A characterization of 3D steady Euler flows using commuting zero-flux homologies

We characterize, using commuting zero-flux homologies, those volume-preserving vector fields on a $3$-manifold that are steady solutions of the Euler equations for some Riemannian metric. This result extends Sullivan's homological characterization of geodesible flows in the volume-preserving case. As an application, we show that the steady Euler flows cannot be constructed using plugs (as in Wilson's or Kuperberg's constructions). Analogous results in higher dimensions are also proved.Comment: 16 pages, we added proofs of analogous results in higher dimensions, and a characterization of 3-dimensional Reeb field

Design and Testing of a Structural Monitoring System in an Almería-Type Tensioned Structure Greenhouse

Greenhouse cultivation has gained a special importance in recent years and become the basis of the economy in south-eastern Spain. The structures used are light and, due to weather events, often collapse completely or partially, which has generated interest in the study of these unique buildings. This study presents a load and displacement monitoring system that was designed, and full scale tested, in an Almería-type greenhouse with a tensioned wire structure. The loads and displacements measured under real load conditions were recorded for multiple time periods. The traction force on the roof cables decreased up to 22% for a temperature increase of 30 °C, and the compression force decreased up to 16.1% on the columns or pillars for a temperature and wind speed increase of 25.8 °C and 1.9 m/s respectively. The results show that the structure is susceptible to daily temperature changes and, to a lesser extent, wind throughout the test. The monitoring system, which uses load cells to measure loads and machine vision techniques to measure displacements, is appropriate for use in different types of greenhouses

Representation of discipline field and professional trainig about psychopedagogy in an academic context, Argentine

El presente trabajo explora las representaciones acerca del campo disciplinar y formación profesional de la Psicopedagogía. A tales fines, se construyó un cuestionario que fue completado de manera anónima por estudiantes y docentes de la Licenciatura en Psicopedagogía que aceptaron participar. Esta carrera pertenece a la Unidad Académica Rosario de la Escuela de Humanidades de la Universidad Nacional de San Martín (Argentina). El trabajo de campo se realizó durante los meses de abril y mayo de 2009. El análisis de los datos se llevó a cabo a través del enfoque francés de AMD –Análisis Multidimensional de Datos, permitiendo una mirada compleja en un tratamiento simultáneo de las variables en estudio. Los principales resultados demuestran la existencia de tres grupos de individuos, agrupados por compartir ciertas representaciones o perfiles característicos: los docentes, los estudiantes de 5º año y los estudiantes de 3º y 4º año. En cuanto al campo disciplinar, los tres grupos plantearon diversas conceptualizaciones en torno a la Psicopedagogía. Del mismo modo, este rasgo particular fue observado en la literatura académica en torno al tema. En alusión a la formación profesional, los estudiantes acuerdan que el perfil académico del graduado se encuentra orientado, fundamentalmente, hacia la aplicación de instrumentos ante problemas de aprendizaje. Asimismo, consideran que existe una predominancia de la Psicología Genética en la formación y que la mayoría de sus docentes son Psicólogos. La coexistencia de estos supuestos, a veces complementaria o francamente antagónica, dan forma a un campo con escasas delimitaciones conceptuales que se transfieren a las prácticas profesionales de los Psicopedagogos. Investigaciones como la que aquí se presenta resultan valiosas en el marco de una “Psicopedagogía en construcción” sin suficientes consensos generalizados, para reconocer los supuestos que circulan y se transmiten, vislumbrando debates académicos subyacentes que permitan una mayor consolidación del campo disciplinar y, al mismo tiempo, de la identidad profesional del Psicopedagogo.This paper explores the representations of the disciplinary field and professional training of Psychopedagogy. To achieve such aim, a questionnaire was constructed. This questionnaire was responded in an anonymous way by Psychopedagogy professors and students, between April and May 2009. This career belongs to the Rosario Academic Unit of the School of Humanities of the National University of San Martín’s (Argentine). The data analysis was carried out from a french approach of MDA – Multidimentional Data Analysis. This computer software allows a complex analysis with a simultaneous treatment of the study’s variables. The main results show the existence of three groups of subjects, grouped by the common sharing of certain representations or characteristic profiles: teachers, students of 5th year, and students of 3 rd and 4th year. In relation to the disciplinary field, the three groups discussed exposed multiple conceptualizations about Psychopedagogy. Similarly, this particular feature was observed in the academic literature on the subject. Referring to the professional training, students agree that graduate academic profile is oriented mainly towards the application of tools towards the solution of learning problems. They believe that there is a predominance of Genetic Psychology in training and that most of their teachers are psychologists. The coexistence of these factors, sometimes complementary to each other, sometimes antagonic, shape a field with few conceptual boundaries that is transferred to the professional practice of psychopedagogists. Research such as the one presented here are valuable in the context of a "Psychopedagogy in the construction" without sufficient generalized consensus to recognize the assumptions that circulate and are transmitted, glimpsing underlying academic debate that allow a greater consolidation of the disciplinary field and at the same time, of the professional identity of psychopedagogist.Fil: Ventura, Ana Clara. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; ArgentinaFil: Borgobello, Ana. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; ArgentinaFil: Peralta, Nadia Soledad. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; Argentin

Imposex in Voluta musica (Caenogastropoda: Volutidae) from Northeastern Península de Araya, Venezuela

Voluta musica is a dioecious marine gastropod endemic of the South Caribbean. Tributyltin (TBT) and copper (Cu) are potential inducers of imposex, an endocrine disorder by which females develop a penis and/or vas deferens. The goal of this work was to determine the imposex incidence in V. musica populations from Northeastern Península de Araya. For this, we selected three sites (Isla Caribe, Isla Lobos and Bajo Cuspe) and made monthly samplings of 15 snails in each site, during one year, and determined: (1) sizes; (2) sex and imposex incidence and (3) the Relative Penis Length Index (RPLI). We also performed histological analysis of the gonads, and measured TBT and Cu concentrations in sediments from the studied localities. Our results showed that the total number of sampled females affected by imposex was 24.5% at Isla Caribe, 12% at Isla Lobos, and none at Bajo Cuspe. In sediments, Cu was detected mostly in Isla Lobos. The female gonads with imposex did not show any development of male cells in any of the sampled sites. The higher percentage of females with imposex matched with the higher boat traffic locality, and higher TBT level (Isla Caribe). No esterilization was evident in this work, nevertheless, the presence of TBT and Cu in the sediments and females with imposex were considered as a potential threat to V. musica populations in this region. In Venezuela there is no control over this particular issue, possibly because of the lack of information and research in this topic, but certainly, this information will be useful in biodiversity conservation policiesVoluta musica es un gasterópodo dioico endémico del Caribe sur. El TBT y el Cu, son potenciales causantes del imposex, fenómeno donde las hembras desarrollan un pene y/o vaso deferente. El objetivo fue determinar la incidencia de imposex en V. musica en el noreste de la Península de Araya. Se seleccionaron tres localidades y se captura-ron mensualmente 15 individuos durante un año para determinar: (1) talla de los individuos; (2) sexo y presencia de imposex; (3) índice Largo Relativo del Pene (RPLI). Se realizó histología de la gónada de los individuos. Se determinó TBT y Cu en el sedimento de cada localidad. En Isla Caribe, el 24.5% de las hembras presentó imposex, y se halló 3.9ngSn/g de TBT; en Isla Lobos, el 12% de las hembras desarrollaron imposex; en Bajo del Cuspe no se observó imposex. Se halló Cu en mayor concentración en Isla Lobos. Las gónadas femeninas con imposex no demos-traron masculinización. El mayor porcentaje de imposex coincide con la localidad de mayor tráfico de embarcaciones y con mayor nivel de TBT (Isla Caribe). No se evidenció esterilización, sin embargo la presencia de TBT, Cu e imposex son potenciales amenazas para las poblaciones de V. musica en la región. Hasta ahora, en Venezuela no se está tomando ninguna medida de control sobre este tema en particular, posiblemente por la escasez de información y orientación de las investigaciones hacia este tema, pero que sin duda se debería tomar en cuenta en las políticas para la conservación de la biodiversidad.Fil: Peralta, Ana Carolina. Universidad Simon Bolivar. Centro de Biodiversidad Marina; VenezuelaFil: Miloslavich, Patricia. Universidad Simon Bolivar. Centro de Biodiversidad Marina; VenezuelaFil: Bigatti, Gregorio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

State of the Industry 4.0 in the Andalusian food sector

The food industry is a key issue in the economic structure of Andalusia, due to both the weight and position of this industry in the economy and its advantages and potentials. The term Industry 4.0 carries many meanings. It seeks to describe the intelligent factory, with all the processes interconnected by Internet of things (IOT). Early advances in this field have involved the incorporation of greater flexibility and individualization of the manufacturing processes. The implementation of the framework proposed by Industry 4.0. is a need for the industry in general, and for Andalusian food industry in particular, and should be seen as a great opportunity of progress for the sector. It is expected that, along with others, the food and beverage industry will be pioneer in the adoption of flexible and individualized manufacturing processes. This work constitutes the state of the art, through bibliographic review, of the application of the proposed paradigm by the Industry 4.0. to the food industry.Telefónica, through the “Cátedra de Telefónica Inteligencia en la Red”Paloma Luna Garrid

The Sociocognitive Conflict as a Learning Tool in Collaborative Contexts

El conflicto sociocognitivo (CSC) ha sido tradicionalmente estudiado por medio de diseños experimentales de investigación como promotor del desarrollo en niños pequeños. En la actualidad, existe una línea de investigación que continúa esta orientación llevando el concepto al contexto del aprendizaje formal, dando lugar a diseños más variados. Sin embargo, muy pocas investigaciones hacen del CSC el eje de sus trabajos. El estudio que se informa buscó incentivar en díadas de estudiantes universitarios el CSC en el aprendizaje colaborativo de conceptos. Con el objetivo de evaluar las producciones escritas que los alumnos realizaban durante el aprendizaje y el efecto de aprendizaje logrado, se constituyeron tres grupos: uno experimental, formado por díadas colaborativas que fueron intervenidas por el investigador y dos grupos control (uno constituido por díadas que también trabajaron colaborativamente pero sin intervención y otro, por sujetos que trabajaron solos y que tampoco fueron intervenidos). La muestra estuvo constituida por 120 sujetos, 60 alumnos de ciencias exactas (Física) y 60 alumnos de ciencias sociales (Psicología). Todos ellos eran estudiantes de primer año. Se elaboraron cuestionarios y textos y se trabajó con un diseño de tipo experimental 'pre-test individual / intervención sobre la colaboración sociocognitiva / pos-test individual', estando el incentivo del CSC a cargo de un investigador que garantizaba la simetría de la participación, la evaluación mutua y la explicitación de las diferencias cognitivas. Los resultados muestran que el incentivo del CSC es altamente eficaz en relación a las dos variables dependientes estudiadas: el aprendizaje logrado y la producción escrita; un efecto no esperado fue la mayor homogeneidad de los aprendizajes en las díadas intervenidas.Socio-cognitive conflict (SCC) has been defined as the exchange of different points of view when two or more people are working in a task together. It is cognitive because the points of view are intellectually supported and social because it takes place during an interaction. The concept of SCC was developed in the Geneva School of Educational Social Psychology and has been traditionally studied as an important factor in children development. These original studies were made using an experimental methodology, with samples of children between 6 and 7 years old. The basic learning tasks evaluated were piagetian tasks of conservation, for example, with liquids, length, quantity, etc. Nowadays, there is a new research field which takes this approach to study the SCC concept in formal learning contexts. This gave place to more varied designs. However, not many designs take SCC as their central aspect. The present study focuses on developing the SCC in pairs of university students using a pretest / post test experimental design. The collaborative learning environment is particularly critical for SCC to take place. This scenario is appropriate for the development of SCC because when pairs are working together sharing the same goal, the interaction increases. In this study the intervention focused on three signs of SCC: symmetry, peer evaluation and the cognitive differences between students. Researchers regulated a 'symmetrical' participation encouraging both students to participate in a similar amount of times and tasks. 'Peer evaluation' takes place when both students express their agreement or disagreement with the other one's speech. Researchers also asked students to express their disagreements even if they were shown as non-verbal expressions to increase the cognitive differences between them. In other words, the intervention was not focused on teaching concepts (as professors usually do in their classes); the goal was to guarantee the interaction between the students themselves. In order to evaluate the effect of the intervention on learning and on the interaction processes, three groups of students were constituted. One of them was the experimental group which was constituted by pairs who received the intervention of a researcher. The other two groups were control groups: one of them was integrated by pairs of students who worked independently, and the other one, by participants who worked alone. The sample had 120 participants, 60 students of an exact science career and 60 of a social science career. All students were in the first year of university. Post test evaluations show that encouraging SCC is effective in academic learning. In the experimental group there was more symmetry in participation and homogeneity in the learning process. In addition the written productions in this group were more complete, coherent, and logically structured than the control groups' productions. Educational implications for university level are discussed. These kinds of results are important because they could be used as an instrument for the classroom organization. It is also important as an example to consider ways to develop (especially with the university students), skills like dialogue, mutual understanding, team work, cognitive explanation, peer evaluation, self-evaluation, and respect for peers' points of view. All these skills can be developed with teachers who are interested in increasing SCC in collaborative learning environments.Fil: Peralta, Nadia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones En Ciencias de la Educación; ArgentinaFil: Roselli, Nestor Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; ArgentinaFil: Borgobello, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; Argentin

Characterizing papers about ‘blended learning’: an unconsolidated field?

El uso de sistemas híbridos en educación y las publicaciones que dan cuenta de estas experiencias han aumentado en la última década. Con el objetivo de conocer sobre este fenómeno para mejorar las experiencias presentes y futuras, se analizaron 245 artículos académicos con “blendedlearning” en el título. Los principales resultados, apoyando el análisis estadístico descriptivo, refieren al análisis de clusters. Se muestran tres grupos de publicaciones cuyas propiedades más importantes marcan tendencias generales: diversidad depapers; foco en la tecnología de comunicación; y foco en la práctica educativa. En general, se encontró una actividad educativa orientada a la práctica más que un objeto separado de investigación mostrando a este campo en una etapa de construcción creciente.Publications and use of hybrid systems in education have increased during the last ten years. This growing field of practice might be analyzed to increase our knowledge and improve present and future experiences. We present a study of 245 academic journal’s papers with ‘blended learning’ in the title. The main results, supporting the descriptive statistical analysis, are related to the cluster analyses. It was pointed out three distinguish groups of publications around their most important properties picturing general tendencies: the diversity of papers; the focus on communicational media; andthe focus on educational practice. In conclusion, blended learningpapers showed a practical educational activity more than a separated object of research revealing itas a growing construction field.Fil: Borgobello, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; ArgentinaFil: Raynaudo, Gabriela Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; ArgentinaFil: Peralta, Nadia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; Argentin

Relação entre experiência e desempenho docente e aprendizagem de universitários

This experimental study approaches characteristics of three university teachers' classes with different levels of experience. According to the literature, experienced teachers more often than not are adaptable to different contexts. However, novice teachers are usually focused on specific class contents to be evaluated. Three teachers were selected, a Professor, and two Assistants (a university level one and an undergraduate). We gave them a source text to teach 10 students each one. After that, students' knowledge was evaluated with a post-test and a self-evaluation. The characteristics of the three classes were evaluated by external judges and the students themselves. Moreover, theme and sequential submission analyses following the source text were made. Results show differences in each of the analyzed aspects according to the literature.O objetivo deste estudo foi relacionar a experiência dos docentes com a apresentação dos conteúdos e a aprendizagem de estudantes no nível universitário. É de se esperar que professores com mais experiência educacional sejam adaptáveis a novos contextos e que não apenas ensinem conteúdos a serem avaliados posteriormente. Metodologicamente, o projeto teve esquema quase-experimental tipo pré-teste/pós-teste. Foram escolhidos três professores de Ciências Exatas: professor experiente, auxiliar com nível superior e auxiliar estudante. Um texto-fonte lhes foi entregue com os conteúdos que deveriam ser ensinados a dez estudantes. As características do ensino foram analisadas quanto ao ajuste das aulas ao texto-fonte e avaliadas por juízes externos à pesquisa e pelos próprios estudantes. A aprendizagem dos conceitos foi avaliada por um pós-teste e uma autoavaliação dos estudantes, ambos de múltipla escolha. Apresentaram-se diferenças nos aspectos analisados nas aulas estudadas. A análise realizada permite evidenciar diferenças nos papéis, possibilitando fortalecer, assim, aspetos diferentes das aprendizagens dos estudantes em futuras aulas que venham a ministrar.Fil: Borgobello, Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; ArgentinaFil: Peralta, Nadia Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; ArgentinaFil: Roselli, Nestor Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; Argentina. Pontificia Universidad Católica Argentina "Santa María de los Buenos Aires."; Argentin

Tutorial function in formal education system: a possible modalities classification

A pesar de la abundante literatura existente sobre las tutorías en los distintos niveles de enseñanza, se advierte una ausencia de consenso acerca de clasifi caciones relativamente unifi - cadas en torno a estas mediaciones o funciones tutoriales. Por tal razón, se propone aquí una posible taxonomía que pretende ser sufi cientemente exhaustiva y con categorías excluyentes para poder abarcar los diferentes estudios empíricos sobre la función tutorial. El análisis de distintas investigaciones permitió establecer las siguientes categorías: tutores pares (con el mismo y con diferente grado de preparación) y expertos (orientadores y docentes). El fi n último de este artículo es que pueda resultar de utilidad para estudios posteriores que se aboquen a esta temática.In despite of the prolifi c literature about tutoring at different levels of education, there is a lack of agreements on unifi ed classifi cations around these tutorial mediations or functions. For this reason, it is proposed here a possible taxonomy with the goal of been enough comprehensive and with restricted categories. The classifi cation was made collecting different kind of data and empirical research papers. This analysis allowed establishing the following categories: peer tutors (with the same and with different degrees of preparation) and experts (counselors and teachers). The fi nal goal of this paper is to be useful for future studies in the area.Fil: Borgobello, Ana. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; ArgentinaFil: Peralta, Nadia Soledad. Universidad Nacional de Rosario; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; ArgentinaFil: Roselli, Nestor Daniel. Universidad Nacional de Rosario; Argentina. Universidad Nacional de Entre Rios; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Rosario. Instituto Rosario de Investigaciones en Ciencias de la Educación; Argentin

Propuesta de reubicación y nuevo layout de una fábrica de poliestireno expandido en el Distrito Metropolitano de Quito

The current study focuses on analyzing available places for the relocation of an expanded polystyrene factory in Quito, Ecuador. It also proposes a new layout that is intended to be more efficient than the existing one. This type of analysis must consider feasible locations designated by the city administration, such as Industrial Zones or Industrial Parks, according to the risk rating and environmental impact of the company. Therefore, two mathematical models were used to determine the optimal location. The first one considers costs associated with the relocation of the factory, and the other considers weighing specific factors with respect to the regular costumers of the company.El presente estudio se enfoca en analizar las opciones disponibles de ubicación para el traslado de una fábrica de poliestireno expandido en el Distrito Metropolitano de Quito, además de proponer un nuevo layout que sea más eficiente que el actual. En este análisis se consideran sitios que el Municipio de Quito califica como Zonas o Parques Industriales de acuerdo a la calificación de riesgo e impacto ambiental de la Empresa. Consecuentemente, se determina la ubicación óptima con dos modelos matemáticos. Uno considerando costos asociados al transporte-traslado de la fábrica y otro considerando criterios y ponderaciones con respecto a los clientes regulares de la fábrica