Academic achievement in sciences: the role of preferences and educative assets

This paper provides new evidence on the effect of pupil´s self-motivation andacademic assets allocation on the academic achievement in sciences acrosscountries. By using the Programme for International Student Assessment 2006 (PISA2006) test we find that both explanatory variables have a positive effect onstudent´s performance. Self-motivation is measured through an instrumentthat allows us to avoid possible endogeneity problems. Quantile regression isused for analyzing the existence of different estimated coefficients over thedistribution. It is found that both variables have different effect on academicperformance depending on the pupil´s score. These findings support theimportance of designing focalized programs for different populations,especially in terms of access to information and communication technologiessuch as internet.PISA, self-motivation, academic assets, academic achievement, Quantile regression

Plasticity in Pinus pinaster populations of diverse origins: Comparative seedling responses to light and Nitrogen availability

The effects of light and N availability, and population on seedling morphology and biomass allocation were assessed in eleven months seedlings from ten Pinus pinaster populations. We conducted a garden experiment using a light gradient (full sunlight, HL= 337.1 μmol m2 s-1; medium light, ML= 120.6 μmol m2 s-1; and low light, LL= 30 μmol m2 s-1) and two contrasting soil fertility regimes: low-N and high-N availability. Light availability was an important factor controlling phenotypic plasticity. However, differences between productivity environments were observed, especially in full sunlight and medium light conditions, which suggest that soil fertility may be very important at early successional stages at open and medium shaded microsites, but would exert low influence in deep shade conditions. Population-specific responses were observed for many traits, which suggest a genetic control of morphological plasticity. All populations produced more total dry weight with HL and high-N. When light and/or N richness varied, growth depended upon which resource was more limiting. Results indicated ontogenetic drift but when seedlings were compared at the same size, results fitted with optimal partitioning theory. Allocation to needles was higher in HL and ML/ high-N conditions, while allocation to root was higher in low-N seedlings in HL and ML conditions. With shade (ML and LL) all populations allocated more dry weight to stem, regardless N availability. A significant increment in stem height was observed with shade increase.Instituto Universitario de Gestión Forestal Sostenibl

Evaluación del programa de salud ocupacional en una embotelladora

La Salud Ocupacional ha venido cobrando importancia al interior de las organizaciones durante los últimos años, ya que el mundo globalizado de hoy es cada vez más exigente; y herramientas como la salud ocupacional permiten que las empresas sean más competitivas. Puesto que una población trabajadora sana y motivada será mucho más rentable en todos los sentidos y aportará un importante grado de desarrollo a las sociedades. El Programa de Salud Ocupacional es un instrumento fundamental para cualquier tipo de organización; ya que con este se busca alcanzar una buena calidad de vida para las personas, puesto que estas son el principal activo de una empresa y por ende todos los esfuerzos que se hagan por mejorar sus condiciones tanto laborales como personales, no serán suficientes. De aquí la importancia de evaluar el funcionamiento de dicho programa, puesto que esta es la única manera de detectar sus fortalezas y debilidades, con el fin de establecer un proceso de mejora continua y así garantizar a sus trabajadores un medio ambiente laboral sano y seguro.The Occupational Health has come charging importance to the interior of the organizations during the last years, since the world today globalizado is more and more demanding; and tools like the occupational health allow that the companies are more competitive. Since a healthy and motivated hard-working population will be much more profitable in all the senses and you/he/she will contribute an important development grade to the societies. The Program of Occupational Health is a fundamental instrument for any organization type; since with this it is looked for to reach a good quality of life for people, since these they are the main asset of a company and for ende all the efforts that are made to improve their conditions so much labor as personal, they won't be enough. Of here the importance of evaluating the operation of this program, since this it is the only way to detect their strengths and weaknesses, with the purpose of establishing a process of continuous improvement and this way to guarantee their workers a healthy and sure labor environment

Economy and Environmental Problems in the Mexican Coastal States

A canonical correspondence analysis (CCA) for environmental and economic variables was performed for 17 Mexican coastal states. The ordination method allowed us to identify three groups, namely hydroelectric energy generation (I), pollution (II) and harbours (III), which were associated to different human activities. Furthermore, CCA is efficient to help us generate hypotheses for future research. It is therefore advised that CCA should be used for routine analyses into economics.Coastal States of Mexico, Canonical Correspondence Analysis, Diversity Index, Economic Development, Environmental Variables.

Effects of shrub and canopy cover on the relative growth rate (RGR) of Pinus pinaster seedlings of different sizes

Shrubs are recognized as important tree regeneration niches. In this study, we experimentally analysed the effects of shrub presence, canopy cover (closed cover and open cover-gaps), and seedling size on Pinus pinaster growth. Objective We expected that (1) seedling–shrub interaction would depend on seedling size and would shift from positive to negative with increasing size; (2) overstorey canopy would affect seedling–shrub interaction, with stronger and positive interactions in gaps, and (3) microsite factors would be affected by vegetation. Social status and plant size appeared to determine the post-shrub-treatment growth response. Results The effect of shrub on seedling growth varied with the canopy cover. Under closed canopy, there was a shift from a positive net effect on smaller seedlings to a negative net effect on mid-size seedlings, and then back to a positive net effect on larger seedling response. Under open canopy, a negative net effect was observed, with no change in the sign of the interaction as seedling size increased. Microenvironmental conditions varied in relation to overstorey and understorey vegetation, while soil conditions varied in relation to overstorey. The seedling–shrub interaction had both positive and negative net effects, which could help define the natural regeneration dynamic of P. pinaster.Instituto Universitario de Gestión Forestal Sostenibl

Climatic variability and other site factor influences on natural regeneration of Pinus pinaster Ait. in Mediterranean forests

Background: How environmental factors affect forest regeneration is relevant for systems that depend partially or fully on natural regeneration. Objective: P. pinaster post-disturbance regeneration and its relationship to environmental factors was studied in five P. pinaster forest populations of central Spain. We expected that 1) different harvesting methods or wildfire would promote natural regeneration in all populations, but with local and regional variations; 2) alternatively, different site-dependent stand factors would affect natural regeneration, although generalized climate effects would be seen. Analysis of variance and multivariate analysis were used to test differences, to classify ecological variations and to search for the most important factors affecting regeneration. Results: The results suggest that the recovery of P. pinaster forest in burnt stands, and stand replacement in harvested stands can be achieved soon after disturbance if climatic conditions and other local-site factors (e.g. soil and overstorey structure in harvested stands, cone bank in burnt stands) make the stand suitable for natural regeneration. Heterogeneous regeneration can be expected in all cases. The time of precipitation strongly influenced seedling density and successive regeneration development stages. Edaphic properties combined with water availability from precipitation can seriously limit the natural establishment of P. pinaster in xeric systems or during years of intense drought. Although many factors contribute to high variability natural regeneration was very effective (successful) in P. pinaster forests, which contributes to the generalization that natural regeneration is a viable forestry option in many forest types.Instituto Universitario de Gestión Forestal Sostenibl

Environmental influences on post-harvest natural regeneration of Pinus pinaster Ait. in Mediterranean forest stands submitted to seed-tree selection method

Research on natural regeneration is crucial for the development of sustainable forestry practices, in light of the global climate changes taking place. In this study, 151 plots were sampled in six Pinus pinaster stands that were naturally regenerated by the seed-tree method in Mediterranean forests in central Spain. The objectives of the survey were to study the suitability of different forest stands designated for natural regeneration as well as to analyse seedling establishment and the relationship between regeneration and different site factors. Analysis of variance and multivariate analysis with canonical ordination techniques were employed. Full and partial redundancy analyses on a correlation matrix were used to carry out a direct gradient analysis of regeneration density as a function of site factors. Nearly all stands presented seedling densities over 2,000 seedlings ha−1 and were thus found to be suitable for natural regeneration of Pinus pinaster by the seed-tree selection method. Significant variables that best explained total seedling and viable seedling density were spring and autumn precipitation of the year prior to establishment, spring and summer precipitation of the year of establishment and percentage cover of litter. There were no signs of competition between shrubs and seedlings, but a negative significant correlation with grass cover was observed. Pinus pinaster natural regeneration was successful with the seed-tree method, although it appeared to be highly dependent on climate and stand conditions.Instituto Universitario de Gestión Forestal Sostenibl

The effect of entrepreneurial orientation on firm performance: a multigroup analysis comparing China, Mexico, and Spain

This article analyzes firm entrepreneurial orientation across different contexts. In the light of the existing literature on entrepreneurship and institutional theory, it departs from the hypothesis that the context in which firms operate determines the importance of each dimension comprised in the multidimensional concept of entrepreneurship orientation, thus moderating its effect of on firm performance. The sample for this study is composed of both small and medium-sized firms from three countries: China, Mexico, and Spain. In the means of testing our hypothesis and thus quantifying the moderating effect of context, a structural equation model PLS-SEM technique and, specifically, a multigroup analysis approach has been implemented. The results have led us to confirm an overall positive effect of entrepreneurial orientation on firm performance regardless of firm context. However, the context of a firm certainly acts as a moderator by determining the effect of entrepreneurial orientation on firm performance. This effect is explained by the conditioning power of context over innovation, proactiveness, and risk-taking, the three main factors defining firm entrepreneurial orientation across contexts

Determinantes estructurales de la sindicalización en Colombia

Las causas y los efectos de la asociación sindical han sido ampliamente estudiados por la literatura econonómica; no obstante en el caso colombiano existe un claro sesgo hacia el estudio de los efectos sobre el salario. Este documento presenta un estudio de los determinantes estructurales de la tasa de densidad sindical para Colombia incluyendo algunos aspectos particulares como los efectos regionales y sectoriales utilizando la Gran Encuesta Integrada de Hogares 2007. Se encuentra que la densidad sindical está determinada por factores semejantes a los de otros mercados de trabajo con patrones similares de negociación sindical, como los reportados por Johnson (2005). Finalmente, dadas sus cifras de asesinato de sindicalistas, consideramos que los determinantes de la afiliación sindical para el caso Colombiano son más complejos que los de otros países latinoamericanos.****Economic literature has focused on both causes and effects of trade union membership; however, most of the studies about trade unions in Colombia have been focused on its effects over wages and inequality. On this document we present an estimation of the structural determinants of trade union membership, including some specific features as region/sector effects, using the Integrated Household Survey (GEIH) 2007. We find that trade union membership in Colombia seems to depend on the same structural determinants found by Johnson (2005) for a sample of countries. Nonetheless, as trade union activists have been specific victims of homicides, we argue that determinants of trade union memberships in Colombia are more complex than their Latin American counterparts.sindicatos, asalariados, contrato de trabajo

Effects of pre-commercial thinning on growth and reproduction in post fire regeneration of Pinus halepensis Mill.

Excessive recruitment in post-fire regeneration of Pinus halepensis can require pre-commercial thinning. The 1994 Moratalla fire (Spain) and the thinning applied there since 2004 provided good conditions for testing pre-commercial thinning effectiveness. Aims To analyse pre-commercial thinning effects on tree size, reproductive potential, stem biomass and annual growth in 15-year-old saplings. Methods Twenty nine circular plots (5 m radius) were established based on (1) years since thinning and (2) aspect. Non-thinned plots were included as controls. Sapling variables were measured and pine cones were counted and classified according to maturity. Three saplings per plot were felled, five sample disks were extracted from each and tree rings were analysed with Windendro® software. Results Sapling size, annual growth and stem biomass were higher in thinned plots than in control plots 2–4 years after thinning. Annual growth declined five years after thinning. Cone counts were higher 2–5 years after thinning, depending on the cone type. Aspect influenced some variables. Conclusion Thinning accelerated stand maturity but positive effects were indiscernible until 2–5 years later. Serotinous cones, which are fundamental to regeneration after fire, increased in number after 5 years. The effects of aspect were inconclusive due to interactions with years since thinning.Instituto Universitario de Gestión Forestal Sostenibl