Judul: Analisis mikrobiologis kolon mencit (Mus musculus) yang diberi pakan prebiotik dari tongkol jagung
Abstrak: Peningkatan hasil pertanian menyebabkan peningkatan limbah pertanian seperti tongkol jagung. Tongkol jagung dapat dijadikan prebiotik melalui tahapan delignifikasi, pemecahan selulosa, dan pemecahan hemiselulosa. Analisis mikrobiologis pada kolon mencit dilakukan untuk melihat jumlah Lactobacillus sp. dan Escherichia coli sebelum dan setelah diberi perlakuan. Perlakuan tersebut berupa ransum kontrol, ransum prebiotik 2,5%, ransum prebiotik 5%, ransum prebiotik 7,5%, ransum kontrol + EPEC K1.1, ransum prebiotik 2,5% + EPEC K1.1, ransum prebiotik 5% + EPEC K1.1, dan ransum prebiotik 7,5% + EPEC K1.1. Kombinasi isolat aktinomiset KBM 6 dan Streptomyces costaricanus 45I-3 merupakan kombinasi isolat terbaik untuk memecah selulosa dan hemiselulosa yang terdapat pada tongkol jagung dibandingkan dengan dua kombinasi isolat lain (Bacillus sp. C5-1 dan Streptomyces sp. 234P-16, aktinomiset KBM 7 dan Streptomyces costaricanus 45I-3). Pengujian sifat prebiotik secara in vivo pada mencit (Mus musculus) terhadap jumlah Lactobacillus sp. menunjukkan pemberian ransum kontrol, prebiotik 2,5%, prebiotik 5%, dan prebiotik 2,5% + EPEC K1.1 tidak berbeda nyata dengan sebelum perlakuan. Penurunan jumlah Lactobacillus sp. ditunjukkan oleh pemberian prebiotik 7,5%, prebiotik 5% + EPEC K1.1, dan prebiotik 7,5% + EPEC K1.1, sedangkan jumlah Escherichia coli pada mencit menunjukkan sebelum perlakuan dengan kontrol tidak berbeda nyata, pemberian prebiotik 2,5% + EPEC K1.1 tidak berbeda nyata dengan pemberian prebiotik 5% + EPEC K1.1, pemberian prebiotik 5% tidak berbeda nyata dengan pemberian prebiotik 7,5% + EPEC K1.1, dan penurunan jumlah E. coli tertinggi pada pemberian prebiotik 7,5%.
Keyword: In vitro, Lactobacillus casei, Escherichia coli, In vivo

Judul: Pengaruh Penggunaan Pakan Prebiotik terhadap Pertumbuhan Mencit (Mus musculus)
Abstrak: The ability of xylanase and cellulase enzymes to degrade corncob can be used to produce oligosaccharide as prebiotic. The prebiotic was mixed in mice ration as the source of carbohydrates. The objective of this research was to study the effect of prebiotic addition in the ration on the growth and feed conversion of mice. The addition of prebiotic in the mice ration was conducled at three different level 2.5%, 5%, and 7.5%. Therefore, there were 8 treatments applied. Beside that in some treatments pathogen bacteria Escherichia coli was added. The combination of isolate KBM 6 and 45I3 has the highest degree of polymerization (DP 2.3), and met the criteria of prebiotic. The production of prebiotic in liquid media showed the highest concentration of oligosaccharide 85.85 g with DP at 2.2. The prebiotic addition decreased the growth of E. coli from 7.23 to 5.79 log cfu/ml. The prebiotic effect on the growth of mice and feed conversion are significantly different compared to control.
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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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