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Efek Ekstrak Etanol Pegagan (Centella Asiatica) Pada Stunting Larva Zebrafish (Danio Rerio) Akibat Induksi Rotenon Melalui Peningkatan Ekspresi Glucose Transporter 4 (Glut 4) Dan Osteocalcin
No full textStunting merupakan retardasi pertumbuhan linear yang ditandai dengan tinggi badan / panjang badan dibandingkan umur (TB/U; PB/U), nilai z-score nya berada dibawah -2 standar deviasi berdasarkan pengukuran WHO. Kriteria stunting yaitu bayi lahir normal tanpa kelainan kongenital dan memiliki panjang badan kurang dari 2 standar deviasi saat anak berusia 2 tahun. Berdasarkan Riset Kesehatan Dasar (2013) prevalensi stunting di Indonesia meningkat dari tahun 2010 (35,6%) menjadi 37,2% pada tahun 2013. Menurut WHO prevalensi balita stunting menjadi masalah kesehatan masyarakat jika prevalensinya ≥ 20%. Salah satu faktor yang mempengaruhi stunting adalah adanya paparan toksin atau pestisida. Pestisida bekerja sebagai Endocrine Disrupting Chemicals (EDCs) yang dapat mengganggu fungsi homeostasis hormon dalam tubuh. Rotenon merupakan salah satu jenis pestisida yang bekerja menghambat komplek I mitokondria yang dapat menyebabkan sistem transpor elektron terganggu, penurunan jumlah Adenosine Triphospate (ATP), meningkatnya ROS serta terjadi stres oksidatif. Stres oksidatif dapat mempengaruhi peran Insulin Reseptor Substrat (IRS) dalam memediasi aktifasinya terhadap jalur PI3K termasuk translokasi Glucose Transporter 4 (GLUT4). GLUT4 merupakan protein yang memediasi penyerapan dan transportasi glukosa yang merupakan sumber utama dalam pembentukan ATP. Selain itu stres oksidatif dapat menurunkan aktifitas osteoblastogenesis dan meningkatkan osteoclastogenesis sehingga pertumbuhan tulang terhambat. Osteoblas yang tidak terbentuk akan mempengaruhi sekresi osteocalcin. Sedangkan osteocalcin berperan penting pada mineralisasi tulang dimana mineral sangat dibutuhkan pada proses osteogenesis yaitu pembentukan dan pertumbuhan tulang. Pegagan (Centella asiatica) merupakan tanaman yang mengandung teriterpenoid berperan sebagai antioksidan yang dapat menyeimbangkan oksidan dalam sel sehingga stres oksidatif dapat diturunkan. Selain itu pegagan mengandung makronutrien, mikronutrien, vitamin dan mineral yang sangat penting dan dibutuhkan pada proses pertumbuhan.
Tujuan penelitian ini adalah mengetahui efek ekstrak etanol pegagan (Centella asiatica) dapat mempengaruhi panjang badan pada stunting larva zebrafish akibat induksi rotenon melalui ekspresi GLUT 4 dan Osteocalcin. Pada penelitian terdahulu telah dibuktikan rotenon konsentrasi 10 ppb mampu menurunkan panjang badan larva zebrafish namun hasilnya belum maksimal. Sehingga pada penelitian ini dilakukan eksplorasi kembali dan dibuktikan rotenon konsentrasi 12,5 ppb mampu menyebabkan stunting.
Metode penelitian ini adalah eksperimen dengan desain post-test-only control group menggunakan hewan coba zebrafish. Sampel diinduksi rotenon konsentrasi 12,5 ppb sejak 2-72hpf. Ekstrak etanol pegagan digunakan konsentrasi 1,25μg/ml; 2,5 μg/ml; dan 5 μg/ml dan dipapar secara bersamaan dengan rotenon. Larva diikuti perkembangannya dan diukur pertumbuhannya dengan cara mengukur panjang badan larva zebrafish usia 3,6 dan 9 dpf menggunakan software Image Raster 3. Pada 9 dpf, dilakukan pengukuran ekspresi GLUT4 dan osteocalcin menggunakan whole mount immunohistochemistry (IHC) dengan pewarnaan DAB. Warna coklat yang terekspresi dikuantifikasi menggunakan software imageJ melalui nilai integrated density dalam satuan pixel.
Hasil penelitian menunjukkan pada usia 3 dpf (analog dengan bayi baru lahir) larva zebrafish yang dipapar rotenon tidak ada perbedaan rerata panjang badan secara signifikan pada seluruh kelompok. Pada usia 6 dpf (analog dengan anak usia 2 tahun) dan 9 dpf (analog dengan anak usia 8 tahun) didapatkan hasil selisih panjang badan larva zebrafish > 2SD dan berbeda signifikan (<0,05) dengan kelompok kontrol. Semua kelompok pada usia 3,6 dan 9 dpf memiliki rasio panjang badan yang sama yaitu 1:5. Sehingga dapat disimpulkan stunting akibat induksi rotenon 12,5 ppb terjadi mulai usia 6 hingga 9 dpf. Pada kelompok rotenon pegagan, rata-rata panjang badan larva zebrafish usia 3 dpf tidak terdapat perbedaan signifikan antara semua kelompok. Rata-rata panjang badan larva zebrafish usia 6 dpf yang dinduksi rotenon pegagan konsentrasi 1,25μg/ml tidak terdapat perbedaan signifikan dengan kelompok rotenon, sedangkan pada konsentrasi 2,5μg/ml dan 5μg/ml terdapat perbedaan signifikan. Pada larva zebrafish usia 9 dpf terdapat perbedaan rata-rata panjang secara signifikan pada konsentrasi 2,5μg/ml dan 5μg/ml dengan kelompok rotenon. Ekspresi GLUT4 dan Osteocalcin pada larva zebrafish yang diinduksi rotenon menurun secara signifikan dibandingkan kelompok kontrol. Ekspresi GLUT4 meningkat secara signifikan dengan penambahan pegagan konsentrasi 5μg/ml, sedangkan ekspresi Osteocalcin meningkat secara signifikan dengan penambahan pegagan konsentrasi 2,5μg/ml dan 5μg/ml.
Korelasi pearson menunjukkan adanya hubungan positif dan sangat kuat antara konsentrasi pegagan dengan ekspresi GLUT4 (0,880) serta hubungan positif dan kuat pada ekspresi Osteocalcin (0,671). Korelasi antara GLUT4 dan Osteocalcin dengan panjang badan memiliki hubungan positif dan kuat. Korelasi antara ekspresi GLUT4 dengan Osteocalcin memiliki hubungan positif dan sangat kuat (0,760).
Kesimpulan penelitian ini adalah rotenon 12,5 ppb dapat menginduksi terjadinya stunting larva zebrafish (Danio rerio). Penambahan ekstrak etanol pegagan dapat memberikan efek terhadap stunting larva zebrafish melalui peningkatan ekspresi GLUT4 dan Osteocalcin yang ditunjukkan dengan adanya peningkatan panjang badan
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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