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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Caracterização da síndrome metabólica utilizando a análise de classes latentes

Ladwig, Ruben January 2015 (has links)
Objetivo: Identificar principais componentes da síndrome metabólica e características associadas, bem como identificar os perfis de anormalidades e sua variabilidade étnica. Métodos: Estudo transversal envolvendo 14544 participantes da linha de base do Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil). Com idade entre 35 e 74 anos de diferentes regiões do Brasil. Foi feita uma análise fatorial exploratória em variáveis associadas à síndrome metabólica, com uma análise de agrupamento dos participantes em função de seus escores fatoriais. Paralelamente, análise de classes latentes foi feita em toda a amostra, após categorização das variáveis. As proporções das classes foram avaliadas em cada estrato de raça/cor dos participantes. Resultados: Na amostra ELSA observou-se três fatores que explicam 97,7% da variabilidade das variáveis associadas à síndrome: componentes da síndrome metabólica e inflamação; hipertensão; enzimas hepáticas. Na análise de classes latentes observaram-se seis perfis de manifestação dos componentes síndrome, sendo que o perfil com maior prevalência no estudo é de pessoas com sobrepeso e hiperglicemia, mas com probabilidade menor de apresentar hipertensão. Nesta classe, a prevalência da síndrome metabólica (definida pelo critério conjunto) é de 42%. Esta classe é mais comum entre os indígenas do que nas demais categorias de raça/cor. Conclusão: A síndrome metabólica se manifesta de formas distintas na população. A investigação da associação destas manifestações com desfechos de interesse poderia aprofundar o conhecimento sobre a síndrome metabólica. / Objective: identify key components of the metabolic syndrome and associated features, as well as identify abnormalities groups and its ethnic variability. Methods: Cross-sectional study involving 14544 baseline participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), aged between 35 and 74 years, from different country regions. A exploratory factorial analysis was done on selected variables associated with the metabolic syndrome, with a cluster analysis done on the participants factor scores. At the same time, a latent class analysis was done on all participants and on the subset that had metabolic syndrome diagnosis, after the variables were categorized. The proportions of classes were evaluated in each stratum of race/color of the participants. Results: We observed 3 factors on the ELSA sample. They explain 97.7% of the variability of the variables associates with the metabolic syndrome: the metabolic syndrome and inflammation components; hypertension, markers of the non-alcoholic fatty liver disease. In the latent class analysis, we observed 6 classes of metabolic syndrome expression. The proportions of classes were evaluated in each stratum of race/color of the participants. The most prevalent class was of overweight and hiperglicemic subjects, with lower probability of having hipertension. In this class, the metabolic syndrome prevalence is of 42%. This class is more common in indians than in other groups of race/color. Conclusion: The metabolic syndrome is manifested in different ways in the population. The research of the association of these different manifestations with selected outcomes could further the current knowledge on the metabolic syndrome.
42

Measuring faculty attitudes and perceptions toward disability at a four-year university: A validity study

Lombardi, Allison, 1977- 03 1900 (has links)
xi, 114 p. : ill. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / The primary purpose of this study was to develop and field test the ExCEL survey instrument, intended to measure faculty attitudes toward and perceptions about students with disabilities at four-year colleges and universities. A secondary purpose was to examine how demographic characteristics of the sample and prior disability-focused training experiences influenced these attitudes and perceptions. A cross validation study was conducted using exploratory and confirmatory factor analysis. The exploratory factor analysis (EFA) resulted in an eight factor structure: Knowledge of Disability Law, Fairness, Invitation to Disclose, Willingness to Invest Time, Accessibility of Course Materials, Willingness to Adjust Course Assignments, Satisfaction with Campus Resources, and Willingness to Make Testing Accommodations. The confirmatory factor analysis (CFA) was intended to confirm the factor structure but resulted in an inadmissible solution, potentially due to model misspecification. These findings show initial reliability and validity of the ExCEL survey and suggest item development as a crucial next step in the development process. Follow-up analyses showed minimal differences between faculty according to gender but significant differences according to faculty rank (e.g., tenured, tenure-track, and non-tenure) and department. In addition, group differences emerged according to prior disability-focused training, where faculty who had previous disability-focused training had greater positive attitudes and perceptions toward students with disabilities than did faculty without such training. These results will inform the field about important constructs to consider in instrument development for measuring faculty attitudes and perceptions toward disability, including knowledge of legal mandates and accommodations and knowledge of and willingness to adjust instruction according to the tenets of Universal Design. As well, the findings will inform four-year college and university administrations when planning targeted interventions for faculty members in disability awareness training. / Committee in charge: K Brigid Flannery, Chairperson, Special Education and Clinical Sciences; Deborah Olson, Member, Special Education and Clinical Sciences; Joe Stevens, Member, Educational Methodology, Policy, and Leadership; Douglas Blandy, Outside Member, Arts and Administration
43

Caracterização da síndrome metabólica utilizando a análise de classes latentes

Ladwig, Ruben January 2015 (has links)
Objetivo: Identificar principais componentes da síndrome metabólica e características associadas, bem como identificar os perfis de anormalidades e sua variabilidade étnica. Métodos: Estudo transversal envolvendo 14544 participantes da linha de base do Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil). Com idade entre 35 e 74 anos de diferentes regiões do Brasil. Foi feita uma análise fatorial exploratória em variáveis associadas à síndrome metabólica, com uma análise de agrupamento dos participantes em função de seus escores fatoriais. Paralelamente, análise de classes latentes foi feita em toda a amostra, após categorização das variáveis. As proporções das classes foram avaliadas em cada estrato de raça/cor dos participantes. Resultados: Na amostra ELSA observou-se três fatores que explicam 97,7% da variabilidade das variáveis associadas à síndrome: componentes da síndrome metabólica e inflamação; hipertensão; enzimas hepáticas. Na análise de classes latentes observaram-se seis perfis de manifestação dos componentes síndrome, sendo que o perfil com maior prevalência no estudo é de pessoas com sobrepeso e hiperglicemia, mas com probabilidade menor de apresentar hipertensão. Nesta classe, a prevalência da síndrome metabólica (definida pelo critério conjunto) é de 42%. Esta classe é mais comum entre os indígenas do que nas demais categorias de raça/cor. Conclusão: A síndrome metabólica se manifesta de formas distintas na população. A investigação da associação destas manifestações com desfechos de interesse poderia aprofundar o conhecimento sobre a síndrome metabólica. / Objective: identify key components of the metabolic syndrome and associated features, as well as identify abnormalities groups and its ethnic variability. Methods: Cross-sectional study involving 14544 baseline participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), aged between 35 and 74 years, from different country regions. A exploratory factorial analysis was done on selected variables associated with the metabolic syndrome, with a cluster analysis done on the participants factor scores. At the same time, a latent class analysis was done on all participants and on the subset that had metabolic syndrome diagnosis, after the variables were categorized. The proportions of classes were evaluated in each stratum of race/color of the participants. Results: We observed 3 factors on the ELSA sample. They explain 97.7% of the variability of the variables associates with the metabolic syndrome: the metabolic syndrome and inflammation components; hypertension, markers of the non-alcoholic fatty liver disease. In the latent class analysis, we observed 6 classes of metabolic syndrome expression. The proportions of classes were evaluated in each stratum of race/color of the participants. The most prevalent class was of overweight and hiperglicemic subjects, with lower probability of having hipertension. In this class, the metabolic syndrome prevalence is of 42%. This class is more common in indians than in other groups of race/color. Conclusion: The metabolic syndrome is manifested in different ways in the population. The research of the association of these different manifestations with selected outcomes could further the current knowledge on the metabolic syndrome.
44

Dietary Patterns among Overweight/Obese Hispanic Women at High Risk for Type 2 Diabetes

January 2018 (has links)
abstract: Background: Hispanic women are at high risk for Type 2 Diabetes (T2D), in part due to their high prevalence of obesity, which may influence the development of insulin resistance and disease onset. Unhealthy eating contributes to T2D risk. Dietary patterns are the combination of total foods and beverages among individual’s over time, but there is limited information regarding its role on T2D risk factors among Hispanic women. Objective: To identify a posteriori dietary patterns and their associations with diabetes risk factors (age, BMI, abdominal obesity, elevated fasting blood glucose, and hemoglobin A1c) among overweight/obese Hispanic women. Design: Cross-sectional dietary data were collected among 191 women with or at risk for T2D using the Southwestern Food Frequency Questionnaire capturing the prior three months of intake. Dietary patterns were derived using exploratory factor analysis. Regression scores were used to explore associations between dietary patterns and diabetes risk factors. Results: The patterns derived were: 1) “sugar and fat-laden”, with high loads of sweets, drinks, pastries, and fats; 2) “plant foods and fish”, with high loads of vegetables, fruits, fish, and beans; 3) “soups and starchy dishes”, with high loads of soups, starchy foods, and mixed dishes; 4) “meats and snacks”, with high loads of red meat, salty snacks, and condiments; 5) “beans and grains”, with high loads of beans and seeds, whole-wheat and refined grain foods, fish, and alcohol; and 6) “eggs and dairy”, with high loads of eggs, dairy, and fats. The “sugar and fat-laden” and “meats and snacks” patterns were negatively associated with age (r= -0.230, p= 0.001 and r= -0.298, p<0.001, respectively). Scores for “plant foods and fish” were associated with fasting blood glucose (r= 0.152, p= 0.037). There were no other statistically significant relationships between the dietary patterns and risk factors for T2D. Conclusions: A variety of patterns with healthy and unhealthy traits among Hispanic women were observed. Being younger may play an important role in adhering to a dietary pattern rich in sugary and high-fat foods and highlights the importance of assessing dietary patterns among young women to early identify dietary traits detrimental for their health. / Dissertation/Thesis / Doctoral Dissertation Exercise and Nutritional Sciences 2018
45

Caracterização da síndrome metabólica utilizando a análise de classes latentes

Ladwig, Ruben January 2015 (has links)
Objetivo: Identificar principais componentes da síndrome metabólica e características associadas, bem como identificar os perfis de anormalidades e sua variabilidade étnica. Métodos: Estudo transversal envolvendo 14544 participantes da linha de base do Estudo Longitudinal de Saúde do Adulto (ELSA-Brasil). Com idade entre 35 e 74 anos de diferentes regiões do Brasil. Foi feita uma análise fatorial exploratória em variáveis associadas à síndrome metabólica, com uma análise de agrupamento dos participantes em função de seus escores fatoriais. Paralelamente, análise de classes latentes foi feita em toda a amostra, após categorização das variáveis. As proporções das classes foram avaliadas em cada estrato de raça/cor dos participantes. Resultados: Na amostra ELSA observou-se três fatores que explicam 97,7% da variabilidade das variáveis associadas à síndrome: componentes da síndrome metabólica e inflamação; hipertensão; enzimas hepáticas. Na análise de classes latentes observaram-se seis perfis de manifestação dos componentes síndrome, sendo que o perfil com maior prevalência no estudo é de pessoas com sobrepeso e hiperglicemia, mas com probabilidade menor de apresentar hipertensão. Nesta classe, a prevalência da síndrome metabólica (definida pelo critério conjunto) é de 42%. Esta classe é mais comum entre os indígenas do que nas demais categorias de raça/cor. Conclusão: A síndrome metabólica se manifesta de formas distintas na população. A investigação da associação destas manifestações com desfechos de interesse poderia aprofundar o conhecimento sobre a síndrome metabólica. / Objective: identify key components of the metabolic syndrome and associated features, as well as identify abnormalities groups and its ethnic variability. Methods: Cross-sectional study involving 14544 baseline participants of the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil), aged between 35 and 74 years, from different country regions. A exploratory factorial analysis was done on selected variables associated with the metabolic syndrome, with a cluster analysis done on the participants factor scores. At the same time, a latent class analysis was done on all participants and on the subset that had metabolic syndrome diagnosis, after the variables were categorized. The proportions of classes were evaluated in each stratum of race/color of the participants. Results: We observed 3 factors on the ELSA sample. They explain 97.7% of the variability of the variables associates with the metabolic syndrome: the metabolic syndrome and inflammation components; hypertension, markers of the non-alcoholic fatty liver disease. In the latent class analysis, we observed 6 classes of metabolic syndrome expression. The proportions of classes were evaluated in each stratum of race/color of the participants. The most prevalent class was of overweight and hiperglicemic subjects, with lower probability of having hipertension. In this class, the metabolic syndrome prevalence is of 42%. This class is more common in indians than in other groups of race/color. Conclusion: The metabolic syndrome is manifested in different ways in the population. The research of the association of these different manifestations with selected outcomes could further the current knowledge on the metabolic syndrome.
46

Evaluating the Construct Validity of the KIDSCREEN-52 Quality of Life questionnaire within a South African context utilizing Exploratory Factor Analysis: Initial validation

Taliep, Naiema January 2010 (has links)
Magister Artium (Psychology) - MA(Psych) / The absence of a suitable measure to assess the health related quality of life (HRQoL) of children and adolescents in South Africa, led to the use of the KIDSCREEN-52 questionnaire in this study. This questionnaire was developed and standardised in Europe and it assesses quality of life from the subjective perception of children and adolescents in terms of their physical, mental and social well-being. The use of assessment measures with different populations or in different milieu from the original standardisation context necessitates establishing the validity of such measures for the new utilization context. Thus, the aim of this quantitative study is specifically directed at examining the construct validity of the KIDSCREEN-52 within a South African context. Accordingly, this study is located within the theoretical framework of construct validation theory. Data for this Secondary Data Analysis study was drawn from the “Impact of Hope and Exposure to Community Violence on children’s perception of Well-being” study. The primary study employed stratified interval criterion sampling to select 565 grade 9 learners, aged 14-18 from six public schools. The dataset for the current study comprised all participants (N=565) of the broader study. As the initial step in validation of the KIDSCREEN-52 within South Africa, the current study examined the factor structure of the KIDSCREEN-52 within this context by means of exploratory factor analysis using principal component analysis with oblimin rotations. It also assessed the internal consistency reliability of each of the scales using Cronbach’s alpha. Exploratory factor analysis revealed the same 10 factors as identified by previous European studies with some deviation in the last two factors, which warrants further examination. Internal consistency of the measure was shown to be acceptable, with Cronbach’s alpha values ranging from 0.76 to 0.81 for the 10 scales. / South Africa
47

Bayesian exploratory factor analysis

Conti, Gabriella, Frühwirth-Schnatter, Sylvia, Heckman, James J., Piatek, Rémi 27 June 2014 (has links) (PDF)
This paper develops and applies a Bayesian approach to Exploratory Factor Analysis that improves on ad hoc classical approaches. Our framework relies on dedicated factor models and simultaneously determines the number of factors, the allocation of each measurement to a unique factor, and the corresponding factor loadings. Classical identification criteria are applied and integrated into our Bayesian procedure to generate models that are stable and clearly interpretable. A Monte Carlo study confirms the validity of the approach. The method is used to produce interpretable low dimensional aggregates from a high dimensional set of psychological measurements. (authors' abstract)
48

Advances in the analysis of event-related potential data with factor analytic methods

Scharf, Florian 04 April 2019 (has links)
Researchers are often interested in comparing brain activity between experimental contexts. Event-related potentials (ERPs) are a common electrophysiological measure of brain activity that is time-locked to an event (e.g., a stimulus presented to the participant). A variety of decomposition methods has been used for ERP data among them temporal exploratory factor analysis (EFA). Essentially, temporal EFA decomposes the ERP waveform into a set of latent factors where the factor loadings reflect the time courses of the latent factors, and the amplitudes are represented by the factor scores. An important methodological concern is to ensure the estimates of the condition effects are unbiased and the term variance misallocation has been introduced in reference to the case of biased estimates. The aim of the present thesis was to explore how exploratory factor analytic methods can be made less prone to variance misallocation. These efforts resulted in a series of three publications in which variance misallocation in EFA was described as a consequence of the properties of ERP data, ESEM was proposed as an extension of EFA that acknowledges the structure of ERP data sets, and regularized estimation was suggested as an alternative to simple structure rotation with desirable properties. The presence of multiple sources of (co-)variance, the factor scoring step, and high temporal overlap of the factors were identified as major causes of variance misallocation in EFA for ERP data. It was shown that ESEM is capable of separating the (co-)variance sources and that it avoids biases due to factor scoring. Further, regularized estimation was shown to be a suitable alternative for factor rotation that is able to recover factor loading patterns in which only a subset of the variables follow a simple structure. Based on these results, regSEMs and ESEMs with ERP-specific rotation have been proposed as promising extensions of the EFA approach that might be less prone to variance misallocation. Future research should provide a direct comparison of regSEM and ESEM, and conduct simulation studies with more physiologically motivated data generation algorithms.
49

THE PSYCHOMETRIC PROPERTIES OF THE ARABIC VERSIONSOF THE SOCIAL NETWORKING TIME USE SCALE AND THE SOCIAL MEDIA AND ACADEMIC PERFORMANCE OF STUDENTS SCALE AMONG UNIVERSITY STUDENTS IN SAUDI ARABIA

Alhaythami, Hassan Mohammed 04 August 2020 (has links)
No description available.
50

The South African personality inventory : a psychometric evaluation of the Afrikaans version

Rautenbach, Amanda Cornelia January 2019 (has links)
Orientation: South Africa’s cultural and linguistic diversity requires special measures to ensure that the assessments used in employment settings are scrupulously fair. To this end, Section 8 of The Employment Equity Act requires that psychometric tests are scientifically proved to be valid and reliable and not to discriminate unfairly against any individual or group. The South African Personality Inventory (SAPI) sets out to meet these criteria by incorporating culture-specific elements and by providing versions in each of South Africa’s 11 official languages. o Research purpose: The key determination of this study was to investigate the psychometric properties of the Afrikaans version of the South African Personality Inventory (SAPI). The aforementioned properties include item analysis, exploratory factor analysis (EFA), reliability analysis, product-moment correlation and multivariate analysis of variance (MANOVA). o Motivation for the study: To contribute to the fair, valid and reliable use of the SAPI questionnaire in all language versions of the instrument by examining the psychometric properties of the Afrikaans version and comparing it with the validated English version. Once this has been done for each of the 11 official South African languages versions, a culturally neutral instrument will be available for the full diversity of employment settings in South Africa. o Research design, approach and method: This study used a quantitative cross-sectional research design with an emic approach, objectivist ontology and a post-positivist research paradigm. Primary data was collected by administering the Afrikaans version of the SAPI questionnaire to a non-probability sample of 201 purposively selected white Afrikaans-speaking South Africans who are economically and non-economically active and have a minimum qualification of Grade 12. An online Afrikaans version of the SAPI along with a biographical questionnaire was used to collect data. Item analysis was investigated by means of a descriptive statistical analysis. An initial principle component analysis followed with exploratory factor analysis was performed to determine the instrument’s factor structure. A reliability analysis was conducted in order to measure the internal consistency of the instrument. Product-moment correlations explored the relationships between variables. Further analysis was done to detect the relationships of the variables and to detect differences. Main findings: The White Afrikaners attach immense importance to the social-relational factors. From the six factors, only three factors were extracted, namely the Social-relational Positive, combined Social-relational Negative/Conscientiousness, and Intellect/Openness factors. These factors showed adequate validity and reliability. The item functionality needs to be re-evaluated in order to measure all the six factors of the SAPI and different analytical techniques should be applied. The relationships between the remaining three factors were sufficient, and only age differences were detected in the experience of Social Relational Negative/Conscientiousness o Practical/managerial implications: The results of this study provide a firm foundation for the further investigation of the validity of the Afrikaans version of the questionnaire. Furthermore, insight is given to researchers and practitioners on the need to develop, adapt or translate psychometric instruments, especially for use in an environment which is multicultural and multilingual. o Contribution/value-add: This study contributes to cultural-specific research on the assessment of personality in South Africa. Its thorough investigation and attempt to validate the Afrikaans version of the SAPI is supported by an extensive body of literature relevant to standardizing the SAPI. Practitioners and organisations will now be able to administer a culturally informed personality assessment where the home language of the employees is Afrikaans. / Dissertation (MCom)--University of Pretoria, 2019. / Human Resource Management / MCom / Unrestricted

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