107 research outputs found

    Kinetic Properties of a Bose-Einstein Gas at Finite Temperature

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    We study, in the framework of the Boltzmann-Nordheim equation (BNE), the kinetic properties of a boson gas above the Bose-Einstein transition temperature TcT_c. The BNE is solved numerically within a new algorithm, that has been tested with exact analytical results for the collision rate of an homogeneous system in thermal equilibrium. In the classical regime (T>6 TcT > 6~ T_c), the relaxation time of a quadrupolar deformation in momentum space is proportional to the mean free collision time τrelaxT1/2\tau_{relax} \sim T^{-1/2}. Approaching the critical temperature (Tc<T<2.7 TcT_c < T < 2.7~ T_c), quantum statistic effects in BNE become dominant, and the collision rate increases dramatically. Nevertheless, this does not affect the relaxation properties of the gas that depend only on the spontaneous collision term in BNE. The relaxation time τrelax\tau_{relax} is proportional to (TTc)1/2(T - T_c)^{-1/2}, exhibiting a critical slowing down. These phenomena can be experimentally confirmed looking at the damping properties of collective motions induced on trapped atoms. The possibility to observe a transition from collisionless (zero-sound) to hydrodynamic (first-sound) is finally discussed.Comment: RevTeX, 5 figures. Submitted to Phys. Rev.

    Preparing arbitrary pure states of spatial qudits with a single phase-only spatial light modulator

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    Spatial qudits are -dimensional (≥2) quantum systems carrying information encoded in the discretized transverse momentum and position of single photons. We present a proof-of-principle demonstration of a method for preparing arbitrary pure states of such systems by using a single phase-only spatial light modulator (SLM). The method relies on the encoding of the complex transmission function corresponding to a given spatial qudit state onto a preset diffraction order of a phase-only grating function addressed at the SLM. Fidelities of preparation above 94% were obtained with this method, which is simpler, less costly, and more efficient than those that require two SLMs for the same purpose.Instituto de Física La Plat

    Galician consensus on management of cardiotoxicity in breast cancer: risk factors, prevention, and early intervention

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    This Galician consensus statement is a joint oncologists/cardiologists initiative indented to establish basic recommendations on how to prevent and to manage the cardiotoxicity in breast cancer with the aim of ensuring an optimal cardiovascular care of these patients. A clinical screening of the patients before treatment is recommended to stratify them into a determined risk group based on their intrinsic cardiovascular risk factors and those extrinsic arose from breast cancer therapy, thereby providing individualized preventive and monitoring measures. Suitable initial and ongoing assessments for patients with low and moderate/high risk and planned treatment with anthracyclines and trastuzumab are given; also, measures aimed at preventing and correcting any modifiable risk factor are pointed out .TEVA Farma Españ

    Sarcoma fibromixoide intracraneal primario de bajo grado: reporte de caso y revisión de la literatura.

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    Low-grade fibromyxoid sarcoma (LGFMS) is a soft tissue tumor of mesenchymal origin. Sarcomas are a heterogeneous group, representing 1% of all neoplasm diagnoses. Primary sarcomas of the central nervous system (CNS) are rare, and represent only 0.7% of all sarcomas, with an estimated incidence of 3 per 10 million people per year. The case of a 59-year-old woman who developed a low-grade intracranial fibromyxoid sarcoma in the right parietal region, is described. The clinical course, imaging studies, histopathological features, and treatment approach of this unusual diagnosis, are discussed. Low-grade intracranial fibromyxoid sarcoma is a rare and probably under- reported condition. The definitive diagnosis is usually made through histo-pathological studies.El sarcoma fibromixoide de bajo grado (LGFMS) es un tumor de tejidos blandos de origen mesenquimal. Los sarcomas son un grupo heterogéneo, que representa el 1% de todas las neoplasias. Los sarcomas primarios del sistema nervioso central (SNC) son raros y representan solo el 0,7% del total de sarcomas, con una incidencia estimada de 3 por cada 10 millones de personas por año. En este artículo, se describe el caso de una mujer de 59 años que presentó un sarcoma fibromixoide intracraneal de bajo grado, localizado en la región parietal derecha. Se discute el curso clínico, estudios de imágenes, características histopatológicas y tratamiento de este diagnóstico infrecuente y, por lo mismo, muy poco reportado. El diagnóstico definitivo se obtiene, ciertamente, mediante estudios histo- patológicos

    PELLETS DE KAOLIN POROSOS UTILIZADOS COMO SISTEMA DE LIBERACIÓN LENTA DE FEROMONA BENZALDEHYDE PARA CAPTURAR TRIATOMINOS

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    El objetivo de este trabajo es estudiar las propiedades de los gránulos de caolín porosos que se aplicarán como un sistema de liberación lenta de feromonas, para la captura de vectores de la enfermedad de Chagas.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

    The ecology of peace : preparing Colombia for new political and planetary climates

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    ABSTRACT: Colombia, one of the world’s most species-rich nations, is currently undergoing a profound social transition: the end of a decadeslong conflict with the Revolutionary Armed Forces of Colombia, known as FARC. The peace agreement process will likely transform the country’s physical and socioeconomic landscapes at a time when humans are altering Earth’s atmosphere and climate in unprecedented ways. We discuss ways in which these transformative events will act in combination to shape the ecological and environmental future of Colombia. We also highlight the risks of creating perverse development incentives in these critical times, along with the potential benefits – for the country and the world – if Colombia can navigate through the peace process in a way that protects its own environment and ecosystems

    Permanent Genetic Resources added to Molecular Ecology Resources Database 1 February 2013-31 March 2013

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    This article documents the addition of 142 microsatellite marker loci to the Molecular Ecology Resources database. Loci were developed for the following species: Agriophyllum squarrosum, Amazilia cyanocephala, Batillaria attramentaria, Fungal strain CTeY1 (Ascomycota), Gadopsis marmoratus, Juniperus phoenicea subsp. turbinata, Liriomyza sativae, Lupinus polyphyllus, Metschnikowia reukaufii, Puccinia striiformis and Xylocopa grisescens. These loci were cross-tested on the following species: Amazilia beryllina, Amazilia candida, Amazilia rutila, Amazilia tzacatl, Amazilia violiceps, Amazilia yucatanensis, Campylopterus curvipennis, Cynanthus sordidus, Hylocharis leucotis, Juniperus brevifolia, Juniperus cedrus, Juniperus osteosperma, Juniperus oxycedrus, Juniperus thurifera, Liriomyza bryoniae, Liriomyza chinensis, Liriomyza huidobrensis and Liriomyza trifolii. © 2013 John Wiley & Sons Ltd.Peer Reviewe

    Implant Composed of Demineralized Bone and Mesenchymal Stem Cells Genetically Modified with AdBMP2/AdBMP7 for the Regeneration of Bone Fractures in Ovis aries

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    Adipose-derived mesenchymal stem cells (ADMSCs) are inducible to an osteogenic phenotype by the bone morphogenetic proteins (BMPs). This facilitates the generation of implants for bone tissue regeneration. This study evaluated the in vitro osteogenic differentiation of ADMSCs transduced individually and in combination with adenoviral vectors expressing BMP2 and BMP7. Moreover, the effectiveness of the implant containing ADMSCs transduced with the adenoviral vectors AdBMP2/AdBMP7 and embedded in demineralized bone matrix (DBM) was tested in a model of tibial fracture in sheep. This graft was compared to ewes implanted with untransduced ADMSCs embedded in the same matrix and with injured but untreated animals. In vivo results showed accelerated osteogenesis in the group treated with the AdBMP2/AdBMP7 transduced ADMSC graft, which also showed improved restoration of the normal bone morphology

    Impaired IL-23-dependent induction of IFN-gamma underlies mycobacterial disease in patients with inherited TYK2 deficiency

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    Human cells homozygous for rare loss-of-expression (LOE) TYK2 alleles have impaired, but not abolished, cellular responses to IFN-alpha/beta (underlying viral diseases in the patients) and to IL-12 and IL-23 (underlying mycobacterial diseases). Cells homozygous for the common P1104A TYK2 allele have selectively impaired responses to IL-23 (underlying isolated mycobacterial disease). We report three new forms of TYK2 deficiency in six patients from five families homozygous for rare TYK2 alleles (R864C, G996R, G634E, or G1010D) or compound heterozygous for P1104A and a rare allele (A928V). All these missense alleles encode detectable proteins. The R864C and G1010D alleles are hypomorphic and loss-of-function (LOF), respectively, across signaling pathways. By contrast, hypomorphic G996R, G634E, and A928V mutations selectively impair responses to IL-23, like P1104A. Impairment of the IL-23-dependent induction of IFN-gamma is the only mechanism of mycobacterial disease common to patients with complete TYK2 deficiency with or without TYK2 expression, partial TYK2 deficiency across signaling pathways, or rare or common partial TYK2 deficiency specific for IL-23 signaling.ANRS Nord-Sud ; CIBSS ; CODI ; Comité para el Desarrollo de la Investigación ; Fulbright Future Scholarshi
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