882 research outputs found

    SuperCDMS: Recent results on low-mass WIMPs

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    We present the rst search for weakly interacting massive particles (WIMPs) using the back- ground rejection capabilities of SuperCDMS 1. A blind analysis of data from an exposure of 577 kg-days leads to an upper limit on the spin-independent WIMP-nucleon cross section of 1:2 10????42 cm2 at 8 GeV. This result probes new parameter space for WIMP-nucleon scat- tering cross section for light WIMPs with masses < 6 GeV/c2 and is in tension with WIMP interpretations of recent experiments

    Uso del lufenurón en el control de la dematitis alérgica a la picadura de pulgas en los perros

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    Uso del Lufenurón en el control de la Dermatitis Alérgicá a la Picadura de la Pulga en perros Debido al poco conocimiento que existe de los factores óptimos para prevenir la sensibilización a las pulgas , es difícilproponer programas efectivos que controlen a largo plazo la Dermatitis Alérgica a la Picadura de la Pulga (DAPP). En España, los veterinarios documentaron casos de perros con DAPP que presentaban una notable mejoría de su sintomatología con el uso del Lufenuron (PROGRAMa). Este estudio multicéntrico abierto fue diseñado para investigar estos hechos y probar el interés del tratamiento mensual con lufenurón como método de control y prevención de la DAPP en perros, bajo condiciones clínicas prácticas. Entre 14 centros, se seleccionó un total de 78 perros que fueron seguidos durante 12 meses. Los resultados mostraron que el uso continuado de Lufenurón es beneficioso para el perro con dermatitis alérgica a la picadura, ya que disminuye de manera significativa el riesgo de sufrir recidivas. Este hecho fue también demostrado en un ensayo multicèntrico, randornizado, paralelo doble ciego realizado en Francia.The use of Lufenuron in the control of Flea Allergy Dermatitis in Dogs As there is little knowledge of the optimum factors to prevent flea sensitisation, it is often difficult for veterinarians to propose effective programmes for the long-term control of Flea Allergy Dermatitis (FAD). In Spain, reports from veterinarians suggested that dogs with FAD were free or relieved of the symptoms after using Lufenuron (PROGRAMa). This multicentric open study was designed to verify the role of monthly Lufenuron treatment in the control and prevention of FAD in dogs under veterinary practice conditions. 14 investigators recruited 78 dogs that were followed up during 12 months. The results showed that the continuous use of Lufenuron is of siqnificant benefit to dogs suffering from FAD, reducing significantly the risk of FAD relapses in susceptibles dogs as it has also been demonstrated in a multicenter, placebo-centrolled, randomised, parallel, double-blind trial in France

    Heavy ion irradiation of crystalline water ice

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    Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. Crystalline ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. We experimentally investigate heavy ion irradiation amorphisation of crystalline ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. We irradiated thin crystalline ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (induced amorphisation of the initial crystalline state into a compact amorphous phase). The crystalline ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic stopping power. The final state of cosmic ray irradiation for porous amorphous and crystalline ice, as monitored by infrared spectroscopy, is the same, but with a large difference in cross-section, hence in time scale in an astrophysical context. The cosmic ray water-ice sputtering rates compete with the UV photodesorption yields reported in the literature. The prevalence of direct cosmic ray sputtering over cosmic-ray induced photons photodesorption may be particularly true for ices strongly bonded to the ice mantles surfaces, such as hydrogen-bonded ice structures or more generally the so-called polar ices.Comment: 22pages, 11 figures, accepted in A&

    Radioscience simulations in General Relativity and in alternative theories of gravity

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    In this communication, we focus on the possibility to test GR with radioscience experiments. We present a new software that in a first step simulates the Range/Doppler signals directly from the space time metric (thus in GR and in alternative theories of gravity). In a second step, a least-squares fit of the involved parameters is performed in GR. This software allows one to get the order of magnitude and the signature of the modifications induced by an alternative theory of gravity on radioscience signals. As examples, we present some simulations for the Cassini mission in Post-Einsteinian gravity and with the MOND External Field Effect.Comment: 4 pages; Proceedings of "Les Rencontres de Moriond 2011 - Gravitation session

    Serial block-face scanning electron microscopy applied to study the trafficking of 8D3-coated gold nanoparticles at the blood-brain barrier

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    Due to the physical and physiological properties of the blood-brain barrier (BBB), the transport of neurotherapeutics from blood to brain is still a pharmaceutical challenge. We previously conducted a series of experiments to explore the potential of the anti-transferrin receptor 8D3 monoclonal antibody (mAb) to transport neurotherapeutics across the BBB. In that study, gold nanoparticles (AuNPs) were coated with the 8D3 antibody and administered intravenously to mice. Transmission electron microscopy was used and a two-dimensional (2D) image analysis was performed to detect the AuNPs in the brain capillary endothelial cells (BCECs) and brain parenchyma. In the present work, we determined that serial block-face scanning electron microscopy (SBF-SEM) is a useful tool to study the transcytosis of these AuNPs across the BBB in three dimensions and we, therefore, applied it to gain more knowledge of their transcellular trafficking. The resulting 3D reconstructions provided additional information on the endocytic vesicles containing AuNPs and the endosomal processing that occurs inside BCECs. The passage from 2D to 3D analysis reinforced the trafficking model proposed in the 2D study, and revealed that the vesicles containing AuNPs are significantly larger and more complex than described in our 2D study. We also discuss tradeoffs of using this technique for our application, and conclude that together with other volume electron microscopy imaging techniques, SBF-SEM is a powerful approach that is worth of considering for studies of drug transport across the BBB

    Determination of the branching ratios Γ(KL3π0)/Γ(KLπ+ππ0)\Gamma (K_L \to 3 \pi^0) / \Gamma (K_L \to \pi^+ \pi^- \pi^0) and Γ(KL3π0)/Γ(KLπeν)\Gamma (K_L \to 3 \pi^0) / \Gamma (K_L \to \pi e \nu )

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    Improved branching ratios were measured for the KL3π0K_L \to 3 \pi^0 decay in a neutral beam at the CERN SPS with the NA31 detector: Γ(KL3π0)/Γ(KLπ+ππ0)=1.611±0.037\Gamma (K_L \to 3 \pi^0) / \Gamma (K_L \to \pi^+ \pi^- \pi^0) = 1.611 \pm 0.037 and Γ(KL3π0)/Γ(KLπeν)=0.545±0.010\Gamma (K_L \to 3 \pi^0) / \Gamma (K_L \to \pi e \nu ) = 0.545 \pm 0.010. From the first number an upper limit for ΔI=5/2\Delta I =5/2 and ΔI=7/2\Delta I = 7/2 transitions in neutral kaon decay is derived. Using older results for the Ke3/Kμ\mu 3 fraction, the 3π0\pi^0 branching ratio is found to be Γ(KL3π0)/Γtot=(0.211±0.003)\Gamma (K_L \to 3 \pi^0 )/ \Gamma_{tot} = (0.211 \pm 0.003), about a factor three more precise than from previous experiments

    Memorial meshwork: the making of the commemorative space of the Hyde Park 7/7 memorial

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    How do memorials act to transmit memory through the organization of space? In this paper we contrast a ‘preservation’ model of the endurance of encoded memory with a ‘meshwork’ model which treats memory as emergent on the perdurance of the memorial site. Developing a theoretical framework from Tim Ingold’s (2011; 2013) work, we describe how memorialization receives its spatial form through a collective work of braiding together multiple threads of activities and material flows. To illustrate, we examine the spatial and temporal organization of the Hyde Park 7/7 memorial from its initial designs, through to installation and contemporary use. We draw on interview data featuring various stakeholders in the 7/7 memorial project to analyse the relationship between memorial space and material relations. We develop an approach to organizational space as an unfinished meshwork that folds together wanted and unwanted memory, making the historical a matter of ongoing live concern but with the absence of a permanent guiding narrative
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