Anticipating Adulthood: Expected Timing of Work and Family Transitions Among Rural youth

This study examined family and individual processes influencing the future expectancies of adolescents (N = 345) from an economically stressed rural community. The anticipated timing and sequencing of key role transitions (school completion, job entry, marriage, and parenthood) were examined for each gender. In addition, factors contributing to individual differences in expected timing were examined, and gender differences in predictors were tested. Results indicated that rural adolescents\u27 expectancies about adult role transitions diverged somewhat from societal norms with respect to timing. Family background and relationships, adolescents\u27 attitudes and behaviors, and educational aspirations all contributed to individual differences in expected timing, with somewhat different factors being salient for boys and girls. These findings provide clues to the psychological processes linking adolescent experiences to the construction of the adult life course

On Consistency of Self- and Proxy-reported Regular Smoking Initiation Age

Early onset of smoking is associated with heavier tobacco consumption and longer smoking careers. Consequently, obtaining accurate estimates of early smoking is a priority. The purpose of this study was to examine the utility of proxy reports of the age of smoking initiation, and specifically to explore whether there are differences in the consistency of proxy-reported and self-reported smoking behaviors. Data came from the 2002–2003 Tobacco Use Supplement to the Current Population Survey, where the current smoking behaviors and smoking history of participants were reported by self-and proxy-respondents on two occasions, one year apart. Sequential multiple-testing methods were used to assess significance of the differences in reported prevalence of consistent reports among specific sub-populations defined by age, gender and survey administration mode. Results indicated that self-reports are more reliable (more consistent over time) than proxy reports or mixed reports that include self-report at one time point and proxy reports at another. The rate of perfect agreement was also highest for self-reports. The impact of respondent type on the consistency of reports also depended on the target subjects’ age and the survey administration mode (phone or in-person)

Perception of Time Since Smoking Cessation: Time in Memory Can Elapse Faster

Self-reports concerning smoking behaviors are subject to different types of response bias that may severely affect the data quality. This study examined the evidence and extent of backward telescoping bias in reports on time since completely quitting smoking among former smokers. The study goals were to determine whether the extent of bias differs, on average, across subpopulations with diverse sociodemographic characteristics, prior smoking habits and duration of smoking abstinence, and across the survey administration mode (phone, in-person, mixed). The sample included 1,611 subjects who responded to the 2002–2003 Tobacco Use Supplement to the Current Population Survey. Multiple regressions for subjects who quit smoking recently, some time ago, and a long time ago were fitted, where the variance was estimated via the Balanced Repeated Replications approach. The model-based estimates were used to compare the extent of response bias across diverse subpopulations of respondents. Analyses revealed a significantly smaller overall extent of response bias for respondents who were younger (p \u3c 0.01), female (p \u3c 0.01), Non-Hispanic White (p = 0.02), employed (p \u3c 0.01), who were regular (rather than occasional) smokers in the past (p \u3c 0.01), and who quit smoking recently or some time ago as opposed to a long time ago (p \u3c 0.01); a significant overall effect of survey mode was also detected (p \u3c 0.01). Male respondents who smoked occasionally in the past tended to provide the most disagreeing reports. The discrepancy in reports may be due to backward telescoping bias. Studies which use the national survey smoking cessation measures should be aware of not only possible forward telescoping (that has been addressed in the literature) but also backward telescoping. This will help correctly account for possible impaired perception of time elapsed since smoking cessation in former smokers

On Consistency of Self- and Proxy-reported Regular Smoking Initiation Age

Early onset of smoking is associated with heavier tobacco consumption and longer smoking careers. Consequently, obtaining accurate estimates of early smoking is a priority. The purpose of this study was to examine the utility of proxy reports of the age of smoking initiation, and specifically to explore whether there are differences in the consistency of proxy-reported and self-reported smoking behaviors. Data came from the 2002–2003 Tobacco Use Supplement to the Current Population Survey, where the current smoking behaviors and smoking history of participants were reported by self-and proxy-respondents on two occasions, one year apart. Sequential multiple-testing methods were used to assess significance of the differences in reported prevalence of consistent reports among specific sub-populations defined by age, gender and survey administration mode. Results indicated that self-reports are more reliable (more consistent over time) than proxy reports or mixed reports that include self-report at one time point and proxy reports at another. The rate of perfect agreement was also highest for self-reports. The impact of respondent type on the consistency of reports also depended on the target subjects’ age and the survey administration mode (phone or in-person)

Perception of Time Since Smoking Cessation: Time in Memory Can Elapse Faster

Self-reports concerning smoking behaviors are subject to different types of response bias that may severely affect the data quality. This study examined the evidence and extent of backward telescoping bias in reports on time since completely quitting smoking among former smokers. The study goals were to determine whether the extent of bias differs, on average, across subpopulations with diverse sociodemographic characteristics, prior smoking habits and duration of smoking abstinence, and across the survey administration mode (phone, in-person, mixed). The sample included 1,611 subjects who responded to the 2002–2003 Tobacco Use Supplement to the Current Population Survey. Multiple regressions for subjects who quit smoking recently, some time ago, and a long time ago were fitted, where the variance was estimated via the Balanced Repeated Replications approach. The model-based estimates were used to compare the extent of response bias across diverse subpopulations of respondents. Analyses revealed a significantly smaller overall extent of response bias for respondents who were younger (p \u3c 0.01), female (p \u3c 0.01), Non-Hispanic White (p = 0.02), employed (p \u3c 0.01), who were regular (rather than occasional) smokers in the past (p \u3c 0.01), and who quit smoking recently or some time ago as opposed to a long time ago (p \u3c 0.01); a significant overall effect of survey mode was also detected (p \u3c 0.01). Male respondents who smoked occasionally in the past tended to provide the most disagreeing reports. The discrepancy in reports may be due to backward telescoping bias. Studies which use the national survey smoking cessation measures should be aware of not only possible forward telescoping (that has been addressed in the literature) but also backward telescoping. This will help correctly account for possible impaired perception of time elapsed since smoking cessation in former smokers

Follow-Up Observations of PTFO 8-8695: A 3 MYr Old T-Tauri Star Hosting a Jupiter-mass Planetary Candidate

We present Spitzer 4.5\micron\ light curve observations, Keck NIRSPEC radial velocity observations, and LCOGT optical light curve observations of PTFO~8-8695, which may host a Jupiter-sized planet in a very short orbital period (0.45 days). Previous work by \citet{vaneyken12} and \citet{barnes13} predicts that the stellar rotation axis and the planetary orbital plane should precess with a period of $300 - 600$ days. As a consequence, the observed transits should change shape and depth, disappear, and reappear with the precession. Our observations indicate the long-term presence of the transit events ($>3$ years), and that the transits indeed do change depth, disappear and reappear. The Spitzer observations and the NIRSPEC radial velocity observations (with contemporaneous LCOGT optical light curve data) are consistent with the predicted transit times and depths for the $M_\star = 0.34\ M_\odot$ precession model and demonstrate the disappearance of the transits. An LCOGT optical light curve shows that the transits do reappear approximately 1 year later. The observed transits occur at the times predicted by a straight-forward propagation of the transit ephemeris. The precession model correctly predicts the depth and time of the Spitzer transit and the lack of a transit at the time of the NIRSPEC radial velocity observations. However, the precession model predicts the return of the transits approximately 1 month later than observed by LCOGT. Overall, the data are suggestive that the planetary interpretation of the observed transit events may indeed be correct, but the precession model and data are currently insufficient to confirm firmly the planetary status of PTFO~8-8695b.Comment: Accepted for publication in The Astrophysical Journa

Differential Charge Sensing and Charge Delocalization in a Tunable Double Quantum Dot

We report measurements of a tunable double quantum dot, operating in the quantum regime, with integrated local charge sensors. The spatial resolution of the sensors is sufficient to allow the charge distribution within the double dot system to be resolved at fixed total charge. We use this readout scheme to investigate charge delocalization as a function of temperature and strength of tunnel coupling, showing that local charge sensing allows an accurate determination of interdot tunnel coupling in the absence of transport.Comment: related papers at http://marcuslab.harvard.ed