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At least 487 records · Page 27Linked to original sources
PubMed2000

Applications of a quadratic variance model for counting data.

A quadratic variance model expressed as a function of sample mean is used to describe counting variance for a mechanical system that exhibits extra-Poisson variance. The nonlinear term describes the extra-Poisson variance, and the linear terms describe the intrinsic and propagated Poisson variance. The quadratic variance model also is applied to repetitive bioassay data, where the nonlinear term describes the well-known phenomenon of biological variance, which is a special case of extra-Poisson variance. The model was found to be suitable for the bioassay data as well. Detection limits for extra-Poisson variance are discussed, as well as the estimation of net signal detection limits, intake, and committed effective dose equivalent using the quadratic variance model.

Biological Assay↗
PubMed2005

Block observations of neighbourhood physical disorder are associated with neighbourhood crime, firearm injuries and deaths, and teen births.

STUDY OBJECTIVE: To provide reliability information for a brief observational measure of physical disorder and determine its relation with neighbourhood level crime and health variables after controlling for census based measures of concentrated poverty and minority concentration. DESIGN: Psychometric analysis of block observation data comprising a brief measure of neighbourhood physical disorder, and cross sectional analysis of neighbourhood physical disorder, neighbourhood crime and birth statistics, and neighbourhood level poverty and minority concentration. SETTING: Pittsburgh, Pennsylvania, US (2000 population=334 563). PARTICIPANTS: Pittsburgh neighbourhoods (n=82) and their residents (as reflected in neighbourhood level statistics). MAIN RESULTS: The physical disorder index showed adequate reliability and validity and was associated significantly with rates of crime, firearm injuries and homicides, and teen births, while controlling for concentrated poverty and minority population. CONCLUSIONS: This brief measure of neighbourhood physical disorder may help increase our understanding of how community level factors reflect health and crime outcomes.

Adolescent↗
PubMed2006

Impact of chronic conditions on quality of life in patients with inflammatory bowel disease.

BACKGROUND: Although studies suggest that inflammatory bowel disease (IBD) has a significant impact on an individual's health-related quality of life, the added weight of other health conditions and comorbidities has not been investigated. The purpose of this study was to expand on prior research by taking into account the impact of other chronic health conditions on the health-related quality of life of individuals with IBD, and to develop a model to help clinicians understand the relative impact of various predictors of their patients' physical and mental health-related quality of life. METHODS: 615 patients from the gastroenterology outpatient practice of a large, urban university hospital received a self-administered survey including questions about their health conditions, the severity of their bowel symptoms, and their health-related quality of life (measured using the SF-36 instrument). RESULTS: 314 completed surveys were returned, resulting in a response rate of 51.1%. Two regression analyses were conducted to identify the role of patient demographic variables and other chronic conditions on the 2 primary outcomes of interest: the SF-36 Physical Component and Mental Component Summary scores. Statistically significant predictors of physical quality of life included IBD disease severity, arthritis, heart disease, age, anemia, back/shoulder pain, and hypertension; statistically significant predictors of mental health-related quality of life were IBD disease severity, depression/anxiety, age, and headaches. CONCLUSIONS: IBD disease severity is the most important predictor of both physical and mental health-related quality of life in patients with this condition despite the presence of other chronic conditions.

Adult↗
PubMed1984

Optimized acquisition parameters and statistical detection limit in quantitative EELS.

Optimizing the acquisition parameters for EELS recording has to be accomplished simultaneously from the physical and the statistical points of view; the statistical aspect of the question is covered here. Approximate probability density functions of the variables of interest are derived, which provide a global measure of signal-to-noise ratio taking into account every step of the EELS edge area estimation process. Qualitative and quantitative advice is given regarding the critical choice of the estimation and integration energy regions. The notion of visual contrast is presented; it permits the introduction of the concept of statistical detection limit. It is found that for typical experimental conditions, when other factors are equal, the required analysis time for the sample varies approximately as the inverse square of the concentration.

Electron Probe Microanalysis↗
PubMed2005

Low physical activity among adolescents in practical education.

The aim of this study was to investigate physical activity levels and factors related to physical activity among 16-year-old girls and boys in secondary school practical and theoretical programs. An additional aim was to identify factors contributing to differences in physical activity patterns between the educational programs. Sixteen-year-old students in the first year of secondary school in Sweden (n=585) were systematically selected and 93% agreed to complete a questionnaire. Compared with students in theoretical programs, those in practical programs spent less time and energy per day in physical activity. Girls in practical programs were the least physically active, and boys in theoretical programs the most physically active students. Statistical analysis showed that, among students in practical programs, the influence of educational program on physical activity level was explained by lower socio-economic level, less parental support, lower perceived health level, and negative attitudes toward outdoor physical activities. These data suggest that promotion of physical activity should focus on students, especially girls, in practical programs. Because the difference in physical activity levels between educational programs was partly an effect of less positive parental influence, school-based programs may be especially influential in increasing physical activity levels among secondary school students.

Adolescent↗
PubMed2002

Roots and wings: a pilot of a mind-body-spirit program.

The overwhelming supply and demand for holistic health information and services suggest the need for integrative medical centers to offer experientially based educational programs. Seventeen individuals participated in a pilot of a 12-week multidisciplinary program titled Roots and Wings. Self-reported pre- and postmeasures were completed by 11 participants and indicated promising outcomes across the dimensions of physical, emotional, and spiritual health. Participants had a statistically significant decrease in physical and psychological symptoms and an increase in daily spiritual experiences. Statistically significant positive changes were also found for psychological attitudes and health locus of control in addition to indicators of behavior, satisfaction and attitudes relevant to the goals of Roots and Wings. The content of the program and the implications of these findings for nurse educators are discussed.

Adult↗
PubMed2006

Attitudes toward physical education classes of primary school students in Turkey.

The purposes of this study were to report an investigation of attitudes toward physical education in a sample of primary school students and examine the predictive influence of students' sex, grades in physical education classes, and parents' education and socioeconomic status on students' attitudes. Participants, 963 (474 girls and 489 boys) primary school students from Grades 6 (12.7%), 7 (10.3%) and 8 (77%), completed the Wear Attitude Inventory. Analysis indicated students had positive scores on General Attitudes rather than on Social, Emotional, and Physical Attitudes. In addition, girls (M = 32.6, SD = 3.9) had more positive General Attitudes than boys (M = 32.0, SD = 4.6). Also, students' grades in physical education classes were statistically significantly related to their Attitudes toward physical education (Wilks lambda, F1,1110 = 2.88, p < .05). However, parents' education and socioeconomic status were not. One may infer that ways of encouraging more favorable attitudes might be planned.

Adolescent↗