994 resultados para Internal problems
Resumo:
The concept of parameter-space size adjustment is pn,posed in order to enable successful application of genetic algorithms to continuous optimization problems. Performance of genetic algorithms with six different combinations of selection and reproduction mechanisms, with and without parameter-space size adjustment, were severely tested on eleven multiminima test functions. An algorithm with the best performance was employed for the determination of the model parameters of the optical constants of Pt, Ni and Cr.
Resumo:
Neurobiological models support an involvement of white matter tracts in the pathophysiology of obsessive-compulsive disorder (OCD), but there has been little systematic evaluation of white matter volumes in OCD using magnetic resonance imaging (MRI). We investigated potential differences in the volume of the cingulum bundle (CB) and anterior limb of internal capsule (ALIC) in OCD patients (n = 19) relative to asymptomatic control subjects (n = 15). White matter volumes were assessed using a 1.5T MRI scanner. Between-group comparisons were carried out after spatial normalization and image segmentation using optimized voxel-based morphometry. Correlations between regional white matter volumes in OCD subjects and symptom severity ratings were also investigated. We found significant global white matter reductions in OCD patients compared to control subjects. The voxel-based search for regional abnormalities (with covariance for total white matter volumes) showed no specific white matter volume deficits in brain portions predicted a priori to be affected in OCD (CB and ALIC). However, large clusters of significant positive correlation with OCD severity scores were found bilaterally on the ALIC. These findings provide evidence of OCD-related ALIC abnormalities and suggest a connectivity dysfunction within frontal-striatal-thalamic-cortical circuits. Further studies are warranted to better define the role of such white matter alterations in the pathophysiology of OCD, and may provide clues for a more effectively targeting of neurosurgical treatments for OCD. (C) 2009 Elsevier Ireland Ltd. All rights reserved.
Resumo:
Alouatta guariba clamitans (brown howler monkey) is an endemic primate from the southeastern Brazil tropical forests, classified as near threatened by the IUCN Red List 2007. The genus Aloualta is one of the most difficult New World monkeys to breed and rear in captivity. In this study we examined the macroscopic and histological aspects of the female genital tract of wild brown howler monkeys to provide baseline information for future reproduction research. The anatomical relationship between the vagina, uterus, broad ligament, oviducts and ovaries are those of a typical primate reproductive tract. The fundic portion of the uterus is globoid, the cervix is well developed, which confers to the uterus an elongated shape, and the vagina is a long flattened channel. Histological analysis conducted in females in the follicular phase revealed large quantities of interstitial luteinized tissue in the ovaries, a stratified nonkeratinized vaginal epithelium, lack of glands in the vaginal mucosa and simple tubular endometrial glands. The observed anatomical features should be considered in the adaptation and application of assisted reproductive techniques aimed at improving captive reproduction for species conservation. Am. J. Primatol. 71:145-152, 2009. (C) 2008 Wiley-Liss, Inc.
Resumo:
Background: The perception of improvement by a patient has assumed a central role in functional evaluation after a variety of knee problems. One of the instruments most used in clinical research is the International Knee Documentation Committee (IKDC) Subjective Knee Form because its psychometric properties are considered to be excellent. Nonetheless, this questionnaire was originally developed for use in the English language. Therefore, to use this questionnaire in the Brazilian population, it is essential to translate and validate it. Purpose: The aim of this study was to translate the IKDC Subjective Knee Form into a Brazilian version and to test its validity and reproducibility. Study Design: Cohort study (diagnosis); Level of evidence, 2. Methods: The translation of the original IKDC Subjective Knee Form into a Brazilian version was accomplished in accordance with the American Orthopaedic Society for Sports Medicine guidelines and was tested in 32 patients with knee pathologic conditions to develop the first Brazilian version. To test validity and reproducibility, 117 patients with several knee complaints completed the Brazilian IKDC Subjective Knee Form, the Short Form 36 (SF-36), the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), and the Lysholm score. From these patients, 85 were retested within a week to achieve reproducibility. The validation was addressed by correlating the Brazilian IKDC Subjective Knee Form to the other outcome measures. The reproducibility was tested by measuring internal consistency, test-retest reliability, and agreement. Results: The Brazilian IKDC Subjective Knee Form was highly related to the physical component summary of the SF-36, the Lysholm score, and the WOMAC, and weakly related to the mental component summary of SF-36 (r=.79, .89, .85, and .51, respectively). The internal consistency was strong, with a Cronbach a value of .928 and .935 in the test and retest assessment, respectively. The test-retest reliability proved to be excellent, with a high value of the intraclass correlation coefficient (.988), as well as the agreement, demonstrated by the low differences between the means of the test and retest, and the short limit of agreement, observed in the Altman-Bland and survival-agreement plots. Conclusion: The results of this study provide evidence that the Brazilian IKDC Subjective Knee Form has psychometric properties similar to the original version. In addition, it was a reliable evaluation instrument for patients with knee-related problems.