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1.
Dethier  Michel  de Sousa  José  Molander  Christina  Knispel  Sandra 《Hydrobiologia》1995,300(1):149-155
The Allodon River, a tributary of the Rhône, has suffered considerably from the recent expansion of human activities in the Geneva region. This study documents changes in its benthic fauna by comparing species richness before and after 1986 and by considering the possibilities of recolonization by drift.
Résumé L'Allondon, affluent du Rhône, est une rivière qui a considérablemen t souffert d'une expansion récente des activités humaines dans la région genevoise. Cette étude met en lumière l'évolution de certains éléments de la faune benthique en comparant les richesses specifiques avant et après 1986, année critique pour la macrofaune benthique du bassin genevois. Elle met en évidence les possibilités de recolonisation par dérive de certains recours de l'Allondon à partir d'affluents moins perturbés.
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SUMMARY 1. In the upper Rhône catchment (Swiss Alps), modifications in the longitudinal pattern of environmental conditions and the benthic macroinvertebrate fauna were investigated in a glacier-fed stream (Rhône) at its confluence with a smaller glacier-fed tributary (Mutt) in June, August and September 1998. The distance to the source glacier was greater for the Mutt than for the Rhône.
2. Environmental conditions were harsher for the biota in the main stream upstream of the confluence than in the tributary. The tributary upstream of the confluence was characterised by higher taxonomic richness and abundance of the zoobenthos than the Rhône upstream.
3. Although environmental conditions in the main stream were little modified by the tributary, the fauna was richer and more diverse below the confluence. During the period of ice melt, colonisation from the Mutt led to the occurrence of faunal elements atypical of glacial streams in the main glacial stream upstream of the confluence, where water temperature remains below 4 °C.
4. Although contributing an average of only 10% to the Rhône discharge, the Mutt tributary is suggested to be the faunal driver of the system.  相似文献   
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Lichens are compound entities of a fungal partner (“mycobiont”) and one or more photosynthetically active algae or cyanobacteria (“photobionts”). The organisms live in an intimate, symbiotic association which has been classified as a mutualistic or controlled parasitic relationship. Several metabolites from lichens display unique structures with unknown functions, and only a few model species have been analysed comprehensively. The complex metabolic interplay between the organisms in lichens is also incompletely understood. Earlier experiments with 14C-labelled precursors indicated that the photobionts produce from CO2 glucose or sugar alcohols (e.g. ribitol and arabitol) which are then transferred to the mycobionts. In the fungi, these compounds are believed to be converted into mannitol serving as the carbon and energy source in the downstream metabolic processes. Recent methodological developments in spectroscopy and “systems biology” now enable a concise analysis of the metabolite profiles, networks and fluxes by non-targeted quantitative approaches. In this review, we summarize the current knowledge about lichen metabolism and report on the potential of the advanced methods to reinvestigate lichen chemistry and metabolism on a quantitative basis.  相似文献   
6.
The Egyptian jackal (Canis aureus lupaster) has hitherto been considered a large, rare subspecies of the golden jackal (C. aureus). It has maintained its taxonomical status to date, despite studies demonstrating morphological similarities to the grey wolf (C. lupus). We have analyzed 2055 bp of mitochondrial DNA from C. a. lupaster and investigated the similarity to C. aureus and C. lupus. Through phylogenetic comparison with all wild wolf-like canids (based on 726 bp of the Cytochrome b gene) we conclusively (100% bootstrap support) place the Egyptian jackal within the grey wolf species complex, together with the Holarctic wolf, the Indian wolf and the Himalayan wolf. Like the two latter taxa, C. a. lupaster seems to represent an ancient wolf lineage which most likely colonized Africa prior to the northern hemisphere radiation. We thus refer to C. a. lupaster as the African wolf. Furthermore, we have detected C. a. lupaster individuals at two localities in the Ethiopian highlands, extending the distribution by at least 2,500 km southeast. The only grey wolf species to inhabit the African continent is a cryptic species for which the conservation status urgently needs assessment.  相似文献   
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Lupeol-3-(3′R-hydroxy)-stearate, also known as procrim b (1), was isolated from the methanolic stem extract of Pentalinon andrieuxii and initially mistaken as lupeol acetate when analyzed by GC–MS only. The correct structure of 1 was established following a careful analysis of its NMR and MS data.  相似文献   
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Abstract

The factors influencing the N,O-regioselectivity during preparation of 3-Me-cycloSal-ddAMP were studied.  相似文献   
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Abstract

Novel lipophilic cycloSal-triesters 3 and 4 from the ara- and ribo-configurated 2′-fluorinated ddAs 1 and 2, respectively, were prepared. The title compounds 3 and 4 delivered the corresponding monophosphates and thus, increasing the bioactivity or convert a formerly inactive compound into a RT inhibitor.  相似文献   
10.
Large numbers of woodpigeons (Columba palumbus) winter each year in southwestern Spain and Portugal, where they feed on acorns. Although mortality in these wintering roosts is generally low, in winter and spring 2001 approximately 2,600 woodpigeons died from trichomoniasis. Diagnosis of the disease was based on postmortem examination, culture and identification of the parasite, Trichomonas gallinae, by PCR. Other viral, bacterial or fungal pathogens were ruled out as cause for the die-off. The gathering of the woodpigeons at game bird feeders set up for red-legged partridges may have contributed to the outbreak. Mortality ceased after treatment with dimetridazole via the game bird feeders. Supplementary feeding of game birds constitutes a risk factor for the appearance of disease outbreaks. Close monitoring of infectious diseases in these populations is important, but treatment of free-living birds should be avoided in favour of other measures, as it poses risks.  相似文献   
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