Judul: Pengklonan kandidat gen resisten terhadap selenium dari isolat bakteri termofilik Geobacillus sp20k
Abstrak: Termophilic bacteria which is resistant to selenium has a specific mechanism enabling it to accumulate and make the toxic selenium becomes nontoxic to the bacteria itself. The mechanism of action is believed because of the existence of a gene that function to confer resistance to Se (Selenium). However, the existence of the gene itself has not been scientifically proven. Therefore it is necessary to do research on thermophilic bacteria to obtain isolate of thermophilic bacteria from hot springs that have gene encoding resistance to selenium (Se) and clone the gene into an E. coli. Isolated genomic DNA of the thermophilic bacteria as well as the plasmid were cut with Eco RI enzyme. Fragments of bacterial DNA was ligated into the vector and then transformed into E. coli cells. Transformants were tested by using blue white colony to show the growth of white colonies indicated the presence of inserted DNA fragment in pGEM3zf while the growth of blue colonies indicated the absence of DNA fragments inserted in pGEM3zf. Molecular weight of the recombinant plasmid was measured using standard curve with obtained assistance line following equation: Y = 19473.807-6294.596X; where X = distance migration and Y = base pairs. Molecular weight of the recombinant plasmid obtained was 14 438 bp.
Keyword: 

Judul: Deteksi Gen Penyandi Resistensi Antibiotik pada Escherichia coli dan Salmonella sp. yang Diisolasi dari Beberapa Peternakan Unggas di Jawa Barat.
Abstrak: Industri perunggasan menggunakan antibiotik sebagai pencegahan, pemacu pertumbuhan dan pengobatan penyakit infeksi bakerial. Oleh karena itu banyak menimbulkan bakteri resisten. Escherichia coli dan Salmonella sp. adalah bakteri penting pada hewan. Penelitian ini bertujuan untuk mengisolasi dan mengidentifikasi E. coli dan Salmonella sp., menguji sensitivitas dan deteksi gen penyandi resistensi E. coli and Salmonella sp.. Seratus lima sampel swab kloaka unggas digunakan dalam penelitian ini. Isolasi dan identifikasi bakteri menggunakan kaldu tetrationat (khusus Salmonella sp.), kemudian dikultur pada media agar selektif (agar Mac Conkey dan eosin methylene blue untuk E.coli, Salmonella-Shigella untuk Salmonella sp.), pengujian biokimia dan pewarnaan Gram. Isolat bakteri dikonfirmasi dengan amplifikasi gen uspA E. coli dan invA Salmonella sp. menggunakan PCR. Tetrasiklin, oksitetrasiklin, ampisilin, gentamisin, asam nalidiksat, siprofloksasin, enrofloksasin, eritromisin dan kloramfenikol adalah antibiotik yang digunakan dalam penelitian ini. Metode difusi cakram Kirby-Bauer digunakan untuk mendeteksi resistensi bakteri terhadap antibiotik. Hasil uji sensitivitas menunjukkan bahwa E. coli resisten terhadap tetrasiklin (92.3%), oksitetrasiklin (92.3%), ampisilin (100%), gentamisin (61.6%), asam nalidiksat (94.3%), siprofloksasin (69.2%), enrofloksasin (65.4%), eritromisin (96.2%) dan kloramfenikol (0%). Salmonella sp. resisten terhadap tetrasiklin (75%), oksitetrasiklin (75%), ampisilin (75%), gentamisin (12.5%), asam nalidiksat (100%), siprofloksasin (12.5%), enrofloksasin (0%), eritromisin (100%) dan kloramfenikol (0%). Hasil deteksi gen penyandi resistensi antibiotik pada E. coli dan Salmonella sp. berturut-turut yaitu tetA (83.3% dan 33.3%) positif, blaTEM (100% dan 100%) positif, aac(3)-IV (3.1% dan 0%) positif, gyrA (100% dan 100%) positif ermB (6% dan 0%) positif. Hasil penelitian menunjukkan bahwa E. coli dan Salmonella sp. dapat diisolasi dari swab kloaka unggas. Semua isolat E. coli resisten terhadap ampisilin. Semua isolat Salmonella sp. resisten terhadap asam naidiksat dan eritromisin. Gen penyandi resistensi antibiotik yaitu tetA, blaTEM, aac(3)-IV, gyrA dan ermB genes terdeteksi pada isolat E. coli dan gen tetA, blaTEM dan gyrA terdeteksi pada isolat Salmonella sp..
Keyword: antibiotik, resisten, Escherichia coli, gen, Salmonella sp

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: