Browsing
     by title


0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

or enter first few letters:   
OK
See detailA Investigacao Sociologica os "pragamatic" americanos
Stassart, Pierre M ULg

Scientific conference (2011)

Detailed reference viewed: 12 (0 ULg)
See detailLa investigación experimental en educación
De Landsheere, Gilbert ULg

Book published by UNESCO (1982)

Detailed reference viewed: 72 (0 ULg)
See detailLa investigación pedagógica
de Landsheere, Gilbert ULg; Mialaret, Gaston

Book published by Angel Estrada - 1ère éd. (1971)

Detailed reference viewed: 10 (0 ULg)
See detailInvestigación y Desarrollo más Innovación
Artige, Lionel ULg; Nicolini, Rosella

Book published by Consejo Económico y Social de España (2008)

Detailed reference viewed: 30 (5 ULg)
Peer Reviewed
See detailInvestigaciones sobre el aceite de Mauritia flexuosa L.
Lognay, Georges ULg; Trevejo, E.; Jordan, E. et al

in Grasas Y Aceites (1987), 38(5), 303-307

Detailed reference viewed: 14 (0 ULg)
Peer Reviewed
See detailInvestigating a bottom-up approach for extracting domain ontologies from urban databases
Chaidron, Christophe; Teller, Jacques ULg; Billen, Roland ULg

in Proceedings of the 1st Workshop of COST Action C21 Towntology (2006)

Detailed reference viewed: 34 (4 ULg)
Full Text
See detailInvestigating a Bottom-up Approach for Extracting Ontologies from Urban Databases
Chaidron, Christophe; Billen, Roland ULg; Teller, Jacques ULg

in Teller, Jacques; Lee, John; Roussey, Catherine (Eds.) Ontologies for Urban Development (2007)

Detailed reference viewed: 51 (9 ULg)
See detailInvestigating a two-level dynamic estimation algorithm for large-scale electric power systems
Rousseaux, Patricia ULg; Van Cutsem, Thierry ULg; Ribbens-Pavella, Mania

in Proceedings of the 1st European Workshop on the Real Time Control of Large Scale Systems (1984)

Detailed reference viewed: 16 (0 ULg)
Full Text
Peer Reviewed
See detailInvestigating apical adverse effects of four endocrine active substances in the freshwater gastropod Lymnaea stagnalis
Giusti, Arnaud ULg; Lagadic, Laurent; Barsi, Alpar et al

in Science of the Total Environment (2014), 493

The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active ... [more ▼]

The hermaphroditic gastropod Lymnaea stagnalis is proposed as a candidate species for the development of OECD guidelines for testing of the reprotoxicity of chemicals, including endocrine active substances (EASs). Up to now, only a few putative EASs have been tested for their reproductive toxicity in this species. In this study, we investigate the effects of four EASs with different affinities to the vertebrate estrogen and androgen receptors (chlordecone as an estrogen; cyproterone acetate, fenitrothion and vinclozolin as anti-androgens) on the reproduction of L. stagnalis in a 21-day semi-static test. Testosterone and 17α-ethinylestradiol (EE2) were used as the reference compounds. The tested EASs had no significant effect on growth and survival at the tested concentration ranges (ng to μg/L). Classical reproduction endpoints (i.e., oviposition and fecundity) were not responsive to the tested chemicals, except for chlordecone and 17α-ethinylestradiol, which hampered reproduction from 19.6 μg/L and 17.6 μg/L, respectively. The frequency of polyembryonic eggs, used as an additional endpoint, demonstrated the effects of all compounds except EE2. The molecular pathways, which are involved in such reproduction impairments, remain unknown. Our results suggest that egg quality is a more sensitive endpoint as compared to other reproductive endpoints commonly assessed in mollusk toxicity tests. [less ▲]

Detailed reference viewed: 14 (1 ULg)
Full Text
Peer Reviewed
See detailInvestigating Circumferential Non-Uniformities in Throughflow Calculations using an Harmonic Reconstruction
Thomas, Jean-Philippe ULg; Léonard, Olivier ULg

in Proceedings of the ASME Turbo Expo 2008 (2008, June)

The flow field in a multistage turbomachine is very complex. It is 3D, unsteady and turbulent. Even if modern simulation tools can describe most of the flow features, the computation time needed and the ... [more ▼]

The flow field in a multistage turbomachine is very complex. It is 3D, unsteady and turbulent. Even if modern simulation tools can describe most of the flow features, the computation time needed and the extraction of useful information remain severe drawbacks to systematic use of URANS codes in a design procedure. In this context the throughflow simulation proved to be more convenient. Nevertheless the need for empiricism limits the potential of throughflow solvers. As an alternative, Admaczyck (1984) proposed three averaging operators (ensemble, time and passage) that lead to the average-passage model, linking the unsteady turbulent flow field to a steady flow field in a typical blade passage. This model involves additional terms that respectively bring back the mean effect of turbulence, deterministic unsteadiness and aperiodicity on the mean periodic flow. These terms need to be modelled; it is the closure problem. Harmonic closure, which consists in solving a linearized perturbation system in the frequency domain, revealed to be an efficient method to approximate deterministic stresses (He and Ning, 1998, Stridh, 2005, Vilmin, 2006). A fourth averaging can be performed, a circumferential averaging, giving rise to the throughflow model. Additional terms appear: the so-called circumferential stresses. It has been proven that these terms play an important role in the description of the flow (Jennions, 1986, Perrin, 1995), being at least as considerable as deterministic stresses. Introducing these terms in a throughflow simulation allows to reproduce the averaged 3D steady flow field (Simon, 2007). The aim of the present contribution is to prove that harmonic method can potentially be used to reconstruct circumferential stresses. The importance of circumferential stresses in a throughflow simulation is first highlighted on a single stage low speed compressor testcase, for viscous and non-viscous flow fields. The second step is the characterization of the frequency spectrum of the circumferential perturbation field. Next are compared the stresses associated to a Fourier reconstruction of the perturbation field with the real ones. Finally the approximated circumferential stresses are injected into a throughflow simulation tool to analyse and demonstrate their capability to reproduce a 3D averaged flow field. [less ▲]

Detailed reference viewed: 71 (18 ULg)
Full Text
Peer Reviewed
See detailInvestigating Depth-Fanout Trade-Off in WiMAX Mesh Networks
Nahle, Salim; Iannone, Luigi; Donnet, Benoît ULg et al

in 1st WEIRD Workshop on WiMAX, Wireless and Mobility (2007, May)

In the last years, Wireless Mesh Networks (WMNs) have been an emerging technology for providing cost/effective broadband Internet access. The research done insofar usually assumes that the wireless ... [more ▼]

In the last years, Wireless Mesh Networks (WMNs) have been an emerging technology for providing cost/effective broadband Internet access. The research done insofar usually assumes that the wireless backbone of a WMN is built using IEEE 802.11 technologies. Such an approach has the drawback of leading to dense and sub-optimal deployments, due to the short transmission range of this standard. Recently standardized, the WiMAX technology is supposed to transcend this limitation by a transmission range of several miles. In particular, the mesh mode of the WiMAX standard enables direct communications between subscriber stations and, hence, reduces dead zones while increasing the global throughput. In this paper, we investigate the throughput capacity of a WiMAX mesh tree. More specifically, we are interested in balancing the impact of the depth of the tree with its fanout. We provide a traffic model and evaluate the WiMAX mesh tree by simulations. [less ▲]

Detailed reference viewed: 24 (0 ULg)
Full Text
Peer Reviewed
See detailInvestigating Effect of Holidays on Daily Traffic Counts: Time Series Approach
Cools, Mario ULg; Moons, Elke; Wets, Geert

in Transportation Research Record: Journal of the Transportation Research Board (2007), 2019

In this paper, different modeling philosophies are explored in order to explain and forecast daily traffic counts. The main objectives of this study are the analysis of the impact of holidays on daily ... [more ▼]

In this paper, different modeling philosophies are explored in order to explain and forecast daily traffic counts. The main objectives of this study are the analysis of the impact of holidays on daily traffic, and the forecasting of future traffic counts. Data coming from single inductive loop detectors, collected in 2003, 2004 and 2005, were used for the analysis. The different models that were investigated showed that the variation in daily traffic counts could be explained by weekly cycles. The Box-Tiao modeling approach was applied to quantify the effect of holidays on daily traffic. The results showed that traffic counts were significantly lower for holiday periods. When the different modeling techniques were compared with respect to forecasting with a large forecast horizon, Box-Tiao modeling clearly outperformed the other modeling strategies. Simultaneous modeling of both the underlying reasons of travel, and revealed traffic patterns, certainly is a challenge for further research. [less ▲]

Detailed reference viewed: 25 (4 ULg)
Full Text
Peer Reviewed
See detailInvestigating Effect of Holidays on Daily Traffic Counts: Time Series Approach
Cools, Mario ULg; Moons, Elke; Wets, Geert

in Proceedings of the 86th Annual Meeting of the Transportation Research Board (CD-ROM) (2007)

In this paper, different modeling philosophies are explored in order to explain and forecast daily traffic counts. The main objectives of this study are the analysis of the impact of holidays on daily ... [more ▼]

In this paper, different modeling philosophies are explored in order to explain and forecast daily traffic counts. The main objectives of this study are the analysis of the impact of holidays on daily traffic, and the forecasting of future traffic counts. Data coming from single inductive loop detectors, collected in 2003, 2004 and 2005, were used for the analysis. The different models that were investigated showed that the variation in daily traffic counts could be explained by weekly cycles. The Box-Tiao modeling approach was applied to quantify the effect of holidays on daily traffic. The results showed that traffic counts were significantly lower for holiday periods. When the different modeling techniques were compared with respect to forecasting with a large forecast horizon, Box-Tiao modeling clearly outperformed the other modeling strategies. Simultaneous modeling of both the underlying reasons of travel, and revealed traffic patterns, certainly is a challenge for further research. [less ▲]

Detailed reference viewed: 23 (2 ULg)
Peer Reviewed
See detailInvestigating Expertise, Flexibility and Resilience in Socio-technical Environments : A Case Study in Robotic Surgery.
Nyssen, Anne-Sophie ULg; Blavier, Adelaïde ULg

in Hollnagel, Erik; Braithwaite, Jeffrey; Wears, Robert (Eds.) Resilient Health Care (2013)

Detailed reference viewed: 26 (6 ULg)
Full Text
Peer Reviewed
See detailInvestigating Hardy-Weinberg equilibrium in case-control or cohort studies or meta-analysis.
Ziegler, Andreas; Van Steen, Kristel ULg; Wellek, Stefan

in Breast Cancer Research and Treatment (2011), 128(1), 197-201

Yu et al. (Breast Cancer Res Treat 117:675-677, 2009) recently stated that testing for deviation from Hardy-Weinberg equilibrium (HWE) is necessary to identify systematic genotyping errors in case-control ... [more ▼]

Yu et al. (Breast Cancer Res Treat 117:675-677, 2009) recently stated that testing for deviation from Hardy-Weinberg equilibrium (HWE) is necessary to identify systematic genotyping errors in case-control studies. They criticized a meta-analytic study for the deviation from HWE in the case group of one study. The aim of this article is twofold. First, we derive recommendations on how to test for deviations from HWE in different study designs. Second, we develop a meta-analytic framework for assessing compatibility with HWE or measuring deviation from HWE. The authors sketch the possible reasons behind deviation from HWE and provide guidelines for proper investigation of HWE deviations in different study designs. The authors argue that the standard HWE chi(2) lack of fit test is logically flawed and provide a logically unflawed approach for measuring deviation from HWE using confidence intervals. The proposed method is applicable to meta-analyses of both case-control or cohort association studies. The proposed approach is illustrated using the meta-analysis criticized by Yu et al. Heterogeneity between studies can be assessed. The critique of Yu et al. to the article of Frank et al. (Breast Cancer Res Treat 111:139-144, 2008) can be refuted. Even more, validity of HWE can be proven for the pooled control sample. The authors advocate the use of a confidence interval-based approach to assess HWE. The latter should only be investigated in control populations. In multicenter studies or meta-analysis, deviation from HWE should be analyzed using a meta-analytic approach. [less ▲]

Detailed reference viewed: 27 (5 ULg)
See detailInvestigating iron and organic matter incorporation in growing sea ice
Janssens, J.; Delille, Bruno ULg; de Jong et al

Conference (2014, March)

High concentration of exopolysacharides (EPS) and iron have been found in sea ice surrounding the Antarctic continent. However, the mechanisms leading to that enrichment remain unclear. Scavenging of iron ... [more ▼]

High concentration of exopolysacharides (EPS) and iron have been found in sea ice surrounding the Antarctic continent. However, the mechanisms leading to that enrichment remain unclear. Scavenging of iron by organic matter in seawater and entrainment during sea ice formation are thought to be responsible for the accumulation of iron in sea ice. EPS could also play a role in the iron passive chelative scavenging process in sea ice and in the increase of iron bioavailability. Our study investigates the processes responsible for the accumulation of iron (dissolved, particulate and total dissolvable iron), EPS, dissolved and particulate organic matter, macro-nutrients (silicic acid, nitrate and nitrite, phosphoric acid and ammonium), chlorophyll a and sea ice algae in young sea ice during an Australian-lead spring voyage off East Antarctica (SIPEX II September – November 2012) and a German-lead winter voyage to the Weddell Sea (AWECS June – August 2013). We used a combination of field- (“in situ”) and laboratory- based sea ice growth time-series experiments. In addition different types of newly formed sea ice as pancake ice, grey ice, frost flowers and slush were collected during both voyages as a means to compare and validate the experimental data. To our knowledge, this is the first report on the biogeochemical properties of newly formed Antarctic pack ice samples in the winter. Ice temperature, salinity and textures are also presented to support the biogeochemical observations at the onset of sea ice formation. [less ▲]

Detailed reference viewed: 54 (1 ULg)
See detailInvestigating Prostaglandin E2 activation of the p38 pathway of oesophageal squamous cell carcinoma
Rambout, Xavier ULg

Master's dissertation (2008)

Background, aim and objectives: Oesophageal squamous cell carcinoma (OSCC) is an endemic disease. Epidemiologic studies driven by investigation of Sammon in a region with one of the highest prevalence ... [more ▼]

Background, aim and objectives: Oesophageal squamous cell carcinoma (OSCC) is an endemic disease. Epidemiologic studies driven by investigation of Sammon in a region with one of the highest prevalence, linked a predisposition to develop OSCC to a high consumption of maize via reflux disease and chronic oesophagitis. In that context, it was postulated that prostaglandin E2 (PGE2), a hormone derived from a main component of maize, continuously triggers activation of proliferation and inflammation pathways. This work aimed at assessing the role of p38, a mitogen-activated protein kinase (MAPK), in the potential of PGE2 to trigger cellular proliferation, transcription and expression of proliferative (Cyclin D1) and inflammatory (IL-6) mediators in a human epithelial oesophageal cell line (Het1a). Methods: The proliferation potential of PGE2 via p38 was assessed by MTT assay on Het1a. The effect of H2O2 treatments was also assessed as a positive control. Then, RNA and protein samples were extracted from that cell line previously PGE2-treated. Transcription and expression profiles were studied over time respectively by quantitative polymerase chain reaction (qPCR) and western blot. The role of p38 was assessed by addition of a specific inhibitor, SB203580, to the cells under investigation. Results and Discussion: It was shown that PGE2 alone could not trigger proliferation of the Het1a cell line. Though, the effect of p38 might be positive. Acute H2O2 treatments turned out encouraging in the development of a model of p38 activation. Regulation of Cyclin D1 and IL-6 transcription was suggested to occur through PGE2 and via the p38 pathway. The Cyclin D1 and IL-6 transcripts were respectively overexpressed and downregulated in a bimodal manner, the second peak relying exclusively on p38 activation. Both observations could be supported by a positive feedback theory involving cyclooxygenase (COX)-2. Conclusions: Even though PGE2 was shown not to be sufficient to promote Het1a proliferation, regulation of Cyclin D1 and IL-6 transcription via p38 was observed. Furthermore, the expression profile might support the Sammon-Pink theory. [less ▲]

Detailed reference viewed: 13 (0 ULg)
Full Text
Peer Reviewed
See detailInvestigating relationships between Landsat ETM+ data and LAI in a semi-arid grassland of northwest China
Lu, L; Li, X; Ma, M G et al

in Geoscience and Remote Sensing Symposium, 2004. Proceedings IGARSS '04. (2004)

Detailed reference viewed: 12 (0 ULg)