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1.
We evaluated the influence on milk production of feeding early lactation cows a diet that included 14.5% crude protein (CP) and that did not meet methionine (Met) requirements or that met them by supplying rumen‐protected Met (RPMet). Thirty‐nine multiparous Holstein cows were allocated into two groups. For 15 weeks after calving, each group was fed one of the two total mixed rations, Control (= 20) or Treatment (= 19). The Treatment group received added RPMet at 0.034% (8 g/day) of the Control diet on dry matter basis. The adequacies of Met for the Control and Treatment groups were 96% and 106%, respectively, and for other amino acids, >110%. The CP level (14.5%) was 1 percentage point lower than that recommended by the Japanese Feeding Standard (2006). No between‐group differences were found in milk yield (40 kg/day), milk composition, plasma profile, rumen fermentation, nitrogen balance, or cow health. Met intake and the amount of rumen‐undegradable feed Met were higher in the Treatment group (< 0.05). Microbial Met and total metabolizable Met did not differ between groups. Supplying RPMet in a 14.5% CP diet during early lactation did not dramatically affect milk production, because the amount of total metabolizable Met was unchanged.  相似文献   
2.
ABSTRACT Transgenic Nicotiana occidentalis plants expressing a movement protein (P50) and partially functional deletion mutants (DeltaA and DeltaC) of the Apple chlorotic leaf spot virus (ACLSV) showed resistance to Grapevine berry inner necrosis virus (GINV). The resistance is highly effective and GINV was below the level of detection in both inoculated and uninoculated upper leaves. In contrast, GINV accumulated in inoculated and uninoculated leaves of nontransgenic (NT) plants and transgenic plants expressing a dysfunctional mutant (DeltaG). On the other hand, in some plants of a transgenic plant line expressing a deletion mutant (DeltaA', deletion of the C-terminal 42 amino acids), GINV could spread in inoculated leaves, but not move into uninoculated leaves. In a tissue blot hybridization analysis of DeltaA'-plants inoculated with GINV, virus could be detected in leaf blade, midribs, and petiole of inoculated leaves, but neither in stems immediately above inoculated leaves nor in any tissues of uninoculated leaves. Immunohistochemical analysis of GINV-inoculated leaves of DeltaA'-plants showed that GINV could invade into phloem parenchyma cells through bundle sheath of minor veins, suggesting that the long-distance transport of GINV might be inhibited between the phloem cells and sieve element (and/or within sieve element) rather than bundle sheath-phloem interfaces. Immunogold electron microscopy using an anti-P50 antiserum showed that P50 accumulated on the parietal layer of sieve elements and on sieve plates. The results suggested that resistance in P50-transgenic plants to GINV is due to the interference of both long-distance and cell-to-cell movement of the virus.  相似文献   
3.
Pluripotent stem cells, such as embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) are able to differentiate into all cell lineages of the embryo proper, including germ cells. This pluripotent property has a huge impact on the fields of regenerative medicine, developmental biology and reproductive engineering. Establishing the germ cell lineage from ESCs/iPSCs is the key biological subject, since it would contribute not only to dissection of the biological processes of germ cell development but also to production of unlimited numbers of functional gametes in vitro. Toward this goal, we recently established a culture system that induces functional mouse primordial germ cells (PGCs), precursors of all germ cells, from mouse ESCs/iPSCs. The successful in vitro production of PGCs arose from the study of pluripotent cell state, the signals inducing PGCs and the technology of transplantation. However, there are many obstacles to be overcome for the robust generation of mature gametes or for application of the culture system to other species, including humans and livestock. In this review, we discuss the requirements for a culture system to generate the germ cell lineage from ESCs/iPSCs.  相似文献   
4.
ABSTRACT:   During the fermentation of mackerel to narezushi , the concentration of peptides required to inhibit 50% of the ACE activity in the assay media (IC50), as an index of the angiotensin  I-converting enzyme (ACE) inhibitory activity, was remarkably decreased with a rapid increase in peptide contents. Systolic blood pressure (SBP) in spontaneously hypertensive rats (SHR) decreased between 2 and 4 h after the single oral administration of greater than 10 mg peptide/kg narezushi extract, and recovered to the initial level by 8 h thereafter. The SBP decreased at seven successive daily doses of 10 mg/kg of narezushi extract and then recovered to the initial level 5 days after stopping a total of 10 daily administrations. The extract was administered to five-week-old SHR rats for 70 days and SBP decreased 21 days after starting and continued for 28 days after the end of administration. The peptide-rich fraction from narezushi extract had a powerful antihypertensive effect, whereas the other fraction had a similar, but weak effect.  相似文献   
5.
Recently, the analysis of the microbial community structure in soil has received a great deal of attention. Various analytical methods based on biomarkers have been developed: 16S-rDNA, total DNA, phospholipid fatty acids, ergosterols, muramic acids, etc. (Tunlid and White 1992; Carter and Lynch 1993). In a previous paper, we reported that respiratory quinones are useful biomarkers to characterize the microbial community structure in soil (Fujie et al. 1998). In these analyses, only fresh moist soils or frozen soils had been used as samples. However, the soil samples are generally stored in the dark after air drying in many research institutes and experimental stations. It was considered that the analysis of microbial communities in dried soil samples was not possible.

In this paper, we observed that the drying of soils did not affect the proportions of quinone species in soil although the treatment decreased the amount of extracted quinones. These findings suggest that the analysis of the respiratory quinone profile of dried soils reflects the micro biota present in fresh moist soils before drying.  相似文献   
6.
Solutions of sucrose, glucose and fructose were artificially injected into the stems of sweet potato plants. The effects of solution injection on both dry matter production and the activity of adenosine 5'-diphosphate glucose pyrophosphorylase (AGPase) in tuberous roots were investigated and compared. The total weight of carbon (TC) artificially and photosynthetically supplied to a plant during the treatment period of 40 days was 0.987–1.869 times the weight of photosynthetically assimilated carbon alone. At the final sampling time, the dry matter weight of tuberous roots in the plants injected with sugar solutions showed a 2.73–9.13-fold increase over that of the control plant. The root weight linearly increased with TC. The activity of AGPase was also enhanced by solution injections, with 27–63 % increases compared to the control, but was not significantly related to TC. The injection of sugar solutions is concluded to have a dual effect on root production in sweet potato. One effect is that the increased sugar concentration in the plant increases AGPase and sink activities, and the other effect is that the increased carbon supply quantitatively promotes starch synthesis and accumulation in roots.  相似文献   
7.
Adenosine 5'-diphosphate pyrophosphorylase (AGPase) is a key enzyme governing starch synthesis and is regarded as an important determinant of the sink activity of the sweet potato root. In this study, assuming that the expression of AGPase is under the direct or indirect control of sucrose, we investigated the effect of exogenous injection of sucrose solution into a plant on the activity of AGPase and tuberous root production. Sucrose solutions of 6 and 12 %, and distilled water as the control, were injected into the top of the shoot. The application of sucrose solution was effective in increasing tuberous root production and increasing the ratio of tuberous root weight to total root weight in a plant. AGPase activity in roots was enhanced by about 25 % by injecting sucrose solution. These results suggest that AGPase and sink activities are controlled by sucrose transported from the leaves. To increase sweet potato production effectively, AGPase activity and sink function must be enhanced, and so a genetic and physiological improvement in photosynthetic function or sucrose productivity in the leaves is necessary to increase AGPase activity in sink organs.  相似文献   
8.
针对结构优化设计中先分解后组合的重复优化问题,提出一种焊点布局的结构多目标拓扑优化方法.在连续设计域中,给定载荷和约束的情况下,同时优化整个结构的拓扑空间和几何造型,并决定子结构间的连接位置和布局形态.通过有限元分析和基于几何学交叉过程的多目标遗传算法得到Pareto解集,可根据不同需求确定权重,选择最优方案.  相似文献   
9.
Method for the analysis of respiratory quinones in soil was developed to characterize soil microbiota. The respiratory quinones were extracted with a mixture of chloroform and methanol using a Wahling blender or a sonicator and cleaned-up by a silicagel column cartridge. The quinone species were determined by reverse-phase high performance liquid chromatography. Spectra of peaks were measured with a photodiode array detector to examine the purity. More than 90% of extractable quinones in soil were recovered by three extractions. The recovery of quinones, added to soil as freeze-dried powder of microorganisms, was higher than 96%. This procedure led to higher representative results as follows. Fluctuations within 95% of cumulative frequency were 13% for the extracted amount of quinones and 20% for the dissimilarity, respectively. The quinone profiles of four soils were determined as follows: a soil from the aerobic layer of a paddy field, an ando soil and two yellow upland soils which had received chemical fertilizers with and without farmyard manure. The quinone profiles displayed clear differences in the microbial composition and in the microbial diversity among the soils. It was demonstrated that the analysis of the respiratory quinone profile was useful to characterize the microbial community structure in soil.  相似文献   
10.
To analyze the sensory characteristics of meat samples with a crude fat content between 23.8% and 48.6% taken from 34 Japanese Black steers, we grilled the meat and subjected it to analytical sensory evaluation. We also measured the amounts of moisture, protein, nucleic acid and glutamic acid. An increase in crude fat content increased the tenderness, juiciness, and fattiness in the meat quality evaluation. An increase in crude fat content reduced the crude protein and moisture contents; it also slightly reduced the nucleic acid and glutamic acid contents, although when the reductions in these umami components were assessed relative to the moisture content they changed little. Increasing the fat content up to a certain point greatly enhanced the umami intensity and beef flavor intensity in the meat quality evaluation and raised the overall evaluation score; the peak of the appropriate crude fat content for these purposes was about 36%.  相似文献   
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