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91.
Dr P. P. Srivastava A. K. Bansal R. M. Shukla N. D. Banerjee N. N. Saxena S. S. Sinha 《Mycopathologia》1994,128(2):81-84
The major cuticular components of Indian tasar silkworm,Antheraea mylitta Drury, were sequentially extracted and estimated to ascertain preferential utilization of these components for growth by the entomopathogenic fungusPenicillium citrinum Thom. Proteins which constituted 61.64% dry weight of cuticule were found to play a key role in the growth ofP. citrinum whereas lipids (7.15%) and chitin (30.02%) were least involved. Also, this study suggests absence of any mycocidal substance in the cuticle ofA. mylitta. 相似文献
92.
Role of Neutral Metabolites in Microbial Conversion of 3β-Acetoxy-19-Hydroxycholest-5-Ene into Estrone 下载免费PDF全文
Biotransformation of 3β-acetoxy-19-hydroxycholest-5-ene (19-HCA, 6 g) by Moraxella sp. was studied. Estrone (712 mg) was the major metabolite formed. Minor metabolites identified were 5α-androst-1-en-19-ol-3,17-dione (33 mg), androst-4-en-19-ol-3,17-dione (58 mg), androst-4-en-9α,19-diol-3,17-dione (12 mg), and androstan-19-ol-3,17-dione (1 mg). Acidic metabolites were not formed. Time course experiments on the fermentation of 19-HCA indicated that androst-4-en-19-ol-3,17-dione was the major metabolite formed during the early stages of incubation. However, with continuing fermentation its level dropped, with a concomitant increase in estrone. Fermentation of 19-HCA in the presence of specific inhibitors or performing the fermentation for a shorter period (48 h) did not result in the formation of acidic metabolites. Resting-cell experiments carried out with 19-HCA (200 mg) in the presence of α,α′-bipyridyl led to the isolation of three additional metabolites, viz., cholestan-19-ol-3-one (2 mg), cholest-4-en-19-ol-3-one (10 mg), and cholest-5-en-3β,19-diol (12 mg). Similar results were also obtained when n-propanol was used instead of α,α′-bipyridyl. Resting cells grown on 19-HCA readily converted both 5α-androst-1-en-19-ol-3,17-dione and androst-4-en-19-ol-3,17-dione into estrone. Partially purified 1,2-dehydrogenase from steroid-induced Moraxella cells transformed androst-4-en-19-ol-3,17-dione into estrone and formaldehyde in the presence of phenazine methosulfate, an artificial electron acceptor. These results suggest that the degradation of the hydrocarbon side chain of 19-HCA does not proceed via C22 phenolic acid intermediates and complete removal of the C17 side chain takes place prior to the aromatization of the A ring in estrone. The mode of degradation of the sterol side chain appears to be through the fission of the C17-C20 bond. On the basis of these observations, a new pathway for the formation of estrone from 19-HCA in Moraxella sp. has been proposed. 相似文献
93.
B. L. Srivastava M. Cooper R. T. Mullins 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1994,87(6):627-640
An objective of the CSR sugarcane breeding programme in Australia was to assess the scope for broadening the genetic base of the commercial sugarcane germ plasm through interspecific hybridization with Saccharum spontaneum clones. The contribution of both selection history and S. spontaneum to sugar yield and its components was investigated in the germ plasm pool assembled. The analysis was conducted on a data-set of 256 clones, consisting of parents and full-sib families generated from 32 biparental crosses, tested in six environments. The minimum number of generations back to S. spontaneum ancestor in the clone's pedigree was used as a germ plasm score. The geographical origin and selection history of each parent and their use in the biparental crosses were used to develop a selection history score for parents and offspring. The variation for seven attributes, cane yield, commercial cane sugar %, sugar yield, stalk number per stool, stalk weight, fibre % and ash % juice was partitioned according to the germ plasm and selection history scores. Significant (P<0.05) clone variation and clone x environment interaction for all attributes was present. The germ plasm scores accounted for a significant (P<0.05) component of the clone variation for all of the attributes except cane yield. There was an increase in sugar yield with an increase in the minimum number of generations back to a S. spontaneum clone. The selection history groups accounted for a high proportion of the variation among parental clones for all of the attributes except cane yield. This suggested that parents were the outcome of strong selection pressure for the commercial cane attributes. However, the selection history groups for the offspring produced by random mating of parents did not account for a high proportion of the variation for the attributes. Using the mixture method of classification we partitioned the 256 clones into five groups for patterns of performance for the seven attributes across the six environments. The five groups emphasized major differences in the patterns of performance for the seven attributes across environments. The distribution of germ plasm and selection history scores in each of the five groups indicated that their patterns of performance were associated with selection history and minimum generations to S. spontaneum. Therefore, both the analysis on selection history and germ plasm scores (extrinsic classification) and the analysis on the mixture method of classification (intrinsic classification) emphasized the influence of selection history on the sugar yield of sugarcane. 相似文献
94.
95.
Carola Borries Volker Sommer Arun Srivastava 《International journal of primatology》1994,15(3):421-443
We studied grooming among adults of a one-male multifemale troop of free-ranging Hanuman langurs (Presbytis entellus)living near Jodhpur, India, for 9 years. The 11–13 females devoted about 6% of their day to allogrooming. Adult males, whose
tenures averaged 2.2 years, were transient figures in the troop's history, as reflected by their rather peripheral role in
the grooming network. Females groomed males 4–40 times more frequently (1006 episodes) than vice versa- (176 episodes). Adult
females received 97% of all grooming from other adult females (6655 episodes). Although females exhibited an age- inversed
dominance hierarchy, they did not compete for grooming access to particular troop mates. Dyads of all possible rank differences
occurred as frequently as expected: 51% of grooming was directed up the hierarchy and 49% down it. Young, high- ranking individuals
gave and received significantly more grooming than the oldest, low- ranking females did. The pattern seemed to be influenced
by kin selection because of the presumably high degree of female relatedness. They invested most in troopmates with the highest
reproductive value, i.e., the youngest individuals. This trend was coupled with a preference of closest kin (mothers and daughters).
Reciprocity was the outstanding feature since all adult females groomed and were groomed by all others. Such a tight social
net might establish the necessary cohesion during frequent territorial disputes with neighboring troops. 相似文献
96.
Q. M. R. Haq K. M. Srivastava R. K. Raizada B. P. Singh R. K. Jain A. Mishra D. D. Shukla 《Journal of Phytopathology》1994,140(1):55-64
Biological, serological and coat protein properties of a potyvirus (Poty-Rape) causing a mosaic disease of Brassica campestris and B. juncea in India were investigated. The virus readily infected 4 of the 5 plant species in the family Brassicaceae in which it induced severe systemic mosaic symptoms; it also induced chlorotic and necrotic local lesions in Chenopodium amaranticolor , but failed to infect 4 other species of Chenopodiaceae or 20 species of Amaranthaceae, Apiaceae, Canabinaceae, Compositae, Cucurbitaceae, Euphorbiaceae, Leguminosae and Solanaceae. The virus was transmitted in a non-persistant manner by Myzus persicae, Brevicoryne brassicae and Aphis gossypii. The Average size, of the virus particles in a purified preparation was 740 nm × 12 nm. SDS-PAGE analysis of the viral coat protein showed two major bands of approximately 37 kDa and 31 kDa, a pattern very similar to that of a reference isolate of turnip mosaic virus (TuMV) from the U.S. In Western-blot immunoassay, an antiserum to TuMV reacted with both the coat protein bands of the Poty-Rape islate and the reference TuMV, but not with the coat proteins of four other potyviruses. The high performance liquid chromatographic profile of tryptic peptides from the coat protein of Poty-Rape was found to be very similar to that of the reference TuMV, but differed substantially from those of four other potyviruses. The Poty-Rape isolate is considered to be a distinct strain of, TuMV. 相似文献
97.
Christopher M. R. Bax Vijai S. Shankar A. S. M. Towhidul Alam Bridget E. Bax Baljit S. Moonga Christopher L. -H. Huang Mone Zaidi Barry R. Rifkin 《Bioscience reports》1993,13(3):169-174
We report the effects of tetracycline analogues on cytosolic Ca2+ transients resulting from application of ionic nickel (Ni2+), a potent surrogate agonist of the osteoclast Ca2+ receptor. Preincubation with minocycline (1 mg/l) or a chemically modified tetracycline, 4-dedimethyl-aminotetracycline (CMT-1) (1 or 10 mg/l), resulted in a significant attenuation of the magnitude of the cytosolic [Ca2+] response to an application of 5 mM-[Ni2+]. Preincubation with doxycycline (1 or 10 mg/l) failed to produce similar results. In addition, application of minocycline alone (0.1–100 mg/l) resulted in a 3.5-fold elevation of cytosolic [Ca2+]. The results suggest a novel action of tetracyclines on the osteoclast Ca2+ receptor. 相似文献
98.
99.
Cycling of six mineral elements (N, P, K, Na, Ca and Mg) was studied in a humid subtropical grassland at Cherrapunji, north-eastern
India during 1988-1989. Elemental concentrations in the shoot of four dominant grass species,viz., Arundinella khaseana, Chrysopogon gryllus, Eragrostiella leioptera andEulalia trispicata were very low, and none of the species appears suitable for fodder use. Among different vegetation compartments, live root
was the largest reservoir of all the nutrients (except Ca) followed by live shoot, dead shoot, litter and dead root. For Ca,
live shoot was the major storage compartment. The total annual uptake (kg ha-1) was 137.3, 10.4, 51.1, 5.5, 8.7 and 18.2 for N, P, K, Na, Ca and Mg, respectively. In an annual cycle 98% N, 77% P, 49%
K, 109% Na, 87% Ca and 65% Mg returned to the soil through litter and belowground detritus. A major portion of N, P and Na
was recycled through the belowground system, whereas nearly half of K, Ca and Mg was recycled through the shoot system. Precipitation
acts as the source of N and P input, but at the same time causes loss of cations. 相似文献
100.
Lahiri V. L. Srivastava R. K. Hazra D. K. Gupta A. K. Painuly N. K. Sharma S. K. Khanna-Hazra P. Khanna P. Gupta R. K. Pathak Manish 《Cell biochemistry and biophysics》1994,24(1-3):9-14
Cell Biochemistry and Biophysics - Despite attempts to maintain asepsis, good manufacturing practices, and the use of terminal sterilization by millipore filtration, the nuclear practitioner is... 相似文献