676 research outputs found
La aproximación minimax y el algoritmo de Remez. Aplicaciones
El proyecto hará una presentación unificada de la teoría sobre la aproximación polinómica minimax continua y discreta, y la solución minimax de sistemas lineales: condición de Haar, algoritmo del intercambio y algoritmo de Remez. Parte del proyecto es la implementación efectiva en Matlab de los distintos algoritmos para la computación de aproximaciones óptimas en la norma infinito. El trabajo consta de tres partes: En el primer capítulo se repasan nociones fundamentales de teoría de la aproximación. Entre ellas se encuentran definiciones elementales como son la convexidad o envolvente convexa y ciertos teoremas de convexidad como el de Helly o el de Carathéodory, que posteriormente serán utilizados. También, ciertos resultados que garantizan la existencia y la unicidad de las mejores aproximaciones en espacios normados, algunos estudiados en el Grado. En el segundo capítulo se consideran los problemas de aproximación asociados a la solución de sistemas lineales de ecuaciones sobredeterminados. Cuando se trata de aproximaciones en la norma infinito, se enuncian teoremas de caracterización de la solución; se analiza el caso particular de hallar la solución minimax de un sistema de n+1 ecuaciones con n incógnitas. Para conseguir resolver los problemas, se estudian dos algoritmos: el ascendente y el descendente. Ambos están analizados y programados con el lenguaje de programación MATLAB. En el tercer y último capítulo se trata el problema general de la aproximación de una función continua en un intervalo compacto mediante un polinomio. Se habla también de un problema más general en que los polinomios serán reemplazados por otras funciones continuas. Se estudiará la teoría minimax, exponiendo el teorema de caracterizacion y ciertos teoremas que garantizan la unicidad y que acotan el error en dicha teoría. Además, se explicará el algoritmo de intercambio de Remez, el cual se implementará en MATLAB.Grado en Matemática
Understanding the Meaning of Conformity to Feminine Norms in Lifestyle Habits and Health: A Cluster Analysis
Background: Gender roles impact different spheres of life and lead women to behavioral patterns and lifestyle habits associated with femininity, generating important differences between men and women in health. The present study analyzed relationships between conformity to the feminine norms and different lifestyle indicators: Educational level, marital status, alcohol consumption, tobacco consumption, sleeping hours, social support, and physical activity. Additionally, cluster analysis was developed in order to identify different patterns of gender role conformity.
Methods: The sample was made up of 347 women age 18–70 from Spain. Data collection was conducted during 2014.
Results: Multiple logistic regression analyses produced odds ratios showing that women with lower feminine role conformity were more likely to use tobacco and alcohol, but less likely to share their lives with someone. Cluster analysis found four different profiles of gender role conformity related to different patterns of alcohol consumption and marital status.
Conclusions: Conformity to feminine norms was associated with basic affective conditions such as sharing life with others and with alcohol and tobacco consumption, but not with physical activity, social support, and sleep duration. Whereas tobacco and alcohol use have important health implications, public health systems should pay attention to gender-related variables in order to design and implement specific prevention programs
Prediction of standard particleboard mechanical properties utilizing an artificial neural network and subsequent comparison with a multivariate regression model
The physical properties (specific gravity, moisture content, thickness swelling and water absorption) and mechanical properties (internal bond strength, bending strength and modulus of elasticity) were determined on 93 Spanish-manufactured standard particleboards of different thicknesses selected randomly at the end of the production process. The testing methods of the corresponding European standards (EN) were used, except in the case of the thickness swelling and absorption tests, for which the Spanish UNE standard was used. The thickness and the values obtained for the physical properties were entered into an artificial neural network in order to predict the mechanical properties of the board. The fit was compared with the usual multivariate regression models. The use of a neural network made it possible to obtain the values of bending strength, modulus of elasticity and internal bond strength of the boards utilizing the known data, not only of thickness, moisture content and specific gravity, but also of thickness swelling and water absorption. The neural network proposed is much better adapted to the observed values than any of the multivariate regression models obtained
Interest group perceptions on water policy reforms: insight from a water-stressed basin
[EN] Water policies have been implemented worldwide to face water stress. However, the existence of water users' groups with opposite interests and different political power results in the plain failure or low effectiveness of water policy reforms. A better understanding of users' perceptions regarding policy outcomes is important to avoid the failure of water policies and the intensification of water conflicts. This paper empirically examines the divergent perception of interest groups on the implementation of different policies dealing with water scarcity and their proactive involvement with water agencies. We have conducted a survey in the Jucar River Basin (a water-stressed basin in southeastern Spain) to analyze interest group opinions regarding water policy effectiveness and water institutions' performance in water management. Questionnaires were sent to the main irrigation districts and urban water utilities within the basin. The collected information gives a general picture of the behavior of opposite water interest groups in this basin. The analysis of the perceptions on water policy reform between the groups highlights the existence of significant differences between preferred measures to address water scarcity and lobbying capacity. These differences depend on the size of the group, the specific basin location, and other group characteristics.Esteban, E.; Dinar, A.; Albiac-Murillo, J.; Calera, A.; García Molla, M.; Avella Reus, LF. (2018). Interest group perceptions on water policy reforms: insight from a water-stressed basin. Water Policy. 20(4):794-810. https://doi.org/10.2166/wp.2018.114S794810204Böhmelt, T., Bernauer, T., Buhaug, H., Gleditsch, N. P., Tribaldos, T., & Wischnath, G. (2014). Demand, supply, and restraint: Determinants of domestic water conflict and cooperation. Global Environmental Change, 29, 337-348. doi:10.1016/j.gloenvcha.2013.11.018Devlin, C., & Hendrix, C. S. (2014). Trends and triggers redux: Climate change, rainfall, and interstate conflict. Political Geography, 43, 27-39. doi:10.1016/j.polgeo.2014.07.001Estrela T. , (2004). Jucar Pilot River Basin: Provisional Article 5 Report. Oficina de Planificación Hidrográfica. Confederación Hidrográfica del Júcar. Ministerio de Medio Ambiente, Valencia, Spain.Gandure, S., Walker, S., & Botha, J. J. (2013). Farmers’ perceptions of adaptation to climate change and water stress in a South African rural community. Environmental Development, 5, 39-53. doi:10.1016/j.envdev.2012.11.004Gizelis, T.-I., & Wooden, A. E. (2010). Water resources, institutions, & intrastate conflict. Political Geography, 29(8), 444-453. doi:10.1016/j.polgeo.2010.10.005Greiner, R., & Gregg, D. (2011). Farmers’ intrinsic motivations, barriers to the adoption of conservation practices and effectiveness of policy instruments: Empirical evidence from northern Australia. Land Use Policy, 28(1), 257-265. doi:10.1016/j.landusepol.2010.06.006Greiner, R., Patterson, L., & Miller, O. (2009). Motivations, risk perceptions and adoption of conservation practices by farmers. Agricultural Systems, 99(2-3), 86-104. doi:10.1016/j.agsy.2008.10.003Hendrix, C. S., & Glaser, S. M. (2007). Trends and triggers: Climate, climate change and civil conflict in Sub-Saharan Africa. Political Geography, 26(6), 695-715. doi:10.1016/j.polgeo.2007.06.006Kahil, M. T., Ward, F. A., Albiac, J., Eggleston, J., & Sanz, D. (2016). Hydro-economic modeling with aquifer–river interactions to guide sustainable basin management. Journal of Hydrology, 539, 510-524. doi:10.1016/j.jhydrol.2016.05.057Mekonnen, M. M., & Hoekstra, A. Y. (2016). Four billion people facing severe water scarcity. Science Advances, 2(2), e1500323. doi:10.1126/sciadv.1500323Mertz, O., Mbow, C., Reenberg, A., & Diouf, A. (2008). Farmers’ Perceptions of Climate Change and Agricultural Adaptation Strategies in Rural Sahel. Environmental Management, 43(5), 804-816. doi:10.1007/s00267-008-9197-0Ortega-Reig, M., Palau-Salvador, G., Cascant i Sempere, M. J., Benitez-Buelga, J., Badiella, D., & Trawick, P. (2014). The integrated use of surface, ground and recycled waste water in adapting to drought in the traditional irrigation system of Valencia. Agricultural Water Management, 133, 55-64. doi:10.1016/j.agwat.2013.11.004Pérez-Martín, M. A., Estrela, T., Andreu, J., & Ferrer, J. (2014). Modeling Water Resources and River-Aquifer Interaction in the Júcar River Basin, Spain. Water Resources Management, 28(12), 4337-4358. doi:10.1007/s11269-014-0755-3Raleigh, C., & Urdal, H. (2007). Climate change, environmental degradation and armed conflict. Political Geography, 26(6), 674-694. doi:10.1016/j.polgeo.2007.06.005Sanz, D., Gómez-Alday, J. J., Castaño, S., Moratalla, A., De las Heras, J., & Martínez-Alfaro, P. E. (2009). Hydrostratigraphic framework and hydrogeological behaviour of the Mancha Oriental System (SE Spain). Hydrogeology Journal, 17(6), 1375-1391. doi:10.1007/s10040-009-0446-yUrquijo, J., & De Stefano, L. (2015). Perception of Drought and Local Responses by Farmers: A Perspective from the Jucar River Basin, Spain. Water Resources Management, 30(2), 577-591. doi:10.1007/s11269-015-1178-5Van Oel, P. R., Krol, M. S., & Hoekstra, A. Y. (2009). A river basin as a common‐pool resource: A case study for the Jaguaribe basin in the semi‐arid Northeast of Brazil. International Journal of River Basin Management, 7(4), 345-353. doi:10.1080/15715124.2009.9635393Ward, F. A., & Pulido-Velazquez, M. (2008). Water conservation in irrigation can increase water use. Proceedings of the National Academy of Sciences, 105(47), 18215-18220. doi:10.1073/pnas.080555410
The Political Economy of Water Policy Design and Implementation in the Jucar Basin, Spain
Water scarcity has intensified conflicts between regions and interest groups
for the use of water resources. Water policies have been implemented worldwide to
face with water stress; however, existence of opposite interest between water users
together with differences in their political power hinder the effectiveness of the water
policy reform. A better understanding of users’ behavior is necessary to avoid the
failure of water policies and the intensification of water scarcity problems and water
conflicts. This paper empirically examines the perception of interest group about the
implementation of different water policies to deal with water scarcity, and also their
proactive involvement, or lobbying, with water organizations. We have conducted a
survey in a water stressed basin in Southeastern Spain (Jucar River Basin) to analyze
interest group opinions regarding water institutions’ performance and management;
and the cost and benefits from group influence or lobbying on policy makers. The
results highlight the existence of notably differences between the preferred measure to
face with water scarcity together with sizable divergences in the active lobbying
capacity of the interest groups depending on the size of the group, the specific basin
location (upstream or downstream), and group characteristics.This Project
was possible because the support of the project INIA RTA2014-00050-00-00. Ariel Dinar would
like to acknowledge support by the Multistate Hatch Project W3190- Management and Policy
Challenges in a Water-Scarce WorldPublishe
Proyecto IPSO: síntesis de experiencias de incentivos en sostenibilidad
El proyecto IPSO se ha creado por iniciativa del Comisionado para el desarrollo sostenible de la Universitat Politècnica de Catalunya (UPC) y tiene como finalidad proponer un conjunto de medidas para incentivar la introducción de criterios de sostenibilidad en la actividad académica del Personal Docente e Investigador (PDI) de la universidad.
La UPC, mediante sus dos planes de medio ambiente para los periodos 1996-2001 y 2001-2006, ha sido pionera en su compromiso con el medio ambiente. Al finalizar el segundo plan, se ha decidido dar un salto cualitativo y apostar por una estrategia global que integre las actividades formativas, de investigación e institucionales, asumiendo el liderazgo que le corresponde en la obtención de una sociedad más sostenible. Este compromiso, que se concreta en la Declaración de Sostenibilidad de la UPC, fue aprobado por el Claustro de la UPC el 18 de febrero de 2008.
Aunque en la UPC se están llevando a cabo múltiples iniciativas docentes y de investigación en el ámbito de la sostenibilidad, existe la percepción de qué estas no están debidamente reconocidas en el funcionamiento cotidiano de la Universidad.
Se ha iniciado, por lo tanto, una primera tarea de recopilación de información, experiencias y propuestas de reconocimiento de las actividades desarrolladas alrededor del Desarrollo Humano Sostenible (DHS) y de las diferentes perspectivas que contempla.
En este artículo se presenta una primera síntesis de resultados, tanto de la UPC como de otros referentes nacionales e internacionales, que deberá servir como base para elaborar un documento de propuestas que permita a la Universidad definir una estrategia de mejora del compromiso institucional hacia la sostenibilidadPeer Reviewe
Development of an empirical model for seasonal forecasting over the Mediterranean
Número monográfico dedicado al "18th EMS Annual Meeting: European Conference for Applied Meteorology and Climatology 2018"In the frame of MEDSCOPE project, which mainly aims at improving predictability on seasonal timescales over the Mediterranean area, a seasonal forecast empirical model making use of new predictors based on a collection of targeted sensitivity experiments is being developed. Here, a first version of the model is presented. This version is based on multiple linear regression, using global climate indices (mainly global teleconnection patterns and indices based on sea surface temperatures, as well as sea-ice and snow cover) as predictors. The model is implemented in a way that allows easy modifications to include new information from other predictors that will come as result of the ongoing sensitivity experiments within the project. Given the big extension of the region under study, its high complexity (both in terms of orography and landsea distribution) and its location, different sub regions are affected by different drivers at different times. The empirical model makes use of different sets of predictors for every season and every sub region. Starting from a collection of 25 global climate indices, a few predictors are selected for every season and every sub region, checking linear correlation between predictands (temperature and precipitation) and global indices up to one year in advance and using moving averages from two to six months. Special attention has also been payed to the selection of predictors in order to guaranty smooth transitions between neighbor sub regions and consecutive seasons. The model runs a three-month forecast every month with a one-month lead time.This research has been supported by MEDSCOPE project, cofunded by the European Comission as part of ERA4CS, an ERANET initiated by JPI Climate (grant agreement 690462.5)
Evolución histórica de las enfermedades causadas por micobacterias no pigmentadas de crecimiento rápido en un Hospital Universitario
Non-pigmented rapidly growing
mycobacteria (NPRGM) are a group of organisms of increasing
interest due to the growing number of potential patients
and the difficulties for a proper treatment in many of them.
However, the evolution of these diseases in a long period of
time and its evolutionary changes has been described only in a
scanty number of reports.
Material and methods. We performed a retrospective
study between January 1st 2004 and December 31st 2017 in
order to evaluate the clinical significance and types of diseases
caused by NPRGM. Patients with isolates of NPRGM during
this period were selected for the study, and clinical charts were
reviewed using a predefined protocol.
Results. During this period we identified 59 patients
(76 clinical samples) with isolates of NPRGM, with 12 cases
of clinical disease and one patient with doubtful significance
(including 6 respiratory tract infections, 2 catheter infections,
1 skin and soft tissue infection, 1 disseminated infection, 1
conjunctivitis, 1 prosthetic joint infection and 1 mastitis). Fifty
percent of M. chelonae isolates, 37.5% of M. abscessus isolates
and 23.33% of M. fortuitum isolates were clinically significant.
None of the isolates of other species were significant.
Conclusions. Most isolates in respiratory samples were
contaminants/colonizations. M. abscessus was the main
etiological agent in respiratory syndromes, whereas M.
chelonae and M. fortuitum were more frequently associated
with other infections, especially clinical devices and skin and
soft tissue infections.Las micobacterias no pigmentadas de
crecimiento rápido (MNPCR) son un grupo de organismos
de interés creciente debido al número cada vez mayor de
pacientes potenciales y a las dificultades en el tratamiento.
Sin embargo, el número de estudios que analizan la evolución
de estos casos a lo largo de un periodo de tiempo largo es
escaso.
Material and métodos. Se realizó un estudio
retrospectivo entre el 1 de enero de 2004 y el 31 de diciembre
de 2017 para evaluar el significado clínico y los tipos de
enfermedades causados por MNPCR. Se seleccionaron para ello
aquellos pacientes con aislamientos de MNPCR, y se revisaron
las historias clínicas mediante un protocolo predefinido.
Resultados. Se identificaron 59 pacientes (76 muestras)
con aislamientos de MNPCR, de los cuales 12 presentaron
enfermedad y uno tuvo un significado dudoso (incluyendo 6
infecciones respiratorias, 2 infecciones asociadas a catéter,
1 infección de piel y partes blandas, 1 infección diseminada,
1 conjuntivitis, 1 infección de prótesis osteoarticular y 1
mastitis). El 50 % de los aislamientos de Mycobacterium
chelonae, el 37,5 % de Mycobacterium abscessus y el
23,33 % de Mycobacterium fortuitum fueron clínicamente
significativos. Ninguno de los aislamientos de otras especies
fue significativo La mayoría de los aislamientos de
muestras respiratorias resultaron ser contaminantes/
colonizaciones. M. abscessus fue el principal agente etiológico
en las infecciones respiratorias, mientras que M. chelonae y
M. fortuitum fueron asociados con mayor frecuencia a otras infecciones, especialmente infecciones de piel y partes blandas
e infecciones asociadas a dispositivos biomédico
Comunitat amigable per a les persones amb demència. Fem-ho possible!
[cat] Aquest capítol pretén justificar la necessitat de crear una comunitat conscienciada, respectuosa i facilitadora de la inclusió social de les persones afectades per diferents tipus de demències, partint de la hipòtesi que aquestes iniciatives produeixen beneficis en la qualitat de vida de les persones, les seves famílies cuidadores i la societat. En primer lloc, exposem un recull de les experiències i els models d’intervenció que s’han fet en l’àmbit internacional i nacional, així com un seguiment dels procediments per implementar aquestes comunitats. A continuació, presentem l’experiència i els primers resultats recollits després de la posada en marxa, per part de la Creu Roja, en col·laboració amb altres entitats, d’un projecte pilot d’enfocament comunitari. El projecte, basat en els models explorats i l’estudi de necessitats en l’àmbit local, pretén crear espais amigables amb la demència en diferents barris de la ciutat de Palma. Finalment, emmarquem la iniciativa de la creació de la Comunitat Amigable amb la Demència en la línia d’actuació de l’Ajuntament de Palma com a membre de la Xarxa Espanyola de Ciutats i Comunitats Amigables amb la Gent Gran.[spa] Este capítulo pretende justificar la necesidad de crear una comunidad concienciada, respetuosa y facilitadora de la inclusión social de las personas afectadas por diferentes tipos de demencias, partiendo de la hipótesis que iniciativas de este tipo producen beneficios en la calidad de vida de estas personas, sus familias cuidadoras y la sociedad. En primer lugar, exponemos una recopilación de las experiencias y los modelos de intervención que se han realizado a nivel internacional y nacional, así como un seguimiento de los procedimientos para implementar dichas comunidades. A continuación, presentamos la experiencia y los primeros resultados recogidos después de la puesta en marcha, por parte de Cruz Roja en colaboración con otras entidades, de un proyecto piloto de enfoque comunitario. El proyecto, basado en los modelos explorados y el estudio de necesidades a nivel local, pretende crear espacios amigables con la demencia en diferentes barrios de Palma. Finalmente, enmarcamos la iniciativa de la creación de la Comunidad Amigable con la Demencia dentro de la línea de actuación del Ayuntamiento de Palma como miembro de la Red Española de Ciudades y Comunidades Amigables con las Personas Mayores
Potential postbiotic activities of extracellular products of probiotic bacteria from gilthead seabream gastrointestinal tract
Probiotics have been established as a potential tool for improving gut health and environmental quality in aquaculture. However, recent evidence suggests that bacterial viability is not necessary to attain the beneficial-promoting effects. In this way, postbiotics have emerged providing a potential opportunity in the field of functional foods. They are soluble factors resulting from the metabolic activity of a probiotic or any released molecule, including short-chain fatty acids, enzymes, extracellular products, etc. that can have interesting properties inducing biological responses on health similar to probiotics while avoiding the administration of live microorganisms. Interestingly, its production can be affected by different factors such as the components of the culture media among others. Information on this type of postbiotic activities is very scarce, especially in the case of aquaculture, so the evaluation of the nutraceutical use of postbiotics to improve health management in fish and other cultivated aquatic organisms is an emerging area of research in aquaculture.
In a previous work, we characterized four potential probiotics that were isolated from the gastrointestinal tract of Sparus aurata specimens fed with a diet containing a blend of microalgae. This diet involves a selection pressure on the intestinal microbiota of the fish that will be used to achieve enrichment in bacteria with a set of extracellular enzymatic activities capable of metabolizing and mobilizing the components of the diet enriched with microalgae. Here, we investigate the postbiotic potential of the extracellular products (ECPs) obtained from the four candidate probiotics grown on different microalgae-supplemented medium, and evaluate its enzymatic and antibacterial activity, and its cytotoxicity against the SAF-1 cell line. Our objective is to select different ECPs with a variety of activities that help the digestive process of seabream, with the aim to be included in aquafeeds.This work was funded by Junta de Andalucía (grant no. P20_00085) and co-financed by FEDER funds
- …