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Changing sink demand of developing shoot affects transitory starch biosynthesis in embryonic tissues of germinating rice seeds
No full textStudies on Starch Accumulation and Sucrose Transport in Rice Embryos during Seed Germination and Seedling Establishment
No full text第一部份：稻種子發芽及幼苗生長時，發育中的莖葉及根組織主要之能量來源為胚乳澱粉分解生成之醣類：葡萄糖及麥芽糖。種子發芽時，葡萄糖及麥芽糖由胚乳運入胚中並可進一步被轉變為蔗糖以運至胚中其他部位，或由維管束組織運至生長中的莖葉或根組織，此為其生長發育之主要能量來源；運至胚中之醣類亦會重新合成澱粉並暫時儲存於胚中，於種子發芽初期短暫累積於胚盤組織，之後胚中澱粉主要累積部位則轉移至胚軸維管束組織周圍。由去除莖葉組織造成胚中澱粉過量累積或將植株移至全黑暗處理抑制光合作用造成胚中澱粉減少之現象，推測莖葉等積儲組織對碳素的需求會影響胚中澱粉之代謝。並且，由黑暗處理後胚中澱粉代謝酵素α-amylase之活性並未受到影響，而澱粉合成酵素granule-bound starch synthase (GBSS)Ⅰ, Ⅱ及starch branching enzyme(SBE) Ⅰ, Ⅱ, Ⅳ基因表現受到抑制，推測澱粉合成酵素扮演黑暗處理下胚中澱粉代謝之調控關鍵角色，並由黑暗處理後胚中水溶性醣類含量下降及黑暗處理同時外加葡萄糖後SBEIII表現相較黑暗處理有升高之現象，推測黑暗處理下水溶性醣類含量亦為胚中澱粉之代謝調控之間接調控因子。二部份：糖轉運蛋白(sucrose transporter; SUT)為負責運輸蔗糖進行跨膜運輸之轉運蛋白，經由水稻基因組序列分析，目前已知水稻具有五個SUT基因，分別命名為OsSUT1, 2, 3, 4, 5。本研究之目的為探討葡萄糖分子對水稻胚發芽時，胚中OsSUT1及OsSUT2基因表現之影響及其調控機制，首先藉由水稻分離胚培養之實驗，發現於培養液中加入葡萄糖，其於短時間(一天)培養後，OsSUT1之基因表現會被抑制，但在長時間(五天)於含葡萄之培養液中培養的胚組織中，OsSUT1之表現則會明顯的升高，由乾燥或是浸潤後四天之水稻胚處理葡萄糖一天後OsSUT1表現皆會受到抑制，得知此葡萄糖短時間與長時間效應對於OsSUT1之不同影響主要為葡萄糖處理時間長短所造成；另一方面，外加葡萄糖於培養液中，不論於短時間或長時間培養皆會促進OsSUT2表現，且其促進之效果隨培養時間增長而更為明顯。藉由葡萄糖衍生物3-O-Methylglucose以及六碳糖激酶(hexokinase)抑制物N-acetyl glucosamine對胚中SUT1, 2之影響得知葡萄糖對於OsSUT1基因之表現調控，不論於短時間或長時間之影響皆為Hexokinase-dependent pathway，而對OsSUT2基因之表現調控則為Hexokinase-independent pathway。Part1: ndosperm starch would be hydrolyzed to glucose and maltose and further being sent to the newly synthesized shoot and root through embryo during rice (Oryza sativa L.) seed germination and seedling establishment. In embryos, the soluble sugar from endosperm could be converted to starch and transiently accumulated in scutellums for few days. Following, the starch resynthesis was began to be presented in the cells surrounding the vascular bundles of embryos. Since the hyperaccumulation of starch in embryo tissues was observed in shoot-removing seedlings and low levels of starch content were found in low-photosynthetic efficiency seedling embryos in dark conditions, it was suggested that the amount of starch biosynthesis in embryo tissues were depended on the sink tissue demand. Accroding to the expressions of granule-bound starch synthase (GBSS)Ⅰ, Ⅱ, and starch branching enzyme (SBE) Ⅰ, Ⅱ, Ⅳ responsive to dark treatment, it indicated that the starch level in embryo tissues of growing seedlings in dark was mainly controlled by starch synthetic efficiency. Moreover, SBEIII expression in dark was recovered when glucose was supplied into medium. It was suggested that sugar may function as one of the factors to regulate SBEⅢ gene expression in embryos of young seedlings.art 2:ucrose transporters are transmembrane proteins in charge of transporting sucrose across cell membrane. There are five sucrose transporter isogenes in rice (Oryza sativa L.) and named OsSUT1, 2, 3, 4, 5. During embryo germination, effect of glucose on OsSUT1 expression in embryos presented a bi-phase process. OsSUT1 expression was repressed in embryos when germinated in glucose-containing medium after 1-d treatment; however, it was enhanced after 5-d treatment. It was proposed that the differential effects of glucose on OsSUT1 expression were mainly affected by glucose treatment period. Besides, OsSUT2 expression was enhanced in embryos when germinated in glucose-containing medium after 1 and 5-d treatment. According to the effects of sugar analog, 3-O-Methylglucose, and hexokinase inhibitor, N-acetyl glucosamine, on OsSUT1 expressions, it was suggested that the signal transduction for regulating glucose-responsive OsSUT1 expressions in embryos were mediated by hexokinase-dependent pathway. On the other hand, glucose affected OsSUT2 expression was through a hexokinase-independent.目錄-Ⅱ表目錄-Ⅲ寫對照表-Ⅳ一部份：水稻幼苗生長時期胚中暫存性澱粉累積之調控機制-1文摘要-2文摘要-3言-4料與方法-9果-18論-21考文獻-24表-30二部分：水稻種子發芽時期葡萄糖影響胚中蔗糖轉運蛋白基因表現之訊息傳導途徑-37文摘要-38文摘要-39言-40料與方法-46果-50論-54考文獻-58表-6
Hormone and sugar effects on rice sucrose transporter OsSUT1 expression in germinating embryos
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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