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1.
The RAINFOR database: monitoring forest biomass and dynamics 总被引:1,自引:0,他引:1
Problem: Data from over 100 permanent sample plots which have been studied for 10–20 years need a suitable system for storage which allows simple data manipulation and retrieval for analysis. Methods: A relational database linking tree records, taxonomic nomenclature and corresponding environmental data has been built in MS Access as part of the RAINFOR project. Conclusion: The database allows flexible and long‐term use of a large amount of data: more than 100 tree plots across Amazonia, incorporating over 80 000 records of individual trees and over 300 000 total records of tree diameter measurements from successive censuses. The database is designed to enable linkages to existing soil, floristic or plant‐trait databases. This database will be a useful tool for exploring the impact of environmental factors on forest structure and dynamics at local to continental scales, and long term changes in forest ecology. As an early example of its potential, we explore the impact of different methodological assumptions on estimates of tropical forest biomass and carbon storage. 相似文献
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E K Lund M W Smith M A Peacock 《Comparative biochemistry and physiology. A, Comparative physiology》1986,85(1):175-181
The influence of parental spleen cells on the postnatal development of brush border microvillus membrane structure and the ability to transport lysine and alanine has been studied in the mouse jejunum during the second week of postnatal life. Control tissue taken from 7-11 day old mice has an unchanging crypt-villus structure and a low enterocyte migration rate of about 1 micron hr-1. Microvillus elongation in crypt enterocytes takes 6 days to complete under these conditions. Lysine and alanine transport begin 2 days after structural differentiation has ceased. Parental spleen cells injected into 1-2-day-old F1 mice cause crypt cell hyperplasia, villus shortening and a 3-6-fold increase in enterocyte migration rate after a period of 8 days. These effects are associated with large reductions in the time needed to complete microvillus membrane development and first express absorptive function. Lysine and alanine transport begin approximately 6 hr after structural differentiation has ceased under these conditions. Adaptive changes in the development of enterocyte structure and function, induced by injection of parental spleen cells, bear some resemblance to other changes found to occur normally at weaning and in adult animals subjected to controlled changes in diet and environmental temperature. The possibility that common principles govern enterocyte adaptation and that some of these still apply in an intestine undergoing an immune reaction is discussed. 相似文献
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The phytophagous fruit fly Rhagoletis meigenii harbors the bacterium Wolbachia pipientis and, together with Japanese barberry, form a tri-partite symbiosis. R. meigenii is a seed predator of invasive Japanese barberry plants and is dependent on this insect-plant interaction for reproductive success. The endosymbiotic bacterium W. pipientis is a reproductive parasite known to alter the sex ratios of offspring and the fitness of infected host insects. We investigated Japanese barberry fruit for the degree of infestation by R. meigenii and characterized the Wolbachia strain infecting R. meigenii. Densities of R. meigenii in four naturalized stands of Japanese barberry revealed low numbers of fruit flies with high variability in the population densities observed among individual plants. Overall, R. meigenii infested roughly 10–20 % of the Japanese barberry fruits analyzed; fruit with two seeds (vs. one seed) were the most frequently infested. Approximately, 90 % of the R. meigenii tested positive for Wolbachia infection via PCR amplification of the Wolbachia surface protein (wsp) gene. No bacterial strain diversity was observed when comparing multi-locus sequence typing (MLST) profiles within or among five R. meigenii populations in Maine, although the MLST profile obtained from R. meigenii differed from three co-occurring Rhagoletis. The Wolbachia endosymbiont of R. meigenii is a member of the Wolbachia supergroup A and the ST-13 cluster complex. 相似文献
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G M Duchesne J H Peacock 《International journal of radiation biology and related studies in physics, chemistry, and medicine》1987,51(2):365-375
The radiation sensitivity of two small-cell lung carcinoma cell lines growing as multicellular spheroids in static culture was determined using clonogenic cell survival and growth delay as endpoints. Growth delay determination suggested that clonogenic cell kill was less than was obtained by direct assay of cell survival. Recovery from potentially lethal damage was assayed in one line (HC12) but was not demonstrable, and clonogenic cell survival decreased with time in treated spheroids with diameters greater than 300 microns which contained a hypoxic cell population. Microscopic examination of the treated spheroids showed the emergence of an abnormal giant-cell population, and the progressive clonogenic cell loss that occurred after treatment was thought to be due to oxygen and nutrient deprivation of the remaining viable cells by this doomed cell population. Correction of the growth delay measurements for changes in cell size and clonogenic cell population allowed correlation of the growth delay and cell survival data. 相似文献
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E A McGuire M E Peacock R C Inhorn N R Siegel D M Tollefsen 《The Journal of biological chemistry》1988,263(4):1942-1945
Incubation of human plasma with 27 nM [gamma-32P]ATP in the presence of 20 mM MnCl2 results in the phosphorylation of several proteins detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. About 60% of the incorporated radioactivity is found in a 75-kDa protein containing [32P] phosphoserine. The amino-terminal amino acid sequence of the purified 75-kDa [32P]phosphoprotein is identical to that of vitronectin (also termed serum spreading factor or complement S protein). Rabbit antiserum against vitronectin precipitates greater than 90% of the 75-kDa [32P]phosphoprotein from plasma. Reverse phase chromatography of [32P]vitronectin degraded sequentially with CNBr and chymotrypsin yields one major labeled peptide. The sequence of the peptide, Ser-Arg-Arg-Pro-[32PO4]Ser-Arg-Ala-Thr, corresponds to residues 374-381 which are located in the heparin-binding fragment of vitronectin identified by Suzuki et al. [1984) J. Biol. Chem. 259, 15307-15314). Vitronectin could potentially be phosphorylated in vivo with ATP released from injured cells or secreted by platelets activated during hemostasis. 相似文献
9.
Studies on the cryopreservation of Dictyocaulus viviparus (Nematoda) third-stage larvae 总被引:1,自引:0,他引:1
Various cooling (0.1-5,100 degrees C min-1) and warming (20-6,800 degrees C min-1) rates, stepped cooling schedules and four cryoprotective additives (dimethyl sulphoxide, methanol, ethanediol and glycerol) were investigated in cryopreservation studies with Dictyocaulus viviparus third-stage larvae. Exsheathment with sodium hypochlorite was essential to achieve significant survival. With uninterrupted cooling, highest survival (30% normally motile) was achieved with rates of 10-70 degrees C min-1. Survival was higher (50-75%) using 1 degree C min-1 to -10 degrees C followed by plunging into liquid nitrogen. The optimum warming rate was 6,800 degrees C min-1. The use of cryoprotectants led to marginally lower survival while varying the suspending media had no significant effect on survival. X-irradiated, exsheathed third-stage larvae cryopreserved by the optimum protocol yielded 38.3 +/- 4.2% survival. Two calves each infected with 45,000 (15,000 viable) exsheathed, unirradiated, cryopreserved third-stage larvae harboured 494 worms (1.1% infectivity) and 355 worms (0.8%) at necropsy. Numbers of first-stage larvae in the faeces reached 420/g and 105/g respectively 27 days after infection. 相似文献
10.
E S Dennis M M Sachs W L Gerlach E J Finnegan W J Peacock 《Nucleic acids research》1985,13(3):727-743