Design and Tests of the Silicon Sensors for the ZEUS Micro Vertex Detector

To fully exploit the HERA-II upgrade,the ZEUS experiment has installed a Micro Vertex Detector (MVD) using n-type, single-sided, silicon micro-strip sensors with capacitive charge division. The sensors have a readout pitch of 120 micrometers, with five intermediate strips (20 micrometer strip pitch). The designs of the silicon sensors and of the test structures used to verify the technological parameters, are presented. Results on the electrical measurements are discussed. A total of 1123 sensors with three different geometries have been produced by Hamamatsu Photonics K.K. Irradiation tests with reactor neutrons and Co-60 photons have been performed for a small sample of sensors. The results on neutron irradiation (with a fluence of 1 x 10^{13} 1 MeV equivalent neutrons / cm^2) are well described by empirical formulae for bulk damage. The Co-60 photons (with doses up to 2.9 kGy) show the presence of generation currents in the SiO_2-Si interface, a large shift of the flatband voltage and a decrease of the hole mobility.Comment: 33 pages, 25 figures, 3 tables, accepted for publication in NIM

Preliminary study of kaonic deuterium X-rays by the SIDDHARTA experiment at DAFNE

The study of the KbarN system at very low energies plays a key role for the understanding of the strong interaction between hadrons in the strangeness sector. At the DAFNE electron-positron collider of Laboratori Nazionali di Frascati we studied kaonic atoms with Z=1 and Z=2, taking advantage of the low-energy charged kaons from Phi-mesons decaying nearly at rest. The SIDDHARTA experiment used X-ray spectroscopy of the kaonic atoms to determine the transition yields and the strong interaction induced shift and width of the lowest experimentally accessible level (1s for H and D and 2p for He). Shift and width are connected to the real and imaginary part of the scattering length. To disentangle the isospin dependent scattering lengths of the antikaon-nucleon interaction, measurements of Kp and of Kd are needed. We report here on an exploratory deuterium measurement, from which a limit for the yield of the K-series transitions was derived: Y(K_tot)<0.0143 and Y(K_alpha)<0.0039 (CL 90%). Also, the upcoming SIDDHARTA-2 kaonic deuterium experiment is introduced.Comment: Accepted by Nuclear Physics

X-ray transition yields of low-Z kaonic atoms produced in Kapton

The X-ray transition yields of kaonic atoms produced in Kapton polyimide (C22H10N2O5) were measured for the first time in the SIDDHARTA experiment. X-ray yields of the kaonic atoms with low atomic numbers (Z = 6, 7, and 8) and transitions with high principal quantum numbers (n = 5-8) were determined. The relative yield ratios of the successive transitions and those of carbon-to-nitrogen (C:N) and carbon-to-oxygen (C:O) were also determined. These X-ray yields provide important information for understanding the capture ratios and cascade mechanisms of kaonic atoms produced in a compound material, such as Kapton.Comment: Accepted in Nucl. Phys. A (2013

First measurement of kaonic helium-3 X-rays

The first observation of the kaonic 3He 3d - 2p transition was made using slow K- mesons stopped in a gaseous 3He target. The kaonic atom X-rays were detected with large-area silicon drift detectors using the timing information of the K+K- pairs of phi-meson decays produced by the DAFNE e+e- collider. The strong interaction shift of the kaonic 3He 2p state was determined to be -2+-2 (stat)+-4 (syst) eV.Comment: Accepted for publication in Phys. Lett.

The impact of immune response on endochondral bone regeneration

Tissue engineered cartilage substitutes, which induce the process of endochondral ossification, represent a regenerative strategy for bone defect healing. Such constructs typically consist of multipotent mesenchymal stromal cells (MSCs) forming a cartilage template in vitro, which can be implanted to stimulate bone formation in vivo. The use of MSCs of allogeneic origin could potentially improve the clinical utility of the tissue engineered cartilage constructs in three ways. First, ready-to-use construct availability can speed up the treatment process. Second, MSCs derived and expanded from a single donor could be applied to treat several patients and thus the costs of the medical interventions would decrease. Finally, it would allow more control over the quality of the MSC chondrogenic differentiation. However, even though the envisaged clinical use of allogeneic cell sources for bone regeneration is advantageous, their immunogenicity poses a significant obstacle to their clinical application. The aim of this review is to increase the awareness of the role played by immune cells during endochondral ossification, and in particular during regenerative strategies when the immune response is altered by the presence of implanted biomaterials and/or cells. More specifically, we focus on how this balance between immune response and bone regeneration is affected by the implantation of a cartilaginous tissue engineered construct of allogeneic origin

Leishmania spp. epidemiology of canine leishmaniasis in the Yucatan Peninsula

Canine Leishmaniasis is widespread in various Mexican states, where different species of Leishmania have been isolated from dogs. In the present study, we describe the detection of L. braziliensis, L. infantum, and L. mexicana in serum of dogs from the states of Yucatan and Quintana Roo in the Yucatan Peninsula (Mexico). A total of 412 sera were analyzed by ELISA using the total extract of the parasite and the iron superoxide dismutase excreted by different trypanosomatids as antigens. We found the prevalence of L. braziliensis to be 7.52%, L. infantum to be 6.07%, and L. mexicana to be 20.63%, in the dog population studied. The results obtained with ELISA using iron superoxide dismutase as the antigen were confirmed by western blot analysis with its greater sensitivity, and the agreement between the two techniques was very high

A New Measurement of Kaonic Hydrogen X rays

The $\bar{K}N$ system at threshold is a sensitive testing ground for low energy QCD, especially for the explicit chiral symmetry breaking. Therefore, we have measured the $K$-series x rays of kaonic hydrogen atoms at the DA$\Phi$NE electron-positron collider of Laboratori Nazionali di Frascati, and have determined the most precise values of the strong-interaction energy-level shift and width of the $1s$ atomic state. As x-ray detectors, we used large-area silicon drift detectors having excellent energy and timing resolution, which were developed especially for the SIDDHARTA experiment. The shift and width were determined to be $\epsilon_{1s} = -283 \pm 36 \pm 6 {(syst)}$ eV and $\Gamma_{1s} = 541 \pm 89 {(stat)} \pm 22 {(syst)}$ eV, respectively. The new values will provide vital constraints on the theoretical description of the low-energy $\bar{K}N$ interaction.Comment: 5 figures, submitted to Physics Letters

Análisis espacial del índice energético temprano-tardío en aulas universitarias

Ponencia presentada en el IX Congreso Iberoamericano de Acústica, FIA2014, Valdivia, ChilePor lo general, la claridad con que se percibe la voz en un aula no es constante para toda el área de audición. Los principales factores que la afectan son la reverberación y la relación señal-ruido. El índice energético temprano-tardío es un indicador objetivo que permite evaluar mediante fracciones energéticas de la respuesta impulsiva del recinto la claridad con que la señal original es percibida. En este trabajo, se presentan los resultados del análisis espectral de este índice para el caso de la palabra hablada en una muestra de 9 aulas universitarias representativa, en términos de dimensiones y características constructivas, de una población de 78 aulas. Finalmente, se realiza el análisis espacial en un recinto seleccionado.Fil: Tommasini, Fabián Carlos. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Tommasini, Fabián Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Tommasini, Fabián Carlos. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Cravero, G. A. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Cravero, G. A. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ferreyra, S. P. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ferreyra, S. P. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Longoni, H. C. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Longoni, H. C. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Flores, M. D. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Flores, M. D. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ramos, O. A. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ramos, O. A. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ramos, O. A. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Óptica (incluida Óptica Láser y Óptica Cuántica), Acústic

Análisis de parámetros acústicos de recintos para dos condiciones de ocupación : estudio de caso de un aula universitaria

Ponencia presentada en el IX Congreso Iberoamericano de Acústica, FIA2014, Valdivia, ChileEl campo sonoro de un aula depende de múltiples factores tales como: absorción y difusión sonora, ruido de fondo, entre otros. La respuesta impulsiva del recinto caracteriza completamente dicho campo sonoro para cada ubicación de la fuente y el receptor. En este trabajo, se presentan los resultados del análisis espacial de parámetros acústicos monoaurales y binaurales de recintos siguiendo las directrices de la norma ISO 3382, para el caso de estudio de un aula de la Facultad Regional Córdoba, Universidad Tecnológica Nacional en dos condiciones de ocupación (sala vacía y 60 % de ocupación).Fil: Tommasini, Fabián Carlos. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Tommasini, Fabián Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; ArgentinaFil: Tommasini, Fabián Carlos. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; ArgentinaFil: Cravero, G. A. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Cravero, G. A. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ferreyra, S. P. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ferreyra, S. P. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Longoni, H. C. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Longoni, H. C. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Flores, M. D. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Flores, M. D. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ramos, O. A. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ramos, O. A. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación y Transferencia en Acústica; Argentina.Fil: Ramos, O. A. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Óptica (incluida Óptica Láser y Óptica Cuántica), Acústic

Grassroots Agency: Participation and Conflict in Buenos Aires Shantytowns seen through the Pilot Plan for Villa 7 (1971–1975)

open access articleIn 1971, after more than a decade of national and municipal policies aimed at the top-down removal of shantytowns, the Buenos Aires City Council approved the Plan Piloto para la Relocalización de Villa 7 (Pilot Plan for the Relocation of Shantytown 7; 1971–1975, referred to as the Pilot Plan hereinafter). This particular plan, which resulted in the construction of the housing complex, Barrio Justo Suárez, endures in the collective memory of Argentines as a landmark project regarding grassroots participation in state housing initiatives addressed at shantytowns. Emerging from a context of a housing shortage for the growing urban poor and intense popular mobilizations during the transition to democracy, the authors of the Pilot Plan sought to empower shantytown residents in novel ways by: 1) maintaining the shantytown’s location as opposed to eradication schemes that relocated the residents elsewhere, 2) formally employing some of the residents for the stage of construction, as opposed to “self-help” housing projects in which the residents contributed with unpaid labor, and 3) including them in the urban and architectural design of the of the new housing. This paper will examine the context in which the Pilot Plan was conceived of as a way of re-assessing the roles of the state, the user, and housing-related professionals, often seen as antagonistic. The paper argues that residents’ fair participation and state intervention in housing schemes are not necessarily incompatible, and can function in specific social and political contexts through multiactor proposals backed by a political will that prioritizes grassroots agency