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D. E. S. Truman R. M. Clayton J. C. Campbell 《Cellular and molecular life sciences : CMLS》1967,23(6):502-504
Résumé On décrit 2 modifications apportées à la méthode d'immunoélectrophorèse. L'une d'elles comprend l'électrophorèse dans 2 sens, aux pH divers, en milieu gélifié suivie par l'analyse immunologique, permettant une définition plus avantageuse. L'autre comprend l'électrophorèse sur un fil de rayonne ou d'acétate de cellulose suivie par l'analyse immunologique en milieu gélifié, permettant l'analyse des quantités d'antigène à partir de 3 µg. 相似文献
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Aflatoxin M1 in human urine 总被引:2,自引:0,他引:2
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Caffeine as a repellent for slugs and snails 总被引:1,自引:0,他引:1
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The Wood River sculpin Cottus leiopomus is endemic to the Wood River Basin in central Idaho and is a nongame species of concern because of its limited distribution. However, status and genetic population structure, 2 factors often central to the conservation and management of species of concern, have not been assessed for this species. We used backpack electrofishers to survey streams that were small enough (i.e., a priori to contain, possibly contain, or not contain the sculpin, respectively. Native redband trout Oncorhynchus mykiss gairdneri were present at 21 study sites, including 18 of the 20 sites that contained Wood River sculpin. Sixty-one study sites (60%) were dry or had too little water to contain any fish. We estimated that a minimum of 1.36 million Wood River sculpin (≥20 mm total length) currently reside in the basin. The presence of Wood River sculpin was positively associated with stream width:depth ratio and percent cobble/boulder substrate and negatively associated with stream gradient. Mitochondrial DNA haplotype differences were observed between and within the 3 major river subbasins supporting sculpin, with the most striking differences observed between populations in the Camas Creek subbasin and the other 2 subbasins, among which no haplotypes were shared, suggesting relatively long-term isolation. Our results suggest that the Wood River sculpin remains relatively widespread and abundant within its endemic range, despite obvious changes in historical stream connectivity caused by irrigation diversions and other chronic habitat alterations. 相似文献
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B. C. Campbell 《Cellular and molecular life sciences : CMLS》1986,42(4):451-452
Summary The honeydew of the aphidSchizaphis graminum (Rondani) contains hetero-oligosaccharides (mol. wt>2200 D) having neutral sugar and uronic acid compositions similar to the pectic substances of the host plant,Sorghum biocolor (L.) Moench. These oligosaccharides are pectic fragments which result from the depolymerization of pectic substances in the phloem by aphid salivary polysaccharases. 相似文献
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Summary Increased methylation of middle lamellar pectin in plants hinders aphids in penetrating host-plant tissue. In sorghum, a new aphid biotype has overcome this host-plant barrier by having increased pectin methylesterase activity. Results suggest that resistance in crop-plants against sap-feeding insects may possibly be manipulated by altering middle lamellar chemistry either through breeding or use of certain plant-growth regulators. 相似文献