8,747 research outputs found

    Development of a species-specific coproantigen ELISA for human taenia solium taeniasis

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    Taenia solium causes human neurocysticercosis and is endemic in underdeveloped countries where backyard pig keeping is common. Microscopic fecal diagnostic methods for human T. solium taeniasis are not very sensitive, and Taenia saginata and Taenia solium eggs are indistinguishable under the light microscope. Coproantigen (CoAg) ELISA methods are very sensitive, but currently only genus (Taenia) specific. This paper describes the development of a highly species-specific coproantigen ELISA test to detect T. solium intestinal taeniasis. Sensitivity was maintained using a capture antibody of rabbit IgG against T. solium adult whole worm somatic extract, whereas species specificity was achieved by utilization of an enzyme-conjugated rabbit IgG against T. solium adult excretory-secretory (ES) antigen. A known panel of positive and negative human fecal samples was tested with this hybrid sandwich ELISA. The ELISA test gave 100% specificity and 96.4% sensitivity for T. solium tapeworm carriers (N = 28), with a J index of 0.96. This simple ELISA incorporating anti-adult somatic and anti-adult ES antibodies provides the first potentially species-specific coproantigen test for human T. solium taeniasis

    Vacuolating cytotoxin (vacA) alleles of Helicobacter pylori comprise two geographically widespread types, m1 and m2, and have evolved through limited recombination

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    Vacuolating cytotoxin (vacA) alleles of Helicobacter pylori vary, particularly in their mid region (which may be type m1 or m2) and their signal peptide coding region (type s1 or s2). We investigated nucleotide diversity among vacA alleles in strains from several locales in Asia, South America, and the USA. Phylogenetic analysis of vacA mid region sequences from 18 strains validated the division into two main groups (m1 and m2) and showed further significant divisions within these groups. Informative site analysis demonstrated one example of recombination between m1 and m2 alleles, and several examples of recombination among alleles within these groups. Recombination was not sufficiently extensive to destroy phylogenetic structure entirely. Synonymous nucleotide substitution rates were markedly different between regions of vacA, suggesting different evolutionary divergence times and implying horizontal transfer of genetic elements within vacA. Non-synonymous/synonymous rate ratios were greater between m1 and m2 sequences than among m1 sequences, consistent with m1 and m2 alleles encoding functions fitting strains for slightly different ecological niches

    Mechanical Systems with Symmetry, Variational Principles, and Integration Algorithms

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    This paper studies variational principles for mechanical systems with symmetry and their applications to integration algorithms. We recall some general features of how to reduce variational principles in the presence of a symmetry group along with general features of integration algorithms for mechanical systems. Then we describe some integration algorithms based directly on variational principles using a discretization technique of Veselov. The general idea for these variational integrators is to directly discretize Hamilton’s principle rather than the equations of motion in a way that preserves the original systems invariants, notably the symplectic form and, via a discrete version of Noether’s theorem, the momentum map. The resulting mechanical integrators are second-order accurate, implicit, symplectic-momentum algorithms. We apply these integrators to the rigid body and the double spherical pendulum to show that the techniques are competitive with existing integrators

    Papel da análise discriminante no aprimoramento da avaliação da satisfação dos usuários

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    OBJECTIVE: To test discriminant analysis as a method of turning the information of a routine customer satisfaction survey (CSS) into a more accurate decision-making tool. METHODS: A 7-question, 10-multiple choice, self-applied questionnaire was used to study a sample of patients seen in two outpatient care units in Valparaíso, Chile, one of primary care (n=100) and the other of secondary care (n=249). Two cutting points were considered in the dependent variable (final satisfaction score): satisfied versus unsatisfied, and very satisfied versus all others. Results were compared with empirical measures (proportion of satisfied individuals, proportion of unsatisfied individuals and size of the median). RESULTS: The response rate was very high, over 97.0% in both units. A new variable, medical attention, was revealed, as explaining satisfaction at the primary care unit. The proportion of the total variability explained by the model was very high (over 99.4%) in both units, when comparing satisfied with unsatisfied customers. In the analysis of very satisfied versus all other customers, significant relationship was identified only in the case of the primary care unit, which explained a small proportion of the variability (41.9%). CONCLUSIONS: Discriminant analysis identified relationships not revealed by the previous analysis. It provided information about the proportion of the variability explained by the model. It identified non-significant relationships suggested by empirical analysis (e.g. the case of the relation very satisfied versus others in the secondary care unit). It measured the contribution of each independent variable to the explanation of the variation of the dependent one.OBJETIVO: Testar a análise discriminante como um método de transformar a informação obtida num inquérito de satisfação dos usuários de rotina numa acurada ferramenta de tomada de decisão. MÉTODOS: Utilizou-se questionário auto-aplicável com sete questões de dez opções numa amostra dos pacientes atendidos em duas unidades ambulatórias públicas, em Valparaíso, Chile, sendo uma de cuidados primários (n=100) e a outra de atenção secundária (n=249). Utilizaram-se dois pontos de corte na variável dependente (índice final de satisfação): satisfeitos vs insatisfeitos e muito satisfeitos vs os demais. Os resultados foram comparados com medidas empíricas habitualmente utilizadas (proporção de satisfeitos, proporção de insatisfeitos e dimensão da mediana). RESULTADOS: O nível de resposta foi muito elevado (sempre acima de 97,0%). Uma variável adicional revelou-se (atendimento médico), explicando a satisfação com o atendimento na unidade primária. Ao comparar satisfeitos com insatisfeitos, a proporção total da variabilidade explicada pelo modelo foi muito elevada (acima de 99,4%) em ambas unidades. Ao comparar muito satisfeitos com os demais, observou-se relação significativa apenas no caso da unidade primária. Explicou-se uma baixa proporção da variabilidade (41,9%). CONCLUSÕES: A análise discriminante revelou relações não percebidas pela análise empírica e indicou a proporção exata da variabilidade explicada pelo modelo utilizado. A técnica afastou como não significativas relações sugeridas pela análise empírica (por exemplo, muito satisfeitos versus os demais no caso da unidade secundária). A técnica permitiu medir a intensidade da contribuição de cada variável na explicação da variação da satisfação

    Reference values for bone mineral density in healthy Mexican children and adolescents

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    Introduction: Clinical assessment of bone health by Dual‐Energy X-ray Absorptiometry (DXA) in the paediatric population requires robust reference values. The International Society for Clinical Densitometry (ISCD) recommends that country/regional reference values ideally should be used to improve precision in bone health assessment. / Objective: The aim of this study was to provide reference values for relevant bone health variables for healthy Mexican children and adolescents aged 5 to 18 years. / Methods: This was a cross-sectional, stratified and population-based study, that measured a representative sample of healthy Mexican children and adolescents with DXA. We constructed age- and sex-smoothed reference values for areal bone mineral density (aBMD) of total body less head (TBLH), total body (TB), lumbar spine (LS), and bone mineral apparent density (BMAD) for LS, by means of Generalized Additive Models for Location, Scale and Shape (GAMLSS). / Results: Reference data including the 3th, 5th, 10th, 25th, 50th, 75th, 90th, 95th and 97th centiles, along with lambda (L), mu (M) and sigma (S) values, are given for each variable of interest for each sex at 0.25 years intervals. Reference values relative to height and Tanner-stage for both sexes are also provided. Finally, formulas to enable Z score estimation for clinical use are also presented. / Conclusions: The sex, age, height, Tanner-stage and ethnic-specific reference data provided in this study should enable more precise assessment of bone health in the Mexican paediatric population. The data presented may also allow for future evaluation of potential similarities and differences across different ethnic groups

    Improving GENCODE reference gene annotation using a high-stringency proteogenomics workflow.

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    Complete annotation of the human genome is indispensable for medical research. The GENCODE consortium strives to provide this, augmenting computational and experimental evidence with manual annotation. The rapidly developing field of proteogenomics provides evidence for the translation of genes into proteins and can be used to discover and refine gene models. However, for both the proteomics and annotation groups, there is a lack of guidelines for integrating this data. Here we report a stringent workflow for the interpretation of proteogenomic data that could be used by the annotation community to interpret novel proteogenomic evidence. Based on reprocessing of three large-scale publicly available human data sets, we show that a conservative approach, using stringent filtering is required to generate valid identifications. Evidence has been found supporting 16 novel protein-coding genes being added to GENCODE. Despite this many peptide identifications in pseudogenes cannot be annotated due to the absence of orthogonal supporting evidence

    THE HIGH CADENCE TRANSIENT SURVEY (HITS). I. SURVEY DESIGN AND SUPERNOVA SHOCK BREAKOUT CONSTRAINTS

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    Indexación: Web of Science; Scopus.We present the first results of the High Cadence Transient Survey (HiTS), a survey for which the objective is to detect and follow-up optical transients with characteristic timescales from hours to days, especially the earliest hours of supernova (SN) explosions. HiTS uses the Dark Energy Camera and a custom pipeline for image subtraction, candidate filtering and candidate visualization, which runs in real-time to be able to react rapidly to the new transients. We discuss the survey design, the technical challenges associated with the real-time analysis of these large volumes of data and our first results. In our 2013, 2014, and 2015 campaigns, we detected more than 120 young SN candidates, but we did not find a clear signature from the short-lived SN shock breakouts (SBOs) originating after the core collapse of red supergiant stars, which was the initial science aim of this survey. Using the empirical distribution of limiting magnitudes from our observational campaigns, we measured the expected recovery fraction of randomly injected SN light curves, which included SBO optical peaks produced with models from Tominaga et al. (2011) and Nakar & Sari (2010). From this analysis, we cannot rule out the models from Tominaga et al. (2011) under any reasonable distributions of progenitor masses, but we can marginally rule out the brighter and longer-lived SBO models from Nakar & Sari (2010) under our best-guess distribution of progenitor masses. Finally, we highlight the implications of this work for future massive data sets produced by astronomical observatories, such as LSST.http://iopscience.iop.org/article/10.3847/0004-637X/832/2/155/meta;jsessionid=76BDFFFE378003616F6DBA56A9225673.c4.iopscience.cld.iop.or

    Klebsiella pneumoniae bacteraemia complicating rotavirus gastroenteritis in two infants with glucocorticoid deficiency

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    Rotavirus gastroenteritis was complicated by Klebsiella Pneumoniae bacteraemia in two infants with glucocorticoid deficient conditions who were treated with 'stress dose' hydrocortisone during their illness. Delayed healing in the context of glucocorticoid administration combined with damage from rotavirus infection may result in increased risk of mucosal invasion by gastrointestinal bacteria and subsequent enteric gram-negative bacteraemia

    SIGMAR1 mutation associated with autosomal recessive Silver-like syndrome

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    OBJECTIVE: To describe the genetic and clinical features of a simplex patient with distal hereditary motor neuropathy (dHMN) and lower limb spasticity (Silver-like syndrome) due to a mutation in the sigma nonopioid intracellular receptor-1 gene (SIGMAR1) and review the phenotypic spectrum of mutations in this gene. METHODS: We used whole-exome sequencing to investigate the proband. The variants of interest were investigated for segregation in the family using Sanger sequencing. Subsequently, a larger cohort of 16 unrelated dHMN patients was specifically screened for SIGMAR1 mutations. RESULTS: In the proband, we identified a homozygous missense variant (c.194T>A, p.Leu65Gln) in exon 2 of SIGMAR1 as the probable causative mutation. Pathogenicity is supported by evolutionary conservation, in silico analyses, and the strong phenotypic similarities with previously reported cases carrying coding sequence mutations in SIGMAR1. No other mutations were identified in 16 additional patients with dHMN. CONCLUSIONS: We suggest that coding sequence mutations in SIGMAR1 present clinically with a combination of dHMN and pyramidal tract signs, with or without spasticity, in the lower limbs. Preferential involvement of extensor muscles of the upper limbs may be a distinctive feature of the disease. These observations should be confirmed in future studies
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