Judul: Keragaman Mikroalga Berbasis Morfologi serta Teknik Isolasi dan Amplifikasi DNA Mikroalga dari Pantai Ujung Genteng
Abstrak: Identifikasi keragaman mikroalga berdasarkan morfologi dan molekuler baik dari air laut maupun air tawar telah banyak dipublikasikan. Pantai Ujung Genteng di Sukabumi yang memiliki karakteristik wilayah dengan tutupan padang lamun yang luas serta merupakan wilayah zona intertidal belum dilakukan penelitian tentang keragaman mikroalganya. Penelitian yang telah dilaksanakan ini bertujuan mengidentifikasi keragaman mikroalga yang bersumber dari air laut Pantai Ujung Genteng berdasarkan ciri morfologi serta mengembangkan teknik isolasi dan amplifikasi DNA mikroalga. Pengambilan sampel dilakukan sebanyak tiga kali pada 3 lokasi penelitian yang telah ditentukan. Metode yang dilakukan adalah purposive sampling sebanyak 10 liter air laut dan dianalisis di Laboratorium Fisiologi dan Biologi Molekuler Tumbuhan, identifikasi morfologi menggunakan mikroskop binokuler, isolasi dan amplifikasi DNA menggunakan marka 18S rDNA. Berdasarkan hasil identifikasi morfologi jumlah spesies yang ditemukan di Pantai Ujung Genteng adalah 47 spesies yang mencakup 6 kelas mikroalga. Hasil uji kualitas DNA menggunakan PCR dan elektroforesis dapat memunculkan pita DNA yang mengindikasikan bahwa tahapan amplifikasi DNA mikroalga berhasil dilakukan, meskipun hanya satu dari tujuh sampel DNA yang diisolasi., The identification of microalgae diversity based on morphology and molecules from both seawater and fresh water has been widely published. Ujung Genteng Beach in Sukabumi, which has the characteristics of an area with extensive seagrass cover and is an intertidal zone, has not been studied on the diversity of microalgae. The research that has been carried out is aimed at identifying the diversity of microalgae sourced from seawater at Ujung Genteng Beach based on morphological characteristics and developing techniques for isolation and amplification of microalgae DNA. Sampling was carried out three times at 3 predetermined research locations. The method used was purposive sampling of 10 liters of seawater and analyzed in the Laboratory of Physiology and Plant Molecular Biology, morphological identification using a binocular microscope, isolation and DNA amplification using 18S rDNA markers. Based on the results of morphological identification, the number of species found at Ujung Genteng Beach is 47 species which includes 6 classes of microalgae. The results of DNA quality tests using PCR and electrophoresis can reveal DNA bands indicating that the microalgae DNA amplification step was successful, although only one of the seven DNA samples was isolated.
Keyword: diversity, microalgae, molecular, morphological, seawater

Judul: Analisis Metagenomik Mikroalga Prokariot dari Perairan Laut Jawa Timur
Abstrak: Mikroalga adalah kumpulan mikroorganisme uniseluler yang dapat berfotosintesis dan menjadi alternatif bioenergi yang potensial untuk dikembangkan. Sebelumnya, penelitian mengenai boidiversitas mikroalga di laut Jawa Timur telah dilakukan secara morfologis. Penelitian ini bertujuan menganalisis metagenomik mikroalga prokariot di perairan laut Jawa Timur. Sampel dari penelitian sebelumnya, yang berasal dari Madura (M3, M4, M6, M9), Banyuwangi (BW) dan Situbondo (ST), dikulturkan kemudian disekuensing dengan metode NGS (Next Generation Sequencing) menggunakan primer 16S rRNA. Data sekuens dianalisis menggunakan Geneious Prime 2020.1.2 dengan mengacu pada database 16S microbial dari NCBI. Terdapat 6 ordo dan 17 spesies teridentifikasi dari divisi Cyanobacteria. Ordo Oscillatoriales terdapat pada seluruh sampel dengan rata-rata frekuensi 43,25%. Crocosphaera watsonii dan Laspinema etoshii terdapat pada kelima sampel kecuali M6. Situbondo memiliki spesies paling banyak yaitu 16 spesies sedangkan M6 hanya memiliki satu spesies. Indeks keanekaragaman tergolong rendah hingga sedang, sedangkan indeks dominansi tergolong rendah hingga tinggi., Microalgae are mixture of unicellular photoautotroph organisms and have big potential to be developed as an alternative bioenergy. Previous research has been carried out on the diversity of microalgae from East Java Coastal Area using morphological identification. This study aims to analyze the prokaryotic microalgae diversity using metagenomics approach. Seawater samples from previous studies, which came from Madura (M3, M4, M6, and M9), Banyuwangi (BW) and Situbondo (ST), were cultured and then sequenced by NGS applying 16S rRNA primers. Analysis was carried using the Geneious Prime 2020.1.2 program referring to the 16S microbial database from NCBI. There are 6 orders and 17 species classified from the Cyanobacteria division. The Oscillatoriales order is found in all samples with an average frequency of 43,25%. Crocosphaera watsonii and Laspinema etoshii were found in five samples, except M6. Situbondo had the most species, namely 16 species, while the M6 sample only had 1 species. Diversity index is classified as low to moderate, while the dominance index is classified as low to high.
Keyword: 16S rRNA, Cyanobacteria, metagenomics, microalgae, prokaryotes

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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