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See detailAnthropogenic effects on African Landscapes: Spatial Structure, Typologies, Ecological Impact
Vranken, Isabelle ULg

Poster (2014, February)

The problematique of anthropogenic disturbance on African landscapes is studied within the double framework of DPSIR (Drivers Pressures States Impact Response) and Pattern/Process Paradygm (Landscape ... [more ▼]

The problematique of anthropogenic disturbance on African landscapes is studied within the double framework of DPSIR (Drivers Pressures States Impact Response) and Pattern/Process Paradygm (Landscape Ecology). 20 landscae images from D.R. Congo, Ivory Coast and Benin were studied using indexes of spatial (compositional and configurational) heterogeneity and anthropogenic disturbance in order to highlight the relationship between spatial structure and disturbance intensity. The results show maximal heterogeneity at intermediate anthropogenic disturbances and fasten the triangular relationship between anthropogenic effect, biodiversity and spatial heterogeneity, that had been partially theoretised with the intermidiate disturbance and habitat heterogeneity hypotheses. [less ▲]

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See detailDevelopment of the ultrastructure of sonic muscles: a kind of neoteny?
Millot, Sandie; Parmentier, Eric ULg

in BMC Evolutionary Biology (2014), 14

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See detailBayesian methods for predicting and modelling winter wheat biomass
Mansouri, Majdi ULg; Dumont, Benjamin ULg; Destain, Marie-France ULg

Poster (2014, February)

The objectives of this paper are threefold. The first objective is to propose to use an Improved Particle Filtering (IPF) based on minimizing Kullback-Leibler divergence for crop models' predictions. The ... [more ▼]

The objectives of this paper are threefold. The first objective is to propose to use an Improved Particle Filtering (IPF) based on minimizing Kullback-Leibler divergence for crop models' predictions. The performances of the proposed technique are compared with those of the conventional Particle Filtering (PF) for improving nonlinear crop model predictions. The main novelty of this task is to develop a Bayesian algorithm for nonlinear and non-Gaussian state and parameter estimation with better proposal distribution. The second objective is to investigate the effects of practical challenges on the performances of state estimation algorithms PF and IPF. Such practical challenges include (i) the effect of measurement noise on the estimation performances and (ii) the number of states and parameters to be estimated. The third objective is to use the state estimation techniques PF and IPF for updating prediction of nonlinear crop model in order to predict winter wheat biomass. PF and IPF are applied at a dynamic crop model with the aim to predict a state variable, namely the winter wheat biomass, and to estimate several model parameters. Furthermore, the effect of measurement noise (e.g., different signal-to-noise ratios) on the performances of PF and IPF is investigated. The results of the comparative studies show that the IPF provides a significant improvement over the PF because, unlike the PF which depends on the choice of sampling distribution used to estimate the posterior distribution, the IPF yields an optimum choice of the sampling distribution, which also accounts for the observed data. [less ▲]

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See detailChronische Bronchitis Hund
Clercx, Cécile ULg

in Proceedings 35 Internationaler Fortbildungskurs Kleintierkrankheiten (2014, February)

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See detailLong fibrosis
Clercx, Cécile ULg

in proceedings 35 Internationaler Fortbildungskurs Kleintierkrankheiten (2014, February)

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See detailBacterial and viral pneumonia
Clercx, Cécile ULg

in Proceedings 35 Internationaler Fortbildungskurs Kleintierkrankheiten (2014, February)

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See detailBronchiectasis
Clercx, Cécile ULg

in Proceedings 35 Internationaler Fortbildungskurs Kleintierkrankheiten (2014, February)

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See detailCROSSROADS - magazine sonore des musiques noires US
Sacré, Robert ULg

Diverse speeche and writing (2014)

CROSSROADS : émission radio hebdomadaire diffusée sur EQUINOXE FM 100.1 (on line via www.equinoxefm.be) : tous les mercredis de 18 à 20h : contenu : blues,R&B,Soul, gospel, Zydeco, jazz

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See detailParameter identification of the STICS crop model, using an accelerated formal MCMC approach
Dumont, Benjamin ULg; Leemans, Vincent ULg; Mansouri, Majdi ULg et al

in Environmental Modelling & Software (2014), 52

This study presents a Bayesian approach for the parameters’ identification of the STICS crop model based on the recently developed Differential Evolution Adaptive Metropolis (DREAM) algorithm. The ... [more ▼]

This study presents a Bayesian approach for the parameters’ identification of the STICS crop model based on the recently developed Differential Evolution Adaptive Metropolis (DREAM) algorithm. The posterior distributions of nine specific crop parameters of the STICS model were sampled with the aim to improve the growth simulations of a winter wheat (Triticum aestivum L.) culture. The results obtained with the DREAM algorithm were initially compared to those obtained with a Nelder-Mead Simplex algorithm embedded within the OptimiSTICS package. Then, three types of likelihood functions implemented within the DREAM algorithm were compared, namely the standard least square, the weighted least square, and a transformed likelihood function that makes explicit use of the coefficient of variation (CV). The results showed that the proposed CV likelihood function allowed taking into account both noise on measurements and heteroscedasticity which are regularly encountered in crop modelling [less ▲]

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See detailMeasurement of urinary biomarkers of parabens, benzophenone-3 and phthalates in a Belgian population
Dewalque, Lucas ULg; PIRARD, Catherine ULg; Charlier, Corinne ULg

in BioMed Research International (2014), 2014(Article ID 649314,), 1-13

Parabens, benzophenone-3 (BP3) and phthalates are commonly used as antimicrobial conservator, UV-filter and plasticizer respectively, and are thought to exhibit endocrine disrupting properties. These ... [more ▼]

Parabens, benzophenone-3 (BP3) and phthalates are commonly used as antimicrobial conservator, UV-filter and plasticizer respectively, and are thought to exhibit endocrine disrupting properties. These endocrine disrupting activities have been recently assumed to lead to cutaneous malignant melanoma. Humans are exposed to these chemicals through different sources such as food, personal care products or cosmetics. In this study we measured urinary levels of 4 parabens, BP3 and 7 metabolites of phthalates in samples collected from 261 participants living in and around Liege (Belgium). The analyses were carried out by liquid chromatography tandem mass spectrometry (LC-MS/MS) using isotopic dilution. To the best of our knowledge, this is the first time that the urinary levels of these 3 classes of chemicals are reported for the same general population in Belgium. Most of the parabens, the BP3 and all the phthalate metabolites were detected in 82.8 to 100.0% of the samples. For most of these chemicals, the exposure patterns significantly differ between children and adults, but also between males and females, especially with higher concentrations of parabens and phthalate metabolites in female and children subjects respectively. [less ▲]

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See detailEpigenetic modulators mitigate angiogenesis through a complex transcriptomic network
Shiva Shankar, T.V.; Willems, Luc ULg

in Vascular Pharmacology (2014), 60

In this review, we summarize the knowledge pertaining to the role of epigenetics in the regulation of angiogenesis. In particular, we show that lysine acetylation and cytosine methylation are important ... [more ▼]

In this review, we summarize the knowledge pertaining to the role of epigenetics in the regulation of angiogenesis. In particular, we show that lysine acetylation and cytosine methylation are important transcriptional regulators of angiogenic genes in endothelial cells. Lysine acetylation and cytosine methylation inhibitors idiosyncratically tune the transcriptome and affect expression of key modulators of angiogenesis such as VEGF and eNOS. Transcriptomic profiling also reveals a series of novel genes that are concomitantly affected by epigenetic modulators. The reversibility and overall tolerability of currently available epigenetic inhibitors open up the prospect of therapeutic intervention in pathologies where angiogenesis is exacerbated. This type of multitargeted strategy has the major advantage of overcoming the compensatory feedback mechanisms that characterize single anti-angiogenic factors. [less ▲]

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See detailLa politique énergétique de l'Union européenne
Habran, Maxime ULg

Learning material (2014)

Il s'agit d'un cours sur l'introduction de la politique énergétique de l'UE. Il se compose de quatre parties. L'énergie européenne en quelques chiffres; Les multiples aspects de la politique énergétique ... [more ▼]

Il s'agit d'un cours sur l'introduction de la politique énergétique de l'UE. Il se compose de quatre parties. L'énergie européenne en quelques chiffres; Les multiples aspects de la politique énergétique; Les aspects extérieures de la politique énergétique; Comment produire autrement? [less ▲]

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See detailSoil Seed Bank : a poorly know component of forest regeneration
Douh, Chauvelin ULg; Daïnou, Kasso ULg; Fernandez Pierna, Juan-Antonio et al

Poster (2014, February)

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See detail7. Lutte intégrée contre les ravageurs
Chavalle, Sandrine; Censier, Florence ULg; Jacquemin, Guillaume et al

in Destain, Jean-Pierre; Bodson, Bernard (Eds.) Livre Blanc Céréales (2014, February)

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See detailContribution of Spray Droplet Pinning Fragmentation to Canopy Retention
Boukhalfa, Hassina dite Hafida ULg; Massinon, Mathieu ULg; Belhamra, Mohamed et al

in Crop Protection (2014), 56

Drop behaviour during impact affects retention. The increase of adhesion is usually seen as the objective when applying crop protection products, while bouncing and shattering are seen as detrimental to ... [more ▼]

Drop behaviour during impact affects retention. The increase of adhesion is usually seen as the objective when applying crop protection products, while bouncing and shattering are seen as detrimental to spray retention. However, observation of drop impacts on barley (Hordeum vulgare L.) using high speed shadowgraphy shows that bouncing and fragmentation can occur in Cassie-Baxter as well as in Wenzel wetting regimes. In this last regime, a part of the drop may remain stuck on the surface, contributing to retention. Using simultaneous measurements of drop impacts with high speed imaging and of retention with fluorophotometry for spray mixtures on excised barley leaves using a Teejet 11003 nozzle at 0.2 MPa, it is observed that about 50% of the drops that fragmented in the Wenzel state remain on the horizontal leaf. Depending on the spray mixture, these impact outcomes accounted for 28 to 46% of retention, the higher contribution being correlated with bigger VMD (Volume Median Diameter). This contribution is not negligible and should be considered when modelling spray retention processes. [less ▲]

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See detailL’aporie de la mathématisation de la physique en contexte aristotélicien
Dubouclez, Olivier ULg

Scientific conference (2014, February)

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See detailQue peut le métalangage ? What can metalanguage do ?
Dondero, Maria Giulia ULg; Provenzano, François ULg; Klinkenberg, Jean-Marie ULg et al

Book published by Presses Universitaires de Liège (2014)

In the social sciences, research that is conveyed in a display of technical language is not always seen in a good light. This is a trend particularly in semiotics. As a field of study, it has a reputation ... [more ▼]

In the social sciences, research that is conveyed in a display of technical language is not always seen in a good light. This is a trend particularly in semiotics. As a field of study, it has a reputation for eagerness to use semio-jargon at the worst, or at best, a reputation for walling itself off in a self-reflective meta-language. It is true that the best known and most cited treatise on structural semiotics, by Greimas and Courtés, was published as an Analytical Dictionary. And it is also true that Peirce's work is prodigiously crammed with terminological inventions and speculations. It would seem that in both cases, the quest for scientific rigor took precedence over elegance of expression and of so-called natural discourse. Nothing new under the sun, n'est-ce pas? They say that a courtesan under Louis XIV scandalized the Sun King's court by uttering a technical term in the king's bedchamber, which illustrates how far back the issue goes; it certainly didn't begin with the development of the academic study of signs. In issue 4 of Signata we would like to examine the various aspects of building the meta-language of semiotics. The intention is not to adopt a philological perspective, but to look at the issue of terminologies in current scientific epistemology. We will examine the diversity of the possible meta-languages (natural language versus technical language?), the influence of related disciplines (what implications do the borrowed terms from grammar, logic, mathematics, and so on have for semiotics?), the reasons — explicit or not — for the choices made, and the stylistic impacts of those choices. An inquiry of this sort could go in many directions. What follows is an open-ended, non-exhaustive enumeration: Semiotics: A special case? Is it actually true that the semiotic approach generates a more prolific meta-linguistic output than other disciplines? How and why? It would be interesting, for example, to do comparisons with these more or less related disciplines (linguistics, sociology, psychology, etc.), to assess whether their rapport with the meta-language might possibly be different, and the reasons for and effects of those differences. In these assessments, of course, there arises the issue of "natural language", which is so readily its own meta-language: Are there disciplines that reconcile themselves with this supposed naturalness without any detriment? An updated meta-language may be deemed as unavoidable for a discipline whose vocation is to generalize, which implies substantial modeling power. But what do we find in philosophy, which can be expressed without abandoning natural language, and which seems to incur less reproach for its jargon than semiotics? The archaeology of meta-languages Another line of inquiry would be of a genealogical nature: This would involve examining the theoretical justifications that underpin meta-language borrowings from this or that other discipline, at this or that other time in its history, and the repercussions, both stylistic and epistemological, of the trade in terminology. On this score, we note that classical structuralism has expressed itself to a great extent in a grammatical and more broadly linguistic language (actants, modalities, deixis, articulation, semes, etc.). But it is common knowledge that other approaches to semantic facts have favored the language of logic. And yet others have shown that it is both possible and effective to use language taken from geometry or optics. In addition to these, from the perspective of the primacy of perception, the language of the natural sciences must be included — particularly that of the neurosciences —, and the language of sensory forms from phenomenology. Whether one is helping oneself to terms like "isotopy" and "valence" from physics and chemistry or "topology" from mathematics, these are not innocent choices in a discipline that has blazed its trail through the social sciences. The epistemological influence of the meta-language. Without any doubt, herein lies the most complex, ambivalent issue. Firstly, when one adopts a meta-language, by definition one views the object of study as a language (whether it is the natural language or the language of images, or the language of social practices). Yet this operation is so laden with consequences that to enumerate them would be an impossible task. We will merely note that many theoretical categories and analytical tools seem to emerge directly from the choice of a particular meta-language and the distance dictated by it. Secondly, opting for one meta-language over another is ipso facto a choice of which explanatory form the analysis will use. It follows that working on the meta-language, far from being a deathly sterile activity, is a practice intended to generate the form the explanation will take (which is without any doubt a major issue in scientific discussion). But these two epistemological impacts of meta-language generation can trigger a great deal of discussion on what we might call "the adverse effects" of the chosen options. For example, if there is a consensus within a group on a particular meta-language (such as in Greimassian semiotics), it may become just a template to apply, simply a schema to project onto objects; but if it is an object of inquiry (such as in Peirce's work), it may yield an approach that is more theoretical than practical. Hence the question: Hasn't semiotics in fact been above all a field with a mix of applied and self-reflective approaches? And in any case, does it truly explain things when one supports a meta-language and seeks to apply it and think within its terms? For example, we might question whether the meta-linguistic power of semiotics hasn't made it a discipline that is quick to generalize, and kept it from focusing on the singularity of its objects. We might also question whether semiotic research isn't all too often more formal than substantial, both in the Hjelmselvian sense and the usual sense. Ultimately, even further up the line, one could debate the epistemological possibility of the meta-language itself — as the poststructuralist philosophies have done. Isn't the distinction between object language and meta-language actually a bit utopian in the natural languages, since it assumes that the terms completely lose their reflexivity? Lastly, we might question whether the meta-language as a theoretical tool doesn't entail more than just artless transparency, but also an effort to define the theory within a restrictive set of evidence. For example, to bring up the "semiotic square" presupposes that there is always a semiotic square that explains the basis of the discourse (in such a way that what was a working hypothesis could become a non-falsifiable theory). The socio-rhetorical effects of the meta-language Aside from the epistemological requirements, when technical terminology is reworked, this has impacts on the circulation of concepts and their appropriation by different groups, which then affects group members' recognition of one another and how they differentiate one group from another. The boundary drawn on a conceptual system by a terminological apparatus thus gives rise to corollary inclusion-exclusion repercussions that are not unimportant. There are fights over terminological legitimacy, whose foremost characteristic is actually that they are not formulated as such. Any meta-language also has impacts on the social aspects of thinking. This is especially true of the meta-language of semiotics, because, due to its dedication to generality and transposability, it must fully support deconstruction. On the other side of the coin, one can maintain that meta-language is to objects what bureaucracy is to communities: It is helpful in creating order and making distinctions, in establishing levels and empty slots, but the risk, then, is that it may become an end in itself that must be maintained and tended, and that it ultimately disallows acting and thinking in other ways. In the light of this rhetorical approach, finally, we will set down some things to consider on the manner in which semiotics talks to itself: Are "techno-speak" and "jargon" inevitable? Are "elegance" and "practicality" valid criteria for a meta-language? What impacts on the meta-language are due to the obligation we often have in semiotics to dialogue with those outside our field: Can/ should this influence the way semiotics is communicated? And what is the cost of this influence? [less ▲]

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See detailSubspace and nonlinear-normal-modes-based identification of a beam with softening-hardening behaviour
Grappasonni, Chiara ULg; Noël, Jean-Philippe ULg; Kerschen, Gaëtan ULg

in Proceedings of the International Modal Analysis Conference (IMAC) XXXII (2014, February)

The capability to reproduce and predict with high accuracy the behaviour of a real system is a fundamental task of numerical models. In nonlinear structural dynamics, additional parameters compared to ... [more ▼]

The capability to reproduce and predict with high accuracy the behaviour of a real system is a fundamental task of numerical models. In nonlinear structural dynamics, additional parameters compared to classical linear modelling, which include the nonlinear coefficient and the mathematical form of the nonlinearity, need to be identified to bring the numerical predictions in good agreement with the experimental observations. In this context, the present paper presents a method for the identification of an experimental cantilever beam with a geometrically nonlinear thin beam clamped with a prestress, hence giving rise to a softening-hardening nonlinearity. A novel nonlinear subspace identification method formulated in the frequency domain is first exploited to estimate the nonlinear parameters of the real structure together with the underlying linear system directly from the experimental tests. Then a finite element model, built from the estimated parameters, is used to compute the backbone of the first nonlinear normal mode motion. These numerical evaluations are compared to a nonlinear normal modes-based identification of the structure using system responses to stepped sine excitation at different forcing levels. [less ▲]

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See detailArts et sciences. Approches sémiotiques et philosophiques des images
Dondero, Maria Giulia ULg; Beyaert-Geslin, Anne

Book published by Presses universitaires de Liège (2014)

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