RESUMEN
Microsatellite markers are a useful genetic tool to answer ecological and conservation genetics questions. Microsatellite primers were developed and characterized to evaluate forest fragmentation effects on genetic structure, diversity and gene flow patterns in the dioecious tropical tree Astroniumgraveolens (Anacardiaceae). Using genomic library enrichment, sixteen microsatellite loci were developed for A.graveolens. Polymorphism was evaluated in 80 individuals from four localities in Mexico. The overall number of alleles detected was 63, average alleles per locus 3.9 with a range from one to 11 per locus. Cross amplification trails on related species in the Anacardiaceae family: Spondiaspurpurea and Amphipterygiumadstringens, achieved successful amplification for all primers. Microsatellite markers described here are the first to be characterized for A.graveolens. These genetic markers will be a useful tool to assess the genetic consequences of habitat fragmentation and selective logging on A.graveolens populations. Cross amplification success on S.purpureaandA.adstringens suggest that they may be used for population genetic studies in other species within the family.
Asunto(s)
Anacardiaceae/genética , Repeticiones de Microsatélite/genética , Alelos , Anacardiaceae/metabolismo , Cartilla de ADN/genética , ADN de Plantas/genética , Flujo Génico/genética , Frecuencia de los Genes/genética , Sitios Genéticos/genética , Marcadores Genéticos/genética , Biblioteca Genómica , Genotipo , Heterocigoto , Desequilibrio de Ligamiento/genética , México , Polimorfismo Genético/genética , Especificidad de la Especie , Árboles/genética , Árboles/metabolismoRESUMEN
Random (L) and aligned (A) multi-walled carbon nanotubes (MWNTs) were modified by Diels-Alder (DA) [4+2] cycloaddition, Sandmeyer (SM) reaction and by catalytic oxidation (OX). The properties of modified carbon nanotubes were studied by dispersability tests, elemental analysis, thermogravimetry/mass spectrometry, X-ray photoelectron spectroscopy, and NMR spectroscopy. The cycloaddition reaction could only be successfully performed with the L-MWNTs in molten and in solution state by using an aluminum chloride homogeneous catalyst. The efficiency and thermal stability of the solution phase cycloaddition were much higher than in the case of modification in the molten phase. The functionalization of both types of MWNTs by Sandmeyer reaction was carried out by copper(I) and iron(ll) ions that helped in the radical decomposition of diazonium salts. Successful functionalization of nanotubes is achieved by a long decomposition time of the thermally activated diazonium salts. To the contrary, in the case of radical decomposition of diazonium salts, the time is not a decisive parameter. The dispersability tests have proved the changes in the physical features of modified carbon nanotubes depending on the hydrophobic and hydrophilic character of the solvents. The presence of the modifying groups and their fragments from the functionalized MWNTs has been demonstrated by thermogravimetry/mass spectrometry (TG/MS). Relatively high concentration of sulfur atoms was detected by X-ray photoelectron spectroscopy in nanotubes modified by sulfur substituent groups. In the case of catalytic oxidation, the X-ray photoelectron spectroscopic signal of oxygen bound to nanotubes showed considerable change as compared to pristine nanotubes. Due to the high thermal stability of modified multi-walled carbon nanotubes, the functionalized derivatives are applicable in several industrial fields.
Asunto(s)
Nanotecnología/métodos , Nanotubos de Carbono/química , Catálisis , Electroquímica , Espectroscopía de Resonancia Magnética , Espectrometría de Masas/métodos , Conformación Molecular , Oxígeno/química , Polímeros/química , Solventes/química , Espectrometría por Rayos X/métodos , Temperatura , Termogravimetría , Rayos XRESUMEN
An epidemiologic survey of JCA was carried out in two regions of France, the western part of Paris and Brittany, differing in terms of geological background and demography. The prevalence was 0.77 and 0.100% and the incidence 0.019 and 0.013%, respectively. The type of onset, the course of the disease, the immunological data and the degree of final disability were similar in both regions. These data were compared to other studies and the factors of possible discrepancy analysed.