Un passage de l'Évangile selon Matthieu illustré : O.Moen inv. 631

Conference given outside the academic context (2012)

Communication présentée au cours de "Copte II" dirigé par A. Delattre, tirée de l'article "Un passage de l'Évangile selon Matthieu illustré : O.Moen inv. 631", à paraître dans la Chronique d'Égypte (voir ... [more ▼]

Communication présentée au cours de "Copte II" dirigé par A. Delattre, tirée de l'article "Un passage de l'Évangile selon Matthieu illustré : O.Moen inv. 631", à paraître dans la Chronique d'Égypte (voir : http://hdl.handle.net/2268/127795). [less ▲]

Race cycling: biological evolution

in Meeusen, R; Duchateau, J; Roelands, B (Eds.) et al Book of Abstracts of the 17th annual Congress of the ECSS (2012, July)

Introduction: The metabolic and cardiac impact of a cycling effort on blood biology is not very well described in the literature. We aimed to measure the concentration of different biomarkers (cardiac and ... [more ▼]

Introduction: The metabolic and cardiac impact of a cycling effort on blood biology is not very well described in the literature. We aimed to measure the concentration of different biomarkers (cardiac and metabolic) released during an international cycling race. Materials and methods: Venous blood samples of 15 young men (25.1 ± 6.4 y.o.) were collected just before (T1), just after (T2), 3 hours (T3) after an international cycling race of 179.6 kilometers in Belgium for the determination of cardiac and metabolic biomarkers: red blood cell (RBC), haemoglobin (HgB), creatinin (Cr), highly sensitive troponin T (hsTnT), myoglobin (MYO) and NT-proBNP. All automated assays were performed according to the manufacter’s specifications. For the statistical analysis, an Anova calculated with the Statistica Software version 9.1 was used. Results and discussions: RBC and HgB levels varied significantly between T0 and T3 (respectively p=0.0026, and p=0.002). Cr concentration also varied significantly between all times (T0-T1:p<0.0001, T1-T3:p=0.0326 and T0-T3 p=0.0001). These changes might be related to renal flow depletion during exercice. MYO increased significantly between T0 and T1 (p<0.0001), but quickly decreased between T1 and T3, however the T3 level stay higher than T0 (p=0.014). The stress delivered from the physical activity performed during the race induced a significant variation of hsTnT which increased significantly between T0 and T1 (p<0.0001) and stayed higher 3 hours after the end of the exercise (T0-T3: p<0.0001). The intense exercise delivery by the race induced a significant variation of NT-proBNP, that followed the same kinetic of hsTnT but in smaller proportion. We noticed variations statistically significant between T0 and T1 and between T0 and T3 for NT-proBNP. These increases of cardiac biomarkers were significant but reasonable and could not allow us to talk about cellular necrosis or irreversible injury. Conclusion: Our results show that stress generated by a cycling race could be the cause for the different metabolic variations observed. Troponin T stays without a doubt the most specific marker for stress related to myocardial tissue. Its increase can then be considered as being of interest. [less ▲]

A “start to swim” program for health-enhancement purpose: a Delphi study

Conference (2012, July)

Introduction Popularity of “start to run” or “start to cycle” programs increases with the evidence that regular physical activity contributes to the prevention and management of a wide range of chronic ... [more ▼]

Introduction Popularity of “start to run” or “start to cycle” programs increases with the evidence that regular physical activity contributes to the prevention and management of a wide range of chronic diseases (Rippe and Angelopoulos, 2010). Nevertheless, start to swim programs could lead to even more health-enhancing outcomes (Chase et al., 2008). The aim of this study was to obtain a “start to swim” model program by means of a two-round Delphi study. Methods In the first round, 10 key-experts in sport physiology (n=4) or in swimming coaching (n=6) outlined possible relevant components of the “start to swim” program in a semi-structured interview. Initial exclusion criterion, program set-up, program key principles, program progression and final goals were interrogated. Then, a facilitator provided an anonymous summary of the experts’ suggestions from the previous round as well as the arguments they provided for their choice. In the second round, experts were asked to comment on this summary before providing a final form to this program. Results After two rounds, the experts agreed on a collective and coached intervention with 2 sessions per week and a progressive replacing of the coach by a group leader during a 4 months program. People without medical contraindication and able to swim 25 meters could take part to this program. The final goal-setting is personal and based on each individual progression and motivation. Sessions are endurance-oriented and divided between traditional swimming sessions and diversified aquatic activities. In order to support this active lifestyle in a long-term basis, referring to swimming clubs or other aquatic activities associations are performed by the coach at the end of the program. Discussion The start to swim program take into consideration behavioural and social aspects necessary for a successful adoption and maintenance of physical activity (Khan et al, 2002). Consistent with previous findings, a group-based program (Cox et al., 2008) with individually adapted-goals (Marcus and Forsyth, 2003) could lead to a long-term adherence to exercise. Future studies should include systematic evaluation of the “start to swim” program before translation into the community. [less ▲]

Understanding angiogenesis through novel epigenetic modulators

Scientific conference (2012, June 22)

DNA methylation and histone deacetylation are two key epigenetic modifications that play central role in regulation of gene expression. Several studies have shown that histone deacetylases (HDAC) and DNA ... [more ▼]

DNA methylation and histone deacetylation are two key epigenetic modifications that play central role in regulation of gene expression. Several studies have shown that histone deacetylases (HDAC) and DNA methyltransferases (DNMT) inhibitors are potent anti-angiogenic compounds. Though combination of HDAC and DNMT inhibitors are now being examined in clinical trials of hematological malignancies, little work has been done to understand the effect of this combination on physiological and tumoral angiogenesis. We have designed and tested a family of twin drugs with intrinsic HDAC and DNMT inhibitory activities in relevant models of angiogenesis in vitro (Human Umbilical Vein Endothelial Cells – HUVEC and aortic ring) and in vivo (chick chorioallantoic membrane and Zebrafish). We have identified a lead compound having quantifiable anti-angiogenic effect without cytotoxicity affecting global histone acetylation and DNA methylation levels. In order to elucidate its anti-angiogenic mechanism, we characterized gene expression pattern simultaneously with the methylation profile of HUVEC cells treated with the lead compound and reference epigenetic modulators. This approach based on parallel microarray analyses permitted us to underscore a list of genes exclusively affected by the lead compound but not by other HDAC or DNMT inhibitors. These genes were then analyzed using the Ingenuity Pathway software revealing potential involvement of a subset of genes in angiogenesis. Our present work is focused on exploring the exact role of these genes on angiogenesis using RNA silencing and vectors cloned with genes of interest. We are using these novel epigenetic modulators as a tool to understand the regulatory mechanism of angiogenesis and to develop effective approaches to treat cancer. [less ▲]

Distribution and origin of suspended matter and organic carbon pools in the Tana River Basin, Kenya

in Biogeosciences (2012), 9

We studied patterns in organic carbon pools and their origin in the Tana River Basin (Kenya), in February 2008 (dry season), September–November 2009 (wet season), and June–July 2010 (end of wet season ... [more ▼]

We studied patterns in organic carbon pools and their origin in the Tana River Basin (Kenya), in February 2008 (dry season), September–November 2009 (wet season), and June–July 2010 (end of wet season), covering the full continuum from headwater streams to lowland mainstream sites. A consistent downstream increase in total suspended matter (TSM, 0.6 to 7058 mg l−1) and particulate organic carbon (POC, 0.23 to 119.8 mg l−1) was observed during all three sampling campaigns, particularly pronounced below 1000m above sea level, indicating that most particulate matter exported towards the coastal zone originated from the mid and low altitude zones rather than from headwater regions. This indicates that the cascade of hydroelectrical reservoirs act as an extremely efficient particle trap. Although 7Be / 210Pbxs ratios/age of suspended sediment do not show clear seasonal variation, the gradual downstream increase of suspended matter during end of wet season suggests its origin is caused by inputs of older sediments from bank erosion and/or river sediment resuspension. During wet season, higher TSM concentrations correspond with relatively young suspended matter, suggesting a contribution from recently eroded material.With the exception of reservoir waters, POC was predominantly of terrestrial origin as indicated by generally high POC : chlorophyll a (POC : Chl a) ratios (up to 41 000). Stable isotope signatures of POC ( 13CPOC) ranged between −32 and −20‰and increased downstream, reflecting an increasing contribution of C4-derived carbon in combination with an expected shift in 13C for C3 vegetation towards the more semi-arid lowlands. 13C values in sediments from the main reservoir (−19.5 to −15.7 ‰) were higher than those found in any of the riverine samples, indicating selective retention of particles associated with C4 fraction. Dissolved organic carbon (DOC) concentrations were highest during the end of wet season (2.1 to 6.9 mg l−1), with stable isotope signatures generally between −28 and −22 ‰. A consistent downstream decrease in % organic carbon (%OC) was observed for soils, riverine sediments, and suspended matter. This was likely due to better preservation of the organic fraction in colder high altitude regions, with loss of carbon during downstream spiraling. 13C values for soil and sediment did not exhibit clear altitudinal patterns, but values reflect the full spectrum from C3-dominated to C4-dominated sites. Very low ratios of organic carbon to mineral surface area (OC : SA) were found in reservoir sediments and suspended matter in the lower Tana River, indicating that these are stable OC pools which have undergone extensive degradation. Overall, our study demonstrates that substantial differences occur in both the quantities and origin of suspended sediments and organic carbon along the river profile in this tropical river basin, as well as seasonal differences in the mechanisms causing such variations. [less ▲]

Can performance-based financing be used to reform health systems in developing countries?

in Bulletin of the World Health Organization (2011), 89(9), 695-698

Over the past 15 years, performance-based financing has been implemented in an increasing number of developing countries, particularly in Africa, as a means of improving health worker performance. Scaling ... [more ▼]

Over the past 15 years, performance-based financing has been implemented in an increasing number of developing countries, particularly in Africa, as a means of improving health worker performance. Scaling up to national implementation in Burundi and Rwanda has encouraged proponents of performance-based financing to view it as more than a financing mechanism, but increasingly as a strategic tool to reform the health sector. We resist such a notion on the grounds that results-based and economically driven interventions do not, on their own, adequately respond to patient and community needs, upon which health system reform should be based. We also think the debate surrounding performance-based financing is biased by insufficient and unsubstantiated evidence that does not adequately take account of context nor disentangle the various elements of the performance-based financing package. [less ▲]

The partial proportional odds model in the analysis of

Conference (2010, May 18)

Exploration of perceptual and motor inhibition in children with traumatic brain injury

Poster (2010)

Inhibitory control, which is commonly considered as one of the essential components of executive functions (Barkley, 1997; Miyake et al., 2000), is not considered as an unitary construct (for example ... [more ▼]

Inhibitory control, which is commonly considered as one of the essential components of executive functions (Barkley, 1997; Miyake et al., 2000), is not considered as an unitary construct (for example, Friedman & Miyake, 2004; Nassauer & Halperin, 2003). In this study, perceptual and motor inhibition were studied in 12 children who had sustained a moderate to severe traumatic brain injury and in 24 matched control children, with the Conflict Resolution task (Nassauer & Halperin, 2003). The perceptual inhibition task required the children to respond to the direction of an arrow while ignoring the conflicting arrow location. In the motor inhibition task, the subject had to press a key corresponding to the opposite direction of a centrally located arrow. Direct comparisons of inhibition performances between traumatic brain injury children and matched controlled subjects showed a specific and disproportionate impairment for motor inhibition (compared to perceptive inhibition) in the traumatic brain injury children, suggesting that inhibition processes might be differentially impaired after traumatic brain injury in children. Interestingly, impairments in behavioural inhibition in day-to-day activities (as reported by the parents), was found to strongly correlate with both types of inhibition. [less ▲]

Analysis of ordinal longitudinal data

Conference (2007, November 24)

Modélisation de la pyrolyse dans un gazogène à lit fixe

Master's dissertation (2005)

Choix d'un modèle de pyrolyse pour un gazogène à lit fixe. Dans un premier temps une résolution analytique a été effectuée. Des corrélations de dégagement de gaz ont été élaborées et implémentées dans une ... [more ▼]

Choix d'un modèle de pyrolyse pour un gazogène à lit fixe. Dans un premier temps une résolution analytique a été effectuée. Des corrélations de dégagement de gaz ont été élaborées et implémentées dans une modélisation du gazogène par éléments finis (CFD via Fluent). [less ▲]