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See detailLa modélisation à l’aide du modèle SWAT des flux hydriques et du transport en suspension sur le bassin versant de la vallée de l’oued EL-Hachem
Tadrist, Nassima ULg; Debauche, Olivier ULg

in Revue des Régions Arides (2014)

Dans le Maghreb, les barrages souffrent régulièrement d’un envasement excessif lié aux problèmes d’érosion présent dans les impluviums situés en amont des barrages. Les origines de cette érosion sont ... [more ▼]

Dans le Maghreb, les barrages souffrent régulièrement d’un envasement excessif lié aux problèmes d’érosion présent dans les impluviums situés en amont des barrages. Les origines de cette érosion sont multiples : aménagement du territoire, déforestation, affectation des terres,… L’hydrologie couplée aux systèmes d’informations géographiques permet à l’aide de modèles distribués et physiquement basés de prédire l’évolution de l’envasement des barrages. L’application de ces modèles en Algérie permettra à terme, de prédire l’impact d’aménagement anti érosifs, de schémas d’aménagement du territoire sur l’envasement des barrages en estimant précisément la quantité de sédiments produit par l’érosion par ruissellement ainsi que le taux de remplissage. Une méthodologie basée sur les données cartographiques (modèle numérique de terrain, carte pédologie, carte géologie et la cartographie d’occupation du sol) ainsi que les données météorologiques journalières (température, humidité relative, vitesse du vent, radiation solaire) est en cours d’élaboration et de test sur le barrage de Bourkourdane. Cette méthodologie utilise le modèles SWAT Le modèle SWAT est utilisé pour prédire la quantité de sédiment s’accumulant dans le barrage, les flux hydriques débit entrants, sortants, ainsi que les volumes d’eau et de sédiments stockés dans le barrage. Une gestion adéquates des lâchers, couplée à une meilleure gestion de l’érosion en amont du barrage permettra d’allonger la durée de vie des barrages Algériens. Plus particulièrement pour le barrage de Boukourdane, une amélioration de la gestion des lâchers est primordiale pour améliorer la recharge de la nappe, lutter contre l’intrusion des eaux marines, et prévenir l’accumulation des particules fines qui réduisent la perméabilité du sol. [less ▲]

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See detailCOMMON Tool
Defays, Aurore ULg; Jeunejean, Aurélie ULg

Software (2014)

COMMON Tool is web application that allows to cross multimodal data from observations or experiments. Multimodal data coming from manual or automatic coding are imported in CSV format. This application ... [more ▼]

COMMON Tool is web application that allows to cross multimodal data from observations or experiments. Multimodal data coming from manual or automatic coding are imported in CSV format. This application gives the user the opportunity to observe on a time-line whenever a participant engages a particular mode of communication (such as speech, gesture, gaze, or graphics productions). The main advantage of this time-line is that it allows to dynamically display the data. Indeed, the user can set different display filters according to its criteria and desired outcomes. This software enables the user to perform quantitative analysis on the utilisation of each modality (number, total time, time average, standard deviation) for all or a single participant. Another advantage of this software is its ability to analyze in detail the multimodal articulations (detection of simultaneity or patterns). Plug-ins are also available to analyze in detail the speech content and to determine how verbal and non-verbal modalities are simultaneously mobilized to support the construction and maintenance of a shared representation of the activity (common ground). [less ▲]

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See detailLateral Magnetic Near-Field Imaging of Plasmonic Nanoantennas With Increasing Complexity
Denkova, D.; Verellen, N.; Silhanek, Alejandro ULg et al

in Small : Nano Micro (2014)

The design of many promising, newly emerging classes of photonic metamaterials and subwavelength confinement structures requires detailed knowledge and understanding of the electromagnetic near-field ... [more ▼]

The design of many promising, newly emerging classes of photonic metamaterials and subwavelength confinement structures requires detailed knowledge and understanding of the electromagnetic near-field interactions between their building blocks. While the electric field distributions and, respectively, the electric interactions of different nanostructures can be routinely measured, for example, by scattering near-field microscopy, only recently experimental methods for imaging the magnetic field distributions became available. In this paper, we provide direct experimental maps of the lateral magnetic near-field distributions of variously shaped plasmonic nanoantennas by using hollow-pyramid aperture scanning near-field optical microscopy (SNOM). We study both simple plasmonic nanoresonators, such as bars, disks, rings and more complex antennas. For the studied structures, the magnetic near-field distributions of the complex resonators have been found to be a superposition of the magnetic near-fields of the individual constituting elements. These experimental results, explained and validated by numerical simulations, open new possibilities for engineering and characterization of complex plasmonic antennas with increased functionality. [less ▲]

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See detailChemical composition, cytotoxicity and in vitro antitrypanosomal and antiplasmodial activity of the essential oils of four Cymbopogon species from Benin.
Kpoviessi, Salome; Bero, Joanne; Agbani, Pierre et al

in Journal of ethnopharmacology (2014), 151

ETHNOPHARMACOLOGICAL RELEVANCE: Cymbopogon species are largely used in folk medicine for the treatment of many diseases some of which related to parasitical diseases as fevers and headaches. As part of ... [more ▼]

ETHNOPHARMACOLOGICAL RELEVANCE: Cymbopogon species are largely used in folk medicine for the treatment of many diseases some of which related to parasitical diseases as fevers and headaches. As part of our research on antiparasitic essential oils from Beninese plants, we decided to evaluate the in vitro antiplasmodial and antitrypanosomal activities of essential oils of four Cymbopogon species used in traditional medicine as well as their cytotoxicity. MATERIALS AND METHODS: The essential oils of four Cymbopogon species Cymbopogon citratus (I), Cymbopogon giganteus (II), Cymbopogon nardus (III) and Cymbopogon schoenantus (IV) from Benin obtained by hydrodistillation were analysed by GC/MS and GC/FID and were tested in vitro against Trypanosoma brucei brucei and Plasmodium falciparum respectively for antitrypanosomal and antiplasmodial activities. Cytotoxicity was evaluated in vitro against Chinese Hamster Ovary (CHO) cells and the human non cancer fibroblast cell line (WI38) through MTT assay to evaluate the selectivity. RESULTS: All tested oils showed a strong antitrypanosomal activity with a good selectivity. Sample II was the most active against Trypanosoma brucei brucei and could be considered as a good candidate. It was less active against Plasmodium falciparum. Samples II, III and IV had low or no cytotoxicity, but the essential oil of Cymbopogon citraus (I), was toxic against CHO cells and moderately toxic against WI38 cells and needs further toxicological studies. Sample I (29 compounds) was characterised by the presence as main constituents of geranial, neral, beta-pinene and cis-geraniol; sample II (53 compounds) by the presence of trans-p-mentha-1(7),8-dien-2-ol, trans-carveol, trans-p-mentha-2,8-dienol, cis-p-mentha-2,8-dienol, cis-p-mentha-1(7),8-dien-2-ol, limonene, cis-carveol and cis-carvone; sample III (28 compounds) by beta-citronellal, nerol, beta-citronellol, elemol and limonene and sample IV (41 compounds) by piperitone, (+)-2-carene, limonene, elemol and beta-eudesmol. CONCLUSIONS: Our study shows that essential oils of Cymbopogon genus can be a good source of antitrypanosomal agents. This is the first report on the activity of these essential oils against Trypanosoma brucei brucei, Plasmodium falciparum and analysis of their cytotoxicity. [less ▲]

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See detailLignin extraction from Mediterranean agro-wastes: Impact of pretreatment conditions on lignin chemical structure and thermal degradation behavior
Manara, Panagiota; Zabaniotou, Anastasia; Vanderghem, Caroline ULg et al

in Catalysis Today (2014), 223

Three different types of Mediterranean, agro-industrial wastes (olive kernels, grape pomace/seeds, peach kernels), were subjected to two pretreatment processes, a chemical/organosolv and a physicochemical ... [more ▼]

Three different types of Mediterranean, agro-industrial wastes (olive kernels, grape pomace/seeds, peach kernels), were subjected to two pretreatment processes, a chemical/organosolv and a physicochemical one. The organosolv process included lignocellulosic biomass treatment with formic acid/acetic acid/water (30/50/20, v/v%), for 3 h at 107 °C, while the physicochemical method was conducted by immersing the biomass in a water/ethanol (8/92, v/v%), H2SO4 0.32 M, solvent and further exposing the slurry to microwave irradiation (maximum 250 W) for 1/2 h at 150 °C. Both processes were evaluated regarding the achieved delignification and the purity of the extracted lignins. The effect of the pretreatment processes onto the structure and thermal decomposition behavior of the extracted lignins was investigated via FT-IR and TGA analysis, respectively. The objective of the research work was to investigate potential valorization routes for these biomass agro-residues in the context of a biorefinery, focusing on lignin extraction. The pretreatment results showed that the obtained lignins, derived from both procedures, were of high purity (>82 wt%). Under the organosolv procedure, peach kernel delignification showed the maximum value (∼16 wt%), while under microwave pretreatment, olive kernel delignification showed the maximum value (∼35 wt%). Grape pomace/seeds appeared to be the most resistant in both treatments. [less ▲]

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See detailMulti-scale optimal interpolation: application to DINEOF analysis spiced with a local optimal interpolation
Beckers, Jean-Marie ULg; Barth, Alexander ULg; Tomazic, Igor ULg et al

in Ocean Science Discussions (2014), 11

We present a method in which the optimal interpolation of multi-scale processes can be untangled into a succession of simpler interpolations. First, we prove how the optimal analysis of a superposition of ... [more ▼]

We present a method in which the optimal interpolation of multi-scale processes can be untangled into a succession of simpler interpolations. First, we prove how the optimal analysis of a superposition of two processes can be obtained by different mathematical formulations involving iterations and analysis focusing on a single process. From the 5 different mathematical equivalent formulations we then select the most efficient ones by analyzing the behavior of the different possibilities in a simple and well controlled test case. The clear guidelines deduced from this experiment are then applied in a real situation in which we combine large-scale analysis of hourly SEVIRI satellite images using DINEOF with a local optimal interpolation using a Gaussian covariance. It is 10 shown that the optimal combination indeed provides the best reconstruction and can therefore be exploited to extract the maximum amount of useful information from the original data [less ▲]

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See detailOptimization of a formic/acetic acid delignification treatment on beech wood and its influence on the structural characteristics of the extracted lignins
Simon, Mathilde; Brostaux, Yves ULg; Vanderghem, Caroline ULg et al

in Journal of Chemical Technology & Biotechnology (2014), 89(1), 128-136

Background In order to replace petrochemicals by bio-based lignin products in a lot of high value-added applications, a formic/acetic acid treatment was adapted to beech wood (Fagus sylvatica L.) for ... [more ▼]

Background In order to replace petrochemicals by bio-based lignin products in a lot of high value-added applications, a formic/acetic acid treatment was adapted to beech wood (Fagus sylvatica L.) for lignin extraction. Results Beech wood particles were delignified at atmospheric pressure by a formic acid/acetic acid/water mixture. Cooking time and temperature were optimized for delignification, pulp yield and 2-furfural concentration. Response surface design analysis revealed that delignification yield increased with cooking time and temperature. Conclusion The multi-criteria optimization of delignification was used to find the ideal cooking conditions (5h07 min, 104.2°C) which could be satisfactory for the maximization of delignification (70.5%) and pulp yield (58.7%) and, to a lesser extent, for the minimization of 2-furfural production. Treatment conditions were found to influence the chemical structure of extracted lignins. Cooking time and temperature influenced inversely lignin molecular weights. [less ▲]

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See detailThe Tax Disputes and Litigation Review - Belgium
Docclo, Caroline ULg

in Simon Whitehead (Ed.) The Tax Disputes and Litigation Review (2014)

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See detailCoherent Backscattering in Fock Space: A Signature of Quantum Many-Body Interference in Interacting Bosonic Systems
Engl, Thomas; Dujardin, Julien ULg; Argüelles, Arturo et al

in Physical Review Letters (2014), 112

We predict a generic signature of quantum interference in many-body bosonic systems resulting in a coherent enhancement of the average return probability in Fock space. This enhancement is robust with ... [more ▼]

We predict a generic signature of quantum interference in many-body bosonic systems resulting in a coherent enhancement of the average return probability in Fock space. This enhancement is robust with respect to variations of external parameters even though it represents a dynamical manifestation of the delicate superposition principle in Fock space. It is a genuine quantum many-body effect that lies beyond the reach of any mean-field approach. Using a semiclassical approach based on interfering paths in Fock space, we calculate the magnitude of the backscattering peak and its dependence on gauge fields that break time-reversal invariance. We confirm our predictions by comparing them to exact quantum evolution probabilities in Bose-Hubbard models, and discuss their relevance in the context of many-body thermalization. [less ▲]

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See detailDe l'alimentation à la médecine : l'utilisation du vin dans les papyrus littéraires grecs et latins relatifs à la cuisine et à la médecine
Marganne, Marie-Hélène ULg

in de Haro Sanchez, Magali; Boudon-Millot, Véronique (Eds.) « Des grains et du vin dans l’Antiquité : entre aliments et médicaments ». Journée d’étude organisée le 17 mai 2013 à Paris, Maison de la Recherche (2014)

Unlike the Egyptians who produced and consumed wine and beer from the earliest times, the Greeks and Romans are known mainly as producers and drinkers of wine. This paper attempts to address the question ... [more ▼]

Unlike the Egyptians who produced and consumed wine and beer from the earliest times, the Greeks and Romans are known mainly as producers and drinkers of wine. This paper attempts to address the question of the use of wine in cooking and medical recipes on Greek and Latin literary papyri from Egypt (IV/III BC – VI/VII AD). Do these texts manifest a local influence through mentions of Egyptian wine or beer or do they refer only to Greek (after the conquest of Alexander the Great in 332 BC) and Italian (after the annexation to the Roman state in 30 BC) wines? Furthermore, this study lists the properties and functions ascribed to wine(s) in these writings. [less ▲]

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See detailBiostratigraphic significance of brachiopods near the Devonian–Carboniferous boundary
Mottequin, Bernard ULg; Brice, Denise; Legrand-Blain, Marie

in Geological Magazine (2014), 151

The biostratigraphic significance of selected uppermost Famennian (Upper Devonian) and lower Tournaisian (Mississippian) brachiopod genera, belonging to the orders Rhynchonellida (e.g. Araratella ... [more ▼]

The biostratigraphic significance of selected uppermost Famennian (Upper Devonian) and lower Tournaisian (Mississippian) brachiopod genera, belonging to the orders Rhynchonellida (e.g. Araratella), Spiriferida (e.g. Sphenospira, Prospira), Spiriferinida (Syringothyris) and Productida (except Chonetidina), is discussed. Owing to the difficulties of identifying productidine and strophalosiidine genera, in contrast to rhynchonellides and spiriferides, the biostratigraphic potential of the former has generally been overlooked. Brachiopods flourished in neritic environments that were unfavourable for conodonts and ammonoids. In the absence of the latter traditional marker fossils, they are potentially important for locating the Devonian–Carboniferous boundary in shallow water depositional settings in conjunction with rugose corals and foraminifers. On a worldwide scale, further work is required to reach a better assessment of the aftermath of the Hangenberg biological Crisis on brachiopods, notably in revising the faunas from the classical areas of the Famennian and Tournaisian stages in Western Europe. [less ▲]

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See detailStrontiohurlbutite, SrBe2(PO4)2, a new mineral from Nanping no. 31 pegmatite, Fujian Province, Southeastern China
Rao, C; Wang, R; Hatert, Frédéric ULg et al

in American Mineralogist (2014), 99

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See detailEvolution récente des extrêmes pluviométriques en Mauritanie (1933-2010)
Ozer, Pierre ULg; Hountondji, Yvon-Carmen; Gassani, Jean et al

in Actes du 27e Colloque International de l'Association Internationale de Climatologie (2014)

Un ensemble d’indicateurs a été compilé pour vérifier si la fréquence et/ou l’intensité des précipitations a significativement évolué au cours des dernières décennies dans la République Islamique de ... [more ▼]

Un ensemble d’indicateurs a été compilé pour vérifier si la fréquence et/ou l’intensité des précipitations a significativement évolué au cours des dernières décennies dans la République Islamique de Mauritanie. Cette étude s’appuie sur des indices nationaux basés les séries quotidiennes de précipitations de neuf stations synoptiques qui couvrent la période 1933-2010. L’analyse des précipitations a été réalisée en calculant annuellement treize indices pluviométriques : le total pluviométrique (PTOT), le nombre total de jours humides (précipitations ≥1 mm, JP), la lame d’eau moyenne précipitée par jour humide (Simple day intensity index, SDII), la pluviométrie maximale enregistrée sur 1 jour (Px1J), la fréquence des événements pluviométriques ≥ 10 mm (P10), ≥ 20 mm (P20), intenses (P95) et extrêmes (P99). Le poids relatif des cinq derniers indices dans le total pluviométrique annuel étant également apprécié. Les résultats montrent que les indices PTOT, JP, P10 et P20 présentent une tendance à la baisse significative sur la période 1933-2010. Dans le même temps, la fréquence des précipitations intenses et extrêmes évolue peu. De facto, la lame d’eau moyenne précipitée par jour humide (SDII) augmente de manière significative. Les résultats obtenus vont dans le sens des conclusions du Groupe d’expert intergouvernemental sur l’évolution du climat (Giec) à l’échelle globale, à savoir des précipitations extrêmes inchangées dans un contexte global de dessiccation. Selon de nombreux modèles, la dégradation pluviométrique pourrait s’amplifier dans les décennies à venir. Dès lors, des stratégies d’adaptation transfrontalières devraient être envisagées d’urgence car le processus de réchauffement de la planète n'est pas susceptible de diminuer dans les prochaines décennies. [less ▲]

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See detailImpacts des récentes variations pluviométriques sur le droit du sol, l’accès a l’eau et l’agriculture en Mauritanie : l’exemple du lac de Mâle
Gassani, Jean; De Longueville, Florence ULg; Gemenne, François ULg et al

in Actes du 27e Colloque International de l'Association Internationale de Climatologie (2014)

La République islamique de Mauritanie est à un carrefour sociopolitique de son histoire. Les crises environnementales conjuguées à la transformation des activités économiques et à la pression ... [more ▼]

La République islamique de Mauritanie est à un carrefour sociopolitique de son histoire. Les crises environnementales conjuguées à la transformation des activités économiques et à la pression démographique bouleversent les structures sociales du pays. La « grande sécheresse » qui a débuté en 1970 a transformé le mode de vie des nomades en les obligeant à se sédentariser. Cette sédentarisation ‘forcée’ par les déficits pluviométriques a modifié la conception des tribus tant par rapport à la propriété foncière qu’à l’accès aux ressources en eau, et a entrainé une pression accrue sur les haratines (anciens esclaves noirs) en matière de production agricole. Avec la diffusion des droits de l’homme, la promulgation d’une loi foncière, et la prise en compte de la chariâa, les anciens esclaves ont revendiqué la propriété des terres qu’ils cultivaient auparavant pour leurs maîtres. Devant le refus de ces derniers d’accéder à leur requête, les haratines se sont dirigés vers des terres non exploitées et ont interféré dans la pratique coutumière de la gestion de l’eau des bassins versants. Le conflit latent a dégénéré en conflit ouvert dans le bassin versant du lac de Mâle. Aujourd’hui, la situation ne s’améliore pas car la volonté politique se heurte aux pouvoirs tribaux locaux. [less ▲]

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See detailImpact of the invasive Asian clam, Corbicula spp., on a large river ecosytem
Pigneur, Lise-Marie; Falisse, Elodie; Roland, Kathleen et al

in Freshwater Biology (2014), 59(3), 573-583

During the past recent decades, Asiatic clams (Corbicula spp.) have spread spectacularly in several large European rivers. In the River Meuse, a transnational lowland river, an important chlorophyll a ... [more ▼]

During the past recent decades, Asiatic clams (Corbicula spp.) have spread spectacularly in several large European rivers. In the River Meuse, a transnational lowland river, an important chlorophyll a decline has been recorded since the mid-2000s, which seems to be related to the invasion by these exotic bivalves. This study aimed at verifying that hypothesis, using clam density data from field surveys, water quality monitoring data, and a simulation model. Estimated Corbicula densities were between 50 and 900 individuals m-2, depending on the site. Using a maximum filtration rate per clam body mass of 0.086 m3 g C-1 day-1 at 20°C derived from the literature, we ran simulations with a non-stationary model to estimate the impact of the exotic bivalve on the river plankton and water quality. In the stretches where the invasive clams developed best, comparison with a clam-free scenario allowed estimating a 70 % phytoplankton biomass loss due to their filtration, leading to a 61 % loss of annual primary productivity. Model simulations also showed that zooplankton may have suffered as much as 75 % loss in terms of biomass. The simulations also point to substantial effects of the invasive Corbicula on the river oxygen budget and on nutrient cycling. We expect that, in the heavily regulated sectors of the river, the loss of planktonic production due to the invasive filter-feeders will negatively affect other suspension feeders and alter ecosystem function and productivity. [less ▲]

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See detailEpidemiological and nonclinical studies investigating effects of iron in carcinogenesis-A critical review
Beguin, Yves ULg; Aapro, M.; Ludwig, H. et al

in Critical Reviews in Oncology/Hematology (2014), 89

The efficacy and tolerability of intravenous (i.v.) iron in managing cancer-related anemia and iron deficiency has been clinically evaluated and reviewed recently. However, long-term data in cancer ... [more ▼]

The efficacy and tolerability of intravenous (i.v.) iron in managing cancer-related anemia and iron deficiency has been clinically evaluated and reviewed recently. However, long-term data in cancer patients are not available; yet, long-term i.v. iron treatment in hemodialysis patients is not associated with increased cancer risk. This review summarizes epidemiological and nonclinical data on the role of iron in carcinogenesis. In humans, epidemiological data suggest correlations between certain cancers and increased iron exposure or iron overload. Nonclinical models that investigated whether iron can enhance carcinogenesis provide only limited evidence relevant for cancer patients since they were typically based on high iron doses as well as injection routes and iron formulations which are not used in the clinical setting. Nevertheless, in the absence of long-term outcome data from prospectively defined trials in i.v. iron-treated cancer patients, iron supplementation should be limited to periods of concomitant anti-tumor treatment. [less ▲]

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See detailPotentiality of clay raw materials from northern Morocco in ceramic industry: Tetouan and Meknes areas
El Ouahabi, Meriam ULg; Daoudi, Lahcen; De Vleeschouwer, François et al

in Journal of Minerals and Materials Characterization and Engineering (2014)

This study aims at evaluating the potential suitability of Tetouan and Meknes (central Morocco) clay material as raw materials in various ceramic applications by investigating their textural, chemical ... [more ▼]

This study aims at evaluating the potential suitability of Tetouan and Meknes (central Morocco) clay material as raw materials in various ceramic applications by investigating their textural, chemical, thermal and firing characteristics. Textural properties were identified by specific surface area, cation exchange capacity (CEC) and bulk density (ρs). Chemical and thermal properties were assessed using XRF and TG/DTA techniques, respectively. Firing characteristics at temperatures from 800°C to 1100°C were determined by linear firing shrinkage, loss on weight and water absorption capacity. The Meknes clays are characterised by medium cation exchange capacity (CEC) and specific surface area (SSA) values due to their moderate smectite content. The Tetouan clays have medium to low CEC and medium SSA values. The main oxides in the clayey samples are SiO2 (35 – 54.3 wt.%), Al2O3 (20.6 – 43.9 wt.%), and Fe2O3 (9.7 – 22.4 wt.%). The amount of CaO in Meknes clays ranges from 8 to 12 wt.%, whereas CaO is only present in some Tetouan clay (TE4, TE7, TN4 and TN5). A significant densification of ceramic behaviour could be noticed for most of Tetouan clays at firing temperatures above 1000°C. Meknes clays show earlier densification from 800 °C. The chemical, textural and ceramic properties of Tetouan and Meknes clays indicate their suitability as raw materials for the production of structural ceramics. The high amount of Fe2O3 in all clays makes them inappropriate in fine ceramics. [less ▲]

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See detailFacultative paedomorphosis and the pattern of intra- and interspecific variation in cranial skeleton: lessons from European newts (Ichthyosaura alpestris and Lissotriton vulgaris)
Ivanović, Ana; Cvijanović, Milena; Denoël, Mathieu ULg et al

in Zoomorphology (2014), 133(1), 99-109

Paedomorphosis, the presence of ancestral larval and juvenile traits that occur at the descendent adult stage, is an evolutionary phenomenon that shaped morphological evolution in many vertebrate lineages ... [more ▼]

Paedomorphosis, the presence of ancestral larval and juvenile traits that occur at the descendent adult stage, is an evolutionary phenomenon that shaped morphological evolution in many vertebrate lineages, including tailed amphibians. Among salamandrid species, paedomorphic and metamorphic phenotypes can be observed within single populations (facultative paedomorphosis). Despite wide interest in facultative paedomorphosis and polymorphism produced by heterochronic changes (heterochronic polymorphism), the studies that investigate intraspecific morphological variation in facultative paedomorphic species are largely missing. By quantifying the cranium size and development (bone development and remodeling), we investigated the variation at multiple levels (i.e., between sexes, populations and species) of two facultatively paedomorphic European newt species: the alpine and the smooth newt. The pattern of variation between paedomorphs (individuals keeping larval traits at the adult stage) and metamorphs (metamorphosed adult individuals) varied between species and among populations within a single species. The patterns of variation in size and skull formation appear to be more uniform in the alpine than in the smooth newt, indicating that developmental constraints differed between species (more pronounced in alpine than in smooth newt). Our study shows that the cranial skeleton provides detailed insight in the pattern of variation and divergence in heterochronic polymorphism within and between species and open new questions related to heterochronic polymorphism and evolution of cranial skeleton. [less ▲]

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