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: Antibiotic Resistance in Escherichia coli from Cats at Several Veterinary Clinics in Bogor Regency.
Abstrak: Escherichia coli menjadi penyebab beberapa jenis penyakit pada kucing. Infeksi bakteri ini dapat menyebabkan pyometra, septikemia, Urinary Tract Infection (UTI), dan diare. Penelitian mengenai resistansi E. coli terhadap antibiotik pada kucing belum pernah di lakukan di Kabupaten Bogor. Penelitian ini bertujuan untuk mengisolasi dan identifikasi serta menguji resisitansi E. coli pada pasien kucing di beberapa klinik hewan di Kabupaten Bogor. Sampel yang digunakan adalah swab rektal dari 30 pasien kucing pada lima klinik hewan di Kabupaten Bogor. Metode yang digunakan pada penelitian ini meliputi pengambilan sampel, isolasi dan identifikasi, serta uji resistansi antibiotik mengikuti metode Disk Diffusion Kirby-Bauer yang mengacu pada Clinical and Laboratory Standards Institute guidelines (CLSI) tahun 2021. Hasil penelitian menunjukan bahwa 19 isolat E. coli berhasil diisolasi. Escherichia coli resistan terhadap eritomisin 100% (19/19), metronidazol 94,8% (18/19), dan ampisilin 57,9% (11/19). Persentase resistansi rendah terhadap amoksisilin-klavulanat 21,05% (4/19), gentamisin 15,18% (3/19), doksisiklin 15,18% (3/19) dan enrofloksasin 21,05% (4/19).
Keyword: antibiotics, E. coli, cat, resistance

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.
Keyword: