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Because consumer reviews leverage the wisdom of the crowd, the way in which they are aggregated is a central decision faced by platforms. We explore this "rating aggregation problem" and offer a structural approach to solving it, allowing for (1) reviewers to vary in stringency and accuracy, (2) reviewers to be influenced by existing reviews, and (3) product quality to change over time. Applying this to restaurant reviews from Yelp.com, we construct an adjusted average rating and show that even a simple algorithm can lead to large information efficiency gains relative to the arithmetic average.

Reducing Administrative Burdens in Social Safety Net Programs Reduces Mortality

As a strategy for combating physical inactivity, obesity, and other health conditions, the apperception of greenspace and importance of human-nature relationships have increased in recent decades. With this raised awareness in greenspace, the development of park auditing tools has been positioned primarily in the material conditions (e.g., physical environmental conditions) of parks. An examination of existing park auditing tools has shown that by focusing on particular material conditions, built environment and active living scholars have set aside other characteristics, namely, those that consider the user (e.g., the active human), as a separate concern from the focus of these tools. We have sought to engage with these tools to examine how they can be more effective in analyzing both the physical and human elements of parks and other natural environments.

NIH $3.7 million interdisciplinary grant will focus on residential air quality, state policies and legal protections

Purpose Psychosocial stress has been associated with susceptibility to many infectious pathogens. We evaluated the association between perceived stress and incident sexually transmitted infections (STIs;  Chlamydia trachomatis ,  Neisseria gonorrhoeae , and  Trichomonas vaginalis  genital infections) in a prospective study of women. Stress may increase vulnerability to STIs by suppressing immune function and altering the protective vaginal microbiota. Methods Using the 1999 Longitudinal Study of Vaginal Flora (n  = 2439), a primarily African American cohort of women, we fitted Cox proportional hazards models to examine the association between perceived stress and incident STIs. We tested  bacterial vaginosis  (measured by Nugent Score) and sexual behaviors (condom use, number of partners, and partner concurrence) as mediators using VanderWeele's difference method. Results Baseline perceived stress was associated with incident STIs both before and after adjusting for confounders (adjusted hazard ratio = 1.015; 95% confidence interval, 1.005–1.026). Nugent score and sexual behaviors significantly mediated 21% and 65% of this adjusted association, respectively, and 78% when included together in the adjusted model. Conclusions This study advances understanding of the relationship between perceived stress and STIs and identifies high-risk sexual behaviors and development of bacterial vaginosis—both known risk factors for STIs—as mechanisms underlying this association.

Judith Hellerstein, University of Maryland; Mark Duggan, University of Pennsylvania; Abby Alpert, University of California Irvine; 2013-021

Agricultural water withdrawals account for the largest proportion of global freshwater use. Increasing municipal water demands and droughts are straining agricultural water supplies. Therefore, alternative solutions to agricultural water crises are urgently needed, including the use of nontraditional water sources such as advanced treated wastewater or reclaimed water, brackish water, return flows, and effluent from produce processing facilities. However, it is critical to ensure that such usage does not compromise soil, crop, and public health. Here, we characterized five different nontraditional water types (n = 357 samples) for the presence of pharmaceuticals, herbicides, and disinfectants using ultra-high-pressure liquid chromatography tandem mass spectrometry based method (UPLC-MS/MS). We then evaluated whether the levels of these contaminants were influenced by season. The highest level of herbicides (atrazine) was detected in untreated pond water (median concentration 135.9 ng/L). Reclaimed water had the highest levels of antibiotics and stimulants including azithromycin (215 ng/L), sulfamethoxazole (232.1 ng/L), and caffeine (89.4 ng/L). Produce processing plant water also tended to have high levels of atrazine (102.7 ng/L) and ciprofloxacin (80.1 ng/L). In addition, we observed seasonal variability across water types, with the highest atrazine concentrations observed during summer months, while the highest median azithromycin concentrations were observed in reclaimed water during the winter season. Further studies are needed to evaluate if economically feasible on-farm water treatment technologies can effectively remove such contaminants from nontraditional irrigation water sources.

Police departments across the country are reporting a spike in domestic violence cases as stay-at-home orders put victims and their abusers in constant proximity.

The Care Work System. Changes and Continuities in the Provision of Care