4,059 research outputs found

    How to distinguish between a block cipher and a random permutation by lowering the input entropy

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    IEEE 35th International Carnahan Conference on Security Technology. Londres, 16-19 October 2001A novel cryptanalysis technique is presented, and its suitability for distinguishing a block cipher algorithm or a hash function from a random permutation is explained. Additionally, we propose a genetic algorithm based implementation and show some preliminary results of these ideas on reduced rounds versions of the block cipher TEA

    ¿Las características centrales del puesto son un antecedente de la satisfacción laboral?: Un estudio con profesores universitarios

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    La satisfacción laboral ocupa un lugar central en la consideración de la experiencia laboral, lo que ha dado lugar a numerosas investigaciones y diversidad de instrumentos de evaluación. A nivel práctico y aplicado, el interés de la investigación se ha centrado en identificar los antecedentes de la satisfacción, lo cual permitirá y facilitará la intervención. El objetivo de este trabajo es analizar el rol de los recursos laborales (características centrales del puesto) y variables sociodemográficas (género y tipo de contrato) como antecedentes de la satisfacción laboral en el marco del Modelo de Demandas y Recursos laborales. La muestra está compuesta por 39 profesores universitarios de la Universidad Jaume I, donde el 43,6 % son mujeres. La edad promedio de los participantes es de 42,31 años (DT=7,27). En cuanto a la relación contractual, puede ser P. Titular de universidad, P. Titular de escuela universitaria, P. Contratado doctor, pic/Ayudante Doctor Tipo I y Tipo II, Ayudante y P. Asociado laboral. El instrumento utilizado es la adaptación del JDS o Job Diagnostic Survey. Los análisis muestran diferencias estadísticamente significativas: en función del género tanto en la Satisfacción como en algunos recursos laborales (Identidad de tareas e Importancia de las tareas); y en función del tipo de relación contractual tanto en Satisfacción como en Variedad de destrezas. Los análisis de regresión muestran como la relación contractual, la Importancia de las tareas y la Retroalimentación del puesto explican la Satisfacción laboral del profesor universitario. Estos datos aportan información relevante para posibles intervenciones que favorezcan y optimicen las condiciones de trabajo y con ello la satisfacción de los profesores universitarios.The job satisfaction takes up a central place in the consideration´s work experience, which produces numerous researches and variety instruments of evaluation. From a practical point of view, research has focused on identifying the antecedents of satisfaction which will allow and facilitate the intervention. The aim of this paper is to analyze the role of work resources (main characteristics of job position) and sociodemographic variables (gender and type of contract) as antecedents of job satisfaction in the framework of the Labours demands and resources Model. The sample is made up of 39 academics from the University Jaume I (43.6 % are women). The average age of participants is 42.31 years (DT = 7.27). The contractual relationship can be: University P. Holder, P. Holder School, P. Contracted Doctor, PIC / Assistant Doctor Type I and Type II, Assistant and Associate P. labor. The instrument used is the adaptation of the Job Diagnostic Survey or JDS. Analysis shows statistically significant differences: gender in both satisfaction and some labor resources (Task identity and Importance of the tasks), and depending on the type of contractual relationship satisfaction in both Variety and skills. Regression analyzes show how the Contractual relationship, the Importance of the tasks and the Feedback explain the Job satisfaction of university professors. These data provide important information for possible interventions to facilitate and optimize the working conditions and thus the satisfaction of university professors

    Antioxidant activity of alkyl gallates and glycosyl alkyl gallates in fish oil in water emulsions: Relevance of their surface active properties and of the type of emulsifier

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    The antioxidant activity of gallic acid and a series of alkyl gallates (C4-C18) and glycosylated alkyl gallates (C4-C18) on fish oil-in-water emulsions was studied. Three types of emulsifiers, lecithin, Tween-20 and sodium dodecyl sulphate (SDS) were tested. A nonlinear behavior of the antioxidant activity of alkyl gallates when increasing alkyl chain length was observed for emulsions prepared with lecithin. Medium-size alkyl gallates (C6-C12) were the best antioxidants. In contrast, for emulsions prepared with Tween-20, the antioxidants seem to follow the polar paradox. Glucosyl alkyl gallates were shown previously to be better surfactants than alkyl gallates. Nevertheless, they exhibited a worse antioxidant capacity than their corresponding alkyl gallates, in emulsions prepared with lecithin or Tween-20, indicating the greater relevance of having three OH groups at the polar head in comparison with having improved surfactant properties but just a di-ortho phenolic structure in the antioxidant

    PERSPECTIVAS DE LOS GRADUADOS UNIVERSITARIOS NO TRADICIONALES SOBRE LAS PRÁCTICAS: COMPETENCIAS, EMPLEABILIDAD Y TRANSICIÓN AL MERCADO LABORAL EN ESPAÑA

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    Employability has become a principal aim of universities in Europe and beyond. In this context, internships are a central strategy for the promotion of employability. This qualitative study, conducted in Spain and based on biographical-narrative interviews, focuses on the voices and experiences of 25 non-traditional university graduates, all from the field of social sciences, on employability, internships, and skills. The data collected are analysed based on four categories: training received at the university; the influence of internships on employability; assessment of the internships; and perspectives on skills in demand and mismatches between graduate profiles and labour market demands. Graduates feel the internships has not helped in the transition to the workplace. Graduates have criticised the lack of connection between university and workplace, the short duration of internships, and the insufficient focus on professional and transversal skills. The results also suggest that universities should develop more initiatives to improve internships, working in coordination with employers and other stakeholders.A empregabilidade tornou-se um objetivo principal das universidades na Europa e fora dela. Neste contexto, os estagios são uma estratégia central para a promoção da empregabilidade. Este estudo qualitativo, realizado na Espanha e baseado em entrevistas biográfico-narrativas, enfoca as vozes e experiências de 25 graduados universitários não tradicionais, todos do campo das ciências sociais, sobre empregabilidade, estágios e habilidades. Os dados coletados são analisados com base em quatro categorias: treinamento recebido na universidade; influência dos estágios na empregabilidade; avaliação dos estágios; e perspectivas sobre habilidades em demanda e desencontros entre perfis de graduados e demandas do mercado de trabalho. Os estagiários sentem que os estágios não têm ajudado na transição para o mercado de trabalho. Os graduados têm criticado a falta de conexão entre universidade e mercado de trabalho, a curta duração dos estágios e o foco insuficiente nas habilidades profissionais e transversais. Os resultados também sugerem que as universidades deveriam desenvolver mais iniciativas para melhorar os estágios, trabalhando em coordenação com empregadores e outras partes interessadas.    La empleabilidad se ha convertido en un objetivo importante de las universidades en Europa y fuera de ella. En este contexto, las prácticas son una estrategia fundamental para la promoción de la empleabilidad. Este estudio cualitativo, realizado en España y basado en entrevistas biográficas, se centra en las voces y experiencias de 25 graduados universitarios no tradicionales, todos ellos del ámbito de las ciencias sociales, sobre la empleabilidad, las prácticas y las competencias. Los datos recogidos se analizan sobre la base de cuatro categorías: la formación recibida en la universidad; la influencia de las prácticas en la empleabilidad; la evaluación de las prácticas; y las perspectivas sobre las competencias demandadas y los desajustes entre los perfiles de los graduados y las demandas del mercado de trabajo. Los graduados consideran que las prácticas no han ayudado a la transición al mercado laboral. Los graduados han criticado la falta de conexión entre la universidad y el mercado laboral, la corta duración de las prácticas y la insuficiente atención a las competencias profesionales y transversales. Los resultados también sugieren que las universidades deberían desarrollar más iniciativas para mejorar las prácticas, trabajando en coordinación con los empleadores y otros grupos interesados. &nbsp

    Testing caffeic acid as a natural antioxidant in functional fish-fibre restructured products

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    7 páginas, 4 figuras, 5 tablasThe antioxidant effectiveness of caffeic acid addition to minced fish muscle with or without wheat dietary fibre added was studied. Wheat dietary fibre showed a significant prooxidant effect on minced fish muscle during chilled storage that was significantly inhibited in presence of 100 mg/kg caffeic acid. In samples containing caffeic acid and wheat dietary fibre, lipid oxidation was completely inhibited after 10 days. Results obtained from the instrumental texture profile analysis showed that the inclusion of wheat dietary fibre with or without caffeic acid lowered the texture profile analysis parameters. Caffeic acid did not render any changes on the water binding capacity. These results prove that caffeic acid can be successfully used as a natural antioxidant in wheat dietary fibre minced fish restructured products.This work was performed within the Integrated Research Project SEAFOODplus, contract No FOOD-CT-2004-506359 and the research project AGL2006-26016-E/GAN. The [partial] financing of this work by the European Union and the Spanish Ministerio de Educación y Ciencia is gratefully acknowledged.Peer reviewe

    Fonts i protagonistes de la informació en la televisió de proximitat. El cas del Tele Elx

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    Following the process of regulation of local digital terrestrial television in Spain, some of the academic research has focused on the beleaguered sector of the so-called proximity television. Although some of the studies go back to the eighties, most of the research deals with historicist or legislative issues, not taking into account other aspects such as the content and programming of local broadcasters. This paper presents the case of Tele Elx, a local television channel born in 1987 in Elche, which we regard as a paradigm of the evolution of proximity television. Our objective is to analyze its news sources and the main actors in its newscasts. We have carried out a content analysis of several samples of its prime-time newscast, Tele nit, which has been broadcasted from its launch. The sample includes 35 newscasts, from 1991 to 2015, which allow us to diachronically carry out an analysis of the evolution of news in local television in Spain.Arran de la regulació de la televisió digital terrestre local (TDT-L) a Espanya s'ha reactivat l'atenció investigadora sobre el maltractat sector de la televisió de proximitat. Tot i que els estudis es remunten als anys huitanta, la majoria versen sobre aspectes historicistes o legislatius i menyspreen altres enfocaments sobre l'oferta de programació i continguts d'aquestes televisions. Aquest article presenta el cas de Tele Elx, un canal d'àmbit local nascut el 1987 a Elx i que considerem que és un paradigma de l'evolució de les televisions de proximitat. El propòsit és conèixer-ne les fonts d'informació i els protagonistes de les seues notícies. Per a això s'han realitzat mostres selectives en el seu informatiu capdavanter, Tele nit, que s'emet ininterrompudament des dels seus inicis. La mostra abasta trenta-cinc noticiaris, del 1991 al 2015, que permeten fer una anàlisi diacrònica de la progressió dels informatius locals en televisions de petita escala

    Infestation maps and spatial stability of main weed species in maize culture

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    A study on the spatial distribution of the major weeds in maize was carried out in 2007 and 2008 in a field located in Golegã (Ribatejo region, Portugal). The geo-referenced sampling focused on 150 points of a 10 x 10 m mesh covering an area of 1.5 ha, before herbicide application and before harvest. In the first year, 40 species (21 botanical families) were identified at seedling stage and only 22 during the last observation. The difference in species richness can be attributed to maize monoculture favouring reduction in species number. Three of the most representative species were selected for the spatial distribution analysis: Solanum nigrum, Chenopodium album and Echinochloa crus-galli. The three species showed an aggregated spatial pattern and spatial stability over both years, although the herbicide effect is evident in the distribution of some of them in the space. These results could be taken into account when planning site-specific treatments in maize.Peer Reviewe

    Fracaso de bancos comerciales. Un estudio de eficiencia y productividad

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    El estudio de la relación entre el comportamiento de la productividad de las entidades bancarias y su capacidad de continuar en el mercado, constituye el objetivo de la presente investigación. Será por medio del empleo de los Índices de Malmquist, mismos que se derivan de la técnica econométrica no paramétrica del Análisis de Datos Envolventes (DEA), que se obtendrán los resultados que permitirán concluir que no es posible establecer una relación directa entre la eficiencia, la productividad y el cese de la empresa. El documento se centra en el sistema bancario hondureño en el periodo comprendido entre 1999 y 2002.Malmquist Index; Bank; Honduras
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