20 research outputs found

    Direction of arrival estimation using a cluster of beams in a cone-shaped digital array radar'

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    In this paper some potential system and processing advantages of conformal cone shaped digital array radar have been investigated, in particular in relation to potential alternative approaches for angle estimation with respect to the traditional monopulse. First of all potential benefit in terms of reduction of the number of radiating elements is shown when a conical array is considered with respect to a traditional system formed by four planar arrays, if a coverage of 360° must be assured. Secondly, having in mind an innovative digital array system where the received signals are analog to digital converted at element level and the corresponding data are possibly transferred to a central elaboration unit, an alternative approach is investigated for angular estimation. In this paper we derive the theoretical expression of the Cramer Rao Lower Bound for elevation angle estimation using a cluster of beams; we compare the limit performance of the traditional approach for angle estimation based on Sum and Difference beams with the approach based on a crowded cluster of RX beams properly spaced. The approaches show approximately equivalent performance, making the second particularly interesting for those situations where monopulse is known to experience performance degradation, as low elevation angle estimation; in this particular case an example of cluster design is shown, where the direct signal from a low altitude target must compete with a specular multipath

    Biosynthesis of 5-aminolevulic acid in trypanosoma cruzi

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    Trypanosoma cruzi requires heme-compounds for growing, due to its partially or totally deficient biosynthetic pathway of heme. There are reports that support the functionality of mitochondrial enzymes involved in this pathway, such as 5-aminolevúlico synthetase (ALA-S) and Heme synthetase (Heme-S). T. cruzi genome is known and two homologous genes, Tc00.1047053511899.40 y Tc00.1047053511071.140, were identified by bioinformatic studies. Both of them are candidates to code with high score (50%) for the ALA-S enzyme, responsible for synthesizing ALA from succinyl CoA and glycine. Our hypothesis is that the parasite is able to synthesize ALA (although it cannot be metabolized to heme) and the Tc00.1047053511899.40 y Tc00.1047053511071.140 sequences encodes for a protein with ALA-S activity. Using epimastigotes, we were able to detect and quantify, by spectrophotometric studies and HPLC chromatography, the presence of ALA in the parasite both intra and extracellularly. The mesasurements were made in 30ml of parasite culture which yielded about 608,31 ± 45,20 nmol of ALA. The extracellular content represents 96% of the total synthesized. Such excretion would be avoiding the citotoxicity of ALA since it cannot be metabolized to heme From bioinformatic studies using the Blast, ORF Finder, Mitoprop, Prosite and ClustalW platforms, it was determined that the above genes would code for a mitochondrial protein (98%) which is dependent on pyridoxal phosphate and shown a KBL domain, which is characteristic of enzymes as ALA-S. Both, ALA detection and the computer analysis would support our hypothesis and encourages us to continue trying to confirm it.Fil: Puente, Vanesa Rocío. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; ArgentinaFil: Martinez, Maria del Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; ArgentinaFil: Abou Assali, Lubna. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; ArgentinaFil: Benlolo, Micaela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; ArgentinaFil: Bontempi, Esteban. Dirección Nacional de Instituto de Investigación. Administración Nacional de Laboratorio e Instituto de Salud "Dr. C. G. Malbrán"; ArgentinaFil: Lombardo, Maria Elisa. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Investigaciones sobre Porfirinas y Porfirias. Universidad de Buenos Aires. Centro de Investigaciones sobre Porfirinas y Porfirias; ArgentinaLXIV Reunión Anual de la Sociedad Argentina de Investigación Clínica; LI Reunión Anual de la Asociación Argentina de Farmacología Experimental; XXI Reunión Anual de la Sociedad Argentina de Biología; XXXI Reunión Anual de la Sociedad Argentina de Protozoología; IX Reunión Anual de la Asociación Argentina de Nanomedicinas y VI Reunión Científica Regional de la Asociación Argentina de Ciencia y Tecnología de Animales de LaboratorioMar del PlataArgentinaSociedad Argentina de Investigación ClínicaAsociación Argentina de Farmacología ExperimentalSociedad Argentina de BiologíaSociedad Argentina de ProtozoologíaAsociación Argentina de NanomedicinasAsociación Argentina de Ciencia y Tecnología de Animales de Laboratori

    Matrix metalloproteinases and psychosocial factors in acute coronary syndrome patients

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    Psychosocial factors have been linked to cardiovascular diseases independently of traditional risk factors. The impact of psychosocial factors on plaque destabilizing factors, such as matrix metalloproteinases (MMPs) has been proposed although scarcely studied. Objective: To evaluate the relationships between hostility, perceived stress and social support with MMPs activity in patients after an Acute Myocardial Infarction (AMI). Methods: Blood samples were obtained from 76 patients on admission, post-angioplasty, 24. h, 7 days and 3 months after AMI. Hostility, perceived stress and social support were evaluated by validated questionnaires. Results: Social support was positively correlated with patientś ejection fraction (r = 0.453, p = 0.009). Patients with higher infarct size presented increased MMP-2 activity at admission (p = 0.04). Patients with one diseased vessel had more social support than those with three diseased vessels (p = 0.05). The highest values of MMP-2 and MMP-9 activity were observed at the acute event, decreasing, with the lowest activity at 3 months post-AMI (p < 0.001). Only in patients with low social support, hostility correlated with MMP-2 activity, from AMI onset (r = 0.645, p = 0.013), to 7 days post AMI (r = 0.557, p = 0.038). Hostility explained up to 28% of the variance in MMP-2 activity (R2=0.28, p = 0.005). Finally, in patients with high hostility, MMP-9 was positively correlated with IL-1β (r = 0.468, p = 0.02). Conclusions: This study adds weight to the idea that two psychosocial factors, namely hostility and social support, acting jointly, may affect MMP-2 activity. Moreover, in hostile patients, there is a link between IL-1β and MMP-9. These findings support the role of psychosocial factors in plaque destabilization and in the inflammatory process in AMI.Fil: Fernandez Machulsky, Nahuel Hernan. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: Gagliardino, Juan Jose. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Defensa. Ejército Argentino. Hospital Militar Central Cirujano Mayor "Dr. Cosme Argerich"; ArgentinaFil: Fabre, Bibiana. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: Miksztowicz, Verónica Julieta. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lombardo, Micaela. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: García Escudero, Alejandro. Ministerio de Defensa. Ejército Argentino. Hospital Militar Central Cirujano Mayor "Dr. Cosme Argerich"; ArgentinaFil: Gigena, Gerardo. Ministerio de Defensa. Ejército Argentino. Hospital Militar Central Cirujano Mayor "Dr. Cosme Argerich"; ArgentinaFil: Blanco, Federico Carlos. Ministerio de Defensa. Ejército Argentino. Hospital Militar Central Cirujano Mayor "Dr. Cosme Argerich"; ArgentinaFil: Gelpi, Ricardo Jorge. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiopatología Cardiovascular; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Schreier, Laura Ester. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; ArgentinaFil: Gidron, Yori. Vrije Unviversiteit Brussel; BélgicaFil: Berg, Gabriela Alicia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Departamento de Bioquímica Clínica; Argentin

    Passive multifrequency forward-scatter radar measurements of airborne targets using broadcasting signals

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    This paper demonstrates the feasibility and effectiveness of forward-scatter radar (FSR) target detection based on the signals of opportunity made available by standard radio and TV broadcast transmission stations. This passive FSR (P-FSR) operation is obtained by means of a simple and robust correlation process based on self-mixing. This is shown to be very effective in extracting the characteristic FSR modulation produced by airborne targets, from the signals received from frequency modulated, digital audio broadcasting, and digital video broadcasting transmitters of opportunity. Target detectability is discussed as a function of the carrier frequency, the target size, and its height at the baseline crossing. Experimental results are shown using a wide variety of sources of opportunity, target types, baselines, and receiver configurations. The target signatures obtained from the different illuminators are compared and ways of extracting the kinematic parameters of the aircraft are discussed. This validates the claimed effectiveness and robustness of the P-FSR with the presented processing scheme

    Ahora / Ara

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    La cinquena edició del microrelatari per l’eradicació de la violència contra les dones de l’Institut Universitari d’Estudis Feministes i de Gènere «Purificación Escribano» de la Universitat Jaume I vol ser una declaració d’esperança. Aquest és el moment en el qual les dones (i els homes) hem de fer un pas endavant i eliminar la violència sistèmica contra les dones. Ara és el moment de denunciar el masclisme i els micromasclismes començant a construir una societat més igualitària. Cadascun dels relats del llibre és una denúncia i una declaració que ens encamina cap a un món millor

    Sidelobe control for a MIMO radar virtual array

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    In this paper we address the control of the sidelobe level of the virtual array obtained by a coherent MISO (Multiple Input Single Output) or MIMO (Multiple Input Multiple Output) radar. This is useful for many practical radar systems that could exploit the wide virtual apertures provided by coherent MIMO array, but have a low sidelobe requirement. The solution is obtained by jointly selecting the taper function for the receiving array and the transmitter (TX) displacements to provide a final antenna pattern with the desired properties. Moreover we investigate how beamwidth and SNR change by varying the number of used TXs and the number of isotropic elements used for each TX. © 2013 IEEE

    Antenna Sidelobes Level Control in Transmit Subaperturing MIMO Radar

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    This paper addresses the problem to design a transmitsubaperture multiple-input multiple-output (MIMO) radar showing beam clusters with controlled sidelobe level both for the Tx–Rx pattern experienced from target and clutter and for the Rx-only pattern experienced by external interferences. A design strategy is proposed that provides a MIMO scheme with the desired characteristics, together with a low computational cost and a sensibly narrower main beam than the corresponding single-input-multiple-output scheme. An analysis of the accuracy achievable by the proposed scheme is presented by means of Cram´er–Rao lower bound and Monte Carlo simulations. Moreover, an example application is shown using nonideal waveforms to show the practical effectiveness of this TS-MIMO scheme

    Target motion estimation via multi-node forward scatter radar system

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    The focus of this study is on the estimation of the kinematic parameters of a moving target via a multiple-input-multiple output (MIMO) forward scatter radar (FSR) system. For this purpose, a crossing time-based estimation technique is proposed that exploits the information on the time instants at which the target crosses the individual baselines of multiple FSR nodes to retrieve the target motion parameters. First the accuracy of such technique is investigated from a theoretical point of view through Monte Carlo simulations and then the effectiveness of the proposed approach is demonstrated by applying it to measured MIMO FSR data. Shown results prove the practical applicability of the proposed technique and demonstrate the potential of MIMO FSR configuration

    Descripción de las técnicas de producción del vinagre de sidra de manzana y sus beneficios

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    Introducción: El vinagre es un líquido fermentado que se obtiene por doble fermentación, la primera es una fermentación alcohólica, donde las levaduras Saccharomyces cerevisiae fermentan los azúcares, la segunda es una fermentación acética, donde las bacterias Acetobacter aceti transforman el etanol en ácido acético. Objetivos: Analizar las técnicas de elaboración del vinagre de sidra de manzana. Mencionar los posibles beneficios fisiológicos del consumo de vinagre de sidra de manzana.Introduction: Vinegar is a fermented liquid that is obtained by a double fermentation, the first is an alcoholic fermentation, where the Saccharomyces cerevisiae yeasts ferment the sugars, the second is an acetic fermentation, where the Acetobacter aceti bacteria transform ethanol into acetic acid . Objectives: Discuss the techniques for making apple cider vinegar. Mention the possible physiological benefits of consuming apple cider vinegar

    Role of CT colonography in differentiating sigmoid cancer from chronic diverticular disease

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    To evaluate the accuracy of computed tomography colonography (CTC) in differentiating chronic diverticular disease from colorectal cancer (CRC), using morphological and textural parameters
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