Brain

Atmospheric ozone (O3) has become one of the major air pollutants. Catalytic decomposition is one efficient and economical technology in O3 removal, where metal oxides can serve as cost-effective catalysts substituting for noble metals.

A research team led by Prof. CHEN Yunfa from the Institute of Process Engineering (IPE) of the Chinese Academy of Sciences demonstrated the electron generation, compensation and transfer between ZnO and O3 through tuning crystal defects in ZnO.

The study was published in Applied Catalysis B: Environmental on June 6. The findings may help design and synthesize highly efficient metal oxide catalytic materials for air cleaning.

"The efficiency of metal oxides should be improved to the noble metal level, and thus the electron transfer mechanism between metal oxides and O3 should be investigated," said Prof. CHEN.

The researchers demonstrated that crystal defects such as oxygen vacancy, Zn vacancy, and Ga and Li dopants played a vital role in electron transfer.

They found that in ZnO lattice, oxygen vacancy and Ga substitution for Zn could generate electrons, which were then consumed by O3 to decompose into O2 and surface adsorbed O22-.

Then Zn vacancy and Li substitution for Zn could serve as electron trapper to grasp electrons from O22-, completing the electron cycle and recovering the catalyst. Otherwise, the O22- would fill into the oxygen vacancy in ZnO quickly and deactivated the ZnO catalyst.

In their previous studies, CHEN's group explored the electron transfer between crystal defects in metal oxide catalysts and O3, and synthesized kinds of highly efficient O3 decomposition catalysts (e.g. Applied Catalysis B: Environmental, 2019, 241: 578-587; ACS Applied Nano Materials, 2020, 3: 597).

"This work is expected to benefit the design and synthesis process of more active O3 removal material for air cleaning," said Prof. HAN Ning from IPE.

You're standing in the store's check-out line, and the customer behind you viciously coughs.

Is that person sick or simply have a throat tickle? Chances are you're misidentifying the origins of those sounds, according to a newly published University of Michigan study in the Proceedings of the Royal Society B: Biological Sciences.

The more disgusting people perceive a sound to be, the more likely they were to judge that it came from an infected person, regardless of whether it did.

"We find no evidence that perceivers can reliably detect pathogen threats from cough and sneeze sounds, even though they are reasonably certain they can," said Nicholas Michalak, the study's lead author and a U-M psychology graduate student.

Unlike other research indicating perceivers can accurately diagnose infection using other senses, such as sight and smell, researchers at U-M and University of California-Irvine found that people over perceive pathogen threats in subjectively disgusting sounds.

Participants in four studies judged whether cough and sneeze sounds were produced by people infected with a communicable disease or not. Researchers found no evidence that these participants could accurately identify the origins through auditory cues. On average, they guessed approximately four out of 10 sounds correctly from either an infected or noninfected person.

"Moreover, there was no evidence that accuracy improved when participants knew the true number of infectious sounds in advance or when participants focused on how clear or disgusting they perceived the sounds," Michalak said. "Despite this poor overall accuracy, perceivers consistently reported reasonable certainty in their judgments."

Perceivers believe that what disgusts them is likely to represent a disease threat. This, Mickalak said, could potentially lead them to exhibit biases to avoid interactions with others who make disgusting but noninfectious noises.

The bottom line, according to researchers, is the next time you hear someone cough or sneeze, perhaps leave the diagnosis to the doctor.

A research team at Uppsala University has resurrected several billion-year-old enzymes and reprogrammed them to catalyse completely different chemical reactions than their modern versions can manage. The method can be used to develop sustainable solutions within biotechnology, such as for enzyme bioreactors or to chemically degrade environmental toxins. The study has been published in Chemical Science.

"We use software to simulate billions of years of evolution, and we were actually able to develop an effective enzyme that can catalyse a completely new reaction. It's incredibly exciting," says Lynn Kamerlin, who is leading the research team at Uppsala University.

Enzymes have the ability to catalyse, i.e. speed up, challenging chemical reactions from millions of years to a fraction of a second without being consumed themselves. They are also biodegradable and have a minimal carbon footprint. Most enzymes are catalysts for a specific chemical reaction, which serves an important function in biological processes, for example in our bodies.

Within biotechnology, intensive work is being done to develop new enzymes that can catalyse unusual reactions for green chemistry, sustainable catalysis and the chemical breakdown of environmentally toxic substances.

The research team at Uppsala University has worked with colleagues at Universidad de Granada in Spain to resurrect ancestral enzymes, first on a computer, and then in the laboratory. The primitive enzymes have many characteristics that are desirable within biotechnology. They can withstand extreme temperatures and they are structurally more flexible, making them easier to modify than their modern equivalents.

The researchers succeeded in repurposing ancient antibiotic-degrading enzymes to catalyse a completely new non-natural reaction. But even though the repurposed enzymes sped up the reaction significantly, it was much slower than most naturally occurring enzymes.

Therefore, to improve the efficiency of the enzyme, the researchers used powerful computers to calculate what changes in the structure would result in a faster reaction. They used a new method called FuncLib, which uses a combination of evolutionary information and calculations of protein stability, to predict more effective enzyme variants.

A total of 3,000 potential new enzyme variants were predicted by FuncLib and the 20 most promising of these were tested in the lab. Of these, four were much faster than the original enzyme. The best was as effective as the average modern, naturally occurring enzymes.

"Our study shows that it is possible to design new, effective enzymes for a more sustainable future," says Lynn Kamerlin.

Wits University (University of the Witwatersrand, Johannesburg, South Africa) PhD student, Willem Kruger's study on the state of magma within plutonic magmatic systems in the Earth's crust has been published in the high impact journal, Nature Communications.

Working alongside his PhD supervisor, Professor Rais Latypov, from the Wits School of Geosciences, Kruger's paper shows that basaltic magma chambers may develop as large bodies of crystal-free melts in the Earth's crust. This study challenges a recently-emerged paradigm that magma chambers are huge masses of crystal-rich mush - in other words, crystals with just a very small amount of melt.

Attempts to understand the processes that operate in magma chambers in our planet's crust is incredibly challenging as they are hidden from direct observations. Geologists must follow an indirect approach to study these features, such as examining their ancient fossilised remains that are exposed on Earth's surface after millions of years of erosion.

To examine the state of magma within a chamber is very demanding, as it requires the study of the very contact between the crystallising margins of magma bodies (also called solidification fronts) and their liquid interiors.

Difficulties in understanding the behaviour of solidification fronts can fortunately be overcome by studying a particularly fascinating rock type, called massive magnetitite, from the Bushveld Complex in South Africa.

"Magnetitite contains chromium that is an extremely sensitive indicator of magma chamber processes and can be used to study solidification fronts in extreme detail," says Kruger.

"By mapping the distribution of chromium in magnetitite in the field we can observe the two-dimensional propagation patterns of solidification fronts on a scale never done before."

Kruger and Latypov found that all evolved liquid is effectively removed from the solidification front of magnetitite as it propagates towards the chamber interior. "This is because of extremely effective compositional convection that occurs during the crystallisation of magnetite. The process results in the solidification front to propagate as almost a completely solid surface." says Latypov.

This research shows that such powerful compositional convection may inhibit the formation of crystal-rich mushes in basaltic magma chambers.

There are many reasons to believe that this process is not unique to magnetitite layers of the Bushveld Complex but will likely operate in other rock types as well, for instance, in the Bushveld's economically important chromitite layers.

"Our results thus argue for the existence of large, liquid-dominated magma chambers hidden within the Earth's crust," says Kruger.

Researchers at Linköping University, Sweden, are attempting to convert carbon dioxide, a greenhouse gas, to fuel using energy from sunlight. Recent results have shown that it is possible to use their technique to selectively produce methane, carbon monoxide or formic acid from carbon dioxide and water. The study has been published in ACS Nano.

Plants convert carbon dioxide and water to oxygen and high-energy sugars, which they use as "fuel" to grow. They obtain their energy from sunlight. Jianwu Sun and his colleagues at Linköping University are attempting to imitate this reaction, known as photosynthesis, used by plants to capture carbon dioxide from air and convert it to chemical fuels, such as methane, ethanol and methanol. The method is currently at a research stage, and the long-term objective of the scientists is to convert solar energy to fuel efficiently.

"By converting carbon dioxide to fuel with the aid of solar energy, this technique could contribute to the development of sources of renewable energy and reduce the impact on the climate of the combustion of fossil fuels", says Jianwu Sun, senior lecturer in the Department of Physics, Chemistry and Biology at Linköping University.

Graphene is one of the thinnest materials that exist, consisting of a single layer of carbon atoms. It is elastic, flexible, transparent to sunlight, and a good conductor of electricity. This combination of properties ensures that graphene has potential for use in applications such as electronics and biomedicine. But graphene alone is not suitable for the solar energy conversion application sought by the LiU researchers, and they have therefore combined the graphene with a semiconductor, cubic silicon carbide (3C-SiC). Scientists at Linköping University have previously developed a world-leading method to grow graphene on cubic silicon carbide, which consists of carbon and silicon. When the silicon carbide is heated, the silicon is vaporised, while the carbon atoms remain and re-construct in the form of a graphene layer. The researchers have previously shown that it is possible to place up to four layers of graphene on top of each other in a controlled manner.

They have combined the graphene and cubic silicon carbide to develop a graphene-based photoelectrode that preserves the ability of cubic silicon carbide to capture the energy of sunlight and create charge carriers. The graphene functions as a conducting transparent layer while protecting the silicon carbide.

The performance of the graphene-based technique is controlled by several factors, an important one of which is the quality of the interface between the graphene and the semiconductor. The scientists have looked at the properties of this interface in detail. They show in the article that they can tailor the layers of graphene on the silicon carbide and control the properties of the graphene-based photoelectrode. The conversion of carbon dioxide is in this way made more efficient, while the stabilities of the components are at the same time improved.

The photoelectrode developed by the researchers can be combined with cathodes of various metals, such as copper, zinc or bismuth. Different chemical compounds, such as methane, carbon monoxide and formic acid, can be selectively formed from carbon dioxide and water by selecting suitable metal cathodes.

"Most importantly, we have demonstrated that we can use solar energy to control the conversion of carbon dioxide to methane, carbon monoxide or formic acid", says Jianwu Sun.

Methane is used as a fuel in vehicles adapted to use gaseous fuels. Carbon monoxide and formic acid can either be further processed such that they can function as fuels, or they can be used in industry."

PITTSBURGH (June 9, 2020) -- Computational catalysis, a field that simulates and accelerates the discovery of catalysts for chemicals production, has largely been limited to simulations of idealized catalyst structures that do not necessarily represent structures under realistic reaction conditions.

New research from the University of Pittsburgh's Swanson School of Engineering, in collaboration with the Laboratory of Catalysis and Catalytic Processes (Department of Energy) at Politecnico di Milano in Milan, Italy, advances the field of computational catalysis by paving the way for the simulation of realistic catalysts under reaction conditions. The work, published in ACS Catalysis, was authored by Raffaele Cheula, Ph.D. student in the Maestri group; Matteo Maestri, full professor of chemical engineering at Politecnico di Milano; and Giannis "Yanni" Mpourmpakis, Bicentennial Alumni Faculty Fellow and associate professor of chemical engineering at Pitt.

"With our work, one can see, for example, how metal nanoparticles that are commonly used as catalysts can change morphology in a reactive environment and affect catalytic behavior. As a result, we can now simulate nanoparticle ensembles, which can advance any field of nanoparticles application, like nanomedicine, energy, the environment and more," says Mpourmpakis. "Although our application is focused on catalysis, it has the potential to advance nanoscale simulations as a whole."

In order to model catalysis in reaction conditions, the researchers had to account for the dynamic character of the catalyst, which is likely to change throughout the reaction. To accomplish this, the researchers simulated how the catalysts change structure, how probable this change is, and how that probability affects the reactions taking place on the surface of the catalysts.

"Catalysis is behind most of the important processes in our daily lives: from the production of chemicals and fuels to the abatement of pollutants," says Maestri. "Our work paves the way towards the fundamental analysis of the structure-activity relation in catalysis. This is paramount in any effort in the quest of engineering chemical transformation at the molecular level by achieving a detailed mechanistic understanding of the catalyst functionality. Thanks to Raffaele's stay at Pitt, we were able to combine the expertise in microkinetic and multiscale modeling of my group with the expertise in nanomaterials simulations and computational catalysis of Yanni's group."

Lead author Raffaele Cheula, a PhD student in the Maestri Lab, worked for a year in the Mpourmpakis Lab at Pitt on this research.

"It has been very nice to be involved in this collaboration between Yanni and Matteo" says Cheula. "The combination of my research experiences at Pitt and at PoliMi has been very important for the finalization of this work. It was a challenging topic and I am very happy with this result".

Princeton University researchers may have solved a long-standing mystery in conservation that could influence how natural lands are designated for the preservation of endangered species.

Around the world, the migratory shorebirds that are a conspicuous feature of coastal habitats are losing access to the tidal flats -- the areas between dry land and the sea -- they rely on for food as they travel and prepare to breed. But a major puzzle has been that species' populations are plummeting several times faster than the rate at which coastal ecosystems are lost to development.

Nowhere is the loss of tidal flats and shorebird species more acute than along the East Asia-Australasian Flyway (EAAF). An estimated 5 million migratory birds from 55 species use the flyway to travel from southern Australia to northern Siberia along the rapidly developing coast of China -- where tidal flats can be more than 6 miles wide -- at which birds stop to rest and refuel.

Since the 1980s, the loss of tidal flats around the Yellow Sea has averaged 1.2% per year. Yet, the annual loss of the most endangered bird species has averaged between 5.1 and 7.5%, with populations of species such as the critically endangered spoon-billed sandpipers (Calidris pygmaea) climbing as high as 26% each year.

In exploring this disparity, Princeton researchers Tong Mu and David Wilcove found a possible answer -- the birds don't use all parts of the tidal flat equally. They discovered that migratory shorebirds overwhelmingly rely on the upper tidal flats closest to dry land, which are the exact locations most often lost to development.

They report in the journal Proceedings of the Royal Society B that China's upper tidal flats provided more than 70% of the cumulative foraging time for the species they studied at two Yellow Sea sites along the EAAF. The middle and lower flats that birds are increasingly pushed toward by human activity were less frequently foraged upon due to the tide cycle, which may be impacting species health and breeding success.

The findings stress the need for integrating upper tidal flats into conservation plans focused on migratory shorebirds, the authors reported.

"This is a new insight into Asian shorebirds, but I suspect that the upper intertidal is disproportionately important to shorebirds in other places, too, such as the East and West coasts of North America," said Wilcove, who is a professor of ecology and evolutionary biology and public affairs and the Princeton Environmental Institute (PEI).

"People start at the upper zone and work their way outward, so the best spots for the birds are the first to go," he said. "It would probably be best to extend current developments farther into the intertidal zone rather than keep building parallel to the coast, which consumes more of the upper intertidal.

"Think of it as advocating for a rectangle with the long side pointing into the sea versus a rectangle with the long side hugging the shore," Wilcove said.

The study results also suggest that protecting species and their habitats may mean more than designating land for wildlife -- it may require identifying the right land to set aside by gaining a detailed understanding of exactly how animals interact with the landscape.

"Recognizing the importance of a kind of habitat to specific species or groups of species takes time, effort and thought," said Mu, who is the paper's first author and a Ph.D. candidate in ecology and evolutionary biology.

"Sometimes we just don't know what to look for, or looking requires challenging some prevalent and maybe false perceptions," he said. "But the situation is getting better and better. People are paying more attention to environmental issues, and the advances in technology are helping us gain more and newer insight into these questions."

Mu conducted fieldwork between September 2016 and May 2017 at two well-known stopover sites -- one outside of Beijing, the other near Shanghai -- for migratory shorebirds in the Yellow Sea region. He focused on 17 species of birds, noting where along the tidal flat the animals preferred to feed.

A key difference to his approach, Mu said, is that most previous research focused on the low-tide period when all the tidal flats are exposed and the full range of intertidal species can be observed.

"It makes sense from an ecological point of view. During the high tides when only a portion of the tidal flats is accessible, the relationship usually still holds for the exposed area," Mu said. "So, there's little incentive to look at the periods other than low tide when researchers can get a more complete picture."

What Mu thinks was missed, however, was that the upper tidal flats provide the most amount of foraging time for birds that have places to be. Even if the lower half of a 6-mile wide mudflat is set aside for migratory birds, they're not getting the energy they need for the trip ahead during the high tide, he said.

"The value of the tidal flats comes from not only their size, but also how much foraging time they can provide," Mu said. "The upper tidal area is exposed for a longer period during tidal cycles, compared to the middle and lower areas, which I think permits shorebirds to forage for a longer time and thus get more energy."

The preservation of shorebirds should be driven by how integral the animals are to the health of intertidal zones, Mu and Wilcove said. In turn, tidal flats are not only vital to other marine life, but also provide people with seafood such as clams and crabs and protection from storms and storm surges that cause coastal flooding.

"Shorebirds facilitate the energy and nutrient exchanges between land and sea," Mu said. "Because a lot of them are long-distance migrants, they also facilitate the energy and nutrient exchanges across different ecosystems and continents, something that is usually overlooked and underappreciated."

Wilcove and Mu cited recent research showing that more than 15%, or more than 12,000 square miles, of the world's natural tidal flats were lost between 1984-2016.

"Some of the greatest travelers on Earth are the shorebirds that migrate from Siberia to Southeast Asia and Australia," Wilcove said. "Now, they're declining in response to the loss of the tidal areas, and the full range of benefits those tidal flats provide are in some way being diminished."

Mexican immigrants, especially those who are undocumented and fear deportation, have limited access to healthy foods and are at increased risk for obesity because of stress, anxiety and depression, according to a Rutgers study.

The study, published in the journal Progress in Community Health Partnerships, evaluated the barriers to healthy eating faced by Mexican immigrants in New Brunswick, N.J., where about 50 percent of residents are Mexican immigrants and nearly one-third of children in immigrant families are obese.

The research found that Mexican immigrants are at increased risk for obesity after arriving in the United States because in the city neighborhoods where they settle, they are forced to rely on cheap, readily available, high-sugar foods. Fear of deportation discourages these adults from leaving their homes or contacting agencies that can help them get quality food, said study lead author Karen D'Alonzo, director of the Center for Community Health Partnerships at Rutgers School of Nursing.

Researchers partnered with promotoras, or Hispanic community members trained in basic health education, to lead discussion groups with 70 Mexican adults and teens to identify the most important factors contributing to their weight gain. The promotoras, which are common in Latin American culture, helped the researchers gain the participants' trust and better understand the cultural context of their responses.

They found that stress, anxiety and depression resulting from fear of immigration raids affected eating habits and limited physical exercise.

"Many Mexican-born parents reported feeling guilty about their U.S.-born children's deportation concerns and cope by allowing them to eat whatever they want," D'Alonzo said. "In addition, few children joined sports teams, especially if significant parental involvement was required. Parents were either working or staying home to keep out of sight."

The study also found that parents often send their children to shop for food and expected teenagers to prepare the meals even though parents were too busy working to teach them how to cook. Participants said lack of time also contributed to their food choices.

"Fast food and neighborhood bodegas are more affordable and accessible than healthier alternatives in grocery stores that could be miles away," said D'Alonzo. "Complicating matters, many of these parents work multiple jobs without meal breaks, then eat cheap, available food later at night. If they share an apartment, they may not have kitchen access when they need it."

High school students reported that ordering fast food for lunch was preferred because it identified them as "American."

"While much attention has been drawn to the public health threats posed by new immigrants, this study shows that we are only beginning to understand the dangers of anti-immigrant sentiment and policies on the physical and mental health of immigrant families themselves," D'Alonzo said.

D'Alonzo said individuals in immigrant communities can regain control over aspects of their lives and stay healthy in the midst of long-term stress by maintaining a regular schedule that includes meals, exercise and time with family; avoiding contact with people who cause stress; identifying places to shop that offer an assortment of fresh fruits and vegetables, dairy products and meats or fish at reasonable prices; avoiding stress eating; and identifying community organizations that can help them in dealing with immigration-related stressors and promote healthy living.

A research team from Ruhr-Universität Bochum (RUB) and Carleton University in Ottawa has manufactured a novel, highly versatile cobalt compound. The molecules of the compound are stable, extremely compact and have a low molecular weight so that they can be evaporated for the production of thin films. Accordingly, they are of interest for applications such as battery or accumulator production. Because of their special geometry, the compound also has a very unusual spin configuration of ½. A cobalt compound like that was last described in 1972. The team published their report in the journal Angewandte Chemie International Edition from 5 May 2020.

The geometry makes the difference

"The few known cobalt(IV) compounds exhibit high thermal instability and are very sensitive towards air and moisture exposure. This impedes their implementation as model systems for broad reactivity studies or as precursors in material synthesis," explains lead author David Zanders from the Inorganic Materials Chemistry research group in Bochum, headed by Professor Anjana Devi. In his ongoing binational PhD project, which has been agreed upon by Ruhr University and Carleton University by a Cotutelle agreement, David Zanders and his Canadian colleagues Professor Seán Barry and Goran Bači? discovered a cobalt(IV) compound that does not only possess the aforementioned properties but also exhibits an unusually high stability.

Based on theoretical studies, the researchers demonstrated that a nearly orthogonal embedding of the central cobalt atom in a tetrahedrally arranged environment of connected atoms - so-called ligands - is the key to stabilising the compound. This specific geometric arrangement within the molecules of the new compound also enforces the unusual electron spin of the central cobalt atom. "Under these extraordinary circumstances, the spin can only be ½," points out David Zanders. A cobalt compound with this spin state and similar geometry has not been described for almost 50 years.

Following a series of experiments, the team also showed that the compound has a high volatility and can be evaporated at temperatures of up to 200 degrees Celsius with virtually no decomposition, which is unusual for cobalt(IV).

Promising candidate for ultra-thin layers

Individual molecules of the compound dock onto surfaces in a controllable manner after evaporation. "Thus, the most fundamental requirement of a potential precursor for atomic layer deposition has been fulfilled," asserts Seán Barry. "This technique has increasingly gained in importance in industrial material and device manufacturing, and our cobalt(IV) compound is the first of its kind that is fit for this purpose." "Our discovery is even more exciting as the high-valent oxides and sulfides of cobalt are considered to have great potential for modern battery systems or microelectronics," adds Anjana Devi. Following frequent charging and discharging, electrodes in rechargeable batteries become more and more unstable, which is why researchers are looking for more stable and, consequently, more durable materials for them. At the same time, they also focus on using new manufacturing techniques.

"This binational collaboration, which was initiated by David Zanders, has pooled the creativity and complementary expertise of chemical engineers from Bochum and Ottawa. All this has produced unexpected results and was certainly the key to success," concludes Anjana Devi.

When it comes to education and mentorship, Northwestern University researchers believe that Albert Einstein had the right idea. The most important aspect of teaching, Einstein thought, isn't relaying facts but imparting tacit knowledge that students will build on for the rest of their lives.

In one of the largest ever multidisciplinary investigations into mentorship and mentee performance, the Kellogg School of Management researchers found that the most impactful mentors are those who teach students to think independently and communicate their unique viewpoints effectively.

"Communicating codified knowledge is relatively straightforward," said corresponding author Brian Uzzi. "It's written down in books and presentations. But it's the unwritten knowledge we intuitively convey through our interactions and demonstrations with students that makes a real difference for mentees."

The researchers note that remote learning, which is becoming more common during the COVID-19 pandemic, may not be as effective a means of transferring such tacit knowledge, which could have long-term effects.

"Face-to-face interaction is essential. When we teach by doing, we are conveying tacit knowledge we don't even realize we have," said Uzzi, the Richard L. Thomas Professor of Leadership at Northwestern's Kellogg School of Management and co-director of the Northwestern Institute on Complex Systems. "If we limit the face-to-face channel by which tacit knowledge is communicated, we potentially slow down the pace of learning and scientific breakthroughs, and that will affect us all."

When mentors excel in transferring tacit knowledge, their protégés achieve two to four times greater success than similarly talented students of mentors who convey regimented knowledge but not tacit know-how, the researchers found. Protégé success was determined by whether they won a scientific prize of their own during their career, were elected to the National Academy of Sciences or were in the top 25% of citations for their field.

The most successful protégés also were more likely to pioneer their own research topics, rather than follow in their mentors' research path. This finding contradicts the popular belief that the most successful protégés will be those who carry on their mentors' already successful work.

The study, "Mentorship and protégé success in science," publishes the week of June 8 in PNAS. The study is among the first to look at objective protégé performance over the course of a career, drawing from genealogical datasets that track the relationships between mentors and students.

Previous research into the topic of mentorship has been done largely through self-reporting, often many years after the students graduate. That makes it subject to memory errors and personal biases, researchers say.

The researchers studied genealogical data on 40,000 scientists who published 1.2 million papers in biomedicine, chemistry, math or physics between 1960 and 2017. They also used the ProQuest Dissertations and Theses databank, an official record of advisor/student relationships taken from Ph.D. theses, and supplemented it with additional crowdsourced data from AcademicTree.org and the Mathematics Genealogy Project to ensure they correctly matched mentor/mentee relationships.

To account for the fact that more successful mentors naturally attract more talented students, the researchers grouped mentors with similar records and reputation based on factors including institutional resources, productivity, number of students, citations and other measures of a mentor's skills, and they compared the performance of students within the same mentor peer group. However, one mentor in each peer group had a hidden talent for identifying key problems and producing compelling solutions that the other mentors did not have. These mentors were future scientific prizewinners.

To assess protégé success, the researchers considered only those students who studied under a mentor before that mentor won their scientific prize to control for selection bias and the halo effect a prizewinning mentor casts over their students.

After controlling for differences in mentorship skills and mentee talent, the researchers found that the most successful protégés studied under mentors who demonstrated a unique skill in ideating and publishing celebrated research and who displayed independent thought by breaking away from their mentors' lines of research.

LEXINGTON, Ky. (June 8, 2020) - A study led by University of Kentucky Markey Cancer Center researchers showed that patients who already used opioids, sedatives or antidepressants prior to colorectal surgery experience significantly more complications post-surgery.

Published in Diseases of the Colon & Rectum, the study examined 1,201 patients 18 years of age and older who underwent colorectal resection for any indication other than trauma at UK HealthCare. Of these patients, roughly 30% used opioids, 28% used antidepressants and 18% used sedatives, all legally prescribed by a doctor pre-operatively.

Patients on any of these medications showed an increase in several common complications post-surgery, including infections, prolonged intubation, longer length of stay, readmissions, respiratory failure and even mortality. These problems were particularly pronounced in patients who regularly used opioids prior to surgery.

The preoperative use of opioids, sedatives and antidepressants is on the rise in the U.S. Though the current opioid crisis has raised awareness for limiting opioid use, many patients still receive opioids for pain management, and finding the right balance of medication is an ongoing issue for many patients and doctors. Patients with anxiety disorders or other mental health issues often receive sedatives or antidepressants.

However, risk prediction models for postoperative complications do not take these common medications into consideration, says Dr. Avinash Bhakta colorectal surgeon at the UK Markey Cancer Center and lead author on the study. To reduce complications post-surgery, he says more needs to be done to help patients reduce their need for these drugs in managing pain and anxiety prior to any major surgery.

"Most colorectal resections are elective in nature, so we want to focus on the use of opioids and sedatives and counsel patients on the need to decrease the use of these drugs before surgery," Bhakta said. "These drugs are necessary for many patients, but if we can decrease how much they're using, we can help decrease long-term complications. Not only do we want to improve their surgical outcomes, we want to improve their overall health."

WASHINGTON -- Education appears to protect older adults, especially women, against memory loss, according to a study by investigators at Georgetown University Medical Center, published in the journal Aging, Neuropsychology, and Cognition.

The results suggest that children--especially girls--who attend school for longer will have better memory abilities in old age. This may have implications for memory loss in Alzheimer's disease and other dementias.

The study tested declarative memory in 704 older adults (58-98 years of age). Declarative memory refers to our ability to remember events, facts, and words, such as where you put your keys or the name of that new neighbor.

Participants were shown drawings of objects, and then were tested several minutes later on their memory of these objects. The investigators found that their memory performance became progressively worse with aging. However, more years of early-life education countered these losses, especially in women.

In men, the memory gains associated with each year of education were two times larger than the losses experienced during each year of aging. However, in women, the gains were five times larger.

For example, the declarative memory abilities of an 80-year-old woman with a bachelor's degree would be as good as those of a 60-year-old woman with a high school education. So, four extra years of education make up for the memory losses from 20 years of aging.

"Simply said, learning begets learning" says the study's senior investigator, Michael Ullman, PhD, a professor in Georgetown's Department of Neuroscience and Director of the Brain and Language Lab. Ullman's research on the relationship between language, memory and the brain has been a cornerstone in the fields of language and cognitive neuroscience.

"Since learning new information in declarative memory is easier if it is related to knowledge we already have, more knowledge from more education should result in better memory abilities, even years later," adds the study's lead author, Jana Reifegerste, PhD, a member of the scientific staff at the University of Potsdam, Germany, who worked on this study as a postdoctoral researcher in Ullman's lab.

"Evidence suggests that girls often have better declarative memory than boys, so education may lead to greater knowledge gains in girls," says Ullman. "Education may thus particularly benefit memory abilities in women, even years later in old age."

The study tested individuals in a non-Western (Taiwanese) population. Participants varied in the number of years of education, from none at all to graduate studies. Future research is needed to test whether the findings generalize to other populations, Ullman says.

"These findings may be important, especially considering the rapidly aging population globally," Reifegerste says. "The results argue for further efforts to increase access to education."

"Education has also been found to delay the onset of Alzheimer's disease," Ullman says. "We believe that our findings may shed light on why this occurs."

Human mothers grow babies in their bellies for nine months, and then after giving birth proceed to spend years raising and nurturing their children, teaching them how to perform both basic and advanced survival tasks. Fruit flies, on the other hand, lay eggs that are left to develop on their own. This makes them seem like irresponsible parents, just abandoning their young. However, a new study by the laboratory of Asifa Akhtar at the Max Planck Institute of Immunobiology and Epigenetics in Freiburg suggests that fruit fly moms in fact ensure the success of their offspring by providing them with an instruction manual for life encoded deep in their epigenomes.

From genome to epigenome

We inherit genetic information from our parents encoded in the DNA sequence. However, even though all cells in the human body contain the same DNA, they "express" different genes to fulfill different functions. DNA is wrapped around histone proteins forming a single repeating unit called the nucleosome. Many nucleosomes join together to form the "chromatin" located in the nucleus of all cells.

Epigenetic modifications such as the addition of chemical groups to histones lead to changes in chromatin organization, which can trigger either gene activation ("expression") or gene silencing. Epigenetics thereby represents an additional layer of information that helps cells to determine which genes to activate. Despite their common genome, cells in our body therefore possess different "epigenomes".

Intergenerational transmission of information from the mother

The parent's germ cells, the oocyte and the sperm, fuse to make a new organism during fertilization. It is thought that most epigenetic marks are erased between each generation. This epigenetic reset allows all genes to be read afresh for each new individual. Now, scientists from the laboratory of Asifa Akhtar discovered that one particular histone modification, the acetylation of histone H4 on the 16th lysine (H4K16ac in short) is intergenerationally maintained from the mother's oocyte to the young embryo.

„H4K16ac is an epigenetic modification that is typically associated with the activation of genes. However, we know that genes are not expressed in either the oocyte or in the first 3 hours of the embryo's life. This begs the question: what is H4K16ac doing at this early stage?" says Asifa Akhtar. To investigate the function of this histone mark in early fly development, the team performed a panel of genome-wide analyses. They found that numerous DNA regions were "marked" by H4K16ac during the early developmental stages before the onset of their gene activation.

Mother's epigenetic advice is essential for embryonic development

The importance of H4K16ac for the offspring became apparent when the mother failed to transmit this mark to her children. The scientists designed experiments using genetic approaches and transgenic flies to remove the enzyme MOF from fly mothers. MOF is known to be responsible for the deposition of the H4K16ac modification.

Remarkably, when the scientists studied the offspring that were laid without the H4K16ac information, they found that genes marked by H4K16ac under normal conditions were now no longer appropriately expressed, and their chromatin organization was severely disrupted. The majority of embryos which failed to get the maternal H4K16ac instructions subsequently died from catastrophic developmental defects. „H4K16ac has an instructive function in the germline and is indispensable for embryonic development later on. It is almost like the mother leaves sticky notes with instructions on where to find the food or who to call in an emergency and so on, when the child is home alone for the first time", says Maria Samata, the first author of the study.

Lessons from flies to humans

"The fact that fly mothers ensure their offspring's success through epigenetics even before they are conceived is a fascinating result," says Asifa Akhtar. The researchers next turned to mammals and found that female mice also pass the H4K16ac histone modification to their progeny through their oocytes. This raises the intriguing possibility that humans might also use H4K16ac from the mother as a "blueprint" for successful embryonic development. Whether this is the case and what information this blueprint might encode are open questions for future investigation.

WINSTON-SALEM, N.C. - June 4, 2020 - Among people who have the most common type of lung cancer, up to 40% develop metastatic brain tumors, with an average survival time of less than six months.

But why non-small-cell lung cancer so often spreads to the brain has been poorly understood.

Now scientists at Wake Forest School of Medicine have found that nicotine, a non-carcinogenic chemical found in tobacco, actually promotes the spread, or metastasis, of lung cancer cells into the brain.

"Based on our findings, we don't think that nicotine replacement products are the safest way for people with lung cancer to stop smoking," said Kounosuke Watabe, Ph.D., professor of cancer biology at Wake Forest School of Medicine and lead author of the study.

In the study, published in the June 4 edition of the Journal of Experimental Medicine, Watabe's team first examined 281 lung cancer patients and found that cigarette smokers exhibited a significantly higher incidence of brain cancer.

Then, using a mouse model, the researchers discovered that nicotine enhanced brain metastasis by crossing the blood-brain barrier to change the microglia - a type of immune cell in the brain - from being protective to supporting tumor growth.

Watabe and colleagues then looked for drugs that might reverse the effects of nicotine and identified parthenolide, a naturally occurring substance in the medicinal herb feverfew, which blocked nicotine-induced brain metastasis in the mice.

Because feverfew has been used for years and is considered safe, Watabe believes parthenolide may provide a new approach to fight brain metastasis, particularly for patients who have smoked or still smoke.

"Currently, the only treatment for this devastating illness is radiation therapy," Watabe said. "Traditional chemotherapy drugs can't cross the blood-brain barrier, but parthenolide can, and thus holds promise as a treatment or possibly even a way to prevent brain metastasis."

Watabe said he hopes to work with oncologists at Wake Forest School of Medicine, part of Wake Forest Baptist Health, to develop a clinical trial to test parthenolide in the near future.

PULLMAN, Wash. - When it comes to vaccination, words matter as do perceptions of what is normal behavior. An experiment by Washington State University researchers revealed that relatively small differences in messages influenced people's attitudes about the human papillomavirus or HPV vaccine, which has been shown to help prevent cancer.

Young adult subjects in the study recently published in the journal Health Communication were more interested in learning about the HPV vaccine when exposed to messages that were both injunctive and normative--meaning statements that implied their friends and family thought they should get the vaccine--versus messages that gave basic information about the vaccine's benefits.

The subjects were also less likely to be interested in the vaccine when they received descriptive messages that were negatively worded: for instance, ones that said that 3 out of 10 people missed out on the HPV vaccine.

"We should be careful about using these types of messages," said Porismita Borah, an associate professor in WSU's Edward R. Murrow College of Communication and one of the study's authors. "Whether you say that 3 out of 10 did not get the vaccine, or that 7 out of 10 did get it--that makes a difference. It influences people's attitudes and behavior."

Many health organizations, including the World Health Organization and the CDC, often use these types of negatively worded, norm-based messages, but this is the first experimental study that tested the influence of social norms on behavior.

More than a decade of research has supported the HPV vaccine's safety and effectiveness in preventing genital warts and cancers associated with the sexually transmitted infection including cervical, anal and penile cancer. Yet according to the CDC, the vaccine has a low uptake in the United States with 48.5% of women and 78.8% of men aged 19 to 26 remaining unvaccinated, pointing to the need for better promotional messaging.

For the study, Borah and Xizhu Xiao, a recent WSU Ph.D. graduate, tested messages on nearly 200 young adults between the ages of 18 and 29. The participants were randomly assigned into four groups that each received a different set of messages about the HPV vaccine based on social media posts typically used by health organizations. They found that the negatively worded normative messaging frequently increased vaccine risk perceptions, compared to the positively worded normative and basic information messages.

Also, the students who were exposed to the injunctive normative messages had a greater intention to seek vaccine information, which in turn increased their intention to get the HPV vaccine.

"This study implies that using messages that highlight the importance of others' approval of vaccination, such as parents and peers, may be especially helpful in piquing individuals' interest to get more information about the vaccination. The information seeking in turn is likely to raise their intention to get vaccinated," said Xiao.

While the authors cautioned that this study was limited and specifically focused on promotional messages for the HPV vaccine, they did say the results may have some implications for the promotion of other vaccinations, including a potential COVID-19 vaccine.