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21.
J. M. F. Wyatt P. B. Siegel J. A. Cherry 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1982,61(3):257-262
Summary The research presented here was designed to investigate the mode of inheritance of fat and lean tissue deposition, and the relationship between them and body weight in Japanese quail. Heterotic effects were found for weight, size, and number of adipocytes in the abdominal fat depots, weight of the sartorial fat depot and percentage carcass fat with means for the hybrids being lower than those for the parental lines. General inferences concerning the importance of nonadditive genetic variation for lean and body weight were precluded due to inconsistencies observed among mating combinations. Thus, although heterosis and recombination effects were general for characteristics associated with fat deposition, the situation for body weight and lean was unique to the populations involved. It may be hypothesized that heterosis in the efficiency of feed utilization is reflected by the heterosis for fat deposition which explains why hybrids utilize feed better than their parental lines. 相似文献
22.
In maize (Zea mays L.) and pine (Pinus taeda L.) seedlings, cellulose microfibril impressions are present on freeze-fractured plasma membranes. It has been proposed that impressions of newly synthesized microfibrils are a record of the movement of terminal synthesizing complexes through the plasma membrane (Mueller and Brown, 1980, J. Cell Biol. 84, 315–326). The association of terminal complexes with the ends of microfibril impressions or with the ends of microfibrils torn through the membrane indicates the orientation of microfibril tips. Unidirectionally-oriented microfibril tips (all pointing in the same direction) are associated with the organized deposition of parallel arrays of microfibrils. Multidirectionally-oriented microfibril tips were observed in a cell in which microfibril deposition was unusually disorganized. Microfibril patterns around pit fields are asymmetric and resemble flow patterns. Unidirectionally-oriented tears are associated with these microfibrils. Although microfibril orientations are deflected around pit fields, the main axis of microfibril orientation is maintained across the surface of the cell. The hypothesis is proposed that the interaction of a flowing plasma membrane with microfibril synthesizing complexes in the plane of the membrane may result in unidirectional deposition and asymmetric microfibril impressions around pit fields.Some of this work has been published in preliminary form (Brown 1979) 相似文献
23.
Martin Pilhofer Marko PavlekovicNatuschka M. Lee Wolfgang LudwigKarl-Heinz Schleifer 《Systematic and applied microbiology》2009
Few reports on in situ mRNA detection in bacteria have been published, even though a major aim in environmental microbiology is to link function/activity to the identity of the organisms. This study reports a reliable approach for the in situ detection of nifH mRNA using fluorescence hybridization based on a previously described protocol for pmoA. nifH codes for a dinitrogenase reductase, a key enzyme in dinitrogen fixation. nifH mRNA was hybridized with a digoxigenin-labelled polynucleotide probe. The hybrid was detected with an anti-DIG-antibody labelled with horseradish peroxidase. Subsequently, the signal was amplified by catalyzed reporter deposition (CARD) with fluorochrome-labelled tyramides. Furthermore, the imaged organisms were identified using standard fluorescence in situ hybridization of rRNA. Thus, the approach enabled us specifically to link in situ the information from the dinitrogen fixation activity of an organism to its identity. Unexpectedly, the signals derived from nifH mRNA hybridization showed a distinct uneven pattern within the cells. This indicated that the method used could even give insights about the localization of the detected mRNA within the cell, which is a potential use of mRNA fluorescence in situ hybridization (FISH) that has not been reported up to now for bacterial cells. 相似文献
24.
基于连续 5年的观测 ,对比研究了马占相思人工林和果园两种地表类型上地表径流的各自特点 ;讨论了季节性地表径流的差异与系统水分结构问题 ;探讨了根据实际资料求取发生地表产流的降雨量临界值的方法 ,此方法以综合考虑未发生产流的最大降雨量和已发生产流的最小降雨量为基础 ;并得到了如下的一些结果 :1)本区域不同强度的大气降水频度分布比较均匀 ,但降水量主要由少数几场特大降水带来 ,并且降水量的季节分配极不平均 ,湿季 (4~ 9月 )降水量占全年的 85 .5 %。 2 )地表径流的季节差异更大 ,果园在湿季的地表径流量占全年的93.8% ,马占相思林占 95 .1% ,作者认为在降水量存在较大干湿季差别的地区 ,对于越难于发生地表径流的下垫面 ,这个值会越高。3)马占相思地表径流系数在逐年减小 ,果园的变化较大。4)一次性降雨量对地表径流量的影响在这两种地表类型上都很明显 (r>0 .85 ) ;一次性降雨强度对地表径流的影响只有在中等降雨量 (6~ 16 mm)下才表现明显 (r>0 .87) ,对于较小和较大降水量 ,径流量与降雨强度关系都不大 ;径流系数受一次性降雨强度的影响很明显 (林地 r>0 .92 ,果园 r>0 .77)。 5 )马占相思和果园一次性“最大可能”地表径流产流的雨量临界值 ,分别为5 .1m m和 2 .8mm。 相似文献
25.
Formation of wheat protein bodies: Involvement of the Golgi apparatus in gliadin transport 总被引:1,自引:0,他引:1
Developing wheat (Triticum aestivum L.) endosperm was examined using ultrathin sections prepared from tissues harvested at 5, 9, 16 and 25 d after flowering. Protein bodies were evident by 9 d and displayed a variety of membranous structures and inclusions. The Golgi apparatus was a prominent organelle at all stages, and by 9 d was associated with small electron-dense inclusions. By immunocytochemical techniques, gliadin (wheat prolamine) was localized within these vesicles and in homogeneous regions of protein bodies, but not in the lumen of the rough endoplasmic reticulum. The protein bodies appear to enlarge by fusion of smaller protein bodies resulting in larger, irregular-shaped organelles. The affinity of the Golgi-derived vesicles for gliadin-specific probes during the period of maximal storage-protein synthesis and deposition indicates that this organelle includes the bulk, if not all, of the gliadin produced. The involvement of the Golgi apparatus in the packaging of gliadins into protein bodies indicates a pathway which differs from the mode of prolamine deposition in other cereals such as maize, rice and sorghum, and resembles the mechanism employed for the storage of rice glutelin and legume globulins.Abbreviations ER
endoplasmic reticulum
- IgG
immunoglobulin G
- DAF
days after flowering 相似文献
26.
《Animal : an international journal of animal bioscience》2020,14(2):277-284
The dietary inclusion of feed additives to improve the carcass characteristics of the final product is of great importance for the pork production chain. The aim of our study was to evaluate the effects of the association of ractopamine (RAC) and conjugated linoleic acid (CLA) on the performance traits of finishing pigs during the last 26 days prior to slaughter. In total, 810 commercial hybrid barrows were used. Animals were distributed among treatments according to a randomised block design in a 3 × 3 factorial arrangement, with three RAC levels (0, 5 or 10 ppm) and three CLA levels (0, 0.3 or 0.6%). Pigs fed the diet with 5 ppm RAC had higher average daily feed intake (ADFI) (2.83 kg; P < 0.05) when compared with those fed 10 ppm RAC and the control diet (2.75 and 2.74 kg, respectively). Lower ADFI values (P < 0.01) were observed with the diets containing CLA compared with the control diet with no CLA (2.73 and 2.75 v. 2.85 kg/day, respectively). The average daily weight gain of pigs fed 5 and 10 ppm RAC was +148 and +173 g/dayhigher (P < 0.001), respectively, than those fed the control diet. Dietary RAC levels influenced (P < 0.001) feed conversion ratio (FCR), which was reduced as RAC levels increased, with the pigs fed 10, 5 and 0 ppm RAC presenting FCR values of 2.57, 2.71 and 3.05, respectively. FCR also improved (P < 0.05) with the inclusion of 0.6% CLA relative to the control diet (2.70 v. 2.84, respectively). There was a significant interaction between CLA × RAC levels (P < 0.01) for final BW, loin eye area (LEA) (P < 0.05) and backfat thickness (BT) (P < 0.05). The treatments containing 10 ppm RAC + 0.6% or 0.3% CLA increased LEA and reduced BT. In conclusion, the level of 10 ppm inclusion of RAC increased the overall performance parameters of pigs and therefore improved production efficiency. The combined use of RAC and CLA promoted a lower feed conversion ratio as well as better quantitative carcass traits, as demonstrated by the higher LEA and lower BT. The dietary inclusion of CLA at 0.3% improved feed efficiency, however, without affecting LEA or BT yields. 相似文献
27.
Marika A. Schulhof Andrew E. Allen Eric E. Allen Natalie Mladenov John P. McCrow Natalie T. Jones Jessica Blanton Hamanda B. Cavalheri Drishti Kaul Celia C. Symons Jonathan B. Shurin 《Molecular ecology》2020,29(11):2080-2093
Warming, eutrophication (nutrient fertilization) and brownification (increased loading of allochthonous organic matter) are three global trends impacting lake ecosystems. However, the independent and synergistic effects of resource addition and warming on autotrophic and heterotrophic microorganisms are largely unknown. In this study, we investigate the independent and interactive effects of temperature, dissolved organic carbon (DOC, both allochthonous and autochthonous) and nitrogen (N) supply, in addition to the effect of spatial variables, on the composition, richness, and evenness of prokaryotic and eukaryotic microbial communities in lakes across elevation and N deposition gradients in the Sierra Nevada mountains of California, USA. We found that both prokaryotic and eukaryotic communities are structured by temperature, terrestrial (allochthonous) DOC and latitude. Prokaryotic communities are also influenced by total and aquatic (autochthonous) DOC, while eukaryotic communities are also structured by nitrate. Additionally, increasing N availability was associated with reduced richness of prokaryotic communities, and both lower richness and evenness of eukaryotes. We did not detect any synergistic or antagonistic effects as there were no interactions among temperature and resource variables. Together, our results suggest that (a) organic and inorganic resources, temperature, and geographic location (based on latitude and longitude) independently influence lake microbial communities; and (b) increasing N supply due to atmospheric N deposition may reduce richness of both prokaryotic and eukaryotic microbes, probably by reducing niche dimensionality. Our study provides insight into abiotic processes structuring microbial communities across environmental gradients and their potential roles in material and energy fluxes within and between ecosystems. 相似文献
28.
KMgSO4F:Ce and KMgSO4F:Mn phosphors were prepared by a wet chemical method and studied for their photoluminescence (PL) and thermoluminescence (TL) characteristics. PL emission of KMgSO4F:Ce peaked at around 440 nm for the excitation at 377 nm due to 5d → 4f transition, while KMgSO4F:Mn had a peak at 540 nm for an excitation at 363 nm and 247 nm due to 4T1g → 6A1g transition. The phosphors also showed good thermoluminescence characteristics when they were exposed to γ‐rays at a 5 Gy dose at the rate of 0.36 kGyh?1. KMgSO4F:Ce exhibited a single thermoluminescence (TL) peak at around 167 °C and KMgSO4F:Mn also exhibited a single TL peak at around 177 °C. Possible trapping parameters such as order of kinetics (b), the geometrical factor (μg), the frequency factor (s) and the activation energy were also evaluated by Chen's half width method. This article discusses fundamental PL and TL characteristics in inorganic fluoride material activated by Ce3+ and Mn2+ ions and prepared by a wet chemical method. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
29.
Contemporary and pre-industrial global reactive nitrogen budgets 总被引:50,自引:6,他引:50
Elisabeth A. Holland Frank J. Dentener Bobby H. Braswell James M. Sulzman 《Biogeochemistry》1999,46(1-3):7-43
Increases and expansion of anthropogenic emissions of both oxidized nitrogen compounds, NOx, and a reduced nitrogen compound, NH3, have driven an increase in nitrogen deposition. We estimate global NOx and NH3 emissions and use a model of the global troposphere, MOGUNTIA, to examine the pre-industrial and contemporary quantities and spatial patterns of wet and dry NOy and NHx deposition. Pre-industrial wet plus dry NOx and NHx deposition was greatest for tropical ecosystems, related to soil emissions, biomass burning and lightning emissions. Contemporary NOy+NHx wet and dry deposition onto Northern Hemisphere (NH) temperate ecosystems averages more than four times that of preindustrial N deposition and far exceeds contemporary tropical N deposition. All temperate and tropical biomes receive more N via deposition today than pre-industrially. Comparison of contemporary wet deposition model estimates to measurements of wet deposition reveal that modeled and measured wet deposition for both NO
3
–
and NH
4
+
were quite similar over the U.S. Over Western Europe, the model tended to underestimate wet deposition of NO
3
–
and NH
4
+
but bulk deposition measurements were comparable to modeled total deposition. For the U.S. and Western Europe, we also estimated N emission and deposition budgets. In the U.S., estimated emissions exceed interpolated total deposition by 3-6 Tg N, suggesting that substantial N is transported offshore and/or the remote and rural location of the sites may fail to capture the deposition of urban emissions. In Europe, by contrast, interpolated total N deposition balances estimated emissions within the uncertainty of each.Abbreviations EMEP
European Monitoring and Evaluation Program
- GEIA
Global Emissions Inventory Activity
- NADP/NTN
National Atmospheric Deposition Program/National Trends Network in the US
- NH
Northern Hemisphere
- NHx=NH3+NH
+
4
NOx=NO+NO2
NOy total odd nitrogen=NOx+HNO3+HONO+HO2NO2+NO3+radical (NO3
.)+Peroxyacetyl nitrates+N2O5+organic nitrates
- SH
Southern Hemisphere
- Gg
109 g
- Tg
1012 g 相似文献
30.
Isamu Tanaka Akio Horie Joji Haratake Yasushi Kodama Kenzaburo Tsuchiya 《Biological trace element research》1988,16(1):19-26
There are few inhalation studies of nickel carcinogenesis. In this study, Wistar male rats were exposed to green nickel oxide
(NiO(G)) aerosols (mass median aerodynamic diameter, 0.6 μm) for 7 h/d, 5 d/wk for up to 12 mo. The average exposure concentration
was controlled at 0.3 and 1.2 mg/m3 during the exposure. For histopathological examination and measurement of the nickel concentration in rat organs, the rats
were sacrificed at 3, 6, and 12 mo of exposure and 8 mo clearance period following 12 mo of exposure.
The nickel content in rat lungs that was observed up to 2.6 mg after 12 mo exposure, was proportional to the exposure concentration
during the exposure. The clearance of the nickel from the lungs was very slow and the biological half time was determined
7.7 mo.
Although the rats were exposed continuously to NiO(G), for 12 mo and kept for 8 mo clearance period, there were no malignant
tumors in any of the exposed animals. 相似文献