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See detailDEM modeling of ball mills with experimental validation: influence of contact parameters on charge motion and power draw
Boemer, Dominik ULg; Ponthot, Jean-Philippe ULg

in Computational Particle Mechanics (2016)

Discrete element method simulations of a 1:5-scale laboratory ball mill are presented in this paper to study the influence of the contact parameters on the charge motion and the power draw. The position ... [more ▼]

Discrete element method simulations of a 1:5-scale laboratory ball mill are presented in this paper to study the influence of the contact parameters on the charge motion and the power draw. The position density limit is introduced as an efficient mathematical tool to describe and to compare the macroscopic charge motion in different scenarios, i.a. with different values of the contact parameters. While the charge motion and the power draw are relatively insensitive to the stiffness and the damping coefficient of the linear spring-slider-damper contact law, the coefficient of friction has a strong influence since it controls the sliding propensity of the charge. Based on the experimental calibration and validation by charge motion photographs and power draw measurements, the descriptive and predictive capabilities of the position density limit and the discrete element method are demonstrated, i.e. the real position of the charge is precisely delimited by the respective position density limit and the power draw can be predicted with an accuracy of about 5 %. [less ▲]

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See detailPolymeric Nanoparticles as siRNA Drug Delivery System for Cancer Therapy: The Long Road to Therapeutic Efficiency
Frère, Antoine ULg; Evrard, Brigitte ULg; Mottet, Denis ULg et al

in Holban, Alina Maria; Grumezescu, Alexandru (Eds.) Nanoarchitectonics for Smart Delivery and Drug Targeting (2016)

Polyplexes are nanoparticles composed of small-interfering RNA (siRNA) and natural or synthetic polymers. To meet the challenge of gene therapy and deliver siRNA into the cytoplasm of target cells ... [more ▼]

Polyplexes are nanoparticles composed of small-interfering RNA (siRNA) and natural or synthetic polymers. To meet the challenge of gene therapy and deliver siRNA into the cytoplasm of target cells, several barriers must be overcome. In this chapter, the main steps, from the formulation of polyplexes to the efficient release of the siRNA into the cytoplasm of cancer cells, are described, taking into account the different strategies used to overcome the obstacles linked to the formulation of this type of nanovector. To allow a parenteral administration of the nanocolloids, the polyplex production methods should result in identical, stable, and reproducible nanostructures. Charge interactions occur between the anionic siRNA and the cationic/amphiphilic polymer. Once in the blood circulation, polyplexes must keep their physical stability. The positively charged surface can cause aggregation of the nanoparticles with plasma proteins, as well as complement activation and recognition by the mononuclear phagocytic system, with a consequent reduction of their pharmacological activity. Polyethylene glycol (PEG) can be added on the surface of the nanovectors to confer “the stealth” properties and increase plasma half-life. Then, particles have to preferentially accumulate in the tumor tissue following an active or passive targeting. Endocytosis process enables the polyplex cellular uptake, but some strategies like “the proton sponge effect” have to be used to allow the escape of the nanovectors from the cellular endosomes. Once released into the cytoplasm, polymer and siRNA must dissociate for an effective degradation of the targeted mRNA, leading finally to a decrease of the corresponding protein. [less ▲]

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See detailImpacts of entomopathogenic fungi on biology and behaviour of the invasive Brown Marmorated Stink Bug (Hemiptera, Pentatomidae)
Fingu Mabola, Junior Corneille ULg; Serteyn, Laurent ULg; Bawin, Thomas ULg et al

Poster (2016, July 25)

Halyomorpha halys St˚al (Hemiptera, Pentatomidae) is an invasive stink bug coming from Eastern Asia. Besides causing important yields losses in orchards, crop and vegetable fields, it overwinters inside ... [more ▼]

Halyomorpha halys St˚al (Hemiptera, Pentatomidae) is an invasive stink bug coming from Eastern Asia. Besides causing important yields losses in orchards, crop and vegetable fields, it overwinters inside houses as agglomerates of dozens. In Europe, this Brown Marmorated Stink Bug (BMSB) was accidentally introduced in Switzerland in 2007 and has been later observed in surrounding countries (France, Italy, Germany). Based on the current US situation, we can reasonably fear that BMSB will have colonized most of Europe countries in less than a decade. If we already discern a few fungus strains that are efficient against BMSB, very little is known about their actual impact on the insect itself. So we investigated the in- fluence of a fungal infection on insect development parameters and behaviour. Olfactometry was settled to investigate the dispersion and aggregation trends, while electropenetography was used to assess the feeding behaviour. Our results will be discussed to present changes according to healthy/fungus-infected status, in relation to potential biological control for that pest. [less ▲]

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See detailFactors controlling spatial patterns and time trends of multiple pesticides in groundwater (Hesbaye chalk aquifer, Belgium)
Hakoun, Vivien ULg; Orban, Philippe ULg; Dassargues, Alain ULg et al

Conference (2016, July 25)

Groundwater contamination by pesticides compounds (parent and degradation by-products) is a well identified environmental issue, however factors influencing their spatial patterns and time trends remain ... [more ▼]

Groundwater contamination by pesticides compounds (parent and degradation by-products) is a well identified environmental issue, however factors influencing their spatial patterns and time trends remain unclear. In this context, 18 years long time series (1996-2013) of 3 banned (atrazine, diuron, simazine), 2 metabolites (deethyaltrazine –DEA, and 2,6-dichlorobenzamide –BAM) and one regulated (bentazone) pesticides compounds are explored, taking into account concentrations below detection limits. Using a bivariate and multivariate (PCA and hierarchical clustering) statistical framework, these time series are related to nitrate (NO3-) and the fraction of young water recharged since 50 years, land use, to aquifer settings (i.e. confining conditions, thickness of the unsaturated zone) and to groundwater table fluctuations. Results show that pesticides compounds are always below detection limits in the confined area where old groundwater lies. However these compounds are detected every year in the unconfined zone with maximal concentrations exceeding the current European water drinking standard of 100 ng.L-1 every year since 2007 for atrazine. We find the greatest significant (p-value < 0.05) positive correlations between the trio atrazine-DEA (tau=0.62), atrazine-NO3- (tau=0.48) and DEA-NO3- (tau=0.49). We identify positive correlations between most compounds, atrazine (tau=0.44), bentazone (tau=0.36), simazine (tau=0.71); DEA (tau=0.58) and BAM (tau=0.44), and water table fluctuations with periods spanning several years. We determine two groups (6 and 9 sites each) of site which relate to the discharge and recharge areas. Sites from the recharge area where higher diuron, simazine and BAM concentrations occurs correlate with a dense localized urban area. Atrazine and bentazone relates to sites with thin unsaturated zones and high mixing in the wells. Our analysis reveals critical factors affecting 7 pesticides compounds. It improves our understanding of the interplay between land use, aquifer settings and transient processes (water fluctuations) on controlling pesticides concentrations in groundwater. [less ▲]

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See detailGd-nanoparticles functionalization with specific peptides for ß-amyloid plaques targeting.
Plissonneau; Pansieri, Jonathan; Heinrich-Balard, L et al

in Journal of Nanobiotechnology (2016), 14(1), 10118612951-016-0212-

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See detailHydrogeochemical mechanisms driving the occurrence of elevated fluoride contents in crystalline aquifers in Benin, Western Africa
Tossou, Yao ULg; Orban, Philippe ULg; Gesels, Julie ULg et al

Conference (2016, July 24)

Elevated concentrations of fluoride in drinking water is the source of severe healthy problems such as dental or skeletal fluorosis. High concentrations of fluoride are often observed in fractured and ... [more ▼]

Elevated concentrations of fluoride in drinking water is the source of severe healthy problems such as dental or skeletal fluorosis. High concentrations of fluoride are often observed in fractured and altered crystalline aquifers around the world. However, the hydrogeochemical mechanisms leading to such elevated fluoride concentrations are usually not fully understood. In particular, it is important to make the link between these elevated concentrations and the geological context in order to make efficient recommendations on appropriate locations of further groundwater abstraction wells. This is the case in Benin, Western Africa, where groundwater from crystalline bed-rock aquifers is the main source for drinking-water supply. In this context, this research aims to identify the hydrogeochemical processes governing groundwater mineralization and the origin of the high fluoride concentrations. The investigations are based on groundwater samples collected in the central part of the country (Department of Collines), characterized by hard Precambrian aquifers. The hydrogeological system consists of a thin altered bedrock layer (shallow aquifer) and a deeper fractured crystalline bedrock (deep aquifer). The most significant groundwater quality problems in the area relate to the high fluoride (more than 7 mg / l) and nitrate (over 400 mg / l) concentrations in groundwater. The collected hydrogeochemical dataset was explored using geochemical approaches and multivariate statistics. The results reveal that the water mineralization derives from hydrolysis of silicate minerals, but it is also influenced by anthropogenic effects, particularly in the shallow reservoir. However, fluoride has a natural origin, essentially related to weathering of silicate minerals, mainly from biotite. Ion exchanges between groundwater and the rock matrix also contributes to increase fluoride concentrations in groundwater. Earlier saturation of water with calcite and the precipitation of this mineral due to bicarbonate excess reduce calcium activity are favorable of the release of fluoride by rocks. Further investigations are going on to make the link between crystalline rock types, associated primary minerals and fluoride concentrations in order to identify the geological contexts which are more prone to such problems. [less ▲]

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See detailLa succession du prince-évêque de Liège dans les biens des ecclésiastiques
Lagasse, Benoît ULg

Conference (2016, July 23)

Explication du régime spécifique au diocèse de Liège de la succession du prince-évêque dans les biens des ecclésiastiques (distinction meubles/immeubles versus distinction biens propres/biens de l'Eglise ... [more ▼]

Explication du régime spécifique au diocèse de Liège de la succession du prince-évêque dans les biens des ecclésiastiques (distinction meubles/immeubles versus distinction biens propres/biens de l'Eglise en droit canonique général). [less ▲]

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See detailSelf-inhibition of synthesis reduces antigen presentation of the alcelaphine herpesvirus 1-encoded latency-associated protein, aLANA
Sorel, Océane; Myster, Françoise; Vanderplasschen, Alain et al

Conference (2016, July 23)

Alcelalphine herpesvirus 1 (AlHV-1) persistently infects its natural host, the wildebeest, without inducing any clinical signs. However, cross-transmission to other ruminant species leads to the ... [more ▼]

Alcelalphine herpesvirus 1 (AlHV-1) persistently infects its natural host, the wildebeest, without inducing any clinical signs. However, cross-transmission to other ruminant species leads to the development of a deadly lymphoproliferative disease named malignant catarrhal fever (MCF). AlHV-1 ORF73 encodes the latency-associated nuclear antigen (LANA)-homolog protein termed aLANA. Similarly to other viral genome maintenance proteins encoded by gammaherpesviruses, aLANA has recently been shown to be essential for viral persistence and induction of MCF. Here we have investigated the self-inhibition of antigen presentation by aLANA and the potential role of such mechanism during the development of MCF. We showed that the GE-rich repeat domain of aLANA was sufficient to inhibit the presentation of an epitope linked to it. Though antigen presentation in absence of GE was dependent upon proteasomal degradation of aLANA, a lack of GE did not affect protein turnover. We further found that similarly to EBNA-1 GAr, aLANA GE downregulated protein self-synthesis. Likewise, such mechanism could be associated with reduced antigen presentation in vitro. In addition, in-frame insertion of GE repeat domain in a heterologous eGFP protein significantly down-regulated protein steady-state levels and self-antigen presentation. Next, we modified the AlHV-1 ORF73 gene sequence to reduce the purine bias in GE, without affecting the peptidic sequence. Such codon-modified aLANA GEm construct displayed increased antigen presentation. Finally, we generated an AlHV-1 recombinant strain expressing a GE-deficient aLANA protein and observed that viral growth was not affected in vitro by the absence of aLANA GE domain and MCF could be induced in rabbits irrespective of the expression of full-length aLANA or GE-deficient aLANA protein. [less ▲]

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See detailLe surréalisme curacien : une construction néerlandaise ?
Andringa, Kim ULg

Conference (2016, July 22)

Depuis les années 1930, une riche littérature « locale » s’est développée sur l’île de Curaçao, qui fait alors partie des Antilles néerlandaises. Presque d’emblée, plusieurs de ses auteurs, poètes comme ... [more ▼]

Depuis les années 1930, une riche littérature « locale » s’est développée sur l’île de Curaçao, qui fait alors partie des Antilles néerlandaises. Presque d’emblée, plusieurs de ses auteurs, poètes comme romanciers, se voient attribuer l’étiquette « surréaliste » par la critique littéraire néerlandaise, et ce malgré l’absence de liens ou de contacts avec des groupes surréalistes d’autres pays. Encore en 2012, quatre poètes caribéens, dont trois curaciens, figurent dans la Nieuwe anthologie van de Nederlandse surrealistische poëzie. Nous tâcherons d’analyser les motifs et les critères sous-jacents à cette catégorisation, depuis quelque temps souvent récusée, afin d’établir s’il y a une réelle sensibilité surréaliste dans cette littérature antillaise néerlandophone, ou s’il s’agit d’une tentative d’apprivoisement de la métropole face à l’émergence de cette nouvelle littérature néerlandaise transatlantique, issue d’une culture différente et qui contribue à une décolonisation des esprits. [less ▲]

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See detailSelf-assembly of capillary multipoles
Poty, Martin ULg; Lagubeau, Guillaume; Lumay, Geoffroy ULg et al

Conference (2016, July 21)

Self-assembly of floating particles driven by capillary forces at some liquid-air interface leads to the formation of two-dimensionnal structures. Using a 3d printer, millimeter scale objets are produced ... [more ▼]

Self-assembly of floating particles driven by capillary forces at some liquid-air interface leads to the formation of two-dimensionnal structures. Using a 3d printer, millimeter scale objets are produced. Their 3d shape is chosen in order to create capillary multipoles. The capillary interactions between these components can be either attractive or repulsive depending on the interface local deformations along the liquid-air interface. In order to understand how the shape of an object deforms the interface, we developed an original profilometry method. The measurements show that specific structures can be programmed by selecting the 3d branched shapes. [less ▲]

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See detailSoil fiction: the experience of a neglected urban thing
Meulemans, Germain ULg

Conference (2016, July 21)

This paper starts with the story of the Soil Fiction project – a residence in which artists, anthropologists and a soil-scientist worked together on developing an exhibition on urban soils – in order to ... [more ▼]

This paper starts with the story of the Soil Fiction project – a residence in which artists, anthropologists and a soil-scientist worked together on developing an exhibition on urban soils – in order to address what speculative realism might bring to anthropological modes of inquiry. For more than 150 years, urban soils were left unnoticed by modern science because of their messiness and boundedness with human activities. Yet, they are a prevalent aspect of urban conditions of life. Through six months of collective work, Soil Fiction explored some of the neglected paths that attach us to urban soils. Departing from attempts to adapt modern-day science to urban soils, it imagined the practices of a minor science developed through a journey along them. These practices were given consistence through the creation of installations and films. Drawing on Stengers’s approach to speculative thinking, I discuss the importance of inventing propositions that work as ‘lures for feelings’. In this, rather than being a figment of the imagination, the craft of speculative imagining can attract experience. Fiction and exhibition making become ways to inquire into the world, to intensify hypothesis, and to forge other relationships with the world. I conclude that imaginative experiments such as Soil Fiction are not only knowledge practices in themselves, but also add more reality to the world. Responding to Ingold’s call for an anthropology that re-unites imagination and reality together, they conjure up research modes that do not discriminate between soils and our knowledge of them. [less ▲]

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See detailThe influence of COMT on the neural substrates of short-term memory in normal aging
Collette, Fabienne ULg; Manard, Marine ULg; Salmon, Eric ULg

Conference (2016, July 21)

Working memory dopaminergic modulation is generally expressed in healthy aging by an advantage for carriers of the Met allele at behavioral and brain activity levels. However, most tasks used did not ... [more ▼]

Working memory dopaminergic modulation is generally expressed in healthy aging by an advantage for carriers of the Met allele at behavioral and brain activity levels. However, most tasks used did not allow to easily disentangle the contribution of maintenance and manipulation processes. We explored the effect of COMT genotype on the maintenance process using a Sternberg memory task varying the amount of information presented, in young and older homozygous carriers for the Val and Met alleles of the COMT gene. Although no clear behavioral difference was observed between groups, patterns of cerebral activity indicate difficulties for Met older individuals to maintain stable representations. These results will be discussed in terms of dopaminergic contribution to stability/flexibility of cognitive processes during aging. [less ▲]

Detailed reference viewed: 44 (2 ULg)
See detailIntegrating biological indicators in a monitoring network to improve soil quality diagnosis – a case study in Southern Belgium
Krüger, Inken ULg; Chartin, Caroline; van Wesemael, Bas et al

Conference (2016, July 21)

Detailed reference viewed: 28 (4 ULg)
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See detailHCOOH distributions from IASI for 2008-2014: comparison with ground-based FTIR measurements and a global chemistry-transport model
Pommier, M.; Clerbaux, C.; Coheur, P.-F. et al

in Atmospheric Chemistry and Physics (2016), 16

Formic acid (HCOOH) is one of the most abundant volatile organic compounds in the atmosphere. It is a major contributor to rain acidity in remote areas. There are, however, large uncertainties on the ... [more ▼]

Formic acid (HCOOH) is one of the most abundant volatile organic compounds in the atmosphere. It is a major contributor to rain acidity in remote areas. There are, however, large uncertainties on the sources and sinks of HCOOH and therefore HCOOH is misrepresented by global chemistry-transport models. This work presents global distributions from 2008 to 2014 as derived from the measurements of the Infrared Atmospheric Sounding Interferometer (IASI), based on conversion factors between brightness temperature differences and representative retrieved total columns over seven regions: Northern Africa, southern Africa, Amazonia, Atlantic, Australia, Pacific, and Russia. The dependence of the measured HCOOH signal on the thermal contrast is taken into account in the conversion method. This conversion presents errors lower than 20 % for total columns ranging between 0.5 and 1 × 1016 molec/cm2 but reaches higher values, up to 78 %, for columns that are lower than 0.3 × 1016 molec/cm2. Signatures from biomass burning events are highlighted, such as in the Southern Hemisphere and in Russia, as well as biogenic emission sources, e.g., over the eastern USA. A comparison between 2008 and 2014 with ground-based Fourier transform infrared spectroscopy (FTIR) measurements obtained at four locations (Maido and Saint-Denis at La Réunion, Jungfraujoch, and Wollongong) is shown. Although IASI columns are found to correlate well with FTIR data, a large bias (> 100 %) is found over the two sites at La Réunion. A better agreement is found at Wollongong with a negligible bias. The comparison also highlights the difficulty of retrieving total columns from IASI measurements over mountainous regions such as Jungfraujoch. A comparison of the retrieved columns with the global chemistry-transport model IMAGESv2 is also presented, showing good representation of the seasonal and interannual cycles over America, Australia, Asia, and Siberia. A global model underestimation of the distribution and a misrepresentation of the seasonal cycle over India are also found. A small positive trend in the IASI columns is observed over Australia, Amazonia, and India over the 2008–2014 period (from 0.7 to 1.5 %/year), while a decrease of ∼ 0.8 %/year is measured over Siberia. [less ▲]

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See detailThe verbal overshadowing effect in children and adults is unrelated to the specific content of descriptions
Vanootighem, Valentine ULg; Brédart, Serge ULg; Dehon, Hedwige ULg

Poster (2016, July 21)

Verbal descriptions of unfamiliar faces have been found to impair later identification of these faces in children and adults, a phenomenon known as the “verbal overshadowing effect” (VOE, Schooler and ... [more ▼]

Verbal descriptions of unfamiliar faces have been found to impair later identification of these faces in children and adults, a phenomenon known as the “verbal overshadowing effect” (VOE, Schooler and Engstler-Schooler, 1990). The present study thoroughly examined the person descriptive abilities of 7–8, 10–11, and 13–14-year-old children and adults and their influence on later identification performance. Our aim was to specifically assess the prediction of the “content” account suggesting that a verbal overshadowing arises because participants generate an inadequate verbal description and later rely upon it during retrieval. Results showed a verbal overshadowing effect in all age groups but neither accuracy, length nor content of descriptions were found to be associated with identification accuracy. [less ▲]

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See detailEpiphytic bryozoans on Neptune grass – a sample-based data set
Lepoint, Gilles ULg; Heughebaert, André; Michel, Loïc ULg

in ZooKeys (2016), 606

Background The seagrass Posidonia oceanica L. Delile, commonly known as Neptune grass, is an endemic species of the Mediterranean Sea. It hosts a distinctive and diverse epiphytic community, dominated by ... [more ▼]

Background The seagrass Posidonia oceanica L. Delile, commonly known as Neptune grass, is an endemic species of the Mediterranean Sea. It hosts a distinctive and diverse epiphytic community, dominated by various macroalgal and animal organisms. Mediterranean bryozoans have been extensively studied but quantitative data assessing temporal and spatial variability have rarely been documented. In Lepoint et al. (2014a, b) occurrence and abundance data of epiphytic bryozoan communities on leaves of P. oceanica inhabiting the Revellata Bay (Corsica, Mediterranean Sea) were reported and trophic ecology of Electra posidoniae Gautier assessed. New information Here, we provide metadata information on data set discussed in Lepoint et al. 2014a and published on the GBIF portal as a sampling-event data set: http://ipt.biodiversity.be/resource?r=ulg_bryozoa&v=1.0). The data set, compared to Lepoint et al. 2014a, is enriched by data concerning species settled on Posidonia scales (dead petiole of Posidonia leaves, remaining after limb abscission). [less ▲]

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See detailenseigner massivement la littérature jeunesse : la Formation en Ligne Ouverte à tous de l'Université de Liège
Centi, Valérie; D'Anna, Vincianne; Delbrassine, Daniel ULg et al

Conference (2016, July 20)

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See detailPublic Participation in Science and Technology and its Normative Context. The Participatory Turn’s Legacy and the European ‘Responsible Research and Innovation’ Emerging Framework
Macq, Hadrien ULg

Master's dissertation (2016)

Over the last two decades in Europe, science and technology’s unforeseen impacts led many STS scholars to plead for a ‘participatory turn’ in order to make our democracies more able to handle ... [more ▼]

Over the last two decades in Europe, science and technology’s unforeseen impacts led many STS scholars to plead for a ‘participatory turn’ in order to make our democracies more able to handle sociotechnical controversies. However, since the outset of this participatory turn, critiques sharing the common emphasize on the importance of taking into account the context in which public participation takes place have pointed to the risk of participation being either romanticized or instrumentalized. This thesis contributes to the critical scrutinizing of public participation in science and technology. By drawing on a set of qualitative data collection strategies and on a discourse analysis of collected materials, it investigates the normative context in which public participation is currently conceived and promoted at the European level and links it to historical perspectives in order to grasp the way in which the participatory turn’s legacy has been impacted. At it shows, far from being left opened-up, public participation is strongly closed-down by normative forces that lies in the context is which its promotion is currently taking place. As argued, public participation appears as instrumentalized in Horizon 2020 due to the increasing economization of policies and the steering of science and innovation toward tackling societal challenges. However, while acknowledging that these trends are characteristic of current developments, some longer ones are highlighted. Indeed, as this research suggests, the instrumentalization of public participation goes largely beyond the mere Horizon 2020. From the Sixth Framework Programme already, it appears that the normative context in which public participation in science and technology has been conceived and promoted has always tended to instrumentalized and to close down the deliberative governance of science. [less ▲]

Detailed reference viewed: 44 (5 ULg)