1,583 research outputs found

    Development of indices of larval bluefin tuna (Thunnus thynnus) in the western Mediterranean sea

    Get PDF
    Fishery independent indices of bluefin tuna larvae in the western Mediterranean Sea are presented utilizing ichthyoplankton survey data collected from 2001 through 2005 by the Spanish Institute of Oceanography. Indices were developed using larval catch rates collected using two different types of bongo gear by employing a delta-lognormal modeling approach, including following covariates: water temperature at 25 m, salinity at 25 m, water depth, time of day, geostrophic water velocities, year, and a gear variable for the combined modelSe presentan índices de larvas de atún rojo independientes de la pesquería en el mar Mediterráneo occidental utilizando datos de prospecciones de ictioplancton recopilados desde 2001 hasta 2005 por el Instituto Español de Oceanografía. Los índices se desarrollaron utilizando tasas de captura larval recopiladas utilizando dos tipos diferentes de red bongo y empleando un enfoque delta-lognormal de modelación, que incluía las siguientes covariables: temperatura del agua a 25 m, salinidad a 25 m, profundidad del agua, hora del día, velocidad del agua geostrófica, año y una variable de arte para el modelo combinad

    Sobre la relación de intensidades características del espectro K de rayos X

    Get PDF
    La variación de la energía de transición de un elemento en función de su número de coordinación, es un parámetro que proporciona información sobre la estructura electrónica de un elemento en diferentes compuestos, por lo que ha sido estudiado con especial interés. En este trabajo se demuestra que la relación de intensidades entre las líneas características de un elemento en diferentes tipos de enlace, es un parámetro sensible con respecto a la estructura electrónica. Esto se prueba en los casos del Si y Al.The variation of the transiction energy of an element in function of bis coordination number, is a parameter that gives information about the electronic structure of an element in different compounds. This aspect has been studied with special interest. In this work it has been outlined that the relation of intensities between the characteristic lines of an element in different chemical bounds is a sensitive parameter comported with the electronic structure. It has been proved in the cases of silicium and aluminium

    In Vitro and In Situ Characterization of Fish Thymic Nurse Cells

    Get PDF
    We present an enzyme- and immuno-cytochemical, and ultrastructural characterization of trout thymic nurse cells (TNCs). Our data suggest that isolated trout thymic multicellular complexes are epithelial cells with acidic compartments that may be involved in the processing of antigens and in the generation of the MHC-II proteins that these cell express, and also that isolated TNCs are the In Vitro equivalent of the pale and intermediate electronlucent epithelial cells located in the inner zone of the trout thymus, constituting indirect evidence of the phylogenetical relationships of the inner zone of the teleost thymus with the thymic cortex of higher vertebrates

    Conservación de cepas bacterianas por congelación sobre discos de celulosa

    Get PDF
    Se estudia la conservación de cepas bacterianas pertenecientes a diferentes géneros y especies, por congelación a 300C utilizando como soporte discos de papel de celulosa. Asímismo se compruebe si esta técnica puede ser utilizada para la conservación de bacterias estructural y fisiologicamente diferentes entre sí o si por el contrario no es aconsejable para determinados tipos bacterianos. Los resultados obtenidos, muestran que la congelación de suspensiones bacterianas sobre discos de celulosa, mantiene la viabilidad en condiciones suficientemente satisfactorias para considerar que esta técnica es un procedimiento eficaz de conservación de cepas bacterianas. Debe resaltarse el hecho de que la recuperación de las cepas no halófilas, tanto de Colección como de muestras clínicas, no requiere, en la mayoría de los casos de medios de enriquecimiento.The conservation of bacterial strains adscribed to different genus and species, by freezing at - 300C using disc paper of cellulose have been studied. It has also tested wether this technique can be utilized for maintenance of rnicroorganisms with structural and physiologic differences. The results show how the freezing of bacterial cultures on cellulose disc pa per, keep the bacterial viability in good conditions. This technique is a good way of mainteneance of bacterial strains. It is significative that for recuperation of non halophiles strains, no enrichment medium is required

    Momento Económico (8)

    Get PDF
    En este número Temas de hoy, 2/ La energía del programa, Ignacio Cabrera, 3/ Se recupera la industria automotriz, 6/ Más apoyo del Estado a los industriales exportadores, Lucia Alvarez Mosso, 7/ La danza de las divisas, Ma. Luisa González Marín, 10/ La planeación del desarrollo científico tecnológico en México. Adrián Chavero Gonrález, 12/ La política científico-tecnológica en México (1980-1984), Alberto León, 1

    Reseñas

    Get PDF

    Forecasting confined spatiotemporal chaos with genetic algorithms

    Get PDF
    A technique to forecast spatiotemporal time series is presented. it uses a Proper Ortogonal or Karhunen-Lo\`{e}ve Decomposition to encode large spatiotemporal data sets in a few time-series, and Genetic Algorithms to efficiently extract dynamical rules from the data. The method works very well for confined systems displaying spatiotemporal chaos, as exemplified here by forecasting the evolution of the onedimensional complex Ginzburg-Landau equation in a finite domain.Comment: 4 pages, 5 figure

    Phase transitions in geometrothermodynamics

    Full text link
    Using the formalism of geometrothermodynamics, we investigate the geometric properties of the equilibrium manifold for diverse thermodynamic systems. Starting from Legendre invariant metrics of the phase manifold, we derive thermodynamic metrics for the equilibrium manifold whose curvature becomes singular at those points where phase transitions of first and second order occur. We conclude that the thermodynamic curvature of the equilibrium manifold, as defined in geometrothermodynamics, can be used as a measure of thermodynamic interaction in diverse systems with two and three thermodynamic degrees of freedom

    Transcultural adaptation and validation of the Spanish language version of the questionnaire OQLQ for the assessment of quality of life in orthognathic patients

    Get PDF
    Orthognathic surgery is the cornerstone of the treatment of dentofacial deformities, which have a great psychological and social impact on the life of the patient. Patient satisfaction and the impact on quality of life have recently become clinical parameters of growing importance. The aim of this study was to undertake a transcultural adaptation, translation to Spanish and validation of this version of the questionnaire OQLQ, used to measure quality of life in the context of Spanish culture. Validation of the OQLQ questionnaire to the Spanish language was carried out through the methodology of translation and back translation, conceptual equivalence and piloting. The Spanish version was applied through a cross-sectional study to a total of 50 patients undergoing orthognathic surgery. The adapted and validated version showed adequate metric properties of reliability, change sensitivity and validity. In this study, a positive impact of orthognathic surgery on the specific quality of life was evident in 96% of patients, with an average improvement of 58% with respect to the initial score. Dentofacial deformities have a marked negative impact on the lives of patients, with orthognathic surgery being a therapeutic tool of great value in improving the quality of life in social, functional and aesthetic terms. The pilot test of this Spanish language version of the OQLQ proved valid for the assessment of quality of life in Spanish-speaking orthognathic patients or those with a Spanish culture

    Recent Overview of Solar Photocatalysis and Solar Photo-Fenton Processes for Wastewater Treatment

    Get PDF
    This literature research, although not exhaustive, gives perspective to solar-driven photocatalysis, such as solar photo-Fenton and TiO2 solar photocatalysis, reported in the literature for the degradation of aqueous organic pollutants. Parameters that influence the degradation and mineralization of organics like catalyst preparation, type and load of catalyst, catalyst phase, pH, applied potential, and type of organic pollutant are addressed. Such parameters may also affect the photoactivity of the catalysts used in the studied solar processes. Solar irradiation is a renewable, abundant, and pollution-free energy source for low-cost commercial applications. Therefore, these solar processes represent an environmentally friendly alternative mainly because the use of electricity can be decreased/avoided
    corecore