Elección temporal de los viajes turísticos: una aproximación con modelos de recuento

Comunicación presentada en el XIII Congreso Nacional de ACEDE, Salamanca, 21-23 septiembre 2003.

Elección de la duración del viaje vacacional: una aproximación con modelos de recuento

La duración del viaje vacacional es una decisión del turista con unas implicaciones fundamentales para las organizaciones turísticas, pero que ha recibido una escasa atención por la literatura. Además, los escasos estudios se han centrado en los destinos costeros, cuando el turismo de interior se está erigiendo como una alternativa importante en algunos países. El presente trabajo analiza los factores determinantes de la elección temporal del viaje turístico, distinguiendo el tipo de destino elegido -costa e interior-, y proponiendo varias hipótesis acerca de la influencia de las características de los individuos relacionadas con el destino, de las restricciones personales y de las características sociodemográficas. La metodología aplicada estima, como novedad en este tipo de decisiones, un Modelo Binomial Negativo Truncado que evita los sesgos de estimación de los modelos de regresión y el supuesto restrictivo de igualdad media-varianza del Modelo de Poisson. La aplicación empírica realizada en España sobre una muestra de 1.600 individuos permite concluir, por un lado, que el Modelo Binomial Negativo es más adecuado que el de Poisson para realizar este tipo de análisis. Por otro lado, las dimensiones determinantes de la duración del viaje vacacional son, para ambos destinos, el alojamiento en hotel y apartamento propio, las restricciones temporales, la edad del turista y la forma de organizar el viaje; mientras que el tamaño de la ciudad de residencia y el atributo “precios baratos” es un aspecto diferencial de la costa; y el alojamiento en apartamentos alquilados lo es de los destinos de interior.

Evaluación de la calidad de vida relacionada con la salud mediante las láminas Coop-Wonca en una población de hemodiálisis

Ante la necesidad de disponer de instrumentos que permitan medir calidad de vida relacionada con la salud (CVRS) de una manera ágil y rápida, nos planteamos estudiar, en un grupo de pacientes en hemodiálisis, las propiedades de medición de las láminas Coop-Wonca con el objetivo de establecer si reúnen las condiciones para su uso rutinario en este tipo de pacientes. Métodos: Estudio transversal en 163 pacientes de hemodiálisis (106 varones y 57 mujeres) procedentes de 3 centros. Para medir la CVRS de la población estudiada se ha utilizado la versión validada española de las láminas Coop-Wonca completa. Este cuestionario comprende nueve dimensiones de función y bienestar de un único ítem: 1.– Forma física; 2.–Sentimientos; 3.–Actividades cotidianas; 4.–Actividades sociales; 5.–Cambio en el estado de salud; 6.–Estado de salud; 7.–Dolor; 8.–Apoyo social; y 9.–Calidad de vida en general. Las posibles respuestas se puntúan de 1 a 5, siendo las puntuaciones mayores las que reflejan una peor salud percibida. El instrumento permite la obtención de un índice (Coop total) que es un sumatorio de las puntuaciones de todas las dimensiones salvo la 5 (Cambio en el estado de salud). Resultados: El tiempo medio de cumplimentación del cuestionario fue inferior a 5 minutos. Las láminas resultaron fácilmente comprensibles para los pacientes y la autoadministración de las mismas no planteó problemas. Las puntuaciones más altas (peor CVRS) se obtuvieron en las dimensiones «forma física» (3,66 ± 0,8) y «estado de salud» (3,43 ± 0,8), y la menor (mejor CVRS) en la dimensión «actividades sociales» (1,98 ± 1,3). Entre los principales factores asociados a un peor estado de salud percibida figuran el sexo (mujer), la comorbilidad (presencia de diabetes y/o hepatopatía), la situación laboral (pensionista) y el medio de transporte (taxi-ambulancia). Un mayor tiempo en hemodiálisis se asoció a peores puntuaciones en las dimensiones «calidad de vida en general» y «Dolor». Los pacientes que se trasladaban en taxi o ambulancia presentaban peores puntuaciones en las dimensiones «Forma física», «Actividades cotidianas» y «Estado de salud». Una mayor se asoció a peor puntuación en «Forma física». Un número elevado de fármacos prescritos (más de seis) se asoció a peor puntuación en las dimensiones «Forma física», «Actividades sociales» y «Apoyo social». Los varones, los viudos y los solteros puntuaron peor en «Apoyo social». Los pacientes con mayor nivel de estudios mostraron puntuaciones más altas (peor CVRS) en la dimensión «Forma física». Conclusiones: Las láminas Coop-Wonca podrían ser un buen instrumento de medida de CVRS en los pacientes de hemodiálisis, por la rapidez de su cumplimentación y por ser de fácil comprensión lo que favorece la autoadministración que evita el posible sesgo del entrevistador. Todo ello favorecería su uso rutinario como indicador par valorar la evolución en el tiempo de la CVRS de los pacientes en hemodiálisis. No obstante, se precisan estudios ulteriores que permitan evaluar en mayor profundidad las propiedades psicométricas del instrumento en este tipo de pacientes.

Elysia timida (Risso, 1818) three decades of research

During the last 30 years, studies on Elysia timida (Risso, 1818) have addressed various aspects related to food sources, photosynthetic efficiency of kleptoplasts, population genetics, chemical ecology and reproductive biology, both in the Mediterranean Sea and in the Mar Menor coastal lagoon. E. timida shows a strong specific interaction with Acetabularia acetabulum, retaining functional chloroplasts for at least 45 days and obtaining extra energy in periods when food resources are scarce. It shows control of parapodia, avoiding pigment photodestruction under oversaturated light conditions. The chemical ecological relationships established between E. timida and its potential predator fish, Thalassoma pavo, have also been evaluated, and it has been found that that the extracts of the mollusc contain repellent and unpalatable polypropionate compounds. Population genetics has demonstrated the genetic divergence between populations showing high and significant values of FST and genetic distances, and at least six privative alleles that are not shared with Mediterranean populations have been detected in lagoon populations. This sacoglossan is a poecilogonic species, and its lagoon populations show a greater reproductive output than Mediterranean populations; they produce a greater number of egg masses and embyros per individual, and the capsules have a wider diameter.

En busca de la ecuanimidad en las responsabilidades compartidas

El ciclo de desconfianza entre los Estados miembro de la UE que evita la solidaridad sólo puede romperse si la responsabilidad se evalúa de forma ecuánime y basándose en indicadores objetivos.

Aclaración, corrección, subsanación y complementos de sentencias en el Derecho Procesal Laboral

A lo largo de este trabajo se abordarán vías por las que el legislador ha tratado de dar una mayor celeridad al proceso para impedir el problema de las dilaciones indebidas, al ser esta una de las grandes trabas de la actualidad debido al exceso de carga de trabajo que recae sobre los órganos judiciales. Con la aclaración, corrección, subsanación y complementos de sentencias se logra dar una solución ágil a problemas relativamente sencillos, puesto que evita la necesidad de acudir a la nulidad de actuaciones o a la interposición de los recursos pertinentes, al ofrecer otros cauces para obtener de igual forma una solución óptima, que garantice una mayor efectividad y eficacia en la resolución de errores patentes y claros sobre los que no sea necesario realizar ningún juicio valorativo o apreciación jurídica.

Conservação de cereja com aplicação de revestimento comestível

Dissertação apresentada à Escola Superior Agrária do Instituto Politécnico de Castelo Branco para cumprimento dos requisitos necessários à obtenção do grau de Mestre em Fruticultura Integrada.

Processos metafóricos no desenvolvimento da escrita em aprendentes chineses de PLE

Esta é uma investigação em linguística aplicada que, ao procurar perceber melhor o modo como o processo de aprendizagem do aprendente chinês de português como língua estrangeira(PLE)pode ser afetado pela aquisição do significado metafórico, assume um pendor linguístico, não deixando de se situar no âmago do ato pedagógico. Admitindo a hipótese da existência de uma correlação positiva entre a frequência do uso da metáfora gramatical e o nível de proficiência dos aprendentes na expressão escrita, esta dissertação pretende aprofundar a compreensão dos mecanismos de aquisição do Português por aprendentes (PLE/PL2) que têm como língua materna o Chinês, designadamente os que se prendem com a aquisição de processos metafóricos. Neste estudo, teremos como referência a teorização sobre o significado metafórico proposto por Halliday (1985, 1994, 2004). A ocorrência de metáforas gramaticais foi escrutinada emdois manuais de ensino de PLE concebidos para os níveis A2 e B1 do QECR, de forma a poder identificar, qualitativa e quantitativamente, os padrões textuais metafóricos com que os aprendentes têm que lidar nestes momentos específicos do processo de aprendizagem. Para compreender a produção escrita de pendor metafórico dos aprendentes, é realizada análise sistemática de amostras da expressão escrita de alunos de PLE chineses dos mesmos dois níveis, constantes no Corpus de Português Língua Estrangeira/Língua Segunda, COPLE2. Do confronto dos dados dos dois planos de análise, foi possível confirmar que a transição entre os dois níveis subsequentes escolhidos (A2 e B1) representa uma mudança crucial no padrão metafórico, quer dos textos propostos aos aprendentes, quer dos textos por estes produzidos, mudança esta que pode explicar alguns dos bloqueios de aprendizagem associados ao nível B1 e seguintes. Foi possível, entre outros aspetos, identificar a primazia da metáfora ideacional na acomodação da expressão metafórica, compreender como o aprendente evita o recurso metafórico, tornando a sua escrita menos abstrata e densa, como o aprendente aborda a metáfora interpessoal, restringindo o seu uso a géneros discursivos muito específicos. Sendo, embora, um estudo exploratório, permite confirmar que esta linha de investigação oferece dados inestimáveis aos professores de PLE e agentes de ensino, em geral.

Cortes curriculares de géneros que diseñan al sujeto futbolista

Reflexionando sobre la problemática desafiante si ¿podremos vivir juntos?, y la producción de conocimiento sociológico, (entendiendo al conocimiento con características de provisorio, problematizado y cuestionable), me propongo indagar en los Nuevos Diseños Curriculares de la Provincia de Buenos Aires. En los cuales aparecen explícitamente conceptos paradigmáticos claves, a saber: currículum, interculturalita, inclusión, universalidad, diversidad, sujeto pedagógico, sujetos complejos, atravesados por su historicidad, por ser inconclusos, con derechos y con Género y sexualidad (como dos características diferenciadas). Analizaré la relación y la influencia de estos nuevos discursos pedagógicos en las prácticas docentes con características discriminatoria en las clases que desarrollan el contenido: Fútbol. En este sentido es interesante como los constructos y prejuicios sociales generan tensión y divorcio entre lo prescriptivo y lo que se hace en la clase, donde las niñas, adolescentes y adultas se encuentran en situación de desigualdad y exclusión a la hora de aprender en una institución formal el deporte fútbol, donde claramente se promueve desde el sentido común la invisibilidad y el ninguneo de las mujeres en la formación y apropiación de un saber popular y cultural. El Fútbol Femenino es una realidad lo demuestran Cinco Mundiales de Fútbol, Tres Campeonatos Olímpicos, 24 años en A.F.A., 40 millones de mujeres en todo el planeta registradas en F.I.F.A.

Synthesis and characterization of dual-functionalized core-shell fluorescent microspheres for bioconjugation and cellular delivery

The efficient transport of micron-sized beads into cells, via a non-endocytosis mediated mechanism, has only recently been described. As such there is considerable scope for optimization and exploitation of this procedure to enable imaging and sensing applications to be realized. Herein, we report the design, synthesis and characterization of fluorescent microsphere-based cellular delivery agents that can also carry biological cargoes. These core-shell polymer microspheres possess two distinct chemical environments; the core is hydrophobic and can be labeled with fluorescent dye, to permit visual tracking of the microsphere during and after cellular delivery, whilst the outer shell renders the external surfaces of the microspheres hydrophilic, thus facilitating both bioconjugation and cellular compatibility. Cross-linked core particles were prepared in a dispersion polymerization reaction employing styrene, divinylbenzene and a thiol-functionalized co-monomer. These core particles were then shelled in a seeded emulsion polymerization reaction, employing styrene, divinylbenzene and methacrylic acid, to generate orthogonally functionalized core-shell microspheres which were internally labeled via the core thiol moieties through reaction with a thiol reactive dye (DY630-maleimide). Following internal labeling, bioconjugation of green fluorescent protein (GFP) to their carboxyl-functionalized surfaces was successfully accomplished using standard coupling protocols. The resultant dual-labeled microspheres were visualized by both of the fully resolvable fluorescence emissions of their cores (DY630) and shells (GFP). In vitro cellular uptake of these microspheres by HeLa cells was demonstrated conventionally by fluorescence-based flow cytometry, whilst MTT assays demonstrated that 92% of HeLa cells remained viable after uptake. Due to their size and surface functionalities, these far-red-labeled microspheres are ideal candidates for in vitro, cellular delivery of proteins, as described in the accompanying paper.

Synthesis and evaluation of nanoparticle-polymer composites

This thesis describes the synthesis of functionalised polymeric material by variety of free-radical mediated polymerisation techniques including dispersion emulsion, seeded emulsion, suspension and bulk polymerisation reactions. Organic fluorophores and nanoparticles such as quantum dots were incorporated within polymeric materials, in particular, thiol-functionalised polymer microspheres, which were fluorescently labelled either during synthesis or by covalent attachment post synthesis. The resultant fluorescent polymeric conjugates were then assessed for their utility in biological systems as an analytical tool for cells or biological structures. Quantum dot labelled, thiol-functionalised microspheres were assessed for their utility in the visualisation and tracking of red blood cells. Determination of the possible internalisation of fluorescent microspheres into red blood cells was required before successful tracking of red blood cells could take place. Initial work appeared to indicate the presence of fluorescent microspheres inside red blood cells by the process of beadfection. A range of parameters were also investigated in order to optimise beadfection. Thiol-functionalised microspheres labelled successfully with organic fluorophores were used to image the tear film of the eye. A description of problems encountered with the covalent attachment of hydrophilic, thiol-reactive fluorescent dyes to a variety of modified polymer microspheres is also included in this section. Results indicated large microspheres were particularly useful when tracking the movement of fluid along the tear meniscus. Functional bulk polymers were synthesised for assessment of their interaction with titanium dioxide nanoparticles. Thiol-functionalised polymethyl methacrylate and spincoated thiouronium-functionalised polystyrene appeared to facilitate the attachment of titanium dioxide nanoparticles. Interaction assays included the use of XPS analysis and processes such as centrifugation. Attempts to synthesise 4-vinyl catechol, a compound containing hydroxyl moieties with potential for coordination with titanium dioxide nanoparticles, were also carried out using 3,4-dihydroxybenzaldehyde as the starting material.

Energia eólica em alto mar: distribuição dos recursos e complementaridade hídrica

The stabilization of energy supply in Brazil has been a challenge for the operation of the National Interconnected System in face of hydrological and climatic variations. Thermoelectric plants have been used as an emergency source for periods of water scarcity. The utilization of fossil fuels, however, has elevated the cost of electricity. On the other hand, offshore wind energy has gained importance in the international context and is competitive enough to become a possibility for future generation in Brazil. In this scenario, the main goal of this thesis was to investigate the magnitude and distribution of offshore wind resources, and also verify the possibilities of complementing hydropower. A data series of precipitation from the Climatic Research Unit (CRU) Blended Sea Winds from the National Climatic Data Center (NCDC/NOAA) were used. According to statistical criteria, three types of complementarity were found in the Brazilian territory: hydro × hydro, wind × wind and hydro × wind. It was noted a significant complementarity between wind and hydro resources (r = -0.65), mainly for the hydrographical basins of the southeast and central regions with Northeastern Brazil winds. To refine the extrapolation of winds over the ocean, a method based on the Monin-Obukhov theory was used to model the stability of the atmospheric boundary layer. Objectively Analyzed Air-Sea Flux (OAFLUX) datasets for heat flux, temperature and humidity, and also sea level pressure data from NCEP/NCAR were used. The ETOPO1 from the National Geophysical Data Center (NGDC/NOAA) provided bathymetric data. It was found that shallow waters, between 0-20 meters, have a resource estimated at 559 GW. The contribution of wind resources to hydroelectric reservoir operation was investigated with a simplified hybrid wind-hydraulic model, and reservoir level, inflow, outflow and turbine production data. It was found that the hybrid system avoids drought periods, continuously saving water from reservoirs through wind production. Therefore, from the results obtained, it is possible to state that the good winds from the Brazilian coast can, besides diversifying the electric matrix, stabilize the hydrological fluctuations avoiding rationing and blackouts, reducing the use of thermal power plants, increasing the production cost and emission of greenhouse gases. Public policies targeted to offshore wind energy will be necessary for its full development.

AdaptMCloud: uma estratégia para adaptação dinâmica de aplicações Multi-Cloud

Multi-Cloud Applications are composed of services offered by multiple cloud platforms where the user/developer has full knowledge of the use of such platforms. The use of multiple cloud platforms avoids the following problems: (i) vendor lock-in, which is dependency on the application of a certain cloud platform, which is prejudicial in the case of degradation or failure of platform services, or even price increasing on service usage; (ii) degradation or failure of the application due to fluctuations in quality of service (QoS) provided by some cloud platform, or even due to a failure of any service. In multi-cloud scenario is possible to change a service in failure or with QoS problems for an equivalent of another cloud platform. So that an application can adopt the perspective multi-cloud is necessary to create mechanisms that are able to select which cloud services/platforms should be used in accordance with the requirements determined by the programmer/user. In this context, the major challenges in terms of development of such applications include questions such as: (i) the choice of which underlying services and cloud computing platforms should be used based on the defined user requirements in terms of functionality and quality (ii) the need to continually monitor the dynamic information (such as response time, availability, price, availability), related to cloud services, in addition to the wide variety of services, and (iii) the need to adapt the application if QoS violations affect user defined requirements. This PhD thesis proposes an approach for dynamic adaptation of multi-cloud applications to be applied when a service is unavailable or when the requirements set by the user/developer point out that other available multi-cloud configuration meets more efficiently. Thus, this work proposes a strategy composed of two phases. The first phase consists of the application modeling, exploring the similarities representation capacity and variability proposals in the context of the paradigm of Software Product Lines (SPL). In this phase it is used an extended feature model to specify the cloud service configuration to be used by the application (similarities) and the different possible providers for each service (variability). Furthermore, the non-functional requirements associated with cloud services are specified by properties in this model by describing dynamic information about these services. The second phase consists of an autonomic process based on MAPE-K control loop, which is responsible for selecting, optimally, a multicloud configuration that meets the established requirements, and perform the adaptation. The adaptation strategy proposed is independent of the used programming technique for performing the adaptation. In this work we implement the adaptation strategy using various programming techniques such as aspect-oriented programming, context-oriented programming and components and services oriented programming. Based on the proposed steps, we tried to assess the following: (i) the process of modeling and the specification of non-functional requirements can ensure effective monitoring of user satisfaction; (ii) if the optimal selection process presents significant gains compared to sequential approach; and (iii) which techniques have the best trade-off when compared efforts to development/modularity and performance.

Rede de aprendizagem em robótica : uma perspectiva educativa de trabalho com jovens

The present research sought to comprehend what is the development perspective of a collective work of educational robotics with high school students. The work started from the development activities Mathematics Sub Project of PIBID (Programa Institucional de Bolsa de Iniciação à Docência, Institutional Program of Initiation to Teaching Scholarship) in a school network from the state of Minas Gerais. The production process of data of this research was done through the follow up of high school students that participated in workshops robotics at the mentioned public school and were selected to continue the project at the Faculty of Mechanical Engineering in Federal University of Uberlândia (UFU). Subsequently, these students were involved in activities related to Robotics championships, elapsed through different spaces in public and private schools of basic education, University and Non-Governmental Organization. The data at the research were registered by photos, videos, field notes, documents produced by the participants and arising from internet like the social media Facebook, questionnaires and, mainly, interviews. At the analysis process of data the followed axes were constituted: Movement Learning Network with Robotics; The Different Roles at the Robotics Events and Experiences in Engineering and Technology. By this axes we understand what is the trajectory of the constitution process of a learning network in educational robotics that we find in expansion and consolidation. In this network the research participants performed different roles which left imprints responsible for their transformation. As a more evident imprint, we detected the robot construction and programming, which as for as they moved their studies forward, they developed the subject autonomy, collaboration, sharing and technological authorship.

Monitorização da carga de treino em Futsal: estudo piloto com jogadores amadores juniores e seniores

Este foi um estudo piloto que pretendeu monitorizar a carga de treino em Futsal, com jogadores amadores juniores e seniores. A amostra do presente estudo foi composta por 8 jogadores de Futsal do sexo masculino, 4 juniores com idade média de 16.5±0.5 anos (estatura de 1.67±0.04 m e 59.2±2.21 Kg de massa corporal) e 4 seniores com idade média de 27.2±2.7 anos (estatura de 1.71±0.05 m e 69.7±7.5 Kg de massa corporal). Os jogadores competiam nos campeonatos distritais amadores de Futsal, na sua categoria, organizados pela Associação de Futebol de Leiria. Para a realização deste estudo recorreu-se a 4 unidades do ZephyrTM BioHarnessTM System (Zephyr Technology, Auckland, New Zealand). Trata-se de um sistema de monitorização wireless de dados fisiológicos e que tem a capacidade de medir a frequência cardíaca (FC), frequência respiratória (FR) e acelerometria (ACC). Os resultados obtidos mostram que o sistema utilizado registou as variáveis que se pretendiam estudar, sem limitações para o atleta, isto é, sem cabos ou artefactos, que limitassem os movimentos durante a unidade de treino. Verificou-se também que, no somatório de 8 unidades de treino, a frequência cardíaca média no grupo de juniores foi mais elevada do que a dos jogadores seniores (p = 0.029). A monitorização permitiu avaliar a intensidade das unidade de treino, permitindo identificar as respostas fisiológicas por jogador e por treino. Utilizando esta tecnologia é possível fazer um acompanhamento monitorizado de cada atleta por forma a analisar a sua adaptação e evolução fisiológica e fazer uma prescrição/planificação da sessão de treino mais adaptada a cada atleta.