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See detailHow do harpacticoid copepods colonize detrital seagrass leaves?
Mascart, Thibaud ULg; Agusto, Laura; Lepoint, Gilles ULg et al

in Marine Biology (2015), 162(5), 929-943

An experiment was carried out investigating the colonization ability and specific pattern of copepods towards a provisional benthic habitat. Since copepods are known to disperse passively and actively ... [more ▼]

An experiment was carried out investigating the colonization ability and specific pattern of copepods towards a provisional benthic habitat. Since copepods are known to disperse passively and actively, the experiment aimed to investigate the pool of colonizers of macrophytodetritus and the species-specific active colonization pathways. The experiment was performed in a Mediterranean seagrass Posidonia oceanica meadow on defaunated macrophytodetritus accumulations (mainly dead seagrass leaves) for two time intervals (24 h and 96 h). Active colonization by copepods, independently of their adjacent potential source pool habitat (bare sandy sediments, P. oceanica canopy, water column and macrophytodetritus) occurred within 24 h. Natural densities (as in the control treatments) were only reached by active colonization through the water column. Both neither diversities nor species composition of natural macrophytodetritus were ever reached by one single migratory pathway, therefore only a combination of interstitial migration and water column migration can explain the species occurrence under natural condition. Moreover, every potential adjacent source pool habitat, contributed species to the newly colonized macrophytodetritus. However, the main colonizers were mostly species with good swimming capabilities. The diverse pool of species present in the newly colonized macrophytodetritus underlines the complex communities and dispersion capabilities of copepods. Hence, macrophytodetritus possesses the potential ability to be a colonizer source pool for every adjacent habitat and thus behaves as a copepod hub for the entire seagrass ecosystem. [less ▲]

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See detailIconologie critique : présentation de la méthode, initiation aux débats scientifiques contemporains, mise en pratique
Hagelstein, Maud ULg

Scientific conference (2015, March 04)

Cadre problématique : Evocation brève des débats actuels sur la question de l’image. Warburg et Panofsky (modèle et repoussoir) sont souvent mis dos à dos : l’un est sauvé (et connaît d’ailleurs ... [more ▼]

Cadre problématique : Evocation brève des débats actuels sur la question de l’image. Warburg et Panofsky (modèle et repoussoir) sont souvent mis dos à dos : l’un est sauvé (et connaît d’ailleurs aujourd’hui un certain effet de mode) quand l’autre est désavoué. On a reproché à l’iconologie panofskienne d’étudier les contenus symboliques (le quoi visé par l’œuvre) sans se soucier suffisamment de la manière dont ces contenus sont amarrés au sensible (le comment). Or, ce qu’on cherche aujourd’hui, c’est de décrire ce qui fait la spécificité de l’image, à savoir : une expression symbolique non verbale dont la matérialité directement visible affecte la production du sens. Autrement dit : la forme de présentation choisie influence directement la signification des œuvres visuelles. Pour reprendre l’argument de certains, ce ne serait pas le cas du langage verbal : la frappe d’un texte n’affecte a priori pas son sens – changer la police ou la taille des caractères n’altère pas le message (on pourrait bien entendu déstabiliser cette idée, mais on comprend néanmoins la proposition). On reproche encore à cette méthode de se limiter excessivement au contenu intrinsèque de l’image sans voir qu’elle est toujours branchée sur son dehors. S’il y a (une avancée majeure) un acquis de la théorie de l’image actuelle, c’est celui-là : la signification de l’image serait moins dans l’image elle-même que dans le tissu de relations (intersubjectives, pragmatiques, institutionnelles ) qu’elle entretient avec l’extérieur. D’où l’intérêt grandissant pour les usages, pour l’efficacité de l’image et pour les perspectives anthropologiques. Si on veut saisir la logique de l’image (sa logique spécifique), il faut la comprendre sans l’isoler du réseau dans lequel elle s’inscrit (on va voir que cette exigence était déjà chez Warburg qui a travaillé à mettre en valeur l’efficacité politique, sociale et institutionnelle des œuvres). Aujourd’hui, plusieurs théoriciens de l’image réclament donc une critique renouvelée de l’iconologie, qui ne s’appuierait plus sur le paradigme langagier. Une image ne fonctionne pas comme un texte. On pourrait dire qu’elle est à la fois sous-déterminée et surdéterminée. Surdéterminée : L’image ne se laisse pas ramener à un ensemble fini de signifiants. En elle, toutes les dimensions sont susceptibles d’affecter le sens, d’intervenir dans la construction du sens : le tracé, l’épaisseur, les accidents de la matière, les contrastes, etc. L’image peut donc potentiellement être chargée de significations multiples (un ex. me permettra de l’évoquer). Sous-déterminée : il n’y a image au sens fort que lorsqu’un regard construit une représentation à partir d’elle et qu’elle rencontre une « conjoncture » (un ensemble de circonstances par rapport auxquelles elle se détermine). Il y aurait donc une « lacune » ou une « incomplétude » constitutive de l’image. Elle est toujours réarticulée, prise dans une construction. Voilà un peu le cadre problématique dans lequel on est aujourd’hui – et à partir duquel je pourrais décrire la méthode de Warburg. [less ▲]

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See detailAtelier ENMG pratique membre inférieur
WANG, François-Charles ULg

Scientific conference (2015, March 04)

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See detailFalsification des médicaments: Est-il possible d'améliorer la puissance des outils de détection ?
Ziemons, Eric ULg; Sacre, Pierre-Yves ULg; Marini Djang'Eing'A, Roland ULg et al

Conference given outside the academic context (2015)

La mise sur le marché de médicaments falsifiés est une réalité dont on imagine rarement l’importance et la nuisance : on estime pourtant que ce marché rapporte plus que le trafic de drogue et il arrive ... [more ▼]

La mise sur le marché de médicaments falsifiés est une réalité dont on imagine rarement l’importance et la nuisance : on estime pourtant que ce marché rapporte plus que le trafic de drogue et il arrive que localement, des produits falsifiés soient plus nombreux que les produits originaux (cas des anti-malariques au Congo). La lutte contre la falsification s’est d’abord focalisée sur les emballages et les identificateurs tels que les codes-barres, qui aujourd’hui ne garantissent plus le contenu du médicament vu les progrès réalisés par les organisations criminelles en matière de reproduction d’emballage. La solution sûre consiste donc à analyser, sur place, la composition du produit à travers l’emballage et à comparer le résultat à la «carte d’identité» du médicament établie par le producteur. Les besoins portent donc sur des instruments d’analyse portables et capables de dialoguer à distance avec des banques de données de «cartes d’identité». Ceux-ci requièrent une approche pluridisciplinaire impliquant notamment des micro-électroniciens et des informaticiens. [less ▲]

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See detailEnabling technologies and methods for the synthesis of (bio)organic molecules
Monbaliu, Jean-Christophe ULg

Conference (2015, March 03)

We will discuss the development and implementation of continuous-flow multistep strategies for the synthesis of bio(organic) targets. Selected examples include unusual reaction conditions such as working ... [more ▼]

We will discuss the development and implementation of continuous-flow multistep strategies for the synthesis of bio(organic) targets. Selected examples include unusual reaction conditions such as working with solids in microreactors, high temperature reactions and the handling of highly reactive species. [less ▲]

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See detailQui pour nous représenter ? Quand les normes juridiques façonnent le jeu politique
Grandjean, Geoffrey ULg

Scientific conference (2015, March 03)

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See detailInfluence of the textural parameters of resorcinol–formaldehyde dry polymers and carbon xerogels on particle sizes upon mechanical milling
Piedboeuf, Marie-Laure ULg; Léonard, Alexandre ULg; Traina, Karl et al

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (2015), 471

Porous carbons find various applications in catalysis, electrochemical storage or sorption. Prior to use, their particle sizes need however to be controlled according to the targeted application. In this ... [more ▼]

Porous carbons find various applications in catalysis, electrochemical storage or sorption. Prior to use, their particle sizes need however to be controlled according to the targeted application. In this study, the grinding behavior of materials prepared from aqueous resorcinol–formaldehyde mixtures and displaying different pore textures was studied in detail. Both dry polymer gels and pyrolyzed carbon xerogels were compared in terms of particle size distributions after planetary ball-milling. The results show that the pore texture and the qualitative hardness of the materials have a strong influence on the grinding behavior, especially if carbon xerogels pyrolyzed before grinding are considered. On the other hand, it appears that the milling of polymer gels, followed by a pyrolysis step, is the most efficient way to obtain homogeneous particle size distributions, for all of the investigated mesopore textures. In this case, carbon particles displaying a narrow grain size distribution centered on a mode value near 10 μm are successfully obtained after similar grinding durations, with retention of the mesopore texture of the starting materials. This work also demonstrates the possibility of using mercury intrusion porosimetry as an interesting tool to assess simultaneously the mesopore dimensions and the particle sizes of porous powders. [less ▲]

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See detailLa menace climatique sur les plantes
Hambuckers, Alain ULg

Conference given outside the academic context (2015)

L’exposé commence par un bref rappel du contexte climatique (évolution de la température globale au cours des 150 dernières années, grandes tendances des changements climatiques prévus par les modèles ... [more ▼]

L’exposé commence par un bref rappel du contexte climatique (évolution de la température globale au cours des 150 dernières années, grandes tendances des changements climatiques prévus par les modèles globaux). Je présente ensuite quelques exemples d’observations de modification de la végétation au cours des décennies passées (enrichissement en espèces de sommets alpins, augmentation de la mortalité de la végétation ligneuse en région sahélienne, variation de la limite altitudinale de présence d’espèces endémiques sur l’île de Ténérife) et les limites de leur interprétation (prise en compte des modifications de l’occupation du sol, de la pollution atmosphérique, des interactions biotiques). On s’intéresse ensuite à la prédiction des changements dans le futur qui nécessite de comprendre les réponses physiologiques des plantes aux facteurs suivants : l’augmentation de la température, les variations du régime de précipitation, les effets des épisodes climatiques extrêmes (canicules, sécheresses), l’augmentation de la concentration en CO2, l’évolution des conditions biotiques. Armé de ces informations, on peut alors examiner des méthodes d’inférences comme l’analyse des distributions présentes, les modèles de niches, ou les modèles dynamiques de végétation et quelques résultats produits par ces méthodes. Pour les espèces tropicales nos résultats donnent plutôt à penser que les aires de distributions s’étendront dans le futur, avec une très large conservation de l’aire originale. Ces résultats sont finalement mis en perspective avec d’autres facteurs d’altération de l’environnement, et en particulier la destruction des habitats. Ceci nous permet de constater que le principal problème contre lequel il faut continuer à agir, en priorité, reste la destruction des habitats naturels et semi-naturels, y compris en Belgique. [less ▲]

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See detailAssessing the operation rules of a reservoir system based on a detailed modelling chain
Bruwier, Martin ULg; Erpicum, Sébastien ULg; Pirotton, Michel ULg et al

in Natural Hazards & Earth System Sciences (2015), 15

The current operation rules of two muti-purpose reservoirs are analysed based on an integrated model including a hydrological model, a hydraulic model, a model of the reservoir system and a flood damage ... [more ▼]

The current operation rules of two muti-purpose reservoirs are analysed based on an integrated model including a hydrological model, a hydraulic model, a model of the reservoir system and a flood damage model. Five performance indicators have been defined, reflecting the ability to provide drinking water, to control floods, to produce hydropower and to reduce low-flow conditions. Then, impacts of two climate change scenarios are assessed and enhanced operation rules are proposed for mitigation. [less ▲]

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See detailLes droits fondamentaux, une substance malléable pour le juge? Propos sur la "dématérialisation" des droits fondamentaux
Rosoux, Géraldine ULg

in Justice-en-ligne (2015)

Ce texte contient un résumé de la thèse de doctorat de l'auteur; il est disponible en ligne: http://www.justice-enligne.be/article706.html.

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See detailEpidemiology of brucellosis in humans and domestic ruminants in Bangladesh
Rahman, Anisur ULg

Doctoral thesis (2015)

Background Brucellosis is an ancient and one of the world’s most widespread zoonotic diseases affecting both, public health and animal production. It is endemic in many developing countries of Asia ... [more ▼]

Background Brucellosis is an ancient and one of the world’s most widespread zoonotic diseases affecting both, public health and animal production. It is endemic in many developing countries of Asia, Africa and Latin America including Bangladesh. Since the first report in 1970, a lot of brucellosis seroprevalence reports are available in cattle, goats, sheep and humans in Bangladesh. Most of the previously reported prevalence studies were based on non-random samples, which may not give a true representation of the status of the disease in respective populations. Some authors also investigated the risk factors in cattle. The tests used for the diagnosis of brucellosis in domestic ruminants and humans are imperfect and their performance was not evaluated in Bangladesh. The true prevalence of brucellosis in domestic ruminants is not known and is essential for analyzing the impact of this disease in domestic ruminants in Bangladesh. Indeed, when diagnostic tests are used without evaluating their performance in a context usually generate unreliable results, which in turn may lead to wrong epidemiological inferences. In addition, information on risk factors of brucellosis in humans and animals is also scarce. Moreover, the different species of Brucella prevalent in animals is scarce and not known in humans in Bangladesh. The overall objective of this thesis was to investigate the epidemiology of brucellosis in humans and domestic ruminants in Bangladesh in terms of the evaluation of commonly used diagnostic tests, estimation of true prevalence, identification of risk factors and detection of Brucella species in order to provide information that will guide the selection of appropriate control strategies. Study design and data analysis Sampling To collect random samples of animals a system of map digitization and selection of one geographical point from selected unions (Sub-Upazilla) using a hand held GPS machine was used. Blood (milk also where applicable) samples were then collected from livestock farmers and their animals within 0.5 km of the selected points. A convenient blood sample of butchers, dairy hands and veterinary practitioners were collected from Dhaka and Mymensingh districts. The sera of pyretic humans were collected from Mymensingh Medical College hospital randomly once in a week. Random milk samples were collected from Sirajgonj and Chittagong districts. Systematic random milk and blood samples of cattle including breeding bulls (semen also) of central cattle breeding and dairy farm (CCBDF) were also collected. Milk and blood samples of gayals of a herd in regional Bangladesh Livestock Research Institute at Naikhonchari, Bandarban were also collected. Convenient samples of placenta and vaginal swabs were also collected from Mymensingh district. Data collection and Analysis Data on serology was generated by using Rose Bengal test (RBT), Slow Agglutination test (SAT) /Standard tube agglutination test (STAT) (animals/humans) and indirect enzyme linked immunosorbent assay (iELISA). Animal, their herd level data and human data on potential risk factors were collected using a pretested questionnaire. The data was stored in Microsoft Excels worksheets and transferred to respective software for analysis. To estimate true prevalence and evaluate three conditionally dependent serological tests, Bayesian latent class models were used. Random effect and Firth’s logistic regression analyses were used to determine the risk factors of human brucellosis. The STATA, R and OpenBUGS softwares were used for data analyses. Staining, culture, genus and species-specific real time PCR assays were applied to isolate and to detect Brucella Spp./DNA in seropositive human sera and animal samples. Main results: Only 0.29% (95% CI: 0.06-0.86) cattle were acutely infected whereas 0.49% (95% CI: 0.16- 8 1.1) were chronically infected with brucellosis in Mymensingh. On the other hand, in CCBDF 15.58% (95% CI:11.89-19.89) cattle were acutely infected with brucellosis and only 3.2%(95%CI: 1.63-5.72) were chronically infected. The true prevalence of brucellosis among cattle in Mymensingh and CCBDF were 0.3% (95%CI: 0.03-0.7) and 20.5% (95% CI: 16.4-26.3) respectively. The performance of iELISA was best in both Mymensingh and CCBDF with the sensitivity of 90.5% and 91.3% and specificity of 99.3% and 99.2% respectively. The performance of RBT was better in Mymensingh than CCBDF with 81.0% and 76.1% sensitivity and 99.0% and 95.6% specificity respectively. Similar to RBT, the performance of SAT was also better in Mymensingh than CCBDF with 63.5% and 79.7% sensitivity and 98.6% and 95.3% specificity respectively. Through this test validation study, a new cut-off of 5 IU/ml for iELISA was recommended both in low (as at Mymensingh) and high prevalence scenarios in cattle populations (as at CCBDF) for routine screening. It was recommended to do nothing for the control of bovine brucellosis under small-scale dairy and subsistence management systems in Bangladesh. However, vaccination should be applied in herds where the prevalence is very high as like CCBDF. The true prevalence of brucellosis in goats and sheep were estimated as 1% (95% CI): 0.7–1.8) and 1.2% (95% CI: 0.6–2.2) respectively. The sensitivity of iELISA was 92.9% in goats and 92.0% in sheep with corresponding specificities of 96.5% and 99.5% respectively. The sensitivity and specificity estimates of RBT were 80.2% and 99.6% in goats and 82.8% and 98.3% in sheep. The sensitivity and specificity of SAT were 57.1% and 99.3% in goats and 72.0% and 98.6% in sheep. The prevalence of brucellosis in occupationally exposed people (HROG) using three tests was observed to be 4.4% based on a parallel interpretation. The results of the multiple random effects logistic regression analysis with random intercept for district revealed that the odds of brucellosis seropositivity among individuals who had been in contact with livestock for more than 26 years was about 14 times higher as compared to those who had less than 5 years of contact with livestock. In addition, when the contact was with goats, the odds of brucellosis seropositivity were about 60 times higher as compared to when contact was with cattle only. The seroprevalence of brucellosis among patients with pyrexia of unknown origin (PUO) was estimated to be 2.7% (95% CI: 1.2-5.2). The age, residence, type of patient, contact with animals, type of animal handled, arthralgia and backache were found to be significantly associated with a positive serological result in bivariable Firth’s logistic regression. Brucella abortus was detected from seropositive pyretic patients. Conclusion: The true exposure prevalence of brucellosis in cattle under small-scale dairy and subsistence/backyard management systems is very low (0.3%; 95% CI: 0.03-0.7). The active/acute infection is also very low (0.29%: 95% CI: 0.06-0.86) and similar to true exposure prevalence. The brucellosis in cattle under such management system is naturally controlled and further control program is not recommended considering the poor socioeconomic conditions. The true exposure prevalence of brucellosis in CCBDF is very high (20.5%; 95% CI: 16.4-26.3). The acute infection in this farm is also very high (15.58%; 95% CI: 11.89-19.89). Immediate control measures by initiating calf hood (female calf) vaccination are recommended to protect a valuable herd which also provides frozen semen for artificial insemination all over the country. The SAT and iELISA may simultaneously be applied to know the stage of brucellosis infection in domestic ruminants in high prevalence scenarios. The true exposure prevalence of brucellosis in goats and sheep are also low and around 1%. Due to lower positive predictive value, these test results should be interpreted with caution to avoid misleading information. Breeding bulls used for artificial insemination all over the country were found to be infected with brucellosis. Brucellosis is not a serious problem for the general population in Bangladesh as drinking raw milk and milk products is unusual and not a risk factor. The apparent prevalence of brucellosis in high risk occupationally exposed people (4.4%; 95% CI: 2.8-6.6) and in pyretic patients (2.7%; 95% CI: 1.2-5.2) are also low. The RBT may be applied as a screening test in humans having signs and symptoms of brucellosis along with the history of animal contact. In case of suspicion, genus or species specific rt PCR may be applied for confirmation. Only B. abortus DNA was amplified from 19 seropositive human samples (both HROG and PUO) and six animal samples (3 cows milk, one goat milk, one gayal milk and one bull semen). No Brucella like organism was observed under microscope in stained smears. Similarly, no Brucella organism was isolated from any of the clinical samples. [less ▲]

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