Privileged Mexican migrants in Europe: Distinctions and cosmopolitanism on social networking sites

This article examines the ways in which classed distinctions are related to the construction of increasingly cosmopolitan identities on Social Networking Sites (SNSs) amongst Mexican migrants from relatively privileged backgrounds living in Europe. It centres on how user demographics shape many of the concerns and outcomes pertaining to the use of SNSs. It considers the implications of the fact that SNSs are predominantly used by a demographic considered as non-marginalized, mobile and as possessing relatively privileged economic, cultural and social backgrounds. It analyses the ways in which online identities are constructed on SNS profiles using multimedia content to represent specific lifestyles and cultural practices that are used to make distinctions amongst participants, and are related to social, cultural and economic capital. A critical analysis is presented as to how users represent cosmopolitan identities online through the display of tastes and lifestyles in SNS content and into how these representations relate to users’ privileged positions in Mexican society. Bourdieu’s concept of distinction is used to emphasize the utility of considering different forms of capital in analysing the use of SNSs and profile content generated by a specific demographic. This article demonstrates how the analysis of SNS use may contribute towards an understanding of how classed distinctions are made based on this use and of how users negotiate the posting of profile content according to these distinctions and manage (select, edit and share) their representations

Social Evolution: New Horizons

Cooperation is a widespread natural phenomenon yet current evolutionary thinking is dominated by the paradigm of selfish competition. Recent advanced in many fronts of Biology and Non-linear Physics are helping to bring cooperation to its proper place. In this contribution, the most important controversies and open research avenues in the field of social evolution are reviewed. It is argued that a novel theory of social evolution must integrate the concepts of the science of Complex Systems with those of the Darwinian tradition. Current gene-centric approaches should be reviewed and com- plemented with evidence from multilevel phenomena (group selection), the constrains given by the non-linear nature of biological dynamical systems and the emergent nature of dissipative phenomena.Comment: 16 pages 5 figures, chapter in forthcoming open access book "Frontiers in Ecology, Evolution and Complexity" CopIt-arXives 2014, Mexic

On utilization of elliptical rings in assessing cracking tendency of concrete

A new experimental method by utilizing elliptical rings to replace circular rings recommended by ASTM and AASHTO was explored for assessing cracking potential of concrete and other cement-based materials under restrained condition. A series of thin and thick elliptical concrete rings were tested alongside circular ones until cracking. Cracking age, position, and propagation were carefully examined. It is found that thin elliptical rings with appropriate geometry can initiate cracks quicker than circular ones, which is desirable for accelerating the ring test. However, thick elliptical rings seem not to exhibit a desirable geometry effect of accelerating ring test compared with circular ones. There were multiple visible cracks that occurred in an elliptical ring and some cracks were initiated but did not propagate through the ring wall. In comparison, there was only one crack in the circular rings. Finally, the features of multiple cracks in restrained elliptical rings were examined and their impact on interpreting elliptical ring test results was elaborated. © 2014 4th International Conference on the Durability of Concrete Structures

Competition and interaction of polydisperse bubbles in polymer foams

The e®ects of interactions between bubbles of di®erent sizes during bubble growth in a polymeric foam are investigated. Two models are used: a two-dimensional sim-ulation in which both the e®ects of gas di®usion through the polymer and bubble interactions through °uid stresses are included, and a three-dimensional model in which bubbles are assumed to interact only through direct competition for gas, and di®usion of gas into the bubbles is instantaneous. In the two-dimensional model, two di®erent bubble sizes are used in a hexagonal array. For slow gas di®usion, the additional polymer stresses have little e®ect on the ¯nal bubble size distribution. For faster gas di®usion the growth occurs in two phases, just as was found in earlier work for isolated bubbles: an initial rapid viscous phase and a later phase controlled by the rate of polymer relaxation. In this later phase, polymers in the windows between neighbouring bubbles become highly stretched and these regions of high stress determine the dynamics of the growth. In the three-dimensional model we consider the e®ects of rheology on a pair of di®erent-sized spherical bubbles, interacting only through competition for available gas. Viscoelastic e®ects result in a wider distribution of bubble volumes than would be found for a Newtonian °uid. Key words: Polymeric °uid; bubble growth; foam; bubble interactions; size distribution ¤ To whom correspondence should be addressed

The effective temperature

This review presents the effective temperature notion as defined from the deviations from the equilibrium fluctuation-dissipation theorem in out of equilibrium systems with slow dynamics. The thermodynamic meaning of this quantity is discussed in detail. Analytic, numeric and experimental measurements are surveyed. Open issues are mentioned.Comment: 58 page

Analysis of the conformational profiles of fenamates shows route towards novel, higher accuracy, force-fields for pharmaceuticals

In traditional molecular mechanics force fields, intramolecular non-bonded interactions are modelled as intermolecular interactions, and the form of the torsion potential is based on the conformational profiles of small organic molecules. We investigate how a separate model for the intramolecular forces in pharmaceuticals could be more realistic by analysing the low barrier to rotation of the phenyl ring in the fenamates (substituted N-phenyl-aminobenzoic acids), that results in a wide range of observed angles in the numerous fenamate crystal structures. Although the conformational energy changes by significantly less than 10 kJmol-1 for a complete rotation of the phenyl ring for fenamic acid, the barrier is only small because of small correlated changes in the other bond and torsion angles. The maxima for conformations where the two aromatic rings approach coplanarity arise from steric repulsion, but the maxima when the two rings are approximately perpendicular arise from a combination of an electronic effect and intramolecular dispersion. Representing the ab initio conformational energy profiles as a cosine series alone is ineffective; however, combining a cos2ξ term to represent the electronic barrier with an intramolecular atom-atom exp-6 term for all atom pairs separated by three or more bonds (1-4 interactions) provides a very effective representation. Thus we propose a new, physically motivated, generic analytical model of conformational energy, which could be combined with an intermolecular model to form more accurate force-fields for modelling the condensed phases of pharmaceutical-like organic molecules