Stability and change in ethnic labeling among adolescents from Asian and Latin American immigrant families

An important question for the acculturation of adolescents from immigrant families is whether they retain ethnic labels that refer to their national origin (e.g., Mexican, Chinese) or adopt labels that are dominant in American society (e.g., Latino, Asian American, American). Approximately 380 adolescents from Asian and Latin American immigrant families selected ethnic labels during each of the 4 years of high school (age span = 14.87–17.82 years). Results indicated no normative trend either toward or away from identifying most closely with pan-ethnic or American ethnic labels. Significant numbers of adolescents changed their ethnic labels from year to year, however and these changes were associated with fluctuations in adolescents' ethnic affirmation and exploration and proficiency in their heritage languages.     

Reality Therapy and Personalized Instruction: A Success Story

Abstract

A longitudinal pilot study investigating the cumulative effects of reality therapy counseling and individualized instruction on the control expectancy and success rates of high-risk community college students was conducted. Findings support the tentative hypotheses that control expectancy, achievement, and holding power can be modified by instruction and counseling. The study was conducted over a three-year period at a community college in southeastern North Carolina.     

A Tutorial in Bayesian Potential Outcomes Mediation Analysis

Statistical mediation analysis is used to investigate intermediate variables in the relation between independent and dependent variables. Causal interpretation of mediation analyses is challenging because randomization of subjects to levels of the independent variable does not rule out the possibility of unmeasured confounders of the mediator to outcome relation. Furthermore, commonly used frequentist methods for mediation analysis compute the probability of the data given the null hypothesis, which is not the probability of a hypothesis given the data as in Bayesian analysis. Under certain assumptions, applying the potential outcomes framework to mediation analysis allows for the computation of causal effects, and statistical mediation in the Bayesian framework gives indirect effects probabilistic interpretations. This tutorial combines causal inference and Bayesian methods for mediation analysis so the indirect and direct effects have both causal and probabilistic interpretations. Steps in Bayesian causal mediation analysis are shown in the application to an empirical example.     

Effects of volleyball match-induced fatigue on knee joint position sense

Abstract

It has been suggested that a greater number of injuries during the last third of practice sessions or matches could be related to alteration of lower limb neuromuscular control due to neuromuscular fatigue. This fatigue-related effect can be mediated by changes in joint proprioception. In athletes, the use of functional fatigue protocols could have the advantage of mimicking the demands of sporting activity, thus reflecting more specifically the changes in neuromuscular control and proprioception observed in sport settings. The purpose of the present study was to assess the effect of fatigue induced by a volleyball match on knee joint position sense in elite volleyball players. Seventeen female volleyball players aged 18.9±4.2 years from the Portuguese national team volunteered for the study. Knee joint position sense was evaluated by an open kinetic chain technique and active knee positioning, and was reported using absolute, relative, and variable angular errors. Joint position sense measures were obtained before and immediately after a simulated volleyball match of five sets. To ensure that the match was sufficiently intense to induce fatigue, the perceived exertion or exercise intensity was assessed at the end of the match using Borg’ s rating of perceived exertion (RPE) scale. All participants completed the volleyball match (90min duration), reaching or exceeding 15 on the RPE scale (15.59±0.71; range 15–17), equivalent to “hard/heavy work”. After the volleyball match, a significant increase in absolute (2.11°) and relative (1.71°) angular errors was detected. Match-induced fatigue significantly exacerbated the overestimation of the test position. Moreover, the reliability and accuracy in estimating knee angles decreased from rest to the fatigued state, as shown by the increase (264%) in variable error. Our results show that fatigue induced by a volleyball match has a marked effect on knee joint position sense in elite female volleyball players. Knee joint position sense was less accurate and less consistent after the volleyball match. Fatigue induced by a simulated competitive volleyball match resulted in proprioceptive deficits, decreasing sensorimotor system acuity in female volleyball players.     

Ready to learn? Children's pre-academic achievement in pre-Kindergarten programs

We examined children's growth in school-related learning and social skills over the pre-Kindergarten (pre-K) year in state-funded programs designed to prepare children for kindergarten. We expected that children's gains in academic and social skills could be attributed to variations in the structural and classroom process dimensions of program quality. Nearly 3000 (n = 2800) children were randomly selected, four per classroom, from approximately 700 randomly selected, state-funded pre-Kindergarten classrooms in eleven states. Enrollment in pre-K appeared related to gains in academic skills. Children showed larger gains in academic outcomes when they experienced higher-quality instruction or closer teacher–child relationships. Gains were not related to characteristics of the child or program (i.e., ratio, teacher qualifications and program location and length). These findings have implications for a range of state and local policy and program development efforts as well as for theories of contextual influences on development.