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排序方式: 共有60条查询结果,搜索用时 31 毫秒
21.
22.
Ramakrishnan MA Velayudhan BT Anantharaman S Noll SL Halvorson DA Nagaraja KV Goyal SM 《Avian diseases》2007,51(4):979-981
A commercial live attenuated, freeze-dried avian metapneumovirus vaccine, Pneumomune, was assessed for its viability at three different temperatures (5.6 C, 21 C, and 37 C). No significant reduction in virus titer was observed when the vaccine was stored at 5.6 C for a period of 24 hr. However, reductions in virus titer of 1 log10 and 2 log10 were observed after 24 hr at 21 C and 37 C, respectively. Batch-to-batch variation in virus reduction was also observed. The addition of a dye or a vaccine stabilizer to the vaccine preparation did not have any deleterious effect on the survival of vaccine virus. 相似文献
23.
Periyasamy Rathinapriya Lakkakula Satish Subramani Pandian Ramakrishnan Rameshkumar Manoharan Balasangeetha Kasinathan Rakkammal 《Journal of plant nutrition》2020,43(19):2857-2875
Abstract In recent decades, chemical fertilizers create a thread to organic agriculture and food security. To overcome this issue, the present study aimed to investigate the influence of liquid seaweed extracts (LSEs) prepared from Padina boergesenii (PB) and Gracilaria edulis (GE) on growth, development, biochemical characteristics and yield traits of foxtail millet. The various concentrations of individual (20, 40, 60, and 80%; v/v) and combined (10?+?10, 20?+?20, 30?+?30, and 40?+?40%; v/v) PB and GE LSEs were supplied through foliar spray method. The results imply that germination bioassays, vegetative plant growth were significantly increased in lower concentration of LSEs. Further, exposure of foxtail plants to combined foliar spray application of (20?+?20%; v/v) LSEs enriched photosynthetic pigments, total soluble sugar and total soluble protein, compared with single LSEs and control foliar spray methods. Additionally, LSEs enhanced the yield attributes such as the average number of seeds (971.5/panicle) and mean length of panicle (18.4?cm) in PB?+?GE LSEs (20?+?20%; v/v) treatment. This is the first report, to assess the synergistic biostimulant ability of PB and GE LSEs in plant growth, quality improvement and yield attributes of foxtail millet. In conclusion, this present study suggests that combination of PB?+?GE LSEs foliar spray application could serve as an ideal biostimulant and a potential alternate to hazards chemical fertilizer in the green agriculture. 相似文献
24.
Assessment of surface and sub-surface waterlogged areas in irrigation command areas of Bihar state using remote sensing and GIS 总被引:1,自引:0,他引:1
V.M. Chowdary R. Vinu Chandran N. Neeti R.V. Bothale Y.K. Srivastava P. Ingle D. Ramakrishnan D. Dutta A. Jeyaram J.R. Sharma Ravindra Singh 《Agricultural Water Management》2008,95(7):754-766
Satellite remote sensing coupled with Geographical Information Systems (GIS) offers an excellent alternative to conventional mapping techniques in monitoring and mapping of surface and sub-surface waterlogged areas. In the present study, pre-monsoon and post-monsoon surface waterlogged areas were delineated in all the 132 irrigation command areas of the Bihar State, India using Indian Remote Sensing (IRS-1D) Linear Imaging Self Scanning Sensor (LISS-III) data acquired during the period 2002–2003. Normalized Difference Water Index (NDWI) was used primarily to delineate surface waterlogged areas. Perennial waterlogged and seasonal waterlogged areas were identified for the study area by integrating the waterlogged areas derived for both the pre- and post-monsoon seasons under GIS environment. Results show that the total surface waterlogged area in Bihar is 628 × 103 ha, which is 10.57% of command area (5939 × 103 ha) and spread over 132 command areas. Perennial surface inundation covers 2.95% of the waterlogged area in all the command areas. Maximum waterlogged area is observed in Gandak command (212 × 103 ha) followed by Eastern Kosi irrigation scheme (116 × 103 ha) and Sone modernization scheme (82 × 103 ha), respectively. Further, waterlogged areas induced by rise in groundwater level were also assessed spatially under GIS environment using the ground water level data pertaining to pre- and post-monsoon seasons of the year 2002–2003 which were spread all over the study area. The analysis of pre- and post-monsoon groundwater levels indicates that the area under non-critical category during pre-monsoon period was reduced from 4287 × 103 ha (72.72% of command) to 1391 × 103 ha (23.42%) in the post-monsoon. Area under most critical category during post-monsoon period increased from 0.083 × 103 ha of command area in pre-monsoon period to 50 × 103 ha. The study demonstrates utility of integration of remote sensing and GIS techniques for assessment of waterlogged areas particularly in regions where waterlogging conditions occur both due to excessive irrigation and accumulation of rain and floodwaters. 相似文献
25.
Sundaram Ganesh Ram V. Thiruvengadam S. Hari Ramakrishnan J. R. Kannan Bapu 《Euphytica》2008,159(1-2):241-248
Interspecific hybridisation has played significant role in the improvement of economically useful traits such as productivity,
earliness, fibre quality and resistance to pests and diseases in cotton. However, wide crosses are often limited by the operation
of either pre or/and post-fertilization barriers. The present study on pollen tube behaviour of four diploid wild species
viz., G. triphyllum, G. davidsonii, G. thurberi and G. armourianum in the pistils of G. barbadense was taken up to determine the extent of pre-zygotic barriers operating in these crosses. High rate of pollen germination
(∼80%) and normal growth of pollen tubes were observed upon selfing of both G. barbadense and four wild species. Pollen tubes reached the pistils and fertilization was accomplished within 8 HAP in all the five parental
species. In the interspecific crosses, pollen germination was normal in the cross involving G. armourianum and drastically inhibited in the crosses involving G. triphyllum, G. davidsonii and G. thurberi. Even though delayed pollen tube growth was a general feature in all the four crosses, successful fertilization was observed
only in the cross involving G. armourianum. In crosses involving G. triphyllum, G. davidsonii and G. thurberi, pollen tubes failed to reach the ovary even at 24 HAP due to the presence of strong stylar and ovarian incompatibility.
Abnormalities in pollen tubes such as swelling, twisting, intense callose plug formation, breakage, branching and reverse
orientation were frequently observed among the incompatible crosses. 相似文献
26.
S. Ganesh Ram S. Hari Ramakrishnan V. Thiruvengadam J. R. Kannan Bapu 《Plant Breeding》2008,127(3):295-300
Interspecific hybridization among species of cotton has lead to improvement in productivity, earliness, fibre quality and resistance to pests and diseases. However, wide crosses is often limited by the operation of either pre‐ or/and post‐fertilization barriers. An investigation on pollen tube behaviour of four wild species in the pistils of Gossypium hirsutum was taken up. Pollen germination was normal in crosses involving Gossypium triphyllum and Gossypium armourianum and markedly inhibited in the crosses involving Gossypium davidsonii and Gossypium thurberi. Pollen tubes reached the pistils and fertilization was accomplished within 8 h after pollination (HAP) in control cross. Even though delay in pollen tube was a common phenomenon in all the four crosses successful fertilization was observed in crosses involving G. triphyllum and G. armourianum, as they reached the ovary at 24 HAP. In crosses with G. davidsonii and G. thurberi, pollen tubes failed to reach the ovary even at 24 HAP indicating the presence of strong stylar and ovarian incompatibility. Measures to overcome such barriers to interspecific hybridization in the incompatible crosses are discussed. 相似文献
27.
Khulape Sagar A. Maity Hemanta Kumar Pathak Dinesh Chandra Ramamurthy Narayan Ramakrishnan Saravanan Chellappa Madhan Mohan Dey Sohini 《Tropical animal health and production》2019,51(8):2529-2538
Tropical Animal Health and Production - The low potency of genetic immunization has to date impeded development of commercial vaccines against major infectious diseases. The aim of this study was... 相似文献
28.
Raj Kumar Singh Kuldeep Dhama Muthannan Andavar Ramakrishnan Kumaragurubaran Karthik Ruchi Tiwari 《The Veterinary quarterly》2016,36(3):150-175
This review converses the Zika virus which has attained global concern due to its rapid pandemic potential and impact on humans. Though Zika virus was first isolated in 1947, till the recent large-scale outbreak which occurred in Micronesia, in 2007, the virus was placed into the innocuous pathogen category. The World Health Organization on 1 February 2016 declared it as a ‘Public Health Emergency of International Concern.’ Of the note, American as well as Pacific Island strains/isolates is relatively closer to Asian lineage strains. The African and American strains share more than 87.5% and 95% homologies with Asian strains/isolates, respectively. Asian strains form independent clusters, except those isolated from China, suggesting relatively more diversity than African strains. Prevention and control are mainly aimed at the vector population (mosquitoes) with Aedes aegypti being the main species. Surveys in Africa and Asia indicated seropositivity in various animal species. However, so far its natural reservoir is unknown. There is an urgent need to understand why Zika virus has shifted from being a virus that caused mild illness to unforeseen birth defects as well as autoimmune-neurological problems. Unfortunately, an effective vaccine is not available yet. Availability of cryo-electron microscopy based on 3.8 Å resolution revealing mature Zika virus structure and the probable virus attachment site to host cell would provide critical insights into the development of antiviral treatments and vaccines. 相似文献
29.
Distribution of protein and RNA in the 30S ribosomal subunit 总被引:1,自引:0,他引:1
V Ramakrishnan 《Science (New York, N.Y.)》1986,231(4745):1562-1564
In Escherichia coli, the small ribosomal subunit has a sedimentation coefficient of 30S, and consists of a 16S RNA molecule of 1541 nucleotides complexed with 21 proteins. Over the last few years, a controversy has emerged regarding the spatial distribution of RNA and protein in the 30S subunit. Contrast variation with neutron scattering was used to suggest that the RNA was located in a central core of the subunit and the proteins mainly in the periphery, with virtually no separation between the centers of mass of protein and RNA. However, these findings are incompatible with the results of efforts to locate individual ribosomal proteins by immune electron microscopy and triangulation with interprotein distance measurements. The conflict between these two views is resolved in this report of small-angle neutron scattering measurements on 30S subunits with and without protein S1, and on subunits reconstituted from deuterated 16S RNA and unlabeled proteins. The results show that (i) the proteins and RNA are intermingled, with neither component dominating at the core or the periphery, and (ii) the spatial distribution of protein and RNA is asymmetrical, with a separation between their centers of mass of about 25 angstroms. 相似文献
30.
Ogle JM Brodersen DE Clemons WM Tarry MJ Carter AP Ramakrishnan V 《Science (New York, N.Y.)》2001,292(5518):897-902
Crystal structures of the 30S ribosomal subunit in complex with messenger RNA and cognate transfer RNA in the A site, both in the presence and absence of the antibiotic paromomycin, have been solved at between 3.1 and 3.3 angstroms resolution. Cognate transfer RNA (tRNA) binding induces global domain movements of the 30S subunit and changes in the conformation of the universally conserved and essential bases A1492, A1493, and G530 of 16S RNA. These bases interact intimately with the minor groove of the first two base pairs between the codon and anticodon, thus sensing Watson-Crick base-pairing geometry and discriminating against near-cognate tRNA. The third, or "wobble," position of the codon is free to accommodate certain noncanonical base pairs. By partially inducing these structural changes, paromomycin facilitates binding of near-cognate tRNAs. 相似文献