471 research outputs found
Effect of sampling method and storage conditions on albumin, retinol-binding protein, and N-acetyl-β-D-glucosaminidase concentrations in canine urine samples
Urinary markers for renal dysfunction are gaining interest but effects of sampling method, storage conditions, and urinary tract inflammation or infection on these markers are unclear Therefore, the objectives of the current study were to determine the difference in urinary albumin (uALB), urinary retinol-binding protein (uRBP), and urinary N-acetyl-beta D-glucosaminidase (uNAG) concentrations in cystocentesis and voided samples and to investigate concentration changes after storage at -20 degrees C and at -80 degrees C Effects of a protease inhibitor were also assessed in samples stored at -80 degrees C for 12 months In a pilot experiment, influence of in vitro hematuria, pyuria, and bacteriuria on the urinary markers was evaluated A mixed model was used to calculate mean differences and 95% confidence intervals Urinary ALB, uNAG, and uRBP concentrations were similar in voided and cystocentesis samples After storage for 4 months at -20 degrees C, uALB concentration was not affected and uRBP concentration showed a mild and clinically irrelevant decrease, whereas uNAG activity was significantly lower compared with fresh samples After storage for 12 months at -80 degrees C, uALB and uRBP concentrations did not differ from fresh samples but uNAG activity was severely decreased Protease inhibitor addition did not preserve uNAG activity Experimental hematuria, pyuria, and bacteriuria did not seem to affect urinary markers although further research is neede
VIPE: A NEW INTERACTIVE CLASSIFICATION FRAMEWORK FOR LARGE SETS OF SHORT TEXTS - APPLICATION TO OPINION MINING
International audienceThis paper presents a new interactive opinion mining tool that helps users to classify large sets of short texts originated from Web opinion polls, technical forums or Twitter. From a manual multi-label pre-classification of a very limited text subset, a learning algorithm predicts the labels of the remaining texts of the corpus and the texts most likely associated to a selected label. Using a fast matrix factorization, the algorithm is able to handle large corpora and is well-adapted to interactivity by integrating the corrections proposed by the users on the fly. Experimental results on classical datasets of various sizes and feedbacks of users from marketing services of the telecommunication company Orange confirm the quality of the obtained results
Selecting a multi-label classification method for an interactive system
International audienceInteractive classification-based systems engage users to coach learning algorithms to take into account their own individual preferences. However most of the recent interactive systems limit the users to a single-label classification, which may be not expressive enough in some organization tasks such as film classification, where a multi-label scheme is required. The objective of this paper is to compare the behaviors of 12 multi-label classification methods in an interactive framework where "good" predictions must be produced in a very short time from a very small set of multi-label training examples. Experimentations highlight important performance differences for 4 complementary evaluation measures (Log-Loss, Ranking-Loss, Learning and Prediction Times). The best results are obtained for Multi-label k Nearest Neighbours (ML-kNN), Ensemble of Classifier Chains (ECC) and Ensemble of Binary Relevance (EBR)
Supervised Feature Space Reduction for Multi-Label Nearest Neighbors
International audienceWith the ability to process many real-world problems, multi-label classification has received a large attention in recent years and the instance-based ML-kNN classifier is today considered as one of the most efficient. But it is sensitive to noisy and redundant features and its performances decrease with increasing data dimensionality. To overcome these problems, dimensionality reduction is an alternative but current methods optimize reduction objectives which ignore the impact on the ML-kNN classification. We here propose ML-ARP, a novel dimensionality reduction algorithm which, using a variable neighborhood search meta-heuristic, learns a linear projection of the feature space which specifically optimizes the ML-kNN classification loss. Numerical comparisons have confirmed that ML-ARP outperforms ML-kNN without data processing and four standard multi-label dimensionality reduction algorithms
Different Carotenoids and Potential Information Content of Red Coloration of Male Three-Spined Stickleback
Female sticklebacks (Gasterosteus aculeatus) use the red coloration of males as a criterion for mate choice. Redder males are more attractive. However, males often differ not only in the intensity of their coloration (from dull to bright red) but also in color quality (from yellowish to purple-red). We investigated whether the red coloration of the stickleback is actually a multiple signal made by several pigments. We kept wild caught males singly in tanks until they had built a nest and were ready to accept females. Then, we took standard photographs and measured their colors by spectrometer analyses of the slides and by descriptions of human observers. These two measurements were highly correlated. When analyzing the carotenoid content of the sticklebacks' skin we found two groups of carotenoids (astaxanthin and tunaxanthin/lutein) that were quantified for each individual. The differences in color observed in the fish are correlated to this pigment quantification. Redder fish have more astaxanthin in their skin than yellowish fish, while the color of the yellowish fish appears to be made by tunaxanthin/lutein. Our results suggest that the red coloration of sticklebacks is a multiple trait that is made of at least two different carotenoids. This opens the possibility that male sticklebacks signal more detailed information to females than a one-dimensional trait would allo
Plasma and urine profiles of Δ9-tetrahydrocannabinol and its metabolites 11-hydroxy-Δ9-tetrahydrocannabinol and 11-nor-9-carboxy-Δ9-tetrahydrocannabinol after cannabis smoking by male volunteers to estimate recent consumption by athletes
Since 2004, cannabis has been prohibited by the World Anti-Doping Agency for all sports competitions. In the years since then, about half of all positive doping cases in Switzerland have been related to cannabis consumption. In doping urine analysis, the target analyte is 11-nor-9-carboxy-Δ9-tetrahydrocannabinol (THC-COOH), the cutoff being 15ng/mL. However, the wide urinary detection window of the long-term metabolite of Δ9-tetrahydrocannabinol (THC) does not allow a conclusion to be drawn regarding the time of consumption or the impact on the physical performance. The purpose of the present study on light cannabis smokers was to evaluate target analytes with shorter urinary excretion times. Twelve male volunteers smoked a cannabis cigarette standardized to 70mg THC per cigarette. Plasma and urine were collected up to 8h and 11days, respectively. Total THC, 11-hydroxy-Δ9-tetrahydrocannabinol (THC-OH), and THC-COOH were determined after hydrolysis followed by solid-phase extraction and gas chromatography/mass spectrometry. The limits of quantitation were 0.1-1.0ng/mL. Eight puffs delivered a mean THC dose of 45mg. Plasma levels of total THC, THC-OH, and THC-COOH were measured in the ranges 0.2-59.1, 0.1-3.9, and 0.4-16.4ng/mL, respectively. Peak concentrations were observed at 5, 5-20, and 20-180min. Urine levels were measured in the ranges 0.1-1.3, 0.1-14.4, and 0.5-38.2ng/mL, peaking at 2, 2, and 6-24h, respectively. The times of the last detectable levels were 2-8, 6-96, and 48-120h. Besides high to very high THC-COOH levels (245 ± 1,111ng/mL), THC (3 ± 8ng/mL) and THC-OH (51 ± 246ng/mL) were found in 65 and 98% of cannabis-positive athletes' urine samples, respectively. In conclusion, in addition to THC-COOH, the pharmacologically active THC and THC-OH should be used as target analytes for doping urine analysis. In the case of light cannabis use, this may allow the estimation of more recent consumption, probably influencing performance during competitions. However, it is not possible to discriminate the intention of cannabis use, i.e., for recreational or doping purposes. Additionally, pharmacokinetic data of female volunteers are needed to interpret cannabis-positive doping cases of female athletes. Figure Urine concentration ranges of delta-9-tetrahydrocannabinol (THC) and its metabolites 11-hydroxy-delta-9-tetrahydrocannabinol (THC-OH) and 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH) in athletes tested cannabispositive (15ng/mL THC-COOH or more; N=81
Evaluation of evoked potentials to dyadic tones after cochlear implantation
Auditory evoked potentials are tools widely used to assess auditory cortex functions in clinical context. However, in cochlear implant users, electrophysiological measures are challenging due to implant-created artefacts in the EEG. Here, we used independent component analysis to reduce cochlear implant-related artefacts in event-related EEGs of cochlear implant users (n = 12), which allowed detailed spatio-temporal evaluation of auditory evoked potentials by means of dipole source analysis. The present study examined hemispheric asymmetries of auditory evoked potentials to musical sounds in cochlear implant users to evaluate the effect of this type of implantation on neuronal activity. In particular, implant users were presented with two dyadic tonal intervals in an active oddball design and in a passive listening condition. Principally, the results show that independent component analysis is an efficient approach that enables the study of neurophysiological mechanisms of restored auditory function in cochlear implant users. Moreover, our data indicate altered hemispheric asymmetries for dyadic tone processing in implant users compared with listeners with normal hearing (n = 12). We conclude that the evaluation of auditory evoked potentials are of major relevance to understanding auditory cortex function after cochlear implantation and could be of substantial clinical value by indicating the maturation/reorganization of the auditory system after implantatio
Diabetogenic milieus induce specific changes in mitochondrial transcriptome and differentiation of human pancreatic islets
In pancreatic β-cells, mitochondria play a central role in coupling glucose metabolism to insulin secretion. Chronic exposure of β-cells to metabolic stresses impairs their function and potentially induces apoptosis. Little is known on mitochondrial adaptation to metabolic stresses, i.e. high glucose, fatty acids or oxidative stress; being all highlighted in the pathogenesis of type 2 diabetes. Here, human islets were exposed for 3 days to 25 mm glucose, 0.4 mm palmitate, 0.4 mm oleate and transiently to H2O2. Culture at physiological 5.6 mm glucose served as no-stress control. Expression of mitochondrion-associated genes was quantified, including the transcriptome of mitochondrial inner membrane carriers. Targets of interest were further evaluated at the protein level. Three days after acute oxidative stress, no significant alteration in β-cell function or apoptosis was detected in human islets. Palmitate specifically increased expression of the pyruvate carriers MPC1 and MPC2, whereas the glutamate carrier GC1 and the aspartate/glutamate carrier AGC1 were down-regulated by palmitate and oleate, respectively. High glucose decreased mRNA levels of key transcription factors (HNF4A, IPF1, PPARA and TFAM) and energy-sensor SIRT1. High glucose also reduced expression of 11 mtDNA-encoded respiratory chain subunits. Interestingly, transcript levels of the carriers for aspartate/glutamate AGC2, malate DIC and malate/oxaloacetate/aspartate UCP2 were increased by high glucose, a profile suggesting important mitochondrial anaplerotic/cataplerotic activities and NADPH-generating shuttles. Chronic exposure to high glucose impaired glucose-stimulated insulin secretion, decreased insulin content, promoted caspase-3 cleavage and cell death, revealing glucotoxicity. Overall, expression profile of mitochondrion-associated genes was selectively modified by glucose, delineating a glucotoxic-specific signatur
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