“We found dramatically improved memory performance when we increased the excitability of this region,” said Jesse Rissman, a UCLA assistant professor of psychology, and of psychiatry and biobehavioral sciences, the study’s senior author.

The left rostrolateral prefrontal cortex is important for high-level thought, including monitoring and integrating information processed in other areas of the brain, Rissman said. This area is located behind the left side of the forehead, between the eyebrow and the hairline.

“We think this brain area is particularly important in accessing knowledge that you formed in the past and in making decisions about it,” said Rissman, who also is a member of the UCLA Brain Research Institute.

The psychologists conducted experiments with three groups of people whose average age was 20. Each group contained 13 women and 11 men.

Participants were shown a series of 80 words on a computer screen. For each word, participants were instructed to either imagine either themselves or another person interacting with the word, depending on whether the words “self” or “other” also appeared on the screen. (For example, the combination of “gold” and “other” might prompt them to imagine a friend with a gold necklace.)

The following day, the participants returned to the laboratory for three tests — one of their memory, one of their reasoning ability and one of their visual perception. Each participant wore a device that sent a weak electrical current through an electrode on the scalp to decrease or increase the excitability of neurons in the left rostrolateral prefrontal cortex. Increasing their excitability makes neurons more likely to fire, which enhances the connections between neurons, Rissman said.

(The technique, called transcranial direct current stimulation, or tDCS, gives most people a warm, mild tingling sensation for the first few minutes, said the study’s lead author, Andrew Westphal, who conducted the study as a UCLA doctoral student and is now a postdoctoral scholar in neurology at UC San Francisco.)

For the first half of the hour-long study, all participants received “sham” stimulation — meaning that the device was turned on just briefly, to give the sensation that something was happening, but then turned off so that no electrical stimulation was applied. This allowed the researchers to measure how well each participant performed the tasks under normal conditions. For the next 30 minutes, one group of participants received an electrical current that increased their neurons’ excitability, the second group received current that suppressed neuron activity and the third group received only the sham stimulation. The researchers analyzed which group had the best recall of the words they saw the previous day.

First, the scientists noted that there were no differences among the three groups during the first half of the study — when no brain stimulation was used — so any differences in the second half of the experiment could be attributed to the stimulation, Westphal said.

Memory scores for the group whose neurons received excitatory stimulation during the second half of the study were 15.4 percentage points higher than their scores when they received the sham stimulation.

Scores for those who received fake stimulation during both sessions increased by only 2.6 percentage points from the first to the second session — a statistically insignificant change that was likely was due to their increased familiarity with the task, according to the paper. And scores for the group whose neuron activity was temporarily suppressed increased by just five percentage points, which the authors also wrote was not statistically significant.

“Our previous neuroimaging studies showed the left rostrolateral prefrontal cortex is highly engaged during memory retrieval,” Rissman said. “Now the fact that people do better on this memory task when we excite this region with electrical stimulation provides causal evidence that it contributes to the act of memory retrieval.

“We didn’t expect the application of weak electrical brain stimulation would magically make their memories perfect, but the fact that their performance increased as much as it did is surprising and it’s an encouraging sign that this method could potentially be used to boost people’s memories.”

The study’s reasoning task asked participants to decide in seven seconds whether certain pairs of words were analogies. Half of the trials featured word pairs that were true analogies, such as “‘moat’ is to ‘castle’ as ‘firewall’ is to ‘computer.'” (In both pairs, the first word protects the second from invasion.) The other half had word pairs that were related but not actually analogous.

Researchers found no significant differences in performance among the three groups.

For the final task, focusing on perception, subjects were asked to select which of four words has the most straight lines in its printed form. (One example: Among the words “symbol,” “museum,” “painter” and “energy,” the word “museum” has the most straight lines.) Again, the researchers found no significant differences among the three groups — which Rissman said was expected.

“We expected to find improvement in memory, and we did,” Rissman said. “We also predicted the reasoning task might improve with the increased excitability, and it did not. We didn’t think this brain region would be important for the perception task.”

Why do people forget names and other words? Sometimes it’s because they don’t pay attention when they first hear or see it, so no memory is even formed. In those cases, the electrical stimulation wouldn’t help. But in cases where a memory does form but is difficult to retrieve, the stimulation could help access it.

“The stimulation is helping people to access memories that they might otherwise have reported as forgotten,” Westphal said.

Although tDCS devices are commercially available, Rissman advises against anyone trying it outside of supervised research.

“The science is still in an early stage,” he said. “If you do this at home, you could stimulate your brain in a way that is unsafe, with too much current or for too long.”

Rissman said other areas of the brain also play important roles in retrieving memories. Their future research will aim to better understand the contributions of each region, as well as the effects of brain stimulation on other kinds of memory tasks.

Published in PLOS ONE, the University of Minnesota-led study, conducted with researchers from the University of Oxford and the University of Copenhagen, used weather and reported crop data to evaluate the potential impact of observed climate change. The researchers found that:

• observed climate change causes a significant yield variation in the world’s top 10 crops, ranging from a decrease of 13.4 percent for oil palm to an increase of 3.5 percent for soybean, and resulting in an average reduction of approximately one percent (-3.5 X 10e13 kcal/year) of consumable food calories from these top 10 crops;

• impacts of climate change on global food production are mostly negative in Europe, Southern Africa, and Australia, generally positive in Latin America, and mixed in Asia and Northern and Central America;

• half of all food-insecure countries are experiencing decreases in crop production — and so are some affluent industrialized countries in Western Europe;

• contrastingly, recent climate change has increased the yields of certain crops in some areas of the upper Midwest United States.

“There are winners and losers, and some countries that are already food insecure fare worse,” says lead author Deepak Ray of the University of Minnesota’s Institute on the Environment, whose high-resolution global crop statistics databases have also been used to help to identify how global crop production changes over time. These findings indicate which geographical areas and crops are most at risk, making them relevant to those working to achieve the U.N. Sustainable Development Goals of ending hunger and limiting the effects of climate change. Insights like these lead to new questions and crucial next steps.

“This is a very complex system, so a careful statistical and data science modeling component is crucial to understand the dependencies and cascading effects of small or large changes,” says co-author Snigdhansu Chatterjee of the University of Minnesota’s School of Statistics.

The Institute’s Global Landscapes Initiative, whose contributors to this study included Ray, Paul West and James Gerber, has previously produced global scale findings that have been put to use by international organizations such as the U.N., World Bank and Brookings in evaluation of global food security and environmental challenges. The scholars say this report has implications for major food companies, commodity traders and the countries in which they operate, as well as for citizens worldwide.

“The research documents how change is already happening, not just in some future time,” says Ray.

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The brain cells collect damaged lipids secreted by hyperactive neurons, then recycle those toxic molecules into energy, researchers at the Howard Hughes Medical Institute’s Janelia Research Campus report May 23, 2019, in the journal Cell. It’s a mechanism to protect neurons from the damaging side effects of overactivity. And it’s another important role for astrocytes, which support neurons in various ways.

When a neuron fires fast and furious, lipid molecules in the cell get damaged and can become toxic. While most kinds of cells sequester excess fatty acids away or feed them to mitochondria to prevent buildup, neurons don’t seem to rely on those tricks.

Instead, “neurons unload some of the burden to astrocytes,” says study coauthor and Janelia Group Leader Zhe Liu, who worked closely with Maria Ioannou and Jennifer Lippincott-Schwartz, a senior group leader at Janelia. “For a long time, people have suspected there was some mechanism like this. The new work shows how this process actually happens.”

The finding arose from a curious observation: Overactive neurons release damaged fatty acids bundled up in lipid particles. “People didn’t think that neurons could secrete those lipid particles,” Liu says.

But stimulating mouse neurons in a dish led to the buildup of fatty acids and, eventually, lipid particle release, the team showed. Then, nearby astrocytes engulfed the particles and amped up the activity of genes involved in energy production and detoxification.

Astrocytes feed neurons’ off-loaded damaged lipids to their own mitochondria, converting waste into energy, Liu concluded. Tests in mice showed a similar response. After a lesion to the brain that mimics a stroke — a huge stress to neurons — neurons increased production of proteins involved in transporting fatty acids out of the cell, and fatty acids built up in astrocytes.

This pathway for clearing toxic molecules from neurons might be damaged in Alzheimer’s patients, Liu proposes, though that hasn’t been thoroughly investigated. A next step, led by Maria Ioannou in her new lab at the University of Alberta, is to examine what’s different about this mechanism in cell culture and rodent models of Alzheimer’s disease.

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Materials provided by Howard Hughes Medical Institute. Note: Content may be edited for style and length.

Colloidal gels consist of two phases that are intertwined with one another: a solid particle network and a liquid solvent. The result is soft-solid materials with unique properties, including elasticity and mechanical stability, which make them attractive choices for numerous applications. Although these properties have been capitalized upon commercially, they are not completely explained by the theoretical understanding that has been acquired to date.

“Studying colloidal gels that are already formed means that the actual process of gelation remains somewhat of a black box,” one of study leading authors Hideyo Tsurusawa explains. Another leading author Mathieu Leocmach continues “By establishing a method that allows us to follow the kinetics of the complete gelation process, we have gained new insight into the origins of the characteristic properties of colloidal gels. Understanding the individual stages of gelation has enabled us to demonstrate a direct link between the mechanical stability of gels and isostatic structures.”

Isostatic structures are particles or clusters that experience balanced forces. The researchers found that the point in the gelation process when solidity appears corresponds to the point of isotropic percolation of isostatic structures through the gel. Their comparison of the differences in percolation behavior between low and high concentration gels suggested that the space-spanning percolation of isostatic structures are directly linked to mechanical stability.

“The real time nature and resolution of our technique have resulted in a depth of understanding that was not previously achievable,” study corresponding author Hajime Tanaka explains. “We hope that the enhanced insight will be useful for researchers working to address complex mechanical and rheological issues across the wide span of colloidal gel applications.”

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The substantial price increases were not limited to drugs that recently entered the marketplace, as one might expect, or to those lacking generic equivalents. In addition, the increases often were “highly correlated” with price bumps by competitors.

The researchers concluded that the current rebate system, which incentivizes high list prices for drugs and relies heavily on privately-negotiated rebates to pharmacies, plays a central role driving up costs for consumers. The byzantine and secretive rebate system, they noted, prevents consumers from making informed decisions about purchasing medications.

The study appears in the latest issue of JAMA Network Open.

“It’s no secret that health care prices are growing exponentially in the United States, but what has been less clear is the extent to which certain prescription drugs are contributing to that trend — especially when prices are clouded by a complicated rebate system,” says lead author Nathan Wineinger, PhD, director of biostatistics at Scripps Research Translational Institute and assistant professor in Scripps Research’s Department of Integrative Structural and Computational Biology. “By looking at price data for the most popular brand-name drugs, we found striking and consistent price increases occurring at regular intervals, regardless of competition in the marketplace.”

The Scripps Research team obtained the prescription data from a proprietary Blue Cross and Blue Shield data set known as BCBS Axis, which includes commercial insurance claims from more than 35 million Americans covered by independent Blue Cross and Blue Shield companies in the United States.

With a focus on the 49 most popular brand-name drugs with pharmacy claim data available for the entirety of their five-year research window, Wineinger and his team, led by Eric Topol, MD, conducted a high-dimensional data analysis to examine each claim’s total price. This was represented by the total out-of-pocket costs paid by the insured consumer and the amount paid by the insurer.

Researchers determined that prices of top-selling branded prescription drugs increased by a median of 9.5 percent annually, which equates to a doubling in price every seven to eight years. And they found that pairs of brand-name drug competitors that treat similar conditions — such as Humira and Enbrel, both for rheumatoid arthritis — demonstrated highly correlated price increases.

“It’s bad enough to see the relentless increase in drug prices, but this work underscores it is occurring without transparency or accountability,” says Topol, founder and director of Scripps Research Translational Institute and executive vice president of Scripps Research. “It is especially concerning to see drugs in the same class having increases that appear to be coordinated.”

Wineinger explains that a prescription drug’s list price is typically set by the pharmaceutical company that makes the drug, reflecting the payment shared by the insurer and the patient who buys the product at a pharmacy. However, drug companies increasingly offer rebates to organizations called pharmacy benefit managers, or PBMs, which negotiate with pharmacies and insurance companies to determine which drugs are offered as preferred “formulary” options to insurance plan members.

Those rebates are returned to the pharmacy at a later date, paid out by drug companies based on the total sales volume of their products, and cannot be linked directly to any individual purchase. This makes prices especially difficult to track.

Some drug companies have defended list price increases by reasoning that rebates have increased at a similar clip. However, the researchers found that is not the case, and concluded that increases in list prices and a greater reliance on rebates are making drugs more expensive overall.

“Accountability and transparency are essential to developing a better understanding of rising pharmacy costs,” said Maureen Sullivan, chief strategy and innovation officer for the Blue Cross Blue Shield Association (BCBSA). “The Blue Cross Blue Shield Association developed the Alliance for Health Research to engage researchers in collaborative efforts to explore critical health care issues and enable valuable insights that can benefit consumers and the medical community.”

Now, a team of scientists led by physicists Lan Gao of the U.S. Department of Energy’s (DOE) Princeton Plasma Physics Laboratory (PPPL) and Edison Liang of Rice University, has for the first time created a particular form of coherent and magnetized plasma jet that could deepen the understanding of the workings of much larger jets that stream from newborn stars and possibly black holes — stellar objects so massive that they trap light and warp both space and time.

“We are now creating stable, supersonic, and strongly magnetized plasma jets in a laboratory that might allow us to study astrophysical objects light years away,” said astrophysicist Liang, co-author of the paper reporting the results in the Astrophysical Journal Letters.

The team created the jets using the OMEGA Laser Facility at the University of Rochester’s Laboratory for Laser Energetics (LLE). The researchers aimed 20 of OMEGA’s individual laser beams into a ring-shaped area on a plastic target. Each laser created a tiny puff of plasma; as the puffs expanded, they put pressure on the inner region of the ring. That pressure then squeezed out a plasma jet reaching over four millimeters in length and created a magnetic field that had a strength of over 100 tesla.

“This is the first step in studying plasma jets in a laboratory,” said Gao, who was the primary author of the paper. “I’m excited because we not only created a jet. We also successfully used advanced diagnostics on OMEGA to confirm the jet’s formation and characterize its properties.”

The diagnostic tools, developed with teams from LLE and the Massachusetts Institute of Technology (MIT), measured the jet’s density, temperature, length, how well it stayed together as it grew through space, and the shape of the magnetic field around it. The measurements help scientists determine how the laboratory phenomena compare to jets in outer space. They also provide a baseline that scientists can tinker with to observe how the plasma behaves under different conditions.

“This is groundbreaking research because no other team has successfully launched a supersonic, narrowly beamed jet that carries such a strong magnetic field, extending to significant distances,” said Liang. “This is the first time that scientists have demonstrated that the magnetic field does not just wrap around the jet, but also extends parallel to the jet’s axis,” he said.

The researchers hope to expand their research with larger laser facilities and investigate other types of phenomena. “The next step involves seeing whether an external magnetic field could make the jet longer and more collimated,” Gao said.

“We would also like to replicate the experiment using the National Ignition Facility at Lawrence Livermore National Laboratory, which has 192 laser beams, half of which could be used to create our plasma ring. It would have a larger radius and thus produce a longer jet than that produced using OMEGA. This process would help us figure out under which conditions the plasma jet is strongest.”

The team included scientists from PPPL, Rice, LLE, MIT, and the University of Chicago. The research was supported by the DOE’s National Nuclear Security Administration, the National Science Foundation, and Los Alamos National Laboratory. Computer simulations were performed on the Extreme Science and Engineering Discovery Environment (XSEDE), a collaborative partnership of 19 institutions, and the Argonne Leadership Computing Facility, a DOE Office of Science user facility.

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Materials provided by DOE/Princeton Plasma Physics Laboratory. Original written by Raphael Rosen. Note: Content may be edited for style and length.

Pairs of children (ages 8 to 12) were assigned to 1 of 3 versions of the popular video game Minecraft (one child played while the other watched): (1) violent with guns used to kill monsters, (2) violent with swords used to kill monsters or (3) nonviolent with no weapons or monsters. After 20 minutes of game-play, the children played with other toys in another room that included a cabinet with two disabled handguns. The study analysis included 220 children (average age 10) who found a gun while playing. Nearly 62 percent of the 76 children who played the video game with gun violence touched a handgun; about 57 percent of the 74 children who played the game with sword violence touched a gun, and about 44 percent of the 70 children who played the nonviolent version touched a gun, although the differences across groups weren’t significant.

Children exposed to violent versions of the video game were more likely to engage in the dangerous behavior of pulling the trigger at themselves or their partner than children exposed to the nonviolent version.

The violent versions with guns and swords were significant even after accounting for other mitigating factors (sex, age, trait aggressiveness, exposure to violent media, attitudes toward guns, presence of firearms in the home, interest in firearms and whether the child had taken a firearm safety course).

The other outcomes (time spent holding a gun and total trigger pulls) weren’t statistically significant.

Self-reported consumption of violent media was also a risk for total trigger pulls and trigger pulls at self or partner. The study is limited by the artificial setting of a university laboratory and Minecraft is not a very violent game with no blood and gore (researchers could not ethically expose children to a more violent, age-inappropriate game).

The authors encourage gun owners to secure their firearms and reduce children’s exposure to violent video games.

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The team of researchers, including three from Penn State, studied how seven key health measures — like diet, exercise and blood pressure — were related to people’s cardiovascular health over time.

They identified five patterns of how well people did or did not do on the seven health measures over time. These patterns were able to help predict participants’ future risk of CVD.

For example, people who consistently scored well in the seven metrics had a lower chance of CVD than people who did not. The researchers also found that improving these metrics over time was related to a lower risk of CVD in the future.

Xiang Gao, associate professor of nutritional sciences and director of the Nutritional Epidemiology Lab at Penn State, said the study — published today (May 31) in JAMA Network Open — suggests that people can help influence their risk of CVD in the future.

“In our study population, and probably across the world, there are many people who have suboptimal or poor heart health,” Gao said. “But, even though most people don’t meet the ideal criteria for all seven metrics, if we can work to improve those measures, the future risk of CVD can still decrease.”

The American Heart Association identified the seven health metrics as the most important predictors of heart health. They include four behaviors that people have control over and three biometrics that should be kept at healthy levels.

The modifiable behaviors include not smoking, maintaining a healthy weight, eating healthy and staying physically active. The biometrics are blood pressure, cholesterol and blood sugar.

Each metric has a poor, intermediate or ideal score. For example, smoking regularly would be considered “poor,” smoking within the past 12 months would be “intermediate,” and never smoking or quitting more than a year ago would be “ideal.” Combining the score for all seven metrics — 0 for poor, 1 for intermediate and 2 for ideal — results in an overall “cardiovascular health score,” or CHS.

“Only about 2 percent of people in the United States and other countries meet all the ideal requirements for these seven factors,” Gao said. “This raises the question of whether improving these metrics is related to lower future risk of CVD. It should, but no one had the data to support this idea.”

The researchers used data from 74,701 Chinese adults from the Kailuan Study. At the beginning of the study, the participants completed questionnaires about their health and underwent clinical exams and lab tests three times in the first four years. Across the following five years, the researchers kept track of any new onset CVD cases in the participants.

After the information was gathered, the researchers analyzed the data to see how CHS during the first four years was associated with whether or not the participants developed CVD subsequently. They found five distinct patterns — or trajectories — that people followed throughout the four years.

These trajectories included maintaining high, medium or low CHS, as well as increasing and decreasing CHS over time. Gao said these different trajectories were associated with different risks for developing CVD in the future.

“For example, about 19 percent of participants were able to maintain a better cardiovascular health score over the four years,” Gao said. “We found that those people had a 79 percent lower chance of developing heart disease in the future than people who maintained a low cardiovascular health score.”

Gao said they found similar results when they analyzed risk for stroke and myocardial infarction — commonly referred to as a heart attack.

“We also examined whether improving cardiovascular health score over time affected future risk of CVD,” Gao said. “We found that improvement of overall cardiovascular health over time related to lower future CVD in this population, even for those with poor cardiovascular health status at the beginning of the study.”

Additionally, the researchers were curious about whether one health measure was more important than the others. They ran repeated tests, removing a different, single health measure each time. They found that the scores still predicted future CVD risk in similar ways.

“This suggests that overall cardiovascular health is still the most important thing and that one factor isn’t more important than the others,” Gao said. “It also helps confirm that these seven metrics are valid and a very useful tool for developing a strategy for cardiovascular disease prevention.”

Shouling Wu, Kailuan General Hospital; Shasha An, Han Dan Central Hospital; Weijuan Li, Vanderbilt University Medical Center; Alice H. Lichtenstein, Tufts University; Jingsheng Gao, Kailuan General Hospital; Penny M. Kris-Etherton, Penn State; Yuntao Wu, Kailuan General Hospital; Cheng Jin, Kailuan General Hospital; Shue Huang, Penn State; and Frank B. Hu, Harvard T.H. Chan School of Public Health, also participated in this work.