Renormalization group approach to anisotropic superconductivity

The superconducting instability of the Fermi liquid state is investigated by considering anisotropic electron-boson couplings. Both electron-electron interactions and anisotropic electron-boson couplings are treated with a renormalization-group method that takes into account retardation effects. Considering a non-interacting circular Fermi surface, we find analytical solutions for the flow equations and derive a set of generalized Eliashberg equations. Electron-boson couplings with different momentum dependences are studied, and we find superconducting instabilities of the metallic state with competition between order parameters of different symmetries. Numerical solutions for some couplings are given to illustrate the frequency dependence of the vertices at different coupling regimes.Comment: 9 pages, 7 figures. Final version as published in Phys. Rev.

Self-energy corrections to anisotropic Fermi surfaces

The electron-electron interactions affect the low-energy excitations of an electronic system and induce deformations of the Fermi surface. These effects are especially important in anisotropic materials with strong correlations, such as copper oxides superconductors or ruthenates. Here we analyze the deformations produced by electronic correlations in the Fermi surface of anisotropic two-dimensional systems, treating the regular and singular regions of the Fermi surface on the same footing. Simple analytical expressions are obtained for the corrections, based on local features of the Fermi surface. It is shown that, even for weak local interactions, the behavior of the self-energy is non trivial, showing a momentum dependence and a self-consistent interplay with the Fermi surface topology. Results are compared to experimental observations and to other theoretical results.Comment: 13 pages, 10 figure

Polymorphic transformation from body-centered to face-centered cubic vanadium metal during mechanosynthesis of nanostructured vanadium nitride determined by extended x-ray absorption fine structure spectroscopy

The pathway for vanadium nitride VN formation obtained by milling treatment has been traced out. At the initial stages of the process, the reactant, vanadium metal, showing body-centered cubic bcc structure, becomes highly distorted. Simultaneously, the formation of a small nucleus of the product, VN, takes place. X-ray absorption spectroscopy XAS has allowed the quantification of the distortion degree as well as the detection of the VN nucleus in the early stages of their formation, while other standard structural characterization techniques are unable to detect such phenomena. For increasing milling times, apart from the expected increase in the size of the VN nucleus, a polymorphic transformation from bcc to fcc vanadium metal has been recorded. This phase might play a key role in the overall synthesis process and could be a reaction intermediate in other solid state processes involving V metal. The sensitivity of XAS to noncrystalline domains and to highly distorted environments, as well as the use of high resolution x-ray diffraction, has provided the relevant information to understand the whole reaction process.European Synchrotron Radiation Facility (ESRF)-ME-737SpLine CRG (beamline BM25 at the ESRF)-25- 01-657Ministerio de Educación y Ciencias de España-BQU2002-04364-C02-01 y BQU2002- 04364-C02-

Stability behaviour of composite magnetorheological fluids by an induction method

Este artículo puede consultarse en la siguiente dirección de la editorial: http://jim.sagepub.com/content/early/2015/03/26/1045389X15577656.full.pdf+htmlIn this work we study the stability behaviour of composite magnetorheological (MR) fluids consisting of magnetic (iron) and non-magnetic (poly (methylmethacrylate), PMMA) particles dispersed in mineral oil. Because of the opacity of the suspensions, optical methods traditionally employed for evaluation of the gravitational settling in colloidal suspensions are not suitable for sedimentation follow-up in this case. For this reason, we use an alternative method based on the evaluation of the resonant frequency of the inductance of a thin coil surrounding the sample The movement of the coil along the height of the container at specified steps and time intervals allows obtaining information about the local volume fraction of particles inside the tube. The obtained successive profiles for the multi-component suspensions show a decrease of the iron particle settling and of the initial rate of settling as the PMMA volume fraction is increased. Finally, the increase of the PMMA concentration gives rise to an improvement of the rheological properties upon magnetic field application for a given concentration of iron. Both a strongrheological response and a good colloidal stability are essential for practical applications.Proyectos PE2012-FQM694 (Junta de Andalucía, Spain)y FIS2013-47666-C3-1-R (Ministerio de Economía y Competitividad, Spain). L. R.-A. agrradece a la Universidad de Granada su contrato puente (Plan Propio de Investigación, UGR)

Deformation of anisotropic Fermi surfaces due to electron-electron interactions

We analyze the deformations of the Fermi surface induced by electron-electron interactions in anisotropic two dimensional systems. We use perturbation theory to treat, on the same footing, the regular and singular regions of the Fermi surface. It is shown that, even for weak local coupling, the self-energy presents a nontrivial behavior showing momentum dependence and interplay with the Fermi surface shape. Our scheme gives simple analytical expressions based on local features of the Fermi surface.Comment: 7 pages, 3 figure

Adaptation of the person centered therapeutic relationship patient version (PCTR‐PT) to a version for physiotherapists (PCTR‐PHYS) and evaluation of its psychometric properties

[EN] Background and Purpose The therapeutic relationship is a central component for developing person-centered care within physiotherapy services. However, it is necessary to understand how this relationship is perceived by both parties involved. The Person Centered Therapeutic Relationship-Patient scale (PCTR-PT) was constructed to identify patients' perceptions. No instruments are currently available to correlate patients' and physiotherapists' perceptions of the therapeutic relationship. This study sought to adapt the PCTR-PT to develop a version for physiotherapists, the Person Centered Therapeutic Relationship Scale for Physiotherapists (PCTR-PHYS) and to determine its psychometric properties. Methods A three-stage study was performed: (1) item generation, (2) pretesting of the questionnaire, (3) analysis of psychometric properties. Factor validity and psychometric properties were analyzed by confirmatory factor analysis (CFA). Convergent validity was calculated. Internal consistency was verified using the Cronbach's alpha coefficient. The intraclass correlation coefficient (ICC) was used to examine temporal stability. Results Thirty-three physiotherapists participated in two rounds of cognitive interviews and 343 participated in the analysis of psychometric properties. The CFA confirmed the four-structure model. Reliability of the tool was confirmed by Cronbach's alpha (α = 0.863) for all four dimensions, as all were above 0.70, ranging from 0.704 (relational bond) and 0.898 (therapeutic communication). Test-retest was performed with 2-week intervals, indicating an appropriate stability for the scale (ICC = 0.908). Discussion The Person Centered Therapeutic Relationship Scale for Physiotherapists is a useful, valid and applicable instrument to evaluate the person-centered therapeutic relationship during physiotherapy interventions. It will enable the comparison of patients' and physiotherapists' perceptions. To provide person-centered care in physiotherapy services, there is a clear need to incorporate specific resources into clinical practice to evaluate the quality of the therapeutic relationship from the perspective of both the persons being treated and the professionals providing care.SIPublicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCL

Effect of chestnut flour and probiotic microorganism on the functionality of dry-cured meat sausages

The meat industry has made efforts to develop meat and meat products with functional ingredients to prevent the risk of disease and to promote health conditions. Therefore, the aim of the present work was to study the combined use of the probiotic strain, Lactobacillus plantarum, and potential prebiotic chestnut flour in Spanish dry-cured sausage (Longaniza de Pascua). Chestnut flour and the probiotic strain improved LAB counts on Longaniza de Pascua without modifying product flavour. Chestnut flour had a significant effect on pH decrease and residual nitrite values, but lipid oxidation values were increased. The symbiotic meat product could be considered a healthy matrix as a probiotic carrier.Fil: Sirini, Noelí Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Roldán, A.. Universidad de Miguel Hernández; EspañaFil: Lucas González, R.. Universidad de Miguel Hernández; EspañaFil: Fernández López, J.. Universidad de Miguel Hernández; EspañaFil: Viuda Martos, M.. Universidad de Miguel Hernández; EspañaFil: Pérez Álvarez, J.A.. Universidad de Miguel Hernández; EspañaFil: Frizzo, Laureano Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Rosmini, Marcelo Raul. Universidad Nacional del Litoral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Heterozygosity-fitness correlations and inbreeding depression in two critically endangered mammals

The relation among inbreeding, heterozygosity, and fitness has been studied primarily among outbred populations, and little is known about these phenomena in endangered populations. Most researchers conclude that the relation between coefficient of inbreeding estimated from pedigrees and fitness traits (inbreeding-fitness correlations) better reflects inbreeding depression than the relation between marker heterozygosity and fitness traits (heterozygosity-fitness correlations). However, it has been suggested recently that heterozygosity-fitness correlations should only be expected when inbreeding generates extensive identity disequilibrium (correlations in heterozygosity and homozygosity across loci throughout the genome). We tested this hypothesis in Mohor gazelle (Gazella dama mhorr) and Iberian lynx (Lynx pardinus). For Mohor gazelle, we calculated the inbreeding coefficient and measured heterozygosity at 17 microsatellite loci. For Iberian lynx, we measured heterozygosity at 36 microsatellite loci. In both species we estimated semen quality, a phenotypic trait directly related to fitness that is controlled by many loci and is affected by inbreeding depression. Both species showed evidence of extensive identity disequilibrium, and in both species heterozygosity was associated with semen quality. In the Iberian lynx the low proportion of normal sperm associated with low levels of heterozygosity was so extreme that it is likely to limit the fertility of males. In Mohor gazelle, although heterozygosity was associated with semen quality, inbreeding coefficient was not. This result suggests that when coefficient of inbreeding is calculated on the basis of a genealogy that begins after a long history of inbreeding, the coefficient of inbreeding fails to capture previous demographic information because it is a poor estimator of accumulated individual inbreeding. We conclude that among highly endangered species with extensive identity disequilibrium, examination of heterozygosity-fitness correlations may be an effective way to detect inbreeding depression, whereas inbreeding-fitness correlations may be poor indicators of inbreeding depression if the pedigree does not accurately reflect the history of inbreeding.Peer Reviewe

Valoración energética y diseño óptimo de impulsiones con caudal variable

[ES] En este trabajo se presenta una metodología para la valoración energética de estaciones de bombeo que abastecen caudales variables. El caudal impulsado se caracteriza como variable estocástica mediante su función de densidad. Dada la dificultad de conocer dicha función en la realidad cuando no existen aforadores, se deberá estimar mediante la adopción de hipótesis racionales. Las hipótesis de Clèment se han usado para caracterizar dicha función de densidad asociada al caudal distribuido en zonas regables a la demanda. Caracterizado el caudal, se determina el consumo energético a partir del conocimiento de las curvas características (altura-caudal y potencia-caudal) de cada uno de los impulsores. La metodología presentada permite la evaluación de cualquier sistema de bombeo teniendo en cuenta la variabilidad del caudal.López, R.; Reca Cardeña, J.; Camacho, E.; Roldán Cañas, J.; Alcaide García, M. (1995). Valoración energética y diseño óptimo de impulsiones con caudal variable. Ingeniería del Agua. 2(1):19-24. https://doi.org/10.4995/ia.1995.2653192421Clément, R. y Galand (1979) Irrigation par aspersion et réseaux collectifs de distribution sous pression. Editorial Eyrolles.Granados, A. (1990) Infraestructura de regadíos: redes colectivas de riego a presión (2a edición). E.T.S. de Ingenieros de Caminos, Canales y Puertos, Universidad Politécnica de Madrid.ITUR (1992) Catálogo comercial de bombas.López Luque, R. (1991) Optimización de sistemas de impulsión y distribución de agua para riego, Riegos y Drenajes XXI. 50:29-33.Mataix, C. (1975) Turbomáquinas hidráulicas. ICAI.Meyer, P.L. (1974) Introductory probability and statistical aplications. Addison-Wesley Publishing Company, Reading, Massachussets.Unidad Docente Mecánica de Fluidos (1992) Curso de ingeniería hidráulica aplicada a los sistemas de distribución de agua. Universidad Politécnica de Valencia

The psychometric properties of the person-centered therapeutic relationship in physiotherapy scale

[EN] Objective To determine the psychometric properties of the Person-Centered Therapeutic Relationship in Physiotherapy Scale (PCTR-PT) in order to find the most appropriate fit for the tool. Methods Patients who had received treatment at the physiotherapy service of nine hospitals in Spain were invited to complete the 31 items of the PCTR-PT scale. To select the most appropriate items of the PCTR-PT, an exploratory factorial analysis (EFA) was performed using the maximum likelihood and oblique rotation (promin) methods. Factor validity, goodness-of-fit and psychometric properties were analyzed by confirmatory factor analysis (CFA). Convergent (CFA) and discriminant validity were calculated. Internal consistency was verified using the Cronbach's alpha coefficient. The intraclass correlation coefficient (ICC) was used to examine temporal stability. Results 366 patients over 18 years old who had received, at least, 15 physiotherapy treatment sessions completed the questionnaire. The results of the exploratory factor analysis revealed a tool with 15 items in four factors [Relational Bond (N items = 4); Individualized Partnership (N items = 4); Professional Empowerment (N items = 3) and Therapeutic Communication (N items = 4)], explaining 78.4% of the variance of the total variables of this tool. The confirmatory factor analysis further confirmed the four-structure model. Reliability of the tool was approved by Cronbach's alpha in all four dimensions, as all were above .70, ranging from .84 (Individualized Partnership) to .91 (Professional Empowerment). = 0.94. Test-retest was performed with two-week intervals, indicating an appropriate stability for the scale (ICC = 0.900). Conclusion The Person-Centered Therapeutic Relationship in Physiotherapy Scale (PCTR-PT) is a useful, valid and applicable instrument to evaluate the person-centered therapeutic relationship during physiotherapy interventions. It would be interesting to investigate the predictive capacity (sensitivity and specificity) of the PCTR-PT scale.SIAuthors JMB, ORN, are recipients of a grant from CEU Cardenal Herrera University (www. uchceu.es) and the San Pablo University-Santander Foundation (FUSP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript