1,720,962 research outputs found
Isolasi Dan Karakterisasi Dengan Analisis 16s Rrna Bakteri Endofit Dari Tumbuhan Tembelekan (Lantana Camara L.) Sebagai Penghasil Senyawa Antibakteri
No full textPeningkatan kasus penyakit infeksi yang disebabkan oleh bakteri patogen, berdampak pada meningkatnya kejadian resistensi bakteri patogen terhadap antibiotik komersil yang saat ini banyak digunakan. Pemanfaatan tumbuhan akan menjadi sumber terbaik untuk mendapatkan berbagai obat yang alami dan aman. Salah satu tumbuhan yang telah diketahui khasiatnya sebagai obat adalah tumbuhan tembelekan (Lantana camara L.). Lantana camara L. dapat mengobati berbagai jenis penyakit. Bagian akar digunakan untuk mengobati penyakit influenza disertai demam tinggi, TBC kelenjar (skrofulodeurm), rematik, dan penyakit kulit. Bagian daunnya digunakan sebagai obat sakit batuk, kulit, bisul, bengkak, gatal-gatal, panas tinggi, rematik, dan memar. Permasalahannya adalah pengambilan senyawa bioaktif memerlukan biomassa yang cukup banyak. Alternatif terbaru dari permasalahan tersebut adalah dengan pemanfaatan bakteri endofit di dalam jaringan tumbuhan. Bakteri endofit merupakan mikroba yang hidup di dalam jaringan internal tumbuhan hidup tanpa menyebabkan efek negatif langsung yang nyata. Kemampuan bakteri endofit memproduksi senyawa metabolit sekunder sesuai dengan tumbuhan inangnya merupakan peluang yang sangat besar dan dapat diandalkan untuk memproduksi senyawa bioaktif yang berpotensi sebagai antibiotik. Isolasi bakteri dari tumbuhan Lantana camara L. menghasilkan sebanyak 21 isolat bakteri endofit. Semua isolat dilakukan uji aktivitas antibakteri terhadap bakteri patogen Escherichia coli, Salmonella enteritidis, Bacillus cereus, Staphylococcus aureus. Isolat potensial BT22 mampu menghambat keempat bakteri patogen. Selanjutnya dilakukan karakterisasi isolat BT22 dengan analisis sekuen 16S rRNA. Hasil analisis sekuen 16S rRNA menunjukkan bahwa isolat BT22 memiliki kemiripan sebanyak 99% dengan Bacillus amyloliquefaciens YB- 1402. Ekstraksi senyawa antibakteri isolat BT22 dengan menggunakan pelarut kloroform. Identifikasi senyawa antibakteri dengan analisis GC-MS menunjukkan beberapa senyawa antibakteri di antaranya : sikloheksanon, tetrakosan dan oktadekan
STUDI KOMPARASI HASIL BELAJAR BIOLOGI DENGAN PENERAPAN MODEL PEMBELAJARAN INSTAD (INQUIRY- STAD) DAN INKUIRI TERBIMBING (GUIDED INQUIRY) PADA SISWA KELAS X SMA NEGERI GONDANGREJO TAHUN PELAJARAN 2012/2013
Get PDFDina Dyah Saputri. K4309024. STUDI KOMPARASI HASIL BELAJAR
BIOLOGI DENGAN PENERAPAN MODEL PEMBELAJARAN INSTAD
(INQUIRY-STAD) DAN INKUIRI TERBIMBING (GUIDED INQUIRY)
PADA SISWA KELAS X SMA NEGERI GONDANGREJO TAHUN
PELAJARAN 2012/2013. Skripsi. Surakarta: Fakultas Keguruan dan Ilmu
Pendidikan. Universitas Sebelas Maret. April 2013.
Penelitian ini bertujuan untuk mengetahui pengaruh penerapan
pembelajaran Inquiry-STAD (InSTAD) dibandingkan dengan Inkuiri Terbimbing
(Guided Inquiry) terhadap hasil belajar biologi siswa kelas X SMA Negeri
Gondangrejo Tahun Pelajaran 2012/2013.
Penelitian ini adalah penelitian eksperimen semu (Quasy experiment).
Desain penelitian adalah Post-Test Only with Nonequivalent Group dengan
menggunakan kelas eksperimen 1 (penerapan strategi InSTAD) dan kelas
eksperimen 2 (penerapan strategi Inkuiri Terbimbing). Populasi penelitian adalah
seluruh siswa kelas X SMA Negeri Gondangrejo tahun pelajaran 2012/2013.
Teknik pengambilan sampel dengan cluster sampling dan diambil 2 kelas sebagai
kelas eksperimen 1 dan kelas eksperimen 2. Teknik pengumpulan data
menggunakan tes pilihan ganda, lembar observasi, dan dokumen sekolah. Uji
hipotesis menggunakan uji-t.
Kata kunci : Pembelajaran Inquiry STAD (InSTAD), Pembelajaran Inkuiri
Terbimbing (Guided Inquiry), Hasil Belajar Biolog
PHYTOCHEMICAL SCREENING AND GASS CROMATOGRAPHY MASS SPECTROMETER (GC-MS) ANALYSIS ETHANOL EXTRACT OF PURPLE SWEET POTATO (Ipomoea batatas L.)
Get PDFPurple sweet potato (Ipomoea batatas L.) leaves are extremely versatile that possesses high value. Sweet potato (Ipomoea batatas L.) leaves have secondary metabolism compounds that used as antibacterial and antifungal. The content of secondary metabolite compounds contained in plants an important role in providing antibacterial and antifungal activity so that this study was conducted to develop the utilization of purple sweet potato leaves through phytochemical screening. Phytochemical screening aims to provide an overview of the class of compounds contained in purple sweet potato leaf plants including of alkaloids, steroids-triterpenoids, saponins, flavonoids, and tannins test. Samples were taken from the local community of Bogor. The extract is made by extracting the simplicia of positive purple sweet potato leaves containing alkaloid, steroids-triterpenoids, saponins, flavonoids, and tannins. Further identification of active compounds was performed by Gass Cromatography-Mass Spectrometer (GC-MS) analysis to detect the active compound contained in purple sweet potato leaf extract more specifically. GC-MS analysis results show several active compounds including: 1.4-Benzenediol (CAS) Hydroquinone, Benzenesulfonic acid 4-hydroxy (CAS), Hexadecanoic acid (CAS) Palmitic acid
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
ASSESSMENT OF WATER QUALITY IN SITU TLAJUNG HILIR USING POLLUTION INDEX AND SAPROBIC QUOTIENT APPROACHES
Get PDFSitu Tlajung Hilir is a natural lake in West Java, utilized by the local community to support livelihoods and contributing to the balance of the surrounding ecosystem. However, pollution from industrial and residential activities has raised concerns over its declining water quality. This study aims to assess the water quality of Situ Tlajung Hilir using the Pollution Index (PI) and Saprobic Quotient (SQ) methods. A descriptive quantitative approach with purposive sampling was conducted at four observation stations. Research activities included field observation, sample collection, measurement of physical, chemical, and biological parameters, and laboratory analysis. Instruments were calibrated prior to use. PI values ranged from 1.02 to 1.04, indicating a slightly polluted status based on the Decree of the Minister of Environment No. 115 of 2003. SQ values ranged from -0.10 to -0.79, reflecting moderate to fairly heavy pollution. The PI analysis showed that dissolved oxygen (DO) and temperature did not meet Class III water quality standards. SQ analysis revealed a dominance of Euglenophyceae and Paramecium (Ciliates), both indicators of organic pollution. In conclusion, the water quality of Situ Tlajung Hilir is categorized as slightly to fairly heavily polluted. Emphasizing the need for ongoing monitoring and improved waste management to protect the aquatic ecosystem
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