924 resultados para Automatic Analysis of Multivariate Categorical Data Sets
Resumo:
Whether bilateral total extraperitoneal (TEP) inguinal hernia repair is associated with worse outcomes than unilateral TEP continues to be a matter of debate. This study aimed to compare different outcomes of large cohorts of patients undergoing bilateral versus unilateral TEP.
Resumo:
Classical liquid-state high-resolution (HR) NMR spectroscopy has proved a powerful tool in the metabonomic analysis of liquid food samples like fruit juices. In this paper the application of (1)H high-resolution magic angle spinning (HR-MAS) NMR spectroscopy to apple tissue is presented probing its potential for metabonomic studies. The (1)H HR-MAS NMR spectra are discussed in terms of the chemical composition of apple tissue and compared to liquid-state NMR spectra of apple juice. Differences indicate that specific metabolic changes are induced by juice preparation. The feasibility of HR-MAS NMR-based multivariate analysis is demonstrated by a study distinguishing three different apple cultivars by principal component analysis (PCA). Preliminary results are shown from subsequent studies comparing three different cultivation methods by means of PCA and partial least squares discriminant analysis (PLS-DA) of the HR-MAS NMR data. The compounds responsible for discriminating organically grown apples are discussed. Finally, an outlook of our ongoing work is given including a longitudinal study on apples.
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Quality of life is an important outcome in the treatment of patients with schizophrenia. It has been suggested that patients' quality of life ratings (referred to as subjective quality of life, SQOL) might be too heavily influenced by symptomatology to be a valid independent outcome criterion. There has been only limited evidence on the association of symptom change and changes in SQOL over time. This study aimed to examine the association between changes in symptoms and in SQOL among patients with schizophrenia. A pooled data set was obtained from eight longitudinal studies that had used the Brief Psychiatric Rating Scale (BPRS) for measuring psychiatric symptoms and either the Lancashire Quality of Life Profile or the Manchester Short Assessment of Quality of Life for assessing SQOL. The sample comprised 886 patients with schizophrenia. After controlling for heterogeneity of findings across studies using linear mixed models, a reduction in psychiatric symptoms was associated with improvements in SQOL scores. In univariate analyses, changes in all BPRS subscales were associated with changes in SQOL scores. In a multivariate model, only associations between changes in the BPRS depression/anxiety and hostility subscales and changes in SQOL remained significant, with 5% and 0.5% of the variance in SQOL changes being attributable to changes in depression/anxiety and hostility respectively. All BPRS subscales together explained 8.5% of variance. The findings indicate that SQOL changes are influenced by symptom change, in particular in depression/anxiety. The level of influence is limited and may not compromise using SQOL as an independent outcome measure.
Resumo:
Whether total extraperitoneal inguinal hernia repair (TEP) is associated with worse outcomes than transabdominal preperitoneal inguinal hernia repair (TAPP) continues to be a matter of debate. The objective of this large cohort study is to compare outcomes between patients undergoing TEP or TAPP.
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An endovascular approach is increasingly used for the treatment of peripheral arterial trauma (PAT), but evidence supporting this approach is lacking. The objective of our study was to assess outcomes for endovascular repair (ER) versus operative repair (OR) in PAT.
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Franches-Montagnes is the only native horse breed in Switzerland, therefore special efforts should be made for ensuring its survival. The objectives of this study were to characterize the structure of this population as well as genetic variability with pedigree data, conformation traits and molecular markers. Studies were focused to clarify if this population is composed of a heavy- and a light-type subpopulation. Extended pedigree records of 3-year-old stallions (n = 68) and mares (n = 108) were available. Evaluations of body conformation traits as well as pedigree data and molecular markers did not support the two-subpopulation hypothesis. The generation interval ranged from 7.8 to 9.3 years. The complete generation equivalent was high (>12). The number of effective ancestors varied between 18.9 and 20.1, whereof 50% of the genetic variability was attributed to seven of them. Genetic contribution of Warmblood horses ranged from 36% to 42% and that of Coldblood horses from 4% to 6%. The average inbreeding coefficient reached 6%. Inbreeding effective population size was 114.5 when the average increase of the inbreeding coefficient per year since 1910 was taken. Our results suggest that bottleneck situations occurred because of selection of a small number of sire lines. Promotion of planned matings between parents that are less related is recommended in order to avoid a reduction of the genetic diversity.
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The examination of traffic accidents is daily routine in forensic medicine. An important question in the analysis of the victims of traffic accidents, for example in collisions between motor vehicles and pedestrians or cyclists, is the situation of the impact. Apart from forensic medical examinations (external examination and autopsy), three-dimensional technologies and methods are gaining importance in forensic investigations. Besides the post-mortem multi-slice computed tomography (MSCT) and magnetic resonance imaging (MRI) for the documentation and analysis of internal findings, highly precise 3D surface scanning is employed for the documentation of the external body findings and of injury-inflicting instruments. The correlation of injuries of the body to the injury-inflicting object and the accident mechanism are of great importance. The applied methods include documentation of the external and internal body and the involved vehicles and inflicting tools as well as the analysis of the acquired data. The body surface and the accident vehicles with their damages were digitized by 3D surface scanning. For the internal findings of the body, post-mortem MSCT and MRI were used. The analysis included the processing of the obtained data to 3D models, determination of the driving direction of the vehicle, correlation of injuries to the vehicle damages, geometric determination of the impact situation and evaluation of further findings of the accident. In the following article, the benefits of the 3D documentation and computer-assisted, drawn-to-scale 3D comparisons of the relevant injuries with the damages to the vehicle in the analysis of the course of accidents, especially with regard to the impact situation, are shown on two examined cases.
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This paper presents a comparative proteomic analysis of human maternal plasma and amniotic fluid (AF) samples from the same patient at term of pregnancy in order to find specific AF proteins as markers of premature rupture of membranes, a complication frequently observed during pregnancy. Maternal plasma and the corresponding AF were immunodepleted in order to remove the six most abundant proteins before the systematic analysis of their protein composition. The protein samples were then fractionated by IEF Off-Gel electrophoresis (OGE), digested and analyzed with nano-LC-MS/MS separation, revealing a total of 73 and 69 proteins identified in maternal plasma and AF samples, respectively. The proteins identified in AF have been compared to those identified in the mother plasma as well as to the reference human plasma protein list reported by Anderson et al. (Mol. Cell. Proteomics 2004, 3, 311-326). This comparison showed that 26 proteins were exclusively present in AF and not in plasma among which 10 have already been described to be placenta or pregnancy specific. As a further validation of the method, plasma proteins fractionated by OGE and analysed by nano-LC-MS/MS have been compared to the Swiss 2-D PAGE reference map by reconstructing a map that matches 2-D gel and OGE experimental data. This representation shows that 36 of 49 reference proteins could be identified in both data sets, and that isoform shifts in pI are well conserved in the OGE data sets.
Resumo:
Genomic alterations have been linked to the development and progression of cancer. The technique of Comparative Genomic Hybridization (CGH) yields data consisting of fluorescence intensity ratios of test and reference DNA samples. The intensity ratios provide information about the number of copies in DNA. Practical issues such as the contamination of tumor cells in tissue specimens and normalization errors necessitate the use of statistics for learning about the genomic alterations from array-CGH data. As increasing amounts of array CGH data become available, there is a growing need for automated algorithms for characterizing genomic profiles. Specifically, there is a need for algorithms that can identify gains and losses in the number of copies based on statistical considerations, rather than merely detect trends in the data. We adopt a Bayesian approach, relying on the hidden Markov model to account for the inherent dependence in the intensity ratios. Posterior inferences are made about gains and losses in copy number. Localized amplifications (associated with oncogene mutations) and deletions (associated with mutations of tumor suppressors) are identified using posterior probabilities. Global trends such as extended regions of altered copy number are detected. Since the posterior distribution is analytically intractable, we implement a Metropolis-within-Gibbs algorithm for efficient simulation-based inference. Publicly available data on pancreatic adenocarcinoma, glioblastoma multiforme and breast cancer are analyzed, and comparisons are made with some widely-used algorithms to illustrate the reliability and success of the technique.