Harmonic analysis of irradiation asymmetry for cylindrical implosions driven by high-frequency rotating ion beams

Cylindrical implosions driven by intense heavy ions beams should be instrumental in a near future to study High Energy Density Matter. By rotating the beam by means of a high frequency wobbler, it should be possible to deposit energy in the outer layers of a cylinder, compressing the material deposited in its core. The beam temporal profile should however generate an inevitable irradiation asymmetry likely to feed the Rayleigh-Taylor instability (RTI) during the implosion phase. In this paper, we compute the Fourier components of the target irradiation in order to make the junction with previous works on RTI performed in this setting. Implementing a 1D and 2D beam models, we find these components can be expressed exactly in terms of the Fourier transform of the temporal beam profile. If $T$ is the beam duration and $\Omega$ its rotation frequency, "magic products" $\Omega T$ can be identified which cancel the first harmonic of the deposited density, resulting in an improved irradiation symmetry.Comment: 19 pages, 8 figures, to appear in PR

Los organismos incrustantes de las costas argentinas

Se ha estudiado la fijación de flora y fauna marinas sobre Ulva lactuca. Se eligieron dos zonas de trabajo, dentro y fuera del puerto de Mar del Plata, a fin de determinar cuáles son los factores que condicionan los fenómenos de epibiosis. La composición de la epibiosis y organismos refugiados en ambas zonas está directamente relacionada con las diferencias de composición de las comunidades bentónicas mediolitorales y con las condiciones ambientales (turbulencia, contaminación, etc.). Se da una lista de la totalidad de las especies registradas.Settlement of marine flora and fauna on Ulva Lactuca was investigated. In order to determine the variables affecting the epibiosis phenomenon, two areas were studied, inside and outside Mar del Plata's harbor. The composition of the epibiosis, and the organisms which settle in those zones is directly related to the composition of middle-littoral benthic communities and with the environmental conditions (turbulence, pollutiom, etc). All the species registered are listed in this paper

Gravitational Effects on the Neutrino Oscillation

The propagation of neutrinos in a gravitational field is studied. A method of calculating a covariant quantum-mechanical phase in a curved space-time is presented. The result is used to calculate gravitational effects on the neutrino oscillation in the presence of a gravitational field. We restrict our discussion to the case of the Schwartzschild metric. Specifically, the cases of the radial propagation and the non-radial propagation are considered. A possible application to gravitational lensing of neutrinos is also suggested.Comment: 15 pages, RevTex, No figures. Minor modifications and some typos correcte

Michel Foucault y el pensamiento de colón : Entre la trama semántica del mundo y el murmullo incesante de la imaginación

En el siguiente trabajo se analizarán la descripción del nuevo mundo y el funcionamiento de la analogía, a partir de estudios críticos referidos a los Diarios del primer viaje de Cristóbal Colón y su posible relación con el estudio de la Episteme de la Semejanza presente en Las palabras y las cosas de Michel Foucaul

Efectos del factor de crecimiento parecido a la insulina de tipo I (IGF-I) sérico sobre el sistema nervioso

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina. Departamento de Anatomía, Histología e Neurociencia. Fecha de lectura: 6 de Julio de 200

Evaluating national library mission statements in Ibero-America

The purpose of this paper is to review the websites of 22 national libraries in Ibero-America to determine whether and how effectively they display these organisations’ mission statements, as well as any convergence/divergence among these texts

Lateral Habenula determines long-term storage of aversive memories

The Lateral Habenula (LHb) is a small brain structure that codifies negative motivational value and has been related to major depression. It has been shown recently that LHb activation is sufficient to induce aversive associative learning; however the key question about whether LHb activation is required for an aversive memory to be formed has not been addressed. In this article we studied the function of the LHb in memory formation using the Inhibitory Avoidance task (IA). We found that LHb inactivation during IA training does not disrupt memory when assessed 24 h after, but abolishes it 7 days later, indicating that LHb activity during memory acquisition is not necessary for memory formation, but regulates its temporal stability. These effects suggest that LHb inactivation modifies subjective perception of the training experience.Fil: Tomaiuolo, Micol. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia ; ArgentinaFil: González, María Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia ; ArgentinaFil: Medina, Jorge Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Biología Celular y Neurociencia "Prof. Eduardo de Robertis". Universidad de Buenos Aires. Facultad de Medicina. Instituto de Biología Celular y Neurociencia ; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Ciencias Fisiológicas; ArgentinaFil: Piriz, Joaquin. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Fisiología y Biofísica Bernardo Houssay. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Fisiología y Biofísica Bernardo Houssay; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Fisiología, Biología Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Fisiología, Biología Molecular y Neurociencias; Argentin