Author Keywords: behaviour; Colubridae; ecology; Masticophis flagellum; radiotelemetry; Reptilia; Serpentes; temperature; thermoregulation 相似文献
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61.
62.
Geoffrey A. Hammerson 《Journal of thermal biology》1989,14(4):219-224
1. 1.|Body temperature (Tb) and activity of the snake Masticophis flagellum were studied by radiotelemetry in an outdoor enclosure.
2. 2.|Mean diurnal Tb varied little over a wide range of weather conditions, but weather variation was accompanied by major changes in sun exposure and in the timing and duration of activity.
3. 3.|Recently fed snakes reduced activity and exhibited neither a thermophilic response nor increased precision of thermoregulation compared to fasting snakes.
63.
Susan S. Bell Geoffrey R. F. Hicks Keith Walters 《Journal of experimental marine biology and ecology》1989,130(3):291-303
The resettlement behavior of meiobenthic copepods, which actively migrated from sediments in a seagrass bed, was investigated in a shallow subtidal area in Tampa Bay, Florida, U.S.A. Experimental studies were conducted to determine whether meiobenthic copepods after emerging from sediments at sunset reenter the sedimentary substratum or select other subhabitats, water and seagrass blades. Migrating copepods were collected with emergence traps and transferred to experimental aquaria in the field which contained sediment, seagrass-blade and water treatments. Settlement into each type of treatment was measured in separate 2-h and 9-h experiments. Differences in densities of copepod taxa retrieved from emergence traps and introduced into experimental aquaria were recorded as were differing relative proportions of each copepod species returning to the substratum treatments. Settlement patterns of total copepods and three dominant copepod species, Zausodes arenicolus, Halicyclops sp. and Robertsonia hamata, departed from those expected by chance. The populations of R. hamata and Halicyclops sp. which settled were generally skewed towards males and a close matching of males and copepodites within treatment dishes was evident. Similar to nighttime-emergence patterns, timing and magnitude of postmigration reentry differs among copepod taxa and such reentry may be linked to reproductive events. Complex behavioral processes previously noted for fish and macrofaunal organisms in seagrass beds may also be important in recruitment and reassortment of meiobenthic copepods. 相似文献
64.
65.
Substituted enzyme (or ping-pong) mechanisms usually involve enzymes that exist in two forms that alternate during the catalytic
reaction. A method is described here for determining the position of the equilibrium of a half reaction in a ping-pong enzyme
mechanism that is based on the kinetics of the burst reaction which occurs upon addition of reactants that recycle the enzyme
from one form to another. The theoretical basis for the analysis is developed, and the method is applied to the half reaction
of the aldimine form of aspartate transaminase with difluoro-oxaloacetate.
Special issue dedicated to Herman Bachelard 相似文献
66.
Two target polypeptides were detected by photoaffinity labelling of purified mung bean mitochondria using tritiated 2-azido-N6-benzylaminopurine. SDS-PAGE and fluorography of total mitochondrial proteins after the photoaffinity reaction showed a labelled 32 kDa polypeptide (intensely labelled) and a 57 kDa polypeptide (less intensely labelled). The latter was assumed to be the and/or subunit of F1ATPase since it was the most abundant polpeptide in gels stained with Coomassie Blue. Partial purification of F1ATPase demonstrated that the 32 kDa polypeptide was not a component of the ATPase complex. Fractionation experiments showed that the 32 kDa protein was integrally associated with mitochondrial membranes and could be enriched by simple washing and detergent extraction procedures. 相似文献
67.
68.
A general assay for restriction endonucleases and other DNA-modifying enzymes with plasmid substrates 总被引:2,自引:0,他引:2
I. Barry Vipond Geoffrey S. Baldwin Mark Oram Symon G. Erskine Lois M. Wentzell Mark D. Szczelkun Timothy J. Nobbs Stephen E. Halford 《Molecular biotechnology》1995,4(3):259-268
A procedure for measuring the activities of enzymes that alter the covalent structure of DNA is described. The assay utilizes
covalently closed circles of DNA as the substrate and yields quantitative data on the fraction of this DNA converted to both
open-circle and linear forms. 相似文献
69.
R. Geoffrey Richards Iolo ap Gwynn Kirk J. Bundy Berton A. Rahn 《Cell biology international》1995,19(12):1015-1024
Adhesion of cells to biomaterial surfaces is one of the major factors which mediates their biocompatibility. Quantitative or qualitative cell adhesion measurements would be useful for screening new implant materials. Microjet impingement has been evaluated by scanning electron microscopy, to determine to what extent it measures cell adhesion. The shear forces of the impingement, on the materials tested here, are seen to be greater than the cohesive strength of the cells in the impinged area, causing their rupture. The cell bodies are removed during impingement, leaving the sites of adhesion and other cellular material behind. Thus the method is shown not to provide quantification of cell adhesion forces for the metals and culture plastic tested. It is suggested that with highly adherent biomaterials, the distribution and patterns of these adhesion sites could be used for qualitative comparisons for screening of implant surfaces. 相似文献
70.
Purified thermostable alcohol dehydrogenase allozymes ADH-71k and ADH-FCh.D. ofDrosophila melanogaster have been compared with the two common enzyme forms ADH-F and ADH-S. Enzyme kinetic parameters for various primary and secondary alcohols were determined under standard conditions used previously. Both ADH-71k and ADH-FCh.D. show ADH-S-like reaction kinetics andK
m values, due to retrograde evolution at site 214, Pro Ser. Inhibition studies with alcohol dehydrogenase inhibitors pyrazole, 4-methylpyrazole, and cibacron blue 3GA were also performed. Activity measurements on crude extracts of larvae and flies from isogenic lines of ADH-FCh.D. revealed a consistently higher activity than in ADH-71k-containing strains, in contrast to the original strains.K.Th.E is indebted to the Royal Norwegian Council for Technological and Scientific Research for their postdoctoral fellowship. Prof. J. S. McKinley-McKee gave me the opportunity to work in his laboratory. I thank Dr. Knut Sletten of the Biochemical Institute for the kind gift of 2-methoxyethanol and amino acid analysis of some samples. The Biological Institute, Oslo, Section of General Genetics, is gratefully acknowledged for enabling me to use their fly-breeding facilities. Dr. John B. Gibson provided us with a sample of FCh.D. flies for the construction of isogenic lines in which Dr. Johan Hageman participated, owing to Postdoctoral Grant 436-931-P from the Foundation of Biological Research (BION), which is subsidized by the Netherlands Organization for Scientific Research (NWO). J. H. and Paula Truyens were involved in the measurements on the crude extracts. Work at Victoria University was supported by the VUW Internal Grant Committee. 相似文献