Neutron absorption in supermirror coatings: Effects on shielding

The quantification of the dose rate and the composition of the dose in the vicinity of supermirror coated guides is essential for designing shielding for beamlines transporting neutrons with a high flux. We present results on a calculation of radiative neutron absorption in Ni/Ti and NiMo/Ti supermirror coatings which leads to the emission of high energy gamma rays. A simple parameterization of the absorption probability in the coating materials per incident neutron is given as a function of momentum transfer at reflection

El teatro hispanoamericano de post mortem.

El teatro hispanoamericano de post mortem

The Argentine Stage: Temporada ´76

The Argentine Stage: Temporada ´7

The Mexican Stage in the Fall of 1971.

The Mexican Stage in the Fall of 1971

El teatro vanguardista de Eduardo Pavlovsky

El teatro vanguardista de Eduardo Pavlovsk

Jürgen Habermas y la problemática de la neutralidad valorativa: ¿es posible una ciencia social crítica?

Uno de los problemas epistemológicos que se plantean en las ciencias sociales es el referido a la objetividad del conocimiento. En el fondo de la discusión se encuentra el siguiente punto: ¿es posible pensar una ciencia social neutral, sin valores? Abordar la discusión desde una perspectiva crítica permite plantear algunos fundamentos para resignificar el rol de las ciencias sociales en la sociedad actual. Habermas aporta una mirada sobre la posibilidad de recrear la "objetividad científica" que abre un interesante abanico de posibilidades para analizar las condiciones de la producción de conocimiento en las ciencias sociales. Jürgen Habermas, heredero del pensamiento frankfurtiano, desarrolla su enfoque de la objetividad en las ciencias sociales a partir de una lógica de la comprensión en términos de proceso comunicacional. Es posible plantear la objetividad pero, según este autor, no es posible defender la neutralidad valorativa. El postulado de la neutralidad valorativa, nos dice Habermas, demuestra que los procedimientos empírico-analíticos no son capaces de darse cuenta de la referencia respecto de la vida en la que, en realidad, ellos mismos se encuentran objetivamente. Trabajar sobre las nociones de objetividad y neutralidad valorativa enriquece el trabajo intelectual y afianza la posibilidad de poder sostener una ciencia social crítica.One of the epistemological problems that arise in the social sciences is the question of the objectivity of knowledge. At the bottom of the discussion is the following point: Is it possible to think about a neutral social science without values?. Addressing the discussion from a critical perspective, allows us to suggest some grounds for meaning to the role of social sciences in modern society. Habermas gives us a look at the possibility of recreating the scientific objectivity that opens an interesting range of opportunities to analyze the conditions of knowledge production in social sciences. Jurgen Habermas, heir to the thought of Frankfurt, develops its approach to objectivity in science from a social logic of understanding in terms of communication process. It is possible to raise the objectivity but, according to this author, it is not possible to defend the value-neutrality. Habermas thinks that de postulate of value neutrality shows us that the empirical-analytical procedures are not capable to undestand the reference regarding the life in which, in reality, they find themselves objectively. Work on the notions of objectivity and value neutrality enriches intellectuall work and strengthens the possibility of holding a critical social science

The Geographic Synchrony of Seasonal Influenza: A Waves across Canada and the United States

BACKGROUND: As observed during the 2009 pandemic, a novel influenza virus can spread globally before the epidemic peaks locally. As consistencies in the relative timing and direction of spread could form the basis for an early alert system, the objectives of this study were to use the case-based reporting system for laboratory confirmed influenza from the Canadian FluWatch surveillance program to identify the geographic scale at which spatial synchrony exists and then to describe the geographic patterns of influenza A virus across Canada and in relationship to activity in the United States (US). METHODOLOGY/PRINCIPAL FINDINGS: Weekly laboratory confirmations for influenza A were obtained from the Canadian FluWatch and the US FluView surveillance programs from 1997/98 to 2006/07. For the six seasons where at least 80% of the specimens were antigenically similar, we identified the epidemic midpoint of the local/regional/provincial epidemics and analyzed trends in the direction of spread. In three out of the six seasons, the epidemic appeared first in Canada. Regional epidemics were more closely synchronized across the US (3-5 weeks) compared to Canada (5-13 weeks), with a slight gradient in timing from the southwest regions in the US to northeast regions of Canada and the US. Cities, as well as rural areas within provinces, usually peaked within a couple of weeks of each other. The anticipated delay in peak activity between large cities and rural areas was not observed. In some mixed influenza A seasons, lack of synchronization sub-provincially was evident. CONCLUSIONS/SIGNIFICANCE: As mixing between regions appears to be too weak to force a consistency in the direction and timing of spread, local laboratory-based surveillance is needed to accurately assess the level of influenza activity in the community. In comparison, mixing between urban communities and adjacent rural areas, and between some communities, may be sufficient to force synchronization