Brain

WASHINGTON -- Researchers have designed a new chip-integrated light source that can transform infrared wavelengths into visible wavelengths, which have been difficult to produce with technology based on silicon chips. This flexible approach to on-chip light generation is poised to enable highly miniaturized photonic instrumentation that is easy to manufacture and rugged enough to use outside the lab.

In Optica, The Optical Society's (OSA) journal for high impact research, investigators from the National Institute of Standards and Technology (NIST), University of Maryland, and University of Colorado describe their new optical parametric oscillator (OPO) light source and show that it can produce output light that is a very different color, or wavelength, than the input light. In addition to creating light at visible wavelengths, the OPO simultaneously generates near-infrared wavelengths that can be used for telecommunication applications.

"Our power-efficient and flexible approach generates coherent laser light across a range of wavelengths wider than what is accessible from direct chip-integrated lasers," said research team leader Kartik Srinivasan. "The on-chip creation of visible light can be used as part of highly functional compact devices such as chip-based atomic clocks or devices for portable biochemical analyses. Developing the OPO in a silicon photonics platform creates the potential for scalable manufacturing of these devices in commercial fabrication foundries, which could make this approach very cost-effective."

Exploiting nonlinear processes

Although the response of a material to light typically scales linearly, material properties can change more rapidly in response to light at high power, which creates various nonlinear effects. OPOs are a type of laser that use nonlinear optical effects to create a very broad range of output wavelengths.

The researchers wanted to figure out how to take laser emission at a wavelength readily available with compact chip lasers and combine it with nonlinear nanophotonics to generate laser light at wavelengths that are otherwise hard to reach with silicon photonics platforms.

"Nonlinear optical technologies are already used as integral components of lasers in the world's best atomic clocks and many laboratory spectroscopy systems," said Xiyuan Lu, first author of the paper and a NIST-University of Maryland postdoctoral scholar. "Being able to access different types of nonlinear optical functionality, including OPOs, within integrated photonics is important for transitioning technologies currently based in laboratories into platforms that are portable and can be deployed in the field."

In the new work, the researchers designed an OPO based on a microring made from silicon nitride. This optical component is fed by approximately 1 milliwatt of infrared laser power -- about the same amount of power found in a laser pointer. As the light travels around the microring it increases in optical intensity until powerful enough to create a non-linear optical response in silicon nitride. This enables frequency conversion, a nonlinear process that can be used to produce an output wavelength, or frequency, that is different from that of the light going into the system.

"Recent progress in nanophotonic engineering has made this method of frequency conversion very efficient," said Lu. "A key advance in our work was figuring out how to promote the specific nonlinear interaction of interest while suppressing potential competing nonlinear processes that can arise in this system."

Testing the light source

The researchers designed the new on-chip light source using detailed electromagnetic simulations. They then made the device and used it to convert 900-nanometer input light to 700-nanometer-wavelength (visible) and 1300-nanometer-wavelength (telecommunications) bands. The OPO accomplished this using less than 2 percent of the pump laser power required by previously reported microresonator OPOs developed for generating widely separated output colors. In the previous cases, both colors generated were in the infrared. With a few simple changes to the microring dimensions, the OPO also produced light in the 780-nm visible and 1500-nanometer telecommunication bands.

The researchers say that the new OPO could be used to make a complete system by combining an inexpensive commercial near-infrared diode laser with an OPO chip that also integrates components such as filters, detectors and a spectroscopy section. They are continuing to look for ways to increase the output power generated from the OPO.

"This work demonstrates that nonlinear nanophotonics is reaching a level of maturity where we can create a design that connects widely separated wavelengths and then achieve enough fabrication control to realize that design, and the predicted performance, in practice," said Srinivasan. "Going forward, it should be possible to generate a wide range of desired wavelengths using a small number of compact chip lasers combined with flexible and versatile nonlinear nanophotonics."

Washington, DC, December 19, 2019 - Between 30 to 50 percent of youth in the United States diagnosed with an anxiety disorder fail to respond to cognitive-behavior therapy (CBT). A new study in the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP), published by Elsevier, reports that computer-based attention training could reduce anxiety in children and adolescents.

"CBT is the leading evidence-based psychosocial treatment," said co-lead author Jeremy Pettit, PhD, a Professor in the Department of Psychology and Center for Children and Families at Florida International University. "So there is a critical need to have other treatment options available for this population given that persistent anxiety is associated with distress, impairment in functioning, and elevated risk for other psychiatric disorders and suicide."

The study is the first to provide a potentially effective augmentation strategy for children and adolescents with anxiety disorders who do not respond to CBT. The 64 participants, between the ages of 7 and 16 years old, in this study were selected after evaluations determined each still met the criteria for an anxiety disorder after receiving manualized cognitive behavior therapy. After four weeks of attention training, 50 percent of participants no longer met the criteria for their primary anxiety diagnosis, according to the current version of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV).

Participants received one of two forms of computer-based attention training. The first-attention bias modification treatment-trained attention toward neutral stimuli and away from threatening stimuli. The second-attention control training-trained attention to neutral and threatening stimuli equally. Both forms of attention training led to comparable reductions in anxiety.

"Attention training is a promising augment for children who do not respond to CBT," said the article's other co-lead author Wendy Silverman, PhD, the Alfred A. Messer Professor in the Child Study Center at Yale University School of Medicine. "Florida International University and Yale University currently are conducting a two-site treatment study to understand more clearly how attention training produces anxiety-reduction effects and the results of this article in JAACAP give us a promising start."

COLUMBIA, Mo. - The independence that comes with growing up can be scary for any teenager, but for young adults with autism spectrum disorder and their caregivers, the transition from adolescence to adulthood can seem particularly daunting. Tasks such as managing one's own health insurance or applying for a car loan can be especially challenging for individuals with developmental disabilities.

Now, researchers at the University of Missouri are working on improving independence for people with autism by setting personalized goals early in adolescence and providing opportunities to achieve those goals. In the new study, Nancy Cheak-Zamora, associate professor in the MU Department of Health Sciences, School of Health Professions, and researcher at the Thompson Center for Autism and Neurodevelopmental Disorders, measured the self-determination of young adults with autism to better assist their transition to adulthood.

"We found that there was a disconnect between the support the caregivers are providing and what the young adults are doing themselves to become more independent," Cheak-Zamora said. "We need to allow adolescents, particularly those with disabilities, to take on greater responsibilities at an earlier age and raise their expectations by first asking them about their goals and then providing the resources and support systems to help them achieve those goals."

Cheak-Zamora partnered with five autism clinics across the country to survey more than 500 caregivers of young adults with autism between the ages of 16 and 25. She worked with undergraduate and graduate students to analyze the results and found that many young adults with autism are struggling to achieve independence.

Cheak-Zamora explained that increasing self-determination for young adults with autism starts with shifting the perception about what individuals with developmental disabilities can achieve.

"As a society it would be helpful to move away from a focus on deficits and challenges that people with autism and other disabilities face to considering their strengths and skill set. We can then develop ways to help each person build on their strengths," Cheak-Zamora said. "For example, many with autism are incredibly detail-oriented. So, let's think about job opportunities that require very detailed work so they can use that skill as an asset to succeed in employment. Not only will the individual benefit, but society as a whole will as well."

Cheak-Zamora recommends that parents and caregivers provide all adolescents, including those with developmental disabilities, with opportunities to experience mastering a task, such as cooking, shopping, managing money or driving.

Phase transitions have long been of crucial importance to scientific research. The change from water to ice or steam is a simple example. A phase transition important to pioneering research today is that from metal to insulator in materials referred to as “correlated oxides.” Scientists have reaped many insights into phenomena like superconductivity and magnetism by studying what happens when a correlated oxide that conducts electricity with little or no resistance (metallike) changes to one that does not (insulator) as a result of changes in temperature, pressure, or other external fields.

In a paper in the journal Nature, Peter Littlewood, former director of the U.S. Department of Energy’s (DOE) Argonne National Laboratory (2014–2017), and his colleagues propose the most complete picture to date concerning the metal-insulator transition in transition metal oxides. These correlated oxides have fascinated scientists because of their many attractive electronic and magnetic properties.

“Importantly, our theoretical study applies to not just a single material, but a whole class of materials, and has many possible applications, including some relevant to ongoing and planned research programs at Argonne.” — Peter Littlewood, former Argonne director and current professor of physics at the University of Chicago.

“Tuning and control of this metal-insulator transition has been the source of much exciting new physics and promising materials applications, such as low-power and ultrafast microelectronics,” said Littlewood, currently professor of physics in the University of Chicago’s James Franck Institute with a joint appointment in Argonne’s Materials Science division and Executive Chairman of the Faraday Institution.

Joining Littlewood in this research project were Gian Guzmán-Verri and Richard Brierley. Guzmán-Verri began the research as an Argonne postdoc and is now a professor at the University of Costa Rica. Brierley performed the research during postdoctoral appointments at the University of Cambridge and Yale University and is now an editor at Nature Communications.  

 “The way scientists in the past have typically tuned this metal-insulator transition is by adding electrons,” Littlewood said. “Research over several decades by others suggests that adjusting the size of an electronically inactive but structurally important ‘vegetable ion’ within the oxide’s crystal structure also has a strong impact on the transition temperature.” However, the reason for this effect has not been well understood.

The size of the electronically inactive vegetable ion can alter the temperature at which the metal-insulator transition occurs from absolute zero to well above room temperature. The higher the transition temperature and closer to room temperature, the more attractive the material is for practical applications.

The team’s research focused on an important class of transition metal oxide — the perovskites. Along with oxygen, these oxides combine an electronically active ion and the electronically inactive vegetable ion. The latter ion can be any one of the many rare earth elements or alkaline earth metals. As a consequence, scientists can choose its atomic size to be relatively small or large without changing the related chemistry.

The left side of the accompanying image shows the basic crystal structure of a perovskite transition metal oxide. Each unit cell (grey diamonds) has eight sides, with oxygen atoms (red circles) situated at the six apexes and the transition metal (either manganese or nickel) hidden in the center. The green circles represent the vegetable ion, either a rare earth or alkaline earth metal.

Key to the authors’ pivotal discovery is the determination of the effect of the size of the rare earth or alkaline earth metal. Varying the size of this element changes the tilt angle introduced into the eight-sided units, shown in the right side of the accompanying figure. In turn, increasing the tilt angle results in various distortions and movements in the eight-sided units, which can stretch, shrink and rotate as a result of internal stresses.

“It is the dynamical fluctuations of these elastic degrees of freedom that are responsible for the observed thermal effects, which occur at temperatures much lower than accounted for in earlier models based purely on the electronically active ion,” Littlewood said.

On the basis of the above mechanism, the team was able to construct a theory that captures the relationship among the tilt angle induced by the vegetable ion size, the temperature of the metal-insulator transition and the degree of disorder in the perovskite crystal structure. Relatively simple calculations with the theory agreed well with experimental results from absolute zero to above 600 degrees Fahrenheit.

“Importantly, our theoretical study applies to not just a single material, but a whole class of materials, and has many possible applications, including some relevant to ongoing and planned research programs at Argonne,” said Littlewood.

In the emerging research area of next-generation microelectronics, for example, improved tuning and control of the metal-insulator transition holds the promise of a great leap forward in low-power and ultrafast microelectronics for computers that simulate brain processes.

In addition, scientists in Argonne’s world-class battery program might be able to use the theory as inspiration for designing better cathode materials for next-generation lithium-ion batteries. Some of the inspiration for the research by Littlewood’s team was John Goodenough’s trailblazing research on the metal-insulator transition many decades ago. Goodenough translated that understanding into the inspiration to invent the Li-ion battery, and this year won the Nobel Prize in chemistry for his work.

A research team has created a microneedle platform using fluorescent quantum dots that can deliver vaccines and invisibly encode vaccination history in the skin. The dots, which can be detected in infrared with smartphones, resisted photobleaching (simulating five years of sunlight) after delivery in isolated human skin, and remained detectable for up to nine months when tested in rats. The platform's ease-of-use could provide clinicians with a more dependable way of keeping accurate medical records, which is challenging in both low- and high-income countries. Medical recordkeeping is essential for proper vaccination coverage and a plethora of other health interventions. However, maintaining or accessing records can be difficult, particularly in low-resource settings that lack centralized databases, which contributes to the 1.5 million vaccine-preventable deaths that occur each year worldwide. Furthermore, problems with recordkeeping have also exacerbated outbreaks of diseases such as measles in the U.S. and Australia. Seeking a solution, Kevin McHugh and colleagues created a platform that records the delivery of vaccines with microparticles that contain biocompatible quantum dots. Their approach uses an array of microneedles that delivers the microparticles into the skin in various patterns, which remain invisible to the naked eye but can be detected in infrared with modified smartphones. In rats, the quantum dots could be delivered alongside a vaccine for polio, and they could also be detected after delivery in isolated pig and human skin. The technology could be highly valuable in the developing world by enabling decentralized data storage and biosensing, the authors say. They add that future safety studies and improvements to manufacturing will help take their idea beyond the proof-of-concept stage and towards real-world implementation.

What The Study Did: Researchers in this observational study looked at the number of concussions(both sports-related and not related to sports) experienced by undergraduate students at a large U.S. public university over three academic years.

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

Authors: John Breck, D.O., of Medical Services at University of Colorado in Boulder, is the corresponding author.

(doi:10.1001/jamanetworkopen.2019.17626)

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

Teenage girls are suffering far worse mental health and wellbeing issues than boys, according to a major new study published in the peer-reviewed journal Research Papers in Education.

The findings based on more than 11,000 UK teenagers found that around 15% (approximately 1,650) reported self-harm in the last year. Among them more than seven in ten (73%) were girls - more than double the rate for boys (27%).

One in ten teenagers reported depressive characteristics and low mood and, among them, teenage girls were significantly more likely to experience negative moods (78% vs 22%). Similar trends are seen in reports of happiness and self-image. A quarter of teenagers felt completely unhappy with girls nearly doubling the rate (63% vs 37%). Over a quarter of young people reported a low sense of their own value including poor self-image, with girls being over three times more likely than boys (79% vs 21%).

The University of Warwick study suggests 14-year-old girls have become the new high-risk group, and this is linked to gender inequality such as sexist notions around body type. Poverty is another significant factor -- the study found teenagers from families earning the least were significantly (48%) more likely to report low life satisfaction than those from the wealthiest homes.

This has implications for policymakers on how to tackle an increase in mental health issues among young people, especially females in mid-adolescence.

The researchers criticise current approaches which make schools responsible for supporting children with mental health issues, without providing sufficient resources and training. They are calling for prevention strategies based on an understanding of societal trends and triggers, such as wealth inequality and sexism.

"Current policy places the onus to resolve inequality on individuals, such as young people, teachers and parents," says lead author Dr Dimitra Hartas from the Centre for Education Studies, at the University of Warwick.

"Young people respond by focusing more on the self and less on the societal structures likely to promote mental ill health. Girls and young women tend to internalise systemic problems and blame themselves.

"A good starting point for appropriate public health and education strategies is to understand the pernicious consequences of gender inequality and poverty for young people's wellbeing."

The study's aim was to examine the impact of socio-economic status, gender, parenting, interactions with peers and social media use on mental health and wellbeing.

They analysed data collected in 2015 by the Millennium Cohort Study, a major research project into children's lives. Questions included how often teenagers self-harmed, their closeness to their parents, how often they were bullied or bullied others, and the number of hours spent on social media.

In addition to gender, bullying and social media also had negative consequences for 14-year-olds. Those bullied most days or once a week were ten times more likely to report negative feelings than teenagers who were seldom victims. Young people spending less than two hours a day online were 37 per cent less likely to report lower life satisfaction than those spending five or more hours.

The study also identifies links between positive parenting and good mental health. Self-harm and negative outlooks decreased in boys and girls who were emotionally close to their parents, and whose mothers and fathers always knew their children's whereabouts.

An explanation could be, says Dr Hartas, that vigilant parents are more likely to alert children to the possibility of risk and violence. As parental influence declines, relationships with young people the same age become more important --meeting friends often out of school or playing with them unsupervised was found to have a positive impact on mood and outlook.

One of the limitations of this study is its reliance on young people's self-reports rather than measures derived from diagnostic interviews, especially with regard to depressive feelings and moods.

Also, the authors state, an "absence of a general sense of wellbeing should not equate with mental health problems".

Whether children will enjoy academic success can be now predicted at birth, a new study suggests.

The study, led by the University of York, found that parents' socioeconomic status and children's inherited DNA differences are powerful predictors of educational achievement.

However, the research suggests that having the genes for school success is not as beneficial as having parents who are highly educated and wealthy. Only 47% of children in the study sample with a high genetic propensity for education but a poorer background made it to university, compared with 62% with a low genetic propensity but parents that are more affluent.

The researchers found that children with a high genetic propensity for education who were also from wealthy and well-educated family backgrounds had the greatest advantage with 77% going to University. Meanwhile, only 21% of children from families with low socioeconomic status and low genetic propensity carried on into higher education.

The findings of the study may help to identify children most at risk of poor educational outcomes, the researchers suggest.

Lead author of the study, Professor Sophie von Stumm from the Department of Education at the University of York said: "Genetics and socioeconomic status capture the effects of both nature and nurture, and their influence is particularly dramatic for children at the extreme ends of distribution.

"However, our study also highlights the potentially protective effect of a privileged background. Having a genetic makeup that makes you more inclined to education does make a child from a disadvantaged background more likely to go to university, but not as likely as a child with a lower genetic propensity from a more advantaged background.

"While the findings of our study are observational, they do suggest that children don't have equal opportunity in education because of their different genetics and family backgrounds. Where you come from has a huge impact on how well you do in school."

The study looked at data from 5,000 children born in the UK between 1994 and 1996. The researchers analysed their test results at key stages of their education as well as their parents' educational level and occupational status.

The researchers used genome-wide polygenic scoring - a statistical technique which adds up the effect of DNA variants - to test how inherited genetic differences predict children's educational success.

They found that children with high polygenic scores differed significantly in achievement at age seven from children with low polygenic scores. This achievement gap steadily widened between the groups throughout the school years leading to an equivalent difference in grades of an A- and a C- by the time children were taking their GCSEs.

Professor von Stumm added: "More research is required, but we hope that this paper will stimulate discussion around the potential to predict if children are at risk for poor academic outcomes - the basis of these discussions goes beyond purely scientific criteria to issues of ethics and social values.

"We hope that results like these can open doors for children, rather than close them, by stimulating the development and provision of personalised environments that can appropriately enhance and supplement a child's education."

Scientists of the Organic Chemistry Department of the Samara Polytech have developed original methods for producing high-temperature lubricants for gas turbine engines. The scientific project is lead under the guidance of the head of the department, Professor Yuriy Klimochkin. The results of recent studies published in the journal "Petroleum Chemistry"

With the development of aviation industry, the requirements for the lubricants quality are constantly increasing. Primarily it occures due to an increase in temperature loads in the units and an increase in the time for replacing oils, - explains Candidate of Chemical Science Associate Professor Elena Ivleva.

Among all the requirements for oil quality, the most important is high thermo-oxidative stability - the ability of the lubricant at high temperatures and long-term engine operation to maintain its physicochemical and operational properties at the required level. Scientists achieved this by synthetising oil composition with esters gained from adamantane derivatives.

Scientists explain the choice of these compounds by its unique adamantane frame that is as close as possible to the spherical structure. The carbon atoms in it replicates the diamond cell structure, therefore, adamantane demonstrates exceptional thermal stability. Therefore, the formylation of an adamantyl radical increases the thermal stability of the substance and its resistance to oxidation.

DALLAS (SMU) - It takes a tremendous amount of computer simulations to create a device like an MRI scanner that can image your brain by detecting electromagnetic waves propagating through tissue. The tricky part is figuring out how electromagnetic waves will react when they come in contact with the materials in the device.

SMU researchers have developed an algorithm that can be used in a wide range of fields - from biology and astronomy to military applications and telecommunications - to create equipment more efficiently and accurately.

Currently, it can take days or months to do simulations. And because of cost, there is a limit to the number of simulations typically done for these devices. SMU math researchers have revealed a way to do a faster algorithm for these simulations with the help of grants from the U.S. Army Research Office and the National Science Foundation.

"We can reduce the simulation time from one month to maybe one hour," said lead researcher Wei Cai, Clements Chair of Applied Mathematics at SMU. "We have made a breakthrough in these algorithms."

"This work will also help create a virtual laboratory for scientists to simulate and explore quantum dot solar cells, which could produce extremely small, efficient and lightweight solar military equipment," said Dr. Joseph Myers, Army Research Office mathematical sciences division chief.

Dr. Bo Wang, a postdoctoral researcher at SMU (Southern Methodist University) and Wenzhong Zhang, a graduate student at the university, also contributed to this research. The study was published today by the SIAM Journal on Scientific Computing.

The algorithm could have significant implications in a number of scientific fields.

"Electromagnetic waves exist as radiation of energies from charges and other quantum processes," Cai explained. 

They include things like radio waves, microwaves, light and X-rays. Electromagnetic waves are also the reason you can use a mobile phone to talk to someone in another state and why you can watch TV. In short, they're everywhere.

An engineer or mathematician would be able to use the algorithm for a device whose job is to pick out a certain electromagnetic wave. For instance, she or he could potentially use it to design a solar light battery that lasts longer and is smaller than currently exists.

"To design a battery that is small in size, you need to optimize the material so that you can get the maximum conversion rate from the light energy to electricity," Cai said. "An engineer could find that maximum conversion rate by going through simulations faster with this algorithm."

Or the algorithm could help an engineer design a seismic monitor to predict earthquakes by tracking elastic waves in the earth, Cai noted.

"These are all waves, and our method applies for different kinds of waves," he said. "There are a wide range of applications with what we have developed."

Computer simulations map out how materials in a device like semiconductor materials will interact with light, in turn giving a sense of what a particular wave will do when it comes in contact with that device.

The manufacturing of many devices involving light interactions uses a fabrication process by layering material on top of each other in a lab, just like Legos. This is called layered media. Computer simulations then analyze the layered media using mathematical models to see how the material in question is interacting with light.

SMU researchers have found a more efficient and less expensive way to solve Helmholtz and Maxwell's equations - difficult to solve but essential tools to predict the behavior of waves.

The problem of wave source and material interactions in the layer structure has been a very challenging one for the mathematicians and engineers for the last 30 years.

Professor Weng Cho Chew from Electrical and Computer Engineering at Purdue, a world leading expert on computational electromagnetics, said the problem "is notoriously difficult."

Commenting on the work of Cai and his team, Chew said, "Their results show excellent convergence to small errors. I hope that their results will be widely adopted."

The new algorithm modifies a mathematical method called the fast multipole method, or FMM, which was considered one of the top 10 algorithms in the 20th century.

To test the algorithm, Cai and the other researchers used SMU's ManeFrame II - which is one of the fastest academic supercomputers in the nation - to run many different simulations.

Human life expectancy worldwide rose dramatically over the past century, but people's health spans -- the period of life spent free from chronic, age-related disease or disability -- have not increased accordingly.

But in the latest issue of the journal Public Policy & Aging Report (PP&AR) from The Gerontological Society of America, experts demonstrate that through interventions that impact the aging process itself, rather than through a focus on individual diseases, the scientific community can achieve a greater impact on both life and health expectancies.

Titled "Is Aging Still a Disease? Perspectives from Geroscience," the journal highlights existing studies as well as recommended areas for further research.

"Twenty-first century medicine should adopt the strategy of directly targeting the molecular mechanisms that cause biological aging," wrote guest editor and University of Washington Professor Matt Kaeberlein, PhD, FGSA, in his introduction. "Only in this way will it be possible to slow the onset and progression of multiple age-related diseases simultaneously, in order to extend the health span proportionately with the life span."

Among the six articles that follow, the authors write that aging itself is not a disease, but rather is the biggest risk factor for a wide range of chronic diseases. This is a central tenet of the emerging field of geroscience, which seeks to define the biological mechanisms that underly the diseases of aging -- with the goal of slowing human aging to delay or prevent many diseases simultaneously.

"The impacts on life and health expectancies from targeting aging are much greater than waiting until people get sick and trying to cure or ameliorate their individual diseases," Kaeberlein wrote. "Instead of increasing life expectancies by only a few years from curing one disease, delaying aging could increase life expectancies by a few decades. Importantly, those added years would be spent in relatively good health, because instead of only fixing one disease, all of the functional declines and diseases of aging would be targeted simultaneously."

The contents of the new PP&AR:

"It is Time to Embrace 21st-Century Medicine," by Matt Kaeberlein, PhD, FGSA

"The Longevity Dividend: A Brief Update," by S. Jay Olshansky, PhD, FGSA

"Time for a New Strategy in the War on Alzheimer's Disease," by Matt Kaeberlein, PhD, FGSA

"Is Old Age or Aging a Disease, in a Literal or a Metaphorical Sense?" by Stephen B. Kritchevsky, PhD, FGSA

"Is Aging a Disease? A Geriatrician's Perspective," by Peter A. Boling, MD

"A Regulatory Pathway for Medicines That Target Aging," by G. Alexander Fleming, MD, Jennifer H. Zhao, BA, Thomas C. Seoh, JD, and Nir Barzilai, MD,

"International Investment in Geroscience," by Sean X. Leng, MD, PhD, FGSA, and Brian K. Kennedy, PhD, FGSA

December 9, 2019 - Studying how people get around cities and travel between countries helps scientists anticipate a population's needs. For example, forecasting commuter traffic can help engineers decide where to build a road. However, only a few studies have examined human mobility in smaller settings. New research analyzed the way people move in a smaller spaces by modeling customers' movement patterns through Tesco supermarkets. Fabian Ying and his colleagues compared different mobility models to determine which ones best forecast how consumers travel through stores. They then introduced a method to reduce congestion in grocery stores. This analysis often found that it could be helpful to place popular goods near the perimeter of a store. Understanding how customers move through stores adds to scientists' ability to forecast human mobility on any scale. It could also help retailers improve their customers' shopping experiences.

Since the end of the 19th century, physicists have known that the transfer of energy from one body to another is associated with entropy. It quickly became clear that this quantity is of fundamental importance, and so began its triumphant rise as a useful theoretical quantity in physics, chemistry and engineering. However, it is often very difficult to measure. Professor Dietmar Block and Frank Wieben of Kiel University (CAU) have now succeeded in measuring entropy in complex plasmas, as they reported recently in the renowned scientific journal Physical Review Letters. In a system of charged microparticles within this ionized gas, the researchers were able to measure all positions and velocities of the particles simultaneously. In this way, they were able to determine the entropy, as it was already described theoretically by the physicist Ludwig Boltzmann around 1880.

Surprising thermodynamic equilibrium in plasma

"With our experiments, we were able to prove that in the important model system of complex plasma, the thermodynamic fundamentals are fullfilled. What is surprising is that this applies to microparticles in a plasma, which is far away from thermodynamic equilibrium," explains PhD student Frank Wieben. In his experiments, he is able to adjust the thermal motion of the microparticles by means of a laser beam. Using video microscopy, he can observe the dynamic behaviour of the particles in real time, and determine the entropy from the information collected.

"We thus lay the fundation for future fundamental studies on thermodynamics in strongly coupled systems. Theseare applicableto other systems as well," states Professor Dietmar Block from the Institute of Experimental and Applied Physics at the CAU. The origin for this success is largely attributable to the results and diagnostic techniques developed in Kiel in the framework of the Collaborative Research Center Transregio 24 "Fundamentals of Complex Plasmas" (2005-2017).

Explaining entropy with a water experiment

An everyday experiment illustrates entropy: if you pour a container of hot water into a container of cold water, the mixture is cooler than the hot water, and warmer than the cold water. However, you cannot undo this process - it is irreversible: water at medium temperature cannot be split into a container of hot water and a container of cold water.

The reason for the irreversibility of this process is entropy.The second law of thermodynamics states that the entropy in a closed system never decreases over time. Therefore, the mixing of hot and cold water must increase the entropy. Alternatively, entropy can also be associated with the degree of disorder or randomness. In highly simplified terms, you could say that systems do not change into a more orderly state by themselves. Someone has to create order, but disorder can arise by itself.

New research from Mauricio Ibanez-Mejia, an assistant professor of Earth and environmental sciences at the University of Rochester, and Francois Tissot, an assistant professor of geochemistry at the California Institute of Technology, gives scientists better insight into the geological processes responsible for the formation of Earth's crust.

In a paper published in the journal Science Advances, Ibanez-Mejia and Tissot studied the isotopes of the element zirconium. Most elements in the periodic table have multiple isotopes; that is, different atoms of the same element can have different masses due to the varying number of sub-atomic particles in their nuclei. Researchers have traditionally assumed that processes occurring within the solid Earth, particularly in high-temperature environments such as those found in volcanoes and magma chambers, do not have the ability to 'fractionate'--distribute unevenly--isotopes of the heavy elements amongst solids and liquids because of the isotopes' minute differences in mass.

In the study, the researchers showed that stable isotopes of the element zirconium, a heavy transition metal, can be fractionated by magnitudes much larger than those previously thought and predicted by theory.

"This changes our view of how this element behaves in the solid Earth," Ibanez-Mejia says. "By recognizing this variability, we developed a tool that can help us gain further insights into the changing chemistry of magmas as they crystallize within Earth's crust."

Scientists of Sechenov University jointly with their colleagues from Australia proposed a new, quicker and cheaper way to assess meat quality. It is based on exposing a small sample to UV light and measuring the spectrum of emission. The method proved to be precise in the classification of meat into standard quality categories. The description of the method and the results of the work were published in Journal of Biophotonics.

Conventionally, to evaluate the quality of beef, specialists pay attention to its colour, pattern of the fibers (marbling), carcass weight etc. But such measurement is time-consuming and relies on a subjective opinion of the experts to a significant extent. Fluorescence spectroscopy can become an alternative: it allows to detect and measure the concentration of various compounds that can emit light of a specific frequency range. These substances include many organic molecules which can be found in meat.
Earlier studies described the spectrum of fluorescence of some meat ingredients (various cell types of muscle, adipose (fat), connective tissue); several scientific groups tried to use these data to assess particular characteristics of the product, e.g. the percentage of connective tissue or fatty acids. The authors of the paper in Journal of Biophotonics linked the spectrum of the fluorescence of meat with its quality defined by 3 categories: MSA3, MSA4 or MSA5. The results were additionally validated by histological (cell and tissue) analysis of the samples and measuring the concentrations of water and fat in them.

In their work scientists used five pieces of meat for each of three classes: MSA5 marks slices of the highest quality and MSA3 - of the lowest among the qualified meat types. Six samples, each of about 8 mm in diameter, were cut from different sites of the meat steaks, where the relative content of fat and muscle tissues varied. Researchers exposed the samples to the light with the wavelength of 250-350 nm (near and middle ultraviolet) and measured the spectrum of the fluorescence in a range of 285-635 nm (from middle ultraviolet to the border between visible light and infrared). The intensity of the emission was set on the matrix 'frequency of excitation - frequency of emission'.

The results showed that the spectra of fluorescence of the samples with various ratios of muscle and adipose tissues are discernible. On the matrices of the samples with adipose tissue one can distinguish spots that match the spectrum of fluorescence of fat-soluble vitamins (A, D, K1, K2, K3), vitamin B and its components, while the spectrum of the samples with muscle tissue coincides with the spectrum of amino acid tryptophan it contains. The authors selected features that enabled them to define the category of any piece of meat. For example, the highest quality meat (MSA5) has the most intensive fluorescence and can be distinguished from the lower quality samples by the difference in brightness of various ranges. The data received also agree with the assumption that the presence of connective and adipose tissue makes meat more tender, and fat is responsible for its marbling.

'This work shows the new opportunities to evaluate the quality of meat objectively by LED illumination and registration of the tissue optical response. It's interesting to note that this technology, having being originally developed for the meat industry, can be further translated into medicine and biomedical research. The principle on which this study was based, i.e. the detection of specific autofluorescence of various tissue components, allows evaluation of the structure and functional state of tissues without taking tissue fragments for biochemical of histological analysis. Therefore, our study can be considered as a possible step towards non-invasive and pain free diagnostics in medicine as well', said Dr Anna Guller, coauthor of the paper, senior research fellow of Sechenov University.