Search results for "ALGORITHMS"
showing 10 items of 1716 documents
Facial patterns in Cercopithecoidea and Hominoidea: a geometric approach.
2006
The maxillofacial and orbital compartments of the primate skull contribute to the ontogenetic and phylogenetic variability of the viscerocranium and are of crucial evolutionary relevance. As the form of organisms changes depending on endo- and exogenous factors, metrical evaluation of specific adaptations and incorporation of the results into a biological framework could be helpful in identifying valid characters for separation of taxa (e.g. family, genus, and species) and in understanding divergence and convergence. During the last two decades a morphometric "revolution" heralded by Rohlf & Marcus (1993), Adams et al. (2004) and Oxnard (2004) brought about a synthesis of traditional quanti…
Mining parasite data using genetic programming.
2005
Genetic programming is a technique that can be used to tackle the hugely demanding data-processing problems encountered in the natural sciences. Application of genetic programming to a problem using parasites as biological tags demonstrates its potential for developing explanatory models using data that are both complex and noisy.
A novel class of potent nonglycosidic and nonpeptidic pan-selectin inhibitors.
2006
An early step of the inflammatory response, the rolling of leukocytes on activated endothelial cells, is mediated by selectin/carbohydrate interactions. The tetrasaccharide sialy Lewisx is a ligand for E-, P-, and L-selectin and therefore serves as a lead structure for the development of analogues. A combination of synthesis and structure-based design allowed rapid optimization. The current lead 2a was evaluated in our E-selectin cell flow chamber assay where it proved to inhibit rolling and adhesion with an IC50 of 28+/-7 microM. The assays used are predictive for the in vivo efficacy of test compounds as shown for 2a in a proteose peptone induced peritonitis model of acute inflammation in…
Effect of age on complexity and causality of the cardiovascular control: comparison between model-based and model-free approaches.
2014
The proposed approach evaluates complexity of the cardiovascular control and causality among cardiovascular regulatory mechanisms from spontaneous variability of heart period (HP), systolic arterial pressure (SAP) and respiration (RESP). It relies on construction of a multivariate embedding space, optimization of the embedding dimension and a procedure allowing the selection of the components most suitable to form the multivariate embedding space. Moreover, it allows the comparison between linear model-based (MB) and nonlinear model-free (MF) techniques and between MF approaches exploiting local predictability (LP) and conditional entropy (CE). The framework was applied to study age-related…
Temporal structure of the rat's behavior in elevated plus maze test
2012
Aim of the research was to evaluate, by means of quantitative and multivariate temporal pattern analyses, the behavior of Wistar rat in elevated plus maze (EPM) test. On the basis of an ethogram encompassing 24 behavioral elements, quantitative results showed that 130.14 ± 8.01 behavioral elements occurred in central platform and in closed arms (protected zones), whereas 88.62 ± 6.04 occurred in open arms (unprotected zones). Percent distribution was characterized by a prevalence of sniffing, walking and vertical exploration. Analysis of minute-by-minute duration evidenced a decrease for time spent in open arms and central platform and an increase for time spent in closed arms. As to multiv…
Extended Granger causality: a new tool to identify the structure of physiological networks.
2015
Granger causality (GC) is a very popular tool for assessing the presence of directional interactions between two time series of a multivariate data set. In its original formulation, GC does not account for zero-lag correlations possibly existing between the observed time series. In the present study we compare the GC with a novel measure, termed extended GC (eGC), able to capture instantaneous causal relationships. We present a two-step procedure for the practical estimation of eGC based on first detecting the existence of zero-lag correlations, and then assigning them to one of the two possible causal directions using pairwise measures of non-Gaussianity. The proposed method was validated …
SPM-based count normalization provides excellent discrimination of mild Alzheimer's disease and amnestic mild cognitive impairment from healthy aging☆
2008
Statistical comparisons of [(18)F]FDG PET scans between healthy subjects and patients with Alzheimer's disease (AD) or amnestic mild cognitive impairment (aMCI) using Statistical Parametric Mapping (SPM) usually require normalization of regional tracer uptake via ROIs defined using additional software. Here, we validate a simple SPM-based method for count normalization. FDG PET scans of 21 mild, 15 very mild AD, 11 aMCI patients and 15 age-matched controls were analyzed. First, we obtained relative increases in the whole patient sample compared to controls (i.e. areas relatively preserved in patients) with proportional scaling to the cerebral global mean (CGM). Next, average absolute counts…
Comparison of the men's and the women's pole vault at the 2000 Sydney Olympic Games
2004
The aim of this study was to identify differences between elite male and female pole vaulters in terms of their mechanical energy and angular momentum. The vaulter's total mechanical energy and angular momentum were calculated from the three-dimensional kinematic data of the pole vault finals at the Sydney 2000 Olympic Games. The development of total, kinetic and potential energy showed similar characteristics for men and women. The initial energy of the vault, the energy at maximum pole bend position and the final energy were significantly higher for male athletes (P0.05), while the energy gain produced by the athletes during the vault showed no significant differences (male vaulters 5.88 …
Is hospital discharge administrative data an appropriate source of information for cancer registries purposes? Some insights from four Spanish regist…
2010
Abstract Background The use of hospital discharge administrative data (HDAD) has been recommended for automating, improving, even substituting, population-based cancer registries. The frequency of false positive and false negative cases recommends local validation. Methods The aim of this study was to detect newly diagnosed, false positive and false negative cases of cancer from hospital discharge claims, using four Spanish population-based cancer registries as the gold standard. Prostate cancer was used as a case study. Results A total of 2286 incident cases of prostate cancer registered in 2000 were used for validation. In the most sensitive algorithm (that using five diagnostic codes), e…
New insights into autoantibody profiles from immune privileged sites in the eye: a glaucoma study.
2011
Glaucoma is a chronic neurodegenerative disease and one of the leading causes of blindness. Autoantibody based immune processes are assumed to be involved in its pathogenesis. However, it is still unclear to what extent autoantibody patterns found in the eye (aqueous humor) are congruent to systemic autoantibodies (blood). Consistency would underline the specificity of known serum antibody markers for glaucoma. In this study we used antigen microarrays to analyze autoantibody reactivities in sera and corresponding aqueous humor samples of primary open-angle glaucoma patients (N=37) and non-glaucomatous controls (N=31). Compared to control subjects several divergent immunoreactivities were i…