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See detailTemporal evolution of sediment supply in Lago Puyehue (Southern Chile) during the last 600 yr and its climatic significance
Bertrand, S.; Boes, X.; Castiaux, J. et al

in Quaternary Research (2005), 64(2), 163-175

Short-term climate changes in Southern Chile are investigated by a multi-proxy analysis of a 53-cm-long sedimentary sequence selected among eight short cores retrieved in Lago Puyehue (Chile, 40 degrees S ... [more ▼]

Short-term climate changes in Southern Chile are investigated by a multi-proxy analysis of a 53-cm-long sedimentary sequence selected among eight short cores retrieved in Lago Puyehue (Chile, 40 degrees S). This core contains a 600-yr-long undisturbed record of paleo-precipitation changes. Two measurement methods for sediment density, organic matter and biogenic silica contents are compared and the most appropriate techniques are selected. Together with aluminium and titanium concentrations, grain size and geochemical properties of the organic matter, these proxies are used to demonstrate paleo-precipitation changes around 40 degrees S. Increase of terrigenous particle supply between A.D. 1490 and A.D. 1700 suggests a humid period. Contemporaneously, delta C-13 data show increasing lake productivity, in response to the high nutrient supply. The A.D. 1700-1900 interval is characterized by a decreasing terrigenous supply and increasing delta C-13 values, interpreted as a drying period. The magnetic susceptibility signal, reflecting the terrigenous/biogenic ratio, demonstrates that similar variations occur in all the undisturbed sedimentary environments of Lago Puyehue. The A.D. 1490-1700 wet period is associated with the onset of the European Little Ice Age (LIA) and interpreted as its local signature. This work supports the fact that the LIA was a global event, not only restricted to the Northern Hemisphere. (c) 2005 University of Washington. All rights reserved. [less ▲]

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See detailThree metacognitive indices of realism in self assessment
Leclercq, Dieudonné ULg; Poumay, Marianne ULg

Learning material (2005)

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See detailSedimentary dynamics on isolated highs in Lake Baikal: evidence from detailed high-resolution geophysical data and sediment cores
Charlet, F.; Fagel, Nathalie ULg; De Batist, M. et al

in Global and Planetary Change (2005), 46(1-4), 125-144

High- and very-high-resolution seismic data, side-scan sonar mosaics and piston cores from three isolated highs in Lake Baikal (Vydrino Shoulder, Posolsky Bank, Continent Ridge) have allowed to document ... [more ▼]

High- and very-high-resolution seismic data, side-scan sonar mosaics and piston cores from three isolated highs in Lake Baikal (Vydrino Shoulder, Posolsky Bank, Continent Ridge) have allowed to document in unprecedented detail the depositional, re-depositional and tectonic processes and to characterise the overall sedimentary environment on such isolated highs. Our data show that Vydrino Shoulder actually represents a turbidity- or underflow-sourced slope fan, with a distinct channel-levee morphology, and affected by tectonics and stratigraphic unconformities. Sediment cores contain up to 90% of terrigenous material. Posolsky Bank is a major tilted fault block, clearly affected by tectonic activity, by stratigraphic unconformities and by mass wasting along its margins. Sedimentation on its crest is undisturbed, but average sedimentation rates are high due to the influence of the nearby Selenga River. Continent Ridge is also affected by active faulting, stratigraphic unconformities and by mass-wasting along its flanks. The area receives only 30% of terrigenous input. There are no signs of sediment reworking due to bottom-currents. Our study thus shows that in comparison with other environments in Lake Baikal, the isolated highs probably hold the best potential to contain a high-quality, continuous, undisturbed and undiluted sedimentary record suitable for paleoclimate research. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailEstimation de la pollution particulaire naturelle de l’air en 2003 à Niamey (Niger) à partir de données de visibilité horizontale
Ozer, Pierre ULg

in Environnement Risques & Santé (2005), 4(1), 43-49

There is no longer any question that air pollution in the form of large quantities of total suspended particulates (TSP) and particulate matter less than 10 µm in aerodynamic diameter (PM 10) harms human ... [more ▼]

There is no longer any question that air pollution in the form of large quantities of total suspended particulates (TSP) and particulate matter less than 10 µm in aerodynamic diameter (PM 10) harms human health. Deterioration in air quality due to high concentrations of mineral dust from Africa affects the US and Europe, although most of these countries are far from the Sahara. Surprisingly, no estimates of TSP or PM 10 levels near the Saharan dust source are available. Measurements taken at Niamey-Airport in Niger of horizontal visibility, which is reduced by the presence of dust in the atmosphere, allowed us to estimate TSP and PM 10 levels according various relations found in the literature. Both the magnitude and frequency of mineral particle concentrations are very high. The average yearly concentration is estimated at 103 µg.m -3 TSP and 67 µg.m -3 PM 10. These very high particulate levels present a real public health threat to which national and international policy-makers must respond. [less ▲]

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See detailTsunami en Asie du Sud-Est : analyse de son importance dans la presse écrite, des coûts assurés et du nombre de victimes à Sumatra
De Longueville, Florence ULg; Ozer, Pierre ULg

in Bulletin de la Société Géographique de Liège (2005), 46

The tsunami that affected the Indian ocean’s rims on December 26, 2004 claimed close to 300 000 deaths, essentially on the island of Sumatra, Indonesia, which suffered overwhelming devastation. This ... [more ▼]

The tsunami that affected the Indian ocean’s rims on December 26, 2004 claimed close to 300 000 deaths, essentially on the island of Sumatra, Indonesia, which suffered overwhelming devastation. This article is focused on three specific aspects of the disaster. On one side, we analyse the tribune offered to the tsunami catastrophe by the press in Le Soir and Le Monde. On the other side, we present an analysis of the distribution of insured losses from the latest data made available by the two largest reinsurance world companies, Swiss Re and Munich Re. Finally, we try to compare the estimated death toll with available demographic data for the province of Aceh. Here we show that the place given to the tsunami is enormous when compared to other natural tragedies, and we try to explain what motivated such a coverage. In addition, the analysis of insured losses highlights the North-South differences as local victims (99 %) concentrate less than 10 % of the losses supported by insurers. For what regards the death toll, we conclude that the number of about 235 000 for northern Indonesia is a broad estimation and that a realistic approach is impossible since no census was made in this region over the last three decades. [less ▲]

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See detailDésertification au Sahel : Crise climatique ou anthropique ?
Ozer, André ULg; Ozer, Pierre ULg

in Bulletin des Séances de l’Académie Royale des Sciences d’Outre-Mer = Mededelingen der Zittingen van de Koninklijke Academie voor Overzeese Wetenschappen (2005), 51(4), 395-423

Over the last decades, the Sahel suffered two dramatic contiguous droughts. At present, and since the early 1990s, rainfalls have recorded an amelioration that tends towards the average of precipitation ... [more ▼]

Over the last decades, the Sahel suffered two dramatic contiguous droughts. At present, and since the early 1990s, rainfalls have recorded an amelioration that tends towards the average of precipitation previous to the 1970s. However, this improvement may be due to increasing rainfall intensity and it seems that the length of the rainy season did not show any extension when compared to the 1970s and 1980s. Moreover, the Sahelian population has been multiplied by 3 since 1950 and is foreseen to be multiplied by 10 by the second half of the 21st century. Increasing urban population levels are much more impressive and bring about important environmental disruptions every day. Such increasing human pressure leads to uncontrolled deforestation in order to meet the needs in fuel wood, wood for construction and shifting cultivation. In addition, the ever-increasing number of herds for contracting range conditions leads to overgrazing. All these processes cause the degradation of the vegetation cover, a constant diminution of crop yields, as well as a strong reduction of biodiversity. One of the consequences is the reactivation of previously fixed dunes that were formed during the last interpluvial phase (18,000 BP). This article provides a state-of-the-art of the present controversy about desertification processes and concludes that if the droughts of the 1970s and 1980s have had dramatic consequences for the population of the Sahel, current and coming increasing human pressure will intensify the desertification of the southern fringe of the Sahara. [less ▲]

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See detailAeolian dust falls in northern Italy in autumn 1996: chemical and mineralogical comparison
Ozer, Pierre ULg; LUCCHETTI, Gabriella

in Periodico di Mineralogia (2005), 74(2), 103-116

This paper describes two dust fall events in Genoa and Turin (northern Italy) on 12 November 1996 and 7 December 1996 respectively. Meteorological data suggest that the dust-bearing rain that fell on ... [more ▼]

This paper describes two dust fall events in Genoa and Turin (northern Italy) on 12 November 1996 and 7 December 1996 respectively. Meteorological data suggest that the dust-bearing rain that fell on Genoa originated in north-eastern Morocco, where dust mobilisation was reported two days earlier, and had been carried straight to the north-western Italian coast by very strong winds. But the dust fall observed in Turin was not characterised by any specific synoptic situation inducing dust transport from the southern Mediterranean. The analyses include a quantitative and a qualitative study of two dust samples collected in downtown Genoa and Turin. The total amounts of dust that fell give two very high values of 4.05 g m-2 for Genoa and 0.54 g m-2 for Turin. The median sizes of the dust particles were 14.6 µm and 25.8 µm respectively. Most of the dust material collected in Genoa showed a yellowish-brown to red colour due to surface weathering by ferric hydroxides, and was sometimes coated with clayey particles. This attests to the Saharan origin of the particles. On the contrary, only 15% of the material sampled in Turin was coated with red-like clayey material from the desert. A large part of the sample was covered with a carbon-like substance. In addition, the proportion of organic matter (pollen grains and seeds) and anthropogenic fibrous material was much higher. This suggests that the dust fall observed in Turin very likely originated from local pollution mixed with a low proportion of long-distance Saharan dust. [less ▲]

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See detailDifferential Equations of Stiffened Panels and Fourier Series Expansion
Rigo, Philippe ULg; Richir, Thomas

in The Annals of “Dunarea De Jos” University of Galati (2005) (2005)

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See detailDifferential Equations of Stiffened Panels of Ship Structures & Fourier Series Expansions
Rigo, Philippe ULg

in Ship Technology Research = Schiffstechnik (2005)

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See detailDevelopment of biofilters to treat the pesticides wastes from spraying applications.
Pigeon, O.; de Vleeschouwer, C.; Cors, F. et al

in Communications in Agricultural and Applied Biological Sciences (2005), 70(4),

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See detailReproductive Strategies Of Tribolium Flour Beetles
Arnaud, Ludovic; Brostaux, Yves ULg; Lallemand, Stéphane et al

in Journal of Insect Science [=JIS] (2005), 5(33),

Although, beetles of the genus Tribolium first evolved as saprophylic insects, they have adapted to the stored products environment for several thousand years. In this study reproductive strategies are ... [more ▼]

Although, beetles of the genus Tribolium first evolved as saprophylic insects, they have adapted to the stored products environment for several thousand years. In this study reproductive strategies are described for eight species of Tribolium that are known to occur in this environment. Experiments were conducted under the same conditions for every species, and several life history traits, including egg mass, adult mass, developmental time and fecundity were examined and compared among these species. Common reproductive strategies were not found among the different species and univariate analysis highlighted strong differences between the species for most of the traits investigated. Some species showed reproductive traits that are likely to give a fitness advantage in the environment of stored products. Multivariate statistical analysis allowed the detection of different sub-groups with respect to their reproductive strategy. Adult mass and egg-to-adult developmental time discriminated between groups. Intraspecific allometric relationships were further investigated but only a few correlations appeared to be significant. [less ▲]

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See detailDiagnostic de l'intoxication aiguë par les insecticides organophosphorés basé sur la détermination de l'activité cholinestérasique
Turcant, Alain; Dehon, Betty; Ganière-Monteil, Catherine et al

in Annales de Toxicologie Analytique (2005), XVII(3), 207-210

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See detailEquiper des filières durables? L'élevage Bio en Belgique
Stassart, Pierre M ULg; Jamar, Daniel

in Natures Sciences Sociétés (2005), 13(4), 413-420

Résumé – L’agriculture biologique est actuellement à un tournant de son développement : sollicitée de plus en plus fréquemment pour entrer dans une filière de type long, elle apparaît comme « sous-équipée ... [more ▼]

Résumé – L’agriculture biologique est actuellement à un tournant de son développement : sollicitée de plus en plus fréquemment pour entrer dans une filière de type long, elle apparaît comme « sous-équipée »,se confrontant ainsi d’autant plus durement à une filière conventionnelle qui, elle, est « suréquipée ». Les auteurs analysent ce déplacement difficile en se référant au débat anglo-saxon sur la « conventionnalisation ». Ensuite, plutôt que de l’analyser en termes de « conversion de système de production », ils proposent la notion de « référentiel » qui envisage et compare l’équipement des deux filières en termes de normes, de connaissances et d’images. Cette grille de lecture permet à la fois de comprendre le caractère non questionné et non questionnable de la filière conventionnelle et de mettre en évidence la fragilité de la filière bio à se maintenir comme alternative durable. [less ▲]

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See detailConstruction d’un marché alternatif de viande bovine fermière
Stassart, Pierre M ULg

in Economie Rurale (2005), (286-287), 28-43

Food quality standards can be analysed as results of a convention process. This paper focuses on a beef farm production and commercialisation chain. It analyses the confrontation between a farmer’s ... [more ▼]

Food quality standards can be analysed as results of a convention process. This paper focuses on a beef farm production and commercialisation chain. It analyses the confrontation between a farmer’s project and the industrial norms that are ruling the Belgian beef market. This confrontation leads to a kind of hybridation of quality definition, but the paper shows how quality definition is closely linked with the kind of underlying commitments. Principles and criteria of collective organisation are modelling quality standards in such a way that flexibility and sensitivity to mutual demands are more important that stability and generalisation. [less ▲]

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See detailCaryl Phillips: A Master of Ambiguity
Ledent, Bénédicte ULg

in Ledent, Bénédicte (Ed.) The Caryl Phillips Bibliography (2005)

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See detailReview of Chris Abani's Graceland and Chimamanda Ngozi Adichie's Purple Hibiscus
Tunca, Daria ULg

in Wasafiri (2005), 45(Summer), 81-83

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See detailMise en évidence de la résilience de la végétation sahélienne par télédétection basse résolution au Niger à la suite d’épisodes de sécheresse.
Hountondji, Yvon ULg; Nicolas, Jacques ULg; Sokpon, Nestor et al

in Belgeo (2005), 2005(4), 499-516

In order to identify areas where desertification may have occurred over the last two decades, 109 stations located in three bioclimatic zones of Niger are analyzed. Time series of remote sensing data are ... [more ▼]

In order to identify areas where desertification may have occurred over the last two decades, 109 stations located in three bioclimatic zones of Niger are analyzed. Time series of remote sensing data are well suited to this task. Here, we use time series of NOAA AVHRR normalized difference vegetation index (NDVI) data and rainfall data. In this study, trend analysis is used to identify areas within the biomes from 1981 to 1999 in Niger with apparent land degradation in semi-arid areas. It appears that most of Niger (82,5%) recorded increasing rainfall while only 78,9 % experienced increasing in integrated vegetation index (iNDVI). However, the combination of the two variables through the ratio iNDVI/RR shows a widespread reduction of the rain-use efficiency with highly significant trend for the stations grouped by bioclimatic area (p<10-6) during the studied period (1981-1999). These negative trends suggest a progressive diminution of the vegetation productivity as highlighted by the lowering of the iNDVI/RR ratio. This situation suggested a consistently environmental degradation and that desertification processes continued during the last two decades over most of the Sahelian belt of Niger. [less ▲]

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