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Postural effect on ventilatory control 总被引:1,自引:0,他引:1
14.
The site specificity of the apicomplexans Gregarina cuneata and Gregarina sleini , in larval Tenebrio molitor was investigated. Gregarina cuneata was found to inhabit the anteriormost region of the larval midgut, while G. steini was restricted to the posterior portion of the intestine. The site specificity of the pair was conserved in single and concurrent infections. Interspecific interactions do not seem to be presently responsible for the resource partitioning by the 2 gregarine species. Key words. Gregarina, site specificity, Tenebrio molitor. 相似文献
15.
VESSEY J KEVIN; RAPER C DAVID JR; HENRY LESLIE TOLLEY 《Journal of experimental botany》1990,41(12):1579-1584
Net uptake of by non-nodulated soybean plants [Glycme max(L ) Merr cv Ransom] growing in flowing hydroponicculture was measured daily during a 63 d period of reproductivedevelopment between the first florally inductive photopenodand late seed growth Removal of from a replenished solution containing 10 mol m was determined by ion chromatography Uptake of continued throughout reproductive development The net uptakerate of cycled between maxima and minima with a periodicity of oscillation of 3 to 7 d during the floralstage and about 6 d during the fruiting stage. Coupled withincreasing concentrations of carbon and C:N ratios in tissues,the oscillations in net uptake rates of are evidence that the demand for carbohydrate by reproductiveorgans is contingent on the availability of nitrogen in theshoot pool rather than that the demand for nitrogen followsthe flux of carbohydrate into reproductive tissues. Key words: Nitrate uptake rate, carbon-nitrogen partitioning, Glycme max (L ) Merrill 相似文献
16.
ROWLAND-BAMFORD AMANDA J; ALLEN L HARTWELL JR; BAKER JEFFREY T; BOOTE KEN J 《Journal of experimental botany》1990,41(12):1601-1608
The atmospheric carbon dioxide (CO2) concentration has beenrising and is predicted to reach double the present concentrationsometime during the next century. The objective of this investigationwas to determine the long-term effects of different CO2 concentrationson carbohydrate status and partitioning in rice (Oryza sativaL cv. IR-30). Rice plants were grown season-long in outdoor,naturally sunlit, environmentally controlled growth chamberswith CO2 concentrations of 160, 250, 330, 500, 660, and 900µmolCO2 mol1 air. In leaf blades, the priority between the partitioningof carbon into storage carbohydrates or into export changedwith developmental stage and CO2 concentration. During vegetativegrowth, leaf sucrose and starch concentrations increased withincreasing CO2 concentration but tended to level off above 500µmolmol1 CO2. Similarly, photosynthesis also increased withCO2 concentrations up to 500µmol mol1 and thenreached a plateau at higher concentrations. The ratio of starchto sucrose concentration was positively correlated with theCO2 concentration. At maturity, increasing CO2 concentrationresulted in an increase in total non-structural carbohydrate(TNC) concentration in leaf blades, leaf sheaths and culms.Carbohydrates that were stored in vegetative plant parts beforeheading made a smaller contribution to grain dry weight at CO2concentrations below 330µmol mol1 than for treatmentsat concentrations above ambient Increasing CO2 concentrationhad no effect on the carbohydrate concentration in the grainat maturity Key words: CO2 enrichment, starch, sucrose 相似文献
17.
A Dynamic Growth Model of Vegetative Soya Bean Plants: Model Structure and Behaviour under Varying Root Temperature and Nitrogen Concentration 总被引:1,自引:0,他引:1
LIM JUNE TAEG; WILKERSON GAIL G.; RAPER C. DAVID JR; GOLD HARVEY J. 《Journal of experimental botany》1990,41(2):229-241
A differential equation model of vegetative growth of the soyabean plant (Glycine max (L.) Merrill cv. Ransom)was developed to account for plant growth in a phytotron systemunder variation of root temperature and nitrogen concentrationin nutrient solution. The model was tested by comparing modeloutputs with data from four different experiments. Model predictionsagreed fairly well with measured plant performance over a widerange of root temperatures and over a range of nitrogen concentrationsin nutrient solution between 0.5 and 10.0 mmol in the phytotron environment. Sensitivity analyses revealedthat the model was most sensitive to changes in parameters relatingto carbohydrate concentration in the plant and nitrogen uptakerate. Key words: Glycine max (L.) Merrill, dry matter, nitrogen uptake, partitioning, photosynthesis, respiration, sensitivity analysis 相似文献
18.
CARLOS ABEYTA JR. CHARLES A. KAYSNER JAN M. HUNT MARLEEN M. WEKELL 《Journal of Rapid Methods and Automation in Microbiology》1995,4(1):51-64
A method has been developed to detect thermophilic species of Campylobacter in shellfish, marine and tributary waters, sediment and farm runoff by-products such as manure and silage. The method consists of a 48 h enrichment incubation and subcultured to selective agars. Presumptive colonies confirmed with a latex agglutination (antibodies) to common flagellar antigens of C. jejuni, C. coli and C. lardi. Over an 8 year period, West Coast estuaries (Washington, Oregon, and California) were sampled, resulting in analysis of a total of 512 samples. Results suggest that Campylobacter spp. are well distributed in the marine environment. Two enrichment broths were compared for the recovery of campylobacters from environmental samples. The method described in the Food and Drug Administration Bacteriological Analytical Manual (FDA/BAM) (1984), was compared to a modified method. Use of the modified method described here resulted in higher recovery rates of Campylobacter spp. Recoveries of campylobacters from sediment, shellfish, and water were 10,13, and 28% higher for the modified method, respectively. 相似文献
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ABSTRACT. A new species of malaria parasite, Plasmodium (Sauramoeba) heischi , is described from African skinks (Mabuya striata). Eleven individuals of 90 specimens collected in Nairobi were found to be infected. The new parasite is a large species, characterized by spindle-shaped gametocytes, the female often with a subterminal nucleus. The schizonts produce up to 65 nuclei and cause great hypertrophy and distortion of the host cell. Although similar to P. (Sauramoeba) giganteum in dimensions and merozoite numbers, P. heischi is easily distinguished by gametocyte and schizont shapes. 相似文献