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See detailSelection of wavelengths for the quantification of nitrogen concentration in winter wheat by multispectral vision
Marlier, Guillaume ULg; Leemans, Vincent ULg; Destain, Marie-France ULg et al

Poster (2016, April 18)

Hand-held sensors (SPAD meter, N-Tester, …) are used for detecting the leaves nitrogen concentration (Nc) on basis of an optical detection of the chlorophyll concentration. These devices are active ... [more ▼]

Hand-held sensors (SPAD meter, N-Tester, …) are used for detecting the leaves nitrogen concentration (Nc) on basis of an optical detection of the chlorophyll concentration. These devices are active sensors: an internal radiation source emits light and transmission through a leaf is measured in the red (650 nm) and in the near-infrared (920 nm) spectral regions. These devices present several drawbacks. The nitrogen concentration is gained by an indirect way through the chlorophyll concentration and the leaves have to be fixed in a defined position for the measurements. These drawbacks could be overcome by an imaging device that measures the canopy reflectance. Hence, the objective of the paper is to analyse the potential of multispectral imaging for detecting nitrogen concentration. The tests were carried out on parcels submitted to nitrogen inputs varying from 0 to 180 kg N.ha-1. Reference Nc measurements were obtained by the Kjeldahl method and a Hydro N-Tester (Yara). The developed imaging system comprised a CMos camera and a set of 22 interference filters ranging from 450 to 950 nm mounted on a wheel steered by a stepper motor. The image acquisition and the motor rotation were controlled by a program written in C++. The crop was imaged vertically at one meter height. The raw images presented 1280*1024 pixels covering an area approximately 0.5*0.4 m and were recorded with a 12 bits luminance resolution. To deal with the natural irradiance variability of the scene, a white reference was used and the integration time was automatically adjusted for each image. The image treatment included the segmentation of Photosynthetically Active Leaves (PAL) by using Bayes theorem and the computation of the mean PAL reflectance after correction of background and illumination fluctuations. Nc was estimated on basis of the 22 filters by Partial Least Square (PLS) method and by four filters selected by Best Subset Selection (BSS). In comparison with the Kjeldahl method, the estimation of Nc by the Hydro N-Tester, the PLS and the BSS (filters 600-80, 950-100, 650-40 and 450-80 nm) gave determination coefficient and standard error respectively equal to of 0.53, 0.29 %; 0.67, 0.21%; 0.56 and 0.25%. This indicated that the full multi-spectral approach gave significantly better Nc estimation than a portable device and suggested that a camera equipped with four filters would give similar results. [less ▲]

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See detailPISA expliqué à tous : que faire pour améliorer notre enseignement en Belgique francophone ?
Lafontaine, Dominique ULg

Conference given outside the academic context (2016)

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See detailEmilio Salgari e l’avventura
Curreri, Luciano ULg

Scientific conference (2016, April 18)

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See detailPrésentation de "Vivre dans la peur" d'Akira Kurosawa
Tomasovic, Dick ULg

Conference given outside the academic context (2016)

Présentation du contexte de création et de production du film de Kurosawa "Vivre dans la peur" (1955) et analyse stylistique de l'oeuvre.

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See detailReactive gases in the chemistry climate model ECHAM6-HAMMOZ
Schultz, Martin; Franco, Bruno ULg; Kaffashzadeh, Najmeh et al

Poster (2016, April 18)

The recently developed global chemistry climate model ECHAM6-HAMMOZ contains comprehensive and detailed schemes for tropospheric aerosol (HAM) and reactive gases chemistry (MOZ). The Jülich Atmospheric ... [more ▼]

The recently developed global chemistry climate model ECHAM6-HAMMOZ contains comprehensive and detailed schemes for tropospheric aerosol (HAM) and reactive gases chemistry (MOZ). The Jülich Atmospheric (chemical) Mechanism (JAM002) consists of more than 300 species and 650 reactions, including relatively detailed degradation pathways for various volatile organic compounds in the troposphere and stratosphere. State-of-the-art parameterisations for chemical and physical processes are included. Here we present evaluation results from a multi-year simulation of the present-day atmospheric composition. [less ▲]

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See detailA forskolin free method for measuring cAMP modulation by Gi coupled receptors
Hanson, Julien ULg

Conference (2016, April 18)

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See detailChemical and mineralogical proxies of erosion episodes in the dried lake sediments (Amik Lake, Southern Turkey): paleoenvironmental implications
El Ouahabi, Meriam ULg; Hubert, Aurelia ULg; Lebeau, Héléne et al

Poster (2016, April 17)

The Amik Basin in the Eastern Mediterranean region has been continuously occupied since 6000-7000 BC. The landscape has sustained with highly variable anthropic pressure culminating during the Late Roman ... [more ▼]

The Amik Basin in the Eastern Mediterranean region has been continuously occupied since 6000-7000 BC. The landscape has sustained with highly variable anthropic pressure culminating during the Late Roman Period when the Antioch city reached its golden age. The basin also sustained a high seismic activity (M≥7) as it is a releasing step-over along the Dead Sea Fault. The study focuses on the sedimentary record of the Amik Lake occupying the central part of the Basin. Our objective is to constrain major paleo-environmental changes in the area over the last 4000 years and to unravel possible human impacts on the sedimentation. A diverse array of complementary methods was applied on the 6 m long record. High resolution of mineralogical (XRD) and geochemical (XRF) analyses were performed. Quantitative mineralogical phases of sediments by the Rietveld method were computed using Topaz software. The age of the record is constrained combining radionuclide and radiocarbon dating, and checked using the correlation between the earthquake history and rapidly deposited layer identified. A high sedimentation rate of 0.12 cm/yr was inferred at the coring site. The 4000 years old record shows that significant fluctuations of the lake level and the riverine system inflow into the Amik Lake occurred. The Late Bronze lowstand leaded to punctual dryings of the lake at the end of the Bronze/Iron transition marked by the collapse of the Hittite Empire and during the Dark ages. At that time, the riverine was carrying a large terrigenous input linked to strong soil erosion related to deforestation, exploitation of mineral resources and the beginning of upland cultivation. During the Roman Period and in the later periods, upland soils were partly depleted and the riverine system completely transformed by channelization that leaded to a mashification of the Amik Basin. Chemical and mineralogical composition of sediments is quite diversified reflecting the significant geological variation of drainage basins. Abundant calcareous minerals, especially calcite, aragonite, dolomite and small amount of wollastonite characterize the different sedimentary levels recorded in the lake. Levels relatively rich in fluorite, richerite, enstatite, and wollastonite are a result of the erosion of the ophiolitic rocks from the surrounding Amanos Mountains. These levels are interpreted as corresponding to relatively high erosive periods, while more humid periods lead to more intensive weathering and consequently to the dominance of kaolinite, muscovite/illite and talc more advanced in the relative stability scale, indicating a climate with contrasting seasons. During the most recent Period a marked increase in terrigeneous minerals associated with a rise in dolomite indicates ungoing erosion as well as the drying-out of the lake. [less ▲]

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See detailContrasted terrace systems of the lower Moulouya valley as indicator of crustal deformation in NE Morocco
Rhixon, Gilles; Bartz, Melanie; El Ouahabi, Meriam ULg et al

Conference (2016, April 17)

The Moulouya has the largest catchment in Morocco and drains an area which is characterized by active crustal deformation during the Late Cenozoic due to the convergence between the African and Eurasian ... [more ▼]

The Moulouya has the largest catchment in Morocco and drains an area which is characterized by active crustal deformation during the Late Cenozoic due to the convergence between the African and Eurasian plates. As yet, its Pleistocene terrace sequence remains poorly documented. Our study focuses on the lowermost reach of the river in NE Morocco, which drains the Triffa sedimentary basin directly upstream of the estuary. New field observations, measurements and sedimentological data reveal contrasted fluvial environments on either side of a newly identified thrust zone, which disrupts the whole sedimentary basin and is associated with N–S compressive shortening in this region. Long-lasting fluvial aggradation, materialized by ≥37 m-thick stacked fill terraces, and the development of a well-preserved terrace staircase, with (at least) three Pleistocene terrace levels, occur in the footwall and the hanging wall of the thrust, respectively. Same as for the Pleistocene terrace sediments of the middle Moulouya, a recurrent sedimentary pattern, characterized by fining-upward sequences was observed in the studied terrace profiles. Assessing the rates of crustal deformation along this main thrust zone requires age estimations for these Pleistocene terrace deposits of the lower Moulouya on each side of the thrust. Samples for luminescence (OSL/IRSL), electron spin resonance (ESR) and cosmogenic nuclide dating (26Al/10Be, burial dating) were collected in terrace deposits located both in the foot- and hanging walls. Sample preparation and analysis as well as age determination are in progress. The preliminary data mentioned above, soon to be completed by chronological data, agree well with morphometric indicators stating that the whole Moulouya catchment is at disequilibrium state (Barcos et al., 2014). This is confirmed by several knickpoints in its longitudinal profile. Late Cenozoic uplift associated with crustal shortening, which occurred in the lowermost reach of the river, may have both hindered profile rectification of the Moulouya and, at the same time, buffered the effects of long-term base-level changes due to eustatic sea-level variations. [less ▲]

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See detailTowards a better understanding of ephemeral stream morphodynamics during the last 100 ka in the vicinity of the prehistoric site of Ifri n’Ammar (Morocco)
Bartz, Melanie; Rhixon; Khel, Martin et al

Conference (2016, April 17)

Our study focusses on the ephemeral stream deposits of Wadi Selloum to reconstruct the palaeoenvironmental evolution in direct vicinity of the rock shelter Ifri n’Ammar. As one of the oldest settlement ... [more ▼]

Our study focusses on the ephemeral stream deposits of Wadi Selloum to reconstruct the palaeoenvironmental evolution in direct vicinity of the rock shelter Ifri n’Ammar. As one of the oldest settlement sites of anatomically modern humans (AMH) in North Africa, Ifri n’Ammar documents periodical occupations since ~170 ka. Since these discontinuous settlement dynamics may be related to or influenced by landscape changes and climate forcing, our study aims (i) to identify phases of morphodynamic activity and stability in the deposits of Wadi Selloum by using micromorphological (sixteen thin sections), sedimentological (laser diffractometry, loss on ignition, magnetic susceptibility), geochemical ( XRF and Scheibler method) and mineralogical (X-ray diffractometry) proxies. Furthermore, (ii) a robust chronology for the ephemeral stream deposits is established by applying a combination of optically stimulated luminescence (OSL) and post infrared stimulated luminescence (pIRIR290) dating. Additionally, one collected pottery shard was dated by thermoluminescence (TL) dating for an inter method comparison. The application of luminescence dating techniques to Wadi Selloum deposits yielded burial ages between 1.3 ± 0.2 ka and 102 ± 8 ka covering different phases of morphodynamically stable and active phases. Enhanced aggradation is evident between ~100 and 60 ka, ~21 and 14 ka and during the Holocene. Overbank fines are distinguished by high amounts of allochthonous minerals such as quartz, muscovite, K-feldspar and plagioclase which give rise to higher eolian activity. This leads to the suggestion that morphodynamical activity was dominant during more arid phases. Landscape stability was observed in form of one palaeosol (2B-2C-sequence; OIS 3) and a recent soil (Ap/Ah-Bw-Bk-BC-C-sequence; after LGM), both attributed to the Calcisol group. Pedogenenesis is evident in thin sections by well-developed subangular blocky peds. The main soil forming process is secondary carbonate precipitation in subsoil horizons, supported by pedofeatures such as calcite infillings and hypocoatings. Holocene deposits (6.4 ± 4 to 1.3 ± 0.2 ka) seem to be affected by short-termed changes between landscape stability and hydromorphic activity due to strong variations in its mineralogical and geochemical characteristics. This is supported by a homogeneous and sterile stratigraphy, as well as an insignificant differentiation in soil horizons with only weakly developed pedofeatures. The sediment characteristics present a weak Ap-C-sequence of a calcaric Fluvisol. After ~1.3 ± 0.2 ka fluvial discharge was reduced and incision took place in the Wadi Selloum. Our study provides first insights in the palaeoenvironment around Ifri n’Ammar during the last glacial interglacial cycle and gives first suggestions about climatic conditions during the time of human occupation in Ifri n’Ammar. [less ▲]

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See detailTowards regenerative and positive impact architecture: A comparison of two net zero energy buildings
Attia, Shady ULg

in Sustainable Cities and Society (2016)

Abstract Regenerative design holds great promise for a new era of sustainable and positive impact architecture, sparking considerable interest among architects, building professionals and their clients ... [more ▼]

Abstract Regenerative design holds great promise for a new era of sustainable and positive impact architecture, sparking considerable interest among architects, building professionals and their clients. However, the translational arm of regenerative design in practice is in a relatively primitive state. Although a number of theoretical definitions and studies have been initiated, the early returns point to several inherent application problems. In this regard, the professional and scientific potential of regenerative architecture can only be fully realized by the identification of the key barriers to projects design, construction and operation. In this paper, we compare two state of the art buildings to address the critical steps in the transition from the negative impact reduction architecture to the positive impact regenerative architecture, utilizing life cycle analysis. The case studies analysis and comparison can serve as an inspiring eye opener and provide a vision for architects and building professionals in the fields of high performance buildings and regenerative architecture. [less ▲]

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See detailHypnose: on it’s very existence
VANHAUDENHUYSE, Audrey ULg

Conference (2016, April 16)

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See detailActualités dans la prise en charge des tendinopathies
Kaux, Jean-François ULg

Conference (2016, April 16)

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See detailDrug-induced thyroid dysfunction
Geenen, Vincent ULg

Conference (2016, April 16)

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See detailLe manuel numérique
Vintila, Elena-Georgiana ULg

Scientific conference (2016, April 16)

Digital textbooks, their recent version, completely new in terms of form and presentation, have risen not only numerous economic or sociological, but also educational and pedagogical issues. Should the ... [more ▼]

Digital textbooks, their recent version, completely new in terms of form and presentation, have risen not only numerous economic or sociological, but also educational and pedagogical issues. Should the digital textbook replace the traditional, printed version? Or do we rather speak of a product altogether different, built on novel principles of subject matter exploitation and shaped according to a teaching philosophy that intensifies activism, interactivity, progression and creativity? We attempt to answer the two above mentioned questions by analyzing three FLE textbooks for A1 level learners. [less ▲]

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See detailLa Soif du mal : crime et alcool à l’écran
Tomasovic, Dick ULg

Conference given outside the academic context (2016)

Tout au long de son histoire, le cinéma policier a souvent associé l’alcool au crime. Des films de gangsters réalisés durant la prohibition au thriller contemporain, en passant par le film noir ... [more ▼]

Tout au long de son histoire, le cinéma policier a souvent associé l’alcool au crime. Des films de gangsters réalisés durant la prohibition au thriller contemporain, en passant par le film noir hollywoodien, l’eau-de-vie est souvent une eau de mort. La conférence s’intéresse particulièrement au célèbre film de William Wellman, "L’Ennemi public" (1931), le chef-d’oeuvre des films de gangsters avec James Cagney. [less ▲]

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See detailLe développement territorial en Wallonie : entre dispersion des populations et concentration de l'activité
Halleux, Jean-Marie ULg

Conference given outside the academic context (2016)

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See detailPour une rhétorique sémiotique de l’image en sciences biologiques
Dondero, Maria Giulia ULg

in Argumentation et Analyse du Discours (2016), 16(1), 1-18

This article examines the rhetoric of images in the biological sciences. The epistemological context of our study is found in Bruno Latour’s sociology of science and Françoise Bastide’s semiotics of ... [more ▼]

This article examines the rhetoric of images in the biological sciences. The epistemological context of our study is found in Bruno Latour’s sociology of science and Françoise Bastide’s semiotics of scientific images, in the theory and methodology of post-Greimassian discourse semiotics, and in the rhetorical theories of Groupe µ and Jean-François Bordron. We use these different perspectives in an analysis of rhetorical operations (addition, deletion, selection, superposition, and more) performed by laboratory scientists, as represented in our corpus of images. Our particular focus is on a rhetoric that is “mereological”, so named because it is based on the relation between the whole and the parts. [less ▲]

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See detailGondwanan Palaeozoic plant spores: A review
Steemans, Philippe ULg; Gerrienne, Philippe ULg

Conference (2016, April 15)

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See detailFirst record of cryptospores in post-Hirnantian (latest Ordovician-early Silurian) sediments from Ethiopia
Brocke, R.; Bussert, R.; Lebenie, D. et al

Conference (2016, April 15)

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See detailLe billonnage cloisonné en agriculture des montagnes: évaluation et facteurs d'acceptation. Cas des Hauts Plateaux de l'Ouest-Cameroun
Djoukeng, Henri Grisseur ULg

Doctoral thesis (2016)

In the Western Highlands of Cameroon as in all other regions of the world where mountain agriculture is practiced, erosion and runoff pose a real threat to the sustainable preservation of natural ... [more ▼]

In the Western Highlands of Cameroon as in all other regions of the world where mountain agriculture is practiced, erosion and runoff pose a real threat to the sustainable preservation of natural resources. Generally, plots located on the slopes of the mountains in the Western Highlands have either become less productive or totally unproductive; this situation is exasperated by the scarcity of arable land which is largely attributed to cultural practices that do not take into account soil and water conservation methods. To better quantify the impacts of erosion and runoff on the different functions assigned to agriculture and agricultural holdings, this thesis has implemented tied ridging which is an unused soil and water conservation technique. We have thus compared the effectiveness of the existing soil preparation methods (ridging along the steepest slopes and flatbed cultivation) with tied ridging on two operating slopes namely 11% and 29%. The results showed a significant difference between the current practice (flatbed and ridging along the steepest slopes) and tied ridging in terms of soil loss (p = 0.003), yields (p = 0.003), and runoff water (p < 0.001). Under sole cropping of potato on a hectare of land, the tied ridging led to: (i) increase in populations of cultivated plants by 7%, (ii) significant reduction of runoff (lowered by a factor of seven) and soil loss (lowered by a factor of five), (iii) increase in yields by 80%, (iv) increase in farmer’s profitability by approximately 908388 FCFA.ha-1. The tied ridging needed 41% extra work regardless the slope of the land on which it was practiced. The tied ridging showed undeniable advantages: the stress of additional work was offset by the gain in yields for producer; additional work created additional job opportunities for the community; and tied ridging improved the conservation of soil and water for a healthy environment. Although the technique has several advantages, the provision of financial means for its implementation could be a negative point, because family labor supply is generally insufficient for its realization and the hired labor is expensive. Further work was dedicated to measuring the rate of adoption of the tied ridging technique and analysis of the determinants for adoption. The study showed that exploiting land ownership by farmers is a key factor in the implementation of soil conservation techniques. The results showed tied ridging adoption rates of 93% and 62% for dignitaries and other farmers respectively. Overall, access to land, operating slopes, and adoption of soil and water conservation techniques were significantly influenced by agronomic potentials of plots and socio-economic situation of farmers (p <0.05). Finally, in order to quantify the overall impact of tied ridging on the quality of surface water, we measured the proportion of sediments migrating from plots under the three soil preparation methods and entering to the river’s bed. The collected and measured sediments consisted of soil, plant residues, and other wastes (chemical packages, plastic casing used for irrigation, and food packages). The results showed that tied ridging cultivation method significantly reduced siltation of the Méloh River (p<0.05). Compared to 2012 and 2013, quantities of sediment decreased by 66% in 2014, the year in which the tied ridging technique was adopted on 75% of the plots. Thus the flatbed and ridging along the steepest slopes soil preparation methods are the principal cause of siltation and pollution of the Méloh River. The results of this research led to the following prospective approaches for improvement: (i) test the tied ridging technique with other crops and with different inter mounds’ spacing, (ii) study the facilitation of access to credit and creating farmer's organizations for promoting the adoption of tied ridging, (iii) test other soil and water conservation techniques such as live hedges, direct-sowing mulch-based crop (agroecology), and agroforestry, and (iv) conduct general limnologic studies of watersheds. The general limnology studies the surface waters according to their seasonal variations, and their physico-chemical and biological aspects. [less ▲]

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