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See detailEcology and evolution of facultative paedomorphosis in newts and salamanders
Denoël, Mathieu ULg

Scientific conference (2013, February 21)

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See detailEcology and evolution of invasive plants: what to study next?
Monty, Arnaud ULg; Brown, Cynthia; Tepolt, Carolyn et al

Poster (2010, September)

In recent decades, a growing number of studies have addressed connections between ecological and evolutionary concepts in biologic invasions. These connections may be crucial for understanding the ... [more ▼]

In recent decades, a growing number of studies have addressed connections between ecological and evolutionary concepts in biologic invasions. These connections may be crucial for understanding the processes underlying invaders’ success. However, the extent to which scientists have worked on the integration of the ecology and evolution of invasive plants is poorly documented, as few attempts have been made to evaluate these efforts in invasion biology research. Such analysis can facilitate recognize well-documented relationships and identify gaps in our knowledge. In this study, we used a network-based method for visualizing the connections between major aspects of ecology and evolution in the primary research literature. Using the family Poaceae as an example, we show that ecological concepts were more studied and better interconnected than were evolutionary concepts. Several possible connections were not documented at all, representing knowledge gaps between ecology and evolution of invaders. Among knowledge gaps, the concepts of plasticity, gene flow, epigenetics and human influence were particularly under-connected. We discuss five possible research avenues to better understand the relationships between ecology and evolution in the success of Poaceae, and of alien plants in general. [less ▲]

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See detailEcology and management of Pericopsis elata (Harms) Meeuwen (Fabaceae) populations: a review
Bourland, Nils ULg; Kouadio, Yao Lambert; Fétéké, Fousséni et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(4), 486-498

Pericopsis elata (Fabaceae) is a valuable timber species occurring in moist semi-deciduous African forests. While it is at present substantially reduced, the tree’s natural distribution previously covered ... [more ▼]

Pericopsis elata (Fabaceae) is a valuable timber species occurring in moist semi-deciduous African forests. While it is at present substantially reduced, the tree’s natural distribution previously covered several distinct areas from Côte d’Ivoire to the Democratic Republic of Congo. This species has been logged since the second half of the 20th century. Because it suffers from a lack of regeneration, P. elata is now included in CITES Appendix II and is recorded as “Endangered A1cd” on the IUCN Red List. As with other long-lived light-demanding species, the survival of P. elata may have been favored by important disturbances that occurred in the Congo Basin during the last millennia. While both international trade and industrial uses of the wood of P. elata are well documented, information about its ecology are very sparse or contradictory, and even absent in some cases (e.g., regarding its effective flowering diameter). Furthermore, data describing the management of P. elata are scarce, including potential solutions to compensate for the deficit of natural regeneration. Along the same lines, genetic studies still remain at an early stage and only vague hypotheses have been offered to explain the origins of the tree’s populations. We emphasize the need for new research on those topics. Further studies would be useful in deciding whether P. elata populations can continue to be logged without the species being threatened with extinction. Finally, such research needs to target effective and inexpensive management procedures that could secure the future of the species in a logging context. [less ▲]

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See detailEcology and silviculture of black alder (Alnus glutinosa (L.) Gaertn.)
Claessens, Hugues ULg; Oosterbaan, Anne; Savill, Peter

Poster (2008, October)

Black alder (Alnus glutinosa (L.) Gaertn.) is widespread across Europe, both in forest and on open land along the watercourses. It plays a major role in nature conservation, thanks to its relation with ... [more ▼]

Black alder (Alnus glutinosa (L.) Gaertn.) is widespread across Europe, both in forest and on open land along the watercourses. It plays a major role in nature conservation, thanks to its relation with the river ecosystems and its network distribution on open land. [less ▲]

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See detailAn Ecology of Knowledges and Practices : The Salamanca Island Project (Colombia)
Melard, François ULg

Conference (2004, December 03)

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See detailThe ecology of Lake Kivu: a puzzle solved?
Darchambeau, François ULg; Sarmento, Hugo; Isumbisho, Mwapu et al

Conference (2010, January 14)

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See detailEcology of mosquitoes (Diptera, Culicidae) potentially vectors of arboviruses according to the kinds of animal husbandry in Belgium
Boukraa, Slimane ULg; De la Grandière de Noronha Cotta, Maria Ana ULg; Bawin, Thomas ULg et al

Poster (2013, November 12)

Human activity, commercial exchanges and climate changes current and future, could favor the (re)-emergence of vector-borne diseases, by inducing changes on Culicidae populations. This study aims to ... [more ▼]

Human activity, commercial exchanges and climate changes current and future, could favor the (re)-emergence of vector-borne diseases, by inducing changes on Culicidae populations. This study aims to determine the potential importance of agricultural environments, especially cattle farms and equestrian, to welcome and favor the proliferation of some species of mosquito responsible for transmission of arboviruses. To better understand the structure of the Culicidae population and identify habitats favorable to the development of each species, a taxonomic inventory was conducted in 2008 (III, VI and X) and 2009 (V and IX) in ten cattle farms, and in 2011 (VI-X) and 2012 (VI-IX) in six equestrian farms located in Belgium. The harvest of mosquitoes is based on adult trapping by CO2-traps (Mosquito magnet) and on larval sampling at the level of 64 biotopes such as water troughs, used tires, abandoned utensils and temporary puddles or not. The morphotaxonomic of larvae and genitalia, and molecular study showed the presence of 15 species: Culiseta annulata Schrank, 1776; Cs. morsitans Theobald, 1901 Anopheles claviger s.s. Meigen, 1804; An. maculipennis s.s. Meigen, 1818; An. messeae Falleroni, 1926; An. plumbeus Stephens, 1828; Culex pipiens molestus Forskal, 1775; Cx. pipiens pipiens L., 1758; Cx. torrentium Martini, 1925; Cx. hortensis hortensis Ficalbi, 1889; Cx. territans Walker, 1856; Coquillettidia richiardii Ficalbi, 1889; Ochlerotatus geniculatus Olivier, 1791; Oc. cantans Meigen, 1818 and Aedes cinereus Meigen, 1818. Among the 57,680 individuals examined, Cx. pipiens s.l., Cx. torrentium and Cs. annulata are the dominants species and ubiquitous in all farms visited. The species of the genus Anopheles have strong ecological requirements and are therefore associated with some special habitats; other species however have a strong ability to adapt and therefore attend a wide variety of biotopes (Cx. pipiens s.l., Cx. torrentium and Cs. annulata). Water troughs, used tires and ponds are the most favorable habitats for larval development of Culicidae. The species potentially vectors of arboviruses that can cause problems in epidemiological farms are Cx. pipiens s.l., Cx. torrentium and Cq. richiardii. Therefore, despite the low diversity of mosquito observed within the livestock environments, they represent a significant risk for the reproduction of some potential vectors of arboviruses. In addition, some larval habitats constitute very favorable sites for proliferation of mosquito, causing a real problem of nuisance for animals of farms. [less ▲]

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See detailEcology of Pericopsis elata (Fabaceae), a Timber Species Considered as Endangered, in Southeastern Cameroon
Bourland, Nils ULg; Kouadio, Yao Lambert; Lejeune, Philippe ULg et al

in Biotropica (2012), 44(6), 840-847

Pericopsis elata (Fabaceae) is a tall tree of high commercial value of the moist semi-deciduous African forests. As a result of logging which started decades ago, it is considered as threatened and ... [more ▼]

Pericopsis elata (Fabaceae) is a tall tree of high commercial value of the moist semi-deciduous African forests. As a result of logging which started decades ago, it is considered as threatened and included on both IUCN Red List and CITES Appendix II even though essential biological parameters controlling its population dynamics remain unknown. This study aims at improving the knowledge of the species ecological parameters and at assessing the impact of selective logging on its populations in an 118,052 ha forest in Cameroon. After inventorying the species in 1,432 ha, mortality and growth were assessed over continuous 5- and 2-year periods in unlogged and logged areas, respectively. Phenology was monitored in the unlogged forest during 5 years. The population structure followed a bell-shaped curve. Mean annual diameter increments in both environments did not differ significantly between unlogged and logged areas. P. elata is a deciduous species that flowers at the end of the main dry season. The minimum reproduction and effective flowering diameters were, respectively, 32 and 37 cm. Fruit maturation took place during 7 months. With a minimum logging diameter of 90 cm, the recovery rate computed over a 30-year period was greater than 100%. Selective logging harvested only 12.1% of the total number of seed trees and had little influence on the species biological parameters. Securing sufficient regeneration as a post-logging action is probably the most important consideration for achieving long-term sustainability. Implications for the conservation status of the species are discussed at the regional level. [less ▲]

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See detailEcology of Salmonella in slaughter pigs digestive tract and study of the contamination of carcasses
Boudry, Christelle ULg; Korsak Koulagenko, Nicolas ULg; Jacob, Benoit et al

in Annales de Médecine Vétérinaire (2002), 146(6, DEC-JAN), 353-360

This article presents a study on the Salmonella asymptomatic carriage of finishing pigs and its consequences on the contamination of carcasses. Twenty finishing pigs were followed to determine the faecal ... [more ▼]

This article presents a study on the Salmonella asymptomatic carriage of finishing pigs and its consequences on the contamination of carcasses. Twenty finishing pigs were followed to determine the faecal shedding of Salmonella. No sample was positive but at the slaughterhouse, the analysis of tonsils and certain parts of the digestive tract (mesenterial lymph nodes, ileum and large intestine content) revealed that 70% of the pigs were positive. The strains isolated from the faecal samples of the large intestine and from tonsils were identical, which might indicate that there has been an oral contamination from pig to pig due to the shedding of Salmonella or a carriage of different strains in different organs. The mesenterial lymph nodes (40 % positive) were contaminated by strains which were different from those from the faecal samples and tonsils. Salmonella strains were only found on the swabs of one carcass. A complementary assay has shown the negative role played by the scalding step. This latter may contaminate the oral and rectal cavities of slaughtered animals. This entire study reveals the difficulty to predict the contamination risk at the slaughterhouse from the analysis of finishing pigs faecal samples. Therefore, a better knowledge of the carriage and the shedding of Salmonella during the finishing period and during the slaughter is necessary to minimise meat contamination. [less ▲]

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See detailEcology of the Belizean black howler monkey (Alouatta pigra): a comparison between two populations living in a riparian forest and on coastal limestone hills
Trolliet, Franck ULg

Master's dissertation (2010)

This study reports on the ecology of the Belizean black howler monkey (Alouatta pigra) in two different habitats. Monkey River is a riparian secondary forest whereas Runaway Creek Nature Reserve (RCNR) is ... [more ▼]

This study reports on the ecology of the Belizean black howler monkey (Alouatta pigra) in two different habitats. Monkey River is a riparian secondary forest whereas Runaway Creek Nature Reserve (RCNR) is a primary and mature forest situated in a limestone karst hills landscape. This type of ecosystem, neither the population inhabiting this reserve, has been studied before. We contrasted food availability, diet, group size and composition, population density, home range size and activity patterns between those two populations. We predicted the disturbed riparian forest to have higher food availability but a less diverse diet with a higher consumption of fruits. Thus, we predicted howlers to have higher population density, larger groups with more males and more infants, smaller home ranges with more overlapping. Also, we predicted activity budget to be biased toward a less active lifestyle with less travel but more inactivity, and more social interactions. Our results confirm some of those predictions as food availability is higher in Monkey River with food species accounting for 80% of the diet and all food species of howlers diet having a higher total relative basal area. This is likely to be associated with the higher population density (44.82ind/km² in Monkey River against 26in/km² in RCNR) and smaller average home range size (3.27 ha against 11.87 ha) with a higher proportion of overlapping (11.87% against 0%). Predictions on group size and composition are not confirmed as the difference in mean group size is not statistically significant and as many males per group are found in both habitats (one) but sex ratios (M:F) indicate the presence of more females in Monkey River (1:1.6 against 1:1.3). Also, more infants per group are found in RCNR (0.6 in Monkey River against 1 in RCNR). Those results are likely to be associated with different stage of population growth between the two habitats and more precisely of the hurricane Iris that have lowered the population in Monkey River and allowed more dispersal opportunities and, resulting effects of social factors such as infanticide. Nevertheless, our results indicate howler population to increase again in this disturbed forest. Howlers in RCNR have a more diverse diet (18 food sources in Monkey River against 23 in RCNR) which is likely to be due to higher diversity of plants present in the limestone karst hills. Diets in both habitats differ as only 19.5% of species are similar and species composition in both habitats are pretty different too, which confirms howlers having a flexible diet and being able to adapt their diet to the species found in the habitat. Both populations feed preferentially on leaves but howlers in the secondary forest spent more time feeding on fruits (20.46%) and less on flowers (6.46%) than in the primary forest (11% and 11.75% respectively), although those differences are not significant. Howlers in Monkey River are more active and travel significantly more (9.45% against 5.45%) which is likely to be due to the higher amount of fruits in the diet. Less time is spent in social interactions in Monkey River, which is likely to be due to the smaller number of infants per group. Finally, monkeys in the secondary forest spent significantly more time vocalizing than in the primary forest, which is likely to be due to the higher population density and level of overlap between neighboring groups. No overlap has been recorded in the limestone karst hills and percentage of vocalization is quite low. [less ▲]

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See detailEcology of the edible dormouse (Glis glis) in a western edge population in southern Belgium
Hürner, H.; Michaux, Johan ULg

in Vie et Milieu (2009), 59(2), 243-250

Population dynamics, diet and spatial use of the edible dormouse Glis glis were studied in a peripheral population in Belgium, on the western limit of its distribution area. The main results showed that ... [more ▼]

Population dynamics, diet and spatial use of the edible dormouse Glis glis were studied in a peripheral population in Belgium, on the western limit of its distribution area. The main results showed that the proportion of occupied nest boxes varied between 2 and 44 %. The dormice occupied nest boxes approximately between June and October. The densities of adults varied between 0.6 and 2.3/ha. Reproduction was observed in 2006 and 2007 but not in 2005. The results of the diet study revealed a basically herbivorous diet. Home range (MCP) of males varied from 0.68 to 1.23 ha and that of females from 0.37 to 0.71 ha. Marked individuals moved on average 252 m/night (range = 60-497 m/night). In general, these results are in accordance with those observed in other countries. Only few differences appeared and they concern mainly a smaller number of occupied nest boxes, a smaller density and a higher proportion of birds in the diet of the species. [less ▲]

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See detailEcomorfologia y evolucion del sistema locomotor de la familia Pomacentridae
Aguilar-Medrano, Rosalia; Frederich, Bruno ULg; Barber, Paul

Conference (2014, November)

Due their productivity, structural diversity, and potential to promote ecological, functional and morphological evolution, coral reefs have the highest species richness of fishes. As swimming is the ... [more ▼]

Due their productivity, structural diversity, and potential to promote ecological, functional and morphological evolution, coral reefs have the highest species richness of fishes. As swimming is the primary form of locomotion and interaction their aquatic environment, small morphological variations can have profound implications on the fitness of fishes. The damselfish family, Pomacentridae, has inhabited coral reef ecosystems for more than 50 million years. As such, habitat preferences and behavior could significantly contribute to the evolution of the morphology of damselfish through the impacts of shape on locomotion. To test this hypothesis, we employed comparative morphometric analyses of fish shape and ecology. While body elongation represented the primary source of variation in locomotor system shape, results also showed a diverse suit of morphological combinations in between the morphological extremes. Results showed strong associations between behavior and habitat preferences, suggesting that behavior may constrain the shape of the locomotor system in damselfishes. Position in the water column show relation with the cephalic region and truck, behavior is related to the cephalic angle and the angle of insertion of the pectoral fin, while maximum depth is related to the caudal peduncle. Was found little relation between the caudal peduncle, the angle of pectoral fin attachment and the rest modules, therefore, this two modules may be the main responsible of swimming fitness in damselfishes. Finally, cephalic region is highly related to most modules, especially to trunk. This strong integration may be responsible of the limit morphological variation of damselfishes. [less ▲]

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See detailEcomorphology of the Pomacentridae skull: a landmark-based geometric morphometric approach
Pilet, Arnaud; Frederich, Bruno ULg; Parmentier, Eric ULg et al

Poster (2005, October)

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See detailEcomorphology of the vertebral column: preliminary study
Gillet, Amandine; Ninane, Catherine; Zaeytydt, Esther et al

Poster (2014, April)

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See detailAn Econometric Analysis of Homeownership Determinants in Belgium
Xhignesse, Guillaume ULg; Bianchet, Bruno ULg; Cools, Mario ULg et al

in Lecture Notes in Computer Science (2014, July), 8581

In market economies, homeownership is associated with positive ex- ternalities. Increasing the levels of homeownership has been an objective of governments for the last decades. The analysis of the ... [more ▼]

In market economies, homeownership is associated with positive ex- ternalities. Increasing the levels of homeownership has been an objective of governments for the last decades. The analysis of the determinants of tenure sta- tus provides information to this end. This paper proposes an econometric analysis of housing tenure in Belgium. We review the main variables that have been considered in the literature as influencing housing tenure, after what we estimate a logit model. We observe a strong influence of income and age on the probability of homeownership. Couple relationship and the presence of dependent children have a positive influence, but this influence is less significant. Urban location is associated with lower probability of homeownership, compared with other areas. Our observations follow the trends described for other countries in the literature. [less ▲]

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See detailÉconométrie du droit de la concurrence, un essai de conceptualisation
Fegatilli, Ermano ULg; Petit, Nicolas ULg

in Revue Internationale de Droit Economique (2009), I

The present paper reviews in a plain language and with only limited statistical formalization, the virtues of econometrics in the field of competition law. Following a brief introduction to the origins of ... [more ▼]

The present paper reviews in a plain language and with only limited statistical formalization, the virtues of econometrics in the field of competition law. Following a brief introduction to the origins of econometrics, we explain first that econometrics provides assistance to decision-making in a variety of fields (merger control, abuse of dominance, etc.). Second, we show that econometrics also constitute a decision-reading instrument, which may assist competition agencies, courts, firms and their counsels in understanding the content of the law. The econometric models discussed in the paper are illustrated by examples coming from well-known legal cases. Our conclusion is that in light of the novel sophisticated issues arising in antitrust enforcement (damages estimation, etc.), the nascent "econometrics of competition law" exhibit promising features. [less ▲]

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See detailEconométrie I
Lejeune, Bernard ULg

Learning material (2011)

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See detailLa economia social y cooperativa en la revista del Ciriec, Anales de economia publica y cooperativa
Fecher-Bourgeois, Fabienne ULg; Lévesque, Benoit

in Revista Cooperativismo & Desarrollo (2012), 20(100), 24-56

Detailed reference viewed: 27 (14 ULg)