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Tetraploidisasi Kejut Suhu Dingin pada Ikan Patin Siam (Pangasianodon hypophthalmus) dengan Suhu dan Umur Zigot yang Berbeda
No full textIkan patin siam (Pangasianodon hypophthalmus) merupakan salah satu
komoditas ikan air tawar yang memiliki nilai prospektif dari segi pembenihan,
pembesaran, pengolahan serta luasnya wilayah produksi budidaya. Sentra usaha
ikan patin telah banyak dikembangkan di beberapa daerah di Indonesia
seperti Sumatera Selatan, Riau, Jambi, Kalimantan Barat dan Jawa Barat.
Pengembangan budidaya ikan patin siam telah berhasil dilakukan,
namun ikan patin siam memiliki pertumbuhan yang relatif lambat. Sehingga
biaya operasional produksi menjadi tinggi sementara harga jualnya rendah,
yang mengakibatkan budidaya ikan patin tidak efisien.
Perbaikan mutu genetik melalui rekayasa set kromosom (poliploidisasi)
yaitu menghasilkan ikan triploid (3n) steril, diharapkan dapat mengatasi masalah
tersebut. Pada ikan triploid (3n) steril memungkinkan peralihan energi metabolisme
untuk perkembangan gonad digunakan untuk pertumbuhan somatik sehingga
pertumbuhannya lebih cepat. Produksi secara massal dapat dilakukan melalui
perkawinan ikan diploid (2n) dengan ikan tetraploid (4n). Ikan tetraploid dihasilkan
dengan proses pencegahan pembelahan mitosis pada telur yang telah terfertilisasi
dengan pemberian kejutan suhu, sehingga telur yang mempunyai dua set kromosom
(2n) akan mengalami penggandaan menjadi empat set kromosom (4n). Kejutan
suhu dapat dilakukan dengan kejutan dingin (cold shock). Penelitian ini bertujuan
untuk mengevaluasi kondisi optimum tetraploidisasi menggunakan kejutan dingin
pada suhu dan umur zigot berbeda pada ikan patin siam (Pangasianodon
hypophthalmus).
Rancangan Acak Lengkap (RAL) faktorial dengan enam perlakuan
dan lama kejutan selama 30 menit, yaitu (P1) suhu 8 oC umur zigot 29 (menit
setelah fertilisasi), (P2) suhu 8 oC umur zigot 31 (msf), (P3) suhu 12 oC umur
zigot 29 (msf), (P4) suhu 12 oC umur zigot 31 (msf), (P5) 16 oC umur zigot
29 (msf), (P6) suhu 16 oC umur zigot 31 (msf), dan satu kontrol (P0) tanpa
pemberian perlakuan kejutan suhu. Setiap perlakuan menggunakan tiga kali
ulangan.
Pemijahan ikan dilakukan dengan perangsangan hormonal menggunakan
hormon human chorionic gonadotropin (hCG) dan Ovaprim (sGnRH +
Domperidone) pada induk betina, sedangkan pada induk jantan menggunakan
Ovaprim. Telur dan sperma yang telah di stripping dicampur dan diaduk
menggunakan bulu ayam, setelah itu diaktivasi dengan menambahkan 100 mL air
mineral dan umur zigot mulai dihitung. Telur yang telah terfertilisasi dicuci
menggunakan suspensi tanah untuk menghilangkan daya rekat telur, kemudian telur
dimasukkan dalam pipa PVC untuk selanjutnya diberi kejutan suhu pada wadah
perlakuan. Wadah perlakuan yang digunakan yaitu styrofoam yang telah diisi air
dan suhu dingin diatur menggunakan es batu sesuai dengan masing-masing
perlakuan. Setelah perendaman telur diangkat dan diinkubasi dalam setiap
akuarium sebanyak ±1500 butir. Larva ikan hasil penetasan dipelihara selama 15
hari di dalam toples yang telah dicuci dan diisi air serta dilengkapi sistem aerasi,
dengan kepadatan 100 ekor/toples. Pakan yang diberikan berupa Artemia dan
cacing sutra sesuai dengan umur larva. Pergantian air media pemeliharaan
dilakukan saat larva umur 6 hari, sedangkan sisa-sisa pakan dibuang dengan cara
penyifonan dan pengamatan kualitas air dilakukan 2 kali sehari dengan parameter
suhu, pH dan oksigen terlarut.
Identifikasi tetraploid dilakukan dengan penghitungan jumlah maksimum
nukleolus yang dikonfirmasi dengan penghitungan jumlah kromosom dilakukan
pada 30 sampel untuk setiap perlakuan. Parameter penelitian yang diamati pada
penelitian ini adalah derajat pembuahan, derajat penetasan, abnormalitas,
kelangsungan hidup dan persentase tetraploid. Data hasil penelitian dianalisis
secara statistik dengan uji ANOVA (analysis of variance) dan menggunakan uji
Duncan, pada parameter derajat pembuahan dan persentase tetraploid dianalisis
secara deskriptif.
Hasil pengamatan derajat pembuahan diperoleh nilai rata-rata sebesar
65.20%. Berdasarkan hasil uji statistik derajat penetasan dan abnormalitas
menunjukkan hasil yang berbeda nyata (P<0.05) antar perlakuan, namun
kelangsungan hidup tidak berbeda nyata (P>0.05) antar perlakuan. Hasil derajat
penetasan menunjukkan bahwa semakin tinggi intensitas suhu yang diberikan maka
hasil yang diperoleh semakin rendah, sedangkan hasil abnormalitas menunjukkan
bahwa semakin tinggi intensitas suhu yang diberikan maka persentase abnormalitas
semakin tinggi. Hasil pengamatan pada ikan tetraploid diperoleh jumlah maksimum
nukleolus yaitu empat per sel dan pada ikan diploid diperoleh jumlah maksimum
nukleolus yaitu dua per sel, sedangkan pada pengamatan kromosom diperoleh
jumlah kromosom tetraploid 112 (4n=112) dan jumlah kromosom diploid yaitu 56
(2n=56). Hasil pengamatan persentase tetraploid menunjukkan bahwa semakin
tinggi intensitas suhu yang diberikan maka persentase tetraploid yang diperoleh
semakin tinggi, sedangkan semakin lama umur zigot maka persentase tetraploid
yang diperoleh semakin rendah.
Berdasarkan hasil penelitian diperoleh kondisi optimum tetraploidisasi
menggunakan kejutan dingin pada ikan patin siam yaitu pada suhu 12 oC, umur
zigot 29 msf dengan lama kejutan 30 menit menghasilkan ikan tetraploid 66.67%
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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