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See detailThe impact of small physical obstacles on upstream movements of six species of fish - Synthesis of a 5-year telemetry study in the River Meuse basin
Ovidio, Michaël ULg; Philippart, Jean-Claude ULg

in Hydrobiologia (2002), 483(1-3), 55-69

In the course of the 'Meuse Salmon 2000' programme, most weirs and dams (3-8 m in height) in the regulated River Meuse have been progressively equipped with new fishways in order to restore the free ... [more ▼]

In the course of the 'Meuse Salmon 2000' programme, most weirs and dams (3-8 m in height) in the regulated River Meuse have been progressively equipped with new fishways in order to restore the free circulation of all amphibiotic fish species. Nevertheless, fish entering into major spawning tributaries are still confronted with various kinds of physical obstacles of which the overall impact on fish migration has never been investigated. In order to test their ability to negotiate physical obstacles, 128 individuals of fish ( Salmo trutta, Thymallus thymallus, Salmo salar, Chondrostoma nasus, Barbus barbus and Esox lucius) were captured several weeks before their spawning migrations and tagged with radio-transmitters. They were tracked from 30 to 466 days in the River Ourthe and six spawning tributaries over the period October 1995 to June 2001. All obstacles recorded in this study have been classified according to their type and main characteristics (i.e. slope, length and height). Results indicated that most fish migrate during or outside the spawning period and that some small obstacles are not as insignificant as initially thought and can significantly disrupt and/or obstruct their upstream movements. There is a need to harmonize interests in the sustainable conservation of fish populations and the development of small-scale hydropower generation and tourism. [less ▲]

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See detailImpact of social protection programs on economic resilience of poor households in Eastern Province of Rwanda
Militery Ngamata, Olivier ULg; Mbonyinkebe, Deo; Lebailly, Philippe ULg

in Kovacevic, Dusan (Ed.) Fourth International Scientific Symposium "Agrosym 2013“ : proceedings (2013)

This paper analyses the contribution of three programs of poverty reduction in Rwanda. It uses data from different reports and surveys with beneficiary poor households of social protection programs. The ... [more ▼]

This paper analyses the contribution of three programs of poverty reduction in Rwanda. It uses data from different reports and surveys with beneficiary poor households of social protection programs. The activities developed by these programs have allowed the poor in general and the widows of genocide in the Eastern Province of Rwanda in particular to improve their socioeconomic conditions, notably access to education, accommodation and medical care. Moreover, the beneficiaries have developed activities that diversify households’ revenues and improve their economic resilience. [less ▲]

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See detailImpact of soil and water conservation measures on catchment hydrological response-a case in north Ethiopia
Nyssen, J.; Clymans, W.; Descheemaeker, K. et al

in Hydrological Processes (2010), 24(13), 1880-1895

Impact studies of catchment management in the developing world rarely include detailed hydrological components. Here, changes in the hydrological response of a 200-ha catchment in north Ethiopia are ... [more ▼]

Impact studies of catchment management in the developing world rarely include detailed hydrological components. Here, changes in the hydrological response of a 200-ha catchment in north Ethiopia are investigated. The management included various soil and water conservation measures such as the construction of dry masonry stone bunds and check dams, the abandonment of post-harvest grazing, and the establishment of woody vegetation. Measurements at the catchment outlet indicated a runoff depth of 5 mm or a runoff coefficient (RC) of 1·6% in the rainy season of 2006. Combined with runoff measurements at plot scale, this allowed calculating the runoff curve number (CN) for various land uses and land management techniques. The pre-implementation runoff depth was then predicted using the CN values and a ponding adjustment factor, representing the abstraction of runoff induced by the 242 check dams in gullies. Using the 2006 rainfall depths, the runoff depth for the 2000 land management situation was predicted to be 26·5mm(RCD 8%), in line with current RCs of nearby catchments. Monitoring of the ground water level indicated a rise after catchment management. The yearly rise in water table after the onset of the rains (ΔT) relative to the water surplus (WS) over the same period increased between 2002-2003 (ΔT/WS D 3·4) and 2006 (ΔT/WS >11·1). Emerging wells and irrigation are other indicators for improved water supply in the managed catchment. Cropped fields in the gullies indicate that farmers are less frightened for the destructive effects of flash floods. Due to increased soil water content, the crop growing period is prolonged. It can be concluded that this catchment management has resulted in a higher infiltration rate and a reduction of direct runoff volume by 81% which has had a positive influence on the catchment water balance. © 2010 John Wiley & Sons, Ltd. [less ▲]

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See detailImpact of soil management on earthworm diversity according to differential plowing and plant residue incorporation
Lemtiri, Aboulkacem ULg; Alabi, Taofic; Zirbes, Lara ULg et al

Poster (2012, July 02)

Earthworms are largely distributed in terrestrial ecosystems and their abundance and diversity in soils are significantly affected by biotic (macro- and micro-organisms) and abiotic factors: soil ... [more ▼]

Earthworms are largely distributed in terrestrial ecosystems and their abundance and diversity in soils are significantly affected by biotic (macro- and micro-organisms) and abiotic factors: soil properties (pH, texture, structure…); agricultural management system and climate change. Here, tillage effect of earthworm population combined with crops residual management was investigated and correlated with soils properties. From wheat experimental field plots, the diversity of earthworm according to the field crop management was assessed. Application of particular crop production practices such as the integration of different levels of crop residues, diverse parts of wheat straws, at the field level regulate earthworm diversity and population abundance. Indeed, tillage reduced earthworm population with a 35% rate also corresponding to changes in soil properties. Agricultural practices had to be adapted to include consideration on macro-invertebrate abundance and diversity to maintain efficient soil fertility and allow sustainable crop production [less ▲]

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See detailThe impact of soil texture on the selection of nesting sites by the Malachite Kingfisher (Alcedinidae: Alcedo cristata Pallas 1764)
Kisasa Kafutshi, Robert ULg; Aloni Komanda, Jules

in Ostrich: Journal of African Ornithology (2011), 82(3), 243-246

The first granulometrical analysis of soil samples from nesting banks of the Malachite Kingfisher Alcedo cristata is reported. In total 56 samples from the Kinshasa area were analysed. Three standardised ... [more ▼]

The first granulometrical analysis of soil samples from nesting banks of the Malachite Kingfisher Alcedo cristata is reported. In total 56 samples from the Kinshasa area were analysed. Three standardised particle size fractions were determined in all groups of samples (percentage of sand, clay and silt). Mean particle percentage of soil samples from banks occupied by Malachite Kingfishers averaged 10.8 ± 6.1 of silt, 11.6 ± 6.5 of clay and 81.4 ± 11.4 of sand. A significant difference was found in the proportion of clay between banks with and without kingfisher nests. The results of the present study hence suggest that, as has been documented in other burrowing bird species, soil texture determines the selection of nesting sites in the Malachite Kingfisher. Our results indicate that even a slight difference in the proportion of clay can substantially affect the suitability of banks for the establishment of nests. In fact, burrowing birds must find suitable soils whose structure allows for a good compromise between stability and hardness to dig out, which poses an energy challenge just before the breeding season. [less ▲]

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See detailImpact of sowing density and nitrogen fertilization on Rumex obtusifolius L. development in organic winter cereal crops
Stilmant, Didier; Bodson, Bernard ULg; Losseau, Céline

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(3), 237-343

The control of Rumex obtusifolius L. (broad-leafed dock) is very important in organic farming systems. Indeed, concerns about managing this weed without the use of herbicides is one of the major factors ... [more ▼]

The control of Rumex obtusifolius L. (broad-leafed dock) is very important in organic farming systems. Indeed, concerns about managing this weed without the use of herbicides is one of the major factors limiting the uptake of these systems by conventional farmers. Against this backround, we analyzed the impact of two management practices on the development of R. obtusifolius populations in two winter cereal trials: spelt (triticum spelta [L.] thell.) and triticale (xtriticosecale [A.Camus]Wittm.). The management factors were sowing density (SD) and nitrogen fertilization (NF) at the tillering stage. The results showed that and increase in SD and NF led to stronger crop growth and better soil coverage by the end of sping, demonstrated by a significant decrease in photosynthetic active radiation (PAR) at soil level. However, although there was an SD effect, it was too weak in April to restrict an increase in R. obtusifolius populations through the recruitment of new R. obtusifulius plants. An increase in R. obtusifolius population density was also linked to an increase in the NF level, illustrating the nitrophilic character of this weed. Although an increase in SD and NF at the tillering stage led to a higher canopy density, these two practices failed to reduce R. Obtusifolius density in the cereal crops. Nevertheless, cereal yields were shown to be maintained or improved. Our results indicate that, even when combining weed harrowing and some cultural weed control methods, this perennial weed is difficult to control. [less ▲]

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See detailImpact of spatial resolution on the modelling of the Greenland ice sheet surface mass balance between 1990–2010, using the regional climate model MAR
Franco, Bruno ULg; Fettweis, Xavier ULg; Lang, Charlotte et al

in Cryosphere (The) (2012), 6

With the aim to force an ice dynamical model, the Greenland ice sheet (GrIS) surface mass balance (SMB) was modelled at different spatial resolutions (15-50 km) for the period 1990-2010, using the ... [more ▼]

With the aim to force an ice dynamical model, the Greenland ice sheet (GrIS) surface mass balance (SMB) was modelled at different spatial resolutions (15-50 km) for the period 1990-2010, using the regional climate model MAR (Modèle Atmosphérique Régional) forced by the ERA-INTERIM reanalysis. This comparison revealed that (i) the inter-annual variability of the SMB components is consistent within the different spatial resolutions investigated, (ii) the MAR model simulates heavier precipitation on average over the GrIS with diminishing spatial resolution, and (iii) the SMB components (except precipitation) can be derived from a simulation at lower resolution with an intelligent interpolation. This interpolation can also be used to approximate the SMB components over another topography/ice sheet mask of the GrIS. These results are important for the forcing of an ice dynamical model, needed to enable future projections of the GrIS contribution to sea level rise over the coming centuries. [less ▲]

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See detailImpact of spatio-temporal shade dynamics on wheat growth and yield, perspectives for temperate agroforestry
Artru, Sidonie ULg; Garré, Sarah ULg; Dupraz, Christian et al

in European Journal of Agronomy (2017)

A stumbling block to the adoption of silvoarable agroforestry systems is the lack of quantitative knowledge on the performance of different crops when competing for resources with trees. In North-Western ... [more ▼]

A stumbling block to the adoption of silvoarable agroforestry systems is the lack of quantitative knowledge on the performance of different crops when competing for resources with trees. In North-Western Europe, light is likely to be the principal limiting resource for understorey crops, and most agronomic studies show a systematic reduction of final yield as shade increases. However the intensity of the crop response depends on both the environmental conditions and the shade characteristics. This study addressed the issue by monitoring winter wheat (Triticum aestivum L.) growth, productivity and quality under artificial shade provided by military camouflage shade-netting, and using the Hi-sAFe model to relate the artificial shade conditions to those applying in agroforestry systems. The field experiment was carried out over two consecutive years (2013–14 and 2014–15) on the experimental farm of Gembloux Agro-Bio Tech, Belgium. The shade structures recreated two shade conditions: periodic shade (PS) and continuous shade (CS), with the former using overlapping military camouflage netting to provide discontinuous light through the day, and the latter using conventional shade cloth. The experiment simulated shading from a canopy of late-flushing hybrid walnut leaves above winter wheat. Shading was imposed 16 (2013–14) and 10 (2014–15) days before flowering and retained until harvest. The crop experienced full light conditions until the maximum leaf area index stage (LAImax) had been reached. In both years, LAI followed the same dynamics between the different treatments, but in 2013–2014 an attack of the take-all disease (Gaeumannomyces graminis var. tritici) reduced yields overall and prevented significant treatment effects. In season 2014–15 the decrease in global radiation reaching the crop during a period of 66 days (CS: – 61% and PS: – 43%) significantly affected final yield (CS: – 45% and PS: – 25%), mainly through a reduction of the average grain weight and the number of grain per m2. Grain protein content increased by up to 45% under the CS treatment in 2015. Nevertheless, at the plot scale, protein yield (t/ha) did not compensate for the final grain yield decrease. The Hi-sAFe model was used to simulate an agroforestry plot with two lines of walnut trees running either north-south or east-west. The levels of artificial shade levels applied in this experiment were compared to those predicted beneath trees growing with similar climatic conditions in Belgium. The levels used in the CS treatment are only likely to occur real agroforestry conditions on 10% of the cropped area until the trees are 30 years old and only with east-west tree row orientation. [less ▲]

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See detailThe impact of sperm precedence in malathion resistance transmission in populations of the red flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae)
Haubruge, Eric ULg; Arnaud, Ludovic; Mignon, Jacques ULg

in Journal of Stored Products Research (1997), 33(2), 143-146

Malathion resistance in the red flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) is actually a worldwide problem, and studies on resistance transmission are needed to improve ... [more ▼]

Malathion resistance in the red flour beetle Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) is actually a worldwide problem, and studies on resistance transmission are needed to improve insecticide resistance management. Females of Tribolium castaneum commonly mate with several males, and the last batch of male sperm preferentially fertilizes subsequent eggs. This phenomenon, a particular form of sexual selection, helps to increase resistance transmission in populations of stored product insects. We confirmed the last male sperm precedence and, in the absence of further matings, examined the evolution of mixed susceptible and malathion-resistant progeny during a 3-month period. The proportion of resistant phenotypes in female progeny was 99.6 and 3%, respectively, after the first mating with a resistant male and the second mating with a susceptible one. When females thus mated twice were isolated from males, the proportion of the resistant phenotype increased to 34.1% after 30 days. From 72 days onwards, this proportion ranged from 14.2 to 29.7%. (C) 1997, Published by Elsevier Science Ltd. [less ▲]

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See detailImpact of steam explosion treatment on chemical configuration of Tall Fescue lignin : structural elucidation using NMR spectroscopy
Maniet, Guillaume ULg; Jacquet, Nicolas ULg; Gillet, Sébastien ULg et al

Poster (2014, November 24)

In the economic and energy context of our society, it is universally recognized that alternatives to petrochemicals products must be found. To overcome this problem, renewable lignocellulosic biomass ... [more ▼]

In the economic and energy context of our society, it is universally recognized that alternatives to petrochemicals products must be found. To overcome this problem, renewable lignocellulosic biomass could be used to produce high value products. To achieve this objective, pretreatment processes are required to allow the breakdown of lignocellulosic structure and increase accessibility of the material. In this way, steam explosion is a thermo-mechano-chemical pretreatment which allows the opening of lignocellulosic material structural components and includes modifications of the physical properties of the material, hydrolysis of hemicellulosic components and modification of the chemical structure of lignin [1]. This study is focused on the impact of various steam explosion treatments on the chemical configuration of tall fescue lignin. NMR analyses perform on the Festuca L. pretreated samples show variations of links with treatment intensity. Observations show double phenomen :re-polymerization and depolymerization of the lignin structure during steam explosion process [2]. In parallel, HPSEC analyses show modifications in the molecular weight of the lignin obtained after the steam explosion treatment. [less ▲]

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See detailImpact of stone content on soil moisture measurement with capacitive sensors 10HS (Decagon)
Deraedt, Deborah ULg; Bernard, Julien ULg; Biettlot, Louise ULg et al

in Geophysical Research Abstracts (2015), 17

Lot of soil survey focused on agricultural soils. For practical reasons, those soils have a low stone content. So, most of the soil water content sensors are placed on low stone content soils and the ... [more ▼]

Lot of soil survey focused on agricultural soils. For practical reasons, those soils have a low stone content. So, most of the soil water content sensors are placed on low stone content soils and the calibration equations are developed for them. Yet some researches take an interest in forest soils that are often much different from the previous ones. The differences lie in their stone content and their slope. Lots of studies have proved the importance of making soil specific calibration of the soil water content sensor. As our lab use regularly the 10HS sensors (Decagon Devices, United States) in forested soil, we decided to evaluate the importance of the stone content in the soil moisture measurement. The soil used for this experimentation comes from Gembloux (50◦33’54.9”N, 4◦42’11.3”E). It is silt that has been sieved at 2 mm to remove the gravel. The stones used to form the samples come from an experimental site located in the Belgian Ardennes (50◦1’52.6”N, 4◦53’22.5”E). They are mainly composed of schist with some quartz and sandstone elements. Initially, only five samples were constructed with three replications each. The size and the proportion of stones were the variables. Stones were classified in two groups, the first contains gravels whose size is less than 1,5 cm and a the second contains gravels whose size is comprised between 2 and 3 cm. The proportions of stone selected for the experiment are 0, 20 and 40%. In order to generate validation data, two more samples were constructed with intermediate proportion of stone content (30%). The samples were built in PVC container which dimensions are slightly bigger than the sensor volume of influence (1.1-1.3l). The soil samples were saturated and then dried on a thermal chamber set at about 32◦C. During at least 14 days, the samples soil water content was determined by the sensor measurement with the Procheck read-out system (Decagon Devices, United State) and by weighting the samples thrice a day. The evolution of the soil sample height was monitored as well. As first result, the stone content is a parameter that seems to influence soil water content. The stone size is no important. Because soil moisture deserves to be measured accurately in every soil and to confirm the first results the experiment is going on with more samples, different stone proportions, other sensor positioning and a natural air drying. [less ▲]

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See detailimpact of stopping vitamin K antagonist therapy on concentrations of dephospho-uncarboxylated Matrix Gla protein
DELANAYE, Pierre ULg; DUBOIS, Bernard ULg; LUKAS, Pierre ULg et al

in Clinical Chemistry & Laboratory Medicine (2015), 53(8), 191-193

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See detailImpact of storage and handling on metabolites in a human plasma standard reference material
Eppe, Gauthier ULg; Dodder, Nathan; Lippa, Katrice et al

Conference (2010, June)

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See detailImpact of storage at 4°C on the study of sludge drying emissions
Fraikin, Laurent ULg; Herbreteau, Benjamin; Chaucherie, Xavier et al

Conference (2010, September)

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See detailImpact of storage duration on the emissions of ammonia and VOC during the convective drying of urban residual sludges
Fraikin, Laurent ULg; Herbreteau, Benjamin; Chaucherie, Xavier et al

in Tsotsas, E.; Metzger, T.; Peglow, M. (Eds.) Proceedings of IDS 2010 - Drying 2010 (2010, October)

Detailed reference viewed: 84 (20 ULg)