Energy conversion in Purple Bacteria Photosynthesis

The study of how photosynthetic organisms convert light offers insight not only into nature's evolutionary process, but may also give clues as to how best to design and manipulate artificial photosynthetic systems -- and also how far we can drive natural photosynthetic systems beyond normal operating conditions, so that they can harvest energy for us under otherwise extreme conditions. In addition to its interest from a basic scientific perspective, therefore, the goal to develop a deep quantitative understanding of photosynthesis offers the potential payoff of enhancing our current arsenal of alternative energy sources for the future. In the following Chapter, we consider the trade-off between dynamics, structure and function of light harvesting membranes in Rps. Photometricum purple bacteria, as a model to highlight the priorities that arise when photosynthetic organisms adapt to deal with the ever-changing natural environment conditions.Comment: Chapter, to appear in Photosynthesis 2011, INTEC

Memory in the Photon Statistics of Multilevel Quantum Systems

The statistics of photons emitted by single multilevel systems is investigated with emphasis on the nonrenewal characteristics of the photon-arrival times. We consider the correlation between consecutive interphoton times and present closed form expressions for the corresponding multiple moment analysis. Based on the moments a memory measure is proposed which provides an easy way of gaging the non-renewal statistics. Monte-Carlo simulations demonstrate that the experimental verification of non-renewal statistics is feasible.Comment: 5 pages, 3 figure

Can family firms overcome better an economic crisis carrying out innovations with universities?

Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech.According to previous researches, the intersection between the concepts of Family Business (FB) and Innovation is not sufficiently studied and developed and new knowledge should be drawn on how the characteristics of a FB influence the possibilities and attitudes towards innovation; or if there are differences or not among them in the way of innovating. Of all the possible variables that can influence the innovation of FBs, this study will focus on the environment in which these types of companies operate (Padilla-Meléndez et al., 2015). After a review of the literature, it can be said that a deeper analysis of this this field of study, being the reasons twofold. First, in order to know if family-type businesses depend more or less on the environment than other companies (Donckels & Fröhlich, 1991). Second, to examine if the environment is a determining variable for the decisions taken by the company's executives (Dess et al., 1997) Besides, Open Innovation is a relatively recent paradigm for innovation management (Chesbrough, 2006; Gassmann, 2006). And more specifically, universities and research institutions have been widely studied in the literature from several different aspects (Agrawal, 2001; Geiger, 2005; Hall, 2004; McMillan & Hamilton, 2003; Poyago-Theotoky et al., 2002), and it can be concluded that cooperation with these institutions, such as universities, is more beneficial than cooperation with other companies (Arvanitis & Bolli, 2011; Ayari, 2010; Belderbos et al., 2004; Bercovitz & Feldman, 2007; Blanco Hernández, 2014; Fabrizio, 2009; Fitjar & Rodríguez-Pose, 2016

Concrete constitutive model, calibration and applications

A methodology has been developed for characterising the mechanical behaviour of concrete, based on the damaged plasticity model, enriched with a user subroutine (V)USDFLD in order to capture better the ductility of the material under moderate confining pressures. The model has been applied in the context of the international benchmark IRIS_2012, organised by the OECD/NEA/CSNI Nuclear Energy Agency, dealing with impacts of rigid and deformable missiles against reinforced concrete targets. A slightly modified version of the concrete damaged plasticity model was used to represent the concrete. The simulation results matched very well the observations made during the actual tests. Particularly successful predictions involved the energy spent by the rigid missile in perforating the target, the crushed length of the deformable missile, the crushed and cracked areas of the concrete target, and the values of the strains recorded at a number of locations in the concrete slab

Configuración de VLANS desarrollo de prácticas en Packet Tracer curso de profundización Cisco CCNA2

Dada la importancia de la presente unidad para el desarrollo y puesta en marcha de los protocolos de seguridad, implementación de enrutamiento en IPv4 e IPv6, procesamiento de paquetes de bloqueos, accesos y peticiones de los usuarios, asignaciones de direccionamiento estático y dinámicos, establecimiento de la NAT con sus respectivas sobrecarga tanto dinámica como nativa, configuraciones de la red y PAT, Configuración de OSPFv2 y OSPFv3 con sus áreas resueltas, y de igual manera la configuración de una ACL en VTY Líneas.Given the importance of this unit for the development and implementation of security protocols, implementation of routing in IPv4 and IPv6, blocking packet processing, access and user requests, static and dynamic addressing assignments, establishment of NAT with its respective dynamic and native overload, network and PAT configurations, OSPFv2 and OSPFv3 configuration with their resolved areas, and likewise the configuration of an ACL in VTY Lines

Fecal sacs attract insects to the nest and provoke an activation of the immune system of nestlings

Background: Nest sanitation is a widespread but rarely studied behavior in birds. The most common form of nest sanitation behavior, the removal of nestling feces, has focused the discussion about which selective pressures determine this behavior. The parasitism hypothesis, which states that nestling fecal sacs attract parasites that negatively affect breeding birds, was proposed 40 years ago and is frequently cited as a demonstrated fact. But, to our knowledge, there is no previous experimental test of this hypothesis. Results: We carried out three different experiments to investigate the parasitism hypothesis. First, we used commercial McPhail traps to test for the potential attraction effect of nestling feces alone on flying insects. We found that traps with fecal sacs attracted significantly more flies (Order Diptera), but not ectoparasites, than the two control situations. Second, we used artificial blackbird (Turdus merula) nests to investigate the combined attraction effect of feces and nest materials on arthropods (not only flying insects). Flies, again, were the only group of arthropods significantly attracted by fecal sacs. We did not detect an effect on ectoparasites. Third, we used active blackbird nests to investigate the potential effect of nestling feces in ecto- and endoparasite loads in real nestlings. The presence of fecal sacs near blackbird nestlings did not increase the number of louse flies or chewing lice, and unexpectedly reduced the number of nests infested with mites. The endoparasite prevalence was also not affected. In contrast, feces provoked an activation of the immune system as the H/L ratio of nestlings living near excrements was significantly higher than those kept under the two control treatments. Conclusions: Surprisingly, our findings do not support the parasitism hypothesis, which suggests that parasites are not the main reason for fecal sac removal. In contrast, the attraction of flies to nestling feces, the elevation of the immune response of chicks, and the recently described antimicrobial function of the mucous covering of fecal sacs suggest that microorganisms could be responsible of this important form of parental care behavior (microbial hypothesisPeer reviewe

Concrete Swelling in a Double Curvature Dam

Se describe el problema del hinchamiento del hormigón en las presas de doble curvatura. Several chemical reactions are able to produce swelling of concrete for decades after its initial curing, a problem that affects a considerable number of concrete dams around the world. The object of the work reported is to simulate the underlying mechanisms with sufficient accuracy to reproduce the past history and to predict the future evolution reliably. Having studied the available formulations, that considered to be more promising was adopted and introduced via user routines in a commercial finite element code. It is a non isotropic swelling model,compatible with the cracking and other non-linearities displayed by the concrete. The paper concentrates on the work conducted for a double-curvature arch dam. The model parameters were determined on the basis of some parts of the dam’s monitored histories, reliability was then verified using other parts and, finally, predictions were made about the future evolution of the dam and its safety margin

Effect of Concrete Swelling on the Equilibrium and Displacements of an Arch Dam

The Kariba dam is undergoing concrete expansion as a result of an alkali-aggregate reaction. The model adopted to simulate the process is explained in the paper; it is based on the model first proposed by Ulm et al, as later modified by Saouma and Perotti. It has been implemented in the commercial finite element code Abaqus and applied to solve the benchmark problem. The parameters of the model were calibrated using the data recorded up to 1995. The calibrated model was then used for predicting the evolution of the dam up to the present date. Apart from this prediction the paper offers a number of conclusions, such as the fact that the stress level appears to have a major influence on the expansion process; and it presents some suggestions to improve the formulation of the benchmark, such as providing temperature data and widening the locations and conditions of the data employed in the calibratio

Fluid-Structure Interaction in Civil Engineering Structures

The problems being addressed involve the dynamic interaction of solids (structure and foundation) with a liquid (water). Various numerical procedures are reviewed and employed to solve the problem of establishing the expected response of a structure subjected to seismic excitations while duly accounting for those interactions. The methodology is applied to the analysis of dams, lock gates, and large storage tanks, incorporating in some cases a comparison with the results produced by means of simplified analytical procedures