Search results for "molecular"
showing 10 items of 32340 documents
Coupling high-resolution satellite imagery with ALS-based canopy height model and digital elevation model in object-based boreal forest habitat type …
2014
We developed a classification workflow for boreal forest habitat type mapping. In object-based image analysis framework, Fractal Net Evolution Approach segmentation was combined with random forest classification. High-resolution WorldView-2 imagery was coupled with ALS based canopy height model and digital terrain model. We calculated several features (e.g. spectral, textural and topographic) per image object from the used datasets. We tested different feature set alternatives; a classification accuracy of 78.0 % was obtained when all features were used. The highest classification accuracy (79.1 %) was obtained when the amount of features was reduced from the initial 328 to the 100 most imp…
Genome size evolution in macroparasites.
2014
Reduction in genome size has been associated not only with a parasitic lifestyle in intracellular microparasites but also in some macroparasitic insects and nematodes. We collected the available data on genome size for flatworms, annelids, nematodes and arthropods, compared those with available data for the phylogenetically closest free-living taxa and found evidence of smaller genome sizes for parasites in six of nine comparisons. Our results suggest that despite great differences in evolutionary history and life cycles, parasitism as a lifestyle promotes convergent genome size reduction in macroparasites. We discuss factors that could be associated with small genome size in parasites whic…
Crystal Structures and Density Functional Theory Calculations of o-and p-Nitroaniline Derivatives: Combined Effect of Hydrogen Bonding and aromatic i…
2013
The interplay of strong and weak hydrogen bonds, dipole–dipole interactions, and aromatic interactions of o- and p-nitroaniline derivatives was studied by combining crystal structure analysis and density functional theory (DFT) calculations. Crystal structures of four 2-nitroaniline derivatives, 2-((2-nitrophenyl)amino)ethyl methanesulfonate (1A), 2-((2-nitrophenyl)amino)ethyl 4-methylbenzenesulfonate (2A), N,N′-((1,3-phenylenebis(oxy))bis(ethane-2,1-diyl))bis(2-nitroaniline) (3A), and N-(2-chloroethyl)-2-nitroaniline (4A), and crystal structures of three 4-nitroaniline derivatives, 2-((4-nitrophenyl)amino)ethyl methanesulfonate (1B), 2-((4-nitrophenyl)amino)ethyl 4-methylbenzenesulfonate (…
Evidence of Weak Halogen Bonding: New Insights on Itraconazole and its Succinic Acid Cocrystal
2012
Exact knowledge of the crystal structure of drugs and lead compounds plays a significant role in the fields of crystal engineering, docking, computational modeling (drug–receptor interactions), and rational design of potent drugs in pharmaceutical chemistry. The succinic acid cocrystal of the systemic antifungal drug, itraconazole, reported by Remenar et al. (J. Am. Chem. Soc.2003, 125, 8456–8457) (CSD: IKEQEU), represents one of the classical examples displaying a molecular fitting mechanism in the solid state. In this work, we disclose the X-ray single-crystal structure of the cis-itraconazole–succinic acid (2:1) cocrystal and found that it differs slightly from the previously reported st…
Efectos mutacionales, evolución y adaptación en bacteriófagos de RNA y DNA de cadena sencilla
2012
Las dificultades que plantean los virus para su control se deben, en gran medida, a su rápida evolución. Factores responsables de esta rápida evolución son su rápida tasa de replicación, sus elevados tamaños poblacionales y su elevada variabilidad genética. Estos dos últimos factores aumentan la efectividad de la selección natural, permitiendo a los virus escapar no sólo a las defensas del hospedador, sino también a los fármacos antivirales o de las vacunas. La mutación es la fuente última de variación genética. Por ello, la tasa de mutación es un parámetro fundamental para entender la evolución. No obstante, la relación entre tasa de mutación y adaptación no es inmediata. Por un lado, la p…
Taste and oral microbiota
2021
International audience
Role of human metabolizing enzymes in food perception
2022
Flavor is the main factor determining food acceptability. Flavor corresponds to the combination of the signals from the gustatory system, the olfactory system and the trigeminal system. Interactions between proteins and flavor molecules in oral/nasal cavities are proposed to modulate flavor perception through a series of events knowns as perireceptor events. Among these proteins involved in this modulation are found enzymes mainly known for their role in the detoxification process. These enzymes are able to recognize a large panel of molecules. We proposed to explore the role of these enzymes in food perception. We demonstrated that enzymatic activities present in the oral epithelium and sa…
The question of Organic Unity in Flavour: The whole is not equal to the sum of the parts
2021
International audience
Role of odorant-binding proteins in Drosophila melanogaster chemosensory perception
2019
Chemoperception is used by animals to detect nutritive food and avoid toxic compounds. It also allows animals to identify suitable ecological niche and mating partners. Like many other insects, Drosophila melanogaster possesses a very sensitive chemosensory ability and can detect and discriminate a wide panel of semiochemicals. Chemosensory detection is mostly mediated by olfactory and gustatory systems involving several multigene chemoreceptor families. Volatile and non-volatile chemical compounds entering the sensory organ (sensillum) must be solubilized before being transported through the hydrophilic sensillum lymph bathing the dendrites of chemosensory neurons. These perireceptor event…
Direct visualization of pyrrole reactivity by confined oxidation in a Cyclodextrin Metal‐Organic Framework
2019
Metal-organic frameworks can be used as porous templates to exert control over polymerization reactions. Shown here are the possibilities offered by these crystalline, porous nanoreactors to capture highly‐reactive intermediates for a better understanding of the mechanism of polymerization reactions. By using a cyclodextrin framework the polymerization of pyrrole is restricted, capturing the formation of terpyrrole cationic intermediates. Single‐crystal X‐ray diffraction is used to provide definite information on the supramolecular interactions that induce the formation and stabilization of a conductive array of cationic complexes.