Judul: Studi Kasus: Tumor Kulit Pada Beruang Coklat (Ursus Arctos).
Abstrak: Seekor beruang coklat (Ursus arctos) berjenis kelamin betina yang berasal dari Taman Margasatwa Ragunan, DKI Jakarta-Indonesia didiagnosa menderita tumor kulit. Studi kasus ini bertujuan mengetahui jenis tumor pada beruang coklat yang telah berumur 39 tahun. Beruang sakit (nafsu makan dan aktifitas menurun) sekitar dua bulan dan dilakukan perawatan di kandang individu. Terapi dilakukan dengan pemberian antibiotik dan vitamin. Beruang tersebut mati pada 7 Oktober 2014, kemusian nekropsi segera dilakukan di Divisi Patologi Departemen Klinik, Reproduksi, dan Patologi Fakultas Kedokteran Hewan Institut Pertanian Bogor. Hasil nekropsi ditemukan multinodular berwarna merah tua dengan diameter 5,5 cm. Tumor terlihat menyatu dengan jaringan sekitar tanpa memperlihatkan batas atau tidak terlihat adanya kapsul yang membatasi, pola pertumbuhan yang tidak teratur serta menginvasi jaringan sekitar. Sampel jaringan tumor kemudian diperiksa secara histopatologi. Massa tumor terlihat sel-sel berbentuk pipih atau gelendong(spindled) poligonal dengan ukuran yang bervariasi (Anisositosis). Sitoplasma sel-sel tumor berwarna eosinofilik membentuk penjuluran, dan memiliki nukleus berbentuk bulat sampai oval (tidak seragam) dengan nukleolus berjumlah 1-2. Sel-sel tumor tersusun dalam kelompok yang tidak beraturan dengan jarak yang renggang. Kadang-kadang pada beberapa daerah ditemukan sel-sel tumor yang memiliki pigmen coklat sampai hitam (melanin). Pewarnaan Masson's Trichrome (MT) memperlihatkan adanya pertumbuhan kolagen minimal yang dihasilkan oleh jaringan ikat diantara sel-sel tumor. Pewarnaan imunohistokimia terhadap Desmin, Vimentin, dan S100 memperlihatkan hasil positif dan negatif terhadap Glial Fibrillary Acidic Protein (GFAP). Berdasarkan morfologi dan hasil imunohistokimia, tumor didiagnosa sebagai malignant melanoma.
Keyword: Beruang (Ursus arctos), malignant, melanoma, tumor kulit

Judul: Studi Kasus: Leiomioma pada Seekor Singa (Panthera leo)
Abstrak: This report described an abdominal leiomyoma in a female old lion (Panthera leo) from the Ragunan Zoo, Jakarta. The aim of this study was to identify the type of tumor from an old aged female lion with anamnese suffered from chronic gangrene on the right-rear leg. The lion was euthanized and then accompanied with necropsy. Gross findings were recorded and then histopathological examination of some organ samples done. Macroscopic observations showed several lesions. A tumor was found in abdominal cavity, has 14.5 x 9.8 x 6.5 cm in sized. The tissue sample from the tumor mass was further examined using histopathological examination. Based on the morphology, the tumor consisted of spindle-shaped cells with a cigar-shaped nuclei with blunt ends. Mitotic figure was <3, indicated that the tumor was benign. Masson's Trichrome staining showed that among the tumor cells are found collagen bundles (blue). Desmin immunohistochemical staining showed a positive result, that mean the tumor cells derived from smooth muscle cells. Other immunohistochemical stainings e.g. Vimentin, Glial Fibrillary Acidic Protein (GFAP), and Proliferating Cell Nuclear Antigen (PCNA) were negative. According to morphological and immunohistochemical characters, the tumor was diagnosed as leiomyoma.
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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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