LOVMI : vers une méthode interactive pour la validation d'ontologies

International audienceLes méthodes de construction d'ontologies se sont fortement développées au travers du traitement automatique du langage et de l'intérêt croissant aux corpus de données volumineux, engendrant un effacement progressif des acteurs du domaine au profit du traitement des données du domaine. Cependant, quelle que soit la ressource utilisée, la validation des ontologies demeure une question centrale de l'ingénierie des connaissances. Elle s'articule autour de deux problématiques complémentaires : (1) la validation structurelle et (2) la validation sémantique (de l'adéquation au domaine modélisé). Dans le premier cas, de nombreuses méthodes ont vu le jour offrant des supports réalisant automatiquement les tâches de validation. A contrario, les méthodes pour la recherche du second cas sont encore peu nombreuses. Nous proposons dans cet article la méthode LOVMI, mise en oeuvre pour la validation structurelle et sémantique du module « facteurs sociaux et environnementaux des maladies psychiatriques » de notre ontologie ONTOPSYCHIA. Mots-clés : Ontologies, validation d'ontologies, évaluation d'ontologies, psychiatrie, facteurs sociaux et envi-ronnementaux

Inhibition of bone turnover by milk intake in postmenopausal women

Increased postmenopausal bone turnover leads to bone loss and fragility fracture risk. In the absence of osteoporosis, risk preventive measures, particularly those modifying nutritional lifestyle, are appropriate. We tested the hypothesis that milk supplementation affects bone turnover related to biochemical markers in a direction that, in the long term, may be expected to reduce postmenopausal bone loss. Thirty healthy postmenopausal women aged 59·3 (sd 3·3) years were enrolled in a prospective crossover trial of 16 weeks. After a 4-week period of adaptation with diet providing 600mg calcium plus 300mg ingested as 250ml semi-skimmed milk, participants were maintained during 6 weeks under the same 600mg calcium diet and randomized to receive either 500ml semi-skimmed milk, thus providing a total of 1200mg calcium, or no milk supplement. In the next 6 weeks they were switched to the alternative regimen. At the end of the each period, i.e. after 4, 10 and 16 weeks, blood and urinary samples were collected. The changes in blood variables between the periods of 6 weeks without and with milk supplementation were: for parathyroid hormone, −3·2pg/ml (P=0·0054); for crosslinked telopeptide of type I collagen, −624pg/ml (P<0·0001); for propeptide of type I procollagen, −5·5ng/ml (P=0·0092); for osteocalcin, −2·8ng/ml (P=0·0014). In conclusion, a 6-week period of milk supplementation induced a decrease in several biochemical variables compatible with diminished bone turnover mediated by reduction in parathyroid hormone secretion. This nutritional approach to postmenopausal alteration in bone metabolism may be a valuable measure in the primary prevention of osteoporosi

Ulcerative Colitis-Associated Colorectal Cancer Prevention by 5-Aminosalicylates: Current Status and Perspectives

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Formant Structures of Vowels Produced by Stutterers in Normal and Fast Speech Rates

The aim of this study is to analyse the steady--state portion of the first two formants (F1) and (F2) in the production of [CV] sequences, containing vowels [i, a, u], pronounced in two speech rates (normal and fast), by groups of untreated and treated stutterers, and control subjects. Locus equations have been calculated to observe for potential differences in coarticulatory strategies between the three groups. Data analyses reveal a reduction of vowel space for stutterers at a normal speaking rate. When speech rate increases, no reduction of vowel space is noticeable for the latter group of speakers, contrary to treated stutterers and controls. No significant differences between the three groups have been observed in coarticulatory strategies

Alertness can be improved by an interaction between orienting attention and alerting attention in schizophrenia

<p>Abstract</p> <p>Background</p> <p>Attention is impaired in schizophrenia. Early attention components include orienting and alerting, as well as executive control networks. Previous studies have shown mainly executive control deficits, while few of them found orienting and alerting abnormalities. Here we explore the different attentive networks, their modulation and interactions in patients with schizophrenia.</p> <p>Methods</p> <p>Twenty-one schizophrenic patients (DSMIV), compared to 21 controls, performed a modified version of the Attention Network Task, in which an orienting paradigm (with valid, invalid and no cues) was combined with a flanker task (congruent/incongruent) and an alerting signal (tone/no tone), to assess orienting, executive control and alerting networks independently.</p> <p>Results</p> <p>Patients showed an abnormal alerting effect and slower overall reaction time compared to controls. Moreover, there was an interaction between orienting and alerting: patients are helped more than controls by the alerting signal in a valid orientation to solve the incongruent condition.</p> <p>Conclusion</p> <p>These results suggest that patients with schizophrenia have altered alerting abilities. However, the orienting and alerting cues interact to improve their attention performance in the resolution of conflict, creating possibilities for cognitive remediation strategies.</p

Modèle mécaniste de l’utilisation métabolique du phosphore et du calcium alimentaires et de la dynamique de dépôt des cendres corporelles : version 2.0

Precision feeding reduces environmental impacts of current phase-feeding systems but requires an accurate estimate of phosphorus (P) and calcium (Ca) requirements. The aim is to adjust to precision feeding a mechanistic model recently developed to predict the fate of dietary P and Ca. The first step was to modify the model’s potential Ca and P deposition into bone to make it independent of protein deposition. This was done by using recent results for pigs fed excess P and Ca. Then, body composition data from pigs receiving contrasting Ca and P supplies were used to evaluate the predictive ability of the model. Mean squared prediction error (MSPE) and its decomposition into central tendency error (ECT), regression (ER) and disturbance (ED) were calculated. The results show good prediction overall, with MSPE less than 9% from more than 70% of ED not related to model parameters. For predictive ability by contribution group, control pigs have higher ECT (P: ECT = 30%, ER = 0%, ED = 70%; Ca: ECT = 22%, ER = 2 %, ED = 76%), showing that the model underestimates requirements (slope = 0.99). For pigs fed deficient dietary Ca and P diets, higher ER was observed (P: ETC = 6%, ER = 11%, ED = 83%; Ca: ECT = 51%, ER = 23%, ED = 26%), showing that the model overestimates requirements in the finishing phase. Areas for improvement have been identified, and in the next steps the model will be modified to improve its prediction of its weak points before moving to the inversion stage to predict requirements of pigs fed on group basis and then on an individually basis.L’alimentation de précision permet de diminuer les impacts environnementaux des systèmes d’alimentation actuels, mais nécessite l’estimation précise des besoins de phosphore (P) et de calcium (Ca). L’objectif est d’adapter un modèle mécaniste récemment développé portant sur l’utilisation du P et du Ca alimentaires, à l’alimentation de précision. Une première étape a consisté à modifier le potentiel de dépôt de P et Ca dans l’os pour le rendre indépendant du dépôt protéique. Ceci a été réalisé à partir de résultats récents obtenus sur des porcs nourris avec des excès de P et Ca. Ensuite, des données de composition corporelle de porcs recevant des apports de Ca et P contrastés (rations couvrant ou non les besoins et dont l’apport de Ca et de P est déséquilibré ou non) ont été utilisées pour estimer la capacité de prédiction du modèle par l’erreur quadratique moyenne de prédiction (EMP) et sa décomposition en erreur de tendance centrale (ETC), de régression (ER) et de bruit (EB). Les résultats montrent une prédiction globale qui est très bonne avec des EMP de moins de 9% provenant à plus de 70% d’EB, donc non liées aux paramètres du modèle. Lorsque la qualité de prédiction est étudiée par groupes d’apport (témoins, carencés, stratégies de déplétion-réplétions), les témoins présentent une ETC plus élevée (P : ETC = 30%, ER = 0%, EB = 70% ; Ca : ETC = 22%, ER = 2%, EB = 76%) montrant que le modèle sous-estime le Ca et P corporels (pente = 0,99 et 0,98 respectivement). Pour les porcs carencés, l’ER est plus élevée (P : ETC = 6%, ER = 11%, EB = 83% ; Ca : ETC = 51%, ER = 23%, EB = 26%) mettant en évidence que le modèle surestime la teneur corporelle en P et Ca des porcs en phase de finition. Des pistes d’amélioration ont été proposées pour améliorer sa prédiction sur ses points faibles avant de passer à l’étape de l’inversion pour prédire les besoins de porcs en groupe puis ceux d'animaux alimentés individuellement de façon journalière

Glycerol Acetals and Ketals as Bio-based Solvents: Positioning in Hansen and COSMO-RS spaces, Volatility and Stability towards Hydrolysis and Autoxidation

Four recently launched cyclic glycerol acetals or ketals are evaluated as bio-based solvents. Three of them are industrially available and result from the condensation of glycerol with formaldehyde, acetone and isobutyl methyl ketone. The fourth is under development and is prepared by the reaction of glycerol with benzaldehyde under heterogeneous acidic catalysis. Their solvent properties are evaluated through Hansen and COSMO-RS (COnductor-like Screening MOdel for Real Solvents) approaches, in comparison to traditional petrochemical solvents. Dioxolane- and dioxane-type isomers have close solubility parameters; however the nature of the starting aldehyde/ketone significantly impacts the solvency properties. Stability to hydrolysis depends heavily on both the aldehyde/ketone part and on the size of the ring. In acidic medium, acetals are found to be more stable than ketals and glycerol-based ketals are more stable than ethylene glycol-based ketals. In the case of benzaldehyde glycerol acetal, it is shown that the 6-member ring isomer (dioxane-type) is approximately 8 times more stable than the 5-member ring counterpart (dioxolane-type) at low pH. Stability towards autoxidation by O2 is high for formaldehyde and acetone-derived acetals and drops for the other two compounds. Glycerol acetals and ketals are promising potential alternatives to some harmful solvents such as glycol ethers and aniline