Tech

WEST LAFAYETTE, Ind. -- Most of today's batteries are made up of rare lithium mined from the mountains of South America. If the world depletes this source, then battery production could stagnate.

Sodium is a very cheap and earth-abundant alternative to using lithium-ion batteries that is also known to turn purple and combust if exposed to water - even just water in the air.

Worldwide efforts to make sodium-ion batteries just as functional as lithium-ion batteries have long since controlled sodium's tendency to explode, but not yet resolved how to prevent sodium-ions from "getting lost" during the first few times a battery charges and discharges. Now, Purdue University researchers made a sodium powder version that fixes this problem and holds a charge properly.

"Adding fabricated sodium powder during electrode processing requires only slight modifications to the battery production process," said Vilas Pol, Purdue associate professor of chemical engineering. "This is one potential way to progress sodium-ion battery technology to the industry."

The study was made available online in June 2018 ahead of print on August 31, 2018 in the Journal of Power Sources.

This work aligns with Purdue's giant leaps celebration, acknowledging the university's global advancements made in health, space, artificial intelligence and sustainability as part of Purdue's 150th anniversary. Those are the four themes of the yearlong celebration's Ideas Festival, designed to showcase Purdue as an intellectual center solving real-world issues.

Even though sodium-ion batteries would be physically heavier than lithium-ion technology, researchers have been investigating sodium-ion batteries because they could store energy for large solar and wind power facilities at lower cost.

The problem is that sodium ions stick to the hard carbon end of a battery, called an anode, during the initial charging cycles and not travel over to the cathode end. The ions build up into a structure called a "solid electrolyte interface."

"Normally the solid electrolyte interface is good because it protects carbon particles from a battery's acidic electrolyte, where electricity is conducted," Pol said. "But too much of the interface consumes the sodium ions that we need for charging the battery."

Purdue researchers proposed using sodium as a powder, which provides the required amount of sodium for the solid electrolyte interface to protect carbon, but doesn't build up in a way that it consumes sodium ions.

They minimized sodium's exposure to the moisture that would make it combust by making the sodium powder in a glovebox filled with the gas argon. To make the powder, they used an ultrasound - the same tool used for monitoring the development a fetus - to melt sodium chunks into a milky purple liquid. The liquid then cooled into a powder, and was suspended in a hexane solution to evenly disperse the powder particles.

Just a few drops of the sodium suspension onto the anode or cathode electrodes during their fabrication allows a sodium-ion battery cell to charge and discharge with more stability and at higher capacity - the minimum requirements for a functional battery.

Scientists have long prized the roundworm Caenorhabditis elegans as a model for studying the biology of multicellular organisms. The millimeter-long worms are easy to grow in the lab and manipulate genetically, and have only around 1,000 cells, making them a powerful system for probing intricacies of development, behavior and metabolism.

Now, a team at Princeton's Lewis-Sigler Institute for Integrative Genomics has produced new resources for C. elegans research: a comprehensive view of which genes are active in each of the four major tissues of adult worms, as well as a tool for predicting gene activity across 76 more specific cell types. The team, led by co-senior authors Professor of Molecular Biology Coleen Murphy and Professor of Computer Science Olga Troyanskaya, reported their results in an August 10 article in the journal PLOS Genetics.

The work builds on a collaboration that dates back to 2009, when the two labs first teamed up to analyze gene activity patterns in C. elegans tissues. "Olga and I both had an interest in tissue specificity. Most of the biology that we hear about is done in whole organisms, but the truth is, if you have a disease, it's usually of a particular tissue," said Murphy, who directs Princeton's Glenn Center for Quantitative Aging Research. "For C. elegans we know that, for example, insulin signaling in the brain or the gut of the animal actually can affect the longevity of the entire animal."

Researchers have previously analyzed the activity of the worm's more than 20,000 genes under different conditions in embryos, larvae or whole adult worms, but separating the tissues of adult animals for such experiments has been difficult because of the worm's anatomy. Rachel Kaletsky, an associate research scholar in Murphy's lab and co-first author of the work, developed a technique to isolate specific tissues. Kaletsky, Murphy and their colleagues first used the method in 2015 to study memory-related genes in neurons. Here, they applied it to conduct a global analysis of gene activity, or expression, in the adult worm's four major tissues: muscle, neuron, intestine and epidermis tissues.

"This really lets us refine our hypotheses," said Kaletsky. "We can now ask questions about what is happening in neurons, for example, under a whole variety of conditions affecting various diseases or things that happen with age, and we can go and directly answer those questions."

After separating cells from the worms' four major tissues, the researchers isolated and sequenced the cells' messenger RNAs, the intermediate molecules that enable the information encoded in genes' DNA to be translated into proteins, which carry out all of a cell's basic and more specialized functions. In any given cell only a subset of genes is actively expressed -- meaning that messenger RNA exists for only the subset of genes that are active in that tissue.

Analyzing the RNA data revealed distinct patterns of gene expression in each tissue. Intestinal cells, for instance, expressed high levels of genes associated with digestion, while genes related to learning and memory were highly expressed in neurons. More than 5,000 genes were expressed in all tissue types; these were involved in such universal processes as glucose metabolism or stress responses.

Comparing the results to human gene expression profiles yielded some unexpected insights. For example, the C. elegans epidermis did not express genes similar to those active in human skin, as researchers have long assumed. Rather, epidermis cells expressed many metabolic genes comparable to those that are active in the human liver. "This is the kind of thing that could inform studies of organ-specific diseases in humans, using worms as a model," said Murphy.

But what about investigating which genes are expressed in the worm's head muscle cells or sensory neurons? Or in its excretory system? To gain a higher-resolution picture of gene expression across cell types and life stages, Murphy's group worked with Troyanskaya and Victoria Yao, a recently graduated Ph.D. student from Troyanskaya's lab and co-first author of the work.

The team applied computational methods to analyze data from more than 4,000 publicly available C. elegans gene expression experiments -- including data from the present study on the worm's four major tissues. While most of these experiments were done with whole animals, the researchers devised a machine-learning approach to tease out tissue-specific patterns. The method combines the high-throughput data sets with the best available information from small-scale experiments demonstrating that a gene is expressed in a particular tissue.

"We can't fully characterize every single little cell type in any kind of tractable way very soon," explained Yao. "The idea is that all those whole-worm expression data sets still have useful information. It's kind of like everything mushed up in a blender, but we can use computational methods to try to pull out which genes are potentially expressed in which tissues." Researchers can access the gene activity prediction tool at worm.princeton.edu.

As a case study, the team used the prediction tool to examine genes controlled by CREB, a gene that serves as a key regulator of both metabolism and long-term memory, which Murphy's lab has studied for its roles in aging processes. While CREB's activities in neurons are well known, this investigation suggested that CREB also regulates genes in the worm's epidermis, intestine and reproductive system.

Murphy emphasized that the paper includes just a few examples of new findings enabled by the team's tissue-specific gene expression data and prediction tool. "We really hope that people in the worm research community will use this to find things we haven't even thought of yet," she said.

Air pollution is now an established risk factor for heart disease/stroke and respiratory disease, but its potential role in neurodegenerative diseases, such as dementia, isn't clear.

To try and explore this further, the researchers used carefully calculated estimates of air and noise pollution levels across Greater London to assess potential links with new dementia diagnoses.

To do this, they drew on anonymised patient health records from the Clinical Practice Research Datalink (CPRD). This has been collecting data from participating general practices across the UK since 1987.

For the purposes of this study, the researchers focused on just under 131,000 patients aged 50 to 79 in 2004, who had not been diagnosed with dementia, and who were registered at 75 general practices located within the London orbital M25 motorway.

Based on the residential postcodes of these patients, the researchers estimated their yearly exposure to air pollutants-specifically nitrogen dioxide (NO2), fine particulate matter (PM2.5), and ozone (O3)-as well as proximity to heavy traffic and road noise, using validated modelling methods, validated with recorded measurements.

The health of these patients was then tracked for an average of 7 years, until a diagnosis of dementia, death, or deregistration from the practice, whichever came first.

During the monitoring period, 2181 patients (1.7%) were diagnosed with dementia, including Alzheimer's disease.

These diagnoses were associated with ambient levels of NO2 and PM2.5, estimated at the patients' homes at the start of the monitoring period in 2004.

Those living in areas in the top fifth of NO2 levels ran a 40 per cent heightened risk of being diagnosed with dementia than those living in the bottom fifth. A similar increase in risk was observed for higher PM2.5 levels.

These associations were consistent and unexplained by known influential factors, such as smoking and diabetes, although when restricted to specific types of dementia, they remained only for patients diagnosed with Alzheimer's disease.

This is an observational study, and as such, can't establish cause, and the findings may be applicable only to London. Nor were the researchers able to glean long term exposures, which may be relevant as Alzheimer's disease may take many years to develop.

Many factors may be involved in the development of dementia, the exact cause of which is still not known, the researchers point out, and while there are several plausible pathways for air pollutants to reach the brain, how they might contribute to neurodegeneration isn't clear.

But they suggest: "Traffic related air pollution has been linked to poorer cognitive development in young children, and continued significant exposure may produce neuroinflammation and altered brain innate immune responses in early adulthood."

And they conclude that even if the impact of air pollution were relatively modest, the public health gains would be significant if it emerged that curbing exposure to it might delay progression of dementia.

The remains of a buried pine forest at the foot of Mont Saint Genis in Southern France yield insightful information on a drastic climate change event. The pine tree stand initiated around 12,900 years ago during the relatively warm "Allerød" period, and continued growing into the cold snap of the "Younger Dryas" period. Researchers at the GFZ German Research Centre for Geosciences in Potsdam, together with international colleagues, have for the first time combined classic tree-ring width measurements with chemical (stable isotope) analyses of carbon and oxygen in tree-rings to reconstruct climate variables. Thus, they were able to calculate local soil water composition (precipitation) and relative humidity at annual time resolution. This resulted in novel insights into the hydrological variability and atmospheric circulation changes during an abrupt climate change event. The team reports about its findings in the journal Scientific Reports.

The sudden cold snap in the northern hemisphere between 12,700 and 11,600 years ago has been found in climate records from Greenland ice cores and Central European lake sediments. It was named after the mountain avens (Latin: Dryas octopetala) - an Arctic plant species that predominantly spreads during cold conditions. The discovery of fossil pines in a French river valley near Avignon now close an important knowledge gap, as they shows how the climate in the Mediterranean changed in this period. With accurate radiocarbon dating, the scientists were able to prove that the buried pines had started their growth in the warm days of the Allerød just before the Younger Dryas and had survived the sudden cold snap for several decades. They were thus witnesses of this extreme climate change.

In their analyzes, the researchers found signs of increased air mass transport from the North Atlantic. "We were surprised that about sixty years before the actual climate change, a significant alteration in the precipitation source was recognized," says first author Maren Pauly of the GFZ. According to the results, humid air masses arriving from the Atlantic side enhanced, while rainfall originating from the Mediterranean side diminished, evidenced by a steadily increasing variability of the oxygen isotopes of the soil water. Isotopes are atoms with a different number of neutrons in the nucleus. From the ratios of light and heavy isotopes conclusions can be drawn on the origin of air masses and thus of precipitation. "Especially striking is the increase of extreme polar air surges, winter precipitation and winter storms at the beginning of the Younger Dryas," adds Achim Brauer, Head of GFZ's section Climate Dynamics and Landscape Evolution and Director of Department 5 at GFZ. Maren Pauly works as a PhD student in his group.

With this study, the scientists proved that it was not a change in mean temperatures that was problematic, but rather the environmental stress presumably leading to the tree die off. This stress was caused by the accumulation of extreme weather conditions in single years or even decades. In general, this study shows that periods of massive climate change can be associated with more instability in atmospheric circulation patterns, leading to greater variability on annual or decadal scales. "Here, paleoclimate research shows how it can close knowledge gaps with information from natural climate archives," says Achim Brauer. This is also important because "we lack experience on what exactly happens during a sudden climate change, how quickly the climate can change, and what regional differences occur."

Artificial neural networks--algorithms inspired by connections in the brain--have "learned" to perform a variety of tasks, from pedestrian detection in self-driving cars, to analyzing medical images, to translating languages. Now, researchers at the University of California San Diego are training artificial neural networks to predict new stable materials.

"Predicting the stability of materials is a central problem in materials science, physics and chemistry," said senior author Shyue Ping Ong, a nanoengineering professor at the UC San Diego Jacobs School of Engineering. "On one hand, you have traditional chemical intuition such as Linus Pauling's five rules that describe stability for crystals in terms of the radii and packing of ions. On the other, you have expensive quantum mechanical computations to calculate the energy gained from forming a crystal that have to be done on supercomputers. What we have done is to use artificial neural networks to bridge these two worlds."

By training artificial neural networks to predict a crystal's formation energy using just two inputs--electronegativity and ionic radius of the constituent atoms--Ong and his team at the Materials Virtual Lab have developed models that can identify stable materials in two classes of crystals known as garnets and perovskites. These models are up to 10 times more accurate than previous machine learning models and are fast enough to efficiently screen thousands of materials in a matter of hours on a laptop. The team details the work in a paper published Sept. 18 in Nature Communications.

"Garnets and perovskites are used in LED lights, rechargeable lithium-ion batteries, and solar cells. These neural networks have the potential to greatly accelerate the discovery of new materials for these and other important applications," noted first author Weike Ye, a chemistry Ph.D. student in Ong's Materials Virtual Lab.

The team has made their models publicly accessible via a web application at http://crystals.ai. This allows other people to use these neural networks to compute the formation energy of any garnet or perovskite composition on the fly.

The researchers are planning to extend the application of neural networks to other crystal prototypes as well as other material properties.

On Sunday, Sept. 16, Typhoon Mangkhut had made landfall in southern China and Hurricane signal #10 was still in force. NASA's Aqua satellite passed over the storm and captured an image that showed the storm after landfall.

A Red Alert, the most severe warning was issued by authorities in southern China.

At 5 a.m EDT (0900 UTC) on Sunday, Sept. 16, Mangkhut was centered near 21.6 north latitude and 113.6 east longitude, about 54 miles southwest of Hong Kong. Mangkhut was moving to the west-northwest at 17 knots and had maximum sustained winds 80 knots (92 mph/148 kph)

NASA's Aqua satellite provided a visible look at the storm on Sept. 16 on 2:20 a.m. EDT (0620 UTC) after it made landfall in China. The image showed the cloud-filled center of the storm over the coast. The storm brought surges as high as 3 meters (approx. 9 feet) around Hong Kong.

On Sunday evening, local time, Typhoon Mangkhut made landfall in southern China's Guangdong province,

After landfall, the storm moved inland and continued to weaken, dropping very heavy rainfall.

Students who witness violence in school at age 13 are at later risk of psycho-social and academic impairment at age 15, according to a new longitudinal study by researchers at Université de Montréal with colleagues in Belgium and France.

In the study, published today in the Journal of Epidemiology and Community Health, Michel Janosz of UdeM's School of Psycho-Education and his international team looked at a stratified cohort of nearly 4,000 Quebec high-school students. The researchers statistically tested the relationship between witnessing school violence in Grade 8 and subsequent antisocial behavior (drug use, delinquency), emotional distress (social anxiety, depressive symptoms), and academic adjustment (school achievement, engagement) in Grade 10. They also compared the relative contribution of differing forms of witnessing school violence and compared them to experiencing violence directly over the long term.

"Previous studies suspected that adolescents who witness violence might be at risk of experiencing post-traumatic psychological problems, but they could not rule out whether the students showing bystander effects were not already having such problems beforehand," said Janosz noted.

"The Quebec cohort was ideal because we had psychological information on the students before witnessing the violence and this really makes a big difference scientifically in terms of rigor," he continued. "There was less interference from confounders and other plausible explanations. Plus, we were able to follow up with the the students a couple of years later - a huge advantage."

Added co-author Linda Pagani, also a professor at the School of Psycho-Education: "There were several take-home messages. First, witnessing school violence in Grade 8 predicted later impairment at Grade 10. Second, bystander effects were very similar to being victimized by violence directly."

Different forms of violence

In their study, the researchers examined different forms of violence. Witnessing major violence (physical assaults, carrying weapons) was associated with later drug use and delinquency. The effect was the same for hidden or veiled violence (theft and vandalism). On the other hand, witnessing minor violence (threats and insults) predicted increases in drug use, social anxiety, depressive symptoms, and decreases in engagement and participation at school.

"Most students reported witnessing violence," said Janosz. "It is clear that approaches to prevention and intervention should include witnesses as well victims and perpetrators and target all forms of school violence. Of course, actively supportive family and community relationships represent important resources for facilitating coping strategies after having been exposed to events associated that inflict psychological or physical harm. These also prevent emotional desensitization to violence which also contributes to aggressive behavior in youth."

He continued: "We believe that after-violence intervention programs would benefit from a population-based approach that encourages and normalizes concern for others and intolerance for disrespect. More importantly, schools should seek to empower bystander students who are not directly involved in acts of school violence, rather than giving them messages to stay uninvolved. Schools need to understand that discouraging student involvement can be interpreted by youth as promoting self-centeredness at the expense of community well-being. Nobody should feel powerless."

Careful sample preparation, electron tomography and quantitative analysis of 3D models provides unique insights into the inner structure of reverse osmosis membranes widely used for salt water desalination wastewater recycling and home use, according to a team of chemical engineers.

These reverse osmosis membranes are layers of material with an active aromatic polyamide layer that allows water molecules through, but screens out 99 to 99.9 percent of the salt.

"As water stresses continue to grow, better membrane filtration materials are needed to enhance water recovery, prevent fouling, and extend filtration module lifetimes while maintaining reasonable costs to ensure accessibility throughout the world," said Enrique Gomez, professor of chemical engineering, Penn State. "Knowing what the material looks like on the inside, and understanding how this microstructure affects water transport properties, is crucial to designing next-generation membranes with longer operational lifetimes that can function under a diverse set of conditions."

Gomez and his team looked at the internal structure of the polyamide film using high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) tomography. HAADF-STEM's image intensity is directly proportional to the density of the material, allowing mapping of the material to nanoscale resolution.

"We found that the density of the polyamide layer is not homogeneous," said Gomez. "But instead varies throughout the film and, in this case, is highest at the surface."

This discovery changes the way the engineers think about how water moves through this material, because the resistance to flow is not homogeneous and is highest at the membrane surface.

HAADF-STEM allowed the researchers to construct 3D models of the membrane's internal structure. With these models, they can analyze the structural components and determine which characteristics must remain for the membrane to function and which could be manipulated to improve membrane longevity, antifouling, and enhance water recovery.

Another characteristic revealed through HAADF-STEM was the presence, or rather absence, of previously reported enclosed voids. Researchers thought that the membranes fine structure would contain enclosed void spaces that could trap water and alter flow patterns. The 3D models show that there are few closed voids in the state-of-the-art material studied.

"Local variations in porosity, density and surface area will lead to heterogeneity in flux within membranes, such that connecting chemistry, microstructure and performance of membranes for reverse osmosis, ultrafiltration, virus and protein filtration, and gas separations will require 3D reconstructions from techniques such as electron tomography," the researchers report in a recent issue of Proceedings of the National Academy of Sciences.

The researchers would like to push the resolution of this technique to below 1 nanometer resolution.

"We don't know if sub nanometer pores exist in these materials and we want to be able to push our techniques to see whether these channels exist," said Gomez. "We also want to map how flow moves through these materials to directly connect how the microstructure affects water flow, by marking or staining the membrane with special compounds that can flow through the membrane and be visualized in the electron microscope."

ANN ARBOR, Mich. -- It's no secret that many teenagers stay up late to scroll through social media or catch up with friends on phones.

And 56 percent of parents of teens who have sleep troubles believe this use of electronics is hurting their child's shut-eye.

Forty-three percent of parents report that their teen struggles to fall asleep or wakes up and can't get back to sleep, according to the C.S. Mott Children's Hospital National Poll on Children's Health at the University of Michigan. A fourth of these parents say their child experiences occasional sleep problems (one to two nights per week) while 18 percent believe their teen struggles with sleep three or more nights per week.

Not being able to stay off electronics - including social media and cell phones - was the no.1 reason parents cited for sleep disturbance.

Other reasons included irregular sleep schedules due to homework or activities (43 percent), worries about school (31 percent), and concerns about social life (23 percent). Ten percent of parents say their teen's sleep problems are related to a health condition or medication, cited more often by parents of teens who experience frequent sleep problems.

The new report is based on responses from a nationally representative household survey that included responses from 1,018 parents with at least one child 13-18 years old.

"This poll suggests that sleep problems are common among teens and parents believe late-night use of electronics are a main contributor," says poll co-director Sarah Clark, M.P.H.

"Teens' hectic schedules and homework load, as well as anxiety about school performance and peer relationships, also are seen by parents as contributing to sleep problems."

Parents polled say they've encouraged their teen to try different strategies at home to help with sleep problems, including limiting caffeine in the evening (54 percent), turning off electronics and cell phones at bedtime (53 percent), having a snack before bed (44 percent), and natural or herbal remedies, such as melatonin (36 percent). A quarter of parents (28 percent) say their teen has tried some type of medication to address sleep problems.

Forty percent of parents of teens with frequent sleep problems, and 22 percent of parents of teens with occasional sleep problems, say they have talked to a doctor about sleep struggles. Parents who have consulted with doctors say the top recommendations from experts included turning off electronics and cell phones at bedtime (72 percent), adhering to a regular sleep schedule (64 percent), limiting caffeine (47 percent), and taking natural remedies (42 percent).

When doctors recommended medication for teens' sleep problems, it was twice as likely to be prescription sleep medication rather than over-the-counter sleep or "nighttime" medicine, parents recalled. Yet parents rated over-the-counter sleep medicine as safer for teens than prescription sleep medicine.

"Parents whose teens continue to have frequent sleep problems, despite following recommendations for healthy sleep hygiene, may want to talk with a health care provider, particularly when considering which type of medication to try," says Clark.

"Inadequate or disrupted sleep can have long-lasting health effects that go beyond moodiness and irritability for teens," Clark adds.

"Sleep-deprived teens may have difficulty concentrating in school and those who drive have an increased risk of auto accidents. Inadequate sleep has also been linked to health problems ranging from obesity to depression.

COLUMBUS, Ohio - Many women in doctoral degree programs in fields like engineering and physics are in a class of their own - and that's not a good thing.

A new study found that the fewer females who enter a doctoral program at the same time, the less likely any one of them will graduate within six years.

In the worst-case scenario - where there's just one woman in a new class - she is 12 percentage points less likely to graduate within six years than her male classmates, the study found.

However, for each additional 10 percent of women in a new class, that gender gap in on-time graduation rates closes by more than 2 percentage points.

The findings suggest that the "female-friendliness" of doctoral programs may play a key role in the gender gap in STEM (Science, Technology, Engineering and Mathematics) fields.

"It has been nearly impossible to quantify the climate for women in male-dominated STEM fields," said Valerie Bostwick, co-author of the study and a post-doctoral researcher in economics at The Ohio State University.

"But our data gave us a unique opportunity to try to measure what it is like for women in STEM. What we found suggests that if there are few or no other women in your incoming class, it can make it more difficult to complete your degree."

Bostwick conducted the research with Bruce Weinberg, professor of economics at Ohio State. Their results will be published Monday, Sept. 17 on the website of the National Bureau of Economic Research.

They used a new data set that previously had not been available to researchers. They linked transcript records from all public universities in Ohio to data from the UMETRICS project, which provides information on students supported by federal research grants.

A key advantage of this data is that it shows when and if students drop out - something that most data sets on graduate students don't show.

"Most datasets are based on students who graduate - they don't see you if you don't get your degree," Bostwick said. "That makes it impossible to find out why students drop out."

This study examined all 2,541 students who enrolled in 33 graduate programs at six Ohio public universities between 2005 and 2016.

Overall, the average incoming class of doctoral programs included about 17 students and was about 38 percent female. But there was wide variation in class sizes and the percentage of female students.

The researchers separated the programs into those that were typically male and typically female. Typically male programs (including chemical engineering, computer science and physics) were those that were less than 38.5 percent female.

In typically male programs, the average number of women who joined a class in any particular year was less than five.

The study shows the importance for women of having a support system of other women in their entering class, Weinberg said.

A woman joining a class that was more male than typical for her doctoral program was about 7 percent less likely to graduate within six years than were her male peers.

"But if there were more women than average in the program, that graduation gap goes away," Weinberg said.

Findings showed that when women dropped out of male-dominated programs, they usually did it in the first year. Women who joined a doctoral class with no other females were 10 percentage points more likely to drop out in that first year.

The researchers looked at two potential reasons why women may be dropping out: research funding and grades.

If female students were less likely to obtain research funding than their male peers, that could be an important reason why they're failing to finish. But the study found no real differences in funding for men and women.

Results did show that women had slightly lower grades than men when they were in male-dominated classes. Women who joined a class with no other females had first-term GPAs that were 0.11 grade points lower than their male peers.

"That's not enough to make a big difference," Bostwick said. "We estimate that grades could not explain more than a quarter of the difference between the number of women and men who graduate within six years."

Bostwick said that if grades or research funding are not the main reason for why women are not completing their STEM degrees, that suggests the reason must be something that can't be directly measured: the academic climate for women.

"We can only speculate about what it is in the climate that is making it more difficult for women," Bostwick said.

"It may be hard to feel like you belong when you don't see other women around you. There may be subtle discrimination. We don't know. But it highlights the fact that women need support, particularly if they are the only ones entering a doctoral class. They need to know about resources that could help them, particularly in that first key year."

Insect pollination played an important role in the evolution of angiosperms. Little is known, however, about ancient pollination insects and their niche diversity during the pre-angiosperm period due to the rarity of fossil evidence of plant-pollinator interactions.

Recently, a research group led by Prof. WANG Bo from the Nanjing Institute of Geology and Palaeontology of the Chinese Academy of Sciences (NIGPAS) has provided new insight into the niche diversity, chemical communication, and defense mechanisms of Mesozoic pollinating insects. Its findings were published in Nature Communications on September 17.

One of the most intensely investigated examples of pollination niches is the morphological match between insect proboscis and floral tube length, which Darwin described in a publication in 1877. Kalligrammatid lacewings are among the largest and most conspicuous Mesozoic insects with siphoning mouthparts.

The NIGPAS researchers reported 27 well-preserved kalligrammatids from late Cretaceous Burmese amber (99 Ma) and Chinese Early Cretaceous (125 Ma) and Middle Jurassic (165 Ma) compression rocks.

Kalligrammatid proboscides vary greatly in length, from 0.6 to 3.2 mm in amber inclusions and about 5 to 18 mm in compression fossils. The high diversity of kalligrammatids and large variation in proboscis length strongly suggest diverse plant hosts with different floral tube lengths. Therefore, pollination niche partitioning may have been present among some Mesozoic insects.

If pollination niches were partitioned, as in extant ecosystems, this likely increased pollination effectiveness and reduced the cost of pollination mutualism, thus contributing to the high diversity of pollinating insects and the success of pollinator-dependent plants during the Cretaceous period.

Kalligrammatid species diversification was potentially promoted by coevolution between pollinating kalligrammatids and their host plants under highly partitioned pollination niches.

Traits such as wing eyespots, which likely functioned as a defense in large-sized species, and sexually dimorphic antennae, which were likely used for pre-mating chemical communication, elucidate how kalligrammatids survived in the Mesozoic terrestrial ecosystem under intense competition.

However, such elaborate associations between kalligrammatids and their host plants (mostly confined to gymnosperms) could have been a key factor contributing to the extinction of kalligrammatids, which likely occurred during the late Cretaceous with the decline in gymnosperm diversity.

Scientists have developed a topological photonic chip to process quantum information, promising a more robust option for scalable quantum computers.

The research team, led by RMIT University's Dr Alberto Peruzzo, has for the first time demonstrated that quantum information can be encoded, processed and transferred at a distance with topological circuits on the chip. The research is published in Science Advances.

The breakthrough could lead to the development of new materials, new generation computers and deeper understandings of fundamental science.

In collaboration with scientists from the Politecnico di Milano and ETH Zurich, the researchers used topological photonics - a rapidly growing field that aims to study the physics of topological phases of matter in a novel optical context - to fabricate a chip with a 'beamsplitter' creating a high precision photonic quantum gate.

"We anticipate that the new chip design will open the way to studying quantum effects in topological materials and to a new area of topologically robust quantum processing in integrated photonics technology," says Peruzzo, Chief Investigator at the ARC Centre of Excellence for Quantum Computation and Communication Technology (CQC2T) and Director, Quantum Photonics Laboratory, RMIT.

"Topological photonics have the advantage of not requiring strong magnetic fields, and feature intrinsically high-coherence, room-temperature operation and easy manipulation" says Peruzzo.

"These are essential requirements for the scaling-up of quantum computers."

Replicating the well known Hong-Ou-Mandel (HOM) experiment - which takes two photons, the ultimate constituents of light, and interfere them according to the laws of quantum mechanics - the team was able to use the photonic chip to demonstrate, for the first time, that topological states can undergo high-fidelity quantum interference.

HOM interference lies at the heart of optical quantum computation which is very sensitive to errors. Topologically protected states could add robustness to quantum communication, decreasing noise and defects prevalent in quantum technology. This is particularly attractive for optical quantum information processing.

"Previous research had focussed on topological photonics using 'classical' -laser- light, which behaves as a classical wave. Here we use single photons, which behave according to quantum mechanics" says lead-author Jean-Luc Tambasco, PhD student at RMIT.

Demonstrating high-fidelity quantum interference is a precursor to transmitting accurate data using single photons for quantum communications - a vital component of a global quantum network.

"This work intersects the two thriving fields of quantum technology and topological insulators and can lead to the development of new materials, new generation computers and fundamental science" says Peruzzo.

The research is part of the Photonic Quantum Processor Program at CQC2T. The Centre of Excellence is developing parallel approaches using optical and silicon processors in the race to develop the first quantum computation system.

CQC2T's Australian researchers have established global leadership in quantum information. Having developed unique technologies for manipulating matter and light at the level of individual atoms and photons, the team have demonstrated the highest fidelity, longest coherence time qubits in the solid state; the longest-lived quantum memory in the solid state; and the ability to run small-scale algorithms on photonic qubits.

COLLEGE PARK, Md. - Ever-expanding viewing options make it increasingly harder for a movie or television series to stand out in a saturated market. With trailers alone not drawing enough attention, marketers increasingly depend on shorter video snippets -- video clips -- to promote content across a variety of digital channels, including ones without sound.

But that hyper-short video format presents a challenge -- tackled by researchers from the University of Maryland, Netflix, Harvard Business School and Santa Clara University. They have developed a method to effectively compress the plot of a feature-length film in just a few, sometimes, silent seconds. It's described via Video Content Marketing: The Making of Clips, published in the July 2018 issue of the Journal of Marketing.

"It's not enough to simply lift the first few scenes of the trailer," says co-author and marketing professor Michel Wedel, at Maryland's Robert H. Smith School of Business. But that's what many content creators have been doing.

Wedel and his co-authors -- Xuan Liu (Netflix), Savannah Wei Shi (Santa Clara University) and Thales Teixeira (Harvard) -- conducted extensive field experiments, using a web-based facial-expression tracking system to study the emotional responses of volunteers in real time while they watched comedy movie trailers. The researchers used the data to predict how likely those viewers -- and countless others -- were to see the film.

The findings not only helped researchers detail what key elements are contained within the most effective trailers, they also helped the authors calibrate a highly effective model for slicing trailers into short but compelling video clips, of just 10, 20 or 30 seconds. The method, they say, improves upon the current hands-on approach to making clips, and can be automated.

It is the first known research to develop a model for editing trailers to produce short promotional clips, Wedel says.

The research focuses on trailers for comedy films as an illustration. Comedy has been Hollywood's leading genre in the past two decades, with a market share of more than 20 percent and an average gross revenue of about $20 million per film.

While not all moments in the trailer or clip are expected to have a huge impact, the start, peak, end and trajectory of audio and emotions matters. The researchers say their integrated model can be used to produce optimal short movie clips for use in emails, messages, social media, and in the apps, landing pages and user interfaces of content providers.

By studying the timing and intensity of the emotion, the researchers say, marketers can create clips that have the potential to be even more effective than the original trailers, with some clips aimed at platforms that support sound (such as those on IMDB.com) and other aimed for those that don't (such as Facebook).

The research finds that audiences generally don't like comedy trailers to contain too many scenes or to be too fast-paced. The same held true in shorter clips, the researchers found. A clip with a larger number of scenes resulted in a lower level of happiness, and consequently, a lower number of people who expressed a desire to see the film.

The sequence of scenes also had an impact. When the key scene (typically the longest scene) is placed toward the end of the comedic trailer or clip, happiness levels and watching intention both increased.

Happy, happier, happiest is the best order for scenes in a comedy movie clip, the researchers say, finding that a positive trend in happiness results in higher watching intentions and larger success at the box office.

Movies are very big business, and movie marketing is a big part of it. Global cinema ad spending was roughly $2.7 billion in 2015 and is expected to top $3.3 billion in 2020. Roughly half of a major Hollywood studio movie budget is spent on production, and the other half on marketing.

Film trailers are inherently different from other types of commercials. They are more like a sample of the product than a testimonial to its better qualities. Audiences go to a movie for the emotions they expect to experience there -- fear during a horror film, sadness during a drama, happiness during a comedy. And that's what a trailer delivers, a sample of the emotional content of a movie.

In the study, volunteers were asked to view a webpage that contained comedy movie trailers, in a familiar environment, at home or at work, for example. Facial expressions were recorded remotely, and at the end of the experiment, they were asked which movies they would watch. In all, 100 trailers for 50 movies were used in the study, with the content of each trailer analyzed for scene cuts.

The researchers measured the "intensities of happiness" of each participant on a second-by-second basis via analysis of the participants' facial expressions, gauging the emotions intensity at the start, (or first scene), the trend (calculated fit to each emotion curve), the peak (average happiness of the scene with the highest average emotion level), and the end (the total emotional intensity at the final scene.) They also noted the "PeakIndex," the exact location of the peak emotion scene in the trailer.

Together, the data enabled researchers to edit down a longer trailer into a seconds-long clip that they say could be almost as persuasive, and sometimes more, for the average viewer.

Super Typhoon Mangkhut is a powerful tropical cyclone headed toward the northern Philippines. It is a Category 5 storm on the Saffir-Simpson hurricane wind scale. NASA-NOAA's Suomi NPP satellite provided a visible image as it passed over the Northwestern Pacific Ocean and stared the storm in its eye.

Many warnings are posted in the Philippines. They include: Public storm warning signal #3 for the Luzon provinces of Batanes, southern Isabela, Ilocos Sur, La Union, Mountain Province, Benguet, Ifugao, Nueva Vizcaya, Quirino, Northern Aurora. Public storm warning signal #2 is in effect for the Luzon provinces of Pangasinan, Tarlac, Nueva Ecija, southern Aurora, Zambales, Pampanga, Bulacan, Northern Quezon incl. Polillo Island. Public storm warning signal #1 is in effect for the Luzon provinces of Bataan, Rizal, Metro Manila, Cavite, Batangas, Laguna, Rest of Quezon, Lubang Is.,Marinduque, Camarines Norte, Camarines Sur, Catanduanes, Albay, Burias Island.

In the Philippines, Mangkhut is known locally as Ompong.

At 12:54 a.m. EDT (0454 UTC) on Sept. 14, the VIIRS instrument aboard NASA's Aqua satellite captured a visible image of Mangkhut. The image showed a symmetrical storm with a clear eye surrounded by powerful thunderstorms. At the time of the image, the western quadrant of the storm was already spreading over the eastern Philippines.

The Joint Typhoon Warning Center noted on Sept. 14 at 11 a.m. EDT (1500 UTC) Barijat's maximum sustained winds were near 167 mph (145 knots/268 kph). It was located near 17.4 degrees north latitude and 124.4 east longitude. That's approximately 245 nautical miles northeast of Manila, Philippines. Mangkhut is moving to the west-northwest.

Mangkhut is moving northwest and is forecast to pass over the north of Luzon as a category 5 equivalent typhoon. After re-emerging over water, the system is forecast to re-strengthen slightly to pass close the south coast of China towards a landfall in northern Vietnam.

Pollinating insects are endangered globally, with a particularly steep decline over the last 40 years. An extensive 3-year study from Lund University in Sweden has found that organic farming methods can contribute to halting the pollinator decline. This beneficial effect is due to both the absence of insecticides and a higher provision of flower resources.

Organic farming is known to promote pollinator diversity in crop fields. However, it has also been suggested that organic fields might simply attract pollinators from other habitats in the landscape, and therefore not sustain their populations in the long run.

The 3-year field experiment, conducted by researchers from the Centre for Environmental and Climate Research at Lund University, found that the number of bumblebee species in organic farms was higher and more stable over time and space than in conventional farms.

"This is the first large-scale study over the course of several years to show that organic farming has a consistent, stabilizing effect on pollinator diversity ", says Romain Carrié, a postdoctoral researcher at CEC.

Romain and his colleagues sampled bumblebees, butterflies and flowering plants throughout the growing season in 10 organic and 9 conventional farms in Scania, Sweden. Their study showed that, depending on the type of crop, the stabilizing effect was either due to a more stable provision of flowers or the absence of pesticides.

"An interesting result of our study is the fact that stable and abundant flower resources stabilizes pollinator communities, even in conventional farms where insecticides are used", explains Romain Carrié.

"This is strongly suggesting that both flower-enhancing management options and a reduced use of insecticides can help reverse pollinator declines", Romain Carrié concludes.