Culture

Researchers from North Carolina State University have found that an elastic polymer possesses broad-spectrum antimicrobial properties, allowing it to kill a range of viruses and drug-resistant bacteria in just minutes - including methicillin-resistant Staphylococcus aureus (MRSA).

"We were exploring a different approach for creating antimicrobial materials when we observed some interesting behavior from this polymer and decided to explore its potential in greater depth," says Rich Spontak, co-corresponding author of a paper on the work and Distinguished Professor of Chemical and Biomolecular Engineering at NC State. "And what we found is extremely promising as an alternate weapon to existing materials-related approaches in the fight against drug-resistant pathogens. This could be particularly useful in clinical settings - such as hospitals or doctor's offices - as well as senior-living facilities, where pathogen transmission can have dire consequences."

The polymer's antimicrobial properties stem from its unique molecular architecture, which attracts water to a sequence of repeat units that are chemically modified (or functionalized) with sulfonic acid groups.

"When microbes come into contact with the polymer, water on the surface of the microbes interacts with the sulfonic acid functional groups in the polymer - creating an acidic solution that quickly kills the bacteria," says Reza Ghiladi, an associate professor of chemistry at NC State and co-corresponding author of the paper. "These acidic solutions can be made more or less powerful by controlling the number of sulfonic acid functional groups in the polymer."

The researchers tested the polymer against six types of bacteria, including three antibiotic-resistant strains: MRSA, vancomycin-resistant Enterococcus faecium, and carbapenem-resistant Acinetobacter baumannii. When 40% or more of the relevant polymer units contain sulfonic acid groups, the polymer killed 99.9999% of each strain of bacteria within five minutes.

The researchers also tested the polymer against three viruses: an analog virus for rabies, a strain of influenza and a strain of human adenovirus.

"The polymer was able to fully destroy the influenza and the rabies analog within five minutes," says Frank Scholle, an associate professor of biological sciences at NC State and co-author of the paper. "While the polymer with lower concentrations of the sulfonic acid groups had no practical effect against human adenovirus, it could destroy 99.997% of that virus at higher sulfonic acid levels."

One concern of the researchers was that the polymer's antimicrobial effect could progressively worsen over time, as sulfonic acid groups were neutralized when they interacted with positively charged ions (cations) in water. However, they found that the polymer could be fully "recharged" by exposing it to an acid solution.

"In laboratory settings, you could do this by dipping the polymer into a strong acid," Ghiladi says. "But in other settings - such as a hospital room - you could simply spray the polymer surface with vinegar."

This "recharging" process works because every time one of the negatively charged sulfonic acid groups combines with a cation in water - which can happen when the polymer comes into contact with microbes - the sulfonic acid group becomes electrically neutral. That makes the acid group ineffective against microbes. But when the neutralized polymer is subjected to acid, those functional groups can exchange bound cations with protons from the acid, making the sulfonic acid groups active again - and ready to kill microbial pathogens.

"The work we've done here highlights a promising new approach to creating antimicrobial surfaces for use in the fight against drug-resistant pathogens - and hospital-acquired infections in particular," Ghiladi says.

"Functional block polymers like this are highly versatile - usable as water-treatment media, soft actuators, solar cells and gas-separation membranes - and environmentally benign since they can be readily recycled and re-used," Spontak adds. "These features make them particularly attractive for widespread use.

"And this work focused on only one polymer series manufactured by Kraton Polymers," Spontak says. "We are very eager to see how we can further modify this and other polymers to retain such effective and fast-acting antimicrobial properties while improving other attributes that would be attractive for other applications."

A novel experimental vaccine against respiratory syncytial virus (RSV), a leading cause of severe respiratory illness in the very young and the old, has shown early promise in a Phase 1 clinical trial. The candidate, DS-Cav1, was engineered and developed by researchers at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, who were guided by their atomic-level understanding of the shape of an RSV protein. An interim analysis of study data showed that one dose of the investigational vaccine prompted large increases in RSV-neutralizing antibodies that were sustained for several months. The findings are reported in Science.

First described in 1956 as a cause of infant pneumonia, the health burden of RSV has long been underappreciated. In fact, the virus is an important contributor to serious illness worldwide and causes as many as 118,000 deaths annually among young children. In the United States each year, RSV infections account for approximately 57,000 hospitalizations and 2 million outpatient clinic visits among children younger than five years old, according to the Centers for Disease Control and Prevention. Among people older than 65, RSV is estimated to cause 14,000 annual deaths in the United States. Globally, a recent large study led by the International Vaccine Access Center found that the virus was responsible for 31% of all cases of severe pneumonia requiring hospitalization in young children in seven low- and middle-income countries.

"A vaccine to prevent RSV is a long-sought goal that has eluded us for decades," said NIAID Director Anthony S. Fauci, M.D. "The early results of this trial suggest that this structure-based strategy for developing an RSV vaccine may bring that goal within reach."

The development of DS-Cav1 was spearheaded by NIAID Vaccine Research Center (VRC) scientists Barney S. Graham, M.D., Ph.D., and Peter D. Kwong, Ph.D., along with Jason McLellan, Ph.D., a former postdoctoral researcher at VRC who is now at the University of Texas at Austin. Dr. Graham has studied RSV for many years and notes that previous candidate RSV vaccines made with traditional techniques, such as by inactivating the whole virus or by making subunit vaccines without attention to protein conformation, have failed.

"In retrospect," said Dr. Graham, "many of these failures can be explained by the loss of neutralization-sensitive sites on the fusion glycoprotein that RSV uses to enter cells and begin the infection process. This protein undergoes spontaneous rearrangement and, if not stabilized, the key vaccine targets are lost."

Structural biology techniques now permit researchers to visualize in minute detail areas of viral proteins, called epitopes, recognized by the immune system. Over several years, Drs. Graham and Kwong and their colleagues have used structural information to develop a candidate RSV vaccine that could stimulate neutralizing antibodies. To do this, they first determined the atomic-level structure of a surface protein, fusion (F) glycoprotein, in its rearranged postfusion and functional prefusion states. The prefusion state displays the epitopes best able to elicit strong-binding neutralizing antibodies, but those epitopes are lost once the F protein changes into the irreversible postfusion shape.

Next, the VRC scientists used structural engineering techniques to stabilize F protein in its prefusion shape. In 2013 they tested several versions as a vaccine in both mice and nonhuman primates. These protein variants elicited high levels of neutralizing antibodies and protected the animals against RSV infection. The most promising, DS-Cav1, was selected for clinical evaluation and subsequently manufactured for clinical testing by the VRC.

"The ability of our multidisciplinary teams to rapidly take a laboratory-based discovery into human clinical testing is one of the unique features of our center," said VRC Director, John R. Mascola, M.D.

The Science report is an interim analysis of data from the first 40 healthy adult volunteers enrolled in the trial, which began in the NIH Clinical Center in 2017. Volunteers received a dose of either 50 or 150 micrograms (μg) of investigational vaccine. Half the volunteers received vaccine with an alum adjuvant (a compound commonly added to vaccines to boost the body's immune response) and half received unadjuvanted vaccine.

After four weeks, levels of RSV-neutralizing antibodies in those who received 50 μg of vaccine (with or without alum) had increased sevenfold over the levels present prior to vaccination. A single dose of 150 μg without alum boosted neutralizing antibody levels 12-fold, while alum-adjuvanted vaccine at that dose prompted a 15-fold surge in neutralizing antibodies. The vaccine-induced antibody levels greatly exceed those seen following natural RSV infection in human challenge trials (where healthy volunteers are exposed to pathogens under carefully controlled conditions in order to observe the course of infection), when neutralizing antibody levels merely triple over those present before infection.

At 12 weeks after vaccination, neutralizing antibodies remained five- to tenfold above baseline levels in all vaccine dosage groups, the interim analysis showed.

"Compared to previous RSV subunit vaccines, the DS-Cav1 vaccine candidate elicits neutralizing antibodies with a superior functional profile, providing the basis for the next steps in developing an effective vaccine against RSV," said Dr. Graham. "The clinical data from this trial demonstrate the feasibility of using information about viral protein structure to rationally design vaccines and represents an important step toward a future of precision vaccines," he added.

Using decades-old frozen fish, researchers have discovered roots of rapid evolutionary adaptation to human activity in the Anthropocene. Similar traits - at least in the fish they studied - can arise through highly divergent genetic pathways, the researchers say. "Interestingly," write Christian Jørgensen and Katja Enberg in a related Perspective, "the genes that strongly increased in one population did not change in parallel populations subject to the same treatment, supporting the view that genetically speaking there are multiple ways to Rome." Mounting evidence shows that the myriad of human-induced environmental change creates strong selective pressures, leading to rapid, yet significant, evolutionary change in many species. For example, selective pressures set in motion by the activities of global fisheries have resulted in marked changes in growth rates and reproductive timing of many commercially fished species. Often, these changes occur within a handful of generations. However, the underlying genetics that makes this type of rapid adaptation possible remains poorly understood. And there are two schools of thought that purport to predict evolutionary change - one suggesting DNA in a species has come about through ages of careful evolutionary tinkering, and the other suggesting traits in a species today, based on its genetics, are influenced by the joint effects of maybe hundreds of genes. Nina Therkildsen and colleagues revisited a near twenty-year-old study, which simulated intensive fishing on thousands of small Atlantic silversides over several generations, and found pronounced evolutionary shifts in overall growth rate. Therkildsen et al. sequenced the genomes of the since-frozen experimental silversides and tracked genomic changes that correlated to changes in fish body size. According to the results, the observed rapid decline in body size occurred through two contrasting polygenic mechanisms. The authors observed many small parallel changes in hundreds of unlinked genes related to growth variation in the wild. Others, however, showed big shifts in large blocks of tightly linked genes, which can result in big changes at some genomic loci. In a related Perspective, Christian Jørgensen and Katja Enberg explain how this finding fits within the two schools of thought that purport to predict evolutionary change.

A contagious canine cancer that conquered the world by spreading between dogs during mating likely arose around 6,000 years ago in Asia and spread around the globe through maritime activities, scientists say.

A detailed genetic study, published today in Science, reveals some surprising - and even mysterious - findings about how this cancer, that has survived for thousands of years, has mutated and evolved over time.

'Canine transmissible venereal tumour' is a cancer that spreads between dogs through the transfer of living cancer cells, primarily during mating. The disease usually manifests as genital tumours in both male and female domestic dogs. It first arose in an individual dog, but survived beyond the death of the original dog by spreading to new dogs. The cancer is now found in dog populations worldwide, and is the oldest and most prolific cancer lineage known in nature.

One of the most remarkable aspects of these tumours is that their cells are those of the original dog in which the cancer arose, and not the carrier dog. The only differences between cells in the modern dogs' tumours and cells in the original tumour are those that have arisen over time either through spontaneous changes in the cells' DNA or through changes caused by carcinogens.

An international team of researchers, led by scientists at the Transmissible Cancer Group at the University of Cambridge, has compared differences in tumours taken from 546 dogs worldwide to try to understand how the disease arose and how it managed to spread around the world.

"This tumour has spread to almost every continent, evolving as it spreads," says Adrian Baez-Ortega, a PhD student in the Transmissible Cancer Group, part of Cambridge's Department of Veterinary Medicine. "Changes to its DNA tell a story of where it has been and when, almost like a historical travel journal."

Using the data, they created a phylogenetic tree - a type of family tree of the different mutations in the tumours. This allowed them to estimate that the cancer first arose between 4,000 and 8,500 years ago, most likely in Asia or Europe. All of the modern tumours can be traced back to a common ancestor around 1,900 years ago.

The researchers say that the cancer first spread from Europe to the Americas around 500 years ago, when European settlers first arrived at the continent by sea. Almost all the tumours found today in North, Central and South America descend from this single introduction event.

From the Americas, the disease spread further, to Africa and back into the Indian subcontinent - almost all places that were, at the time, European colonies. For example, the cancer is seen in Reunion, but this was where European travellers would stop off on the way to India. All of this evidence suggests that the tumour was spread by sea-faring dogs, transported through maritime activities.

While the findings related to the historical spread of the disease are interesting, it is the tumour's evolution that particularly excites the researchers.

Recent developments in cancer biology have enabled scientists to look at the mutations in tumour DNA and identify unique signatures left by carcinogens. This allows them to see, for example, the damage that ultraviolet (UV) light causes.

Using these techniques, the researchers identified signatures for five different biological processes that have damaged the canine tumour over its history. Four of these, including exposure to UV light, are known processes already linked to human cancers. However, one of them - termed 'Signature A' - has a very distinctive mutational signature, different to any seen previously: it caused mutations only in the tumour's distant past, several thousand years ago, and has never been seen since.

"This is really exciting - we've never seen anything like the pattern caused by this carcinogen before," says Dr Elizabeth Murchison, who leads the Transmissible Cancer Group at the University of Cambridge.

"It looks like the tumour was exposed to something thousands of years ago that caused changes to its DNA for some length of time and then disappeared. It's a mystery what the carcinogen could be. Perhaps it was something present in the environment where the cancer first arose."

Another intriguing discovery related to how the tumours evolve. There are two main types of selection in evolutionary theory - positive and negative. Positive selection is where mutations that provide an organism with a particular advantage are more likely to be passed down generations; negative selection is where mutations that are likely to have a deleterious effect are less likely to be passed on. Such selection tends to occur by way of sexual reproduction.

When the researchers analysed the tumours, they found no evidence of either positive or negative selection. This implies that the tumour will be accumulating more and more potentially damaging mutations over time, making it less and less fit to its environment.

Baez-Ortega explains: "Normally, we see selection pressures acting on an organism's evolution. These canine tumours are foreign bodies, so one would expect to see a battle between them and the dog's immune system, leading to only the strongest tumours successfully being transmitted. This doesn't seem to be happening here.

"This cancer 'parasite' has proved remarkably successful at surviving over thousands of years, yet is steadily deteriorating. It suggests that its days may be numbered - but it's likely to be tens of thousands of years before it disappears."

For primary care physicians caring for patients with type 2 diabetes, it's a familiar conversation: Exercise. Improve your diet. Lose weight. Patients with diabetes are at increased risk of having a heart attack, stroke or other cardiovascular event so physicians counsel their patients on how to make lifestyle changes to help regain control of their blood sugar levels and diminish that risk. But does this counseling help? Should physicians continue advising patients repeatedly? A new study in Diabetes Care suggests that patients who received lifestyle counseling at least once a month were at decreased risk of cardiovascular events such as heart attacks, strokes and hospitalization for chest pain as well as death from any cause compared to those who received counseling less frequently.

"Our study provides real-life evidence that lifestyle counseling can prevent strokes, heart attacks, disabilities and even death. The message here for physicians is that it's important to continue having these conversations with patients about the lifestyle changes they can make to lower their risk and to have patients come back in to continue the conversation until their blood glucose levels are under control," said corresponding author Alexander Turchin, MD, MS, an endocrinologist in the Brigham's Division of Endocrinology, Diabetes and Hypertension. "And the message for patients is to bring up questions about what you can do to prevent heart attacks and strokes when you see your doctor. Patients can solicit these conversations too and take control of their disease."

Turchin and colleagues conducted a retrospective analysis of 19,293 patients with uncontrolled blood glucose levels ((HbA1c ?7.0% [53 mmol/mol]) who were seen at primary care clinics affiliated with the Brigham and Massachusetts General Hospital between 2000 and 2014. To determine how frequently the patients received lifestyle counseling, the team used natural language processing to comb through physicians' notes recorded in electronic medical records, looking for keywords such as watch his/her diet or healthier eating habits.

The team found that most patients (16,057) received lifestyle counseling less than monthly. Patients who received at least monthly counseling had a greater decrease in their blood glucose levels (1.8 percent vs. 0.7 percent) and had a lower rate of incidences of cardiovascular events and death over the next two years (33 percent vs. 38 percent) compared to the group that received less frequent counseling.

Unlike a randomized, controlled clinical trial, the current study analyzed data retrospectively from clinics. A previously published randomized clinical trial, known as Look AHEAD, found that a lifestyle intervention did not reduce the incidence of cardiovascular events in patients with diabetes. Turchin's study looked at data from nearly four times as many patients and extends previous work indicating that frequent lifestyle counseling can help reduce blood glucose levels.

"As a physician, it's encouraging to see that these conversations can change outcomes that matter to our patients," said Turchin. "We're not talking about just changing the numbers, we're talking about preventing strokes, heart attacks, disability and death."

Scientists using an experimental treatment have slowed the progression of scrapie, a degenerative central nervous disease caused by prions, in laboratory mice and greatly extended the rodents' lives, according to a new report in JCI Insight. The scientists used antisense oligonucleotides (ASOs), synthetic compounds that inhibit the formation of specific proteins.

Prion diseases occur when normally harmless prion protein molecules become abnormal and gather in clusters and filaments in the body, including the brain. The diseases are thought to be always fatal. Scrapie, which affects sheep and goats and can be adapted to rodents, is closely related to human prion diseases such as Creutzfeldt-Jakob disease, which is currently untreatable. Thus, scrapie is a valuable experimental model for the development of human prion disease therapies.

In the studies, National Institutes of Health scientists and their colleagues injected ASOs into the spinal fluid of mice already infected with scrapie or that were challenged with scrapie proteins within weeks of the injection. Ionis Pharmaceuticals specifically designed ASO1 and ASO2 to reduce the rodents' supply of normal prion protein. Rodent studies using different dosages of ASO1 and ASO2 were conducted at Rocky Mountain Laboratories (RML) in Hamilton, Montana, (part of the NIH's National Institute of Allergy and Infectious Diseases) and at the Broad Institute of Cambridge, Massachusetts.

RML scientists injected either ASO1 or ASO2 into mice 14 days prior to infecting them with scrapie, and then seven or 15 weeks after infection. Mice treated with ASO1 did not show clinical signs of disease for a median 250 days, or 82% longer than untreated mice (137 days), and they lived 81% longer than untreated mice (259 days versus 143 days). Mice treated with ASO2 did not show clinical signs of disease for a median 272 days, or 99% longer than untreated mice (137 days), and they lived 98% longer than untreated mice (283 days versus 143 days). In the Broad Institute experiments, mice received either ASO1 or ASO2 2 weeks before infection with scrapie and then seven weeks after infection. Both ASOs delayed rodent weight loss. Mice treated with ASO1 and ASO2 both lived longer than untreated mice, by 61% (274 days versus 170 days) and 76% (300 days versus 170 days), respectively.

The RML group also tested the ASOs against established prion disease, treating mice 17 weeks after they were infected with scrapie - near the onset of clinical signs. Mice treated with ASO1 did not show signs of clinical disease for a median 189 days, or 33% longer than untreated mice (142 days). They also showed slower disease progression and lived 55% longer than untreated mice (244 days versus 157 days). ASO2 had no beneficial effect.

The researchers plan to expand their scrapie ASO studies to human prion diseases. Other researchers have seen promising initial results in humans with ASOs directed against Alzheimer's disease, amyotrophic lateral sclerosis (Lou Gehrig's disease), and Huntington's disease.

Fuels made from agricultural or forestry wastes known as lignocellulosic biomass have long been a champion in the quest to reduce use of fossil fuels. But plant cell walls have some innate defenses that make the process to break them down more difficult and costly than it could be.

In a leap forward that could be a game changer for understanding how plant biomass can be more efficiently broken down, a research team at the University of California, Riverside have joined forces with teams at Oak Ridge National Laboratory and the University of Central Florida to create a chemical roadmap to breach these defenses.

In order to access the energy-rich sugars found in the plant cell walls, researchers have renewed focus on solvating lignin, a complex polymer also found in plant cell walls that acts as a natural shield, blocking both chemical and biological attack. Lignin is particularly effective in preventing commercial enzymes from digesting cellulose, which makes up the bulk of sugars found in biomass.

In the past, different specialized chemicals and pretreatment methods have been used to improve enzyme access to cellulose but were ineffective at removing lignin. The use of strong acids, ionic liquids, ammonia, and sulfite treatments have somewhat improved the digestibility of cellulose, but these methods also leave lignin behind, making cellulose expensive to recover. Other methods have applied co-solvents such as ethanol and acetone solvate to remove lignin, but they require very high reaction temperatures that also cause the remaining sugars to degrade.

As a result, economically viable methods of transforming biomass into biofuels have yet to be realized.

Charles Cai, an assistant research engineer at the Center for Environmental Research and Technology in the Marlan and Rosemary Bourns College of Engineering at UC Riverside, and Abhishek S. Patri, a doctoral student in chemical and environmental engineering, led a team of researchers taking a new direction to focus on identifying highly specialized co-solvents, substances added to a primary solvent to make it more effective, that can facilitate milder temperature solvation and release of lignin from the plant cell walls. This is known as a "lignin-first" approach to breaking down biomass.

The UC Riverside researchers enlisted the research team at Oak Ridge National Laboratory's Center of Molecular Biophysics, led by Jeremy Smith, to help construct a 1.5 million atom molecular simulation to reveal how the co-solvent pair consisting of tetrahydrofuran, or THF, and water are particularly effective at altering the interactions between lignin and cellulose, helping to drive multiple key mechanisms responsible for breaking down biomass.

The team discovered that pretreating plant biomass with THF-water caused lignin globules on the cellulose surface to expand and break away from one another and away from the cellulose fibers. The expanded lignin was also more exposed to catalytic fragmentation by dilute acid. As a result, lignin could be more efficiently depolymerized, solubilized, and transported out of the cell wall at milder treatment conditions.

The nearly complete removal of lignin also allowed the remaining cellulose fibers to be more susceptible to enzyme attack. In fact, after mild THF co-solvent treatment, the enzymes added to the remaining cellulose-rich solids achieved complete hydrolysis to glucose sugars.

Collaborating researchers at the University of Central Florida, led by Laurene Tetard, helped to confirm the observations made from the molecular simulations and enzymatic studies by using powerful lasers and nano-infrared imaging to optically track lignin's rearrangement and removal from the cell wall of micron-thick slices of hardwood.

Finally, Oak Ridge National Laboratory researchers Yunqiao Pu and Arthur Ragauskas showed that lignin extracted from hardwood pretreated with THF co-solvent was significantly depolymerized and contained fewer unwanted reactions than lignin produced from other acidic pretreatment methods.

By putting lignin first, highly functional co-solvents can help to integrate multiple processing steps while allowing both lignin and sugars to be easily recovered as valuable chemical building blocks, making renewable fuel production easier and more cost-effective. The research team hopes that by revealing the synergistic mechanisms of biomass breakdown by co-solvents THF and water, they can inspire others to identify additional multifunctional co-solvent pairs.

COLLEGE STATION -- Is cheating a product of the environment or a character trait?

Dr. Marco Palma, director of the Human Behavior Lab at Texas A&M University and professor in the department of agricultural economics, and Dr. Billur Aksoy, assistant professor of economics at Rensselaer Polytechnic Institute, New York, took a closer look at cheating during periods of relative economic abundance and scarcity to determine whether cheating for monetary gain is a product of the economic environment.

During the experiment, they found evidence that cheating is more likely caused by an individual's propensity to cheat than external factors. To view the paper supporting their work, visit http://bit.ly/scarcityoncheating.

Famous criminals' propensity for cheating has been attributed to their circumstances and being a product of an impoverished upbringing, Palma explained. So to test this theory, researchers selected a remote community in Guatemala for a field experiment to help determine whether scarcity, or impoverished situations, truly influence a person's propensity to cheat and lie.

THE EXPERIMENT

According to Palma, the experiment gave participants the opportunity to cheat without any repercussions, and they were tested both during times of scarcity and relative abundance. Since the village where the experiment was held relied solely on coffee production for their livelihood, the abundance period would be during the five-month window when coffee is harvested weekly, and scarcity would be tested during the seven months of no harvest, and therefore no income.

The experiment included giving participants a cup and dice and asking them to roll the dice with the cup. Depending on the number rolled, participants received monetary compensation for filling out a survey. If a one was rolled, the participant received five quetzales, which is a little bit less than a dollar. Rolling a two paid 10 quetzales, a three paid 15 quetzales and so on. Rolling a six received nothing. Participants were asked to roll the dice twice by shaking the cup.

"The first time is the one that counts, and then they shake it again so nobody else sees what they rolled," Palma said. "So now people have an opportunity to cheat in order to increase their earnings. We did this in the scarcity period, and again in the abundance period."

By even distribution, each number should be rolled about one-sixth of the time, he said.

CHEATING FOR PERSONAL GAIN

"If you look at the high paying numbers, there are three numbers out of six. So, 50% of the time they should report a high payoff and 50% of the time a low payoff," he said. "We find that they reported about 90% of high numbers during scarcity and about 90% in abundance. So, there was no change in cheating across the two periods."

"This tells us there is no real change for the propensity to cheat during scarcity and abundance. Meaning, this is more like an inner characteristic of an individual."

CHEATING FOR A FRIEND

The second part of the experiment gave people the opportunity to cheat for someone in their village, the in-group, like a family member or friend, and increase their monetary benefit.

"In general, people cheat for the in-groups, but at a lower rate than they would for themselves. And this doesn't really change across the scarcity and abundance conditions," he said.

CHEATING FOR A STRANGER

Next, they were given the opportunity to cheat for a stranger, the out-group, someone outside of the community.

"During the abundance period, people did not cheat for the out-group," Palma said. "In other words, if it is somebody who is outside of the group, the level they reported for the high payoffs was exactly 50%, which is the expectation. But during the scarcity period, the gap between the in-group and the out-group was closed. All of a sudden people started cheating for the out-group at the same rate as they did for the in-group."

RESULTS

Palma explained that the participants' willingness to cheat during scarcity was unexpected. During the scarcity period, the boundaries of the in-group and out-group disappear not only because people are willing to incur a moral cost, but they are also willing to incur monetary costs by giving the same amount of money to both groups.

"This experiment helped bridge the gap between the lab and the real world, and we can inform policy makers and make accurate predictions of how humans will react under different types of environments," Palma said.

According to Aksoy, these findings appear to be universal.

"In our experiment, we did not find any significant impact of scarcity on cheating behavior when the beneficiaries were the subjects themselves," she said. "In a recent unpublished study, titled "Poverty negates the impact of social norms on cheating," other researchers also reach the same conclusion in their experiment with rice farmers in Thailand. This suggests that our findings are not exclusive to Guatemalan coffee farmers, but, of course, there is more research that needs to be done in order to better understand this phenomenon. In fact, a study conducted in 23 countries highlights very little differences in cheating behavior across the countries. "

DURHAM, N.C. -- The primary reason gun fatalities result in arrests more frequently than nonfatal shootings is police devote more time and resources to the fatal cases, a new study by scholars at Duke and Northeastern universities finds.

This suggests that persistence pays off, yet staying with an investigation that may last months is a luxury afforded only to homicide detectives, the researchers say.

"With respect to preventing gun violence, an arrest in a nonfatal shooting is every bit as important as an arrest in a fatal shooting," said Philip J. Cook, professor emeritus at Duke's Sanford School of Public Policy and the study's lead author. "Our results suggest that police departments should invest additional resources to investigate nonfatal gun assaults."

The study, "Why do gun murders have a higher clearance rate than gunshot assaults?," appears in the journal Criminology and Public Policy.

Researchers analyzed how resources affect the likelihood that an investigation will be successful, defined as leading to at least one arrest. They examined data from 2010 to 2014 from the Boston Police Department that included all gun homicides and a sample of criminal cases in which the victims survived a gunshot wound.

Specifically, they analyzed 204 shootings that included at least one homicide, as well as a representative sample of 231 shooting cases in which no one died. Data came from detectives' investigation files, forensic evidence databases and interviews with investigators.

The study found that fatal and nonfatal cases were nearly indistinguishable with respect to circumstances and victim characteristics. However, fatal cases were more than twice as likely to lead to an arrest (43 percent) than nonfatal cases (19 percent).

During the first two days after the crime, arrest rates for fatal and nonfatal cases were identical -- 11 percent. However, for cases that did not lead promptly to an arrest, an additional 32 percent of homicides subsequently led to an arrest, compared to an additional 8 percent in nonfatal cases.

The difference, researchers concluded, is tied to the higher level of resources and sustained effort typically dedicated to homicide investigations. The difference could be seen from the very beginning, at the scene of the crime: More investigators were assigned to homicide scenes, which subsequently yielded more evidence.

In addition, the study found a distinguishing characteristic of successful investigations was a cooperating witness.

"When investigators put in additional effort, they are more successful in gaining the cooperation of key witnesses," Cook said. "They also collect and analyze more evidence. This leads to more arrests, which enhances the capacity of the police to hold violent gun offenders accountable, deliver justice to victims and prevent further gun attacks."

Police are increasingly called on to combat crimes related to sex and labor trafficking. A new study sought to determine how the victims of these crimes are served by police. Based on researchers' review of human trafficking investigations and interviews with police and service providers in three communities in Northeast, West, and South United States, the study concluded that victims of human trafficking often do not trust the police and rarely seek their assistance. The study also found that these views are due in part to victims' beliefs that police are not trained adequately and hold biases and stereotypes about them. The authors offer recommendations to improve police responses to these victims.

The study, by researchers at Northeastern University and the John Jay College of Criminal Justice, appears in Criminology & Public Policy, a publication of the American Society of Criminology.

"Central to their public safety mission, police officers have an obligation to help victims feel safe, assess their immediate needs, connect them with providers who can help, and give them opportunities to tell their stories without revictimization," according to Amy Farrell, associate professor of criminology and criminal justice at Northeastern University, who led the study. "When this doesn't happen--as is the case with many victims of human trafficking--victims of crime grow to distrust police, which in turn reduces the effectiveness of detecting and preventing crime."

Despite the important role of the police in engaging with crime victims, past studies have shown that police commonly fall short in responding to the needs of this group, particularly victims of interpersonal violence. And although the field of law enforcement has increased training to improve responses to crime victims, studies evaluating the effectiveness of these efforts have overlooked questions about how well the police respond to and meet the needs of those who are victimized.

In this study, researchers identified human trafficking crimes as representing a unique opportunity to examine police responses to people victimized by crime. Human trafficking is a crime involving recruiting and exploiting individuals by means of force, fraud, or coercion for the purposes of commercial sex, labor, or services. Despite advances in this field, police identification of victims of human trafficking remains low.

To determine why these victims may be reluctant to seek police assistance, researchers examined police responses to human trafficking crimes in three unnamed U.S. communities that varied in region, population size, and crime rates. They used data from a project that included information about 871 human trafficking incidents reported to the police between 2013 and 2016, and interviews with 23 law enforcement and 41 service providers who were involved with responding to human trafficking crimes.

Researchers found that many victims of human trafficking deal with complex trauma and have had negative experiences with the police, such as being arrested. Furthermore, human trafficking crimes are usually identified by nonspecialized officers who encounter victims during routine duties and are not trained to work with victims of this type of crime. As a result, victims of human trafficking are less likely to receive specialized services.

The study also identified victims' perceptions of police biases and stereotypes about them as factors that prevent victims from providing full details of the crimes in which they are involved to police, which further limits the ability of law enforcement to identify and respond in these cases.

The researchers also found that victims of human trafficking are less interested in seeking traditional forms of retributive justice for their traffickers, such as incarceration. Instead, they seek recognition of the crime, safety from future victimization, and the ability to move past their trauma, outcomes that are not typically addressed in their interactions with police.

Among the recommendations made by the researchers:

Front-line officers and investigators in non-trafficking units should be taught how to screen for and appropriately classify incidents of human trafficking.

Comprehensive policies should be adopted to discourage police from arresting victims of human trafficking as a way to get them to provide evidence or ensure their safety.

Police should adopt a victim-centered approach in their work with victims of human trafficking.

Since many victims of human trafficking want assistance connecting with services in the community but few law enforcement agencies have specialized units dedicated to victim assistance, police should partner with service providers in the community and refer victims to these groups for support following report of a crime.

Victims should be asked about their wishes for justice and offered approaches such as restorative justice.

"The police play a critical role in protecting victims of crime by building trust and meeting their needs," notes Meredith Dank, a research professor at the John Jay College of Criminal Justice, who coauthored the study. "Victims of human trafficking need the police to recognize their humanity, promote their safety, and facilitate meaningful connections with service providers who can help restore victims to their places in their communities."

The study's authors note that their research is exploratory and qualitative, and that their findings are limited to the sites they studied. Also, the study did not include the experiences of victims of human trafficking, and the authors encourage future research to take into account their voices.

Bottom Line: Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.

Journal in Which the Study was Published: Cancer Research, a journal of the American Association for Cancer Research

Author: Donghao Lu, MD, PhD, a postdoctoral researcher in the Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm.

Background: "Patients receiving a cancer diagnosis are at increased risk of several stress-related psychiatric disorders, such as depression, anxiety, and stress-reaction and adjustment disorders," Lu said. "Emerging evidence from both experimental and epidemiological studies indicates that psychological distress might affect the progression of many cancer types."

How the Study Was Conducted and Results: In this study, researchers examined the potential influence of stress on the cancer-specific mortality of patients with cervical cancer. They examined records of 4,245 patients diagnosed with cervical cancer in Sweden between Jan. 1, 2002, and Dec. 31, 2011. Using Swedish personal identification numbers, they linked the patients to the Swedish Patient Register, which collects nationwide information on hospital discharge records and specialist visits. Data from this register were used to identify patients who had been clinically diagnosed with any of three psychiatric disorders: stress-reaction and adjustment disorders, depression, and anxiety.

The researchers also identified patients who had experienced a stressful life event, such as the death or severe illness of a family member, divorce, or being between jobs, as these events would further reflect an emotional burden on patients, Lu explained.

The researchers used Sweden's Causes of Death Register to identify women who had cervical cancer or unspecified uterine cancers as the underlying cause of death. During the follow-up period, 1,392 patients died, and cervical cancer was listed as the cause of death for 1,005 of them.

In all, the researchers found that 1,797 patients either had stress-related disorders or had undergone stressful life events. Patients with either a stress-related disorder or a stressful life event were 33 percent more likely to die of the disease than those who had not reported stress. Those who had stress-related disorders were 55 percent more likely to die of their cervical cancer, and those who had experienced a stressful life event were 20 percent more likely to die of their disease.

Lu pointed out that the association of stress with higher risk of dying of cervical cancer remained, independent of tumor characteristics, mode of diagnosis, and type of treatment. The associations were also consistent across demographic groups and clinical characteristics.

Author's Comments: Lu said there are several possible explanations for the link between psychological stress and cervical cancer-specific mortality. For one, a woman suffering from a psychological disorder may be less likely to seek treatment and may be diagnosed at a later stage. Biologically, he noted, previous research has shown that chronic stress may reduce cellular immune response, which may affect the progression of infection-related cancers, such as cervical cancer. Moreover, a previous study by Lu and his colleagues further supports the role of psychological stress in cervical cancer development, potentially through oncogenic infection of human papillomavirus.

Fellow author Karin Sundström, MD, PhD, a project coordinator in the Department of Laboratory Medicine, Karolinska Institutet, said that in Sweden, psychological support is available for patients at large, university-based clinics, but not in smaller regional facilities. She said many patients do not receive emotional support, partially because of lack of awareness of the toll emotional stress can take.

"Our findings support that oncologists or gynecologists perform active evaluation of psychiatric status on return visits to see how patients with cervical cancer are doing, not only somatically, but also mentally," Sundström said. "If confirmed in other populations and countries, psychological screening and intervention may be considered as an integral component in cervical cancer care."

Study Limitations: Lu pointed out that this study suggests an association between stress and cervical cancer prognosis and should not be interpreted as a causal link.

Funding & Disclosures: This study was supported by the Swedish Cancer Society, the Swedish Research Council for Health, Working Life, and Welfare, and the Karolinska Institutet. The authors declare no conflict of interest.

A diverse and inclusive education workforce can play a critical role in ensuring that students receive a robust, quality educational experience. While students of color comprise more than half of P-12 classroom populations in the United States, overcoming the shortage of educators of color has been a decades-long dilemma for U.S. schools.

The shortage is especially alarming among Black male educators, who represent less than two percent of the total teaching population. The recruitment of these teachers continues to be a critical topic in educational reform, but studies on the factors contributing to the shortage remain scarce. As a result, there has been little improvement in attracting and retaining Black male educators.

To uncover factors affecting the shortage of Black male teachers, researchers from University of Phoenix (UOPX) Center for Workplace Diversity and Inclusion Research - in partnership with the National Network of State Teachers of the Year (NNSTOY) - examined the current status of Black male educators in our nation's classrooms. This exploration highlighted insights of fellows of the 2018 cohort of NNSTOY Outstanding Black Male Educators. Their reflective quotes and personal narratives were published in a joint white paper, entitled, "Having Our Say: Examining Career Trajectories of Black Male Educators in P-12 Education." Three areas of focus were spotlighted as potential solutions to the shortage: improved recruitment efforts, greater representation in teacher preparation programs and enriched experiences in school settings.

"With limited insight into the factors affecting Black male educators in P-12 education, the voices of the NNSTOY fellows served as the 'coal miner's canary' - calling attention to the challenges experienced within the career trajectory of many Black male educators at every phase," said Dr. Kimberly Underwood, University of Phoenix research chair and lead author of the paper. "While this paper will help identify potential solutions, we must continue to champion efforts to create sustainable actions to diversify the teaching profession and improve recruitment and retention efforts."

Additional authors included University of Phoenix Center for Workplace Diversity and Inclusion Research fellows Dr. Donna Smith, Dr. Hilary Johnson-Lurtz, Dr. Joy Taylor and Dr. J. Medgar Roberts. Based on their experience as faculty members, educators and administrators, they provide a critical examination of the career trajectories of Black male educators as they enter into and advance within the P-12 school setting.

As highlighted in the paper, various studies suggest that the lack of Black male educators has negative implications for all students, both culturally and academically. In their absence, students lose access to valuable insights and perspectives that can dramatically decrease bias and prejudice. Additionally, direct results can be seen among the benefits to students of color, which include lower dropout rates, a more positive view of schooling, fewer disciplinary issues and better test scores.

While there are varying schools of thought surrounding how Black male educators specifically impact P-12 classrooms, one common thread remained consistent within the research and among all the narratives of NNSTOY fellows - representation is critical. The voices of these fellows serve as a resounding acknowledgment of the ubiquitous need to increase Black male educator representation to improve student learning.

To develop a strategic approach to the issue, the UOPX and NNSTOY team will build off the voices of these dynamic fellows and conduct research to examine socialization experiences of Black male educators, including the root cause of the attrition. Their findings will be shared in future papers and conference presentations. Once identified, University of Phoenix will seek to implement solutions to recruit and teach the next generation of Black male educators.

This is an important initiative for the University, as its faculty and student bodies represent more than double the national average of representations of African American faculty and students. As of 2019, nearly a third (31 percent) of College of Education faculty identify as African American and 34 percent of University of Phoenix students identify as African American. As a part of its collective diversity, the University is committed to championing for the diversification of our nation's workforces, in every community of practice.

Read the complete paper at https://www.phoenix.edu/having-our-say.

When Earth was a lifeless planet about 4 billion years ago, chemical components came together in tiny molecular chains that would later evolve into proteins, crucial life building blocks. A new study has shown how fortuitously some early predecessors of protein may have fallen into line.

In the laboratory, under conditions mimicking those on pre-life Earth, a small selection of amino acids linked up spontaneously into neat segments in a way that surprised researchers at the Georgia Institute of Technology. They had given these amino acids found in proteins today some stiff competition by adding amino acids not found in proteins, thinking these non-protein, or non-biological, amino acids would probably not allow predominantly biological segments to come together.

The non-biological amino acids had the potential to chemically react equally well or better than the biological ones and frequently become part of the tiny chains, perhaps serving as an in-between step in the greater evolution toward proteins. The experiment dashed those expectations -- but to the researchers' delight. The reactions resulted mostly in strings that were closer to today's actual proteins and less in chains that included non-biological amino acids.

"The non-biological amino acids were being excluded to some extent," said Nick Hud, one of the study's principal investigators and a Regents Professor in Georgia Tech's School of Chemistry and Biochemistry.

Doorway to evolution

In particular, the researchers had thought the non-biological amino acids would outcompete the biological amino acid lysine, but it was not the case. They also thought lysine would often not fit neatly into the chains the way it does in proteins. The reaction surprised them again.

"Lysine went into the chains predominantly in the way that it is connected in proteins today," said Hud, who is also director of the National Science Foundation/NASA Center for Chemical Evolution (CCE), which is headquartered at Georgia Tech and explores the chemistry that may have paved the way to first life.

The research team, which included collaborators from The Scripps Research Institute, published their results in the journal Proceedings of the National Academy of Sciences on July 29, 2019. The research was funded by the NSF and NASA.

The study's experiment points to chemical evolution having prefabricated some amino acid chains useful in living systems before life had evolved a way to make proteins. The preference for the incorporation of the biological amino acids over non-biological counterparts also adds to possible explanations for why life selected for just 20 amino acids when 500 occurred naturally on the Hadean Earth.

"Our idea is that life started with the many building blocks that were there and selected a subset of them, but we don't know how much was selected on the basis of pure chemistry or how much biological processes did the selecting. Looking at this study, it appears today's biology may reflect these early prebiotic chemical reactions more than we had thought," Loren Williams, another principal investigator in the study and a professor in Georgia Tech's School of Chemistry and Biochemistry.

Mono, oligo, poly

To help understand the study's significance, let's look at how proteins form, then at the study's core experiment, which revealed an unexpectedly high preference for bonds between sites called alpha-amines (α-amines) on the biological amino acids. Those bonds gave resulting molecular segments a protein-like shape in the lab.

In a protein, one amino acid is a single chemical unit, or monomer. A few of them linked together is called an oligomer, and really long chains are polymers. In proteins, the polymer is called a polypeptide -- named after the peptide bonds that link its monomers together.

Polypeptides are long chains that often form helices, like old phone cords, or flat sheets. They kink and fold up into specific, mostly functional wads, sheets, and other shapes, which are called proteins. The study looked at how amino acid monomers linked up to make interesting oligomers that look like small pieces of proteins.

Hadean Eon experiment

Late in the Hadean Eon, Earth's earliest phase, when prebiotic chemistry was taking shape, the planet's surface was awash in vulcanism and rain, and large meteors pummeled it with new chemicals. The researchers' experimental lab setup reflected relatively mild conditions for those times and feasibly present ingredients.

First author Moran Frenkel-Pinter placed the biological amino acids lysine, arginine, and histidine together with three non-biological competitors in water containing hydroxy acids. Hydroxy acids are known to facilitate amino acid reactions and would have been common on prebiotic Earth.

The mixture was heated to 85 degrees Celsius, pushing the reaction and evaporating the water, and the researchers analyzed the products formed.

"We found this high preference for the inclusion of these biological amino acids and the linkage via the α-amine," said Frenkel-Pinter, a NASA postdoctoral researcher in the CCE.

Amine groups are made of nitrogen and hydrogen and are quite reactive, but the α-amine is part of the core of an amino acid, and other amines in this experiment were at the end of a sidechain extending off the core. The latter is often more reactive.

"It surprised us that this chemistry favored the α-amine connection found in proteins, even though chemical principles might have led us to believe that the non-protein connection would be favored," Frenkel-Pinter said. "The preference for the protein-like linkage over non-protein was about seven to one."

Easy chemical evolution

Most resulting oligomers had evenly placed links in the chain, which are used in life, as opposed to non-α-amine bonded oligomers, which built more irregular chains.

The finished products were mostly depsipeptides, which the CCE previously established as stepping stone products in an easy, reliable pathway to peptides.

In another reflection of life chemistry, the abiotic depsipeptide transition to peptides is the same basic reaction (ester-amide) carried out by ribosomes, the cellular machines that make proteins today.

Surprise reactions, in which potential pre-life chemistry casually falls into place, have happened often in the CCE's research. They have shored up the center's core hypothesis that most biological polymers formed in wet and dry cycles, perhaps on rain-swept dirt flats or lakeshore rocks regularly baked by the sun's heat.

Despite its grounded simplicity, the premise of everyday wet-dry cycles being key to the origin of life is unconventional, challenging a more established narrative that improbable concurrences of cataclysms and multiple ingredients were necessary to produce life's early materials in rare and volatile events.

The vast cultural and linguistic diversity of Latin American countries is still far from being fully represented by genetic surveys. Western South America in particular holds a key role in the history of the continent due to the presence of three major ecogeographic domains (the Andes, the Amazonia, and the Pacific Coast), and for hosting the earliest and largest complex societies. A new study in Molecular Biology and Evolution by an international team lead by scholars from the Max Planck Institute for the Science of Human History and from the University of Zurich reveals signatures of history, ecology and cultural diversity in the genetic makeup of living rural populations.

A thorough study, a collaboration between scientists and institutes from Europe, the USA, Mexico, Ecuador, Colombia and Peru, including geneticists, linguists and anthropologists, has shed new light on the population history of South America. The study, which involved working closely with local populations in numerous regions, was published in Molecular Biology and Evolution. The results confirmed the impact of large, complex societies already known from archaeological evidence, but also revealed previously unknown migrations and connections across vast distances, including in Amazonia, an area that has not been as deeply studied archaeologically.

Genetic studies have played a fundamental role in understanding the population history of the American continent. By reconciling genetic evidence with the archaeological record and with paleoclimatic data, scientists have been able to pinpoint the time and scale of the earliest migrations, possible routes through the continent, the subsequent formation of population structure, and preferential routes of population migration and contact. Yet the picture is necessarily superficial because of the lack of representative data from all the diverse regions of the continent. One recurrent simplification relies on the contrast between the Andes, site of the famous large complex societies of the Wari, Tiahuanaco and Inca who built a vast network of roads, and Amazonia, where people apparently have been living in small isolated groups. The Pacific Coast, key player in the earliest migration routes and theatre of other large-scale societies (like the Moche and Chimú, among others) is not properly incorporated in this traditional model.

"We wanted to bring attention to the fine-grained, complex events taking place during the pre-colonial and post-European contact times. We therefore visited diverse regions of South America, collecting new samples from rural populations with different cultural backgrounds. In our analysis, we focused on signals of contact and shared ancestry, trying to find exceptions to the current paradigm on the diversity of the continent," explains Chiara Barbieri, a geneticist from the Max Planck Institute for the Science of Human History in Jena now working at the University of Zurich, and lead author of the study.

"On a continental scale, one of the major findings is the presence of a distinct ancestry component in Amazonia, present at high frequency in populations from Ecuador and Colombia, near the Eastern Andes slope. This genetic component, previously undetected, might have started to differentiate from other ancestry components (for example the one frequently found in Amazonia and the one found in the Coast and Andes) more than 4,000 years ago. This has implications for understanding the early migrations and structure of the continent, and suggests that human diversity in Amazonia is larger than we thought," adds Barbieri.

On a local scale, the high-resolution genomic data generated for this study was able to distinguish fine-grained cases of genetic exchange that correspond to population contact. These exchanges connect populations separated by hundreds of kilometers and who live in different ecogeographic domains. "Connections have been found between speakers of Quechua (a widely-spoken Andean language) through the Andes and part of Amazonia. Also, some populations of Loreto and San Martín (Amazonian regions) of Peru are genetically very close to the Cocama speakers (an Amazonian language) of Colombia. These genetic signatures suggest that here languages are diffused by movement of actual people instead of by cultural diffusion alone," explain José Sandoval and Ricardo Fujita of the University of San Martín de Porres in Lima, Peru, who coauthored the study.

Finally, the genetic analyses show demographic traces of a large population that correspond to ancient complex societies both in the Andes and on the North Coast of Peru. Signatures of relatively large populations are also found in a few populations of Amazonia, suggesting the possibility of complex interactions in this region. Here archaeological excavations are less numerous, making the chances of uncovering relevant archaeological findings less likely. Lars Fehren-Schmitz, a biological anthropologist from the University of California, Santa Cruz, who contributed to the study, concludes, "Taken all together, these findings bring attention to the diversity and complexity of people from Amazonia and their interactions with neighboring regions of the Andes. The genetic inheritance of South American people still bears traces of the important events that took place before the historical record in colonial times."

Special permeable concrete pavement can help reduce the "urban heat island effect" that causes cities to sizzle in the summer, according to a Rutgers-led team of engineers.

Their study appears in the Journal of Cleaner Production.

Impermeable pavement made of concrete or asphalt covers more than 30 percent of most urban areas and can exceed 140 degrees Fahrenheit in the summertime. It heats the air, posing human health risks, and surface runoff, threatening aquatic life.

In cities with 1 million or more people, average air temperatures can be 1.8 to 5.4 degrees Fahrenheit higher than in less densely populated areas. The difference can be up to 22 degrees at night. The heat can increase peak demand for energy in the summertime, air conditioning costs, air pollution and greenhouse gas emissions, heat-related illness and deaths, and water pollution, according to the U.S. Environmental Protection Agency.

The engineering team at Rutgers developed designs for permeable concrete that is highly effective in handling heat. Permeable pavement contains large connected pores, allowing water to drain through and reducing pavement temperature. Water in pores will also evaporate, reducing pavement surface temperature. Moreover, permeable concrete pavement does a better job reflecting heat than asphalt pavement.

The study found that permeable concrete pavement gives off slightly more heat on sunny days compared with conventional concrete pavement, but 25 to 30 percent less heat on days after rainfall. The engineers improved the design of permeable concrete with high thermal conductivity - meaning it can transfer heat more quickly to the ground - further reducing heat output by 2.5 percent to 5.2 percent.

"Highly efficient permeable concrete pavement can be a valuable, cost-effective solution in cities to mitigate the urban heat island effect, while benefitting stormwater management and improving water quality," said corresponding author Hao Wang, an associate professor in the Department of Civil and Environmental Engineering in the School of Engineering at Rutgers University-New Brunswick. He is also an affiliated researcher at the Center for Advanced Infrastructure and Transportation.

Incorporating industry byproducts and waste into permeable concrete can increase its economic and environmental benefits. In another study in the Journal of Cleaner Production, Wang's team designed permeable concrete with fly ash and steel slag to reduce the costs, energy consumption and greenhouse gas emissions linked to raw materials.

Previously, permeable pavement has been used as green infrastructure to reduce stormwater runoff and flooding risk in urban areas. Today, permeable concrete is mainly used in lightly trafficked areas, such as sidewalks, parking lots and rest areas. The Rutgers-led team is studying how to make permeable concrete stronger and more durable so it can be used in urban streets.