Association entre l'attachement mère-enfant et les récits d'attachement à la période scolaire.

The objective of the present study was to examine which narrative dimensions distinguish attachment groups. Children's attachment pattern with mother was assessed at age 6 (n = 127; M = 75 months; SD = 12.55) using the Main and Cassidy (1988) separation-reunion classification system. Two years later (n = 109; M = 103 months; SD = 7.13), these children completed the Narrative Story Stem Battery (Bretherton, Oppenheim, Buchsbaum, Emde, & The MacArthur Narrative Group, 1990). In line with predictions, secure children depicted significantly fewer conflict themes in their narratives than did disorganized- controlling children. Secure children also produced significantly more discipline themes than avoidant children and had higher coherence scores than did ambivalent children. Furthermore, girls' narratives were more likely to evoke discipline and affection/affiliation themes, and to be more coherent than boys' narratives. These results suggest that attachment narratives are a promising way of evaluating internal working models of attachment during the school-age years. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An annotation model to reduce ambiguity in design communication

This paper describes an annotation model of digital design representations which aims to provide the design actors with a way to communicate more clearly in asynchronous situations. Our objective is to develop a model that improves design communication through the elicitation of knowledge related to the context of design. We present a case study based on our observations in an industrial vehicle company where we observed and analysed annotation practices during design reviews. The speech act theory is used in order to propose a model based on the concept of locutionary and illocutionary annotation acts, and annotation categories are drawn from cognitive approaches of design. An annotation scenario is then developed on the basis of the case study as an illustration of our model.     

Thermal and mechanical behavior of Al-Si alloy cast using magnetic molding and lost foam processes

Magnetic molding technology is an original alternative process aimed at improving the metallurgical quality and dimensional tolerances of the final components that are currently produced using the lost foam process. The initial development of the magnetic molding process took place at the same time as the lost foam process, more than 30 years ago, but the magnetic moldin process has never achieved the same level of industrial development. The purposes of this study are to introduce the magnetic molding process and to define its advantages and characteristics. The comparative results obtained with both the lost foam and the magnetic molding processes for aluminum casting are given. The main factors involved in the magnetic molding process are also discussed.     

The Design and Characterisation of an Optical VLSI Processor for Real Time Centroid Detection

The integration of photo-detectors onto a standard CMOS integrated circuit is presented. This device provides the optical front end for a real time centroid detection system to be used as part of a larger system for implementing a Shack-Hartmann wavefront sensor. A hardware emulation system containing a Field Programmable Gate Array is used to prototype suitable algorithms prior to IC fabrication. Data is presented on the performance of photodetectors and the ability to extract in real time a centroid coordinate.     

Selective interactions of ethidiums with G-quadruplex DNA revealed by surface-enhanced Raman scattering

Complexes formed between G-quadruplex (G4)-conformed oligonucleotides and four ethidium derivatives were studied by surface-enhanced Raman spectroscopy (SERS) to detail the topology of complexes that support a G4 stabilization. Ethidium bromide (EB), which presents a weak ability to stabilize oligonucleotides in G4 conformation, displayed no SERS intensity modification when bound to G4, as compared with the free EB. Three ethidium derivatives have been selected due to their higher ability to stabilize G4 than EB. Bound with G4-conformed oligonucleotides, SERS intensity of these three ethidiums decreased by factors of about 6, 3.5, and 15. The high SERS quenching was interpreted as a loss of accessibility of silver colloids for G4-bound ethidiums. This could represent a new selective parameter useful to identify G4-stabilizing molecules. To apraise the role of the oligonucleotide sequence on the interaction mode, complexes were formed with eight G4-conformed oligonucleotides in which the three loops were either 5'-TTA-3' or 5'-AAA-3'. Spectra of ethidiums were sensitive to both lateral loops, opposite to the 3' and 5' G4 ends. The sequence of these loops are believed to be selective in the interaction mode of ethidiums for G4.     

Measured and modeled radiometric quantities in coastal waters: toward a closure

Accurate radiative transfer modeling in the coupled atmosphere-sea system is increasing in importance for the development of advanced remote-sensing applications. Aiming to quantify the uncertainties in the modeling of coastal water radiometric quantities, we performed a closure experiment to intercompare theoretical and experimental data as a function of wavelength lambda and water depth z. Specifically, the study focused on above-water downward irradiance E(d)(lambda, 0+) and in-water spectral profiles of upward nadir radiance L(u)(lambda, z), upward irradiance E(u)(lambda, z), downward irradiance E(d)(lambda, z), the E(u)(lambda, z)/L(u)(lambda, z) ratio (the nadir Q factor), and the E(u)(lambda, z)/E(d)(lambda, z) ratio (the irradiance reflectance). The theoretical data were produced with the finite-element method radiative transfer code ingesting in situ atmospheric and marine inherent optical properties. The experimental data were taken from a comprehensive coastal shallow-water data set collected in the northern Adriatic Sea. Under various measurement conditions, differences between theoretical and experimental data for the above-water E(d)(lambda, 0+) and subsurface E(d)(lambda, 0-) as well as for the in-water profiles of the nadir Q factor were generally less than 15%. In contrast, the in-water profiles of L(u)(lambda, z), E(d)(lambda, z), E(u)(lambda, z) and of the irradiance reflectance exhibited larger differences [to approximately 60% for L(u)(lambda, z) and E(u)(lambda, z), 30% for E(d)(lambda, z), and 50% for the irradiance reflectance]. These differences showed a high sensitivity to experimental uncertainties in a few input quantities used for the simulations: the seawater absorption coefficient; the hydrosol phase function backscattering probability; and, mainly for clear water, the bottom reflectance.     

Multi-Modal Locomotion Robotic Platform Using Leg-Track-Wheel Articulations

Other than from its sensing and processing capabilities, a mobile robotic platform can be limited in its use by its ability to move in the environment. Legs, tracks and wheels are all efficient means of ground locomotion that are most suitable in different situations. Legs allow to climb over obstacles and change the height of the robot, modifying its viewpoint of the world. Tracks are efficient on uneven terrains or on soft surfaces (snow, mud, etc.), while wheels are optimal on flat surfaces. Our objective is to work on a new concept capable of combining different locomotion mechanisms to increase the locomotion capabilities of the robotic platform. The design we came up with, called AZIMUT, is symmetrical and is made of four independent leg-track-wheel articulations. It can move with its articulations up, down or straight, allowing the robot to deal with three-dimensional environments. AZIMUT is also capable of moving sideways without changing its orientation, making it omnidirectional. By putting sensors on these articulations, the robot can also actively perceive its environment by changing the orientation of its articulations. Designing a robot with such capabilities requires addressing difficult design compromises, with measurable impacts seen only after integrating all of the components together. Modularity at the structural, hardware and embedded software levels, all considered concurrently in an iterative design process, reveals to be key in the design of sophisticated mobile robotic platforms.This research is supported financially by the Canada Research Chair (CRC) program, the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canadian Foundation for Innovation (CFI) and the Faculty of Engineering of the Université de Sherbrooke. Patent pending.François Michaud is the Canada Research Chairholder in Autonomous Mobile Robots and Intelligent Systems, and an Associate Professor at the Department of Electrical Engineering and Computer Engineering of the Université de Sherbrooke. He is the principal investigator of LABORIUS, a research laboratory working on applying AI methodologies in the design of intelligent autonomous systems that can assist humans in everyday lives. His research interests are architectural methodologies for intelligent decision making, autonomous mobile robotics, social robotics, robot learning and intelligent systems. He received his bachelors degree, Masters degree and Ph.D. degree in Electrical Engineering from the Université de Sherbrooke. He is a member of IEEE, AAAI and OIQ (Ordre des ingénieurs du Québec).Dominic Létourneau has a Bachelor degree in Computer Engineering and a Masters degree in Electrical Engineering from the Université de Sherbrooke. Since 2001, he is a research engineer at the LABORIUS Mobile Robotics and Intelligent Systems Laboratory. His research interests cover combination of systems and intelligent capabilities to increase the usability of autonomous mobile robots in the real world. His expertise lies in artificial vision, mobile robotics, robot programming and integrated design. He is a member of OIQ (Ordre des ingénieurs du Québec).Martin Arsenault has a Bachelor degree in Mechanical Engineering and from the Université de Sherbrooke. For AZIMUT, he developed the Direction subsystem.Yann Bergeron is a Mechanical Junior Engineer working in a consulting engineering firm, Groupe HBA. His field of activity is most oriented in industrial projects and construction. He received his bachelors degree in Mechanical Engineering from the University de Sherbrooke. For AZIMUT, he worked on the Track-Wheel subsystem. He is a member of OIQ (Ordre des ingénieurs du Québec) and JECQ (Jeunes entrepreneurs du Centre-du-Québec).Richard Cadrin has a Bachelor degree in Mechanical Engineering from the Université de Sherbrooke. For AZIMUT, he worked on the Propulstion subsystem.Frédéric Gagnon has a Bachelor degree in Mechanical Engineering and from the Université de Sherbrooke. For AZIMUT, he designed the chassis and worked on the integration of the articulations, the bodywork and the hardware. He is currently a research engineer at LABORIUS, working on AZIMUTs second prototype and other robotic projects. He also contributes in a mobile robotic.Marc-Antoine Legault has a Bachelor degree in Mechanical Engineering from the Université de Sherbrooke, and is currently pursuing a Masters degree at LABORIUS on serial-elastic actuators. He worked on AZIMUTs Propulsion subsystem. He also works on the design of other mobile robotic platforms. He is a member of OIQ (Ordre des ingénieurs du Québec).Mathieu Millette has a Bachelor degree in Mechanical Engineering from the Université de Sherbrooke. For AZIMUT, he developed the Tensor subsystem and he designed and integrated the battery support inside the chassis. He is now working as a junior mechanical engineer in process and technical development in a third sector mill.Jean-François Paré graduated in Mechanical Engineering from the Université de Sherbrooke. He is also trained as a professional coach from R.I.C.K. (Réseau International de Coaching Kokopelli). He launched is own business in individual coaching, team coaching, team building and coaching workshops. For businesses and individuals, he assists people in reaching their well-being and efficiency and to manifest their leadership.Marie-Christine Tremblay has obtained a Bachelor degree in Mechanical Engineering from the Université de Sherbrooke. As a part of the AZIMUTõs team, she contributed the Track-Wheel subsystem and developed a new track with high adherence and wear resistance to climb stairs. She is working in the Engineering Department at Hydra-Fab Industriel, a company conceiving electro-hydraulic systems for high speed trains.Pierre Lepage has a Computer Engineering degree from the Université de Sherbrooke. For AZIMUT, he designed the user interface to control the robot and the propulsion system. He is currently a research engineer at LABORIUS, working on AZIMUTs second prototype and other robotic projects. He is involved in research projects on coordinated behavior of a group of mobile robots. He is also actively involved in a mobile robotic startup.Yan Morin has an Electrical Engineering degree from the Université de Sherbrooke. For AZIMUT, he designed the electrical interface to control the motors of the robot. He is currently a research engineer at LABORIUS, working on AZIMUTs second prototype and other robotic projects. He is also actively involved in a mobile robotic startup.Jonathan Bisson has a Bachelor degree in Computer Engineering and a Masters degree in Electrical Engineering from the Université de Sherbrooke. His contribution to AZIMUT was on the modular distributed computing architecture. His expertise lies in electronics, motor control, embedded systems and ultrasonic transducers.Serge Caron is technician in computer systems at the Department of Electrical Engineering and Computer Engineering of the Universit de Sherbrooke. His interests are in designing mobile robotic platforms, from four-legged to wheeled robots. He is also a writer for hobbyist robotic journals.     

Fast DNA translocation through a solid-state nanopore

We report experiments and modeling of translocation of double-strand DNA through a siliconoxide nanopore. Long DNA molecules with different lengths ranging from 6500 to 97000 base pairs have been electrophoretically driven through a 10 nm pore. We observe a power-law caling of the translocation time with the length, with an exponent of 1.27. This nonlinear scaling is strikingly different from the well-studied linear behavior observed in similar experiments performed on protein pores. We present a theoretical model where hydrodynamic drag on the ection of the polymer outside the pore is the dominant force counteracting the electrical driving force. We show that this applies to our experiments, and we derive a power-law scaling with an exponent of 1.22, in good agreement with the data.     

Photonic devices based on preferential etching

We introduce a design concept of optical waveguides characterized by a practical and reproducible process based on preferential etching of crystalline silicon substrates. Low-loss waveguides, spot-size converters, and power dividers have been obtained with polymers. We have also aligned liquid crystals in the waveguides and demonstrated guided propagation. Therefore this technology is a suitable platform for soft-matter photonics and heterogeneous integration.     

Aluminum buffer rods for ultrasonic monitoring at elevated temperatures

Aluminum (Al) buffer rods, having circular, square, and rectangular cross-section shapes with and without cladding, were experimentally investigated to achieve high performance in ultrasound for industrial process monitoring. Focus was devoted to the signal-to-noise ratio (SNR) aspect in pulse-echo mode because high SNR can make many practical ultrasonic monitoring applications feasible. If the size of the rod cross section can be properly selected, spurious echoes induced in the rod having finite dimensions--due to mode conversion, wave reverberation, and diffraction--do not overlap the desired echoes during pulse-echo measurements. Thus, a sufficient SNR may be obtained using nonclad rods for certain applications, which is of low cost. Clad buffer rods, having the above three shapes and consisting of an Al core and a stainless steel cladding, also were manufactured through thermal spray method. These clad Al rods achieved a SNR of more than 40 dB and had better SNR than clad steel rods. It was shown that the rod with a larger cross-section area exhibited a wider ultrasonic beam. The Al rods are handy in real-time, nonintrusive and nondestructive ultrasonic monitoring.