Uso de alcohol y tabaco y variables cognitivo-motivacionales en el ámbito escolar: efectos sobre el rendimiento académico en adolescentes españoles

El objetivo de este estudio fue analizar: (a) la relación entre el consumo de tabaco y alcohol y el rendimiento académico y (b) la capacidad predictiva de los factores psicoeducativos y el abuso de alcohol y tabaco sobre el rendimiento académico en una muestra de 352 adolescentes españoles de 2º a 4º de Educación Secundaria Obligatoria (ESO). Para analizar las variables cognitivo-motivacionales se utilizaron el Self-Description Questionnaire-II, la Sydney Attribution Scale y el Achievement Goal Tendencies Questionnaire. El consumo abusivo de alcohol y tabaco, el sexo y la repetición de curso fueron también evaluados utilizando medidas autoinformadas. El rendimiento académico fue evaluado a partir de los registros escolares. Se utilizaron análisis de frecuencias y regresión logística para analizar los datos. Los análisis de frecuencias revelaron que los estudiantes que abusan del tabaco y el alcohol presentan un rendimiento académico más pobre. Los análisis de regresión logística destacaron que los comportamientos saludables así como las variables educativas y cognitivo-motivacionales ejercieron un efecto predictivo diferente sobre el rendimiento académico dependiendo del área académica analizada. Estos resultados señalan que para mejorar el rendimiento académico en la adolescencia se han de tener en consideración no sólo variables académicas sino también variables relacionadas con la salud.

Adaptación de las escalas de actitudes hacia el tabaco, el alcohol y otras drogas en adolescentes portugueses

El presente estudio muestra los resultados de la adaptación de las escalas de actitudes hacia el tabaco (López-Sánchez, Garcia-Rodriguez, Mira y Estévez, 2000), el alcohol (Garcia-Rodriguez y López-Sánchez, 2001) y otras drogas (López-Sánchez et al., 2000) en población portuguesa. Se trata de tres escalas, cada una con trece ítems, de respuesta tipo Likert con cinco opciones de respuesta, que diferencian tres sub-escalas. Para realizar el estudio de adaptación de las escalas a la población portuguesa, se han utilizado dos muestras independientes, constituidas por 329 y 443 adolescentes, alumnos de bachillerato del norte del país, a quienes se administraron los instrumentos. Los datos recogidos, después de ser sometidos a un análisis factorial exploratorio y confirmatorio, permitieron encontrar una solución adecuada para cada una de las escalas, dando como resultando una buena validez y fiabilidad. En la validez concurrente, los resultados sugieren diferencias de género con todas las sub-escalas y una relación negativa con la edad, así como diferencias en las actitudes de acuerdo con la experiencia y el consumo.

Electrocatalytic activity of Ni-doped nanoporous carbons in the electrooxidation of propargyl alcohol

Herein, we explore the immobilization of nickel on various carbon supports and their application as electrocatalysts for the oxidation of propargyl alcohol in alkaline medium. In comparison with massive and nanoparticulated nickel electrode systems, Ni-doped nanoporous carbons provided similar propargyl alcohol conversions for very low metallic contents. Nanoparticulated Ni on various carbon supports gave rise to the highest electrocatalytic activity in terms of product selectivity, with a clear dependence on Ni content. The results point to the importance of controlling the dispersion of the Ni phase within the carbon matrix for a full exploitation of the electroactive area of the metal. Additionally, a change in the mechanism of the propargyl alcohol electrooxidation was noted, which seems to be related to the physicochemical properties of the carbon support as well. Thus, the stereoselectivity of the electrooxidative reaction can be controlled by the active nickel content immobilized on the anode, with a preferential oxidation to (Z)-3-(2-propynoxy)-2-propenoic acid with high Ni-loading, and to propiolic acid with low loading of active Ni sites. Moreover, the formation of (E)-3-(2-propynoxy)-2-propenoic acid was discriminatory irrespective of the experimental conditions and Ni loadings on the carbon matrixes.

On the Electric Breakdown in Liquid Argon at Centimeter Scale

We present a study on the dependence of electric breakdown discharge properties on electrode geometry and the breakdown field in liquid argon near its boiling point. The measurements were performed with a spherical cathode and a planar anode at distances ranging from 0.1 mm to 10.0 mm. A detailed study of the time evolution of the breakdown volt-ampere characteristics was performed for the first time. It revealed a slow streamer development phase in the discharge. The results of a spectroscopic study of the visible light emission of the breakdowns complement the measurements. The light emission from the initial phase of the discharge is attributed to electro-luminescence of liquid argon following a current of drifting electrons. These results contribute to set benchmarks for breakdown-safe design of ionization detectors, such as Liquid Argon Time Projection Chambers (LAr TPC).

Enriching plant diversity in grasslands by large-scale experimental sward disturbance and seed addition along gradients of land-use intensity

Aims The relationship between biodiversity and ecosystem functioning is among the most active areas of ecological research. Furthermore, enhancing the diversity of degraded ecosystems is a major goal in applied restoration ecology. In grasslands, many species may be locally absent due to dispersal or microsite limitation and may therefore profit from mechanical disturbance of the resident vegetation. We established a seed addition and disturbance experiment across several grassland sites of different land use to test whether plant diversity can be increased in these grasslands. Additionally, the experiment will allow us testing the consequences of increased plant diversity for ecosystem processes and for the diversity of other taxa in real-world ecosystems. Here we present details of the experimental design and report results from the first vegetation survey one year after disturbance and seed addition. Moreover, we tested whether the effects of seed addition and disturbance varied among grassland depending on their land use or pre-disturbance plant diversity. Methods A full-factorial experiment was installed in 73 grasslands in three regions across Germany. Grasslands were under regular agricultural use, but varied in the type and the intensity of management, thereby representing the range of management typical for large parts of Central Europe. The disturbance treatment consisted of disturbing the top 10 cm of the sward using a rotavator or rotary harrow. Seed addition consisted of sowing a high-diversity seed mixture of regional plant species. These species were all regionally present, but often locally absent, depending on the resident vegetation composition and richness of each grassland. Important findings One year after sward disturbance it had significantly increased cover of bare soil, seedling species richness and numbers of seedlings. Seed addition had increased plant species richness, but only in combination with sward disturbance. The increase in species richness, when both seed addition and disturbance was applied, was higher at high land-use intensity and low resident diversity. Thus, we show that at least the early recruitment of many species is possible also at high land-use intensity, indicating the potential to restore and enhance biodiversity of species-poor agricultural grasslands. Our newly established experiment provides a unique platform for broad-scale research on the land-use dependence of future trajectories of vegetation diversity and composition and their effects on ecosystem functioning.

A guide to commercial-scale ethanol production and financing : a product of the Solar Energy Information Data Bank /

"SERI/SP-751-877, UC-61."

Prototype scale mooring load and transmission tests for a floating tire breakwater /

Prototype scale tests of the mooring load and wave transmission characteristics of a floating tire breakwater were conducted in the large wave tank at the Coastal Engineering Research Center. Standard Goodyear Tire and Rubber Co. 18-tire modules connected to form breakwaters, 4 and 6 modules (8.5 and 12.8 meters, 28 and 42 feet) wide in the direction of wave advance, were tested in water depths of 2 and 4 meters (6.56 and 13.12 feet). Monochromatic waves with a 2.64- to 8.25-second period range and heights up to 1.4 meters (4.6 feet) were used in the tests. Test results indicate that wave transmission is mainly a function of the breakwater width to incident wavelength ratio with a slight dependence on the incident wave height. However, the mooring forces are mainly a function of the incident wave height with only a slight dependence on the incident wavelength and breakwater width. Recommended design curves for the wave transmission coefficient versus breakwater width to wavelength ratio and mooring load as a function of incident wave height are presented. (Author).

Behavioral pharmacology of human drug dependence /

Mode of access: Internet.

Testing drugs for physical dependence potential and abuse liability /

Mode of access: Internet.

Mechanisms of tolerance and dependence /

Mode of access: Internet.

A family response to the drug problem : a family program for the prevention of chemical dependence.

Mode of access: Internet.

Farm and forest produced alcohol [microform] : the key to liquid fuel independence : a compendium of papers /

Reuse of record except for individual research requires license from Congressional Information Service, Inc.

The contribution of research to Australian policy responses to heroin dependence 1990-2001: a personal retrospection

Periodic public concern about heroin use has been a major driver of Australian drug policy in the four decades since heroin use was first reported. The number of heroin-dependent people in Australia has increased from several hundreds in the late 1960s to around 100000 by the end of the 1990s. In this paper I do the following: (1) describe collaborative research on heroin dependence that was undertaken between 1991 and 2001 by researchers at the National Drug and Alcohol Research Centre: (2) discuss the contribution that this research may have made to the formulation of policies towards the treatment of heroin dependence during a period when the policy debate crystallized around the issue of whether or not Australia should conduct a controlled trial of heroin prescription; and (3) reflect on the relationships between research and policy-making in the addictions field, specifically on the roles of investigator-initiated and commissioned research, the interface between researchers, funders and policymakers: and the need to be realistic about the likely impact of research on policy and practice.

Of sheep and rain: large-scale population dynamics of the red kangaroo

1. We analysed time-series data from populations of red kangaroos (Macropus rufus, Desmarest) inhabiting four areas in the pastoral zone of South Australia. We formulated a set of a priori models to disentangle the relative effects of the covariates: rainfall, harvesting, intraspecific competition, and domestic herbivores, on kangaroo population-growth rate. 2. The statistical framework allowed for spatial variation in the growth-rate parameters, response to covariates, and environmental variability, as well as spatially correlated error terms due to shared environment. 3. The most parsimonious model included all covariates but no area-specific parameter values, suggesting that kangaroo densities respond in the same way to the covariates across the areas. 4. The temporal dynamics were spatially correlated, even after taking into account the potentially synchronizing effect of rainfall, harvesting and domestic herbivores. 5. Counter-intuitively, we found a positive rather than negative effect of domestic herbivore density on the population-growth rate of kangaroos. We hypothesize that this effect is caused by sheep and cattle acting as a surrogate for resource availability beyond rainfall. 6. Even though our system is well studied, we must conclude that approximating resources by surrogates such as rainfall is more difficult than previously thought. This is an important message for studies of consumer-resource systems and highlights the need to be explicit about population processes when analysing population patterns.

The gambling related cognitions scale (GRCS): development, confirmatory factor validation and psychometric properties

Aims The aims of this study are to develop and validate a measure to screen for a range of gambling-related cognitions (GRC) in gamblers. Design and participants A total of 968 volunteers were recruited from a community-based population. They were divided randomly into two groups. Principal axis factoring with varimax rotation was performed on group one and confirmatory factor analysis (CFA) was used on group two to confirm the best-fitted solution. Measurements The Gambling Related Cognition Scale (GRCS) was developed for this study and the South Oaks Gambling Screen (SOGS), the Motivation Towards Gambling Scale (MTGS) and the Depression Anxiety Stress Scale (DASS-2 1) were used for validation. Findings Exploratory factor analysis performed using half the sample indicated five factors, which included interpretative control/bias (GRCS-IB), illusion of control (GRCS-IC), predictive control (GRCS-PC), gambling-related expectancies (GRCS-GE) and a perceived inability to stop gambling (GRCS-IS). These accounted for 70% of the total variance. Using the other half of the sample, CFA confirmed that the five-factor solution fitted the data most effectively. Cronbach's alpha coefficients for the factors ranged from 0.77 to 0.91, and 0.93 for the overall scale. Conclusions This paper demonstrated that the 23-item GRCS has good psychometric properties and thus is a useful instrument for identifying GRC among non-clinical gamblers. It provides the first step towards devising/adapting similar tools for problem gamblers as well as developing more specialized instruments to assess particular domains of GRC.