Warm inflation in presence of magnetic fields

We present preliminary results on the possible effects that primordial magnetic fields can have for a warm inflation scenario, based on global supersymmetry, with a new-inflation-type potential. This work is motivated by two considerations: first, magnetic fields seem to be present in the universe on all scales, which rises the possibility that they could also permeate the early universe; second, the recent emergence of inflationary models where the inflaton is not assumed to be isolated but instead it is taken as an interacting field, even during the inflationary expansion. The effects of magnetic fields are included resorting to Schwinger proper time method.Comment: Published in AIP Conf. Proc. 1548, 288 (2013), IX Mexican School on Gravitation and Mathematical Physics: Cosmology for the XXIst Centur

Urban spatial structure and suburbanisation. The case of the Barcelona Metropolitan

The metropolitan spatial structure displays various patterns, sometimes monocentricity and sometimes multicentricity, which seems much more complicated than the exponential density function used in classic works such as Clark (1961), Muth (1969) or Mills (1973) among others, can effectively represent. It seems that a more flexible density function,such as cubic spline function (Anderson (1982), Zheng (1991), etc.) to describe the density-accessibility relationship is needed. Also, accessibility, the fundamental determinant of density variations, is only partly captured by the inclusion of distance to the city centre as an explanatory variable. Steen (1986) has proposed to correct that miss-especification by including an additional gradient for distance to the nearest transportation axis. In identifying the determinants of urban spatial structure in the context of inter-urban systems, some of the variables proposed by Muth (1969), Mills (1973) and Alperovich (1983) such as city age or population, make no sense in the case of a single urban system. All three criticism to the exponential density function and its determinants apply for the Barcelona Metropolitan Region, a polycentric conurbation structured on well defined transportation axes.Suburbanisation, decentralisation, Barcelona

Precoding in multigateway multibeam satellite systems

This paper considers a multigateway multibeam satellite system with multiple feeds per beam. In these systems, each gateway serves a set of beams (cluster) so that the overall data traffic is generated at different geographical areas. Full frequency reuse among beams is considered so that interference mitigation techniques are mandatory. Precisely, this paper aims at designing the precoding scheme which, in contrast to single gateway schemes, entails two main challenges. First, the precoding matrix shall be separated into feed groups assigned to each gateway. Second, complete channel state information (CSI) is required at each gateway, leading to a large communication overhead. In order to solve these problems, a design based on a regularized singular value block decomposition of the channel matrix is presented so that both intercluster (i.e., beams of different clusters) and intracluster (i.e., beams of the same cluster) interference is minimized. In addition, different gateway cooperative schemes are analyzed in order to keep the inter-gateway communication low. Furthermore, the impact of the feeder link interference (i.e., interference between different feeder links) is analyzed and it is shown both numerically and analytically that the system performance is reduced severely whenever this interference occurs even though precoding reverts this additional interference. Finally, multicast transmission is also considered. Numerical simulations are shown considering the latest fixed broadband communication standard DVB-S2X so that the quantized feedback effect is evaluated. The proposed precoding technique results to achieve a performance close to the single gateway operation even when the cooperation among gateways is low.Postprint (author's final draft

Precoding in multigateway multibeam satellite systems

This paper considers a multigateway multibeam satellite system with multiple feeds per beam. In these systems, each gateway serves a set of beams (cluster) so that the overall data traffic is generated at different geographical areas. Full frequency reuse among beams is considered so that interference mitigation techniques are mandatory. Precisely, this paper aims at designing the precoding scheme which, in contrast to single gateway schemes, entails two main challenges. First, the precoding matrix shall be separated into feed groups assigned to each gateway. Second, complete channel state information (CSI) is required at each gateway, leading to a large communication overhead. In order to solve these problems, a design based on a regularized singular value block decomposition of the channel matrix is presented so that both intercluster (i.e., beams of different clusters) and intracluster (i.e., beams of the same cluster) interference is minimized. In addition, different gateway cooperative schemes are analyzed in order to keep the inter-gateway communication low. Furthermore, the impact of the feeder link interference (i.e., interference between different feeder links) is analyzed and it is shown both numerically and analytically that the system performance is reduced severely whenever this interference occurs even though precoding reverts this additional interference. Finally, multicast transmission is also considered. Numerical simulations are shown considering the latest fixed broadband communication standard DVB-S2X so that the quantized feedback effect is evaluated. The proposed precoding technique results to achieve a performance close to the single gateway operation even when the cooperation among gateways is low.Postprint (author's final draft

Voces of Little Michoacan: A Collective Narrative of Resistance and Preservation of Home

This empirical study captured the ongoing community organizing, led primarily by Chicanas and young people in a Latinx community in the San Francisco Bay Area. This community has experienced historic neglect, inequities, gentrification, and economic displacement. Through muxersita portraiture, a critical qualitative methodology, with young people as co-researchers, this study captures the collective narrative of the community of North Fair Oaks through platicas, encuentros y acción. In the process, this collective narrative disrupts the negative impact of gentrification by providing a historical context of the contributions of Latinx in North Fair Oaks. This study uses a critical coraje framework; a homemade theory that aims to transform the world through HERstory education, uplifting and acknowledging the contributions of oppressed people and the fostering of advocacy, for the preservation of home. The methodology offers a HERstory course to lead young people into their collection of narratives, through an intergenerational encuentro. In doing so, we centralize the experiences of Latinx community in North Fair Oaks where over 70% self-identify as Latinx, disrupt gender norms and heteropatriarchy, elevate women voices- because women are often silenced, ignored, or cast aside, and recast young people as active agents capable of promoting social justice within their own communities (Cammarota & Fine, 2008). This intergenerational encuentro brings together the narratives and experiences of young people and mujeres to form a common story of struggle against the rapid gentrification and displacement in the community of North Fair Oaks. Through this research, young people learn valuable stories from mujeres through pláticas and encuentros, and mujeres learn new ways of being from the next generation. Whereby, the legacy of community activism, intergenerational learning, and new knowledge production inform the framework of critical coraje. The findings offer four tenets of critical coraje: collective HEARTwork, critical hope, m[other]work, and liberatory spirit

Comparison of two ketamine/xylazine anesthesic protocols in pigs (Sus crofa domestica)

The pig (Sus scrofa domestica) is an animal used as an experimental model in surgical procedures. This makes the use of anaesthesia necessary. The present study constitutes a comparison between two different ketamine/xylazine concentration protocols. One protocol used ketamine 10% + xylazine 10% (high concentration), and the other ketamine 5% + xylazine 2% (low concentration). Concentrations were chosen since these are the most common presentations in the veterinary market. In the present experiments, twenty male and female pigs (Sus crofa domestica; 20 kg each), were assigned into two different groups. The first one was integrated by pigs treated with high concentration protocol (n = 10), and the second one, composed by pigs that received low concentration protocol (n = 10). Parameters measured were the time in which the animals were placed in sternal decubitus, and the heart rate. The effects of these drugs were considered not only specifically in its sedative effects, but also in the respiratory system. Based on these results, we conclude that the first protocol showed better results than the second one. The time in which the animals were placed in sternal decubitus was lower in the first one (p < 0.001). Differences between the effects on the respiratory system (p = 0.37) and sedative effects (p = 0.87) were not significant, even when focusing on the last measurement, higher concentration protocol was twenty percent (20%) more effective than lower.Fil: Guevara, Manuel Alejandro. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lorenzo Aquaro, Sofía Ana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; ArgentinaFil: Giai, Marcos. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Gargiulo, Pascual Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza; Argentina. Universidad Nacional de Cuyo. Facultad de Ciencias Médicas; Argentina. Fundación Corporación Tecnológica Latinoamericana; Argentin

Is it possible to discriminate the body weight loss?

Most studies have described how the weight loss is when different treatments are compared (1-3), while others have also compared the weight loss by sex (4), or have taken into account psychosocial (5) and lifestyle (6, 7) variables. However, no studies have examined the interaction of different variables and the importance of them in the weight loss