This research examines whether transportation network companies (TNCs), such as Uber and Lyft, live up to their stated vision of reducing congestion in major cities. Existing research has produced conflicting results and has been hampered by a lack of data. Using data scraped from the application programming interfaces of two TNCs, combined with observed travel time data, we find that contrary to their vision, TNCs are the biggest contributor to growing traffic congestion in San Francisco. Between 2010 and 2016, weekday vehicle hours of delay increased by 62% compared to 22% in a counterfactual 2016 scenario without TNCs. The findings provide insight into expected changes in major cities as TNCs continue to grow, informing decisions about how to integrate TNCs into the existing transportation system.
Vaginal microbicides currently under development are substances that may prevent the transmission of HIV. Qualitative, in-depth post-trial interview data from a Phase III clinical trial of 6% Cellulose Sulfate microbicide gel in two sites in Africa (Uganda and Benin) and two in India (Chennai and Bagalkot) were examined in order to better understand factors that influence microbicide acceptability and adherence in a clinical trial setting. Women found the gel relatively easy to use with partners with whom there were no expectations of fidelity, in situations where they had access to private space and at times when they were expecting to engage in sexual intercourse. Adherence to gel seemed significantly more difficult with primary partners due to decreased perceptions of risk, inconvenience or fear of partner disapproval. Findings suggest that women in a variety of settings may find a microbicide gel to be highly acceptable for its lubricant qualities and protective benefits but that adherence and consistent use may depend greatly on contextual and partner-related factors. These findings have important implications for future trial designs, predicting determinants of microbicide use and acceptability and marketing and educational efforts should a safe and efficacious microbicide be found.
the HVTN 704/HPTN 085 study group Background: The Antibody-Mediated Prevention trials (HVTN 704/ HPTN 085 and HVTN 703/HPTN 081) are the first efficacy trials to evaluate whether VRC01, a broadly neutralizing monoclonal antibody targeting the CD4-binding site of the HIV envelope protein, prevents sexual transmission of HIV-1. HVTN 704/HPTN 085 enrolled 2701 cisgender men and transgender (TG) individuals who have sex with men at 26 sites in Brazil, Peru, Switzerland, and the United States.Methods: Participants were recruited and retained through early, extensive community engagement. Eligible participants were randomized 1:1:1 to 10 mg/kg or 30 mg/kg of VRC01 or saline placebo. Visits occurred monthly, with intravenous (IV) infusions every 8 weeks over 2 years, for a total of 10 infusions. Participants were followed for 104 weeks after first infusion.
Results:The median HVTN 704/HPTN 085 participant age was 28 years; 99% were assigned male sex; 90% identified as cisgender men, 5% as TG women and the remaining as other genders. Thirtytwo percent were White, 15% Black, and 57% Hispanic/Latinx. Twenty-eight percent had a sexually transmitted infection at enrollment. More than 23,000 infusions were administered with no serious IV administration complications. Overall, retention and adherence to the study schedule exceeded 90%, and the dropout rate was below 10% annually (7.3 per 100 person-years) through week 80, the last visit for the primary end point.Conclusions: HVTN 704/HPTN 085 exceeded accrual and retention expectations. With exceptional safety of IV administration and operational feasibility, it paves the way for future large-scale monoclonal antibody trials for HIV prevention and/or treatment.
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