Stationary state after a quench to the Lieb-Liniger from rotating BECs

We study long-time dynamics of a bosonic system after suddenly switching on repulsive delta-like interactions. As initial states, we consider two experimentally relevant configurations: a rotating BEC and two counter-propagating BECs with opposite momentum, both on a ring. In the first case, the rapidity distribution function for the stationary state is derived analytically and it is given by the distribution obtained for the same quench starting from a BEC, shifted by the momentum of each boson. In the second case, the rapidity distribution function is obtained numerically for generic values of repulsive interaction and initial momentum. The significant differences for the case of large versus small quenches are discussed.Comment: 28 pages, 6 figures; v2) added proof and clarifications in the appendix; matches published versio

Probing Klein tunneling through quantum quenches

We study the interplay between an inhomogeneous quantum quench of the external potential in a system of relativistic fermions in one dimension and the well-known Klein tunneling. We find that the large time evolution is characterized by particle production at a constant rate which we derive analytically. The produced particles can be physically interpreted according to a semiclassical picture and the state reached in the long time limit can be classified as a non-equilibrium-steady-state. Such a quantum quench can be used in order to observe macroscopic effects of Klein tunneling in transport, raising the possibility of an experimental implementation.Comment: 15 pages, 8 figure

Antiretroviral drug resistant HIV-1 in women and children living in Honduras

Antiretroviral therapy (ART) in HIV infected pregnant women contributes to the prevention of HIV transmission to the newborn. However, as ART can also induce HIV drug resistance during suboptimal levels of virological suppression a major concern is the subsequent risk for transmitted drug resistant (TDR) virus to the child. In Honduras and Belize, like in many other countries around the world, mono-therapy was used to prevent mother-to-child transmission of HIV-1 (MTCT) until relatively recently when it was changed to a more effective combination antiretroviral therapy (cART). Prior to this study there was no information about antiretroviral drug resistance in HIV-1 infected women and children in Honduras and Belize, and limited data other from parts of Latin America. The first aim (Paper I) was to evaluate the prevalence of drug resistance in HIV-1 infected infants born in Honduras and Belize between 2001 to 2004, before cART was implemented for prevention of MTCT. Genotypic resistance was performed by sequencing of the HIV pol region and was successfully in dried blood spots from 66 HIV-1-infected infants (55 from Honduras and 11 from Belize). Mutations associated with antiretroviral drug resistance were detected in sequences from 13% of the Honduran infants and 27% of Belizean infants. Thus the study documented, for first time, the presence of drug resistance in HIV-1 infected Honduran and Belizean infants. Resistance probably was transmitted from the mothers since none of the infants had received antiretroviral drugs as prophylaxis or therapy. The second aim (Paper II) was to evaluate antiretroviral drug resistance in pregnant HIV-1-infected women in Honduras and risk for MTCT subsequent to ART prophylaxis. In addition, we investigated changes in immune activation during pregnancy by evaluating LPS levels. A total of 50 mother-child pairs and 95 HIV-negative pregnant women were enrolled. The presence of antiretroviral drug resistance was monitored in samples drawn during pregnancy and shortly after delivery. Twenty-nine women (58%) were treatment-naïve at study entry and started antiretroviral prophylaxis against MTCT during pregnancy while 21 women were already identified as HIV-1 infected and on ART at study entry. Antiretroviral drug resistance was detected in 20% of the samples obtained from the mothers at baseline; 10% among treatment-naïve patients and 29% among treatment-experienced patients. Furthermore, despite ART prophylaxis 22 of 50 (44%) women were viremic. No MTCT were observed, but still the high prevalence of resistance and viremia indicated that there was a significant risk for MTCT. The LPS levels declined between pregnancy and after delivery in the HIV-1 infected women indicates that pregnancy might influence the LPS levels, a novel finding that merits further investigation. This study demonstrated for the first time a high prevalence of antiretroviral drug resistance and viremia in pregnant Honduran women, which could limit the effectiveness of antiretroviral prophylaxis against MTCT. Taken together the studies indicate that there is a need for improvements of prevention against MTCT in Belize and Honduras. This includes better access to monitoring of plasma HIV-1 RNA levels and antiretroviral drug resistance testing

Formación de profesores en la interrelación arte, educación y cultura: una mirada sobre patrimonios posibles.

Este texto reflexiona sobre la formación para la enseñanza de las artes visuales, señalando cruces entre arte, educación, cultura y patrimonio y presentando situaciones en las que la educación artística dialoga con los contextos contemporáneos. En mi propuesta, el debate sobre patrimonio cultural, así como las acciones pedagógicas relacionadas con estas cuestiones, pretende avivar los procesos de formación de los maestros para la enseñanza del arte basada en experiencias pedagógicas trabajando con situaciones donde las fronteras entre las instancias académicas se desafían constantemente. Busco estimular el interés investigativo por las culturas populares, el arte público o el arte en el contexto de comunidad, que generan cuestiones de identidad, memoria, patrimonio y acervo cultural, entre otras cosas, escapando de la centralización de conceptos hegemónicos sobre lo que es «arte», o sobre nociones determinadas de lo que se debe enseñar en cuanto a arte. El texto presenta un ejemplo de cómo cuatro estudiantes de la Licenciatura en Artes Visuales en la Universidad Federal de Goiás-Brasil - en el año 2006 enfrentó estos retos propiciando la aportación de la experiencia del estudiante, su familia y la comunidad para el plan pedagógico de enseñanza en el Museo y la escuela. Palabras clave: formación, enseñanza artística, arte, cultura, patrimonio. Abstract: This text reflects on the training process for the teaching of the Visual Arts, pointing out a crossings between art, education, culture and heritage and presenting situations in which arts education dialogues with contemporary contexts.  In my proposal, the debate on cultural heritage, as well as the pedagogical actions related to these issues, it aims to enliven the processes of formation of art teachers  based on pedagogical experiences which works with situations where the boundaries between academic institutions constantly challenge. I stimulate the investigative interest in popular cultures, public art, or art in the context of community, that generate questions of identity, memory, heritage and cultural heritage, among other things, escaping from the centralization of hegemonic concepts on what is 'art', or certain notions of what should be taught in terms of art. The text presents an example of how four students of the Bachelor of Visual Arts at the Federal University of Goiás - Brazil - in 2006 faced these challenges promoting the contribution of the experience of the student, family and the community to  plan lessons connecting museum and school education. Keywords: Teacher training, Art Education, Art, Culture, Heritage.

Polygamy: An Inappropriate Relationship

Polygamy is a general term that means multiple spouses (White & White, 2005). There are two types of polygamy: polygyny, which occurs when one man has many wives, and polyandry, which occurs when one woman has many husbands. Polygamy has been practiced in the United States as well as in other parts of the world for many centuries. When a family decides to add a new wife to the family, the decision is carefully considered and must be approved before the husband and new wife can get married (Altman & Ginat, 1996). The effect of polygamy on children has been researched but is still unclear. There are many who believe that polygamy is beneficial because it allows men to have many children and helps society (White & White, 2005). On the other hand, many view polygamy as an inappropriate relationship (Moore-Emmett, 2004)

Comment on “Bilaterian Burrows and Grazing Behavior at >585 Million Years Ago”

Pecoits et al. (Reports, 29 June 2012, p. 1693) describe bilaterian trace fossils and assign them an Ediacaran age based on the age of a granite interpreted as intrusive. We argue that the granite is not intrusive but in fact represents the basement of the sedimentary succession. Moreover, we show that identical trace fossils occur in nearby Carboniferous-Permian glacigenic rocks.Fil: Gaucher, Claudio. Universidad de la República; UruguayFil: Poire, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigaciones Geológicas. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Investigaciones Geológicas; ArgentinaFil: Bossi, Jorge. Universidad de la República; UruguayFil: Bettucci Sanchez, Leda. Universidad de la República; UruguayFil: Beri, Angeles. Universidad de la República; Urugua

A aventura da crítica

The adventure of the critic. The aim of this paper is to reply the critical observations made by Fernandes, Rego and Gala in this number of Revista de Economia Política about a paper of mine, also published in this same journal in January 2006, which deals with the relationship between Economics and Rethoric and its unfolding in Brazil. Answering these critical observations I have tried to show that: a) it is not easy, as they do, to associate Habermas’s project to the defense of the approach of Rethoric in Economics; Habermas himself has a lot of objections to the association of his project with Rorty’s pragmatism which seems to be the strongest McCloskey’s influence; b) it is not true that my considerations have a kind of epistemological immunity and that they are not liable to contestations; if it seems so it is because the nature of the materialistic approach itself. At the end I observe that my carpers didn’t reply my observations about the unfolding of the rethorical project in Brazil and that this is, at some measure, surprising, because they are central personages in it