Judul: Species Identification in Fisheries Products using Genetic Molecular Marker Cytochrome B Minibarcode
Abstrak: Fish is one of the largest food commodities, so market demand for fish is high. Fish with high economic value is one of the high market demands, this causes fraud in the sale of fish. DNA barcoding is used to identify fishery processed products as well as the authenticity of raw materials so as to reduce food safety problems. The isolation method used was Cetyltrymethyl Ammonium Bromide (CTAB) with concentration and purity testing using a Nanodrop spectrophotometer. The 25 samples consisting of frozen fish fillets, processed fishery product, and salted fish fillets from traditional and supermarket in Jabodetabek. DNA isolates have a concentration of 4,65-3172,6 ng/μL, with a purity of 1,067-2,125. An electrophoregram showed 7 samples sampled on a target DNA of 200-300bp. Analysis using BLAST showed samples detected as Makaira nigricans, Rachycentron canadum, Lates calcarifer, Priacanthus tayenus, Lepidocybium flavobrunneum, and Salmo salar. Phylogeny analysis showed the samples formed a group corresponding to database from Genbank., Ikan menjadi salah satu komoditi pangan yang cukup besar, sehingga permintaan pasar terhadap ikan menjadi tinggi. Ikan dengan nilai ekonomis tinggi menjadi salah satu permintaan pasar yang tinggi, hal tersebut menyebabkan terjadinya kecurangan dalam penjualan ikan. DNA barcoding dengan penanda genetik cytochrome b digunakan untuk mengidentifikasi produk olahan perikanan serta keaslian bahan baku sehingga dapat mengurangi permasalahan keamanan pangan. Metode isolasi yang digunakan adalah Cetyl Trymethyl Ammonium Bromide (CTAB) dengan pengujian konsentrasi dan kemurnian menggunakan spektrofotometer Nanodrop. Sampel berjumlah 25 terdiri dari filet ikan beku, produk olahan perikanan, dan filet ikan asin yang didapat dari pasar tradisional dan swalayan di Jabodetabek. Isolat DNA memiliki konsentrasi 4,65-3172,6 ng/µL, dengan kemurnian 1,067-2,125. Elektroforegram menunjukan 7 sampel teramplifikasi pada DNA target 200-300bp. Hasil analisis menggunakan BLAST menunjukan sampel terdeteksi sebagai Makaira nigricans, Rachycentron canadum, Lates calcarifer, Priacanthus tayenus, Lepidocybium flavobrunneum, dan Salmo salar. Analisis filogeni menunjukan sampel membentuk kelompok yang sesuai dengan basis data dari Genbank.
Keyword: Cytochrome b, DNA barcoding, fishery products, PCR

Judul: Molecular Marker Gen Cytochrome B to Detect Species in Processed Fish Products
Abstrak: DNA barcoding dengan penanda genetik cytochrome b (cyt b) serta autentifikasi berbasis PCR digunakan untuk mengidentifikasi produk olahan perikanan serta keaslian bahan baku sehingga dapat mengurangi permasalahan keamanan pangan. Penelitian ini bertujuan untuk mendeteksi dan melihat ketertelusuran produk olahan perikanan. Sampel berjumlah 25 terdiri dari fillet ikan beku, asin, dan produk olahan perikanan yang diisolasi serta gen diperbanyak dengan primer universal. Isolat DNA memiliki konsentrasi 1,1-3.786,96 ng/μL dengan kemurnian 0,4-2,08. Primer universal berhasil mengamplifikasi gen cyt b sebanyak 22 dari 25 produk perikanan. Hasil analisis menunjukkan sampel terdeteksi sebagai Salmo salar, Lates calcarifer, Thunnus albacares. Hasil penelitan menunjukkan; Mislabelling untuk spesies Pangasianodon sp. yang dipasarkan sebagai produk fillet ikan dori dan kemudian Psettodes erumei yang dipasarkan sebagai ikan kerapu; serta dalam sampel terdeteksi juga ikan yang terancam punah yaitu spesies Carcharhinus falciformis, Sphyrna mokarran dan Himantura chaophraya., PCR-based DNA barcoding with genetic marker cytochrome b (cyt b) can be used to identify species in processed products as well as the authenticity of raw materials. This study aims to detect and see the traceability of fishery processed products. Twenty-five samples consisting of frozen fish fillets, salted fish fillets, and processed fishery product were isolated and their gene was amplified using universal primer. The DNA isolates had a concentration of 1.1-3,786.96 ng/μl, with a purity of 0.4-2.08. The universal primer was successfully amplified the cyt b gene in 22 out of 25 fish products. Analysis showed samples detected as Salmo salar, Lates calcarifer, Thunnus albacares. The results showed; Mislabelling for Pangasionodon sp. species which is marketed as a Dori fish fillet product and then Psettodes erumei which is marketed as Grouper fish fillet; And in the sample detected also endangered fish namely the species Carcharhinus falciformis, Sphyrna mokarran, and Himantura chaophraya.
Keyword: Cytochrome b, DNA barcoding, fishery products, PCR.

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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