for assessment every 48 hours to assess mortality risk.
Discharge Readiness Score (DRS): Designed to assist ICU discharge decisions by estimating the risk of death in the first 48 hours after the patient leaves the ICU.

Hourly values for all three scores were evaluated as predictors of mortality risk. Overall, 4.8 percent of patients died in the ICU.

As continuous markers, all three models showed good accuracy in predicting the risk of death in the ICU, as well as risk of death within 24 hours. Of the three scores, the DRS had the highest predictive value. For patients in the highest ten percent of risk based on average score, the percentage who died was 30.4 percent with APACHE (average score > 80.0), 26.5 percent with SOFA (average score >7.6), and 36.4 percent with DRS (average score >13.0). The results were similar on analysis of hospitals with larger numbers of patients and deaths.

Looking closely at trends in each score during the ICU stay provided insights into the differences between the three models. Even in survivors, APACHE and SOFA scores tended to increase throughout the first 24 hours in the ICU. In contrast, the DRS decreased during the first 24 hours for survivors. That suggests that the DRS was more responsive to changes in patient condition--especially improvements.

The authors hypothesize that these differences may be attributed to model design. Both APACHE and SOFA primarily rely on the "worst" values of the preceding 24 hours to calculate a score. In contrast, DRS relies primarily on summary measures of the preceding 24 hours, such as averages and coefficient of variation.

Those observations highlight the need to be aware of differences in model design, and how the predictions may vary across ICU settings and in patients with varying characteristics. To help ICU clinicians understand these differences, Dr. Badawi and colleagues have created an online interactive data visualization tool.

"These findings suggest that it is possible to repurpose risk models for use outside of their original design, but with caveats," Dr. Badawi and coauthors conclude. They emphasize the need for further studies to determine the clinical relevance of continuous severity of illness indicators, and the need for caution when introducing these models in differing ICU settings. Dr. Badawi added, "Risk models provide objective data regarding patient status but users must combine their clinical judgment with an understanding of the model design in order to interpret the score for specific patients."

Click here to read "Evaluation of ICU Risk Models Adapted for Use as Continuous Markers of Severity of Illness Throughout the ICU Stay."

DOI: 10.1097/CCM.0000000000002904

Since the pioneering description made in 1758 by Swedish naturalist and father of taxonomy Carl Nilsson Linnaeus (1707-1778), there was officially one single silky anteater species. This short-snouted, pigmy-sized anteater would then be known for its scientific name, Cyclopes didactyla, after its inclusion on the 10th edition of Systema Naturae, Linnaeus' magnum opus responsible for describing more than 4,2 animal species. It is found in tropical forests in South and Central America, as well as in the few remaining fragments of Atlantic rainforest in Northeast Brazil.

Six populations of C. didactylus scattered through this territory were discovered in the nineteenth and early twentieth centuries. However, because all the collected specimens appeared to be practically identical, it was thought that the subtle morphological differences could only justify the creation of subspecies of C. didactylus, therefore the only species in the family Cyclopedidae.

But now, a Brazilian group of taxonomists, zoologists and geneticists states that silky anteaters are comprised of at least seven different species, after concluding a study which studied the biology and the ecology of the new species and also sequenced mithocondrial and nuclear DNA from 287 specimens.

An article published in the Zoological Journal of the Linnean Society shows the results of the research supported by the São Paulo Research Foundation - FAPESP via a scholarship for a research internship abroad and a PhD scholarship, as well as by Fundação Boticário, the Wildlife Conservation Society, the Minas Gerais State Agency for Research and Development (Fapemig), the Brazilian Ministry of Education's Office for Faculty Development (CAPES) and Brazil's National Council for Scientific & Technological Development (CNPq).

Silky anteaters: an elusive presence

Among the scientists linked to the University of São Paulo (USP) and to the Federal University of Minas Gerais (UFMG) who were involved in the research is the vet Flávia Miranda, a Zoology PhD student at UFMG who has worked with the order Xenarthra for over 20 years and leads Project Anteater, whose mission is the conservation of sloths, anteaters and armadillos.

In 2005 Miranda took part as an expert on xenarthrans in a meeting of the International Union for Conservation of Nature (IUCN) to verify the status of C. didactylus with a view to its conservation. One of the points raised was whether a population of silky anteaters still existed in Northeast Brazil. No sightings had been reported for years.

Decided to verify the presence of silky anteaters in situ, Miranda spent the last ten years organizing and undertaking expeditions to all parts of Brazil where they had been reported. There have been ten expeditions, to Santa Isabel do Rio Negro (Amazonas State), Oriximiná (Pará), the Parnaíba River Delta (Piauí State), Maranhão, Amapá, and Surinam, among other places.

"It was always very hard to spot the animals in the forest. Imagine a little creature that weighs only 250 g, lives in the crowns of tall trees beside creeks or in mangroves and flooded areas, never comes down to the ground, never vocalizes, and is active only at night. I'd been in the field for two years before I made my first sighting."

DNA analysis reconstruct speciation in Cyclopes

Miranda undertook 17 expeditions to collect specimens in Brazil and Surinam, measuring and photographing them, and taking blood samples for molecular analysis. Sex and geographic location were recorded. Age was determined on the basis of body mass, fur density, and fur length. Morphological and morphometric information was also sought from 20 natural history collections in several countries.

Analysis of the animals' nuclear and mitochondrial DNA removed all doubt about the existence of several species in the genus Cyclopes, supported by morphological and morphometric differences, as well as geographic location.

The most surprising discoveries came from analysis using the molecular clock technique, which estimates when two species diverged on the basis of the number of molecular differences in their DNA.

The molecular clock showed that the separation of several species is not at all recent. On the contrary, it is very ancient. The authors estimate that the Cyclopedidae diverged from other anteaters in the early Oligocene, 30 million years ago (giving rise to the giant anteater, Myrmecophaga tridactyla, and the collared anteater, Tamandua tetradactyla).

Molecular evidence suggests the first divergence in the genus Cyclopes occurred 10.3 million years ago, during the late Miocene. This was when the ancestors of the lineages found west of Amazonas State, Acre and Rondônia States and also in the Peruvian Amazon separated.

This diversification is probably associated with a change in the course of the Amazon River, which once ran from east to west but reversed direction approximately 10 million years ago, when the Andes rose. An immense floodplain formed at that time in western Amazonia.

The wetlands disappeared approximately 7 million years ago, isolating there the ancestors of two new species now described, C. rufus and C. thomasi. These may have separated 3.4 million years ago owing to the formation of the Purus and Madeira Basins, which functioned as biogeographic barriers that isolated the two populations. The Bolivian species C. catellus may also have emerged as a result of the same events.

The researchers estimate that C. ida diverged approximately 5.8 million years ago in the western Amazon and Ecuador, while C. xinguensis probably separated 4.6 million years ago in the area of the Xingu River, to which it has remained confined.

The Mesoamerican lineage C. dorsalis would have separated from its South American kin approximately 3 million years ago, with the continuing rise of the Andean barrier.

The species originally described by Linnaeus, C. didactylus, which lives on the left bank of the Amazon (and in the Negro River basin), in the Brazilian states of Amapá and Pará and also in Northeast Brazil from Maranhão to Alagoas (as well as in Venezuela and Surinam), is thought to have diverged some 2.3 million years ago, with the advent of the first glaciations of the Pleistocene.

So many millions of years of separation between species would be more than sufficient for these anteaters to have accumulated various modifications. However, this is not what has happened. The genus Cyclopes has proved extremely conservative throughout its evolutionary history, changing very little or not all in morphological terms.

"The reason for this may be the life habits of these animals. All species occupy a similar and highly specialized ecological niche with no competition," Miranda said.

Morphological differences

While molecular evidence is definitive for the naming of new species, the analysis of morphological and ecological data is important to corroborate the descriptions.

"Historically this genus has always been considered monospecific," explained zoologist Fabio de Andrade Machado , former holder of a scholarship from FAPESP and currently at the Bernardo Rivadavia Natural Science Museum in Buenos Aires, Argentina.

Machado specializes in analyzing morphometric traits that differentiate species. In this project he helped diagnose morphometric differences in search of evidence to confirm the descriptions of new species.

"I used a technique called geometric morphometrics," he said. "It's based on multivariate analysis of point sets, or anatomical marks, which are used to map the shapes of biological structures. This technique can be used to investigate overall skull structure and identify general differences between species in terms of form."

According to Machado, this analysis showed that the main difference in the species studied referred to the Mesoamerican taxon (C. dorsalis), which has a smaller rostrum (snout) than the other South American groups.

Another conclusion was that the animals from the Northeast of Brazil, French Guiana (C. didactylus) and Xingu (C. xinguensis) have a slimmer, less robust skull than the rest. "Despite the lack of a precise diagnosis, as in the case of C. dorsalis, this suggests there are more than one or two species in the genus," Machado said.

What is inside an atom, between the nucleus and the electron? Usually there is nothing, but why could there not be other particles too? If the electron orbits the nucleus at a great distance, there is plenty of space in between for other atoms. A "giant atom" can be created, filled with ordinary atoms. All these atoms form a weak bond, creating a new, exotic state of matter at cold temperatures, referred to as "Rydberg polarons".

A team of researchers has now presented this state of matter in the journal Physical Review Letters. The theoretical work was done at TU Wien (Vienna) and Harvard University, the experiment was performed at Rice University in Houston (Texas).

Ultracold Physics

Two very special fields of atomic physics, which can only be studied at extreme conditions, have been combined in this research project: Bose-Einstein condensates and Rydberg atoms. A Bose-Einstein condensate is a state of matter created by atoms at ultracold temperatures, close to absolute zero. Rydberg atoms are atoms, in which one single electron is lifted into a highly excited state and orbits the nucleus at a very large distance.

"The average distance between the electron and its nucleus can be as large as several hundred nanometres - that is more than a thousand times the radius of a hydrogen atom", says Professor Joachim Burgdörfer. Together with Prof. Shuhei Yoshida (both TU Wien, Vienna), he has been studying the properties of such Rydberg atoms for years. The idea for the new research project was developed in their long-standing cooperation with Rice University in Houston.

First, a Bose-Einstein condensate was created with strontium atoms. Using a laser, energy was transferred to one of these atoms, turning it into a Rydberg atom with a huge atomic radius. The perplexing thing about this atom: the radius of the orbit, on which the electron moves around the nucleus, is much larger than the typical distance between two atoms in the condensate. Therefore the electron does not only orbit its own atomic nucleus, numerous other atoms lie inside its orbit too. Depending on the radius of the Rydberg atom and the density of the Bose-Einstein condensate, as many as 170 additional strontium atoms may be enclosed by the huge electronic orbit.

Neutral Atoms do not Disturb the Electron's Orbit

These atoms hardly have an influence on this Rydberg electron's path. "The atoms do not carry any electric charge, therefore they only exert a minimal force on the electron", says Shuhei Yoshida. But to a very small degree, the electron still feels the presence of the neutral atoms along its path. It is scattered at the neutral atoms, but only very slightly, without ever leaving its orbit. The quantum physics of slow electrons permits this kind of scattering, which does not transfer the electron into a different state.

As computer simulations show, this comparatively weak kind of interaction decreases the total energy of the system, and so a bond between the Rydberg atom and the other atoms inside the electronic orbit is created. "It is a highly unusual situation", says Shuhei Yoshida. "Normally, we are dealing with charged nuclei, binding electrons around them. Here, we have an electron, binding neutral atoms."

This bond is much weaker than the bond between atoms in a crystal. Therefore, this exotic state of matter, called Rydberg polarons, can only be detected at very low temperatures. If the particles were moving any faster, the bond would break. "For us, this new, weakly bound state of matter is an exciting new possibility of investigating the physics of ultracold atoms", says Joachim Burgdörfer. "That way one can probe the properties of a Bose-Einstein condensate on very small scales with very high precision."

AUGUSTA, Ga. (Feb. 26, 2018) - Two distinctive handfuls of short molecules that regulate gene expression have been found in the eye fluid of patients with two distinct types of vision degenerating glaucoma.

These differentially expressed microRNAs point the way toward finding more genes associated with glaucoma, more clues about how these glaucoma types each go about damaging our optic nerve and potential new points of intervention, the scientists say.

"If we know the pathways involved, maybe we can reverse this, find better targets and design better drugs," says Dr. Yutao Liu, vision scientist and human geneticist in the Department of Cellular Biology and Anatomy at the Medical College of Georgia at Augusta University.

Currently only a handful of known genetic mutations have been found to account for about 10 percent of glaucoma, says Liu, corresponding author of the study in the journal Human Molecular Genetics.

"Differential expression" means the microRNA, or miRNA, expression could be higher or lower in the different conditions, but it's the fact that they are significantly different that makes them of interest and potential help in better understanding and treating a leading cause of vision loss worldwide, Liu says.

The scientists examined miRNA in the aqueous humor that nourishes the front of the eye in a dozen patients with the common, primary open angle glaucoma, another dozen with the rare and even more difficult-to-treat exfoliation glaucoma, and compared the miRNA profile of each to that of 11 people with healthy eyes of a similar age.

They found expression of three miRNAs - miR-125b-5p, miR-302d-3p and miR-451a - significantly different between primary open angle glaucoma and controls. They found five - miR-122-5p, miR-3144-3p, miR-320a, miR-320e and miR-630 - markedly different between exfoliation glaucoma and controls.

Most of the miRNAs have never been associated with glaucoma. However, they do have some evidence that miR122-5p, present in exfoliation glaucoma, may target three genes, OPTN, TMCO1 and TFG-β1, already associated with glaucoma, Liu says. Their early look at the pathways of the other miRNAs they identified, shows likely glaucoma involvement with those as well.

Liu notes that each miRNA can quite literally target hundreds of genes and - in keeping with the concept of location, location, location - where they are determines which genes. Generally when miRNA expression is up, expression of impacted genes is down.

They already are exploring what these miRNA do in the trabecular meshwork that manages the continuous drainage of fluid made by the ciliary body to nourish and oxygenate a portion of the eye that has no direct blood supply.

"Now we have primary cells cultured primarily from the outflow area of the human eye, so we can take these miRNAs, synthesize them, then give them to these cells and see what kind of genes they affect and how many of those genes are related to glaucoma," Liu says.

All of us daily lose some of the 2 million nerve fibers in our optic nerve and we can lose 50-60 percent of them without it really affecting our vision, Liu says. But glaucoma accelerates the loss and these two glaucoma types go about that damage in different ways.

In primary open angle glaucoma, pressure inside the eyeball is high because of increased fluid production, decreased excretion or both, and the optic nerve gets damaged as a result. "We think it's a local disease in the eye," Liu says.

The less-common and generally more severe exfoliation glaucoma occurs in people with exfoliation syndrome, which increases their chance of glaucoma about six times, according to The Glaucoma Foundation. With this glaucoma type, cells that normally secrete proteins inexplicably start to secrete more and the proteins cluster, forming structures that are too big to pass through the eye's normal fluid outflow pathway.

Liu has evidence that a crosslinking enzyme, also secreted at high levels in these patients, effectively glues together these pieces that resemble dandruff. Collateral damage apparently also occurs in the colored-part of the eye, the iris, as pigment also starts to slough off, adding to the mounting pile of trash in the eye. This form of glaucoma is all about high pressure and traditional eye drops won't help, Liu notes. Outflow pathways reopened by surgery quickly become blocked again. Liu notes that this abnormal protein secretion occurs in other parts of the body as well with exfoliation syndrome, but appears to be problematic only in the eye.

Using eye drops that improve outflow or decrease fluid production can reduce the risk of eye damage in most patients with more common types of glaucoma, Liu says. Patients often need a combination of drops that have to be taken several times daily. Surgery or laser treatment can also increase outflow. But Liu and his colleagues would like to find more targeted and effective options.

The eye's aqueous humor also helps support the eye's shape and enables waste removal. The fluid comes from the general circulation and gets dumped back into it. That means that high blood pressure in the body also can impact eye pressure and that exercise can help reduce eye pressure, Liu adds. In fact, eye pressure can even be reactive like blood pressure: Liu notes that his goes up when he wears a tie. Our intraocular pressure tends to be highest in the morning and lowest when we are lying down and sleeping.

Does life really begin at 40? Is 50 the new 30? For people in these age groups, the answer appears to be yes.

But for young adults in their teens and early 20s, turning 50 equates to hitting old age.

A new study of more than a half-million Americans led by a Michigan State University scholar shows just how skewed views of aging can be - particularly among the young. The findings come as people are living longer than ever; life expectancy in the U.S. was about 79 years in 2015 - up nearly nine years from 1965.

But perception may not be keeping up with reality. Nearly 30,000 people in the study thought middle age starts at 30.

"I find it interesting that there's a ton of people who have skewed perceptions about aging - mostly young adults," said William Chopik, assistant professor of psychology and principal investigator of the research.

The study, published in Frontiers in Psychology, is the largest investigation to date of age perceptions, with 502,548 internet respondents ranging in age from 10 to 89.

A key finding: People's perception of old age changes as they age. Essentially, the older we get, the younger we feel.

"I think the most interesting finding of this study is that our perceptions of aging aren't static - they change as we change ourselves," Chopik said. "What you consider to be old changes as you become old yourself."

Part of this is understandable, he said. People view older adulthood as a negative experience and want to avoid it because it's painful to think of ourselves as old.

"But, of course, older adults actually have really enriching lives and some studies suggest that they're happier than young adults," Chopik noted.

Interestingly, when asked how long they wanted to live, the different age groups gave different answers. While kids and young adults wanted to live into their early 90s, that ideal age dropped among the 30- and 40-year age groups, hitting a low of about 88. But the ideal age started rising steadily starting with 50-year-olds and reached about 93 among 80-year-olds.

A new article in CMAJ (Canadian Medical Association Journal) practical tips for physicians on airplanes who may step in to help in a medical emergency.

"Hearing the call go out for a doctor onboard at 36 000 feet can be anxiety-provoking for any physician," says Dr. Alun Ackery, an emergency physician at St. Michael's Hospital and the University of Toronto. "If the health professional offers their expertise, they may have to manage an unfamiliar clinical scenario, in a foreign and limited environment without knowledge of the available resources. This article provides practical tips to inform physicians about what to expect if they are in this situation."

The article reviews the policies and procedures of Canada's two major airlines, Air Canada and WestJet Airlines Ltd. and literally unpacks the medical equipment found onboard these carriers in a video to help health care professionals understand what they might encounter during an in-flight medical emergency and what resources are available to help with treatment.

An estimated 2.75 billion passengers worldwide fly each year on commercial airlines, with 133.4 million fliers in Canada in 2015, a 27% increase over 2009. The increased number of passengers is one reason for an increase in in-flight medical emergencies. Another reason is longer flights, which subject people to stressors, such as lower oxygen humidity levels, for a longer period of time.

There are no standardized methods for identifying in-flight emergencies making it difficult to find reliable incidence rates. Estimates range from one medical emergency per every 604 flights (16 events per one million passengers) to one per 7700 passengers. The top five causes of medical emergencies are lightheadedness/loss of consciousness (37.4%), respiratory symptoms (12.1%), nausea or vomiting (9.5%), cardiac symptoms (7.7%) and seizures (5.8%).

Physicians are the primary responders in 40% to 50% of in-flight emergencies, nurses and paramedics in 5% to 25% and flight attendants alone in almost half (45%) of incidents. The authors suggest that in complex medical situations, a team-based approach, assigning clear roles and responsibilities to use the skills of other health care professionals, is valuable. Flight attendants should be involved as key resources who know the aircraft, emergency procedures and can liaise with the cockpit and ground communications staff for telemedicine support and potential emergency landings.

"The incidence of in-flight medical emergencies continues to rise and it is likely that many physicians will hear a call to attend to a fellow passenger. Knowing what to expect may help physicians be better prepared the next time that fateful call goes out at 36 000 feet," says Dr. Ackery.

Watch the authors unpack in-flight medical kits from Air Canada and WestJet Airlines Ltd. in a video https://youtu.be/h5iKxHO5oVY.

Researchers from St. Michael's Hospital, the University of Toronto, Air Canada, WestJet Airlines Ltd. and ORNGE Air Ambulance collaborated on the article.

""Is there a doctor on board?": Practical recommendations for management of in-flight medical emergencies" is published February 26, 2018.

Video link pre-embargo: https://youtu.be/h5iKxHO5oVY

Journal

Canadian Medical Association Journal

MINNEAPOLIS - People who eat vegetables, fruit and whole grains may have lower rates of depression over time, according to a preliminary study released today that will be presented at the American Academy of Neurology's 70th Annual Meeting in Los Angeles, April 21 to 27, 2018.

The study found that people whose diets adhered more closely to the Dietary Approaches to Stop Hypertension (DASH) diet were less likely to develop depression than people who did not closely follow the diet. In addition to fruit and vegetables, the DASH diet recommends fat-free or low-fat dairy products and limits foods that are high in saturated fats and sugar. Studies have shown health benefits such as lowering high blood pressure and bad cholesterol (LDL), along with lowering body weight.

"Depression is common in older adults and more frequent in people with memory problems, vascular risk factors such as high blood pressure or high cholesterol, or people who have had a stroke," said study author Laurel Cherian, MD, of Rush University Medical Center in Chicago and a member of the American Academy of Neurology. "Making a lifestyle change such as changing your diet is often preferred over taking medications, so we wanted to see if diet could be an effective way to reduce the risk of depression."

For the study, 964 participants with an average age of 81 were evaluated yearly for an average of six-and-a-half years. They were monitored for symptoms of depression such as being bothered by things that usually didn't affect them and feeling hopeless about the future. They also filled out questionnaires about how often they ate various foods, and the researchers looked at how closely the participants' diets followed diets such as the DASH diet, Mediterranean diet and the traditional Western diet.

Participants were divided into three groups based on how closely they adhered to the diets. People in the two groups that followed the DASH diet most closely were less likely to develop depression than people in the group that did not follow the diet closely. The odds of becoming depressed over time was 11 percent lower among the top group of DASH adherers versus the lowest group. On the other hand, the more closely people followed a Western diet--a diet that is high in saturated fats and red meats and low in fruits and vegetables--the more likely they were to develop depression.

Cherian noted that the study does not prove that the DASH diet leads to a reduced risk of depression; it only shows an association.

"Future studies are now needed to confirm these results and to determine the best nutritional components of the DASH diet to prevent depression later in life and to best help people keep their brains healthy," said Cherian.

The nights in the German federal states („Bundesländer") have been getting brighter and brighter - but not everywhere at the same rate and with one peculiar exemption: light emissions from Thuringia decreased between 2012 and 2017. This is the result of a recent study by scientists Chris Kyba and Theres Küster from the GFZ German Research Centre for Geosciences together with Helga Kuechly from "Luftbild - Umwelt - Planung, Potsdam". Kyba and colleagues published the study in the International Journal of Sustainable Lighting IJSL. This week, they updated the maps by including the 2017 data from a satellite-born instrument.

The team measured the change of light emissions for every German state, studying both the lit area and total radiance. The trends in the lit area show a clear distinction between East and West. The lit area of the states of the former GDR including Berlin stayed basically the same (growth less than 1 per cent), whereas the states in the western part of Germany increased in the area that is lit in the night. The lit area in Thuringia decreased by about 7%. With respect to the intensity of the lighting, the picture is more complex. Large areas in both East and West Germany show only marginal changes, while some states show growth rates of three to four per cent annually. Once again, Thuringia decreased in radiance.

The trend towards increasing night light emissions could be explained by a widespread change in outdoor lighting: LED lamps are replacing older technologies, and changing the ways in which light is used in both public and private lighting. The researchers are still in the dark as to the reason why Thuringia shows a decreasing trend. In the study in IJSL which did not include the 2017 data, two other states appeared to decrease from 2012 to 2016: Saxony and Saxony-Anhalt. This trend, however, vanished after the team re-calculated the changes with the latest data from 2017.

Chris Kyba can only guess why Thuringia sticks out. "Maybe the data reflect the fact that older high pressure sodium lights are aging and decreasing in brightness," says Kyba. On the other hand, it could as well be that municipalities have already changed to LED lights, which appear darker to the satellite. The instrument that measured the changes, the Visible Infrared Imaging Radiometer Suite Day Night Band (DNB), detects light with wavelengths between 500 and 900 nanometers, corresponding to the colours green to red, and including invisible infrared. White LED light includes a large component of blue light that the DNB instrument is not sensitive to. "So maybe Thuringia only looks darker simply because of the satellite's inability to see the blue light emitted from LEDs", says Kyba. He adds: "We definitely intend to follow up on this in the next years to understand the reasons behind lighting change in all of the states."

NEW YORK, NY (Feb. 23, 2018) - Single-cell analysis holds enormous potential to study how individual cells influence disease and respond to treatment, but the lack of cost-effective and user-friendly instrumentation remains challenging. As described in a study published today in Nature Communications, researchers at the New York Genome Center (NYGC) and New York University (NYU) have taken steps to facilitate broad access to single-cell sequencing by developing a 3D-printed, portable and low-cost microfluidic controller. To demonstrate the utility of the instrument in clinical environments, the researchers deployed the device to study synovial tissue from patients with rheumatoid arthritis (RA) at the Hospital for Special Surgery (HSS).

In the study, the researchers describe the 3D-printed custom device, which, along with its electronic and pneumatic components, can be easily obtained and assembled for a total cost of about $600, a fraction of the cost of comparable commercial systems. The device occupies a small footprint as well, not much larger than a tissue box. "Most commercial microfluidic instruments are very costly; as a result, not every lab has access to exciting technology for single-cell analysis," said William Stephenson PhD, Senior Research Engineer in the NYGC's Technology Innovation Lab, who led the development of the instrument and is a lead author on the study. "We designed the instrument to perform droplet microfluidics and in particular Drop-seq, a massively parallel technology for single cell RNA-sequencing."

In collaboration with researchers and clinicians at HSS, a world leader in rheumatology research and disease treatment, the group used the instrument to profile joint synovial tissue from RA patients. RA is an autoimmune disease that affects 1% of the population and is associated with painful swelling in the joints. The precise cause of RA is undetermined and muddled by the diversity of cells found in the swollen joints of patients.

The portability of the controller permitted patient samples to be processed on-site and immediately after surgery, minimizing handling and transport to optimize sample quality. The researchers collected samples from five RA patients totaling 20,387 cells and looked at the individual gene expression patterns for each cell. "This dataset gave us the opportunity to identify individual subpopulations of cells that could drive the progression of RA, even if they have not been previously characterized," said Rahul Satija PhD, a Core Faculty Member at NYGC, Assistant Professor of Biology at NYU, and senior author on the study.

By analyzing the complete dataset and searching for clusters of similar cells, the researchers identified 13 groups, representing both infiltrating immune and inflamed stromal populations. Of particular interest were distinct groups of fibroblasts with strikingly different gene expression patterns. "Roughly an hour after surgical excision, individual cells from patient tissues were labeled for single-cell sequencing. From this work, we have classified unrecognized fibroblast subtypes that may prove to be important drug targets for our RA patients," said Laura Donlin, Co-Director of the HSS Precision Medicine Lab and Assistant Professor at Weill Cornell Medicine, and a lead author on the study. The researchers were able to validate the presence of these multiple groups using flow cytometry, and discovered that they exhibited distinct localization patterns with the joint tissue as well.

The dataset is a step towards creating a comprehensive "cell atlas" for synovial tissue from RA patients. Moving forward, the researchers are compiling data from additional RA patients, and aim to obtain patient samples from other arthritic conditions such as psoriatic arthritis and osteoarthritis. In addition, they plan to use CITE-seq, a technique also developed in the Technology Innovation Lab at the NYGC, to more precisely classify cell types by measuring the presence of surface proteins in addition to the transcriptome. They also envision that technology will be useful for profiling samples that are difficult to study in a standard lab, such as highly infectious samples in biocontainment facilities or samples being collected in field research settings. To facilitate its widespread use in the scientific and medical community, the instrument has been fully "open-sourced." Instructions and assembly manuals for the instrument can be found online at the popular microfluidics repository Metafluidics. "We hope that this instrument lowers the hurdles associated with performing single-cell transcriptome profiling experiments in basic research and clinical settings," Dr. Stephenson said.