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See detailCatchment modelling and sensitivity analysis to spatial interpolation methods of daily rainfall
Ly, Sarann ULg

Doctoral thesis (2012)

Spatial interpolation of precipitation data is of great importance for hydrological modelling. Geostatistical methods (kriging) are widely applied in spatial interpolation from point measurement to ... [more ▼]

Spatial interpolation of precipitation data is of great importance for hydrological modelling. Geostatistical methods (kriging) are widely applied in spatial interpolation from point measurement to continuous surfaces. The objective of this dissertation is to confront the performances of the several spatial interpolation methods, in particular the geostatistics for daily rainfall data in the nested catchments to realize a sensitivity analysis on discharges modelled at the outlets to the daily rainfall input in the modelling. The previous studies in the literature emphasized a requirement of novel investigation on the essential means to recover the rainfall data and eventually, the quality of the hydrological modelling. This study leaned on 30-year daily rainfall data of 70 raingages in the hilly landscape of the Ourthe and Ambleve catchments in Belgium (2908 km²). Two common deterministic methods are employed here. The Thiessen Polygon (THI) assigns the value from the nearest observation to a certain grid cell. The Inverse Distance Weighting (IDW) is an advanced nearest neighbour approach that allows including more observations than only the nearest points. The value at a certain grid cell is obtained from a linear combination of the surrounding locations. In the geostatistical algorithms, the spatial variation may be better described by a stochastic function. Four versions of kriging are used. The Ordinary Kriging (ORK) is the basic form of Kriging that the prediction is also a linear combination of the measured values. But the spatial correlation between the data, as described by the variogram, determines the weights, assuming that the mean is constant but unknown. The Universal Kriging (UNK) is based on the hypothesis that this mean is a polynomial function of spatial coordinates. So, this type of kriging is not stationary with regard to the mean. The Kriging with External Drift (KED) supposes that the mean of the interest variable depends on auxiliary variables; the theory of this kriging is in fact the same as the theory of UNK, which also contains a non-constant mean. The drift is defined externally through some auxiliary variables. The Ordinary Cokriging (OCK) suggests estimating the variable of interest by weighted linear combination of its observations and the observations of the auxiliary variables. This technique requires the study of the spatial dependence between variables besides the study of the simple spatial dependences. All types of kriging use a variogram model to characterise spatial correlation. A variogram describes in terms of variances how spatial variability changes as a function of distance. Seven semi-variogram models (logarithmic, power, exponential, Gaussian, rational quadratic, spherical and penta-spherical) were fitted to daily sample semi-variogram on a daily basis. These seven variogram models were also adopted to avoid negative interpolated rainfall. The elevation, extracted from a digital elevation model, was incorporated into multivariate geostatistics. Seven validation raingages and cross validation were used to compare the interpolation performance of these algorithms applied to different densities of raingages. The areal rainfalls are calculated for the catchment area and used for analysis of extreme rainfall. The effects of the interpolation methods on the extreme rainfall are analysed. The interpolated rainfalls are also used as rainfall input of the physically-based and distributed EPIC-GRID model. The long series of model results are analysed by comparison with the observed discharges at the different outlets of the catchments. Then, the extreme discharges at the outlets are computed. All of these investigations always take into account of the raingage density and the raingage position for very sparse raingage cases. The main results show that among the methods based on the only rainfall data, the geostatistics and IDW are the best ones. The performances change according to the density of the raingages. For the extreme rainfall and long term modelling results, no big difference is found for a high density of raingage but large difference are found for the case of the scattered raingage. For the latter case, UNK and KED are very sensitive to the position of the raingages. IDW, ORK and OCK are found to be the best performance. However for the extreme flow, KED and OCK is the best whereas IDW is not better for the high density of the raingages. For the case of the scattered raingages, the difference in extreme discharge between the interpolation methods is very large and larger than shown in the extreme rainfall and the long term modelling results. IDW, ORK and OCK always perform better. UNK and KED still are sensitive to the positions of raingages. The index of position is used to describe the form of polygon defined by the four raingages. This index is defined as the relation between the polygon perimeter and a circle perimeter having an area equivalent to that of the polygon. The best raingage position for all interpolation methods used in this research should be arround the catchment area, its index should be close to one. [less ▲]

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See detailCatéchisme correct d'astronomie sphérique
Folie, François ULg

in Memorie della Pontificia Accademia dei Nuovi Lincei (1894), 1 et 2(9-10), 93

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See detailLe catéchisme et la grammaire
Kurth, Godefroid ULg

Conference given outside the academic context (1896)

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See detailCatecholamine and HPA axis dysfunction in depression : relationship with suicidal behavior
Pitchot, William ULg; Reggers, Jean ULg; Pinto, Emmanuel ULg et al

in Neuropsychobiology (2003), 47(3), 152-157

A large body of evidence suggests a potential role for catecholaminergic function as a possible biological factor in the control of suicidal behavior. Recently, we have used a neuroendocrine strategy to ... [more ▼]

A large body of evidence suggests a potential role for catecholaminergic function as a possible biological factor in the control of suicidal behavior. Recently, we have used a neuroendocrine strategy to study dopaminergic and noradrenergic activities in depressed suicide attempters. However, some problems are associated with the use of growth hormone (GH) response to catecholaminergic challenge, because GH release could be decreased by a direct effect of corticosteroids at the pituitary level. Therefore, the purpose of the present study was to assess GH response to both apornorphine, a dopaminergic agonist, and clonidine, an alpha2-adrenergic agonist, according to the dexamethasone suppression test (DST) status in a sample of 20 major depressed inpatients with a history of suicide attempt compared with nonattempters. Our results tended to show that hypercortisolemia as assessed by post-DST cortisol values did not inhibit GH response to apornorphine or clonidine, suggesting that hypothalamo-pituitary-adrenal axis overactivity does not explain the impaired GH response to apornorphine in major depressed patients with a history of suicide attempt. [less ▲]

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See detailCatecholamine biosynthesis pathway potentially involved in banana defense mechanisms to crown rot disease
Lassois, Ludivine ULg; De Clerck, Caroline ULg; Frettinger, Patrick et al

in Communications in Agricultural and Applied Biological Sciences (2011), 76(4), 591-601

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See detailCatecholaminergic function and P300 amplitude in major depressive disorder (P300 and catecholamines).
Hansenne, Michel ULg; Pitchot, William ULg; Gonzalez Moreno, Antonio et al

in Electroencephalography and Clinical Neurophysiology (1995), 96(2), 194-6

The neurobiology of P300 is still a subject of controversy. P300 amplitude appears to be modulated by multiple neurotransmitter systems, especially dopaminergic, noradrenergic as well as cholinergic and ... [more ▼]

The neurobiology of P300 is still a subject of controversy. P300 amplitude appears to be modulated by multiple neurotransmitter systems, especially dopaminergic, noradrenergic as well as cholinergic and GABAergic. In this study, we investigated the relationship between P300 amplitude and catecholaminergic neurotransmission as assessed by the growth hormone (GH) response to clonidine and apomorphine challenges in 20 major depressive patients. Results showed a correlation of P300 amplitude with the apomorphine test (r = 0.54; P = 0.01), but not with the clonidine test (r = 0.22; NS). This study supports a role for dopamine in the neurobiological modulation of P300 amplitude. [less ▲]

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See detailCatecholaminergic function and temperament in major depressive disorder: a negative report.
Hansenne, Michel ULg; Ansseau, Marc ULg

in Psychoneuroendocrinology (1998), 23(5), 477-83

In the biosocial model of Cloninger, the three personality dimensions are related to different central neurotransmission systems. In agreement with this model, a recent study (Wiesbeck et al., 1995 ... [more ▼]

In the biosocial model of Cloninger, the three personality dimensions are related to different central neurotransmission systems. In agreement with this model, a recent study (Wiesbeck et al., 1995) showed an association between growth hormone response to apomorphine, an indirect assessment of the dopaminergic system, and novelty seeking score in alcohol-dependent men. In the present study we investigated the same methodology in a sample of major depressive patients. In addition, we assessed the relationship between noradrenergic function and Cloninger's dimensions using the clonidine test, an indirect assessment of the noradrenergic system. Growth hormone responses to apomorphine and clonidine were not associated with novelty seeking, reward dependence or harm avoidance dimension scores. This study therefore does not confirm the results of Wiesbeck et al. (1995), and does not support an association between noradrenergic activity and reward dependence dimension. However, given the complexity of central neurotransmission systems and the limitations of neuroendocrine challenges for the assessment of those processes, this study could not be considered as definitive evidence against the association between personality dimensions and their hypothesized central substrates. [less ▲]

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See detailCatecholaminergic inputs to aromatase cells in the canary auditory forebrain
Appeltants, D.; Ball, G. F.; Balthazart, Jacques ULg

in Neuroreport (2004), 15(11), 1727-1730

The caudomedial nidopallium in songbirds is a specialized forebrain auditory region involved in the processing of species-typical vocalizations. It receives a prominent catecholaminergic projection with ... [more ▼]

The caudomedial nidopallium in songbirds is a specialized forebrain auditory region involved in the processing of species-typical vocalizations. It receives a prominent catecholaminergic projection with many fibers forming basket-like structures around non-immunoreactive cells. We investigated in male canaries the anatomical relationship between tyrosine hydroxylase and cells immunoreactive for the steroid metabolizing enzyme, aromatase, in the caudomedial nidopallium using double-label immunocytochemistry. Fibers immunoreactive for tyrosine hydroxylase established numerous close contacts with aromatase-immunoreactive cells and often encircled these cells to form basket-like structures. Aromatase containing cells in the caudomedial nidopallium are therefore a major target of catecholaminergic inputs in canary. Interactions between catecholaminergic systems and aromatase in the caudomedial nidopallium may provide one mechanism for the regulation of estrogens involved in song perception and memorization. [less ▲]

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See detailThe Catecholaminergic System of the Quail Brain: Immunocytochemical Studies of Dopamine Beta-Hydroxylase and Tyrosine Hydroxylase
Bailhache, T.; Balthazart, Jacques ULg

in Journal of Comparative Neurology (The) (1993), 329(2), 230-56

The distribution of dopamine beta-hydroxylase and tyrosine hydroxylase, two key enzymes in the biosynthesis of catecholamines, was investigated by immunocytochemistry in the brain of male and female ... [more ▼]

The distribution of dopamine beta-hydroxylase and tyrosine hydroxylase, two key enzymes in the biosynthesis of catecholamines, was investigated by immunocytochemistry in the brain of male and female Japanese quail. Cells or fibers showing dopamine beta-hydroxylase and tyrosine hydroxylase immunoreactivity were considered to be noradrenergic or adrenergic, while all structures showing only tyrosine hydroxylase immunoreactivity were tentatively considered to be dopaminergic. The major dopaminergic and noradrenergic cell groups that have been identified in the brain of mammals could be observed in the Japanese quail, with the exception of a tuberoinfundibular dopaminergic group. The dopamine beta-hydroxylase-immunoreactive cells were found exclusively in the pons (locus ceruleus and nucleus subceruleus ventralis) and in the medulla (area of the nucleus reticularis). The tyrosine hydroxylase-immunoreactive cells had a much wider distribution and extended from the preoptic area to the level of the medulla. They were, however, present in larger numbers in the area ventralis of Tsai and in the nucleus tegmenti pedunculo-pontinus, pars compacta, which respectively correspond to the ventral tegmental area and to the substantia nigra of mammals. A high density of dopamine beta-hydroxylase- and tyrosine hydroxylase-immunoreactive fibers and punctate structures was found in several steroid-sensitive brain regions that are implicated in the control of reproduction. In the preoptic area and in the region of the nucleus accumbens-nucleus stria terminalis, immunonegative perikarya were completely surrounded by immunoreactive fibers forming basket-like structures. Given that some of these cells contain the enzyme aromatase, these structures may represent the morphological substrate for a regulation of aromatase activity by catecholamines. The dopamine beta-hydroxylase-immunoreactive fibers were also present in a larger part of the preoptic area of females than in males. This sex difference in the noradrenergic innervation of the preoptic area presumably reflects the sex difference in norepinephrine content in this region. [less ▲]

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See detailLes catécholamines et la tension artérielle
Krzesinski, Jean-Marie ULg

Conference (2011, May 04)

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See detailCatechols as versatile platforms in polymer chemistry
Faure, Emilie; Falentin-Daudré, Céline; Jérôme, Christine ULg et al

in Progress in Polymer Science (2013), 38(1), 236-270

Catechols represent an important and versatile building block for the design of mussel-inspired synthetic adhesives and coatings. Indeed, their ability to establish large panoply of interactions with both ... [more ▼]

Catechols represent an important and versatile building block for the design of mussel-inspired synthetic adhesives and coatings. Indeed, their ability to establish large panoply of interactions with both organic and inorganic substrates has promoted catechol as a universal anchor for surface modifications. In addition to its pivotal role in adhesive interfaces, the catechol unit recently emerged as a powerful building block for the preparation of a large range of polymeric materials with intriguing structures and fascinating properties. The importance of catechols as efficient anchoring groups has been highlighted in recent excellent reviews partly dedicated to the characterization of their adhesive mechanisms onto surfaces and to their applications. The aim of this paper is to review for the first time the main synthetic approaches developed for the design of novel catechol-based polymer materials. We will also highlight the importance of these groups as versatile platforms for further functionalization of the macromolecular structures, but also surfaces. This will be illustrated by briefly discussing some advanced applications developed from these catechol-modified polymers. The review is organized according to the chemical structure of the functionalized catechol polymers. Chapter 1 discusses polymers bearing catechols embedded into the polymer main chain. Chapter 2 focuses on the attachment of catechol moieties as pendant groups and Chapter 3 describes the different approaches for incorporation of the catechol unit at the extremity of well-defined polymers. [less ▲]

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See detailCatégories adverbiales, fonctions et ordre des syntagmes chez les historiens latins
Longrée, Dominique ULg

in Fruyt, Michèle; Brachet, Jean-Paul; Lecaudé, Peggy (Eds.) Les adverbes latins, Syntaxe et sémantique (2012)

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See detailLes catégories au seuil de la phénoménologie
Gauvry, Charlotte ULg; Fagniez, Guillaume

in Etudes Philosophiques (Les) (2016)

Le tournant du XXe siècle est marqué par un retour de la problématique catégoriale sur le devant de la scène philosophique, que ce soit chez Franz Brentano et ses élèves, chez Wilhelm Dilthey, chez les ... [more ▼]

Le tournant du XXe siècle est marqué par un retour de la problématique catégoriale sur le devant de la scène philosophique, que ce soit chez Franz Brentano et ses élèves, chez Wilhelm Dilthey, chez les Néokantiens de l’école de Bade, ou chez les premiers pionniers de la phénoménologie. Tant et si bien qu’une certaine philosophie (celle d’Emil Lask par excellence) a pu se présenter comme une doctrine des catégories à part entière. L’enjeu de ce numéro est d’interroger la place historique et le rôle conceptuel qu’ont joué ces questions formelles dans l’émergence de la phénoménologie. Kant avait certes renoué avec la question aristotélicienne des catégories pour postuler l’existence de « purs concepts de l’entendement » ou « catégories », seuls susceptibles de « fournir de l’unité aux diverses représentations dans un jugement et [de] donner aussi à la simple synthèse de diverses représentations dans une intuition une unité » (KRV, §10). L’intérêt proto-phénoménologique pour les catégories se présente-t-il cependant comme un retour, par-delà l’idéalisme allemand, à cette problématique transcendantale kantienne ou bien plutôt comme un retour, par-delà Kant lui-même, à la question aristotélicienne ? Si les philosophes du début XXe se sont ressaisis de la question des catégories, il semble qu’ils aient à tout le moins reformulé, voire abandonné la méthode de la « déduction ». C’est ce travail de reformulation de la déduction transcendantale que le numéro entend également clarifier. Peut-on encore dire que ces catégories sont « déduites » des formes logiques du jugement, des objets logiques ou du mouvement même de la vie ? S’il y a lieu de mettre au jour un processus « génétique » de la catégorie, quelles sont les implications d’un tel déplacement relativement à la validité du catégorial ? Plus généralement, c’est le statut même de ces « catégories » qui sera analysé. Leur domaine d’application redéfini, peut-on les déterminer comme des concepts purs transcendantaux susceptibles d’unifier l’expérience sensible ? Les catégories ne doivent-elles pas plutôt être repensées comme des formes logiques, sémantiques ou même ontologiques ? Ainsi, c’est l’enjeu stratégique de la résurgence de cette problématique catégoriale, et ses répercussions directes sur l’émergence de la phénoménologie naissante (husserlienne et heideggérienne) que ce numéro interrogera. [less ▲]

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See detailCatégories et termes de la politique à la Renaissance
Moreno, Paola ULg; Miesse, Hélène ULg; Fournel, Jean-Louis et al

Book published by Peter Lang (2014)

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See detailCatégories logiques et catégories ontologiques
Dewalque, Arnaud ULg; Leclercq, Bruno ULg; Seron, Denis ULg

Book published by Bibliothèque de la Faculté de Philosophie et Lettres (2011)

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See detailCategories of donation after cardiocirculatory death.
DETRY, Olivier ULg; Le Dinh, Hieu ULg; NOTERDAEME, Timothée et al

in Transplantation Proceedings (2012), 44(5), 1189-95

The interest in donation after cardiocirculatory death (DCD) was renewed in the early 1990s, as a means to partially overcome the shortage of donations after brain death. In some European countries and in ... [more ▼]

The interest in donation after cardiocirculatory death (DCD) was renewed in the early 1990s, as a means to partially overcome the shortage of donations after brain death. In some European countries and in the United States, DCD has become an increasingly frequent procedure over the last decade. To improve the results of DCD transplantation, it is important to compare practices, experiences, and results of various teams involved in this field. It is therefore crucial to accurately define the different types of DCD. However, in the literature, various DCD terminologies and classifications have been used, rendering it difficult to compare reported experiences. The authors have presented herein an overview of the various DCD descriptions in the literature, and have proposed an adapted DCD classification to better define the DCD processes, seeking to provide a better tool to compare the results of published reports and to improve current practices. This modified classification may be modified in the future according to ongoing experiences in this field. [less ▲]

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See detailCatégories sémantiques et catégories syntaxiques. Relecture critique des Recherches logiques par la philosophie analytique
Leclercq, Bruno ULg

in Dewalque, Arnaud; Leclercq, Bruno; Seron, Denis (Eds.) La théorie des catégories. Entre logique et ontologie (2011)

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