709 research outputs found

    Intermediate deviation regime for the full eigenvalue statistics in the complex Ginibre ensemble

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    We study the Ginibre ensemble of N×NN \times N complex random matrices and compute exactly, for any finite NN, the full distribution as well as all the cumulants of the number NrN_r of eigenvalues within a disk of radius rr centered at the origin. In the limit of large NN, when the average density of eigenvalues becomes uniform over the unit disk, we show that for 0<r<10<r<1 the fluctuations of NrN_r around its mean value NrNr2\langle N_r \rangle \approx N r^2 display three different regimes: (i) a typical Gaussian regime where the fluctuations are of order O(N1/4){\cal O}(N^{1/4}), (ii) an intermediate regime where NrNr=O(N)N_r - \langle N_r \rangle = {\cal O}(\sqrt{N}), and (iii) a large deviation regime where NrNr=O(N)N_r - \langle N_r \rangle = {\cal O}({N}). This intermediate behaviour (ii) had been overlooked in previous studies and we show here that it ensures a smooth matching between the typical and the large deviation regimes. In addition, we demonstrate that this intermediate regime controls all the (centred) cumulants of NrN_r, which are all of order O(N){\cal O}(\sqrt{N}), and we compute them explicitly. Our analytical results are corroborated by precise "importance sampling" Monte Carlo simulations.Comment: 10 pages, 3 Figure

    Maximising embryo production in endangered sheep breeds: in vitro procedures that complement in vivo techniques

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    This study investigated the use of previously superovulated ovaries as a source of oocytes, assessing the competence of them for in vitro embryo production. Two superovulatory treatments were performed: equine Chorionic Gonadotrophin (eCG) plus porcine Follicle-Stimulating Hormone (pFSH) in a single dose or the conventional protocol of six decreasing doses of pFSH. Thirty donor ewes of the endangered Ojalada breed were given either the simplified (group S; n=15) or the decreasing-dose (group D; n=15) treatments three times at intervals of ≥50 days. Ovaries were recovered on day 7 after the oestrus following the third treatment, just after embryo flushing, and the oocytes were collected to assess in vitro maturation, fertilisation and development to the blastocyst stage. The two superovulatory treatments did not differ in the mean number of oocytes selected for maturation (7.1±1.2 and 8.5±1.5 per ewe in the D and S groups, respectively). The oocytes recovered from ewes in Group D (87.5%) had a significantly (p<0.05) higher maturation rate than did those recovered from ewes in group S (75%), but no differences were found in fertilisation rate (94% and 94.6% in the D and S groups, respectively); both groups did not differ in their blastocyst rates and the total number of cells in in vitro-produced blastocysts. In the two experimental groups, 1.7 (D) and 1.8 (S) in vitro-produced blastocysts were generated per ewe, which indicate that it is feasible to combine in vivo and in vitro techniques to maximise embryo production in endangered sheep breeds.EEA ChubutFil: Forcada, Fernando. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Buffoni, Andres. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Chubut; ArgentinaFil: Abecia, José Alfonso. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Asenjo, B. Universidad de Valladolid. Escuela Universitaria de Ingenierías Agrarias de Soria; EspañaFil: Palacin, José Ignacio. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Vázquez, M.I. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Rodriguez Castillo, José del Carmen. Benemérita Universidad Autónoma de Puebla. Facultad de Medicina Veterinaria y Zootecnia; MéxicoFil: Sanchez Prieto, L. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; EspañaFil: Casao, A. Universidad de Zaragoza. Instituto de Investigación de Ciencias Ambientales de Aragón. Grupo de Biología y Fisiología de la Reproducción; Españ

    State Orthogonalization by Building a Hilbert Space: A New Approach to Electronic Quantum Transport in Molecular Wires

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    Quantum descriptions of many complex systems are formulated most naturally in bases of states that are not mutually orthogonal. We introduce a general and powerful yet simple approach that facilitates solving such models exactly by embedding the non-orthogonal states in a new Hilbert space in which they are by definition mutually orthogonal. This novel approach is applied to electronic transport in molecular quantum wires and is used to predict conductance antiresonances of a new type that arise solely out of the non-orthogonality of the local orbitals on different sites of the wire.Comment: 4 pages 1 figur

    Iberian cured-ham consumption improves endothelial function in healthy subjects

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    Objectives: Previous studies have shown that dietary components such as oleic acid or polyphenols exert beneficial effects on endothelium. We aimed to assess the impact of regular consumption of Iberian cured-ham (ICH) on endothelial function. Design: An open-label, randomized controlled parallel study. Setting: Volunteers recruited through advertisements at a hospital in Madrid, Spain. Participants: 102 Caucasian adults (76.8% females) aged 25-55 years, and free from cardiometabolic disease. Intervention: Participants were randomized to an ICH-enriched ad libitum diet or an ad libitum diet without ICH for 6 weeks. Subjects in ICH group were randomly provided with either acorn- or mixed-fed ICH, and followed up for an additional 6-week period under their usual diet. Measurements: Clinical parameters, biomarkers of endothelial function and oxidative stress, microvascular vasodilatory response to hyperemia and arterial stiffness were measured before and after the intervention. Results: After 6 weeks, a larger decrease in PAI-1 was observed in subjects consuming ICH compared to the Control group (-6.2±17.7 vs. 0.3±1.4 ng/ml; p=0.020). Similarly, microvascular vasodilatory response to hyperemia showed a significant increase (112.4±391.7 vs. -56.0±327.9%; p=0.007). However, neither oxidative stress, hemodynamic nor clinical parameters differed significantly over the study. Additionally, after stopping ICH consumption, improvements in PAI-1 remained for 6 additional weeks with respect to baseline (p=0.006). Conclusion: The present study demonstrates, for the first time, that regular consumption of ICH improves endothelial function in healthy adults. Strategies aimed to preserve or improve the endothelial function may have implications in vascular aging beyond the prevention of the atherothrombotic disease

    Influence of the activation time on the development of the porosity of physically activated carbons

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    En este trabajo se estudia la influencia en la porosidad de carbones activados mediante una mezcla de vapor de agua y nitrógeno, en función del tiempo de activación. Este estudio se basa en la aplicación de tres métodos de análisis distintos: el conocido método DFT, un método analítico basado en una combinación de las ecuaciones de BET y de Kelvin, y un método de simulación de Monte Carlo. Dichos métodos son aplicados sobre los datos obtenidos de las isotermas de adsorción de nitrógeno a 77K sobre una serie de muestras de carbón activado obtenidas bajo condiciones cuidadosamente controladas. Los resultados obtenidos son consistentes para los tres métodos, lo que permite extraer conclusiones confiables sobre la influencia del tiempo de activación en las características de los carbones obtenidos.In this work, the influence of the activation time on the development of the porosity is studied for carbons activated by means of a mixture of water vapor and nitrogen. The study is based on the application of three different methods of analysis: the well known DFT method, an analytical method base don a combination of the BET and Kelvin equations, and a Monte Carlo simulation method. These methods are applied to experimental data of nitrogen adsorption isotherms at 77K for a series of activated carbons obtained under carefully controlled conditions. Results turn out to be consistent among the three methods, leading to reliable conclusions about the influence of the activation time on the characteristics of the obtained carbons.Fil: Toso, Juan Pablo. Universidad Nacional de San Luis. Facultad de Ciencias Fisico Matematicas y Naturales. Departamento de Fisica. Laboratorio de Ciencias de Superficies y Medios Porosos; ArgentinaFil: Aja Muñiz, R.. Centro de Investigación para la Industria Minero ; CubaFil: Vallone, Andrea Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Fernández Rodriguez, A.. Centro de Investigación para la Industria Minero ; CubaFil: Castillo, C.R.. Centro de Investigación para la Industria Minero ; CubaFil: Sapag, Manuel Karim. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Zgrablich, Jorge Andres. Universidad Nacional de San Luis. Facultad de Ciencias Fisico Matematicas y Naturales. Departamento de Fisica. Laboratorio de Ciencias de Superficies y Medios Porosos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis; Argentin

    Phenoloxidase activity acts as a mosquito innate immune response against infection with semliki forest virus

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    Several components of the mosquito immune system including the RNA interference (RNAi), JAK/STAT, Toll and IMD pathways have previously been implicated in controlling arbovirus infections. In contrast, the role of the phenoloxidase (PO) cascade in mosquito antiviral immunity is unknown. Here we show that conditioned medium from the Aedes albopictus-derived U4.4 cell line contains a functional PO cascade, which is activated by the bacterium Escherichia coli and the arbovirus Semliki Forest virus (SFV) (Togaviridae; Alphavirus). Production of recombinant SFV expressing the PO cascade inhibitor Egf1.0 blocked PO activity in U4.4 cell- conditioned medium, which resulted in enhanced spread of SFV. Infection of adult female Aedes aegypti by feeding mosquitoes a bloodmeal containing Egf1.0-expressing SFV increased virus replication and mosquito mortality. Collectively, these results suggest the PO cascade of mosquitoes plays an important role in immune defence against arboviruses

    Prioritization strategies in clinical practice guidelines development: a pilot study

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    Objective: Few methodological studies address the prioritization of clinical topics for the development of Clinical Practice Guidelines (CPGs). The aim of this study was to validate a methodology for Priority Determination of Topics (PDT) of CPGs. Methods and results: Firstly, we developed an instrument for PDT with 41 criteria that were grouped under 10 domains, based on a comprehensive systematic search. Secondly, we performed a survey of stakeholders involved in CPGs development, and end users of guidelines, using the instrument. Thirdly, a pilot testing of the PDT procedure was performed in order to choose 10 guideline topics among 34 proposed projects; using a multicriteria analysis approach, we validated a mechanism that followed five stages: determination of the composition of groups, item/domain scoring, weights determination, quality of the information used to support judgments, and finally, topic selection. Participants first scored the importance of each domain, after which four different weighting procedures were calculated (including the survey results). The process of weighting was determined by correlating the data between them. We also reported the quality of evidence used for PDT. Finally, we provided a qualitative analysis of the process. The main domains used to support judgement, having higher quality scores and weightings, were feasibility, disease burden, implementation and information needs. Other important domains suc
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