Judul: In Vitro Antibacterial Activity of Bird's Eye Chilli (Capsicum frutescens L.) Extract Against Escherichia coli Isolate from Cat
Abstrak: Cabai rawit (Capsicum frustescens L.) merupakan tanaman yang banyak ditemukan di Indonesia, dan diketahui memiliki banyak fungsi selain sebagai makanan. Penggunaan bahan tanaman herbal sebagai pengobatan alternatif sudah banyak digunakan sejak lama. Escherichia coli adalah bakteri Gram negatif yang merupakan flora normal usus manusia maupun hewan. Namun, dalam beberapa keadaan dapat menimbulkan penyakit yang cukup serius. Resistensi bakteri terhadap berbagai jenis obat menjadi suatu masalah yang cukup serius bagi dunia kedokteran hewan. Penelitian ini bertujuan untuk mengamati aktivitas antibakteri dari ekstrak cabai rawit terhadap isolat E. coli dari kucing secara in vitro. Ekstrak cabai rawit dibuat dengan metode maserasi dan pelarut etanol 96% dan pengujian antibakteri dengan metode difusi sumur. Didapatkan hasil bahwa ekstrak cabai rawit memiliki aktivitas antibakteri kategori lemah terhadap isolat E. coli asal kucing yang dilakukan secara in vitro., Bird’s eye chilli (Capsicum frutescens L.) is a plant that is can be found a lot in Indonesia and known has many other uses than just for food. Herbal plant has been used as an alternative medicine for a long period of time. Escherichia coli is a Gram-negative bacteria which a normal flora of human’s and animal’s gut. But in some condition, it can cause serious disease. Multidrug resistance is a serious problem to veterinary medicine. This study aimed to provide the in vitro antibacterial activity of bird’s eye chilli extract against E. coli isolate from cats. Extraction of bird’s eye chilli done by maseration with ethanol 96% as solvent, and the antibacterial test done by using well diffusion method. The result form this study is the extract of bird’s eye chilli has weak antibacterial activity against E. coli isolate from cat.
Keyword: antibacterial, bird's eye chilli, Capsicum, Escherichia coli

Judul: Resistansi Escherichia coli yang Diisolasi dari Kucing di Klinik Hewan Kota Depok Terhadap Antibiotik
Abstrak: Kejadian resistansi antibiotik pada Escherichia coli pada hewan kesayangan sangat erat kaitannya dengan penggunaan antibiotik yang tidak tepat dalam waktu panjang dan tidak terkontrol. Penelitian ini bertujuan mengetahui gambaran resistansi E. coli yang diisolasi dari kucing rawat inap di klinik hewan Kota Depok terhadap antibiotik amoksisilin, gentamisin, sefotaksim, enrofloksasin, dan doksisiklin. Uji kepekaan antibiotik pada penelitian ini menggunakan metode Disk Diffusion Kirby-Bauer. Didapati sebanyak 12 isolat merupakan Escherichia coli. Hasil uji menunjukkan sampel resistan terhadap doksisiklin (sembilan isolat), amoksisilin (lima isolat), dan sefotaksim (lima isolat). Hasil intermediet ditunjukkan oleh amoksisilin dan sefotaksim, 16.7% resistan terhadap gentamisin, dan 8.3% resistan terhadap enrofloksasin. Escherichia coli pada penelitian ini masih cenderung sensitif terhadap gentamisin dan enrofloksasin., Antibiotic resistance in Escherichia coli in pets is closely linked to the long term and uncontrolled use of antibiotics. The study aims to determine the resistance of isolated E. coli cats in the City Depok veterinary clinic to the antibiotics amoxicillin, gentamicin, cefotaxime, enrofloxacin, and doxycycline. Antibiotic sensitivity test in this study using the Kirby-Bauer Disk Diffusion method. Twelve isolates were found to be Escherichia coli. The test results showed samples resistant to doxycycline (nine isolates), amoxicillin (five isolates), and cefotaxime (five isolates). Intermediate results were shown by amoxicillin and cefotaxime, with 16.7% resistance to gentamicin, and 8.3% to enrofloxacin. Escherichia coli in this study still tends to be sensitive to gentamicin and enrofloxacin.
Keyword: antibiotics, antibiotic resistance, escherichia coli

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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