Active transportation: Do current traffic safety policies protect non-motorists?

Objective

This study investigated the impact that state traffic safety regulations have on non-motorist fatality rates.

Methods

Data obtained from the National Highway Traffic Safety Administration (NHTSA), the Federal Highway Administration (FHWA), and the National Institute on Alcohol Abuse and Alcoholism (NIAAA) were analyzed through a pooled time series cross-sectional model using fixed effects regression for all 50 states from 1999 to 2009. Two dependent variables were used in separate models measuring annual state non-motorist fatalities per million population, and the natural log of state non-motorist fatalities. Independent variables measuring traffic policies included state expenditures for highway law enforcement and safety per capita; driver cell phone use regulations; graduated driver license regulations; driver blood alcohol concentration regulations; bike helmet regulations; and seat belt regulations. Other control variables included percent of all vehicle miles driven that are urban and mean per capita alcohol consumption per year.

Results

Non-motorist traffic safety was positively impacted by state highway law enforcement and safety expenditures per capita, with a decrease in non-motorist fatalities occurring with increased spending. Per capita consumption of alcohol also influenced non-motorist fatalities, with higher non-motorist fatalities occurring with higher per capita consumption of alcohol. Other traffic safety covariates did not appear to have a significant impact on non-motorist fatality rates in the models.

Conclusion

Our research suggests that increased expenditures on state highway and traffic safety and the initiation/expansion of programs targeted at curbing both driver and non-motorist intoxication are a starting point for the implementation of traffic safety policies that reduce risks for non-motorists.     

A nanoscale mechanism of fatigue in ionic solids

We employ periodic density functional theory to explore the effect of cyclic tensile loading on the behavior of alumina in the threshold region of crack formation. We find evidence for nanoscale fatigue when the alumina lattice is subjected to uniaxial tensile loading and unloading and tensile stresses normal to the applied load. It is possible that such atomic-scale fatigue impacts the durability of ceramics, since the highly ionic bonding requires near-ideal lattice structures in order to maintain cohesive strength.     

Sleep timing and quantity in ecological and family context: A nationally representative time-diary study.

Associations between demographic characteristics, school schedules, activity choices, family functioning, and sleep behaviors were estimated using nationally representative time-diary data from 2,454 children (ages 5.5 to 11.9 years) and adolescents (ages 12.0 to 19.1 years). For weekdays, African American adolescents, Asian children, and those with earlier school start times and longer travel times to school reported fewer sleep hours. More time spent watching television (for children), doing homework (for adolescents), and engaging in religious activities predicted fewer hours, whereas a longer time spent on meals predicted greater hours of weekday sleep. For younger children, greater parental warmth predicted more hours of weekday sleep, whereas for adolescents, stricter household rules were protective. On weekends, African American adolescents and Hispanic children slept less, and there were strong effects of activity choices including time spent on television, computer and videogames, sports, religious activities, socializing, and employment. In accounting for age-related decreases in sleep hours from childhood to adolescence, earlier school start times, greater hours of homework, greater paid employment, less time spent on meals, and fewer household rules were all significant mediators. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Toward Oxidation-Resistant ZrB<Subscript>2</Subscript>-SiC Ultra High Temperature Ceramics

Ultra high temperature ceramics (UHTCs), including ZrB₂-SiC, are designed for extreme environment applications in which temperatures exceed 2273 K (2000 °C). A key material property of UHTCs in many applications is their resistance to oxidation. Recent research into UHTCs is described, revealing a variety of different methods for improving the oxidation performance, which include control of starting powders, composition and size distribution, mixing, and densification techniques. The use of additives has also been researched widely, for example, to increase the viscosity of any liquid phase formed or provide protective refractory phases at high temperatures. SiC additions are effective in forming protective silica but only in static environments and to ~1873 K (1600 °C). For higher temperature applications, additions of La lead to the formation of a dense ZrO₂ scale probably via liquid phase sintering. Such ceramic systems, which produce self-generating refractory oxidation barriers or dense ZrO₂ scales, show the greatest promise in providing oxidation-resistant UHTCs.     

Mother and child interpretations of threat in ambiguous situations: Relations with child anxiety and autonomic responding.

This study examined maternal and child interpretive bias to threat (IBT) during dyadic conversation, child physiological reactivity and regulation during dyadic conversation, and maternal report of child anxiety in a community sample of 35 mothers and their 8- to 10-year-old children. Mothers and children discussed one neutral and six ambiguous scenarios, which were subsequently coded for frequency of maternal and child initiation, minimization, and expansion of threat-related themes. Child electrocardiogram data were collected during these conversations and maternal reports of child anxiety and internalizing problems were obtained. Across the sample, children initiated threat-related discussion more often than mothers. Maternal threat expansions were significantly positively correlated with child anxiety and internalizing behaviors. Maternal minimizations of threat were significantly associated with augmented child vagal tone throughout the IBT paradigm. Implications for prevention of child anxiety and directions for extending IBT research within the context of the mother–child dyad are discussed. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Growth trajectories of exercise self-efficacy in older adults: Influence of measures and initial status.

Objective: This study examined differential trajectories of exercise-related self-efficacy beliefs across a 12-month randomized controlled exercise trial. Method: Previously inactive older adults (N = 144; M age = 66.5) were randomly assigned to one of two exercise conditions (walking, flexibility-toning-balance) and completed measures of barriers self-efficacy (BARSE), exercise self-efficacy (EXSE), and self-efficacy for walking (SEW) across a 12-month period. Changes in efficacy were examined according to efficacy type and interindividual differences. Latent growth curve modeling was employed to (a) examine average levels and change in each type of efficacy for the collapsed sample and by intervention condition and (b) explore subpopulations (i.e., latent classes) within the sample that differ in their baseline efficacy and trajectory. Results: Analyses revealed two negative trends in BARSE and EXSE at predicted transition points, in addition to a positive linear trend in SEW. Two subgroups with unique baseline efficacy and trajectory profiles were also identified. Conclusion: These results shed new light on the relationship between exercise and self-efficacy in older adults. They also highlight the need for strategies for increasing and maintaining efficacy within interventions, namely targeting participants who start with a disadvantage (lower efficacy) and integrating efficacy-boosting strategies for all participants prior to program end. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Health and turnover of working mothers after childbirth via the work–family interface: An analysis across time.

This study examined organizational levers that impact work–family experiences, participant health, and subsequent turnover. Using a sample of 179 women returning to full-time work 4 months after childbirth, we examined the associations of 3 job resources (job security, skill discretion, and schedule control) with work-to-family enrichment and the associations of 2 job demands (psychological requirements and nonstandard work schedules) with work-to-family conflict. Further, we considered subsequent impact of work-to-family conflict and enrichment on women's health (physical and mental health) 8 months after women returned to work and the impact of health on voluntary turnover 12 months after women returned to work. Having a nonstandard work schedule was directly and positively related to conflict, whereas schedule control buffered the effect of psychological requirements on conflict. Skill discretion and job security, both job resources, directly and positively related to enrichment. Work-to-family conflict was negatively related to both physical and mental health, but work-to-family enrichment positively predicted only physical health. Physical health and mental health both negatively influenced turnover. We discuss implications and opportunities for future research. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Malleability in communal goals and beliefs influences attraction to stem careers: Evidence for a goal congruity perspective.

The goal congruity perspective posits that 2 distinct social cognitions predict attraction to science, technology, engineering, or mathematics (STEM) fields. First, individuals may particularly value communal goals (e.g., working with or helping others), due to either chronic individual differences or the salience of these goals in particular contexts. Second, individuals hold beliefs about the activities that facilitate or impede these goals, or goal affordance stereotypes. Women's tendency to endorse communal goals more highly than do men, along with consensual stereotypes that STEM careers impede communal goals, intersect to produce disinterest in STEM careers. We provide evidence for the foundational predictions that gender differences emerge primarily on communal rather than agentic goals (Studies 1a and 3) and that goal affordance stereotypes reflect beliefs that STEM careers are relatively dissociated from communal goals (Studies 1b and 1c). Most critically, we provide causal evidence that activated communal goals decrease interest in STEM fields (Study 2) and that the potential for a STEM career to afford communal goals elicits greater positivity (Study 3). These studies thus provide a novel demonstration that understanding communal goals and goal affordance stereotypes can lend insight into attitudes toward STEM pursuits. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Alcohol dependence symptoms among college freshmen: Prevalence, stability, and person-environment interactions.

College students are at risk for problematic alcohol use. Few studies, however, have examined alcohol dependence symptoms within a college sample. The current study assesses the prevalence, predictors, and stability of proxy Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) alcohol dependence symptoms among college freshmen. Participants were 3,720 freshmen taking part in a longitudinal study. Participants completed measures of alcohol use, fraternity and sorority membership, and behavioral undercontrol. Results revealed that alcohol dependence symptoms were prevalent and moderately stable among college freshmen. Both membership in a Greek organization and behavioral undercontrol predicted responses to our alcohol dependence proxy. In addition, Greek status interacted with behavioral undercontrol to predict alcohol dependence symptoms, such that Greek members high in behavioral undercontrol were especially vulnerable to symptoms of dependence. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Everyday magical powers: The role of apparent mental causation in the overestimation of personal influence.

These studies examined whether having thoughts related to an event before it occurs leads people to infer that they caused the event--even when such causation might otherwise seem magical. In Study 1, people perceived that they had harmed another person via a voodoo hex. These perceptions were more likely among those who had first been induced to harbor evil thoughts about their victim. In Study 2, spectators of a peer's basketball-shooting performance were more likely to perceive that they had influenced his success if they had first generated positive visualizations consistent with that success. Observers privy to those spectators' visualizations made similar attributions about the spectators' influence. Finally, additional studies suggested that these results occur even when the thought-about outcome is viewed as unwanted by the thinker and even in field settings where the relevant outcome is occurring as part of a live athletic competition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)