1,721,016 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Association between Lung Cancer/Multiple Myeloma Mortality and Exposure to Oncogenic Viruses- Statistical Analysis Using Non-model and Model-based Statistical Methods and Various Control Sampling Schemes for Cancer Mortality in Occupational Cohorts
Get PDFNdetan, Harrison Tatandam, M.Sc., MPH. Association between Lung Cancer/Multiple Myeloma Mortality and Exposure to Oncogenic Viruses – Statistical Analysis Using Non-model- and Model-based Statistical Methods and Various Control Sampling Schemes for Cancer Mortality in Occupational Cohorts. Doctor of Public Health (Biostatistics), December 2009; 119 pp., 9 tables, 7 appendices, 38 titles.
This study was designed to compare non-model- and model- based statistical techniques typically applied in cohort mortality analyses, and various schemes for selecting controls in nested case-control studies to document risk for lung cancer and multiple myeloma mortality, among workers in poultry slaughtering/processing plants. These workers are conceived to have a high exposure to oncogenic viruses compared to the general public. Data from the ongoing Cancer Risk in Workers Exposed to Oncogenic Viruses (CRIWETOV) project for members in a local Union Pension Fund belonging to the United Food & Commercial Workers (UFCW) international union, and followed–up for mortality from January 1, 1972 to December 31, 2003 were used for analyses. This cohort comprised of two large groups: poultry slaughtering/processing and non-poultry workers. The statistical methods applied were direct and indirect standardizations, Poisson, Cox proportional hazards, and binary/multiple logistic regression models and the sampling schemes for selecting controls were the cumulative survival, cumulative incidence, case-cohort, and incidence density sampling schemes.
The entire cohort and sub groups of poultry and non-poultry separately had higher risks of mortality from both malignant diseases (statistically significant for lung cancer) compared to the United States’ general population, but slightly lower (statistically not significant) risks among poultry compared to non-poultry workers. Results of comparative effect measures from the various statistical methods under consideration were similar with a very slight difference in variability/precision within the cohort analyses. The effect measures were also similar for nested case-control analyses that applied the cumulative survival, cumulative incidence and case-base sampling schemes in selecting controls. However, the incidence density sampling scheme led to markedly different results (both in magnitude and statistical significance), that were more profound with the Cox regression model. Where the Cox model was not appropriate the interval Poisson (exponential) model was used and predictions were similar to those obtained using other methods
Autism: Association Between Autism and Parenting Stress
No full textAutism is a developmental disorder, whose etiology is still an active research. Objectives of this study are to identify: risk factors of parenting stress; statistical tools for analysis and interpretations of data to ascertain and reinforce risk factors; and recommendations to mitigate parenting stress of autistic children. Data: National Survey of Children with Special Care Needs (NS-CSHCN), 2005-06. Analysis was performed on NS-CSHCN (n=40,723). Among parents with autistic children (n=2,123), the highest adjusted odds of stress were reported associated with primary language (OR= 9.44), insurance (OR=0.34), and Respite care (OR=3.71). Parents with non-autistic children (n=38,133) was the reference population with 467 missing values. Recommendations: Re-evaluation to improve provider language services especially for CSHCN; Family centered public health delivery rather than patient-provider interactive approach
Periodontal Health and the Perception of Treatment Versus Actual Treatment Needs Based on NHANES 2003-2004
Get PDFPeriodontal disease is a silent and neglected epidemic which is in the spotlight of health disparities of the US. The aim is to determine trends of periodontal disease and patients’ perceived need of periodontal treatment versus the reality of treatment needs based on NHANES 2003-2004 data. Datasets were merged, analyzed and reported utilizing demographic information, periodontal examination and oral health questionnaire. Non- Hispanic Whites have the highest frequencies of periodontal disease rather than the previously highest Non-Hispanic Blacks. Based on perception of treatment needs 35.62% believed they did not need treatment when clinical findings indicated a need for NSPT, whereas only 12.23% perceived they needed NSPT which coincided with clinical findings
Dietary Quality In The United States: An Evaluation Of The American Diet Using The Mediterranean Diet Index
No full textLaFontaine, Laura Jean, Dietary Quality in the United States: An Evaluation of the American Diet Using the Mediterranean Diet Index. Master of Public Health (Epidemiology), December 2003, 69 pp., 10 tables, 3 figures, reference list, 92 titles. Mediterranean Diet Index (MDI) score is positively associated with increased longevity in diverse populations. High scores are characterized by high intake of fruit, vegetables, legumes, fish, and grains; low intake of meat and dairy; moderate alcohol intake; and high monounsaturated to saturated fat ratio. Dietary quality 7,772 individuals ages 2 and older in the NHANES 1999-2000 sample was assessed using the MDI. Mean MDI scores were low overall and across all population groups. Highest mean scores (3.03-3.13) were observed in children 2-3 and adult men; lowest scores (2.76-2.77) were observed in adolescents. High scores were associated with foreign-born status, higher education level, increasing age in adults, and decreasing age in children
Using Generalized Estimating Equations to Analyze Alcohol Consumption and Job Displacement among Older Workers
Get PDFThe objectives of this dissertation were to compare differences in alcohol consumption among the older workers (aged 51 to 61 years) who have experienced job displacement compared to those who remain continuously employed. Generalized estimating equations were used to model this relationship using longitudinal data from the Health and Retirement Study from 1992 to 2006. Approximately 39% of respondents had died during the study period. We analyzed four models. One model excluded data for deceased respondents. Another model retained data for deceased respondents. For the remaining two models, data was imputed using multiple imputation by chained equations. Data was imputed for only the predictors in one imputation, imputed for both the dependent variable and the predictors in the second imputation. All models were weighted and adjusted for key sociodemographic variables. The results of this study show that being continuously employed, compared to experiencing job displacement, has a protective effect on the onset of alcohol consumption. Older workers who were not displaced were less likely to report consuming alcohol compared to those who had been displaced. This finding remained statistical significant even after adjusting for key sociodemographic variables. Complete case analysis and observed sample models provided biased estimates (i.e. wider confidence intervals, smaller p values) compared to the two multiple imputation models. Our findings have important public health implications. Older workers are likely to have varied participation in the labor market. They are likely to be more experienced and hold senior or management positions, thereby earning higher wages. They may be at a higher risk of layoff during uncertain economic times, such as a recession. The effects of alcohol consumption among older individuals have been shown to be negative and particularly harmful, especially in terms of ethanol toxicity. Additional studies are needed to examine the health effects of late onset of drinking among older Americans
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Effects of Cardiorespiratory Fitness on Serum Ferritin Concentration and Type 2 Diabetes: Evidence from the Aerobics Center Longitudinal Study (ACLS)
No full textLe, Tuan D., Effects of Cardiorespiratory Fitness on Serum Ferritin Concentration and Type 2 Diabetes: Evidence from the Aerobics Center Longitudinal Student (ACLS). Doctor of Public Health (Clinical Research). May 2008, 114 pp., 12 tables, 8 figures, bibliography, 68 titles. Recent studies suggest that an elevated serum ferritin concentration is considered an independent factor associated with increased risk of type 2 diabetes and cardiorespiratory fitness (CRF) is inversely associated with diabetes. Using secondary data from Aerobics Center Longitudinal Study at the Cooper Institute, Dallas, Texas, the author explored the association between serum ferritin levels and diabetes, CRF and diabetes, and the effect of CRF on the association between serum ferritin levels and diabetes. A cross-sectional study and a longitudinal cohort study were used. In the cross-sectional study, an increased CRF level found to be associated with a decreased serum ferritin concentration and a lowered prevalence of type 2 diabetes. Participants with high ferritin levels and high triglyceride levels were 1.89 and 1.57 times more likely to have diabetes respectively. Overweight or obese individuals were 1.35 to 1.40 times more likely to have diabetes. Participants with a family history of diabetes were 3.69 times more likely to have diabetes. Participants in the highest CRF quintile levels were 40% and 15% less likely to have type 2 diabetes among persons with normal and high blood glucose, respectively. In the prospective cohort study, it was found that serum ferritin might predict the development of type 2 diabetes in males and high serum ferritin concentration levels. The incidence rate among males increased with serum ferritin quartile (ptrend [less than] 0.05). A reduction of serum ferritin concentration was associated with a reduction of diabetes risk in those participating in physical activity. It suggests physicians might use patients' serum ferritin concentrations as a marker for predicting risk for new-onset diabetes and patients should be encouraged to participate in physical activities
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