432 research outputs found

    Random walks on the Apollonian network with a single trap

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    Explicit determination of the mean first-passage time (MFPT) for trapping problem on complex media is a theoretical challenge. In this paper, we study random walks on the Apollonian network with a trap fixed at a given hub node (i.e. node with the highest degree), which are simultaneously scale-free and small-world. We obtain the precise analytic expression for the MFPT that is confirmed by direct numerical calculations. In the large system size limit, the MFPT approximately grows as a power-law function of the number of nodes, with the exponent much less than 1, which is significantly different from the scaling for some regular networks or fractals, such as regular lattices, Sierpinski fractals, T-graph, and complete graphs. The Apollonian network is the most efficient configuration for transport by diffusion among all previously studied structure.Comment: Definitive version accepted for publication in EPL (Europhysics Letters

    The support model for people with legally modified abilities according to United Nations

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    Este artículo se basa en una investigación social sobre el sistema de protección jurídica de las personas con algún tipo de discapacidad o en situación de dependencia que se encuentran sometidas a las figuras de tutela o curatela, en aplicación de lo previsto y establecido en el Código Civil Español, en sus artículos 199 y 200, así como en la Ley de Enjuiciamiento Civil. La investigación se plantea como un estudio comparado entre diferentes países de la Unión Europea para ver su adecuación a lo establecido en el artículo 12 de la Convención de Naciones Unidas sobre derechos de las Personas con Discapacidad (en adelante, CDPD) en los procedimientos de incapacitación. Los resultados se analizan sobre la base de modelos técnico-sociales de intervención, los análisis jurídicos y la experiencia adquirida por las Fundación Tutelares de Castilla y León. Se proponen y diseñan algunas alternativas y servicios que pueden mejorar la calidad de vida de las personas adultas incapacitadas judicialmente y el tipo de apoyos que se les puede prestar, de acuerdo a lo establecido en la Convención de Naciones Unidas.This article is based on social research into the system of legal protection for persons with disabilities or in a situation of dependence who are subject to the figures of guardianship or conservatorship pursuant to the provisions in the Spanish Civil Code, sections 199 and 200, as well as the Code of Civil Procedure. The research is presented as a comparative study between different countries of the European Union regarding the adaptation to the provisions of Article 12 of the UN Convention on Rights of Persons with Disabilities (hereinafter CRPD) Incapacitation procedures. The results are analyzed on the basis of technical-social intervention models, legal analysis and the experience of Guardianship Foundations of Castilla y León. Some alternatives and services are proposed and designed that can improve the quality of life of legally incapacitated persons and the type of support that can be provided to them in accordance with the provisions of the United Nations Convention

    Extending reference assembly models

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    The human genome reference assembly is crucial for aligning and analyzing sequence data, and for genome annotation, among other roles. However, the models and analysis assumptions that underlie the current assembly need revising to fully represent human sequence diversity. Improved analysis tools and updated data reporting formats are also required

    Cooperation, Norms, and Revolutions: A Unified Game-Theoretical Approach

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    Cooperation is of utmost importance to society as a whole, but is often challenged by individual self-interests. While game theory has studied this problem extensively, there is little work on interactions within and across groups with different preferences or beliefs. Yet, people from different social or cultural backgrounds often meet and interact. This can yield conflict, since behavior that is considered cooperative by one population might be perceived as non-cooperative from the viewpoint of another. To understand the dynamics and outcome of the competitive interactions within and between groups, we study game-dynamical replicator equations for multiple populations with incompatible interests and different power (be this due to different population sizes, material resources, social capital, or other factors). These equations allow us to address various important questions: For example, can cooperation in the prisoner's dilemma be promoted, when two interacting groups have different preferences? Under what conditions can costly punishment, or other mechanisms, foster the evolution of norms? When does cooperation fail, leading to antagonistic behavior, conflict, or even revolutions? And what incentives are needed to reach peaceful agreements between groups with conflicting interests? Our detailed quantitative analysis reveals a large variety of interesting results, which are relevant for society, law and economics, and have implications for the evolution of language and culture as well

    Thioflavine-T and Congo Red reveal the polymorphism of insulin amyloid fibrils when probed by polarization-resolved fluorescence microscopy.

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    International audienceAmyloid fibrils are protein misfolding structures that involve a β-sheet structure and are associated with the pathologies of various neurodegenerative diseases. Here we show that Thioflavine-T and Congo Red, two major dyes used to image fibrils by fluorescence assays, can provide deep structural information when probed by means of polarization-resolved fluorescence microscopy. Unlike fluorescence anisotropy or fluorescence detected linear dichroism imaging, this technique allows to retrieve simultaneously both mean orientation and orientation dispersion of the dye, used here as a reporter of the fibril structure. We have observed that insulin amyloid fibrils exhibit a homogeneous behavior over the fibrils' length, confirming their structural uniformity. In addition, these results reveal the existence of various structures among the observed fibrils' population, in spite of a similar aspect when imaged with conventional fluorescence microscopy. This optical nondestructive technique opens perspectives for in vivo structural analyses or high throughput screening

    Flaxseed supplementation improved insulin resistance in obese glucose intolerant people: a randomized crossover design

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    <p>Abstract</p> <p>Background</p> <p>Obesity leads to an increase in inflammation and insulin resistance. This study determined antioxidant activity of flaxseed and its role in inflammation and insulin resistance in obese glucose intolerant people.</p> <p>Methods</p> <p>Using a randomized crossover design, nine obese glucose intolerant people consumed 40 g ground flaxseed or 40 g wheat bran daily for 12 weeks with a 4-week washout period. Plasma inflammation biomarkers (CRP, TNF-α, and IL-6), glucose, insulin, and thiobaribituric acid reactive substance (TBARS) were measured before and after of each supplementation.</p> <p>Results</p> <p>Flaxseed supplementation decreased TBARS (p = 0.0215) and HOMA-IR (p = 0.0382). Flaxseed or wheat bran supplementation did not change plasma inflammatory biomarkers. A positive relationship was found between TBARS and HOMA-IR (r = 0.62, p = 0.0003).</p> <p>Conclusions</p> <p>The results of the study weakly support that decreased insulin resistance might have been secondary to antioxidant activity of flaxseed. However, the mechanism(s) of decreased insulin resistance by flaxseed should be further determined using flaxseed lignan.</p

    Measurement of flavor asymmetry of light-quark sea in the proton with Drell-Yan dimuon production in p+pp+p and p+dp+d collisions at 120 GeV

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    Evidence for a flavor asymmetry between the uˉ\bar u and dˉ\bar d quark distributions in the proton has been found in deep-inelastic scattering and Drell-Yan experiments. The pronounced dependence of this flavor asymmetry on xx (fraction of nucleon momentum carried by partons) observed in the Fermilab E866 Drell-Yan experiment suggested a drop of the dˉ(x)/uˉ(x)\bar d\left(x\right) / \bar u\left(x\right) ratio in the x>0.15x > 0.15 region. We report results from the SeaQuest Fermilab E906 experiment with improved statistical precision for dˉ(x)/uˉ(x)\bar d\left(x\right) / \bar u\left(x\right) in the large xx region up to x=0.45x=0.45 using the 120 GeV proton beam. Two different methods for extracting the Drell-Yan cross section ratios, σpd/2σpp\sigma^{pd} /2 \sigma^{pp}, from the SeaQuest data give consistent results. The dˉ(x)/uˉ(x)\bar{d}\left(x\right) / \bar{u}\left(x\right) ratios and the dˉ(x)uˉ(x)\bar d\left(x\right) - \bar u\left(x\right) differences are deduced from these cross section ratios for 0.13<x<0.450.13 < x < 0.45. The SeaQuest and E866/NuSea dˉ(x)/uˉ(x)\bar{d}\left(x\right) / \bar{u}\left(x\right) ratios are in good agreement for the x0.25x\lesssim 0.25 region. The new SeaQuest data, however, show that dˉ(x)\bar d\left(x\right) continues to be greater than uˉ(x)\bar u\left(x\right) up to the highest xx value (x=0.45x = 0.45). The new results on dˉ(x)/uˉ(x)\bar{d}\left(x\right) / \bar{u}\left(x\right) and dˉ(x)uˉ(x)\bar{d}\left(x\right) - \bar{u}\left(x\right) are compared with various parton distribution functions and theoretical calculations

    Preliminary phytochemical screening and In vitro antioxidant activities of the aqueous extract of Helichrysum longifolium DC

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    <p>Abstract</p> <p>Background</p> <p>Many oxidative stress related diseases are as a result of accumulation of free radicals in the body. A lot of researches are going on worldwide directed towards finding natural antioxidants of plants origins. The aims of this study were to evaluate <it>in vitro </it>antioxidant activities and to screen for phytochemical constituents of <it>Helichrysum longifolium </it>DC. [Family Asteraceae] aqueous crude extract.</p> <p>Methods</p> <p>We assessed the antioxidant potential and phytochemical constituents of crude aqueous extract of <it>Helichrysum longifolium </it>using tests involving inhibition of superoxide anions, DPPH, H<sub>2</sub>O<sub>2</sub>, NO and ABTS. The flavonoid, proanthocyanidin and phenolic contents of the extract were also determined using standard phytochemical reaction methods.</p> <p>Results</p> <p>Phytochemical analyses revealed the presence of tannins, flavonoids, steroids and saponins. The total phenolic content of the aqueous leaf extract was 0.499 mg gallic acid equivalent/g of extract powder. The total flavonoid and proanthocyanidin contents of the plant were 0.705 and 0.005 mg gallic acid equivalent/g of extract powder respectively. The percentage inhibition of lipid peroxide at the initial stage of oxidation showed antioxidant activity of 87% compared to those of BHT (84.6%) and gallic acid (96%). Also, the percentage inhibition of malondialdehyde by the extract showed percentage inhibition of 78% comparable to those of BHT (72.24%) and Gallic (94.82%).</p> <p>Conclusions</p> <p>Our findings provide evidence that the crude aqueous extract of <it>H. longifolium </it>is a potential source of natural antioxidants, and this justified its uses in folkloric medicines.</p
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