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561.
Objective: Research has identified correlates (eg, drug use, risky sex, smoking) of using alcohol mixed with energy drinks (AMEDs). Few studies have investigated common mental health-related concerns (eg, depression, sleep). Participants: Alcohol-using college students (n = 380 never used AMEDs, n = 180 used AMEDs) were recruited in the study during the fall 2011 semester. Methods: The study examined demographics, substance use, depressive symptoms, and sleep problems in association with AMED use. Results: Multivariable logistic regression indicated that alcohol use severity (AOR = 1.24; 95% CI = 1.14+1.34), drug use severity (AOR = 1.20; 95% CI = 1.04–1.39), depressive symptoms (AOR = 1.06; 95% CI = 1.01–1.12), and smoking (AOR = 2.12; 95% CI = 1.22–3.68) were independently associated with AMED use; sleep problems were non-significant. Conclusions: Administrators may consider policies regarding energy drink availability on campus, and campus health personnel may increase screening and education surrounding AMED use to reduce risks among students.  相似文献   
562.
Human neonates exhibit individually distinctive patterns of variation—sometimes called cry “signatures”—in the acoustics of their cries. For tests of group differences (e.g., age, health status, or ambient language differences), the uniqueness of cry sounds to individuals means that multiple cries from same infant cannot appropriately be treated as independent events for analysis. This approach violates the assumption of independence that underlies many statistical techniques and runs the risk of uncovering “significant” group effects that do not actually exist. Nonetheless, publications continue to appear in which multiple cries from the same infant have been treated as independent events for analysis. To demonstrate the perils, we have compared the cries of infants born into a Mandarin Chinese language environment with cries of infants born into an American English language environment. We show (1) that treating each cry sound as an independent event yields numerous “significant” group effects and (2) that these effects all but disappear when cries are treated appropriately, as “nested” within individual infants. The latter outcome is in keeping with prevailing models of neonatal cry production and casts doubt on the claim that neonates alter their cries to match features of the language spoken in their environment.  相似文献   
563.
Many parents in Britain make huge financial sacrifices to send their children to private schools. Are those sacrifices worthwhile? What return, if any, do they get? Do their children end up in better careers, earning more, than if they have been educated at the expense of the state? Francis Green, Stephen Machin, Richard Murphy and Yu Zhu examine who exactly benefits from the privileges of the Old School Tie.  相似文献   
564.
While much attention has been devoted to measuring levels of social mobility over time, less attention has been given to the possibility of changing pathways to social mobility. This paper examines pathways from social origins to socio-economic destinations in midlife for two British cohorts, born in 1958 and 1970 respectively, using Structural Equation Modelling (SEM). We address the roles of cognitive attainment, private schooling and educational attainment in mediating the link between social origins and destinations. Have these mechanisms become more or less important over time, in a context of structural change in the state schooling system and educational expansion? We find that private schools displayed greater academic selectivity and an increased link to high levels of educational attainment for the younger cohort. Essentially, private schools adapted to changing circumstances, becoming more academically selective and less socially selective, and more focused on educational credentials. Childhood social origins were less strongly linked to childhood cognitive scores in the younger cohort, but cognitive scores were also more weakly linked to educational attainment for this cohort. We also find a decreased association between social origins and educational attainment for the younger cohort. While the finding that educational inequalities weakened over this time period is positive, the lack of a corresponding reduction in the overall link between social origins and destinations suggests that reducing educational inequalities was not sufficient to increase social mobility when accompanied by countervailing changes in the role of private schools.  相似文献   
565.

High rates of intercontinental exchange of plant species have caused scientists to ask whether floristic areas with similar environments are undergoing global homogenization. We focused on riparian forests of the urban Salt River (Sonoran Desert, USA) to ask: (1) Is the forest dominated by cosmopolitan or provincial elements? (2) Which trees planted in the irrigated cityscape have established along the river? (3) Which types of restoration interventions have favored provincial species? We surveyed tree abundance, size and vigor in belt transects among five reaches that differed in degree of restoration, and obtained data on tree species composition of the urban landscape and pre-development riparian zone. Our results reveal the urban riparian forest to have many cosmopolitan elements, owing in part to spillover of trees from the cultivated cityscape (e.g., Acacia stenophylla, Vitex agnus-castus). Global spread of some regional (Neotropical) riparian taxa (e.g., Parkinsonia aculeata, Prosopis) also has contributed to the cosmopolitan status. Yet, the forests retain a distinct regional signature. Unintentional restoration of winter floods has allowed for regeneration of Salix gooddingii, a vernally-adapted provincial pioneer, although its long-term survivorship is restricted to limited micro-sites (storm drain outfalls). Urbanization-related changes in stream hydrogeomorphology explain increases in some regional species (e.g., Washingtonia spp.) that historically were excluded from the river.

Reaches restored by planting, weeding, watering, and geocountouring had the greatest abundance of provincial species and greatest floristic similarity to historic conditions.

  相似文献   
566.
Riparian areas in Arizona are being encroached upon by urban developments. This study investigated the impacts of different urban housing densities on riparian vegetation structure along ephemeral streams. Nine sites representing three levels of housing density were selected within the town of Marana, located in southeast Arizona. The housing densities were categorized as high (7–8 houses ha?1), moderate (2.5–4.5 houses ha?1), and low (< 1.5 houses ha?1). Each treatment had three replications. The urban developments were relatively young (less than 15 years). No significant differences were found among the treatments for the tree variables (density, height, mean canopy volume and total canopy volume) or the herbaceous vegetation variables (species richness, percentage of introduced species and percentage of ground cover). However, the shrub variables (mean density, mean height, mean canopy volume, total canopy volume and species richness) showed some significant differences. Shrub density and species richness was significantly greater adjacent to ephemeral channels than just three meters upland. In addition, whitethorn acacia shrubs were significantly taller and larger adjacent to the stream channels in the high and moderate housing density sites than in the low housing density sites. Creosote shrubs showed the opposite trend. Increased runoff in the more heavily urbanized streams may have promoted the growth of the facultative riparian species (whitethorn acacia) but not the non-riparian species (creosote). Overall, in these young developments, vegetation was resilient across the levels of urbanization explored in the study.  相似文献   
567.
This article is based on the belief that students should learn the computational aspects of decision science techniques outside the classroom, thus freeing the instructor from this task and enabling him to devote more class time to focusing on the theoretical and/or application-oriented elements which will take students further in their learning experience. An experiment was designed to determine the learning value of one way of achieving this, namely the use of a Learning Center where students learned individually using a programmed instruction learning machine. The research involved both graduates and undergraduates learning the fundamentals of PERT—some with the learning machine approach while others were involved in more conventional pedagogies. Surprising success was discovered relative to both the approach and the quality of the PERT program used, with far-reaching implications regarding futuristic approaches to decision science education.  相似文献   
568.
National Institutes of Health (NIH) K award recipients and their mentors were surveyed to investigate the role of the mentor. We found that a majority of mentors provided guidance in responsible research conduct (RCR), and that most of these relationships were deemed helpful. Mentors also responded that they played a greater importance in RCR training of their mentees than the mentees reported. Our results suggest both mentors and mentees report that mentors ideally should play a more important role in RCR training than was actually the case. For conflicting interests, subjects' protection, and misconduct, approximately 50% of K recipients found the mentor to be not at all important or only somewhat important for these areas of RCR training. We conclude the mentor's role is important but not optimal based on the results of our study cohort.  相似文献   
569.
Lídia Farr  Francis Vella 《LABOUR》2008,22(3):383-410
Abstract. This paper analyses the impact of changes in macroeconomic con ditions on the income distribution in Spain. Using household data from the Encuesta Continuada de Presupuestos Familiares (ECPF) from 1985 to 1996 we disentangle the effect of aggregate variables on the income distribution by estimating counterfactual densities conditional on different macroeconomic scenarios. In estimation, we use a semi‐parametric least squares procedure that allows a flexible interaction between the level of income and a first index of individual characteristics and a second index that captures the role of macroeconomic variables. We find that although inequality displays a decreasing trend over the earlier part of the period examined, the poor performance of the Spanish economy during the early 1990s appears to have reversed this trend. We also conclude that while inflation appears to have no impact on the distribution of income for the period examined, there were important redistributive roles for unemployment, government expenditure, and the level of GDP.  相似文献   
570.
Objectives . The study of crime directed at gay and lesbian targets is hampered by two measurement problems: Police agencies provide unreliable data on hate crime, and tract-level census data contain no direct information about gay or lesbian population density. This article attempts to gauge two quantities that cannot be measured directly or unambiguously: the size of the gay and lesbian populations and the number of hate crimes directed at gay and lesbian targets. Methods . Population data for New York City were gathered from market research lists and from a special tabulation of the 1990 Census. Hate crime data were obtained from the Anti-Violence Project and the New York Police Department. Confirmatory factor analysis was used to assess the reliability of each measure and the correlation between latent population density and hate crime. Results . Each of these measures offers a reliable means by which to assess cross-sectional differences in the population density and victimization of gay men. Census and police data prove to be inferior indicators of lesbian population density and antilesbian hate crime. For both men and women, population density is strongly correlated with the incidence of hate crime. Conclusions . Despite the fact that advocacy groups record many more antigay incidents than do the police, both sources of data are in agreement about where hate crimes occur. The strong correlation between population density and hate crime against gay men implies that Census data could be used to forecast the occurrence of hate crime in areas where no police records exist.  相似文献   
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