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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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Peer Reviewed
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)
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See detailEconomic analysis of Stainless Steel- Reinforced Concrete members designed for a Fire Resistance of 2 hours
Gernay, Thomas ULg; Franssen, Jean-Marc ULg

Report (2011)

While Stainless steel is used primarily for its corrosion resistance, there is a growing interest in other properties, such as mechanical, high temperature resistance, aesthetics and others. The ... [more ▼]

While Stainless steel is used primarily for its corrosion resistance, there is a growing interest in other properties, such as mechanical, high temperature resistance, aesthetics and others. The properties at high temperatures (400 – 650°C ) of stainless steels are known and put to use in a number of applications such as steam turbines and equipment for the chemical industry. Some research on the fire resistance of stainless steels has been carried out for welded I beams and for concrete-filled tubes, with positive results. However, there are no published results on the behavior of concrete reinforced with stainless steel rebar. In a preliminary research program conducted by the University of Liege for ISSF, a preliminary assessment of the performance of stainless steel reinforced concrete has been carried out, using computer simulation methods. This preliminary study has shown that stainless steel reinforced concrete members can behave better than carbon steel reinforced concrete members in fire situation. However, an economic analysis is still needed to determine whether stainless steel reinforcement can be interesting for practical applications. This report is divided in two parts. The first part presents the assumptions and the results of the numerical simulations performed by University of Liege. The numerical simulations aim to design stainless and carbon steel -reinforced concrete members satisfying to a fire resistance of 2 hours (Standard fire conditions). The two structural members considered in this study are a reinforced concrete beam and a composite slab (with the so-called « membrane » behavior). The numerical simulations are performed with the SAFIR 20011.a.3 software developed in University of Liege. The second part presents the assumptions and the results of the economic analysis of the structural members designed in the first part. The stainless and carbon steel –reinforced solutions for a fire resistance of 2 hours are compared on an economic basis. [less ▲]

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See detailEconomic and Economical Statistical Design of Hotelling’s T2 Control Chart with Two-State Adaptive Sample Size
Faraz, Alireza ULg; Saniga, Erwin; kazemzadeh, R. B.

in Journal of Statistical Computation & Simulation (2010), 80(12), 12991316

The Hotelling’s T 2 control chart, a direct analogue of the univariate Shewhart ¯X chart, is perhaps the most commonly used tool in industry for simultaneous monitoring of several quality characteristics ... [more ▼]

The Hotelling’s T 2 control chart, a direct analogue of the univariate Shewhart ¯X chart, is perhaps the most commonly used tool in industry for simultaneous monitoring of several quality characteristics. Recent studies have shown that using variable sampling size (VSS) schemes results in charts with more statistical power when detecting small to moderate shifts in the process mean vector. In this paper, we build a cost model of a VSS T 2 control chart for the economic and economic statistical design using the general model of Lorenzen and Vance [The economic design of control charts: A unified approach, Technometrics 28 (1986), pp. 3–11].We optimize this model using a genetic algorithm approach.We also study the effects of the costs and operating parameters on theVSS T 2 parameters, and show, through an example, the advantage of economic design over statistical design forVSS T 2 charts, and measure the economic advantage of VSS sampling versus fixed sample size sampling. [less ▲]

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See detailThe economic and environmental feasibility of biogas buses in Liege
Mostert, Martine ULg; Limbourg, Sabine ULg

in 2013 BIVEC-GIBET Transport Research Days - Proceedings (2013, May 30)

Everyday, many students at the University of Liège have to drive to the Sart-Tilman village to attend their courses. These journeys are responsible for the emission of harmful particles which have ... [more ▼]

Everyday, many students at the University of Liège have to drive to the Sart-Tilman village to attend their courses. These journeys are responsible for the emission of harmful particles which have negative impacts on climate and human health. This paper analyzes the economic and environmental feasibility of using biogas buses for public transport in Liège. The idea of implementing biogas buses is based on the proposed recycling of organic waste by the company INTRADEL, which manages and treats waste in the region. The economic and environmental advantages and drawbacks of biogas buses are developed and compared with those of the current diesel bus fleet. The main conclusion of this study is that, while internalizing external costs due to pollution, the use of biogas buses becomes an attractive option compared with classical diesel buses. Nevertheless, it requires investment and might lead to resistance to change. However, it remains a good solution for the reduction of CO2 emissions. [less ▲]

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See detailEconomic and environmental impacts of several retrofit options for residential buildings
Gendebien, Samuel ULg

Master's dissertation (2011)

Nowadays, important efforts are deployed to reduce our actual residential building consumption which represents about 40% (25% for the residential sector and 15% for the non-residential sector) of the ... [more ▼]

Nowadays, important efforts are deployed to reduce our actual residential building consumption which represents about 40% (25% for the residential sector and 15% for the non-residential sector) of the total energy consumption in Europe. The aim of this paper is to evaluate the environmental and economical impact of several retrofit options for residential buildings. Our study focuses on the Walloon Region of Belgium. A “bottom-up” methodology is applied: this methodology focuses first on a micro-analysis. Results from this micro-analysis are then used and extended to a macro-analysis. The presented methodology does not permit to determine with precision the global consumption of residential buildings in the Walloon Region. However, the latter methodology allows pointing out some economical and environmental trends related to the different investigated retrofit options. The first part of this end-of-study work offers an overview of the Walloon building stock by presenting statistic data on the Walloon residential houses. From these latter statistic data, it is possible to divide the Walloon building stock by means of arborescence. Each type of building is characterized by constructive data (mean area, Uwall, Uwindow…) and by heating production system efficiency. Thanks to these data, it is possible to determine the gas and electrical annual consumption for each type of residential building by means of a computer program that simulates residential building. The latter computer program is also used to determine the annual energy consumption of envelope retrofitted houses. Retrofit options related to heat and/or cool production are also investigated. A macro-point of view study is carried out in order to determine the potential of energy saving of each investigated options. An environmental comparison between the several envisaged retrofit options is realized in terms of CO2 emission, final and primary annual energy consumption for each type of building. An economical study is carried out in order to determine the profitability of each investigated options for citizens. The work also proposes a reflection about the actual incentive policies. [less ▲]

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See detailEconomic and financial crisis and pooling of military resources
Dumoulin, André ULg

in Europe Diplomatie and Defence (2010), (326), 2

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See detailEconomic and Production Consequences of Liver Fluke Disease in Double-Muscled Fattening Cattle
Genicot, Bruno; Mouligneau, Frédéric; Lekeux, Pierre ULg

in Zentralblatt für Veterinarmedizin. Reihe B = Journal of Veterinary Medicine. Series B (1991), 38(3), 203-208

The frequency of liver fluke disease in fattening units was determined by the analysis of random faeces samples issued from 1,513 Belgian White Blue bulls aged from 5 to 7 months and weighing from 200 to ... [more ▼]

The frequency of liver fluke disease in fattening units was determined by the analysis of random faeces samples issued from 1,513 Belgian White Blue bulls aged from 5 to 7 months and weighing from 200 to 300 kg. 12.5% of the investigated bulls were positive for liver fluke disease. These bulls were spread over 56.5% of the investigated fattening units. Furthermore the infestation rate varied from 0 to 33.3% inside the fattening units. In order to assess the economic consequences of bovine fascioliasis in double-muscled cattle and the beneficial effects of a treatment against such a disease, a trial including 30 Belgian White Blue bulls, weighing 365 +/- 9 kg and aged from 10 to 12 months, was conducted in a selected fattening unit. On the basis of faecal examinations, the 30 animals were subdivided in negative (group A; n = 10) and positive animals (n = 20) for fascioliasis, the latter being either treated with nitroxinil (group B; n = 10) or not (group C; n = 10) on day 0 of this trial which was conducted during 75 days. The daily body gains in group C (1.661 +/- 0.140 kg) were significantly lower than those in group A (1.975 +/- 0.120 kg). On the other hand there was no significant difference between the daily body gains registered in group B (1.960 +/- 0.085 kg) and A. The estimated financial loss, due to flukes and accounted on a 75 day-period, averaged 2,748 Belgian Francs per bull in group C.(ABSTRACT TRUNCATED AT 250 WORDS) [less ▲]

Detailed reference viewed: 33 (1 ULg)