Manifold embedding for curve registration

We focus on the problem of finding a good representative of a sample of random curves warped from a common pattern f. We first prove that such a problem can be moved onto a manifold framework. Then, we propose an estimation of the common pattern f based on an approximated geodesic distance on a suitable manifold. We then compare the proposed method to more classical methods

Retention and permeability properties of damaged porous rocks

International audienceThe objective of this research work is to model the influence of deformation and damage on the permeability and retention properties of cracked porous media. This is achieved thanks to the introduction of microscale information into a macroscopic damage model. To this end, the Pore Size Distribution (PSD) of the material is coupled to the mechanical behaviour of the rock. Changes to this distribution due to deformation and damage are modelled and then used to capture induced changes to the retention and permeability properties of partially saturated materials. Rock microstructure is characterized by the size distributions of natural pores and cracks, which are used to update intrinsic permeability with Hagen-Poiseuille flow equation and Darcy's law. The void space occupied by water is computed by integrating the pore size distributions of natural pores and cracks up to the capillary pore radius (r(sat)). Laplace equation is used to relate r(sat) to the capillary pressure. The paper explains how to update PSD parameters with the macroscopic variables (such as deformation and damage), and then how to update permeability and retention properties with the PSD parameters. Conventional triaxial compression tests are simulated under controlled capillary pressure and under controlled water content. The proposed model captures well the intrinsic permeability decrease associated to the elastic compression of the natural pores, followed by the permeability jump due to crack opening. The modeling framework can be adapted to any rock constitutive model, including thermo-hydro-chemo-mechanical couplings. Applications may be found in energy production, ore exploitation and waste management

Les territoires de l’homosexualité à Bruxelles : visibles et invisibles

À l’image de nombreuses villes occidentales, Bruxelles a récemment vu émerger un quartier gai dans une portion de son espace central, à savoir le quartier Saint-Jacques. Fondé sur des recherches empiriques, cet article veut mettre en lumière la nature de ce nouveau type d’espace d’homosociabilité et à l’inscrire dans une géographie des multiples territoires homosexuels, plus ou moins marqués dans le paysage urbain, à l’échelle de l’ensemble de la ville. La concentration des manifestations les plus visibles de l’homosexualité (par exemple les bars ou associations) au centre-ville, dans le quartier Saint-Jacques en particulier, ne peut masquer une diffusion spatiale à la fois plus large et plus hétérogène d’autres types de territoires homosexuels moins directement visibles dans l’espace urbainBrussels has recently seen the emergence of a Gay Village in an area of the inner city known as the Saint-Jacques district. Based on empirical studies, this article investigates the nature of this new kind of space, increasingly common in Western cities, for homosociability. It also tries to position the phenomenon within a wider geography of homosexual territory on a city-wide scale. The study highlights the contrast between a concentration of visible marks of homosexual presence in the inner city (such as bars and associations), particularly in the Saint-Jacques district, and a wider spatial diffusion of more heterogeneous and less visible types of homosexual territory in urban space

No-till banana planting on crop residue mulch: Effect on soil quality and crop functioning

Introduction. In the French West Indies, farmers generally consider that periodical soil tillage is necessary to increase soil porosity and maintain high yield. However, in the nontilled perennial banana plantations of the highlands, the soil exhibits better physical and biological properties than in the conventional banana plantations. To determine if tillage before banana planting is necessary for proper banana crop functioning and to assess the effect of tillage on soil quality, banana planting after conventional tillage was compared with no-till banana planting on crop residue mulch on an experimental plot. Materials and methods. Soil quality was assessed through indicators such as porosity, organic status, microbial biomass and structure of nematode communities. Crop functioning was assessed through plant growth, root distribution, and soil water and nitrogen availability. Results. We found that tillage reduced soil microbial biomass and the number of nematode functional guilds. Tillage had only a short-term effect on soil porosity and did not allow deeper extension of the root system. Although soil organic nitrogen mineralization was higher with conventional tillage, banana nitrogen nutrition was not better, probably because the high nitrogen fertilization offset the variations in availability of nitrogen from organic origin. We found that banana growth was better with no-till treatment. This could be explained by less drying out of soil due to the crop residue mulch left on the soil surface with no-till treatment. Conclusion. Relative to conventional tillage, no-till banana planting improved soil quality and crop performance. (Résumé d'auteur

Music and Dyslexia: A New Musical Training Method to Improve Reading and Related Disorders

International audienceNumerous arguments in the recent neuroscientific literature support the use of musical training as a therapeutic tool among the arsenal already available to therapists and educators for treating children with dyslexia. In the present study, we tested the efficacy of a specially-designed Cognitivo-Musical Training (CMT) method based upon three principles: (1) music-language analogies: training dyslexics with music could contribute to improve brain circuits which are common to music and language processes; (2) the temporal and rhythmic features of music, which could exert a positive effect on the multiple dimensions of the " temporal deficit " characteristic of some types of dyslexia; and (3) cross-modal integration, based on converging evidence of impaired connectivity between brain regions in dyslexia and related disorders. Accordingly, we developed a series of musical exercises involving jointly and simultaneously sensory (visual, auditory, somatosensory) and motor systems, with special emphasis on rhythmic perception and production in addition to intensive training of various features of the musical auditory signal. Two separate studies were carried out, one in which dyslexic children received intensive musical exercises concentrated over 18 h during 3 consecutive days, and the other in which the 18 h of musical training were spread over 6 weeks. Both studies showed significant improvements in some untrained, linguistic and non-linguistic variables. The first one yielded significant improvement in categorical perception and auditory perception of temporal components of speech. The second study revealed additional improvements in auditory attention, phonological awareness (syllable fusion), reading abilities, and repetition of pseudo-words. Importantly, most improvements persisted after an untrained period of 6 weeks. These results provide new additional arguments for using music as part of systematic therapeutic and instructional practice for dyslexic children

Willows for environmental projects: A literature review of results on evapotranspiration rate and its driving factors across the genus Salix

Willows are increasingly used for a wide range of environmental projects, including biomass production, leachate treatment, riparian buffers and treatment wetlands. Evapotranspiration (ET), assumed to be high for most willow species used in environmental projects, affects hydrological cycles and is of key interest for project managers working with willows. Here, we present a comprehensive review of ET rates provided in the literature for the genus Salix. We aim to summarize current knowledge of willow ET and analyze its variability depending on context. We compiled and analyzed data from 57 studies, covering 16 countries, 19 willow species and dozens of cultivars. We found a mean reported ET rate of 4.6 ± 4.2 mm/d, with minimum and maximum values of 0.7 and 22.7 mm/d respectively. Although results reported here varied significantly between some species, overall interspecific standard deviation (±3.6 mm/d) was similar to intraspecific variation (±3.3 mm/d) calculated for S. viminalis, suggesting a greater influence of the growing context on ET than species identity. In terms of environmental and management variables, water supply, fertilization and contamination were identified as driving factors of ET across willow species. Effects of root age, experimental context, planting density and soil type were more nuanced. Our findings provide synthetic data regarding willow ET. We encourage practitioners who use ET data from the literature to be aware of the main drivers of ET and to consider the influence of the experimental aspects of a study in order to interpret data accurately and improve project planning