Judul: Pengaruh enzim pepsin dan tripsin terhadap titer IgG anti H5N1 dari kolostrum sapi yang divaksin H5N1
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh paparan enzim pepsin dan tripsin terhadap titer IgG anti H5N1 dalam kolostrum. Tiga buah sampel kolostrum berasal dari 2 ekor induk sapi yang telah divaksin H5N1 pada masa kebuntingan trimester akhir. Pengujian titer antibodi dilakukan melalui pemaparan enzim pepsin dan tripsin, masing-masing pada masa inkubasi 30 dan 60 menit. Deteksi antibodi dilakukan dengan uji hemaglutinasi inhibisi (HI). Hasil uji HI terhadap kolostrum menunjukkan adanya penurunan titer antibodi akibat pemaparan enzim pepsin dan trispin. Semua sampel kolostrum yang direaksikan dengan enzim tripsin, mengalami penurunan titer antibodi hingga 20 (2 log 0) baik pada masa inkubasi 30 maupun 60 menit. Sementara itu, sampel kolostrum yang direaksikan dengan enzim pepsin juga menunjukkan penurunan titer antibodi hingga 23 pada masa inkubasi 30 menit dan 22 pada masa inkubasi 60 menit. Berdasarkan hasil penelitian ini dapat disimpulkan bahwa IgG akan mengalami penurunan titer akibat aktivitas enzim pepsin dan tripsin yang merupakan enzim proteolitik dalam saluran pencernaan manusia.
Keyword: IgG, Pepsin, Trypsin, Colostrums, Bogor Agricultural University

Judul: Pengaruh Ph Terhadap IgG Anti H5N1 Asal Kolostrum Sapi Yang Divaksin Dengan Vaksin Avian Influenza H5N1
Abstrak: The aims of this study is to determine the stability of IgG anti-H5 from bovine colostrum (BC) after exposure to acid and basic pH. Two samples of BC, whole colostrum and whey colostrum incubated at pH 4, 5, 9, and 10 for 30 and 60 minutes. Haemagglutination Inhibition (HI) test is used to determine IgG titer after incubation. IgG titers decreased after exposure to acid or basic pH. Acid exposure (pH 5) decreased antibodi titer of whole colostrum as much as 3,75% and 16,25% after incubation 30 and 60 minutes respectively. Antibody titer to pH 4 also decreased until 12,5% and 16,5% after for 30 and 60 minutes respectively. In whey colostrum, both pH 4 and pH 5 reduce 18,75% antibody titer. On other hand, IgG titers is decreased until 100% at basic pH (pH 9-10). In conclusion, IgG from BC is degraded in acidic and alkaline conditions.
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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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