Research Brief

The ways an urban neighborhood is built and the characteristics of the people who live there are both related to how hot it gets. That is the result of our study, published by the Journal of Buildings. If you have ever noticed that some parts of a city feel significantly hotter than others, you have experienced a phenomenon known as the urban heat island effect. This effect is most noticeable at night and when comparing rural and suburban surroundings with urban ones. How we did our work Our interdisciplinary group of researchers studied two Philadelphia census tracts and found a clear link between outdoor temperature and specific urban characteristics. We then asked whether these urban characteristics can be related to the social vulnerability of the residents. Social vulnerability is a concept that goes beyond the residents’ income to include housing conditions and characteristics of the people – such as their age, education, disability and race. Our social vulne...

Many sharks and rays are known to breach, leaping fully or partly out of the water. In a recent study, colleagues and I reviewed research on breaching and ranked the most commonly hypothesized functions for it. We found that removal of external parasites was the most frequently proposed explanation, followed by predators chasing their prey; predators concentrating or stunning their prey; males chasing females during courtship; and animals fleeing predators, such as a ray escaping from a hammerhead shark in shallow water. We found that the highest percentage of breaches, measured by the number of studies that described it, occurred in manta rays and devil rays, followed by basking sharks and then by eagle rays and cownose rays. However, many other species of sharks, as well as sawfishes and stingrays, also perform this behavior. A breaching white shark surprises researchers off Cape Cod, Massachusetts. Why it matters It takes a lot of ene...

Citrus trees showing natural tolerance to citrus greening disease host bacteria that produce novel antimicrobials that can be used to fight off the disease, our recent study shows. We found the trees at an organic farm in Clermont, Florida. Citrus greening disease – known more formally as Huanglongbing, or HLB, is caused by the bacterium Candidatus Liberibacter asiaticus. It is spread by an insect called the Asian citrus psyllid. There is no known cure for the disease. We are Florida-based researchers who study sustainable farming practices, a discipline also known as agroecology. Our team has isolated these antimicrobial compounds in the lab and is now working to test them with the goal of producing an effective treatment for HLB. Why it matters HLB has dealt a massive blow to Florida’s iconic citrus industry. Since citrus greening disease was first detected in the state in 2005, Florida citrus production is down by more than 92%. The disease is just one factor....

The Research Brief is a short take about interesting academic work. The big idea Consumer products released more than 5,000 tons of chemicals in 2020 inside California homes and workplaces that are known to cause cancer, adversely affect sexual function and fertility in adults or harm developing fetuses, according to our newly published study. We found that many household products like shampoos, body lotions, cleaners and mothballs release toxic volatile organic compounds, or VOCs, into indoor air. In addition, we identified toxic VOCs that are prevalent in products heavily used by workers on the job, such as cleaning fluids, adhesives, paint removers and nail polish. However, gaps in laws that govern ingredient disclosure mean that neither consumers nor workers generally know what is in the products they use. For this study we analyzed data from the California Air Resources Board (CARB), which tracks VOCs released from consumer products in an effort to reduce smog. The agen...

The Research Brief is a short take about interesting academic work. The big idea Psychological trauma from extreme weather and climate events, such as wildfires, can have long-term impacts on survivors’ brains and cognitive functioning, especially how they process distractions, my team’s new research shows. Climate change is increasingly affecting people around the world, including through extreme heat, storm damage and life-threatening events like wildfires. In previous research, colleagues and I showed that in the aftermath of the 2018 fire that destroyed the town of Paradise, California, chronic symptoms of post-traumatic stress disorder (PTSD), anxiety and depression were highly prevalent in the affected communities more than six months after the disaster. We also found a graded effect: People whose homes or families were directly affected by fire showed greater mental health harm than those where who were indirectly effected, meaning people who witnessed the e...