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Glucose-oxidase based self-destructing polymeric vesicles
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Isolasi dan Karakteristik Enzim Selulase dari Bacillus sp. 13843 B15 dan Bacillus licheniformis C55
Get PDFLimbah padat karagenan merupakan salah satu Iimbah yang belum dimanfaatkan dan menjadi masalah pencemaran lingkungan k.ar.ena limbah tersebut mengandung selulosa yang sulit larut dalam air. Selama ini Iimbah padat dari industri karagenan dimanfaatkan sebagai biomaterial pengisi, penguat komposit dan pupuk untuk tanaman. Isolasi mikroba selulolitik dari Iimbah karagenan diharapkan Iebih mampu menguraikan selulosa pada Iimbah karagenan. Tujuan Penelitian ini untuk mengetahui isolat penghasil selulase yang diisolasi dari limbah karagenan serta karakteristik enzim selulase yang dihasilkan. Tahapan penelitian ini meliputi isolasi mikroba dari Iimbah karagenan, identifikasi isolat terpilih, karakterisasi enzim serta aplikasi enzim selulase dari isolat terpilih dan memanfaatkan Iimbah karagenan sebagai komponen media produksi enzim selulase. Identifikasi isolat terpilih meliputi identifikasi secara morfologi, biokimia dan molekuler menggunakan 16S rRNA. Karakterisasi enzim meliputi penentuan massy molekul menggunakan SDS-PAGE dan zimogram, pengaruh suhu dan pH terhadap aktivitas enzim serta pengaruh ion logam terhadap aktovitas enzim. Data yang diperoleh kemudian dianalisa secara deskriptif kuantitatif. Hasil penelitian ini didapatkan dua bakteri yaitu B15 dan C55. Isolat ini tumbuh pada media pH 8 suhu 50°C, bersifat gram positif berbentuk batang. Berdasarkan hasil sekuensing gen penyandi 16S rRNA dari isolat B15 sebanyak 1393 pasang basa diperoleh kemiripan sebesar 99% dengan bakteri Bacillus sp. 13843 dan isolat Bacillus licheniformis C55 sebanyak 1397 pasang basa diperoleh kemiripan sebesar 100% dengan bakteri Bacillus licheniformis. Karakteristik enzim selulase kasar isolat Bacillus sp. 13843 B15 memiliki Aktivitas optimum pada pH 8 sebesar 0,72 U/mL dan suhu inkubasi 50°C sebesar 0,62 U/mL. Enzim relatif stabil terhadap inkubasi suhu 50°C pada pH 8 selama 30 menit. Terdapat 1 pita selulase dengan perkiraan berat molekul yaitu 30 kDa. Pengujian substrat spesifik dari filter paper dan CMC menghasilkan aktivitas enzim tertinggi sebesar 0,35 U/mL. Keberadaaan ion logam yang dapat meningkatkan aktivitas enzim selulase adalah Mg2+. Sedangkan karakteristik enzim selulase kasar isolat Bacillus licheniformis C55 memiliki aktivitas optimum pada pH 8 sebesar 0,70 U/mL dan suhu inkubasi 50°C sebesar 0,35 U/mL. Enzim relatif stabil terhadap inkubasi suhu 50°C pada pH 8 selama 30 menit. Terdapat 1 pita selulase dengan perkiraan berat molekul yaitu 18 kDa. Pengujian substrat spesifik dari CMC menghasilkan aktivitas enzim sebesar 0,25 U/mL Iebih tinggi daripada aktivitas enzim dari filter paper sebesar 0,13 U/mL. Penambahan enzim selulase dari isolat terpilih berpotensi dalam menghidrolisi Iimbah karagenan menghasilkan kadar gula pereduksi tertinggi pada limbah karagenan dengan perlakuan NaOH 6% sebesar 1,18 mg/mL (isolat Bacillus sp. 13843 B15) dan 0,76 mg/mL (isolat Bacillus licheniformis C55). Pemanfaatan Iimbah karagenan sebagai komponen media produksi selulase menghasilkan aktivitas enzim tertinggi sebesar 0,43% (isolat Bacillus sp. 13843 B15 dan Bacillus licheniformis C55) pada Iimbah karagenan dengan perlakuan NaOH 4%
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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