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391.
The oceanic sink for anthropogenic CO2   总被引:6,自引:0,他引:6  
Using inorganic carbon measurements from an international survey effort in the 1990s and a tracer-based separation technique, we estimate a global oceanic anthropogenic carbon dioxide (CO2) sink for the period from 1800 to 1994 of 118 +/- 19 petagrams of carbon. The oceanic sink accounts for approximately 48% of the total fossil-fuel and cement-manufacturing emissions, implying that the terrestrial biosphere was a net source of CO2 to the atmosphere of about 39 +/- 28 petagrams of carbon for this period. The current fraction of total anthropogenic CO2 emissions stored in the ocean appears to be about one-third of the long-term potential.  相似文献   
392.
The properties of garlic (Allium sativum L.) are attributed to organosulfur compounds. Although these compounds change during cultivation and storage, there is no report of their simultaneous analysis. Here, a newly developed analytical method with a rapid and simple sample preparation to determine four sulfoxides and three gamma-glutamyl peptides in garlic is reported. All garlic samples were simply extracted with 90% methanol solution containing 0.01 N hydrochloric acid and prepared for analysis. Alliin, isoalliin, methiin, cycloalliin, and gamma-l-glutamyl-S-methyl-l-cysteine were determined by normal-phase HPLC using an aminopropyl-bonded column. gamma-l-Glutamyl-S-(2-propenyl)-l-cysteine and gamma-l-glutamyl-S-(trans-1-propenyl)-l-cysteine were separated on an octadecylsilane column. The overall recoveries were 97.1-102.3%, and the relative standard deviation values of intra- and interday precision were lower than 2.6 and 4.6%, respectively. This newly developed method offers some advantages over the currently accepted techniques including specificity, speed, and ease of use and would be useful for chemical and biological studies of garlic and its preparations.  相似文献   
393.
This experiment aimed to determine the changes in chemical composition, fermentation profile, in situ disappearance characteristics, and nutrient losses of ensiled total mixed ration (TMR) containing steam‐flaked corn or brown rice (BR) during storage. TMRs for dairy cows, containing either steam‐flaked corn or BR at 31.9% with 15.2% rye silage, 40.5% alfalfa silage, 5.0% beet pulp and 7.0% soybean meal, were prepared (dry matter (DM) basis). Each TMR was placed in a plastic drum silo, stored at 23°C in an air‐conditioned room and sampled 0, 7, 14, 30, 90 and 210 days after preparation. In both grain sources, the fermentation products increased, while DM and starch storage losses increased and starch content greatly decreased during storage. The rapidly degradable fraction and effective ruminal degradability of DM, crude protein and starch increased during storage. These changes of dietary characteristics were large during 30 days of storage, but small after 90 days of storage. Replacing corn with BR led to increased fermentation products, starch loss and effective ruminal degradability of the ensiled TMR. These results indicate that the ensiling process of TMR changes the dietary characteristics and replacing corn with BR in TMR had a large impact on these dietary characteristics.  相似文献   
394.
395.
Cell‐cell fusion has been a great technology to generate valuable hybrid cells and organisms such as hybridomas. In this study, skeletal muscle myoblasts were utilized to establish a novel method for autonomous xenogenic cell fusion. Myoblasts are mononuclear myogenic precursor cells and fuse mutually to form multinuclear myotubes. We generated murine myoblasts (mMBs) expressing green fluorescent protein (GFP) termed mMB‐GFP, and the chick myoblasts (chMBs) expressing Discosoma red fluorescent protein (DsRed) termed chMB‐DsRed. mMB‐GFP and chMB‐DsRed were cocultured and induced to differentiate. After 24 h, the multinuclear myotubes expressing both GFP and DsRed were observed, indicating that mMBs and chMBs interspecifically fuse. These GFP+/DsRed+ hybrid myotubes were able to survive and grew to hyper‐multinucleated mature form. We also found that undifferentiated mMB‐GFP efficiently fuse to the chMB‐DsRed‐derived myotubes. This is the first evidence for the autonomous xenogenic fusion of mammalian and avian cells. Myoblast‐based fusogenic technique will open up an alternative direction to create novel hybrid products.  相似文献   
396.
Clubroot disease caused by Plasmodiophora brassicae is one of the most serious diseases in cruciferous crops. To classify isolates, we developed simple sequence repeat (SSR) markers for P. brassicae. Twenty-four Japanese isolates were used in this study: 12 isolates of an unknown pathotype from the Kyoto Prefecture, as well as 12 isolates of known pathotypes, including three single-spore lines. From the 12 isolates from Kyoto Prefecture, 11 were classified into either pathotype 2 (three isolates) or 4 (eight isolates). We designed 23 SSR markers based on the P. brassicae genome, of which 11 markers from intergenic regions showed polymorphisms in the 24 isolates. Many haploid isolates belonging to pathotypes 2 and 4 were monomorphic, and typical alleles were detected in some isolates not belonging to pathotype 4. Two bands were detected for eight SSR loci in five isolates, indicating that different genotypes were mixed in these isolates. We constructed a phylogram based on the 11 polymorphic SSRs. Pathotypes 2 and 4 formed a cluster, from which pathotypes 3 and 1 were successively placed. These results strongly suggest a close genetic relationship between isolates in pathotypes 2 and 4, consistent with our finding that isolates in these two pathotypes were found at one collection site. In combination with pathotype classification and other marker systems, the SSR markers can be used for more detailed analyses to improve the control of clubroot disease.  相似文献   
397.
ABSTRACT

To successfully afforest coastal forest belts ensuring high disaster prevention, growth bases for them have been constructed by piling up soil in the low wetlands along the Kujukuri coastline. Ground surfaces in such bases are often covered with water because of soil compaction, leaving them susceptible to stagnant water. Water stagnation in soil is problematic, potentially interfering with afforesting coastal forests. Therefore, row deep tillage was conducted for parts of growth bases to combat the poor physical properties of the existing soil. Here, we surveyed soil profiles and measured vertical soil hardness distribution in two forest stands with piling up soil to evaluate the effectiveness of tillage for man-made soil. Soil hardness measurements indicated that the vertical areas with ‘soft’ and ‘hard/consolidated’ soil alternately appeared in growth base profiles. Generally, soil of the dense and very hard layers was apt to be formed by strong compaction of the filled-up soil because of heavy machinery usage during growth base preparation. Such dense and hard soils in the untilled areas of the profiles were also observed in this study. By contrast, it was confirmed that row deep tillage drastically improved soil physical properties, i.e., decreased hardness and increased water permeability, because the sequential hardened subsoil layers were well-broken-up. Moreover, it was observed many thick and large roots penetrated deeper layers with deep tillage areas. These results suggest that row deep tillage of hardened soil is quite effective at securing the areas and providing the physical conditions for deeply penetrated roots into deeper soils, which increases healthy root development. They show the effects of soil hardness reduction and water permeability improvement have been maintained for two decades, at least, after construction. These findings will be useful for alleviating some problems of soil compaction, water stagnation, and tree-growth hindrance that have been encountered on afforestation sites with man-made soil.  相似文献   
398.
茶园高架风扇防霜系统设计与试验   总被引:3,自引:0,他引:3  
早春倒春寒气候条件下,茶树遭受严重的晚霜冻害,造成茶叶产量和品质的下降。在分析倒春寒逆温气象特点的基础上,研究了将近地上方高温空气与近地低温空气混合,实现防霜的作用机理;总体设计了以轴流风扇为核心部件的高架风扇防霜系统;对系统作用区域的风速分布特征、温度分布和温升效果,进行了试验研究。结果表明,一套功率3kW的风扇防霜系统有效覆盖面积大于1000m2,在外界气温-4℃的霜冻条件下,可提高冠层温度4℃,能够有效预防消除茶园晚霜冻害。  相似文献   
399.
为研究纤维素酶和乳酸菌对玉米秸秆青贮饲料品质的影响,分别设乳酸菌处理组、纤维素酶处理组、纤维素酶和乳酸菌共同处理组及对照组进行玉米秸秆青贮饲料的发酵试验。结果表明:添加纤维素酶使玉米秸秆青贮饲料中氮态氮与总氮质量比(m(VBN)/m(TN))和丁酸与总酸摩尔比分别下降28%和100%,ADF质量分数下降20%,显著提高了玉米秸秆青贮饲料的营养价值。乳酸菌的添加虽然使青贮饲料的色泽、气味和质地明显改善,但也使NDF,ADF含量明显提高,氢态氮与总氮质量比也明显上升,这说明玉米秸秆青贮饲料的品质明显下降。乳酸菌和纤维素酶的共同作用使玉米秸秆青贮饲料的干物质消失率提高8%,氨态氮与总氮质量比降低33%,丁酸质量分数降低82%,同时使NDF,ADF质量分数分别降低10%和7%,说明玉米秸秆青贮饲料的品质明显提高。  相似文献   
400.
In the previous study, we investigated effect of physical state of nonpolar lipids of gluten‐starch model dough. This experiment examined a real wheat flour dough system to assess the role of fat crystals in the breadmaking processes. These experiments were performed with a baking test and an investigation of wheat flour dough through rheological measurements (both large and small deformations), scanning electron microscopy, and ultracentrifugation. As a result, we found that the added oil was absorbed in the gluten structure, causing the aggregation of the gluten, which gave rise to more elastic behavior. In contrast, solid fat seemed to be distributed uniformly between the starch granules in the dough, reducing the friction between the starch granules and facilitating thin gluten gel layers. These properties lead to the lower G′ value and the increased viscous behavior, which yields an increase in loaf volume. In addition, the supposed mechanism behind the large loaf volume described in the previous study was that fat provides a uniform distribution of the dough components, and that the dough can thus expand easily, resulting in a larger loaf volume, which was supported in the wheat flour dough system. In conclusion, we found that thin, expandable gluten films and the uniform dispersion of gluten and starch granules in the dough are prerequisites for attaining better baking performance.  相似文献   
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