Alexandre François

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1 Introduction We present a system to perform real-time adaptive background modeling and segmentation of video streams. Our goal is to segment non background object silhouettes in video streams taken from a fixed camera. A number of systems performing segmentation of moving objects rely on image differencing, with various enhancements (e.g. [6]). A binary(More)
Direct measurement of the biomechanical stress induced by a live cell during endocytosis is reported. Fluorescent dye-doped polystyrene microspheres were used as microscopic remote optical sensors applying whispering gallery modes (WGMs) as transducer mechanism. Monitoring of the WGMs throughout the incorporation of the microsphere into the cell enabled the(More)
Whispering gallery modes (WGMs) within microsphere cavities enable highly sensitive label-free detection of changes in the surrounding refractive index. This detection modality is of particular interest for biosensing applications. However, the majority of biosensing work utilizing WGMs to date has been conducted with resonators made from either silica or(More)
Whispering gallery modes (WGMs) in surface-fixated fluorescent polystyrene microbeads are studied in view of their capability of sensing the formation of biochemical adsorption layers on their outer surface with the well-established biotin-streptavidin specific binding as the model system. Three different methods for analysis of the observed shifts in the(More)
Building upon the model of Semantic Maps (Haspelmath 2003), which typologists have designed mainly for grammatical semantics, this chapter discusses methodological issues for a model in lexical typology. By breaking up polysemous lexemes of various languages into their semantic 'atoms' or senses, one defines an etic grid against which cross-linguistic(More)
UNLABELLED Surface plasmon resonance (SPR)-based sensors enable the rapid, label-free and highly sensitive detection of a large range of biomolecules. We have previously shown that, using silver-coated optical fibers with a high surface roughness, re-scattering of light from the surface plasmons is possible, turning SPR into a radiative process. The(More)
Data collected on the 17 languages spoken in the Banks and Torres Islands (northern Vanuatu) reveal strikingly diverse vowel systems, differing both in the quality and the quantity of their phonemes. Except for Mota, which still perpetuates the ²ve vowels of Proto-Oceanic, the languages of this area have historically increased their inventories to as many(More)
High index Er-Yb codoped tellurite spheres with diameter of 9 μm and good sphericity were fabricated using a CO(2) laser. Upconversion modulated whispering gallery modes with a quality factor of 45,000 were observed in the sphere dipped in methanol. Refractometric sensing with detection sensitivity of 7.7 nm/RIU was demonstrated using a 9 μm diameter(More)
Sensors based on surface plasmon resonance (SPR) allow rapid, label-free, highly sensitive detection, and indeed this phenomenon underpins the only label-free optical biosensing technology that is available commercially. In these sensors, the existence of surface plasmons is inferred indirectly from absorption features that correspond to the coupling of(More)
The number of languages spoken on the planet has oscillated up and down throughout the history of mankind. 1 Different social factors operate in opposite ways, some resulting in the decrease of language diversity, others favouring the emergence of new languages. Thus, languages fade away and disappear when their speakers undergo some pressure towards(More)