Search results for "Multivariate Analysis"
showing 10 items of 1076 documents
Affinities of European Upper Palaeolithic Homo sapiens and later human evolution
1992
Abstract We investigate the evolutionary affinities of European Upper Palaeolithic populations, using cranial measurements and multivariate techniques. Results indicate that cranial morphology of these populations accords with long-term phyletic trends within Pleistocene hominids. The data indicate an interpretation of differential velocities of change, and results do not support the view that Neanderthals contributed to recent populations.
Applying univariate vs. multivariate statistics to investigate therapeutic efficacy in (pre)clinical trials: A Monte Carlo simulation study on the ex…
2020
BackgroundSmall sample sizes combined with multiple correlated endpoints pose a major challenge in the statistical analysis of preclinical neurotrauma studies. The standard approach of applying univariate tests on individual response variables has the advantage of simplicity of interpretation, but it fails to account for the covariance/correlation in the data. In contrast, multivariate statistical techniques might more adequately capture the multi-dimensional pathophysiological pattern of neurotrauma and therefore provide increased sensitivity to detect treatment effects.ResultsWe systematically evaluated the performance of univariate ANOVA, Welch's ANOVA and linear mixed effects models ver…
Embryonic stem cell differentiation studied by FT-IR spectroscopy
2007
We propose, here, an FT-IR method to monitor the spontaneous differentiation of murine embryonic stem (ES) cells in their early development. Principal component analysis and subsequent linear discriminant analysis enabled us to segregate stem cell spectra into separate clusters corresponding to different differentiation times - and to identify the most significant spectral changes during differentiation. Between days 4 to 7 of differentiation, these spectral changes in the protein amide I band (1700-1600 cm(-1)) and in the nucleic acid absorption region (1050-850 cm(-1)) indicated that mRNA translation was taking place and that specific proteins were produced, reflecting the appearance of a…
Neurosurgical resident training in Czech Republic
2018
Introduction: Resident training is essential to be able and offer high-quality medical care. Neurosurgical training in its traditional form is currently challenged by law-enforced working hour restrictions and general re-structuring within Europe. We aimed to evaluate the current situation of resident training in the Czech Republic. Methods: An electronic survey was sent to European neurosurgical trainees between 06/2014 and 03/2015. The responses of Czech trainees were compared to those of trainees from other European countries. Logistic regression analysis was used to assess the effect size of the relationship between a trainee being from Czech Republic and the outcomes (e.g. satisfaction…
Resolution of overlapped non-absorbing and absorbing solutes using either an absorption null-balance detection window or multivariate deconvolution a…
2004
Abstract Non-absorbing alkyl ether sulfates (AES) can be separated using anthraquinone-2-carboxylic acid (AQCA) as a probe; however, absorbing alkyl benzene sulfonates (ABS), if present, interfere indirect detection of most AES oligomers. Overcoming of this interference, as well as the simultaneous characterisation and evaluation of AES, fatty acids and ABS, was accomplished by using a diode-array detector and the procedures here discussed. First, it was shown that ABS can be made undetectable by using a 9 nm wide and 227 nm centred charge-absorptivity null-balance detection window (NBDW), where its contribution to the absorbance cancels the dilution effects that its presence induces on the…
Parenting in the digital era: Protective and risk parenting styles for traditional bullying and cyberbullying victimization
2019
Abstract This study analyzes the parenting styles that could act as risk or protective factors for bullying and cyberbullying victimization in Spain, considering the predisposition to aggression of the adolescents. The protective or risk effect of parenting styles for adolescents' related behavior such as antisocial behavior, school adjustment, and self-esteem was also analyzed. Study sample was 1109 adolescents aged between 12 and 17 years (49.96%, females, M = 13.88, SD = 1.38). A 4 × 2 × 2 × 2 MANOVA was applied for the outcome variables of bullying victimization (traditional bullying and cyberbullying), antisocial behavior, school adjustment, and self-esteem; with parenting style, predi…
Outlier analysis and principal component analysis to detect fatigue cracks in waveguides
2009
Ultrasonic Guided Waves (UGWs) are a useful tool in structural health monitoring (SHM) applications that can benefit from built-in transduction, moderately large inspection ranges and high sensitivity to small flaws. This paper describes a SHM method based on UGWs, discrete wavelet transform (DWT), outlier analysis and principal component analysis (PCA) able to detect and quantify the onset and propagation of fatigue cracks in structural waveguides. The method combines the advantages of guided wave signals processed through the DWT with the outcomes of selecting defectsensitive features to perform a multivariate diagnosis of damage. The framework presented in this paper is applied to the de…
Predictive factors for sustained virological response after treatment with pegylated interferon α-2a and ribavirin in patients infected with HCV geno…
2014
BackgroundPrevious trials have often defined genotype 2 and 3 patients as an "easy to treat" group and guidelines recommend similar management.AimsThe present study looks for differences between the two genotypes and analyzes predictive factors for SVR.MethodsProspective, community-based cohort study involving 421 physicians throughout Germany. The analysis includes 2,347 patients with untreated chronic HCV genotype 2 (n = 391) and 3 (n = 1,956) infection treated with PEG-IFN α-2a plus ribavirin between August 2007 and July 2012.ResultsWhen compared with genotype 2 patients, those with genotype 3 were younger, had a shorter duration of infection, lower values of total cholesterol, LDL chole…
Drug-drug interactions in a cohort of hospitalized elderly patients
2013
Purpose The aim of this study is to assess the prevalence of patients exposed to potentially severe drug–drug interactions (DDIs) at hospital admission and discharge and the related risk of in-hospital mortality and adverse clinical events, readmission, and all-cause mortality at 3months. Methods This cross-sectional, prospective study was held in 70 Italian internal medicine and geriatric wards. Potentially severe DDIs at hospital admission and discharge; risk of in-hospital mortality and of adverse clinical events, readmission, and all-cause mortality at 3-month follow-up. Results Among 2712 patients aged 65years or older recruited at hospital admission, 1642 (60.5%) were exposed to at le…
Early alterations of the behavioural structure of mice affected by Duchenne muscular dystrophy and tested in open-field
2020
Present study has been carried out to assess whether early alterations of the behavioural structure may be detected in mice affected by Duchenne muscular dystrophy (DMD). To this purpose, both quantitative and T-pattern analysis (TPA) were used to analyse the behaviour of two groups of male, two months old mice, 18 MDX and 18 normal as control, tested in an open-field apparatus. T-pattern analysis is a multivariate technique able to reveal hidden structural features of behaviour and, in particular, its temporal characteristics. As to quantitative analyses, mean durations evidenced a significant increase of Walking, Modified Climbing and Rearing and a significant reduction of Immobile-Sniffi…