696 research outputs found

    Observation of a tricritical wedge filling transition in the 3D Ising model

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    In this Letter we present evidences of the occurrence of a tricritical filling transition for an Ising model in a linear wedge. We perform Monte Carlo simulations in a double wedge where antisymmetric fields act at the top and bottom wedges, decorated with specific field acting only along the wegde axes. A finite-size scaling analysis of these simulations shows a novel critical phenomenon, which is distinct from the critical filling. We adapt to tricritical filling the phenomenological theory which successfully was applied to the finite-size analysis of the critical filling in this geometry, observing good agreement between the simulations and the theoretical predictions for tricritical filling.Comment: 5 pages, 3 figure

    Phenological and molecular studies on the introduced seaweed Dictyota cyanoloma (Dictyotales, Phaeophyceae) along the Mediterranean coast of the Iberian Peninsula

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    Dictyota cyanoloma, a distinctive brown algal species characterized by a blue-iridescent margin, was recently reported as an introduced species in the Mediterranean Sea but little is known about its distribution dynamics, morphological plasticity and genetic structure. In this integrative study, we evaluate its past and present occurrence along the Mediterranean Iberian coast, assess the species' phenology in Palamos (Girona, Spain) and analyze the haplotype diversity by sequencing 49 individuals from nine sampling sites for different chloroplast and mitochondrial DNA regions. Although D. cyanoloma currently occurs along all the Mediterranean Iberian coasts (in 19 of 36 localities sampled, mostly in marinas and harbour environments), we were not able to find any herbarium material of this species (at BCN-Phyc and MA) predating the year 1987. In Palamos, D. cyanoloma is present all through the year, with a maximum development in winter and a minimum in summer. Fertile specimens are absent during summer (July and August). Sporophytes are dominant from January to June and gametophytes were found only in February, March and June. Information about the antheridia, which has never been described before, is provided. Two chloroplast and three mitochondrial haplotypes were observed, indicating that multiple introductions of D. cyanoloma occurred in the study area. Additionally, the genetic structure suggests that spread did not occur through simple advancing wave fronts but by several longdistance dispersal events. Further studies employing microsatellite markers could potentially offer a better resolution to unravel expansion and colonisation dynamics of D. cyanoloma in the Mediterranean Sea

    Computer simulations of nematic drops: Coupling between drop shape and nematic order

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    We perform Monte Carlo computer simulations of nematic drops in equilibrium with their vapor using a Gay-Berne interaction between the rod-like molecules. To generate the drops, we initially perform NPT simulations close to the nematic-vapor coexistence region, allow the system to equilibrate and subsequently induce a sudden volume expansion, followed with NVT simulations. The resultant drops coexist with their vapor and are generally not spherical but elongated, have the rodlike particles tangentially aligned at the surface and an overall nematic orientation along the main axis of the drop. We find that the drop eccentricity increases with increasing molecular elongation, κ. For small κ the nematic texture in the drop is bipolar with two surface defects, or boojums, maximizing their distance along this same axis. For sufficiently high κ, the shape of the drop becomes singular in the vicinity of the defects, and there is a crossover to an almost homogeneous texture; this reflects a transition from a spheroidal to a spindle-like dro

    La Termogènesi als calorímetres per conducció: característiques dinàmiques i possibilitats deconvolutives

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    Es descriuen les característiques generals dels dispositius calorimètrics, les possibilitats de tractament mitjançant models i els mètodes per aproximar-se a la termogènesi o dissipació instantània al si de la cèl•lula laboratori. La descripció dinàmica es fa dins de l'espai freqüencial, que permet introduir de manera natural diferents límits de freqüència segons les característiques dels dispositius i del procés que vol estudiar-se. Per al tractament global dels calorímetres s'utilitza una escala relativa de temps i de freqüència. Això permet tractar sistemàticament les condicions imposades per les tècniques deconvolutives, l'aparellatge experimental i els propis fenòmens físics.General features of flow or conduction calorimeters are briefly described together with several methods to obtain the thermogenesis or instantaneous power dissipated inside the laboratory cell. The possibi l ities of solvable models are also discussed. The dynamic behaviour of the calorimeter is readily described in frequency space, thus allowing the intrcduction of several frequential limits depending on the characteristics both of the device and of the phenomenon under study. A systematic treatment of conduction calorimeters may be attained if relative scales, i n time (t/τ1) and frequency (θ τ1), are considered. Now, the efficiency of a given deconvolutive technique and the limits imposed by the experimental device itself or by the physical phenomena studied are easily evaluated

    Lipidomics Reveals Reduced Inflammatory Lipid Species and Storage Lipids after Switching from EFV/FTC/TDF to RPV/FTC/TDF: A Randomized Open-Label Trial

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    HIV and antiretroviral therapy affect lipid metabolism. Lipidomics quantifies several individual species that are overlooked using conventional biochemical analyses, outperforming traditional risk equations. We aimed to compare the plasma lipidomic profile of HIV patients taking efavirenz (EFV) or rilpivirine (RPV). Patients >/= 18 years old on EFV co-formulated with emtricitabine and tenofovir disoproxil fumarate (FTC/TDF) with HIV-RNA /=6 months were randomized to continue EFV/FTC/TDF (n = 14) or switch to RPV/FTC/TDF (n =15). Lipidomic analyses conducted by mass spectrometry (MS) were performed at baseline and after 12 and 24 weeks. OWLiver((R)) Care and OWLiver((R)) tests were performed to estimate the presence of fatty liver disease (NAFLD). No significant differences (83% male, median age 44 years, 6 years receiving EFV/FTC/TDF, CD4(+) count 740 cells/mm(3), TC 207 [57 HDL-C/133 LDL-C] mg/dL, TG 117 mg/dL) were observed between the groups at baseline. Significant reductions in plasma lipids and lipoproteins but increased circulating bilirubin concentrations were observed in patients who switched to RPV/FTC/TDF. Patients on RPV/FTC/TDF showed a decrease in the global amount of storage lipids (-0.137 log2 [fold-change] EFV vs. 0.059 log2 [fold-change] RPV) but an increase in lysophosphatidylcholines (LPCs) and total steroids. Compared with EFV, RPV increased metabolites with anti-inflammatory properties and reduced the repository of specific lipotoxic lipids

    Random mating and reproductive compatibility among Argentinean and southern Brazilian populations of Anastrepha fraterculus (Diptera: Tephritidae)

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    As a prerequisite for area-wide application of the sterile insect technique in an area encompassing northern Argentina and southern Brazil, prezygotic and postzygotic reproductive compatibility among three geographically distant populations in the area was tested. In field cages, sexually mature adults of each population were found to be sexually compatible, mating duration was not affected by fly origin and there was no clear evidence of spatial partition of mating location. In the laboratory, homotypic and heterotypic crosses for all possible combinations displayed similar levels of fertility and yielded F1 adults without distortion of the sex ratio. Finally, F1 hybrid and parental adults produced equally viable F2 eggs. Put together, our results and those from earlier studies suggest that a large area, ranging from Buenos Aires to the surroundings of São Paulo, could be managed using a single A. fraterculus mass-reared strain. At the northern margin of this area, two A. fraterculus morphotypes appear to coexist in sympatry. We delineate future research to further delimit the distribution of the aff1 morphotype (Argentina-southern Brazil) and to gain insight into evolutionary patterns producing divergence and radiation of tropical fruit fly species.Fil: Rull, J.. Instituto de Ecología; MéxicoFil: Abraham, Solana. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra Terapéutica Vegetal; ArgentinaFil: Kovaleski, A.. Estação Experimental de Vacaria. Embrapa Uva e Vinho; Brasil. International Atomic Energy Agency; AustriaFil: Segura, Diego Fernando. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas. Instituto de Agrobiotecnología y Biología Molecular. Grupo Vinculado Instituto de Genética "Ewald A. Favret" al Iabimo | Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Agrobiotecnología y Biología Molecular. Grupo Vinculado Instituto de Genética "Ewald A. Favret" al Iabimo; ArgentinaFil: Islam, A.. International Atomic Energy Agency; AustriaFil: Wornoayporn, V.. International Atomic Energy Agency; AustriaFil: Dammalage, T.. International Atomic Energy Agency; AustriaFil: Tomas, U. Santo. International Atomic Energy Agency; AustriaFil: Vera, María Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia. Cátedra Terapéutica Vegetal; Argentin

    An ontology-based framework for describing discoverable data services

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    Data-services are applications in charge of retrieving certain data when they are called. They are found in different communities such as the Internet Of Things, Cloud Computing, Big Data, etc. So, there is a real need to discover how can an application that requires some data automatically find a data-service which is providing it. To our knowledge, the problem of automatically discovering these data-services is still open. To make a step forward in this direction, we propose an ontology-based framework to address this problem. In our framework, input and output values of the request are mapped into concepts of the domain ontology. Then, data-services specify how to obtain the output from the input by stating the relationship between the mapped concepts of the ontology.Peer ReviewedPostprint (author's final draft
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