No abstract

Limited research has examined polysubstance use profiles among young adults focusing on the various tobacco products currently available. We examined use patterns of various tobacco products, marijuana, and alcohol using data from the baseline survey of a multiwave longitudinal study of 3418 students aged 18-25 recruited from seven U.S. college campuses. We assessed sociodemographics, individual-level factors (depression; perceptions of harm and addictiveness,), and sociocontextual factors (parental/friend use). We conducted a latent class analysis and multivariable logistic regression to examine correlates of class membership (Abstainers were referent group). Results indicated five classes: Abstainers (26.1% per past 4-month use), Alcohol only users (38.9%), Heavy polytobacco users (7.3%), Light polytobacco users (17.3%), and little cigar and cigarillo (LCC)/hookah/marijuana co-users (10.4%). The most stable was LCC/hookah/marijuana co-users (77.3% classified as such in past 30-day and 4-month timeframes), followed by Heavy polytobacco users (53.2% classified consistently). Relative to Abstainers, Heavy polytobacco users were less likely to be Black and have no friends using alcohol and perceived harm of tobacco and marijuana use lower. Light polytobacco users were older, more likely to have parents using tobacco, and less likely to have friends using tobacco. LCC/hookah/marijuana co-users were older and more likely to have parents using tobacco. Alcohol only users perceived tobacco and marijuana use to be less socially acceptable, were more likely to have parents using alcohol and friends using marijuana, but less likely to have friends using tobacco. These findings may inform substance use prevention and recovery programs by better characterizing polysubstance use patterns.

Using the earth‐orbiting spacecraft IMP‐8, we have performed a high time‐resolution (2.5‐min) study of the linear cross‐correlations of a quantitative indicator of magnetospheric substorm activity, the auroral electrojet (AE) index, with several interplanetary (IP) parameters. The present study includes all available satellite data (from an eight‐month period) rather than selecting a small number of substorm events, or a relatively small number of chosen days. Prior published studies have suggested that geomagnetic activity is related to a variety of solar wind parameters: solar wind speed (V); north‐south magnetic field component (Bz); total interplanetary magnetic field (IMF) strength (B); and various combinations of these parameters. Very recently, a new parameter, ϵ(= VB² sin4(θ/2)ℓo²), has been suggested as a superior predictor of substorm activity. The other major preferred correlator with geomagnetic activity is VBs, where Bs is the southward (Bz < 0) component of the IMF. Substantial discussion has ensued as to which parameter is the "best" predictor of substorm activity. The present non‐selective, high‐resolution analysis reveals that VBs generally reaches a higher peak correlation than ϵ (0.6 vs 0.54). Both parameters reach a peak correlation at the same lag time (with AE lagging the IP parameters by ∼40 min.), but VBs also appears to have a preferable qualitative lag profile shape for AE prediction purposes.

The link between fear of infertility and perceived identity was found to be a major factor in young women's contraceptive decision making. In order to increase uptake of IUDs, the beliefs of women must be addressed.

Background Marijuana-tobacco co-use has increased recently, particularly in young adults. Objectives We conducted a mixed-methods study to: (1) examine reasons for co-use; and (2) develop a scale assessing reasons for co-use among participants in a longitudinal cohort study of 3,418 students aged 18-25 from 7 Georgia colleges and universities. Methods Phone-based semi-structured interviews were conducted in Summer 2015 among 46 current (past 30-day, n = 26) or lifetime (n = 20) marijuana users. Subsequently, scale items were developed and included at Wave 3. Participants reporting past 4-month tobacco and marijuana use (n = 328) completed the Reasons for Marijuana-Tobacco Co-use section. Results Per qualitative data, reasons for marijuana-tobacco co-use included synergistic effects, one triggering or preceding the other’s use, using one to reduce the other’s use, co-administration, social context, and experimentation. The survey subsample included 37.1% who used cigarettes, 30.4% LCCs, 9.4% smokeless, 23.7% e-cigarettes, and 30.4% hookah. Four subscale factors emerged: (1) Instrumentality, indicating synergistic effects; (2) Displacement, indicating using one product to reduce/quit the other; (3) Social context, indicating use in different settings/social situations; and (4) Experimentation, indicating experimentation with both but no specific reasons for co-use. These subscales demonstrated distinct associations with tobacco type used; nicotine dependence; marijuana and alcohol use frequency; tobacco and marijuana use motives, respectively; perceptions of tobacco and marijuana; and parental and friend use. Including these subscales in regressions predicting nicotine dependence and days of marijuana use significantly contributed to each model. Conclusions These findings might inform theoretical frameworks upon which marijuana-tobacco co-use occurs and direct future intervention studies.