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1.
1. Treatment of rapeseed meal with calcium hydroxide suspension decreased the sinapine content by up to 90%. Smaller decreases were obtained by autolysis, steaming and treatment with ammonia.

2. When this treated meal was fed to susceptible ("tainting") hens the concentration of trimethylamine in the eggs was decreased to much less than that required to cause taint.  相似文献   

2.
1. Certain rapeseed meals in the diet of hens laying brown eggs result in the production, from some birds, of eggs which have a “ fishy ” or “ crabby ” odour because of the presence of trimethylamine.

2. Such susceptible birds have been used to demonstrate that the activity can be extracted from rapeseed meal with appropriate solvents.  相似文献   

3.
Stimulation of early flowering is required to shorten breeding cycles of eastern cottonwood (Populus deltoides Bartr. ex Marsh. var. deltoides), a commercially important and fast-growing hardwood species. A series of experiments was conducted to evaluate the influence of various treatments on flowering in rooted cuttings from mature and juvenile trees. A combined treatment of water stress, root pruning and paclobutrazol was applied to 3-month-old rooted cuttings from mature trees. These cuttings had been subjected to root restriction and long days. All treated plants flowered, whereas no untreated plants formed flower buds. One-year-old rooted cuttings from juvenile trees did not flower when treated with either paclobutrazol, paclobutrazol plus water stress, paclobutrazol plus root pruning, or paclobutrazol plus girdling. This was true both under continuous or periodic growth. Assessment of the lack of flowering in juvenile trees may require an integrated approach that investigates environmental or physiological stimuli, assimilate shift, gibberellic acid type and concentration, and flowering-time gene activity in the new shoots of mature and juvenile cottonwood trees.  相似文献   
4.
Natural durability of wood is determined by the European standard EN 252 for specimens in ground contact and EN 113 for basidiomycetes in the laboratory, but no test exists for above ground conditions. For above ground conditions, the European prestandard ENV 12037 and EN 330 are used to determine the durability of treated wood. The most important factors for fungal establishment on the surface and within wood are the moisture content, the surrounding temperature, and the relative humidity. Strength tests are the most sensitive for decay detection, but neither strength tests nor identification of fungi responsible for the decay are included in the standards of above ground durability in field tests. To detect decay, visual examination, pick or splinter tests, and mass loss determination are used. Identifying fungi with traditional methods, e.g., growth on solid medium, is time consuming and complicated. Molecular methods like polymerase chain reaction and sequencing do not require mycological skill for identification to species level, and furthermore the methods do not depend on the subjective judgement like most traditional methods, but are based on the objective information of the target organism (e.g., nucleotide sequences). The next generation of standard field tests will probably consider the drawbacks of standard tests today and be rapid and include both quality tests like molecular identification and nondestructive quantitative tests, e.g., acoustic tests. Laboratory tests can be improved by using fungi identified from field trials and by combining different fungi in the same test and thus simulate degradation in practice.  相似文献   
5.
于1986~1988年,在广西六个县、市进行了旱地分带种植试验、示范,已取得了预期效果。(1)经济产量比对照高187.9kg/亩,增产44.4%;(2)纯收入比对照高108.1元/亩,增收83.7%;(3)每个工日产粮、产值比对照分别高7.6 kg、2.7元/工,增54.7%、37.0%;每元投入产粮、产值比对照分别高1.2kg、0.7元,增33.3%、41.2%; (4)产/投能量效率高31%;每投一单位辅助能,产生物能,食物能比对照分剐高400kcal、120kcal;光能利用率及光能生产率此对照分别多0.17%,0.1%;(5)土地等量比率(L.E.R)为对照的4.4倍;(6)土壤肥力比对照有所提高。  相似文献   
6.
为了提高牛体细胞克隆的效率,比较了不同融合电压对核移植胚发育的影响,其中1.7kv/cm电场强度,获得了较高的融合率、卵裂率和囊胚率,分别为67.14%,76.59%和29.16%。比较了血清饥饿处理体细胞对核移植效率的影响,血清饥饿处理体细胞后,融合率、卵裂率和囊胚率分别为68.91%,74.79%和28.26%,与非血清饥饿处理的相比没有明显差异(分别为60.96%,71.91%和20.31%,P>0.05)。而且胚胎移植后的怀孕率和产犊率也没有差异(分别为29.17%,8.33%和33.33%,16.66%,P>0.05)。另外,通过加强克隆牛的产后护理,可以提高克隆牛的成活率。总之,优化生产克隆牛的各环节因素,可以从整体上提高克隆牛的生产效率。  相似文献   
7.
Lanceolate bifacial points, including one fluted specimen, have been collected from beneath an early Holocene tephra at the Uptar site, northeastern Siberia. Thus, the technology associated with the well-known Paleoindian tradition was not confined to the Americas. The Uptar collection does not compare readily with other Beringian complexes and demonstrates that there is greater diversity in the archaeological record of northeastern Siberia than traditional colonization models imply.  相似文献   
8.
Cellular oncogenes and multistep carcinogenesis   总被引:122,自引:0,他引:122  
Two dozen cellular proto-oncogenes have been discovered to date through the study of retroviruses and the use of gene transfer. They form a structurally and functionally heterogeneous group. At least five distinct mechanisms are responsible for their conversion to active oncogenes. Recent work provides experimental strategies by which many of these oncogenes, as well as oncogenes of DNA tumor viruses, may be placed into functional categories. These procedures may lead to definition of a small number of common pathways through which the various oncogenes act to transform cells.  相似文献   
9.
采用秋水仙碱处理湘潭矮脚白二倍体小白菜,经选择淘汰,变异后的植株植物学性状、解剖学结构以及细胞学等方面发生了明显变化:植株生长发育迟缓;叶、花器、单株增大增重;叶单位面积气孔数目减少、气孔增大;花枝数减少;种子大而少.二倍体矮脚白小白菜经秋水仙碱诱变后,已初步育成四倍体(矮脚白小白菜)品种.  相似文献   
10.
Coal combustion is the largest single source of sulfur oxide pollution. Treatment of some major representative U.S. coals with aqueous ferric solution removes 40 to 75 percent of the sulfur content through near quantitative oxidation of the pyritic sulfur contained in the coal matrix. Elemental sulfur and iron sulfate are recovered as products of the reaction. Engineering assessment indicates that the system, when fully developed, offers high potential for the economic abatement of sulfur oxide pollution.  相似文献   
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