2,902 research outputs found

    Further supporting evidence for REEP1 phenotypic and allelic heterogeneity.

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    Heterozygous mutations in REEP1 (MIM #609139) encoding the receptor expression-enhancing protein 1 (REEP1) are a well-recognized and relatively frequent cause of autosomal dominant hereditary spastic paraplegia (HSP), SPG31.1 REEP1 localizes in the mitochondria and endoplasmic reticulum (ER) and facilitates ER-mitochondria interactions.2 In addition to the HSP phenotype, REEP1 has been associated with an autosomal dominant spinal type of Charcot-Marie-Tooth disease in 2 families.3 More recently, a patient with homozygous REEP1 mutation with a much more severe phenotype akin to spinal muscular atrophy with respiratory distress type 1 (SMARD1) was reported.4 In this report, we present a patient with a homozygous mutation in REEP1 manifesting a severe congenital distal spinal muscular atrophy (SMA) with diaphragmatic paralysis, expanding the phenotype from mild autosomal dominant HSP through to severe recessive distal SMA pattern

    On Cosmological Implication of the Trace Anomaly

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    We establish a connection between the trace anomaly and a thermal radiation in the context of the standard cosmology. This is done by solving the covariant conservation equation of the stress tensor associated with a conformally invariant quantum scalar field. The solution corresponds to a thermal radiation with a temperature which is given in terms of a cut-off time excluding the spacetime regions very close to the initial singularity. We discuss the interrelation between this result and the result obtained in a two-dimensional schwarzschild spacetime.Comment: 8 pages, no figure

    A Pareto Front Approach to Bi-objective of Distillation Column Operation Using Genetic Algorithm

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    In this paper, an exergy analysis approach is proposed for optimal design of distillation column by using Genetic algorithm. First, the simulation of a distillation column is performed by using the shortcut results and irreversibility in each tray is obtained. The area beneath the exergy loss profile is used as Irreversibility Index for exergy criteria. Then, two targets optimization algorithm (SA, Simulated Annealing) is used to maximize recovery and minimize irreversibility index in a column by six different variables (Feed Condition, Reflux Rate, Number of theoretical stage, Feed Trays (Feed Splitting, three variables)). SA uses one objective function for the purpose or alters two targets optimization to one target optimization. Then, GA optimization algorithm is used for two targets optimization except Pareto set which is used instead of objective function; finally, the results are compared with SA results. Then, one pump-around is considered to obtain better results (OPT2). Irreversibility index criterion is compared with exergetic efficiency, constant and variable feed composition splitters are considered.Key words: Exergy analysis; Irreversibility index; Genetic algorithm; Process optimization; Distillation colum

    Universe acceleration and fine structure constant variation in BSBM theory

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    In this work we investigate the utility of using SNe Ia observations in constraining the cosmological parameters in BSBM theory where a scalar field is responsible for both fine structure constant variation and late time universe acceleration. The model is discussed in the presence of an exponential self potential for the scalar field. Stability and phase space analysis of the solutions are studied. The model is tested against observational data for Hubble parameter and quasar absorption spectra. With the best fitted model parameters, the theory predicts a good match with the experimental results and exhibits fine structure constant variation. The analysis also shows that for the equation of state parameter, recent universe acceleration and possible phantom crossing in future is forecasted.Comment: 14 pages, 10 figures, final version with minor modification accepted to be published in JCA

    The quality of life in boys with Duchenne muscular dystrophy

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    We conducted a study to evaluate the quality of life in boys with Duchenne muscular dystrophy aged 8–18 years, compared with that in matched healthy controls. A total of 85 boys with Duchenne muscular dystrophy aged 8–18 years and 136 age, sex and living place matched healthy controls were included in this study. Patients and one of their parents separately completed the 27-item Persian version of KIDSCREEN questionnaire (child and adolescent version and parent version). From the children's perspective, the quality of life in patients was found to be lower in two subclasses: “physical activities and health” (p < 0.001) and “friends” (p = 0.005). Parental estimation of their sick child's quality of life was significantly lower than children's own assessment in two subclasses: “physical activities and health” (p < 0.001) and “general mood and feelings” (p < 0.001). Our results indicate that boys with Duchenne muscular dystrophy have quite a satisfactory quality of life. A happier and more hopeful life can be promoted through increasing social support and improving the parental knowledge regarding their child's more positive life perspective. © 2016 Elsevier B.V

    Mach's Principle and Model for a Broken Symmetric Theory of Gravity

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    We investigate spontaneous symmetry breaking in a conformally invariant gravitational model. In particular, we use a conformally invariant scalar tensor theory as the vacuum sector of a gravitational model to examine the idea that gravitational coupling may be the result of a spontaneous symmetry breaking. In this model matter is taken to be coupled with a metric which is different but conformally related to the metric appearing explicitly in the vacuum sector. We show that after the spontaneous symmetry breaking the resulting theory is consistent with Mach's principle in the sense that inertial masses of particles have variable configurations in a cosmological context. Moreover, our analysis allows to construct a mechanism in which the resulting large vacuum energy density relaxes during evolution of the universe.Comment: 9 pages, no figure
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