Analytic Examples, Measurement Models and Classical Limit of Quantum Backflow

We investigate the backflow effect in elementary quantum mechanics - the phenomenon in which a state consisting entirely of positive momenta may have negative current and the probability flows in the opposite direction to the momentum. We compute the current and flux for states consisting of superpositions of gaussian wave packets. These are experimentally realizable but the amount of backflow is small. Inspired by the numerical results of Penz et al (M.Penz, G.Gr\"ubl, S.Kreidl and P.Wagner, J.Phys. A39, 423 (2006)), we find two non-trivial wave functions whose current at any time may be computed analytically and which have periods of significant backflow, in one case with a backwards flux equal to about 70 percent of the maximum possible backflow, a dimensionless number $c_{bm} \approx 0.04$, discovered by Bracken and Melloy (A.J.Bracken and G.F.Melloy, J.Phys. A27, 2197 (1994)). This number has the unusual property of being independent of $\hbar$ (and also of all other parameters of the model), despite corresponding to an obviously quantum-mechanical effect, and we shed some light on this surprising property by considering the classical limit of backflow. We discuss some specific measurement models in which backflow may be identified in certain measurable probabilities.Comment: 33 pages, 14 figures. Minor revisions. Published versio

The Late Quaternary geology of the Housatonic River basin in southwestern Massachusetts and adjacent Connecticut

Guidebook for field trips in western Massachusetts, northern Connecticut and adjacent areas of New York: 67th annual meeting October 10, 11, and 12, 1975: Trip B-7; C-

Sedimentation in a proglacial lake: Glacial Lake Hitchcock

Guidebook for field trips in Connecticut and south central Massachusetts: New England Intercollegiate Geological Conference 74th annual meeting, University of Connecticut, Storrs Connecticut , October 2 and 3, 1982: Trip Q-

Correlates of Homeless Episodes among Indigenous People

This study reports the correlates of homeless episodes among 873 Indigenous adults who are part of an ongoing longitudinal study on four reservations in the Northern Midwest and four Canadian First Nation reserves. Descriptive analyses depict differences between those who have and have not experienced an episode of homelessness in their lifetimes. Multivariate analyses assess factors associated with a history of homeless episodes at the time of their first interview. Results show that individuals with a history of homeless episodes had significantly more individual and family health, mental health, and substance abuse problems. Periods of homelessness also were associated with financial problems. Among the female caretakers who experienced episodes of homelessness over the course of the study, the majority had been homeless at least once prior to the start of the study and approximately one–fifth met criteria for lifetime alcohol dependence, drug abuse, or major depression. Family adversity during childhood was also common for women experiencing homelessness during the study

Factors associated with growth in daily smoking among Indigenous adolescents

North American Indigenous adolescents smoke earlier, smoke more, and are more likely to become regular smokers as adults than youth from any other ethnic group, yet we know very little about their early smoking trajectories. We use multilevel growth modeling across five waves of data from Indigenous adolescents (aged 10-13 years at Wave 1) to investigate factors associated with becoming a daily smoker. Several factors, including number of peers who smoked at Wave 1 and meeting diagnostic criteria for major depressive episode and conduct disorder, were associated with early daily smoking. Only age and increases in the number of smoking peers were associated with increased odds of becoming a daily smoker. © 2012 The Authors. Journal of Research on Adolescence © 2012 Society for Research on Adolescence

Correlates of Homeless Episodes among Indigenous People

This study reports the correlates of homeless episodes among 873 Indigenous adults who are part of an ongoing longitudinal study on four reservations in the Northern Midwest and four Canadian First Nation reserves. Descriptive analyses depict differences between those who have and have not experienced an episode of homelessness in their lifetimes. Multivariate analyses assess factors associated with a history of homeless episodes at the time of their first interview. Results show that individuals with a history of homeless episodes had significantly more individual and family health, mental health, and substance abuse problems. Periods of homelessness also were associated with financial problems. Among the female caretakers who experienced episodes of homelessness over the course of the study, the majority had been homeless at least once prior to the start of the study and approximately one–fifth met criteria for lifetime alcohol dependence, drug abuse, or major depression. Family adversity during childhood was also common for women experiencing homelessness during the study

Factors Associated with Growth in Daily Smoking among Indigenous Adolescents

North American Indigenous adolescents smoke earlier, smoke more, and are more likely to become regular smokers as adults than youth from any other ethnic group yet we know very little about their early smoking trajectories. We use multilevel growth modeling across five waves of data from Indigenous adolescents (aged 10 to 13 years at Wave 1) to investigate factors associated with becoming a daily smoker. Several factors, including number of peers who smoked at Wave 1 and meeting diagnostic criteria for major depressive episode and conduct disorder were associated with early daily smoking. Only age and increases in the number of smoking peers were associated with increased odds of becoming a daily smoker

Factors Associated with Growth in Daily Smoking among Indigenous Adolescents

North American Indigenous adolescents smoke earlier, smoke more, and are more likely to become regular smokers as adults than youth from any other ethnic group yet we know very little about their early smoking trajectories. We use multilevel growth modeling across five waves of data from Indigenous adolescents (aged 10 to 13 years at Wave 1) to investigate factors associated with becoming a daily smoker. Several factors, including number of peers who smoked at Wave 1 and meeting diagnostic criteria for major depressive episode and conduct disorder were associated with early daily smoking. Only age and increases in the number of smoking peers were associated with increased odds of becoming a daily smoker

A Longitudinal Examination of the Measurement Properties and Predictive Utility of the Center for Epidemiologic Studies Depression Scale Among North American Indigenous Adolescents

We examined the longitudinal measurement properties and predictive utility of the Center for Epidemiologic Studies Depression Scale (CES-D) from early to late adolescence among a sample of North American Indigenous youths. Participants were 632 North American Indigenous adolescents (n = 632; 50.3% girls; M age at baseline = 11.11 years) participating in an 8-year, 8-wave longitudinal study. Via in-person interviews, participants completed the CES-D at Waves 1, 3, 5, and 7, and the major depressive disorder (MDD) module of the Diagnostic Interview Schedule for Children at Waves 1, 4, 6, and 8. Confirmatory factor analyses indicated that responses to the CES-D were similarly explained by 2-, 3-, and 4-factor models, as well as a 1-factor model with correlations between the error variances for the positively worded items. Longitudinal measurement equivalence analyses indicated full structural (i.e., factor structure), metric (i.e., factor loadings), and scalar (i.e., observed item intercepts) equivalence for each factor structure. Substantive analyses showed that the CES-D was significantly associated with MDD both concurrently and prospectively, although these effects were smaller than might be expected. Finally, the CES-D negative affect and somatic complaints subscales were the strongest and most consistent predictors of MDD. Among our sample of North American Indigenous youths, the measurement properties of the CES-D were stable from early to late adolescence. Moreover, somatic difficulties and depressed affect were the strongest predictors of MDD