707 research outputs found

    Quantitative Stability of Linear Infinite Inequality Systems under Block Perturbations with Applications to Convex Systems

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    The original motivation for this paper was to provide an efficient quantitative analysis of convex infinite (or semi-infinite) inequality systems whose decision variables run over general infinite-dimensional (resp. finite-dimensional) Banach spaces and that are indexed by an arbitrary fixed set JJ. Parameter perturbations on the right-hand side of the inequalities are required to be merely bounded, and thus the natural parameter space is l(J)l_{\infty}(J). Our basic strategy consists of linearizing the parameterized convex system via splitting convex inequalities into linear ones by using the Fenchel-Legendre conjugate. This approach yields that arbitrary bounded right-hand side perturbations of the convex system turn on constant-by-blocks perturbations in the linearized system. Based on advanced variational analysis, we derive a precise formula for computing the exact Lipschitzian bound of the feasible solution map of block-perturbed linear systems, which involves only the system's data, and then show that this exact bound agrees with the coderivative norm of the aforementioned mapping. In this way we extend to the convex setting the results of [3] developed for arbitrary perturbations with no block structure in the linear framework under the boundedness assumption on the system's coefficients. The latter boundedness assumption is removed in this paper when the decision space is reflexive. The last section provides the aimed application to the convex case

    Single-ion and exchange anisotropy effects and multiferroic behavior in high-symmetry tetramer single molecule magnets

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    We study single-ion and exchange anisotropy effects in equal-spin s1s_1 tetramer single molecule magnets exhibiting TdT_d, D4hD_{4h}, D2dD_{2d}, C4hC_{4h}, C4vC_{4v}, or S4S_4 ionic point group symmetry. We first write the group-invariant quadratic single-ion and symmetric anisotropic exchange Hamiltonians in the appropriate local coordinates. We then rewrite these local Hamiltonians in the molecular or laboratory representation, along with the Dzyaloshinskii-Moriay (DM) and isotropic Heisenberg, biquadratic, and three-center quartic Hamiltonians. Using our exact, compact forms for the single-ion spin matrix elements, we evaluate the eigenstate energies analytically to first order in the microscopic anisotropy interactions, corresponding to the strong exchange limit, and provide tables of simple formulas for the energies of the lowest four eigenstate manifolds of ferromagnetic (FM) and anitiferromagnetic (AFM) tetramers with arbitrary s1s_1. For AFM tetramers, we illustrate the first-order level-crossing inductions for s1=1/2,1,3/2s_1=1/2,1,3/2, and obtain a preliminary estimate of the microscopic parameters in a Ni4_4 from a fit to magnetization data. Accurate analytic expressions for the thermodynamics, electron paramagnetic resonance absorption and inelastic neutron scattering cross-section are given, allowing for a determination of three of the microscopic anisotropy interactions from the second excited state manifold of FM tetramers. We also predict that tetramers with symmetries S4S_4 and D2dD_{2d} should exhibit both DM interactions and multiferroic states, and illustrate our predictions for s1=1/2,1s_1=1/2, 1.Comment: 30 pages, 14 figures, submitted to Phys. Rev.

    Eficacia de una técnica cognitivo-conductual en pacientes quirúrgicos

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    El objetivo del estudio consistió en diseñar y comprobar la eficacia de una técnica psicológica en pacientes quirúrgicos, para reducir los niveles de ansiedad y depresión, y facilitar la recuperación. La muestra estuvo compuesta por 30 mujeres que debían someterse a una histerectomía abdominal. Estas mujeres fueron repartidas al azar en dos grupos: experimental y control. La técnica se compuso de diferentes elementos: 1) información; 2) expresión de emociones; 3) respiración, relajación, visualización; 4) ejercicios para facilitar la recuperación; 5) entrega de hojas informativas. Los resultados fueron: el grupo experimental respecto al grupo control, padeció menos ansiedad y depresión postquirúrgicas, sufrió menos dolor y complicaciones después de la operación, necesitó menos analgésicos, recuperó antes sus funciones orgánicas, y se acortó su estancia hospitalaria. Por tanto podemos concluir que la técnica psicológica diseñada se mostró eficaz como facilitadora de la recuperación en pacientes quirúrgicos.The aim of this study was to design and test the efficiency of a psychological technique to reduce levels of anxiety and depression in surgery patients and to facilitate their recovery. The test group was composed of 30 women who were to have a hysterectomy. These women were divided into two groups: an experimental group and a control group . The technique involved various elements: 1) information, 2) the expression of emotions, 3) breathing, relaxation, visualitation, 4) excercises to facilitate recovery, 5) distribution of summary sheets. The results were as follows: compared to the control group, the experimental group suffered less anxiety, less post-surgical depression, less pain and fewer post-operative complications. The women needed fewer painkillers, regained their normal bodily functions and needed a shorter stay in hospital. We can thus conclude that the psychological technique designed, proved efficient in facilitating the recovery of surgical patients

    High-level expression of Pinus sylvestris glutamine synthetase in Escherichia coli Production of polyclonal antibodies against the recombinant protein and expression studies in pine seedlings

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    AbstractIn a previous work we reported the molecular characterization of a glutamine synthetase (GS; EC 6.3.1.2.) complementary DNA from a woody plant (Cantón et al. (1993) Plant Mol. Biol. 22, 819–828). The isolated cDNA (pGSP114) encoding a Scots pine (Pinus sylvestris) cytosolic subunit, has been subcloned into the expression vector pET3c to overproduce the GS polypeptide in Escherichia coli cells. The recombinant GS protein showed the same molecular size as a native Scots pine GS subunit. Antibodies against the pET3c-GSP114 encoded protein were raised in rabbits by injecting purified preparations and specificity was determined by immunoprecipitation of GS activity present in pine crude extracts. In spite of the antibodies were able to recognize both cytosolic and chloroplastic GS in tomato plants, they were unable to immunodetect chloroplastic GS in green cotyledons of pine seedlings and cytosolic GS was the unique recognized polypeptide. Unlike to that found in other plant species, cytosolic GS was strongly expressed in green tissues as determined by protein and Northern analysis. Our results suggest a key role for cytosolic GS in photosynthetic tissues of conifers

    Facilitation Among Saproxylic Insects Inhabiting Tree Hollows in a Mediterranean Forest: The Case of Cetonids (Coleoptera: Cetoniidae) and Syrphids (Diptera: Syrphidae)

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    Tree hollows offer an ideal niche for saproxylic insects in mature Mediterranean forests, where Diptera and Coleoptera are the richest groups. Co-occurrence is frequently observed among many species of both groups in these microhabitats, and some of these species have been considered to facilitate the presence of other species by acting as ecosystem engineers. One of the systems that is found in Mediterranean tree hollows is formed by cetonid (Coleoptera: Cetoniidae) and syrphid (Diptera: Syrphidae) larvae. Here, cetonid larvae feed on wood and litter and produce a substrate that is easier to decompose. To assess the possible role of these larvae as facilitating agents for the saproxylic guild, we studied whether the presence of saprophagous Syrphidae inside tree hollows is associated with the activity of cetonid larvae. Furthermore, in laboratory conditions, we tested whether cetonid larvae activity can improve the development and fitness of the saprophagous syrphid species. Our results show that “cetonid activity” was the variable that best explained the presence of saprophagous syrphid species in natural conditions. Myathropa florea (L., 1758) was one of the species most influenced by this activity. The laboratory experiment gave similar results, demonstrating that an enriched substrate with Cetonia aurataeformis Curti, 1913 larval feces improves syrphid larval growth rate and fitness of adults (measured as longer wing length) of M. florea.Financial support was provided by the Spanish Minister of Science and Innovation (CGL2008-04472, CGL2009-09656, CG L2011-23658, CGL2012-31669) and the Generalitat Valenciana (PROMETEO/2013/034 Project). I.R.S.G. was supported by Grisolia fellowships of the Generalitat Valencian

    Remote sensing indicators to assess riparian vegetation and river ecosystem health

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    Environmental managers need information to quickly detect which stressor combinations should be addressed to reverse river degradation across large study areas. The pivotal role of riparian vegetation in regulating thermal regimes and inputs of light, nutrients and organic matter has made it a major target of stressor-mitigation and conservation actions. However, due to the dendritic and extensive nature of river networks, field-based monitoring of local riparian conditions is expensive and time-consuming. Ongoing developments in remote sensing offer an unparalleled opportunity to address this challenge. Nonetheless, there is still a limited understanding of the capacity of remote sensing indicators to predict changes in local riparian and river conditions, urging for local calibration with in situ measurements. This study aims to evaluate the capacity of remote sensing to detect impacts on quality elements commonly used in river biomonitoring: riparian vegetation, abiotic river condition and macrophyte biomass. To this end, four remote sensing metrics were tested against field-based indicators in 50 stream locations from four river basins across the Northwest of Portugal: i) the lateral riparian continuity at reach scale (riparian forest buffer width), ii) the riparian vegetation density at reach scale (Normalized Difference Vegetation Index, NDVI100m), and iii) the land use intensification at both reach (LUI100m) and iv) segment (LUI500m) scales. We found that the combination of remote sensing variables (riparian forest buffer width and the land use intensification index) correlated with riparian vegetation quality and dissolved inorganic nitrogen concentrations. We also found that the riparian vegetation density was able to predict changes in vascular plant biomass except for bryophytes. Our study provides new insights on the capacity of satellite-based indicators to assess riparian and river health, illustrating their utility for land and water managers, to identify and monitor, at a reduced cost and time, po- This work was supported by the River2Ocean project (NORTE-01-0145-FEDER-000068), co-financed by the European Regional Development Fund (ERDF), through Programa Operacional Regional do Norte (NORTE 2020).The work was also supported by the "Contrato-Programa" UIDB/04050/2020 funded by national funds through the FCT I.P., the Centre of Molecular and Environmental Biology (CBMA). CG-C was supported by a "Juan de la Cierva -Incoporacion" contract (MINECO, IJC2018-036642-I). CCS was supported by the "Financiamento Programatico" UIDP/04050/2020 funded by national funds through the FCT I.P
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