Judul: Suplementasi Somatotropin untuk Memperbaiki Tampilan Fisiologis Tikus Betina Usia Enam Bulan dan Satu Tahun.
Abstrak: As age increases, aging symptoms such as decrease of stamina, wrinkle of skin, osteoporosis, increase of body fat and menopause will appear. These symptoms are due to the decrease of somatotropin secretion which plays a significant role in cell proliferation. The objective of this study is to investigate the effects of somatotropin supplementation on physiological performaces of six-month and one-year old female rats. Forty eight female rats were assigned into a randomized block design with 4 factors. The first factor was age with 2 levels (6 months and 12 months). The second factor was somatotropin dosage with 2 levels (0 and 9 mg/kg body weight). The third factor was duration of injection with 2 levels (3 weeks and 6 weeks), and the fourth factor was sampling period with 2 levels (0 and 14 days after somatotropin termination). Parameters measured were body weight, total DNA and total RNA of ovary and uterus, plasma estrogen and progesteron levels, bone collagen and skin collagen consentrations. The results showed that somatotropin supplementation had significant effects on body weight, ovary weight, total cell of ovary, total cell of uterus, plasma estrogen and progesteron levels, bone and skin collagen concentrations. It is concluded that somatotropin improve physiological performances of aging female rats.
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Judul: Perangsangan Pertumbuhan dengan Penyuntikan  Somatotropin pada Tikus Jantan Umur Prapubertas
Abstrak: Pertumbuhan hewan dikontrol oleh berbagai hormon, terutama somatotropin. Somatotropin berfungsi sebagai regulator fisiologis dalam tubuh dan pengaruhnya pada pertumbuhan sudah nyata dan berdampak pada banyak proses pertambahan jaringan selama pertumbuhan. Sasaran penelitian ini adalah pengaruh penyuntikan somatotropin pada pertumbuhan tikus jantan. Seratus enam puluh dua tikus jantan galur Sprague-Dawley (SD) berumur 2 minggu digunakan pada penelitian ini. Data dianalisis dengan rancangan tersarang dengan 2 faktor. Faktor pertama adalah dosis yang terdiri atas 3 level (0, 3, dan 9 mg/kg bobot badan/hari). Faktor kedua adalah periode penyuntikan yang tersarang di dalam faktor dosis dan terdiri atas 3 waktu (mulai penyuntikan : hari ke 1 – 14, hari ke 1 – 28, dan hari ke 15 – 28). Penelitian dilakukan dua tahap. Tahap pertama yang berlangsung selama 28 hari penyuntikan somatotropin yang dilanjutkan ke tahap kedua selama 28 hari tanpa penyuntikan somatotropin. Peubah yang diukur antara lain bobot badan (BB), konsumsi pakan, pertambahan bobot badan (PBB), efisiensi penggunaan pakan, laju pertumbuhan relatif (LPR), bobot karkas, kandungan kimiawi karkas (protein, lemak, mineral, dan glikogen), panjang tulang, dan kandungan kimiawi tulang (kalsium dan kolagen). Hasil penelitian menunjukkan bahwa selama periode penyuntikan somatotropin terjadi peningkatan bobot badan, konsumsi pakan, pertambahan bobot badan, efisiensi penggunaan pakan, laju pertumbuhan relatif, bobot karkas, kandungan kimiawi karkas (mineral dan glikogen), bobot organ dalam, panjang tulang, kandungan kimiawi tulang (kalsium dan kolagen), dan terjadi penurunan kandungan lemak karkas tanpa mempengaruhi kandungan protein karkas. Dua puluh delapan hari setelah penghentian penyuntikan somatotropin, pengaruh somatotropin tidak terlihat lagi pada bobot badan, konsumsi pakan, PBB, efisiensi penggunaan pakan, LPR, dan panjang tulang. Dapat disimpulkan bahwa penyuntikan somatotropin dapat meningkatkan penampilan pertumbuhan sedangkan setelah dihentikan penyuntikan tidak meningkatkan penampilan pertumbuhan tikus jantan.
Keyword: Somototropin, Growth performance

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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