An upper bound on the total restrained domination number of a tree

Let G=(V,E) be a graph. A set of vertices S?V is a total restrained dominating set if every vertex is adjacent to a vertex in S and every vertex of $V-\nobreak S$ is adjacent to a vertex in V?S. The total restrained domination number of G, denoted by γ _tr (G), is the smallest cardinality of a total restrained dominating set of G. A support vertex of a graph is a vertex of degree at least two which is adjacent to a leaf. We show that $\gamma_{\mathit{tr}}(T)\leq\lfloor\frac{n+2s+\ell-1}{2}\rfloor$ where T is a tree of order n≥3, and s and ? are, respectively, the number of support vertices and leaves of T. We also constructively characterize the trees attaining the aforementioned bound.     

Life events and peer substance use and their relation to substance use problems in college students

Substance use disorders among college students are not well understood, and the present study examined the relationship of two environmental factors to alcohol and drug use problems in 616 (316 women) college students. Participants completed measures assessing substance use problems, life events, and substance use among peers. Alcohol use problems were significantly associated with higher drug use problems and regular use of illicit drugs among friends. Drug use problems were significantly associated with male gender, higher alcohol use problems, regular use of alcohol and drugs among friends, illicit drug use among romantic partners, and higher numbers of negative life events. Results extend previous research and suggest that college students who experience multiple negative life events and/or affiliate with substance using friends and romantic partners may be at risk for developing a substance use problem.     

The "quality " of early care and education settings: definitional and measurement issues

There is a widespread belief that high-quality early care and education can improve children's school readiness. However, debate continues about the essential elements of a high-quality experience, about whether quality means the same things across different types of care settings, about how to measure quality, and about the level of quality that might make a meaningful difference in outcomes for children. Are the aspects of the child care environment that researchers measure the ones that are most strongly related to children's development? This article argues that the ways in which researchers currently measure early care environments are flawed and that the conclusions drawn about the relationship between these measures and outcomes for children are frequently incorrect or overstated. The article addresses four questions: How is the quality of the child care environment commonly defined and measured? Do the most commonly used measures capture the child's experience? Do they work well across all settings? Are researchers drawing the correct conclusions from studies that relate the child care environment to child outcomes? Finally, the article discusses some possible directions for future research.     

The effects of fatal vision goggles on drinking and driving intentions in college students

The present study was designed to examine the effectiveness of Fatal Vision Goggles in reducing intentions to drink and drive. Participants performed a field sobriety task and drove in a traffic simulator while wearing the goggles. A regression analysis was performed in order to predict changes in intentions to drink and drive, using typical drinking patterns, perceived likelihood of getting into a collision when drinking and driving, self efficacy, and driving independence as predictor variables. Results showed that drinking and driving intentions were reduced following the use of Fatal Vision Goggles among those that typically drink more during outings, among those that believe the likelihood of collisions when drinking and driving are greater, and among those less likely to drive to achieve independence and autonomy. These results indicate that Fatal Vision Goggles can be an effective tool in altering drinking and driving attitudes among drivers with specific attitudinal and personal characteristics.     

Differences between actual and perceived student norms: an examination of alcohol use, drug use, and sexual behavior

Researchers in the social norms area have previously focused primarily on alcohol consumption, paying comparatively less attention to drug use and sexual behavior. The major purposes of this study were to (1) compare perceptions of peer norms in the areas of alcohol use, drug use, and sexual behavior with actual behavior and (2) determine if a relationship existed between a student's perceptions of normative behavior and a student's actual behavior. Participants were 833 college students at a large, public university in the Northeast. Study participants overestimated alcohol use, drug use, and sexual behavior among their peers. There was also a positive relationship between actual behavior and perceived peer norms, although the effect sizes for all behaviors were small to moderate. The authors provide further support for the tenets of social norms theory and suggest that social norms interventions are appropriate both campus-wide and to targeted high-risk groups.     

English perceptions of elder abuse

The purpose of this exploratory study was to investigate an English sample's perceptions on elder abuse, inflicted by adult children against their aging parents. Fifty participants (14 males, 46 females) provided examples of extreme, moderate, and mild elder abuse. As examples of extreme abuse, most participants mentioned neglect and physical aggression. Various forms of neglect and psychological abuse were their most common examples of moderate and mild abuse. References to physical aggression appeared most often as examples of extreme abuse rather than of moderate or mild abuse. Within these main categories, the specific subtypes most frequently mentioned by the sample included physical neglect, psychological neglect, verbal abuse, and deprivation. More females than males provided examples of financial abuse and physical neglect. Females were also more likely than males to list psychological neglect as an extreme form of abuse and disrespect as a form of mild abuse. At the moderate level, males referred to abuse relating to power more often than females. A positive relationship was found between age and the number of examples of physical neglect given at the moderate level and the number of examples of emotional abuse given at the mild level.     

Community exercise program for older adults recovering from hip fracture: a pilot study

Community-based rehabilitative exercise programs might be an effective means to improve functional outcomes for hip-fracture patients. The purpose of this study was to evaluate the effectiveness of a community exercise program (CEP) for older adults recovering from hip fracture. Twenty-five older adults (mean age 80.0 +/- 6.0 years; 24 women; 71 +/- 23 days post-hip fracture) participated in this pilot study (17 exercise, 8 control). The CEP involved functional stepping and lower extremity-strengthening exercises. Control participants received only standard outpatient therapy. Measures of functional mobility, balance confidence, falls efficacy, lower extremity strength, and daily physical activity were evaluated at baseline and at 16 weeks. Improvements for self-reported physical activity, mobility, balance, and knee-extensor strength were observed for the CEP group. This study demonstrated that a CEP is beneficial for community-dwelling older adults post-hip fracture.     

Endurance exercise and leg strength in older women

Quadriceps strength and mass peak in the third decade of life, plateau, and then decline from the fifth decade on. To examine the influence of chronic endurance training and age on lean mass and leg strength, women runners (n = 62, age 43-69 years) and sedentary participants (n = 33, age 43-66 years) were divided into 40-, 50-, and 60-year age groups. Absolute isokinetic concentric torque did not differ between runners and sedentary women (97.9 +/- 19.5 and 104.6 +/- 22.7 N . m, respectively, p = .18) but was different between age groups independent of exercise status (107.6 +/- 18.4, 97.1 +/- 19.9, and 90.1 +/- 21.4 N . m, for 40s, 50s, and 60s, respectively, p < .05). Lean body mass also differed by age group (p < .05) but did not change differently among runners and sedentary women. These findings suggest that chronic endurance training might not influence the loss of muscle mass and muscle strength that occur with aging.