SUMMARYIn this study of the mosquito, Culex pipiens, we examined the impact of multiple bouts of dehydration and rehydration on survival, depletion of metabolic reserves and egg production in both non-diapausing and diapausing females. Mosquitoes provided with access to sugar during rehydration survived longer than those allowed to rehydrate without sugar, and their survival was similar to that of mosquitoes of the same age that were not dehydrated. Among mosquitoes not provided with sugar, each dehydration bout reduced the mosquito's dry mass -an effect likely to be due to the utilization of carbohydrates and lipid reserves. The toll on glycogen and lipid reserves is likely to be especially costly for diapausing mosquitoes that are dependent on these stored reserves for winter survival. Egg production in both non-diapausing and post-diapausing C. pipiens was also reduced in response to multiple bouts of dehydration. Although egg quality was not compromised, the number of eggs produced was reduced. Both non-diapausing and diapausing females can compensate for the nutrient loss due to dehydration by sugar feeding but the opportunity to feed on sugar is likely to be rarely available in the overwintering habitat of diapausing females, thus the impact of dehydration may be especially pronounced in overwintering populations of C. pipiens.

Background In total, 3.2% of American adults report using e-cigarettes every day or some days. The Vaping and Patterns of E-cigarette Use Research (VAPER) Study is a web-based longitudinal survey designed to observe patterns in device and liquid use that suggest the benefits and unintended consequences of potential e-cigarette regulations. The heterogeneity of the e-cigarette devices and liquids on the market, the customizability of the devices and liquids, and the lack of standardized reporting requirements result in unique measurement challenges. Furthermore, bots and survey takers who submit falsified responses are threats to data integrity that require mitigation strategies. Objective This paper aims to describe the protocols for 3 waves of the VAPER Study and discuss recruitment and data processing experiences and lessons learned, including the benefits and limitations of bot- and fraudulent survey taker–related strategies. Methods American adults (aged ≥21 years) who use e-cigarettes ≥5 days per week are recruited from up to 404 Craigslist catchment areas covering all 50 states. The questionnaire measures and skip logic are designed to accommodate marketplace heterogeneity and user customization (eg, different skip logic pathways for different device types and customizations). To reduce reliance on self-report data, we also require participants to submit a photo of their device. All data are collected using REDCap (Research Electronic Data Capture; Vanderbilt University). Incentives are US $10 Amazon gift codes delivered by mail to new participants and electronically to returning participants. Those lost to follow-up are replaced. Several strategies are applied to maximize the odds that participants who receive incentives are not bots and are likely to possess an e-cigarette (eg, required identity check and photo of a device). Results In total, 3 waves of data were collected between 2020 and 2021 (wave 1: n=1209; wave 2: n=1218; wave 3: n=1254). Retention from waves 1 to 2 was 51.94% (628/1209), and 37.55% (454/1209) of the wave 1 sample completed all 3 waves. These data were mostly generalizable to daily e-cigarette users in the United States, and poststratification weights were generated for future analyses. Our data offer a detailed examination of users’ device features and specifications, liquid characteristics, and key behaviors, which can provide more insights into the benefits and unintended consequences of potential regulations. Conclusions Relative to existing e-cigarette cohort studies, this study methodology has some advantages, including efficient recruitment of a lower-prevalence population and collection of detailed data relevant to tobacco regulatory science (eg, device wattage). The web-based nature of the study requires several bot- and fraudulent survey taker–related risk-mitigation strategies, which can be time-intensive. When these risks are addressed, web-based cohort studies can be successful. We will continue to explore methods for maximizing recruitment efficiency, data quality, and participant retention in subsequent waves. International Registered Report Identifier (IRRID) DERR1-10.2196/38732

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ObjectiveThis study, conducted in China, evaluated the effectiveness of four different themes of health warning labels (HWLs) that used both text and pictures: (1) self-harm from using cigarettes, (2) harming family or children with secondhand smoke, (3) reinforcing compliance with existing smoke-free policies and (4) anticigarette gift giving practices.MethodsA cross-sectional randomised experimental survey was conducted among 3247 adult (aged 18+ years) participants in Beijing, Shanghai and Shenzhen in 2017, using quotas for age group, gender and smoking status. Participants were randomly assigned to one of the four HWL themes. Each participant viewed eight HWLs and rated how effective these themed-labels were in terms of credibility, raising awareness of health harms of smoking on family and children, improving compliance with public smoking bans, stopping the practice of gifting cigarettes, thinking about quitting and preventing smoking using a 10-point scale, with 10 being most effective. Analysis of variance and independent t-tests were used to analyse these data.FindingsAll four HWL themes performed well for each outcome with average ratings >6.5. Harming family or children with secondhand smoke was the theme that received the highest ratings for each outcome, with credibility (8.0, 95% CI 7.86 to 8.09) and prevention of smoking (8.8, 95% CI 8.63 to 8.91) outcomes being significantly higher (p<0.05). Overall, analysis of ratings by gender, income and education did not impact outcomes.ConclusionAll four HWL themes tested could be effective in China; the theme of secondhand smoke harming family or children may be a particularly credible/effective theme.