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F Sánchez R González J Carretero M Rubio J M Riesco E Blanco J A Juanes R Vázquez 《Histology and histopathology》1992,7(4):719-724
Using the peroxidase-antiperoxidase immunocytochemical technique, a morphometric study of the magnocellular neurons of the Paraventricular nucleus of the rat hypothalamus, reactive to specific anti-vasopressin rabbit serum, was made. Following systemic and chronic administration of met-enkephalin the number of immunoreactive neurons was higher, especially in females. Additionally, in the females, it was possible to observe an increase in the immunoreactivity and the presence of well-stained fibres. These findings suggest, especially in females, a blockage in the release of vasopressin, facilitating its immunocytochemical visualization. 相似文献
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Juan G. Navedo David Arranz Alejandro G. Herrera Pablo Salmón José A. Juanes José A. Masero 《Biodiversity and Conservation》2013,22(9):1895-1907
Coastal pastures are common agroecosystems adjacent to estuarine areas that can provide valuable habitat for wildlife, particularly for migratory shorebirds. Disentangling the factors that influence coastal pasture use by wintering shorebirds will provide new insights into its role for buffering human disturbances and habitat loss in intertidal areas. We examined whether numbers of two shorebirds (Eurasian curlew and Black-tailed godwit) foraging actively on coastal pastures was affected by weather conditions, tidal stage (low/high tide) and number of harvesters at intertidal areas throughout winter. Both species frequently used coastal pastures and most individuals foraged actively there. The average percentage of the total wintering population of curlews and godwits foraging on coastal pastures was 27.4 and 7.8 %, respectively, and was significantly higher during high tide compared to low tide. The number of harvesters on mudflats also had a positive significant effect in explaining the presence of curlews, and to a lesser extent for godwits, on coastal pastures, and accumulated rainfall had a positive effect for both species too. These supratidal areas were consistently used as alternative foraging grounds during low tide by curlews, as well as supplementary foraging areas during high tide by wintering populations of both large shorebirds. By supplementary foraging, wintering curlews, and probably godwits, seemed to compensate for a negative effect of the presence of harvesters on their foraging activity. We recommend managing of those coastal agricultural fields adjacent to intertidal foraging grounds in order to increase the availability of supratidal foraging habitats for declining shorebird populations. These habitats may thus have a beneficial role in sustaining populations of wintering shorebirds, but further studies are needed to estimate if birds can compensate for any shortfall in daily energy budget by supplementary foraging on coastal pastures, thus providing insights into whether they are involved in large-scale population regulation of migratory birds. 相似文献
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Eukaryotic translation initiation is an intricate process involving at least 11 formally classified eIFs (eukaryotic initiation factors), which, together with the ribosome, comprise one of the largest molecular machines in the cell. Studying such huge macromolecular complexes presents many challenges which cannot readily be overcome by traditional molecular and structural methods. Increasingly, novel quantitative techniques are being used to further dissect such complex assembly pathways. One area of methodology involves the labelling of ribosomal subunits and/or eIFs with fluorophores and the use of techniques such as FRET (F?rster resonance energy transfer) and FA (fluorescence anisotropy). The applicability of such techniques in such a complex system has been greatly enhanced by recent methodological developments. In the present mini-review, we introduce these quantitative fluorescence methods and discuss the impact they are beginning to have on the field. 相似文献
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Looby Audrey Cox Kieran Bravo Santiago Rountree Rodney Juanes Francis Reynolds Laura K. Martin Charles W. 《Reviews in Fish Biology and Fisheries》2022,32(2):581-595
Reviews in Fish Biology and Fisheries - Sound production in fishes is vital to an array of behaviors including territorial defense, reproduction, and competitive feeding. Unfortunately, recent... 相似文献
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Validation of daily increments and a marine‐entry check in the otoliths of sockeye salmon Oncorhynchus nerka post‐smolts 下载免费PDF全文
C. Freshwater M. Trudel T. D. Beacham C.‐E. Neville S. Tucker F. Juanes 《Journal of fish biology》2015,87(1):169-178
Juvenile sockeye salmon Oncorhynchus nerka that were reared and smolted in laboratory conditions were found to produce otolith daily increments, as well as a consistently visible marine‐entry check formed during their transition to salt water. Field‐collected O. nerka post‐smolts of an equivalent age also displayed visible checks; however, microchemistry estimates of marine‐entry date using Sr:Ca ratios differed from visual estimates by c. 9 days suggesting that microstructural and microchemical processes occur on different time scales. 相似文献
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Canello T Engelstein R Moshel O Xanthopoulos K Juanes ME Langeveld J Sklaviadis T Gasset M Gabizon R 《Biochemistry》2008,47(34):8866-8873
Prion diseases are fatal neurodegenerative disorders believed to be transmitted by PrP (Sc), an aberrant form of the membrane protein PrP (C). In the absence of an established form-specific covalent difference, the infectious properties of PrP (Sc) were uniquely ascribed to the self-perpetuation properties of its aberrant fold. Previous sequencing of the PrP chain isolated from PrP(27-30) showed the oxidation of some methionine residues; however, at that time, these findings were ascribed to experimental limitations. Using the unique recognition properties of alphaPrP mAb IPC2, protein chemistry, and state of the art mass spectrometry, we now show that while a large fraction of the methionine residues in brain PrP (Sc) are present as methionine sulfoxides this modification could not be found on brain PrP (C) as well as on its recombinant models. In particular, the pattern of oxidation of M213 with respect to the glycosylation at N181 of PrP (Sc) differs both within and between species, adding another diversity factor to the structure of PrP (Sc) molecules. Our results pave the way for the production of prion-specific reagents in the form of antibodies against oxidized PrP chains which can serve in the development of both diagnostic and therapeutic strategies. In addition, we hypothesize that the accumulation of PrP (Sc) and thereafter the pathogenesis of prion disease may result from the poor degradation of oxidized aberrantly folded PrP. 相似文献
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America G. Valiente Francis Juanes Pablo Nuñez Eva Garcia-Vazquez 《Biological invasions》2010,12(3):451-462
Brown trout of German origin were introduced into Patagonian National Parks in 1905, where they acclimatized and underwent
population expansion endangering populations of native species like Galaxiidae. Spawning adults of two populations were sampled
in 2004. Their age, length-at-age and migratory behaviour were assessed from scale samples, as well as their variation at
the coding LDH-C1* and eight non coding microsatellite loci. Between-population differentiation for life history (spawning time, migratory
behaviour, length and weight at age) and reduced genetic variation were revealed. Based on genetic variation, effective population
size smaller than 50 individuals has been estimated for the founder stock, and its German origin has been genetically traced.
Flexibility in migratory behaviour and spawning time were identified as key factors conferring competitive advantage on those
brown trout populations. 相似文献
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Spatial and temporal dynamics of macroinvertebrate communities have usually been linked to several environmental and anthropic
factors. The aim of this study is to elucidate how important are these factors in structuring macroinvertebrate communities
from temperate regions. Regarding the macroinvertebrate number of taxa, the Habitat Template Model, the Dynamic Equilibrium
Hypothesis and the Intermediate Disturbance Hypothesis will be tested in order to know how important the diversity of instream
elements and the hydrological disturbance frequency are in defining the macroinvertebrate taxonomic richness. Thus, the structure
and composition of macroinvertebrate communities were analysed in nine sites of the Pas River basin, a temperate Atlantic
basin in northern Spain, during winter, spring, summer and autumn 2005, together with water physicochemical and environmental
characteristics. Macroinvertebrate abundance increased downstream and during summer, probably favoured by lower hydraulic
stress and water organic enrichment. As predicts the Habitat Template Model, the macroinvertebrate number of taxa was related
to habitat heterogeneity. However, no clear relationship amongst macroinvertebrate richness and water quality was found. The
macroinvertebrate taxonomic richness did not correspond exactly with the Dynamic Equilibrium Hypothesis and the Intermediate
Disturbance Hypothesis because it was relatively high in the absence of hydrological disturbances (summer). Thus, disturbance
events may play a secondary role in determining the seasonal dynamic of the number of taxa. However, hydrological disturbances
can be considered the most important factors explaining the seasonal pattern of macroinvertebrate abundance. On the other
hand, spatial patterns of macroinvertebrate community structure and composition were mainly determined by resource availability,
hydraulic conditions, habitat heterogeneity and human alterations, whilst hydrological predictability and resource availability
might play a major role in determining seasonal dynamics. 相似文献