235 research outputs found

    Pure spin current manipulation in antiferromagnetically exchange coupled heterostructures

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    We present a model to describe the spin currents generated by ferromagnet/spacer/ferromagnet exchange coupled trilayer systems and heavy metal layers with strong spin-orbit coupling. By exploiting the magnitude of the exchange coupling (oscillatory RKKY-like coupling) and the spin-flop transition in the magnetization process, it has been possible to produce spin currents polarized in arbitrary directions. The spin-flop transition of the trilayer system originates pure spin currents whose polarization vector depends on the exchange field and the magnetization equilibrium angles. We also discuss a protocol to control the polarization sign of the pure spin current injected into the metallic layer by changing the initial conditions of magnetization of the ferromagnetic layers previously to the spin pumping and inverse spin Hall effect experiments. The small differences in the ferromagnetic layers lead to a change in the magnetization vector rotation that permits the control of the sign of the induced voltage components due to the inverse spin Hall effect. Our results can lead to important advances in hybrid spintronic devices with new functionalities, particularly, the ability to control microscopic parameters such as the polarization direction and the sign of the pure spin current through the variation of macroscopic parameters, such as the external magnetic field or the thickness of the spacer in antiferromagnetic exchange coupled systems.Fil: Avilés Félix, L.. Comisión Nacional de Energía Atómica. Gerencia del Área de Energía Nuclear. Instituto Balseiro; ArgentinaFil: Butera, Alejandro Ricardo. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: González Chávez, D. E.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Sommer, R. L.. Centro Brasileiro de Pesquisas Físicas; BrasilFil: Gomez, Javier Enrique. Comision Nacional de Energía Atómica. Gerencia de Área Investigaciones y Aplicaciones no Nucleares. Gerencia de Física (Centro Atómico Bariloche). División Resonancias Magnéticas; Argentin

    Vibrational, non-adiabatic and isotopic effects in the dynamics of the H2 + H2+ → H3+ + H reaction: application to plasma modelling

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    The title reaction is studied using a quasi-classical trajectory method for collision energies between 0.1 meV and 10 eV, considering the vibrational excitation of (Formula presented.) reactant. A new potential energy surface is developed based on a Neural Network many body correction of a triatomics-in-molecules potential, which significantly improves the accuracy of the potential up to energies of 17 eV, higher than in other previous fits. The effect of the fit accuracy and the non-adiabatic transitions on the dynamics are analysed in detail. The reaction cross section for collision energies above 1 eV increases significantly with the increasing of the vibrational excitation of (Formula presented.) ((Formula presented.)), for values up to (Formula presented.) =6. The total reaction cross section (including the double fragmentation channel) obtained for (Formula presented.) =6 matches the new experimental results obtained by Savic, Schlemmer and Gerlich [Chem. Phys. Chem. 21 (13), 1429.1435 (2020). doi:10.1002/cphc.v21.13]. The differences among several experimental setups, for collision energies above 1 eV, showing cross sections scattered/dispersed over a rather wide interval, can be explained by the differences in the vibrational excitations obtained in the formation of (Formula presented.) reactants. On the contrary, for collision energies below 1 eV, the cross section is determined by the long range behaviour of the potential and do not depend strongly on the vibrational state of (Formula presented.). In addition in this study, the calculated reaction cross sections are used in a plasma model and compared with previous results. We conclude that the efficiency of the formation of (Formula presented.) in the plasma is affected by the potential energy surface use

    Extrapolating base-line trunk shrinkage reference equations across olive orchards

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    preprintMaximum daily trunk shrinkage is a common measurement in irrigation scheduling of fruit trees. But the strong relationship between these measurements and the environment severely limit field applications. Reference baselines are the solution for understanding the influence of environmental conditions. Nevertheless, the extrapolation out of the original conditions is not clear. The aim of this study was to compare several approaches to estimate a reference baseline in an olive orchard where there were no previous data from other seasons. Two orchards, separated 60. m, with different tree density were used. Orchard 1 had greater tree density than orchard 2, though the age and the cultivar were the same. Trunk diameters of both orchards were similar but the crown volume of orchard 2 was slightly lower than orchard 1. The current reference baselines of maximum daily trunk diameter in both orchards were not significantly different between them (p<0.05). In orchard 1, the previous reference baseline was calculated in a 5-year study (the so called multi-seasons approach). The multi-seasons approach was not significantly different in slope but it was in the y-interception to the current reference baselines in both orchards (p<0.05). This approach over-estimated the values in both orchards. Two additional approaches were tested. These latter approaches used data before massive pit hardening to estimate the current reference baseline. One of them used the early data to estimate a complete reference baseline (the so-called early approach). The other (the so-called y-early approach) used the same data only to estimate the y-interception and assumed that the slope was the same as in the multi-seasons approach. The early approach under-estimated the value of maximum daily trunk shrinkage. The early-y approach provided a satisfactory estimation of the reference baseline and improved those obtained with the multi-seasons approach. The limitations and uses in irrigation scheduling are also discussed.MINECO AGL2010-19201-CO4-03AECID D/030431/1

    Cardiac troponin I, fructosamine, and cardiovascular parameters in dogs with diabetes mellitus

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    Diabetes mellitus (DM) is a common endocrinopathy in dogs, however, the relationship between canine DM and cardiomyopathy is still unclear. The aims of this study were: to evaluate serum troponin I concentrations in diabetic dogs under treatment with insulin; to evaluate the hypothesis that the time of DM diagnosis could influence the troponin I concentration; and to evaluate the relationship between biochemical and cardiovascular parameters in diabetic dogs. This is a cross-sectional study including diabetic canine patients under NPH insulin treatment. Troponin I concentration, systolic blood pressure (SBP), complete blood count, serum fructosamine concentration, biochemical profile, and Doppler echocardiography assesments were carried out in each patient, as well as in age- and size- matched healthy controls. All diabetic dogs had concentrations of troponin I below the limits of detection of the assay. There was no difference between cardiovascular parameters between diabetic and healthy control dogs. There was no correlation between time of DM diagnosis and cardiovascular parameters. There was a significant positive correlation between SBP and fructosamine in diabetic dogs (r=0.54; P&lt;0.01). Diabetic dogs receiving insulin treatment, regardless of the time of diagnosis, do not have significantly elevated serum troponin I. The results also suggest that fructosamine levels can be associated with high blood pressure, suggesting a possible correlation between fructosamine levels and vascular complications

    Evaluación de la severidad de la incontinencia urinaria de esfuerzo con estudios urodinámicos: un estudio comparativo para detectar deficiencia intrínseca del esfínter uretral externo

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    ResumenObjetivoDeterminar la sensibilidad y especificidad del punto de presión de fuga abdominal (ALPP), para evaluar la presencia de deficiencia intrínseca del esfínter (DIE) comparativamente con la presión máxima de cierre uretral (MUCP, por sus siglas en inglés), estableciendo la correlación clínico-urodinámica correspondiente.ResultadosFueron evaluadas 34 pacientes con incontinencia urinaria de esfuerzo (IUE); 17 paciente (50%) fueron diagnosticadas urodinámicamente con DIE por punto de ALPP; 9 tuvieron IUE severa mientras que sólo 2 (5.8%) lo fueron por MUCP, de las cuales una tuvo IUE severa y otra, IUE moderada. Dieciocho pacientes fueron catalogadas clínicamente como IUE severa, de las cuales 17 tuvieron DIE por ALPP entre severa y moderada (94%).ConclusionesLa evaluación urodinámica de la IUE permite establecer de manera clara la fisiopatología de una disfunción del tracto urinario inferior concomitante, con la posibilidad de objetivar la presencia de IUE con el ALPP en al menos 85% de los casos, con una sensibilidad y especificidad para diagnosticar DIE muy superior a la MUCP.AbstractAimsTo determine the sensitivity and specificity of the abdominal leak point pressure (ALPP) in order to comparatively evalúate the presence of intrinsic sphincter deficiency (ISD) with máximum urethral closure pressure (MUCP) and establish the corresponding clinical and urodynamic correlation.ResultsThirty-four patients with stress urinary incontinence (SUI) were evaluated. Seventeen of those patients (50%) were urodynamically diagnosed with ISD through ALPP and 9 of them had severe SUI. Only 2 patients were diagnosed with ISD through MUCP; one of them had severe SUI and the other presented with modérate SUI. Eighteen patients were clinically classified with severe SUI, 17 of whom had moderate to severe ISD diagnosed through ALPP (94%).ConclusionsUrodynamic evaluation of SUI made it possible to clearly establish the pathophysiology of concomitant lower urinary tract dysfunction and to objectify the presence of SUI through ALPP in at least 85% of the cases. ALPP had a much higher sensitivity and specificity for diagnosing ISD than MUCP

    On The Importance Of Remote Sensing Data To Validate A Distributed Dynamic Vegetation Model Applied To A Semi-Arid Basin

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    Efforts to better understand the components of catchments’ water balance have traditionally been one of the objectives of the hydrological community. Very few hydrological models incorporate vegetation development as state variable. This is beginning to change with the recognition by the hydrological community that biological processes play a key role in catchment’s water balance. In addition, some studies confirm that vegetation density controls most of hydrological processes in semi-arid regions. However, the most of the dynamic vegetation models are too complex to be coupled with hydrological models and they incorporate variables and inputs which are difficult to be estimated across space and through time. For this reason, we have focused on a parsimonious and robust dynamic vegetation model based on the Light Use Efficiency index (LUE), to be coupled with a hydrological model in a semi-arid basin (La Hunde, East of Spain) predominantly covered by Aleppo pine (Pinus halepensis). This model needs to be implemented, i.e. calibrated and validated. Satellite-based remote sensing data are the main source of information employed for this task. In this work, vegetation-related satellite products are analyzed in order to assess their relation with vegetation state at catchment scale. NDVI shows a strong dependence on soil moisture and leaf water content, explainable by the impact of water-stress on chlorophyll content in Aleppo Pine leaves. The EVI proves to be strongly related to biomass dynamics and to LAI in particular

    Alternativas de búsqueda directa en Metalib y SFX

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    La presentación se llevó a cabo durante las 5as. Jornadas de Expania (Grupo de usuarios de ExLibris en España) celebradas en la Universitat Pompeu Fabra (Barcelona, 19-20/06/2008)La presentación describe las alternativas a SFX y Metalib, que la Biblioteca de la Universidad de Navarra, ofrece a sus usuarios para la búsqueda de sus recursos electrónicos. En concreto, un formulario Web, una barra de herramientas, utilizando LibX, y un Gadget para iGoogle

    Multidisciplinary study of mud volcanoes and diapirs and their relationship to seepages and bottom currents in the Gulf of Cádiz continental slope (northeastern sector)

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    The seabed morphology, type of sediments, and dominant benthic species on eleven mud volcanoes and diapirs located on the northern sector of the Gulf of Cádiz continental slope have been studied. The morphological characteristics were grouped as: (i) fluid-escape-related features, (ii) bottom current features, (iii) mass movement features, (iv) tectonic features and (v) biogenic-related features. The dominant benthic species associated with fluid escape, hard substrates or soft bottoms, have also been mapped. A bottom current velocity analysis allowed, the morphological features to be correlated with the benthic habitats and the different sedimentary and oceanographic characteristics. The major factors controlling these features and the benthic habitats are mud flows and fluid-escape-related processes, as well as the interaction of deep water masses with the seafloor topography. Mud volcano eruptions give rise to mud flows and/or aqueous fluid seepage. These processes sustain chemosynthesis-based communities, closely associated with fluid seepage. Large depressions in the nearby area are influenced by collapse-related phenomena, where active fluid escape and the erosive effect of bottom currents have been identified. When the extrusion activity of the mud volcano is low and the seepage is diffuse, authigenic carbonates form within the edifice sediments. The bottom current sweeps the seafloor from the SE to the NW. When the velocity is moderate, sedimentary contourite processes take place on both sides of the edifices. At high velocities, the authigenic carbonates may be exhumed and colonised by species associated with hard substrates. Small carbonate mounds are found at the summits of some volcanoes and diapirs. Living corals have been found on the tops of the shallowest mud volcanoes, revealing different oceanographic conditions and strong bottom currents that favour the availability of nutrients and organic particles. The edifices affected by very high current velocities are located in the channels where erosive processes dominate.Postprint2,517

    A comprehensive platform for the analysis of ubiquitin-like protein modifications using in vivo biotinylation

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    Post-translational modification by ubiquitin and ubiquitin-like proteins (UbLs) is fundamental for maintaining protein homeostasis. Efficient isolation of UbL conjugates is hampered by multiple factors, including cost and specificity of reagents, removal of UbLs by proteases, distinguishing UbL conjugates from interactors, and low quantities of modified substrates. Here we describe bioUbLs, a comprehensive set of tools for studying modifications in Drosophila and mammals, based on multicistronic expression and in vivo biotinylation using the E. coli biotin protein ligase BirA. While the bioUbLs allow rapid validation of UbL conjugation for exogenous or endogenous proteins, the single vector approach can facilitate biotinylation of most proteins of interest. Purification under denaturing conditions inactivates deconjugating enzymes and stringent washes remove UbL interactors and non-specific background. We demonstrate the utility of the method in Drosophila cells and transgenic flies, identifying an extensive set of putative SUMOylated proteins in both cases. For mammalian cells, we show conjugation and localization for many different UbLs, with the identification of novel potential substrates for UFM1. Ease of use and the flexibility to modify existing vectors will make the bioUbL system a powerful complement to existing strategies for studying this important mode of protein regulation

    Cunning defects: Emission control by structural point defects on Cu(i)I double chain coordination polymers

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    The following version is an accepted manuscript in Journal of Materials Chemistry C 8.4 (2020): 1448-1458 and may be found at ttps://doi.org/10.1039/C9TC05185FThe direct reaction between CuI and 3,5-dichloropyridine, in acetonitrile at room temperature, gives rise to [Cu(Cl2-py)I]n (Cl2-py = 3,5-dichloropyridine), which consists of a Cu(i)-I double chain based coordination polymer (CP) grafted with 3,5-dichloropyridine. In this simple one-pot process, the modulation of the reaction conditions, i.e. slight variations in the CuI and Cl2-py ratio caused by in situ disproportion, can, however, produce significant changes in the physical properties of the materials. For instance, the reaction carried out in a 1 : 1 ratio under ambient conditions leads to compound 1, while compound 1′ is obtained upon a solvothermal process of stoichiometric reaction mixture, Cl2-py and CuI, which produces partial disproportion (<0.5% in weight) of the initial Cu(i). Interestingly, compounds 1 and 1′ show an identical chemical composition and structure as determined by both single crystal and powder X-ray diffraction. However, they display remarkable differences in the luminescence behavior, featuring broad emission bands centered at 515 and 670 nm and associated to photoluminescence quantum yields of 12 and 5% for 1 and 1′, respectively. Density functional theory (DFT) calculations allowed us to rationalize the nature of this rare behavior. This is attributed to structural defects related to the weaker coordination bond present in these structures that provoke the strong red-shifted emissionThe authors thank financial support from the Spanish Ministerio de Economıa y Competitividad (MAT2016-77608-C3-1-P, MAT2016-75883-C2-2-P, MAT2010-20843-C02-01, CTQ2016-75816- C2-1P, MAT2016-75586-C4-4-P) and by EU-FEDER funds. JGP thanks to Servicios Generales de Apoyo a la Investigacion (SEGAI) at La Laguna University. J. I. M. acknowledges the financial support by the ‘‘Ramo´n y Cajal’’ Program of MINECO (Grant RYC-2015- 17730) and the EU via the ERC-Synergy Program (Grant ERC-2013- SYG-610256 NANOCOSMOS). J. C. E. acknowledges the financialsupport by the ‘‘FPI-MINECO’’ Program of MINECO (Grant BES2015-071534). R. D. C. acknowledges the program ‘‘Ayudas para la atraccio´n de talento investigador—Modalidad 1 of the Consejerı´a de Educacio´n, Juventud y Deporte—Comunidad de Madrid with the Reference No. 2016-T1/IND-1463.’’, Spanish MINECO for the Ramo´n y Cajal program (RYC-2016-20891), the Europa Excelencia program (ERC2019-092825), and HYNANOSC (RTI2018-099504-A-C22). R. D. C. also acknowledges the 2018 Leonardo Grant for Researchers and Cultural Creators from BBVA Foundation and the FOTOART-CM project funded by Madrid region under programm P2018/NMT-4367. J. F.-C. acknowledges the Marie Skłodowska-Curie Individual Fellowships (H2020-MSCA-IF-2017). This paper is dedicated to Dmitri Mendele´yev in honour of the 150th anniversary of the discovery of the periodic tabl
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