208 research outputs found

    Performance study update of observations in divergent mode for the Cherenkov Telescope Array

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    Due to the limited field of view (FoV) of Cherenkov telescopes, the time needed to achieve target sensitivity for surveys of the extragalactic and Galactic sky is large. To optimize the time spent to perform such surveys, a so-called "divergent mode" of the Cherenkov Telescope Array Observatory (CTAO) was proposed as an alternative observation strategy to the traditional parallel pointing. In the divergent mode, each telescope points to a position in the sky that is slightly offset, in the outward direction, from the original center of the field of view. This bring the advantage of increasing the total instantaneous arrays' FoV. From an enlarged field of view also benefits the search for very-high-energy transient sources, making it possible to cover large sky regions in follow-up observations, or to quickly cover the probability sky map in case of Gamma Ray Bursts (GRB), Gravitational Waves (GW), and other transient events. In this contribution, we present the proposed implementation of the divergent pointing mode and its first preliminary performance estimation for the southern CTAO array.Comment: Presented at the 38th International Cosmic Ray Conference (ICRC 2023), 2023 (arXiv:2309.08219

    Extremely high frequency RF effects on electronics.

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    The objective of this work was to understand the fundamental physics of extremely high frequency RF effects on electronics. To accomplish this objective, we produced models, conducted simulations, and performed measurements to identify the mechanisms of effects as frequency increases into the millimeter-wave regime. Our purpose was to answer the questions, 'What are the tradeoffs between coupling, transmission losses, and device responses as frequency increases?', and, 'How high in frequency do effects on electronic systems continue to occur?' Using full wave electromagnetics codes and a transmission-line/circuit code, we investigated how extremely high-frequency RF propagates on wires and printed circuit board traces. We investigated both field-to-wire coupling and direct illumination of printed circuit boards to determine the significant mechanisms for inducing currents at device terminals. We measured coupling to wires and attenuation along wires for comparison to the simulations, looking at plane-wave coupling as it launches modes onto single and multiconductor structures. We simulated the response of discrete and integrated circuit semiconductor devices to those high-frequency currents and voltages, using SGFramework, the open-source General-purpose Semiconductor Simulator (gss), and Sandia's Charon semiconductor device physics codes. This report documents our findings

    Estilos de aprendizaje de los estudiantes de medicina veterinaria de la Universidad Nacional de Rosario, Argentina

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    El objetivo del trabajo fue identificar los estilos de aprendizaje predominantes de los estudiantes de medicina veterinaria y determinar si existen diferencias en las preferencias cognitivas entre los alumnos del ciclo de formación básica y superior de la carrera. Para ello se encuestaron 76 estudiantes de la Universidad Nacional de Rosario (Argentina), aplicando el inventario de estilos de aprendizaje de Felder y Silverman, que valora la preferencia hacia los estilos activo o reflexivo (tipo de procesamiento), sensorial o intuitivo (tipo de percepción), visual o verbal (tipo de representación) y secuencial o global (tipo de comprensión). Las preferencias cognitivas de los estudiantes encuestados de ambos ciclos de formación se orientaron hacia lo activo, sensorial, visual y secuencial. Sin embargo, en el ciclo básico se hallaron diferencias estadísticamente significativas en los estilos de procesamiento y percepción según año de ingreso. Así, los estudiantes con dos o más años de trayectoria en la carrera presentaron mayores grados de preferencia por los estilos activo y sensorial que los ingresantes. Estos resultados apoyan la hipótesis de diferencias cognitivas en el aprendizaje. En este estudio se comprobó que la mayor parte de los estudiantes analizados prefieren aprender mediante los estilos activo, sensorial, visual y secuencial. Además, existe una profundización de estas preferencias a medida que permanecen más años en la carrera. La evaluación de las características psicológicas del alumnado permitiría el diseño de clases adecuadas a sus necesidades educativas facilitando la construcción de conocimientos en la universidad

    Hunting for dark matter and new physics with GECCO

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    We outline the science opportunities in the areas of searches for dark matter and new physics offered by a proposed future MeV gamma-ray telescope, the Galactic Explorer with a Coded Aperture Mask Compton Telescope (GECCO). We point out that such an instrument would play a critical role in opening up a discovery window for particle dark matter with mass in the MeV or sub-MeV range, in disentangling the origin of the mysterious 511 keV line emission in the Galactic Center region, and in potentially discovering Hawking evaporation from light primordial black holes

    Asociación Infrecuente de Síndrome de Gitelman de Reciente Diagnóstico con Proteinuria Glomerular

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    Síndrome de Gitelman es una tubulopatía de herencia autosómica recesiva cuya alteración se halla a nivel del cotransportador Na/Cl en el túbulo distal, caracterizada por alcalosis metabólica, normotensión,hipopotasemia, hipomagnesemia e hipocalciuria. La proteinuria e hiperfiltración glomerular (sobre todo al inicio de la presentación clínica) no son manifestaciones características de esta enfermedad. MÉTODOS:Reporte de Caso.RESULTADOS: Presentamos el caso de una mujer de 25 años con diagnóstico reciente de Síndrome de Gitelman que presentó hiperfiltración y proteinuria glomerular por lo que se realizó biopsia renal evidenciando hipertrofiadel aparato yuxtaglomerular y proliferación mesangial y en microscopia electrónica: desprendimiento focalde podocitos compatible con glomeruloesclerosis focal y segmentaria secundaria. CONCLUSIÓN:Este caso de asociación de la tubulopatía con glomerulopatía secundaria de presentación precoz, pone de manifiesto el camino final que recorre esta tubulopatía al generar isquemia renal sostenida por aumento dela actividad del sistema renina angiotensina aldosterona. Resultó de utilidad la biopsia renal y la microscopíaelectrónica para definir pronóstico y tratamiento en esta paciente.Fil: Gutierrez, R.. Fundación Favaloro; ArgentinaFil: Fortunato, R. M.. Fundación Favaloro; ArgentinaFil: Vigliano, Carlos. Fundación Favaloro; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Medicina Traslacional, Trasplante y Bioingeniería. Fundación Favaloro. Instituto de Medicina Traslacional, Trasplante y Bioingeniería; ArgentinaFil: Toniolo, M.. Centro de Diagnostico Patologico; ArgentinaFil: Nava, A.. Fundación Favaloro; ArgentinaFil: Espinoza, A.. Fundación Favaloro; ArgentinaFil: Raffaele P.M.. Fundación Favaloro; Argentin

    Respuesta reproductiva a la inducción hormonal en Gymnotus sp. (Teleostei, Gymnotiformes)

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    Technological development for Gymnotus sp. farming is relevant because this species has a socio-economic impact in South American regions where sport fishing is an important activity. Although Gymnotus sp. breeds in captivity, fry survival in ponds can be unacceptable for culture systems. The objective of this work was to test the response to hormonal induction of Gymnotus sp. with carp pituitary extract (CPE) and gonadotrophin-releasing hormone (GnRH) in relation to different male and female reproductive parameters. CPE treatment specimens were stripped 12 and 20 hours after the triggering dosage, and GnRH treatment specimens were stripped 10 and 12 hours after hormonal application. We could obtain positive results using CPE with a short capture-induction interval (C-II) with broodstock in mature stages of gonadal development. Percentage of oocytes with peripheral germinal vesicle (%OPGV) and oocyte diameter showed significant differences between groups treated with CPE. Oocytes could be successfully extracted from two females treated with CPE and stripped 12 hours after the last dosage. Semen was only extracted from males treated with CPE. GnRH stimulation did not give positive results because gametes could not be extracted with different doses and C-II used. This work is the first description of semen quality parameters in Gymnotus sp. Future works should focus on combining hormonal induction strategies with CPE and the management of environmental variables.El desarrollo tecnológico para el cultivo de Gymnotus sp. es relevante porque este género tiene un impacto socioeconómico en regiones sudamericanas donde la pesca deportiva es una actividad importante. Aunque Gymnotus sp. se reproduce en cautiverio, la supervivencia de los alevines en los estanques puede ser insuficiente para un sistema de cultivo. El objetivo de este trabajo fue evaluar la respuesta de diferentes parámetros reproductivos a la inducción hormonal en Gymnotus sp. con extracto bruto de hipófisis de carpa (EBH) y hormona liberadora de gonadotrofinas (GnRH). Las muestras de gametos del tratamiento con EBH se extrajeron 12 y 20 horas después de la dosis desencadenante, las muestras del tratamiento con GnRH se extrajeron 10 y 12 horas después de la aplicación hormonal. El porcentaje de ovocitos con vesícula germinal periférica (%OVGP) y el diámetro de los ovocitos mostraron diferencias significativas entre grupos tratados con EBH con un intervalo captura-inducción (IC-I) de corta duración, con reproductores en etapas avanzadas de desarrollo gonadal. Se pudieron extraer ovocitos con éxito a dos hembras inducidas con EBH, 12 horas después de la dosis desencadenante y, además, se extrajo semen sólo de los machos inducidos con EBH. La estimulación con GnRH no dio resultados positivos en las diferentes dosis e IC-I utilizados, dado que no se pudieron extraer gametos. Este trabajo es la primera descripción de los parámetros de calidad del semen en Gymnotus sp. Futuras líneas de trabajo deberán centrarse en el manejo de variable

    Association of intronic variants of the KCNAB1 gene with lateral temporal epilepsy.

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    The KCNAB1 gene is a candidate susceptibility factor for lateral temporal epilepsy (LTE) because of its functional interaction with LGI1, the gene responsible for the autosomal dominant form of LTE. We investigated association between polymorphic variants across the KCNAB1 gene and LTE. The allele and genotype frequencies of 14 KCNAB1 intronic SNPs were determined in 142 Italian LTE patients and 104 healthy controls and statistically evaluated. Single SNP analysis revealed one SNP (rs992353) located near the 3'end of KCNAB1 slightly associated with LTE after multiple testing correction (odds ratio=2.25; 95% confidence interval 1.26-4.04; P=0.0058). Haplotype analysis revealed two haplotypes with frequencies higher in cases than in controls, and these differences were statistically significant after permutation tests (Psim=0.047 and 0.034). One of these haplotypes was shown to confer a high risk for the syndrome (odds ratio=12.24; 95% confidence interval 1.32-113.05) by logistic regression analysis. These results support KCNAB1 as a susceptibility gene for LTE, in agreement with previous studies showing that this gene may alter susceptibility to focal epilepsy

    Impact of aetiological treatment on conventional and multiplex serology in chronic Chagas disease

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    The main criterion for treatment effectiveness in Chagas Disease has been the seronegative conversion of previously reactive serology, generally achieved many years post-treatment. The lack of reliable tests to ensure parasite clearance and to examine the effect of treatment is the main difficulty in evaluating treatment for chronic Chagas disease. Decreases of conventional and non-conventional serological titers can be useful tools to monitor the early impact of treatment. We serially measured changes in antibody levels, including seronegative conversion as well as declines in titers in 53 benznidazole-treated and 89 untreated chronically T. cruzi-infected subjects. Seronegative conversion as well as decreases of titers was significantly higher in treated compared with untreated patients. A strong concordance was found between decreases of titers of conventional and non-conventional serologic tests post-treatment, reaffirming the findings. When seronegative conversion plus decreases of titers were considered altogether, the impact of treatment was higher, in a shorter follow-up period than previously considered. New tools for monitoring the effectiveness of treatment of chronic Chagas disease are necessary, and the results showed in this study is a contribution to researchers and physicians who assist patients suffering from this disease

    Impact of Aetiological Treatment on Conventional and Multiplex Serology in Chronic Chagas Disease

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    The main criterion for treatment effectiveness in Chagas Disease has been the seronegative conversion of previously reactive serology, generally achieved many years post-treatment. The lack of reliable tests to ensure parasite clearance and to examine the effect of treatment is the main difficulty in evaluating treatment for chronic Chagas disease. Decreases of conventional and non-conventional serological titers can be useful tools to monitor the early impact of treatment. We serially measured changes in antibody levels, including seronegative conversion as well as declines in titers in 53 benznidazole-treated and 89 untreated chronically T. cruzi-infected subjects. Seronegative conversion as well as decreases of titers was significantly higher in treated compared with untreated patients. A strong concordance was found between decreases of titers of conventional and non-conventional serologic tests post-treatment, reaffirming the findings. When seronegative conversion plus decreases of titers were considered altogether, the impact of treatment was higher, in a shorter follow-up period than previously considered. New tools for monitoring the effectiveness of treatment of chronic Chagas disease are necessary, and the results showed in this study is a contribution to researchers and physicians who assist patients suffering from this disease
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