Judul: Sensitivitas gen sitokrom B (Cyt b) sebagai marka spesifik pada genus Rattus dan Mus untuk menjamin keamanan pangan produk asal daging
Abstrak: Appropriate techniques for detection and identification of origin of species for meat source are very important in the meat product processing to ensure the safety and halal foods. Multiplex PCR, in which many primers were used together for amplification of multiple target regions, is hopefully a suitable technique for meat sources identification. The aim of this study was to determine the specificity and sensitivity of the cytochrome b (cyt b) gene in rats as well as to design primers that can be used for detection of rat meat contamination in some processed meat products. The amplification of cyt b genes was done in seven species with different lengths of fragments which indicated specificity for cyt b genes sequences between species. The products showed specific DNA fragments of 157, 227, 274, 331, 398, 439 and 603 bp from goat, chicken, cattle, sheep, pig, horse and rat meats, respectively. Cyt b gene is sensitive as a specific marker with rats DNA that could be detected and be amplified with 100% success from as low as 1% level of contamination. Results showed that rat DNA in meatballs could be detected from 1% level contamination, otherwise rat DNA in meat floss could be detected from above 2.5% level contamination.
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Judul: Using cytochrome β (Cyt β) gene for species identification of dog, cat, and tiger to ensure food authenticity and drugs
Abstrak: Adulteration food products from animal still happen until now. Species identification method development in food and medicine derived from animal was needed to prevent falsification information. Molecular genetic improvement allows the detection is carried out at the level of DNA, so the results more accurate, although processed. Research on several meat have been conducted by several researchers using DNA mitochondrial DNA (mtDNA). Using mtDNA because it has high copy number in a cell, compared with nuclear DNA. In this case where the amount of extracted DNA is very small or degraded. Gene used as marker specific species is cytochrome β (cyt β) because it has varied sequences. The objective of this research was to study species authentication (i.e. dog, cat, and tiger) to ensure animal origin in product using cyt β gene specific marker. Total DNA samples for each species which identified are three samples were consisting blood (cat), cooked meat (dog), feces (tiger), and as a comparison used blood sample from several animal (i.e. goat, chicken, cattle, sheep, horse, rat) and pork. Reverse primer specific for dog, cat, and tiger was designed using MEGA 5 software. DNA extraction and fragment amplification was conducted using phenol-chloroform and multiplex PCR method, respectively. Multiplex PCR is a variant of PCR which many primers were used together for amplification of multiple region. This research showed that different length of amplification for the species tested (dog, cat, and tiger) were 523, 331, 319 bp, respectively; and for the comparison species (goat, chicken, cattle, sheep, pig, horse, and rat) were 157, 227, 274, 331, 398, 439, and 603 bp, respectively. Species specificity also indicated by high reverse primer homology percentage. Specific fragment amplification on genome pool with closed fragment length should be separate to avoid band overlapped between species. Taxonomy hierarchy (i.e. dog, cat, and tiger) could be distinguished to the species level.
Keyword: cat, cytochrome β gene, dog, multiplex PCR, tiger

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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