796 research outputs found
Observability in dynamic evolutionary models
In the paper observability problems are considered in basic dynamic evolutionary models for sexual and asexual populations. Observability means that from the (partial) knowledge of certain phenotypic characteristics the whole evolutionary process can be uniquely recovered. Sufficient conditions are given to guarantee observability for both sexual and asexual populations near an evolutionarily stable state
Análisis de la sensibilidad del ensayo de resonancia por impacto como herramienta para determinar las propiedades elásticas de materiales bituminosos
The modulus value of bituminous materials is a key factor in the design of road pavements and the estimation of their life service. This parameter can be measured in laboratory but, unfortunately, this requires the deterioration of the pavement so as the consumption of time and resources. Therefore, this study analyses the feasibility of using impact resonance frequency tests as an alternative to traditional methods for determining the dynamic modulus of bituminous mixtures. The sensitivity of this technique has been studied by analyzing its repeatability and reproducibility, studying the variations in the values measured by modifying the dimensions of the specimens, test temperatures and types of mixture tested. In addition, this non-destructive technique has been compared with other traditional tests used to determine the elastic properties of bituminous materials. The results show that this test could be an interesting tool to characterize the properties and damage state of asphalt layers.El valor de módulo de los materiales bituminosos es un factor clave en el diseño de pavimentos y la estimación de su vida de servicio. Este parámetro puede ser medido en laboratorio pero, desafortunadamente, esto requiere deteriorar el pavimento así como el consumo de tiempo y recursos. Por ello, este estudio analiza la viabilidad de usar el ensayo de frecuencia de resonancia mediante impacto como alternativa a los métodos tradicionales para determinar el módulo dinámico de mezclas bituminosas. La sensibilidad de esta técnica se ha estudiado analizando su repetibilidad y reproducibilidad, estudiando variaciones en los valores medidos al modificar dimensiones de probetas, temperaturas y tipos de mezcla ensayados. Además, esta técnica no destructiva se ha comparado con otros ensayos tradicionales empleados para determinar propiedades elásticas de materiales bituminosos. Los resultados muestran este ensayo como una herramienta interesante para caracterizar las propiedades y estado de daño de las capas de asfalto
Celebrities, violencia de género y derechos de las mujeres: ¿hacia una transformación del marco de reconocimiento?
Introducción. Ante los límites que presenta el actual marco de reconocimiento de la violencia de género, el presente trabajo analiza las posibilidades que abre la acción de celebrities en la transformación de este marco y en relación a la lucha por los derechos de las mujeres. Para ello proponemos el concepto de ethical witnessing. Metodología. Se propone un modelo de análisis a través de la operacionalización de dicho concepto para el estudio de prácticas representacionales que puedan desestabilizar los actuales parámetros de representación en aras de la resignificación del sujeto-víctima de la violencia. Las cuatro dimensiones de análisis son: el tipo de relación que se genera entre el sujeto-víctima y quien atestigua; el grado de transgresión de los modelos reificados de la identificación del sujeto-víctima; la focalización en la capacidad de agencia; y las conexiones que se establecen con las luchas por los derechos de las mujeres y con otras luchas. Este modelo se aplica a tres casos de estudio: las actuaciones musicales de Beyoncé, la entrevista periodística realizada a Carmen Maura y la campaña mediática de Emma Watson. Resultados. Se discuten las posibilidades de las prácticas discursivas que se incardinan en los principios del postfeminismo. Frente a la identidad de la mujer como víctima emerge la de la mujer exitosa que compatibiliza vindicación feminista y lucha contra la violencia de género con consumismo, materialismo y capitalismo. Esto permite desestabilizar la narrativa fijada sobre la violencia pero no llega a constituir una re-significación del marco en tanto que puede quedar co-optado por la ‘economía de las celebrities’, ser absorbido por el feminismo liberal o estar desvinculado de la lucha colectiva, lo que dificulta la aprehensión del carácter compartido de la vulnerabilidad.Introduction. Due to the limitations of the current framework of recognition of gender-based violence, this article analyses the possibilities of the actions performed by celebrities in the transformation of such framework and in the fight for women’s rights. To this end, we propose the concept of “ethical witnessing”. Methods. The study proposes an analytical model based on the operationalisation of this concept applied to the examination of the representational practices that may destabilise the current hegemonic configuration and re-signify the subject-victim relationship of violence. The four dimensions of analysis are: the relations generated between the subject-victim and the witness; the degree of transgression of the reified representational models of the subject-victim; the focus on agency; and the connection with women’s fights for their rights and other social movements. This model is applied to three case studies: Beyoncé’s musical performances; the interview with actress Carmen Maura, and Emma Watson’s #HeForShe media campaign. Results. The study discusses the possibilities of the discursive practices stemming from postfeminist principles. A new image emerges to contrast the image of women as victims: the image of successful women who find a balance between feminist vindications and the fight against gender-based violence with consumerism, materialism and capitalism. This image enables the destabilisation of the narrative about violence, but it does not constitute a re-signification of the framework of recognition, as it can be co-opted by the “celebrity economy”, can be absorbed by liberal feminism, or can be disassociated from the collective fight, which complicates the comprehension of the shared nature of vulnerability
Stratigraphy of the Cordubian-Ovetian (Lower Cambrian) Transition in the Occidental Iberian Chain (Spain)
[Resumen] Este trabajo analiza los afloramientos de la Formación Embid (Cámbrico Inferior) existentes en el borde nororiental de la Cadena Ibérica Occidental, entre las
localidades de Torrijo de la Cañada y Villalengua (unidad estructural de Moros). Con este objetivo se han realizado dos perfiles estratigráficos y estudiado sus litofacies. Asimismo, se pone de manifiesto el contenido paleoicnológico más representativo. La aparición de distintos ejemplares del icnogénero Astropolichnus separados 200 m. en la serie estratigráfica plantea la necesidad de reconsiderar la precisión de este incofósil como indicador bioestratigráfico. Debido a la ausencia de afloramientos superficiales de la Formación Bámbola, estos materiales constituyen las rocas más antiguas.de esta Cadena. Finalmente, se propone al perfil To1 como hipoestratotipo de la Formación Embid en la Cadena Ibérica Occidental.[Abstract] This work presents a study of the Embid Formation, the oldest formation cropped out in the Occidental Iberian Chain (NE Spain). This outcrop is placed in the nucleus of the Moros structural unit (ALVARO et al., 1992), located in the nonheastern contact of this Chain with the Calatayud-Teruel Teniary basin, between Villalengua and Torrijo de la Cañada localities (Zaragoza Province). We have studied two sections of the Embid Formation (To1 and T02). The first one, 250 m. thick, is the most complete and shows the best exposition of the area. It is proposed as the hipostratotype of the Embid Formation in this Chain. In To1, four terms (El to E4) of this formation and other at the beginning of the Jalón Formation al) have been recognized, according to the sandstone/shale ratio. The ichnofossils and other sedimentary structures studied here suggest, for terms E2 and E4-J1, a litoral to shallow sublitoral environment (tidal flat and tidal channels, influenced by tidal and wave effects), and a sublitoral (circalitoral) environment with episodic levels influenced by storms currents and/or hard tides, for the terms El and E3. The northeastwards To2 section, 150 m. thick, shows a similar evolution, but a more distal character. The wide development of subtidal sand bodies as well as the low diversity and wealth of biogenic structures, suggest a shoreface sedimentation, with a intercalated episode influenced by tidal action. The materials of this section are assigned to the Embid Formation for its lithology, the lack of white quarzites (that characterize the underlying Bámbola Formation) and the ichnofossil record. In spite of palichnological, lithological and sedjmentological affinities between both profils, we can not give an accurate correlation of both sequences. The section To1 records a shallower episode (E2), reaching subaerial exposure in the Cordubian-Ovetian transition. It is the first time this episode has been recognized in the Iberian Chains, and it is considered as a local process. A second shallower episode is placed in the transition of the Embid-Jalón Formations (E4-J1). It has been recognized in other outcrops of the Iberian Chains and LIÑAN & GAMEZ (in press) have proposed a correlation of this regressive episode with the Woodlands Regression (BRASIER, 1985). On the other hand, Astropolichnus ichnogenus is recorded in different levels of same section (200 m. separated), for the first-time in the Iberian Chains. This fact will force to reconsider the accuracy of this ichnofossil as biostratigraphical marker. Finally, a progresive eastwards distallity of the sediments is inferred by comparison with similar outcrops of the Oriental Iberian Chain, by the existence of the first local"shallower episode, placed in the more suroccidental outcrop of the basin (To1), and by the northeastwards paleocurrents directions. These data support the existence of an emerged area beside the occidental margin of the Cantabrian-Iberian Basin as was pointed by LOTZE (1961), and also proposed in the cantabrian sector of this basin by ARAMBURU el al. (1992)
Plain cigarette packs do not exert Pavlovian to instrumental transfer of control over tobacco-seeking
Journal ArticleResearch Support, Non-U.S. Gov'tCopyright © 2014 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of AddictionAIMS: To gain insight into the potential impact of plain tobacco packaging policy, two experiments were undertaken to test whether 'prototype' plain compared with branded UK cigarette pack stimuli would differentially elicit instrumental tobacco-seeking in a nominal Pavlovian to instrumental transfer (PIT) procedure. DESIGN, SETTING AND PARTICIPANTS: Two experiments were undertaken at the University of Bristol UK, with a convenience sample of adult smokers (experiment 1, n = 23, experiment 2, n = 121). MEASUREMENT: In both experiments, smokers were trained on a concurrent choice procedure in which two responses earned points for cigarettes and chocolate, respectively, before images of branded and plain packs were tested for capacity to elicit the tobacco-seeking response in extinction. The primary outcome was percentage choice of the tobacco- over the chocolate-seeking response in plain pack, branded pack and no-stimulus conditions. FINDINGS: Both experiments found that branded packs primed a greater percentage of tobacco-seeking (overall mean = 62%) than plain packs (overall mean = 53%) and the no-stimulus condition (overall mean = 52%; Ps ≤ 0.01, ŋp (2) s ≥ 0.16), and that there was no difference in percentage tobacco-seeking between plain packs and the no-stimulus condition (Ps ≥ 0.17, ŋp (2) s ≤ 0.04). Plain tobacco packs showed an overall 9% reduction in the priming of a tobacco choice response compared to branded tobacco packs. CONCLUSIONS: Plain packaging may reduce smoking in current smokers by degrading cue-elicited tobacco-seeking.British Heart FoundationCancer Research UKNIHRMRCESR
Estudio experimental de placas preconformadas en postpandeo
XI CONGRESO NACIONAL DE MATERIALES COMPUESTOS. Celebrado en Móstoles los días 6, 7 y 8 de julio de 2015El pandeo de placas y láminas no necesariamente está asociado al colapso, que en
ocasiones se produce para una carga que es varias veces superior. No obstante,
aprovechar esta capacidad postpandeo no es fácil, siendo el principal inconveniente la
extremada sensibilidad del problema ante imperfecciones de la geometría y las
condiciones de sustentación y de cargas. En este trabajo se muestran los primeros
resultados de un análisis de la evolución en postpandeo de placas de material
compuesto en las que, intencionadamente, se han introducido imperfecciones iniciales.Junta de Andalucía TEP-7093Ministerio de Economía y Competitividad DPI2012-3718
The Cambrian of the Iberian Peninsula : an overview
This work is a brief overview of the Cambrian in the Iberian Peninsula, along with an updated review of lithostratigraphic and biostratigraphic data. A Cambrian correlation chart between the different stratigraphical units that have been established in the Iberian Peninsula is given. We also reappraise the Lower and Middle Cambrian regional stages in the light of new palaeontological data, and the different biozonations proposed with several palaeontological groups
Particle dispersion processes in two-dimensional turbulence: a comparison with 2-D kinematic simulation.
International audienceWe study numerically the comparison between Lagrangian experiments on turbulent particle dispersion in 2-D turbulent flows performed, on the one hand, on the basis of direct numerical simulations (DNS) and, on the other hand, using kinematic simulations (KS). Eulerian space-time structure of both DNS and KS dynamics are not comparable, mostly due to the absence of strong coherent vortices and advection processes in the KS fields. The comparison allows to refine past studies about the contribution of non-homogeneous space-time 2-D Eulerian structure on the turbulent absolute and relative particle dispersion processes. We particularly focus our discussion on the Richardson's regime for relative dispersion
A new occurence of the genus Tonkinella in northern Spain and the Middle Cambrian intercontinental correlation
The genus Tonkinella is a typical polimeroid trilobite in lower Middle Cambrian rocks from Vietnam, Canada, U.S.A., India, Korea, Siberia, China and Argentina. It has recently been found in the Mediterranean region (Iberian Chain, northeastern Spain). In this paper we refer the finding of Tonkinella aff. breviceps in the Leonian (lower Middle Cambrian) of the Cantabrian Mountains (northern Spain), analysing its stratigraphical position, fossil assemblages, biochronology and utility for intercontinental correlation. The presence of this taxon allows us to make a more accurate correlation between the Middle Cambrian biochronological scales of Laurentia, the Mediterranean area and China
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