947 resultados para Blanco, Guillermo P., 1918-2012


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Recent research has shown that, in general, older professors are rated to have more passive-avoidant leadership styles than younger professors by their research assistants. The current study investigated professors' age-related work concerns and research assistants' favorable age stereotypes as possible explanations for this finding. Data came from 128 university professors paired to one research assistant each. Results show that professors' age-related work concerns (decreased enthusiasm for research, growing humanism, development of exiting consciousness and increased follower empowerment) did not explain the relationships between professor age and research assistant ratings of passive-avoidant and proactive leadership. However, research assistants' favorable age stereotypes influenced the relationships between professor age and research assistant ratings of leadership, such that older professors were rated as more passive-avoidant and less proactive than younger professors by research assistants with less favorable age stereotypes, but not by research assistants with more favorable age stereotypes.

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Significant interactions have been demonstrated between production factors and postharvest quality of fresh fruit. Accordingly, there is an attendant need for adaptive postharvest actions to modulate preharvest effects. The most significant preharvest effects appear to be mediated through mineral nutrition influences on the physical characteristics of fruit. Examples of specific influencers include fertilisers, water availability, rootstock, and crop load effects on fruit quality attributes such as skin colour, susceptibility to diseases and physiological disorders, and fruit nutritional composition. Also, rainfall before and during harvest can markedly affect fruit susceptibility to skin blemishes, physical damage, and diseases. Knowledge of preharvest-postharvest interactions can help determine the basis for variability in postharvest performance and thereby allow refinement of postharvest practices to minimise quality loss after harvest. This knowledge can be utilised in predictive management systems. Such systems can benefit from characterisation of fruit nutritional status, particularly minerals, several months before and/or at harvest to allow informed decisions on postharvest handling and marketing options. Other examples of proactive management practices include adjusting harvesting and packing systems to account for rainfall effects before and/or during harvest. Improved understanding of preharvest-postharvest interactions is contributing to the delivery of consistently higher quality of fruit to consumers. This paper focuses on the state of knowledge for sub-tropical and tropical fruits, in particular avocado and mango.

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The lesser grain borer Rhyzopertha dominica (F.) is one of the most destructive insect pests of stored grain. This pest has been controlled successfully by fumigation with phosphine for the last several decades, though strong resistance to phosphine in many countries has raised concern about the long term usefulness of this control method. Previous genetic analysis of strongly resistant (SR) R. dominica from three widely geographically dispersed regions of Australia, Queensland (SRQLD), New South Wales (SRNSW) and South Australia (SRSA), revealed a resistance allele in the rph1 gene in all three strains. The present study confirms that the rph1 gene contributes to resistance in a fourth strongly resistant strain, SR2(QLD), also from Queensland. The previously described rph2 gene, which interacts synergistically with rph1 gene, confers strong resistance on SRQLD and SRNSW. We now provide strong circumstantial evidence that weak alleles of rph2, together with rph1, contribute to the strong resistance phenotypes of SRSA and SR2(QLD). To test the notion that rph1 and rph2 are solely responsible for the strong resistance phenotype of all resistant R. dominica, we created a strain derived by hybridising the four strongly resistant lines. Following repeated selection for survival at extreme rates of phosphine exposure, we found only slightly enhanced resistance. This suggests that a single sequence of genetic changes was responsible for the development of resistance in these insects.

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Phosphine is the only economically viable fumigant for routine control of insect pests of stored food products, but its continued use is now threatened by the world-wide emergence of high-level resistance in key pest species. Phosphine has a unique mode of action relative to well-characterised contact pesticides. Similarly, the selective pressures that lead to resistance against field sprays differ dramatically from those encountered during fumigation. The consequences of these differences have not been investigated adequately. We determine the genetic basis of phosphine resistance in Rhyzopertha dominica strains collected from New South Wales and South Australia and compare this with resistance in a previously characterised strain from Queensland. The resistance levels range from 225 and 100 times the baseline response of a sensitive reference strain. Moreover, molecular and phenotypic data indicate that high-level resistance was derived independently in each of the three widely separated geographical regions. Despite the independent origins, resistance was due to two interacting genes in each instance. Furthermore, complementation analysis reveals that all three strains contain an incompletely recessive resistance allele of the autosomal rph1 resistance gene. This is particularly noteworthy as a resistance allele at rph1 was previously proposed to be a necessary first step in the evolution of high-level resistance. Despite the capacity of phosphine to disrupt a wide range of enzymes and biological processes, it is remarkable that the initial step in the selection of resistance is so similar in isolated outbreaks.

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We report gas phase mid-infrared spectra of 1- and 2- methyl naphthalenes at 0.2 cm(-1) resolution. Assignment of observed bands have been made using scaled quantum mechanical (SQM) calculations where the force fields rather the frequencies are scaled to find a close fit between observed and calculated bands. The structure of the molecules has been optimized using B3LYP level of theory in conjunction with standard 6-311G** basis set to obtain the harmonic frequencies. Using the force constants in Cartesian coordinates from the Gaussian output, scaled force field calculations are carried out using a modified version of the UMAT program in the QCPE package. Potential energy distributions of the normal modes obtained from such calculations helped us assign the observed bands and identify the unique features of the spectra of 1- and 2-MNs which are important for their isomeric identification.

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Nanocrystalline Nd2O3:Ni2+ (2 mol%) phosphor has been prepared by a low temperature (similar to 400 degrees C) solution combustion method, in a very short time (<5 min). Powder X-ray diffraction results confirm the single hexagonal phase of nanopowders. Scanning electron micrographs show that nanophosphor has porous nature and the particles are agglomerated. Transmission electron microscopy confirms the nanosize (20-25 nm) of the crystallites. The electron paramagnetic resonance (EPR) spectrum exhibits a symmetric absorption at g approximate to 2.77 which suggests that the site symmetry around Ni2+ ions is predominantly octahedral. The number of spins participating in resonance (N) and the paramagnetic susceptibility (chi) has been evaluated. Raman study show major peaks, which are assigned to F-g and combination of A(g) + E-g modes. Thermoluminescence (TL) studies reveal well resolved glow peaks at 169 degrees C along with shoulder peak at around 236 degrees C. The activation energy (E in eV), order of kinetics (b) and frequency factor (s) were estimated using glow peak shape method. It is observed that the glow peak intensity at 169 degrees C increases linearly with gamma-dose which suggest that Nd2O3:Ni2+ is suitable for radiation dosimetry applications. (C) 2012 Elsevier B.V. All rights reserved.

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Present work presents a code written in the very simple programming language MATLAB, for three dimensional linear elastostatics, using constant boundary elements. The code, in full or in part, is not a translation or a copy of any of the existing codes. Present paper explains how the code is written, and lists all the formulae used. Code is verified by using the code to solve a simple problem which has the well known approximate analytical solution. Of course, present work does not make any contribution to research on boundary elements, in terms of theory. But the work is justified by the fact that, to the best of author’s knowledge, as of now, one cannot find an open access MATLAB code for three dimensional linear elastostatics using constant boundary elements. Author hopes this paper to be of help to beginners who wish to understand how a simple but complete boundary element code works, so that they can build upon and modify the present open access code to solve complex engineering problems quickly and easily. The code is available online for open access (as supplementary file for the present paper), and may be downloaded from the website for the present journal.

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Three dimensional digital model of a representative human kidney is needed for a surgical simulator that is capable of simulating a laparoscopic surgery involving kidney. Buying a three dimensional computer model of a representative human kidney, or reconstructing a human kidney from an image sequence using commercial software, both involve (sometimes significant amount of) money. In this paper, author has shown that one can obtain a three dimensional surface model of human kidney by making use of images from the Visible Human Data Set and a few free software packages (ImageJ, ITK-SNAP, and MeshLab in particular). Images from the Visible Human Data Set, and the software packages used here, both do not cost anything. Hence, the practice of extracting the geometry of a representative human kidney for free, as illustrated in the present work, could be a free alternative to the use of expensive commercial software or to the purchase of a digital model.

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CAELinux is a Linux distribution which is bundled with free software packages related to Computer Aided Engineering (CAE). The free software packages include software that can build a three dimensional solid model, programs that can mesh a geometry, software for carrying out Finite Element Analysis (FEA), programs that can carry out image processing etc. Present work has two goals: 1) To give a brief description of CAELinux 2) To demonstrate that CAELinux could be useful for Computer Aided Engineering, using an example of the three dimensional reconstruction of a pig liver from a stack of CT-scan images. One can note that instead of using CAELinux, using commercial software for reconstructing the liver would cost a lot of money. One can also note that CAELinux is a free and open source operating system and all software packages that are included in the operating system are also free. Hence one can conclude that CAELinux could be a very useful tool in application areas like surgical simulation which require three dimensional reconstructions of biological organs. Also, one can see that CAELinux could be a very useful tool for Computer Aided Engineering, in general.

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Resumen: En este artículo intento relacionar la mística con la razón, mostrando que hay una razón de la mística. Es un logos analógico, un ana-logos, ya que la analogía es el recurso que han usado los místicos para conocer y expresar el misterio. Ya que se requiere una comprensión y una explicación, se usa la hermenéutica, para interpretar la experiencia mística y el lenguaje de los místicos. Pero tiene que ser una hermenéutica analógica, para que sea acorde con el instrumento conceptualizador que utilizan: la metáfora, la parábola y demás recursos cognoscitivos y expresivos que brinda la rica noción de analogía.

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Oro har finantza-erakunde baten kudeaketa ikuspegi praktiko batetik ezagutu nahi duen edozeinentzat erabilgarria da lan hau. Hain zuzen ere, graduko eta postgraduko finantza-arloko irakasleei, sektore honetako profesionalei eta, baita banku-eragiketak hobetu ulertu nahi dituzten inbertsiogile partikularrei ere zuzentzen da.

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Although Sri Lanka is endowed with favourable climatic conditions and resources for breeding and rearing ornamental fish for export, a considerable number of ornamental fish producers as well as exporters have given up the industry within a relatively short period of time. This study was conducted to understand the present status of the industry and to identify the problems that have caused these failures. The study was conducted from March to December in the year 2007 and covered Colombo, Kaluthara, Polonnaruwa, Negombo, Wattala, Rathnapura, Avissawella, Kandy, Kegalle, Padukka, and Gampaha areas, where ornamental fish culture is known to be popular. The survey was carried out by interviewing ornamental fish farmers using a structured questionnaire survey that was designed to elicit the required information. Most (75%) of those surveyed were identified as small scale farmers. A majority (56%) of them used only cement tanks for their culture activities. Only 47% of farmers had proper technical knowledge or training on fish culture while 42% directly supplied their fish products to the expo1iers. The most important constraints identified by the study were as follows: (1) the sale price offish not changing in keeping with the increase in the material costs of production - Feed, cement, sand, transport and labour - in recent years. (2) Difficulty to find export markets for newcomers to enter the export market. (3) Lack of quality brooders and information on the most suitable fish varieties for the different climatic and water conditions in different areas in the country (3) Feed availability and cost. (4) Lack of adequate knowledge and technical support with regard to disease control and water quality management. (5) Difficulty to survive in the off season. (6) Difficulty in obtaining credit for expansion and the lack of sufficient involvement of responsible authorities in overcoming all these identified constraints.

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Este trabalho teve por objetivo estudar a morfologia e as síndromes de dispersão de Myracrodruon urundeuva, Schinopsis brasiliensis (Anacardiaceae), Sideroxylon obtusifolium (Sapotaceae) e Amburana cearensis (Leguminosae), contribuindo para o entendimento da ecologia dessas espécies, em área de Caatinga, na Reserva Legal do Projeto Salitre, Juazeiro, BA. Para os estudos morfológicos, 200 frutos de cada espécie foram coletados em diferentes indivíduos da população e mensurados. De acordo com o tipo de fruto, foi adotado um método de avaliação da dispersão dos diásporos em campo: parcelas de 1m2 para os frutos secos e observação em campo no período de 5h às 18h, para os frutos carnosos. Para avaliar a taxa de sobrevivência no campo, plântulas das quatro espécies foram identificadas e acompanhadas quinzenalmente por um período de 6 meses. M. urundeuva, S. brasiliensis e A. cearensis apresentaram frutos secos do tipo anemocórico enquanto S. obtusifolium apresentou frutos carnosos adaptados à dispersão zoocórica, podendo ser considerada como importante fonte alimentar para a avifauna da região. Quanto ao estabelecimento das plantas jovens, verificou-se que nas espécies anemocóricas a dispersão ocorre a curta distância, o que ocasionaria a distribuição agregada das mesmas. Para as espécies anemocóricas foram registradas taxas de sobrevivência inferiores a 30%, indicando que o recrutamento de plantas jovens está comprometido, podendo estar associado às condições climáticas adversas e à predação por animais silvestres e domésticos.