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See detailOdours identification in the environment by means of mathematical methods
Maternova, Jidrinska; Nicolas, Jacques ULg; Andre, Philippe ULg et al

in Odours & VOC's journal (1996), 1

The aim of the present paper is to test and compare some mathematical discrimination or pattern recognition methods in order to identify one among three air pollution sources.The basic material in this ... [more ▼]

The aim of the present paper is to test and compare some mathematical discrimination or pattern recognition methods in order to identify one among three air pollution sources.The basic material in this work are : - the standard gas chromatography/mass spectrometry analysis with concentrations values for different chemical compounds observed at about hundred sites in iron and steel industries : either coking plants, or cold rolling mills, or coil-coating plants. - the odours levels, measured by the method of dilution at the threshold. Generally speaking, coil-coating plants emit more chemical compounds than two others, however olfactive threshold is about the same in the three cases. Sums of compounds concentrations for different chemical families (e.g. alkanes, alcohol's, phenols, ...) are calculated and used for the mathematical treatments. Because the frequency histogram of the observed concentrations has a log normal distribution, logarithm of concentration is chosen as operating variable instead of concentration itself. The stepwise multiple linear regression is used in order to express the dilution factor at the olfactory perception threshold as a linear combination of the logarithm of concentrations. Results show that this factor can be estimated quite well on the basis of the concentrations of compounds belonging only to three chemical families. Nevertheless, these families differ following the emission source. To perform the optimal odour description of the three types of industrial plants a larger set of compounds families should be examined in a first step. Factor analysis is used with the aim of regrouping observed variables that are linked together in the plane of the first two factors. The representation of observation points is then superposed on this scheme. Some variable clusters are observed. The method, applied to the whole variables set, classes rather well the observations : the three emissions sources are well discriminated. Cluster analysis, discriminant analysis and neural network have also been used, but only with three variables common to all installations : concentrations of alkylbenzenes, polycyclic aromatics and alkanes. Cluster analysis is not a "supervised method". That means that it is free to create itself some groups showing similar behaviour with regard to the observed variables. Indeed, results show that cluster analysis does not allow to recognise the emission source. In discriminant analysis, target groups membership is provided for each set of variables values : it is a supervised method. The classification functions so deduced allow to discriminate quite well the three industrial plants and to predict the emission origin. A total of 87 % of the observations are correctly on the basis of the classification functions. Neural network approach, with backpropagation algorithm, is a so-called "pattern recognition technique" and is also a supervised method. It provides still better results than statistical ones. After the learning phase, the network is able to identify correctly 99.5 % of observations from 95.5 % the training set.The concentrations of compounds belonging to three chemical families, combined with a pattern recognition technique based either on discriminant analysis, or on neural network, prove to be efficient for recognising the source of odorous gaseous effluents. For the data set considered in this paper, the neural network exhibits better classification performances than discriminant analysis, but its learning phase is slower. However, applying one method or the other for further recognition of unknown patterns is quick and easy. [less ▲]

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See detailL'oedeme aigu pulmonaire cardiogenique
Stainier, P. Y.; Lancellotti, Patrizio ULg; Smeets, V. et al

in Revue Médicale de Liège (2004), 59(4), 196-200

Acute cardiogenic pulmonary oedema frequently occurs in clinical practice, frequently in an old patient. It consists in acute respiratory distress related to rapid development of transsudative fluid ... [more ▼]

Acute cardiogenic pulmonary oedema frequently occurs in clinical practice, frequently in an old patient. It consists in acute respiratory distress related to rapid development of transsudative fluid within the lung interstitium and alveolar accumulation. It requires rapid assessment and therapy to prevent progression to respiratory failure and cardiovascular collapse. The pathogenesis and identification of the underlying disease process are essential for optimal medical approach. The aetiology is multiple. [less ▲]

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See detailOedipe, devenir un homme
Stassart, Martine ULg

in Oedipe. Devenir un homme. (1994)

What is the latent significance of Oedipous' myth? Why is Oedipus a modern hero?

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See detailAn Oedometer for Studying Combined Effects of Temperature and Suction on Soils
François, Bertrand ULg; Laloui, Lyesse

in Geotechnical Testing Journal (2010), 33(2),

This paper reports the development of an advanced thermo-hydro-mechanical (THM) oedometer in order to characterize the behavior of soils under combined non-isothermal and unsaturated conditions. The ... [more ▼]

This paper reports the development of an advanced thermo-hydro-mechanical (THM) oedometer in order to characterize the behavior of soils under combined non-isothermal and unsaturated conditions. The simultaneous control of temperature, suction, and stress states within the sample required rigorous calibration. This THM oedometer accommodates samples 80 mm in diameter and 23 mm in height. The applied vertical stresses can reach values of up to 1 MPa, the controlled temperature ranges from 20 to 80°C, and the applied suction is up to 500 kPa. The paper thoroughly discusses the calibration of the device and presents some results of tests performed on sandy silt. [less ▲]

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See detailOeil en pénombre
Strivay, Lucienne ULg; Gossiaux, Pol-Pierre ULg

in Voir (1997), 14

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See detailL'oeil et la lumière [Introduction à L'Œuvre du regard, de François Jacqmin]
Purnelle, Gérald ULg

in L'Œuvre du regard (2012)

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See detailOesophage de Barrett: mise au point
Delforge, M.; Plomteux, O.; Delfosse, Valérie ULg et al

in Revue Médicale de Liège (2002), 57(8), 535-45

Barrett's oesophagus (BE) is a segment of columnar lined epithelium in the distal oesophagus, above the gastrooesophageal junction. So it is important to localize this junction endoscopically; the ... [more ▼]

Barrett's oesophagus (BE) is a segment of columnar lined epithelium in the distal oesophagus, above the gastrooesophageal junction. So it is important to localize this junction endoscopically; the proximal margin of the gastric folds is the anatomic landmark. Another important feature of BE is the specialized intestinal metaplasia. In the aetiology of this condition, acid reflux is a primary event but there is evidence that other factors are causal. As BE is a well known premalignant condition, detection of dysplastic epithelium and its severity is the crucial element. Practical guidelines are presented for endoscopic surveillance program. The purpose is the early detection of high grade dysplasia and carcinoma to advise oesophagectomy or endoscopic ablation therapy for patients unfit to undergo surgery. [less ▲]

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See detailOesophageal stricture in 5 foals
Christmann, U; Amory, Hélène ULg

in Journal of Equine Veterinary Science (1999), 19

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See detailL'oesophagite à éosinophiles chez l'adulte : à propos d'un cas
Marting, Audrey ULg; Leclercq, Philippe ULg; Gast, Pierrette ULg et al

in Revue Médicale de Liège (2008), 63

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See detailOestrogen-deficient female aromatase knockout (ArKO) mice exhibit 'depressive-like' symptomatology
Dalla, C.; Antoniou, K.; Papadopoulou-Daifoti, Z. et al

in European Journal of Neuroscience (2004), 20(1), 217-228

We recently found that female aromatase knockout (ArKO) mice that are deficient in oestradiol due to a targeted mutation in the aromatase gene show deficits in sexual behaviour that cannot be corrected by ... [more ▼]

We recently found that female aromatase knockout (ArKO) mice that are deficient in oestradiol due to a targeted mutation in the aromatase gene show deficits in sexual behaviour that cannot be corrected by adult treatment with oestrogens. We determined here whether these impairments are associated with changes in general levels of activity, anxiety or 'depressive-like' symptomatology due to chronic oestrogen deficiency. We also compared the neurochemical profile of ArKO and wild-type (WT) females, as oestrogens have been shown to modulate dopaminergic, serotonergic and noradrenergic brain activities. ArKO females did not differ from WT in spontaneous motor activity, exploration or anxiety. These findings are in line with the absence of major neurochemical alterations in hypothalamus, prefrontal cortex or striatum, which are involved in the expression of these behaviours. By contrast, ArKO females displayed decreased active behaviours, such as struggling and swimming, and increased passive behaviours, such as floating, in repeated sessions of the forced swim test, indicating that these females exhibit 'depressive-like' symptoms. Adult treatment with oestradiol did not reverse the behavioural deficits observed in the forced swim test, suggesting that they may be due to the absence of oestradiol during development. Accordingly, an increased serotonergic activity was observed in the hippocampus of ArKO females compared with WT, which was also not reversed by adult oestradiol treatment. The possible organizational role of oestradiol on the hippocampal serotonergic system and the 'depressive-like' profile of ArKO females provide new insights into the pathophysiology of depression and the increased vulnerability of women to depression. [less ▲]

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See detailOestrogen-modulated increase of calmodulin-dependent protein kinase II (CamKII) in rat spinal trigeminal nucleus after systemic nitroglycerin
Pardutz, A.; Hoyk, Z.; Varga, H. et al

in Cephalalgia : An International Journal of Headache (2007), 27(1), 46-53

Migraine can be triggered by systemic administration of the nitric oxide (NO) donor nitroglycerin (NTG) and by abrupt falls in plasma oestradiol. Calmodulin-dependent protein kinase II (CamKII) present in ... [more ▼]

Migraine can be triggered by systemic administration of the nitric oxide (NO) donor nitroglycerin (NTG) and by abrupt falls in plasma oestradiol. Calmodulin-dependent protein kinase II (CamKII) present in superficial dorsal horns is thought to play a role in sensitization of central nociceptors, a phenomen present in migraineurs. We therefore examined in rats the expression of CamKII in the caudal trigeminal nucleus (TNC) after subcutaneous NTG (10 mg/kg) and its modulation by oestrogen. In male rats and in ovariectomized females, after 4 h NTG increased significantly CamKII expression in the superficial layers of TNC, but not in the upper thoracic spinal cord. NTG had no effect on CamKII expression in oestradiol-treated ovariectomized animals. Thus NTG, i.e. NO, selectively enhances CamKII in the rat TNC and oestradiol blocks this effect. These data may help to understand the mechanisms by which NO triggers migraine attacks and oestrogens influence migraine severity. [less ▲]

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See detailOestrogenotherapie apres la menopause et protection cardio-vasculaire: discordance entre les observations epidemiologiques et les resultats d'essais therapeutiques.
Scheen, André ULg

in Revue Médicale de Liège (2000), 55(9), 886-8

Based upon the positive results of a large epidemiological study and the negative results of an interventional clinical trial recently published in the New England Journal of Medicine, we will briefly ... [more ▼]

Based upon the positive results of a large epidemiological study and the negative results of an interventional clinical trial recently published in the New England Journal of Medicine, we will briefly discuss the impact of estrogen replacement therapy on the protection against coronary heart disease in postmenopausal women. [less ▲]

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See detailL'oestrus : manifestations comportementales et méthodes de détection
Hanzen, Christian ULg

in Annales de Médecine Vétérinaire (1981), 125

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See detailOestrus cycle in the cow and hormonal control
Hanzen, Christian ULg

Conference (2008, May 08)

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See detailL'oeuvre du temps. Réflexion sur la conservation et la restauration d'objets d'art
Verbeeck, Muriel ULg

in Images re-vues. Histoire, anthropologie et théorie de l'art (2007), 4

Interroger l'objet, c'est aussi, au-delà de sa forme ou de son sens, interroger le temps — notre rapport à l'origine, au passé ou au devenir. Nulle part cependant, cette question ne se pose de façon plus ... [more ▼]

Interroger l'objet, c'est aussi, au-delà de sa forme ou de son sens, interroger le temps — notre rapport à l'origine, au passé ou au devenir. Nulle part cependant, cette question ne se pose de façon plus cruciale que dans l'acte de conserver ou restaurer l'objet d'art : car l’intervention le situe dans un champ de valeurs parfois hétéroclites. C’est au travers de l’axiologie que prennent corps des pratiques conservatives ou restauratives différenciées. Le praticien devient par conséquent, au sens propre, un « enseignant » : il donne sens aux signes, il éduque notre regard à l'objet préservé dans son authenticité et nous apprend à l’écouter respectueusement. [less ▲]

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