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Development of germ cell transplantation method into the sterile gonads of adult fish.
Get PDF魚類において初めて生殖細胞を欠損する不妊化卵巣内へのドナー生殖細胞の移植を行い、ドナー由来の機能的な卵の生産に成功した。宿主として用いたニベ×シログチの種間雑種は生殖細胞欠損型の不妊を示し、三倍体化により卵巣様生殖腺が分化することを確認した。さらに、この卵巣様生殖腺がドナー由来卵を生産できることを証明した。一方で、XX型の性染色体を有する卵原細胞をドナーとして精巣様生殖腺内に移植したとき、卵原細胞に由来するドナー由来精子が生産された。この精子を用いて次世代子孫を作出したところ、次世代は全てメスとなった。このことは本生殖細胞移植技術が、全メス種苗生産を可能にする新たな手法となることを示している。For the first time in fishes, donor germ cells were transplanted into infertile ovaries lacking germ cells, and functional donor-derived eggs were successfully produced. The interspecies hybrid of Nibe x Shiroguchi used as a recipient showed germ cell-deficient sterility, and it was confirmed that the ovary-like gonads were differentiated by triploidization. Furthermore, we proved that this ovary-like gonad can produce donor-derived eggs. On the other hand, when oogonia with XX sex chromosomes were transplanted into the testis-like gonads as donors, donor-derived sperm derived from the oogonia were produced. When the next generation offspring were produced using these sperm, all of the next generation were females. This indicates that this germ cell transplantation technique can be a new method for the production of all-female seedlings.研究課題/領域番号:18K05826, 研究期間(年度):2018-04-01 – 2021-03-31出典：「海産魚卵巣内への生殖幹細胞移植技術の開発：ドナー由来の卵を短期間で生産する」研究成果報告書 課題番号18K0582
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-18K05826/18K05826seika/）を加工して作成金沢大学理工研究域生命理工学系research repor
RNA干渉法を用いた母性mRNAノックダウンによる不稔化エゾアワビ種苗の作出
Get PDFRNA干渉法による不妊化アワビの種苗生産するための基盤技術の開発を行った。RNA干渉法に着目し、アワビの初期胚内で生殖細胞の発生に必須な母性因子を一時的に減少させた状態で発生させる条件を決定した。標的遺伝子として、vasa遺伝子を選定し、約300bpのdouble strand RNA (ds-RNA）を合成し、産卵直前のアワビ卵巣へ注入した。ds-RNAには、あらかじめDIG標識を施し、注入後のds-RNAの挙動を調べたところ、注入後3時間以降で、卵母細胞内に移行することが明らかとなった。さらに、このアワビを産卵させることで、受精卵内で母性vasa mRNA量を減少させることに成功した。The sterilization of artificial seeds of abalone is an ideal strategy to promote faster growth and to avoid sexual precocity. Recently, RNA interference (RNAi) is the popular method for the production of sterile animals in vertebrates and invertebrates, and identification of target gene for this technology is a crucial step to the production of sterilization. To evaluate effects of vasa gene knockdown, the dispersion and inhibitor effect of vasa dsRNA in ovary were examined. After 12 hours post-injection, dsRNA with vasa DIG-labelled delivered to full-grown oocytes of female. Expression levels of vasa in RNAi group using 3 different dose of dsRNA were significantly lower than control group at 7 days post-injection (dpi) and 14 dpi. Similar inhibitor effects were observed in unfertilized eggs and 8-cell stage of embryos. The results suggest that RNAi of vasa gene can be effectively utilized in oocytes and early embryos of pacific abalone to reduce amount of mRNA level.研究課題/領域番号:15K14802, 研究期間(年度):2015-04-01 - 2018-03-31出典：研究課題「RNA干渉法を用いた母性mRNAノックダウンによる不稔化エゾアワビ種苗の作出」課題番号15K14802
（KAKEN：科学研究費助成事業データベース（国立情報学研究所））
（https://kaken.nii.ac.jp/report/KAKENHI-PROJECT-15K14802/15K14802seika/)を加工して作成金沢大学理工研究域生命理工学系 / 鹿児島大学 / 東京海洋大学research repor
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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