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Search Results: 1 - 10 of 71 matches for " Gaggero "
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VIH - SIDA: su abordaje en la universidad como oportunidad para el ejercicio de los derechos humanos: ?Cual es la situación en nuestro pais?
Cuadernos de la Facultad de Humanidades y Ciencias Sociales. Universidad Nacional de Jujuy , 2004,
Abstract: this research, surrownded by an exploratory line of investigation, has the purpose of glacing at the stage of situation in the development of hiv-aids issue, as problem-investigation subject and wich is aproached from the investigation and extension at the universitary spheres of our country. more precisely, and delimiting the investigation subject, the intention is to find out what real importance degree have the investigations and actions of extensions refered to that issue, but in social sciences field, and not only in the medical science one, having in mind that this importance degree is related with the observance of the human rights. in order to reach this objective, it has been taken as scenaries, and in an random sampling, some state universities wich have career offers in the field of medical sciences and also social sciences. as judgement elements, it has been taken the reports that programs responsible organizations aproaching the problem, had presented to the society and to scientific comunity, in a period of five years (1995-2000), and the university memories selected in the same period. the essential connection between the production of knownledge its publication and its application in extension way, from national universities; its reflection in the technical reports of national and international organisms, and the showing points in the relation to human development, are the components for the triangulation and analysis of the results that it will offer.
Connections between cosmic-ray physics, gamma-ray data analysis and Dark Matter detection
Daniele Gaggero
Physics , 2015,
Abstract: Cosmic-ray (CR) physics has been a prolific field of research for over a century. The open problems related to CR acceleration, transport and modulation are deeply connected with the indirect searches for particle dark matter (DM). In particular, the high-quality gamma-ray data released by Fermi-LAT are under the spotlight in the scientific community because of a recent claim about a inner Galaxy anomaly: The necessity to disentangle the astrophysical emission due to CR interactions from a possible DM signal is therefore compelling and requires a deep knowledge of several non-trivial aspects regarding CR physics. I review all these connections in this contribution. In the first part, I present a detailed overview on recent results regarding modeling of cosmic-ray (CR) production and propagation: I focus on the necessity to go beyond the standard and simplified picture of uniform and homogeneous diffusion, showing that gamma-ray data point towards different transport regimes in different regions of the Galaxy; I sketch the impact of large-scale structure on CR observables, and -- concerning the interaction with the Heliosphere -- I mention the necessity to consider a charge-dependent modulation scenario. In the second part, all these aspects are linked to the DM problem. I analyze the claim of a inner Galaxy excess and discuss the impact of the non-trivial aspects presented in the first part on our understanding of this anomaly.
CR electrons and positrons: what we have learned in the latest three years and future perspectives
Daniele Gaggero,Dario Grasso
Physics , 2011,
Abstract: After the PAMELA finding of an increasing positron fraction above 10 GeV, the experimental evidence for the presence of a new electron and positron spectral component in the cosmic ray zoo has been recently confirmed by Fermi-LAT. We show that a simple phenomenological model which assumes the presence of a primary electron and positron extra component allows a consistent description of all available data sets. We then describe the most relevant astrophysical uncertainties which still prevent to determine the electron+positron source properties from those data and the perspectives of forthcoming experiments.
Model independent interpretation of recent CR lepton data after AMS-02
Daniele Gaggero,Luca Maccione
Physics , 2013, DOI: 10.1088/1475-7516/2013/12/011
Abstract: We model the CR leptonic fluxes above 20 GeV in terms of a superposition of a standard and a charge symmetric extra component, which we generically describe as power-laws in momentum. We investigate under these hypotheses the compatibility between AMS-02, Fermi-LAT and PAMELA datasets on positron fraction, electron+positron spectrum and electron spectrum respectively. We find that it is possible to reconcile AMS and Fermi-LAT data within uncertainties, if energy-dependent effects are present in Fermi-LAT systematics. We also study possible deviations from charge symmetry in the extra component and find no compelling evidence for them.
Transport Properties of Delta-Doped Field Effect Transistor
Outmane Oubram;Luis Manuel Gaggero-Sager
PIER Letters , 2008, DOI: 10.2528/PIERL07122810
Abstract: The first calculation of mobility and conductivity between source and drain as function of gate voltage in a δ-doped Field Effect Transistor is presented. The calculation was performed with a model for the δ-FET that was shown in [1]. The mobility was calculated using a phenomenological expression that was presented in [2]. That expression does not have empirical form, neither empirical parameter. For the first time a phenomenological expression of the conductivity is presented, which is derived from the mobility expression. The conductivity shows three different regions: a parabolic region and two linear regions. The parabolic region represents the region at which the conduction channel begins to close. On the other hand, the mobility shows a more different behavior. In the mobility there are four regions. These regions correspond to the disappearance of the different conduction channels that form the subbands of the deltadoped quantum well. The different behavior between mobility and conductivity relies on the depletion of the delta-doped quantum well as the gate potential grows.
Secondary antiprotons as a Galactic Dark Matter probe
Carmelo Evoli,Daniele Gaggero,Dario Grasso
Physics , 2015,
Abstract: We present a novel determination of the astrophysical uncertainties associated to the secondary antiproton flux originating from cosmic-ray spallation on the interstellar gas. We select a set of propagation models compatible with the recent B/C data from PAMELA, and find those providing minimal and maximal antiproton fluxes in different energy ranges. We use this result to determine the most conservative bounds on relevant Dark Matter (DM) annihilation channels: We find that the recent claim of a DM interpretation of a gamma-ray excess in the Galactic Center region cannot be ruled out by current antiproton data. Finally, we discuss the impact of the recently released preliminary data from AMS-02. In particular, we provide a reference model compatible with proton, helium and B/C spectra from this experiment. Remarkably, the main propagation parameters of this model are in agreement with the best fit presented in our earlier statistical analyses. We also show that the antiproton-to-proton ratio does not exhibit any significant anomaly at high energy with respect to our predictions.
Detección de ADN de parvovirus B19 en donantes de sangre de tres hospitales en Santiago, Chile
Revista médica de Chile , 2011, DOI: 10.4067/S0034-98872011000200001
Abstract: background: parvovirus b19 (b19) is associated with a wide range of diseases in humans, whose severity depends on the immunological and hematological status of the host. it is transmitted mainly through the airway but also by transfusions. aim: to determine the b19 dna carrier frequency in a population of volunteer blood donors from three hospitals blood banks in santiago, chile, and to determine the viral load in dna positive cases. material and methods: a total of477 serum samples were analyzed. the screening of b19 dna was carried out by nested polymerase chain reaction (pcr) directed to the non-structural region of the virus (ns1). the viral load in positives cases was quantified by ns1 real time pcr. results: parvovirus b19 was detected in four samples, rendering a frequency of 1:119. the viral loads ranged from less than 2000 to 5,626 x 105 genome equivalents/ml. conclusions: parvovirus b19 was present in four of 477 blood bank blood donors from three hospitals in santiago.
EFD and CFD Characterization of a CLT Propeller
Daniele Bertetta,Stefano Brizzolara,Edward Canepa,Stefano Gaggero,Michele Viviani
International Journal of Rotating Machinery , 2012, DOI: 10.1155/2012/348939
Abstract: In the present paper an experimental and numerical analysis of an unconventional CLT propeller is carried out. Two different numerical approaches, a potential panel method and an RANSE solver, are employed. Cavitation tunnel experiments are carried out in order to measure, as usual, thrust, torque, and cavity extension for different propeller working points. Moreover, LDV measurements are performed to have a deep insight into the complex wake behind the propeller and to analyze the dynamics of generated tip vortexes. The numerical/experimental analysis and comparison of results highlight the peculiarities of this kind of propellers, the possibility to increase efficiency and reduce cavitation risk, in order to exploit the design approaches already well proven for conventional propellers also in the case of these unconventional geometries. 1. Introduction Energy saving is a primary objective, historically the first, and, probably still now, the most important one, in the design of marine propellers. The constant increase of oil price, the more strict regulations in terms of air pollution, and the limits for NOX and SOX emissions require more and more efficient designs. Modern design approaches, like fully numerical lifting line/lifting surface codes and optimization applied to potential panel methods satisfy this objective and allow to design conventional propellers with maximum efficiency for a given operating point. On the other hand, nonconventional propellers, like Contracted and Loaded Tip CLT and Kappel like geometries, represent a further opportunity to increase efficiency and reduce the risk of cavitation, without the employment of completely different propulsive solutions, like contra- and corotating propellers or by the adoption of ducts, stators or wake regularizers. At the same time, also requirements in terms of radiated noise and vibration emissions became more strict: avoidance of negative effects on marine life and reduction of the risk of hydroacoustic signature are the primary aims of new commercial and navy constructions. CLT propellers may represent a valid answer to these demands, even if the effects of some peculiar phenomena, such as the cavitating vortices at tip, need further investigation. The first concept of tip-loaded propellers goes back to late seventies: Tip Vortex Free propellers were the first application of the Loaded Tip concept, that quickly evolved toward the CLT solution when also contraction of the fluid vein has been taken into account for the definition of the optimal geometry (http://www.sistemar.com/). CLT
Virus herpes canino en Chile: Propiedades biológicas
Navarro,C; Celedón,M; Pizarro,J; Gaggero,A;
Archivos de medicina veterinaria , 2005, DOI: 10.4067/S0301-732X2005000200007
Abstract: the study described here studied the biological properties of the rp5 isolate and confirms the presence of canine herpes virus-1 (chv-1) by means of the immunofluorescence direct method. the preliminary characterization of the rp5 isolate suggested it belongs to the herpesviridae family, subfamily alphaherpesvirinae. as a specific confirmation of the presence of chv-1, biological properties such as the viral title determination, the envelope presence, a kinetic behavior model consisting of one step growth and the intranuclear inclusion bodies formation were conducted. this viral characterization will allow future studies such as an evaluation of the magnitude of infection in the canine population to be conducted and information regarding the repercussion of infection by this virus in breeding places can be collected. a method of rapid laboratory diagnosis can also be developed
Subband structure comparison between n- and p-type double delta-doped GaAs quantum wells
I. Rodriguez Vargas,L.M. Gaggero Sager
Revista mexicana de física , 2004,
Abstract: Calculamos la estructura de niveles electrónicos (tipo-n), así como la de huecos (tipo-p) de pozos cuánticos ±-dopados dobles (DDD) en GaAs. Se han tomando en cuenta los efectos de intercambio en el estudio. Las aproximaciónes de Thomas-Fermi (TF) y Thomas-Fermi- Dirac (TFD) han sido implementadas para describir el doblamiento de la banda de conducción y de valencia respectivamente. El estudio de la estructura de niveles electrónicos y de huecos revela que los efectos de muchos cuerpos son más importantes en los pozos DDD tipo-p que en los DDD tipo-n. De la misma manera nuestros resultados están en buen acuerdo con los datos experimentales disponibles.
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