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371.
Richard L. Lindroth M. T. Stephen Hsia J. Mark Scriber 《Biochemical Systematics and Ecology》1987,15(6):681-686
We monitored seasonal changes in the leaf quality characteristics of three native species of Populus during 1986. Leaf water and nitrogen contents of each species declined during the growing season. The phenolic glycosides salicin, salicortin, tremuloidin and tremulacin occurred in Populus tremuloides and P. gradidentata; all but tremulacin occurred in P. deltoides. Levels of salicin and tremuloidin were low throughout the growing season in all three species. Among the tree species, concentrations of salicortin and tremulacin were highest, and exhibited the least among-plant variation and strongest seasonal declines in P. grandidentata. Levels of salicortin and tremulacin were intermediate in P.tremuloides, varied greatly among individual trees, and did not significantly decrease during the growing season. Levels of salicortin were relatively low, varied considerably among trees, and did not decline seasonally in P. deltoides. Spatial and temporal variation in these constituents produces plant parts, individuals and species with differential resistance to insect herbivores. 相似文献
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In olfactory research,neural oscillations exhibit excellent temporal regularity,which are functional and necessary at the physiological and cognitive levels.In this paper,we employed a bionic tissue biosensor which treats intact epithelium as sensing element to record the olfactory oscillations extracellularly.After being stimulated by odorant of butanedione,the olfactory receptor neurons generated different kinds of oscillations,which can be described as pulse firing oscillation,transient firing oscillation,superposed firing oscillation,and sustained firing oscillation,according to their temporal appearances respectively.With a time-frequency analysis of sonogram,the oscillations also demonstrated different frequency properties,such as δ,θ,α,β and γ oscillations.The results suggest that the bionic biosensor cooperated with sonogram analysis can well improve the investigation of olfactory oscillations,and provide a novel model for artificial olfaction sensor design. 相似文献
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S Hsia D N Howell D B Amos M A Woodbury 《Journal of immunology (Baltimore, Md. : 1950)》1977,118(5):1659-1664
Serum antibodies to adenovirus (ADN), cytomegalovirus (CMV), herpes simplex virus (HSV), influenza (INF), para-influenza (PAR), mumps (MUM), coxsackie B4 (Cox B4) and B5 (Cox B5) viruses were measured from 584 individuals belonging to 21 Indiana Amish families. Sex and age effects on antibody responses to cytomegalovirus were observed. Age effect on CMV, HSV, INF, PAR, MUM responses were also found. The percentage of responders to some of the viruses was shown to be age dependent, but the levels of antibody response were not affected by the difference in age. A familial basis for the antibody response was demonstrated. Attempts at demonstrating association between HLA haplotypes and responses were not successful. The unlikelihood of predominantly HLA-associated control of viral antibody response was discussed. 相似文献
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Complement-immune lysis of liposomes loaded with water-soluble spin label 2,2,6,6-tetramethyl-piperidinoxy-choline chloride (TEMPO-choline) was used to measure specificity of rabbit antisera generated by complete adjuvant with liposomes consisting of sphingomyelin; cholesterol; dicetylphosphate; 5-N-thyroxine-2,4-dinitrophenyl -phosphatidylethanolamine (T4-Dnp-PE) in the ratio 2.0:1.5:0.2:15. Antisera so generated induced complement lysis of the liposomes containing negatively charged amphiphils. No immune lysis of positively charged liposome was observed. This antiliposome specificity is retained in partially purified antibodies. 相似文献