A parallel Branch-and-Fix Coordination based matheuristic algorithm for solving large sized multistage stochastic mixed 0-1 problems

A parallel matheuristic algorithm is presented as a spin-off from the exact Branch-and-Fix Coordination (BFC) algorithm for solving multistage stochastic mixed 0-1 problems. Some steps to guarantee the solution’s optimality are relaxed in the BFC algorithm, such that an incomplete backward branching scheme is considered for solving large sized problems. Additionally, a new branching criterion is considered, based on dynamically-guided and stage-wise ordering schemes, such that fewer Twin Node Families are expected to be visited during the execution of the so-called H-DBFC algorithm. The inner parallelization IH-DBFC of the new approach, allows to solve in parallel scenario clusters MIP submodels at different steps of the algorithm. The outer parallel version, OH-DBFC, considers independent paths and allows iterative incumbent solution values exchanges to obtain tighter bounds of the solution value of the original problem. A broad computational experience is reported for assessing the quality of the matheuristic solution for large sized instances. The instances dimensions that are considered are up to two orders of magnitude larger than in some other works that we are aware of. The optimality gap of the H-DBFC solution value versus the one obtained by a state-of-the-artMIP solver is very small, if any. The new approach frequently outperforms it in terms of solution’s quality and computing time. A comparison with our Stochastic Dynamic Programming algorithm is also reported. The use of parallel computing provides, on one hand, a perspective for solving very large sized instances and, on the other hand, an expected large reduction in elapsed time.MTM2015-65317-P, MTM2015-63710-P, IT928-16; UFI BETS 2011; IZO-SGI SGIke

La publicidad como reclamo: valores y antivalores sociales.

This paper analyses the contents of advertising from a historical point of view and from an iconological perspective, trying to decode the stereotypes and values beyond the subject supposed to be solved.Este ensayo analiza los componentes de la publicidad centrándose en el análisis iconológico y en concreto en los estereotipos humanos más frecuentes con la intención de ver los modelos sociales, culturales y económicos susbsistentes. A partir de un desarrollo histórico podemos observar cómo se profundizan y cimentan determinados valores en la sociedad occidental a partir del reclamo publicitario

Spontaneous circadian rhythms in a cold-Adapted natural isolate of Aureobasidium pullulans

Indexación: Scopus.Circadian systems enable organisms to synchronize their physiology to daily and seasonal environmental changes relying on endogenous pacemakers that oscillate with a period close to 24 h even in the absence of external timing cues. The oscillations are achieved by intracellular transcriptional/translational feedback loops thoroughly characterized for many organisms, but still little is known about the presence and characteristics of circadian clocks in fungi other than Neurospora crassa. We sought to characterize the circadian system of a natural isolate of Aureobasidium pullulans, a cold-Adapted yeast bearing great biotechnological potential. A. pullulans formed daily concentric rings that were synchronized by light/dark cycles and were also formed in constant darkness with a period of 24.5 h. Moreover, these rhythms were temperature compensated, as evidenced by experiments conducted at temperatures as low as 10 °C. Finally, the expression of clock-essential genes, frequency, white collar-1, white collar-2 and vivid was confirmed. In summary, our results indicate the existence of a functional circadian clock in A. pullulans, capable of sustaining rhythms at very low temperatures and, based on the presence of conserved clock-gene homologues, suggest a molecular and functional relationship to well-described circadian systems.https://www.nature.com/articles/s41598-017-14085-

La promoción de salud en la comunidad

En el presente trabajo se analiza el papel que desempeñan las universidades en la transformación y el desarrollo social, con énfasis en el rol de la extensión universitaria como núcleo clave y expresión de su pertinencia, también se estudia el impacto social en la comunidad. La extensión universitaria es una de las vías en donde la Universidad demuestra su carácter de centro cultural significativo para el desarrollo. En el trabajo se valora su importancia en la sociedad, definiciones del concepto de extensión universitaria, se analizan conceptos directamente relacionados con la temática de manera determinante

Challenges and opportunities of groundwater resources management: Examination of the problematic access to water in Central Valleys of Oaxaca, Mexico

Groundwater resources, in addition to being subject to quantitative management mechanisms, are the main source of water supply for certain users. The access, the use and the exploitation of these resources favor the emergence of tensions between governmental and social spheres. The existence of a water withdrawal ban decree and the lack of recognition of the capacity of participation of community actors are factors that potentiate the emergence of conflict. In this sense, organized indigenous leadership favors the formulation of alternative strategies to adapt a long-standing decree. The case of the problematic water access in Central Valleys of Oaxaca teaches us that the great opportunity to adapt groundwater management relies on the community capacities to formulate public policy recommendations aimed at ad hoc water resources management

La publicidad como reclamo: valores y antivalores sociales.

This paper analyses the contents of advertising from a historical point of view and from an iconological perspective, trying to decode the stereotypes and values beyond the subject supposed to be solved

The Visibility of Citizen Participation and the Invisibility of Groundwater in Mexico

The aim of this study is to assess the social responses to protect and prevent conflict over groundwater resources. By means of a qualitative method and a study of the Valles Centrales and Valle de Mexicali aquifers in Mexico, we found that centralized water management, citizens’ socio-environmental awareness, an asymmetry of power between stakeholders, an imposition of government policies, and economic interests are all contributory factors to emerging conflicts over groundwater. However, citizen participation has developed to provide organized individuals with an opportunity to influence public decisions through the recognition of their rights with respect to water inequalities. However, a limitation of the study is the illustration of conflictual events through the interpretation of qualitative data and of the opinions of the actors studied. However, the construction of hydrosocial territory in these aquifers is concretized in the potentiality and significance of citizen participation in promoting sustainable and socially responsible public groundwater policy at the regional level

Electronic transport and vibrational modes in the smallest molecular bridge: H2 in Pt nanocontacts

We present a state-of-the-art first-principles analysis of electronic transport in a Pt nanocontact in the presence of H2 which has been recently reported by Smit et al. in Nature 419, 906 (2002). Our results indicate that at the last stages of the breaking of the Pt nanocontact two basic forms of bridge involving H can appear. Our claim is, in contrast to Smit et al.'s, that the main conductance histogram peak at G approx 2e^2/h is not due to molecular H2, but to a complex Pt2H2 where the H2 molecule dissociates. A first-principles vibrational analysis that compares favorably with the experimental one also supports our claim .Comment: 5 pages, 3 figure

Faraday effect : a field theoretical point of view

We analyze the structure of the vacuum polarization tensor in the presence of a background electromagnetic field in a medium. We use various discrete symmetries and crossing symmetry to constrain the form factors obtained for the most general case. From these symmetry arguments, we show why the vacuum polarization tensor has to be even in the background field when there is no background medium. Taking then the background field to be purely magnetic, we evaluate the vacuum polarization to linear order in it. The result shows the phenomenon of Faraday rotation, i.e., the rotation of the plane of polarization of a plane polarized light passing through this background. We find that the usual expression for Faraday rotation, which is derived for a non-degenerate plasma in the non-relativistic approximation, undergoes substantial modification if the background is degenerate and/or relativistic. We give explicit expressions for Faraday rotation in completely degenerate and ultra-relativistic media.Comment: 20 pages, Latex, uses axodraw.st