772 research outputs found

    Gravitational waves from self-ordering scalar fields

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    Gravitational waves were copiously produced in the early Universe whenever the processes taking place were sufficiently violent. The spectra of several of these gravitational wave backgrounds on subhorizon scales have been extensively studied in the literature. In this paper we analyze the shape and amplitude of the gravitational wave spectrum on scales which are superhorizon at the time of production. Such gravitational waves are expected from the self ordering of randomly oriented scalar fields which can be present during a thermal phase transition or during preheating after hybrid inflation. We find that, if the gravitational wave source acts only during a small fraction of the Hubble time, the gravitational wave spectrum at frequencies lower than the expansion rate at the time of production behaves as ΩGW(f)f3\Omega_{\rm GW}(f) \propto f^3 with an amplitude much too small to be observable by gravitational wave observatories like LIGO, LISA or BBO. On the other hand, if the source is active for a much longer time, until a given mode which is initially superhorizon (kη1k\eta_* \ll 1), enters the horizon, for kη1k\eta \gtrsim 1, we find that the gravitational wave energy density is frequency independent, i.e. scale invariant. Moreover, its amplitude for a GUT scale scenario turns out to be within the range and sensitivity of BBO and marginally detectable by LIGO and LISA. This new gravitational wave background can compete with the one generated during inflation, and distinguishing both may require extra information.Comment: 21 pages, 2 figures, added discussion about numerical integration and a new figure to illustrate the scale-invariance of the GW power spectrum, conclusions unchange

    Trazabilidad y relación con la producción integrada

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    La aparición de las diferentes enfermedades, como la encefalopatía en vacuno y ovinos, las peste porcina, la gripe aviar, etc., y las preocupaciones del consumidor por saber qué tipo de productos están consumiendo, han llevado a las Administraciones Públicas y a distintos empresarios a establecer medidas de seguridad más exigentes que aseguren una garantía del origen y salubridad de los productos. Es en ese momento cuando surgen los distintos sistemas de trazabilidad (normativa de la UE 178/2002) que actualmente se conocen, los cuales dan seguridad y beneficios, tanto al consumidor como al empresario: – Identificación de Materia Auxiliar y Materia Prima – Control de stocks – Control de los procesos productivos – Optimización de los mismos – Coordinación y colaboración con los distribuidores – Localización inmediata de los lotes ante un posible problema – Disminución de costes operativos y productivos, etc

    Morphometric analysis of bite mark patterns caused by domestic dogs (Canis lupus familiaris) using dental wax registers

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    Dog bites are a known public health problem involving physical, mental and emotional traumas. From a forensic point of view, it has been stated that their morphological characters, and the intercanine and interincisive measurements, could allow a taxonomic and specific identification of the implicated animal. The aim of this study was to differentiate and identify the biological profile of a potential aggressor dog by analysing eight morphometric bite patterns belonging to three different dog breeds. The data obtained were analyzed following three categories: a) breeds; b) sexes among breeds; and c) sex within breed. Significant differences were detected among the variables (p <= 0.05), but only the maximum maxillary intercanines width (MaxCW) allowed a breed differentiation. The other variables allowed a differentiation between two breeds or one breed over the others. The principal components analysis (PCA) allowed visualizing the degree of dispersion and relationship among the scores. It showed three well-defined and separated breed groups, and different degrees of dispersion within and among breeds. The most important variable for such a differentiation was MaxCW. When considering sex among breeds for males, it showed a statistically significant difference, but only the diastema located between the third left mandibular, incisive and the left mandibular canine (C-I-ManL) allowed breed differentiation. For females, only MaxCW allowed a differentiation among breeds. The multivariate analysis permitted with a 95 % confidence interval, a breed and sex differentiation. Besides, the PCA models allowed classifying, identifying, separating and graphically showing the relationship among the variables. This made it possible to differentiate between breeds and sexes. Due to the large range of dog breeds around the world, this multivariate analysis could also help determining the dog's weight and size, narrowing down towards an approximate number of offending dogs, focussing on a certain kind of dog breed, and pinpointing any suspect dog

    Análisis multivariante de los horizontes orgánico-minerales de los suelos del Parque Natural de Sierra Mágina (Jaén)

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    Soils are described normally using a great number of properties (variables). This generates a great quantity of data not easily understandable in a direct way. Consequently, multivariate analysis is necessary to support and confirm impressions and interpretations of investigations in field and laboratory. In the present work we quantify, through multivariate analysis, the relative influence of the different factors of soil formation that act on the soil system. We have studied 203 organo-mineral horizons, sampled to a depth between 0 and 25 cm of soils in the Sierra Mágina natural park (Jaén, Spain). The studied soils are from calcareous rocks. Five factors were found to be significant and showed that the organic carbon accumulation, decarbonatation and the argillization/rubefacction, as internal variables, and the hill slope, as external variable, they are those which explain a greater percentage of the natural variability of the soil system

    Low-lying excitations of a trapped rotating Bose-Einstein condensate

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    We investigate the low-lying excitations of a weakly-interacting, harmonically-trapped Bose-Einstein condensed gas under rotation, in the limit where the angular mometum LL of the system is much less than the number of the atoms NN in the trap. We show that in the asymptotic limit NN \to \infty the excitation energy, measured from the energy of the lowest state, is given by 27N3(N31)v0/6827 N_{3}(N_{3}-1) v_0 /68, where N3N_{3} is the number of octupole excitations and v0v_{0} is the unit of the interaction energy.Comment: 3 pages, RevTex, 2 ps figures, submitted to PR

    Solutions of Gross-Pitaevskii equations beyond the hydrodynamic approximation: Application to the vortex problem

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    We develop the multiscale technique to describe excitations of a Bose-Einstein condensate (BEC) whose characteristic scales are comparable with the healing length, thus going beyond the conventional hydrodynamical approximation. As an application of the theory we derive approximate explicit vortex and other solutions. The dynamical stability of the vortex is discussed on the basis of the mathematical framework developed here, the result being that its stability is granted at least up to times of the order of seconds, which is the condensate lifetime. Our analytical results are confirmed by the numerical simulations.Comment: To appear in Phys. Rev.

    Los juegos deportivos y su influencia en la gestión emocional en universitarios

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    Los objetivos de este estudio fueron identicar las intensidades emocionales (positivas, negativas y ambiguas) durante la práctica de jue- gos deportivos de oposición con y sin competición y comprobar la relación existente con el historial deportivo de los participantes. Participaron 147 estudiantes universitarios, los cuales cumplimentaron el cuestionario GES (Game and Emotions Scale) desarrollado y validado por Lavega, March y Filella (2013). Las ecuaciones de estimación generalizadas mostraron di- ferencias signicativas (p &lt; .001) en las variables tipo de emoción, tipo de resultado y huella deportiva del participante. Las emociones positivas se vi- vieron con mayor intensidad en los juegos, mientras que las emociones nega- tivas y ambiguas fueron más bajas que las positivas. La huella deportiva fue determinante para las variaciones emocionales experimentadas, mostrando los jugadores con mayor experiencia y nivel competitivo puntuaciones me- nores en las emociones suscitadas durante la práctica de juegos deportivos de oposición. Los resultados contribuyen a orientar las intervenciones de futuros profesionales gracias a las experiencias prácticas vivenciadas.

    Oscillations of a rapidly rotating annular Bose-Einstein condensate

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    A time-dependent variational Lagrangian analysis based on the Gross-Pitaevskii energy functional serves to study the dynamics of a metastable giant vortex in a rapidly rotating Bose-Einstein condensate. The resulting oscillation frequencies of the core radius reproduce the trends seen in recent experiments [Engels et al., Phys. Rev. Lett. 90, 170405 (2003)], but the theoretical values are smaller by a factor approximately 0.6-0.8.Comment: 7 pages, revtex

    Beneficial effects of paricalcitol on cardiac dysfunction and remodelling in a model of established heart failure

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    The synthetic vitamin D3 analogue paricalcitol acts as a selective activator of the vitamin D receptor (VDR). While there is evidence for cardioprotective effects of paricalcitol associated with the VDR pathway, less information is available about the structural and functional cardiac effects of paricalcitol on established heart failure (HF) and particularly its effects on associated electrophysiological or Ca2+ handling remodelling. EXPERIMENTAL APPROACH: We used a murine model of transverse aortic constriction (TAC) to study the effect of paricalcitol on established HF. Treatment was initiated 4 weeks after surgery over five consecutive weeks, and mice were sacrificed 9 weeks after surgery. Cardiac MRI (CMRI) was performed 4 and 9 weeks after surgery. Hearts were used for biochemical and histological studies and to isolate ventricular myocytes for electrophysiological and calcium imaging studies. KEY RESULTS: CMRI analysis revealed that, compared with vehicle, paricalcitol treatment prevented the progression of ventricular dilation and hypertrophy after TAC and halted the corresponding decline in ejection fraction. These beneficial effects were related to the attenuation of intracellular Ca2+ mishandling remodelling, antifibrotic and antihypertrophic effects and potentially antiarrhythmic effects by preventing the reduction of K+ current density and the long QT, JT and TpTe intervals observed in HF animals. CONCLUSION AND IMPLICATIONS: The results suggest that paricalcitol treatment in established HF hampers disease progression and improves adverse electrophysiological and Ca2+ handling remodelling, attenuating the vulnerability to HF-associated ventricular arrhythmias. Paricalcitol may emerge as a potential therapeutic option in the treatment of HFThis work was supported by the Spanish Ministry of Economy and Competitiveness (SAF2014- 57190R, SAF2017-84777-R), ISCIII (PI17/01093 and PI17/01344), European Regional Development Fund (FEDER), Sociedad Española de Cardiología (SEC), and CIBER-CV, a network funded by ISCIII. MF-V is a Miguel Servet II researcher of ISCIII (MSII16/00047 Carlos III Health Institute). GR-H is a Miguel Servet I researcher of ISCIII (CP15/00129 Carlos III Health Institute). MT is a predoctoral fellow of the Spanish Ministry of Science, Innovation and Universities (FPU-17/06135
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