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Kabamoto S Bhagat NA Suzuki H You M Kamio T Tsuji N Claveria FG Nagasawa H Igarashi I Toyoda Y Fujisaki K 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2002,64(4):355-359
Using macrophage scavenger receptor-A knockout (SRKO) mice, we examined the role of macrophage class A scavenger receptors (MRS-A) on the immune response and acquisition of host resistance against repeated infestation with Haemaphysalis longicornis. Except for one batch of nymphs that infested one of the SRKO (SR-/-) mice and showed no appreciable reduction in body weight, all the other groups of nymphs manifested significant decrease in body weight. Both SR-/- and wild type (SR+/+) mice showed a sustained increase in anti-tick antibody titers, but SR+/+ mice showed significantly higher titers. The IFN-gamma assayed in SR-/- mouse immune sera was substantially less compared with that in SR+/+ mice. Immune sera from SR-/- and SR+/+ mice recognized the 51 and 44 kDa, and 44 kDa proteins, respectively, of the salivary gland antigen. The difference in the level of anti-tick resistance manifested by both groups of mice may be influenced by less efficient trapping and processing of tick antigens by macrophages in mice lacking for the macrophage scavenger receptors, and consequently affected the cascade of Th1 and Th2 responses. We have thus obtained valuable data that strongly infer the role of MSR-A in enhancing host defense against repeated infestation with H. longicornis. 相似文献
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Gregory D. Bowie Andrew A. Millward Nikesh N. Bhagat 《Urban Forestry & Urban Greening》2014,13(4):742-755
Geographic Information Systems (GIS) and web-based GIS platforms are typically used by large organizations and government agencies for the purpose of data storage, query, analysis, and spatial data mapping. Google Fusion Tables, however, provides cloud-based computing services for data management and easy user collaboration through the Google Maps interface. Fusion Tables are oriented towards smaller organizations that previously were unable to publish data online due to limitations of database knowledge, high cost of start-up, and restrictions on implementation. In this research project, we assess the functionality and limitations of Fusion Tables and associated API as a spatial data management system by programming an interactive web-based mapping platform, the CityTrees.ca Project, designed to showcase the benefits of trees growing on the campus of Ryerson University, Toronto. Specifically, Fusion Tables functionality, such as data storage and manipulation, is used to build a query interface (both attribute and spatial) that permits users of CityTrees.ca to search for and map trees by species, diameter, height, and location. We found that Fusion Tables performed well as a storage medium for our campus tree data, which could easily be explored through our creation of a JavaScript-enabled query tool. Our project provides a unique roadmap for small to medium-sized urban forestry organizations and environmental non-profits seeking to create interactive mapping applications where data privacy and advanced spatial analysis are not fundamental. 相似文献
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Pradeep K. Sharma J. K. Ladha T. S. Verma R. M. Bhagat A. T. Padre 《Biology and Fertility of Soils》2003,37(2):108-114
Imbalanced and inadequate use of chemical fertilizers is responsible for low rice- (Oryza sativa L.) wheat (Triticum aestivum L.) productivity in many resource-poor farmers' fields. Wheat yields in post-rice soils are also constrained due to soil conditions created by puddling in rice, especially in fine to medium textured soils. Organic amendments are known to improve soil productivity under rice-wheat cropping by way of improving physical conditions and nutrient status of the soil, but their availability is restricted. There is a need to identify locally available and cost-effective organic materials, which have minimal alternate uses as fodder and fuel. We evaluated lantana (Lantana spp. L.) residues, a fast-growing weed in nearby wastelands, as a potential soil organic amendment. Yield trends, and soil and crop nutrient status in a 12-year rice-wheat experiment at Palampur, India, involving four levels (0, 10, 20, and 30 Mg ha-1 year-1 fresh mass) of lantana addition were investigated. Chopped lantana was incorporated into soil 10–15 days before puddling. Lantana additions at 10, 20 and 30 Mg ha-1 increased rice yields on average by 18%, 23% and 30%, wheat yields by 11%, 14% and 20%, and total system productivity (rice + wheat) by 15%, 20% and 26% over controls, respectively, and at the same time saved NPK fertilizer. Linear regression analyses over 12 years did not show any change in yield trends of rice and wheat at P =0.05. Continuous cultivation of rice-wheat significantly increased total C, labile C, and other C indices of soils. Total N, Olsen's P, and NH4OAc-extractable K in the lantana-amended plots were higher than in the controls. Nutrient concentrations in crop biomass, however, remained generally unaffected by lantana treatments. Results suggest that lantana residues, which improved the nutrient status of soil and system yield, have the potential for resource conservation and sustaining rice-wheat productivity. 相似文献
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Field experiments were conducted during 1989 and 1990 to study the effect of various soil management practices on water conservation during the two prime planting periods in the lower Himalayan region. Treatments studied were: zero tillage with weed control (ZT+W), zero tillage (ZT), fine tilth (FT), coarse tilth (CT), zero tillage with surface-applied lantana (Lantana camara L.) mulch at 10 t ha−1 (ZT+M), fine tilth with surface-applied lantana mulch at 10 t ha−1 (FT+M), fine tilth with surface-applied farmyard manure mulch at 10 t ha−1 (FT+FYM) and fine tilth with FYM incorporated at 10 t ha−1 (FYM). The soils were Typic Hapludalfs with pH 5.8, organic carbon 6.6 g kg−1 and cation exchange capacity 12 cmol (P+) (100 g)−1. The lantana mulch application to fine tilth (FT+M) or zero tillage (ZT+M) maintained higher seed-zone water content and profile water storage as compared with all the other treatments. Highest water depletion was observed under ZT+W treatment. Seed germination is likely to occur only under FT+M and ZT+M during the two prime planting periods, if field capacity water content is considered to be limiting for seed germination. However, for the other treatments rainfall would invariably be required to increase the surface water content, to allow germination and early seedling establishment. 相似文献
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Yakuta Bhagat Chris C. Wilson Michael G. Fox M. Teresa Ferreira 《Ecology of Freshwater Fish》2011,20(2):287-298
Abstract – High levels of morphological differentiation have been found among pumpkinseeds (Lepomis gibbosus) occupying four habitat types in Portuguese reservoirs. To investigate the underlying mechanism behind the phenotypic differentiation among ecomorphs, we used six microsatellite markers to assess patterns of genetic differentiation among and within eight naturalised reservoir populations. Greater genetic differentiation was seen among reservoir populations than within reservoirs (FST > 0.041, P < 0.002). structure analysis revealed the presence of two distinct genetic groups among the set of eight reservoir populations. However, an analysis of co‐occurring forms that were identified a priori by their respective habitats was consistent with a single panmictic group, suggesting that morphological differentiation has arisen in sympatry (i.e., within a reservoir, postintroduction). The observed relationships within and among reservoir populations, combined with the timeframe of ecomorph divergence, suggest the strong likelihood of phenotypic plasticity as the underlying mechanism of diversification in the introduced pumpkinseed. 相似文献
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We report the effects of supplemental chromium (Cr) on interferon-gamma (IFN-gamma) expression in response to Newcastle disease virus (NDV) vaccine in broiler chicken. Two hundred and eighty day old straight run broiler chicks were randomly selected and allocated at random to one of the seven treatment groups replicated four times having 10 chicks in each replication. Treatment 1 (C) was a standard control diet in which no Cr was offered to birds either through feed or drinking water. In treatments 2-4 (F500, F1000 and F1500), Cr in the form of chromium picolinate (CrPic) was added at rates of 500, 1000 and 1500 ppb in diets, respectively. In treatments 5-7 (W250, W500 and W750), Cr as added to the drinking water at rates of 250, 500 and 750 ppb, respectively. The feeding was continued from 1 to 49 d of age. On 49 d, three birds from each replicate, i.e. 12 birds/treatment were inoculated intramuscularly with R(2)B strain of NDV. Twelve unvaccinated birds along with 12 vaccinated birds from each treatment (four birds each day) were then sacrificed on 1, 3 and 7 days post-immunization to study the IFN-gamma expression using quantitative real time PCR. Following the immunization, the IFN-gamma mRNA expression in spleen was significantly (P<0.01) either up-regulated or down-regulated at day 1 and day 3 post-stimulation. Whereas, IFN-gamma mRNA expression reached basal level in all the vaccinated groups at day 7 post-stimulation. IFN-gamma mRNA expression on day 1 was approximately two and four times higher than the control (C) levels in F500 and W500 groups, respectively. On 3 day post-immunization, IFN-gamma mRNA expression in spleen was about 40 and 27 times higher than controls (C) in F500 and W500 groups, respectively. Other groups (F1000, F1500, W250 and W750) showed down-regulation of IFN-gamma mRNA expression. The results suggested that the dosage of chromium modulates the expression of IFN-gamma and route has effect on the onset and duration of the response. Thus, the supplementation of chromium at appropriate dose might be helpful to enhance the IFN-gamma mRNA expression in response to NDV. 相似文献
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R.M. Bhagat 《Soil & Tillage Research》1990,17(3-4):315-326
Field experiments were conducted on a river deposit during 1983–1984 and 1984–1985 in order to study the effect of different soil management practices, such as zero tillage with surface-applied crop residue mulch at a rate of 10 t ha−1 (ZT+M), conventional tillage (CT), CT+ surface-applied crop residue mulch at a rate of 10 t ha−1 (CT + M), CT+crop residue incorporation at a rate of 10 t ha−1 (CT + SI), CT + farmyard manure incorporation at a rate of 10 t ha−1 (CT + FYM), on soil hydro-thermal regime root growth, nutrient uptake and dry matter yield of winter wheat (Triticum aestivum L.). The soils of the site are classified as Entisol, Typic Psammaquent with pH 6.0, cation exchange capacity 10 c mol (p+) per kg in the surface (0–0.3 m) depth. In the CT + M and CT + FYM treatments, higher water retention was observed compared to CI. The minimum soil temperature was also raised by 3°C under CT + M to CT at 0.1-m depth. CT + M and CT + FYM had significantly higher root mass density compared with other treatments at all stages of crop growth. The nitrogen (N) uptake under these two treatments was also significantly higher compared to CT. Under CT+M, plants did not suffer from N stress compared to other treatments. Phosphorus (P) uptake (except at tillering) and potassium (K) uptake under CT+M and CT + FYM were significantly higher than for all the other treatments. Treatments ZT+M and CT+SI behave simply to CT in terms of hydro-thermal regime, root growth, nutrient uptake and dry matter yield. The grain yield under CT+M and CT+FYM during 1983–1984 and 1984–1985 was significantly higher than that under all the other treatments. 相似文献
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Y.S. Saharawat Bhagat Singh R.K. Malik Jagdish K. Ladha M. Gathala M.L. Jat V. Kumar 《Field Crops Research》2010
The rice–wheat rotation covering 13.5 million ha in the Indo-Gangetic Plains is vital for food security. Its sustainability is at risk as the current production practices are inadequate resulting in high cost of cultivation and inefficient use of inputs (i.e. water, labor and energy). In a field study, we evaluated resource conserving and cost-saving alternative tillage and crop establishment options with an aim to improve system productivity and efficiency. Treatments included transplanting and direct-seeding of rice after reduced and no-tillage, followed by wheat after no-tillage. Conventional-tilled (puddled) transplanted rice followed by conventional-tilled wheat was included as a current practice. Rice yields of transplanted rice were similar irrespective of tillage/puddling. However, both dry and wet direct-seeded rice yielded 0.45–0.61 Mg ha−1 lower than puddled transplanted rice. Wheat yield after no-tillage was either higher or equivalent to conventional practice. Wheat provided more economic return (US $35 ha−1) than rice. No-till wheat was 6% more profitable than the conventional practice (T1). Rice transplanting with or without puddling had similar water application but dry direct-seeded rice had 10–12% lower and wet direct-seeded rice 20–24% higher. Machine labor without tillage was lower by maximum of 51 and 43% in rice and wheat, respectively. Similarly, human labor was also 9–16% lower in no-till rice compared to other practices. Two years results consistently showed $35 more net income when rice was transplanted without puddling than that of conventional practice. Direct-seeded/un-tilled rice had variable response in 2 years; US $16 more in year 1 and similar in year 2 to the puddled transplanted rice. Direct-seeded or transplanted rice after no-tillage can be more efficient and profitable alternatives to current practice (puddled transplanted rice), however, require further refinement in areas of cultivar development for no-till direct-seeding condition, nutrient, water and weed management to harness maximal potential. 相似文献