Polymorphisms in genes involved in the estrogen pathway and mammographic density

<p>Abstract</p> <p>Background</p> <p>Single nucleotide polymorphisms (SNPs) in genes involved in the estrogen pathway appear to be associated with breast cancer risk and possibly with mammographic density (MD), but little is known of these associations among premenopausal women. This study examines the association of 11 polymorphisms in five estrogen-related genes (estrogen receptors alpha and beta (<it>ERα, ERβ</it>), 17β-hydroxysteroid dehydrogenase 1 (<it>HSD17B1</it>), catechol-O-methyltransferase (<it>COMT</it>), cytochrome P450 1B1 (<it>CYP1B1</it>)) with premenopausal MD. Effect modification of four estrogen-related factors (parity, age at menarche, hormonal derivatives use and body mass index (BMI)) on this relation is also assessed.</p> <p>Methods</p> <p>Polymorphisms were genotyped in 741 premenopausal Caucasian women whose MD was measured in absolute density (AD, cm²) and percent density using a computer-assisted method. Multivariate linear models were used to examine the associations (<it>P</it>_trend) and interactions (<it>P</it>_i).</p> <p>Results</p> <p>None of the SNPs showed a statistically significant association with AD. However, each additional rare allele of rs1056836 <it>CYP1B1 </it>was associated with a reduction in AD among nulliparous women (<it>P</it>_trend= 0.004), while no association was observed among parous women (<it>P</it>_trend= 0.62; <it>P</it>_i= 0.02). An increase in the number of rare alleles of the <it>HSD17B1 </it>SNP (rs598126 and rs2010750) was associated with an increase in AD among women who never used hormonal derivatives (<it>P</it>_trend= 0.06 and <it>P</it>_trend= 0.04, respectively), but with a decrease in AD among past hormonal derivatives users (<it>P</it>_trend= 0.04; <it>P</it>_i= 0.02 and <it>P</it>_trend= 0.08; <it>P</it>_i= 0.01, respectively). Moreover, a negative association of rs598126 <it>HSD17B1 </it>SNP with AD was observed among women with higher BMI (>median) (<it>P</it>_trend= 0.01; <it>P</it>_i= 0.02). A negative association between an increased number of rare alleles of <it>COMT </it>rs4680 SNP and AD was limited to women who never used hormonal derivatives (<it>P</it>_trend= 0.02; <it>P</it>_i= 0.03) or with late age at menarche (>median) (<it>P</it>_trend= 0.03; <it>P</it>_i= 0.02). No significant association was observed between polymorphisms in the <it>ERα </it>or <it>ERβ </it>genes and AD. Similar results, although less significant, were observed when MD was assessed in percent density.</p> <p>Conclusion</p> <p>SNPs located in <it>CYP1B1</it>, <it>COMT </it>or <it>HSD17B1 </it>genes seem to be associated with MD in some strata of estrogen-related factors. Our findings suggest that modifying effects of estrogen-related factors should be considered when evaluating associations of polymorphisms in estrogen-related genes with premenopausal mammographic density.</p

Dispositif de formation numérique en information documentation : pour une médiation des savoirs

La formation post-capes en information-documentation dans l’Enseignement agricole est basée sur l’alternance et la co-évaluation. Dans ce contexte, la formation peut-elle permettre la construction d'un socle commun de connaissances nécessaires à l'exercice de tous les aspects du métier en prenant en compte les parcours diversifiés ? Un dispositif innovant a été mis en place, au travers duquel les formateurs ont souhaité inscrire un espace de médiation pour permettre une appropriation des contenus sous la forme d’un projet personnel. Ce suivi multiforme est questionné ici afin de mesurer en quoi l'évolution du support de formation et les modalités de diffusion des contenus participent au processus de construction des connaissances dans l'environnement d’enseignement spécifique de futurs professionnels de l'information documentation

Place de l'information professionnelle dans la construction de savoirs émergents : le cas des agriculteurs biologiques

Cette étude fait partie d'un programme de recherche qui vise à comprendre les pratiques informationnelles intuitives d'acteurs engagés dans des communautés professionnelles spécifiques. Il s'agit ici d'interroger la place de l'information dans la circulation et le partage des savoirs, au travers du repérage des pratiques informationnelles des agriculteurs biologiques pour tenter de saisir ce qui se joue quand les individus agissent avec et sur l’information. Les résultats recueillis à partir d'une série d'entretiens ont permis de voir que ces pratiques informationnelles, telles qu'elles nous ont été relatées, semblent effectivement intuitives. Les difficultés et manques pointés par les acteurs montrent un besoin de médiation de l'information et un besoin de dispositifs info-communicationnels qui nous paraissent être un facteur de rupture dans un premier temps. Cependant ils pourraient concourir a contrario à la stabilité de cette communauté professionnelle en assurant un meilleur partage des savoirs sans pour autant exclure la dynamique actuelle de co-construction des savoirs

WYFIWIF: A Haptic Communication Paradigm For Collaborative Motor Skills Learning

International audienceMotor skills transfer is a challenging issue for many applications such as surgery, design and industry. In order to design virtual environments that support motor skills learning, a deep understanding of humans' haptic interactions is required. To ensure skills transfer, experts and novices need to collaborate. This requires the construction of the common frame of reference between the teacher and the learner in order to understand each other. In this paper, human-human haptic collaboration is investigated in order to understand how haptic information is exchanged. Furthermore, WYFIWIF (What You Feel Is What I Feel), a haptic communication paradigm is introduced. This paradigm is based on a hand guidance metaphor. The paradigm helps operators to construct an efficient common frame of reference by allowing a direct haptic communication. A learning virtual environment is used to evaluate this haptic communication paradigm. Hence, 60 volunteer students performed a needle insertion learning task. The results of this experiment show that, compared to conventional methods, the learning method based on haptic communication improves the novices' performance in such a task. We conclude that the WYFIWIF paradigm facilitate expert-novice haptic collaboration to teach motor skills

Influence des systèmes de référence sur les profils de collaboration dans un environnement virtuel

International audienceLes Environnements Virtuels Collaboratifs sont des espaces 3D partagés dans lesquels les personnes travaillent ensemble. Pour que la collaboration soit efficace, les utilisateurs doivent avoir des compréhensions compatibles du monde virtuel. Dans cette étude exploratoire nous avons manipulé le contenu de l'environnement virtuel partagé pour comprendre comment les utilisateurs construisent verbalement des représentations communes de cet environnement. Les résultats montrent que la présence d'un indice visuel fixe dans l'environnement virtuel influence la façon dont les opérateurs collaborent

Elaboration of a common frame of reference in Collaborative Virtual Environments

International audienceMotivation – To design virtual environments that support collaborative activities. Research approach – An experimental approach in which 44 students were asked to work in pairs to reconstruct five 3D figures. Findings/Design – The results show that including a contextual clue in virtual environments improves collaboration between operators. Research limitations – Further investigative work must be carried out to extract accurate female collaboration profiles. Originality/Value – The results enable three collaboration profiles to be identified. They also allow the extraction of some characteristics of a contextual clue which can be added to a virtual environment to improve collaboration. Take away message – The contents of a collaborative virtual environment influences the way that users collaborate

Haptic communication to support biopsy procedures learning in virtual environments

International audienceIn interventional radiology, physicians require high haptic sensitivity and fine motor skills development because of the limited real-time visual feedback of the surgical site. The transfer of this type of surgical skill to novices is a challenging issue. This paper presents a study on the design of a biopsy procedure learning system. Our methodology, based on a task-centered design approach, aims to bring out new design rules for virtual learning environments. A new collaborative haptic training paradigm is introduced to support human-haptic interaction in a virtual environment. The interaction paradigm supports haptic communication between two distant users to teach a surgical skill. In order to evaluate this paradigm, a user experiment was conducted. Sixty volunteer medical students participated in the study to assess the influence of the teaching method on their performance in a biopsy procedure task. The results show that to transfer the skills, the combination of haptic communication with verbal and visual communications improves the novices' performance compared to conventional teaching methods. Furthermore, the results show that, depending on the teaching method, participants developed different needle insertion profiles. We conclude that our interaction paradigm facilitates expert-novice haptic communication and improves skills transfer; and new skills acquisition depends on the availability of different communication channels between experts and novices. Our findings indicate that the traditional fellowship methods in surgery should evolve to an off-patient collaborative environment that will continue to support visual and verbal communication, but also haptic communication, in order to achieve a better and more complete skills training

Haptic communication to enhance collaboration in virtual environments

International audienceMotivation – To study haptic communication in collaborative virtual environments. Research approach – An experimental study was conducted, in which 60 students were asked to perform in dyads a shared manual task after a training period. Findings/Design – The results show that haptic communication can influence the common frame of reference development in a shared manual task. Research limitations/Implications – Deeper verbalization analyses are needed to evaluate the common frame of reference development. Originality/Value – This study highlights haptic interactions importance when designing virtual environment that support shared manual tasks. Take away message – Haptic communication, combined with visual and verbal communication, enriches interactions in virtual environments

WYFIWIF: A Haptic Communication Paradigm For Collaborative Motor Skills Learning

International audienceMotor skills transfer is a challenging issue for many applications such as surgery, design and industry. In order to design virtual environments that support motor skills learning, a deep understanding of humans' haptic interactions is required. To ensure skills transfer, experts and novices need to collaborate. This requires the construction of the common frame of reference between the teacher and the learner in order to understand each other. In this paper, human-human haptic collaboration is investigated in order to understand how haptic information is exchanged. Furthermore, WYFIWIF (What You Feel Is What I Feel), a haptic communication paradigm is introduced. This paradigm is based on a hand guidance metaphor. The paradigm helps operators to construct an efficient common frame of reference by allowing a direct haptic communication. A learning virtual environment is used to evaluate this haptic communication paradigm. Hence, 60 volunteer students performed a needle insertion learning task. The results of this experiment show that, compared to conventional methods, the learning method based on haptic communication improves the novices' performance in such a task. We conclude that the WYFIWIF paradigm facilitate expert-novice haptic collaboration to teach motor skills

Influence of Contextual Objects on Spatial Interactions and viewpoints sharing in Virtual Environments

International audienceCollaborative virtual environments (CVEs) are 3D spaces in which users share virtual objects, communicate, and work together. To collaborate efficiently, users must develop a common representation of their shared virtual space. In this work, we investigated spatial communication in virtual environments. In order to perform an object co-manipulation task, the users must be able to communicate and exchange spatial information, such as object position, in a virtual environment. We conducted an experiment in which we manipulated the contents of the shared virtual space to understand how users verbally construct a common spatial representation of their environment. Forty-four students participated in the experiment to assess the influence of contextual objects on spatial communication and sharing of viewpoints. The participants were asked to perform in dyads an object co-manipulation task. The results show that the presence of a contextual object such as fixed and lateralized visual landmarks in the virtual environment positively influences the way male operators collaborate to perform this task. These results allow us to provide some design recommendations for CVEs for object manipulation tasks