803 research outputs found

    Las historias de vida en la formación inicial del profesorado de educación física

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    En este trabajo se plantea la utilización de las ¿Historias de Vida¿ en la Formación del Profesorado de Educación Física como punto de partida en el desarrollo de procesos de formación del profesorado reflexivos y críticos. En un primer apartado realizamos una revisión sobre el estado de la cuestión a partir de los trabajos realizados en nuestro área curricular. En un segundo apartado explicamos como las historias de vida sirven como técnica de introspección y toma de conciencia de sus creencias y planteamientos sobre Educación Física Escolar. En este sentido la utilización de historias de vida en la Formación Inicial del Profesorado de Educación Física es extraordinariamente interesante como punto de partida a la hora de comprender mejor el sentido de las diferentes asignaturas y la necesidad de ir elaborando sus propios modelos como profesores de Educación Física

    Gas exchange and water relations of young apricot plants under drought conditions

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    Potted 1.5-year-old apricot plants (Prunus armeniaca L.), growing under polycarbonate glasshouse conditions with a cooling system, were subjected to two successive water stress/recovery periods until pre-dawn leaf water potential (Ypd) reached values between -2.0 and -2.5 MPa, during summer 1996. Control plants were irrigated daily to maintain the soil matric potential at c. -20 kPa. Water stress limited plant growth and induced a significant reduction in leaf area, caused by mature leaf abscission. The parallel behaviour of leaf turgor potential and epinasty in stressed plants indicated that these movements are turgor-dependent. Osmotic adjustments of 0.27 and 0.60 MPa were observed at the end of the first and second stress period, respectively. Relative apoplastic water content (RWCa) values were high, ranging from 27 to 42%, and were not affected by water stress. The rapid decrease in leaf conductance (gl) from the beginning of the stress periods, together with the delay in stomatal reopening after rewatering the plants, indicated that stomatal behaviour was not a simple passive response to water deficits. Net photosynthesis decreased only at the end of both stress periods and recovered quickly. These observations indicate that leaf productivity may be affected only slightly by short-term water stress. The results indicate that drought resistance in apricot is based mainly on avoidance mechanisms, such as stomatal control, epinasty and limitation of transpiration by reducing leaf area. However, some tolerance characteristics, including osmotic adjustment, high RWCa and low leaf osmotic potential at turgor loss point (Ytlp) values were observed.The authors are grateful to J. Soto-Montesinos, M.D. Velasco, M. García and E. Nicolás for their assistance. The study was supported by CICYT (AMB95- 0071) and Consejería de Medio Ambiente, Agricultura y Agua de Murcia grants to the authors

    Whipping of electrified liquid jets

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    Weapply an electric field to amoderately conducting liquid surrounded by another coflowing liquid, all inside a glass-based microfluidic device, to study nonaxisymmetric instabilities.Wefind that the bending of the electrified jet results in a steady-state, helicoidal structure with a constant opening angle. Remarkably, the characteristic phase speed of the helicoidalwave only depends on the charge carried by the jet in the helicoidal region and its stability critically depends on the properties of the coflowing liquid. In fact, the steady-state helical structure becomes chaotic when the longest characteristic time is that of the inner liquid rather than that of the outer coflowing liquid. We also perform a numerical analysis to show that the natural preference of the jet is to adopt the conical helix structure observed experimentally

    Influencia del riego deficitario controlado precosecha sobre la calidad de la cereza ´Prime Giant`

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    El uso de redes de sensores para el manejo del riego deficitario controlado (RDC) en cerezo puede incidir en la mejora de la productividad del agua, calidad de la fruta y en su comportamiento poscosecha, al permitir el conocimiento y control del estado hídrico del suelo y árbol en todo momento. En el primer año de ensayo, el riego deficitario aplicado en precosecha para satisfacer el 85% de las necesidades máximas del cultivo (ETcg) permitió un ahorro de agua del 17% (380 m3 ha-1) respecto al tratamiento control, que se regó al 110% de la ETcg. Este déficit hídrico ligero no afectó a la producción (16,13 t ha-1) e incluso mejoró la calidad del fruto. Así, en el momento de la cosecha (t0) los frutos bajo déficit ligero presentaron matices más rojos y mayor acidez que los de riego completo. Esta mayor acidez no afectó al índice de madurez debido a la compensación por sólidos solubles totales (SST). El carácter de mayor acidez perduró tras 30 días de conservación en frio (t1) y 5 días de simulación de las condiciones de comercialización (t2). Igualmente, los frutos bajo déficit hídrico presentaron una tendencia a menores pérdidas de peso por deshidratación a finales de los periodos de conservación en frio y de simulación de la comercialización.Ministerio de Economía y Competitividad AGL2013-49047-C2-1

    On Sylow normalizers of finite groups

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    Electronic version of an article published as Journal of Algebra and Its Applications Vol. 13, No. 3 (2014) 1350116 (20 pages). DOI 10.1142/S0219498813501168. © [copyright World Scientific Publishing Company] http://www.worldscientific.com/[EN] The paper considers the influence of Sylow normalizers, i.e. normalizers of Sylow subgroups, on the structure of finite groups. In the universe of finite soluble groups it is known that classes of groups with nilpotent Hall subgroups for given sets of primes are exactly the subgroup- closed saturated formations satisfying the following property: a group belongs to the class if and only if its Sylow normalizers do so. The paper analyzes the extension of this research to the universe of all finite groups.The second and third authors have been supported by Proyecto MTM2010-19938C03-02, Ministerio de Econom ia y Competitividad, Spain. The first author would like to thank the Universitat de Valencia and the Universitat Politecnica de Valencia for their warm hospitality during the preparation of this paper. He has been also supported by RFBR Project 13-01-00469.Kazarin, L.; Martínez Pastor, A.; Perez Ramos, MD. (2014). On Sylow normalizers of finite groups. Journal of Algebra and Its Applications. 13(3):1-20. https://doi.org/10.1142/S0219498813501168S12013

    Epidemics in Networks of Spatially Correlated Three-dimensional Root Branching Structures

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    Using digitized images of the three-dimensional, branching structures for root systems of bean seedlings, together with analytical and numerical methods that map a common 'SIR' epidemiological model onto the bond percolation problem, we show how the spatially-correlated branching structures of plant roots affect transmission efficiencies, and hence the invasion criterion, for a soil-borne pathogen as it spreads through ensembles of morphologically complex hosts. We conclude that the inherent heterogeneities in transmissibilities arising from correlations in the degrees of overlap between neighbouring plants, render a population of root systems less susceptible to epidemic invasion than a corresponding homogeneous system. Several components of morphological complexity are analysed that contribute to disorder and heterogeneities in transmissibility of infection. Anisotropy in root shape is shown to increase resilience to epidemic invasion, while increasing the degree of branching enhances the spread of epidemics in the population of roots. Some extension of the methods for other epidemiological systems are discussed.Comment: 21 pages, 8 figure

    Physical activity and leisure habits and relation with Ruffier index in adolescents

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    El objetivo del estudio fue medir y correlacionar la práctica de actividad física y con el Índice de Ruffier (IR) en adolescentes. A un total de 884 alumnos (edad=16,4±0,8 años) se les midió la actividad física con la Versión modificada del Assessment of Physical Activity Level Questionnaire (APALQ) y se evaluó la capacidad de adaptación al esfuerzo mediante el Test Ruffier. La media del Índice de Ruffier fue 11,1±4,6 y el Índice de actividad física (IAF) 13,8±4,4. Las relaciones entre IAF y el IR, y entre horas de ocio sedentario e IR resultaron ser significativas aunque débiles (r=-0,31; p=0,000). En el IR los chicos presentaron valores superiores (t= -8,78; p= 0,000) a las chicas. También destinan más tiempo a la práctica de AF y estas diferencias fueron significativas en AF reglada y no reglada y en participación en competición (p=0,000), mientras que las chicas destinan más tiempo a actividades sedentarias como leer y estudiar (p=0,000). Es necesario promover la práctica de actividades físico-deportivas, especialmente entre las chicasThe aim of the study was to assess and correlate physical activity practice and fitness level in adolescents. A total of 884 students (age=16,4±0,8 years) answered the modified version of the “Assessment of Physical Activity Level Questionnaire (APALQ)” and aerobic capacity was assessed through the Ruffier Test. The mean Ruffier Index (IR) was 11,1±4,6 and the mean Physical Activity Index (IAF) was 13,8±4,4. The relationship between IAF and IR, and between sedentary activities in leisure time and IR, was significant (r=-0,31; p=0,000). although weak. Boys showed higher physical fitness values (t= -8,78; p= 0,000) and spent more time practicing physical activity. These differences were significant for both regulated and not regulated physical activity and for participation in competition (p=0.000). Girls spent more time in sedentary activities like reading and studying (p=0.000). It is necessary to promote physical activity and sport practice, especially among girls

    Synergy in spreading processes: from exploitative to explorative foraging strategies

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    An epidemiological model which incorporates synergistic effects that allow the infectivity and/or susceptibility of hosts to be dependent on the number of infected neighbours is proposed. Constructive synergy induces an exploitative behaviour which results in a rapid invasion that infects a large number of hosts. Interfering synergy leads to a slower and sparser explorative foraging strategy that traverses larger distances by infecting fewer hosts. The model can be mapped to a dynamical bond-percolation with spatial correlations that affect the mechanism of spread but do not influence the critical behaviour of epidemics.Comment: 16 pages, 15 figures. 4 pages for main text and 6 appendices published as supplemental material at http://link.aps.org/supplemental/10.1103/PhysRevLett.106.21870

    Análisis de la relevancia y factibilidad de indicadores de calidad en las unidades de nutrición

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    Introducción: La evaluación de la calidad en las actividades sanitarias exige la elección de unos indicadores acordes con los resultados que queremos medir. De todos los posibles, debemos priorizar aquellos que nos permitan obtener la información más relevante sin sobrecargar el trabajo habitual de nuestras Unidades. Objetivo: Conocer la opinión de los socios de SENPE respecto a la relevancia y la viabilidad del uso de una selección de indicadores de calidad para su aplicación en nutrición clínica. Métodos: Encuesta remitida mediante correo electrónico a los socios de SENPE solicitando a los mismos su opinión sobre 12 indicadores de calidad, valorándose cada uno en cuanto a su relevancia y factibilidad de la aplicación en su medio. Resultados: Contestaron 40 encuestados de 40 centros diferentes de 12 comunidades autónomas. En general, los indicadores fueron considerados más relevantes que factibles. Los indicadores mejor puntuados fueron: “identificación en las bolsas de nutrición artificial”, “posición semi-incorporada del paciente con nutrición enteral por sonda nasogástrica” y “protocolos clínicos básicos”. Considerando los indicadores por grupos (de estructura, proceso o resultado) los mejor valorados fueron: “identificación del paciente en las bolsas de nutrición artificial” (estructura), “posición semi-incorporada” y “protocolos clínicos básicos” (proceso), y “cumplimiento del objetivo calórico” (resultado). Conclusión: Los resultados de la encuesta permiten seleccionar indicadores prioritarios para su aplicación en las Unidades de NutriciónIntroduction: The quality assessment in health activities requires the choice of indicators in line with the results we want to measure. Of all possible, we should prioritize those that allow us to obtain the most relevant information without overloading the regular work of our units. Objective: To determine the opinion of the members of SENPE regarding the relevance and feasibility of using a selection of quality indicators designed for use in clinical nutrition. Methods: E-mail survey sent to members of SENPE asking them their views on 12 quality indicators, evaluating each in terms of their relevance and feasibility of implementation in their environment. Results: 40 respondents answered from 40 centers in 12 different regions. In general, the indicators were considered more relevant than feasible. The indicators best rated were: “identification in artificial nutrition bags, “semi-recumbent position in patient with nasogastric tube feeding” and “basic clinical protocols”. Considering the type of indicator: “patient identification in the bags of artificial nutrition (structure),” a semi-incorporated “and” basic clinical protocols (process), and “fulfillment of the caloric goal” (result). Conclusion: The results of the survey can make a selection of indicators that could be considered for first-line introduction in a Nutrition Uni
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