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191.
The recent development of small diameter optical fibers, which are also very flexible allows us to realise percutaneous coronary angioscopy. First of all we visualized normal dog's arteries, bifurcations, origin of small branches; then we created and visualized intimal tears, dissections and experimental thrombi. The second part of this work consisted in applying this new technic in three patients who had an evolving myocardial infarction and an occluded right coronary artery. In all three cases a clot has been visualized, occluding the lumen of the artery. This small experiment shows that percutaneous angioscopy is a feasible, quick and save procedure. Its developments will be very important according to the development of percutaneous interventional therapies.  相似文献   
192.
Database interconnection requires the development of links between related objects from different databases. We built a database of links, called Virgil, to manage and distribute rich (documented) links between GDB genes and GenBank human sequences. Virgil contains 18 667 unique links. In addition to a simple Web form for ad-hoc queries, we propose a generic Web interface and a prototype CORBA server for link distribution. Materials described in this paper are available from http://www.infobiogen.fr/services/virgil/home. html  相似文献   
193.
Abstract. The aim of this study was to characterize the vibratory signals produced by the parasitoid Sympiesis sericeicornis Nees (Hymenoptera: Eulophidae) while foraging on apple leaves infested by one of its hosts, the spotted tentiform leafminer Phyllonorycter malella (Ger.) (Lepidoptera: Gracillariidae).This leafminer changes its behaviour as a function of the parasitoid's behaviour to escape parasitization.We propose that the leafminer uses vibrations triggered by the parasitoid to detect the presence of its enemy.We measured vibrations produced by a foraging parasitoid on a mine with a laser vibrometer.By recording concurrently the behaviour of the parasitoid on video, vibrations could be assigned to particular behaviours.Subsequently, vibrations were characterized by their dominant frequencies and intensities.The behaviours Landing and Take-off both produced strong impact-like vibrations characterized by an initial irregular phase during which frequencies up to 25 kHz occurred followed by a slow decaying regular phase.Vibrations elicited by Moving, Standing and Probing showed no clear temporal pattern.During Probing , dominant frequencies of up to 5.6 kHz were observed frequently at intensities well above the background noise (>10 dB).During Moving and Standing , vibrations were more scarce and of lower frequencies and intensities.Due to their impact-like nature, vibrations produced by Landing and Take-off are probably not specific to the parasitoid.Vibrations produced by Moving and Standing are difficult to detect and not reliable because of their non-specificity.Therefore, only Probing provides a reliable and detectable source of information for the host.The vibrations elicited during Probing could account for the evasive behaviour that is observed in this and other leafminers.  相似文献   
194.
Pollination ecology of Arum italicum (Araceae)   总被引:1,自引:1,他引:0  
The pollination ecology of Arum italicum was studied in south-western France. This plant attracts olfactory dung-breeding flies through deceit. These insects are principally represented by Diptera, all belonging to saprophyte families. The volatilization of the odouriferous compounds, responsible for their attraction, is achieved through the production of heat by the appendix. The insects are trapped for 24 h in order to participate in both sexual phases of the protogynous inflorescence. The male flowers produce three heat events during flowering. These peaks of heat seem to be involved in the spathe movements, since they occur during the opening of the inflorescence and the liberation of the insects. The last male heat event may be linked with the liberation of pollen and its dispersion by stimulating trapped flies. According to their frequency and pollen-load, two Psychoda species appear to be the most efficient pollinators ( P. crassipenis and P. pusilla ). Nevertheless, each of the other attracted species could play a significant role under different spatio-temporal conditions. Experiments on self-pollination have shown that obligate cross-pollination is necessary for A. italicum to set seeds. Moreover, hand- and natural-pollinated plants showed similarly high abortion frequencies suggesting that seed set may be more constrained by resources rather than by pollination limitation.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 205–214.  相似文献   
195.
The impact of climate fluctuations during the Pleistocene on the geographic structure of genetic variation in plant populations is well documented, but there is a lack of studies of annual species at the European scale. The present study aimed to infer the history of the widespread European annual Rhinanthus angustifolius C. C. Gmelin (Orobanchaceae). We explored variation in chloroplast DNA (cpDNA) sequences and amplified fragment length polymorphism (AFLP) in twenty-nine populations covering the entire distribution area of the species. Five AFLP groups were identified, suggesting at least two glacial refugial areas: one area in southwestern Europe and one large eastern area in the Balkan/Caucasus. Recolonization of previously glaciated areas mainly took place from the east of Europe. Despite the difference in life-history traits, the patterns found for the annual R. angustifolius show similarities with those of perennial species in terms of genetic diversity and geographic organization of genetic variation. Although organelle markers have typically been preferred in phylogeographic studies, the cpDNA variation in R. angustifolius did not show any clear geographic structure. The absence of geographic structure in the cpDNA variation may reflect persistence of ancestral polymorphisms or hybridization and introgression with closely-related species.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 98 , 1–13.  相似文献   
196.
197.
Effects of chorda tympani nerve anesthesia on taste responses in the NST   总被引:1,自引:0,他引:1  
Dinkins  ME; Travers  SP 《Chemical senses》1998,23(6):661-673
Human clinical and psychophysical observations suggest that the taste system is able to compensate for losses in peripheral nerve input, since patients do not commonly report decrements in whole mouth taste following chorda tympani nerve damage or anesthesia. Indeed, neurophysiological data from the rat nucleus of the solitary tract (NST) suggests that a release of inhibition (disinhibition) may occur centrally following chorda tympani nerve anesthesia. Our purpose was to study this possibility further. We recorded from 59 multi- and single- unit taste-responsive sites in the rat NST before, during and after recovery from chorda tympani nerve anesthesia. During anesthesia, average anterior tongue responses were eliminated but no compensatory increases in palatal or posterior tongue responses were observed. However, six individual sites displayed increased taste responsiveness during anesthesia. The average increase was 32.9%. Therefore, disinhibition of taste responses was observed, but infrequently and to a small degree in the NST At a subset of sites, chorda tympani-mediated responses decreased while greater superficial petrosal-mediated responses remained the same during anesthesia. Since this effect was accompanied by a decrease in spontaneous activity, we propose that taste compensation may result in part by a change in signal-to-noise ratio at a subset of sites.   相似文献   
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