Judul: Resistance of Staphylococcus sp. Against Antibiotics from Animal Clinics in Depok City
Abstrak: Staphylococcus sp. is an opportunistic bacteria that is often found in animals and humans. Various studies have shown Staphylococcus sp. can become resistant to at least one antibiotic. This study aims to identify the Staphylococcus sp. isolated from hospitalized cats at the veterinary clinic in Depok City and understand Staphylococcus sp. resistance against amoxicillin, gentamicin, cefotaxime, doxycycline, and enrofloxacin. Antibiotic sensitivity test was conducted by Kirby-Bauer Disk Diffusion method. The results showed that 9 isolates (45%) were Staphylococcus sp. consisting of 7 isolates of S. aureus and 2 isolates of S. epidermidis. The test results showed the resistance of S. aureus isolates to amoxicillin (1 isolate), cefotaxime (7 isolates), doxycycline (1 isolate), enrofloxacin (1 isolate). S. epidermidis isolates were resistant to amoxicillin (1 isolate), cefotaxime (1 isolate), doxycycline (1 isolate). Antibiotics that can still be used for S. aureus infection are enrofloxacin, gentamicin, doxycycline, and amoxicillin, while those from S. epidermidis used gentamicin and enrofloxacin., Staphylococcus sp. merupakan bakteri oportunistik yang sering ditemukan pada hewan dan manusia. Berbagai penelitian menunjukkan isolat Staphylococcus sp. dapat menjadi resistan terhadap setidaknya satu jenis antibiotik. Penelitian ini bertujuan mengidentifikasi bakteri Staphylococcus sp. yang diisolasi dari kucing rawat inap di klinik hewan Kota Depok dan mengetahui gambaran resistansi Staphylococcus sp. terhadap antibiotik amoksisilin, gentamisin, sefotaksim, doksisiklin, dan enrofloksasin. Pengujian kepekaan antibiotik menggunakan metode Disk Diffusion Kirby-Bauer. Hasil penelitian menunjukkan 9 isolat (45%) merupakan Staphylococcus sp. yang terdiri dari 7 isolat S. aureus dan 2 isolat S. epidermidis. Hasil uji menunjukkan resistansi isolat S. aureus terhadap amoksisilin (1 isolat), sefotaksim (7 isolat), doksisiklin (1 isolat), enrofloksasin (1 isolat). Isolat S. epidermidis resistan terhadap amoksisilin (1 isolat), sefotaksim (1 isolat), doksisiklin (1 isolat). Antibiotik yang masih dapat digunakan untuk infeksi S. aureus adalah enrofloksasin, gentamisin, doksisiklin, dan amoksisilin, sedangkan infeksi S. epidermidis dapat diobati dengan gentamisin dan enrofloksasin.
Keyword: kucing/cats, antibiotik, antibiotics, Staphylococcus sp., Staphylococcus sp.

Judul: Resistance of Klebsiella pneumoniae from Hospitalized Cats at the Animal Clinic of Depok City to Antibiotics
Abstrak: Resistansi bakteri Klebsiella pneumoniae terhadap antibiotik telah menjadi masalah kesehatan global, mengakibatkan penurunan efektivitas terhadap banyak antibiotik. Penelitian ini bertujuan mendapatkan gambaran resistansi K. pneumoniae yang diisolasi dari kucing rawat inap di klinik Kota Depok terhadap beberapa antibiotik. Metode penelitian ini terdiri dari kuesioner, koleksi sampel, isolasi, identifikasi, dan uji kepekaan terhadap antibiotik. Sebanyak tujuh isolat K. pneumoniae berhasil diidentifikasi, resistansi terjadi pada sefotaksim sebanyak tujuh isolat, amoksisilin tiga isolat, gentamisin satu isolat, dan enrofloksasin satu isolat. Hasil intermediet ditunjukan oleh amoksisilin, enrofloksasin, dan doksisiklin dengan jumlah yang sama yakni satu isolat serta hasil sensitif ditunjukan oleh gentamisin sebanyak enam isolat, doksisiklin enam isolat, enrofloksasin lima isolat dan amoksisilin tiga isolat. Informasi ini diharapkan dapat membantu dokter hewan dalam memilih antibiotik yang tepat untuk pengobatan penyakit yang disebabkan oleh bakteri ini., The resistance of bacteria Klebsiella pneumoniae to antibiotics has become a global health problem, resulting in a reduction in the efficacy of many antibiotics. This study aims to illustrate the resistance of K. pneumoniae isolated from hospitalized cats on veterinary clinics in Depok City to several antibiotics. The research method consisted of questionnaires, sample collection, isolation, identification, and antibiotic sensitivity test. A total of seven K. pneumoniae isolates were identified. Resistance occurred in seven isolates of cefotaxime, three isolates of amoxicillin, one isolate of gentamicin and enrofloxacin. The intermediate results were shown by amoxicillin, enrofloxacin, and doxycycline with the same amount, one isolate. The sensitive results were shown by six gentamicin isolates, six doxycycline isolates, five enrofloxacin isolates, and three amoxicillin isolates. Hopefully, this information can help veterinarians choose the appropriate antibiotic to treat diseases caused by these bacteria.
Keyword: animal clinic, antibiotic, antibiotic resistance, Klebsiella pneumoniae

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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