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Search Results: 1 - 10 of 19347 matches for " Richard LeDuc "
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Means of Choice for Interactive Management of Dynamic Geometry Problems Based on Instrumented Behaviour  [PDF]
Philippe R. Richard, Michel Gagnon, Josep Maria Fortuny, Nicolas Leduc, Michèle Tessier-Baillargeon
American Journal of Computational Mathematics (AJCM) , 2013, DOI: 10.4236/ajcm.2013.33B008

Our paper presents a project that involves two research questions: does the choice of a related problem by the tutorial system allow the problem solving process which is blocked for the student to be restarted? What information about learning do related problems returned by the system provide us? We answer the first question according to the didactic engineering, whose mode of validation is internal and based on the confrontation between an a priori analysis and an a posteriori analysis that relies on data from experiments in schools. We consider the student as a subject whose adaptation processes are conditioned by the problem and the possible interactions with the computer environment, and also by his knowledge, usually implicit, of the institutional norms that condition his relationship with geometry. Choosing a set of good problems within the system is therefore an essential element of the learning model. Since the source of a problem depends on the student’s actions with the computer tool, it is necessary to wait and see what are the related to problems that are returned to him before being able to identify patterns and assess the learning. With the simultaneity of collecting and analysing interactions in each class, we answer the second question according to a grounded theory analysis. By approaching the problems posed by the system and the designs in play at learning blockages, our analysis links the characteristics of problems to the design components in order to theorize on the decisional, epistemological, representational, didactic and instrumental aspects of the subject-milieu system in interaction.

Urban Soundscape Informational Quantization: Validation Using a Comparative Approach  [PDF]
Philippe Woloszyn, Thomas Leduc
Journal of Service Science and Management (JSSM) , 2010, DOI: 10.4236/jssm.2010.34049
Abstract: Through interaction with environmental parameters such as light or sound, urban and architectural spaces generate ambiences with identifiable characteristics. This notion of ambiences is related to the human being position through its perception of environmental physical phenomenon during a pedestrian walk. Presented work aims to evaluate, so as to characterize, the impact of sound ambiences (soundscape) onto an urban pedestrian pathway using GIS spatial dynamical mapping. To carry out this scheme, our research work within AMBIOFLUX project concerns spatial interaction between sound ambience (soundscape) and man urban spatial trajectory (soundwalk). Spatial impression of soundsources or soundmarks has to be both defined through acoustical measurement and perception informational evaluation. The remainder of this paper is dedicated to the evaluation’s methodology of the pedestrian pathway’s acoustic fingerprint using the GearScape spatial formalism described thereafter. Preliminary results we have obtained will also be presented and validated.
Gene-interleaving patterns of synteny in the Saccharomyces cerevisiae genome: are they proof of an ancient genome duplication event?
Nicolas Martin, Elizabeth A Ruedi, Richard LeDuc, Feng-Jie Sun, Gustavo Caetano-Anollés
Biology Direct , 2007, DOI: 10.1186/1745-6150-2-23
Abstract: We focus on (1) pairwise comparison of gene arrangement sequences in A. gossypii and S. cerevisiae, (2) reconstruction of gene arrangements ancestral to A. gossypii, S. cerevisiae, and K. waltii, (3) synteny patterns arising within and between lineages, and (4) expected gene orientation of duplicate gene sets. The existence of syntenic patterns between ancestral gene sets and A. gossypii, S. cerevisiae, and K. waltii, and other evidence, suggests that gene-interleaving relationships are the natural consequence of topological rearrangements in chromosomes and that a more gradual scenario of genome evolution involving segmental duplication and recombination constitutes a more parsimonious explanation. Furthermore, phylogenetic trees reconstructed under alternative hypotheses placed the putative whole-genome duplication event after the divergence of the S. cerevisiae and K. waltii lineages, but in the lineage leading to K. waltii. This is clearly incompatible with an ancient genome duplication event in S. cerevisiae.Because the presence of syntenic patterns appears to be a condition that is necessary, but not sufficient, to support the existence of the whole-genome duplication event, our results prompt careful re-evaluation of paleopolyploidization in the yeast lineage and the evolutionary meaning of syntenic patterns.This article was reviewed by Kenneth H. Wolfe (nominated by Nicolas Galtier), Austin L. Hughes (nominated by Eugene Koonin), Mikhail S. Gelfand, and Mark Gerstein.The existence of an ancient whole-genome duplication (WGD) event in Saccharomyces cerevisiae [1] has been debated over the past several years. WGD followed by massive gene loss could explain duplicated genes that are interspersed throughout the genome and syntenic relationships with other hemiascomycete yeasts [2-4]. An alternative view is that evolution proceeded gradually through segmental chromosomal duplications that occurred independently, sometimes massively, and were extensively shuffled
ESTIMA, a tool for EST management in a multi-project environment
Charu G Kumar, Richard LeDuc, George Gong, Levan Roinishivili, Harris A Lewin, Lei Liu
BMC Bioinformatics , 2004, DOI: 10.1186/1471-2105-5-176
Abstract: A web application, Expressed Sequence Tag Information Management and Annotation (ESTIMA), has been created to meet the EST annotation and data management requirements of multiple high-throughput EST sequencing projects. It is anchored on individual ESTs and organized around different properties of ESTs including chromatograms, base-calling quality scores, structure of assembled transcripts, and multiple sources of comparison to infer functional annotation, Gene Ontology associations, and cDNA library information. ESTIMA consists of a relational database schema and a set of interactive query interfaces. These are integrated with a suite of web-based tools that allow a user to query and retrieve information. Further, query results are interconnected among the various EST properties. ESTIMA has several unique features. Users may run their own EST processing pipeline, search against preferred reference genomes, and use any clustering and assembly algorithm. The ESTIMA database schema is very flexible and accepts output from any EST processing and assembly pipeline.ESTIMA has been used for the management of EST projects of many species, including honeybee (Apis mellifera), cattle (Bos taurus), songbird (Taeniopygia guttata), corn rootworm (Diabrotica vergifera), catfish (Ictalurus punctatus, Ictalurus furcatus), and apple (Malus x domestica). The entire resource may be downloaded and used as is, or readily adapted to fit the unique needs of other cDNA sequencing projects.The scripts used to create the ESTIMA interface are freely available to academic users in an archived format from http://titan.biotec.uiuc.edu/ESTIMA/ webcite. The entity-relationship (E-R) diagrams and the programs used to generate the Oracle database tables are also available. We have also provided detailed installation instructions and a tutorial at the same website. Presently the chromatograms, EST databases and their annotations have been made available for cattle and honeybee brain EST projects. No
La construction du temps chez les historiens universitaires fran ais de la seconde moitié du XXe siècle The building of Time by French University historians during the second half of the XXe
Jean Leduc
Temporalités , 2009,
Abstract: Les historiens fran ais de la seconde moitié du XXe siècle sont plus conscients que leurs prédécesseurs que le travail de recherche et d’écriture de l’histoire est une interaction continuelle entre présent et passé. La plupart d’entre eux ont substitué le présent au passé simple comme temps de base de la narration. Ils sont plus attentifs aux tendances et aux phénomènes de longue durée qu’au temps court des événements. Ils sont moins réticents à étudier le passé le plus récent mais, sur ce point, la controverse n’est pas close. Ouvertement ou non, le récit chronologique demeure le modèle de plan prédominant, de même que continue à prévaloir un système de datation absolue se référant au calendrier. Les historiens font attention à éviter les coupures chronologiques abusives et prennent soin de ne pas suggérer qu’une séquence d’événements implique nécessairement une relation causale entre eux. Les débats théoriques se développent mais, le plus souvent, résultent d’incitations extérieures au corps des historiens. French historians of the second half of the XXe century are more aware than their predecessors that historical research and writing means continuous interaction between past and present. Most of them have substituted the grammatical present for the preterit as the basic tense of the narrative. They pay more attention to trends and long-term phenomena than to short-term events. They are less reluctant to study the most recent past, but this issue remains controversial. Openly or not, chronological story is still the prevailing model, as is the absolute dating system according to the calendar. Historians are careful to avoid arbitrary chronological divisions and they stress that a sequence of events does not imply a relationship of cause and effect between them. Theorical discussions are on-going but, more often than not are the result of encouragement from outside the historical professions.
‘Dans les pas de Nicole Loraux’.
Claudine Leduc
EspacesTemps.net , 2005,
Abstract: Depuis Les enfants d’Athéna , qui connurent une fulgurante échappée hors du cercle des Hellénistes, le lectorat de Nicole Loraux est très composite. Porteur d’intérêts très divers, il est parfois enclin à parcelliser son uvre : le politique, l’histoire, le théatre, le genre… Cet article est une invitation à refaire le chemin parcouru par l’auteure en sa compagnie et à construire sa biographie intellectuelle dans sa totalité. Since the publication of Les enfants d'Athéna , which was a dazzling breakthrough beyond the circle of Hellenic scholars, the readers of Nicole Loraux have adopted different standpoints. Involved in various fields of knowledge, they are sometimes inclined to segment her works: politics, history, theater, gender… This article is meant to entice the readers to size up the full scope of the writer's research so that her intellectual biography may be conceived as a whole.
Deep-sea nematodes (Comesomatidae) from the Southwest Pacific Ocean: five new species and three new species records
Daniel Leduc
European Journal of Taxonomy , 2012, DOI: 10.5852/ejt.2012.24
Abstract: The present study describes five new free-living nematode species and provides three new species records of the family Comesomatidae (genera Cervonema Wieser, 1954, Dorylaimopsis Ditlevsen, 1918, Hopperia Vitiello, 1969, and Kenyanema Muthumbi et al., 1997) from the continental margin of New Zealand, Southwest Pacific. Dichotomous identification keys are provided for all known species of Dorylaimopsis and Hopperia. Cervonema shiae Chen & Vincx, 2000 is recorded for the first time outside the type locality (Beagle Channel, Chile). C. kaikouraensis sp. nov. is characterised by amphideal fovea with 5.5 turns situated at 1.7 head diameter from anterior end, jointed outer labial setae, equal in length to cephalic setae, sperm dimorphism, and 5-6 small pre-cloacal supplements. C. multispira sp. nov. is characterised by amphideal fovea with 8.0-8.5 turns situated at 2.6-4.0 head diameter from anterior end, cephalic setae 2-3 μm long, slightly shorter than outer labial setae, presence of six uninucleated cells in males (potentially pseudocoelomocytes or supplementary excretory cells), 5 small pre-cloacal supplements, and strongly cuticularised, arcuate spicules with capitulum. C. proberti sp. nov. is characterised by amphideal fovea with 5 turns and located at < 1 head diameter from anterior end, cephalic setae 1.6-2.0 times longer than outer labial setae, and 8 small pre-cloacal supplements. Dorylaimopsis nodderi sp. nov. is characterised by cuticle with lateral differentiation consisting of three longitudinal rows of larger dots in the pharyngeal and caudal regions, two rows of larger dots in middle region of body, and spicules with rounded ventral projection at one third of spicule length from distal end, giving appearance of a joint. Hopperia ancora sp. nov. is characterised by short conical cephalic setae, spicules with hook-like projection at distal end, gubernaculum with bent apophyses, and 11-13 pre-cloacal supplements. H. beaglense Chen & Vincx, 1998 is recorded from Kaikoura Canyon, the first record of this species outside the type locality (Beagle Channel, Chile). Kenyanema monorchis Muthumbi et al., 1997 is also recorded for the first time outside the type locality (Indian Ocean).
What Is the Role of Work-Related Factors in Self-Reported Health Inequalities among Employed Individuals? A Longitudinal Study in Luxembourg  [PDF]
Anastase Tchicaya, Nathalie Lorentz, Kristell Leduc
Health (Health) , 2018, DOI: 10.4236/health.2018.109087
Abstract: Objectives: We measured health inequalities among employed Luxembourg residents over time and the socio-economic and work-related determinants. Design and Setting: Longitudinal data were obtained from the Socio-economic Liewen zu Lëtzebuerg/European Union Survey on Income and Living Conditions, which has been conducted each year since 2003 in Luxembourg. Participants: Participants comprised 727 Luxembourg residents (58% men), aged between 21 and 55 years in 2003, who were employed between 2003 and 2012. Primary and Secondary Outcomes Measured: The variable of interest was self-reported health. We used transition indicators on work-related factors to consider changes that individuals may have experienced in their job over this period. Results: People who moved from a part-time to a full-time contract (odds ratio (OR): 5.52, confidence interval (CI): 1.55 - 19.73), and those who moved from the 3rd or 4th quartile of earnings to the 1st or 2nd quartile (OR: 2.48, CI: 1.02 - 6.05) between 2003 and 2012, had a higher risk of being in poor health in 2012. The risk of deterioration in self-reported health in 2012 among people who were healthy in 2003 was associated with the type of contract, economic activity, and occupation. Conclusion: Health inequalities occur among employed people in Luxembourg. Their importance varies according to work-related characteristics and economic activity. Our findings showed that declined health status was associated with contract type, profession, and economic activity. This suggests that measures should be taken to maintain good health for people working in these specific occupations or economic sectors (e.g. preventive action, reduction of risk exposure, change of occupation in the same company, and so on).
Energy and Exergy Balances for Modern Diesel and Gasoline Engines Bilans d’énergie et d’exergie pour des moteurs Diesel et essence récents
Bourhis G.,Leduc P.
Oil & Gas Science and Technology , 2009, DOI: 10.2516/ogst/2009051
Abstract: The aim is here to evaluate the difference between the energy and exergy (or available energy) balances when heat recovery is considered in an internal combustion engine. In the first case, the entropy of the system is not taken into account so that, the maximum useful work recoverable from a system can not be estimated. Then, the second case is much more adapted to estimate heat recovery potential. In this paper, two modern engines are evaluated. First, an up-to-date gasoline engine: three-cylinder, downsized, low friction, then a modern common rail downsized Diesel engine. For each one, two energy and exergy balances are given for two different part-load operating points representative of the NEDC cycle using experimental data from steady state engine test benches. For the Diesel engine, it is shown that effective work represents around 30% and that around 55% of the energy introduced into the combustion chamber is lost (in the form of heat), especially in exhaust gas, in water coolant and oil. But when considering exergy balance, only 12% of the total exergy introduced through the fuel can be recovered, in order to produce useful work. Expecting a 25% exergy recovery efficiency, the effective engine efficiency could be increased by 10%. For the gasoline engine, the increase of the output work could be around 15%. L’objectif est ici d’évaluer la différence entre bilan d’énergie et d’exergie (ou énergie utile) pour des moteurs à combustion interne lorsque la problématique de récupération d’énergie est prise en compte. Dans le premier cas, l’entropie du système n’est pas considérée, si bien que le travail utile maximal qu’il est possible de récupérer d’un système ne peut pas être estimé. Tandis que le second cas est bien mieux adapté pour estimer le potentiel de la récupération d’énergie. Dans cet article, deux moteurs modernes sont étudiés. Le premier est un moteur essence récent, 3 cylindres, de cylindrée réduite, à faible frottement, et le second un moteur Diesel à injection directe à rampe commune, également de cylindrée réduite. Pour chacun de ces deux moteurs, à l’aide de données expérimentales obtenues sur banc moteur, deux bilans d’énergie et d’exergie ont été effectués pour deux points de fonctionnement à charge partielle, représentatifs du cycle NEDC. Dans le cas du moteur Diesel, le travail effectif, représentant environ 30 % et 55 % de l’énergie introduite dans la chambre de combustion, est perdu (sous forme de chaleur), et plus spécifiquement dans les gaz d’échappement, l’eau de refroidissement et l’huile. Mais, lorsque l’on considère le bi
Variations in Transnational Tutoring in Distance Learning : the Form@sup Experience
Airina Volungeviciene,Laurent Leduc
Revue Internationale des Technologies en Pédagogie Universitaire , 2006,
Abstract: [Fran ais] Cet article décrit plusieurs r les tenus par des tuteurs transnationaux à travers les points de vue de deux d’entre eux occupant des positions différentes dans un dispositif de formation recourant à l’Enseignement à Distance : Form@sup (dans sa version anglaise). Les r les et les positions sont présentés à travers deux modèles théoriques. On insistera sur les relations entre l’Unité centrale et une tutrice transnationale le représentant localement. [English] This paper describes several roles of transnational tutors from the standpoint of two of them, holding different positions in the design of a curriculum based on Distance Learning (Form@sup in its English version). These roles and positions will be presented according to two theoretical models. Particular focus will be placed on the relationship between the Central unit and a transnational tutor representing it locally.
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