14 research outputs found

    Hair-based rapid analyses for multiple drugs in forensics and doping : application of dynamic multiple reaction monitoring with LC-MS/MS

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    This is the first report of the application of this proprietary system to investigate the presence of drugs in human hair samples. The method is selective, sensitive and robust for the screening and confirmation of multiple drugs in a single analysis and has potential as a very useful tool for the analysis of large array of controlled substances and drugs of abuse

    Inventaire des moustiques (Diptera : Culicidae) des îles du sud-ouest de l’océan Indien, Madagascar excepté — Une revue critique

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    International audienceInventory of the mosquitoes (Diptera: Culicidae) of the islands of southwestern Indian Ocean, Madagascar excluded-A Critical Review. The biodiversity of mosquitoes in the islands of southwestern Indian Ocean is the concern of numerous publications. Here, we propose a synthetic inventory and the analysis of the mosquito diversity, based on the available literature. A comprehensive annotated checklist of mosquito species has been recently published on Madagascar; this is the reason why this land is excluded from our work. Studied area encompasses 28 tropical islands in the southern hemisphere: 4 islands in the Comoros archipelago, 5 Scattered Islands (îles Éparses), 5 in Mascarene, 11 in the Seychelles and 3 in the Chagos archipelago. In total, the mosquito list presents 73 valid species, of which 10 are Anophelinae and 63 Culicinae. The number of species that are distributed in these islands only is 19, i.e. 26%, which is a remarkable level for endemism. The richness in mosquito species in these islands is analysed through several aspects including geography, local speciation and natural or human dissemination. This updated inventory increases by 33% the number of known species by regard to the previous inventory published by Julvez & Mouchet in 1994. The historical responsibility of humans in the introduction of new mosquito species in these islands is strongly documented. For instance, the species with the highest distribution among islands are Aedes aegypti, Ae. albopictus and Culex quinquefasciatus. The islands belong to the afrotropical biogeographic area and, logically, the majority (63%) of mosquito species present phylogenetic affinities with continental Africa and/or Madagascar; interestingly, the number of species present in these islands and in Madagascar but absent in continental Africa is higher than the number of species present in these islands and in continental Africa but absent in Madagascar (respectively 12 and 2 species). Thanks to valuable increase in the sampling effort, our knowledge of the culicidian fauna is increasing in these islands that constitute indisputably hotspots of biodiversity.Résumé. La biodiversité des moustiques dans les îles du sud-ouest de l'océan Indien a fait l'objet de nombreuses publications. Nous proposons ici un inventaire des espèces et une analyse des peuplements, en se basant sur les données disponibles dans la littérature. Madagascar est exclu de cette étude car un inventaire des espèces de moustiques vient d'y être réalisé. La présente étude retient 28 îles tropicales de l'hémisphère sud : 4 îles dans l'archipel des Comores, 5 îles Éparses, 5 aux Mascareignes, 11 aux Seychelles et 3 dans l'archipel des Chagos. Au total, 73 espèces valides de moustiques ont été recensées, dont 10 Anophelinae et 63 Culicinae. Le nombre d'espèces exclusivement présentes dans ces îles est de 19, soit un remarquable endémisme concernant 26 % des espèces. La richesse spécifique est analysée sous plusieurs aspects incluant la géographie, la spéciation sur place, la dissémination des populations par des voies naturelles ou humaines. Le présent inventaire accroit de 33 % le nombre d'espèces connues par rapport à l'inventaire précédemment publié par Julvez & Mouchet en 1994

    Kinetics of the natural evolution of hydrogen cyanide in plants in neotropical Pteridium Arachnoideum and its ecological significance.

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    Kinetics of the natural evolution of hydrogen cyanide in plants in neotropical Pteridium Arachnoideum and its ecological significance (Alonso Amelot, Miguel and Oliveros, Alberto) Abstract The time-dependent natural release of hydrogen cyanide (HCN) was studied quantitatively using young croziers of the neotropical bracken fern Pteridium arachnoideum. HCN production was quantified in crushed tissue using a flow reactor at 30.0 ± 0.1?C. Released HCN was carried into appropriate traps with a moist air flow. Aliquots were drawn from the traps at fixed time intervals, and the HCN concentration was evaluated spectroscopically. All available prunasin (Pru), the only cyanogenic glycoside present, underwent decomposition into HCN in less than 1200 min. Fiddleheads (N = 76) contained 1.84-107.70 mg Pru g-1 dw in a continuous fashion suggesting genetic polymorphism. Acyanogenic morphs were rare (1/77). From the kinetics of the samples with Pru content near the median histographic distribution (N = 46), accumulated HCN formation as a function of time, initial velocities, average HCN production rate, and corresponding rate equations were obtained. Initial and average velocities correlated well with total Pru content. The yield of cyanide liberation varied widely between 0.51 and 47.86 µg HCN min-1 g-1 dw and was a linear function of [Pru]t. However, the Ăź-glucosidase enzyme involved in this reaction was not rate limiting and occurs in excess in the natural system. Enzyme activity was found to be independent of [Pru]t . The contribution of HCN as an allomone-upon-request against herbivores was assessed quantitatively. Bracken fiddleheads produced a pulse of HCN soon after tissue injury that waned rapidly, leaving a large portion of intact prunasin to decompose more slowly in the herbivore's lumen. The balance between the external and internal courses was found to depend on the concentration of prunasin in the plant, the amount of crozier eaten, and the time used to consume it. Journal of Chemical Ecology, Vol. 31, No. 2, February 2005 (©2005) DOI: 10.1007/[email protected]@ula.veNivel monográfic
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