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381.
An individual behaviour-based model can predict shorebird mortality using routinely collected shellfishery data 总被引:3,自引:0,他引:3
382.
383.
Kate L. Durrant Jennifer L. Reed Peter J. Jones Martin Dallimer Robert A. Cheke rew N. McWilliam Robert C. Fleischer 《Journal of avian biology》2007,38(6):662-671
The red-billed quelea Quelea quelea , one of the most abundant birds in the world, presents two fundamental conundrums that we investigate here with a novel approach using blood parasite assemblages at two spatial scales, landscape and individual. The quelea of southern Africa Q. q. lathamii are split by a hypothesized migratory divide, where birds follow rain fronts in one of two directions (NW or SE). This divide is not detectable in the host population using microsatellite data, and here we show that it is also not apparent from our large-scale phylogeographical analyses of the haematozoan parasite. At a finer scale, the colourful and variable breeding plumage of male red-billed quelea has not previously shown a correlation with predictors of quality, as it does in many other bird species. The male's breeding plumage is partially based on carotenoid colouration, the quality of which has been correlated with haematozoan infection in other bird species. However, we found no correlation between intensity of male carotenoid colouration and haematozoan infection. Our results do not contradict the hypothesis that male breeding plumage in this species serves to identify individuals rather than to indicate quality. Finally, we recovered the greatest number of haematozoan lineages from any phylogenetic survey of a single host species to date. Understanding the reasons for the extreme diversity of parasite lineages in this species may assist in explaining the success of the red-billed quelea in anthropogenic landscapes. 相似文献
384.
Aim To compare different quantitative approaches for estimating rates of spread in the exotic species gypsy moth, Lymantria dispar L., using county-level presence/absence data and spatially extensive trapping grids.
Location USA
Methods We used county-level presence/absence records of the gypsy moth's distribution in the USA, which are available beginning in 1900, and extensive grids of pheromone-baited traps, which are available in selected areas beginning in 1981. We compared a regression approach and a boundary displacement approach for estimating gypsy moth spread based on these sources of data.
Results We observed relative congruence between methods and data sources in estimating overall rates of gypsy moth spread through time, and among regions.
Main conclusions The ability to estimate spread in exotic invasive species is a primary concern in management programmes and one for which there is a lack of information on the reliability of methods. Also, in most invading species, there is generally a lack of data to explore methods of estimating spread. Extensive data available on gypsy moth in the USA allowed for such a comparison. We show that, even with spatially crude records of presence/absence, overall rates of spread do not differ substantially from estimates obtained from the more costly deployment of extensive trapping grids. Moreover, these methods can also be applied to the general study of species distributional changes, such as range expansion or retraction, in response to climate change or other environmental effects. 相似文献
Location USA
Methods We used county-level presence/absence records of the gypsy moth's distribution in the USA, which are available beginning in 1900, and extensive grids of pheromone-baited traps, which are available in selected areas beginning in 1981. We compared a regression approach and a boundary displacement approach for estimating gypsy moth spread based on these sources of data.
Results We observed relative congruence between methods and data sources in estimating overall rates of gypsy moth spread through time, and among regions.
Main conclusions The ability to estimate spread in exotic invasive species is a primary concern in management programmes and one for which there is a lack of information on the reliability of methods. Also, in most invading species, there is generally a lack of data to explore methods of estimating spread. Extensive data available on gypsy moth in the USA allowed for such a comparison. We show that, even with spatially crude records of presence/absence, overall rates of spread do not differ substantially from estimates obtained from the more costly deployment of extensive trapping grids. Moreover, these methods can also be applied to the general study of species distributional changes, such as range expansion or retraction, in response to climate change or other environmental effects. 相似文献
385.
Estrella Hernández‐Suárez Aurelio Carnero Antonio Aguiar Gerhard Prinsloo John LaSalle Andrew Polaszek 《分类学与生物多样性》2013,11(1):55-108
Data on the whitefly parasitoid species known from the Macaronesian archipelagos of the Canary Islands, Madeira and the Azores are presented, based largely on recently collected material. A total of 26 species are treated, including six new species, six new records for the Canary Islands, two new records for Madeira, and two new records for the Azores. All species are fully described and illustrated. New species described are: Encarsia atlantica Polaszek & Hernández; Encarsia levadicola Polaszek & Hernández; Encarsia melanostoma Polaszek & Hernández; Encarsia noahi Polaszek & Hernández; Euderomphale gomer LaSalle & Hernández; Euderomphale insularis LaSalle & Hernández. A fully illustrated identification key based on females is provided for recognition of whitefly parasitoids in these archipelagos. Data on the known distribution and hosts are provided, as well as references to biology and use in biological control. 相似文献
386.
高原鼠兔(Ochotona curzoniae)冬季自然死亡率 总被引:8,自引:5,他引:8
以耳标观察法。1985年4-7月共捕标了样地内高原鼠兔(Ochotona curzoniae)幼鼠114只。到入冬前,死亡率为50.88%。第2胎出生的鼠死亡率明显地高于第1胎的死亡率。冬季死亡率呈现波动,入冬及开春时死亡率较高。鼠兔种群进入繁殖前期死亡率趋于零。初春样区存活标志鼠6只,经夏秋冬3季总计死亡率达94.74%。如按入冬时实有标志鼠计算,冬季死亡率为91.04%。 相似文献
387.
The existence of periodic oscillations in populations of forest Lepidoptera is well known. While information exists on how the periods of oscillations vary among different species, there is little prior evidence of variation in periodicity within the range of a single Lepidopteran species. The exotic gypsy moth is an introduced foliage-feeding insect in North America. Its populations are characterized by high amplitude oscillations between innocuously low densities and outbreak levels during which large regions of forests are defoliated. These outbreaks are recognized to arise periodically with considerable synchrony across much of the gypsy moth's North American range. Our analysis indicates that gypsy moth outbreaks in North America are periodic but they exhibit two dominant periodicities: a primary period of 8–10 yr (as previously reported) and a secondary period of 4–5 yr (a new finding in this study). The outbreak periodicity varied geographically and this variation was associated with forest type. We found that in the most susceptible forest types, those on xeric sites where oak is often mixed with pines, outbreak periodicity had a more dominant 5-yr period while in forest types characteristic of more mesic sites where oak was mixed with maples and other species, cycles were clearly operating on a 10-yr period. 相似文献
388.
Marie-Anne Barny Eric Schoonejans Anastassios Economou rew W. B. Johnston & J. Allan Downie 《Molecular microbiology》1996,19(3):443-453
The nod C genes from rhizobia encode an N -acetylglucosaminyl transferase (chitin synthase) involved in the formation of lipo-chito-oligosaccharide Nod factors that initiate root nodule morphogenesis in legume plants. NodC proteins have two hydrophobic domains, one of about 21 residues at the N-terminus and a longer one, which could consist of two or three transmembrane spans, near the C-terminus. These two hydrophobic domains flank a large hydrophilic region that shows extensive homology with other β-glycosyl transferases. The topology of NodC in the inner membrane of Rhizobium leguminosarum biovar viciae was analysed using a series of gene fusions encoding proteins in which NodC was fused to alkaline phosphatase (PhoA) lacking an N-terminal transit sequence or to β-galactosidase (LacZ). Our data support a model in which the N-terminal hydrophobic domain spans the membrane in a Nout –Cin orientation, with the adjacent large hydrophilic domain being exposed to the cytoplasm. This orientation appears to depend upon the presence of the hydrophobic region near the C-terminus. We propose that this hydrophobic region contains three transmembrane spans, such that the C-terminus of NodC is located in the periplasm. A short region of about 40 amino acids, encompassing the last transmembrane span, is essential for the function of NodC. Our model for NodC topology suggests that most of NodC, including the region showing most similarity to other β-glycosyl transferases, is exposed to the cytoplasm, where it is likely that polymerization of N -acetyl glucoasamine occurs. Such a model is incompatible with previous reports suggesting that NodC spans both inner and outer membranes. 相似文献
389.
Joanna D. Holbrook Catherine H. Gill† Noureddine Zebda† Jon P. Spencer† Rebecca Leyland† Kim H. Rance Han Trinh Gemma Balmer Fiona M. Kelly Shahnaz P. Yusaf Nicola Courtenay Jane Luck rew Rhodes Sundip Modha Stephen E. Moore† Gareth J. Sanger† Martin J. Gunthorpe† 《Journal of neurochemistry》2009,108(2):384-396
The 5‐HT3 receptor is a member of the ‘Cys‐loop’ family of ligand‐gated ion channels that mediate fast excitatory and inhibitory transmission in the nervous system. Current evidence points towards native 5‐HT3 receptors originating from homomeric assemblies of 5‐HT3A or heteromeric assembly of 5‐HT3A and 5‐HT3B. Novel genes encoding 5‐HT3C, 5‐HT3D, and 5‐HT3E have recently been described but the functional importance of these proteins is unknown. In the present study, in silico analysis (confirmed by partial cloning) indicated that 5‐HT3C, 5‐HT3D, and 5‐HT3E are not human–specific as previously reported: they are conserved in multiple mammalian species but are absent in rodents. Expression profiles of the novel human genes indicated high levels in the gastrointestinal tract but also in the brain, Dorsal Root Ganglion (DRG) and other tissues. Following the demonstration that these subunits are expressed at the cell membrane, the functional properties of the recombinant human subunits were investigated using patch clamp electrophysiology. 5‐HT3C, 5‐HT3D, and 5‐HT3E were all non‐functional when expressed alone. Co‐transfection studies to determine potential novel heteromeric receptor interactions with 5‐HT3A demonstrated that the expression or function of the receptor was modified by 5‐HT3C and 5‐HT3E, but not 5‐HT3D. The lack of distinct effects on current rectification, kinetics or pharmacology of 5‐HT3A receptors does not however provide unequivocal evidence to support a direct contribution of 5‐HT3C or 5‐HT3E to the lining of the ion channel pore of novel heteromeric receptors. The functional and pharmacological contributions of these novel subunits to human biology and diseases such as irritable bowel syndrome for which 5‐HT3 receptor antagonists have major clinical usage, therefore remains to be fully determined. 相似文献
390.
Mycoplasma gallisepticum infection dynamics in a house finch population: seasonal variation in survival, encounter and transmission rate 总被引:1,自引:0,他引:1