Judul: Identification of Molds in the Feces of Wild  Orangutan in Mount Leuser National Park Aceh
Abstrak: Penelitian ini bertujuan untuk mengidentifikasi jenis kapang pada feses orang utan liar di Taman Nasional Gunung Leuser Aceh. Metode penelitian tersusun atas koleksi sampel, isolasi dan identifikasi. Koleksi dilakukan dengan mengambil feses segar pada bagian dalam (tengah) dan dilakukan isolasi pada media Sabouraud Dextrose Agar (SDA). Koloni yang tumbuh pada media SDA disubkultur pada media Potato Dextrose Agar (PDA). Koloni yang tumbuh pada media PDA diidentifikasi secara makroskopis dan mikroskopis. Identifikasi secara makroskopis dilakukan dengan melihat warna permukaan atas, permukaan bawah, bentuk dan tepi koloni, sedangkan identifikasi secara mikroskopis dilakukan dengan membuat preparat metode langsung dan metode Riddle. Hasil isolasi dan identifikasi menunjukkan sebanyak empat spesies kapang ditemukan pada dua belas isolat. Jenis kapang yang teridentifikasi adalah Aspergillus niger, Rhizopus microsporus, Aspergillus fumigatus dan Aspergillus flavus. Penelitian menggunakan metode lain perlu dilakukan agar hasil yang diperoleh lebih baik.
Keyword: Aspergillus, molds, orangutan, Rhizopus

Judul: Identification and Total of Lactic Acid Fermentative Bacteria in Primate Feces
Abstrak: Bakteri asam laktat (BAL) bermanfaat bagi kesehatan, terutama peranannya sebagai probiotik dan antimikroba dalam pengobatan penyakit saluran pencernaan pada primata. Penelitian ini bertujuan untuk mengidentifikasi serta menghitung total koloni bakteri asam laktat pada feses lima jenis primata yaitu orang utan, owaungko hitam, owa ungko coklat, siamang, dan lutung yang dikoleksi dari Kebun Binatang Bukittinggi. Sampel dilakukan pengenceran 10-1 hingga ke 10-7 dandiinokulasikan ke dalam media selektif MRSA (de Man Rogosa Sharpe Agar) dengan metode pour plate. Koloni bakteri asam laktat yang tumbuh pada media diamati dan dihitung total koloninya. Koloni terpilih diisolasi untuk selanjutnya diidentifikasi menggunakan beberapa uji biokimia yaitu uji katalase, uji oksidase, uji Sulfide Indol Motility, uji Methyl Red-Voges Proskauer, dan uji fermentasi karbohidrat. Penelitian berhasil mengisolasi bakteri dari genus Lactobacillus, Leuconostoc, dan Weissella. Hasil penelitian menunjukkan orang utan menghasilkan total bakteri asam laktat tertinggi yaitu sebesar 3,1 x 108 CFU/ml., Lactic acid bacteria (LAB) are beneficial for health, especially their role as probiotics and antimicrobials in the treatment of digestive tract diseases in primates. This research aims to identify and count the total colonies of lactic acid bacteria in the feces of five primate species, namely orangutans, black gibbons, brown gibbons, siamang, and langurs collected from the Bukittinggi Zoo. Samples were diluted 10- 1 to 10-7 and inoculated into MRSA (de Man Rogosa Sharpe Agar) selective media using the pour plate method. Colonies of lactic acid bacteria growing on the media were observed and the total colonies were counted. Selected colonies were isolated for further identification using several biochemical tests, namely catalase test, oxidase test, Sulfide Indole Motility test, Methyl Red-Voges Proskauer test, and the carbohydrate fermentation test. The results of the research succeeded in isolating lactic acid bacteria from the genera Lactobacillus, Leuconostoc, and Weissella. Orangutans produced the highest total lactic acid bacteria, which was 3.1 x 108 CFU/ml.
Keyword: lactic acid bacteria, primates, total plate count

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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