926 resultados para photography - sociology


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Social Sciences can, on occasions, be similar to the so called “hard” sciences. However, in many cases, neither the object nor the classical methods fit in with the objectives of the work. The object requires methodological and technical adjustments, which are often avoided by means of an improper rigidity of the object’s needs. These adjustments can even alter the original research idea. The main objective of this article consists of proving that those objects of study, less suitable to be addressed by rigid positivistic strategies, can be approached both scientifically and sociologically. This can be achieved with the use of different strategies and flexible methodologies to ensure validity and reliability standards. This paper will be posed, firstly, a reflection on the epistemological nature of the debate about the rigid-flexible perspectives. Secondly, the strategies and tools used by the research team to achieve the reduction of the uncertainty about the size and characteristics of the population studied will be described. Finally, some of the survey results obtained in this project will be compared to those provided by the FAMILITUR Survey (2008), conducted by the Spanish Institute of Tourist Studies (IET).

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Background To analyze and compare the relationship between anterior and posterior corneal shape evaluated by a tomographic system combining the Scheimpflug photography and Placido-disc in keratoconus and normal healthy eyes, as well as to evaluate its potential diagnostic value. Methods Comparative case series including a sample of 161 eyes of 161 subjects with ages ranging from 7 to 66 years and divided into two groups: normal group including 100 healthy eyes of 100 subjects, and keratoconus group including 61 keratoconus eyes of 61 patients. All eyes received a comprehensive ophthalmologic examination including an anterior segment analysis with the Sirius system (CSO). Antero-posterior ratios for corneal curvature (k ratio) and shape factor (p ratio) were calculated. Logistic regression analysis was used to evaluate if some antero–posterior ratios combined with other clinical parameters were predictors of the presence of keratoconus. Results No statistically significant differences between groups were found in the antero–posterior k ratios for 3-, 5- and 7-mm diameter corneal areas (p ≥ 0.09). The antero–posterior p ratio for 4.5- and 8-mm diameter corneal areas was significantly higher in the normal group than in the keratoconus group (p < 0.01). The k ratio for 3, 5, and 7 mm was significantly higher in the keratoconus grade IV subgroup than in the normal group (p < 0.01). Furthermore, significant differences were found in the p ratio between the normal group and the keratoconus grade II subgroup (p ≤ 0.01). Finally, the logistic regression analysis identified as significant independent predictors of the presence of keratoconus (p < 0.01) the 8-mm anterior shape factor, the anterior chamber depth, and the minimal corneal thickness. Conclusions The antero-posterior k and p ratios are parameters with poor prediction ability for keratoconus, in spite of the trend to the presence of more prolate posterior corneal surfaces compared to the anterior in keratoconus eyes.

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