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See detailFrom photons to biomass in green microalgae: fluorimetric and oxymetric studies on the regulation of photosynthetic electron transport
de Marchin, Thomas ULg

Doctoral thesis (2015)

Analyzing the photosynthetic performances of microalgae has become an important topic in view of the ecological importance of these microorganisms and of the growing field of their biotechnological ... [more ▼]

Analyzing the photosynthetic performances of microalgae has become an important topic in view of the ecological importance of these microorganisms and of the growing field of their biotechnological applications. In this thesis, we developed methods which allow effective use of fluorescence and oxygen experimental signals for a more complete analysis of the functioning of the photosynthetic apparatus of green microalgae under different conditions. We applied these methods to analyze the adaptations of the photosynthetic apparatus under selected conditions, especially regarding CO2 supply. In the first part of this work, we applied a fluorescence-based method for determining the PSII antenna size based on the kinetics of the fast chlorophyll a fluorescence transient in presence of DCMU (or DCMU Fluorescence Rise). We then performed a detailed analysis of the different phases of this transient which are associated with different types of PSII formerly described as PSIIalpha and PSIIbeta (PSII heterogeneity). Our results on PSII heterogeneity during a transition from state 2 to state 1 in Chlamydomonas reinhardtii showed for the first time in vivo that this transition correlates with a conversion of PSIIbeta to PSIIalpha. We also discuss the possible relationships between PSIIalpha and PSIIbeta and the PSII mega-, super- and core- complexes described by biochemical studies. In photoautotophic atmospheric conditions, microalgae often have to deal with limited CO2 availability. The unicellular green algae Chlamydomonas reinhardtii can adapt to low CO2 concentration with the inorganic carbon concentration mechanism (CCM). This has been extensively studied in the past. However, other functional adaptations of the photosynthetic apparatus to CO2 limitation have been much less studied. In the second part of this work, we used combined fluorescence-based electron transport and oxygen measurements to evaluate the responses to low and high CO2 in Chlamydomonas reinhardtii grown in photobioreactors at different light intensities. We developed a method to rationalize the relationship between the apparent quantum yields of oxygen evolution and of electron transport at PSII while taking into account the variations in the proportion of energy absorbed by PSII. We used this relationship as a tool to evidence a significant O2-dependent alternative electron transport in low CO2 acclimated cells. We showed that this alternative electron transport can represent up to 60% of the total electron transport in low CO2 cells even upon removal of the CO2 limitation by bicarbonate addition. In contrast, no significant alternative electron transport was detected in high CO2 cells. We suggest that the alternative electron transport to O2 observed in low CO2 cells represents an adaptation that could help to meet the higher ATP demand for the concentration of CO2 by the CCM. In contrast, in high CO2 conditions, the absence of the CCM would reduce the need for ATP and thus the need for electron transport to O2. Using mutants and inhibitors, we studied the involvement of known O2-dependent electron sinks such as the mitochondrial cytochrome and alternative oxidase pathways and also of chlororespiration in this light-dependent O2 uptake and we found no evidence for the involvement of any of these processes. The alternative electron transport was even higher in a mitochondrial mutant devoid of complexes I and III and we suggest that this alternative electron transport could compensate for the absence of mitochondrial ATP synthesis in this mutant. By elimination, our results suggest that the alternative electron transport to O2 evidenced here could be driven by a Mehler-type reaction although we did not find direct evidences for increased Mehler-type activity in low CO2 cells. Additionally from fluorescence measurements performed directly in the cultures, we concluded that low CO2 cells had a lowest PSII photosynthetic efficiency and developed strong qE NPQ. Our results indicate that Chlamydomonas reinhardtii is capable to induce an ample thermal dissipation of excitation energy and the extent of this process is influenced essentially by the CO2 availability. In contrast with results obtained in previous studies, low temperature fluorescence spectra showed that in high light, high CO2 cells were characterised by a higher proportion of light energy absorbed by PSI compared to low CO2 cells. This was accompanied by a decrease of PSII antenna size as shown by DCMU-FR measurements. These findings are discussed in relation with the conflicting theories concerning the role of state transitions in the regulation of the cyclic electron transport around PSI. Our results support the idea that CEF is regulated by the redox state of the chloroplast rather than by state transitions. Over the last decades, microalgae have been increasingly studied because of their potential applications in industry. Despite a growing interest in microalgae mass cultures, the majority of studies on microalgae have been carried out at a laboratory scale and only few studies have addressed the question of photosynthetic adaptations in mass cultures. It is well known that CO2 addition increases the growth rate of microalgae and for this reason, some mass microalgae cultures are CO2 supplemented. Among the studies on microalgae mass culture, as far as we know, none directly compared high CO2 (CO2 supplemented air) and low CO2 (air) conditions. In the last part of our work, two outdoor open thin-layer cascade systems operated as batch cultures with the alga Scenedesmus obliquus were used to compare the productivity and photosynthetic adaptations in control and CO2 supplemented cultures in relation with the outdoor light irradiance. We found that the culture productivity was limited by CO2 availability beyond a threshold of daily irradiance. In the CO2 supplemented culture, we obtained a productivity of up to 25 g dw.m-2.day-1 and found a photosynthetic efficiency of 2.6%. Fluorescence and oxygen evolution measurements showed that ETR and oxygen evolution light saturation curves, as well as alternative electron transport were similar in algal samples from both cultures when the CO2 limitation was removed. In contrast, we found that CO2 limitation conducted to a decreased PSII photochemical efficiency and an increased light-induced heat-dissipation in the control culture compared to the CO2 supplemented culture. These features may contribute to the lower productivity observed in absence of CO2 supplementation in outdoor mass cultures of Scenedesmus obliquus. [less ▲]

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See detailFrom polyester grafting onto POSS nanocage by ring-opening polymerization to high performance polyester/POSS nanocomposites
Goffin, Anne-Lise; Duquesne, Emmanuel; Raquez, Jean-Marie et al

in Journal of Materials Chemistry (2010), 20

Polyester-grafted polyhedral oligomeric silsesquioxane (POSS) nanohybrids selectively produced by ring-opening polymerization of epsilon-caprolactone and L,L-lactide (A.-L. Goffin, E. Duquesne, S. Moins ... [more ▼]

Polyester-grafted polyhedral oligomeric silsesquioxane (POSS) nanohybrids selectively produced by ring-opening polymerization of epsilon-caprolactone and L,L-lactide (A.-L. Goffin, E. Duquesne, S. Moins, M. Alexandre, Ph. Dubois, Eur. Polym. Journal, 2007, 43, 4103) were studied as ‘‘masterbatches’’ by melt-blending within their corresponding commercial polymeric matrices, i.e., poly(epsilon-caprolactone) (PCL) and poly(L,L-lactide) (PLA). For the sake of comparison, neat POSS nanoparticles were also dispersed in PCL and PLA. The objective was to prepare aliphatic polyester-based nanocomposites with enhanced crystallization behavior, and therefore, enhanced thermo-mechanical properties. Wide-angle X-ray scattering and transmission electron microscopy attested for the dispersion of individualized POSS nanoparticles in the resulting nanocomposite materials only when the polyester-grafted POSS nanohybrid was used as a masterbatch. The large impact of such finely dispersed (grafted) nanoparticles on the crystallization behavior for the corresponding polyester matrices was noticed, as evidenced by differential scanning calorimetry analysis. Indeed, well-dispersed POSS nanoparticles acted as efficient nucleating sites, significantly increasing the crystallinity degree of both PCL and PLA matrices. As a result, a positive impact on thermo-mechanical properties was highlighted by dynamic mechanical thermal analysis. [less ▲]

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See detailFrom practice-based game research to game design as a cultural technique
Werning, Stefan; Kamp, Michiel; De Smale, Stephanie et al

Conference (2016, August 02)

Panel : de Smale, Stephanie: Game Essays in the Digital Humanities : The paper addresses the use of prototyping for creating game essays, the applicability of game essays within a digital humanities ... [more ▼]

Panel : de Smale, Stephanie: Game Essays in the Digital Humanities : The paper addresses the use of prototyping for creating game essays, the applicability of game essays within a digital humanities framework and the challenges and opportunities of taking a research-centric rather than a player-centric perspective on game design. Kamp, Michiel: Parameters of Musical Interaction in Games : The paper proposes exploring game music by experimenting with the ways in which the soundtrack responds to game states and player interaction beyond adapting analytical techniques borrowed from film music studies, like masking or replacing parts of the soundtrack. Hurel, Pierre-Yves: Amateur Game Design as Reflexive Practice : The paper presents an ethnographic perspective on amateur game design with a particular focus on the use of distinct tools such as RPG Maker and their affordances for reflective practice. Werning, Stefan: From Analytical Play to Analytical Game Design : The paper outlines the transition from intrinsically analytical aspects in (meta-)ludic practices (speed-running, in-game photography, cosplaying, let’s playing etc.) to game design as a cultural technique, i.e. a mode of expression and civic engagement in a gamified society. [less ▲]

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See detailFrom propaganda to commemoration: reworking the national narrative.
Hamers, Jérémy ULg; Van Cauwenberge, Geneviève ULg

in Rethinking History (2014), 18(3), 423-437

In Belgium, memories of the World War I have contributed to the production and the perpetuation of a fractured national narrative. While the official narration emphasizes the unity of the Belgian state ... [more ▼]

In Belgium, memories of the World War I have contributed to the production and the perpetuation of a fractured national narrative. While the official narration emphasizes the unity of the Belgian state and glorifies the heroism of Belgian soldiers acting as a unified force against the German invader, a counter-narrative presents the Flemish soldiers as victims who were used as cannon fodder by the French-speaking commanding elite. In the immediate postwar period, newsreels largely reinforced the image of a national unity during the Great War. Ten years later, however, cinema took an active part in the production of a counter-memory. Met onze jogens aan den IJzer/With Our Troops on the Yser (Clemens De Landtsheer, 1928), a Flemish film, is a key work in this regard. This article first examines the narratives and formal strategies the film resorts to in order to forcefully deconstruct the patriotic narrative and to forge a ‘Flamingant,’ Flemish activist collective memory. It subsequently analyzes more recent Frenchspeaking documentary film projects aiming to commemorate the memory of the Great War. Lacking any overt problematization of their relationship to the Flemish separatist narrative, the documentaries are still shaped by it. Indeed, they either attempt to overcome it by reinforcing Belgium’s sense of national identity or to counterbalance it by putting forward a regional narrative that specifically revives the French-speaking Belgians’ memory of the War. [less ▲]

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See detailFrom psychometric research to implementation and back: selected examples
Magis, David ULg

Conference (2015, February 13)

Current psychometric research is most often supported by computer software. New research perspectives often imply intensive simulation studies to validate the tested theories or hypotheses, and therefore ... [more ▼]

Current psychometric research is most often supported by computer software. New research perspectives often imply intensive simulation studies to validate the tested theories or hypotheses, and therefore require accurate implementation as e.g., R packages. However, it may happen that unexpected psychometric phenomena are detected almost accidentally, through such implementations with basically totally different purposes. This talk will illustrate this phenomenon by means of two recent examples from item response theory (IRT) with polytomous models: (a) the equivalence between the weighted likelihood estimator (WLE) and the Bayes modal estimator with Jeffreys prior, and (b) the relationships between observed and expected information functions. Rather than focusing on the technical details, the purpose of this talk is to highlight how the results were identified first through R implementation, then confirmed by theoretical derivations. The talk concludes by advocating for flexible and stable open-source implementations (such as R packages) to support current and ongoing psychometric research. [less ▲]

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See detailFrom RE-211 to RE-123. How to control the final microstructure of superconducting single-domains
Cloots, Rudi ULg; Koutzarova, T.; Mathieu, J.-P. et al

in Superconductor Science and Technology (2005), 18(3), 9-23

This paper reviews the usual techniques for producing YBCO-type single-domains and the microstructure of the as-obtained samples. The problems of seed dissolution and parasite nucleations are discussed in ... [more ▼]

This paper reviews the usual techniques for producing YBCO-type single-domains and the microstructure of the as-obtained samples. The problems of seed dissolution and parasite nucleations are discussed in detail. The formation of microstructural defects, such as pores and cracks, is examined. An important part of this review is devoted to the study of the influence of RE-211 particles (RE2BaCuO5 where RE denotes Y, Yb, Nd, Sm, Dy, Gd, Eu or a mixture of them. Generally Nd4Ba2Cu 2O10 is preferred to Nd2BaCuO5) for the microstructure and properties of RE-Ba-Cu-O single-domains. Pushing/trapping theory is described in order to explain the spatial distribution of RE-211 particles in the RE-123 ((RE)Ba2Cu3O7-δ) monoliths. The formation of RE-211-free regions is discussed. Different ways to limit the RE-211 coarsening are reviewed. Microstructural defects in the RE-123 matrix caused by the RE-211 particles are presented. It is also shown that RE-211 particles play a significant role in the mechanical properties of single-domain samples. We finish this review by discussing the infiltration and growth process as a good technique to control the microstructure. © 2005 IOP Publishing Ltd. [less ▲]

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See detailFrom reactive intervention to proactive prevention: The evolution of occupational dysphonia
Epstein, Ruth; Remacle, Angélique ULg; Morsomme, Dominique ULg

in SIG 3 Perspectives on Voice and Voice Disorders (2011), 21

Voice clinicians long have been aware of the concept of professional voice users: individuals who work in professions that have a higher incidence and increased risk for voice disorders. This realization ... [more ▼]

Voice clinicians long have been aware of the concept of professional voice users: individuals who work in professions that have a higher incidence and increased risk for voice disorders. This realization, coupled with the documented impact of work-related dysphonia on the economy, has resulted in a growing international interest in developing occupational health benchmarks for voice use, similar to other standards developed for work-related factors such as noise-induced hearing loss. In this article, we review current perspectives and examine some issues related to occupational vocal health. [less ▲]

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See detailFrom renewable vegetables resources to microorganisms: new trends in surfactants
Deleu, Magali ULg; Paquot, Michel ULg

in Comptes Rendus Chimie (2004), 7(6-7), 641-646

Surfactants are an important class of chemical products in view of the volumes sold and of their great variety of applications. Biosurfactants produced by microorganisms, and surfactants derived from ... [more ▼]

Surfactants are an important class of chemical products in view of the volumes sold and of their great variety of applications. Biosurfactants produced by microorganisms, and surfactants derived from renewable raw materials are coming progressively onto the market. Considering their many properties and large field of applications, their development needs extensive cooperation across disciplines (chemists, physicochemists, biologists, product developers, formulators...) in order to fully characterize them (chemical structure, surface activity, self assembly properties...) and identify their potential uses. New value adding opportunities will result from the identification of specific activities of biosurfactants, especially in relation with their biological effects (antibiotic, antifungal, insecticide, antiviral and antitumoral agent, immunomodulator or specific toxins and enzyme inhibitors). (C) 2004 Academie des sciences. Published by Elsevier SAS. All rights reserved. [less ▲]

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See detailFrom reporting incidents in a radiation therapy department to enterprise risk management (ERM) based on the European Foundation for Quality Management philosophy (EFQM)
COUCKE, Philippe ULg; BOGA, Deniz ULg; LENAERTS, Eric ULg et al

in International Journal of Healthcare Technology & Management (2014), 7(2), 127-131

The radiation therapy department (RTD) initiated in 2009 a policy of open and transparent reporting of events not harming (near incidents) and potentially harming patients (incidents and accidents). This ... [more ▼]

The radiation therapy department (RTD) initiated in 2009 a policy of open and transparent reporting of events not harming (near incidents) and potentially harming patients (incidents and accidents). This approach was immediately followed by the leader’s decision to engage towards the European Foundation for Quality Management (EFQM) excellence model. The EFQM approach structured the journey of the RTD to enterprise risk management. We intend to demonstrate in the five main fields of the EFQM approach (leadership, policy and strategy, people/personnel, partnership and resources, processes), how the journey to continuous improvement in quality and safety did evolve and was accelerated in RTD. The assessment made by external evaluators evolved from a minimum of 90 points (basic requirement for level 1 in 2009) to a at least 180 points (basic requirement for level 2 in 2011), to reach 400 points in 2013 (270 required for level 3 and 450 required for level 4). [less ▲]

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See detailFrom resource to process efficiency. Educating a new generation of georesources engineers
Pirard, Eric ULg; Fiorentino, Rosalia ULg

in Mazijn, Bernard (Ed.) Proceedings 8th Conference on Engineering Education for Sustainable Development (2016, September)

Even though the Circular Economy paradigm clearly puts the emphasis on recycling, it is essential to understand that we will still need for decades to explore and find resources in the earth crust. Mining ... [more ▼]

Even though the Circular Economy paradigm clearly puts the emphasis on recycling, it is essential to understand that we will still need for decades to explore and find resources in the earth crust. Mining is vital to feed the loop and make sure enough metals and minerals are made available to society. But, mining is also one of the most challenging industrial operations when it comes to sustainability objectives. A modern education in mineral resources engineering must build on a strong technical background but give students the opportunity to confront their knowledge with societal needs and responsibilities. The EMerald Erasmus Mundus Master program in Georesources Engineering was set up by four leading European universities with the clear objective to educate responsible professionals who will be actors of sustainable solutions. Therefore, the University of Lorraine, the Lulea Technical University, the TU Bergakademie Freiberg and the University of Liege (coordinator) designed a unique curriculum bridging the traditional gap between natural sciences and engineering, encompassing the valley too often separating the industrial operators from the stakeholders of a mining project. The program offers a unique blend of courses from geology to mineral processing with the aim to familiarize students with the most advanced tools for improving the efficiency of processes. Field trips and industrial visits are a key component of this program as are the non-technical seminars delivered by professionals (lawyers, entrepreneurs, NGO leaders, etc.). Evaluation is often based on written reports, documentary research and short oral presentations to make sure students acquire the indispensable soft skills for efficient communication on environmental and societal issues linked to the impact of extractive activities. Internships and hands-on practices on pilot platforms or laboratory equipments are absolutely essential to reach the highest standards and meet the objectives of the master program. This is costly and can only be maintained thanks to the strong presence of the participating universities in research programs. All four universities are core partners of the EIT Raw Materials knowledge innovation community. This gives an additional leveraging effect when it comes to the education of young entrepreneurs with a strong sustainability mindset. [less ▲]

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See detailFrom Rome to the Southern Netherlands: Spectacular sceneries to celebrate the canonization of Ignatius of Loyola and Francis Xavier
Delfosse, Annick ULg

in DeSilva, Jennifer Mara (Ed.) The Sacralization of Space and Behavior in the Early Modern World (2015)

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See detailFrom Root Zone Modelling To Regional Forecasting Of Nitrate Concentration In Recharge Flows - The Case Of The Walloon Region (Belgium)
Sohier, Catherine ULg; Degre, Aurore ULg; Dautrebande, Sylvia

in Journal of Hydrology (2009), 369(3-4), 350-359

In order to model the nitrate concentration of the recharge water in a spatially distributed way for the agricultural areas of the Walloon Region of Belgium, the EPIC model was first adapted to the ... [more ▼]

In order to model the nitrate concentration of the recharge water in a spatially distributed way for the agricultural areas of the Walloon Region of Belgium, the EPIC model was first adapted to the specific soil description by modifying the reservoir sizes. It was also adapted to the regional crop production by modifying classcrop files in relation with observed data (both aerial and underground crop growth, yield) in wheat, sugar beet, and potato fields. As the vadose zone presents a depth between 1.5 and 104 m in this region, new reservoirs were added according to the geological descriptions available. Deep nitrate transfer was validated in a specific site where cropping history was known. Nitrate nitrogen after harvest in the root zone was validated for wheat within different crop rotations using the first results of a nitrate-monitoring program planned by the authorities to test the effectiveness of the mitigation measures in agriculture. This extended model was also linked to a GIS (geographical information system) using 1 km2-cells. All the required data were rasterised to allow HRU (hydrological response unit) identification within the cells. The cell’s daily water flows are weighted flows of each HRU depending on their relative area within the cell. Water balances at catchment scale allow us to validate the calculation. Taking into account the evolution of distributed land use and observed climatic data, we have built maps of fast indicators and long-term indicators. The first map represents nitrate concentration in the water leaving the root zone and the second one represents the time transfer for nitrate from 1.5 m depth to the groundwater table and nitrate concentration in recharge water. These maps constitute major tools for nitrogen management at a regional level. [less ▲]

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See detailFrom sample hunt to sequence processing, the journey of a biologist
André, Adrien ULg; Millien, Virginie; Michaux, Johan ULg

Conference (2015, December 08)

Metabarcoding studies are becoming more and more popular with a field of applications constantly increasing. However, the methods used are sometimes complex and might remain “obscure” for most of us. The ... [more ▼]

Metabarcoding studies are becoming more and more popular with a field of applications constantly increasing. However, the methods used are sometimes complex and might remain “obscure” for most of us. The objective of this presentation is therefore to familiarize people with this field of research by giving an overview of the different steps permitting the achievement of metabarcoding studies. Field work, lab work and bioinformatics will be subsequently detailed and accessibly explained. [less ▲]

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See detailFrom sample size to effect-size : small study effect investigation (SSEi)
Richy, F.; Ethgen, Olivier ULg; Bruyère, Olivier ULg et al

in Internet Journal of Epidemiology (2004), 1(2),

Detailed reference viewed: 51 (6 ULg)