803 research outputs found
Las historias de vida en la formación inicial del profesorado de educación física
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
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
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`
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
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
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
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
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
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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