On the computation of reducible invariant tori on a parallel computer

We present an algorithm for the computation of reducible invariant tori of discrete dynamical systems that is suitable for tori of dimensions larger than 1. It is based on a quadratically convergent scheme that approximates, at the same time, the Fourier series of the torus, its Floquet transformation, and its Floquet matrix. The Floquet matrix describes the linearization of the dynamics around the torus and, hence, its linear stability. The algorithm presents a high degree of parallelism, and the computational effort grows linearly with the number of Fourier modes needed to represent the solution. For these reasons it is a very good option to compute quasi-periodic solutions with several basic frequencies. The paper includes some examples (flows) to show the efficiency of the method in a parallel computer. In these flows we compute invariant tori of dimensions up to 5, by taking suitable sections

First time III-nitride photonic crystals

AbstractThe development of compound semiconductor photonic crystals (PCs) based on infrared devices (wavelengths longer than 700nm) has been quite rapid during the last few years, mostly focused on Indium Phosphide materials for optical communication uses in the 1.3 and 1.55nm transmission windows. The property being exploited is the ability of lattices of varying refractive index to form photonic bandgaps in which the propagation of specific light wavelengths is prohibited or modified. This property can be used to control or enhance the spontaneous emission and or light extraction efficiencies from both active and passive devices (including LEDs)

Educational resource scheduling based on socio-inspired agents

Revised Selected Papers of 4th International Conference, ICSOFT 2009, Sofia, Bulgaria, July 26-29, 2009.The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-20116-5_17Scheduling a set of constrained resources is a difficult task, specially when there is no clear definition of ‘optimal’. When the constraints depend not only on physical or temporal issues but also in human desires or preferences the task gets harder. This is the case of educational resources, for example when a set of students must be distributed into a limited set of laboratories to attend to periodical practical sessions, in this case weekly. The preferences of the students may vary during the process for reasons such as the number of people already in that group. This paper presents a socio–inspired solution implemented as a multiagent system. The agents enroll themselves in the lab sessions based on their preferences and negotiate with other agents, using the resources they already have, to obtain desired groups that were already full.This work has been partially supported by the Spanish Ministry of Science and Innovation under grants TIN 2007-65989, TIN 2007-64718, and TIN2010-19872

Influence of the Slaughter Method on the Hygienic Quality of Beef Cattle Meat and Animal Welfare Biomarkers

The main objective of this research was to carry out a comparative study between different types of slaughter in beef cattle with and without stunning. In addition, the hygienic quality of the obtained meat was determined through microbiological analysis and the animal welfare at the time of slaughtering was assessed by means of physiological parameters. A total of 52 blood samples collected at the slaughterhouse during slaughter (10 for each type of slaughter: regular, halal, and halal with stunning; 10 at the time of resting; and 12 from rotating box slaughter) were analysed for physiological parameters indicating animal welfare status, namely, glucose, cortisol, lactate dehydrogenase (LDH) and creatine kinase (CK). In addition, the meat from 30 of the above animals was analysed for aerobic mesophilic bacteria, enterobacteria and coliforms. Moreover, a radiological study of the possible skull damage due to the non-penetrative captive bolt used at the time of stunning in the halal rite slaughter was carried out. A significance difference (p < 0.05) in the microbiological counts per type of slaughter was observed. It was proven that the amounts of glucose, LDH, CK, and cortisol in plasma were influenced (p < 0.05) by the type of slaughter. The halal rite slaughter using stunning with a non-penetrative captive bolt resulted in the best hygienic quality of meat and obtained the lowest values for all animal welfare biomarkers

Uncertainties in Retrieval of Remote Sensing Reflectance from Ocean Color Satellite Observations

Ocean Color radiometry uses remote sensing to interpret ocean dynamics by retrieving remote sensing reflectance () from satellite imagery at different scales and over different time periods. spectrum characterizes the ocean color that we observe, and from which we can discern concentrations of chlorophyll, organic and inorganic particles, and carbon fluxes in the ocean and atmosphere. is derived from the total radiance at the top of the atmosphere (TOA). However, it only represents up to ten percent of the total signal. Hence, the retrieval of from the total radiance at TOA involves the application of atmospheric correction (AC) algorithms, which include accurate modeling of Rayleigh and aerosol scattering, glint, and water variability. Each of these components yields uncertainties in the retrieved value of , especially in the blue bands. It is important to understand the main sources of uncertainties in , as uncertainties propagate into the retrieval of water parameters, which in turn inform climate models. In this study, a model was developed that quantifies the uncertainties of the main components in the current AC algorithm and used to analyze holistically the influence of these components on the uncertainties spatially and temporally in different water types taking advantage of the spectral differences between the components. The uncertainties were determined by comparing satellite and in situ data, with the in situ data obtained from the AErosol RObotic NETwork - Ocean Color (AERONET-OC) around the Northern Hemisphere and the Marine Optical BuoY (MOBY), Lanai, Hawaii. The satellite sensor data are from the Visible Infrared Imaging Radiometer Suite (VIIRS) on the S-NPP platform, the Ocean and Land Colour Instruments (OLCI) on Sentinel 3A and 3B, and the Operational Land Imager (OLI) on Landsat 8. Results showed that the Rayleigh component (molecular scattering and surface effects) is the main source of uncertainties for all water types, followed by water variability, which is more influential in coastal areas. The contributions of other components, including aerosol scattering, are usually smaller. In addition, wind speed ranges can influence results, especially in coastal regions. Across spatial scales, water variability played a dominant role in uncertainty and increased proportionally to the ground sampling distance

Allocating educational resources through happiness maximization and traditional CSP approach

This is an electronic version of the paper presented at the 4th International Conference on Software and Data Technologies, held in Sofia on 2009An instance of an Educational Resources Allocation (ERA) problem is the distribution of a set of students in different laboratories. This can be a complex and dynamic problem if non-quantitative considerations (i.e. how close the final allocation is to the student preferences or desires) are involved in the decision process. Traditionally, different approaches based on Constraint-Satisfaction techniques and Multi-agent negotiation have been applied to the general problem of Resource Allocation. This paper shows how a Multi-agent approach can be used to model and simulate the assignment of sets of students to several predefined laboratories, by using their preferences to guide the allocation process. This approach aims at finding new solutions that try to satisfy individual student needs with no knowledge about the general allocation problem. The paper shows some experimental results and a comparison, between a CSP-based solution modeled in CHOCO, a CSP Java-based library, and a Multi-agent model implemented using MASON, a multi-agent simulation platform.This work has been supported by research projects TIN2007-65989 and TIN2007-64718. We also thank IBM for its support to the Linux Reference Cente

Effects of ripening stages and of plant vegetative vigor on the phenolic composition of grapes (Vitis vinifera L.) cv. Cabernet Sauvignon in the Maipo Valley (Chile)

Quantitative changes in the composition of phenolic compounds in skins and seeds were determined during ripening of grape of Cabernet Sauvignon vines growing with low, medium or high vigor. Compounds in the skins were gallic and syringic acid, (+)-catechin, (-)-epicatechin, quercetin-3-galactoside, quercetin-3-rutinoside, quercetin-3-arabinglucoside, quercetin-3-glucoside, and quercetin-3-rhamnoside, kaempferol-3-rutinoside and kaempferol-3-glucoside. The following compounds were identified in seeds: gallic acid, (+)-catechin, (-)-epicatechin, and procyanidins B1, B2, B3 and B4. The composition of compounds depended on the stage of ripening and vigor. No clear relationship was found between groups of compounds.

Physical modeling of a stepped spillway without sidewalls

The interest of a consulting company in designing stepped spillways in roller compacted concrete (RCC) dams led us to propose the possibility of building this type of spillway without sidewalls. Previous research on stepped spillways has focused on characterizing the complex hydraulic behavior of flow on these structures, as well as design criteria. Such studies have usually been conducted on stepped spillways with a constant width along the spillway, that is, with sidewalls. In the present work, we report the results of the physical modeling of a generic stepped spillway without sidewalls (slope 1v:0.8h). In general terms, the lack of sidewalls produces a lateral expansion of water and therefore a non-uniform longitudinal and transversal discharge distribution. Consequently, the flow type, characteristic water depth, velocity, air concentration, and pressure fields change along and across the spillway. The resulting data demonstrate that the distribution of the different variables studied depend on the specific discharge at the entrance and the spillway heightPeer ReviewedPostprint (author's final draft

La gestión de la responsabilidad social corporativa : el caso Unilever España /

En los últimos años hemos visto que, tanto en nuestro país como a nivel internacional, han salido a la luz escándalos empresariales que han provocado una creciente desconfianza de la ciudadanía hacia las empresas. Esta pérdida de confianza, junto a otros cambios producidos en el entorno empresarial, han llevado a las organizaciones a cambiar su manera de actuar, ya que han comprendido que no son un ente aislado, sino que forman parte de la sociedad y que su existencia a largo plazo depende de su legitimación ante ésta. Y para ello es imprescindible recuperar la confianza de los ciudadanos. Ante esta situación, la responsabilidad social corporativa (RSC) se presenta como una vía para restablecer el equilibrio entre empresa y sociedad. Por tanto es imprescindible conocer cómo debe ser gestionada. En este sentido, la presente tesis doctoral tiene como objeto de estudio analizar la gestión de la RSC de las organizaciones desde el enfoque de la disciplina de la comunicación corporativa. Para ello se ha realizado una investigación basada en el método del caso, concretamente el caso de la RSC de Unilever España. Las técnicas e instrumentos de recolección de datos han sido: revisión de documentos, 11 entrevistas a agentes clave en la gestión de la RSC y 7 observaciones. Los resultados demuestran que la RSC de Unilever supone un planteamiento estratégico alineado con la visión, misión y valores de la compañía. Su gestión, aunque recae en el Departamento de Comunicación, implica a todos los departamentos, por lo que se gestiona de manera transversal en la organización. También se ha podido constatar que la gestión de la RSC de Unilever España se realiza siguiendo los principios básicos de transparencia, materialidad, verificabilidad, visión amplia, mejora continua y naturaleza social de la organización.In the last years we have seen that, in our country and at international level as well, some corporate scandals has raised-up, which has created an up-growing lack of confidence from the citizenship towards corporations. This lack of confidence, in addition to other changes in the corporation environments, has led organizations to change their way to behalf, due to the fact that they have understood that they are not isolated entities, but that they belong to the society and their existence at long-term depends on the legitimation of the society. And for that it is essential to recover the trust of the citizenship. Against this challenge, Corporate Social Responsibility (CSR) is a way to re-establish the balance between enterprises and society. This is the reason why it is essential understand how it has to be managed. In this sense, the present thesis has as object of study to analyse of the CSR management on the corporations from the point of view of the corporate communication discipline. In that way, an investigation has been carried out based on the case study, specifically in the CSR Unilever Spain case. Technics and instruments of data collection has been: documentary revision, eleven interviews with key agents on CSR management, and seven observations. Results proof that CSR at Unilever implies a strategic mind-set perfectly aligned with the vision, the mission and the values of the company. Even though it's management belong to the communication department, it involves all the departments, that's way it is managed in an transversal way inside the corporation. As matter of fact it's been demonstrated that CSR management at Unilever Spain is done following the basic principles of transparency, materiality, verifiability, wide vision, continuous improvement, and social nature of the organization

The effect of Helicobacter pylori infection on growth velocity in young children from poor urban communities in Ecuador

SummaryObjectiveTo characterize the potential effects of Helicobacter infections on growth velocity in low socioeconomic status young children in a developing country.MethodsChildren were recruited in poor suburbs of Quito, Ecuador. Normally nourished, mildly and substantially malnourished children (defined using weight-for-age Z-scores at recruitment) formed equal strata. Six height and weight measurements were collected during one year. Enrollment and exit serum samples were analyzed for anti-Helicobacter IgG and exit non-diarrheal feces tested for Helicobacter antigen.ResultsAmong 124 participants (enrollment age 19±9 months), 76 (61%) excreted fecal antigen at exit (were infected). Of these, 44 were seropositive at least once (chronic infections) and 32 tested seronegative both times (new or acute phase infections). The adjusted linear growth velocity during follow-up in children with new infections was reduced by 9.7 (3.8, 15.6) mm/year compared to uninfected controls and 6.4 (0.0, 12.9) mm/year compared to children with chronic infections. The effects of Helicobacter infections on ponderal growth were not significant.ConclusionThese results suggest that linear growth velocity is reduced in young children during the initial phase of Helicobacter infection