458 research outputs found

    Appendix to "Approximating perpetuities"

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    An algorithm for perfect simulation from the unique solution of the distributional fixed point equation Y=dUY+U(1−U)Y=_d UY + U(1-U) is constructed, where YY and UU are independent and UU is uniformly distributed on [0,1][0,1]. This distribution comes up as a limit distribution in the probabilistic analysis of the Quickselect algorithm. Our simulation algorithm is based on coupling from the past with a multigamma coupler. It has four lines of code

    Salivary cortisol to assess the hypothalamic-pituitary-adrenal axisin healthy children under 3 years old

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    OBJECTIVE: To establish reference concentration intervals for salivary cortisol in healthy children, in the morning and in the afternoon, investigating factors that interfere with the concentration measured and the possibility that circadian rhythms are present. METHODS: A controlled observational study was carried out with 91 children aged 45 days to 36 months, selected at random and living in Santo André, state of São Paulo, Brazil. Inclusion criteria were: healthy, well-nourished, free from fever and corticoid use, subdivided by age group (five subsets) at 6-month intervals. Saliva was collected during home visits in the morning and afternoon. Cortisol was radioimmunoassayed with cortisol 3-oxime-bovine albumin antiserum. RESULTS: The five subsets exhibited higher cortisol concentration during the morning than in the afternoon (p < 0.001), and this difference passed 30% from 1 year of age onwards. Mean concentrations, in nmol/L, were 557.86 (morning) and 346.36 (afternoon). A negative linear correlation was observed between morning concentrations and hours' sleep and frequency of meals (p < 0.05), and in the afternoon with anthropometric measurements (p < 0.05). CONCLUSIONS: Reference values for normal salivary cortisol in healthy children were established. At 45 days it was possible to observe circadian rhythms, which reached maturity at 12 months of life. Sleep and food deprivation increased morning cortisol levels.OBJETIVO: Estabelecer intervalos de concentrações referenciais de cortisol salivar em crianças saudáveis, nos períodos matutino e vespertino, verificando os fatores de interferência nessa dosagem e a possibilidade de presença de ritmo circadiano. MÉTODOS: Pesquisa observacional controlada, incluindo aleatoriamente 91 crianças com idade de 45 dias a 36 meses, residentes em comunidade de Santo André (SP). Critérios de inclusão: nutridas, saudáveis, sem febre ou uso de corticóide, subdivididas em faixas etárias (cinco subgrupos) com intervalo de 6 meses. Houve coleta de saliva domiciliar nos períodos manhã e tarde para dosagem de cortisol, sob radioimunoensaio com anticortisol 3-oxima-albumina bovina. RESULTADOS: Os cinco subgrupos apresentaram dosagens matutinas superiores às vespertinas (p < 0,001), com diferença superior a 30% a partir de 1 ano de idade. Valor médio em nmol/L foi de 557,86 (manhã) e 346,36 (tarde). Observou-se correlação linear negativa na dosagem matutina para horas de repouso e freqüência de dieta (p < 0,05); na vespertina, para medidas antropométricas (p < 0,05). CONCLUSÕES Foram estabelecidos valores de referência de normalidade de cortisol salivar em crianças saudáveis, e aos 45 dias foi possível observar ritmo circadiano, que atingiu maturidade aos 12 meses de vida. Privações de sono e dieta elevaram valores de cortisol matutino.Universidade Estadual PaulistaFaculdade de Medicina do ABCUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de MedicinaUNESP Faculdade de Medicina de Botucatu Departamento de PediatriaUNIFESP, EPMSciEL

    The effect of versican G3 domain on local breast cancer invasiveness and bony metastasis

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    Abstract Introduction Increased versican expression has been associated with local breast cancer invasiveness and a more aggressive tumor phenotype. The cellular mechanisms are not fully understood and this study evaluated versican G3 domain with its EGF-like motifs in influencing tumor invasion and metastasis. Methods One recombinant construct was synthesized (a signal peptide for product secretion and the versican G3 domain). The construct was stably transfected into human breast carcinoma MT-1 cells. Cell viability in vitro was evaluated in low serum and serum starvation conditions. In vivo study of tumor growth was evaluated in a nude mouse model. G3 effects on rodent vascular endothelial cells were evaluated in vitro on cell survival, apoptosis, migration, and vascular formation. The effects of VEGF, fibronectin, and G3 on vascular formation were examined. An intracardiac injection model of metastatic human breast carcinoma tested the effect of G3 on distant bony and soft tissue metastasis. Analysis of metastatic burden included histology, radiographs, and micro-CT quantification of osteolysis. Results A greater viability of cancer cells was observed in low serum and serum-free conditions in the presence of versican G3. Larger subcutaneous tumors were obtained in the G3 group following tumor cell injection into CD1 mice. G3 induced a greater degree of rodent vascular endothelial cell proliferation and migration in vitro. Simultaneous presence of fibronectin, VEGF, and G3 promoted endothelial cell migration in wound-healing assays as compared to the treatments containing none, one or two of these molecules. Systemic tumor burden to distant bony and soft tissue metastatic sites was greater in the G3 group using the intracardiac injection metastatic model Conclusion Versican G3 domain appears to be important in local and systemic tumor invasiveness of human breast cancer. Effects include enhancing cell viability, proliferation, migration and enhancing local tumor growth. Potential effects on angiogenesis include enhancing vascular endothelial proliferation, migration, and vessel formation. The interactions between tumor cells, surrounding stromal components and neo-vascularization in breast cancer may include interactions with VEGF and fibronectin. The propensity of versican G3 to influence tumor invasion to bone and the mechanisms of G3 mediated osteolysis warrants ongoing studies

    Factors associated with poor asthma symptom control in adult Angolan regularly seen at an outpatient respiratory clinic

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    Background: Asthma is one of the most common chronic respiratory diseases and one of the most frequent causes of hospital care. Objectives: To describe the clinical characteristics of asthma and factors associated with its control. Methods: A cross-sectional study was conducted at the Military Hospital in Luanda, from April 2018 to March 2019. Data collection was performed using questionnaires on asthma symptoms and treatment, socio-demographic and environmental questions, and a Global Initiative for Asthma (GINA) questionnaire to assess the level of asthma control. Ordinal logistic regression analyses were performed. We estimated odds ratios, for higher categories of asthma control. P<0.05 was considered significant. Results: The sample consisted of 305 asthmatics ≥18-years-old, 56% women, with a mean age of 41.3 years. About 28% of patients had controlled asthma, 36% partially controlled and 35% uncontrolled. Poor asthma control was associated with frequent use of short-acting beta-2 agonists [OR 5.70 (95%CI 2.37;13.7)], oral corticosteroids [OR 3.68 (95%CI 2.24;6.04)], and incorrect inhaler technique [OR 4.08 (95%CI 1.25;13.3)]. Conclusions: A significant number of adults living in Luanda have uncontrolled asthma due to the under-use of inhaled corticosteroid therapy. It is necessary to develop strategic management and prevention plans to improve Angolan asthmatics' medical care.info:eu-repo/semantics/publishedVersio

    Text-in-context: a method for extracting findings in mixed-methods mixed research synthesis studies

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    Our purpose in this paper is to propose a new method for extracting findings from research reports included in mixed-methods mixed research synthesis studies

    Parent-to-Child Transition in Managing Cystic Fibrosis: A Research Synthesis: Parent-Child Transition: Managing Cystic Fibrosis

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    Although parents and children must adhere to five primary treatments for cystic fibrosis (CF), and their roles transition over time, the scope of CF studies often has been limited to one treatment regimen or to children within a specified age range. The purpose of this mixed research synthesis study is to integrate findings from qualitative and quantitative studies addressing the transition of CF management from parent to child, as well as factors related to adherence across treatments and over time. An existing grounded theory was used as a framework to synthesize findings in 17 reports from 16 studies. The results confirm the theory and posit three additional factors that may influence parent-to-child transition of care management

    Estudo da evolução da cafeicultura na região de São Sebastião do Paraíso - MG, utilizando geotecnologias.

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    O uso da terra é dinâmico e influenciado por fatores entre os quais se incluem a necessidade de produção de alimentos e energias alternativas para uma população crescente, a oscilação de preços e exigências para os produtos agrícolas nos mercados interno e externo e a necessidade de conciliar a produção agrícola com a conservação do ambiente. Mudanças na área ocupada pela cultura do café refletem mudanças nestes fatores sócio-econômicos e ambientais. O monitoramento e a compreensão dessa dinâmica são fundamentais para a construção de uma cafeicultura sustentável e competitiva. Geotecnologias, como o sensoriamento por meio de imagens de satélites e sistemas de informações geográficas, possibilitam a realização de estudos que evidenciam como o parque cafeeiro de uma determinada região evolui num determinado período de tempo. Neste trabalho, geotecnologias foram utilizadas para mapear a cafeicultura da região de São Sebastião do Paraíso, no sul de Minas Gerais. Foram avaliadas as relações espaçotemporais entre o uso e ocupação das terras da região

    Mapping the Mixed Methods–Mixed Research Synthesis Terrain

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    Mixed methods–mixed research synthesis is a form of systematic review in which the findings of qualitative and quantitative studies are integrated via qualitative and/or quantitative methods. Although methodological advances have been made, efforts to differentiate research synthesis methods have been too focused on methods and not focused enough on the defining logics of research synthesis—each of which may be operationalized in different ways—or on the research findings themselves that are targeted for synthesis. The conduct of mixed methods–mixed research synthesis studies may more usefully be understood in terms of the logics of aggregation and configuration. Neither logic is preferable to the other nor tied exclusively to any one method or to any one side of the qualitative/quantitative binary

    Bayesian data augmentation methods for the synthesis of qualitative and quantitative research findings

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    The possible utility of Bayesian methods for the synthesis of qualitative and quantitative research has been repeatedly suggested but insufficiently investigated. In this project, we developed and used a Bayesian method for synthesis, with the goal of identifying factors that influence adherence to HIV medication regimens. We investigated the effect of 10 factors on adherence. Recognizing that not all factors were examined in all studies, we considered standard methods for dealing with missing data and chose a Bayesian data augmentation method. We were able to summarize, rank, and compare the effects of each of the 10 factors on medication adherence. This is a promising methodological development in the synthesis of qualitative and quantitative research
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