Normalized abundance spectra of fish community reflect hydro-peaking on a Mediterranean large river

The European Water Framework Directive requires the integration of body size characters as an important part of fish-based bioassessment tools for freshwaters ecological status determination. The study of the entire fish community size-structure provides valuable information about food web capacity, food web stability and ecological efficiency of aquatic ecosystems. One of the most used representations of community size structure is the Normalized Abundance Spectra (NAS) that provides an approximation of the total fish abundance and food web capacity (through the parameter y-intercept) and an estimation of food web efficiency (through the slope of the linear regression). In this study we explored NAS of the lower Ebro River fish community by integrating data from monthly electrofishing samplings during a whole year (November 2014- October 2015). We found that the percentage of total alien and alien-prey individuals were directly related with y-intercept and inversely related with slope of NAS. This is because the bulk of the community consists of introduced species of small body length. Furthermore, we detected significant relationships between NAS-related parameters and the hydrological variables describing diel flow oscillations and daily flow variability. Based on this, we suggest that high flow variability conditions and, above all, high hydro-peaking conditions, caused a diminution of the total abundance of fish and a decrease of the proportion of small sized fish (i.e. lower y-intercept and flatter slopes of NAS, respectively). Finally, a significant interaction between hydro-peaking and the percentage of alien-predators suggests that high hydro-peaking conditions benefit predation by facilitating predator-prey encounters. This is reflected by strong linear relationship between NAS parameters and percentage of piscivorous at high hydropeaking conditions that disappears at low hydro-peaking fluctuations. We concluded that the high proportion of alien fishes and the presence of a hydropower generation plant that operates by hydro-peaking are important factors determining fish size structure in the lower Ebro River.info:eu-repo/semantics/acceptedVersio

Giant barocaloric effect in all-d-metal Heusler shape memory alloys

We have studied the barocaloric properties associated with the martensitic transition of a shape memory Heulser alloy Ni50Mn31.5Ti18.5 which is composed of all-d-metal elements. The composition of the sample has been tailored to avoid long range ferromagnetic order in both ausenite and martensite. The lack of ferromagnetism results in a weak magnetic contribution to the total entropy change thereby leading to a large transition entropy change. The combination of such a large entropy change and a relatively large volume change at the martensitic transition gives rise to giant barocaloric properties in this alloy. When compared to other shape memory Heusler alloys, our material exhibits values for adiabatic temperature and isothermal entropy changes significantly larger than values reported so far for this class of materials. Furthermore, our Ni50Mn31.5Ti18.5 also compares favourably to the best state-of-the-art magnetic barocaloric materials.Peer ReviewedPostprint (author's final draft

Response of stream ecosystem structure to heavy metal pollution: context-dependency of top-down control by fish

The stress-gradient hypothesis predicts that biotic interactions within food webs are context dependent, since environmental stressors can attenuate consumer-prey interactions. Yet, how heavy metal pollution influences the impacts of predatory fish on ecosystem structure is unknown. This study was conducted in the Osor stream (Spain), which features a metal (mainly Zn) pollution gradient. We aimed to determine how the responses of benthic communities to the presence and absence of predatory fish interact with environmental stress and to test whether the top-down control of top predators is context dependent. To address these questions, periphyton biomass and macroinvertebrate densities were determined throughout an exclosure/enclosure mesocosm experiment using the Mediterranean barbel (Barbus meridionalis) as a top predator. The monitoring study showed that metal accumulation in periphyton and macroinvertebrates reflected patterns observed in water. The mesocosm study showed that fish predation effects on larval chironomids were not context-dependent and that periphyton biomass was markedly lower in the presence of fish regardless of metal pollution levels. This strong top-down control on periphytic algae was attributed to the foraging behaviour of fish causing bioturbation. In contrast, the top predator removal revealed grazer-periphyton interactions, which were mediated by heavy metal pollution. That is, periphyton benefitted from a lower grazing pressure in the metal-polluted sites. Together, our results suggest that the top-down control by fishes depends more on functional traits (e.g. feeding behaviour) than on feeding guild, and demonstrate the capacity of top predators to modify anthropogenic stressor effects on stream food-web structure.Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This research was supported by the Spanish Ministry of Science, Innovation and Universities (projects CGL2013-43822-R and CGL2016-80820-R, AEI/FEDER/EU) and the Government of Catalonia (ref. 2017 SGR 548 and CERCA Programme). F. Rubio-Gracia and M. Argudo benefitted from a predoctoral fellowship from the University of Girona (IFUdG2017) and the Agency for Management of University and Research Grants (AGAUR) of the Government of Catalonia (2016 FI-B 00284), respectively

Low Time Complexity Algorithms for Path Computation in Cayley Graphs

International audienceWe study the problem of path computation in Cayley Graphs (CG) from an approach of word processing in groups. This approach consists in encoding the topological structure of CG in an automaton called Diff , then techniques of word processing are applied for computing the shortest paths. We present algorithms for computing the K-shortest paths, the shortest disjoint paths and the shortest path avoiding a set of nodes and edges. For any CG with diameter D, the time complexity of the proposed algorithms is O(KD|Diff |), where |Diff | denotes the size of Diff. We show that our proposal outperforms the state of art of topology-agnostic algorithms for disjoint shortest paths and stays competitive with respect to proposals for specific families of CG. Therefore, the proposed algorithms set a base in the design of adaptive and low-complexity routing schemes for networks whose interconnections are defined by CG

Impact of dietary habit, iodine supplementation and smoking habit on urinary iodine concentration during pregnancy in a catalonia population

1) Background: The nutritional status of women during pregnancy can have a considerable effect on maternal and fetal health, and on the perinatal outcome. Aim: to assess the changes occurring in dietary iodine intake, potassium iodide supplementation, and smoking habit, and the impact of these changes on the urinary iodine concentration (UIC) during pregnancy in a population of women in Catalonia (Spain). (2) Methods: Between 2009-2011, an observational study included a cohort of women whose pregnancies were monitored in the public health system in the Central and North Metropolitan areas of Catalonia. Women received individual educational counseling, a dietary questionnaire was completed, and a urine sample was collected for iodine determination at each trimester visit. (3) Results: 633 (67.9%) women answered the questionnaire at all 3 visits. The percentage of women with a desirable UIC (≥150 μg/L) increased from the first to the second trimester and remained stable in the third (57.3%, 68.9%, 68%; p < 0.001). Analysis of the relationship between UIC≥150 μg/L and the women's dietary habits showed that the percentage with UIC ≥150 μg/L increased with greater consumption of milk in the first trimester, and the same was true for iodized salt use in all three trimesters and iodine supplementation in all three. (4) Conclusion: During pregnancy, increased intake of milk, iodized salt, and iodine supplements were associated with an increase in the UIC. Keywords: pregnancy; iodine; dietary habits; iodine supplement; urinary iodine concentratio

Evaluación de competencias transversales en asignaturas relacionadas con Ingeniería Mecánica y de Materiales: Análisis y Resolución de Problemas, Aplicación y Pensamiento Práctico

[EN] Although the competence based curricula approach has been used in the development of the new programmes for Master and Bachelor degrees within the European Higher Education Area in recent years, the assessment of generic competences is still a pending task. This work presents a methodological proposal for the assessment of the competences of capacity for problem-solving and capacity for applying knowledge in practice, in subjects related to mechanical and materials engineering. In particular, this paper proposes a scale in order to quantify the level of achievement of each competence, and shows some assessment tools developed for this purpose. These tools are based on Checklists to evaluate the learning outcomes of each competence, that can be observed as evidences obtained from the assessment activities proposed during the course. These assessment activities are refered to the resolution of problems, individually and in groups. The learning outcomes, levels of achievement and the Checklist of each competence are presented. Some preliminary results from a first attempt to use this methodology in two subjects of Bachelor and Master degrees, are also described here. Finally, conclusions about preliminary results and the difficulties found in the development of these tools and its aplication are also presented.[ES] A pesar de que las competencias que se trabajan en los nuevos títulos de Grado y Máster figuran explícitamente en sus planes de estudios a partir de los cambios introducidos por el Espacio Europeo de Educación Superior, su evaluación sigue siendo una tarea pendiente a día de hoy. Este trabajo presenta una propuesta metodológica para la evaluación de las competencias de Análisis y Resolución de Problemas y de Aplicación y Pensamiento Práctico, en asignaturas relacionadas con la Ingeniería Mecánica y de Materiales. En particular, este trabajo propone una escala de valoración para cuantificar el nivel de logro de cada competencia, y muestra herramientas de evaluación desarrolladas para este propósito. Dichas herramientas están basadas en Listas de Control que evalúan resultados de aprendizaje de cada competencia, observados mediante las evidencias derivadas de la actividad de evaluación propuesta durante el curso, consistente en la resolución de problemas de forma autónoma y en grupo. Se detallan las escalas de desarrollo de cada competencia, sus resultados de aprendizaje y los ítems de cada Lista de Control. Se analizan algunos resultados preliminares derivados de un primer intento de uso de la metodología propuesta, en dos asignaturas de Grado y Máster. Finalmente se presentan conclusiones sobre los resultados preliminares, junto con las dificultades encontradas tanto en la elaboración de las herramientas de evaluación como en su implementación.Los autores quieren agradecer la ayuda económica y el apoyo institucional recibidos de la Universitat Politècnica de València a través del proyecto PIME/2014/A/012/B.Martínez Casas, J.; Sahuquillo Navarro, O.; Sonseca Olalla, A.; Carballeira, J.; Denia Guzmán, FD.; Suñer Martinez, JL.; Vila Tortosa, MP. (2015). Evaluación de competencias transversales en asignaturas relacionadas con Ingeniería Mecánica y de Materiales: Análisis y Resolución de Problemas, Aplicación y Pensamiento Práctico. En In-Red 2015 - CONGRESO NACIONAL DE INNOVACIÓN EDUCATIVA Y DE DOCENCIA EN RED. Editorial Universitat Politècnica de València. https://doi.org/10.4995/INRED2015.2015.1630OC

Desarrollo de estrategias de evaluación de competencias transversales en asignaturas de ingeniería mecánica y de materiales

[EN] The international accreditation for the Master and Bachelor degrees offered at our university, together with the demands of the employers, have made it clear that students’ curricula should specify not only what they have studied, but also what they are actually able to do. This work presents the results obtained within the frame of an innovative project (UPV – PIME program) on the evaluation of three generic competences that have been traditionally worked in subjects of mechanical and materials engineering: capacity for problem solving; capacity for applying knowledge in practice; and communication skills (both oral and written). Different tools for the assessment of these competences have developed with two main objectives: first, to quantify the level of achievement of the students in order to give a numerical evaluation; and second, to be used by the students as a learning material so that they can improve their capacities. These tools are based on the observation of some learning outcomes associated to these competences. Some evaluation activities have been proposed within the different subjects that allow to assess not only the specific scientific-technical competences, but also some of the generic ones.[ES] La acreditación internacional de los títulos de Grado y Máster en nuestra universidad, junto con las demandas de los empleadores, han puesto en evidencia que los planes de estudio deben especificar no sólo lo que se ha estudiado, sino también lo que se es capaz de hacer realmente. Este trabajo presenta los resultados obtenidos en el marco de un proyecto de innovación docente (programa PIME) sobre la evaluación de tres competencias transversales que se han trabajado tradicionalmente en asignaturas de ingeniería mecánica y materiales: la capacidad para la resolución de problemas; la capacidad para aplicar los conocimientos a la práctica; y habilidades de comunicación (oral y escrita). Se han desarrollado diferentes herramientas para la evaluación de estas competencias con dos objetivos principales: en primer lugar, para cuantificar el nivel de logro de los estudiantes con el fin de dar una evaluación numérica; y en segundo, como material de aprendizaje para que los estudiantes puedan mejorar sus capacidades. Estas herramientas se basan en la observación de algunos resultados de aprendizaje asociados a estas competencias. Se han propuesto algunas actividades de evaluación en las diferentes asignaturas que permiten evaluar no sólo las competencias científico-técnicas específicas, sino también algunas de las transversales.Por último, los autores quieren agradecer la ayuda económica y el apoyo institucional recibidos de la Universitat Politècnica de València a través del proyecto PIME/2014/A/012/B.Carballeira, J.; Martínez Casas, J.; Sahuquillo Navarro, O.; Sonseca Olalla, A.; Denia Guzmán, FD.; Suñer Martinez, JL.; Vila Tortosa, MP.... (2015). Desarrollo de estrategias de evaluación de competencias transversales en asignaturas de ingeniería mecánica y de materiales. En In-Red 2015 - CONGRESO NACIONAL DE INNOVACIÓN EDUCATIVA Y DE DOCENCIA EN RED. Editorial Universitat Politècnica de València. https://doi.org/10.4995/INRED2015.2015.1542OC

Tailoring barocaloric and magnetocaloric properties in low-hysteresis magnetic shape memory alloys

We report on the barocaloric and magnetocaloric effects in a series of low-hysteresis Ni-Mn-In magnetic shape memory alloys. We show that the behaviour exhibited by several quantities that characterise these caloric effects (isothermal entropy change, adiabatic temperature change and refrigerant capacity) can be rationalised in terms of the relative distance between the Curie point of the austenite and the martensitic transition temperature. It is found that the two caloric effects exhibit opposite trends. The behaviour of the barocaloric effect parallels that exhibited by the transition entropy change, thereby showing larger values for weakly magnetic samples. Regarding the magnetocaloric effect, the isothermal entropy change is maximum for those samples transforming martensitically close to the Curie point of the austenite. Such a maximum value does not correspond to the maximum adiabatic temperature change, and samples with martensitic transition slightly below the Curie point do have larger temperature changes as a result of the strongest sensitivity of the transition to the magnetic field. (C) 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.Postprint (author's final draft

Innovative public procurement guide

Podeu consultar la versió en català a: http://hdl.handle.net/11703/113907Podeu consultar la versió en castellà a: http://hdl.handle.net/11703/11563