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21.
EARL OF CRANBROOK PHILIP J. PIPER 《Biological journal of the Linnean Society. Linnean Society of London》2008,94(2):413-419
Fossil mandibles of the Bornean shrew Crocidura foetida recovered from excavations at the west mouth of Niah cave, Sarawak, Malaysia, show that the late Pleistocene population at this lowland location was comparable in size with the large subspecies Crocidura foetida doriae , presently occurring at inland, upland locations. Two Holocene specimens fall in the size range of the smaller lowland subspecies C. f. foetida . Comparable post-Pleistocene size-reduction is known among other mammals of Borneo, but this is the first instance of dated examples. The evolutionary trend conforms with Bergmann's 'rule' but, other than climate change, no selective agent is apparent. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society , 2008, 94 , 413–419. 相似文献
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Specificity of Chroomonas (Cryptophyceae) as a source of kleptochloroplast for Nusuttodinium aeruginosum (Dinophyceae) 下载免费PDF全文
The unarmoured dinoflagellate Nusuttodinium aeruginosum retains a kleptochloroplast, which is a transient chloroplast stolen from members of the cryptomonad genus, Chroomonas. Both N. aeruginosum and the closely related N. acidotum have been shown to restrict their diet to a limited number of species of this blue‐green genus of cryptophyte. However, it is still unclear how flexible the predators are with regard to the ingestion and utilization of Chroomonas spp. as a source of kleptochloroplast. To address specificity of cryptomonad in N. aeruginosum, we collected the cells of N. aeruginosum from several ponds in Japan, and analysed the phylogeny of the kleptochloroplasts based on their plastidial 16S rDNA sequences. All sequences obtained in this study were restricted to only one (the subclade 4) of four subclades known to comprise the Chroomonas/Hemiselmis clade. Therefore, N. aeruginosum is specific in its dietary requirements, selecting their prey within the subclade level. 相似文献
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本文记述采自新疆的皿蛛科蜘蛛一新届——颚齿蛛属Maxillodens gen.nov.及其一新种——鞭状颚齿蛛M.flageuatus sp.nov。 相似文献
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Hu W Onuma T Birukawa N Abe M Ito E Chen Z Urano A 《Cellular and molecular neurobiology》2008,28(4):519-528
Elevation of the intracellular cAMP level induces morphological changes of astrocyte-like differentiation in C6 glioma cells.
Such changes may be accompanied with expression of cytoskeletal protein genes. We therefore analyzed morphological changes
after a treatment with dibutyryl cAMP (dbcAMP) and then assessed the expression of cytoskeletal protein genes by a quantitative
real-time polymerase chain reaction. The cell number remained unaltered upon incubation with 1 mM dbcAMP in medium supplemented
with 0.1% fetal bovine serum (FBS), whereas the number and lengths of processes increased, when compared with those of cells
incubated in medium supplemented with 0.1% or 10% FBS only. The amounts of β-actin, γ-actin, and β-tubulin mRNAs in C6 cells,
but not α-tubulin mRNA, increased during the early proliferation in DMEM containing 10% FBS. The expression of cytoskeletal
protein genes decreased when incubated with 0.1% FBS or 1 mM dbcAMP in 0.1% FBS, compared with those of cells cultured in
10% FBS. These results indicated that, during the early proliferation in normal culture condition, the expression of cytoskeletal
protein genes in C6 cells, except α-tubulin, increased, while in differentiating or differentiated C6 glioma cells, cAMP-induced
morphological changes were not accompanied with elevation of gene expression for cytoskeletal proteins, such as actin and
tubulin. 相似文献
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Luís Fernando Parizi Kiyoko Uemura Utiumi Saiki Imamura Misao Onuma Kazuhiko Ohashi Aoi Masuda Itabajara da Silva Vaz Jr. 《Experimental parasitology》2011,(1):113-118
Recombinant Glutathione S-transferase of Haemaphysalis longicornis (rGST-Hl) was expressed in Escherichia coli, purified by affinity chromatography and used in the immunization of cattle. Western blot analysis showed positive antibody response in cattle immunized with rGST-Hl. The tests also showed that immunized bovine sera recognize native Rhipicephalus microplus proteins in different tissue extracts. Furthermore, the vaccine potential of rGST-Hl was investigated against infestation of Hereford cattle by R. microplus. Vaccination of cattle with rGST-Hl conferred partial cross-protection immunity against R. microplus. Considering the effect on number of engorged ticks, egg laying capacity and egg fertility, the overall efficacy of vaccination was of 57%, as compared with control group. 相似文献
29.
Comparing global models of terrestrial net primary productivity (NPP): the importance of water availability 总被引:1,自引:0,他引:1
G. Churkina S. W. Running A. L. Schloss ThE. Participants OF. ThE. Potsdam NpP. Model Intercomparison 《Global Change Biology》1999,5(Z1):46-55
Given that neither absolute measures nor direct model validations of global terrestrial net primary productivity (NPP) are feasible, intercomparison of global NPP models provides an effective tool to check model consistency. For this study, we tested the assumption that water availability is the primary limiting factor of NPP in global terrestrial biospheric models. We compared a water balance coefficient (WBC), calculated as the difference of mean annual precipitation and potential evapotranspiration to NPP for each grid cell (0.5° × 0.5° longitude/latitude) in each of 14 models. We also evaluated different approaches used for introducing water budget limitations on NPP: (1) direct physiological control on evapotranspiration through canopy conductance; (2) climatological computation of constraints from supply/demand for ecosystem productivity; and (3) water limitation inferred from satellite data alone. Plots of NPP vs. WBC showed comparable patterns for the models using the same method for water balance limitation on NPP. While correlation plots revealed similar patterns for most global models, other environmental controls on NPP introduced substantial variability. 相似文献
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Molecular cloning of bovine leukemia virus DNA integrated into the bovine tumor cell genome 总被引:3,自引:0,他引:3
The bovine leukemia virus (BLV) DNA harbored in the bovine tumor cell genome was cloned in lambda Charon 4A phage. Using either representative or 3' half-enriched BLV cDNA as a blot hybridization probe, clone lambda BLV-1 was shown to carry 9 kb of the BLV genome, flanked by cellular sequences at both ends. Restriction mapping with twelve endonucleases and hybridization of the DNA fragments to BLV cDNA representing a 3'-end portion of the viral genome revealed the presence and precise location of two long terminal repeats (LTRs) and virus-cell junctions. Thus, lambda BLV-1 appears to contain the complete BLV genome and flanking tumor cellular sequences. The restriction map of the cloned BLV proviral DNA closely resembles that previously reported for unintegrated linear proviral DNA, but differs significantly from that of the integrated provirus of another BLV isolate, the difference occurring preferentially in the putative gag and pol genes. 相似文献