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See detailEcological and pathological factors related to trace metal concentrations in harbour seal Phoca vitulina in the North Sea
Drouguet, Olivier; Siebert, Ursula; Jauniaux, Thierry ULg et al

Poster (2005)

During the last decade, recurrent epizootics have affected harbour seal (Phoca vitulina) populations in the North Sea. Recent data on their trophic habits and pollutant levels are of primary importance ... [more ▼]

During the last decade, recurrent epizootics have affected harbour seal (Phoca vitulina) populations in the North Sea. Recent data on their trophic habits and pollutant levels are of primary importance for their conservation. As isotopic composition of an animal is related to that of its prey, δ13C and δ15N were measured by mass spectrometry in the muscles of 66 harbour seals beached along the coasts of France (n = 10), Belgium (n = 30) and Netherlands (n = 26) between 1994 and 2004. Trace metals concentrations (Zn, Cu, Fe, Cd, Hg and Se) were also determined in liver, kidney and muscles by Inducted Plasma Spectrometry. δ13C and δ15N values remained similar between harbour seals from France (-15.7 0/00; 18.7 0/00, respectively), Belgium (-15.7 0/00; 19.0 0/00, respectively) and Netherlands (-14.7 0/00; 18.7 0/00, respectively). These data are in good agreement with their coastal and piscivorous life style. Isotopic value remained similar between males and females and between body conditions. Hg levels were significantly higher in seals from the southern North Sea when compared to previously published data from seals collected in Norway, probably due some geographical differential exposure. Hepatic Hg was positively correlated to hepatic Se, both increasing with the length of the seals. Such a relationship reflected an age accumulation process coupled to a detoxication mechanism involving antagonism between Hg and Se in the liver. No relationship between stable isotopes and Hg and Cd levels was observed. Increasing Zn and Hg hepatic levels were observed with degrading body condition of the harbour seals, which is reflected by decreasing blubber thickness and high hepatic to total body mass ratio. These observations tend to indicate a global redistribution of trace metals from muscle and blubber to liver, as a result of protein and lipid catabolism linked to disease and starvation. [less ▲]

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See detailEcological characteristic's of small farmland ponds: Associations with land use practices at multiple spatial scales
Declerck, Steven; De Bie, Tom; Ercken, Dirk et al

in Biological Conservation (2006), 131(4), 523-532

Despite their restricted surface area, small farmland ponds often have a high conservation value because they contribute significantly to regional biodiversity and contain rare or unique species. For this ... [more ▼]

Despite their restricted surface area, small farmland ponds often have a high conservation value because they contribute significantly to regional biodiversity and contain rare or unique species. For this reason, the creation of new ponds has become a widely applied practice in many countries. information on the effects of land use on farmland ponds is very scarce. Farmland ponds differ from larger ponds, lakes and livers in many aspects and can therefore be expected to be affected by land use via other mechanisms operating at different spatial scales. We here present a study on 126 ponds distributed over the entire territory of Belgium (surface area: 30.500 km(2)). We assessed variables related to turbidity state and vegetation complexity and related them to land use variables assessed at several spatial scales ranging from the pond edge up to 32 km(2) circular areas. According to redundancy analysis, trampling by cattle and percentage cover of nearby crop land were positively associated with turbid state related variables. Conversely, ponds with high coverage by forest in the immediate neighbourhood tended to be more associated with the clear water state. Multiple regression analysis demonstrated a negative effect of trampling and coverage by crop land on vegetation complexity. Effects of crop lands and forest were strongest at the local scale (< 200 m radius) which indicates that adverse external influences can most efficiently be mitigated at a small scale. Based on these results we suggest several recommendations for pond construction and conservation. (c) 2006 Elsevier Ltd. All rights reserved. [less ▲]

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See detailEcological characterization of Lophira alata (Ekki), a vulnerable timber tree species, in order to develop silvicultural effective strategies
Biwole, Achille ULg; Doucet, Jean-Louis ULg

Poster (2011, December 02)

Ekki, Lophira alata Banks ex C.F.Gaertn., is an African timber species occurring in tropical rainforests. Of important commercial value, this species is logged for its excellent timber properties and has ... [more ▼]

Ekki, Lophira alata Banks ex C.F.Gaertn., is an African timber species occurring in tropical rainforests. Of important commercial value, this species is logged for its excellent timber properties and has been classified by the IUCN as «vulnerable" species. As for many other tropical tree species, the commercial exploitation of Ekki is confronted to an insufficient knowledge about the species’ ecological profile. With a distribution range limited to the Guinea-Congolian region, Ekki often displays insufficient natural regeneration, but the biotic and abiotic factors explaining this deficiency have been hardly characterized. This lack of knowledge makes it difficult to model the population dynamics on the long term. The reproductive biology of Ekki and the genetic variability of its population remains poorly studied too. To address this situation, a fundamental and applied research is being undertaken in the forest concessions managed by Wijma Cameroun SA., covering over 250,000 hectares of rainforest in Southern Cameroon. This study aims to answer four essential questions: (1) what is the phylogenetic relationship between L. alata and L. lanceolata, (2) how paleoclimate and human disturbances impact its distribution and abundance, (3) how to these populations respond to logging over several rotation periods, (4) does logging promote or inhibit the natural regeneration of the species. Several study devices have thus been installed to collect the data needed to improve the characterization of Ekki’s ecology and to conceive silvicultural strategies. [less ▲]

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See detailEcological fitness of Bacillus subtilis BGS3 regarding production of the surfactin lipopeptide in the rhizosphere
Nihorimbere, Venant ULg; Fickers, Patrick ULg; Thonart, Philippe ULg et al

in Environmental Microbiology Reports (2009), 1(2), 124-130

Cyclic lipopeptides and particularly surfactins produced by Bacillus species retain antibacterial, antiviral, biofilm-forming and plant resistance-inducing activities. In most cases, their role in ... [more ▼]

Cyclic lipopeptides and particularly surfactins produced by Bacillus species retain antibacterial, antiviral, biofilm-forming and plant resistance-inducing activities. In most cases, their role in biological control of plant diseases was evoked on the basis of in vitro assays or by using non-producing/ overproducing mutants but there is a need for more direct evidence of an efficient lipopeptide biosynthesis in the rhizosphere. In this work, we coupled LC-MS quantification of the lipopeptides secreted by cells colonizing tomato plants with the use of psrfA– lacZ reporter system integrated within the BGS3 chromosome to study the expression of the surfactin operon in planta. Results showed that a higher level of psrfA induction was observed upon the establishment of a stable BGS3 population on roots and surfactins extracted from the rhizosphere were produced in biologically significant quantities. Our results also demonstrate that BGS3 efficiently utilizes the main substrates from plant exudates to produce surfactins. This synthesis is also efficient in cells forming colonies and the production may be favoured in bacteria developing slowly in the rhizosphere. This provides a first understanding of how environmental factors may influence lipopeptide production by beneficial Bacillus strains. [less ▲]

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See detailEcological fitness of plant-beneficial Bacillus subtilis strains in soil: influence of rhizosphere specific parameters on surfactin synthesis.
Nihorimbere, V.; Fickers, P.; Thonart, Philippe ULg et al

in Journal of Plant Pathology [=JPP] (2008), 90

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See detailEcological impact of habitat loss on African landscapes and diversity
Vranken, Isabelle ULg; Djibu Kabulu, J P; Munyemba Kankumbi, F et al

in Daniels, J A (Ed.) Advances in environmental research, volume 14 (2011)

Detailed reference viewed: 79 (28 ULg)
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See detailEcological Impacts of Invasive Plant Species
Vanderhoeven, Sonia ULg

Conference (2007)

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See detailEcological modeling and paedomorphosis: a study case in Montenegrin newts
Denoël, Mathieu ULg; Ficetola, Gentile; Cirovic, Rusa et al

Poster (2009)

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See detailEcological modeling of the upper layers of Lake Kivu: a progress report
Leblanc, Christophe; Darchambeau, François ULg; Descy, Jean-Pierre et al

Conference (2009, January 19)

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See detailEcological network and local authorities - sociological instrument
Mougenot, Catherine ULg; Roussel, Laurence

in Nature and environment (2002), (126), 37

Ever closer links have been forged between caring for nature on the one hand and human activities on the other. In recent years there has been a shift from an interest in reserve-based nature, which ... [more ▼]

Ever closer links have been forged between caring for nature on the one hand and human activities on the other. In recent years there has been a shift from an interest in reserve-based nature, which excluded man and human activities, to an increasingly powerful nature-culture relationship. Nature protection became nature conservation and then nature development with the integration of socio-economic and cultural aspects. Within the framework of the setting-up of the pan-european ecological network, these sociological aspects have a great importance for establishing an ecological network where the scientific aspects of biodiversity protection must co-exist with nature management and development. [less ▲]

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See detailEcological or recalled assessments in chronic musculoskeletal pain? A comparative study of prospective and recalled pain assessments in low back pain and lower limb painful osteoarthritis.
Perrot, Serge; Marty, Marc; Legout, Valerie et al

in Pain Medicine : The Official Journal of the American Academy of Pain Medicine (2011), 12(3), 427-36

OBJECTIVES: The objective of this study was to compare ecological and recalled pain intensity assessments over 29 days in hip and knee osteoarthritis (O) and chronic low back pain (L). PATIENTS AND ... [more ▼]

OBJECTIVES: The objective of this study was to compare ecological and recalled pain intensity assessments over 29 days in hip and knee osteoarthritis (O) and chronic low back pain (L). PATIENTS AND METHODS: Rheumatologists were asked to enroll patients with O and L, with pain intensity above 40 mm, in a prospective study for 29 days. Pain intensity was assessed with physicians on Days 1 and 29, and ecologically, over the intervening 28-day period, by random phone calls. RESULTS: We carried out correlation analyses for 353 (159 O, 194 L) patients: Overall recalled daily pain was strongly correlated with calculated 3-day mean pain assessments (r=0.96 [O]; 0.93 [L]) and evening pain (r=0.96 [O], 0.90 [L]). Correlations between ecological and recalled measures were stronger for recall over the last 7 days than for recall over the last 28 days in osteoarthritis patients (r=0.78, r=0.63), but were similar for both recall periods in low back pain patients (r=0.70, r=0.72). Correlations between assessments for the last 7 and 28 days were stronger for ecological (r=0.88 [O], 0.91 [L]) than for clinical (r=0.77 [O]; 0.86 [L]) assessments. After adjustment for current pain intensity, correlations remained significant for ecological assessments, but not for clinical assessments. Recalled pain assessments were more accurate when made after 24 hours (r=0.71 [O]; 0.70 [L]) than when made after 48 hours (r=0.63 [O]; 0.61 [L]). CONCLUSIONS: For both low back pain and osteoarthritis, overall daily pain recall is a reliable measurement correlated with daily ecological measurements, whereas a rapid decrease in recall occurs after 48 hours. The most reliable period for pain recall was 7 days, but the results obtained were influenced by current pain. [less ▲]

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See detailEcological requirements for black grouse. A case study in the belgian Hautes-Fagnes.
Keulen, C.; Pieper, Y.; Doyen, A. et al

in Silvia (2003), 39

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See detailEcological requirements for black grouse. A case study in the belgian Hautes-Fagnes.
Keulen, Christine; Pieper, Y.; Doyen, A. et al

Conference (2003, September 08)

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See detailEcological review of black-grass (Alopecurus myosuroides Huds.) propagation abilities in relationship with herbicide resistance
Maréchal, Pierre-Yves ULg; Henriet, François; Vancutsem, Françoise ULg et al

in Biotechnologie, Agronomie, Société et Environnement = Biotechnology, Agronomy, Society and Environment [=BASE] (2012), 16(1),

Alopecurus myosuroides Huds. (vulpin des champs) a toujours été une préoccupation majeure pour les céréaliculteurs et le développement de la résistance aux herbicides n’améliore pas la situation. Cet ... [more ▼]

Alopecurus myosuroides Huds. (vulpin des champs) a toujours été une préoccupation majeure pour les céréaliculteurs et le développement de la résistance aux herbicides n’améliore pas la situation. Cet article de synthèse résume les différents critères impliqués dans les modèles de dispersion d’individus de vulpin des champs au sein d’un champ ou d’une population sensible. Pour ce faire, le cycle complet du vulpin est décrit de la semence à la semence. Depuis le développement végétatif précoce jusqu’à la chute de la graine, chaque étape est décrite en prenant en compte comment la résistance aux herbicides peut influencer ou exercer un impact différent par rapport à des plantes sensibles. [less ▲]

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See detailThe ecological study of an unknown non-timber forest product (NTFP): the African walnut (Coula edulis Baill.)
Moupela, Christian ULg; Vermeulen, Cédric ULg; Lebailly, Philippe ULg et al

Conference (2011, November 15)

Le noisetier d’Afrique, Coula edulis Bail., produit des graines de grande valeur nutritive régulièrement collectées et commercialisées par les populations locales. Toutefois, certains aspects fondamentaux ... [more ▼]

Le noisetier d’Afrique, Coula edulis Bail., produit des graines de grande valeur nutritive régulièrement collectées et commercialisées par les populations locales. Toutefois, certains aspects fondamentaux de son écologie, dont le potentiel de production, la dispersion et la prédation des fruits, demeurent inconnus, ce qui pourrait constituer un frein à sa valorisation. L’étude s’est déroulée au Gabon et s’est attachée à quantifier la production fruitière de l’espèce et à identifier les prédateurs et disperseurs des fruits. Trente-neuf collecteurs circulaires ont été installés sous les houppiers, les données récoltées (nombre et masse des fruits) étant ensuite mises en relation avec le diamètre. Par ailleurs, sept semenciers ont fait l’objet d’observations indirectes grâce à un dispositif de caméras-pièges. Les premières fructifications apparaissent sur les semenciers à partir de 12,3 cm de diamètre. Elle se produit de janvier à avril. Les quantités de fruits sont corrélées positivement au diamètre (r² = 0,493 ; p = 0,001). Dix espèces animales ont été observées aux pieds des arbres en fruits, leur rôle dans la dynamique de population de l’espèce est potentiellement important. [less ▲]

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See detailThe ecological study of an unknown non-timber forest product (NTFP) : The African walnut (Coula edulis Baill.)
Moupela, Christian; Vermeulen, Cédric ULg; Brostaux, Yves ULg et al

Conference (2011, November)

Le noisetier d’Afrique, Coula edulis Bail., produit des graines de grande valeur nutritive régulièrement collectées et commercialisées par les populations locales. Toutefois, certains aspects fondamentaux ... [more ▼]

Le noisetier d’Afrique, Coula edulis Bail., produit des graines de grande valeur nutritive régulièrement collectées et commercialisées par les populations locales. Toutefois, certains aspects fondamentaux de son écologie, dont le potentiel de production et la prédation des fruits, demeurent inconnus, ce qui peut constituer un frein à sa valorisation. L’étude s’est déroulée au Gabon et s’est attachée à quantifier la production fruitière de l’espèce et à identifier les prédateurs potentiels des fruits. Trente-neuf collecteurs circulaires ont été installés sous les houppiers, les données récoltées (nombre et masse des fruits) étant ensuite mises en relation avec le diamètre. Par ailleurs, sept semenciers ont fait l’objet d’observations indirectes grâce à un dispositif de caméras-pièges. Le diamètre minimum de fertilité est de 12,3 cm, tandis que 23 cm dhp constitue pour l’espèce le diamètre effectif de fructification. Celle-ci se produit de décembre à avril. Les quantités de fruits sont corrélées positivement au diamètre. Dix espèces animales ont été observées aux pieds des arbres en fruits, leur rôle dans la dynamique de l’espèce est potentiellement important. [less ▲]

Detailed reference viewed: 45 (20 ULg)