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1.
J. Sellei 《Animal genetics》1975,6(1):41-48
The average titre scores varied from zero to 24.7 for the cattle red cells (CRC) from different MZ pairs. These CRC were sensitized with different blood-typing reagents and were titre-tested against the double dilution series of an anti-bovine y-globulin serum. A significant negative correlation (r = - 0.82; P <0.001) was found between the degree of agglutinability and the amount of neuraminic acid of the surface component of CRC cleaved by pronase.
After pronase treatment of the CRC it could be demonstrated that (1) the activity of the V and E'3 blood factors became destroyed; (2) three new specific receptors became evolved; (3) the degree of 'direct' agglutinability due to the A2 , O3 W, S2 and Z anti-sera did not parallel with the titre scores obtained in the anti-globulin tests. 相似文献
After pronase treatment of the CRC it could be demonstrated that (1) the activity of the V and E'
2.
J. Sellei 《Animal genetics》1974,5(4):205-214
Neuraminidase treatment made cattle red cells (CRC) agglutinable by the agglutinins of the different heterologous but not of the homologous sera. These agglutinins were, however, absorbed by both the nauraminidase-treated and the intact CRC.
Proteolytic treatment made CRC agglutinable also by the normal cattle, isoimmune and autologous sera. Agglutination titres of the CRC ranged from 1: 2 to 1: 256, but the variation between CRC from members of monozygous (MZ) pairs was not greater than ± 2 agglutination score units the range of experimental error.
Treatment with trypsin made the A1 , A2 factors more emergent on the surface of CRC for agglutination by anti-A2 , while pronase treatment had a similar effect upon agglutination of Z-positive cells by anti-Z. 相似文献
Proteolytic treatment made CRC agglutinable also by the normal cattle, isoimmune and autologous sera. Agglutination titres of the CRC ranged from 1: 2 to 1: 256, but the variation between CRC from members of monozygous (MZ) pairs was not greater than ± 2 agglutination score units the range of experimental error.
Treatment with trypsin made the A
3.
J. Sellei 《Animal genetics》1975,6(1):31-39
Addition of both complement and conglutinin was necessary to conglutinate the cattle red cells (CRC) when they were sensitized by different blood typing reagents. Although the degree of conglutinability of the CRC was influenced by the particular blood factor-reagent combination the average conglutinability (i.e. average titre scores) of CRC from different MZ pairs varied from 1.9 to 16.2.
The titres of complement varied from zero to 1:32, while the litres of conglutinin ranged from 1:8 to 1:1024 in the different sera from MZ cattle twins. The variance due to differences in the titre scores between MZ pairs was 82.2 % for conglutinin and 68.3 % for complement. There was no evident association between the titres of conglutinin and complement. 相似文献
The titres of complement varied from zero to 1:32, while the litres of conglutinin ranged from 1:8 to 1:1024 in the different sera from MZ cattle twins. The variance due to differences in the titre scores between MZ pairs was 82.2 % for conglutinin and 68.3 % for complement. There was no evident association between the titres of conglutinin and complement. 相似文献
4.
J Sellei 《Animal blood groups and biochemical genetics》1975,6(1):31-39
Addition of both complement and conglutinin was necessary to conglutinate the cattle red cells (CRC) when they were sensitized by different blood typing reagents. Although the degree of conglutinability of the CRC was influenced by the particular blood factor-reagent combination the average conglutinability (i.e. average titre scores) of CRC from different MZ pairs varied from 1.9 to 16.2. The titres of complement varied from zero to 1:32, while the titres of conglutinin ranged from 1:8 to 1:1024 in the different sera from MZ cattle twins. The variance due to differences in the titre scores between MZ pairs was 82.2% for conglutinin and 68.3% for complement. There was no evident association between the titres of conglutinin and complement. 相似文献
5.
Josef Sellei 《Animal genetics》1972,3(1):35-49
A colorimetric method was used to study the variations in the haemolytic rates between red cells from different individuals and with different blood factors. Marked differences were observed between the heterozygous and homozygous genotypes of 18 out of 20 different blood factors and between the B1 or E3 factors, when they occurred in heterozygous genotypes but in different phenogroups. Between MZ twin pairs a continuous variation was found in the haemolytic rates for 17 out of 18 different blood factors, which indicated a quantitative genetic variation depending on individuality, in addition to the dosage- and pheotype-dependent variation.
The similar rankings of the haemolytic rates of the blood factors of the B1 O3 Y2 A'E3 phenotype in red cells from 11 MZ twin pairs suggested their simultaneous regulation. When the haemolytic rates of different blood factors at four or more loci were compared for 15 MZ twin pairs, the ranking results of a given locus were independent of those of the other loci in all pairs, except one. 相似文献
The similar rankings of the haemolytic rates of the blood factors of the B
6.
J Sellei 《Animal blood groups and biochemical genetics》1975,6(1):41-48
The average titre scores varied from zero to 24.7 for the cattle red cells (CRC) from different MZ pairs. These CRC were sensitized with different blood-typing reagents and were titre-tested against the double dilution series of an anti-bovine gamma-globulin serum. A significant negative correlation (r = - 0.82; P less than 0.001) was found between the degree of agglutinability and the amount of neuraminic acid of the surface component of CRC cleaved by pronase. After pronase treatment of the CRC it could be demonstrated that (1) the activity of the V and E'3 blood factors became destroyed; (2) three new specific receptors became evolved; (3) the degree of 'direct' agglutinability due to the A2, O3, W, S2 and Z anti-sera did not parallel with the titre scores obtained in the anti-globulin tests. 相似文献
7.
J. Sellei 《Animal genetics》1975,6(1):49-56
Pronase treatment of cattle red cells produced various effects: (a) an increase in reactivity of the J factor and evolution of a specific cryptoantigen; (b) decrease in the A-B, G2 , K, I2 O2 , O3 , P, Q, T1; Y2 , A, B', E'2 , E'3 , I', K', O'-L'-V-L and M, factors, but (c) no change in the specifity or in the titre of the remaining 16 different blood factors. Most of the pronase-affectable blood factors were destroyed in a rather narrow but characteristic range of pronase treatment intensities. However, at like intensities, variations were demonstrable due to the fact that the blood factor occurred (a) in red cells from different individuals, and (b) in different phenogroups or subgroups of the B locus. 相似文献
8.
Aims: To evaluate the effectiveness of organic acids and supercritical carbon dioxide (SC-CO2 ) treatments as well as their combined effect for the reduction of nonpathogenic Escherichia coli and three pathogenic bacteria in fresh pork.
Methods and Results: The different treatment conditions were as follows: (i) treatment with acetic (1%, 2% or 3%) or lactic acid (1%, 2% or 3%) only, (ii) treatment with SC-CO2 at 12 MPa and 35°C for 30 min only and (iii) treatment with 3% acetic or lactic acid followed by treatment with SC-CO2 . Within the same organic acid concentration, the lactic and acetic acid treatments had similar reductions. For the combined treatment of lactic acid and SC-CO2 , micro-organism levels were maximally reduced, ranging from 2·10 to 2·60 log CFU cm−2 ( E. coli , 2·58 log CFU cm−2 ; Listeria monocytogenes , 2·60 log CFU cm−2 ; Salmonella typhimurium , 2·33 log CFU cm−2 ; E. coli O157:H7, 2·10 log CFU cm−2 ).
Conclusions: The results of this study indicate that the combined treatments of SC-CO2 and organic acids were more effective at destroying foodborne pathogens than the treatments of SC-CO2 or organic acids alone.
Significance and Impact of the Study: The combination treatment of SC-CO2 and organic acids may be useful in the meat industry to help increase microbial safety. 相似文献
Methods and Results: The different treatment conditions were as follows: (i) treatment with acetic (1%, 2% or 3%) or lactic acid (1%, 2% or 3%) only, (ii) treatment with SC-CO
Conclusions: The results of this study indicate that the combined treatments of SC-CO
Significance and Impact of the Study: The combination treatment of SC-CO
9.
Production of clover broomrape seed germination stimulants by red clover root requires nitrate but is inhibited by phosphate and ammonium 总被引:4,自引:0,他引:4
The effect of nutrients (nitrate, ammonium, urea, phosphate and potassium) on the production and/or exudation of germination stimulants for clover broomrape ( Orobanche minor Sm.), a root holoparasite, by its host red clover ( Trifolium pratense L.) was examined using hydroponically grown material. Potassium (K2 SO4 ) concentrations up to 100 mg l–1 (based on K) did not affect the production of germination stimulants by red clover while, in contrast, phosphate (NaH2 PO4 ) was highly inhibitory even at concentrations as low as 1 mg l–1 (based on P). Nitrate (NaNO3 ) markedly promoted stimulant production in a dose-dependent manner from 2 to 50 mg l–1 (based on N). Ammonium [(NH4 )2 SO4 ] had no effect at 2 mg l–1 (based on N) but was inhibitory at higher concentrations. Ammonium is known to be a seed germination inhibitor of root parasites, indicating that ammonium has a dual inhibitory action. Urea had no effect at 2 mg l–1 (based on N) but was promotive at higher concentrations. These results provide a basis for the inhibitory effects of nitrogen fertilizer on infection by root parasitic weeds, broomrapes and witchweeds, and explain why these parasites prevail in areas where there is lower phosphorus availability in soils. 相似文献
10.
Michael Blaut Susanne Peinemann Uwe Deppenmeier Gerhard Gottschalk 《FEMS microbiology letters》1990,87(3-4):367-372
Abstract Everted vesicles of the methanogenic strain Gö1 synthesized ATP in response to methanogenesis from methyl-coenzyme M and H2 . Simultaneously, a transmembrane pH gradient (ΔpH) was generated as evident from fluorescence quenching of acridine orange. Protonophorous uncouplers prevented ΔpH generation and ATP synthesis, but did not affect methanogenesis. The ATP synthase inhibitor diethylstilbestrol (DES) inhibited ATP synthesis but had no effect on methanogenesis and on ΔpH formation, indicating the essential role of the transmembrane proton potential in ATP synthesis. Progress has also been made in assigning specific functions to membrane components in methanogenesis from methyl-CoM and H2 . Separation of cell extracts into cytoplasmic and membrane fraction revealed an essential role of membrane-bound components in electron transfer: methanogenesis catalyzed by the cytoplasmic fraction from strain Gö1 was stimulated several fold by membranes from various methanogens. This stimulation was prevented if the membranes had been treated with oxidants (O2 , K3 [Fe(CN)6 ]) or SH reagents (Ag+ , p -chloromercuribenzoate, iodoacetamide) pointing to the involvement of functional SH groups in methanogenesis from methyl-CoM and H2 . 相似文献
11.
Stefano Predieri Donald T. Krizek Chien Y. Wang Roman M. Mirecki Richard H. Zimmerman 《Physiologia plantarum》1993,87(2):109-117
In vitro shoots of cv. Doyenne ďHiver pear ( Pyrus communis L.) were irradiated under controlled environments for 6 h per day at 5 different levels of biologically effective UV-B radiation (UV-BBE ). UV-B exposure caused a progressive increase in apical necrosis above background levels and stimulated leaf abscission. Shoots grown for 2 weeks at 7. 8 mol m−2 day −1 of photosynthetic photon flux (PPF) and treated with 8. 4 or 12. 0 kJ m−2 day −1 UV-BBE produced up to 4 times more ethylene than those given 2. 2 or 5. 1 kJ m−2 day−1 UV-BBE or untreated controls. Exposure of shoots to 12 kJ m−2 day −1 of UV-BBE caused an increase in free putreseine content after 4 to 14 days of irradiation. Shoots showed a decrease in CO2 uptake after 3 days of UV-B: thereafter, they appeared to recover their photosynthetic capacity. Under typical PPF conditions used in micropropagation (90 μmol m−2 S−1 ). 8. 4 kJ m−2 day −1 of UV-B radiation was injurious to realatively tender tissues of in vitro pear shoots: increasing the level of UV-BBE to 12 kJ m−2 day−1 produced even more adverse effects. 相似文献
12.
Abstract. The physiologically active form of vitamin D3 , 1,25-dihydroxy-vitamin D3 , (1,25(OH)2 , D3 ), induces differentiation of several types of myeloid leukaemia cells. The acquisition of monocyte-like phenotype is accompanied by slower progression through the cell cycle, and G1 , block has been reported to be the basis of this effect. It is shown here that human promyelocytic leukaemia HL60 cells treated with analogues of vitamin D3 , which are potent inducers of monocytic differentiation, have an additional cell cycle block. Exposure to 10-7 m 1,25(OH)2 , D3 , or 1,25-(OH)2 ,-16-ene-D3 resulted in monocytic differentiation and the expected G1 , block evident at approximately 48 h in a rapidly differentiating variant of HL60 cells (HL60-G), and at 96 h in the more slowly differentiating HL60-240 cells. In addition, a G2 ,+M block was noted at approximately 72 h in HL60-G and HL60-240 cells. Exposure to vitamin D3 , analogues also markedly increased the number of dikaryons, suggesting that cytokinesis was impaired more than karyokinesis. Treatment with a third analogue 25-hydroxy-16,23-diene-D3 , produced little differentiation and had minimal effects on the cell cycle parameters. These findings indicate that vitamin D3 , analogues regulate cell proliferation by control of the transition of G1 , and G2 ,+M phases, reminiscent of the cdc2/CDK2 type of cell cycle control. 相似文献
13.
Abstract. The semiochemicals carbon dioxide (CO2 ) and l-octen-3-ol (octenol) were evaluated as attractants at several release rates, alone and in combination, for the major coastal species of biting midges in Georgia: Culicoides furens, C.hollensis and C.melleus (Diptera: Ceratopogonidae). The data show that CO2 is an effective attractant for the females of all three species, but each has a different response pattern. In contrast, octenol was an effective attractant only for C.furens , either alone or in combination with CO2 ; octenol had a repellent effect on the other two species. The combination of octenol and C02 had a synergistic effect on the collections of C.furens. 相似文献
14.
1. The affinity of photosynthesis for CO2 is calculated here as the initial slope of net-photosynthetic rate against concentration of CO2 . The affinity for CO2 for pairs of freshwater macrophytes with similar leaf morphology but able or unable to use HCO– 3 as a carbon source was compared.
2. Species restricted to CO2 had a higher affinity for CO2 than species that were also able to use HCO– 3 when rates were expressed on the basis of area, dry mass and content of chlorophyll a .
3. Published values for the affinity for CO2 and the concentration of CO2 which half-saturated rate of photosynthesis were compiled and compared. Despite a large range of values, affinity for CO2 was greater for species restricted to CO2 than for those also able to use HCO– 3 and statistically different when the slope was expressed on the basis of dry mass and chlorophyll a content.
4. The difference in affinity is consistent with predicted benefits of a high permeability to CO2 for species relying on passive diffusion of CO2 and a lower permeability for species able to use HCO– 3 in order to reduce efflux of CO2 from a high internal concentration generated by active transport.
5. The implications of the different affinities are discussed in terms of species distribution. 相似文献
2. Species restricted to CO
3. Published values for the affinity for CO
4. The difference in affinity is consistent with predicted benefits of a high permeability to CO
5. The implications of the different affinities are discussed in terms of species distribution. 相似文献
15.
The plant fraction of alfalfa ( Medicago sativa L. cv. Aragon) nodules contained both nitrate reductase (NR) and nitrite reductase (NiR). Specific activity of NADH-NR from the cytosol of nodules not treated with NO3 - was about 30 nmol (mg protein)-1- h-1 and was not basically affected by NO3 addition. In contrast, typical specific activity for cytosolic NiR was 1.5 umol (mg protein)-1 h-1 using methyl viologen as electron donor. This activity strongly increased with NO3 concentration, probably due to substrate induction. Maximal activity was 3.5 μmol (mg protein)-1 h-1 at 50 to 200 mM NO3 .
Estimates indicate that the contribution of cytosol to the overall NR and NiR activities of alfalfa nodules is distinctly different: less than 10% and about 70%, respectively. The increasing amounts of NO2 accumulating in the cytosol upon NO3 , supply, and the different response to NO3 of bacteroid and cytosolic NRs support the concept that most of this NO2 comes from the bacteroids. 相似文献
Estimates indicate that the contribution of cytosol to the overall NR and NiR activities of alfalfa nodules is distinctly different: less than 10% and about 70%, respectively. The increasing amounts of NO
16.
ABSTRACT. According to the different reactions to the juvenoid Altosid®, the last larval instar (L5 ) of Laspeyresia pomonella (L.) (Tortricidae) reared under 'long day' conditions (constant light) was subdivided into three sensitive phases: an additional larval instar, a larval–pupal intermediate, or a pupa. Under short day conditions, the prothoracotropic effect of juvenile hormone (JH) in L5 , which have a continuous high titre of JH during the whole instar, indicated that it is not a particular titre of JH but a rise in the titre that can induce the production of moulting hormone. Neck-ligation experiments showed that JH acts not directly on the prothoracic glands but via the head, probably via the neurosecretory system. The meaning of the JH-peak in mature L5 reared under long days was determined either by injections with the anti-JH, precocene II, in combination with applications of Altosid, or by forcing precocene-treated larvae to a precocious moult by injecting them with ecdysterone. Precocene delayed, and JH accelerated pupation if administered 4.5 days after the L5 -moult. JH was also found to stimulate the growth and differentiation of the imaginal discs. Moulting hormone in long-days reared insects was detected one day after the larvae had spun their cocoon, with a maximum on the second day after spinning. The hormone was also present in freshly moulted pupae. Neck-ligation of mature larvae indicated that the delay between activation of the prothoracic glands and the production of an effective amount of moulting hormone is less than one day. 相似文献
17.
The aim of this study was to analyse individual polar lipid analogues, within each lipid family present, of fusobacteria using fast atom bombardment mass spectrometry (FAB-MS). Polar lipid extracts were prepared, washed and dried. Samples, dispersed in a matrix of m -nitrobenzyl alcohol, were analysed by negative ion FAB-MS using xenon as the reagent gas. Major anion peaks observed in the low mass region of mass/charge (m/z), 211, 221, 225, 227, 239, 241, 249, 251, 253, 255, 273, 277, 279, 281, 289 and 291, were consistent with the presence of C13:1 , C14:3 , C14:1 , C14:0 , C15:1 , C15:0 , C16:3 , C16:2 , C16:1 , C16:0 , unknown, C18:3 , C18:2 , C18:1 , unknown and C19:3 carboxylate anions. In the high mass region, major anion peaks observed with m/z 644, 646, 648, 660, 662, 672, 673, 674, 686, 688, 689, 690, 698, 700, 701, 703, 714, 716, 717 and 719 were consistent with the presence of phosphatidylethanolamine (PE) (29:2), PE (29:1), PE (29:0), PE (30:1), PE (30:0), PE (31:2), first isotope of PE (31:2), PE (31:1), PE (32:2), PE (32:1), first isotope peak of PE (32:1), PE (30:0), PE (33:3), PE (33:2), phosphatidylglycerol (PG) (31:3), PG (31:2), PE (34:2), PE (34:1), PG (32:2) and PG (32:1). We conclude that FAB-MS can provide data on individual analogues of PE and PG from Fusobacterium spp. not readily obtained by other means. Furthermore, the phospholipid profile is diagnostic for the genus. 相似文献
18.
CO2 enrichment of soybeans. Effects of leaf/pod ratio 总被引:2,自引:0,他引:2
Mary M. Peet 《Physiologia plantarum》1984,60(1):38-42
The effect of varying leaf number on response of soybean ( Glycine max (L.) Merr. cv. Fiskeby V) to CO2 enrichment was studied. Plants were trimmed at pod set to 15 pods and 1 or 3 leaves (15:1 and 5:1 pod/leaf ratio) and placed in 350 or 1000 μl/l CO2 growth chambers. Photosynthetic rates and dry weights were measured 6 times in all plants at each CO2 concentration over a period of 39 days. Measured at treatment CO2 concentration, photosynthetic rates deelined rapidly in enriched plants, but remained higher than those of non-enriched plants. When all plants were measured at the same CO2 concentration, for most sampling dates, neither growth, CO2 concentration or pod/leaf ratio significantly affected rates of photosynthesis per unit area of comparable leaves. CO2 enrichment significantly increased total weights and pod weights in 15:1 but not 5:1 pod/leaf ratio plants. Plants with a 5:1 pod/leaf ratio had significantly higher total and pod weights than 15:1 ratio plants. Both the photosynthesis and dry weight data suggest that plants in the 5:1 ratio enriched treatment were sink-limited, but plants in all other treatments were source limited. 相似文献
19.
Kirsten Olrik 《Nordic Journal of Botany》1992,12(5):557-568
The distribution of Peridinium willei and P. volzii was studied in Danish lakes. Both species were confined to lakes with concentrations of Total P < 0.15 mg 1-1 , with the majority of occurrences at Total P concentration between 0.020–0.040 mg 1-1 and concentrations of PO4 P between detection limit and 0.040 mg 1-1 . The occurrence of the species in relation to inorganic N compounds (NH4 N and NO2 + NO3 N) was significantly broader for P. willei than for P. volzii: P. willei had an almost even distribution within a wide range of NH4 N, whereas P. volzii mainly occurred between 0.001 and 0.10 NH4 N 1-1 . P. willei had an almost even distribution at values beween 0.005 and 0.42 mg NO2 + NO3 N 1-1 , whereas P. volzii mainly occurred below 0.050 mg NO2 + NO3 N 11 . P. willei was found at pH values between 4.2 and 8.5, whereas P. volzii was confined to lakes with a slightly basic pH. The study confirmed the broad limits of P. willei and the much more narrow limits of P. volzii in relation to seasonal occurrence and pH, as well as an affinity of the former to ponds and lakes with a rich bottom vegetation. The study also showed, however, that the species were not as widespread and common in recent Danish lake phytoplankton as generally stated by previous authors. The use of different ecological factors to give weight to species separation is discussed. The inclusion of P. volzii in P. willei proposed by Popovsky & Phiester is not supported by the present study, as the two taxa appear to have different ecological tolerances. 相似文献
20.
Symbiotic N2 fixation in a high Alpine grassland: effects of four growing seasons of elevated CO2 总被引:1,自引:0,他引:1
J. A. Arnone Iii 《Functional ecology》1999,13(3):383-387
1. Increasing carbon dioxide concentration (E: 680 μl CO2 litre–1 vs ambient, A: 355 μl CO2 litre–1 ) around late-successional Alpine sedge communities of the Swiss Central Alps (2450 m) for four growing seasons (1992–1995) had no detectable effect on symbiotic N2 fixation in Trifolium alpinum —the sole N2 -fixing plant species in these communities (74 ± 30 mg N m–2 year–1 , A and E plots pooled).
2. This result is based on data collected in the fourth growing season showing that elevated CO2 had no effect on Trifolium above-ground biomass (4·4 ± 1·7 g m–2 , A and E plots pooled, n = 24) or N content per unit land area (124 ± 51 mg N m–2 , A and E pooled), or on the percentage of N Trifolium derived from the atmosphere through symbiotic N2 fixation (%Ndfa: 61·0 ± 4·1 across A and E plots) estimated using the 15 N dilution method.
3. Thus, it appears that N inputs to this ecosystem via symbiotic N2 fixation will not be dramatically affected in the foreseeable future even as atmospheric CO2 continues to rise. 相似文献
2. This result is based on data collected in the fourth growing season showing that elevated CO
3. Thus, it appears that N inputs to this ecosystem via symbiotic N