Organic matter content influence on soil phy-sical properties

[Abstract] Soil physical characteristics of agricultural soils with a range of texture and organic matter content, i. e., dry and wet pore space organisation, were investigated. In order to study the specific effect of organic matter for each soil, frequently both grassland and cultivated adjacent land were sampled. Because of the complexity of the soil particle structure, measurements were performed at the textural level on 2-3 mm aggregates. The compactness of grassland horizons was found to be lower than that of its cultivated counterparts. Mercury intrusion porosimetry showed that lacunar pores prevailed, whose volume increased as organic carbon content increased. The volume of clay-fabric pores was very small and did not appear to depend on the variation in organic matter content. Water content near saturation increased with increasing organic matter content and for potentials of about 1,500 kPa water retention curves tended to converge. Pore size distribution patterns as measured mercury intrusion porosimetry and derivedfrom water retention characteristics were compared. The low shrinkage potential of moderately coarse and medium textured soils was also verified. A lack of potential for regeneration of good soil structure by fragmentation was deduced from the shrinkage curves

QuadStack: An Efficient Representation and Direct Rendering of Layered Datasets

We introduce QuadStack, a novel algorithm for volumetric data compression and direct rendering. Our algorithm exploits the data redundancy often found in layered datasets which are common in science and engineering fields such as geology, biology, mechanical engineering, medicine, etc. QuadStack first compresses the volumetric data into vertical stacks which are then compressed into a quadtree that identifies and represents the layered structures at the internal nodes. The associated data (color, material, density, etc.) and shape of these layer structures are decoupled and encoded independently, leading to high compression rates (4× to 54× of the original voxel model memory footprint in our experiments). We also introduce an algorithm for value retrieving from the QuadStack representation and we show that the access has logarithmic complexity. Because of the fast access, QuadStack is suitable for efficient data representation and direct rendering. We show that our GPU implementation performs comparably in speed with the state-of-the-art algorithms (18-79 MRays/s in our implementation), while maintaining a significantly smaller memory footprint

Conservadurismo del resultado contable bajo las Normas Internacionales de Contabilidad: Un estudio comparativo.

In this study we analyse whether the use of IASB standards affects the conservatism of earnings of the firms that adopt them. We compare the conservatism of firms by groups of firms/countries using or not IAS. Our results show that 1) Earnings conservatism is, as pointed out in prior research, more pronounced in common-law-based developed economies; 2) The voluntary use of IASB standards in Europe (prior to 2005) has significantly increased the measures of earnings conservatism in adopting firms, and 3) The use of IAS fails to improve the relevance and reliability of accounting information in emerging/developing countries, where enforcement and investor protection is lowEn este trabajo se analiza si el uso de las normas del IASB afecta al conservadurismo del resultado de las empresas que las adoptan. Para ello comparamos el conservadurismo por grupos de empresas/países que usan o no las normas internacionales (NIC). Nuestros resultados muestran que: 1) El conservadurismo del resultado es, tal y como pone de manifiesto la literatura previa, más pronunciado en los países desarrollados basados en el derecho común, 2) La adopción voluntaria de las normas del IASB en Europa (antes de 2005) aumentó significativamente las medidas de conservadurismo del resultado de las empresas que las adoptaron, y 3) El uso de las NIC no logró mejorar la relevancia/fiabilidad de la información contable en los países emergentes o en vías de desarrollo, donde la protección de los intereses de los inversores es escasa

Conservadurismo del resultado bajo las normas internacionales de contabilidad: un estudio comparado

El presente trabajo muestra que la adopción de la normativa del IASB en los países europeos ha contribuido a aumentar el conservadurismo del resultado de las empresas que las implantaron antes de ser obligatorias en 2005, acercando las medidas de conservadurismo a los niveles estadounidenses. Este no es el caso de las empresas de países menos desarrollados que han adoptado la normativa internacional. Para estas empresas, pese a la adopción de las NIC, el conservadurismo no ha aumentado. De hecho, no hay indicios de asimetría en el reconocimiento de noticias en el resultado. Además, parte del aumento en el conservadurismo observado en las empresas europeas desaparece si se controla de manera adecuada por sus características específicas

Atenção e raciocínio visuoespacial em jogadores de voleibol de alto rendimento

The present study aims at analyzing the relationship of attention and visuospatial reasoning to sports performance in the volleyball context. Participants were 159 high-level volleyball athletes of both sexes, with an average age of 21.60 years (SD= 4.11). Participants completed the Psychological Battery of Attention Assessment (BPA), the Visual Selective Attention Scale and the Cubes test, which were applied collectively. The sports performance was assessed using the DataVolley program. Results indicated that athletes scored above average on all tests when compared to available normative data. BPA scores and sports performance were correlated among adolescents, and Cubes test and sports performance were correlated among children. Overall and across sport categories, test scores (BPA, EASV and Cubes) did not associate with sports performance.Este estudio tuvo como objetivo analizar las relaciones de la atención y el raciocínio visoespacial con el rendimiento deportivo, en el contexto de voleibol Participaron 159 jugadores de voleibol de alto nivel, de ambos sexos, con edad promedio de 21.60 años (DE= 4.11). Los instrumentos utilizados fueron la Bateria Psicológica de Evaluación de la Atención (BPA), Escala de Atención Selectiva Visual (EASV) y Test de los Cubos. El rendimiento deportivo fue medido utilizando el software Data Volley. Los resultados indican que los jugadores obtuvieron medias superiores a los patrones normativos de los manuales, en todas las pruebas, y sólo se encontraron correlaciones significativas entre los test y el rendimiento deportivo en el test BPA en la categoría juvenil, y en el Test de los Cubos en la categoría infanto. Los resultados de los test (BPA, EASV y Test de los Cubos) de forma general, y en categorías deportivas, no presentaron correlaciones significativas con el rendimiento deportivo.Este estudo teve como objetivo analizar as relações entre atenção e raciocínio visuoespacial com o rendimento esportivo no contexto do voleibol. Participaram 159 jogadores de voleibol de alto rendimento, ambos os sexos, com idade média de 21,60 anos (DP= 4,11). Os instrumentos utilizados foram a Bateria Psicológica para Avaliação da Atenção (BPA), Escala de Atenção Selectiva Visual (EASV) y Teste dos Cubos. O rendimento esportivo foi mensurado por meio do software Data Volley. Os resultados indicam que os jogadores tiveram, em todas as provas, medias superiores às medias normativas dos manuais dos testes, y foram verificadas correlações significativas apenas entre os testes e o rendimento esportivo na BPA na categoria juvenil, e no Teste dos Cubos na categoria infantil. Os resultados dos testes (BPA, EASV e Teste dos Cubos) de forma geral, e em categorias esportivas não apresentaram correlações significativas com o rendimento esportivo

A System for the Measurement of the Subjective Visual Vertical Using a Virtual Reality Device

The Subjective Visual Vertical (SVV) is a common test for evaluating the perception of verticality. Altered verticality has been connected with disorders in the otolithic, visual or proprioceptive systems, caused by stroke, Parkinson’s disease or multiple sclerosis, among others. Currently, this test is carried out using a variety of specific, mostly homemade apparatuses that include moving planes, buckets, hemispheric domes or a line projected in a screen. Our aim is to develop a flexible, inexpensive, user-friendly and easily extensible system based on virtual reality for the measurement of the SVV and several related visual diagnostic tests, and validate it through an experimental evaluation. Our evaluation showed that the proposed system is suitable for the measurement of SVV in healthy subjects. The next step is to perform a more elaborated experimentation on patients and compare the results with the measurements obtained from traditional methods

Evolución tecnológica del hardware de vídeo y las GPU en los ordenadores personales

En este artículo se ofrece una revisión de los hitos más importantes en la evolución del hardware gráfico. La comunicación entre los ordenadores y las personas ha ido avanzando a lo largo del tiempo, alcanzando la interactividad con la aparición de los sistemas de tiempo compartido a principios de la década de los 60 del siglo pasado. Los ordenadores personales, cuya expansión se inició casi dos décadas después, adoptaron desde un inicio la visualización de información en una pantalla como medio principal de comunicación con el usuario. El hardware a cargo de esa tarea ha ido evolucionando paulatinamente hasta, en la actualidad, convertirse en parte indispensable de la arquitectura del computador, hasta tal punto que una gran parte de los ordenadores portátiles y de sobremesa incorporan el hardware gráfico en el mismo circuito integrado que aloja al microprocesador.This article provides a review of the most important milestones in the evolution of graphics hardware. Communication between computers and people has been advancing over time, reaching interactivity with the emergence of timesharing systems in the early 1960s. Personal computers, whose expansion began almost two decades later, used the visualization of information on a screen as the main means of communication with the user from the very beginning. The hardware in charge of this task has gradually evolved to become an indispensable part of the computer architecture, to such an extent that a large part of laptops and desktop computers incorporate the graphic hardware into the same integrated circuit that houses the microprocessor.Universidad de Granada: Departamento de Arquitectura y Tecnología de Computadores; Vicerrectorado para la Garantía de la Calidad

Validating a theory of planned behavior questionnaire to measure entrepreneurial intentions

The Theory of Planned Behavior (TPB, Ajzen, 1991) has been widely employed to predict entrepreneurial intentions. The TPB offers a coherent and generally applicable theoretical framework, which enables us to understand and predict entrepreneurial intentions by taking into account not only personal but also social factors (Krueger et al., 2000). This study presents the validation of an Entrepreneurial Intention Questionnaire (EIQ) in a sample of more than three thousand Spanish university graduates. The EIQ comprises four subscales: attitudes towards entrepreneurship, subjective norms, self-efficacy, and entrepreneurial intention. Unlike other questionnaires used in the field (Autio, Keeley, Klofsten, Parker & Hay, 2001; Krueger, Reilly & Carsrud, 2000; Liñán & Chen, 2009), EIQ follows Ajzen’s (Ajzen, 2002) methodological recommendations on how to construct a TPB questionnaire using composite measures of attitudes and subjective norms. Structural equation modeling (SEM) confirmed that the EIQ has a high reliability and predictive validity for Spanish university graduates’ entrepreneurial intentions.Junta de Andalucía. Consejería de Innovación, Ciencia y Empresas P08-SEJ-0354

Brighter-colored paper wasps (Polistes dominula) have larger poison glands

Introduction Aposematism is a defense system against predators consisting of the toxicity warning using conspicuous coloration. If the toxin production and aposematic coloration is costly, only individuals in good physical condition could simultaneously produce abundant poison and striking coloration. In such cases, the aposematic coloration not only indicates that the animal is toxic, but also the toxicity level of individuals. The costs associated with the production of aposematic coloration would ensure that individuals honestly indicate their toxicity levels. In the present study, we examine the hypothesis that a positive correlation exists between the brightness of warning coloration and toxicity level using as a model the paper wasp (Polistes dominula). Results We collected wasps from 30 different nests and photographed them to measure the brightness of warning coloration in the abdomen. We also measured the volume of the poison gland, as well as the length, and the width of the abdomen. The results show a positive relationship between brightness and poison-gland size, which remained positive even after controlling for the body size and abdomen width. Conclusion The results suggest that the coloration pattern of these wasps is a true sign of toxicity level: wasps with brighter colors are more poisonous (they have larger poison glands)