Consideraciones previas para un análisis antropológico de las comunidades de alcohólicos anónimos en el norte de México

This work has the pretension to serve like space for “aloud thinking” some of the problematic, obstacles, and also, like no, potentialities that we are finding in the development of an ethnographic investigation on the communities of rehabilitation of alcoholic, Alcoholic Anonymous, in a city in the north of Mexico. For it a review will become of all this according to several points of view, theoretical, methodological and epistemic.Este trabajo tiene la pretensión de servir como espacio para “pensar en voz alta” algunas de las problemáticas, obstáculos, y también, como no, potencialidades que estamos encontrando en el desarrollo de una investigación etnográfica sobre las comunidades de rehabilitación de alcohólicos, Alcohólicos Anónimos, en una ciudad del norte de México. Para ello se hará un repaso de todo esto según varios puntos de vista, teórico, metodológico y epistémico

An orbital-free molecular dynamics study of melting in K_20, K_55, K_92, K_142, Rb_55 and Cs_55 clusters

The melting-like transition in potasium clusters K_N, with N=20, 55, 92 and 142, is studied by using an orbital-free density-functional constant-energy molecular dynamics simulation method, and compared to previous theoretical results on the melting-like transition in sodium clusters of the same sizes. Melting in potasium and sodium clusters proceeds in a similar way: a surface melting stage develops upon heating before the homogeneous melting temperature is reached. Premelting effects are nevertheless more important and more easily established in potasium clusters, and the transition regions spread over temperature intervals which are wider than in the case of sodium. For all the sizes considered, the percentage melting temperature reduction when passing from Na to K clusters is substantially larger than in the bulk. Once those two materials have been compared for a number of different cluster sizes, we study the melting-like transition in Rb_55 and Cs_55 clusters and make a comparison with the melting behavior of Na_55 and K_55. As the atomic number increases, the height of the specific heat peaks decreases, their width increases, and the melting temperature decreases as in bulk melting, but in a more pronounced way.Comment: LaTeX file. 6 pages with 17 pictures. Final version with minor change

Geographical patterns in blood lead in relation to industrial emissions and traffic in Swedish children, 1978–2007

<p>Abstract</p> <p>Background</p> <p>Blood lead concentrations (B-Pb) were measured in 3 879 Swedish school children during the period 1978–2007. The objective was to study the effect of the proximity to lead sources based on the children's home and school location.</p> <p>Methods</p> <p>The children's home address and school location were geocoded and their proximity to a lead smelter and major roads was calculated using geographical information system (GIS) software. All the statistical analyses were carried out using means of generalized log-linear modelling, with natural-logarithm-transformed B-Pb, adjusted for sex, school year, lead-exposing hobby, country of birth and, in the periods 1988–1994 and 1995–2007, parents' smoking habits.</p> <p>Results</p> <p>The GIS analysis revealed that although the emission from the smelter and children's B-Pb levels had decreased considerably since 1978, proximity to the lead smelter continued to affect levels of B-Pb, even in recent years (geometric mean: near smelter: 22.90 μg/l; far from smelter 19.75 μg/l; p = 0.001). The analysis also revealed that proximity to major roads noticeably affected the children's B-Pb levels during the period 1978–1987 (geometric mean near major roads: 44.26 μg/l; far from roads: 38.32 μg/l; p = 0.056), due to the considerable amount of lead in petrol. This effect was, however, not visible after 1987 due to prohibition of lead in petrol.</p> <p>Conclusion</p> <p>The results show that proximity to the lead smelter still has an impact on the children's B-Pb levels. This is alarming since it could imply that living or working in the vicinity of a former lead source could pose a threat years after reduction of the emission. The analysis also revealed that urban children exposed to lead from traffic were only affected during the early period, when there were considerable amounts of lead in petrol, and that the prohibition of lead in petrol in later years led to reduced levels of lead in the blood of urban children.</p

Status and Trends of Physical Activity Surveillance, Policy, and Research in 164 Countries: Findings From the Global Observatory for Physical Activity—GoPA! 2015 and 2020 Surveys

Background: Physical activity (PA) surveillance, policy, and research efforts need to be periodically appraised to gain insight into national and global capacities for PA promotion. The aim of this paper was to assess the status and trends in PA surveillance, policy, and research in 164 countries. Methods: We used data from the Global Observatory for Physical Activity (GoPA!) 2015 and 2020 surveys. Comprehensive searches were performed for each country to determine the level of development of their PA surveillance, policy, and research, and the findings were verified by the GoPA! Country Contacts. Trends were analyzed based on the data available for both survey years. Results: The global 5-year progress in all 3 indicators was modest, with most countries either improving or staying at the same level. PA surveillance, policy, and research improved or remained at a high level in 48.1%, 40.6%, and 42.1% of the countries, respectively. PA surveillance, policy, and research scores decreased or remained at a low level in 8.3%, 15.8%, and 28.6% of the countries, respectively. The highest capacity for PA promotion was found in Europe, the lowest in Africa and low- and lower-middle-income countries. Although a large percentage of the world’s population benefit from at least some PA policy, surveillance, and research efforts in their countries, 49.6 million people are without PA surveillance, 629.4 million people are without PA policy, and 108.7 million live in countries without any PA research output. A total of 6.3 billion people or 88.2% of the world’s population live in countries where PA promotion capacity should be significantly improved. Conclusion: Despite PA is essential for health, there are large inequalities between countries and world regions in their capacity to promote PA. Coordinated efforts are needed to reduce the inequalities and improve the global capacity for PA promotion

El paradigma de la evaluación educativa y sus implicaciones en el aprendizaje contructivista

The work to evaluate must be always supported in a sociocultural reflection of the surroundings in which it is developed to the intrincate relation of the evaluador and the evaluated one. The traditional vision of this concept is treated by means of a series of experenciales considerations and theoretical character that repel in the educational work and the expectations of the students. The cognitive approach and constructivist this being propped up from the perspective to improve the evaluation instruments that are used with numerous groups and where the main complaint of the conductismo is the lack of a "evaluation" strictly based on the "objective". Before this reduccionista vision of the evaluation our proposal reviews the opinion of Vigotsky and the authors whom the cognoscitivismo and the constructivism see in solutions and alternatives different to evaluate the capacity of social participation and analysis and discussion of the problems relative to the social Psychology. The clear definition of a philosophy of the evaluation becomes necessary for educational in the this field of formation then this considerably repels in the situation of conceptual defenselessness that the student to the being faced examinations closed with little opportunity lives on opinion and trims in answers previously considered by which it has in his hands the power of the evaluation.El trabajo de evaluar debe estar siempre apoyado en una reflexión sociocultural del entorno en el que se desarrolla la intrincada relación del evaluador y el evaluado. La visión tradicional de este concepto es tratada mediante una serie de consideraciones experenciales y de carácter teórico que repercuten en el trabajo docente y en las expectativas de los estudiantes. El enfoque cognitivo y constuctivista esta siendo apuntalado desde la perspectiva de mejorar los instrumentos de evaluación que se utilizan con grupos numerosos y donde la queja principal del conductismo es la falta de una "evaluación" estrictamente basada en lo "objetivo". Ante esta visión reduccionista de la evaluación nuestra propuesta revisa la opinión de Vigotsky y de los autores que ven en el cognoscitivismo y el constructivismo soluciones y alternativas diferentes para evaluar la capacidad de participación social y de análisis y discusión de los problemas relativos a la sicología social. La definición clara de una filosofía de la evaluación se hace necesaria para el docente en este campo de formación pues esto repercute considerablemente en la situación de indefensión conceptual que vive el alumno al ser enfrentado a exámenes cerrados con poca oportunidad de opinión y centrados en respuestas previamente consideradas por el que tiene en sus manos el poder de la evaluación

Temperature control via robust compensation of heat generation: Isoparaffin/olefin alkylation

The temperature control of the heterogeneous alkylation, where H2SO4 is used as catalyst, is discussed in this paper. The problem is to design a control function to stabilize temperature in face of uncertain kinetic model. The proposed controller, whose structure resembles a PI-controller, is based on energy balance. The resulting feedback controller is robust, leads to an acceptable performance, and computes the temperature of the coolant from the refrigeration section to the reactor. The effectiveness and robustness of the designed controller for computing the coolant temperature is tested by means of simulations in such a manner that we study the effects of: (i) load disturbances, (ii) model uncertainties and (iii) initial conditions for estimation values. © 2006

Temperature Control of a Catalytic Reactor for the Hydrocarbon Alkylation with Unknown Kinetics [Control de Temperatura en un Reactor Catal�tico para la Alquilaci�n de Hidrocarburos con Cin�tica Incierta]

The stabilization of a catalytic reactor for hydrocarbon alkylation reactions in the presence of unknown kinetics is presented in this paper. A robust approximation to a controller obtained by geometric control techniques was employed. The controller consists of a linear-like feedback and a dynamic uncertainty estimator. Two versions are presented for this estimator, a discrete-time scheme and a continuous time scheme. The proposed controller is able to stabilize the catalytic reactor close to the set-point (practical stability), despite parametric variations and internal model uncertainties. A comparison of both schemes is finally presented to show that they present similar performance. Therefore, any of the controller versions can be used

Testing the genetic predictions of a biogeographical model in a dominant endemic Eastern Pacific coral (Porites panamensis) using a genetic seascape approach

The temperature control of the heterogeneous alkylation, where H 2SO 4 is used as catalyst, is discussed in this paper. The problem is to design a control function to stabilize temperature in face of uncertain kinetic model. The proposed controller, whose structure resembles a PI-controller, is based on energy balance. The resulting feedback controller is robust, leads to an acceptable performance, and computes the temperature of the coolant from the refrigeration section to the reactor. The effectiveness and robustness of the designed controller for computing the coolant temperature is tested by means of simulations in such a manner that we study the effects of: (i) load disturbances, (ii) model uncertainties and (iii) initial conditions for estimation values. " 2007 Springer-Verlag Berlin Heidelberg.",,,,,,"10.1007/978-3-540-73188-7_2",,,"http://hdl.handle.net/20.500.12104/44978","http://www.scopus.com/inward/record.url?eid=2-s2.0-35648980600&partnerID=40&md5=270b1da5cd53b36d3babab910b16d81e",,,,,,,,"Lecture Notes in Control and Information Sciences",,"3

Temperature Control of a Catalytic Reactor for the Hydrocarbon Alkylation with Unknown Kinetics [Control de Temperatura en un Reactor Catalítico para la Alquilación de Hidrocarburos con Cinética Incierta]

The stabilization of a catalytic reactor for hydrocarbon alkylation reactions in the presence of unknown kinetics is presented in this paper. A robust approximation to a controller obtained by geometric control techniques was employed. The controller consists of a linear-like feedback and a dynamic uncertainty estimator. Two versions are presented for this estimator, a discrete-time scheme and a continuous time scheme. The proposed controller is able to stabilize the catalytic reactor close to the set-point (practical stability), despite parametric variations and internal model uncertainties. A comparison of both schemes is finally presented to show that they present similar performance. Therefore, any of the controller versions can be used