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31.
Branchotenthes octohamatus sp. n. (Monogenea: Hexabothriidae) is described from the gills of the southern fiddler ray, Trygonorrhina fasciata Müller et Henle (Elasmobranchii: Rhinobatidae), off Adelaide, South Australia. It is distinguished from the type species, Branchotenthes robinoverstreeti Bullard et Dippenaar, 2003, by producing eggs that are joined end to end forming a chain, in the morphology of the male copulatory organ that has a pronounced constriction in duct diameter between proximal and distal regions, the possession of a thin muscular layer surrounding the proximal part of the male copulatory organ and distal region of the vaginae, and by the absence of a raised process on the shaft of the hamulus. An amended generic diagnosis is provided and the reliability of sperm duct number as a generic character is discussed. The oncomiracidium of B. octohamatus is also described and is the first monogenean to be described with only eight hooklets in the larval haptor. This discovery of eight hooklets may be important for higher-level monogenean evolutionary hypotheses. 相似文献
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Species distribution models (SDMs) often use elevation as a surrogate for temperature or utilise elevation sensitive interpolations
from weather stations. These methods may be unsuitable at the landscape scale, especially where there are sparse weather stations,
dramatic variations in exposure or low elevational ranges. The goal of this study was to determine whether radiation, moisture
or a novel estimate of exposure could improve temperature estimates and SDMs for vegetation on the Illawarra Escarpment, near
Sydney, Australia. Forty temperature sensors were placed on the soil surface of an approximately 12,000 ha study site between
November 2004 and August 2006. Linear regression was used to determine the relationship with environmental factors. Elevation
was correlated more with moderate temperatures (winter maximums, summer minimums, spring and autumn averages) than extreme
temperatures (summer maximums, winter minimums). The correlation (r
2) between temperature and environmental factors was improved by up to 0.38 by incorporating exposure, moisture and radiation
in the regressions. Summer maximums and winter minimums were predominately determined by exposure to the NW and coastal influences
respectively, while exposure to the NE and SW was important during other seasons. These directions correspond with the winds
that are most influential in the study area. The improved temperature estimates were used in Generalised Additive Models for
37 plant species. The deviance explained by most models was increased relative to elevation, especially for moist rainforest
species. It was concluded that improving the accuracy of seasonal temperature estimates could improve our ability to explain
the patchy distribution of many species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Coleman ML Sullivan MB Martiny AC Steglich C Barry K Delong EF Chisholm SW 《Science (New York, N.Y.)》2006,311(5768):1768-1770
Prochlorococcus ecotypes are a useful system for exploring the origin and function of diversity among closely related microbes. The genetic variability between phenotypically distinct strains that differ by less that 1% in 16S ribosomal RNA sequences occurs mostly in genomic islands. Island genes appear to have been acquired in part by phage-mediated lateral gene transfer, and some are differentially expressed under light and nutrient stress. Furthermore, genome fragments directly recovered from ocean ecosystems indicate that these islands are variable among cooccurring Prochlorococcus cells. Genomic islands in this free-living photoautotroph share features with pathogenicity islands of parasitic bacteria, suggesting a general mechanism for niche differentiation in microbial species. 相似文献
36.
Shibata N Chisholm MF Nakamura A Pennycook SJ Yamamoto T Ikuhara Y 《Science (New York, N.Y.)》2007,316(5821):82-85
Little is known about dislocation core structures in oxides, despite their central importance in controlling electrical, optical, and mechanical properties. It has often been assumed, on the basis of charge considerations, that a nonstoichiometric core structure could not exist. We report atomic-resolution images that directly resolve the cation and anion sublattices in alumina (alpha-Al2O3). A dissociated basal edge dislocation is seen to consist of two cores; an aluminum column terminates one partial, and an oxygen column terminates the second partial. Each partial core is locally nonstoichiometric due to the excess of aluminum or oxygen at the core. The implication for mechanical properties is that the mobile high-temperature dislocation core structure consists of two closely spaced partial dislocations. For basal slip to occur, synchronized motion of the partials on adjacent planes is required. 相似文献
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The equine enteric nervous system — Neuron characterization and distribution in adults and juveniles
D. L. Doxey G. T. Pearson E. M. Milne J. S. Gilmour H. K. Chisholm 《Veterinary research communications》1995,19(6):433-449
A study of myenteric and submucosal plexuses was undertaken in the jejunum and ileum of horses and ponies in which no clinical or pathological evidence of intestinal abnormality was apparent. Complete transverse sections of the intestine, stained by a modified haematoxylin and eosin method, were examined using up to 20 sequential sections per animal. Information was gathered from adult, juvenile and fetal equidae. In adults, the longitudinal muscle layers were thinner than the circular muscle layers and the ileum had thicker layers compared to the jejunum. In adults, the submucosal plexus had more neurons per section than the myenteric plexus by mean ratios of 1:3 in the jejunum and 1:1.9 in the ileum. In juveniles, the ratios were respectively 1:1.8 and 1:1.5 and in the fetus 1:2.5 and 1:1.3. The three-dimensional distribution of neurons in both plexuses varied from animal to animal and no consistent pattern was observed. Groups of neurons contained between one and 42 cells per section examined and their length in a cranio-caudal direction varied from 10 to over, 100 µm. There were few statistical differences observed between the cranial, middle and caudal portions of either the jejunum or the ileum when neuron groups or neuron numbers per section were examined in 10 adult animals.Abbreviations H&E
haematoxylin and eosin
Deceased; formerly of the Moredun Research Institute, 408, Gilmerton Road, Edinburgh, EH17 7JH, UK 相似文献
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Willamson JA Kaelble M Chisholm A 《Journal of the American Animal Hospital Association》2011,47(2):112-116
A 9 yr old spayed female cocker spaniel presented for an acute onset of weakness. Rhabdomyolysis and myoglobinuria were found 36 hr after presentation. The dog was managed for several electrolyte and mineral abnormalities and rhabdomyolysis-induced acute renal failure. The diagnosis of idiopathic necrotizing myopathy was determined by histopathology and by the exclusion of underlying infectious agents and metabolic defects. The dog recovered completely from the acute crisis and acute renal failure. 相似文献