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排序方式: 共有171条查询结果,搜索用时 18 毫秒
1.
Gurunadha Rao VV Rao GT Surinaidu L Rajesh R Mahesh J 《Water, air, and soil pollution》2011,217(1-4):503-514
Coastal lands around Bay of Bengal in Central Godavari Delta are mainly agriculture fields and two times annually paddy crops putting in the study area. Canals of Godavari River are the main source of water for irrigation. Geophysical and geochemical investigations were carried out in the study area to decipher subsurface geologic formation and assessing seawater intrusion. Electrical resistivity tomographic surveys carried out in the watershed-indicated low resistivity formation in the upstream area due to the presence of thick marine clays up to thickness of 20-25?m from the surface. Secondly, the lowering of resistivity may be due to the encroachment of seawater in to freshwater zones and infiltration during tidal fluctuation through mainly the Pikaleru drain, and to some extent rarely through Kannvaram and Vasalatippa drains in the downstream area. Groundwater quality analyses were made for major ions revealed brackish nature of groundwater water at shallow depth. The in situ salinity of groundwater is around 5,000?mg/l and there is no groundwater withdrawal for irrigation or drinking purpose in this area except Cairn energy pumping wells which is using for inject brackish water into the oil wells for easy exploration of oil. Chemical analyses of groundwater samples have indicated the range of salt concentrations and correlation of geophysical and borehole litholog data in the study area predicting seawater-contaminated zones and influence of in situ salinity in the upstream of study area. The article suggested further studies and research work that can lead to sustainable exploitation/use and management of groundwater resources in coastal areas. 相似文献
2.
Ogawa H Chahota R Hagino T Ohya K Yamaguchi T Fukushi H 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2006,68(7):743-745
Although birds infected with avian polyomavirus (APV) subclinically could be a source of infection, no epidemiological studies of APV in psittacine birds have been reported in Japan. In the present study, we investigated subclinical morbidity rate of APV in imported and domestically bred psittacine birds by polymerase chain reaction (PCR). Of 402 live birds from which blood or feather samples were taken between April, 2003 and March, 2004, 11 (2.7%) were found to be APV positive. The DNA sequences of the APV t/T antigen region were determined for five APV-positive randomly selected samples and were found to be conserved. 相似文献
3.
Starch has been the most popular and economic size material. Synthetic binders have also been developed to be used as size material to improve weaving loom efficiency. Some synthetic size materials have got restrictions in use mainly because of ecological reasons. In the recent years, many modifications have come up in the starch as a sizing agent. Different modification can give different properties, which can be suited for a particular application. In the present study, for comparative analysis of different varieties of natural starch, modified starch and synthetic size material have been evaluated and mechanical properties like cohesion power, adhesion power, abrasion resistance, bending rigidity etc. were studied. PVA shows best properties among all size material. Among modified starch, starch ester shows better properties. 相似文献
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5.
Establishment of ornamental and aesthetic plants in hot, arid conditions of India is difficult due to the prevailing climatic, edaphic and biotic factors. Effect of turfgrass on the growth of ornamental plants in hot arid conditions has not been studied so far anywhere in the world. A study was conducted on the campus of Arid Forest Research Institute, Jodhpur, India to assess the performance of a few ornamental plant species in combination with turfgrass and without turfgrass with respect to different soil tilling intervals. Growth of plants was better with turfgrass than without turfgrass. We suggest adopting a soil tilling interval of 30 days to achieve optimum growth of ornamental plant species in terms of height and crown diameter. Our results can help reduce labor costs and achieving better landscapes in fewer days in hot urban conditions of Indian sub continent. 相似文献
6.
G. SivanandhanM. Arun S. MayavanM. Rajesh T.S. MariashibuM. Manickavasagam N. SelvarajA. Ganapathi 《Industrial Crops and Products》2012,37(1):124-129
Calli were obtained from leaf, cotyledon and internode explants of in vitro-grown plants of Indian cultivar of Withania somnifera in MS medium supplemented with 2, 4-D (2.0 mg l−1) and Kinetin (0.2 mg l−1). The brown, semi-friable callus (500 mg FW) derived from leaf explants produced higher number of primary adventitious roots (9 roots/callus) in half strength MS medium fortified with IBA (0.5 mg l−1) and NAA (0.1 mg l−1). The primary adventitious roots with an inoculum mass of 15 g FW were cultured for 6 weeks in the same medium for secondary adventitious root proliferation. Elicitation of abiotic elicitor, aluminium chloride at 10 mg l−1 at the end of 4 weeks culture with 4 h exposure time enhanced withanolides productivity. Under similar culture conditions, the biotic elicitor, chitosan at 100 mg l−1 stimulated higher production of all withanolides when compared to aluminium chloride treatment. This is the first report on the use of callus-derived adventitious root culture for the enhanced production of withanolides upon chitosan elicitation. 相似文献
7.
Alexander Ciji Prakash Sharma Manchi Rajesh Biju S. Kamalam Annu Sharma Pragyan Dash M. S. Akhtar 《Aquaculture Research》2021,52(1):130-141
Periodic changes in reproductive hormone levels, gonadal histology and gonadosomatic index (GSI) of snow trout, Schizothorax richardsonii, were examined to ascertain annual cycle of gonadal development and reproductive status in their natural habitat. In females, there were coherent changes in plasma 17β‐oestradiol and vitellogenin along with GSI, oocyte maturation and vitellogenic progression, collectively indicating two distinct maturation peaks during the months of September and February. Coinciding with this, in males, plasma 11‐keto testosterone was also noticeably higher during September and February, with highest GSI values in September. However, plasma 17α, 20β‐dihydroxyprogesterone levels in males were found to be persistently high from September to February. This observation suggests the potential presence of matured oozing males over a longer period, unlike in females. Overall, the close association between reproductive hormone levels, GSI and gonadal maturation stages in males and females (particularly, the presence of postovulatory follicle complexes) with apparent natural synchronization clearly indicates that S. richardsonii breeds twice in a year, possibly during late September to early November and late February to early April in the coldwater riverine habitats of the Indian Himalayan region. 相似文献
8.
9.
Frederick J. Muehlbauer Seungho Cho Ashutosh Sarker Kevin E. McPhee Clarice J. Coyne P. N. Rajesh Rebecca Ford 《Euphytica》2006,147(1-2):149-165
Summary Lentil is a self-pollinating diploid (2n = 14 chromosomes) annual cool season legume crop that is produced throughout the world and is highly valued as a high protein
food. Several abiotic stresses are important to lentil yields world wide and include drought, heat, salt susceptibility and
iron deficiency. The biotic stresses are numerous and include: susceptibility to Ascochyta blight, caused by Ascochyta lentis; Anthracnose, caused by
Colletotrichum truncatum; Fusarium wilt, caused by
Fusarium oxysporum; Sclerotinia white mold, caused by
Sclerotinia sclerotiorum; rust, caused by
Uromyces fabae; and numerous aphid transmitted viruses. Lentil is also highly susceptible to several species of
Orabanche prevalent in the Mediterranean region, for which there does not appear to be much resistance in the germplasm. Plant breeders
and geneticists have addressed these stresses by identifying resistant/tolerant germplasm, determining the genetics involved
and the genetic map positions of the resistant genes. To this end progress has been made in mapping the lentil genome and
several genetic maps are available that eventually will lead to the development of a consensus map for lentil. Marker density
has been limited in the published genetic maps and there is a distinct lack of co-dominant markers that would facilitate comparisons
of the available genetic maps and efficient identification of markers closely linked to genes of interest. Molecular breeding
of lentil for disease resistance genes using marker assisted selection, particularly for resistance to Ascochyta blight and
Anthracnose, is underway in Australia and Canada and promising results have been obtained. Comparative genomics and synteny
analyses with closely related legumes promises to further advance the knowledge of the lentil genome and provide lentil breeders
with additional genes and selectable markers for use in marker assisted selection. Genomic tools such as macro and micro arrays,
reverse genetics and genetic transformation are emerging technologies that may eventually be available for use in lentil crop
improvement. 相似文献
10.
Young rabbit appendix is a homologue of chicken bursa of Fabricius; both are crucial sites for preimmune B-cell repertoire diversification. Here, we report that appendix regulates precursor lymphocyte recruitment for further development by modulating the sites of extravasation. The total area of peripheral node addressin-positive (PNAd(+)) high endothelial venules (HEVs) increased from 1 day to 1 week after birth, remained constant up to 2 weeks and declined to a low and persistent amount by 3 weeks. In normal 1-week and manipulated 5-week appendix where growth of follicles was retarded, PNAd(+) HEVs were present in the basolateral sides of B-cell follicles whereas, in normal 5-wk-appendix these were restricted to T-cell areas. The PNAd was expressed on the lumenal surface of HEVs. The proportions of CD62L(+) B cells in appendix declined from approximately 40% at 3 days to 2-3% at 4 weeks. In lymphocyte transfer experiments, CD62L(+) B cells were preferentially recruited compared with CD62L(-) B cells, anti-PNAd antibody blocked migration of B cells by approximately 50%, and 100 times more B cells were recruited in 1-week compared to 6-week appendix. Thus, a unique spatiotemporal expression pattern of PNAd(+) HEVs is associated with development of B-cell follicles. This regulates migration of blood-borne B-lymphocytes into developing appendix by interacting with CD62L. 相似文献