Integrated value model for sustainable assessment of school centers construction

Hundreds of new school centers were built in Catalonia between 2000 and 2009. It was a governmental decision in order to solve an endemic lack of centers that in the early 2000s had worsen. Masonry and poured on site reinforced concrete structures were used to build most of these schools as it had been done previously. The novelty was the use of interesting off site construction processes such as prefabricated concrete, steel and wood technologies. These school edifices and their building processes were analyzed in the author’s thesis in 2009. Later in 2011 the author analyzed the lyfe cycle process of the construction of these centers. In this paper the authors assess the sustainability of these schools using a dynamic evaluation tool optimized for this case study. This tool has been defined using the Integrated Value Model for Sustainable Assessment (Modelo Integrado de Valor para una Evaluación Sostenible - MIVES).Postprint (published version

On the centralizer of generic braids

We study the centralizer of a braid from the point of view of Garside theory, showing that generically a minimal set of generators can be computed very efficiently, as the ultra summit set of a generic braid has a very particular structure. We present an algorithm to compute the centralizer of a braid whose generic-case complexity is quadratic on the length of the input, and which outputs a minimal set of generators in the generic case.Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo Regiona

Preference and performance of Phyllocnistis citrella Stainton (Lepidoptera:Gracillariidae) on three citrus hosts: Laboratory and field assessment

The relationship between preference and performance is crucial to the ecology and evolution of plant-insect interactions. Oviposition preference and offspring performance were evaluated for a citrus pest, the leafminer Phyllocnistis citrella (Lepidoptera: Gracillariidae), on three of its host plants: lemon (Citrus limon L. Burm.), orange (Citrus sinensis L. Osbeck), and grapefruit (Citrus paradisi Macfadyen) in Tucumán province (northwest Argentina). Choice and no-choice tests were performed in open and enclosed environments, and performance parameters (development time, survival, pupal size, and sex ratio) were estimated from laboratory rearing and 3-yr field sampling data. Parasitism rates were studied in laboratory choice test and field assessments. Preference trends were inconsistent, with lemon receiving more eggs in some tests, whereas no preference was observed in others. Patterns of host use in the field did not show significant differences among species. Leafminer performance, including parasitism and predation rates, was generally homogeneous among host plants. From these results, lemon, orange, and grapefruit seem to represent intrinsically similar resources for P. citrella populations in northwest Argentina, a trend that was accompanied by a lack of consistent oviposition preferences in foraging females. Ecological conditions might be more important than physiological adaptation in shaping a probably labile host ranking in this pest species.La relación entre preferencia y rendimiento es crucial para la ecología y evolución de las interacciones insecto-planta. Se evaluó la preferencia de puesta y el rendimiento de la descendencia para una plaga de cítricos, el minador de la hoja Phyllocnistis citrella (Lepidoptera: Gracillariidae), sobre tres de sus plantas hospederas: limonero (Citrus limon [Linn.] Burm.), naranjo (Citrus sinensis [Linn.] Osbeck) y pomelo (Citrus paradisi Macfadyen) en la provincia de Tucumán (Noroeste de Argentina). Se realizaron pruebas con y sin elección en ambientes abiertos y cerrados, y se estimaron parámetros de rendimiento (tiempo de desarrollo, supervivencia, tamaño pupal y proporción de sexos) a partir de individuos criados en laboratorio y datos de tres años de muestreos de campo. Las tasas de parasitismo se estudiaron en pruebas de laboratorio con elección y evaluaciones en campo. Las tendencias de preferencia fueron inconsistentes, con limonero recibiendo más huevos en algunas pruebas, mientras que no se observó preferencia en otras. Los patrones de uso de hospedero en campo no mostraron diferencias significativas entre especies. El rendimiento del minador, incluyendo las tasas de parasitismo y depredación, fue generalmente homogéneo entre plantas hospederas. Con estos resultados, las plantas de limonero, naranjo y pomelo representarían intrínsecamente recursos similares para las poblaciones del minador de los cítricos en el NO de Argentina, tendencia que fue acompañada por la ausencia de preferencias consistentes en la puesta de huevos por parte de las hembras. Las condiciones ecológicas podrían ser más importantes que la adaptación fisiológica al moldear un rango de hospederos probablemente voluble en esta especie plaga.Fil: Goane, Lucía. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; ArgentinaFil: Valladares, Graciela Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Willink, Eduardo. Gobierno de Tucumán. Ministerio de Desarrollo Productivo. Estación Experimental Agroindustrial Obispo Colombres; Argentin

DEFECT ELECTRONIC STATES IN BETA-CAROTENE AND LOWER HOMOLOGS

We present semi-empirical calculations of the atomic geometries and electronic charge distributions of beta-carotene homologues of different chain lengths. We find defects in charged and photoexcited chains that are similar to the defects found in the degenerate polymer trans-polyacetylene, and we show how confinement affects these defects as the chains we shortened. Our results exhibit a generalized form of charge-conjugation symmetry in which the properties of a negatively charged defect are related to those of a positive one and vice versa

Communication apprehension and students’ educational choices: An exploratory analysis of Spanish secondary education students

Purpose - The literature evidences the effects of communication apprehension (CA), defined as the level of fear and anxiety associated with either real or anticipated communication, on educational efforts and suggests that (via the perceived desirability of certain professions) it could affect vocational choices. The main objective of this paper is to investigate the link between CA and the vocational choice of secondary education students. Design/methodology/approach - Data were obtained from two sources: a self-administered questionnaire to measure the students’ CA levels and their academic preferences, and the vocational counsellors’ advice for these students. Findings - The results confirm the existence of a link between CA and both students’ vocational choices and counsellors’ advice. In general terms, apprehensive students tend to choose vocational education, whereas students with lower levels of CA prefer university for further education. Focusing on the latter, more apprehensive students tend to choose science degrees, which are perceived as requiring lower levels of communication skills. Research limitations/implications – Apprehensive students could be avoiding a path, with all the implications for their professional future, because it is perceived as frightening due to the apparent communication level required. As the literature notes, the links between CA and communication self-efficacy enables the development of educational interventions, resulting in a reduction of CA. Limitations include the use of a convenience sample in only one country. Originality/value - The scarce early literature has paid attention to occupational and educational choices in higher and further education, but there is no research focusing on the link between CA and preuniversity academic decisions

Ab Initio studies of the atomic structure and electronic density of states of pure and hydrogenated a-Si

We propose a method to simulate a-Si and a-Si:H using an ab initio approach based on the Harris functional and thermally amorphisized periodically continued cells with at least 64 atoms, and calculate their radial distribution functions. Hydrogen incorporation was achieved via diffusive random addition. The electronic density of states (DOS) is obtained using density functional theory with the aid of both the Harris-functional and Kohn-Sham-LDA approaches. Two time steps are used, 2.44 and 10 fs for the pure, and 0.46 and 2 fs for the hydrogenated, to see their effect on the topological and DOS structure of the samples. The calculated long time-step radial features of a-Si are in very good agreement with experiment whereas for a-Si:H the short time-step partial and total radial features agree well; for the long time-step simulation molecular hydrogen appears during annealing.The long time-step a-Si has a well defined gap with two dangling bonds, that clears and increases upon hydrogen addition and relaxation, as expected. The short time-step structures have more defects, both dangling and floating bonds, that are less characteristic of a good sample; however the radial structures of a-Si:H are in better agreement with experiment indicating that the experimental work was done on defective samples.Comment: 11 pages, RevTeX, 16 figures, submitted to Phys. Rev. B 16 June 200