13,383 research outputs found

    Parsimonious Shifted Asymmetric Laplace Mixtures

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    A family of parsimonious shifted asymmetric Laplace mixture models is introduced. We extend the mixture of factor analyzers model to the shifted asymmetric Laplace distribution. Imposing constraints on the constitute parts of the resulting decomposed component scale matrices leads to a family of parsimonious models. An explicit two-stage parameter estimation procedure is described, and the Bayesian information criterion and the integrated completed likelihood are compared for model selection. This novel family of models is applied to real data, where it is compared to its Gaussian analogue within clustering and classification paradigms

    The Role of Medications in Predicting Activity Restriction Due to a Fear of Falling

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    Objectives: To examine the role of medication use and other factors in predicting activity restriction due to a fear of falling (AR/FF). Methods: Older adults were assessed twice with the interRAI Community Health Assessment and the Berg Balance Scale (BBS). The main outcome was limiting going outdoors due to an AR/FF. Medications were recorded by trained assessors. Results: Participants (n=441) had a mean age of 80.3 (sd=7.1) years, most were aged 65+ (96.8%) and 29.3% reported activity restriction. Taking nervous system active or cardiovascular medications was associated with AR/FF. In a multivariate model, the main predictors were having 3+ comorbid health conditions, lower (i.e., worse) scores on the BBS, having difficulty with climbing stairs, and having a visual impairment. Discussion: Modifiable risk factors, related to functional impairments, such as difficulties with balance and vision, appear to be more important predictors than medications

    Extended-release niacin increases anti-apolipoprotein A-I antibodies that block the antioxidant effect of high-density lipoprotein-cholesterol: the EXPLORE clinical trial.

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    Extended-release niacin (ERN) is the most effective agent for increasing high-density lipoprotein-cholesterol (HDL-C). Having previously identified anti-HDL antibodies, we investigated whether ERN affected the antioxidant capacity of HDL and whether ERN was associated with the production of antibodies against HDL (aHDL) and apolipoprotein A-I (aApoA-I). METHODS: Twenty-one patients older than 18 years, with HDL-C ≤40 mg dl-1 (men) or ≤50 mg dl-1 (women) were randomly assigned to receive daily ERN (n = 10) or placebo (n = 11) for two sequential 12-week periods, with 4 weeks of wash-out before cross-over. Primary outcome was change of paraoxonase-1 (PON1) activity and secondary outcomes were changes in aHDL and aApoA-I antibodies. Clinical Trial Unique Identifier: EudraCT 2006-006889-42. RESULTS: The effect of ERN on PON1 activity was nonsignificant (coefficient estimate 20.83 U l-1 , 95% confidence interval [CI] -9.88 to 51.53; P = 0.184). ERN was associated with an increase in HDL-C levels (coefficient estimate 5.21 mg dl-1 , 95% CI 1.16 to 9.25; P = 0.012) and its subclasses HDL2 (coefficient estimate 2.46 mg dl-1 , 95% CI 0.57 to 4.34; P = 0.011) and HDL3 (coefficient estimate 2.73 mg dl-1 , 95% CI 0.47 to 4.98; P = 0.018). ERN was significantly associated with the production of aApoA-I antibodies (coefficient estimate 0.25 μg ml-1 , 95% CI 0.09-0.40; P = 0.001). aApoA-I titres at baseline were correlated with decreased PON activity. CONCLUSIONS: The rise in HDL-C achieved with ERN was not matched by improved antioxidant capacity, eventually hampered by the emergence of aApoA-I antibodies. These results may explain why Niacin and other lipid lowering agents fail to reduce cardiovascular risk.info:eu-repo/semantics/publishedVersio

    Dephasing in matter-wave interferometry

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    We review different attempts to show the decoherence process in double-slit-like experiments both for charged particles (electrons) and neutral particles with permanent dipole moments. Interference is studied when electrons or atomic systems are coupled to classical or quantum electromagnetic fields. The interaction between the particles and time-dependent fields induces a time-varying Aharonov phase. Averaging over the phase generates a suppression of fringe visibility in the interference pattern. We show that, for suitable experimental conditions, the loss of contrast for dipoles can be almost as large as the corresponding one for coherent electrons and therefore, be observed. We analyze different trajectories in order to show the dependence of the decoherence factor with the velocity of the particles.Comment: 9 pages, 1 eps-figure. To appear in J. Phys. A: Math. Ge

    Methods of isolation and identification of pathogenic and potential pathogenic bacteria from skins and tannery effluents

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    Currently there is no standard protocol available within the leather industry to isolate and identify pathogenic bacteria from hides, skins or tannery effluent. This study was therefore carried out to identify simple but effective methods for isolation and identification of bacterial pathogens from the effluent and skins during leather processing. Identification methods based on both phenotypic and genotypic characteristics were investigated. Bacillus cereus and Pseudomonas aeruginosa were used as indicator bacteria to evaluate the isolation and identification methods. Decontaminated calfskins were inoculated with a pure culture of the above mentioned bacterial species followed by a pre-tanning and chromium tanning processes. Effluent samples were collected and skins were swabbed at the end of each processing stage. Bacterial identification was carried out based on the phenotypic characteristics; such as colony appearance on selective solid media, cell morphology following a standard Gram-staining and spore staining techniques, and biochemical reactions, e.g., the ability of a bacterial species to ferment particular sugars and ability to produce certain enzymes. Additionally, an identification system based on bacterial phenotypic characteristics, known as Biolog® system was applied. A pulsed-filed gel electrophoresis (PFGE) method for bacterial DNA fingerprinting was also evaluated and used for the identification of the inoculated bacteria. The methods described in the study were found to be effective for the identification of pathogenic bacteria from skins and effluent

    The association among diet, dietary fiber, and bowel preparation at colonoscopy

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    BACKGROUND AND AIMS: Pre-colonoscopy dietary restrictions vary widely and lack evidence-based guidance. We investigated whether fiber and various other foods/macronutrients consumed during the 3 days before colonoscopy are associated with bowel preparation quality. METHODS: This was a prospective observational study among patients scheduled for outpatient colonoscopy. Patients received instructions including split-dose polyethylene glycol, avoidance of vegetables/beans 2 days before colonoscopy, and a clear liquid diet the day before colonoscopy. Two 24-hour dietary recall interviews and 1 patient-recorded food log measured dietary intake on the 3 days before colonoscopy. The Nutrition Data System for Research was used to estimate dietary exposures. Our primary outcome was the quality of bowel preparation measured by the Boston Bowel Preparation Scale (BBPS). RESULTS: We enrolled 201 patients from November 2015 to September 2016 with complete data for 168. The mean age was 59 years (standard deviation, 7 years), and 90% of colonoscopies were conducted for screening/surveillance. Only 17% and 77% of patients complied with diet restrictions 2 and 1 day(s) before colonoscopy, respectively. We found no association between foods consumed 2 and 3 days before colonoscopy and BBPS scores. However, BPPS was positively associated with intake of gelatin, and inversely associated with intake of red meat, poultry, and vegetables on the day before colonoscopy. CONCLUSIONS: Our findings support recent guidelines encouraging unrestricted diets >1 day before colonoscopy if using a split-dose bowel regimen. Furthermore, we found no evidence to restrict dietary fiber 1 day before colonoscopy. We also found evidence to promote consumption of gelatin and avoidance of red meat, poultry, and vegetables 1 day before colonoscopy.Dr Jacobson has acted as a consultant for MOTUS GI and Remedy Partners. All other authors disclosed no financial relationships relevant to this publication. Supported by NIH/NIDDK R21DK105476. (R21DK105476 - NIH/NIDDK)Accepted manuscrip

    Biomassa e teores de nutrientes da serrapilheira e caracterização do solo em sistema agroflorestal de castanheira-do-brasil e cupuaçuzeiro em Porto Velho, Rondônia.

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    O objetivo deste trabalho foi avaliar a produção de serrapilheira e nutrientes presentes na mesma e no solo em um sistema agroflorestal de castanheira-do-brasil e cupuaçuzeiro, em Porto Velho, Rondônia
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