Judul: Microbiological Quality of Raw Meat-Based Diets for Pets Based on Total of Enterobacteriaceae dan Escherichia coli
Abstrak: Daging mentah untuk pakan hewan peliharaan (raw meat-based diets/RMBDs) dianggap memiliki nutrisi alami yang lebih baik dibandingkan dengan pakan olahan seperti wet food dan dry food. Penularan mikroorganisme patogen yang dapat mengganggu kesehatan manusia dan hewan dapat terjadi apabila higiene dan sanitasi dalam pengolahan RMBDs, terutama dalam pengemasan, penyimpanan, pengiriman dan penyajian tidak dilakukan dengan baik.Penelitian ini bertujuan mengetahui kualitas mikrobiologi pakan hewan peliharaan berbahan dasar daging mentah berdasarkan jumlah Enterobacteriaceae dan E. coli. Sebanyak 3 merek RMBDs dengan 5 kali ulangan dan 1 merek wet dog food dengan 6 kali ulangan, berbahan dasar daging ayam dan sapi dibeli secara online dari marketplace. Pengujian Enterobacteriaceae menggunakan metode hitungan cawan dan metode most probable number (MPN) untuk menghitung jumlah E. coli. Hasil penelitian ini menunjukkan jumlah Enterobacteriaceae dan E. coli dalam RMBDs lebih tinggi dibandingkan dengan wet dog food. Rata-rata jumlah Enterobacteriaceae dalam RMBDs ayam, RMBDs sapi, dan wet dog food berturut-turut adalah 3,2 × 104 ± 4,8 × 104 CFU/g, 2,8 × 103 ± 2,6 × 103 CFU/g, dan 4,5 × 101 ± 6,4 × 101 CFU/g. Rata-rata jumlah E. coli dalam RMBDs ayam, RMBDs sapi, dan wet dog food berturut-turut yaitu 12,98 ± 16,34 MPN/g, 10,71 ± 14,63 MPN/g, dan 0 MPN/g. Tidak terdapat hubungan yang signifikan antara jenis daging dan jumlah Enterobacteriaceae dalam RMBDs. Jumlah Enterobacteriaceae dan E. coli dalam RMBDs belum memenuhi standar yang telah ditetapkan., Raw meat-based diets (RMBDs) are nutritionally superior compared to wet food and dry food. Transmission of pathogenic microorganisms that interfere with human and animal health occured if hygiene and sanitation in the processing of RMBDs for pets carried out improperly, especially in packaging, storage, delivery and serving. This research aimed to determine the microbiological quality of RMBDs for pets based on total of Enterobacteriaceae and E. coli. A total of 3 brands of RMBDs with 5 replications and 1 brand of wet dog food with 6 replications, the basic ingredients of chicken and beef were purchased from online marketplace. Plate count method was used for Enterobacteriaceae counting and E. coli counted by using the most probable number (MPN). The result showed that the total of Enterobacteriaceae and E. coli was higher in RMBDs compared to wet dog food. The average of Enterobacteriaceae in chicken RMBDs, beef RMBDs, and wet dog food were 3,2 × 104 ± 4,8 × 104 CFU/g, 2,8 × 103 ± 2,6 × 103 CFU/g, and 4,5 × 101 ± 6,4 × 101 CFU/g respectively. The average of E. coli in chicken RMBDs, beef RMBDs, and wet dog food were 12,98 ± 16,34 MPN/g, 10,71 ± 14,63 MPN/g, and 0 MPN/g respectively. There is no significant correlation between the type of meat and the total of Enterobacteriaceae of RMBDs. The total of Enterobacteriaceae and E. coli of RMBDs has not met the maximum standart.
Keyword: Enterobacteriaceae, Escherichia coli, raw meat-based diets, wet dog food

Judul: Total of Microorganisms and Staphylococcus aureus in Raw pet food and Wet pet food.
Abstrak: Status mikrobiologi pakan untuk hewan peliharaan berkaitan secara langsung terhadap kesehatan hewan dan kesehatan manusia secara tidak langsung. Penelitian ini bertujuan mengetahui kualitas mikrobiologi raw pet food dan wet pet food berdasarkan jumlah total mikroorganisme dan jumlah Staphylococcus aureus. Penelitian ini menggunakan pakan jenis raw pet food sebanyak 3 merek dan wet pet food sebanyak 1 merek dari bahan dasar daging ayam dan daging sapi. Pengujian jumlah total mikroorganisme dan jumlah Staphylococcus aureus menggunakan metode hitungan cawan. Rata-rata jumlah total mikroorganisme pada raw pet food berbahan dasar daging ayam dan daging sapi adalah 3,9×105 ± 5,6×105 CFU/g dan 2,7×105 ± 3,0×105 CFU/g, sedangkan pada wet pet food adalah 3,3×102 ± 2,6×102 CFU/g. Rata-rata jumlah Staphylococcus aureus pada raw pet food bahan dasar daging ayam dan daging sapi adalah 2,4×104 ± 3,0×104 CFU/g, dan 2,1×104 ± 5,6×104 CFU/g, sedangkan wet pet food adalah 0 CFU/g. Secara umum penelitian ini menunjukkan jumlah total mikroorganisme dan jumlah Staphylococcus aureus pada raw pet food lebih tinggi dibandingkan dengan wet pet food., The microbiological status of feed for pets is directly related to animal health and human health indirectly. This research was aimed to determine microbiological quality of raw pet food and wet pet food based on the total of microorganisms and Staphylococcus aureus. A total of 3 brands and 1 brand samples from chicken-based and beef-based ingredients were used in this research. The total of microorganisms and Staphylococcus aureus were determined using total plate count method. The average total of microorganisms in chicken-based and beef-based raw pet food was 3,9×105 ± 5,6×105 CFU/g and 2,7×105 ± 3,0×105 CFU/g, whilst in wet pet food was 3,3×102 ± 2,6×102 CFU/g. The average number of Staphylococcus aureus in chicken-based and beef-based raw pet food was 2,4×104 ± 3,0×104 CFU/g, and 2,1×104 ± 5,6×104 CFU/g, whilst wet pet food was 0 CFU/g. This research showed that the total of microorganisms and Staphylococcus aureus in raw pet food was higher than inside wet pet food.
Keyword: microbiological quality, raw pet food, Staphylococcus aureus, total of microorganisms, wet pet food

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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