Tiempo libre: esparcimiento y recreación como dimensiones del bienestar en la frontera norte de México

This work presents results from two studies that took place in 2006 in Mexicali and Tijuana, Baja California, México, where leisure and recreation were considered as dimensions of well-being, which is valued based on what the subjects that participated in a survey declare to be achievements in this matter. Data are analyzed with emphasis on leisure activities and their differences according to city and income level, and show that satisfaction of leisure needs is less achieved among those with the lowest income level, but has no significative differences when comparing urban and rural areas

Generation of mice with longer and better preserved telomeres in the absence of genetic manipulations.

Although telomere length is genetically determined, mouse embryonic stem (ES) cells with telomeres of twice the normal size have been generated. Here, we use such ES cells with ‘hyper-long’ telomeres, which also express green fluorescent protein (GFP), to generate chimaeric mice containing cells with both hyper-long and normal telomeres. We show that chimaeric mice contain GFP-positive cells in all mouse tissues, display normal tissue histology and normal survival. Both hyper-long and normal telomeres shorten with age, but GFP-positive cells retain longer telomeres as mice age. Chimaeric mice with hyper-long telomeres also accumulate fewer cells with short telomeres and less DNA damage with age, and express lower levels of p53. In highly renewing compartments, such as the blood, cells with hyper-long telomeres are longitudinally maintained or enriched with age. We further show that wound-healing rates in the skin are increased in chimaeric mice. Our work demonstrates that mice with functional, longer and better preserved telomeres can be generated without the need for genetic manipulations, such as TERT overexpression.post-print3240 K

Synthesis and characterization of titanium-vanadium ternary nitride (TixV1-xN).

En el presente trabajo se aborda la síntesis del nitruro ternario de titanio y vanadio por reducción carbotérmica de una mezcla de óxidos o bien por nitruración directa de la mezcla de metales, en todo el rango de composiciones empleando el método de análisis térmico a velocidad controlada (ATVC). La caracterización de los productos obtenidos se ha llevado a cabo mediante difracción de rayos-X y microscopia electrónica. El empleo de la técnica EELS ha mostrado su capacidad para la cuantificación de este tipo de materiales, así como la utilización de la técnica espectroscópica XAS nos ha servido para corroborar los datos obtenidos a partir de los diagramas de difracción de rayos-X sobre distancias de enlace, número de coordinación y grado de desorden, esto último no detectado por las otras técnicas usadas en la caracterización de los productos. Los valores de microdureza registrados para las muestras sintetizadas se encuentran dentro del rango de valores reportados para este tipo de materiales.Titanium-Vanadium nitride (TiVN) has been prepared from carbothermal reduction of corresponding oxides and also by direct nitridation of a mix of two metals employing the ATVC method. The characterization of the final product by X-ray diffraction, scanning electron microscopy, electron energy loss (EELS), and X-ray absorption spectroscopy (XAS) is presented.The synthesis of the ternary nitride has been possible in all range of composition and the final product is obtained with nanometric particle size and a high microhardness after sintering

Protein Dynamics Control of Electron Transfer in Photosynthetic Reaction Centers from Rps. Sulfoviridis

In the cycle of photosynthetic reaction centers, the initially oxidized special pair of bacteriochlorophyll molecules is subsequently reduced by an electron transferred over a chain of four hemes of the complex. Here, we examine the kinetics of electron transfer between the proximal heme c-559 of the chain and the oxidized special pair in the reaction center from Rps. sulfoviridis in the range of temperatures from 294 to 40 K. The experimental data were obtained for three redox states of the reaction center, in which one, two, or three nearest hemes of the chain are reduced prior to special pair oxidation. The experimental kinetic data are analyzed in terms of a Sumi–Marcus-type model developed in our previous paper,1 in which similar measurements were reported on the reaction centers from Rps. viridis. The model allows us to establish a connection between the observed nonexponential electron-transfer kinetics and the local structural relaxation dynamics of the reaction center protein on the microsecond time scale. The activation energy for relaxation dynamics of the protein medium has been found to be around 0.1 eV for all three redox states, which is in contrast to a value around 0.4–0.6 eV in Rps. viridis.1 The possible nature of the difference between the reaction centers from Rps. viridis and Rps. sulfoviridis, which are believed to be very similar, is discussed. The role of the protein glass transition at low temperatures and that of internal water molecules in the process are analyzed.España, Ministerio de Educación y Ciencia BFU2004-04914-C02-01/BMCJunta de Andalucía PAI CVI-26

La revisión sistemática de la relación indirecta entre la pertenencia social frustrada y la sensación de ser una carga en el suicidio

Joiner's Interpersonal-Psychological Theory of Suicide (IPTS) considers the interpersonal variables of low social belonging and the perception of being a burden on others as drivers of suicidal ideation. This study has sought to review the empirical evidence on this prediction. In all, 40 studies were found. The findings report a major mediator and moderator role of perceived burdensomeness (PB) and thwarted belongingness (TB) in the relationship between the propensity toward suicide and psychological, social, and environmental factors. As the theory predicts, expecting to find that the interaction of both of these variables would be more closely linked to suicidal ideation, this does not appear to have been fully supported, generally finding a greater significance when they were integrated into separate models. It seems that attributing other forms of relationship with suicide for the variables identified by Joiner would provide IPTS with greater empirical support.La teoría interpersonal psicológica del suicidio de Joiner considera las variables interpersonales de baja pertenencia social y la percepción de ser una carga para los demás como impulsores de la ideación suicida. Este estudio revisa la evidencia empírica sobre esta predicción. En total, se han encontrado 40 estudios. Los hallazgos descubren un importante papel mediador y moderador de la carga percibida y la pertenencia frustrada en la relación entre la propensión al suicidio y los factores psicológicos, sociales y ambientales. Como predice la teoría, esperando encontrar que la interacción de ambas variables estaría más estrechamente ligada a la ideación suicida, esto no parece haber sido totalmente respaldado, encontrando generalmente una mayor significación cuando estas se integraron en modelos separados. Parece que atribuir otras formas de relación con el suicidio para las variables identificadas por Joiner proporcionaría a la teoría interpersonal psicológica del suicidio un mayor apoyo empíric

Assessing the Effect of Drivers' Gender on Their Intention to Use Fully Automated Vehicles

Although fully automated vehicles (SAE level 5) are expected to acquire a major relevance for transportation dynamics by the next few years, the number of studies addressing their perceived benefits from the perspective of human factors remains substantially limited. This study aimed, firstly, to assess the relationships among drivers' demographic factors, their assessment of five key features of automated vehicles (i.e., increased connectivity, reduced driving demands, fuel and trip-related efficiency, and safety improvements), and their intention to use them, and secondly, to test the predictive role of the feature' valuations over usage intention, focusing on gender as a key differentiating factor. For this cross-sectional research, the data gathered from a sample of 856 licensed drivers (49.4% females, 50.6% males; M = 40.05 years), responding to an electronic survey, was analyzed. Demographic, driving-related data, and attitudinal factors were comparatively analyzed through robust tests and a bias-corrected Multi-Group Structural Equation Modeling (MGSEM) approach. Findings from this work suggest that drivers' assessment of these AV features keep a significant set of multivariate relationships to their usage intention in the future. Additionally, and even though there are some few structural similarities, drivers' intention to use an AV can be differentially explained according to their gender. So far, this research constitutes a first approximation to the intention of using AVs from a MGSEM gender-based approach, being these results of potential interest for researchers and practitioners from different fields, including automotive design, transport planning and road safety

Organizaciones de la Sociedad Civil de Asistencia Social que atienden a niños, adolescentes y jóvenes en situación de calle en la ciudad de Hermosillo, Sonora, México

El trabajo aporta información sobre los antecedentes, la regulación social y la problemática de las Organizaciones de la Sociedad Civil (OSC) que atienden a "niños(as), adolescentes y jóvenes en situación de calle"1 en Hermosillo, Sonora, México (OSCASH)2, así como el papel que desempeñan en la sociedad. Con ese fin, se aplicó una encuesta a 30 usuarios y 15 empleados que laboran en estas organizaciones en el estado de Sonora, México. Parte de los resultados señalan que, aunque existe un marco legal que protege a los niños(as), adolescentes y jóvenes en situación de calle, y que hay una serie de organizaciones con amplia experiencia en su cuidado, la mayoría de los niños, adolescentes y jóvenes no están integrados a una institución. Nuestra conclusión es que el Estado no ha resuelto el problema y las instituciones y organizaciones que los atienden no responden a los objetivos para los que fueron creadas, limitando así las posibilidades de integración del grupo social al que pretenden atender

Influence of synthetic method on the properties of La0.5Ba0.5FeO3 SOFC cathode

Power Point presentado en The Energy and Materials Research Conference - EMR2015 celebrado en Madrid (España) entre el 25-27 de febrero de 2015Perovskite type (ABO3) oxides have been widely studied as SOFC cathode materials at high temperatures. Given that several of the challenges hindering SOFC technology are consequence of the high operation temperature (about 1000ºC) [1,2], an important goal is to reduce it to 600-800ºC. To minimize this effect new perovskite-type mixed ionic-electronic conducting oxides have been widely studied as promising IT-SOFC cathodes. Among them, iron perovskites (LSF) seem to be good candidates mainly for their appropriate thermal expansion match with YSZ electrolytes and their good catalytic activity for the oxygen reduction [3,4]. The properties of these compounds and thus their cell performance depends on several factors: the right choice of A and B elements, the amount of doping cations (A1-xAx) and some structural parameters such as the tolerance factor [5], the average size of the A-site cations () and the A cation size disorder (σ2(rA)). Studies on the influence of the hole-doping (x) in the A-site of LSF perovskites have shown good cathode performances in compounds with intermediate doping levels [6]. The change of and σ2(rA) indicate that better performances are observed for highest and lowest σ2(rA) [7]. External parameters, such as the synthetic method, are also important factors that influence the final properties [8]. In this sense it has been observed that porosity, grain size and morphology of the compounds strongly depend on the sample preparation techniques. In this research, a La0.5Ba0.5FeO3 perovskite has been synthesized by two different methods (ceramic and glycine-nitrate routes) in order to study the synthetic method influence on the properties of this compound as IT-SOFC cathode material. This composition has been chosen due to its intermediate hole doping level (0.5) and high average size of the A-site cations ( = 1.48 Å, when rA are standard 12-coordinate ionic radii), these parameters, according with previous studies should show interesting properties for its use as SOFC cathode. It has been observed that the two La0.5Ba0.5FeO3 compounds show different room temperature crystal structure depending on the synthesis route. The sample obtained by the ceramic method has higher oxygen vacancy content, but in the other hand the SEM micrographs show that glycine-nitrate process leads to a compound with porous structure and particles with nanometric grain sizes. At 700 or 800ºC the electrical conductivity of both samples is similar but the sample obtained by glycine-nitrate route shows better electrochemical performance. The ceramic sample has lower adherence than the glycine counterpart and this derivates in higher values of polarization resistance. It is believed that this is a consequence of the heterogenous morphology of this sample. Therefore, it seems that the glycine-nitrate synthetic method is a more appropriate technique for preparing perovskite cathodes

Contribution of migrant coffee labourers infected with Onchocerca volvulus to the maintenance of the microfilarial reservoir in an ivermectin-treated area of Mexico

BACKGROUND: Since 1991, in Mexico, ivermectin has been administered twice a year to all residents in the onchocerciasis endemic foci which are mainly located in the coffee growing areas. However, the presence of a potentially infected itinerant seasonal labour force which is not treated regularly could jeopardise the attainment of the 85% coverage which is the present target for elimination of the disease. METHODS: The prevalence and intensity of Onchocerca volvulus microfilariae (mf), as well as their transmission from humans to vectors, were assessed during the coffee planting-clearing and harvesting seasons of 1997-1998, and 1998-1999 in two localities (I and II) of Southern Chiapas, Mexico, which regularly receive an influx of untreated migrant coffee labourers. RESULTS: Localities I and II had, respectively, an average of 391 (+/- 32) and 358 (+/- 14) resident inhabitants, and 70 (+/- 52) and 498 (+/- 289) temporary labourers. The ratio of migrants to residents ranged from 0.1:1 in locality I to 2.4:1 in locality II. The proportion of infected Simulium ochraceum s.l. parous flies was significantly lower in locality I than in locality II, and significantly higher during the stay of the migrants than before their arrival or after their departure. Parity and infection were higher in May-July than in November-February (in contrast with the latter being typically considered as the peak onchocerciasis transmission season by S. ochraceum s.l.). CONCLUSION: The presence of significant numbers of untreated and potentially infected migrants may contribute to ongoing transmission, and their incorporation into ivermectin programmes should be beneficial for the attainment of the elimination goals of the regional initiative. However, the possibility that the results also reflect transmission patterns for the area cannot be excluded and these should be analyzed further