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161.
A unified approach to the construction of minimax designs 总被引:1,自引:0,他引:1
162.
163.
CLARENCE A. SPEER ROSIE B. WONG ROBERT H. SCHENKEL 《The Journal of eukaryotic microbiology》1983,30(3):548-554
Monoclonal IgG antibodies against sporozoites of Eimeria tenella were obtained from the ascites fluid of BALB/c mice. Oocysts, sporocysts, and sporozoites were exposed to medium 199, normal ascites fluid, or monoclonal antibodies 1A, 9D, 3D3II, or 2G8f. Specimens were then incubated with ferritin-conjugated goat anti-mouse IgG antibody. Ferritin was uniformly distributed over the surface of sporozoites exposed to 1A, 9D, or 3D3II; ferritin was localized in patches on sporozoites exposed to 2G8f. A uniform layer of ferritin was present on the inner layer of oocyst walls and on the Stieda body and outer surface of sporocysts exposed to 1A, 9D or 3D3II. In specimens treated with 2G8f, ferritin was present on the inner layer of the oocyst wall and the Stieda body, but not on the sporocyst wall. No ferritin was found on specimens exposed to medium 199 or normal ascites fluid. Monoclonal antibodies 1A, 9D, and 3D3II, but not 2G8f, caused complement-mediated lysis of sporozoites. These findings indicate that oocysts, sporocysts, and sporozoites of E. tenella contain common antigens specific for each monoclonal antibody tested. 相似文献
164.
Several fundamental questions remain enigmatic concerning human olfactory
sensitivity, including (i) whether detection threshold differences exist
between the two sides of the nose (and, if so, whether such differences are
influenced by handedness) and (ii) whether bilateral (i.e. binasal)
stimulation leads to lower thresholds than unilateral stimulation (and, if
so, whether the degree of facilitation is inversely related to general
olfactory ability). In this study, and well-validated single staircase
procedure was used to establish bilateral and unilateral detection
thresholds for the cranial nerve I stimulant phenyl ethyl alcohol in 130
right- and 33 left-handed subjects. No differences in sensitivity between
the left and right sides of the nose were observed in either group.
Bilateral thresholds were lower, on average, than unilateral thresholds
when the latter were categorized in terms of left and right nares. However,
the bilateral thresholds did not differ significantly from those of the
side of the nose with the lower threshold. Overall smell ability, as
measured by the University of Pennsylvania Smell Identification Test, did
not interact with any of the test measures. These data imply that (i) the
left and right sides of the nose do not systematically differ in detection
threshold sensitivity for either dextrals or sinistrals and (ii) if central
integration of left:right olfactory threshold sensitivity occurs, its
effects do not exceed the function of the better side of the nose.
相似文献
165.
Esterase of rabbit polymorphonuclear leucocytes 总被引:1,自引:0,他引:1
166.
167.
The fungus Cochliobolus carbonum causes leaf spot disease of maize. Highly virulent isolates of the pathogen produce a host-selective, peptide toxin that is active against susceptible genotypes of maize. Prior to infection, spores must germinate and differentiate appressoria, structures specialized for leaf penetration. Analysis of spore germination fluids by plasma desorption mass spectrometry, which allowed detection of as little as 0.5 ng toxin, revealed that spores induced to form appressoria in vitro synthesized and released the toxin at a time coincident with maturation of appressoria. Spores incubated under conditions that did not induce appressorium formation failed to produce toxin. These observations indicate that synthesis of the host-selective toxin, which is essential for successful pathogenesis of maize by C. carbonum, is regulated by infection-related morphogenesis. 相似文献
168.
The paper continues an earlier study of the geometry of inflorescencestructures in the oil palm in which geometry is measured interms of Equivalent Phyllotaxis Index (E.P.I.). In this casethe phyllotaxis of male and female florets along their respectivespikelets is considered. Regardless of the spikelet positionon the inflorescence or the palm age the very small male floretshave a higher E.P.I. than the large female structures and acompletely different apparent parastichy arrangement. TheseE.P.I. estimates seem to be independent of the age of palmsfrom which inflorescences and hence spikelets are sampled. However,there is considerable variation in phyllotaxis within bunches,E.P.I. being lower on spikelets sampled toward the base of theinflorescence and increasing in a more or less linear mannerin spikelets sampled at the tip; this pattern is not so definiteon male spikelets. The results are discussed in relation toother more simple measurements of spikelet architecture. 相似文献
169.
Pseudomonas tolaasi in Mushroom Crops: A Note on Primary and Secondary Sources of the Bacterium on a Commercial Farm in England 总被引:1,自引:0,他引:1
Primary sources of Pseudomonas tolaasi Paine on a mushroom farm were the peat and limestone used in the casing process. The pathogen could not be detected in the farm soil, water supply, the mushroom spawn used, or in compost after spawning, but was isolated from the casing (peat/limestone mixture) layer of symptom-free mushroom beds and both the casing layer and compost of beds bearing diseased mushrooms. Secondary sources were numerous once the pathogen was present in mushroom beds. These included symptomless and diseased mushrooms, the fingers and shoes of people handling the crop, their baskets, knives and ladders. Ps. tolaasi could be isolated from dust in the air in infected houses and also from floors. Spores of infected mushrooms may transport the bacterium, as did sciarid flies and mites which are common pests of mushroom crops. 相似文献
170.
The biomass and metal concentrations of two populations ofPhragmitesaustraliswere studied by growth in a glasshouse in three amelioratedsubstrata [Mai Po (MP) sediment, fly ash (FA) and lead/zincmine tailings (TL)] under flooded and dry conditions for 90d. Plants were raised from seeds from clean (MaiPo, Hong Kong) and metal-contaminated (Plombières, Belgium)sites. Seedling growth was best in fly ash, root dry weightsbeing higher in flooded than dry conditions, and growth poorestin tailings, in which shoot and root dry weights were higherunder dry conditions for both populations. However, in the MPsubstratum conditions did not significantly affect shoot androot dry weights of either population. In the fly ash and tailings,more metals were generally taken up in both roots and shootsin flooded than dry conditions, but there was little differencein the MP substratum. Metal uptake was mostly similar in bothpopulations in seedlings grown in the same substratum, therebeing no clear evidence of ecotypic differentiation.Copyright1998 Annals of Botany Company Biomass, flooded and dry conditions, metal uptake,Phragmites australis. 相似文献