Last 7 days     Results 2321-2340 of 27960.   112 113 114 115 116 117 118 119 120 121 122   A framework for using decision-support tools at various spatial scales for the management of irrigated agriculture in semi-arid West-AfricaWellens, Joost Doctoral thesis (2014)The Kou watershed, situated in the Southwestern part of Burkina Faso, has succumbed since a couple of decades to a typical theater play of anarchistic water management. With its 1.800 km², this small ... [more ▼]The Kou watershed, situated in the Southwestern part of Burkina Faso, has succumbed since a couple of decades to a typical theater play of anarchistic water management. With its 1.800 km², this small watershed includes the second largest city of Burkina Faso (Bobo-Dioulasso), a former state run irrigated rice scheme and several informal agricultural zones. Despite the abundance of water resources, most water users find themselves regularly faced with shortages due to an increase in population and low irrigation efficiencies. Local stakeholders are hence in need of easy to use and low-cost decision support tools for the monitoring and exploitation of the water resources at different spatial and user levels. A top-to-bottom string of adapted water management tools has successfully been installed to tackle the problems: from watershed (top) to field level (bottom), not to mention the 1200 ha irrigation scheme. Land use maps have been derived from satellite and aerial images. Combined with data from a network of hydrologic gauging stations, regional water use maps were established. Hot spots in inefficient water use could be geographically identified and more detailed actions undertaken. Scheme Information Management Information System (SIMIS) was put in place for the management of the regions irrigated rice scheme. A more equitable distribution for the ever diminishing available water resources could be elaborated. A public-private partnership was installed to guarantee its sustainability. Day to day water use on irrigated plots was monitored by soil humidity and crop canopy measurements. A simple field-crop-water balance model AquaCrop was calibrated and validated, and is used by extension workers to draft optimal irrigation charts. Each tool is applied independently, requiring only limited data; but their combined results contribute to an improved integrated water management. [less ▲]Detailed reference viewed: 31 (5 ULg) Modes intentionnelsDewalque, Arnaud Conference (2014, March 07)Je dresse le bilan de la situation des recherches actuelles en théorie de la perception (entre représentationalisme et relationalisme), et je suggère que la voie d'investigations la plus prometteuse est l ... [more ▼]Je dresse le bilan de la situation des recherches actuelles en théorie de la perception (entre représentationalisme et relationalisme), et je suggère que la voie d'investigations la plus prometteuse est l'intentionalisme modal. D'après l'intentionalisme modal, un état mental est individualisé par son contenu intentionnel et par son mode intentionnel. En m'appuyant sur la méthode descriptive de Franz Brentano, je propose alors un argument en faveur de cette conception: l'argument de la complétude. [less ▲]Detailed reference viewed: 15 (1 ULg) Diversification artistique et politiques culturelles dans les villes multiculturellesMartiniello, Marco in SociologieS [Online], Files, Diversification artistique et politiques culturelles (2014)Cet article introductif part du constat que la mondialisation se traduit par une diversification culturelle des villes européennes. Cette diversité donne lieu à deux tendances contradictoires. D'une part ... [more ▼]Cet article introductif part du constat que la mondialisation se traduit par une diversification culturelle des villes européennes. Cette diversité donne lieu à deux tendances contradictoires. D'une part, on observe une tendance à la polarisation et à la fragmentation ethniques dans de nombreuses villes. D'autre part, on observe des mouvements vers plus d'intégration résidentielle et la formation de quartiers multi-ethniques dans lesquels se développent la co-inclusion et les interactions entre les citoyens de différentes origines ethniques et sociales. Ces tendances contradictoires se marquent aussi dans le domaine artistique qui est assez peu étudié dans les débats sociologiques et politiques sur l’immigration, l’intégration et le multiculturalisme. Après avoir proposé un cadre pour cette étude ainsi que les enjeux principaux de la question artistique dans les villes post-migratoires, l’article présente brièvement les autres contributions qui composent ce dossier. [less ▲]Detailed reference viewed: 13 (0 ULg) Using features of mercury and methylmercury to discriminate contamination profiles between sea bass, Dicentrarchus labrax, populationsCransveld, Alice ; Amouroux, David; Koutrakis, Emmanuil et alPoster (2014, March 07)Despite many efforts consented in the last decades, Mercury (Hg) emissions have kept rising worldwide. Currently, anthropogenic inputs dominate Hg emissions to the atmosphere by far, natural releases ... [more ▼]Despite many efforts consented in the last decades, Mercury (Hg) emissions have kept rising worldwide. Currently, anthropogenic inputs dominate Hg emissions to the atmosphere by far, natural releases accounting only for a 4th of the total. Because Hg has a stable gaseous form (Hg0) with a long residence time in the atmosphere (~1year), both natural and industrially produced Hg can be transported far from point sources. Therefore, many uncertainties remain in our knowledge about Hg biogeochemistry. Our study aims at identifying the different Hg forms found in marine predators in order to discriminate different polluted areas and potential pollution sources. More specifically, we seek to discriminate contaminations of local origins versus contamination of global origins. To achieve this, we are currently studying different sea bass, Dicentrarchus labrax, populations from the Atlantic Ocean and Mediterranean. In muscle, liver, kidney and brain tissues, we analyze total Mercury (THg) and methylmercury (MeHg). We are also testing the discrimination power of Hg's stable isotopes (199Hg, 201Hg and 202Hg). Indeed, recent findings show that Hg isotopes can exhibit both mass-dependent (MDF) and mass-independent fractionation (MIF). This means that Hg isotopes provide two different types of information at once, both on biological cycling of Hg, including bioaccumulation (MDF), and on chemical pathways such as photochemical transformations (MIF). Eventually, we are planning to extend our results with compound specific isotope analysis (CSIA) on the carbon of methylmercury. Preliminary analysis performed on 14 juvenile specimens from the North Sea and the Aegean Sea indicate that THg concentrations are higher in individuals from the North Sea than from Greece. The lack of correlation with size and weight indicate that it is likely linked to a difference in contamination levels between the two areas. MeHg is the predominant form of Hg in muscle, while the same cannot be asserted for liver. Mass dependent isotopic values (δ202Hg), were always higher in muscle than in liver and, for each tissue, values were similar between the two areas. This is probably related to the species distribution and to some internal Hg metabolism. For mass independent isotopic signature (MIF), sea bass from the Aegean Sea had a systematically higher Δ201Hg value than individuals from the North Sea. Thus, mass independent values seem definitely site dependent and might be in agreement with differences in both mercury sources and cycling in the North and Aegean Seas. These preliminary results consequently indicate that Hg isotopes may help to discriminate fish from different areas. This promising outcome must be further confirmed by extending our sampling and will be coupled to other results obtained through CSIA. [less ▲]Detailed reference viewed: 23 (3 ULg) Microplastics caught in herring gill rakers: illustration by scanning electron microscopyCollard, France ; Das, Krishna ; Parmentier, Eric Conference (2014, March 07)Plastics are produced in huge quantity (280 million of tons in 2012) and more than 10% end up in the oceans. It is estimated that between 60 and 80% of all marine debris are plastics. Plastics are ... [more ▼]Plastics are produced in huge quantity (280 million of tons in 2012) and more than 10% end up in the oceans. It is estimated that between 60 and 80% of all marine debris are plastics. Plastics are persistent and have accumulated in the oceans for several decades. Plastics may adverse wildlife in many ways: they can be ingested by marine vertebrates and cause internal wounds in the digestive tract. Plastics are also vectors of organic pollutants including. Once ingested, plastics may release these pollutants in the organism. Plastics present in the marine environment fragment in small pieces by mechanical stress and UV radiation leading to the so-called microplastics smaller than 5 mm. Little is known about microplastics ingestion and toxicity in planktivorous fish such as the herring, Clupea harengus. Planktivorous fish have gill rakers, which may function as a trap for microplastics. This study aims to describe and characterise microplastics present on gill rakers of the herring, Clupea harengus. Ten gill cavities were sampled in January 2013 in the Channel and the North Sea during a fishery campaign organized by the IFREMER. Gills cavities were placed in a fixating solution until preparation for scanning electron microscopy (SEM). SEM was used in order to detect microplastics which are too small to be observed by a dissection microscope, to compare them with the distance between gill rakers and to characterise the surface and the shape of microplastics. Scanning electron microscopy revealed large variety of microplastics, which lengths ranged from 0.05 to 5mm. Relationship between microplastics length and distance between gill rakers was analysed on the same branchial arch. The present study revealed the presence of microplastics in an edible species of high economic value and raise question about potential impact on the herring and its consumers, including human beings. [less ▲]Detailed reference viewed: 95 (4 ULg) L'intérêt de la science politique pour les projets d'urbanisme. Le cas des projets d'implantation éoliensRossignol, Nicolas ; Parotte, Céline Speech (2014)Detailed reference viewed: 18 (0 ULg) John McDowell en phénoménologue. Propositions pour une interprétation conceptualiste de l'intentionnalitéZincq, Aurélien Conference (2014, March 07)Detailed reference viewed: 13 (2 ULg) Equations fantaisistes : l'argent comme ressort burlesque dans l'œuvre de Pierre La PoliceBelloi, Livio Conference (2014, March 06)Conçue comme une vaste parodie du discours médiatique en général et de la presse quotidienne en particulier, la série "Véridique !" (Cornélius, 1999-2002) du dessinateur français Pierre La Police met ... [more ▼]Conçue comme une vaste parodie du discours médiatique en général et de la presse quotidienne en particulier, la série "Véridique !" (Cornélius, 1999-2002) du dessinateur français Pierre La Police met volontiers en scène des questions ou des rapports d’argent. Le plus souvent lié à la sphère politique, le thème de l’argent autorise l’auteur à jeter un regard narquois et particulièrement acéré sur des événements qui firent grand bruit dans la France des années 1990 (l’affaire Roland Dumas, le scandale de l’ARC, l’affaire des emplois fictifs à la ville de Paris, etc.). Ma communication étudie au plus près les mises en scène de l’argent dans l’œuvre de Pierre La Police et s'efforce de porter au jour les véritables équations mises au point à cet égard par l’auteur. Toutes à leur manière, ces équations concourent à faire du thème de l’argent un ressort burlesque à part entière ; elles participent également d’une esthétique générale de la distorsion et de l’approximation, qui est comme la marque de fabrique de Pierre La Police. [less ▲]Detailed reference viewed: 14 (0 ULg) Early neuropsychological detection of Alzheimer's diseaseBastin, Christine Conference (2014, March 06)Considering that brain pathology due to Alzheimer’s disease starts many years before the clinical symptoms become evident, subtle cognitive changes may exist already in the predementia phase. Different ... [more ▼]Considering that brain pathology due to Alzheimer’s disease starts many years before the clinical symptoms become evident, subtle cognitive changes may exist already in the predementia phase. Different approaches have been used to detect initial cognitive impairments indicative of Alzheimer’s disease. One approach is the assessment of the predictive power of neuropsychological tools in characterizing patients with stable mild cognitive impairment (MCI) versus MCI patients who subsequently develop Alzheimer’s disease. Another approach is the longitudinal evaluation of large cohorts of older adults in population-based studies. Findings from several studies suggest that a memory test that ensures deep encoding of information and assesses retrieval with free as well as cued recall is a useful tool to distinguish patients at an early stage of Alzheimer disease from MCI non-converters. Impaired semantic memory has also been proposed as a neuropsychological marker of predementia Alzheimer’s disease. Beyond the memory domain, category verbal fluency has been shown to predict progression to Alzheimer’s disease. Moreover, combining neuropsychological scores of memory and executive functions and neuroimaging data allows a better discrimination between stable MCI and converters than neuroimaging data alone. Altogether, it is possible to detect cognitive changes that are predictive of the typical form of probable Alzheimer’s disease already in the predementia stage. Such at risk people are thought to be the best target for therapeutic interventions. [less ▲]Detailed reference viewed: 52 (3 ULg) Proteomic and metabolomic analysis of acetate utilization in Chlamydomonas under different light regimes and carbon sourcesRemacle, Claire Scientific conference (2014, March 06)Detailed reference viewed: 5 (1 ULg) France-Brésil : une relation stratégique ?Santander, Sébastian Scientific conference (2014, March 06)Detailed reference viewed: 6 (0 ULg) Intentionalisme et représentationalisme de Brentano à CraneBoccaccini, Federico Conference (2014, March 06)Detailed reference viewed: 8 (0 ULg) Les quartiers 'ghettos' : des étiquettes collées sur des phénomènes complexes?Ruelle, Christine Conference given outside the academic context (2014)Detailed reference viewed: 11 (1 ULg) Pericopsis elata (Harms) Meeuwen (Fabaceae) in the Congo Basin, where does the threat come from? A contribution of forest ecologyBourland, Nils ; Doucet, Jean-Louis Conference given outside the academic context (2014)Detailed reference viewed: 8 (0 ULg) Implication de la clusterine dans la survie des cellules prostatiques lors de l'apoptoseAmmar, Hayet Doctoral thesis (2014)Prostate cancer is the second leading cause of cancer death in men. Although androgen ablation remains the most effective management option, most patients with advanced disease progress to castration ... [more ▼]Prostate cancer is the second leading cause of cancer death in men. Although androgen ablation remains the most effective management option, most patients with advanced disease progress to castration resistant prostate cancer (CRPC), within two years of treatment. This results, in part, from the increase in the anti-apoptotic molecules expression following androgen withdrawal. Among the proteins involved in this phenomenon, clusterin, also known as testosterone repressed message-2 (TRPM- 2), which exists in two forms: a pro-apoptotic nuclear form (nClU) and a secreted survival factor (sClU). In our study we investigated the role of the secreted form of clusterin in preventing cells from TNFα-induced apoptosis. For this, we first generated a sCLU inducible stable prostatic cancer MLL rat cell line by using the Tet-On gene expression system. With this model we revealed a new mechanism by which sCLU promotes survival in androgenindependent prostate cancer cells, implicating its receptor megalin and the Akt survival pathway. By applying a comparative proteomic analysis in the androgen-independent epithelial cell line MLLTet-sClu induced to overexpress sClu or non induced control-cells, we identified five proteins known to play a role in cancer. These proteins candidates are heat shock proteins Hsp90 and Hsp70, osteopontin (bone sialoprotein, OPN), proliferating cell nuclear antigen (PCNA) and ADP-ribosylation factor 1 (Arf1). Altogether, our data provide new mechanistic insight in sCLU dependent activation of the major survival pathway upregulated in refractory prostate cancer. The identification of the new sCLU protein targets open new avenues for more research to elucidate the significance of clusterin in prostate cancer progression and resistance to therapy. [less ▲]Detailed reference viewed: 6 (1 ULg) L'utilisation de la spectrométrie (NIR) et l’imagerie hyperspectrale (NIR-HIS) proche infrarouge pour étudier la composition chimique et botanique de des fourragesDale, Laura-Monica Doctoral thesis (2014)Forage quality or nutritive value is related to chemical composition, which can be determinated by laboratory methods. The NIR technique in comparison with classical methods is non-destructive, non ... [more ▼]Forage quality or nutritive value is related to chemical composition, which can be determinated by laboratory methods. The NIR technique in comparison with classical methods is non-destructive, non-polluting, fast and relatively inexpensive per analysis. Investigations on nutritional quality of Carpathians Apuseni Mountains (Romania) grasslands are rarely performed with NIR technique. Therefore, the objective of the thesis was to develop non-destructive methods for evaluating the quality of feed originating from the Gârda area of the Carpathians Apuseni Mountains (Romania) potentially and to similar grassland arround the world. The first task was to study the potential of NIR spectroscopy for building a spectral database for forage quality based on a large collection of semi-natural grassland samples, using a ‘local’ calibration model built by the Walloon Agricultural Research Centre (CRA-W), in Belgium, to determine various parameters (e.g., protein, dry matter, ash, fibre, fat, aNDFom, ADF, lignin, digestibility, crude energy) from samples collected worldwide, outside Romania. The second task was to develop calibration models for an NIR-HSI system, which involved larger spectral data registration as an image. Until now, analyses to determine plant species were based on botanical composition evaluation, including visual observation, which is a subjective method involving identifying plants directly in the field. Distinguishing samples of pure grassland species can be time consuming, and it was therefore decided to build a spectral database of pure samples and then discriminate these samples into binary and ternary artificial sample mixtures. The main objective of these tasks was to identify the botanical families to which the samples belonged (Poaceae, Fabaceae and Other Botanical Families [OBF]). The focus was not on quantity monitoring, but rather on determining forage quality from stationary experiments in the grasslands. To conclude, this research has shown that it is possible to develop calibration models not only for quality assessment, but also for sample discrimination in dry powder samples. It was intended, that the mathematical models constructed and the database obtained, would be used for future research. [less ▲]Detailed reference viewed: 64 (8 ULg) A vision-based autonomous inter-row weederKrishna Moorthy Parvathi, Sruthi Moorthy ; Detry, Renaud ; Boigelot, Bernard et alConference (2014, March 05)Autonomous robotic weed destruction plays a significant role in crop production as it automates one of the few unmechanized and drudging tasks of agriculture i.e. manual weed destruction. Robotic ... [more ▼]Autonomous robotic weed destruction plays a significant role in crop production as it automates one of the few unmechanized and drudging tasks of agriculture i.e. manual weed destruction. Robotic technology also contributes to long-term sustainability with both economic and environmental benefits, by minimising the current dependency on chemicals. The aim of this study is to design a small low-cost versatile robot allowing the destruction of weeds that lie between the crop rows by navigating in the field autonomously and using a minimum of a priori information of the field. For the robot to navigate autonomously, necessary and sufficient information can be supplied by a machine vision system. One important issue with the application of machine vision is to develop a system that recognises the crop rows accurately and robustly which is tolerant to problems such as crops at varying growth stages, poor illumination conditions, missing crops, high weed pressure, etc. Aiming at accurate and robust real-time guidance of autonomous robot through the field, the plethora of image processing algorithms like Ostu’s threshold method and hough transform will be explored for two main processes namely the image segmentation and crop row detection respectively. In order to overcome the issue of large variabilities encountered in agriculture such as varying weather conditions, intelligent stochastic data fusion and machine learning algorithms will be used to combine data from heterogeneous sensors. Besides crop row detection, other major challenges foreseen are: mapping the unknown geometry of the field, high-level planning of efficient and complete coverage of the field, controlling the low-level op- erations of the robot, and ensuring security. Specialised sensors such as GPS will be considered to generate the map of the field enabling Simultaneous Localisation And Mapping (SLAM) in real time on a mobile platform. The generated map will be exploited along with the sensorial in- formation from crop row detection to efficiently plan and execute the guidance of the robot au- tonomously in the field, thereby enabling weed elimination. [less ▲]Detailed reference viewed: 61 (6 ULg) Chemical Hydrolysis of Fagus sylvatica Wood: Dilute Acid vs. Alkaline TreatmentMiazek, Krystian ; Goffin, Dorothée ; Richel, Aurore Poster (2014, March 05)Lignocellulosic biomass, found in a large variety of plants such as coniferous trees (Softwood), broad leaved trees (Hardwood), grasses and agricultural or food residues, is the most abundant source of ... [more ▼]Lignocellulosic biomass, found in a large variety of plants such as coniferous trees (Softwood), broad leaved trees (Hardwood), grasses and agricultural or food residues, is the most abundant source of molecules required for production of biofuels and high value - added products. Lignocellulose is composed of three polymers: cellulose, hemicellulose and lignin. Cellulose is a non-branched polymer consisting of glucoses (hexoses). Hemicellulose is a complex carbohydrate containing pentoses (mainly xyloses in the case of Hardwood, grasses and agricultural wastes) or hexoses (usually mannoses in the case of Softwood) as the main sugars. Lignin is a biopolymer with aromatic alcohols as basic monomeric units. Cellulose chains are arranged in bundles and interlinked with hemicellulose. Lignin is cross-linked with hemicellulose and occupies space between cellulose bundles. Due to complex polymeric structure, lignocellulosic materials are resistant to hydrolysis. A number of treatment methods (mechanical, chemical, biochemical) is implemented to successfully hydrolyse lignocellulose. Amongst chemical methods harnessed to break lignocellulose structure, dilute acid and alkaline treatments are commonly mentioned, as the most efficient ones. The objective of this study was to evaluate the effect of dilute acid and alkaline treatment on hydrolysis rate of polymeric components in Fagus sylvatica wood. Fagus sylvatica also known as common beech is a broad leaved, deciduous tree that belongs to the family of Fagaceae, widely spread in Europe. Beech wood was determined to contain 48 % glucose, 18 % xylose and 20 % Klason lignin in its dry material. Results of this study showed that 1 h hydrolysis at 100 °C with the use of 3 % H2SO4 resulted in 71 % removal of xylose and 4 % removal of glucose with Klason lignin remained intact. Additionally, the presence of sugar degradation products: 2 - furfural and hydroxymethylfurfural was detected in dilute acid hydrolysate. Release of 2 - furfural and hydroxymethylfurfural from beech wood was determined as 0.03 % and 0.1 %, respectively. On the other hand, 1 h hydrolysis at 100 °C with the use of 7 % NaOH caused 59 % xylose removal and 11 % removal of Klason lignin with no effect on glucose. Dilute acid hydrolysis proved to be more efficient in removing xylose, but alkaline hydrolysis additionally showed to remove Klason lignin. [less ▲]Detailed reference viewed: 41 (7 ULg) Bott type periodicity for the higher octonionsKreusch, Marie E-print/Working paper (2014)We study the series of complex nonassociative algebras $\bbO_n$ and real nonassociative algebras $\bbO_{p,q}$ introduced in~\cite{MGO2011}. These algebras generalize the classical algebras of octonions ... [more ▼]We study the series of complex nonassociative algebras $\bbO_n$ and real nonassociative algebras $\bbO_{p,q}$ introduced in~\cite{MGO2011}. These algebras generalize the classical algebras of octonions and Clifford algebras. The algebras $\bbO_{n}$ and $\bbO_{p,q}$ with $p+q=n$ have a natural $\Z_2^n$-grading, and they are characterized by cubic forms over the field $\Z_2$. We establish a periodicity for the algebras~$\bbO_{n}$ and $\bbO_{p,q}$ similar to that of the Clifford algebras $\mathrm{Cl}_{n}$ and~$\mathrm{Cl}_{p,q}$. [less ▲]Detailed reference viewed: 39 (20 ULg) Vadose zone studies at an industrial contaminated site: the vadose zone monitoring system and cross-hole geophysicsFernandez de Vera, Natalia ; Pena Hernandez, Juan Angel; Beaujean, Jean et alScientific conference (2014, March 05)Oral presentation of the PhD project at the ENVITAM PhD day in Louvain-la-NeuveDetailed reference viewed: 12 (1 ULg)