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Study of microRNAs involved in wounding response n sweet potato
No full textmicroRNA (miRNA)是一段由生物體內自行合成約21-24鹼基的小分子核醣核酸，不轉譯出任何蛋白，其藉由降解mRNA或抑制mRNA進行蛋白質轉譯來達成調控基因表現。近年來在阿拉伯芥上發現超過百種的miRNA，且研究指出miRNA參與植物不同階段的生長發育及抵抗不同環境的變化，所以我們對於與植物傷害相關的miRNA有著極大興趣，希望探討傷害相關miRNA的訊息傳遞的過程。藉由miRNA序列在演化具有高度保留性的特性，利用阿拉伯芥miRNA的序列當作探針探討甘藷植株在遭受傷害後miR159、miR407、miR828的表現情形。在甘藷植株中無偵測到miR407的表現；miR159可在莖中被偵測到，而在葉中表現量極低；miR828則在葉中被偵測到。此外，在甘藷傷害後，miR159表現量並未隨時間不同有所變化，而miR828表現量卻會被抑制。且處理誘導傷害防禦機制相關的分子，如:過氧化氫(hydrogen peroxide, H2O2)、一氧化氮(nitric oxide, NO)、甲基茉莉酸(Methyl jasmonate, MeJA)、離層酸(abscisic acid, ABA)及乙烯(ethylene)，也會抑制miR828的表現。我們再藉由不同誘導劑與抑制劑探討miR828表現情形進而探討其訊息傳遞的過程，推測植物傷害後，促使NO與MeJA生合成，而MeJA也會而活化NOS產生NO，而NO再活化NADPH oxidase產生H2O2，或者MeJA本身也會透過過其他分子，而抑制miR828表現進而調控miR828標的基因表現。此外，ethylene也會透過MeJA抑制miR828表現，而一氧化碳(carbon monoxide, CO)會在之中清除H2O2進而抑制傳遞過程。而miRNA藉由序列互補性辨識標的基因，進而對標的基因進行靜默 (silencing)。我們利用cDNA clone釣取到三個可能的miR828標的基因，分別為receptor protein kinase (RPK)、TLD和MYB。藉由傷害後因miR828表現被抑制而減少對標的基因mRNA降解或降低抑制標的基因蛋白質轉譯，使得標的基因的表現進而參與傷害防禦調控機制。MicroRNAs (miRNAs) contain approximate 22 nucleotides that post-transcriptionally regulate gene expression by directing mRNA cleavage or translational inhibition. Currently, more than one hundred miRNAs that play multiple roles in growth, development, and stress responses of plants have been identified in Arabidopsis thaliana. Here, I investigated the expression patterns of miR159, miR407, and miRNA828 upon wounding in sweet potato. The expression of miR407 was undetectable in leaves and stems. However, miR159 was expressed in stems and, at low levels, in leaves, whereas miR828 was expressed in leaves and undetectable in stems. Furthermore, the expression of miR828 was decreased upon wounding in sweet potato. Additionally, several defensive responding compounds, including hydrogen peroxide (H2O2), nitric oxide (NO), methyl jasmonate (MeJA), abscisic acid (ABA), and ethylene also suppressed miR828 expression. However, carbon monoxide (CO) suppressed repression of miR828 by wounding. Interactions among these defensive responding compounds for the regulation of miR828 were also studied. Results suggested that wounding stimulates the biosynthesis of MeJA and NO. Then, MeJA activates NO synthase to generate NO. Finally, NO inspires the activity of NADPH oxidase to generate H2O2, which suppress miR828 expression. In addition to miR828, three potential miR828 targeted genes, receptor protein kinase (RPK), TLD, and MYB were isolated and were up-regulated by wounding. In addition, RPK, TLD, and MYB were regulated by NO and H2O2 when miR828 was repressed. These results imply that wounding represses the expression of miR828, and consequently regulates the expression of RPK, TLD, and MYB genes to protect plants from damage.中文摘要 文摘要 一章 前言 一、植物的防禦機制•••••••••••••••••••••••••••••••••••••• 1二、miRNA的作用與機制•••••••••••••••••••••••••••••••••• 3三、實驗方向與目的•••••••••••••••••••••••••••••••••••••• 7二章 材料與方法 一、材料••••••••••••••••••••••••••••••••••••••••••••• 8二、實驗材料處理與藥劑••••••••••••••••••••••••••••••••••• 8三、Total RNA萃取•••••••••••••••••••••••••••••••••••••• 9四、Small RNA電泳•••••••••••••••••••••••••••••••••••••• 9五、北方墨點法分析•••••••••••••••••••••••••••••••••••••• 9六、Rapid Amplification of cDNA Ends (RACE)••••••••••••••••••••• 11七、質體構築•••••••••••••••••••••••••••••••••••••••••• 13八、Reverse transcription-polymerase chain reaction (RT-PCR)••• ••••••••• 14九、Small RNA釣取•••••••••••••••••••••••••••••••••••••• 15三章 結果 一、miRNA在甘藷傷害表現之確認•••••••••••••••••••••••••••• 18二、miR828訊息傳導••••••••••••••••••••••••••••••••••••• 19三、miR828標的基因••••••••••••••••••••••••••••••••••••• 23四、甘藷miRNA釣取••••••••••••••••••••••••••••••••••••• 26四章 討論 一、 miR159、miR407、miR828表現情形••••••••••••••••••••••••• 27二、miR828的訊息傳遞過程•••••••••••••••••••••••••••••••• 28三、miR828標的基因表現情形••••••••••••••••••••••••••••••• 32四、結論••••••••••••••••••••••••••••••••••••••••••••• 35表••••••••••••••••••••••••••••••••••••••••••••••••••••••• 36考文獻•••••••••••••••••••••••••••••••••••••••••••••••••••• 5
Nitric oxide activates superoxide dismutase and ascorbate peroxidase to repress the cell death induced by wounding
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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