Judul: Characterization of DGAT1 Gene as Candidate Marker for Quality and Nutrition of Indonesian Sheep
Abstrak: Kualitas daging domba premium melalui peningkatan nilai gizi yang terkandung dalam daging melalui potensi gen diacylglycerol acyltransferase-1 (DGAT1). Penelitian ini bertujuan mengidentifikasi keragaman gen DGAT1 pada SNP g.8539 C>T serta kaitannya dengan perbaikan kualitas dan gizi (flavour dan odour, asam lemak, kolesterol, mineral, dan karakteristik karkas) daging domba Indonesia. Total sampel domba yang digunakan keragaman gen DGAT1 254 sampel berumur 10–12 bulan dengan jenis kelamin jantan yang terdiri dari domba ekor gemuk (DEG) (n=20), domba ekor tipis (DET) (n=107), domba komposit garut (DKG) (n=10), domba compass agrinak (DCA) (n=10), domba barbados cross (DBC) (n=10), domba garut (DG) (n=20), domba jonggol (DJ) (n=27) dan domba lokal jambi (DLJ) (n=50). 100 sampel digunakan untuk asosiasi gen DGAT1 terhadap flavour dan odour, asam lemak, kolesterol, mineral, dan karakteristik karkas. Identifikasi keragaman DGAT1|ALuI dianalisis dengan metode PCR-RFLP. Hasil keragaman gen DGAT1 bersifat polimorfik dalam DET, DG, dan DEG, sedangkan DCA, DBC, DLJ, dan DKG bersifat monomorfik. Dua genotipe CC, dan CT ditemukan dalam DET, DG, dan DEG. Titik mutasi gen DGAT1 berasosiasi (P<0.05) pada flavour dan odour, asam lemak sedangkan titik mutasi gen DGAT1 tidak berasosiasi (P>0.05) pada kolesterol, mineral, dan karakteristik karkas. Gen DGAT1 memiliki kontribusi dalam flavour dan odour yaitu pada senyawa 4-Ethyloctanoic acid (EOA) serta pada konten lemak, asam palmitoleat, dan asam heptadekanoat, The quality of premium sheep meat through improving the nutritional value contained in the meat through the potential gene diacylglycerol acyltransferase-1 (DGAT1). This study aims to identify the diversity of the DGAT1 gene with SNP g.8539 C>T access number EU178818 and its relationship to the quality and nutritional value (mineral, cholesterol, flavour and odour, fatty acids, and carcass characteristics) of Indonesian sheep. A total of 254 samples and ages 10-12 months, consisted of javanese fat-tail sheep (JFTS) (n=20), javanese thin-tail sheep (JTTS) (n=107), garut composite sheep (GCS) (n=10), compass agrinak sheep (CAS) (n=10), barbados cross sheep (BCS) (n=10), garut sheep (GS) (n=20), jonggol sheep (JS) (n=27), and jambi local sheep (JLS) (n=50). 100 samples use association DGAT1 gene with mineral, cholesterol, flavour and odour, fatty acid, and characteristic carcass. The diversity of DGAT|AluI were analyzed with PCR-RFLP method. DGAT1 gene were polymorphic in JTTS, GS, and JFTS, and monomorphic in CAS, BCS, JLS, and GCS sheep population. Two type genotypes CC and CT were found in JTTS, GS, and JFTS. SNP g.8539 C>T in DGAT was associated to flavour and odour (P<0.05), and fatty acid, but it was not associated to cholesterol, mineral, and characteristic carcass. DGAT1 gene has contribution to level of flavour and odour through stimulate 4-Ethyloctanoic acid (EOA) molecules and fat content, palmitoleac acid, and heptadecanoat acid.
Keyword: sheep, DGAT1 gene, mineral, cholesterol, flavour and odour, fatty  acid, characteristic carcass, PCR-RFLP.

Judul: Keragaman Titik Mutasi g.8539 C>T Gen DGAT1 terhadap Karakteristik Karkas dan Asam Lemak Domba.
Abstrak: Diacylglycerol Acyltransferasel 1 (DGAT1) merupakan gen yang berperan penting dalam regulasi karkas dan asam lemak domba. Penelitian ini bertujuan mengidentifikasi keragaman dan asosiasi DGAT1 dengan karakteristik karkas dan asam lemak pada domba lokal Indonesia. Total sampel yang digunakan sebanyak 150 yang terdiri atas 35 domba compass agrinak (DCA), 36 domba barbados cross (DBC), 41 domba komposit garut (DKG), 20 domba ekor gemuk (DEG), dan 18 domba ekor tipis (DET). Identifikasi keragaman DGAT1|AluI dianalisis menggunakan Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP). Ukuran produk amplifikasi adalah 466 bp. Keragaman gen DGAT1 ditemukan dalam DET dan DEG, sedangkan DCA, DBC, dan DKG bersifat monomorfik. Genotipe CC dan CT ditemukan dalam DET dan DEG. SNP gen DGAT1 berasosiasi (P<0.05) dengan karakteristik karkas, yaitu bobot dan panjang karkas. Keragaman DGAT1 juga berasosiasi (P<0.05) dengan asam lemak jenuh, yaitu asam stearat (C18:0) dan asam arakidat (C20:0) dan asam lemak tak jenuh tunggal, yaitu asam oleat (C18:1n9c). SNP gen DGAT1 disimpulkan memiliki kontribusi dalam karakteristik karkas dan komposisi asam lemak domba.
Keyword: asam lemak, domba, gen DGAT1, karakteristik karkas, PCR-RFLP

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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