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161.
Stability of Perovskite (MgSiO3) in the Earth's Mantle 总被引:1,自引:0,他引:1
SK Saxena LS Dubrovinsky P Lazor Y Cerenius P Haggkvist M Hanfland J Hu 《Science (New York, N.Y.)》1996,274(5291):1357-1359
Available thermodynamic data and seismic models favor perovskite (MgSiO3) as the stable phase in the mantle. MgSiO3 was heated at temperatures from 1900 to 3200 kelvin with a Nd-YAG laser in diamond-anvil cells to study the phase relations at pressures from 45 to 100 gigapascals. The quenched products were studied with synchrotron x-ray radiation. The results show that MgSiO3 broke down to a mixture of MgO (periclase) and SiO2 (stishovite or an unquenchable polymorph) at pressures from 58 to 85 gigapascals. These results imply that perovskite may not be stable in the lower mantle and that it might be necessary to reconsider the compositional and density models of the mantle. 相似文献
162.
Sclerospora graminicola (Sacc.) Schroet., the obligate pathlogen causing downy mildew (green-ear) of pearl millet (Pennisetum typhoides Stapf. and Hubb.) has been successfully cultured for the first time on a known semisynthetic mediumn with no evident loss of fructifications. Sclerospora graminicola was first grown on host callus tissue and subsequently on a modification of White's basal medium that contained casein hydrolyzate (Oxoid). 2,4-dichlorophenoxyacetic acid, and kinetin. 相似文献
163.
D. R. Malaviya A. K. Roy P. Kaushal B. Kumar A. Tiwari C. Lorenzoni 《Plant Breeding》2004,123(6):536-542
This is the first report on the development of interspecific hybrids between Trifolium alexandrinum and T. apertum using embryo rescue and characterization of F1 plants. T. apertum was used as the male parent and T. alexandrinum as the female parent. Development of interspecific hybrids under natural conditions is not successful and so embryo rescue was attempted. Of the several combinations tried, pollination 2 days after emasculation and embryos rescued 11 days after pollination was found to be the best. For embryo culture, EC3 medium consisting of MS basal supplemented with 2.3 μM kinetin and 3% sucrose was used. Germinated embryos were transferred to LSP3 medium 25 days after inoculation wherein most of the cultures showed multiple shoots that were split and subcultured on RL1 medium for rooting. After hardening, about 75% of hybrids were successfully transferred to the field. The hybrids, in general, showed morphological traits intermediate between the two parents; however, a few hybrids showed better growth than either parent. Some F1 plants were almost 3 weeks later in flowering than the female parent. Pollen fertility among these plants ranged from 78 to approximately 100%. Chromosomal associations at diakinesis and isozyme banding patterns for acid phosphatase (ACP), superoxide dismutase (SOD) and peroxidase also confirmed the hybrid nature of the plants. 相似文献
164.
DO Kleemann JM Kelly LJ Arney IL Farley AJ Tilbrook SK Walker 《Reproduction in domestic animals》2014,49(6):894-898
Poor reproductive performance of Merino ewe flocks when mated to Border Leicester rams during spring may be due to seasonality of the Border Leicester breed. Two approaches were taken to test this assumption. Six young (12 months old) or six mixed‐age (12, 24 and ≥36 months old) Border Leicester rams were either treated or not treated with melatonin implants (2 × 2 design) 6 weeks before the four groups of rams were each put with approximately 300 Merino ewes for an 8‐week mating period. Implants were inserted in early September (experiment 1). The second approach was to yard or not yard ewes and mixed‐age rams on several occasions during the first 3 weeks of the mating period (experiment 2). Pregnancy rate and twinning percentage were assessed by ultrasonography. In experiment 1, melatonin treatment in young rams increased (p < 0.001) pregnancy rate from 5.0% to 92.6%, but mixed‐age rams did not respond (90.7% vs 89.5% for melatonin and non‐melatonin treatments, respectively). Twinning rate was similar (p > 0.05) for ewes mated to either melatonin or non‐melatonin‐treated young rams (36.8% vs 40.0%, respectively), whereas melatonin significantly improved (p < 0.05) twinning rate in those ewes mated to mixed‐age rams (49.1% vs 36.1%). After 6 weeks of melatonin treatment, scrotal circumference was greater (p < 0.05) in both young and mixed‐aged rams than in untreated counterparts. In experiment 2, yarding of ewes and rams overnight on several occasions early in the mating period reduced (p < 0.001) pregnancy rate compared with non‐yarded counterparts (89.5% vs 65.5%). Twinning rate was not affected (37.7% vs 36.1%, respectively). In summary, melatonin treatment of Border Leicester rams significantly improved flock reproductive performance in spring due to improved pregnancy rates with young rams and improved litter size with mixed‐age rams. 相似文献
165.
ABSTRACT The study aimed to improve the nutritional quality of wafers by utilizing fish powder developed from small bony fish at 10%, 20%, and 30% inclusion levels. Quality evaluation of produced wafers in terms of nutritional, physical, sensory, and shelf life characteristics was performed. Results revealed a significant increase (p < .05) in protein (8.07 ± 0.34 to 23.34 ± 0.43 g/100 g), fat (1.08 ± 0.85 to 4.69 ± 0.78 g/100 g), and ash content (3.67 ± 0.47 to 8.33 ± 0.30 g/100 g) of wafers with increased supplementation of fish powder. No significant change in diameter, thickness, or weight per wafer was observed; however, water absorption capacity (212.67 ± 2.52 to 71.67 ± 2.89 ml/100 g), fat absorption capacity (164.00 ± 3.60 to 66.00 ± 5.29 ml/100 g), and linear expansion (139.17 ± 6.16 to 76.40 ± 2.11%) reduced significantly (p < .05) on increasing level of fish powder in the produced wafers. Color analyses revealed a significant decrease in L* (89.57 ± 1.25 to 46.89 ± 1.06) and b* (7.25 ± 0.09 to 18.59 ± 0.8) value and significant increase in a* value (?0.54 ± 0.01 to 3.87 ± 0.03) with increasing fish powder supplementation. There was no significant (p > .05) alteration in sensory attributes of wafers with fish powder incorporation up to 20%. The produced wafers also had good storage stability, with peroxide value, free fatty acid, and total plate count within acceptable limits up to two months of storage. 相似文献
166.
Lakshman Santra R.S. Rajmani G.V.P.P.S. Ravi Kumar Shikha Saxena Sujoy K. Dhara Amit Kumar Aditya Prasad Sahoo Lakshya Veer Singh G.S. Desai Uttara Chaturvedi Sudesh Kumar Ashok K. Tiwari 《Research in veterinary science》2014
The Non-Structural protein 1 of Canine Parvovirus-2 (CPV2.NS1) plays a major role in viral cytotoxicity and pathogenicity. CPV2.NS1 has been proven to cause apoptosis in HeLa cells in vitro in our laboratory. Here we report that CPV2.NS1 has no toxic side effects on healthy cells but regresses skin tumors in Wistar rats. Histopathological examination of tumor tissue from CPV2.NS1 treated group revealed infiltration of mononuclear and polymorphonuclear cells with increased extra cellular matrix, indicating signs of regression. Tumor regression was also evidenced by significant decrease in mitotic index, AgNOR count and PCNA index, and increase in TUNEL positive apoptotic cells in CPV2.NS1 treated group. Further, CPV2.NS1 induced anti-tumor immune response through significant increase in CD8+ and NK cell population in CPV2.NS1 treated group. These findings suggest that CPV2.NS1 can be a possible therapeutic candidate as an alternative to chemotherapy for the treatment of cancer. 相似文献
167.
Arvind Tiwari Vijai Pal Prachiti Afley Deepak Kumar Sharma Chandra Shekhar Bhatnagar Bhupendra Bhardwaj Ganga Prasad Rai Subodh Kumar 《Tropical animal health and production》2014,46(8):1519-1522
Bovine brucellosis is endemic in many parts of the world including India. The disease diagnosis and surveillance are usually carried out by serological tests, which however have drawbacks. This study was undertaken to evaluate the potential of real-time PCR (RT-PCR) targeting bcsp31 gene for surveillance of bovine brucellosis. A total of 461 samples, which included 408 stored serum and 53 prospective blood samples, were used. It was found that 33 (7.15 %) samples were positive by RT-PCR, whereas 149 (32.32 %) and 132 (28.63 %) were positive by Rose Bengal plate test (RBPT) or standard agglutination test (STAT), respectively. The results of this study suggest that RT-PCR targeting bcsp31 gene carried out on DNA extracted from serum or blood may not be a suitable method for surveillance of brucellosis in bovines. 相似文献
168.
A. K. Joshi M. Azab M. Mosaad M. Moselhy M. Osmanzai S. Gelalcha G. Bedada M. R. Bhatta A. Hakim P. K. Malaker M. E. Haque T. P. Tiwari A. Majid M. R. Jalal Kamali Z. Bishaw R. P. Singh T. Payne H. J. Braun 《Euphytica》2011,179(1):187-196
An important step towards reducing the vulnerability of wheat in Africa and Asia to the Ug99 race of the stem rust pathogen is the substitution of current susceptible varieties with superior resistant varieties. In the 2008?C2009 cropping season both seed multiplication and dissemination of Ug99 resistant varieties were initiated in Afghanistan, Bangladesh, Egypt, Ethiopia, Iran, India, Nepal and Pakistan. Ug99 resistant varieties must occupy about 5% of the area sown to wheat in each country to ensure sufficient seed to displace current popular varieties. Because of the underdeveloped seed industry and small farm sizes in most of these countries, various strategies are being applied for rapid multiplication and dissemination of resistant varieties. Approaches being used include pre-release seed multiplication while candidate resistant lines are being tested in national evaluation trials and farmer participatory selection. Resistant varieties are already released in Afghanistan, Bangladesh, Egypt and Pakistan and more varieties are expected to be released in 2010 in these and other countries. Our results show that some new Ug99 resistant lines have yield superiority over dominant local varieties. Activities and progress in seed multiplication using existing and new Ug99 resistant varieties are discussed. 相似文献
169.
S. K. Chakrabarti B. P. Singh Garima Thakur Jagesh K. Tiwari S. K. Kaushik Sanjeev Sharma Vinay Bhardwaj 《Potato Research》2014,57(1):1-11
Several quantitative trait loci (QTL) for resistance to late blight have been reported in diploid potatoes. The diploid wild potato species Solanum chacoense possesses a high degree of horizontal resistance to late blight. In the present study, we report on QTL mapping for late blight resistance in a diploid mapping population of 126 F1 of Solanum spegazzinii (susceptible) × S. chacoense (resistant). The area under the disease progress curve (AUDPC) values for late blight resistance using the “whole plant in vitro assay” and the “detached leaf assay” on the mapping population displayed quantitative variation. Out of 64 AFLP primer-pairs combinations and SSR markers, a total of 209 significant AFLP loci were placed onto the 12 linkage group of potato covering a total map length of 6548.1 cM. QTL analysis based on the AUDPC dataset of the “whole plant in vitro assay” using the interval-mapping option identified two QTL (LOD?>?2.5) located on linkage groups IX and X, which explained 14.70 and 3.40% variation, respectively. The present study revealed the presence of potential new genetic loci in the diploid potato family contributing to quantitative resistance against late blight. 相似文献
170.