Judul: Bioactivity of Essential Oil from Suren (Toona sinensis Roemor) Based on the Brine Shrimp Lethality Test (BSLT)
Abstrak: Penelitian ini bertujuan untuk menetapkan rendemen minyak atsiri pada bagian daun, kayu teras, kayu gubal dan kulit serta menentukan bioaktivitas minyak atsiri dari pohon suren (Toona sinensis Roemor). Pada masa sekarang minyak atsiri suren telah diuji untuk digunakan sebagai insektisida. Oleh karena itu, minyak atsiri menarik untuk diteliti pada seluruh bagian pohon. Pohon suren yang diteliti berasal dari hutan masyarakat, di Kecamatan Cibadak, Kabupaten Sukabumi. Pohon ini memiliki tinggi ± 11 m dengan diameter ± 23 cm. Bagian pohon yang digunakan adalah daun, kulit dalam, kayu teras dan kayu gubal. Untuk menghasilkan nilai rendemen, bahan baku disuling dengan metode uap dan air. Untuk menentukan bioaktivitasnya dilakukan pengujian terhadap larva udang Artimia salina Leach. melalui metode Brine Shrimp Lethality Test. Uji Kromatografi Lapis Tipis (KLT) dilakukan untuk menduga jumlah senyawa yang terdapat pada minyak atsiri tersebut.
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Judul: Bioactivity of Essential Oil from Suren (Toona sinensis Roemor) Based on the Brine Shrimp Lethality Test (BSLT)
Abstrak: INTRODUCTION. This study to determine the yield of essential oil from the leaves, heart wood, sap wood and inner bark, and also to determine the bioactivity of essential oil from suren (Toona sinensis Roemor). E ANALYSIS AND METHOD. ssential oil of suren leaves have been tested for use as insecticide. Because of that, essential oil of suren are interesting to studied. Parts of trees that used are the leaves, inner bark, heart wood and sap wood. To generate the yield, the raw materials are destilated using method steam and water. As for determining bioactivity conducted tests on shrimp larvae Artimia salina Leach. through the Brine Shrimp Lethality Test methods. Thin Layer Chromatography Test (TLC) was conducted to estimate the number of compounds contained in the essential oil RESULT AND DISCUSSION. . The results showed that yield of the sap wood is (0.388%), heart wood (0.379%), leaves (0.302%), and inner bark (0.051%), which yield greatest value in the sap wood. The results of bioactivity tests showed LC50 values at the leaf essential oil (11.203 μg/mL), inner bark (6.851 μg/mL), heart wood (3.968 μg/mL), and sap wood (1.293 μg/mL). These results indicate that all essential oils are bioactive against A. salina and sapwood essential oils have the highest bioactivity effect. The results of the analysis by TLC showed that essential oils from various parts of the tree is thought to contain terpenoid compounds. Keyword: Surianwood, cederwood, bioactivity, Artemia salina.
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Judul: Approximation of the Median of Poisson Distribution Using the Relation of Poisson-Gamma Distribution
Abstrak: A major drawback of median is that median cannot usually be defined in closed form, even in the cases where their distribution functions are known. This study gives an approximation of the closed form for the median of the Poisson distribution by using the relation of Poisson-Gamma distribution. The approximation uses elementary techniques based on the monotonicity of certain sequences involving tail probabilities of the Poisson distribution and the Central Limit Theorem. Furthermore, a closed form expression for the mean absolute deviation 􀜧|􀜰􀰒 􀵆 􀜯􀝁􀝀􁈺􀜰􀰒􁈻| is also studied. The median is relevant because of the fact that it minimizes the mean absolute deviation of a Poisson random variable (􀜰􀰒􁈻 by considering median as central tendency.
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