Judul: Screening of Active Compounds based on Biological  Activities and NMR Spectroscopy of Tunicates and Soft Corals from Raja Ampat
Abstrak: Raja Ampat merupakan salah satu daerah di Indonesia yang terletak di pusat wilayah segitiga terumbu karang dan termasuk lokasi dengan biodiversitas laut terkaya di dunia. Penelitian ini bertujuan menapis lapisan etil asetat dari tunikata dan karang lunak asal Raja Ampat berdasarkan data aktivitas hayati dan spektrum NMR ¹H. Penapisan berdasarkan aktivitas dengan Artemia salina menunjukkan hasil baik sekali (faktor-Z = 0,88). Lapisan etil asetat tunikata Lissoclinum patella terpilih memiliki toksisitas terampuh (LC50 = 2,436 ± 0,345 µg/mL) terhadap A. salina dan menyebabkan malformasi mayor pada sumbu tubuh dan edema perikardial pada embrio ikan zebra (Danio rerio) pada konsentrasi 3 µg/mL. Tunikata Clavelina zobustra menunjukkan aktivitas selektif terhadap bakteri Gram negatif Klebsiella pneumoniae (1300 µg/mL atau 260 µg/disk) dengan zona hambat 8,75 ± 0,5 mm. Spektrum NMR ¹H sampel menunjukkan keberadaan beragam gugus fungsi dan substruktur berasal dari terpenoid, alkaloid, peptida, dan poliketida., Raja Ampat is one of the regions in Indonesia located in the center of the coral reef triangle and one of the locations with the richest marine biodiversity in the world. The aim of this study was to screen ethyl acetate layers from tunicates and soft corals from Raja Ampat based on biological activity data and ¹H NMR spectra. Biological activity screening using Artemia salina was proven as an excellent assay (Z-factor = 0,88). The selected ethyl acetate layer of tunicate Lissoclinum patella showed the most potent toxicity (LC50 = 2,436 ± 0,345 µg/mL) against A. salina and caused major malformations in the body axis and pericardial edema of zebrafish embryos (Danio rerio) at 3 µg/mL concentration. Tunicate Clavelina zobustra showed a selective antibacterial activity against Gram-negative bacteria Klebsiella pneumoniae (1300 µg/mL or 260 µg/disk) with an inhibition zone of 8,75 ± 0,5 mm. The ¹H NMR spectra of the sample showed the presence of various functional groups and substructures derived from terpenoids, alkaloids, peptides, and polyketides.
Keyword: antibacterial, Artemia salina, NMR, zebrafish embryos

Judul: Struktur Komunitas Invertebrata Laut di Kolom dan Sedimen  dengan Menggunakan Teknik Environmental DNA (eDNA) Metabarcoding  di Kawasan Terumbu Karang Raja Ampat
Abstrak: Invertebrate biodiversity monitoring activities carried out conventionally using direct fishing techniques and identification will be difficult, costly, time-consuming and can cause damage to the environment and communities. Previous studies related to biodiversity surveys of benthic invertebrate larvae have been carried out conventionally but it is difficult to identify them at the species level and only at the genus or family level. Environmental DNA (eDNA) is a molecular biology technique that has developed rapidly because this technique has been successfully applied as a survey method for new aquatic organisms in aquatic ecosystem research and biomonitoring programs and management on a large scale. This study aims to determine the structure community using the eDNA metabarcoding technique by comparing the water and sediment columns at the protected reefs of Raja Ampat, Indonesia. A total of 66 eDNA samples was collected from water and sediment columns. The sample extraction process was carried out using a protocol from the commercial Kit NucleoSpinTM Macherey-Nagel and followed by a PCR process using universal eukaryote primers targeting the 18S gene then sequencing using the Illumina Miseq technique. The order of the taxonomy is done using QIIME2 software and the SILVA database. This study succeeded in detecting 13 species of invertebrates in the water column and 9 species of sediment using NMDS statistical test with a distance matrix Bray-Curtis similarity and Andonis test showed , the number of sequence readings in the water column and sediment was not significantly different (p > 0.05). Shannon Wiener Index (H ') showed the low to moderate category (1 <H' <3), and not significant different revealed for the No-take zone, utility zone and open access zone the Kruskal-Wallis test, (p > 0.05). Simpson's (D) index ranges from 0.12 -1. SIMPER analysis on the water column of the species that has the highest percentage contribution, namely Strongylocentrotus purpuratus (34.05%) and Littorina littorea (54.21%)
Keyword: Biomonitoring, genetic conservation, Invertebrate, Raja Ampat

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.
Keyword: