180 research outputs found

    Pattern formation in a predator-prey system characterized by a spatial scale of interaction

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    We describe pattern formation in ecological systems using a version of the classical Lotka-Volterra model characterized by a spatial scale which controls the predator-prey interaction range. Analytical and simulational results show that patterns can emerge in some regions of the parameters space where the instability is driven by the range of the interaction. The individual-based implementation captures realistic ecological features. In fact, spatial structures emerge in an erratic oscillatory regime which can contemplate predators' extinction.Comment: 5 pages, 4 figure

    Tratamiento quirúrgico de las roturas del tendón de Aquiles

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    El objetivo del trabajo fue valorar los resultados y complicaciones obtenidos tras tratamiento quirúrgico de las rupturas subcutáneas del tendón de Aquiles. Se revisaron 26 pacientes, con un seguimiento mínimo de 1 año. Detallamos nuestra metodología en cuanto a técnica quirúrgica y manejo postoperatorio. Se valoró el resultado clínico según los siguientes parámetros: movilidad de tobillo, potencia muscular tríceps, engrosamiento tendinoso, claudicación a la marcha, atrofia gemelar, incorporación a actividades deportivas y alteraciones residuales. Los resultados fueron muy buenos en 21 casos (80,7%); buenos en 5 (19,3%), y ningún caso con resultado regular o malo. Destacamos 5 complicaciones postoperatorias inmediatas y 1 caso de reruptura, con resultado final satisfactorio. Dados los buenos resultados obtenidos, recomendamos el tratamiento quirúrgico en pacientes activos, con buen estado general, independientemente de la edad.The objective of this work was to asess the clinical results and complications with the surgical treatment for subcutaneous Achilles tendon ruptures. Twenty six patients were clinically revised with a minimal follow up of one year. We detailed the surgical technique and postoperative management of the patients. Clinical results were assessed with the next parameters: ankle joint motion; triceps muscle strength; Achilles tendinous thickened; walking limp; triceps muscle atrophy, possibility of sports practice and definitive changes. We had excellent results in 21 cases (80,7%); good results in 5 cases (19,3%) and none with fair or poor results. We detached 5 cases with immediate postoperative complications and one case of relapse, all of them with good clinical result. Our excellent and good clinical results with the surgical technique for the Achilles tendon ruptures allow us to recommend this treatment in active patients, with appropriate health conditions in spite of the age

    First order transition and phase separation in pyrochlores with colossal-magnetoresistance

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    Tl2_{2}Mn2_{2}O7_{7} pyrochlores present colossal magnetoresistance (CMR) around the long range ferromagnetic ordering temperature (TC_{C}). The character of this magnetic phase transition has been determined to be first order, by purely magnetic methods, in contrast to the second order character previously reported by Zhao et al. (Phys. Rev. Lett. 83, 219 (1999)). The highest CMR effect, as in Tl1.8_{1.8}Cd0.2_{0.2}Mn2_{2}O7_{7}, corresponds to a stronger first order character. This character implies a second type of magnetic interaction, besides the direct superexchange between the Mn4+^{4+} ions, as well as a phase coexistence. A model is proposed, with a complete Hamiltonian (including superexchange and an indirect interaction), which reproduce the observed phenomenology.Comment: 6 pages. Figures include

    Estudio para la mejora de la calidad del vino albariño

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    Premio de Investigación, Real Academia Galega de Ciencias, convocatoria 2009.[EN]Twenty-two clones from Albariño variety (Vitis vinifera L.), from an initial collection of 115 clones, were selected on the basis of their ampelographic, molecular and sanitary characteristics. These selected clones were studied from the agronomic and oenological point of view, and were also quantified for their levels of susceptibility to Powdery Mildew, Oidium and Botrytis. An ecotypic yeast was selected, its use has been patented and it is being exploited. Musts obtained from the previously selected Albariño clones were fermented with this yeast, essentially by increasing the content in volatile substances of interest (terpens: linalool and geraniol; norisoprenoids: α-ionone and β- damascenone), leading to wines with improved fermentative dynamic and sensorial attributes.[ES]En base a características ampelográficas, moleculares y sanitarias, se seleccionaron 22 clones de la variedad Albariño (Vitis vinifera L.), partiendo de 115 iniciales. Sobre los clones seleccionados se ha llevado a cabo un estudio agronómico y enológico, así como la cuantificación de los niveles de susceptibilidad a Mildiu, Oídio y Botrytis. Se ha seleccionado una levadura ecotípica, cuyo uso ha sido patentado y se encuentra en explotación. Con ella se fermentaron los mostos obtenidos a partir de los clones de Albariño previamente seleccionados, dando lugar a vinos con una dinámica fermentativa xPremio de Investigación, Real Academia Galega de Ciencias, convocatoria 2009 y unos atributos sensoriales mejorados, fundamentalmente en base al aumento del contenido en sustancias volátiles de interés (terpenos: linalool y geraniol; norisoprenoides: α-ionona y β- damascenona).La actividad realizada ha sido financiada, además de por la Bodega Terras Gauda S.A., por la Xunta de Galicia (PGIDIT04TAL035E), y por el propio CSIC (PIE 2004 7 0E 214).Peer reviewe

    Analysis of a spatial Lotka-Volterra model with a finite range predator-prey interaction

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    We perform an analysis of a recent spatial version of the classical Lotka-Volterra model, where a finite scale controls individuals' interaction. We study the behavior of the predator-prey dynamics in physical spaces higher than one, showing how spatial patterns can emerge for some values of the interaction range and of the diffusion parameter.Comment: 7 pages, 7 figure

    The effectiveness of a health promotion with group intervention by clinical trial. Study protocol

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    <p>Abstract</p> <p>Background</p> <p>The promotion of health and the interventions in community health continue to be one of the pending subjects of our health system. The most prevalent health problems (cardiovascular diseases, cancer, diabetes...) are for the most part related to life habits. We propose a holistic and integral approach as the best option for tackling behavior and its determinants. The research team has elaborated the necessary educational material to realize group teaching, which we call "Health Workshops". The goal of the present study is to evaluate the effectiveness of these Health Workshops in the following terms: Health Related Quality of Life (HRQOL), incorporate and maintain a balanced diet, do physical activity regularly, maintain risk factors such as tension, weight, cholesterol within normal limits and diminish cardiovascular risk.</p> <p>Methods/Design</p> <p>Controlled and random clinical testing, comparing a group of persons who have participated in the Health Workshops with a control group of similar characteristics who have not participated in the Health Workshops.</p> <p>Field of study: the research is being done in Health Centers of the city of Barcelona, Spain.</p> <p>Population studied: The group is composed of 108 persons that are actually doing the Health Workshops, and 108 that are not and form the control group. They are assigned at random to one group or the other.</p> <p>Data Analysis: With Student's t-distribution test to compare the differences between numerical variables or their non parametric equivalent if the variable does not comply with the criteria of normality. (Kolmogorov-Smirnof test). Chi-square test to compare the differences between categorical variables and the Logistic Regression Model to analyze different meaningful variables by dichotomous analysis related to the intervention.</p> <p>Discussion</p> <p>The Health Workshop proposed in the present study constitutes an innovative approach in health promotion, placing the emphasis on the person's self responsibility for his/her own health.</p> <p>The rhythm of a weekly session during 8 weeks with recommended activities to put into practice, as well as the support of the group is an opportunity to incorporate healthy habits and make a commitment to self-care. The sheets handed out are a Health Manual that can always be consulted after the workshop ends.</p> <p>Trial registration</p> <p>Clinical Trials.gov Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01440738">NCT01440738</a></p

    A crowdsourcing database for the copy-number variation of the spanish population

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    Background: Despite being a very common type of genetic variation, the distribution of copy-number variations (CNVs) in the population is still poorly understood. The knowledge of the genetic variability, especially at the level of the local population, is a critical factor for distinguishing pathogenic from non-pathogenic variation in the discovery of new disease variants. Results: Here, we present the SPAnish Copy Number Alterations Collaborative Server (SPACNACS), which currently contains copy number variation profiles obtained from more than 400 genomes and exomes of unrelated Spanish individuals. By means of a collaborative crowdsourcing effort whole genome and whole exome sequencing data, produced by local genomic projects and for other purposes, is continuously collected. Once checked both, the Spanish ancestry and the lack of kinship with other individuals in the SPACNACS, the CNVs are inferred for these sequences and they are used to populate the database. A web interface allows querying the database with different filters that include ICD10 upper categories. This allows discarding samples from the disease under study and obtaining pseudo-control CNV profiles from the local population. We also show here additional studies on the local impact of CNVs in some phenotypes and on pharmacogenomic variants. SPACNACS can be accessed at: http://csvs.clinbioinfosspa.es/spacnacs/. Conclusion: SPACNACS facilitates disease gene discovery by providing detailed information of the local variability of the population and exemplifies how to reuse genomic data produced for other purposes to build a local reference database.This work is supported by Grants PID2020-117979RB-I00 from the Spanish Ministry of Science and Innovation; by the Institute of Health Carlos III (project IMPaCT-Data, exp. IMP/00019, IMP/00009 and PI20/01305), co-funded by the European Union, European Regional Development Fund (ERDF, “A way to make Europe”)

    Magnetization dynamics of weakly interacting sub-100 nm square artificial spin ices

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    Artificial Spin Ice (ASI), consisting of a two dimensional array of nanoscale magnetic elements, provides a fascinating opportunity to observe the physics of out-of-equilibrium systems. Initial studies concentrated on the static, frozen state, whilst more recent studies have accessed the out-of-equilibrium dynamic, fluctuating state. This opens up exciting possibilities such as the observation of systems exploring their energy landscape through monopole quasiparticle creation, potentially leading to ASI magnetricity, and to directly observe unconventional phase transitions. In this work we have measured and analysed the magnetic relaxation of thermally active ASI systems by means of SQUID magnetometry. We have investigated the effect of the interaction strength on the magnetization dynamics at different temperatures in the range where the nanomagnets are thermally active. We have observed that they follow an Arrhenius-type Néel-Brown behaviour. An unexpected negative correlation of the average blocking temperature with the interaction strength is also observed, which is supported by Monte Carlo simulations. The magnetization relaxation measurements show faster relaxation for more strongly coupled nanoelements with similar dimensions. The analysis of the stretching exponents obtained from the measurements suggest 1-D chain-like magnetization dynamics. This indicates that the nature of the interactions between nanoelements lowers the dimensionality of the ASI from 2-D to 1-D. Finally, we present a way to quantify the effective interaction energy of a square ASI system, and compare it to the interaction energy computed with micromagnetic simulations

    Inducción a la formación profesional

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    Desarrolla a manera de módulos, la forma y la información que de se debe entregar a los aprendices al momento de que estos ingresen a la institución para conocer el contexto, deberes, derechos, entre otros, que los estarán rodeando en el ámbito académico.It develops as a module, the form and the information that must be given to the apprentices when they enter the institution to know the context, duties, rights, among others, that will be surrounding them in the academic field.Conocimiento e Integración Grupal -- Inducción al SENA -- Inducción a la Formación Profesional Integral -- Inducción al Centro, Programa o Proyecto -- Inducción al Programa de Formación Profesional -- Inducción a los Servicios al Alumnado -- Servicios al Alumnado: Biblioteca -- Servicios al Alumnado: Promoción y contratación de Aprendices -- Servicios al Alumnado: Trabajo Social -- Servicios al Alumnado: Capellanía -- Servicios al Alumnado: Registro y Certificación -- Servicios al Alumnado: Validación -- Servicios al Alumnado: Actividades Recreativas, Culturales y Deportivas.naPara sujetos de formación40 página
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