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See detailDo climate warming and plant species richness affect potential nitrification, basal respiration and ammonia-oxidizing bacteria in experimental grasslands?
Malchair, Sandrine ULg; De Boeck, Hans, J.; Lemmens, Catherine, M.H.M. et al

in Soil Biology & Biochemistry (2010), 42

Ammonia-oxidizing bacteria (AOB) are key organisms in the N cycle, as they control the first, rate-limiting step of the nitrification process. The question whether current environmental disturbances, such ... [more ▼]

Ammonia-oxidizing bacteria (AOB) are key organisms in the N cycle, as they control the first, rate-limiting step of the nitrification process. The question whether current environmental disturbances, such as climate warming and plant diversity losses, select for a particular community structure of AOB and/or influence their activity remains open. The purpose of this research was to study the impact of a 3 °C warming and of plant species richness (S) on microbial activity and diversity in synthesized grasslands, with emphasis on the nitrification process and on the diversity (community structure and richness) of ammonia-oxidizing bacteria (AOB).We measured soil chemical characteristics, basal respiration, potential nitrification and AOB diversity in soils under increasing plant species richness (S ¼ 1, S ¼ 3, S ¼ 9) at ambient and (ambient +3 °C) temperature. Species were drawn from a 9-species pool, belonging to three functional groups: forbs, legumes and grasses. Mixtures comprised species from each of the three functional groups. Warming did not affect AOB diversity and increased potential nitrification at S ¼ 3 only. Under warmed conditions, higher plant species richness resulted in increased potential nitrification rates. AOB richness increased with plant species richness. AOB community structure of monocultures under legumes differed from those under forbs and grasses. Clustering analysis revealed that AOB community structure under legume monocultures and mixtures of three and nine species grouped together. These results indicate that functional group identity rather than plant species richness influenced AOB community structure, especially through the presence of legumes. No clear relationship emerged between AOB richness and potential nitrification whatever plant species richness and temperature treatment. Our findings show a link between aboveground and belowground diversity, namely plant species richness, AOB richness and community structure. AOB richness was not related to soil processes, supporting the idea that increased diversity does not necessarily lead to increased rates of ecosystem processes. [less ▲]

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See detailDo clinical factors help to predict disease course in inflammatory bowel disease?
Louis, Edouard ULg; Belaiche, Jacques ULg; Reenaers, Catherine ULg

in World Journal of Gastroenterology (2010), 16(21), 2600-3

While therapeutic strategies able to change the natural history of the disease are developing, it is of major importance to have available predictive factors for aggressive disease to try and target these ... [more ▼]

While therapeutic strategies able to change the natural history of the disease are developing, it is of major importance to have available predictive factors for aggressive disease to try and target these therapeutic strategies. Clinical predictors have probably been the most broadly studied. In both Crohn's disease (CD) and ulcerative colitis (UC), age at diagnosis, disease location and smoking habit are currently the strongest predictors of disease course. A younger age at onset is associated with more aggressive disease both in CD and UC. Disease location in CD is associated with different types of complications: surgery and recurrence in upper gastrointestinal and proximal small bowel disease; and surgery in distal small bowel disease and peri-anal lesions in rectal disease. In UC, extensive colitis is clearly been associated with more severe disease. Finally, active smoking globally increases disease severity in CD but decreases it in UC. Besides these important factors, others may predispose to some specific disease evolution and complications, and are also reviewed in the present paper. [less ▲]

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See detailDo common principles underlie the representation of order in STM and numerical judgment tasks?
Attout, Lucie ULg; Majerus, Steve ULg

Conference (2012, March 29)

Although many studies have explored magnitude effects in numerical cognition, the representation of order information has received only limited interest. We explored the hypothesis that common abstract ... [more ▼]

Although many studies have explored magnitude effects in numerical cognition, the representation of order information has received only limited interest. We explored the hypothesis that common abstract ordinal representations underlie the representation of order information across different domains. We tested this hypothesis by determining the similarity of distance effects in short-term memory (STM) order probe recognition (did ‘8’ occur before ‘5’ in the list ‘3, 6, 5, 4, 8, 7’ presented a few seconds ago?) and in order judgment tasks (does ‘1’ occur before ‘2’), both numerical and alphabetical stimuli were used. In numerical cognition, adjacent numbers are typically judged more slowly than more distant numbers. In fifty healthy adults, we observed significant distance effects across all tasks: in the order judgment tasks, adjacent numbers/letters were judged more slowly than more distant numbers/letters; in the STM tasks, order recognition was slowed for stimuli stemming from adjacent positions in the STM list as compared to stimuli stemming from more distant positions. Regression slopes for distance effects were identical across the different tasks and conditions. Furthermore, the size of distance effects correlated significantly across tasks, except for the order judgment task with numerical stimuli. We will discuss the implications of these results for a hypothetical common representational system of order information in STM and numerical cognition. [less ▲]

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See detailDo Consumers Pay More for What They Value More? The Case of Local Milk-based Dairy Products in Senegal
Lefevre, Mélanie ULg

in Agricultural and Resource Economics Review (2014), 43(1), 158-177

Senegalese consumers prefer milk-based dairy products that are local and fresh to ones produced with imported powder. However, prices for fresh-milk-based and powder-based products are not significantly ... [more ▼]

Senegalese consumers prefer milk-based dairy products that are local and fresh to ones produced with imported powder. However, prices for fresh-milk-based and powder-based products are not significantly different. I address this puzzle by first confirming the preference using choice-based conjoint data to evaluate whether Senegalese consumers will pay a significant positive premium for fresh local products. I then identify price determinants using a unique dataset of milk product characteristics. The results verify the Senegalese preference for fresh local dairy products and show that consumers’ misinformation regarding product composition prevents them from allocating a higher price to local milk-based products. [less ▲]

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See detailDo consumers pay more for what they value more? The case of local milk-based dairy products in Senegal
Lefevre, Mélanie ULg

E-print/Working paper (2013)

Senegalese consumers seem to prefer local fresh milk-based dairy products rather than the ones produced with imported powder. However, market prices of both products do not appear to be different. This ... [more ▼]

Senegalese consumers seem to prefer local fresh milk-based dairy products rather than the ones produced with imported powder. However, market prices of both products do not appear to be different. This paper addresses this puzzle. First, I confirm the preference for local products. Using choice-based-conjoint data, I evaluate that Senegalese consumers are willing to pay a positive and significant premium for these products. Then, I identify the determinants of prices, based on a unique dataset of milk products characteristics. Evidence suggests that consumers' misinformation regarding the product composition prevents them from allocating a higher price to local milk-based products. [less ▲]

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See detailDo consumers pay more for what they value more? The case of local milk-based dairy products in Senegal
Lefevre, Mélanie ULg

Scientific conference (2013, June 23)

Senegalese consumers seem to prefer local fresh milk-based dairy products rather than the ones produced with imported powder. However, market prices of both products do not appear to be different. This ... [more ▼]

Senegalese consumers seem to prefer local fresh milk-based dairy products rather than the ones produced with imported powder. However, market prices of both products do not appear to be different. This paper addresses this puzzle. First, I confirm the preference for local products. Using choice-based-conjoint data, I evaluate that Senegalese consumers are willing to pay a positive and significant premium for these products. Then, I identify the determinants of prices, based on a unique dataset of milk products characteristics. Evidence suggests that consumers' misinformation regarding the product composition prevents them from allocating a higher price to local milk-based products. [less ▲]

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See detailDo countries of origin contribute to socio-cultural integration of migrants abroad?
Gsir, Sonia ULg

in Fargues, Philippe; Weinar, Agnieszka; Di Bartolomeo, Anna (Eds.) et al From Home to Home? How countries of origin impact immigrant integration outcomes (in press)

Detailed reference viewed: 16 (0 ULg)
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See detailDo Customers Dare to Share? Exploring Risk Perception and Reduction in Access-Based Services
Hazee, Simon ULg; Delcourt, Cécile ULg; Van Vaerenbergh, Yves

Conference (2015, May)

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See detailDo developmental orthopaedic disorders influence future jumping performances in Warmblood stallions?
Verwilghen, D. R.; Janssens, S.; Busoni, Valeria ULg et al

in Equine veterinary journal (2013), 45(5), 578-81

REASONS FOR PERFORMING THE STUDY: Few reports are available on the relationship between developmental orthopaedic diseases (DOD) and future performances in Warmblood horses. OBJECTIVES: To investigate the ... [more ▼]

REASONS FOR PERFORMING THE STUDY: Few reports are available on the relationship between developmental orthopaedic diseases (DOD) and future performances in Warmblood horses. OBJECTIVES: To investigate the relationship between performance and the presence of DOD lesions. METHODS: Records of Warmblood stallions for which radiographic and performance data were available were collected. Showjumping performances were expressed as scores derived from the final ranking of horses in each competition. These scores are available in an established performance database. The relationship between radiographic findings and both performance scores and number of performances was analysed using a linear regression model. RESULTS: Two hundred and fifteen horses met the inclusion criteria. There was no difference in either the number of performances or performance score between horses categorised as affected with DOD lesions (independent of joint location) compared with controls. Significantly lower numbers of performances were recorded for horses with osteochondral fragments (OCD) located at the dorsal aspect of the sagittal ridge of the metacarpo/metatarsophalangeal bone. No significant difference was found between horses affected with DOD lesions of the tarsocrural joint and controls. Horses with osteochondrosis of the lateral trochlear ridge of the femur had both significantly lower performance scores and numbers of performances compared with controls. CONCLUSION: This study demonstrated that specific DOD location and site within the joint have an influence on performance. Osteochondral fragments in the femoropatellar and at the dorsal aspect of the sagittal ridge of the metacarpo/metatarsophalangeal joint resulted in lowered performance. Fragmentation in the tarsocrural joint had no influence on performance. POTENTIAL RELEVANCE: The future athletic performance of Warmblood jumping horses may be limited as a result of OCD in the femoropatellar joint and to a certain extent the metacarpo/metatarsophalangeal joint. [less ▲]

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See detailDo echinoderms store temperature changes in their skeleton?
Ranner, Herwig; Ladrière, Ophélie ULg; Navez, Jacques et al

Poster (2005, April 24)

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See detailDo estrogens effectively prevent osteoporosis-related fractures?
Reginster, Jean-Yves ULg; Bruyère, Olivier ULg; Audan, M. et al

in Calcified Tissue International (2000), 67

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See detailDo evoked potentials contribute to the functional follow-up and clinical prognosis of multiple sclerosis?
GIFFROY, Xavier ULg; MAES, Nathalie ULg; Albert, Adelin ULg et al

in Acta Neurologica Belgica (2016)

The clinical variability and complexity of multiple sclerosis (MS) challenges the individual clinical course prognostication. This study aimed to find out whether multimodal evoked potentials (EP ... [more ▼]

The clinical variability and complexity of multiple sclerosis (MS) challenges the individual clinical course prognostication. This study aimed to find out whether multimodal evoked potentials (EP) correlate with the motor components of multiple sclerosis functional composite (MSFCm) and predict clinically relevant motor functional deterioration. One hundred MS patients were assessed at baseline (T0) and about 7.5 years later (T1), with visual, somatosensory and motor EP and rated on the Expanded Disability Status Scale (EDSS) and the MSFCm, including the 9 Hole Peg Test and the Timed 25 Foot Walk (T25FW). The Spearman correlation coefficient (rS) was used to evaluate the cross-sectional and longitudinal relationship between EP Z scores and clinical findings. The predictive value of baseline electrophysiological data for clinical worsening (EDSS, 9-HPT, T25FW, MSFCm) during follow-up was assessed by logistic regression analysis. Unlike longitudinal correlations, cross-sectional correlations between EP Z scores and clinical outcomes were all significant and ranged between 0.22 and 0.67 (p\0.05). The global EP Z score was systematically predictive of EDSS and MSFCm worsening over time (all p\0.05). EP latency was a better predictor than amplitude, although weaker than latency and amplitude aggregation in the global EP Z score. The study demonstrates that EP numerical scores can be used for motor function monitoring and outcome prediction in patients with MS. [less ▲]

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See detailDo evolutionary floras exist?
Cleal, Christopher J.; Cascales - Miñana, Borja ULg

Conference (2013, October)

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See detailDo excitatory and inhibitory conditioning processes underlie psychomotor sensitization to amphetamine? An analysis using simple and multiple regressions
Brabant, Christian ULg; Tambour, Sophie; Quertemont, Etienne ULg et al

in Behavioural Brain Research (2011), 221

Excitatory or inhibitory conditioning processes have been proposed to account for the context-dependent establishment of amphetamine psychomotor sensitization in rodents. The purpose of this study was to ... [more ▼]

Excitatory or inhibitory conditioning processes have been proposed to account for the context-dependent establishment of amphetamine psychomotor sensitization in rodents. The purpose of this study was to test the predictions of these theories in mice. We first assessed the consequence of the extinction of post-sensitization conditioned activity (CR) on the ulterior expression of sensitization. We also assessed the relations between several measures of sensitization and conditioned hyperactivity revealed on a saline challenge using simple and multiple regression analyses. Context-dependent sensitization was induced via 7 amphetamine injections in the test context given alternately with 7 saline injections in another context in paired mice, unpaired mice receiving the converse pretreatment. Context-dependent sensitization (drug challenge) and the CR (saline challenge) were revealed subsequently. After CR extinction (over 7 every-other-day repetition of the saline challenge), mice were tested again for context-dependent sensitization. Against the excitatory conditioning model, CR extinction spared context-dependent sensitization in paired mice, and regression analyses revealed no significant correlations between the size of the CR and several measures of sensitization. In apparent agreement with the inhibitory conditioning model, unpaired mice expressed higher levels of sensitization in the test context after extinction than before. However, regression analyses did not indicate that activity on the saline challenge was related to measures of sensitization in unpaired mice. Therefore, the present results support neither the excitatory nor the inhibitory conditioning models of context-dependent sensitization, but remain compatible with theories proposing that other inhibitory mechanisms modulate sensitization. [less ▲]

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See detailDo faces capture attention in a bottom-up fashion? An eye-movement study
Devue, Christel ULg; Belopolsky, Artem; Theeuwes, Jan

Conference (2010)

Due to their high social and biological significance, faces should be able to capture attention in a bottom-up fashion. Accordingly, a recent visual search study showed that the presence of an upright ... [more ▼]

Due to their high social and biological significance, faces should be able to capture attention in a bottom-up fashion. Accordingly, a recent visual search study showed that the presence of an upright distractor face slows down the search for a butterfly target while the presence of a butterfly distractor does not affect the search for a target face (Langton et al., 2008). To further test whether upright faces automatically capture attention we recorded eye movements during a cued target search task. We show that when the search alternates between a face and a butterfly target (Experiment 1), faces are found faster and with less saccades than butterflies. The presence of the opposite distractor within the display (e.g. a face during a butterfly search) slows down the search but to a higher extent when the distractor is a face. Similarly, faces capture the eyes more frequently than butterflies. In a control experiment inverted face targets were also found more efficiently than inverted butterfly targets and captured the eyes more frequently than butterflies when presented as distractors (Experiment 2). However, when upright or inverted faces were always presented as irrelevant distractors (Experiment 3), we could not found any sign of disruption caused by their presence during a search for butterfly or flower targets. These results challenge the view that faces capture attention automatically. Rather, they suggest that faces only attract attention when their processing is relevant during the search task and that they can otherwise be ignored. [less ▲]

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See detailDo floral resources influence pollination rates and subsequent fruit set in pear (Pyrus communis L.) and apple (Malus x domestica Borkh) cultivars ?
Quinet, Muriel; Warzée, Martin; Vanderplanck, Maryse ULg et al

in European Journal of Agronomy (2016), 77

Pear and apple are among the main fruit crops worldwide. These species can be planted in mixed orchards,and they both depend on insect pollination for fruit set. As pollinating insects are attracted by ... [more ▼]

Pear and apple are among the main fruit crops worldwide. These species can be planted in mixed orchards,and they both depend on insect pollination for fruit set. As pollinating insects are attracted by the floralresources, we investigated nectar and pollen production and chemical composition in four pear (‘Con-corde’, ‘Conférence’, ‘Doyenné du Comice’, ‘Triomphe de Vienne’) and five apple (‘Braeburn’, ‘GoldenReinders’, ‘Jonagored’, ‘Pinova’, ‘Wellant’) cultivars commonly grown in Belgium. We also investigatedwhether insect flower visitation rate and pollination efficiency are linked to floral resource quantityand quality. The pear cultivars flowered one week before the apple cultivars in early spring, and theirflowers were about six times less visited by insects. The visitors foraged more on the pollen of the peartrees and the nectar of the apple trees. [less ▲]

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See detailDo flower mixtures with high functional diversity enhance aphid predators in wildflower strips?
Hatt, Séverin ULg; Uyttenbroeck, Roel ULg; Chevalier Mendes Lopes, Thomas ULg et al

in European Journal of Entomology (in press)

Among semi-natural elements in agricultural landscapes, wildflower strips sown at field margins or within fields represent potential habitats for the natural enemies of insect pests. As insects are ... [more ▼]

Among semi-natural elements in agricultural landscapes, wildflower strips sown at field margins or within fields represent potential habitats for the natural enemies of insect pests. As insects are sensitive to a variety of flower traits, we hypothesised that mixtures with high functional diversity attract and support a higher abundance and species richness of aphid flower visiting predators compared to mixtures with low functional diversity. During a field experiment, repeated over two years (2014 and 2015) in Gembloux (Belgium), aphid predators (i.e., lacewings, ladybeetles and hoverflies) were pan-trapped in five sown flower mixtures (including a control mixture, with three replicates of each mixture) of low to high functional diversity based on seven traits (i.e., flower colour, ultra-violet reflectance and pattern, blooming start and duration, height and flower class, primarily based on corolla morphology). In both years, flower species in the sown mixtures (i.e., sown and spontaneous flowers) were listed, and the realised functional diversity of each plot was calculated. Over the two years, an increase in functional diversity did not result in an increase in the abundance and richness of aphid predators. Moreover, ladybeetles, representing the majority of trapped predators, were more abundant in mixtures with very low or intermediary functional diversity at sowing, especially in 2014. We hypothesise that certain flower species, which were abundant in certain mixtures (and not in those exhibiting the highest functional diversity), attracted predators and were sufficiently represented to support them. Our results present novel information that could be used to the development of flower mixtures that provide effective ecosystem services, such as pest control. [less ▲]

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See detailDo fluid intelligence and executive functioning protect from age-related decline in cognitive control?
Manard, Marine ULg; Lorant, Caroline ULg; Collette, Fabienne ULg

Poster (2013, July)

Age-related studies on cognitive control suggest a decline in proactive control whereas reactive control remains intact (Braver, Gray, & Burgess, 2007). This study was designed to investigate the ... [more ▼]

Age-related studies on cognitive control suggest a decline in proactive control whereas reactive control remains intact (Braver, Gray, & Burgess, 2007). This study was designed to investigate the potential influence of fluid intelligence (Raven’s Advanced Progressive Matrices) and general executive functioning (Executive composite score from executive assessment) on cognitive control abilities during normal aging. Cognitive control was assessed using a computerized version of the Stroop paradigm in which proactive and reactive control processes were pseudo randomly engaged by varying the amount of interference across the task. Thirteen young and 27 older adults were included in this study. In the whole sample, results confirmed a significant age-related decline in proactive control. However, when older adults were divided in high- and low fluid intelligence subgroups, only older adults with low fluid intelligence showed a significant decline in proactive control compared to younger adults and this difference disappeared for older adults with high fluid intelligence level. When older adults were distinguished according to high and low executive capacities, the analysis revealed that, compared to the young ones, older adults with low executive functioning showed a general cognitive control decline (proactive and reactive processes). However, differences disappeared when young adults were compared to older adults with a high executive functioning. Accuracy results suggested that older adults have a slower but spared access to goal-representations that are necessary to correctly manage interference. So, this study confirmed the previous results obtained by Braver et al. (2007), but also suggest an influence of fluid intelligence and executive resources that seems important to take into account to investigate age-related decline in reactive and proactive cognitive control processes. [less ▲]

Detailed reference viewed: 142 (5 ULg)