排序方式: 共有37条查询结果,搜索用时 15 毫秒
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Spatial prediction on a river network 总被引:1,自引:0,他引:1
Noel Cressie Jesse Frey Bronwyn Harch Mick Smith 《Journal of Agricultural, Biological & Environmental Statistics》2006,11(2):127-150
This article develops methods for spatially predicting daily change of dissolved oxygen (Dochange) at both sampled locations
(134 freshwater sites in 2002 and 2003) and other locations of interest throughout a river network in South East Queensland,
Australia. In order to deal with the relative sparseness of the monitoring locations in comparison to the number of locations
where one might want to make predictions, we make a classification of the river and stream locations. We then implement optimal
spatial prediction (ordinary and constrained kriging) from geostatistics. Because of their directed-tree structure, rivers
and streams offer special challenges. A complete approach to spatial prediction on a river network is given, with special
attention paid to environmental exceedances. The methodology is used to produce a map of Dochange predictions for 2003. Dochange
is one of the variables measured as part of the Ecosystem Health Monitoring Program conducted within the Moreton Bay Waterways
and Catchments Partnership. 相似文献
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O'Doherty A Ruf S Mulligan C Hildreth V Errington ML Cooke S Sesay A Modino S Vanes L Hernandez D Linehan JM Sharpe PT Brandner S Bliss TV Henderson DJ Nizetic D Tybulewicz VL Fisher EM 《Science (New York, N.Y.)》2005,309(5743):2033-2037
Aneuploidies are common chromosomal defects that result in growth and developmental deficits and high levels of lethality in humans. To gain insight into the biology of aneuploidies, we manipulated mouse embryonic stem cells and generated a trans-species aneuploid mouse line that stably transmits a freely segregating, almost complete human chromosome 21 (Hsa21). This "transchromosomic" mouse line, Tc1, is a model of trisomy 21, which manifests as Down syndrome (DS) in humans, and has phenotypic alterations in behavior, synaptic plasticity, cerebellar neuronal number, heart development, and mandible size that relate to human DS. Transchromosomic mouse lines such as Tc1 may represent useful genetic tools for dissecting other human aneuploidies. 相似文献
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Amir N Hamir Janice M Miller Katherine I O'Rourke Jason C Bartz Mick J Stack Melanie J Chaplin 《Journal of veterinary diagnostic investigation》2004,16(1):57-63
To determine the transmissibility of transmissible mink encephalopathy (TME) agent to raccoons and to provide information about clinical course, lesions, and suitability of currently used diagnostic procedures for detection of transmissible spongiform encephalopathies (TSEs) in raccoons, 4 raccoon kits were inoculated intracerebrally with a brain suspension from mink experimentally infected with TME. One uninoculated raccoon kit served as a control. All 4 animals in the TME-inoculated group showed clinical signs of neurologic disorder and were euthanized between 21 and 23 weeks postinoculation (PI). Necropsy examinations revealed no gross lesions. Spongiform encephalopathy was observed by light microscopy, and the presence of protease-resistant prion protein (PrPres) was detected by immunohistochemistry and Western blot techniques. Scrapie-associated fibrils were observed by negative-stain electron microscopy in the brains of 3 of the 4 inoculated raccoons. These findings confirm that TME is experimentally transmissible to raccoons and that diagnostic techniques currently used for TSE in livestock detect prion protein in raccoon tissue. According to previously published data, the incubation period of sheep scrapie in raccoons is 2 years, whereas chronic wasting disease (CWD) had not shown transmission after 3 years of observation. Because incubation periods for the 3 US TSEs (scrapie, TME, and CWD) in raccoons appear to be markedly different, it may be possible to use raccoons for differentiating unknown TSE agents. Retrospective genotyping of raccoons using frozen spleens showed that the raccoon PrP gene is identical to the mink gene at codons 179 and 224. Further studies, such as the incubation periods of bovine spongiform encephalopathy and other isolates of scrapie, CWD, and TME in raccoons, are needed before the model can be further characterized for differentiation of TSE agents. 相似文献
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The strobilurin fungicides 总被引:5,自引:0,他引:5
Bartlett DW Clough JM Godwin JR Hall AA Hamer M Parr-Dobrzanski B 《Pest management science》2002,58(7):649-662
Strobilurins are one of the most important classes of agricultural fungicide. Their invention was inspired by a group of fungicidally active natural products. The outstanding benefits they deliver are currently being utilised in a wide range of crops throughout the world. First launched in 1996, the strobilurins now include the world's biggest selling fungicide, azoxystrobin. By 2002 there will be six strobilurin active ingredients commercially available for agricultural use. This review describes in detail the properties of these active ingredients--their synthesis, biochemical mode of action, biokinetics, fungicidal activity, yield and quality benefits, resistance risk and human and environmental safety. It also describes the clear technical differences that exist between these active ingredients, particularly in the areas of fungicidal activity and biokinetics. 相似文献
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