Judul: Eksplorasi Potensi Daun, Kulit Batang, dan Kulit Ranting Rhizophora mucronata (Lamarck) sebagai Bahan Antidiare
Abstrak: Rhizophora mucronata adalah salah satu tumbuhan yang mempunyai potensi sebagai obat antidiare yang dapat dikonsumsi oleh masyarakat pesisir. Penelitian ini bertujuan menentukan aktivitas antibakteri daun warna hijau muda (DM), daun warna hijau tua (DT), kulit batang (KB), dan kulit ranting (KR) mangrove jenis Rhizophora mucronata berdasarkan terhadap bakteri penyebab diare (Entheropathogenic Escheria coli dan Staphylococcus aureus). Sampel diektraksi dengan metode maserasi dan refluks serta dilakukan uji fitokimia. Metode difusi digunakan untuk menguji aktivitas antibakteri dan metode Fiolin-Ciocalteu dengan standar asam galat digunakan untuk penentuan kuantitatif total fenol. Ekstrak kulit ranting memiliki total fenol tertinggi sebesar 44.0204 mgg-1 dan dihasilkan aktivitas antibakteri yang tinggi terhadap bakteri EPEC dan S. aureus.
Keyword: antibakteri, daun, kulit batang, Rhizophora mucronata, kulit ranting

Judul: Aktivitas Antibakteri Ekstrak Daun Bakau Hitam Rhizophora mucronata terhadap Bakteri Penyebab Diare
Abstrak: Diarrhea is one of the major health problems in Indonesia. One of the first caused is bacteria. Leaves of Rhizophora mucronata have been widely used by coastal people as folk medicine for treating diarrhea. The aims of this study was to determine the effectivity and inhibitory of Rhizophora mucronata leaf extract as antibacterial to diarrhea-causing bacteria. The procedure of this research used antibacterial assay determined by agar well diffusion method. The activity of each extract was tested by using diarrhea-causing bacteria. Methanol extract of R. mucronata leaf was the highest yield (21.47%). The active compounds of methanol and aqueous extracts consisted of tannin, saponin, flavonoid, phenol hydroquinone, and triterpenoid. Alkaloid was only showed in methanol extract. Methanol extract had the highest antibacterial activity with inhibition zone of 3-12 mm. Minimum inhibitory concentrations of methanol extract were 0.4 mg/mL (Escherichia coli dan Pseudomonas aeruginosa), 0.2 mg/mL (Staphylococcus aureus), and more than 0.4 mg/mL (EPEC dan Salmonella typhimurium). Bioautography of antibacterial activity toward E. coli revealed the active fractions with Rf value of 0.11 and 0.72. Preliminary identification using Dragendorff spray reagent detected the active compound was alkaloid
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Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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