7,646 research outputs found

    Analysis of a class of boundary value problems depending on left and right Caputo fractional derivatives

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    In this work we study boundary value problems associated to a nonlinear fractional ordinary differential equation involving left and right Caputo derivatives. We discuss the regularity of the solutions of such problems and, in particular, give precise necessary conditions so that the solutions are C1([0, 1]). Taking into account our analytical results, we address the numerical solution of those problems by the augmented-RBF method. Several examples illustrate the good performance of the numerical method.P.A. is partially supported by FCT, Portugal, through the program “Investigador FCT” with reference IF/00177/2013 and the scientific projects PEstOE/MAT/UI0208/2013 and PTDC/MAT-CAL/4334/2014. R.F. was supported by the “Fundação para a Ciência e a Tecnologia (FCT)” through the program “Investigador FCT” with reference IF/01345/2014.info:eu-repo/semantics/publishedVersio

    Absence of Gluonic Components in Axial and Tensor Mesons

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    A quarkonium-gluonium mixing scheme previously developed to describe the characteristic of the pseudoscalar mesons is applied to axial and tensor mesons. The parameters of the model are determined by fitting the eigenvalues of a mass matrix. The corresponding eigenvectors give the proportion of light quarks, strange quarks and glueball in each meson. However the predictions of the model for branching ratios and electromagnetic decays are incompatible with the experimental results. These results suggest the absence of gluonic components in the states of axial and tensor isosinglet mesons analyzed here.Comment: 12 page

    Structural health monitoring of different geometry structures with optical fiber sensors

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    In this paper, we describe the structural health monitoring of several structures, with different geometry, materials and behaviors, using optical fiber sensors. Those studies aimed to demonstrate the feasibility of such technologies in structural health monitoring, with all the advantages inherent to the optical fiber technology

    Thermoelectric response of Fe1+y_{1+y}Te0.6_{0.6}Se0.4_{0.4}: evidence for strong correlation and low carrier density

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    We present a study of the Seebeck and Nernst coefficients of Fe1+y_{1+y}Te1x_{1-x}Sex_{x} extended up to 28 T. The large magnitude of the Seebeck coefficient in the optimally doped sample tracks a remarkably low normalized Fermi temperature, which, like other correlated superconductors, is only one order of magnitude larger than Tc_c. We combine our data with other experimentally measured coefficients of the system to extract a set of self-consistent parameters, which identify Fe1+y_{1+y}Te0.6_{0.6}Se0.4_{0.4} as a low-density correlated superconductor barely in the clean limit. The system is subject to strong superconducting fluctuations with a sizeable vortex Nernst signal in a wide temperature window.Comment: 4 pages including 4 figure

    Aldosterone signaling through transient receptor potential melastatin 7 cation channel (TRPM7) and its α-kinase domain

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    We demonstrated a role for the Mg2 + transporter TRPM7, a bifunctional protein with channel and α-kinase domains, in aldosterone signaling. Molecular mechanisms underlying this are elusive. Here we investigated the function of TRPM7 and its α-kinase domain on Mg2 + and pro-inflammatory signaling by aldosterone. Kidney cells (HEK-293) expressing wild-type human TRPM7 (WThTRPM7) or constructs in which the α-kinase domain was deleted (ΔKinase) or rendered inactive with a point mutation in the ATP binding site of the α-kinase domain (K1648R) were studied. Aldosterone rapidly increased [Mg2 +]i and stimulated NADPH oxidase-derived generation of reactive oxygen species (ROS) in WT hTRPM7 and TRPM7 kinase dead mutant cells. Translocation of annexin-1 and calpain-II and spectrin cleavage (calpain target) were increased by aldosterone in WT hTRPM7 cells but not in α-kinase-deficient cells. Aldosterone stimulated phosphorylation of MAP kinases and increased expression of pro-inflammatory mediators ICAM-1, Cox-2 and PAI-1 in Δkinase and K1648R cells, effects that were inhibited by eplerenone (mineralocorticoid receptor (MR) blocker). 2-APB, a TRPM7 channel inhibitor, abrogated aldosterone-induced Mg2 + responses in WT hTRPM7 and mutant cells. In 2-APB-treated ΔKinase and K1648R cells, aldosterone-stimulated inflammatory responses were unchanged. These data indicate that aldosterone stimulates Mg2 + influx and ROS production in a TRPM7-sensitive, kinase-insensitive manner, whereas activation of annexin-1 requires the TRPM7 kinase domain. Moreover TRPM7 α-kinase modulates inflammatory signaling by aldosterone in a TRPM7 channel/Mg2 +-independent manner. Our findings identify novel mechanisms for non-genomic actions of aldosterone involving differential signaling through MR-activated TRPM7 channel and α-kinase

    Interparental violence: professionals’ perspectives in the child protection system

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    Study purpose: Based on the cognitive-contextual model developed by Grych and Fincham (1990), this study explored the role of the Exposure to Interparental Violence (EIV) on adolescents’ coping and functioning from the perspectives of Portuguese professionals in the Child Protection System (CPS). Participants: Nineteen professionals from three Child Protection Agencies participated in this study (100% females). The target subjects of professionals perspectives were adolescents aged between 10 and 16 years old (M = 13.58; SD = 1.98) who have a CPS record managed by these professionals. Data was collected through a semi-structured interview guide based on the theoretical model and analysed with a thematic analysis strategy. Results: Findings revealed 7 main themes, of which two emerged exclusively from the data (i.e., Risk Factors for Interparental Conflict; Impact of the Conflict in Individual and Family Functioning) and the remaining five were anchored in the cognitive-contextual theoretical framework (i.e., Interparental Conflict; Distal and Proximal Context; Primary and Secondary Processing; Affect; Coping Behaviour and Consequences). Conclusions: This research enabled a description of the underlying aspects of the multidimensionality of EIV, and the results will be discussed considering its implications for the evaluation and intervention in this context.info:eu-repo/semantics/acceptedVersio

    The role of point-like topological excitations at criticality: from vortices to global monopoles

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    We determine the detailed thermodynamic behavior of vortices in the O(2) scalar model in 2D and of global monopoles in the O(3) model in 3D. We construct new numerical techniques, based on cluster decomposition algorithms, to analyze the point defect configurations. We find that these criteria produce results for the Kosterlitz-Thouless temperature in agreement with a topological transition between a polarizable insulator and a conductor, at which free topological charges appear in the system. For global monopoles we find no pair unbinding transition. Instead a transition to a dense state where pairs are no longer distinguishable occurs at T<Tc, without leading to long range disorder. We produce both extensive numerical evidence of this behavior as well as a semi-analytic treatment of the partition function for defects. General expectations for N=D>3 are drawn, based on the observed behavior.Comment: 14 pages, REVTEX, 13 eps figure

    Comportamento produtivo de novas cultivares de morangueiro na região de Pelotas, RS.

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