1,535 research outputs found

    Estructura en escamas del sector noroccidental de la Sierra de Cazorla (zona prebética) y del borde de la depresión del Guadalquivir (provincia de Jaén)

    Get PDF
    The succession of different stages of deformation, the last of them having taken place in the middle Miocene, has determined the imbricated structure of the Sierra de Cazorla and the easternmost boundary of the Guadalquivir Basin. The evolution of the structural features is analyzed and a tectonic interpretation of the resulting structure is attempted

    Nuestra Experiencia en el Estudio con Ultrasonografía en la Cadera Neonatal

    Get PDF
    Se estudian mediante ultrasonografía las caderas de 112 recién nacidos (224 caderas) con signos clínicos de displasia luxante de cadera. Los resultados se comparan con los datos de exploración clínica y estudio radiográ- fico poniendo en evidencia las limitaciones diagnósticas de las maniobras exploratorias clásicas y la radiografía. Concluye que la ultrasonografía es el método más seguro e inocuo para el diagnóstico precoz de la displasia luxante de cadera en el recién nacido.The authors are studied by ultrasonography 112 newborns (224 hips) with clinical signs of congenital dysplasia and dislocation of the hip. The results obtained are compared with clinical findings and radiographic study emphasizing the diagnostic limitations of the clasics maneuvistes of physical examination and radiography. They conclude that the ultrasonography is the most sure method and innocuous to the early diagnosis of the congenital dysplasia and dislocation of the hip at the newborn

    Los Ultrasonidos en la Cadera Neonatal

    Get PDF
    Los autores describen la técnica de Estudio mediante Ecografía de la cadera neonatal, las imágenes normales, los métodos de mediciones y las características de los distintos grados de displasiaThe authors describe the technique of the study by ultrasound examination of neonatal hip, normal images, methods of measurement and characteristics of differents degrees of dysplasi

    Study of sdO models: mode trapping

    Full text link
    We present the first description of mode trapping for sdO models. Mode trapping of gravity modes caused by the He/H chemical transition is found for a particular model, providing a selection effect for high radial order trapped modes. Low- and intermediate-radial order {\em p}-modes (mixed modes with a majority of nodes in the P-mode region) are found to be trapped by the C-O/He transition, but with no significant effects on the driving. This region seems to have also a subtle effect on the trapping of low radial order {\em g}-modes (mixed modes with a majority of nodes in the G-mode region), but again with no effect on the driving. We found that for mode trapping to have an influence on the driving of sdO modes (1) the mode should be trapped in a way that the amplitude of the eigenfunctions is lower in a damping region and (2) in this damping region significant energy interchange has to be produced.Comment: 10 pages, 13 figures, accepted for publication in MNRAS, 2009 December 1

    Study of sdO models. Pulsation Analysis

    Full text link
    We have explored the possibility of driving pulsation modes in models of sdO stars in which the effects of element diffusion, gravitational settling and radiative levitation have been neglected so that the distribution of iron-peak elements remains uniform throughout the evolution. The stability of these models was determined using a non-adiabatic oscillations code. We analysed 27 sdO models from 16 different evolutionary sequences and discovered the first ever sdO models capable of driving high-radial order g-modes. In one model, the driving is by a classical kappa-mechanism due to the opacity bump from iron-peak elements at temperature ~200,000 K. In a second model, the driving result from the combined action of kappa-mechanisms operating in three distinct regions of the star: (i) a carbon-oxygen partial ionization zone at temperature ~2 10^6 K, (ii) a deeper region at temperature ~2 10^7 K, which we attribute to ionization of argon, and (iii) at the transition from radiative to conductive opacity in the core of the star.Comment: 13 pages, 19 figures, accepted for publication in MNRAS, 2009 September 1

    The structure and ecological function of the interactions between plants and arbuscular mycorrhizal fungi through multilayer networks

    Get PDF
    Arbuscular mycorrhizas are one of the most frequent mutualisms in terrestrial ecosystems. Although studies on plant mutualistic interaction networks suggest that they may leave their imprint on plant community structure and dynamics, this has not been explicitly assessed. Thus, in the context of plant-fungi interactions, studies explicitly linking plant-mycorrhizal fungi interaction networks with key ecological functions of plant communities, such as recruitment, are lacking. 2. In this study, we analyse, in two Mediterranean forest communities of southern Iberian Peninsula, how plant-arbuscular mycorrhizal fungi (AMF) networks modulate plant-plant recruitment interaction networks. We use a new approach integrating plant-AMF and plant recruitment networks into a single multilayer structure. We also develop a new metric (Interlayer Node Neighbourhood Integration, INNI) to explore the impact of a given node on the structure across layers. 3. The similarity of plant species in their AMF communities is positively related to the observed frequency of recruitment interactions in the field. Results reveal that properties of plant-AMF networks, such as plant degree and centrality, can explain about the properties of plant recruitment network, such as in-and out-degree (i.e. sapling bank and canopy service) and its modular structure. However, these relationships differed between the two forest communities. Finally, we identify particular AMF that contribute to integrate the neighbourhood of recruitment interactions between plants. 4. This multilayer network approach is useful to explore the role of plant-AMF interactions on recruitment, a key ecosystem function enhanced by fungi. Results provide evidence that the complex structure of plant-AMF interactions impacts functional and structurally plant-plant interactions, which in turn may potentiallyMinisterio de Ciencia e Innovación, Grant/ Award Number: CGL2015-69118- C2- 2- P and PGC2018-100966- B- I0

    Bulk dynamics for interfacial growth models

    Get PDF
    We study the influence of the bulk dynamics of a growing cluster of particles on the properties of its interface. First, we define a {\it general bulk growth model} by means of a continuum Master equation for the evolution of the bulk density field. This general model just considers arbitrary addition of particles (though it can be easily generalized to consider substraction) with no other physical restriction. The corresponding Langevin equation for this bulk density field is derived where the influence of the bulk dynamics is explicitly shown. Finally, when it is assumed a well-defined interface for the growing cluster, the Langevin equation for the height field of this interface for some particular bulk dynamics is written. In particular, we obtain the celebrated Kardar-Parisi-Zhang (KPZ) equation. A Monte Carlo simulation illustrates the theoretical results.Comment: 6 pages, 2 figure
    corecore