A new formulation and branch-and-cut method for single-allocation hub location problems

A new compact formulation for uncapacitated single-allocation hub location problems with fewer variables than the previous Integer Linear Programming formulations in the literature is introduced. Our formulation works even with costs not based on distances and not satisfying triangle inequality. Moreover, costs can be given in aggregated or disaggregated way. Different families of valid inequalities that strengthen the formulation are developed and a branch-and-cut algorithm based on a relaxed version of the formulation is designed, whose restrictions are inserted in a cut generation procedure together with two sets of valid inequalities. The performance of the proposed methodology is tested on well-known hub location data sets and compared to the most recent and efficient exact algorithms for single-allocation hub location problems. Extensive computational results prove the efficiency of our methodology, that solves large-scale instances in very competitive times

Efficient Heterologous Transformation of Chlamydomonas reinhardtii npq2 Mutant with the Zeaxanthin Epoxidase Gene Isolated and Characterized from Chlorella zofingiensis

In the violaxanthin cycle, the violaxanthin de-epoxidase and zeaxanthin epoxidase catalyze the inter-conversion between violaxanthin and zeaxanthin in both plants and green algae. The zeaxanthin epoxidase gene from the green microalga Chlorella zofingiensis (Czzep) has been isolated. This gene encodes a polypeptide of 596 amino acids. A single copy of Czzep has been found in the C. zofingiensis genome by Southern blot analysis. qPCR analysis has shown that transcript levels of Czzep were increased after zeaxanthin formation under high light conditions. The functionality of Czzep gene by heterologous genetic complementation in the Chlamydomonas mutant npq2, which lacks zeaxanthin epoxidase (ZEP) activity and accumulates zeaxanthin in all conditions, was analyzed. The Czzep gene was adequately inserted in the pSI105 vector and expressed in npq2. The positive transformants were able to efficiently convert zeaxanthin into violaxanthin, as well as to restore their maximum quantum efficiency of the PSII (Fv/Fm). These results show that Chlamydomonas can be an efficient tool for heterologous expression and metabolic engineering for biotechnological applications

Un recurso virtual de apoyo al profesorado universitario para la evaluación de competencias

La evaluación de los aprendizajes dentro del contexto del Espacio Europeo de Educación Superior exige desarrollar competencias docentes nuevas porque los planteamientos formativos son diferentes así como los escenarios profesionales donde se desarrollará una parte importante de la docencia. En consecuencia la continuidad de la evaluación tradicional a base de pruebas de papel y lápiz va a ser parcialmente inviable. Sobre ese problema de la evaluación y sobre el resto de los elementos docentes implicados se ha llevado a cabo una investigación en 5 universidades españolas para determinar primeramente y mediante procedimientos de acuerdo social (grupos de discusión) y de encuesta las competencias docentes clave percibidas por el profesorado como imprescindibles para dar respuesta a este desafío; entre ellas se describieron 11 competencias para la evaluación. En un segundo momento se ha realizado on-line una valoración de las necesidades de formación que el profesorado encuestado entendía tener respecto a las competencias antes identificadas. Los datos obtenidos permiten afirmar que el profesorado encuestado percibe un bloque mayoritario de competencias clave relacionadas con el manejo de los diferentes elementos del sistema de evaluación del alumnado; el resto del bagaje competencial evaluador se relaciona con el aprovechamiento de la información obtenida en el proceso para la mejora de la propia práctica docente. Las necesidades de formación detectadas señalan la evaluación en contextos nuevos de enseñanza aprendizaje y la elaboración de instrumentos de evaluación como ámbitos preferentes para la formación continua así como la necesidad de particularizar en centros y titulaciones dicha oferta de formación.Educational assessment in the teaching context of European Higher Education Area demands specific assessment competencies to university lecturers; main reason is because educational background as well as the learning arenas is going to change substantially in the higher education system of Europe along de next decades. Subsequently traditional pen-and-pencil assessment practices will be of scarce utility for the feature teaching-and-learning processes. A research project has been conducted to identify teaching competencies perceived by lecturers as key-competencies for the new situation. Managing focus-group and survey technics eleven assessment competencies were firstly identified; a need training assessment process on such evaluation competencies have been executed afterward. Research data point out to a majority handful of competencies related with the management of strategies to assess student learning process and outcomes; the minority group speaks on competencies to integrate global assessment information on improving teaching practice. Finally some training need have been stated as assessment strategies in new learning environments, assessment technics, as well as the need of planning context-related (in-service) training offers

Adolescencia, grupo de iguales y consumo de sustancias: Un estudio descriptivo y relacional

Esta investigación fue financiada gracias al Convenio de colaboración firmado entre el Ministerio de Sanidad y Consumo (Dirección General de Salud Pública) y la Universidad de SevillaCon el objetivo de describir la frecuencia con la que chicos y chicas adolescentes escolarizados de entre 15 y 18 años consumen diferentes sustancias y de analizar la relación entre el tipo de amigos y tales consumos, se administró un cuestionario a 6821 chicos y chicas de todo el país. La muestra era representativa en cuanto a hábitat (rural/urbano), tipo de escolarización (pública o privada-concertada) y zona geográfica del país. Los resultados muestran que quienes consumen sustancias de uso frecuente en nuestro contexto (alcohol, tabaco y cannabis) tienen amigos que también realizan estos “consumos normativos”, mientras que quienes consumen sustancias infrecuentes (pegamentos, medicamentos, opiáceos) tienen amigos que, además de consumir esas mismas sustancias, realizan conductas antisociales. Se discuten los datos argumentando que el consumo de sustancias habituales en nuestra sociedad ha terminado formando parte de un sistema más amplio de ritos de transición a la adultez, mientras que el consumo de sustancias infrecuentes se revela como un indicador más de una posible vida marcada por dificultades y problemas de diversa índoleOur aim was to describe how frequently do 15 to 18 year old adolescents attending school engage in certain substance use, and to analyze the correspondence between this use behaviour and types of peers. A questionnaire was answered by 6,821 Spanish boys and girls. This was a representative sample regarding habitat (rural/urban), type of school attended (public or private) and country geographic area. Results show that adolescents who engage in the use of substances which are common within our context (alcohol, tobacco and cannabis) have friends who also engage in this “normative use” behaviour; whereas infrequent substance users (glue, medical drugs, opiates) have friends who not only engage in the use of these substances, but also in antisocial behaviour. Data is discussed arguing that the use of substances which are common in our society has ended up being part of a greater system of rites of passage to adulthood, whereas the use of non frequent substances could be seen as another indicator of a life possibly marked by different problems and adversit

Nursing diagnoses in people with digestive stoma and their association with sociodemographic and clinical factors

Purpose: To determine nursing diagnoses in people with a digestive stoma and their relationship with sociodemographic and clinical variables. Method: A cross-sectional descriptive study of 102 subjects in the General Surgery Unit of a first-level hospital (Granada, Spain) was conducted. Data were collected on the presence of nursing diagnoses, sociodemographic and clinical variables. Results: NANDA-I: "Deficient knowledge (00126)" and "Readiness for enhanced health management (00162)" were present in the entire sample studied. The period of care (postoperative vs. follow-up) was the most common significant variable among diagnoses. Conclusions: This work contributes to the determination of NANDA-I diagnoses in people with digestive stomas. Implications for nursing practice: The results provide a guide to help nursing professionals develop individual care plans

Morphological evolution in the migrating dune of Valdevaqueros (SW Spain) during an eleven-year period

Located in Tarifa, near the Strait of Gibraltar, the migration of Valdevaqueros dune was controlled by sand extractions for building purpose. As the Spanish Shore Act was approved in 1988, the sale of sand was forbidden and the dune started to move forward, burying the leeward pine wood and the only road to Maspalomas village. Consequently, six topographic levellings have been taken during the last eleven years. Sedimentary granulometries and meteorological features were taken into account. D50 values have been calculated for dune foot, windward and dune top. Wind speed threshold is estimated above 15 km/h. East winds are responsible for dune movement, whose advance rate has reached very high values (over 18 m/year). Slope and volumetric changes have been determined, providing a clearer explanation of the dune evolutio