Search results for " Selection"
showing 10 items of 1271 documents
A Constrained Band Selection Method Based on Information Measures for Spectral Image Color Visualization
2011
International audience; We present a new method for the visualization of spectral images, based on a selection of three relevant spectral channels to build a Red-Green-Blue composite. Band selection is achieved by means of information measures at the first, second and third orders. Irrelevant channels are preliminarily removed by means of a center-surround entropy comparison. A visualization-oriented spectrum segmentation based on the use of color matching functions allows for computational ease and adjustment of the natural rendering. Results from the proposed method are presented and objectively compared to four other dimensionality reduction techniques in terms of naturalness and informa…
Arrangements de cercles sur une sphère: Algorithmes et Applications aux modèles moléculaires representés par une union de boules
2008
Since the early work of Richard et al., geometric constructions havebeen paramount for the description of macromolecules and macro-molecularassemblies. In particular, Voronoï and related constructions have beenused to describe the packing properties of atoms, to compute molecularsurfaces, to find cavities. This thesis falls in this realm, andafter a brief introduction to protein structure, makes fourcontributions.First, using the sweep line paradigm of Bentley and Ottmann, wepresent the first effective algorithm able to construct the exactarrangement of circles on a sphere. Moreover, assuming the circlesstem from the intersection between spheres, we present a strategy to reportthe covering …
Pois protéagineux : cheminement de la recherche génétique pour la sélection des paramètres à prendre en compte pour l’amélioration de la stabilité du…
2013
Field Pea: development of genetic research for the selection of parameters to take into account to improve yield stability. Legumes were essential in rotations in the past, but they fell off during the 20th century. Maybe they will come back into favour in the 21st century thanks to its economy, agri-environment and food assets. Field Pea is the main crop of this family in France, but it remains underdeveloped because its unstable yield does not enable the farmers to ensure their income security. Therefore researchers should focus on yield stability. Modelling Pea remains difficult because of its indeterminate development. Parameters to take into account are many and their significance must…
Comparaison de l’efficience de cinq souches de Rhizobium sur 18 génotypes de pois
2014
Legume-rhizobium association leads to the production of nodules on plant roots, in which atmospheric nitrogen is caught by the bacteria and exchanged for plant carbohydrates. This symbiotic association is probably the best way to increase nitrogen fertilization without using biological or chemical input. Symbiosis mechanisms between both species are thus a challenge for the current research. Previous studies have shown that rhizobia are not equally selected by the different pea genotypes. The objective of this study was to assess if peas select the most efficient bacterial strain. In order to answer this question, we sowed 18 pea genotypes and inoculated each of them with five different rhi…
Modelling hydrolysis: Simultaneous versus sequential biodegradation of the hydrolysable fractions
2018
Hydrolysis is considered the limiting step during solid waste anaerobic digestion (including co-digestion of sludge and biosolids). Mechanisms of hydrolysis are mechanistically not well understood with detrimental impact on model predictive capability. The common approach to multiple substrates is to consider simultaneous degradation of the substrates. This may not have the capacity to separate the different kinetics. Sequential degradation of substrates is theoretically supported by microbial capacity and the composite nature of substrates (bioaccessibility concept). However, this has not been experimentally assessed. Sequential chemical fractionation has been successfully used to define i…
Darwin et l'après-Darwin : une histoire de l'hypothèse de sélection dans la théorie de l'évolution
1992
Les historiens et les biologistes n'ont pas assez distingué la théorie et l'hypothèse de sélection naturelle. En tant que théorie générale de l'histoire de la vie, la doctrine de la sélection naturelle a sans aucun doute eu un immense retentissement dans la science et dans la culture de son temps. Mais l'hypothèse centrale de cette théorie, dans la forme très contraignante que lui avait donnée Darwin, s'est trouvée très vite exposée à des difficultés internes suffisamment redoutables pour entrer en crise à peine était-elle née. En liant rigidement l'hypothèse de sélection à l'hérédité, Darwin l'a exposée pour au moins cinquante ans à la menace permanente d'une réfutation. La sélection darwi…
Critics and Criticisms of the Modern Synthesis: the Viewpoint of a Philosopher
1990
International audience
Predicting pesticide biodegradation potential from microbial community composition: new tools for bioremediation
2022
Bioaugmentation is receiving increasing attention as a green technology to treat contaminatedareas by inoculating specific biodegrading microorganisms. However, our understanding of therole of microbial community composition and structure in the expression of contaminantdegradation potential is yet to improve. It could help making wise choice for microorganisms –community or specific strain – to be inoculated in contaminated soils with consideration to theirindigeneous microbiota.Here we tried to predict the microbial degradation of two herbicides, glyphosate andisoproturon by means of penalized regression and machine learning methods routinely used ingenomic selection. To this end, we cond…
Improving IoT Communications Based on Smart Routing Algorithms
2018
International audience; Due to the recorded success by Internet of Things (IoT) technology, more and more domains use it as a communications and exchange network such as e-health, smart cities, vehicles, etc. IoT don’t stop integrating an important number of components and objects that are characterized by their complexity and heterogeneity. Such constraints make the existing routings protocols unsuitable for IoT communications. To accomplish all the expected tasks and satisfy the user services, it is important to guarantee a quality of communication that answers to the requirements of the various applications in terms of data and processing (availability, integrity, efficiency, etc.). The …
Runs of homozygosity in the Italian goat breeds: impact of management practices in low-input systems
2021
Abstract Background Climate and farming systems, several of which are considered as low-input agricultural systems, vary between goat populations from Northern and Southern Italy and have led to different management practices. These processes have impacted genome shaping in terms of inbreeding and regions under selection and resulted in differences between the northern and southern populations. Both inbreeding and signatures of selection can be pinpointed by the analysis of runs of homozygosity (ROH), which provides useful information to assist the management of this species in different rural areas. Results We analyzed the ROH distribution and inbreeding (FROH) in 902 goats from the Italia…