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41.
在孟加拉国吉大港山区选择两块研究地,研究轮换种植对土壤中真菌和细菌群落的影响。两块研究地均包含轮换种植和本地社区管理的乡村森林,第一块研究地点选择在兰加马蒂地区,第二块研究地点选择在吉大港的班多尔班地区。在两个地点和不同用途的地块中,其表面土（0-10cm）和地表下土（10-20cm）的土壤质地不同,分别为砂壤和粘土。轮作地的土壤pH和含水量比乡村森林的低。研究结果表明：在兰加马蒂和班多尔班地区,大多数情况下,轮作地的表面土和地表下土壤中的真菌和细菌群落数量比乡村森林的低。在兰加马蒂和班多尔班地区的轮作地中,炭疽菌属（CoHetrotrichum）和镰孢菌属（Fusarium）真菌稀少,而两个地方的不同用途地块中均有细菌球菌属（Coccus）,芽孢杆菌属（Bacillus）和链球菌属（Streptococcus）。在两个地方的不同用途地块中常见的真菌有曲霉属（Aspergillus）、根霉属（Rhizopus）、木霉属（Trichoderma）和青霉菌属（Penicillium）。在其它的土壤区系中,由于轮换种植导致土壤环境退化的程度还需要进一步的研究。 相似文献
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The effect of forests clear felling and associated burning on the population of soil nitrogen transforming bacteria and actinomycetes are reported at three pair sites of Chittagong University campus, Bangladesh in monsoon tropical climate. Clear felled area or burnt site and 15-21 year mixed plantation of native and exotic species, situated side by side on low hill having Typic Dystrochrepts soil was represented at each pair site. At all the three pair sites, clear felled area or burnt site showed very significantly (p≤0.001) lower population of actinomycetes, Rhizobium, Nitrosomonas, Nitrobacter and ammonifying as well as denitrifying bacteria compared to their adjacent mixed plantation. From environmental consideration, this finding has implication in managing natural ecosystem. 相似文献
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Chandra Prakash Kala Yogesh Dubey Suharyanto Mine Nose Susumu Shiraishi Hai-hua Zhang Guang-yu Li Xiu-mei Xing Er-jun Ren Ying Yang Fu-he Yang Subhash Hathurusingha Nanjappa Ashwath Ya-ni Gao Cheng-rui Tian Li-li Zhao Assan Gnoumou Fidèle Bognounou Karen Hahn Adjima Thiombiano S. M. Sirajul Haque Rahima Ferdoshi Sohag Miah M. Nural Anwar Angel Rolando Endara Agramont Sergio Franco Maass Gabino Nava Bernal Juan Ignacio Valdez Hernández Todd S. Fredericksen 《林业研究》2012,23(1):173-173
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Effect of dietary Rhodobacter capsulatus on lipid fractions and egg-yolk fatty acid composition in laying hens 总被引：1，自引：0，他引：1
Salma U Miah AG Tsujii H Schellander K Südekum KH 《Journal of animal physiology and animal nutrition》2012,96(6):1091-1100
The present study was conducted to investigate the effect of dietary Rhodobacter capsulatus on lipid fractions and egg‐yolk fatty acid composition in laying hens. Thirty‐six laying hens (30 weeks old) were randomly assigned into two dietary groups fed diets with (0.04%) or without (control) R. capsulatus for a 60‐day feeding trial. Dietary R. capsulatus decreased (p < 0.05) serum and hepatic cholesterol and increased (p < 0.05) the excreta cholesterol, and resultant lower (p < 0.05) cholesterol contents in egg yolk. The concentration of polyunsaturated fatty acids (PUFA) and ratio to saturated fatty acids in egg yolk was improved (p < 0.05) by dietary R. capsulatus. The concentration of hepatic bile acid was increased (p < 0.05) and excreta bile acid was decreased (p < 0.01) in the laying hens fed R. capsulatus diet. The incorporation of 1‐14C‐palmitic acid into hepatic lipids and lipid fractions was increased (p < 0.05) in laying hens fed R. capsulatus diet. Moreover, dietary R. capsulatus did not appear to cause any adverse effects on laying hen performances. Therefore, dietary supplementation of R. capsulatus in layer diets may be a feasible means of producing eggs with lower cholesterol and higher PUFA contents for health conscious consumers. 相似文献
45.
Genetic screening of FecB,FecXG and FecXI mutations and their linkage with litter size in Barki and Rahmani sheep breeds 
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下载免费PDF全文 AS El‐Seedy NM Hashem KM El‐Azrak ANM Nour El‐Din TA Ramadan TA Taha MH Salem 《Reproduction in domestic animals》2017,52(6):1133-1137
Characterization of fecundity genes offers the opportunity to improve production efficiency, and the consequent increase in litter size in livestock industry, through utilizing them in breeding programs. The main objective of this study was to detect the BMPR‐IB, BMP15 and GDF9 gene mutations and to investigate whether these mutations are associated with litter size in Egyptian sheep breeds. To achieve this goal, 73 adult ewes representing Barki (n = 33) and Rahmani (n = 40) breeds were used. Polymerase chain reaction–restriction fragment length polymorphism (PCR‐RFLP) screening approach was used to detect the presence of FecB, FecXG and FecXI mutations in the two selected breeds. Results of this study showed that the three different candidate gene mutations, namely FecB, FecXG and FecXI are not present among these selected populations of the Egyptian breeds. Further studies regarding other mutations and/or other genes, which may influence ovulation rate, should be carried out to determine the type and mode of inheritance of such genes in Egyptian sheep breeds. 相似文献
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Lunar surface magnetic fields and their interaction with the solar wind: results from lunar prospector 总被引：1，自引：0，他引：1
RP Lin DL Mitchell DW Curtis KA Anderson CW Carlson J McFadden MH Acuna LL Hood A Binder 《Science (New York, N.Y.)》1998,281(5382):1480-1484
The magnetometer and electron reflectometer experiment on the Lunar Prospector spacecraft has obtained maps of lunar crustal magnetic fields and observed the interaction between the solar wind and regions of strong crustal magnetic fields at high selenographic latitude (30 degreesS to 80 degreesS) and low ( approximately 100 kilometers) altitude. Electron reflection maps of the regions antipodal to the Imbrium and Serenitatis impact basins, extending to 80 degreesS latitude, show that crustal magnetic fields fill most of the antipodal zones of those basins. This finding provides further evidence for the hypothesis that basin-forming impacts result in magnetization of the lunar crust at their antipodes. The crustal magnetic fields of the Imbrium antipode region are strong enough to deflect the solar wind and form a miniature (100 to several hundred kilometers across) magnetosphere, magnetosheath, and bow shock system. 相似文献
48.
Voyager stereoimages of Euboea Montes, Io, indicate that this mountain formed when a large crustal block was uplifted 10.5 kilometers and tilted by approximately 6 degrees. Uplift triggered a massive slope failure on the northwest flank, forming one of the largest debris aprons in the solar system. This slope failure probably involved relatively unconsolidated layers totaling approximately 2 kilometers in thickness, overlying a rigid crust (or lithosphere) at least 11 kilometers thick. Mountain formation on Io may involve localized deep-rooted thrust faulting and block rotation, due to compression at depth induced during vertical recycling of Io's crust. 相似文献
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Analysis of the behavior of slow releasing nitrogen fertilizers in the rhizosphere soil of agricultural crops is essential for their effective use. This work presents a comparative study of the effects of oxamide and ammonium sulfate as different N sources on the relative mobility of some nutritionally important anions and cations and their relevance to plant growth, root development, and pH distribution pattern in the rhizosphere of wheat (Triticum aestivum cv. Nourin No. 61). Experiment was conducted on a Japanese upland alluvial soil through a rhizobox approach. In the central compartment (CC) of the oxamide and ammonium sulfate treated rhizoboxes, four uncontaminated and homogeneous wheat seedlings germinated on a sterile petridish were grown for nearly two months. During the growing period plant height was recorded weekly. After the growing period, rhizoboxes were dismantled for soil sampling and photography of roots. Soil samples from each compartment of the two rhizoboxes were used for the analysis of CI-, N03 -, SO4 2-, Ca2+, Mg2+, K+, NH4 +-N, N03 --N and measurement of pH. Compared with ammonium sulfate, the distribution of anions and cations from the distant compartments to the central ones over a distance of 3–5 mm along with a better plant growth, high rooting density, and high pH confirmed that oxamide was an efficient nitrogen fertilizer. 相似文献
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