Last 7 days
Bookmark and Share    
Full Text
Peer Reviewed
See detailInfluence of players' level on racket speed and ball accuracy in the tennis serve
Tubez, François ULg; Croisier, Jean-Louis ULg; Cordonnier, Caroline ULg et al

Conference (2014, July 06)

INTRODUCTION Serve in modern tennis game is an important offensive weapon for players (1-2). In kinematic analysis, serve is the most studied stroke of this game. The aim of our study was to compare the ... [more ▼]

INTRODUCTION Serve in modern tennis game is an important offensive weapon for players (1-2). In kinematic analysis, serve is the most studied stroke of this game. The aim of our study was to compare the performance of two specific populations: international players versus national players. In particular, racket speed at impact and accuracy of ball were assessed. METHODS A tennis court was reconstructed in a motion analysis laboratory. The position of the racket was evaluated in 3D at a frequency rate of 200 Hz. Tests were performed on 6 professional players (international level) and 9 non-professional players (national level). Each of them served 25 trials in direction of the “T” area of deuce diagonal. Two squares of 1m² and 2 m² respectively were delimited on the corner of the serve square. The instruction for both groups was to serve in the “T” area with the highest ball speed and minimal ball rotation (flat serve). RESULTS Although the forward speed of the racket at impact was identical between the two groups of players (International 36.35 ± 2.37 m/s and national 36.37 ± 2.90 m/s, p-value 0,991), the accuracy and consistency of serves on the target area is better for international players group (1m² area: International 33% ± 7% and national 14% ± 12%, p-value 0.0053; 2m² area (including 1m² area): International 71% ± 8% and national 54% ± 12%, p-value 0.0096; Out of zone: International 29% ± 8% and national 46% ± 12%, p-value 0.014). DISCUSSION High-velocity ball seems to be a key factor for serve performance (3). It is known that there is a relationship between racket speed and ball velocity (4). Both groups have high racket speed. However, international players serve with better accuracy and consistency than national players. We hypothesize that these differences are due to capacity of international players to adapt to a particular environment. Moreover, international players could give priority to consistency over velocity. We conclude that high-velocity serve is not a sufficient criterion to perform at international level; consistency and accuracy are two important factors to reach this level. [less ▲]

Detailed reference viewed: 91 (26 ULg)
Full Text
See detailIslands as reference stations for environmental studies: the case of Calvi Bay in Corsica
Abadie, Arnaud ULg; Gobert, Sylvie ULg; Lejeune, Pierre

Conference (2014, July 05)

Islands are subject to human activities and their impacts on land and marine ecosystems. They are also often isolated from some of the continental influences but on the other hand different kind of human ... [more ▼]

Islands are subject to human activities and their impacts on land and marine ecosystems. They are also often isolated from some of the continental influences but on the other hand different kind of human activities can be concentrated in small areas. These characteristics make possible the management of many programs that use whole islands, or some of their parts, as a reference station for environmental studies. From this perspective, the program STARE-CAPMED has begun in 2012 at STARESO, an oceanographic research station established at Calvi Bay (Corsica) since the early 70’s. It aims to create a reference station for the study of emerging local and global anthropogenic impacts on marine pristine ecosystems. Several universities are involved in this project and provide their expertise in various fields of marine sciences. This program provides a precise view of the environmental processes that occur, which are strongly linked with economic and cultural issues. [less ▲]

Detailed reference viewed: 23 (1 ULg)
Full Text
See detailLe roi Léopold et la Commission nationale des sciences
Pirot, Pascal ULg

Conference (2014, July 05)

Detailed reference viewed: 11 (2 ULg)
See detailChinua Achebe's Arrow of God: More Questions than Answers?
Tunca, Daria ULg

Conference given outside the academic context (2014)

Detailed reference viewed: 17 (1 ULg)
Full Text
Peer Reviewed
See detailInsect pests occurring on Dacryodes edulis (Burseraceae) in rural areas in Gabon
Poligui, René Noël ULg; MOUARAGADJA, ISAAC; Vandereycken, Axel ULg et al

in Neotropical Entomology (2014), 43(4), 322-334

The inventory of pests occurring on Dacryodes edulis (Burseraceae) was carried out in rural areas in Gabon during 2009 and 2010. Yellow traps and visual observations were used to record weekly pests ... [more ▼]

The inventory of pests occurring on Dacryodes edulis (Burseraceae) was carried out in rural areas in Gabon during 2009 and 2010. Yellow traps and visual observations were used to record weekly pests during the tree flowering stage, in five villages. Catches from yellow traps rose to 7,296 and 1,722 insect pests in 2009 and 2010, respectively, whereas records from visual observations corresponded to 1,812 and 171 insect pests in 2009 and 2010, respectively. During both years, abundance from traps and visual monitoring was significantly different between sampling sites (p<0.05). The difference in pests’ diversity between sampling sites was not significant (p>0.05) according to traps, but significant (p≤0.04) according to visual observations in 2010. Mecocorynus loripes Chevrolat (Coleoptera: Cucurlionidae) attacked the stem of D. edulis, while Oligotrophus sp. (Diptera: Cecidomyiidae), Pseudophacopteron serrifer Malenovsky and Burckhardt (Hemiptera: Phacopteronidae), and Selenothrips rubrocinctus Giard (Thysanopera: Thripidae) attacked leaves. Pseudonoorda edulis Maes and Poligui (Lepidoptera: Crambidae) and Lobesia aeolopa Meyrick (Lepidoptera: Tortricidae) infested fruits and inflorescences, respectively. These insects are specifically linked to plant patterns, and their identification provided the first basic information for developing suitable strategies to control pests of D. edulis in Gabon, as well as in neighboring central African countries. [less ▲]

Detailed reference viewed: 15 (4 ULg)
Full Text
See detailPollution lumineuse et santé
JEDIDI, Haroun ULg

Scientific conference (2014, July 04)

Cet exposé détaille les effets néfastes de la pollution lumineuse sur l'environnement et la santé humaine.

Detailed reference viewed: 18 (7 ULg)
Full Text
See detailLet's Talk Ambiguity: Citizen science in new and emerging technologies
Van Oudheusden, Michiel ULg

Conference (2014, July 04)

Citizen science (CS) is a fairly new concept that is rapidly gaining traction in the industrialized democratic world. Although it is often likened to public participation in science, CS takes on many ... [more ▼]

Citizen science (CS) is a fairly new concept that is rapidly gaining traction in the industrialized democratic world. Although it is often likened to public participation in science, CS takes on many forms and orientations. In this presentation, I link CS developments and practices to the advent of new and emerging technologies (NEST), such as bio- and nanotechnologies. I draw on three Flemish cases of CS linked to NEST to illustrate how CS co-evolves with Flemish and European policy shifts towards responsible innovation governance. The cases serve to highlight how various conceptions of CS enact divergent rationales for public involvement in science and promote competing visions of the volatile relationship between science and society. The clash of CS perspectives within and through NEST produces a highly ambiguous innovation context that is simultaneously characterized by excitement and (pre)caution; public and formal expertise; policy dictates and public dialogue; and deterministic and constructionist views of innovation. How implicated actors (policymakers, scientists, citizens, and other stakeholders) make sense of, and deal with, these ambiguities is one of the key challenges CS faces today. [less ▲]

Detailed reference viewed: 88 (1 ULg)
Peer Reviewed
See detail"Muette d'émotion. La Diva recomposée"
Belloi, Livio ULg

Conference (2014, July 04)

Cette communication s'attache à étudier les résurgences de la diva dans le cinéma expérimental contemporain, en particulier dans "Diva Dolorosa" (Peter Delpeut, 1999) et dans "Film ist." (Gustav Deutsch ... [more ▼]

Cette communication s'attache à étudier les résurgences de la diva dans le cinéma expérimental contemporain, en particulier dans "Diva Dolorosa" (Peter Delpeut, 1999) et dans "Film ist." (Gustav Deutsch, 2002). [less ▲]

Detailed reference viewed: 9 (1 ULg)
Full Text
Peer Reviewed
See detailImportance of quantitative return-to-field criteria
Schwartz, Cédric ULg; Cordonnier, Caroline ULg; Lehance, Cédric ULg et al

Conference (2014, July 04)

Detailed reference viewed: 28 (3 ULg)
Full Text
See detail"Faire voir par l'histoire" : l'usage du passé contre Mazarin durant la Fronde
Saal, Caroline ULg

Conference (2014, July 04)

Detailed reference viewed: 17 (2 ULg)
See detailThe Belgian Monuments Men During and After the Second World War
Houbart, Claudine ULg

Conference (2014, July 04)

Detailed reference viewed: 30 (0 ULg)
Full Text
See detailGoverning by numbers or democratizing measurement : The policy and practices of quality management in universities
Fallon, Catherine ULg

Conference (2014, July 04)

Quality management frequently appeals to performance indicators (PI) without questioning their constructed and contextual dimension and the reduction of the social complexity they induce. Practices and ... [more ▼]

Quality management frequently appeals to performance indicators (PI) without questioning their constructed and contextual dimension and the reduction of the social complexity they induce. Practices and discourses in this field tend to swing between two antinomic registers: strenghtening of a managerial approach by the authorities and new participatory expectations by stakeholders. Quality-oriented approaches and performance measurement advocates a quantitative practice based on a top-down, standardised approach focused on statistical knowledge and advocating a desire of transparency and increasing efficiency. The indicator-based measurement also endorses a legitimacy and accountability function (Zittoun 2009). Quantification of social phenomenon leads to a double reductionism : PI reduce social complexity to a single figure, and contribute at the same time to a normative twist of public action when pushing forward the search for performance and efficiency as main objective of policies while downplaying other less measurable social or environmental dimensions (Salais, 2010). In the last decade, public governance focused so much on numbers and benchmarking that the digits and indicators seem to structure the whole decision making process instead of being a simple adjuvant to it (Dahler-Larsen 2012, Ogien 2009). Simutaneously, local actors have to translate in local practices the policy indicators that where defined by experts far away from local concerns. This top down approach puts the autonomy of local professionals under pressure (Chauvière 2007). These tensions could be resolved by defining new modes of coordination between experts and the knowledge of stakeholders. Beyond the criticism of “governing by numbers” the hypothesis is to test the emergence of new families of context rich operational indicators, supporting local participation (Didier et al 2013). This paper proposes to analyze these tensions in the case of the development of quality management processes in universities in Belgium and show how the development of quantification mechanisms resisted participatory processes in the definition of indicators and statistical models (Fallon & Leclercq 2013). It will question how can stakeholders be involved in the definitions of measures, contribution to the framing of the convention of what is locally important and what is not. [less ▲]

Detailed reference viewed: 11 (0 ULg)
See detailHMA4 and metal hyperaccumulation in Arabidopsis halleri
Hanikenne, Marc ULg

Conference (2014, July 04)

Detailed reference viewed: 16 (0 ULg)