Exploring the L1-L2 relationship in the L2 acquisition of prosody

Conference (2009)

Exploring the magnetic topologies of cool stars

in IAU Symposium Proceedings (2010, September 01)

Magnetic fields of cool stars can be directly investigated through the study of the Zeeman effect on photospheric spectral lines using several approaches. With spectroscopic measurement in unpolarised ... [more ▼]

Magnetic fields of cool stars can be directly investigated through the study of the Zeeman effect on photospheric spectral lines using several approaches. With spectroscopic measurement in unpolarised light, the total magnetic flux averaged over the stellar disc can be derived but very little information on the field geometry is available. Spectropolarimetry provides a complementary information on the large-scale component of the magnetic topology. With Zeeman-Doppler Imaging (ZDI), this information can be retrieved to produce a map of the vector magnetic field at the surface of the star, and in particular to assess the relative importance of the poloidal and toroidal components as well as the degree of axisymmetry of the field distribution. The development of high-performance spectropolarimeters associated with multi-lines techniques and ZDI allows us to explore magnetic topologies throughout the Hertzsprung-Russel diagram, on stars spanning a wide range of mass, age and rotation period. These observations bring novel constraints on magnetic field generation by dynamo effect in cool stars. In particular, the study of solar twins brings new insight on the impact of rotation on the solar dynamo, whereas the detection of strong and stable dipolar magnetic fields on fully convective stars questions the precise role of the tachocline in this process. [less ▲]

Exploring the night sky with binoculars -- P. Moore

in Ciel et Terre (1987), 103

Not Available

Exploring the potential of crop specific green area index time series to improve yield estimation at regional scale

in Sobrino, J. A. (Ed.) Proceedings of the 3rd International Symposium on Recent Advances in Quantitative Remote Sensing (RAQRS'III) (2010)

Crop status, such as the Green Area Index (GAI), can be retrieved from satellite observations by modelling and inverting the radiative transfer within the canopy. Providing such information along the ... [more ▼]

Crop status, such as the Green Area Index (GAI), can be retrieved from satellite observations by modelling and inverting the radiative transfer within the canopy. Providing such information along the growing season can potentially improve crop growth modelling and yield estimation. However, such approaches have proven difficult to apply on coarse resolution satellite data due to the fragmented land cover in many parts of the World. Advances in operational crop mapping will sooner or later allow the production of crop maps relatively early in the crop growth season, thereby providing an opportunity to sample pixels from medium/coarse spatial resolution data with relatively high cover fraction of a particular crop type to derive crop specific GAI time series. This research explores how to use such time series derived from MODIS to produce indicators of crop yield using two approaches over part of Belgium. The first method consists in looking at metrics of the decreasing part of the GAI curves when senescence occurs. Such metrics, like the position of the inflexion point, have been shown to be significantly correlated to yield. The second approach is to optimize the WOFOST model used in the European Crop Growth Monitoring System (CGMS) based on the GAI time series. Results show that, although the optimized model shows considerably better performance than the model running on the default parameter, the model is sometimes outperformed by the simpler metric approach. In all cases, indicators including remote sensing information provide better estimates that the average yield of previous years. [less ▲]

Exploring the risk factors for Salmonella in the ten biggest Belgian pig slaughterhouses.

Poster (2007, May)

Exploring the southern sky -- S. Lautsen et al.

in Ciel et Terre (1988), 104

Not Available

Exploring the unity and diversity of the neural substrates of executive functioning

in Human Brain Mapping (2005), 25(4), 409-423

Previous studies exploring the neural substrates of executive functioning used task-specific analyses, which might not be the most appropriate approach due to the difficulty of precisely isolating ... [more ▼]

Previous studies exploring the neural substrates of executive functioning used task-specific analyses, which might not be the most appropriate approach due to the difficulty of precisely isolating executive functions. Consequently, the aim of this study was to use positron emission tomography (PET) to reexamine by conjunction and interaction paradigms the cerebral areas associated with three executive processes (updating, shifting, and inhibition). Three conjunction analyses allowed us to isolate the cerebral areas common to tasks selected to tap into the same executive process. A global conjunction analysis demonstrated that foci of activation common to all tasks were observed in the right intraparietal sulcus, the left superior parietal gyrus, and at a lower statistical threshold, the left lateral prefrontal cortex. These regions thus seem to play a general role in executive functioning. The right intraparietal sulcus seems to play a role in selective attention to relevant stimuli and in suppression of irrelevant information. The left superior parietal region is involved in amodal switching/integration processes. One hypothesis regarding the functional role of the lateral prefrontal cortex is that monitoring and temporal organization of cognitive processes are necessary to carry out ongoing tasks. Finally, interaction analyses showed that specific prefrontal cerebral areas were associated with each executive process. The results of this neuro-imaging study are in agreement with cognitive studies demonstrating that executive functioning is characterized by both unity and diversity of processes. [less ▲]

L'explosion d'une supernova dans le Grand Nuage de Magellan

Article for general public (1987)

The author presents here an overview of the main results obtained so far about the bright supernova SN 1987A which exploded in the Large Magellanic Cloud.

Explosive strength imbalances in professional basketball players.

in Journal of Athletic Training (2009), 44(1), 39-47

CONTEXT: Despite the high rate of lower limb injuries in basketball players, studies of the dominant-limb effect in elite athletes often neglect injury history. OBJECTIVE: To determine lower limb ... [more ▼]

CONTEXT: Despite the high rate of lower limb injuries in basketball players, studies of the dominant-limb effect in elite athletes often neglect injury history. OBJECTIVE: To determine lower limb explosive-strength asymmetries in professional basketball players compared with junior basketball players and control participants. DESIGN: Cohort study. SETTING: Academic medical institution. PATIENTS OR OTHER PARTICIPANTS: 15 professional basketball players, 10 junior basketball players, and 20 healthy men. MAIN OUTCOME MEASURE(S): We performed an isokinetic examination to evaluate the knee extensor (Ext) and flexor (Fl) concentric peak torque at 60 degrees .s(-1) and 240 degrees .s(-1) and (Fl only) eccentric peak torque at 30 degrees .s(-1) and 120 degrees .s(-1). Functional evaluation included countermovement jump, countermovement jump with arms, 10-m sprint, single-leg drop jump, and single-leg, 10-second continuous jumping. Variables were compared among groups using analysis of variance or a generalized linear mixed model for bilateral variables. RESULTS: The 2 groups of basketball players demonstrated better isokinetic and functional performances than the control group did. No differences in functional or relative isokinetic variables were noted between professional and junior basketball players. Professional players with a history of knee injury failed to reach normal knee extensor strength at 60 degrees .s(-1). Knee Ext (60 degrees .s(-1)) and Fl (eccentric 120 degrees .s(-1)) torque values as well as 10-second continuous jumping scores were higher in those professional players without a history of knee injury than those with such a history. Compared with the group without a history of knee injury, the group with a history of knee injury maintained leg asymmetry ratios greater than 10% for almost all isokinetic variables and more than 15% for unilateral functional variables. CONCLUSIONS: The relative isokinetic and functional performances of professional basketball players were similar to those of junior players, with no dominant-side effect. A history of knee injury in the professional athlete, however, was reflected in bilateral isokinetic and functional asymmetries and should be considered in future studies of explosive strength. [less ▲]

Exporation cognitive et neuropsychologique du fonctionnement de la mémoire épisodique: Les processus de reconnaissance et la mémoire du contexte temporel

Doctoral thesis (2004)

The main objective of our dissertation was to contribute to a better understanding of the cognitive processes involved in episodic memory and their cerebral substrates. More specifically, our work focused ... [more ▼]

The main objective of our dissertation was to contribute to a better understanding of the cognitive processes involved in episodic memory and their cerebral substrates. More specifically, our work focused on two questions. First, we were interested in the contribution of recollection and familiarity to recognition memory. On the one hand, we examined the performance on recognition tasks when recollection cannot be used anymore (studies 1, 2 and 3) and, on the other hand, the influence of frontal lobe lesions on the processes involved in a recognition memory task (study 4). Second, we explored the processes recruited in an important aspect of episodic memory, namely, memory for the temporal context of events, by studying the nature of the difficulties encountered by older adults on a task assessing memory for temporal information (studies 5 and 6). [less ▲]