101 resultados para EFA
Resumo:
We investigated cross-cultural differences in the factor structure and psychometric properties of the 75-item Young Schema Questionnaire-Short Form (YSQ-SF). Participants were 833 South Korean and 271 Australian undergraduate students. The South Korean sample was randomly divided into two sub-samples. Sample A was used for Exploratory Factor Analysis (EFA) and sample B was used for Confirmatory Factor Analysis (CFA). EFA for the South Korean sample revealed a 13-factor solution to be the best fit for the data, and CFA on the data from sample B confirmed this result. CFA on the data from the Australian sample also revealed a 13-factor solution. The overall scale of the YSQ-SF demonstrated a high level of internal consistency in the South Korean and Australian groups. Furthermore, adequate internal consistencies for all subscales in the South Korean and Australian samples were demonstrated. In conclusion, the results showed that YSQ-SF with 13 factors has good psychometric properties and reliability for South Korean and Australian University students. Korean samples had significantly higher YSD scores on most of the 13 subscales than the Australian sample. However, limitations of the current study preclude the generalisability of the findings to beyond undergraduate student populations. (c) 2006 Elsevier B.V. All rights reserved.
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This multi-modal investigation aimed to refine analytic tools including proton magnetic resonance spectroscopy (1H-MRS) and fatty acid gas chromatography-mass spectrometry (GC-MS) analysis, for use with adult and paediatric populations, to investigate potential biochemical underpinnings of cognition (Chapter 1). Essential fatty acids (EFAs) are vital for the normal development and function of neural cells. There is increasing evidence of behavioural impairments arising from dietary deprivation of EFAs and their long-chain fatty acid metabolites (Chapter 2). Paediatric liver disease was used as a deficiency model to examine the relationships between EFA status and cognitive outcomes. Age-appropriate Wechsler assessments measured Full-scale IQ (FSIQ) and Information Processing Speed (IPS) in clinical and healthy cohorts; GC-MS quantified surrogate markers of EFA status in erythrocyte membranes; and 1H-MRS quantified neurometabolite markers of neuronal viability and function in cortical tissue (Chapter 3). Post-transplant children with early-onset liver disease demonstrated specific deficits in IPS compared to age-matched acute liver failure transplant patients and sibling controls, suggesting that the time-course of the illness is a key factor (Chapter 4). No signs of EFA deficiency were observed in the clinical cohort, suggesting that EFA metabolism was not significantly impacted by liver disease. A strong, negative correlation was observed between omega-6 fatty acids and FSIQ, independent of disease diagnosis (Chapter 5). In a study of healthy adults, effect sizes for the relationship between 1H-MRS- detectable neurometabolites and cognition fell within the range of previous work, but were not statistically significant. Based on these findings, recommendations are made emphasising the need for hypothesis-driven enquiry and greater subtlety of data analysis (Chapter 6). Consistency of metabolite values between paediatric clinical cohorts and controls indicate normal neurodevelopment, but the lack of normative, age-matched data makes it difficult to assess the true strength of liver disease-associated metabolite changes (Chapter 7). Converging methods offer a challenging but promising and novel approach to exploring brain-behaviour relationships from micro- to macroscopic levels of analysis (Chapter 8).
Resumo:
Purpose Dry eye is a common complaint often encountered in optometric practice. However, it is a difficult condition to treat as clinical signs do not always correlate with patient symptoms. Essential fatty acids (EFA), particularly omega-3 EFA, may be effective in dealing with the underlying causes. Methods A literature review was carried out on the PubMed, ScienceDirect and Ovid databases. Searches included keywords such as ‘dry eye’, ‘essential fatty acids’ and ‘nutrition’ to find articles relating to the treatment of dry eye syndrome (DES) with omega-3 EFAs. Results Omega-3 and -6 EFAs need to be consumed together within a reasonable ratio to be effective. Currently, typical diets in developed countries lack omega-3 EFA and this results in an overexposure to omega-6. Omega-3 supplementation has an anti-inflammatory effect, inhibiting creation of omega-6 prostaglandin precursors. Omega-3 EFAs also demonstrate anti-inflammatory action in the lacrimal gland preventing apoptosis of the secretory epithelial cells. Supplementation clears meibomitis, allowing a thinner, more elastic lipid layer to protect the tear film and cornea. Conclusion Dietary supplementation of omega-3 EFA has already proven to be effective in coronary heart disease and arthritis. Safety is not a concern as it works synergistically with omega-6 in the body. Evidence suggests that supplementation with omega-3 EFA may be beneficial in the treatment and prevention of DES.
Resumo:
This thesis explores efforts to conjoin organisational contexts and capabilities in explaining sustainable competitive advantage. Oliver (1997) argued organisations need to balance the need to conform to industry’s requirements to attain legitimization (e.g. DiMaggio & Powell, 1983), and the need for resource optimization (e.g. Barney, 1991). The author hypothesized that such balance can be viewed as movements along the homogeneity-heterogeneity continuum. An organisation in a homogenous industry possesses similar characteristics as its competitors, as opposed to a heterogeneous industry in which organisations within are differentiated and competitively positioned (Oliver, 1997). The movement is influenced by the dynamic environmental conditions that an organisation is experiencing. The author extended Oliver’s (1997) propositions of combining RBV’s focus on capabilities with institutional theory’s focus on organisational context, as well as redefining organisational receptivity towards change (ORC) factors from Butler and Allen’s (2008) findings. The authors contributed to the theoretical development of ORC theory to explain the attainment of sustainable competitive advantage. ORC adopts the assumptions from both institutional and RBV theories, where the receptivity factors include both organisational contexts and capabilities. The thesis employed a mixed method approach in which sequential qualitative quantitative studies were deployed to establish a robust, reliable, and valid ORC scale. The adoption of Hinkin’s (1995) three-phase scale development process was updated, thus items generated from interviews and literature reviews went through numerous exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) to achieve convergent, discriminant, and nomological validities. Samples in the first phase (semi structured interviews) were hotel owners and managers. In the second phase, samples were MBA students, and employees of private and public sectors. In the third phase, samples were hotel managers. The final ORC scale is a parsimonious second higher-order latent construct. The first-order constructs comprises four latent receptivity factors which are ideological vision (4 items), leading change (4 items), implementation capacity (4 items), and change orientation (7 items). Hypotheses testing revealed that high levels of perceived environmental uncertainty leads to high levels of receptivity factor. Furthermore, the study found a strong positive correlation between receptivity factors and competitive advantage, and between receptivity factors and organisation performance. Mediation analyses revealed that receptivity factors partially mediate the relationship between perceived environmental uncertainty, competitive advantage and organisational performance.
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The Center for Epidemiologic Studies-Depression Scale (CES-D) is the most frequently used scale for measuring depressive symptomatology in caregiving research. The aim of this study is to test its construct structure and measurement equivalence between caregivers from two Spanish-speaking countries. Face-to-face interviews were carried out with 595 female dementia caregivers from Madrid, Spain, and from Coahuila, Mexico. The structure of the CES-D was analyzed using exploratory and confirmatory factor analysis (EFA and CFA, respectively). Measurement invariance across samples was analyzed comparing a baseline model with a more restrictive model. Significant differences between means were found for 7 items. The results of the EFA clearly supported a four-factor solution. The CFA for the whole sample with the four factors revealed high and statistically significant loading coefficients for all items (except item number 4). When equality constraints were imposed to test for the invariance between countries, the change in chi-square was significant, indicating that complete invariance could not be assumed. Significant between-countries differences were found for three of the four latent factor mean scores. Although the results provide general support for the original four-factor structure, caution should be exercised on reporting comparisons of depression scores between Spanish-speaking countries.
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This study evaluates applicability of E-service quality measurements in the context of online hotel bookings. Data was collected from an online survey of undergraduate college students at two universities in the United States. The Transaction Process-based Framework (eTransQual) conceptualized by Bauer et al. (2006) was adapted, and the dimensionality of e-service quality was identified. The study identified process/reliability as the most important factor influencing overall quality of booking websites.
Resumo:
Abstract The number of students engaged in Massive Open Online Courses (MOOCs) is increasing rapidly. Due to the autonomy of students in this type of education, students in MOOCs are required to regulate their learning to a greater extent than students in traditional, face-to-face education. However, there is no questionnaire available suited for this online context that measures all aspects of self-regulated learning (SRL). In this study, such a questionnaire is developed based on existing SRL questionnaires. This is the self-regulated online learning ques- tionnaire. Exploratory factor analysis (EFA) on the first dataset led to a set of scales differing from those theoretically defined beforehand. Confirmatory factor analysis (CFA) was conducted on a second dataset to compare the fit of the theoretical model and the exploratively obtained model. The exploratively obtained model provided much better fit to the data than the theoretical model. All models under investigation provided better fit when excluding the task strategies scale and when merging the scales measuring metacognitive activities. From the results of the EFA and the CFA it can be concluded that further development of the questionnaire is necessary.
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Objectives: Because there is scientific evidence that an appropriate intake of dietary fibre should be part of a healthy diet, given its importance in promoting health, the present study aimed to develop and validate an instrument to evaluate the knowledge of the general population about dietary fibres. Study design: The present study was a cross sectional study. Methods: The methodological study of psychometric validation was conducted with 6010 participants, residing in ten countries from 3 continents. The instrument is a questionnaire of self-response, aimed at collecting information on knowledge about food fibres. For exploratory factor analysis (EFA) was chosen the analysis of the main components using varimax orthogonal rotation and eigenvalues greater than 1. In confirmatory factor analysis by structural equation modelling (SEM) was considered the covariance matrix and adopted the Maximum Likelihood Estimation algorithm for parameter estimation. Results: Exploratory factor analysis retained two factors. The first was called Dietary Fibre and Promotion of Health (DFPH) and included 7 questions that explained 33.94 % of total variance ( = 0.852). The second was named Sources of Dietary Fibre (SDF) and included 4 questions that explained 22.46% of total variance ( = 0.786). The model was tested by SEM giving a final solution with four questions in each factor. This model showed a very good fit in practically all the indexes considered, except for the ratio 2/df. The values of average variance extracted (0.458 and 0.483) demonstrate the existence of convergent validity; the results also prove the existence of discriminant validity of the factors (r2 = 0.028) and finally good internal consistency was confirmed by the values of composite reliability (0.854 and 0.787). Conclusions: This study allowed validating the KADF scale, increasing the degree of confidence in the information obtained through this instrument in this and in future studies.
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El hambre es un tema fundamental dentro de la agenda política internacional en la actualidad. Diariamente, según la FAO, mueren alrededor de 24.000 personas a causa de no ingerir alimentos. Las estrategias planteadas por parte de las empresas y los gobiernos están enfocadas a generar una mayor producción de alimentos para disminuir el hambre y garantizar la seguridad alimentaria. Este artículo explica cómo el significado del alimento se transformó para ser entendido como mercancía, a partir del establecimiento del régimen alimentario corporativo. Las normas aquí creadas influyen en la construcción de las políticas públicas nacionales. Este estudio de caso evidencia la relación entre ambas en Colombia a partir del 2008 y el nivel de dependencia alimentaria y de insumos químicos del país hacia actores internacionales, analizado a partir de la importación y producción de alimentos. Finalmente, este trabajo investigativo permitirá determinar el estado de la soberanía alimentaria en Colombia.
Resumo:
Background Entrepreneurship has been considered essential to create value, being a powerful driver of economic and social development. Academy must invest in the development of entrepreneurial skills in students ("Entrepreneurial Academy"). Objective: To analyse the psychometric proprieties of the EMQ-Entrepreneurial Motivations Questionnaire. Methods Sample: 6,532 students from 17 polytechnic Institutes of Portugal. Measure: EMQ, composed by measures of Entrepreneurial motives for the business, Entrepreneurial influences, and Support Services. Results Exploratory factor analysis (EFA) for Entrepreneurial-Motives-for-thebusiness (KMO = .921, X2 = 54387.94, p < .001) extracted 4 factors, explaining 53.81 % of variance (EV): F1-Family security (19.92 % EV; M= 4.07, SD = 0.67), F2-Prestige (14.60 % EV; M= 3.25, SD = 0.75), F3- Independence (13.13 % EV; M= 3.33, SD = 0.75), and F4-Realization of an opportunity (11.15 % EV; M= 4.08, SD = 0.56). This factorial structure was supported by Confirmatory factor analysis (CFA), with an acceptable fit: RMSEA = .084. EFA of Entrepreneurial-Influences (KMO = .916, X2 = 60584.93, p < .001), extracted 4 factors, EV 60.08 %: F1-Resources availability (21.25 % EV; M= 3.86, SD = 0.68), F2-Stable customers and incentives (19.70 % EV; M= 3.82, SD = 0.65), F3-Social and economic instability (11.11 % EV; M= 2.96, SD = 1.06), and F4-Opportunities in the sector and residence area (8.03 % EV; M= 3.29, SD = 0.95). This factorial structure was supported by CFA, with an acceptable fit: RMSEA = .073. EFA of Support-Services (KMO = .995, X2 = 57311.43, p < .001) extracted 2 factors, EV 58.43 %: F1-Financial support (32.59 % EV; M= 3.93, SD = 0.69) and F2-Prestige (25.84 % EV; M= 3.95, SD = 0.65). This factorial structure was supported by CFA, with an acceptable fit: RMSEA = .090. The health group showed scores mostly above global average in factors. Conclusions EMQ showed adequate psychometric properties. The instrument is useful for measuring entrepreneurships motivations in health.