842 resultados para non-parametric background modeling


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BACKGROUND: Low vitamin D status has been shown to be a risk factor for several metabolic traits such as obesity, diabetes and cardiovascular disease. The biological actions of 1, 25-dihydroxyvitamin D, are mediated through the vitamin D receptor (VDR), which heterodimerizes with retinoid X receptor, gamma (RXRG). Hence, we examined the potential interactions between the tagging polymorphisms in the VDR (22 tag SNPs) and RXRG (23 tag SNPs) genes on metabolic outcomes such as body mass index, waist circumference, waist-hip ratio (WHR), high- and low-density lipoprotein (LDL) cholesterols, serum triglycerides, systolic and diastolic blood pressures and glycated haemoglobin in the 1958 British Birth Cohort (1958BC, up to n = 5,231). We used Multifactor- dimensionality reduction (MDR) program as a non-parametric test to examine for potential interactions between the VDR and RXRG gene polymorphisms in the 1958BC. We used the data from Northern Finland Birth Cohort 1966 (NFBC66, up to n = 5,316) and Twins UK (up to n = 3,943) to replicate our initial findings from 1958BC. RESULTS: After Bonferroni correction, the joint-likelihood ratio test suggested interactions on serum triglycerides (4 SNP - SNP pairs), LDL cholesterol (2 SNP - SNP pairs) and WHR (1 SNP - SNP pair) in the 1958BC. MDR permutation model testing analysis showed one two-way and one three-way interaction to be statistically significant on serum triglycerides in the 1958BC. In meta-analysis of results from two replication cohorts (NFBC66 and Twins UK, total n = 8,183), none of the interactions remained after correction for multiple testing (Pinteraction >0.17). CONCLUSIONS: Our results did not provide strong evidence for interactions between allelic variations in VDR and RXRG genes on metabolic outcomes; however, further replication studies on large samples are needed to confirm our findings.

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Background: The oral health conditions of indigenous peoples in Amazonia are closely associated with ecological and dietary changes related to interaction with non-Indians. Aim: The study investigated the incidence of caries in an indigenous community from Central Brazil focusing on gender differences. Subjects and methods: The research was conducted among the Xavante Indians and was based on longitudinal data collected in two surveys (1999 and 2004). The study included 128 individuals, 63 (49.2%) males and 65 (50.8%) females, divided in four age brackets (6-12, 13-19, 20-34, 35-60 years of age). The DMFT (decayed, missing and filled teeth) index and incidences (difference between 1999 and 2004) were calculated for each individual. The proportion of incidence was also calculated. Differences in caries risk between gender and age brackets were compared by parametric and non-parametric tests. Results: There were statistically significant differences in relation to caries incidence between age brackets and gender. The greatest incidence was observed in the 20-34 age bracket, which presented 3.30 new decayed teeth, twice the risk of the 6-12 age bracket (p0.01), chosen as reference. While females in most age groups did not show higher risk for caries when compared to males, there was a 4.04-fold risk in the 20-34 age bracket (p0.01). Conclusion: It is concluded that factors related to the social functions of each sex (gender issues) and differential access to information, health services, and education may help to understand the differences observed in the incidence of caries.

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This work is an assessment of frequency of extreme values (EVs) of daily rainfall in the city of Sao Paulo. Brazil, over the period 1933-2005, based on the peaks-over-threshold (POT) and Generalized Pareto Distribution (GPD) approach. Usually. a GPD model is fitted to a sample of POT Values Selected With a constant threshold. However. in this work we use time-dependent thresholds, composed of relatively large p quantities (for example p of 0.97) of daily rainfall amounts computed from all available data. Samples of POT values were extracted with several Values of p. Four different GPD models (GPD-1, GPD-2, GPD-3. and GDP-4) were fitted to each one of these samples by the maximum likelihood (ML) method. The shape parameter was assumed constant for the four models, but time-varying covariates were incorporated into scale parameter of GPD-2. GPD-3, and GPD-4, describing annual cycle in GPD-2. linear trend in GPD-3, and both annual cycle and linear trend in GPD-4. The GPD-1 with constant scale and shape parameters is the simplest model. For identification of the best model among the four models WC used rescaled Akaike Information Criterion (AIC) with second-order bias correction. This criterion isolates GPD-3 as the best model, i.e. the one with positive linear trend in the scale parameter. The slope of this trend is significant compared to the null hypothesis of no trend, for about 98% confidence level. The non-parametric Mann-Kendall test also showed presence of positive trend in the annual frequency of excess over high thresholds. with p-value being virtually zero. Therefore. there is strong evidence that high quantiles of daily rainfall in the city of Sao Paulo have been increasing in magnitude and frequency over time. For example. 0.99 quantiles of daily rainfall amount have increased by about 40 mm between 1933 and 2005. Copyright (C) 2008 Royal Meteorological Society

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Background and aims Evaluating status in patients with motor fluctuations is complex and occasional observations/measurements do not give an adequate picture as to the time spent in different states. We developed a test battery to assess advanced Parkinson patients' status consisting of diary assessments and motor tests. This battery was constructed and implemented on a handheld computer with built-in mobile communication. In fluctuating patients, it should typically be used several times daily in the home environment, over periods of about one week. The aim of this battery is to provide status information in order to evaluate treatment effects in clinical practice and research, follow up treatments and disease progression and predict outcome to optimize treatment strategy. Methods Selection of diary questions was based on a previous study with Duodopa® (DIREQT). Tapping tests (with and without visual cueing) and a spiral drawing test were added. Rapid prototyping was used in development of the user interface. An evaluation with two pilot patients was performed before and after receiving new treatments for advanced disease (one received Duodopa® and one received DBS). Speed and proportion missed taps were calculated for the tapping tests and entropy of the radial drawing velocity was calculated for the spiral tests. Test variables were evaluated using non-parametric statistics. Results Post-treatment improvement was detected in both patients in many of the test variables. Conclusions Although validation work remains, preliminary results are promising and the test battery is currently being evaluated in a long-term health economics study with Duodopa® (DAPHNE).

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Background: Established in 1999, the Swedish Maternal Health Care Register (MHCR) collects data on pregnancy, birth, and the postpartum period for most pregnant women in Sweden. Antenatal care (ANC) midwives manually enter data into the Web-application that is designed for MHCR. The aim of this study was to investigate midwives? experiences, opinions and use of the MHCR. Method: A national, cross-sectional, questionnaire survey, addressing all Swedish midwives working in ANC, was conducted January to March 2012. The questionnaire included demographic data, preformed statements with six response options ranging from zero to five (0 = totally disagree and 5 = totally agree), and opportunities to add information or further clarification in the form of free text comments. Parametric and non-parametric methods and logistic regression analyses were applied, and content analysis was used for free text comments. Results: The estimated response rate was 53.1%. Most participants were positive towards the Web-application and the included variables in the MHCR. Midwives exclusively engaged in patient-related work tasks perceived the register as burdensome (70.3%) and 44.2% questioned the benefit of the register. The corresponding figures for midwives also engaged in administrative supervision were 37.8% and 18.5%, respectively. Direct electronic transfer of data from the medical records to the MHCR was emphasised as significant future improvement. In addition, the midwives suggested that new variables of interest should be included in the MHCR ? e.g., infertility, outcomes of previous pregnancy and birth, and complications of the index pregnancy. Conclusions: In general, the MHCR was valued positively, although perceived as burdensome. Direct electronic transfer of data from the medical records to the MHCR is a prioritized issue to facilitate the working situation for midwives. Finally, the data suggest that the MHCR is an underused source for operational planning and quality assessment in local ANC centres.

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Against the background of increasing competition from globalization and the trend towards consolidation, diversification and rationalization, the study of efficiency is most relevant in the Malaysian Islamic banking context, where all domestic commercial banks operate Islamic banking schemes. Using the non-parametric method of Data Envelopment Analysis (DEA), this study investigates the recent efficiency of the Malaysian Islamic Banking system. The attributions of technical efficiency (utilization of capacity) and scale efficiency (optimality of scale achieved) are identified. Further, Islamic Banking Schemes operating under the dual banking system of foreign and domestic commercial banks were benchmarked to the country's two full-fledged Islamic banks to provide insight of the relative efficiencies. Amidst an overall improvement in TE and SE, it was noted that foreign banks (FB) increased efficiency levels to achieve full efficiency over the six-year period, and domestic banks (DB) followed by smaller improvement while the fully-fledged Islamic banks (FFIE) experienced a general decline in efficiency which was solely attributed to scale inefficiency. The findings provide useful guidelines for policy implications and may also assist banks concerned with their strategic planning with regard to the future of Islamic banking.

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Background and Purpose: The number of degree-awarding programmes in medical education is steadily increasing. Despite the popularity and extensive investment in these courses, there is little research into their impact. This study investigated the perceived impact of an internationally-renowned postgraduate programme in medical education on health professionals’ development as educators.

Methods: An online survey of the 2008–12 graduates from the Centre for Medical Education, University of Dundee was carried out. Their self-reported shifts in various educational competencies and scholarship activities were analysed using non-parametric statistics. Qualitative data were also collected and analysed to add depth to the quantitative findings.

Results: Of the 504 graduates who received the online questionnaire 224 responded. Participants reported that a qualification in medical education had significantly (p < 0.001) improved their professional educational practices and engagement in scholarly activities. Masters graduates reported greater impact compared to Certificate graduates on all items, including ability to facilitate curriculum reforms, and in assessment and feedback practices. Masters graduates also reported more engagement in scholarship activities, with significantly greater contributions to journals. These qualifications equally benefited all participants regardless of age. International graduates reported greater impact of the qualification than their UK counterparts.

Conclusion: A postgraduate medical education programme can significantly impact on the practices and behaviours of health professionals in education, improving self-efficacy and instilling an increased sense of belonging to the educational community.

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Essa dissertação trata de algumas variáveis que podem influenciar a percepção dos consumidores no contexto de análises comparativas de preços durante o processo de compra. As variáveis estudadas foram: a forma de apresentação das ofertas dos produtos, a escolaridade dos participantes do estudo e a familiaridade para com o uso do produto. A importância desse estudo está fundamentada na necessidade de entendimento de como a percepção de vantagem na aquisição de produtos ocorre na presença das variáveis de influência estudadas, com o propósito prático de aplicação dos resultados no mercado varejista. A pesquisa foi realizada por meio de um estudo empírico, na cidade de São Luís ¿ MA, utilizando uma amostra de cento e noventa e duas pessoas, divididas igualmente entre estudantes de escolaridade média e superior. Os participantes do estudo avaliaram situações de compra em cenários fictícios com formas de apresentação de ofertas distintas, em que a percepção de vantagem foi avaliada em função das escolaridades e das familiaridades utilizadas no estudo. A base teórica para desenvolvimento do trabalho considerou a Teoria dos Prospectos de Kahneman e Tversky (1979) e a Teoria da Contabilidade Mental de Thaler (1985). Em função da natureza da base de dados foram utilizados testes não-paramétricos de Friedman, Kruskal-Wallis, Wilcoxon e Mann-Withney. Os resultados obtidos confirmaram as hipóteses levantadas e geraram subsídios para pesquisa futura envolvendo o aspecto familiaridade relacionada às marcas. Palavras-chave: contabilidade mental, percepção, preço de referência.

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FUNDAMENTO: Anestesia para cirurgia cardíaca pediátrica é sistematicamente realizada em pacientes graves sob condições fisiológicas anormais. No intraoperatório, existem variações significativas da volemia, temperatura corporal, composição plasmática e fluxo sanguíneo tecidual, além de ativação da inflamação, com consequências importantes. Medidas seriadas da glicemia podem indicar estados de exacerbação da resposta neuroendocrinometabólica ao trauma servindo como marcadores prognóstico de morbidade nessa população. OBJETIVO: Correlacionar os níveis de glicemia do período perioperatório de crianças submetidas a cirurgia cardíaca com a ocorrência de complicações no pós-operatório e comparar os níveis intraoperatórios de glicemia de acordo com as condições perioperatórias. MÉTODOS: Informações referentes ao procedimento anestésico-cirúrgico e condições perioperatórias dos pacientes foram coletadas em prontuário. Comparações das médias dos valores perioperatórios da glicemia nos grupos de pacientes que apresentaram, ou não, complicações pós-operatórias e as frequências referentes às condições perioperatórias foram estabelecidas conforme cálculo da razão de chances e em análises univariáveis não paramétricas. RESULTADOS: Valores mais elevados de glicemia intraoperatória foram observados nos indivíduos que apresentaram complicações pós-operatórias. Prematuridade, faixa etária, tipo de anestesia e caráter do procedimento não apresentaram influência na média glicêmica do intraoperatório. O emprego de Circulação Extracorpórea (CEC) esteve associado a maiores valores de glicemia durante a cirurgia. Nos procedimentos com CEC, maiores níveis glicêmicos foram observados nos indivíduos que evoluíram com infecção e complicações cardiovasculares, nas cirurgias sem CEC essa mesma associação ocorreu com complicações infecciosas e hematológicas. CONCLUSÃO: Níveis intraoperatórios mais elevados de glicemia estão associados com maior morbidade no pós-operatório de cirurgia cardíaca pediátrica.

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Background. To evaluate insulin release and insulin sensitivity in women with prior gestational diabetes mellitus (GDM) to gain a better understanding of type 2 diabetes pathogenesis.Methods. GDM women were individually matched for age, body mass index, and waist/hip ratio with those who were normal glucose tolerant in a previous pregnancy (NGT). All women presented with normal glucose tolerance. Twenty pairs were submitted to the oral glucose tolerance test (OGTT) with plasma glucose, insulin, and C-peptide determinations. of the 20 pairs, 18 participated in hyperglycemic (10.0 mmol/l) clamp experiments with frequent plasma glucose and insulin determinations, allowing us to calculate first- and second-phase insulin release and the insulin sensitivity index. GDM and NGT women were compared using Student's t-test, the Mann-Whitney U-test, Friedman's non-parametric test, and the two proportion test for independent groups.Results. GDM women showed higher glycosylated hemoglobin values; at OGTT, they showed late insulin peak with increased plasma insulin levels only during the second hour, and a similar plasma C-peptide response despite a higher plasma glucose curve; during hyperglycemic clamp procedures, they showed similar biphasic insulin release and insulin sensitivity index. Considering that a woman with previous GDM had a defect in insulin release and/or insulin sensitivity, if its magnitude was at least 25% lower than that of the matched NGT woman, 43.8% showed impairment of first-phase insulin release and 55.6% insulin resistance.Conclusions. GDM women showed some degree of glucose intolerance. It is therefore necessary to follow them for a longer time.

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This work is an assessment of frequency of extreme values (EVs) of daily rainfall in the city of São Paulo. Brazil, over the period 1933-2005, based on the peaks-over-threshold (POT) and Generalized Pareto Distribution (GPD) approach. Usually. a GPD model is fitted to a sample of POT Values Selected With a constant threshold. However. in this work we use time-dependent thresholds, composed of relatively large p quantities (for example p of 0.97) of daily rainfall amounts computed from all available data. Samples of POT values were extracted with several Values of p. Four different GPD models (GPD-1, GPD-2, GPD-3. and GDP-4) were fitted to each one of these samples by the maximum likelihood (ML) method. The shape parameter was assumed constant for the four models, but time-varying covariates were incorporated into scale parameter of GPD-2. GPD-3, and GPD-4, describing annual cycle in GPD-2. linear trend in GPD-3, and both annual cycle and linear trend in GPD-4. The GPD-1 with constant scale and shape parameters is the simplest model. For identification of the best model among the four models WC used rescaled Akaike Information Criterion (AIC) with second-order bias correction. This criterion isolates GPD-3 as the best model, i.e. the one with positive linear trend in the scale parameter. The slope of this trend is significant compared to the null hypothesis of no trend, for about 98% confidence level. The non-parametric Mann-Kendall test also showed presence of positive trend in the annual frequency of excess over high thresholds. with p-value being virtually zero. Therefore. there is strong evidence that high quantiles of daily rainfall in the city of São Paulo have been increasing in magnitude and frequency over time. For example. 0.99 quantiles of daily rainfall amount have increased by about 40 mm between 1933 and 2005. Copyright (C) 2008 Royal Meteorological Society

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Background/Aims. Chronic hepatitis by HCV is progressive towards cirrhosis, with variable rate. We evaluated the rate of fibrosis progression (RFP), risk factors associated with advanced fibrosis (F3 and F4), and estimated the evolution time to cirrhosis. Methods. We transversely selected 142 blood donors infected only with HCV, with a known route of infection, submitted to liver biopsy at admission. RFP= ratio between stage of fibrosis (METAVIR)/estimated duration of infection in years. Non-parametric tests and logistic regression analysis, with significance level of 5% were used. Results. Median RFP was 0.086 U/year (0.05 - 0.142). Ten patients had F4 and 25 had F3. Median RFP values were significantly different (p=0.001) from one age group at contamination to the others and ALT and AST levels. There were no differences in the expected evolution to cirrhosis between intermediate fibrosers (F2) and the rapid fibrosers (F3 and F4). The independent variables associated with advanced fibrosis were ALT (OR 7.2) and GGT (OR 6.4) and age at inclusion (OR 1.12). Conclusion. This study suggests that RFP is extremely variable, it is exponential with age, and mainly influenced by host characteristics, especially age at contamination and possibly ethnical group. These asymptomatic patients had high percentage of fibrosis F2, F3 and F4.

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The object of this investigation was to identify and analize aspects of the health status related to absenteism in physical education teachers in the municipal education system of the city of Campinas, Brazil, as related to the medical leave program. The non-concurrent prospective study was accomplished by means of a comparison with teachers who work only in the classroom, refering to a three year period. In the variables of greatest interest, the Pearson non-parametric chi-square (X2) statistical test was adopted. Calculations of relative risk and level of confidence were made using the Epi-info computer program. Significant differences were observed in the following diagnostic groups favoring the not exposed group: i) Supplementary Classification of factors that exercise influence over the health status and access to health services and ii) Digestive system illness; while the physical education teachers showed a significant difference in: i) diseases of the musculoskeletal and connective tissue system and ii) Injuries and poisoing. Possible explications for some of the adverse effects as well as the protective ones that were observed include physical activity as a way of life along with being a physical education teacher and on the other side, peculiar behavior of epidemiological descriptive characteristics, like sex and age, within the socio-economic context of the country. © Copyright Moreira Jr. Editora.

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Background: Amifostine is an efficient cytoprotector against toxicity caused by some chemotherapeutic drugs. Doxorubicin, a potent anticancer anthracycline, is known to produce spermatogenic damage even in low doses. Although some studies have suggested that amifostine does not confer protection to doxorubicin-induced testicular damage, schedules and age of treatment have different approach depending on the protocol. Thus, we proposed to investigate the potential cytoprotective action of amifostine against the damage provoked by doxorubicin to prepubertal rat testes (30-day-old) by assessing some macro and microscopic morphometric parameters 15, 30 and 60 days after the treatment; for fertility evaluation, quantitative analyses of sperm parameters and reproductive competence in the adult phase were also carried out.Methods: Thirty-day-old male rats were distributed into four groups: Doxorubicin (5 mg/kg), Amifostine (400 mg/kg), Amifostine/Doxorubicin (amifostine 15 minutes before doxorubicin) and Sham Control (0.9% saline solution). Standard One Way Anova parametric and Anova on Ranks non-parametric tests were applied according to the behavior of the obtained data; significant differences were considered when p < 0.05.Results: The rats killed 30 and 60 days after doxorubicin treatment showed diminution of seminiferous epithelium height and reduction on the frequency of tubular sections containing at least one type of differentiated spermatogonia; reduction of sperm concentration and motility and an increase of sperm anomalous forms where observed in doxorubicin-treated animals. All these parameters were improved in the Amifostine/Doxorubicin group only when compared to Doxorubicin group. Such reduction, however, still remained below the values obtained from the Sham Control group. Nevertheless, the reproductive competence of doxorubicin-treated rats was not improved by amifostine pre-administration.Conclusions: These results suggest that amifostine promotes a significant reduction of the doxorubicin long-term side effects on the seminiferous epithelium of prepubertal rats, which is reflected in the epidydimal fluid parameters in the adult phase. However, fertility status results suggest that such protection may not be effective against sperm DNA content damage. Further investigation of sperm DNA integrity must be carried out using amifostine and doxorubicin-treated experimental models. © 2010 Vendramini et al; licensee BioMed Central Ltd.

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Pós-graduação em Matemática Universitária - IGCE