Brain

They are small, almost transparent, similar to jellyfish, and they occur in the ocean in huge quantities. Cnidaria, Ctenophora and Urochordata belong to the gelatinous plankton communities that are omnipresent in the ocean and are among the primary food sources for more highly developed marine organisms. Thus, they have a very important function in the marine ecosystem. Another one is their contribution to the marine carbon cycle, as they bind large amounts of carbon which is transported into the deep ocean. An international group of marine scientists under the leadership of the Future Ocean Network in Kiel has now been able to quantify this contribution in a r study recently published in the scientific journal Global Biogeochemical Cycles.

"We have used databases taking into account more than 90,000 observations over the period from 1934 to 2011", explains Dr. Mario Lebrato from Kiel University, lead author of the study, which he prepared as part of his doctoral thesis at the GEOMAR Helmholtz Centre for Ocean Research Kiel. "Through strong reproduction of the jelly organisms, so-called plankton blooms, large amounts of organic carbon episodically accumulate in the upper ocean and -upon death of the organisms- sink into the deep sea", Lebrato continues. "The significance of this study is the finding of how much carbon is transferred by the jelly organisms to the deep ocean globally, and in particular, how much more efficient this process is compared to previously considered 'normal' plankton".

Even though the total biomass of the jelly organisms amounts only to a small fraction of the total mass of organisms in the upper ocean, their highly efficient and fast sinking makes them a significant source of organic carbon for deep-ocean ecosystems.

"The quantification of the episodic jelly blooms and their subsequent export to the deep ocean is of considerable importance for correctly modelling the functioning of marine ecosystems and the biological carbon pump", adds Prof. Dr. Andreas Oschlies, head of Biogeochemical Modelling group at GEOMAR. "We have to take such processes into account correctly to further improve our models and reduce uncertainties in our understanding of the ocean's role in the global carbon cycle", Oschlies continues.

Montreal, January 8 2020 -- About one in ten women in Québec will suffer from depression during pregnancy. Without treatment, the illness carries risks for both mother and child. Yet antidepressants are not without consequences for fetal development. The team of professor Cathy Vaillancourt at the Institut National de la Recherche Scientifique (INRS) is studying the effects of these drugs in order to identify the least harmful ones.

Professor Vaillancourt, in collaboration with the teams of Professors J. Thomas Sanderson and Nicolas Doucet of the INRS, has just modelled for the first time the interaction of commonly used antidepressants with estrogen, and more specifically with the enzyme that synthesizes the estrogen: aromatase. It is an important contribution, since estrogen production is essential to the development of the fetus and to the mother's physiological adaptation during pregnancy. The results of their study were recently published in The Journal of Steroid Biochemistry and Molecular Biology.

Prescribing antidepressants for pregnant women is controversial. Studies show that, when administered to mothers during pregnancy, some of these treatments are associated with a risk of heart and lung malformations in newborns. Others are thought to result in impaired cognitive development, including autism, in children.

Estrogen as a target for antidepressants

The harmful effects of antidepressants are thought to be due to their interaction with certain key hormones. Most antidepressants prescribed to pregnant women target serotonin, a hormone produced both in the brain and, as shown by Professor Vaillancourt's team in 2017, in the placenta. This is the family of antidepressants called selective serotonin reuptake inhibitors (SSRIs) such as Zoloft, Celexa or Prozac. However, estrogen would also be targeted by these treatments.

"We wanted to see how the antidepressants that have been developed to block the serotonin transporter also affect aromatase. Using molecular models, we found that all the antidepressants we analyzed seemed to be able to bind directly to the enzyme and regulate its activity. This remains to be confirmed and the precise mechanism needs to be further investigated," reports Cathy Vaillancourt, lead author of the study.

Her doctoral student tested the effect of different types of antidepressants on placenta samples collected after delivery. "The antidepressants we chose to test are those most commonly prescribed in pregnant women, namely sertraline (Zoloft), venlafaxine (Effexor), fluoxetine (Prozac), paroxetine (Paxil), and citalopram (Celexa)," says Andrée-Anne Hudon Thibeault "By comparing different doses and molecules, we were able to uncover some of their specificities."

By observing the effects of antidepressants on the placenta's hormonal system, the team can determine in advance if there will be a risk for the fetus. "Fetal development is strongly linked to the placenta. Every healthy fetus has a healthy placenta," maintains Vaillancourt.

Safer antidepressants

Not all types of antidepressants have these harmful effects. Not all pharmacological molecules have the same hormonal affinity. "Depending on its form, a molecule may not interact the same way with estrogen and may therefore be less harmful to the developing fetus," asserts Professor Vaillancourt, who specializes in the involvement of maternal exposure to environmental and drugs factors in the endocrinology of the human placenta.

It's more a matter of the pharmacological molecule being administered and the dosage. "By testing several types of antidepressants at varying doses, our work will contribute to better choices regarding the type of antidepressant and the dose prescribed for pregnant women, while minimizing the side effects on the course of pregnancy and on fetal development," says Andrée-Anne Hudon Thibeault, primary author and recent PhD graduate of INRS.

Discontinuing medication isn't always advisable. Depression can have serious consequences if left untreated. "Depression is one of the leading risk factors for suicide in pregnant women," says Vaillancourt. "Some studies suggest that depression can also compromise fetal development, due in part to poor lifestyle habits."

At the same time, Professor Vaillancourt is collaborating with a team of researchers in Vancouver who are studying a cohort of pregnant women and following their children over the long term. "This will give us a nice map of the various effects in women and the consequences for children's heart and brain development," says Vaillancourt. "We're still in the early stages of the project, but I'm confident that some antidepressants are safer and others can be developed for use during pregnancy."

A law passed in Japan in 1992 aimed to improve urban air quality by banning vehicles that violated certain emission standards from being registered in designated areas. A new study published in Contemporary Economic Policy provides evidence that the intervention reduced emissions, contributing to air quality improvements in metropolitan regions.

The law has been controversial because of its expense to owners of non-compliant vehicles and because of its unclear benefit. The study suggests that the law led to a 3% to 6% reduction in the monthly average ambient concentration of nitrogen dioxide over more than two decades, yielding benefits equal to about US $104 million as a result of reduced mortality from asthma.

"Japan's automobile law seems to work well, but to formally evaluate the validity of the law, full cost-benefit analyses would need to be undertaken," said corresponding author Shuhei Nishitatano, PhD, of Kwansei Gakuin University.

While regular fish have flat scales, shark 'scales' look more like teeth. But their denticles also cover their body and in particular influence their ability to swim. The denticles are made up of a compounds containing calcium.

The increasing amount of carbon dioxide (CO2) in the atmosphere due to climate change has also led to a higher concentration of CO2 in the oceans. The CO2 dissolves in the seawater to create carbonic acid that acidifies the oceans.

This higher acidity has already been found to damage the calcium carbonate in corals and other animals with calcium-based structures. The research team from three South African research institutions, from the University of Duisburg-Essen and HHU has now examined whether the more acidic seawater is also affecting sharks.

The study was performed on puffadder shysharks, which live in the Atlantic Ocean off the coast of Cape Town and are also kept in aquariums in the DAFF Research Aquarium in Cape Town. A number of sharks were exposed to more acidic water over a period of several weeks and compared with control sharks in normal seawater. After that time, the researchers found that an average of around 25 percent of the denticles had been damaged compared to a figure of less than ten percent for sharks in a benchmark group living in normal water. The harm to the group exposed to acid can be so great that it limits their ability to swim. Because the sharks' teeth are made from a similar material, they can also be negatively affected, which can in turn have an impact on their food intake.

In a further series of studies, the researchers analysed the blood of the animals kept in both acidic and normal seawater. They found that both CO2 and bi-carbonate concentrations were higher in the exposed group, with bi-carbonate preventing the blood itself from becoming more acidic. This means that sharks have acid-base regulatory mechanism for adapting to the environmental conditions.

Students in the HHU working group of Prof. Dr. Christopher Bridges from the Institute of Metabolic Physiology undertook several research trips to South Africa. They carried out experiments there and took samples which they brought back to Düsseldorf and then analysed the structure and chemistry of the samples at HHU.

MANHATTAN, KANSAS -- Private well owners should test water quality annually, according to a recent Kansas State University study that revealed nitrate levels in shallow wells above U.S. Environment Protection Act standards.

"The changes we measured in the Great Bend Prairie Aquifer appear to be large relative to changes observed in a national study by the U.S. Geological Survey," said Matthew Kirk, Kansas State University associate professor of geology and the study's principal investigator.

The Great Bend Prairie Aquifer, a part of High Plains Aquifer, was the focus of a 40-year comparison study of rural water wells recently published in the Hydrogeology Journal. Kirk and Alexandria "Allie" Richard Lane, Kansas State University 2018 master's degree graduate in geology, published the study along with Donald Whittemore, Kansas Geological Survey; Randy Stotler, University of Kansas Department of Geology; and John Hildebrand and Orrin Feril, both with Big Bend Groundwater Management District No. 5.

"The Great Bend Prairie Aquifer is very vulnerable to contamination and if rural well owners don't know there is a problem, they obviously can't do anything about it," Kirk said. "Municipalities are required to test and provide safe drinking water for city residents but private rural well owners should take responsibility to test their wells at least every year."

According to Lane, who now works for the Kansas Department of Health and Environment, there are many kits that can be purchased online for under $40 that test for bacteria, pesticides, lead, copper, iron, nitrate and water hardness in water wells.

"Those kits are good to use for basic readings and if anything is concerning, then residents can send a sample to a lab for further testing," Lane said. "At KDHE, we try to inform private water well communities that it's important to test their wells annually."

Kirk and Lane's 2016 study measured water chemistries and compared them with 1970s measurements at the same sites. Twenty of 21 wells had increases of nitrate concentrations, or NO3-, compared to the 1970s samples. Seven wells exceeded the nitrate concentrations allowed by the EPA standard for drinking water. In the 1970s study, only one of the wells was above the current EPA standard.

"There hasn't been as much work on water quality as water quantity in the High Plains Aquifer," Kirk said. "Groundwater storage in the Great Bend Prairie Aquifer is relatively stable, but if the water is there and the quality degrades, that's also bad."

According to Kirk, high nitrate levels in drinking water can cause human and livestock health issues by interfering with transport of oxygen by blood and possibly causing a higher risk of cancer. Too much nitrate in groundwater can also stimulate a release of uranium and selenium from the sediment into the water. While water quantity may be a top concern for many rural areas currently, Kirk said water quality issues may soon rise to the top of the list of rural water problems.

"Other parts of the High Plains Aquifer are most likely going to see changes too but it's just taking it longer to show up because of transport time between the surface and the water table," Kirk said.

That transport time is fairly quick in the study area since the soil is sandy and the water table is closer to the surface, Kirk said. In addition, the aquifer and sandy soil are not ideal living environments for the microbes that help clean the water by consuming nitrate.

"Groundwater in the Great Bend Prairie Aquifer often has oxygen and where that is the case, microorganisms typically respire the oxygen instead of nitrate," Kirk said.

According to the study results, the wells with the highest contamination were those in fields used for crops, and the isotopic evidence -- like a chemical signature -- show that the nitrate in the aquifer is from fertilizer. Kirk said that fertilizers help farmers increase crop yields but excess fertilizer can contaminate water supplies.

"I don't know what the future looks like or how we balance these issues -- growing food for the world and maintaining health of natural resources to grow that food -- but we need to find ways to slow down nitrate accumulation and better manage nitrate into the future," Kirk said.

Kirk advocates for precision agriculture to apply fertilizer and planting cover crops -- which use excess nitrate in the soil when planted in between the harvest of one food crop and the planting of the next. Kirk said these two practices help reduce runoff of excess fertilizer and are becoming more common with irrigated agriculture in the region. He also said that more studies are needed to evaluate if the drastic increase between the two time periods of the study is leveling off or if it has just ramped up in recent years.

"We need more data about the seasonal variation in nitrate levels and multiple years of data to really understand the trend of the increase," Kirk said. "We also hope to sample additional wells to evaluate change over more of the aquifer. We wanted to document this finding and try to spread the word because, at the end in the day, it's a big increase of nitrate and could affect people's health."

In 2019, when Wolf Cukier finished his junior year at Scarsdale High School in New York, he joined NASA's Goddard Space Flight Center in Greenbelt, Maryland, as a summer intern. His job was to examine variations in star brightness captured by NASA's Transiting Exoplanet Survey Satellite (TESS) and uploaded to the Planet Hunters TESS citizen science project.

"I was looking through the data for everything the volunteers had flagged as an eclipsing binary, a system where two stars circle around each other and from our view eclipse each other every orbit," Cukier said. "About three days into my internship, I saw a signal from a system called TOI 1338. At first I thought it was a stellar eclipse, but the timing was wrong. It turned out to be a planet."

TOI 1338 b, as it is now called, is TESS's first circumbinary planet, a world orbiting two stars. The discovery was featured in a panel discussion on Monday, Jan. 6, at the 235th American Astronomical Society meeting in Honolulu. A paper, which Cukier co-authored along with scientists from Goddard, San Diego State University, the University of Chicago and other institutions, has been submitted to a scientific journal.

The TOI 1338 system lies 1,300 light-years away in the constellation Pictor. The two stars orbit each other every 15 days. One is about 10% more massive than our Sun, while the other is cooler, dimmer and only one-third the Sun's mass.

TOI 1338 b is the only known planet in the system. It's around 6.9 times larger than Earth, or between the sizes of Neptune and Saturn. The planet orbits in almost exactly the same plane as the stars, so it experiences regular stellar eclipses.

TESS has four cameras, which each take a full-frame image of a patch of the sky every 30 minutes for 27 days. Scientists use the observations to generate graphs of how the brightness of stars change over time. When a planet crosses in front of its star from our perspective, an event called a transit, its passage causes a distinct dip in the star's brightness.

But planets orbiting two stars are more difficult to detect than those orbiting one. TOI 1338 b's transits are irregular, between every 93 and 95 days, and vary in depth and duration thanks to the orbital motion of its stars. TESS only sees the transits crossing the larger star; the transits of the smaller star are too faint to detect.

"These are the types of signals that algorithms really struggle with," said lead author Veselin Kostov, a research scientist at the SETI Institute and Goddard. "The human eye is extremely good at finding patterns in data, especially non-periodic patterns like those we see in transits from these systems."

This explains why Cukier had to visually examine each potential transit. For example, he initially thought TOI 1338 b's transit was a result of the smaller star in the system passing in front of the larger one -- both cause similar dips in brightness. But the timing was wrong for an eclipse.

After identifying TOI 1338 b, the research team used a software package called eleanor, named after Eleanor Arroway, the central character in Carl Sagan's novel "Contact," to confirm the transits were real and not a result of instrumental artifacts.

"Throughout all of its images, TESS is monitoring millions of stars," said co-author Adina Feinstein, a graduate student at the University of Chicago. "That's why our team created eleanor. It's an accessible way to download, analyze and visualize transit data. We designed it with planets in mind, but other members of the community use it to study stars, asteroids and even galaxies."

TOI 1338 had already been studied from the ground by radial velocity surveys, which measure motion along our line of sight. Kostov's team used this archival data to analyze the system and confirm the planet. Its orbit is stable for at least the next 10 million years. The orbit's angle to us, however, changes enough that the planet transit will cease after November 2023 and resume eight years later.

NASA's Kepler and K2 missions previously discovered 12 circumbinary planets in 10 systems, all similar to TOI 1338 b. Observations of binary systems are biased toward finding larger planets, Kostov said. Transits of smaller bodies don't have as big an effect on the stars' brightness. TESS is expected to observe hundreds of thousands of eclipsing binaries during its initial two-year mission, so many more of these circumbinary planets should be waiting for discovery.

Think of the blade of a wind turbine or a part of an airplane. After a heavy storm, you want to investigate whether it has been hit by hail stones or loaded beyond a certain threshold, even if no clear damage is visible. Researchers from Ghent University in Belgium have developed a pressure-sensitive light-emitting material that can visualize where such a hit occurred, up to three days after the event. To achieve this, they developed a so-called mechanoluminescent material which shows specific sensitivities to pressure (or mechanical action) and infrared radiation.

Mechanoluminescent materials are a specific class of luminescent materials which can emit light when they are deformed or when pressure is applied to them. This process is known for hundreds of years - just crush some sugar crystals in a dark place and you will observe sparks of light - but in most materials it is related to the breaking of chemical bonds in crystals. This destructive type of mechanoluminescence is not very convenient for sensing and monitoring of the structural integrity of constructions. In the past decades, several materials were reported and developed which can repeatedly emit light upon application of pressure. Most of them are based on the storage of energy in the crystal lattice of the luminescent material after exposure to ambient or UV light. When pressure is applied, this stored energy is released under the form of light. The higher the pressure or deformation, the stronger the obtained signal, which allows for quantification of a wide range of stresses in materials, over larger areas and with good spatial resolution. A disadvantage for several applications is that the mechanoluminescent emission needs to be constantly monitored, as the emission only occurs when the pressure is applied.

In a new paper published in Light Science & Applications, scientists from the LumiLab research group have added memory to a specific mechanoluminescent material. Using the imperfections (or defects) in this material in a selective way, it was possible to visualize where the pressure had been applied, up to three days after the deformation of the material occurred.

The authors Robin Petit, Ang Feng, Simon Michels and Philippe Smet summarize the operational principle of their approach:

"Mechanoluminescent material was incorporated in polymer plates and briefly exposed to ultraviolet light. During this illumination, defects in the material are populated with electrons originating from the luminescent centers. When pressure is applied to the luminescent material, these electrons are released again from the defects, or traps, as we commonly call them. Some of the released electrons return to the luminescent centers, with the emission of light as a consequence. This is the standard mechanoluminescence process. A fraction of the released electrons are however transferred to other types of defects. Those defects are called 'deep traps' as the electrons are not easily released again, except when infrared light is used. By scanning an infrared laser beam over the sample surface, those areas where electrons had been stored after the application of pressure light up as soon as the infrared photons are kicking them out of their traps. The electrons return to the luminescent center and the material locally lights up again."

The key message is that different types of defects in the luminescent material can have different responses to stimuli like heat, pressure or light. In this way, electrons can be moved by pressure - the "write" action - and then be "read out" by optical means. Because the deep traps are very stable, the researchers were able to demonstrate that the signal was still visible after waiting three days between the "write" and "read" steps. But the researchers' work is far from finished. First, they want to improve the sensitivity of the mechanoluminescent material and optimize the write and read conditions. Second, they plan to bring the material to specific applications where optimal use of the memory function can be exploited. "Think of components of buildings, vehicles or infrastructure where constant monitoring is not possible", Smet adds. "Furthermore, this approach will not only help the development of new pressure indicating materials. This work also revealed that the defects responsible in the energy storage and read out process are not of a single type. This insight will prove beneficial for the development of other light-emitting materials, where researchers use defects for other purposes or try even to suppress the occurrence of defects. Think of LED lamps which might be even more efficient in the conversion of electricity to light, brighter glow-in-the-dark materials or faster scintillating materials used in medical imaging," the scientists forecast.

The new year means it's time to set resolutions for 2020 and new research from the Journal of the American College of Cardiology suggests running a marathon for the first time could have several health benefits. The study found that for first-time marathon runners, training and completion of the marathon was associated with reductions in blood pressure and aortic stiffening in healthy participants that were equivalent to a four-year reduction in vascular age, with the greatest benefits seen in older, slower male marathon runners with higher baseline blood pressure.

"As clinicians are meeting with patients in the new year, making a goal-oriented exercise training recommendation--such as signing up for a marathon or fun-run--may be a good motivator for our patients to keep active," said senior author Charlotte H. Manisty, MD, of the Institute of Cardiovascular Science at University College London and Barts Heart Centre in London. "Our study highlights the importance of lifestyle modifications to slow the risks associated with aging, especially as it appears to never be too late as evidenced by our older, slower runners."

Arterial stiffening is a normal part of aging, but it also increases cardiovascular risk in otherwise healthy individuals by contributing to increased pulse pressure and ventricular overload, which are associated with dementia and cardiovascular and kidney diseases, even in the absence of plaque in the arteries. While blood pressure medication can modify arterial stiffness in established heart disease, more cardiovascular events occur in individuals without diagnosed high blood pressure.

Regular aerobic exercise is a lifestyle modification that has real-world implications, particularly with the growth in mass participation running as an increasingly popular form of non-prescribed exercise. The researchers used a cohort of 138 healthy, first-time marathon runners from the 2016 and 2017 London Marathon. They examined the participants before training and after marathon completion to determine if age-related aortic stiffening would be reversible with real-world exercise training.

Participants had no significant past medical or cardiac history and were not running for more than two hours per week at baseline. On average, participants were 37 years old and 49% were male. Exclusion criteria included pre-existing heart disease during the preliminary investigations or contraindication on a cardiovascular magnetic resonance imaging scan.

The researchers conducted all measurements before training started six months prior to the marathon and repeated them all within three weeks of completing the London Marathon, but no earlier than one week after the marathon to avoid any acute effects of exercise. Assessments included blood pressure measurements and measurements of aortic stiffness by cardiovascular magnetic resonance imaging. Biological aortic age was determined from the relationship between the participant's age and aortic stiffness at three levels of the aorta.

All participants were recommended to follow the "Beginner's Training Plan" provided by the marathon, which consists of approximately three runs per week that increase in difficulty for a 17-week period prior to the marathon. However, the researchers did not discourage participants who wished to use alternative training plans. The average marathon running time was 5.4 hours for women and 4.5 hours for men. When compared to training data and marathon completion times from 27,000 runners, these times were found to be consistent with a training schedule of six to 13 miles per week.

Training decreased systolic and diastolic blood pressure by 4 and 3 mmHg, respectively. Overall, aortic stiffness reduced with training and was most pronounced in the distal aorta with increases in distensibility--the capacity to swell with pressure--of 9%. This amounted to the equivalent of an almost four-year reduction in 'aortic age.' Older patients had greater changes with exercise training, with males and those running slower marathon times deriving greatest benefit.

"Our study shows it is possible to reverse the consequences of aging on our blood vessels with real-world exercise in just six months. These benefits were observed in overall healthy individuals across a broad age range and their marathon times are suggestive of achievable exercise training in novice participants," Manisty said.

Although the study only recruited healthy participants, those with hypertension and stiffer arteries might be expected to have an even greater cardiovascular response to exercise training.

In an accompanying editorial, Julio A. Chirinos, MD, PhD, from the Division of Cardiovascular Medicine at the Hospital of the University of Pennsylvania, said "Despite some limitations, including its observational nature, the study adds to the body of evidence supporting beneficial effects of exercise on multiple aging phenotypes. Given the profound implications of arterial stiffness for human health, this study is important and should stimulate further research to identify potential molecular mechanisms by which exercise reduces aortic stiffness. In addition, training for marathons usually involves various concomitant approaches such as better sleep and dietary patterns, and in some instances, over-the-counter supplements, that may confound or interact with exercise training per se. More research to identify optimal integrated training regimens is needed."

CHICAGO--January 6, 2020--Despite the prestige of becoming a physician, 80 percent of medical students report a low sense of personal achievement, according to a new study in The Journal of the American Osteopathic Association.

Researchers surveyed 385 first- through fourth-year medical students to assess their levels of burnout, a psychological syndrome resulting from prolonged exposure to stressful work. Study authors say burnout has three dimensions: emotional exhaustion, depersonalization, and low sense of personal achievement.

"That 80 percent feel a low sense of achievement is a bit ironic, considering that these are all high-performing individuals," says Elizabeth Beverly, PhD, associate professor in family medicine at Ohio University Heritage College of Osteopathic Medicine and lead author on this study. "However, it also makes sense in that they have gone from an environment where they were standouts to one where they are now on an equal academic playing field."

Beverly adds that each year of medical school has its own unique and significant stresses that prevent students from ever fully acclimating to the challenge. In year one, students are overwhelmed by the vast amount of knowledge they have to learn. In year two, they begin studying for board examinations. Year three sends students on clinical rotations to begin real world application of their knowledge. Year four is focused on graduation and matching into a residency program.

"Throughout medical school there is always another test or requirement for students to prove themselves in a new way," says Beverly. "Over time that can feel quite discouraging."

Other areas of burnout

Beverly says only 2.3 percent of participants reported high levels of emotional exhaustion, while 17 percent reported high levels of depersonalization, a form of clinical detachment. Both of those dimensions of burnout are associated with higher perceived stress, poorer sleep quality and higher smartphone addiction scores.

Conversely, only higher perceived stress is associated with feeling a low sense of personal achievement. Beverly says she is still concerned about the role of smartphone addiction in medical students as 22 percent of participants met the basic score qualifying for smartphone addiction.

"I think the findings warrant additional research into how smartphone addiction can exacerbate burnout," says Beverly. "Increasingly, medical education incorporates smart devices, so we want to be mindful of how much we condition students to rely on them."

Scientists have shown for the first time that brittle stars use vision to guide them through vibrant coral reefs, thanks to a neat colour-changing trick.

The international team, led by researchers at Oxford University Museum of Natural History, described a new mechanism for vision in the red brittle star Ophiocoma wendtii, a relative to sea stars and sea urchins, which lives in the bright and complex reefs of the Caribbean Sea. Their findings are published in Current Biology today.

This species first captured scientific attention more than 30 years ago thanks to its dramatic change in colour between day and night and its strong aversion to light. Recently , researchers demonstrated that O. wendtii was covered in thousands of light-sensitive cells, but the exact behaviours they control remained a mystery. The new research shows that O. wendtii is able to see visual stimuli, and that its signature colour-change might play an important role in enabling vision.

Lauren Sumner-Rooney, a research fellow at Oxford University Museum of Natural History who studies unusual visual systems, has been working with Ophiocoma for several years at the Smithsonian Tropical Research Institute in Panama and the Museum für Naturkunde in Berlin. Alongside team members from the Museum für Naturkunde, Lund University, and the Georgia Institute of Technology, Sumner-Rooney ran hundreds of behavioural experiments to test the brittle stars' 'eyesight'.

"These experiments gave us not only the first evidence that any brittle star is able to 'see'," says Sumner-Rooney, "but only the second known example of vision in any animal lacking eyes". The animals were able to seek out areas of contrast, which the researchers think may mimic structures that could offer shelter from predators. Although it appears that their vision is very coarse, on the crowded tropical reefs disturbed brittle stars never have to look too far to make a dash for the nearest cover.

However, an unexpected discovery raised new questions about how this visual system worked. "We were surprised to find that the responses we saw during the day disappeared in animals tested at night, yet the light-sensitive cells still seemed to be active," says Sumner-Rooney.

The team set about trying to identify what caused this dramatic shift in behaviour, eliminating possible factors such as loss of motivation and low light intensity making vision too difficult. The one they couldn't rule out was O. wendtii's characteristic change in colour, from a deep red during the day to beige at night. Previously, Sumner-Rooney's team showed that another closely related brittle star, Ophiocoma pumila, was also covered in light sensors, but it doesn't exhibit the same colour change. Curiously, this paler species also failed their eye-test.

Combining a suite of techniques, the researchers reconstructed digital models of individual light-sensing cells in the two species, with and without O. wendtii's dark daytime pigmentation. They demonstrated that, during the day, the pigment restricted light reaching the sensors to a narrower angle that corresponds to their hypothesised visual resolution. Without this pigment - in O. pumila, or during the night in O. wendtii - light could reach the sensors from a much wider angle, making vision impossible.

"It's a very exciting discovery," explains Sumner-Rooney. "It had been suggested 30 years ago that changing colour might hold the key to light-sensitivity in Ophiocoma, so we're very happy to be able to fill in some of the gaps that remained and describe this new mechanism."

Although this is the first visual system proposed to work using whole-body colour change, the scientists have also identified potential similarities with a sea urchin, distant relatives of brittle stars. Only one species of sea urchin has 'passed' the same tests for vision, and it also, independently, changes colour in response to light levels. Future work will probe whether this sea urchin, the only other animal in the world known to see without eyes, might be using a similar trick to Ophiocoma.

Global warming is driving rapid environmental change in the Arctic. "To understand these changes, field measurements that adequately represent environmental variation across the Arctic as a whole are crucial", says PhD student Anna-Maria Virkkala from the University of Helsinki.

A new study by researchers from University of Helsinki and Lund University shows that northern Arctic regions remain under-sampled and provides detailed maps of potential new sampling locations for each environmental science discipline across the Arctic.

The changing Arctic requires a sampling strategy for the future

Doing field work in the harsh Arctic conditions is not easy. Resources and accessibility strongly constrain Arctic research. Understanding what kind of conditions and regions remain under-studied is important when researchers plan new field campaigns.

However, studies dealing with the representativeness of sampling have been conducted mainly for very specific fields, or in smaller regions. Thus, the current state of field sampling across broad environmental science disciplines across the Arctic has not been fully understood.

A literature database and open spatial data sets as a tool to map the representativeness of sampling

"We utilize an existing literature database of around 1 800 field studies across the Arctic", says Dan Metcalfe, a senior lecturer in Lund University. This database contains information about the field sampling locations and citations, including their primary discipline/s within environmental sciences featured in the article.

Open spatial data sets describing topography, vegetation, and soils were used to characterize the environmental conditions of each sampling location. "The availability of these data sets has increased during the past decade which allows us to explore the environmental coverage of Arctic field sampling comprehensively", says a Post-Doc researcher Hakim Abdi from Lund University.

New field studies are needed in the northernmost Arctic regions

The study shows that more research is needed particularly in the Canadian Arctic Archipelago, northern Greenland, northern Taimyr, and central and eastern Siberia. These under-sampled regions are characterized by cold soils and climate and modest vegetation cover. Many of these regions are predicted to experience rapid permafrost thaw and vegetation shifts due to global warming in the future. The lack of data from these conditions suggests that we do not necessarily understand the whole range of changes that the global warming might cause.

Differences in sampling across environmental science disciplines

There are differences in the representativeness of sampling locations across environmental science disciplines. Sampling locations in Botany and Biogeochemistry cover environmental gradients the best, and Microbiology, Meteorology, Geosciences and Geographic Information Systems / Remote Sensing / Modeling have the largest research gaps across the Arctic. Although northern Alaska and Fennoscandia remained the best sampled regions, research gaps were found even in central Arctic Alaska or southern Arctic Fennoscandia in some disciplines.

Let's keep exploring the Arctic together

Luckily, many of these under-sampled regions are close to existing infrastructure (https://eu-interact.org/field-sites/), so making a change is possible. "We hope these results will help prioritize future research efforts across all environmental science disciplines, thus increasing our knowledge about the Arctic environmental change", summarizes Professor Miska Luoto from University of Helsinki.

Scientists at the Laboratory for Attosecond Physics have developed a unique laser technology for the analysis of the molecular composition of biological samples. It is capable of detecting minimal variations in the chemical make up of organic systems.

At the biochemical level, organisms can be thought of as complex collections of different species of molecules. In the course of their metabolism, biological cells synthesize chemical compounds, and modify them in multifarious ways. Many of these products are released into the intercellular medium and accumulate in body fluids like the blood. One major aim of biomedical research is to understand what these immensely complex mixtures of molecules can tell us about the state of the organism concerned. All differentiated cell types contribute to this 'soup'. But precancerous and malignant cells add their own specific molecular markers - and these provide the first indications of the presence of tumour cells in the body. So far, however, very few of these indicator molecules have been identified, and those that are known appear in minuscule amounts in biological samples. This makes them extremely difficult to detect. It is assumed that many of the most informative molecular signatures comprise combinations of compounds that belong to all the various types of molecules found in cells - proteins, sugars, fats and their diverse derivatives. In order to define them, a single analytical method that is versatile and sensitive enough to detect and measure the levels of all of them is needed.

An interdisciplinary team led by Prof. Ferenc Krausz has now built a new laser-based system that is specifically designed for this purpose. The group is based at the Laboratory for Attosecond Physics (LAP), which is run jointly by Ludwig-Maximilians-Universitaet (LMU) in Munich and the Max Planck Institute for Quantum Optics (MPQ), and it includes physicists, biologists and data scientists. This system enables one to obtain chemical fingerprints in the form of spectra of infrared light, which reveal the molecular compositions of samples of all sorts, including samples of biological origin. The technique offers unprecedented sensitivity and can be used for all known classes of biomolecules.

The new laser spectrometer builds on technologies that were originally developed in the LAP for the production of ultrashort laser pulses, which are used to study the ultrafast dynamics of subatomic systems. The instrument, which was built by physicist Ioachim Pupeza and his colleagues, is designed to emit trains of extremely powerful pulses of laser light that cover a broad segment of the spectrum in the infrared wavelength. Each of these pulses lasts for a few femtoseconds (in scientific notation 1 fs = 10 -15 s, one millionth of a billionth of a second). These extremely brief flashes of infrared light cause the bonds that link atoms together to vibrate. The effect is analogous to that of striking a tuning fork. After the passage of the pulse, the vibrating molecules emit coherent light at highly characteristic wavelengths or, equivalently, oscillation frequencies. The new technology makes it possible to capture the complete ensemble of wavelengths emitted. Since every distinct compound in the sample vibrates at a specific set of frequencies, it contributes its own well defined 'subspectrum' to the emission. No molecular species has anywhere to hide.

"With this laser, we can cover a wide range of infrared wavelengths - from 6 to 12 micrometers - that stimulate vibrations in molecules," says Marinus Huber, joint first author of the study and a member of biologist Mihaela Zigman's group, which was also involved in the experiments carried out in the LAP. "Unlike mass spectroscopy, this method provides access to all the types of molecules found in biological samples," she explains.

Each of the ultrashort laser pulses used to excite the molecules consists of only a few oscillations of the optical field. Moreover, the spectral brightness of the pulse (i.e. its photon density) is up to twice as high as those generated by conventional synchrotrons, which have hitherto served as radiation sources for comparable approaches to molecular spectroscopy. In addition, the infrared radiation is both spatially and temporally coherent. All of these physical parameters together account for the new laser system's extremely high sensitivity, enabling molecules present in very low concentrations to be detected and high-precision molecular fingerprints to be produced. Not only that, samples of living tissue up to 0.1 mm thick can, for the first time, be illuminated with infrared light and analyzed with unparalleled sensitivity. In initial experiments, the team at the LAP has applied the technique to leaves and other living cells, as well as blood samples. "This ability to accurately measure variations in he molecular composition of body fluids opens up new possibilities in biology and medicine, and in the future the technique could find application in the early detection of disorders," Zigman says.

Life as we know it requires phosphorus. It's one of the six main chemical elements of life, it forms the backbone of DNA and RNA molecules, acts as the main currency for energy in all cells and anchors the lipids that separate cells from their surrounding environment.

But how did a lifeless environment on the early Earth supply this key ingredient?

"For 50 years, what's called 'the phosphate problem,' has plagued studies on the origin of life," said first author Jonathan Toner, a University of Washington research assistant professor of Earth and space sciences.

The problem is that chemical reactions that make the building blocks of living things need a lot of phosphorus, but phosphorus is scarce. A new UW study, published Dec. 30 in the Proceedings of the National Academy of Sciences, finds an answer to this problem in certain types of lakes.

The study focuses on carbonate-rich lakes, which form in dry environments within depressions that funnel water draining from the surrounding landscape. Because of high evaporation rates, the lake waters concentrate into salty and alkaline, or high-pH, solutions. Such lakes, also known as alkaline or soda lakes, are found on all seven continents.

The researchers first looked at phosphorus measurements in existing carbonate-rich lakes, including Mono Lake in California, Lake Magadi in Kenya and Lonar Lake in India.

While the exact concentration depends on where the samples were taken and during what season, the researchers found that carbonate-rich lakes have up to 50,000 times phosphorus levels found in seawater, rivers and other types of lakes. Such high concentrations point to the existence of some common, natural mechanism that accumulates phosphorus in these lakes.

Today these carbonate-rich lakes are biologically rich and support life ranging from microbes to Lake Magadi's famous flocks of flamingoes. These living things affect the lake chemistry. So researchers did lab experiments with bottles of carbonate-rich water at different chemical compositions to understand how the lakes accumulate phosphorus, and how high phosphorus concentrations could get in a lifeless environment.

The reason these waters have high phosphorus is their carbonate content. In most lakes, calcium, which is much more abundant on Earth, binds to phosphorus to make solid calcium phosphate minerals, which life can't access. But in carbonate-rich waters, the carbonate outcompetes phosphate to bind with calcium, leaving some of the phosphate unattached. Lab tests that combined ingredients at different concentrations show that calcium binds to carbonate and leaves the phosphate freely available in the water.

"It's a straightforward idea, which is its appeal," Toner said. "It solves the phosphate problem in an elegant and plausible way."

Phosphate levels could climb even higher, to a million times levels in seawater, when lake waters evaporate during dry seasons, along shorelines, or in pools separated from the main body of the lake.

"The extremely high phosphate levels in these lakes and ponds would have driven reactions that put phosphorus into the molecular building blocks of RNA, proteins, and fats, all of which were needed to get life going," said co-author David Catling, a UW professor of Earth & space sciences.

The carbon dioxide-rich air on the early Earth, some four billion years ago, would have been ideal for creating such lakes and allowing them to reach maximum levels of phosphorus. Carbonate-rich lakes tend to form in atmospheres with high carbon dioxide. Plus, carbon dioxide dissolves in water to create acid conditions that efficiently release phosphorus from rocks.

"The early Earth was a volcanically active place, so you would have had lots of fresh volcanic rock reacting with carbon dioxide and supplying carbonate and phosphorus to lakes," Toner said. "The early Earth could have hosted many carbonate-rich lakes, which would have had high enough phosphorus concentrations to get life started."

Another recent study by the two authors showed that these types of lakes can also provide abundant cyanide to support the formation of amino acids and nucleotides, the building blocks of proteins, DNA and RNA. Before then researchers had struggled to find a natural environment with enough cyanide to support an origin of life. Cyanide is poisonous to humans, but not to primitive microbes, and is critical for the kind of chemistry that readily makes the building blocks of life.

A new study revealed that one dose of the HPV vaccine may prevent infection from the potential cancer-causing virus, according to research published in JAMA Network Open from The University of Texas Health Science Center at Houston (UTHealth).

According to the Centers for Disease Control (CDC), 34,800 new cancer diagnoses are linked to human papillomavirus (HPV) annually. The virus is thought to account for more than 90% of all cervical and anal cancers, more than 60% of all penile cancers, and approximately 70% of all oral cancers.

While results of the paper showed that a single dose may be as effective as the currently recommended two- or three-dose series, it's too early for people to rely on a single dose of the vaccine for protection, according to senior author Ashish A. Deshmukh, PhD, MPH, an assistant professor at UTHealth School of Public Health.

"HPV vaccine coverage is less than 10% globally because of poor vaccine uptake rates in many resource-limited countries. Ensuring boys and girls receive their first dose is a big challenge in several countries and a majority of adolescents are not able to complete the recommended series due to a lack of intensive infrastructure needed to administer two or three doses," Deshmukh said. "If ongoing clinical trials provide evidence regarding sustained benefits of a one-dose regimen, then implications of single-dose strategy could be substantial for reducing the burden of these cancers globally."

Although the study participants included only women, the CDC recommends a two-dose regimen for all children starting the series before age 15 or a three-dose regimen if the series is started between ages 16 to 26. The latest generation of HPV vaccine can protect against nearly 90% of cancer-causing HPV infections. Yet, current vaccinations rates are less than ideal - half of people in the U.S. are not vaccinated against this common sexually transmitted infection.

"The current HPV vaccine dosing regimen can be cumbersome for people to understand. If one dose is proven effective in trials, the vaccine regimen will be simplified. This will help improve the coverage rate among adolescents that are currently below the Healthy People 2020 goal and possibly will also increase the momentum of uptake in the newly approved age group," said lead author Kalyani Sonawane, PhD, who is an assistant professor at UTHealth School of Public Health.

COLUMBUS, Ohio - How much you enjoy the new Star Wars movie will depend a lot on your expectations going in, a new study suggests.

Researchers surveyed 441 people before and after they saw the last episode in the popular franchise, Star Wars VIII: The Last Jedi, released in 2017. They wanted to see how audiences' expectations affected their actual enjoyment of the movie.

The findings suggest that it is probably best not to go into Star Wars: The Rise of Skywalker thinking you're really going to love it or really going to hate it, said James Alex Bonus, co-author of the study and assistant professor of communication at The Ohio State University.

As you might expect, people who had the highest expectations for The Last Jedi but were disappointed in the movie had the lowest enjoyment of anyone taking the survey.

But what was most interesting, Bonus said, were people who expected very little from the movie but ended up feeling intensely happy after seeing the film. Their overall enjoyment was lower than those who felt similarly joyful but who went into the movie with higher expectations.

"It wasn't really helping people to go in with those low expectations," Bonus said.

"The negative bias going in dragged them down and even if they were pleasantly surprised by the movie, they still didn't like it as much as other people did."

The study was published online this month in the Journal of Media Psychology.

The results show how much our expectations can influence our enjoyment of a movie, particularly one in a franchise like Star Wars, where audiences have a history with the characters or storyline.

"It becomes a lot less about what is in the movie and a lot more about what you expected it to be," Bonus said.

In this study, online participants recruited through Amazon Mechanical Turk were interviewed three weeks before the release of The Last Jedi in 2017. They were asked to rate on a 7-point scale how happy, sad and nostalgic they thought the film would make them feel.

Three weeks later, those who had seen the movie were asked how happy, sad and nostalgic seeing the movie had made them feel. They also rated their enjoyment and appreciation of the movie.

Results showed that many people weren't very accurate at predicting how they would react to seeing The Last Jedi, Bonus said. That goes along with other research that shows people are bad at predicting how various experiences will make them feel.

In this study, about 55 percent of participants did not accurately predict how the movie would make them feel. Most of them didn't get their prediction entirely wrong, such as saying the movie would make them happy when it didn't.

But many were off in the strength of their feelings, predicting, for example, the movie would make them very happy when it made them only somewhat happy.

"We are really bad at predicting how future events will make us feel," Bonus said.

One other interesting fact from the study: People who in the first survey expected that The Last Jedi would make them feel nostalgic were more likely to have seen the movie when re-interviewed three weeks later. Expectations about how happy they would feel did not predict viewing behavior.

"That shows the important role nostalgia plays for audiences of established franchises like Star Wars," Bonus said.