744 research outputs found

    Bottomonium Production at the Tevatron and the LHC

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    Inclusive bottomonium hadroproduction at the Tevatron is firstly examined in a Monte Carlo framework with the colour-octet mechanism implemented in the event generation. We extract some NRQCD colour-octet matrix elements relevant for Υ(1S)\Upsilon(1S) hadroproduction. Remarkably we find a quite small contribution (compatible with zero) from feeddown of χbJ\chi_{bJ} states produced through the colour-octet mechanism: Υ(1S)\Upsilon(1S) indirect production via χbJ\chi_{bJ} decays should be mainly ascribed to the colour-singlet model. Finally we extrapolate to LHC energies to predict prompt Υ(1S)\Upsilon(1S) production rates.Comment: LaTeX, 11 pages, 6 EPS figure

    Results from Bottomonia Production at the Tevatron and Prospects for the LHC

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    We extend our previous analysis on inclusive heavy quarkonia hadroproduction to the whole Upsilon(nS) (n=1,2,3) resonance family. We use a Monte Carlo framework with the colour-octet mechanism implemented in the PYTHIA event generator. We include in our study higher order QCD effects such as initial-state emission of gluons and Altarelli-Parisi evolution of final-state gluons. We extract some NRQCD colour-octet matrix elements relevant for Upsilon(nS) (n=1,2,3) hadroproduction from CDF data at the Fermilab Tevatron. Then we extrapolate to LHC energies to predict prompt bottomonia production rates. Finally, we examine the prospect to probe the gluon density in protons from heavy quarkonia inclusive hadroproduction at high transverse momentum and its feasibility in LHC general-purpose experiments.Comment: LaTeX, 30 pages, 30 EPS figure

    Variations in the basic biokinematic pattern in three breeds of horses at the hand-led walk

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    In this study the lineal and temporal parameters of the stride of andalusian (n=10), angloarabian (n=6) and arabian (n=7) mature horses were compared at the walk. The speeds were similar in the three breeds (1.63±0.10 m/s), for what the Archivos de zootecnia vol. 48, núm. 183, p. 328. GALISTEO ET AL. statistical comparisons were carried out by an analysis of the variance, and a means comparison test (Tukey test). The stride lenght was shorter in arabians and andalusians than in angloarabians, while the overtracking lenght was bigger in the arabians. The duration of the forelimb cycle was bigger in angloarabians due to a bigger duration in this breed of the stance phase. The midstace position (expressed as a percentaje of the stride duration) differed among the three breeds, indicating that each one shows times of braking and propulsion of the forelimb different to the other ones; but not in the instant in which the hoof reaches the highest point in its trajectory. In the hind limb the differences were much less marked, since small differences were detected in the duration of the cycle between arabians and angloarabians, while the stride duration was longer in andalusians and angloarabians than in the Arabians; the braking and propulsion phases (determined by the position along the stride of the midstance position) didn’t differ among breeds, the same with the instant in which the hindhoof reach the highest point in its trajectory. It can be concluded that marked differences exist between equine breeds in the lineal parameters of the stride at the walk, and the temporal parameters of the forelimb, while in the hind limb are less marked, probably because this member is functionally committed in the propulsion of the horse.En este estudio se compararon los parámetros lineales y temporales del tranco de paso de caballos adultos de Pura Raza Española (n=10), Angloárabe (n=6) y Árabe (n=7). Las velocidades fueron similares en las tres razas (1,63±0,10 m/s), por lo que las comparaciones estadísticas se realizaron mediante un análisis de la varianza y un test de comparación de medias (Test de Tukey). La amplitud de tranco fue más corta en Árabes y Españoles que en Angloárabes, mientras que la longitud de sobrehuella fue mayor en los Árabes. La duración del ciclo del miembro torácico fue mayor en Angloárabes debido a una mayor duración en esta raza de la fase de apoyo. La posición de apoyo medio (expresada porcentualmente a la duración total del ciclo) difirió entre las tres razas, indicando que cada raza presenta tiempos de frenada y propulsión del miembro torácico diferentes a las demás; no así en el instante en el que el casco alcanza el punto más alto de su trayectoria. En el miembro pelviano las diferencias fueron mucho menos marcadas, ya que se detectaron pequeñas diferencias en la duración del ciclo entre Árabes y Angloárabes, mientras que la duración del tranco fue mayor en Españoles y Angloárabes que en los Árabes; los tiempos de frenada y propulsión (determinada por la posición a lo largo del tranco del apoyo medio) no difirió entre razas, lo mismo que el instante en que el casco pelviano se encuentra en el punto más alto de su trayectoria. Se puede concluir que existen marcadas diferencias entre razas equinas en los parámetros lineales del tranco al paso, al igual que sucede con los parámetros temporales del miembro torácico, mientras que en el pelviano son menos marcadas, probablemente porque este miembro está funcionalmente más comprometido que el torácico en la propulsión del caballo

    Morocco as a possible domestication center for barley: biochemical and agromorphological evidence.

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    The distribution of genetic variants of a group of low molecular weight, chloroform-methanol soluble proteins (CM proteins), among Moroccan and non-Moroccan accessions of Hordeum spontaneum and among selections from several Moroccan landraces of H. vulgare and cultivars of the same species with widespread European origin, suggests that domestication of barley might have taken place in Morocco. An agromorphological characterization of the H. spontaneum accessions further supports this hypothesis. The possible Moroccan origin of the French cultivar Hatif de Grignon and of several Spanish 6-rowed barleys is also presented

    Refining a Bayesian network using a chain event graph

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    The search for a useful explanatory model based on a Bayesian Network (BN) now has a long and successful history. However, when the dependence structure between the variables of the problem is asymmetric then this cannot be captured by the BN. The Chain Event Graph (CEG) provides a richer class of models which incorporates these types of dependence structures as well as retaining the property that conclusions can be easily read back to the client. We demonstrate on a real health study how the CEG leads us to promising higher scoring models and further enables us to make more refined conclusions than can be made from the BN. Further we show how these graphs can express causal hypotheses about possible interventions that could be enforced

    The sensitivity of LaBr3:Ce scintillation detectors to low energy neutrons: Measurement and Monte Carlo simulation

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    AbstractThe neutron sensitivity of a cylindrical ⊘1.5in.×1.5in. LaBr3:Ce scintillation detector was measured using quasi-monoenergetic neutron beams in the energy range from 40keV to 2.5MeV. In this energy range the detector is sensitive to γ-rays generated in neutron inelastic and capture processes. The experimental energy response was compared with Monte Carlo simulations performed with the Geant4 simulation toolkit using the so-called High Precision Neutron Models. These models rely on relevant information stored in evaluated nuclear data libraries. The performance of the Geant4 Neutron Data Library as well as several standard nuclear data libraries was investigated. In the latter case this was made possible by the use of a conversion tool that allowed the direct use of the data from other libraries in Geant4. Overall it was found that there was good agreement with experiment for some of the neutron data bases like ENDF/B-VII.0 or JENDL-3.3 but not with the others such as ENDF/B-VI.8 or JEFF-3.1

    Palaeoenvironmental analysis of the Aragonian (middle Miocene) mammalian faunas from the Madrid Basin based on body-size structure

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    As a consequence of the growth of the Antarctic ice-sheet during the middle Miocene, a global decrease of temperatures and an associated increase in aridity provoked several environmental changes all around the world. Such environmental variations can be detected in the continental record of the mammalian prey community structure using a synecological approach. Because of the good quality of its faunas, the rich Aragonian vertebrate fossil record from the Madrid Basin (Spain) appears as a good candidate to explore these environmental changes. In order to analyse the climatic evolution of the Iberian Peninsula associated to the Global Cooling Event, two classic palaeosynecological methodologies (cenograms and body size diversity), based on body-size community structure, were applied to 6 fossil sites from the Madrid Basin, ranging over 2 million years (15.5 – 13.5 Ma). To establish a comparative framework, we used the ecological faunal data from 100 modern localities uniformly distributed all around the world. Our palaeoenvironmental inference is based on multivariate discriminant analysis of the dataset containing both modern and fossil mammals. Finally, we can conclude that the Aragonian mammalian assemblage from the Madrid Basin showed a predominance of semiarid environments with pulses of higher aridity in biozones Dc, E and F associated with the Global Cooling Event of the middle Miocene.Como consecuencia del crecimiento del casquete polar Antártico, durante el Mioceno medio, se produjo un descenso global de la tem­peratura asociado a un aumento de la aridez. Este tipo de cambios ambientales pueden ser detectados en el registro continental, siguiendo un modelo sinecológico para analizar la estructura de las comunidades de las faunas de mamíferos herbívoros. Debido a la calidad de sus faunas, el registro fósil de las faunas de vertebrados del Aragoniense de la Cuenca de Madrid se antoja como un buen candidato para explorar estos patrones de cambio ambiental. Con el objetivo de analizar la evolución climática de la Península Ibérica asociada al evento de enfriamiento global durante este lapso temporal, dos metodologías paleosinecológicas clásicas (cenogramas y espectros de diversidad de tamaño corporal), basadas en la estructura de tamaños corporales de las comunidades de mamíferos, han sido aplicadas a la fauna de herbívoros fósiles presente en seis yacimientos de la Cuenca de Madrid, abarcando aproximadamente 2 millones de años (15.5 – 13.5 Ma). Se ha establecido un marco comparativo usando los datos ecológicos de la fauna de mamíferos presente en 100 localidades uniformemente distribuidas por todo el planeta. Esta inferencia paleoambiental está basada en la aplicación de análisis discriminante multivariante sobre el conjunto de datos de las faunas actuales y fósiles. Finalmente, las faunas de mamíferos del Aragoniense de la Comunidad de Madrid mostraron una predominancia de ambientes semiáridos con varios pulsos de mayor aridez en las biozonas Dc, E y F asociados al evento de enfriamiento global del Mioceno medio

    Predicted distribution and burden of podoconiosis in Cameroon

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    Introduction: Understanding the number of cases of podoconiosis, its geographical distribution and the population at risk are crucial to estimating the burden of this disease in endemic countries. We assessed each of these using nationwide data on podoconiosis prevalence in Cameroon. Methods: We analysed data arising from two cross-sectional surveys in Cameroon. The dataset was combined with a suite of environmental and climate data and analysed within a robust statistical framework, which included machine learning-based approaches and geostatistical modelling. The environmental limits, spatial variation of predicted prevalence, population at risk and number of cases of podoconiosis were each estimated. Results: A total of 214,729 records of individuals screened for podoconiosis were gathered from 748 communities in all 10 regions of Cameroon. Of these screened individuals, 882 (0.41%; 95%CI 0.38-0.44) were living with podoconiosis. High environmental suitability for podoconiosis was predicted in three regions of Cameroon (Adamawa, North West and North). The national population living in areas environmentally suitable for podoconiosis was estimated at 5.2 (95% Confidence Interval [CI]: 4.7-5.8) million, which corresponds to 22.3% of Cameroon’s population in 2015. Countrywide, in 2015, the number of adults estimated to be suffering from podoconiosis was 41,556 (95% CI, 1,170- 240,993). Four regions (Central, Littoral, North and North West) contributed 61.2% of the cases. Conclusion: In Cameroon, podoconiosis is more widely distributed geographically than was initially expected. The number of cases and the population at risk are considerable. Expanding morbidity management and follow up of cases is of utmost necessity. Promotion of footwear use and regular foot hygiene should be at the forefront of any intervention plan
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