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Adolescent girls who self-injure feel that they receive more negative feedback than they actually receive, and are more sensitive to "thumbs down" responses, compared to other adolescent girls. These are the findings presented by Irene Perini, researcher at Center for Social and Affective Neuroscience (CSAN) at Linköping University, in a recently published article.

Irene Perini has previously examined what happens in the brains of adolescents when they use social media. She used images taken in a magnetic resonance camera to show that it is an expectation of social judgement that initiates processes in the brain. Those areas of the brain that direct our attention towards what is most relevant for us, which form what is known as the salience network, are particularly strongly affected.

"When we post a picture or a comment on social media, the brain registers an expectation of being judged, receiving affirmation, as something important", Irene Perini explains.

She has continued to examine the effect more deeply and compared a group of 27 healthy girls with 27 girls with nonsuicidal self-injury (NSSI), which refers to the intentional destruction of one´s own body tissue without suicidal intent and for purposes not socially sanctioned. The project is a collaboration with other scientists, including Maria Zetterqvist, clinical psychologist and CSAN researcher, who works with adolescents with NSSI.

"We know that healthy social interactions are particularly important for teenagers, and we also know that social stress and self-injuring are linked in young people. Interpersonal stress, perceived criticism, and perceived social rejection are common triggers of NSSI", says Irene Perini.

In the test, she used an online game that simulates the interaction between young people on social media. They were asked to decide whether they liked the other players, and they were themselves judged. No matter how they interacted, they received an equal number of thumbs up and thumbs down.

With respect to the activation of the salience network, the experiment found no difference between the two groups. However, they were also asked to reply to several questions about the game. How often did you get a thumbs down? How did it make you feel? Do you like to see your own face (a selfie)?

The replies to these questions differed significantly between the two groups.

The girls who self-injured believed that they had received thumbs down significantly more often than was actually the case, and the negative feedback affected them more strongly than the control group. Their liking for their opponent was lower, and their liking for their own face was also lower than the control group.

"The quality of the interaction was kept artificially neutral, in order to investigate potential bias in interpreting social experiences. Indeed, girls with NSSI manifested a clear negative bias", says Irene Perini.

Detailed analysis of the images from the magnetic resonance camera (fMRI) has shown that another part of the brain is activated during expectation in the group of girls who self-injure, the part that is usually associated with emotions and reflection.

"But we must be careful when interpreting images from fMRI, particularly until the results can be reproduced in further studies", she points out. She is at the same time hopeful that the results from the work can help therapists to make advances, now that they know that there is a negative bias - that the patients interpret the situation as being worse than it is.

Should therapists recommend care when using social media?

"It's probably a good idea if parents and therapists make it clear to adolescents with NSSI that they are more sensitive and that they overinterpret the negative", Irene Perini replies.

Learning several new things at once increases cognitive abilities in older adults, according to new research from UC Riverside.

UCR psychologist Rachel Wu says one important way of staving off cognitive decline is learning new skills as a child would. That is, be a sponge: seek new skills to learn; maintain motivation as fuel; rely on encouraging mentors to guide you; thrive in an environment where the bar is set high.

"The natural learning experience from infancy to emerging adulthood mandates learning many real-world skills simultaneously," Wu's research team writes in a paper recently published in The Journals of Gerontology, Series B: Psychological Sciences.

Likewise, the group's hypothesis held, learning multiple new skills in an encouraging environment in older adulthood leads to cognitive growth. The prize: maintaining independence in old age.

Building on lifelong learning research, previous studies have demonstrated the cognitive gains of older people learning new skills, such as photography or acting. But these skills were learned one at a time, or sequentially.

For Wu's studies, the researchers asked adults 58 to 86 years old to simultaneously take three to five classes for three months -- about 15 hours per week, similar to an undergraduate course load. The classes included Spanish, learning to use an iPad, photography, drawing/painting, and music composition.

The participants completed cognitive assessments before, during, and after the studies to gauge working memory (such as remembering a phone number for a few minutes); cognitive control (which is switching between tasks) and episodic memory (such as remembering where you've parked).

After just 1 ½ months, participants increased their cognitive abilities to levels similar to those of middle-aged adults, 30 years younger. Control group members, who did not take classes, showed no change in their performance.

"The participants in the intervention bridged a 30 year difference in cognitive abilities after just 6 weeks and maintained these abilities while learning multiple new skills," said Wu, who is an assistant professor of psychology.

"The take-home message is that older adults can learn multiple new skills at the same time, and doing so may improve their cognitive functioning," Wu said. "The studies provide evidence that intense learning experiences akin to those faced by younger populations are possible in older populations, and may facilitate gains in cognitive abilities."

Bee populations are declining, and neonicotinoid pesticides continue to be investigated -- and in some cases banned -- because of their suspected role as a contributing factor. However, limitations in sampling and analytical techniques have prevented a full understanding of the connection. Now, researchers describe in the ACS journal Environmental Science & Technology a new approach to sample neonicotinoids and other pesticides in plants, which could explain how bees are exposed to the substances.

Neonicotinoids are water-soluble insecticides that are applied to seeds or foliage. But non-target organisms such as pollinating bees can also be exposed to the substances, mainly through residues in nectar and pollen of flowering plants, which bees use to make honey. Most studies to-date have relied on correlating the presence of neonicotinoid residues in plant samples with bee declines. A few studies have measured total neonicotinoids in plants but laborious methods were used. Jay Gan and colleagues wanted to develop a simpler, more direct way to monitor neonicotinoids in living plants that would capture spatial and temporal movement of the insecticides.

The researchers developed a new type of solid-phase microextraction (SPME) probe, a device that can track concentration changes over time in biological systems. SPME probes use a fiber coated with a liquid or solid to quickly extract analytes from a sample. The team developed an SPME probe that they inserted into plants through a needle, allowing repeated sampling of seven neonicotinoids in plant sap. The method was demonstrated in lettuce and soybean plants, with each sampling taking only 20 minutes. The analytes were then recovered from the probe and analyzed. This procedure allowed the researchers to quantify neonicotinoids in plants and study their movement and distribution throughout the plants over time. This method could be used to monitor movement of pesticides into flowers, nectar and pollen to pinpoint where and when maximal pesticide exposure occurs for bees and other pollinators, the researchers note.

PITTSBURGH, July 17, 2019 - Aging research indicates that better healthspan--the quality of life as we age--may be more important than lifespan.

In a report published today in Nature Communications, a surprising new genetic discovery by researchers at the University of Pittsburgh School of Medicine and UPMC Children's Hospital of Pittsburgh suggests that there may be molecular switches that control lifespan and healthspan separately.

Healthspan is represented by a set of parameters like mobility and immune resistance that are distinct from lifespan, which can be easily measured. Though it is harder to study, in the long run, it may be more relevant to modify healthspan, notes senior author Arjumand Ghazi, Ph.D., associate professor of pediatrics, developmental biology and cell biology, Pitt School of Medicine and UPMC Children's Hospital, recalling the Greek myth of Eos and Tithonus to describe the difference. "The goddess Eos fell in love with a mortal man, Tithonus, and asked that he be granted eternal life, but forgot to ask for eternal youth. Tithonus lived forever but as a frail and immobile old man."

In the current study, Ghazi and her team focused on a protein called TCER-1 in the worm Caenorhabditis elegans. Earlier work from their lab showed that TCER-1 promotes longevity in worms and also is critical to its fertility.

Longevity genes in many animals increase resistance to stressors, such as infection, so the researchers expected that removing TCER-1 would make the worms less resilient.

Much to their surprise, they saw the exact opposite. When infected with bacteria, subjected to DNA-damaging radiation or high temperatures, worms without TCER-1 survived much longer than normal worms. They also had improved mobility with age and were less prone to protein clumping that causes human neurodegenerative diseases. Conversely, increasing TCER-1 levels beyond normal suppressed the animal's immune defenses.

"I was sure I'd made a mistake somewhere," says Francis Amrit, Ph.D., the study's lead author and a staff scientist in Ghazi's lab. "But I repeated the experiments and realized that TCER-1 was unlike any other longevity gene we'd seen before--it was actually suppressing immune resistance."

Interestingly, TCER-1 seemed to be able to wield its influence only as long as the animals were young and capable of laying eggs.

"I liken TCER-1 in C. elegans to a DJ who controls the base, treble and other tones to get the music to sound just right," says Amrit. "During its reproductive age, TCER-1 tunes all the molecular dials to ensure that the animal reproduces efficiently to propagate the species, partly by diverting resources meant for stress management."

Ghazi cautions that it is too soon to make any conclusions about human healthspan, but notes that the finding should change how we understand the molecular basis of aging.

"It will be interesting to understand how the body allocates resources," Ghazi speculates. "For example, could women one day take a pill once they decide to stop having children that would improve their healthspan by diverting resources used for reproduction toward improved stress resilience?"

Apathy is the most common neuropsychiatric symptom of dementia, with a bigger impact on function than memory loss - yet it is under-researched and often forgotten in care. A new study has found that apathy is present nearly half of all people with dementia, with researchers finding it is often distinct from depression.

Although common, apathy is often ignored as it is less disruptive in settings such as care homes than symptoms like aggression. Defined by a loss of interest and emotions, it is extremely distressing for families and it is linked with more severe dementia and worse clinical symptoms.

Now, research led by the University of Exeter and presented at the Alzheimer's Association International Conference in LA has analysed 4,320 people with Alzheimer's disease from 20 cohort studies, to look at the prevalence of apathy over time.

At the start of the study, 45% presented with apathy, and 20% had persistent apathy over time. Researchers found that a proportion had apathy without depression, which suggests that the symptom might have its own unique clinical and biological profile when compared to apathy with depression and depression only.

Miguel da Silva Vasconcelos, PhD student at the University of Exeter and King’s College London, said: “Apathy is an under-researched and often ignored symptom of dementia. It can be overlooked because people."

Professor Clive Ballard, of the University of Exeter Medical School, said: "Apathy is the forgotten symptom of dementia, yet it can have devastating consequences. Our research shows just how common apathy is in people with dementia, and we now need to understand it better so we can find effective new treatments. Our WHELD study to improve care home staff training through personalised care and social interaction included an exercise programme that improved apathy, so we know we can make a difference. This is a real opportunity for interventions that could significantly benefit thousands of people with dementia. "

The presentation was entitled ‘The Course of Apathy in People with Dementia’.

Hematopoiesis is the process of forming blood cells, which occurs predominantly in the bone marrow. The bone marrow produces all types of blood cells: red blood cells, platelets, and white blood cells (leucocytes). One of the most prominent white blood cell types are neutrophils - they help the body fight against infections and are the most abundant subpopulation of leukocytes. They are short-lived and highly mobile, and can enter parts of tissue where other cells/molecules cannot.

All hematopoietic cells that develop in the bone marrow must cross the blood vessel wall to enter the circulation system. Blood platelets are released by bigger vessel-penetrating protrusions of huge, largely immobile progenitor cells, named megakaryocytes. In this way mature megakaryocytes produce platelets and release them into the blood circulation to maintain constant platelet counts. In addition, they actively regulate hematopoietic stem cell accumulation in a positive as well as negative manner.

Imaging the entire bone marrow with subcellular resolution to understand how all the players act in concert is still challenging. The research groups of Prof. Katrin Heinze and Dr. David Stegner established a profound 3D image reconstruction and segmentation pipeline for different bone marrow components. These segmented objects, originally derived from Light Sheet Fluorescence Microscopy, then serve as templates (see Figure 1) for computational simulations of cell distributions and their migration behavior in the bone marrow.

Megakaryocytes influence cell migration significantly

In this study, the scientists found that hematopoietic stem cells and neutrophils migration depends on the megakaryocyte size and distributions. Thus, these simulations suggest that megakaryocytes play an important role in cell migration even if not migrating themselves. Instead, the large megakaryocytes represent passive obstacles, and thus significantly influence migration of other cells such as hematopoietic stem cells and neutrophils in the bone marrow. Indeed, intravital microscopy confirmed that neutrophil mobility was reduced in platelet-depleted mice where megakaryocyte volumes are increased (see Figure 2).

This study showcases how the combination of advanced imaging approaches in combination with computational simulations can sharpen this hypothesis. Heinze says, "For simulations, grids and spheres do not sufficiently represent the complexity of the vasculature and its cells. In contrast, our image-derived templates are suitable and thus highly superior, as they reflect the physiological architecture in the bone very well."

"This study points to the importance of biomechanical properties of the bone marrow environment in regulating cell motility, a factor which has so far not been appreciated well. Our data clearly show that volumetric analysis of the number and localization of megakaryocytes provides additional information that sharpens our picture of the bone marrow dynamics and mechanisms," Stegner explains.

The computational tool can not only support 3D studies of dynamic cell behavior, but also help to focus or reduce animal experiments when hypotheses can be tested computationally. Beyond bone and blood research, the method can be used for any organ or tissue to interrogate dynamic maps of selected cell types and structures in health and disease.

Researchers at the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) have developed a graphene device that's thinner than a human hair but has a depth of special traits. It easily switches from a superconducting material that conducts electricity without losing any energy, to an insulator that resists the flow of electric current, and back again to a superconductor - all with a simple flip of a switch. Their findings were reported today in the journal Nature.

"Usually, when someone wants to study how electrons interact with each other in a superconducting quantum phase versus an insulating phase, they would need to look at different materials. With our system, you can study both the superconductivity phase and the insulating phase in one place," said Guorui Chen, the study's lead author and a postdoctoral researcher in the lab of Feng Wang, who led the study. Wang, a faculty scientist in Berkeley Lab's Materials Sciences Division, is also a UC Berkeley physics professor.

The graphene device is composed of three atomically thin (2D) layers of graphene. When sandwiched between 2D layers of boron nitride, it forms a repeating pattern called a moiré superlattice. The material could help other scientists understand the complicated mechanics behind a phenomenon known as high-temperature superconductivity, where a material can conduct electricity without resistance at temperatures higher than expected, though still hundreds of degrees below freezing.

In a previous study, the researchers reported observing the properties of a Mott insulator in a device made of trilayer graphene. A Mott insulator is a class of material that somehow stops conducting electricity at hundreds of degrees below freezing despite classical theory predicting electrical conductivity. But it has long been believed that a Mott insulator can become superconductive by adding more electrons or positive charges to make it superconductive, Chen explained.

For the past 10 years, researchers have been studying ways to combine different 2D materials, often starting with graphene - a material known for its ability to efficiently conduct heat and electricity. Out of this body of work, other researchers had discovered that moiré superlattices formed with graphene exhibit exotic physics such as superconductivity when the layers are aligned at just the right angle.

"So for this study we asked ourselves, 'If our trilayer graphene system is a Mott insulator, could it also be a superconductor?'" said Chen.

Opening the gate to a new world of physics

Working with David Goldhaber-Gordon of Stanford University and the Stanford Institute for Materials and Energy Sciences at SLAC National Accelerator Laboratory, and Yuanbo Zhang of Fudan University, the researchers used a dilution refrigerator, which can reach intensely cold temperatures of 40 millikelvins - or nearly minus 460 degrees Fahrenheit - to cool the graphene/boron nitride device down to a temperature at which the researchers expected superconductivity to appear near the Mott insulator phase, said Chen.

Once the device reached a temperature of 4 kelvins (minus 452 degrees Fahrenheit), the researchers applied a range of electrical voltages to the tiny top and bottom gates of the device. As they expected, when they applied a high vertical electrical field to both the top and bottom gates, an electron filled each cell of the graphene/boron nitride device. This caused the electrons to stabilize and stay in place, and this "localization" of electrons turned the device into a Mott insulator.

Then, they applied an even higher electrical voltage to the gates. To their delight, a second reading indicated that the electrons were no longer stable. Instead, they were shuttling about, moving from cell to cell, and conducting electricity without loss or resistance. In other words, the device had switched from the Mott insulator phase to the superconductor phase.

Chen explained that the boron nitride moiré superlattice somehow increases the electron-electron interactions that take place when an electrical voltage is applied to the device, an effect that switches on its superconducting phase. It's also reversible - when a lower electrical voltage is applied to the gates, the device switches back to an insulating state.

The multitasking device offers scientists a tiny, versatile playground for studying the exquisite interplay between atoms and electrons in exotic new superconducting materials with potential use in quantum computers - computers that store and manipulate information in qubits, which are typically subatomic particles such as electrons or photons - as well as new Mott insulator materials that could one day make tiny 2D Mott transistors for microelectronics a reality.

"This result was very exciting for us. We never imagined that the graphene/boron nitride device would do so well," Chen said. "You can study almost everything with it, from single particles to superconductivity. It's the best system I know of for studying new kinds of physics," Chen said.

This study was supported by the Center for Novel Pathways to Quantum Coherence in Materials (NPQC), an Energy Frontier Research Center led by Berkeley Lab and funded by the DOE Office of Science. NPQC brings together researchers at Berkeley Lab, Argonne National Laboratory, Columbia University, and UC Santa Barbara to study how quantum coherence underlies unexpected phenomena in new materials such as trilayer graphene, with an eye toward future uses in quantum information science and technology.

ITHACA, N.Y. - Researchers at Cornell University are using a rigged card game to shed light on perceptions of inequality.

After noticing that card game winners attributed the game's outcome to skill and losers blamed their defeat on the rules, doctoral students Mario Molina and Mauricio Bucca decided to conduct an experiment. Working with Michael Macy, the Goldwin Smith Professor of Arts and Sciences and director of the Social Dynamics Laboratory, they adapted their idea into the Swap Game, a simple card game they rigged to favor either winners or losers, in a study designed to measure perceptions of inequality.

They found that winners were far more likely to believe the game's outcome was fair, even when it was heavily tilted in their favor by rules requiring losers to hand over their strongest cards. Their paper, "It's Not Just How the Game Is Played, it's Whether You Win or Lose," was published in Science Advances.

Before participating in the experiment, people were taught how to play the Swap Game, in which one player discards a card and the second player must discard a higher card, or pass. The first person to discard all their cards wins the round.

Though the first player had an advantage, the first round's winner was determined mostly by luck, with no skill involved. But at the end of each round, the winners either traded their best card for the loser's worst card - making the game more equal - or their worst card for the loser's best, giving the winner an increased advantage. In other games, the winners exchanged cards randomly, and in some versions the players traded two cards.

The winners' perceptions of the game's fairness declined more sharply than losers' as their advantage increased - "indicating that winner's perceptions are more sensitive than losers' to a system that is rigged in their favor" according to the paper.

As inequality becomes increasingly rampant around the world, the study offers insights into how people perceive opportunity, failure and success. In real life, inequality can operate in opaque ways, making it difficult to determine whether people succeed through talent, skill, luck or advantage. Though the study's findings can't easily be generalized to society at large, they have potential implications for how public policy to combat inequality might be implemented.

"The findings from our study may shed light on perceptions of the fairness of silver spoons and regressive tax codes in an era of rapidly escalating economic and political division," Macy, the paper's senior author, said. "Beliefs about distributive justice and the relative importance of talent versus luck seem to confirm 50 years of research in social psychology on the universal need to reduce cognitive dissonance."

By pumping ocean water onto coastal regions surrounding parts of the West Antarctic ice sheet and converting it to snow, it may be possible to prevent the ice sheet from sliding into the ocean and melting, according to a new modeling study. The authors caution that while the findings offer a potentially feasible and less dangerous solution compared to other proposed methods, they say that implementing their approach would be incredibly costly, present immense technical challenges and may harm sensitive marine ecosystems. Simulations show that the ice sheet is already melting and could cause sea levels to rise up to more than 3 meters, putting populous coastal cities such as New York, Calcutta, Shanghai, and Tokyo at risk. Feldmann et al. used the 3-D Parallel Ice Sheet Model (PISM) to investigate how transferring ocean water onto the coastal regions around the Pine Island and Thwaites Glaciers in West Antarctica would impact the so-called stress balance that supports different forms of glacial ice (including frozen inland ice, fast-flowing ice streams and free-floating ice shelves). Using their model, the researchers artificially enhanced snowfall in these regions, finding that the resulting increase in ice surface elevation near the point at which the glaciers meet the ocean effectively stabilizes the shelf and leads to a two to five-centimeter sea level drop (assuming water for the snowfall is taken from the ocean). The simulations show that a minimum of 7,400 gigatons of artificial snowfall applied over 10 years would be required to stabilize the ice sheet. Importantly, the simulations do not include projected ocean and atmospheric warming due to climate change, possible snowfall increase in coming decades, or fracturing in the ice shelf caused by future atmospheric warming, all of which could influence ice sheet collapse.

It identifies the relevant factors that affect estimates of these remaining carbon budgets and thereby untangles the differences to make estimates more easily comparable, which will help decision-makers in using them. From a climate policy perspective, the bottom line remains the same. Even if the remaining carbon budget for limiting warming to 1.5°C would increase by a half, we would have only 10 years more time before emissions have to be brought down to net zero.

"Bringing CO2 emissions, from industry to transport, to net zero requires urgent action - a couple of years more or less to achieve this do not make a difference for the actions we have to take now," says Elmar Kriegler from the Potsdam Institute for Climate Impact Research (PIK) in Germany, he's one of the study's authors. "Yet, untangling different carbon budget calculations is more than just an academic issue. It tells us about the risks." One main insight of the study now published in Nature is that feedbacks in the Earth system, such as permafrost thawing that releases the powerful greenhouse gas methane, might be an underestimated major factor for carbon budgets.

"Available carbon budget estimates often neglect permafrost thawing and other slow Earth system feedbacks that could lead to further heating of the planet. This means that our wiggling room might be even smaller than we thought", explains Kriegler. "Spelling out the implicit underlying assumptions in carbon budget calculations such as this one is important for supporting policy-makers to make informed choices."

Earth system feedbacks and other factors to be considered

Another example for differences between carbon budget estimates is the way they use temperature measurements. Some estimates refer to Earth's Surface air temperature (SAT). Measured 1.5 meters above the ground, this is basically the temperature people experience. However, some carbon budget estimates include sea surface temperatures in their yardstick to measure warming. Since sea surface temperatures warm slower than air temperatures, it appears as if more CO2 can be emitted before the 1.5 degrees Celsius limit is breached. Yet these budgets would also come with clear climate consequences: a relatively hotter Earth. In their paper, the authors recommend to choose SAT for estimating the remaining carbon budget.

In a key equation they derived for current and future estimates of the remaining carbon budget, the scientists include five factors. One of them, the future warming from non-CO2 emissions depends strongly on policy choices about non-CO2 gases that we are still going to emit. The less we heat the planet with non-CO2 gases like methane, the larger will be our remaining budget for CO2 emissions. Besides Earth system feedbacks, the largest uncertainty relates to our estimate of how strongly the climate warms in response to cumulative emissions of CO2. Further uncertainties relate to the measured range of the historical human-induced warming and the amount of additional warming after CO2 emissions have reached net zero. The authors point to the upcoming 6th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) as an important milestone to narrow these uncertainties.

The authors' approach builds on the reasoning in the Special Report on 1.5 degree warming by the IPCC that they co-authored. The report gave central estimates of the remaining CO2 emissions budget from 2018 onward of 420 GtCO2 for a 66% probability of limiting warming to 1.5°C and 580 GtCO2 for a 50% probability. Different assumptions about future non-CO2 emissions can change these estimates by 250 GtCO2 up and down. Those estimates would need to be reduced by the amount of CO2 outgassing from permafrost thawing and other unrepresented Earth system feedbacks, which are tentatively estimated to be at least 100 GtCO2. "We do not know exactly how big the budget is in the end, due to future choices about Non-CO2 emissions and uncertainties in natural systems. But we know enough to be sure it is past time to enact deep reductions in greenhouse gas emissions", says Kriegler.

Keeping up to date to make informed choices

"All factors in our equation are expected to undergo updates as science progresses -- some of these updates will make carbon budgets smaller while other will make them slightly larger", says Joeri Rogelj from the Grantham Institute at Imperial College London, lead-author of the study. "However, by making these regular updates explicit they can be communicated transparently. It is important that policy makers are kept up to date on the latest science, with the next report of the IPCC in 2021 expected to consolidate our knowledge about the remaining carbon budgets to limit warming to 1.5°C and well below 2°C."

"Choices today will determine whether we will have a decent chance of limiting warming to 1.5°C and our study does not change this bottom line", Rogelj adds. "If anything, the severity of expected climate impacts in a world heated beyond 1.5°C and our better understanding of the various factors that can affect the size of the remaining carbon budget calls for a precautionary approach with decisive climate action in the next five to ten years to limit the risks and keep options open, no matter which direction estimates of the remaining carbon budget might wobble."

A new study by Montreal scientists published today in Nature demonstrates that a gut infection can lead to a pathology resembling Parkinson's disease (PD) in a mouse model lacking a gene linked to the human disease.

This discovery extends recent work by the same group suggesting that PD has a major immune component, providing new avenues for therapeutic strategies.

The collaborative study was the work of a joint team of scientists led by Michel Desjardins and Louis-Eric Trudeau of Université de Montréal, Heidi McBride at the Montreal Neurological Institute, and Samantha Gruenheid at McGill University.

The number of PD patients in the world more than doubled between 1990 and 2016, from 2.5 million to 6.1 million. A relatively conservative projected doubling of the number of patients over the next 30 years would yield more than 12 million patients worldwide by about 2050.

About 10 per cent of cases of PD are due to mutations in genes coding for proteins such as PINK1 and Parkin, which have been linked to mitochondria (the organelle in cells that produces energy). Patients with these mutations develop PD at a much earlier age. However, in mouse models, the same mutations do not generate disease symptoms, leading many researchers to conclude that mice may not be suitable for the study of PD.

Trudeau and McBride, two specialists in the field of PD research, argue that the findings in this new study may explain this disparity: these animals are normally kept in germ-free facilities, conditions not representative of those encountered by human beings who are constantly exposed to infectious microorganisms. Gruenheid, a microbiologist, is confident that the link between infection and PD will stimulate further study of the immune response linked to the initiation of the disease, allowing researchers to develop and test novel therapeutic approaches.

PD is caused by the progressive death of a subset of neurons in the brain, called dopaminergic neurons. This loss of neurons is responsible for the typical motor symptoms observed in PD patients, including tremors and rigidity. What causes the death of the dopaminergic neurons is still unknown.

"Most of the current models of PD are based on the belief that neurons die due to toxic elements accumulating inside them," said Trudeau, a neuroscientist. "This does not explain, however, the fact that PD pathology is initiated in patients several years before the emergence of the motor impairment and any noticeable loss of neurons."

The reason for this is believed to be explained by the results of the present study. The Montreal team has shown that in mice lacking a gene linked to PD, infection with bacteria that cause mild intestinal symptoms in young mice was sufficient to trigger PD-like symptoms in these animals later in life.

The Parkinson's-like symptoms could be temporarily reversed by the administration of L-DOPA, a drug used to treat Parkinson's patients. Desjardins and Diana Matheoud, an immunologist the University of Montreal Hospital Research Centre (CRCHUM), point out that in normal mice, the immune system responded properly to the gut infection; however, in mice lacking the gene PINK1 related to Parkinson's, the immune system overreacted and triggered "auto-immunity", a process that leads the immune system to attack healthy cells in the organism. The results published today suggest that rather than dying from toxin accumulation, the killing of dopaminergic neurons involves immune cells.

In the infected mutant mice, autoreactive toxic T lymphocytes were shown to be present in the brain and able to attack healthy neurons in culture dishes. The co-first authors of the published article, Matheoud and Tyler Cannon, a graduate student in microbiology, emphasize the fact that these results strongly suggest that some forms of PD are an autoimmune disease likely to start in the gut several years before patients notice any motor symptoms, highlighting the fact that a window of time exists for preventive treatment.

thaca, NY--In nature, as in life, there's often more than one way to solve a problem. That includes the evolutionary process. A new study in Evolution Letters finds that different bird species in the same challenging environment--the highly saline ecosystem of tidal marshes along ocean shores--were able to evolve unique species-specific ways to address the same problem.

"For tidal saltmarsh species, the challenge is how to maintain the right balance between water and salt concentrations in their cells," explains lead author Jennifer Walsh, a postdoctoral researcher at the Cornell Lab of Ornithology. "When cells are exposed to salt water, they shrink. If they're exposed to too much fresh water, they expand. Without the right balance, the cells can die."

Walsh and colleagues from eight other universities studied the genomes of four sparrow species: Savannah, Nelson's, Song, and Swamp Sparrow. These were chosen because each of these species has a population living in saltmarsh habitat as well as a separate upland population. This makes it possible to compare the genomes of the two populations and see where they differ. Some of those differences are tied to adaptations evolved in saltmarsh-resident sparrows to control the balance of water and salt concentrations--a process called osmoregulation.

One gene that appears to be important in Savannah Sparrows plays a role in inserting physical channels in the cells. Those channels help the cells resist expansion and contraction from changes in salt levels by allowing exchange of water across the cell wall. Swamp Sparrows show a similar response to salt water, but the genes responsible for forming these channels are completely different. Song Sparrows seem to have adapted through mechanisms that reinforce cell walls so they can expand and contact more quickly in response to salt. The Nelson's Sparrow takes yet another route--evolving a gene that changes its behavior. Their genetic adaption curbs thirst so they only drink the least amount of salt water necessary and salt levels are kept within bounds. The four sparrow species evolved four different, complex mechanisms to deal with salt, each likely governed by many genes working in tandem.

The researchers also found that the osmoregulatory adaptations evolved at a rapid pace, at least on an evolutionary scale--probably over the past 10,000 to 15,000 years--and that New World sparrows have colonized marshes over and over again.

The saltmarsh sparrows also evolved some shared traits across species that may help them survive the hot, salty, harsh conditions of their environment: a larger bill to better dissipate heat, a modified kidney structure, and darker plumage which may provide some UV protection and help feathers withstand abrasive vegetation. But why live in a saltmarsh at all?

"Sometimes birds move into marshes because, if you can adapt to the environment, it's actually a pretty good place to be," Walsh says. "There's no competition because so few species live there, and there is never, ever a shortage of insects for food."

If China takes strong measures to reduce its ozone pollution now, it could save hundreds of thousands of lives in the long run, according to a new study led by researchers at Columbia University's Lamont-Doherty Earth Observatory.

"Air pollution is a major problem in China right now," said lead author Daniel Westervelt, an associate research scientist at Lamont-Doherty. "It's a very serious health risk. So it's important to think about what changes can be made to make progress on this problem."

High up in the atmosphere, the ozone layer protects our planet from harsh ultraviolet radiation. But when ozone gets into the air we breathe, it can lead to premature death from cardiovascular disease, stroke and respiratory problems. On-the-ground ozone pollution is created when other pollutants -- nitrogen oxides and volatile organic compounds -- react together with sunlight. Those pollutants can come from motor vehicles, power plants, factories and other human-made sources.

Ozone pollution is already dangerously common in China, causing an estimated 67,000 premature deaths in 2015. But the new study, published today in Environmental Research Letters, finds that the situation could become quite a bit worse in the future. The researchers, based in both the United States and China, modeled how three different emissions scenarios for China would impact human health.

The first scenario looked at what would happen if China's air pollution levels stay fixed but the climate continues to warm. The second scenario looked at the effects of climate change plus a 10 percent increase in ozone pollution emissions -- representing a 'status quo' strategy, according to Westervelt. And the third scenario analyzed the impacts of climate change plus an aggressive approach of cutting China's ozone-forming emissions by 60 percent.

Plugging those scenarios into a model of atmospheric chemistry and climate, the team found that climate change alone could cause a 11 percent increase in ozone pollution in China. This would cause an additional 62,000 premature deaths by 2050.

In the second scenario, a 10 percent increase in emissions of air pollutants combined with climate change caused an additional 80,000 premature deaths. On the other hand, a 60 percent decrease in ozone-forming emissions prevented 330,000 premature deaths.

In all three simulations, climate change made ozone pollution worse than it would have been otherwise. That wasn't surprising; scientists know that warmer temperatures will speed up the reactions that create ozone and enhance conditions that allow it to accumulate near the surface. However, the study revealed another startling way that climate change could exacerbate ozone pollution: "It turns out that a major portion of the ozone increase we're seeing in the model in western China originates in the stratosphere," said Westervelt.

It's normal for some ozone to trickle down from the ozone layer to the ground, but the model showed that by changing the jetstream and mixing patterns of the atmosphere, climate change could enhance the flow of ozone from the stratosphere to the surface, particularly over western China and the Tibetan plateau.

The team also calculated that emissions from other countries, including India, could significantly detract from China's air quality gains if it does decide to reduce emissions. The authors write that China would benefit by encouraging emissions reductions throughout all of Asia. "If China is able to be a leader on this and say, 'We need to reduce our emissions,' other countries may follow suit," Westervelt suggested.

The study shows that China is at an important crossroads, with its future air quality depending strongly on passing policies to reduce both ozone- and climate change-causing emissions, said Westervelt. "The issues of climate change and air quality go hand-in-hand, so it makes sense to tackle both things simultaneously."

To be sure, cutting ozone-causing emissions by 60 percent wouldn't come easy. It would require many new policies to fall into place, such as increasing fuel efficiency standards, switching to electric vehicles, installing air pollution control devices on power plant smokestacks, and switching to cleaner sources of energy, such as natural gas and renewables. Nevertheless, the 60 percent reduction is feasible based on policy measures and technologies that already exist today, said Westervelt.

"I would hope that policymakers in China will take results like this and see that if you were to aggressively reduce emissions, you would reap the benefits in a pretty significant way," he said. "It's worth it to address these emissions now, so that you don't have to deal with all the health problems in the future. You could save 330,000 over the next few decades. That's a lot of lives."

When it comes to mating displays, a little persistence can go a long way, at least for the greater sage grouse. In "Hidden Markov Models Reveal Tactical Adjustment of Temporally Clustered Courtship Displays in Response to the Behaviors of a Robotic Female," published in The American Naturalist, Anna C. Perry and her colleagues at the University of California in Davis (USA), the Max Planck Institute in Leipzig (Germany) and the University of Florida (USA) use a custom-built statistical model to understand an underexplored dimension of greater sage grouse mating display behavior. The authors report that males that show greater display persistence, even in the face of seemingly uninterested females, have a competitive advantage over their peers.

The greater sage grouse, a bird native to North America, has an elaborate courtship ritual. Every year, males congregate at locations known as "leks" to perform competitive mating displays to entice females to copulate. Each mating display, in which the male performs a series of ritualized movements and sounds with his air sacs inflated, is referred to as a "strut." These "struts" are typically performed one after another in quick succession, in what is referred to as a "bout." Mating success is highly skewed, with a percentage of birds never once mating and a privileged few mating dozens of times.

In studies that seek to understand why some individuals are so much more successful than others, researchers have often counted the total number of display events or averaged the lengths of the intervals separating displays within a bout. "These 'bout agnostic' analyses collapse each animal's multidimensional display effort into a single metric, potentially discarding important information," Perry and her coauthors write.

Perry's custom-built hidden Markov model, on the other hand, offered several advantages over simpler models. For one, it accounted for differences in display persistence--characterized by the number of "struts" that a sage grouse does in a row--as well as the length of time that males rested between struts in a single bout. It also enabled Perry and her coauthors to analyze whether males' display tactics changed depending on the presence and behavior of females.

Strut events were recorded using high definition cameras and on-site observations at three leks in Fremont County, Wyoming. At each location, male display activity was tracked when no female was present, when a robotic female was present and showing either "interested" or "uninterested" behavior, and in the presence of real female sage grouse. "Most males cannot display at their peak levels indefinitely; these males may need to tactically adjust their display bout behavior across different conditions," Perry and her coauthors write.

Perry and her colleagues found that the number of times a male consecutively struts in a bout was a better predictor of male mating success than either the length of time between struts or the average amount the male displayed overall. "In retrospect, this makes sense: within-bout display rates are relatively constrained, with 95% of intervals are between 5 and 9 seconds," Perry writes. "Bout length, on the other hand, varies widely, from 2 struts to more than 20."

Perry and her colleagues also found that sage grouse females seem to prefer males that show greater display persistence, specifically when a female is in close proximity, regardless of whether or not her behavior indicates she's interested in copulation. Males with lower mating success tended to have a higher "baseline" display activity level when females were absent. When females were present, they tended to focus their display efforts on the ones who were already signaling their interest.

One possible explanation for this observation is that younger or lower quality males may need to allocate more display effort toward defending their territory and thus have less energy to expend on courtship. Another possible explanation is that males that mate more are able to do so because they are more skillful at tactically adjusting their display effort to invest more when females are present and in close proximity. Further studies are required to test these and other hypotheses.

Perry predicts her model will be useful for studying other species with complex mating displays. "Our hidden Markov model could prove especially enlightening for studying trade-offs in multiple, dynamic components of display effort," she writes.

NASA's Aqua satellite passed over the Northwester Pacific Ocean after the sixth tropical depression formed. Tropical Depression Danas formed northeast of the Northern Philippines and was already affecting the country.

On July 16, the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite provided a visible image of Danas that showed a large depression the stretched the entire length of the Philippines. Strongest thunderstorms remained off the coast in the image, but the northwestern and western quadrants were already over the Luzon and Visayas regions.

At 5 a.m. EDT (0900 UTC), the center of Danas was located near latitude 17.2 degrees north and longitude 124.9 degrees west. Danas was about 587 nautical miles southwest of Kadena Air Base, Okinawa, Japan. Danas was moving to the west-northwest and had maximum sustained winds near 25 knots (29 mph/46 kph).

The Joint Typhoon Warning Center expects Danas to turn to the north. Danas' center is expected to stay over water until it makes landfall in three days south of Shanghai, China.

By Rob Gutro
NASA's Goddard Space Flight Center