Judul: Kajian bioprospeksi spons laut asal taman nasional kepulauan Wakatobi dan implikasi pengelolaannya
Abstrak: Most of eastern region of Indonesian waters are located in biodiversity center of coral triangle ecoregion and Wakatobi Archipelago Marine Park is one of them. Marine sponge is one of prominent benthic marine organism in coral reef. It is one of the prolific sources of pharmacological bioactive substances that are useful for drug development. About 30% of potentially natural products for drug lead had been isolated from marine sponges. Their bioactive substance has varied potential such as anticancer, antivirus, antimicrobe, anti-inflamation, and antimalaria. Based on preliminary cytotoxic assay on sponge crude extracts in 2008, marine sponge extracts (code W-19-08 and W-36-08) were among marine sponges collected from Wakatobi Archipelago National Park that had the potential of its cytotoxic activity. The purpose of this research were to examine sponge crude extract Lethal Concentration (LC50) and to describe human breast cancer cell line T47D morphology after treating with crude extract. The in vitro cytotoxicity assay was conducted using MTT method. In vitro cytotoxicity assay showed that marine sponge extracts W-19-08 and W-36-08 bioactivity were considered to medium with the LC50 value of 156.14 and 97.04 ppm, respectively. The cell line T47D morphology showed that these extracts were considered of having cytostatic properties.
Keyword: 

Judul: Uji Toksisitas Senyawa Bioaktif dari Bakteri yang Berasosiasi dengan Spons
Abstrak: Marine bacteria associated with sponges have been known as a source of bioactive compounds. Toxicity test of this compounds was done as initial test to determine the potency of bioactive compounds in pharmaceuticals development. The aim of this study was to extract and fractionate bioactive compounds from marine bacteria associated with sponges and to test its toxicity toward Artemia salina. Bacterial isolate of SAB E-31, SAB E-41, SAB E-57, HAL-13, HAL-74, and HAA-01 isolated from sponge were used as source of bioactive compounds. The bioactive compounds were extracted by using ethyl acetate. The ethyl acetate extract of SAB E-31, SAB E-41, SAB E-57, HAL-13, and HAA-01 were active with the lowest LC50 was 251.18 μg mL-1 from ethyl acetate extract of SAB E-41. The three of best ethyl acetate extract, SAB E-31, SAB E-41, and SAB E-57 were fractionated by preparative thin layer chromatography (PTLC) using eluent of nbutanol: ethyl acetate (3:7). Fractionation results of the three best ethyl acetate extract obtained 19 fractions, and 9 fraction among them were active fraction with the lowest LC50 from the fraction was 46.74 μg mL-1 come from SAB E-57.
Keyword: 

Judul: Analysis of M/G/1 Queue Model with Two Phases of Service and Bernoulli Feedback System
Abstrak: Model antrean M/G/1 dengan sistem feedback Bernoulli adalah model antrean dengan proses kedatangan mengikuti proses Poisson. Pada karya ilmiah ini dibahas sistem antrean M/G/1 dengan dua fase layanan. Setelah layanan pertama selesai, pelanggan dapat memilih untuk meninggalkan sistem dengan peluang ... dst, The M/G/1 queueing model with the Bernoulli feedback system is a queueing model with the arrival process following the Poisson process. In this manuscript M/G/1 queueing system with two phases of service is discussed. After the first service is completed, the customer can choose to leave the system with probability ... dst
Keyword: queue, Bernoulli, probability generating function, expected value