3,088 research outputs found

    Synovial inflammation in an experimental model of metabolic syndrome in the rabbit

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    Objetivo: Analizar el efecto del síndrome metabólico (SM) sobre la inflamación sinovial en un modelo experimental en conejo. Material y métodos: Se probaron tres intervenciones dietéticas diferentes para inducir un modelo experimental de SM, en 21 conejos New Zealand hembra, de 8 meses de edad: 1) alimentación con dieta enriquecida con 1% de colesterol y 3% de aceite de cacahuete y agua ad libitum; 2) alimentación con dieta normal y agua con 30% de fructosa ad libitum; 3) alimentación con dieta enriquecida con 1% de colesterol y 3% de aceite de cacahuete y agua con 30% de fructosa ad limitum. Los animales se dejaron evolucionar durante 12 semanas y se hizo un seguimiento semanal de peso, glucosa basal, colesterol HDL, triglicéridos. Tras el sacrificio, se tomaron muestras de membrana sinovial para cuantificar el infiltrado macrofágico sinovial mediante inmunohistoquímica. Resultados: La única intervención dietética con la que conseguimos inducir alteraciones asociadas al SM en los conejos fue alimentándolos con una dieta hiperlipémica. Estos animales, además de presentar hiperglucemia y dislipemia, tenían un infiltrado macrofágico sinovial mayor que el del grupo control. Conclusión: La alimentación con dieta hiperlipémica induce alteraciones típicas del SM en el conejo, acompañadas de un aumento del infiltrado macrofágico sinovial, lo que sugiere que el macrófago podría desempeñar un papel importante en el inicio y/o la progresión de la artrosis descrita que se asocia con el SMObjetive: To analyze the effect of metabolic syndrome (MS) upon synovial inflammation in an experimental model in the rabbit. Material and methodology: Three different diets were used to induce an experimental model of MS in 21 female New Zealand rabbits (aged 8 months): 1) diet enriched with 1% cholesterol and 3% peanut oil, with water, ad libitum; 2) normal diet, with water, and 30% fructose, ad libitum; 3) diet enriched with 1% cholesterol and 3% peanut oil, with water, and 30% fructose, ad libitum. The animals were followed-up on for 12 weeks, with weekly monitoring of body weight, basal glucose, HDL-cholesterol and triglycerides. Following sacrifice, synovial membrane samples were collected to quantify the synovial macrophage infiltrate using immunohistochemical techniques. Results: The only diet to induce alterations associated with MS in the rabbits was the hyperlipidemic diet. These animals, in addition to presenting hyperglycemia and dyslipidemia, showed greater synovial macrophage infiltration than the control group. Conclusion: A hyperlipidemic diet induces alterations typical of MS in the rabbit, accompanied by an increase in synovial macrophage infiltrationEsta investigación ha sido financiada por FUNDACIÓN MAPFR

    Biopython: freely available Python tools for computational molecular biology and bioinformatics

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    Summary: The Biopython project is a mature open source international collaboration of volunteer developers, providing Python libraries for a wide range of bioinformatics problems. Biopython includes modules for reading and writing different sequence file formats and multiple sequence alignments, dealing with 3D macro molecular structures, interacting with common tools such as BLAST, ClustalW and EMBOSS, accessing key online databases, as well as providing numerical methods for statistical learning. Availability: Biopython is freely available, with documentation and source code at www.biopython.org under the Biopython license. Contact: All queries should be directed to the Biopython mailing lists, see www.biopython.org/wiki/[email protected]

    A new method for tracking of motor skill learning through practical application of Fitts’ law

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    This article is made available through the Brunel Open Access Publishing Fund.A novel upper limb motor skill measure, task productivity rate (TPR) was developed integrating speed and spatial error, delivered by a practical motor skill rehabilitation task (MSRT). This prototype task involved placement of 5 short pegs horizontally on a spatially configured rail array. The stability of TPR was tested on 18 healthy right-handed adults (10 women, 8 men, median age 29 years) in a prospective single-session quantitative within-subjects study design. Manipulations of movement rate 10% faster and slower relative to normative states did not significantly affect TPR, F(1.387, 25.009) = 2.465, p = .121. A significant linear association between completion time and error was highest during the normative state condition (Pearson's r = .455, p < .05). Findings provided evidence that improvements in TPR over time reflected motor learning with possible changes in coregulation behavior underlying practice under different conditions. These findings extend Fitts’ law theory to tracking of practical motor skill using a dexterity task, which could have potential clinical applications in rehabilitation

    Nonlinear electron transport in normally pinched-off quantum wire

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    Nonlinear electron transport in normally pinched-off quantum wires was studied. The wires were fabricated from AlGaAs/GaAs heterostructures with high-mobility two-dimensional electron gas by electron beam lithography and following wet etching. At certain critical source-drain voltage the samples exhibited a step rise of the conductance. The differential conductance of the open wires was noticeably lower than e^2/h as far as only part of the source-drain voltage dropped between source contact and saddle-point of the potential relief along the wire. The latter limited the electron flow injected to the wire. At high enough source-drain voltages the decrease of the differential conductance due to the real space transfer of electrons from the wire in GaAs to the doped AlGaAs layer was found. In this regime the sign of differential magnetoconductance was changed with reversing the direction of the current in the wire or the magnetic field, whet the magnetic field lies in the heterostructure plane and is directed perpendicular to the current. The dependence of the differential conductance on the magnetic field and its direction indicated that the real space transfer events were mainly mediated by the interface scattering.Comment: LaTeX 2e (epl.cls) 6 pages, 3 figure

    Minority and mode conversion heating in (3He)-H JET plasma

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    Radio frequency (RF) heating experiments have recently been conducted in JET (He-3)-H plasmas. This type of plasmas will be used in ITER's non-activated operation phase. Whereas a companion paper in this same PPCF issue will discuss the RF heating scenario's at half the nominal magnetic field, this paper documents the heating performance in (He-3)-H plasmas at full field, with fundamental cyclotron heating of He-3 as the only possible ion heating scheme in view of the foreseen ITER antenna frequency bandwidth. Dominant electron heating with global heating efficiencies between 30% and 70% depending on the He-3 concentration were observed and mode conversion (MC) heating proved to be as efficient as He-3 minority heating. The unwanted presence of both He-4 and D in the discharges gave rise to 2 MC layers rather than a single one. This together with the fact that the location of the high-field side fast wave (FW) cutoff is a sensitive function of the parallel wave number and that one of the locations of the wave confluences critically depends on the He-3 concentration made the interpretation of the results, although more complex, very interesting: three regimes could be distinguished as a function of X[He-3]: (i) a regime at low concentration (X[He-3] < 1.8%) at which ion cyclotron resonance frequency (ICRF) heating is efficient, (ii) a regime at intermediate concentrations (1.8 < X[He-3] < 5%) in which the RF performance is degrading and ultimately becoming very poor, and finally (iii) a good heating regime at He-3 concentrations beyond 6%. In this latter regime, the heating efficiency did not critically depend on the actual concentration while at lower concentrations (X[He-3] < 4%) a bigger excursion in heating efficiency is observed and the estimates differ somewhat from shot to shot, also depending on whether local or global signals are chosen for the analysis. The different dynamics at the various concentrations can be traced back to the presence of 2 MC layers and their associated FW cutoffs residing inside the plasma at low He-3 concentration. One of these layers is approaching and crossing the low-field side plasma edge when 1.8 < X[He-3] < 5%. Adopting a minimization procedure to correlate the MC positions with the plasma composition reveals that the different behaviors observed are due to contamination of the plasma. Wave modeling not only supports this interpretation but also shows that moderate concentrations of D-like species significantly alter the overall wave behavior in He-3-H plasmas. Whereas numerical modeling yields quantitative information on the heating efficiency, analytical work gives a good description of the dominant underlying wave interaction physics

    Infrared composition of the Large Magellanic Cloud

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    The evolution of galaxies and the history of star formation in the Universe are among the most important topics in today's astrophysics. Especially, the role of small, irregular galaxies in the star-formation history of the Universe is not yet clear. Using the data from the AKARI IRC survey of the Large Magellanic Cloud at 3.2, 7, 11, 15, and 24 {\mu}m wavelengths, i.e., at the mid- and near-infrared, we have constructed a multiwavelength catalog containing data from a cross-correlation with a number of other databases at different wavelengths. We present the separation of different classes of stars in the LMC in color-color, and color-magnitude, diagrams, and analyze their contribution to the total LMC flux, related to point sources at different infrared wavelengths

    Bayesian Parameter Estimation for Latent Markov Random Fields and Social Networks

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    Undirected graphical models are widely used in statistics, physics and machine vision. However Bayesian parameter estimation for undirected models is extremely challenging, since evaluation of the posterior typically involves the calculation of an intractable normalising constant. This problem has received much attention, but very little of this has focussed on the important practical case where the data consists of noisy or incomplete observations of the underlying hidden structure. This paper specifically addresses this problem, comparing two alternative methodologies. In the first of these approaches particle Markov chain Monte Carlo (Andrieu et al., 2010) is used to efficiently explore the parameter space, combined with the exchange algorithm (Murray et al., 2006) for avoiding the calculation of the intractable normalising constant (a proof showing that this combination targets the correct distribution in found in a supplementary appendix online). This approach is compared with approximate Bayesian computation (Pritchard et al., 1999). Applications to estimating the parameters of Ising models and exponential random graphs from noisy data are presented. Each algorithm used in the paper targets an approximation to the true posterior due to the use of MCMC to simulate from the latent graphical model, in lieu of being able to do this exactly in general. The supplementary appendix also describes the nature of the resulting approximation.Comment: 26 pages, 2 figures, accepted in Journal of Computational and Graphical Statistics (http://www.amstat.org/publications/jcgs.cfm

    Parathyroid hormone-related protein exhibits antioxidant features in osteoblastic cells through its N-terminal and osteostatin domains

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    Objectives: Oxidative stress plays a major role in the onset and progression of involutional osteoporosis. However, classical antioxidants fail to restore osteoblast function. Interestingly, the bone anabolism of parathyroid hormone (PTH) has been shown to be associated with its ability to counteract oxidative stress in osteoblasts. The PTH counterpart in bone, which is the PTHrelated protein (PTHrP), displays osteogenic actions through both its N-terminal PTH-like region and the C-terminal domain. Methods: We examined and compared the antioxidant capacity of PTHrP (1-37) with the C-terminal PTHrP domain comprising the 107-111 epitope (osteostatin) in both murine osteoblastic MC3T3-E1 cells and primary human osteoblastic cells. Results: We showed that both N- and C-terminal PTHrP peptides at 100 nM decreased reactive oxygen species production and forkhead box protein O activation following hydrogen peroxide (H 2 O 2 )-induced oxidation, which was related to decreased lipid oxidative damage and caspase-3 activation in these cells. This was associated with their ability to restore the deleterious effects of H 2 O 2 on cell growth and alkaline phosphatase activity, as well as on the expression of various osteoblast differentiation genes. The addition of Rp-cyclic 3',5'-hydrogen phosphorothioate adenosine triethylammonium salt (a cyclic 3',5'-adenosine monophosphate antagonist) and calphostin C (a protein kinase C inhibitor), or a PTH type 1 receptor antagonist, abrogated the effects of N-terminal PTHrP, whereas protein phosphatase 1 (an Src kinase activity inhibitor), SU1498 (a vascular endothelial growth factor receptor 2 inhibitor), or an anti osteostatin antiserum, inhibited the effects of C-terminal PTHrP. Conclusion: These findings indicate that the antioxidant properties of PTHrP act through its N- and C-terminal domains and provide novel insights into the osteogenic action of PTHrP.This work has been funded by grants from the Fundacion para la Investigacion Osea y Metabolismo Mineral-FEIOMM and the Instituto de Salud Carlos III (PI11/00449, PI15/00340, PI1600065, RD12/0043/0029, RD12/0043/0008 and RD12/0043/0018,). J. A. Ardua, D. Lozano, and S. Portal-Nunez are recipients of postdoctoral contracts from the Ministerio de Economia y Competitividad, Juan de la Cierva program JCI-2011-09548, FPDI-2013-17268, and RETICEF [FEDER “una manera de hacer Europa” (RD12/0043/0008)

    Removing exogenous information using pedigree data

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    Management of certain populations requires the preservation of its pure genetic background. When, for different reasons, undesired alleles are introduced, the original genetic conformation must be recovered. The present study tested, through computer simulations, the power of recovery (the ability for removing the foreign information) from genealogical data. Simulated scenarios comprised different numbers of exogenous individuals taking partofthe founder population anddifferent numbers of unmanaged generations before the removal program started. Strategies were based on variables arising from classical pedigree analyses such as founders? contribution and partial coancestry. The ef?ciency of the different strategies was measured as the proportion of native genetic information remaining in the population. Consequences on the inbreeding and coancestry levels of the population were also evaluated. Minimisation of the exogenous founders? contributions was the most powerful method, removing the largest amount of genetic information in just one generation.However, as a side effect, it led to the highest values of inbreeding. Scenarios with a large amount of initial exogenous alleles (i.e. high percentage of non native founders), or many generations of mixing became very dif?cult to recover, pointing out the importance of being careful about introgression events in populatio
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