References of "Poster"
     in
Bookmark and Share    
Full Text
See detailEvaluation of the genetic diversity of honey bees, Apis mellifera L. in the Walloon Region and selection of strains tolerant to the mite Varroa destructor Anderson and Trueman
Leclercq, Gil ULg; Nguyen, Bach Kim ULg; Gengler, Nicolas ULg et al

Poster (2012, February 10)

For more than a decade, high losses of honey bee colonies have been noticed in several countries, including Belgium. Currently often the mite Varroa destructor is considered a main threat for beekeeping ... [more ▼]

For more than a decade, high losses of honey bee colonies have been noticed in several countries, including Belgium. Currently often the mite Varroa destructor is considered a main threat for beekeeping. In view of the inefficiency of the current chemical treatments, one of the solutions is to select honey bees tolerant to this parasite using genomic selection. To reach this objective the genetic diversity of honey bees needs first to be studied using mainly ‘Single Nucleotide Polymorphisms’ (SNP). Records and samples will be collected all over the Walloon Region in order to create an informative phenotypic and genomic data base that will be used for ‘Genome Wide Association Studies’ (GWAS) to detect associations between SNPs and tolerance, and to select bees tolerant to Varroa destructor. [less ▲]

Detailed reference viewed: 323 (28 ULg)
Full Text
See detailUsing fatty acid contents in milk to improve fertility of dairy cows?
Bastin, Catherine ULg; Berry, D.P.; Soyeurt, Hélène ULg et al

Poster (2012, February 10)

Improving dairy cow fertility by means of genetic selection has become increasingly important over the last years in order to overcome the declining cow fertility. This study investigated whether the ... [more ▼]

Improving dairy cow fertility by means of genetic selection has become increasingly important over the last years in order to overcome the declining cow fertility. This study investigated whether the fatty acids profile in milk could be used as an early predictor of genetic merit for fertility. Genetic covariances among 17 fatty acid contents in milk and the number of days from calving to conception were estimated from 29,792 first-parity Holstein cows. Results substantiated the unfavorable relationship among fertility and body fat mobilization in early lactation. Also, about 75% of the genetic variability of fertility was explained by the variability in milk fatty acids profile over the lactation indicating that these traits could be used to supplement genetic evaluations for fertility. [less ▲]

Detailed reference viewed: 44 (15 ULg)
Full Text
Peer Reviewed
See detailCharacterization of Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) overwintering sites
Fassotte, Bérénice ULg; Durieux, Delphine ULg; Haubruge, Eric ULg et al

Poster (2012, February 10)

The invasive multicoloured Asian ladybird, Harmonia axyridis (Pallas), forms large aggregations inside dwellings to overwinter. In order to highlight the specific features of infested houses, we ... [more ▼]

The invasive multicoloured Asian ladybird, Harmonia axyridis (Pallas), forms large aggregations inside dwellings to overwinter. In order to highlight the specific features of infested houses, we investigated a large number of overwintering sites in Wallonia between 2007 and 2011. These sites were characterized through a survey sent to homeowners confronted to invasion problems. The results indicate that H. axyridis preferentially selects isolated brick houses with red or white fronts to take shelter. Aggregations are mostly located at the first floor, essentially inside south or west oriented rooms. Furthermore, ladybirds generally gathered into wooden windows frames facing south or west, and to a lesser extent, in the upper corners of walls presenting the same orientation. [less ▲]

Detailed reference viewed: 26 (13 ULg)
Full Text
Peer Reviewed
See detailAnthropogenic effect on landscapes: spatial structure, ecological impact, entropy
Vranken, Isabelle ULg; Bogaert, Jan ULg; Visser, Marjolein

Poster (2012, February 10)

Structural and thermodynamic applications of entropy related to spatial heterogeneity under growing anthropogenic pressure have been examined. 16 zones from classified LANDSAT TM scenes presenting ... [more ▼]

Structural and thermodynamic applications of entropy related to spatial heterogeneity under growing anthropogenic pressure have been examined. 16 zones from classified LANDSAT TM scenes presenting different anthropogenic effect intensities have been used. Anthropogenic effects, compositional and configurational entropy have been measured. The scatter plot shows bell curves with maximal entropy at intermediate anthropogenic effects. Distinction of natural and anthropogenic classes shows opposed tendencies according to class and compositional/configurational type. These results have been interpreted as spatial transformation processes, energy production and release, and linked to the habitat heterogeneity and intermediate disturbance hypotheses. [less ▲]

Detailed reference viewed: 48 (4 ULg)
Full Text
See detailToward a single definition of periurban areas? A review of terms, definitions and characteristics relating to the "urban" terminology.
Andre, Marie ULg; Mahy, Grégory ULg; Lejeune, Philippe ULg et al

Poster (2012, February 10)

Remote sensing image interpretation and classification require a clear definition of what is considered as a rural, a periurban, a suburban or an urban area. Such a definition is also essential in order ... [more ▼]

Remote sensing image interpretation and classification require a clear definition of what is considered as a rural, a periurban, a suburban or an urban area. Such a definition is also essential in order to compare results of studies in periurban zones. Different terms, definitions and characteristics relating to these four concepts have been reviewed in the literature and compared according to different criteria like their type, citation frequency, strenghts and weaknesses, in the scope of a landscape evolution analysis. [less ▲]

Detailed reference viewed: 79 (15 ULg)
See detailBanana Streak Virus activation by tissue culture in natural interspecific banana hybrids
NINTIJE, Pierre

Poster (2012, February 10)

Banana and plantains are important in Burundi as a staple food crop and source of income for farmers. Nevertheless, their productions are threatened by pathogens among which viruses are especially harmful ... [more ▼]

Banana and plantains are important in Burundi as a staple food crop and source of income for farmers. Nevertheless, their productions are threatened by pathogens among which viruses are especially harmful. Elimination procedures of viruses are mainly performed by banana tissue culture techniques (TC) giving good sanitation results for most bananas’ viruses. However, Banana Streak Virus (BSV) a pararetrovirus is activated by TC for banana with the B genome. Therefore, there is a risk of encouraging the emergence of BSV in Burundi by the distribution of TC products to growers. In this work, we studied the activation of BSV by tissue culture in 5 banana cultivars collected in Burundi and micropropagated in vitro. The BSV activation was demonstrated in 4 cultivars using molecular tools. [less ▲]

Detailed reference viewed: 51 (1 ULg)
Full Text
See detailModelling realized niche of metallophyte species along copper and cobalt gradients on Katanga copper hills
Boisson, Sylvain ULg; Seleck, Maxime ULg; Guillaume, Arielle et al

Poster (2012, February 10)

In South Central Africa were identified more than 650 plant species tolerant to heavy metals, several of which endemic to Katanga and critically endangered by mining activities. These metallophyte are ... [more ▼]

In South Central Africa were identified more than 650 plant species tolerant to heavy metals, several of which endemic to Katanga and critically endangered by mining activities. These metallophyte are distributed over a hundred hills containing high copper and cobalt concentrations (20 to 10000 mg/kg for copper and 2 to 1000 mg/kg for cobalt). To understand the response of metallophyte to heavy metals, the ecological niches of 80 cupro-cobaltophytes were modeled with general additive models (GAM). Results show that (1) three groups of species were identified according to their optimum along a metal concentrations gradient and (2) a positive relationship exists between niche amplitude and optimum copper concentration. [less ▲]

Detailed reference viewed: 110 (30 ULg)
Peer Reviewed
See detailHymenoptera community of pig carcasse in an urban biotope
Frederickx, Christine ULg; Dekeirsschieter, Jessica ULg; Verheggen, François ULg et al

Poster (2012, February 10)

Most reports published in the field of forensic entomology studies are focused on Diptera pattern colonization and are neglecting Hymenoptera succession. Hymenoptera are part of the entomofaunal ... [more ▼]

Most reports published in the field of forensic entomology studies are focused on Diptera pattern colonization and are neglecting Hymenoptera succession. Hymenoptera are part of the entomofaunal colonization of a dead body as parasitoids of fly pupae. However, one should consider Hymenoptera parasitoids in a forensic entomology context to evaluate the time of death. Blowflies parasitoids may indeed be of particular importance as their time of attack is often restricted to a small, well-defined window of developmental time of the insect host. Because these parasitoids also interfere with developmental times of colonizing Diptera, a better understanding of their ecology is needed. [less ▲]

Detailed reference viewed: 41 (5 ULg)
Full Text
See detailIntegration of external information into genetic evaluations by a Bayesian procedure
Vandenplas, Jérémie ULg; Gengler, Nicolas ULg

Poster (2012, February 10)

One of the most important theoretical assumptions of methods used to assess genetic values is that all available information has to be considered simultaneously to obtain unbiased estimates. However, the ... [more ▼]

One of the most important theoretical assumptions of methods used to assess genetic values is that all available information has to be considered simultaneously to obtain unbiased estimates. However, the widespread international exchange of genetic material and, more recently, the important development of the genomic selection lead to the coexistence of different genetic evaluations. Therefore, the blending of the different sources of information is necessary to achieve better prediction. Integration of external information into genetic evaluations by a Bayesian procedure can partially resolve the problem under some assumptions. Results from such a method that also avoids double counting among external animals are highly similar to those from a joint evaluation. [less ▲]

Detailed reference viewed: 31 (9 ULg)
Full Text
Peer Reviewed
See detailRhizobacterial volatile organic compounds modulate biomass production and root architecture in Arabidopsis thaliana (L.) Heynh.
Varin, Sébastien; Saunier de Cazenave-Mendaluk, Magdalena ULg; Ormeno-Lafuente, Elena et al

Poster (2012, February 10)

Detailed reference viewed: 22 (0 ULg)
Full Text
See detailImpact of cultivation practices on soil respiration
Dufranne, Delphine ULg; Vancutsem, Françoise ULg; Bodson, Bernard ULg et al

Poster (2012, February 10)

Cultivation practices are known to induce a modification of soil organic matter quantity, quality and spatial distribution, which may impact dry matter decomposition kinetics. In order to bring answers to ... [more ▼]

Cultivation practices are known to induce a modification of soil organic matter quantity, quality and spatial distribution, which may impact dry matter decomposition kinetics. In order to bring answers to these questions, a multidisciplinary project (SOLRESIDUS) was set up by the University of Liege, Gembloux Agro-Bio Tech in collaboration with Walloon Agricultural Research Centre (CRA-W). The aim was to investigate the impact of cultivation practices (tillage and residue restitution) on crop growth, yield and environment, as well as on soil properties and on activities. In the present study, we focused on the impacts on soil respiration soil for 3 years. We will present our first results. [less ▲]

Detailed reference viewed: 36 (10 ULg)
Peer Reviewed
See detailAphid predators sampling in agrosystems in Belgium between 2009 and 2011
Vandereycken, Axel ULg; Durieux, Delphine ULg; Joie, Emilie ULg et al

Poster (2012, February 10)

The Multicolored Asian ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was imported in 1997 in Belgium to control aphid populations. Few years ago after its introduction, this exotic ... [more ▼]

The Multicolored Asian ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), was imported in 1997 in Belgium to control aphid populations. Few years ago after its introduction, this exotic insect was well adapted to temperate climate conditions and spread out all over ecosystems in Europe causing decline of other aphidophagous species. In arboreal habitats, H. axyridis is the most dominant Coccinellids but we are still lacking information about this occurrence in agrosystems. An aphidophages sampling between 2009 and 2011 was realized in four agrosystems such as broad bean, wheat, corn and potato. Nevertheless H. axyridis populations rise (5 times) from 2009 to 2011 in 2011, H. axyridis is the third most observed aphidophages after Episyrphus balteatus (De Geer) and Coccinella septempunctata (Linné). H. axyridis is the dominating species in corn with 70.83±6.60 individuals per 100m². [less ▲]

Detailed reference viewed: 28 (6 ULg)
Full Text
See detailRelationships between methane emissions of dairy cattle and farm management.
Vanrobays, Marie-Laure ULg; Vanlierde, Amélie ULg; Kandel, Purna Bhadra ULg et al

Poster (2012, February 10)

Livestock is considered as an important contributor to global methane emissions, predominately due to methanogenesis from ruminants. Moreover, these emissions also represent major losses of energy for ... [more ▼]

Livestock is considered as an important contributor to global methane emissions, predominately due to methanogenesis from ruminants. Moreover, these emissions also represent major losses of energy for dairy cows and therefore are linked to production efficiency. The on-going development of predictive equations (e.g., from milk composition) would allow to relate methane emissions to farm management (e.g., nutrition, environment) on a large scale in the Walloon Region of Belgium. Finally, by acquiring improved knowledge of these relationships, contributions to mitigate methane emissions could be based on an improved management of dairy herds. [less ▲]

Detailed reference viewed: 84 (31 ULg)
Full Text
See detailA new HPLC method to quantify alliin, the major sulfur compound in garlic
DETHIER, Bérénice ULg; Laloux, Morgan ULg; Hanon, Emilien et al

Poster (2012, February 10)

Garlic is recognized for centuries for its health benefits, mostly linked to its sulfur- components. Among the products extracted from the cloves, alliin retained our attention. Alliin was synthesized ... [more ▼]

Garlic is recognized for centuries for its health benefits, mostly linked to its sulfur- components. Among the products extracted from the cloves, alliin retained our attention. Alliin was synthesized. This process leads to two stereoisomers. Their HPLC separation was the aim of this work. The method described in the literature (amino column, detection at 210 nm) showed a resolution of 1,1 between the isomers. A second method was developed: the stationary phase was porous graphitic carbon and a water-ACN gradient was used for the elution. It provided a resolution of 3,2, was shorter and underwent the validation process. The method leads to satisfying results. The separation is excellent, and the validation criteria are fulfilled. This may be valuable for future research on garlic. [less ▲]

Detailed reference viewed: 60 (11 ULg)
Full Text
See detailVolatile organic compounds released by barley roots attract wireworms
Barsics, Fanny ULg; Fiers, Marie ULg; Haubruge, Eric ULg et al

Poster (2012, February 10)

Wireworms are the soil dwelling larvae of click beetles and are pests of many crops worldwide. Alternatives to insecticide treatments are needed in order to develop integrated management strategies. Our ... [more ▼]

Wireworms are the soil dwelling larvae of click beetles and are pests of many crops worldwide. Alternatives to insecticide treatments are needed in order to develop integrated management strategies. Our work consists in elucidating the role of barley root-emitted volatile organic compounds on the orientation behaviour of Agriotes sordidus wireworms. Using a dual choice olfactometer we have evaluated the attractiveness of a variety of baits ranging from barley roots themselves to isolated root-emitted volatile organic compounds. Wireworms were significantly attracted towards most of the tested baits. Our results should be taken into account in varietal selection, in crop rotation, or in trapping systems aiming at the reduction of the populations of this pest. [less ▲]

Detailed reference viewed: 60 (12 ULg)
See detailUse of Chrysoperla carnea larvae for biological control of immature stages of Leptinotarsa decemlineata
Sablon, Ludovic ULg; Haubruge, Eric ULg; Verheggen, François ULg

Poster (2012, February 10)

In laboratory assays, we demonstrated predation of Chrysoperla carnea lacewing larvae against eggs, first and second larval instars of Colorado potato beetle (CPB). When looking at the daily consumption ... [more ▼]

In laboratory assays, we demonstrated predation of Chrysoperla carnea lacewing larvae against eggs, first and second larval instars of Colorado potato beetle (CPB). When looking at the daily consumption, we found that prey consumption by the third larval instar was 3-fold higher compared to the two first instars. Partial or total consumption of prey was also numbered. Different proportions of partial/total consumption were found and these depend on the lacewing larval stage. This study provides new perspectives for possible use of C. carnea as a biological agent to control CPB. Nevertheless, additional work has to be conducted under semi-natural and field to completely evaluate this predatory potential. [less ▲]

Detailed reference viewed: 41 (1 ULg)
Full Text
See detailRelevance of pedotopographical indicators in the assessment of spatial distribution of soil water resources under forest stands. General Methodology.
Ridremont, François ULg; Claessens, Hugues ULg

Poster (2012, February 08)

Water resources constitute one of the most decisive factors of the adaptation of forest ecosystems facing climate changes. The assessment of soil water resources should lead a better understanding of ... [more ▼]

Water resources constitute one of the most decisive factors of the adaptation of forest ecosystems facing climate changes. The assessment of soil water resources should lead a better understanding of forest sites vulnerability to water stress and provide appropriate management recommendations for the choice of trees species and sylvicutlural techniques. This study aims to confront mapping pedotopographical indicators related to the water resource richness of forest sites to the soil moisture regime. The effect of soil moisture on the forest ecosystem productivity and the bioindicator expression of flora will be study too. [less ▲]

Detailed reference viewed: 32 (11 ULg)
Full Text
Peer Reviewed
See detailDesign of a biofilm reactor comprising a metal structured packing for the production of lipopeptides by B. subtilis
Zune, Quentin ULg; Ongena, Marc ULg; Toye, Dominique ULg et al

Poster (2012, February 08)

Abstract : The design of a new single species biofilm bioreactor has been investigated. Bacillus subtilis S499 has been chosen as a model organism for the production of lipopetides. Nevertheless ... [more ▼]

Abstract : The design of a new single species biofilm bioreactor has been investigated. Bacillus subtilis S499 has been chosen as a model organism for the production of lipopetides. Nevertheless, considering the surface active properties for this kind of metabolite, processes based on submerged culture in stirred-tank bioreactor involve the use of important amount of antifoam and therefore downstream processes are tedious. In this work, an original process was developed with an experimental setting leading to the suppression of foam formation during the culture. B. subtilis S499 makes a biofilm on a stainless steel structured packing in the top of a bioreactor, nutrient and oxygen supply being carried out by the media recirculation as liquid film on the packing. Lipopeptides secreted by biofilm are accumulated in the liquid phase under the packing and can reach concentrations as high as 800 mg/l. The colonization of the packing by the biofilm has been monitored by X-ray tomography. [less ▲]

Detailed reference viewed: 120 (30 ULg)
Full Text
See detailBall milling control: the reconciliation of macroscopic SensoMag® data with microscopic optical information.
Leroy, Sophie ULg; Köttgen, Axel ULg; de Haas, Bernard et al

Poster (2012, February 08)

Detailed reference viewed: 74 (11 ULg)
Full Text
See detailDéfinition du profil écologique de l'azobé (Lophira alata Banks ex Gaertn F., Ochnaceae) dans les forêts sempervirentes du Cameroun
Biwole, Achille ULg; Bourland, Nils ULg; Doucet, Jean-Louis ULg

Poster (2012, February 08)

Ekki or L. alata is a commercial timber species in Guinea-Congolian region considered vulnerable (IUCN, 2011). Indeed, its population structure shows a severe lack of regeneration in some rainforests ... [more ▼]

Ekki or L. alata is a commercial timber species in Guinea-Congolian region considered vulnerable (IUCN, 2011). Indeed, its population structure shows a severe lack of regeneration in some rainforests (Palla et al., 2002). Moreover, in logging areas, insufficient knowledge about its ecological profile limits any reliable modeling of population dynamics on a long term. Consequently, original research, to improve its ecological characterization to ensure its sustainable management is conducted in moist evergreen forest in southern Cameroon. First results on population dynamics of this species show, in plots study of recruitment, a population without major deficit regeneration. On its silvicultural ability, although that estimated on plantations on parks under 2 years old, the trends of growth (ca 30 and 0.5 cm / year respectively in height and diameter) and mortality (3, 3% / year) suggest a positive perspective. Current work in relation to other topics of research should provide further insights into its ecological profile in the evergreen forests of Cameroon. [less ▲]

Detailed reference viewed: 150 (37 ULg)
Full Text
See detailStudy of pesticide retention on leaves using high-speed imaging
Massinon, Mathieu ULg; Lebeau, Frédéric ULg

Poster (2012, February 08)

Detailed reference viewed: 45 (17 ULg)
Full Text
See detailContribution to the study of physicochemical and functional properties of hemicelluloses and xylooligosaccharides (XOS) extracted from rapeseed meal
Mertens, Cécile ULg; Paquot, Michel ULg; Destain, Jacqueline ULg et al

Poster (2012, February 08)

Rapeseed meal is one of the main industrial co-products from agriculture in Belgium, with more than 30 000 T produced each year. Beside its agricultural and energetic applications, new paths of ... [more ▼]

Rapeseed meal is one of the main industrial co-products from agriculture in Belgium, with more than 30 000 T produced each year. Beside its agricultural and energetic applications, new paths of valorization are being developed in order to add value to the rapeseed meal, usually by extraction of interesting molecules. In this thesis project, the aimed molecules are hemicelluloses, which are obtained via a global fractionation method that is being developed and optimized, constituting the first part of this project. Indeed, while rapeseed meals are globally already well exploited (mainly for their feed value), rapeseed hemicelluloses have not yet been studied for food application. Yet, hemicelluloses can be used as food additives (thickener, stabilizer, etc) mainly in bakery products. The literature being incomplete regarding the chemical structure of rapeseed hemicelluloses, one of the objectives of this project is to study their physicochemical properties, in regard with their technofunctional properties. Rapeseed hemicelluloses can also be used as raw material to produce an emergent type of prebiotic: xylooligosaccharides (XOS). These molecules can be introduced as well in the food supplement sector. Their production will be achieved by enzymatic hydrolysis, for a polymerization degree between two and five. Thus, the production and the physicochemical and technofunctional characterization of rapeseed XOS constitute the last objective of this project. This thesis is part of the SYNBIOFOR project, which aim is to create new symbiotic ingredients. [less ▲]

Detailed reference viewed: 236 (22 ULg)
Full Text
See detailTraining image scenarios for the Meuse alluvial aquifer and consistency with geophysical data
Hermans, Thomas ULg; Caers, Jef; Nguyen, Frédéric ULg

Poster (2012, February 08)

Recently, multiple-point statistics (MPS) introduced the training image (TI) concept to replace the variogram within an extended sequential simulation in order to describe more accurately multimodal ... [more ▼]

Recently, multiple-point statistics (MPS) introduced the training image (TI) concept to replace the variogram within an extended sequential simulation in order to describe more accurately multimodal distributions, with interconnected and curvilinear structures, such as those of alluvial plains. The role of the TI is to depict the conceptual geological patterns and it should be representative of the geological heterogeneity. MPS consists in extracting patterns from the training image, and anchoring them to subsurface data (e.g. well-log, seismic and production data). The construction of TI is one of the most critical and important step of MPS. Sedimentological studies may not be always available in a particular area. In this work, the alluvial aquifer of the Meuse river in the area of Liege is being investigated and there is few sedimentological data to build directly 3D conceptual model of the aquifer. In this context, we used general features of the Meuse river (slope, rate of flow, type of fluvial system) to select hydrofacies (based on a lithological classification in clay, sand and gravel) and their geometrical characteristics (channels and lobes of different sizes). Then several scenarios were built using these parameters to represent the uncertainty related to different possible geological scenarios. To verify the consistency of these TIs, a comparison with 2D electrical resistivity tomography data was carried out. 2D sections were randomly selected in the TIs and several cases were analyzed including the size of channels and lobes, the influence of surface resistivity in the results and the influence of the electrical resistivity of each facies. Forward and inverse electrical resistivity modelling was conducted on these synthetic models and the results were compared to field cases. The approach followed for the comparison is based on the calculation of a Euclidean distance between models and the visualization in a 2D or 3D space using multidimensional scaling (MDS). This technique allows verifying if field cases fall in the distribution represented by synthetic cases. In a second step, a cluster analysis was achieved on the MDS-map to provide a sensitivity analysis and to highlight which parameters were the most important for building training images. Then, the probability of each scenario was evaluated for the field cases using conditional probability. Conditional probability requires the calculation of the density function corresponding to the probability of the data given a geological scenario. This density function was obtained using a kernel density estimation technique based on the observations of the 2D MDS-map. Both the cluster analysis and the calculation of conditional probabilities for uncertain geological scenarios show that some parameters are not very sensitive (size of clay lenses, surface resistivity distribution) and that we can narrow the range of variations of some parameters (facies electrical resistivity values, gravel bodies size is more likely small, etc.). It shows that the investigation of the consistency of TI is an important step in each study including MPS. The next steps of the study are to generalize the analysis of the consistency of geological scenario with 3D geophysical data instead of 2D sections and to incorporate geophysical data as soft conditioning data for MPS simulations. [less ▲]

Detailed reference viewed: 42 (10 ULg)
See detailRole of western lowland gorilla (Gorilla gorilla gorilla Savage & Wyman, 1847) on the dynamics of tropical logged forest ecosystems
Haurez, Barbara ULg; Petre, Charles-Albert ULg; Doucet, Jean-Louis ULg

Poster (2012, February 08)

The western lowland gorilla (Gorilla gorilla gorilla Savage & Wyman) (WLG) which is considered as a critically endangered species by IUCN, could play a fundamental function in seeds dispersal of several ... [more ▼]

The western lowland gorilla (Gorilla gorilla gorilla Savage & Wyman) (WLG) which is considered as a critically endangered species by IUCN, could play a fundamental function in seeds dispersal of several plant species. This could be related to its frugivorous diet, its stomach capacity and the long gut retention time of the ingested food, its extensive daily path length, and its ability to swallow seeds of variable sizes. In addition, this animal tends to deposit most of ingested seeds in suitable habitats (especially logging gaps and old logging roads) for light-demanding plant development. This research will be conducted within the moist evergreen forest of Central Gabon in a logging concession granted to the company CEB Precious Woods. A preliminary study was undertaken as a Master thesis. It was aiming at obtaining a first insight of interactions between WLG and timber exploitation in Central Gabon and at assessing the extent to which they may benefit of each other. WLG abundances were estimated in unlogged and logged sites in the concession, and nesting behavior described. Seeds dispersed during the study period (February-May) by WLG were identified through fecal analysis. Relatively high WLG abundances were observed in the concession. WLG were found to nest preferentially in open areas and to frequently use old logging road network for nesting and feeding. Sixteen species were observed to be dispersed by WLG. Seeds of the most abundant species, Santiria trimera, were subjected to four treatments: (1) passed seeds, (2) passed seeds in fecal matrix, (3) seeds surrounded by fresh pulp and (3) seeds extracted from fresh fruits. The germination successes of S. trimera were significantly higher after gut passage partly thanks to fruit pulp removal. Our PhD study aims to characterize the functional ecology of WLG in tropical forests dynamics, especially regarding logging biotopes. Our research will be organized in three parts: (1) the survey of gorilla populations in the study area coupled with the characterization of their nests and habitats, (2) the study of dispersed species and of the effect of passage through gorilla gut on seed germination, (3) the estimate of dispersal distances for the species Santiria trimera (Burseraceae) by using molecular markers. Data for the second and third parts will be collected in one site selected thanks to the results of the survey for its high gorilla density, to assess the following assumptions: (1) gorillas favor the regeneration of many plant species, including timber trees; (2) they improve the genetic diversity and limit the genetic structure by widening the genetic pool and dispersing diasporas on large distances. If these hypotheses are accepted, sylvicultural practices may be adapted so as to take advantage from the presence of gorilla population. [less ▲]

Detailed reference viewed: 98 (7 ULg)
Full Text
See detailImpact of cultivation practices on soil respiration
Dufranne, Delphine ULg; Vancutsem, Françoise ULg; Bodson, Bernard ULg et al

Poster (2012, February 08)

In addition to its, evident, food supply function, agriculture is subjected to various pressures and has to respond to many challenges like reducing its CO2 emissions, maintaining or improving the soil ... [more ▼]

In addition to its, evident, food supply function, agriculture is subjected to various pressures and has to respond to many challenges like reducing its CO2 emissions, maintaining or improving the soil quality, maintaining productivity, sequestrating of the carbon stock in soil... Cultivation practices are known to induce a modification of soil organic matter quantity, quality and spatial distribution, which may impact dry matter decomposition kinetics. In order to bring answers to these questions, a multidisciplinary project (SOLRESIDUS) was set up by the University of Liege, Gembloux Agro-Bio Tech in collaboration with Walloon Agricultural Research Centre (CRA-W). The aim was to investigate the impact of cultivation practices (tillage and residue restitution) on crop growth, yield and environment, as well as on soil properties and on activities. In the present study, we focused on the impacts on soil CO2 fluxes. The experimental site is situated in Gembloux, in the Belgian loamy region. The plot is divided into 4 latin squares where two tillage modalities (plough after 2 stubble breaking vs only 2 stubble breaking) and two straw management practices (restitution vs. exportation) were compared. For 3 years, soil respiration was measured with automatic and manual dynamic soil chambers. Moreover, soil respiration was measured as well in cropping zone (total respiration) as in root exclusion zones created with root exclusion cylinders (heterotrophic respiration). As first results, we observed: -a significantly higher flux in plots with residue restitution, which is clearly explained by the larger amount of organic carbon prone to decomposition; -a decrease of standardized heterotrophic respiration (linked with residue decomposition) during growing seasons; -no significant differences in soil respiration between tillage modalities after 3 growing seasons. The experiment is still in progress, more years being necessary in order to evaluate the long-term impacts of cultivation practices on soil respiration. [less ▲]

Detailed reference viewed: 77 (8 ULg)
Full Text
See detailRISQUES DE POLLUTION LIES À LA PULVERISATION DES PESTICIDES
Boukhalfa, Hassina dite Hafida ULg

Poster (2012, February 03)

L'étude de la dispersion des pesticides est fondamentale pour diminuer les pollutions environnementales mais elle s'avère particulièrement complexe. L’application de pesticides consiste généralement en la ... [more ▼]

L'étude de la dispersion des pesticides est fondamentale pour diminuer les pollutions environnementales mais elle s'avère particulièrement complexe. L’application de pesticides consiste généralement en la pulvérisation d’une bouillie liquide constituée d’eau, de matière active et d’adjuvants. La taille et la vitesse initiales des gouttes produites en sortie de buse conditionnent fortement le transport (hors cible: dérive: pollution de l’air) ainsi que le dépôt de ces gouttes (hors cible: pollution de l’eau et des sols). La pollution de l'air par les pesticides est l'un des grands problèmes environnementaux aux quels est confrontée l'agriculture, et la réversibilité de ses effets sur l'environnement et la santé est encore peu connue. Lors des traitements phytosanitaires, une partie relativement importante des produits pulvérisés est perdue dans l'environnement. La toxicité des pesticides est reconnue mais, au contraire des niveaux mesurés dans les eaux destinées à l'alimentation en eau potable, les teneurs en pesticides dans l'air ambiant ne sont pas actuellement normés ou réglementés. Les risques pour la santé dépendent de la toxicité des matières actives et de leurs concentrations dans les milieux d'exposition (air, eau, aliments). Dans le but de pouvoir estimer les risque de pollution de l'air par les pesticides nous avons étudié l'influence de quelque paramètres sur la répartition des jets de pulvérisation issus d'un pulvérisateur à pression de liquide à jet projeté, à savoir: la pression, la vitesse du vent, la hauteur des buses et le type de buse. Les résultats obtenus on permit de mettre en évidence la contribution du réglage du matériel de pulvérisation en la quantité de pertes en produit pulvérisé et d'en déduire approximativement le risque de pollution environnementale. [less ▲]

Detailed reference viewed: 111 (29 ULg)
Full Text
See detailQuantifications en supergéométrie
Leuther, Thomas ULg

Poster (2012, February)

Le poster présente de façon vulgarisée certaines idées sous-jacentes à la recherche de quantifications invariantes en supergéométrie.

Detailed reference viewed: 49 (17 ULg)
Peer Reviewed
See detailLower impact of blue light on non-visual brain functions in older subjects
Daneault, V; Vandewalle, Gilles ULg; Hébert, M et al

Poster (2012, February)

Detailed reference viewed: 11 (3 ULg)
Full Text
Peer Reviewed
See detailARE CAPABILITY INDICES USEFULL TO ASSESS ANALYTICAL METHODS VALIDITY ?
Rozet, Eric ULg; Bouabidi, Abderrahim ULg; Talbi, M. et al

Poster (2012, February)

Analytical methods capability evaluation can be a useful methodology to assess the fitness of purpose of these methods for their future routine application. However, care on how to compute the capability ... [more ▼]

Analytical methods capability evaluation can be a useful methodology to assess the fitness of purpose of these methods for their future routine application. However, care on how to compute the capability indices has to be made. Indeed, the commonly used formulas to compute capability indices such as Cpk, will highly overestimate the true capability of the methods. Especially during methods validation or transfer, there are only few experiments performed and, using in these situations the commonly applied capability indices to declare a method as valid or as transferable to a receiving laboratory will conduct to inadequate decisions. In this work, an improved capability index, namely Cpk-tol and the corresponding estimator of proportion of non conforming results ( ) is proposed. Through Monte-Carlo simulations, they have been shown to greatly increase the estimation of analytical methods capability in particular in low sample size situations as encountered during methods validation or transfer. Additionally, the usefulness of this capability index is illustrated through several case studies covering applications commonly encountered in the pharmaceutical industry. Finally a methodology to determine the optimal sample size required to validate analytical methods is also given using the proposed capability metric. [less ▲]

Detailed reference viewed: 118 (6 ULg)
Full Text
Peer Reviewed
See detailCOMBINATION OF INDEPENDENT COMPONENT ANALYSIS, DESIGN OF EXPERIMENTS AND DESIGN SPACE FOR A NOVEL METHODOLOGY TO DEVELOP CHROMATOGRAPHIC METHODS
Rozet, Eric ULg; Debrus, Benjamin ULg; Lebrun, Pierre ULg et al

Poster (2012, February)

As defined by ICH [1] and FDA, Quality by Design (QbD) stands for “a systematic approach to development that begins with predefined objectives and emphasizes product and process understanding and process ... [more ▼]

As defined by ICH [1] and FDA, Quality by Design (QbD) stands for “a systematic approach to development that begins with predefined objectives and emphasizes product and process understanding and process control, based on sound science and quality risk management”. A risk–based QbD–compliant approach is proposed for the robust development of analytical methods. This methodology based on Design of Experiments (DoE) to study the experimental domain models the retention times at the beginning, the apex and the end of each peak corresponding to the compounds of a mixture and uses the separation criterion (S) rather than the resolution (RS) as a Critical Quality Attribute. Stepwise multiple linear regressions are used to create the models. The estimated error is propagated from the modelled responses to the separation criterion (S) using Monte Carlo simulations in order to estimate the predictive distribution of the separation criterion (S) over the whole experimental domain. This allows finding ranges of operating conditions that will guarantee a satisfactory quality of the method in its future use. These ranges define the Design Space (DS) of the method. In chromatographic terms, the chromatograms processed at operating conditions within the DS will assuredly show high quality, with well separated peaks and short run time, for instance. This Design Space can thus be defined as the subspace, necessarily encompassed in the experimental domain (i.e. the knowledge space), within which the probability for the criterion to be higher than an advisedly selected threshold is higher than a minimum quality level. Precisely, the DS is defined as “the multidimensional combination and interaction of input variables (e.g., material attributes) and process parameters that have been demonstrated to provide assurance of quality” [1]. Therefore, this DS defines a region of operating conditions that provide prediction of assurance of quality rather than only quality as obtained with traditional mean response surface optimisation strategies. For instance, in the liquid chromatography there is a great difference in e.g. predicting a resolution (RS) higher than 1.5 vs. predicting that the probability for RS to be higher than 1.5 (i.e. P(RS> 1.5)) is high. The presentation of this global methodology will be illustrated for the robust optimisation and DS definition of several liquid chromatographic methods dedicated to the separation of different mixtures: pharmaceutical formulations, API and impurities/degradation products, plant extracts, separation of enantiomers, … References [1] International Conference on Harmonisation (ICH) of Technical Requirements for Registration of Pharmaceuticals for Human Use, Topic Q8(R2): Pharmaceutical development, Geneva, 2009. [less ▲]

Detailed reference viewed: 185 (9 ULg)
Full Text
See detailPOST-COMBUSTION CO2 CAPTURE: Global Process Simulation and Solvent Degradation
Léonard, Grégoire ULg; Lepaumier, Hélène; Blandina, Fabrice et al

Poster (2012, February)

One of the biggest upcoming challenges concerning both environmental and energy systems engineering is the control and limitation of greenhouse gas emissions due to human activity. Fossil fuels-fired ... [more ▼]

One of the biggest upcoming challenges concerning both environmental and energy systems engineering is the control and limitation of greenhouse gas emissions due to human activity. Fossil fuels-fired power plants are in this context one of the main contributors due to the large amounts of CO2 emitted. Different technologies have been developed for capturing CO2 from such power plants. This work focuses on post-combustion CO2 capture by reactive absorption into amine solvents like monoethanolamine (MEA). The main drawback of this technology is actually the high energy requirement of the process, especially for solvent regeneration. It is then highly interesting to model the capture process so that optimal operating conditions could be approached by simulation thus reducing the number of expensive experimental tests. Thanks to the simulation, it has been possible to identify the most influent process variables and to optimize their value. It was also possible to study the impact of process modifications on the global capture efficiency. The improvements studied allowed for a reduction by up to 14% of the process exergy consumption. Another major drawback of the post-combustion CO2 capture is solvent degradation, which can be due to thermal as well as oxidative mechanisms. Degradation affects the CO2 capture process since it may cause corrosion, foaming and fouling, possibly inducing a decrease of the solvent efficiency and high additional operating costs due to solvent replacement. In order to study degradation of conventional amine solvents as well as degradation of novel solvents, a degradation test rig has been built at the University of Liège in collaboration with the company Laborelec, member of the GDF SUEZ group. First results show that degradation obtained on this lab installation can be compared to degradation results observed on CO2 capture pilot installation. The final objective of this thesis is to make a link between degradation and simulation. Experimental data obtained on the degradation test rig will be implemented into the existing simulation model so that optimal operating conditions considering both process energy efficiency and solvent degradation can be determined. [less ▲]

Detailed reference viewed: 107 (6 ULg)
Full Text
Peer Reviewed
See detailQUALITY BY DESIGN COMPLIANT METHOD VALIDATION
Rozet, Eric ULg; Boulanger, B.; Hubert, Philippe ULg

Poster (2012, February)

Analytical method validation is a mandatory step to evaluate the ability of developed methods to provide accurate results for their routine application in order to trust the critical decisions that will ... [more ▼]

Analytical method validation is a mandatory step to evaluate the ability of developed methods to provide accurate results for their routine application in order to trust the critical decisions that will be made with them. Even if several guidelines exist to help perform analytical method validations (ICH Q2R1 [1], USP <1225> [2], …) there is still the need to clarify the meaning and interpretation of analytical method validation criteria and methodology. Indeed, actually method validation is mostly realised as the traditional check list implementation of e.g. the ICH Q2R1 or USP <1225> method validation requirements. However, within the trend of Quality by Design [3], there is the need to switch from this traditional vision to an analytical method validation really adding value and providing a high level of assurance of analytical methods results reliability. Yet, different interpretations can be made of the validation guidelines as well as for the definitions of the validation criteria. This will lead to diverse experimental designs implemented to try fulfilling these criteria. Finally, different decision methodologies can also be interpreted from these guidelines. Therefore, the risk that a validated analytical method may be unfit for its future purpose will depend on a personal interpretation of these guidelines. The objective of this presentation is thus to show that analytical method validation should be planned and performed by first starting with the end in mind: what is the objective of the analytical methods under study? In such a way analytical method validation is coherent with the actual Quality by Design regulatory expectations. The risk of having validated an analytical method unfit for its purpose is strongly reduced as well as the risk of generating Out of Specification (OOS) results due to an unfit method. References [1] International Conference on Harmonisation (ICH) of Technical Requirements for registration of Pharmaceuticals for Human Use, Topic Q2 (R1): Validation of Analytical Procedures: Text and Methodology, Geneva, 2005. [2] USP 33 NF 28 S1, U.S. Pharmacopeia, 2007. USP–NF General Chapter <1225>. [3] International Conference on Harmonisation (ICH) of Technical Requirements for Registration of Pharmaceuticals for Human Use, Topic Q8(R2): Pharmaceutical development, Geneva, 2009. [less ▲]

Detailed reference viewed: 158 (10 ULg)
Peer Reviewed
See detailA single synthetic small molecule that generates force against a load
Lussis, Perrine ULg; Svaldo-Lanero, Tiziana; Bertocco, Andrea et al

Poster (2012, February)

Biological molecular machines are able to rectify random thermal motions to generate directional force and carry out tasks on both the molecular and macroscopic length scales1. Although some artificial ... [more ▼]

Biological molecular machines are able to rectify random thermal motions to generate directional force and carry out tasks on both the molecular and macroscopic length scales1. Although some artificial nanomachines have been synthesized2 and used to collectively carry out mechanical tasks3, so far there have been no direct measurements of mechanical processes at the single-molecule level. Here we report measurements of the mechanical work performed by a synthetic molecule less than 5 nm long. We show that biased Brownian motion of the sub-molecular components in a hydrogen bonded [2]rotaxane4 -a molecular ring threaded onto a molecular axle- can be harnessed to generate significant directional forces. We used the cantilever of an atomic force microscope to apply a mechanical load to the ring during single-molecule pulling–relaxing cycle. The ring was pulled along the axle, away from the thermodynamically favoured binding site, and was then found to travel back to this site against an external load of 30 pN5. Using fluctuation theorems6, we were able to relate the measurements of the work done at the level of individual molecules to the free energy change measured previously by ensemble measurements. The results show that individual rotaxane molecules can generate directional forces of similar magnitude to those generated by natural biological machines, and extend the capabilities of AFM-based single molecule mechanics to the world of small molecules. It opens up the possibility of testing modern theories of non-equilibrium statistical mechanics, such as Jarzynski’s equality7 and the Crooks fluctuation theorem6, in single-molecule AFM measurements. 1. Schilva, M. (ed.) Molecular Motors (Wiley-VCH, Weinheim, 2003). 2. Kay, E. R., Liegh, D. A. & Zerbetto, F., Angew. Chem. Int. Ed. 46, 72-191 (2007). 3. Berna, J., Leigh, D. A., Lubomska, M., Mendoza, S. M., Pérez, E. M., Rudolf, P., Teobaldi, G. & Zerbetto, F., Nature Mater. 4, 704-710 (2005). 4. Kay, E. R. & Liegh, D. A., Top. Curr. Chem. 262, 133-177 (2005). 5. Lussis, P., Svaldo-Lanero T., Bertocco, A., Fustin C-A., Leigh, D. A., Duwez A-S., Nature Nanotech. 6, 553-557 (2011). 6. Crooks, G.E., Phys.Rev.E, 60, 2771-2726 (1999) 7. Jarzynski, C., Phys.Rev.Lett., 78, 2690-2693 (1997) [less ▲]

Detailed reference viewed: 12 (1 ULg)
Full Text
Peer Reviewed
See detailLe dosage des acides gras érythrocytaires : comparaison entre une population de référence et des sujets ayant présenté un infarctus aigu du myocarde
LE GOFF, Caroline ULg; Leroy, Ludovic; Kaux, Jean-François ULg et al

Poster (2012, February)

Introduction Un acide gras (AG) est un acide carboxylique avec une longue chaine aliphatique, qui peut être saturé ou insaturé. Récemment, le rôle des AG, particulièrement, celui des oméga-3 et oméga-6, a ... [more ▼]

Introduction Un acide gras (AG) est un acide carboxylique avec une longue chaine aliphatique, qui peut être saturé ou insaturé. Récemment, le rôle des AG, particulièrement, celui des oméga-3 et oméga-6, a émergé comme facteur de risque cardiovasculaire dans la littérature. Le but de ce travail était de comparer les taux d’AG mesurés dans une population saine avec ceux obtenus chez des patients admis aux urgences pour un infarctus du myocarde. Matériels et méthodes Cinquante quatre sujets sains (33±11ans, 31 femmes) ont été sélectionnés comme population de référence. Ces derniers ont été sélectionnés selon leur mode de vie (alimentation, tabac, etc). En parallèle, nous avons dosé les AG chez 33 patients (55±9 ans, 12 femmes) admis dans le service d’urgence de notre institution pour infarctus aigu du myocarde (AMI). Le sang était prélevé sur EDTA. Avant l’analyse, les échantillons étaient lavés et transméthylés. Le dosage des AG était réalisé par chromatographie gazeuse couplée à un détecteur à ionisation de flamme (GCFID). Après le dosage, nous avons réalisés une comparaison des taux, sommes et rapport entre les différents AG ainsi que l’index oméga-3 (somme de l’acide eicosapentaénoïque et docosahexaénoïque) obtenus dans les 2 groupes. Résultats. Des valeurs de référence ont été obtenues pour notre population de référence via le logiciel de statistique MedCalc. Dans le groupe AMI, les taux d’oméga-6 étaient significativement plus élevés (p<0.05) pour C18:2n6 (Figure 1) et C18:3n6 (Figure 2)comparés aux résultats obtenus dans la population de référence. Par contre les taux d’oméga-3 étaient significativement plus bas (p<0.01) par rapport aux sujets de référence pour le C22 :6n3 (Figure 3). L’index oméga-3 montrait une valeur plus basse et le rapport oméga-6/oméga-3 était plus élevé dans le groupe AMI comparé aux sujets de référence. Conclusion Le dosage des AG est un nouvel outil que le laboratoire peut proposer aux cliniciens afin de stratifier les patients présentant le plus de risque cardiovasculaire avant ou après un infarctus du myocarde. Ces patients pourraient ainsi être supplémenté en acides gras oméga-3 afin d’éviter les récidives d’infarctus du myocarde ou de diminuer la formation de la plaque d’athérosclérose avant le premier accident. [less ▲]

Detailed reference viewed: 600 (27 ULg)
Full Text
See detailInvestigations sur les protéines placentaires extraites des cotylédons fœtaux du Cervus elaphus
Fondja, E.; Okuyama, M.; Petrova, A. et al

Poster (2012, February)

Detailed reference viewed: 19 (2 ULg)
Full Text
Peer Reviewed
See detailRepeated cycles of DSS inducing a chronically relapsing inflammation: A novel model to study fibrosis using in vivo MRI T2 relaxometry
Breynaert, C; Dresselaers, T; Cremer, J et al

Poster (2012, February)

Detailed reference viewed: 19 (2 ULg)
Peer Reviewed
See detailDoes pupil constriction under blue and green monochromatic light exposure change with age?
Daneault, V; Vandewalle, Gilles ULg; Hébert, M et al

Poster (2012, February)

Detailed reference viewed: 21 (0 ULg)
Full Text
Peer Reviewed
See detailThe Emotional Side of Paternalism: Do People Share What They Feel?
Silvestre, Aude ULg; Dardenne, Benoît ULg

Poster (2012, January 28)

We were interested in the kind of emotions felt and socially shared after experiencing paternalism (when A acts toward B with a fatherlike attitude) or blatant hostility. Participants had to read either a ... [more ▼]

We were interested in the kind of emotions felt and socially shared after experiencing paternalism (when A acts toward B with a fatherlike attitude) or blatant hostility. Participants had to read either a paternalist, hostile or factual version of the welcome speech of their new boss. They then were asked to write a text about how this day was going (social sharing measure). The results revealed that being the target of paternalism or hostility is an emotional episode which leads to social sharing of emotion. Hostility is a clearly negative episode, leading to negative social sharing. Paternalism is more ambiguous. Participants felt positive emotions (except for distrust) but they shared both positive and negative ones. Paternalism can be perceived as positive but seems to lead to negative outcomes. Our further step would be to test its negative effects on performance (reading span test). [less ▲]

Detailed reference viewed: 102 (10 ULg)
Full Text
See detailMachine learning techniques for atmospheric pollutant monitoring
Sainlez, Matthieu ULg; Heyen, Georges ULg

Poster (2012, January 27)

Machine learning techniques are compared to predict nitrogen oxide (NOx) pollutant emission from the recovery boiler of a Kraft pulp mill. Starting from a large database of raw process data related to a ... [more ▼]

Machine learning techniques are compared to predict nitrogen oxide (NOx) pollutant emission from the recovery boiler of a Kraft pulp mill. Starting from a large database of raw process data related to a Kraft recovery boiler, we consider a regression problem in which we are trying to predict the value of a continuous variable. Generalization is done on the worst case configuration possible to make sure the model is adequate: the training period concerns stationary operations while test periods mainly focus on NOx emissions during transient operations. [less ▲]

Detailed reference viewed: 32 (8 ULg)
Full Text
See detailExtent of paleofires and past human settlements in the current rainforest patchwork of the Northern Republic of Congo
Gillet, Jean-François ULg; Doucet, Jean-Louis ULg

Poster (2012, January 04)

Objectives The origins of the patchwork of lowland semi-deciduous forests in the Northern Republic of Congo were apprehended. The aim of this study was to show that dense forests suffered fewer ... [more ▼]

Objectives The origins of the patchwork of lowland semi-deciduous forests in the Northern Republic of Congo were apprehended. The aim of this study was to show that dense forests suffered fewer disturbances than the open canopy forest types. Old disturbances associated with fires and human settlements seem to have had and still have today a substantial impact on the physiognomy and the composition of the forest types. Understanding past forest dynamics is a major component to predict the effects of both present climate change and human activities. Method Fifteen locations were studied along a 400-km-long SW-NE gradient in the NW of the Congo Basin through the ERA-net BiodivERsA CoForChange project. An anthraco-archaeological study was carried out in association with floristic inventories of three strata. Two main geology substrates were considered: the Mesozoic sandstones and Quaternary alluvial deposits. The abundance of charcoal fragments and human artifacts were evaluated by a network of 1-m-deep boring augers (n =208) and a 1.5-m-deep reference soil pit (n =15) in each site. A rating system was used to quantify the abundance of charcoal, charred Elaeis guineensis seeds and other artifacts (ceramic and metallurgic slag). Estimations were based on 20-cm-depth intervals (augers) or on pedological layers (pits). Twelve radiocarbon dating were performed in the major disturbed layers of each vegetation type studied. Results Two main groups of vegetation were highlighted according to the relative openness of the woody stand, the importance of the woody regeneration, and the development of the herbaceous cover. The two dense forests sampled were preferentially found in the northern part: the dense forest with Manilkara mabokeensis and Haumania dankelmaniana, and the Gilbertiodendron dewevrei forest on dry land. Most parts of the understorey exhibited the woody regeneration. The southern part presented more openness including the largest areas of open canopy vegetation types. Three forest types were identified: the Macaranga barteri pioneer forest, the open canopy vegetation type with Aframomum and Marantaceae, and the sparse forest with Megaphrinium macrostchyum and/or Haumania liebrestisiana. The understorey was a dense thicket of giant herbs belonging to the families Marantaceae and Zingiberaceae, causing a very scarce woody regeneration. Regardless the auger depth, charcoals were more profuse in the soils of the southern open canopy vegetation types (2-Way ANOVA, F=5.46, p=0.02). As in pit layers, charred oil palm nuts were more plentiful in the soils of these vegetation types (Mann-Whitney test, p<0.05). Of the five sites containing artifacts, only one recent potsherd dated 466-302 BP was located in dense forest but near a main river. The oldest signs of ceramic and metallurgical activities dated 2160-1407 BP were found in the current open canopy vegetation types. Within the latter, two expansion phases of the oil palm tree E. guineensis were observed: between 2146-1055 BP and 558-347 BP. Conversely, the oldest palaeofire was discovered in the M. mabokeensis dense forest and dated at 5467-5285 BP. Conclusions The dense forests contained less evidence of ancient fires and human settlements. They currently include evergreen and shade-tolerant tree species such as G. dewevrei and M. mabokeensis. The more sustained and repeated fires in the open canopy vegetation types were often associated with ancient human occupation. Today, the light-demanding giant herbaceous species such as Aframomum sp. and M. macrostchyum proliferate in the understorey below a simplified woody component of pioneer species such as M. barteri. The largest expansion phases of the oil palm tree E. guineensis in the southern part would be linked to ancient human occupation associated with larger canopy openings and fire events. The water availability, more evenly distributed near the heavily-irrigated Congo Basin, would also be a discriminating factor. [less ▲]

Detailed reference viewed: 63 (8 ULg)
Full Text
See detailMultilocus-based phylogeny and species recognition within the cosmopolitan Peltigera neopolydactyla-dolichorhiza complex
Magain, Nicolas ULg; Miadlikowska, Jolanta; Lutzoni, François et al

Poster (2012, January)

The Peltigera neopolydactyla/dolichorhiza complex is broadly distributed, growing in boreal and temperate regions from northern Norway to southern Chile, as well as in tropical mountains. Observed ... [more ▼]

The Peltigera neopolydactyla/dolichorhiza complex is broadly distributed, growing in boreal and temperate regions from northern Norway to southern Chile, as well as in tropical mountains. Observed morphotype and chemotype variation within this complex suggested the presence of multiple undescribed species. We inferred the phylogeny of Peltigera section Polydactylon with a special focus on the Peltigera neopolydactyla/dolichorhiza complex to determine the full breadth of this species complex, and to assess if taxa from different parts of the worlds but with similar morphological features share a most recent common ancestor. About 525 ITS sequences representing 104 distinct haplotypes were generated for representatives of Peltigera section Polydactylon. We selected a representative of each broadly defined phylotype for which three protein-coding loci: RPB1.1, b-tubulin and EFT2.1 were sequenced. Each of the three protein coding loci provided equivalent or more resolution and support than the ITS locus. The greatest proportion of significantly supported nodes across the tree resulted from β-tubulin alone. Many specimens identified as P. neopolydactyla and P. dolichorhiza are placed outside of this species complex. As currently defined both species represent polyphyletic assemblages of taxa including several potentially undescribed species. Our phylogenies suggest the presence of putatively new species within several complexes across the section. [less ▲]

Detailed reference viewed: 118 (13 ULg)
Full Text
See detailEngineering and characterisation of chimeric CXCR4 and CXCR7 chemokine receptors
Szpakowska, Martyna ULg; Fievez, Virginie; Counson, Manuel et al

Poster (2012, January)

Detailed reference viewed: 31 (0 ULg)
See detailPersonality modulation of (un)conscious processing: Novelty seeking and performance following supraliminal and subliminal reward cues
Bustin, Gaëlle ULg; Quoidbach, Jordi; Hansenne, Michel ULg et al

Poster (2012, January)

This study provides evidence that personality traits associated with responsiveness to conscious reward cues also influence responsiveness to unconscious reward cues. Participants with low and high levels ... [more ▼]

This study provides evidence that personality traits associated with responsiveness to conscious reward cues also influence responsiveness to unconscious reward cues. Participants with low and high levels of Novelty Seeking (NS) performed updating tasks in which they could either gain 1 euro or 5 cents. Gains were presented either supraliminally or subliminally at the beginning of each trial. Results showed that low NS participants performed better in the high-reward than in the low-reward condition, whereas high NS participants’ performance did not differ between reward conditions. Interestingly, we found that low NS participants performed significantly better when rewards were presented unconsciously, whereas high NS participants’ performance did not differ whether reward cues were presented subliminally or supraliminally. Our findings highlight the necessity to take personality into account in unconscious cognition research. They also suggest that whether implicit and explicit motives have similar or complementary influences might be determined by individual differences. [less ▲]

Detailed reference viewed: 73 (14 ULg)
Peer Reviewed
See detailMiR-146a an angiostatic miRNA elevated in peripartum cardiomyopathy
Halkein, Julie ULg; Tabruyn, Sébastien ULg; Haghikia, Arash et al

Poster (2012, January)

Detailed reference viewed: 47 (2 ULg)
Full Text
See detailEvaluation of aptamers for targeted radiotherapy: Binding specificity and labelling with natural lutetium
Gijs, Marlies ULg

Poster (2012)

Many cancer patients suffer from serious side effects when treated with external beam radiotherapy or chemotherapy because of damage to healthy tissues by lack of selectivity. In this regard, specific ... [more ▼]

Many cancer patients suffer from serious side effects when treated with external beam radiotherapy or chemotherapy because of damage to healthy tissues by lack of selectivity. In this regard, specific targeting of tumours through radiopharmaceuticals is increasingly considered as a promising strategy in oncology. Radiopharmaceuticals consist of a radionuclide coupled to a vector that specifically targets cancer-related molecules. Aptamers are small (5-15 kDa) synthetic oligonucleotides (DNA or RNA) that possess several advantages compared to other vectors, such as an relatively easy and cheap chemical synthesis allowing the introduction of different chemical modifications, a selection possible against almost every target, a non-immunogenicity and a good tumour penetration. That is why aptamers are regarded as promising molecules for the development of radiopharmaceuticals. An aptamer targeting the Human Epidermal growth factor Receptor 3 (HER3), which plays an important role in cancer development and progression, was chosen for the development of aptamer-based radiopharmaceuticals. [less ▲]

Detailed reference viewed: 24 (3 ULg)
Peer Reviewed
See detailBacillus lipopeptides: Potential new biopesticides against lettuce downy mildew
Deravel, J.; Coutte, F.; Van Hese, N. et al

Poster (2012)

Detailed reference viewed: 35 (1 ULg)
Full Text
Peer Reviewed
See detailIMAGING FINDINGS IN HORSES WITH PHARYNGEAL SQUAMOUS CELL CARCINOMA
Etienne, Anne-Laure ULg; Evrard, Laurence ULg; Bolen, Géraldine ULg et al

Poster (2012)

Introduction Squamous cell carcinoma (SCC) has been occasionally reported in the equine pharyngeal region1-3. The aim of this poster is to describe imaging findings in 4 cases of pharyngeal SCC. Material ... [more ▼]

Introduction Squamous cell carcinoma (SCC) has been occasionally reported in the equine pharyngeal region1-3. The aim of this poster is to describe imaging findings in 4 cases of pharyngeal SCC. Material and methods Four old horses, mean age 19.5, 2 females and 2 geldings, were referred for dyspnea (3/4) and/or dysphagia (3/4). Because of dyspnea radiographs were realized prior to endoscopy. Ultrasound (US) was performed in all cases by ventral and lateral approach using a linear 7,5MHz transducer. A post-mortem computed tomography (CT) of the head was performed in one case (16 slices CT, Somatom 16, Siemens). Results Radiographic opacity of the pharyngeal region was increased in all cases. A soft tissue mass was also visible in the caudal maxillary sinus in 1 horse. The epiglottis was either not recognized or difficult to see with an abnormal shape. Pharyngoepiglottic distance and nasopharyngeal diameter were reduced in all cases. The soft palate was either thick or impossible to be outlined, with an irregular surface. In 1 case it was dorsally displaced. The dorsal pharyngeal wall looked unevenly thickened or impossible to be outlined ventrally due to border effacement. No bony damage was identified on radiographs. A hypoechoic heterogeneous mass was visualized at US in 2 cases and an enlargement of the mandibular lymph nodes was observed in 3 cases. Lymphnodes had also heterogeneous echogenicity and increased doppler signal in 1 case. Oral and pharyngeal endoscopic examination confirmed a pharyngeal mass in 2 cases but was unsuccessful or incomplete because of passage impairment in 2. CT revealed maxillary bone lysis in the horse with a mass in the maxillary sinus. Histopathological examination of local biopsies or necropsy revealed pharyngeal SCC invading epiglottis, pharyngeal wall and soft palate in the 4 horses and the maxillary sinus in one. Discussion/Conclusion Because endoscopy can be impaired by the size of the mass, radiology is helpful in estimating the extent and invasiveness of the process and US to confirm lymphadenopathy. However because of its relatively low sensitivity and the local increased opacity, radiographic examination may underestimate bone lysis. [less ▲]

Detailed reference viewed: 117 (9 ULg)
Peer Reviewed
See detailNeural correlates of hypokinetic gait in Parkinson’s disease: An fMRI study
Cremers, Julien ULg; Stamatakis, Julien; D'Ostilio, Kevin ULg et al

Poster (2012)

Objective: To investigate the neural correlates of hypokinetic gait in Parkinson’s disease (PD) using functional magnetic resonance imaging (fMRI). Background: Although hypokinetic gait is frequent and ... [more ▼]

Objective: To investigate the neural correlates of hypokinetic gait in Parkinson’s disease (PD) using functional magnetic resonance imaging (fMRI). Background: Although hypokinetic gait is frequent and has a negative impact on quality of life in PD, its underlying mechanisms remain poorly understood. Assuming that the brain regions recruited during real and imagined gait strongly overlap, mental imagery of brisk gait may be a successful approach to study hypokinetic gait in PD. Methods: Fifteen ‘‘on-drugs’’ PD patients (8 males; mean age 5 65.1 6 9.4 years) and fifteen controls matched for age, gender and mental imagery skills were trained to perform video-taped trials of comfortable and brisk gait on a 25 meter-path. The study was organ- ized as a block-design fMRI experiment where subjects were instructed to rehearse themselves performing comfortable and brisk gait and to press a key to indicate when they completed each 25 meter-imagined gait trial. The imagined speed reserve (ISR) defined as the difference between imagined brisk and comfortable gait speeds was measured as a control of behavioral performance. Imaging data processing and analyses were performed using SPM8. The first-level individual contrast images representing the comparison between brisk and comfortable gait were entered as two separate groups (controls vs patients) in an ANOVA with the corresponding ISRs as correlation regressors. Results: Compared with controls, patients showed hypokinetic gait during real gait training as their increase in speed during brisk relatively to comfortable gait was related to an increase in step ca- dence (r50.87; p<0.001) but not in step length (r50.11). ISRs meas- ured during fMRI and their real counterparts measured offline strongly correlated in patients (r50.88; p<0.001) and controls (r50.59; p50.02). Between-group comparison (p<0.001, uncorrected) of fMRI data showed that increasing imagined gait speed was strongly associated with increased activity of the left posterior parietal cortex in controls and with decreased activity of this region in patients. Conclusions: Our findings suggest that hypokinetic gait in PD is related to the impaired functioning of the left posterior parietal cortex. This area may represent a target for therapeutic interventions aimed at alleviating gait disturbances in PD. [less ▲]

Detailed reference viewed: 197 (4 ULg)
See detailPrenatal undernutrition of the chicken embryo leads to changes in plasma T3 and corticosterone levels
Willems, Els; Wang, Yufeng; Willemsen, Hilke et al

Poster (2012)

Detailed reference viewed: 12 (0 ULg)
Full Text
See detailHybrid Lens for Solar Concentration: Optimization of the Multilayer Diffractive Lens
Languy, Fabian ULg; Habraken, Serge ULg

Poster (2012)

Manufacture process degrades the ideal shape of multilayer diffractive lens due to draft angle, half radius tool and slope error. We show some shape improvements using an extended scalar theory.

Detailed reference viewed: 78 (16 ULg)
Full Text
Peer Reviewed
See detailMALDI In-Source Decay for High Throughput sequencing of peptide animal toxins
Quinton, Loïc ULg; Degueldre, Michel ULg; Gilles, Nicolas et al

Poster (2012)

Detailed reference viewed: 22 (2 ULg)
See detailDynamique paysagère au Nord-Bénin (Afrique de l'Ouest)
Mama, A; Sinsin, B; Bogaert, Jan ULg et al

Poster (2012)

Detailed reference viewed: 42 (2 ULg)
See detailLes femmes chefs d’entreprises : Quels sont les facteurs qui influencent l’entrepreneuriat ?
Salman, Noura ULg; El Abboubi, Manal ULg; Henda-Guerfelf, Sana

Poster (2012)

Le présent article vise à dresser un état de l’art de l’entrepreneuriat au Maroc à partir d’une approche par le genre. Plusieurs variables contextuelles et socio-économiques interviennent dans la ... [more ▼]

Le présent article vise à dresser un état de l’art de l’entrepreneuriat au Maroc à partir d’une approche par le genre. Plusieurs variables contextuelles et socio-économiques interviennent dans la compréhension des incitants et des mécanismes de ce phénomène au Maroc et nous souhaitons les mettre en évidence dans cet article. Pour cela, nous questionnons les modalités d’entreprendre par les femmes marocaines et les variables contextuelles, religieuses, socio-économiques qui interviennent dans leurs choix d’investissement entrepreneuriaux… Pour cela nous élaborons une revue de la littérature et nous tenterons d’élaborer un modèle intégrateur des variables explicatives de l’entrepreneuriat féminin au Maroc. [less ▲]

Detailed reference viewed: 26 (1 ULg)
See detailEtude des feux d'aménagement en zone tropicale semi-aride: cas du Parc Régional du W du Niger
Diouf, A; Barbier, N; Saadou, M et al

Poster (2012)

Detailed reference viewed: 24 (4 ULg)
Full Text
See detailOrganisation d’une association villageoise adaptée à la foresterie communautaire au Gabon
Meunier, Q.; Angwé, A.; Boldrini, S. et al

Poster (2012)

Detailed reference viewed: 85 (4 ULg)
Peer Reviewed
See detailCKD-EPI GFR estimating equations in kidney transplantation: which added value for the new cystatin C based equations?
Masson, I; Maillard, N; Kamar, K et al

Poster (2012)

Detailed reference viewed: 6 (0 ULg)
Full Text
See detailEnzymatic process development for the extraction of ferulic acid from wheat bran
Giet, Jean-Michel ULg; Blecker, Christophe ULg

Poster (2012)

The agro-industries generate each year thousands of tons of by-products, such as cereal bran or sugar beet pulps. For instance, Walloon wheat transformation industry provides annually about 200.000 tons ... [more ▼]

The agro-industries generate each year thousands of tons of by-products, such as cereal bran or sugar beet pulps. For instance, Walloon wheat transformation industry provides annually about 200.000 tons of bran. Most of those by-products are under-valorized as cattle feed. By the use of biorefinery, this biomass may constitute a renewable source for various value-added molecules like dietary fibres, proteins, antioxidants, and more. [less ▲]

Detailed reference viewed: 71 (4 ULg)
See detailCognitive Flexibility in Mood Disorders
Piguet, C.; Strepenich, V.; Desseilles, Martin ULg et al

Poster (2012)

Detailed reference viewed: 6 (0 ULg)
Full Text
See detailEmpreintes de femmes sur les routes de l'Europe : l'architecture des couvents des annonciades célestes
Piront, Julie ULg

Poster (2012)

Poster présentant les principaux objectifs, les sources et les résultats obtenus de la thèse de doctorat intitulée "Empreintes architecturales de femmes sur les routes de l'Europe : étude des couvents des ... [more ▼]

Poster présentant les principaux objectifs, les sources et les résultats obtenus de la thèse de doctorat intitulée "Empreintes architecturales de femmes sur les routes de l'Europe : étude des couvents des annonciades célestes fondés avant 1800", soutenue le 9 décembre 2013. [less ▲]

Detailed reference viewed: 11 (0 ULg)
Full Text
Peer Reviewed
See detailLe débit de filtration glomérulaire est-il un déterminant de la concentration plasmatique du NGAL aux soins intensifs ?
DELANAYE, Pierre ULg; Claisse, Guillaume; Mehdi, Manoli et al

Poster (2012)

Detailed reference viewed: 28 (6 ULg)
Full Text
See detailcapacité de localisation spatiale des enfants avec Infirmité Motrice Cérébrale (IMC)
Schmetz, Emilie ULg; BARISNIKOV, Kovilkja

Poster (2012)

Detailed reference viewed: 108 (22 ULg)
Full Text
See detailIMPACT OF HEAVY METALS ON PHYSIOLOGICAL AND PROTEOMIC RESPONSES OF WILLOWS (SALIX SP.)
Evlard, Aricia ULg; Sergeant, Kjell; Ferrandis, Salvador et al

Poster (2012)

In 2010, around 3,800 sites in Wallonia (Belgium) were identified as potentially contaminated by heavy metals, a result of their past industrial and agricultural activities [1]. The technique of using ... [more ▼]

In 2010, around 3,800 sites in Wallonia (Belgium) were identified as potentially contaminated by heavy metals, a result of their past industrial and agricultural activities [1]. The technique of using plants to remediate contaminated sites (phytoremediation) has been studied for over twenty years. In particular, the use of trees (alder, willow, poplar) has been considered because of their large biomass production [2] [3] [4] [5]. The aim of this study was to identify the potential of local willow ecotypes to grow in the presence of heavy metals using lysimeters filled with dredging sludge. Several willow ecotypes were compared realizing morphological and physiological measurements (chlorophyll fluorescence, electrolyte leakage, carbohydrate content). The plant responses to metal stress were also investigated using a proteomic approach. Heavy metals contents in leaves and stems were analysed. With this study, the potential of these trees to valorise contaminated, abandoned sites in Belgium was evaluated. [1] Cellule Etat de l'environnement wallon (2010). Tableau de bord de l'environnement wallon. SPW-DGARNE-DEMNA-DEE. [2] Dickinson N. M. (2000). Strategies for sustainable woodland on contaminated soils. Chemosphere 41(1-2): 259-263. [3] Meers E., Lamsal S., Vervaeke P., Hopgood M., Lust N. and Tack F. M. G. (2005). Availability of heavy metals for uptake by Salix viminalis on a moderately contaminated dredged sediment disposal site. Environ Pollut 137(2): 354-364. [4] Meers E., Vandecasteele B., Ruttens A., Vangronsveld J. and Tack F. M. G. (2007). Potential of five willow species (Salix spp.) for phytoextraction of heavy metals. Environ Exp Bot 60(1): 57-68. [5] Rosselli W., Keller C. and Boschi K. (2003). Phytoextraction capacity of trees growing on a metal contaminated soil. Plant Soil 256(2): 265-272. [less ▲]

Detailed reference viewed: 84 (8 ULg)
Peer Reviewed
See detailRééducation attentionnelle chez l’enfant avec Trouble Déficitaire de l’Attention (TDA) : Analyse de deux cas.
Turine, Hélène ULg; Lejeune, Caroline ULg; Catale, Corinne ULg

Poster (2012)

L’objectif de cette étude est d’évaluer l’efficacité d’une prise en charge cognitive basée sur des exercices spécifiques d’entraînement de l’attention (informatisés et papier-crayon) sur les performances ... [more ▼]

L’objectif de cette étude est d’évaluer l’efficacité d’une prise en charge cognitive basée sur des exercices spécifiques d’entraînement de l’attention (informatisés et papier-crayon) sur les performances cognitives et le comportement de deux enfants TDA. L’impact d’une prise en charge attentionnelle chez des enfants avec TDA reste, à ce jour, mal connu même si quelques rares travaux suggèrent un bénéfice de ce type d’intervention sur des mesures attentionnelles et comportementales chez ces enfants (e.g., Noël et al., 2007). Deux enfants TDA avec troubles attentionnels objectivés par un examen neuropsychologique ont bénéficié de 40 séances de rééducation, lesquelles proposaient des exercices spécifiques aux difficultés de ces deux enfants (inhibition, attention soutenue et sélective et flexibilité). Chaque enfant était apparié à quatre enfants de contrôle. Les analyses de comparaison pré et post-rééducation montrent une amélioration des performances pour le cas 1 au niveau de différents composants attentionnels (inhibition, attention soutenue, attention sélective et flexibilité) ainsi qu’au niveau comportemental (p<.05) qui se maintient au-delà de 6 mois après la rééducation. En revanche, les analyses réalisées pour le cas 2 ne montrent aucune amélioration mais plaident en faveur d’un changement de stratégie cognitive (amélioration de la performance qualitative au détriment de la vitesse de réalisation). Cette étude confirme l’intérêt d’une prise en charge attentionnelle chez des enfants avec TDA et souligne l’importance de différents paramètres (variabilité interindividuelle, âge, motivation, profil attentionnel,…) dans le succès d’une telle rééducation. [less ▲]

Detailed reference viewed: 545 (46 ULg)
See detailDynamique des paysages forestiers et savanicoles du Sud et du Nord-Est du Burundi
Havyarimana, F; Bigendako, M J; Bogaert, Jan ULg et al

Poster (2012)

Detailed reference viewed: 32 (6 ULg)
Full Text
See detailEarly detection of alien plants in xeric Natura 2000 sites in Southern Belgium
Monty, Arnaud ULg; Frisson, Gwenn; Mahy, Grégory ULg

Poster (2012)

The Natura 2000 network consists of sites designated by the member States of the European Union, under the Habitats and Birds Directives. Setting up that network is one of the biggest challenge in nature ... [more ▼]

The Natura 2000 network consists of sites designated by the member States of the European Union, under the Habitats and Birds Directives. Setting up that network is one of the biggest challenge in nature conservation in Europe, since habitats and species for which Natura 2000 sites are designated must be maintained in a “favorable conservation status”. Little is known so far, however, about how Natura 2000 sites are invaded by exotics species. Xeric habitats of high biological value included in the Natura 2000 network are among the most species-rich in Southern Belgium. They include calcareous grasslands, sandy meadows, dry heathlands, boxwood stands, siliceous rocks and calcareous rocks. We randomly sampled 15% of sites in each of these six categories (with a minimum of five sites per category) , with a total of 86 sites out of 470 existing sites. In each site, we recorded the presence/absence of 63 alien plants know to develop in xeric habitats (species list based on Verloove (2006) and expert’s personnal observations.), and estimated species cover. 25 naturalized alien plant species were observed in xeric habitats of the Natura 2000 network in Southern Belgium. Generally, alien species populations were still limited. [less ▲]

Detailed reference viewed: 35 (3 ULg)
Peer Reviewed
See detailEffect of humic substances on in vitro rooting and acclimatization of Alder (Alnus glutinosa (L.) Gaertn).
Tahiri, Abdelghani ULg; Destain, Jacqueline ULg; Druart, Philippe et al

Poster (2012)

Humic substances (HS) are organic compounds resulting from the physical, chemical and microbiological transformations of organic residues. Present every where in the nature; they are taking part in basic ... [more ▼]

Humic substances (HS) are organic compounds resulting from the physical, chemical and microbiological transformations of organic residues. Present every where in the nature; they are taking part in basic functionalities in any ecosystems involving soils, sediments, waterand landfills. They are heterogeneous and complex carbon macromolecules. Our study aims to compare the effect of HS on in vitro rooting and acclimatization of the Alder species (Alnus glutinosa (L.) Gaertn) as tree growing on river banks or wasted areas. [less ▲]

Detailed reference viewed: 33 (5 ULg)
Full Text
See detailThe tomato leafminer reproduces without a mate: New case of parthenogenesis in Lepidoptera
Caparros Megido, Rudy ULg; Haubruge, Eric ULg; Verheggen, François ULg

Poster (2012)

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), originates from South America and is now considered to be one of the most damaging invasive pests of tomatoes in the Mediterranean Basin ... [more ▼]

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), originates from South America and is now considered to be one of the most damaging invasive pests of tomatoes in the Mediterranean Basin countries of Europe and North Africa. The preventing pest mating control methods include: (1) the use of synthetic pheromones for male attraction and annihilation inside insecticide-contain- ing traps; (2) mating disruption by saturating the atmosphere with sex pheromones which alter the ability of males to locate females; and (3) massive applications of sterile males to alter the overall reproductive success of the pest popula- tion. However, all these methods achieve only a poor success rate in controlling T. absoluta populations under greenhouse conditions. Sex pheromone management and sterile insect techniques are both based on an important biological trait: the insect must breed through sexual reproduction. Here, we report for the first time laboratory evidence of deuterotokous parthenogenesis, an asexual reproduction where both males and females are produced from unfertilized eggs. [less ▲]

Detailed reference viewed: 76 (12 ULg)