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61.
The influence of varying light intensity and quality on thecarbon labelling patterns in Rumex vesicarius (a C3 plant),Setaria italica (a malate-formingC4 plant), and Amaranthus paniculatus(an aspartate-forming C4 plant) was studied. In A. paniculatusand B. vesicarius blue light decreased the transfer of radioactivityto sugars and starch but in S. italica only slightly decreasedradioactivity in sugar phosphates, sucrose, and insolubles.Negligible transfer was observed from the C4 acids to sugarphosphates, sucrose, and starch under dim blue-green and blue-yellowlights in S. italica and A. paniculatus. Blue light favouredthe formation of malate, aspartate, and alanine in all threeplants. The differential effect of blue and red light suggesteda variation in the mechanisms of C4-photosynthesis in Setariaand Amaranthus. Leaves of S. italica and A. paniculatus were allowed to photosynthesizein 14CO2 for 5 s and then the distribution of the labelled productsbetween the mesophyll and the bundle sheath cells was determinedduring subsequent photosynthesis in 12CO2. Malate and aspartatewhich appeared initially in the mesophyll layer moved rapidlyinto the bundle sheath cells. Phosphoglyceric acid originatingin the bundle sheath moved swiftly to the mesophyll layer. Sugarphosphates were recovered from both the mesophyll and the bundlesheath cells. Most of the starch was found in the bundle sheathcells while sucrose and alanine were localized in the mesophyllcells.  相似文献   
62.
Experiments on the interactions of auxins and anti-auxins inroots have been extended to studies with concentrations givinggrowth stimulations using 2-mm. sections excised from the extensionzone of roots of Pisum sativum. The curves relating growth responsesto log10 concentration for ß-indolylacetic acid (IAA)and three anti-auxins, -(I-naphthylmethylsulphide) propionicacid (NMSP), I-naphthylmethylsulphide acetic acid (NMSA), and4-chloro-3-nitrobenzoic acid (CNB), are of very similar shape.A fourth anti-auxin, p-chlorophenoxy-iso butyric acid (PCIB),shows negligible stimulation of growth in any concentration.In multifactorial experiments involving stimulatory concentrationsof IAA (10–4 and 10–5 p.p.m.) with several stimulatoryconcentrations of the first three anti-auxins (NMSP, NMSA, andCNB), consistent mutual antagonisms were clearly demonstrated.PCIB in non-inhibitory concentrations markedly antagonized stimulationby IAA Similar mutual antagonisms were shown in various mixturesof two anti-auxins. Both the similarities of the concentration-response curves andthe consistent mutual antagonisms suggest that both auxins andanti-auxins in stimulating root growth are exerting identicalphysiological actions in the same growth system. On the assumptionthat these substances are active when adsorbed at some enzymeor other protoplasmic surface, it has been demonstrated thatthese experimental results are more easily explained by a directaction at those growth centres than by a competitive antagonismof a natural endogenous growth inhibitor, as suggested in aprevious paper. The bearing of these results on current theories relating auxinand anti-auxin activities to molecular structure is discussed.  相似文献   
63.
SYNOPSIS. A hyperparasite probably related to some lower protistan was found in the cytoplasm of Entamoeba suis Hartmann. These were very minute bodies with a central Feulgen-positive dot, the nucleus, and a bordering cytoplasmic ring with an alcian blue-positive reaction. This organism appeared to interfere with the synthesis of DNA & RNA in the host amoeba as reflected in its relative stainability with Feulgen or pyronin-methyl green. The suggestion is that the parasitized amoebic cysts were most likely rendered nonviable.  相似文献   
64.
Lemna paucicostata HEGELM., a short-day plant, can be inducedto flower under long days by provision of cytokinins in themedium. Of several cytokinins tested, zeatin and 6-benzylaminopurineare the most potent. They are effective when added in a mediumcontaining excess of iron and thus can bring about the sameaffect as EDDHA. Interestingly, when both EDDHA and a cytokininare provided together, flowering occurs even in the medium containingnormal level of iron. Other cytokinins such as SD 8339, kinetinand 6-(,-dimethylallylamino)-purine are also effective in mediumcontaining a slightly higher level of ferric citrate. In contrastto cytokinins, indole-3-acetic acid and gibberellic acid arenot only ineffective by themselves, but even nullify the inductiveeffect of cytokinins on flowering. Growth retardants such asCCC and abscisic acid have been found to inhibit flowering athigh levels. (Received September 8, 1969; )  相似文献   
65.
ABSTRACT. Extracts of the pathogenic ameba Naegleria fowleri, prepared by freeze-thawing and sonication, were analyzed for their content of various hydrolytic enzymes that have acid pH optima. The organism is rich in acid phosphatase activity as well as a variety of glycosidases which include β-glucosidase, β-galactosidase, β-fucosidase, α-mannosidase, hexosaminidase, arylsulfatase A, and β-glucuronidase. The crude extract contained only negligible levels of sphingomyelinase, neuraminidase, or arylsulfatase B. All of the hydrolases exhibited higher activity at pH 5.5 than at 7.0, indicating that they are truly “acid” hydrolases. In general, after centrifugation (100,000 g, 1 h), except for arylsulfatase B, more than half of the activity of each of the various hydrolases was recovered in the supernatant fraction. The acid phosphatase in the high-speed supernatant was purified 45-fold (32% yield) by chromatography on QAE-Sephadex and Sephadex G-200 and shown to have the following properties: 1) pH optima, 5.5; 2) Km (4-methylumbelliferyl phosphate), 0.60 mM; 3) molecular weight (estimated by gel filtration chromatography), 92,000; 4) inhibited by heteropolymolybdate complexes but not by L(+) sodium tartrate (0.5 mM) or sodium fluoride (0.5 mM). In addition, unlike the tartrate-resistant acid phosphatase of Leishmania donovani, the major acid phosphatase of N. fowleri is less than 5% as effective in inhibiting superoxide anion production by f-Met-Leu-Phe-stimulated human neutrophils. The finding of high levels of a number of acid hydrolases in Naegleria fowleri raises several questions that merit further study: Do the hydrolases perform a housekeeping function in this single cell eukaryote or do they play some role in the pathogenic process that ensues when the organism infects a suitable host?  相似文献   
66.
The quality of roasted grain powders is greatly affected bythe roasting process variables; viz., initial moisture content (IMC), grain-to-sand ratio (GSR), sand temperature (ST) and roasting time (RT). The sensory optimization for these variables was done in two phases. The IMC (12 ± 0.2%) and GSR (1:4) were standardized in the first phase, whereas ST (215C) and RT (1.5–2.0 min), in the second. The overall quality of the roasted grain powders was found to be greatly affected by ST followed by RT.  相似文献   
67.
Amongst 1061 breast lesions diagnosed by fine needle aspiration (FNA) over a period of 6 years (1985-1990), 128 were reported to be showing changes consistent with an inflammatory lesion. On review, the cytodiagnosis was found to be inaccurate in 31 cases. The cytological features of the 97 cases that were correctly reported are described in this report. The cytological diagnoses issued in these 97 cases were acute mastitis or breast abscess (57 cases) and tuberculous mastitis (30 cases). Non-specific chronic mastitis and miscellaneous conditions accounted for four and six cases respectively. Acid fast bacilli (AFB) were demonstrated in 28.0% of tuberculous mastitis cases and 10.0% of those diagnosed as acute mastitis or breast abscess. FNA cytology was found to be useful for the diagnosis of inflammatory lesions of breast and their classification, as only five out of 57 cases of acute mastitis/breast abscess and one out of 30 tuberculous mastitis cases were suspected on clinical grounds.  相似文献   
68.
The value of fine catheter aspiration cytology in the diagnosis of metastatic tumours is illustrated by a case of pleomorphic giant cell carcinoma of the pancreas which had metastasized to the peritoneal cavity. The finding of unequivocal malignant cells obviated the need for further diagnostic procedures. Electron microscopy and immunostaining further substantiated the light microscopic cytodiagnosis and identified the tumour type and source of the primary tumour. Furthermore, subsequent cell block preparation from the aspirated material demonstrated the histological features of this tumour.  相似文献   
69.
Five pitfall traps baited with 150–200 g of fresh cattle dung were installed for 24 h at weekly intervals. A total of 991 dung beetles from 11 genera, 31 species and three subfamilies was obtained. The community was dominated by Oniticellus spinipes individuals by 32.3%. Ten species appeared only once during the collection period and species composition and dominance changed throughout the period. The overall pattern we detected in the organization of the dung beetle community is that the species richness, abundance and diversity rise in September and the 2nd week of October. The dung beetle community was found to be affected by season.  相似文献   
70.
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