Judul: Mange (kudis) pada kucing lokal di lingkungan kampus Institut Pertanian Bogor Dramaga
Abstrak: This study was conducted to identify the mite that cause mange to local stray cats found around Bogor Agricultural University, Dramaga. The skin scraping from seven cats with pruritus, alopecia, and hyperkeratosis were examined microscopically. Two of seven cats, two showed Otodectes sp. on their skin scraping examination. Otodectes were found on ear and head area. The mites can be found outside the ear, as the natural habitat for Otodectes, because cat use to shake and scratch on the exact area where the mites live which causes the mites being thrown away and stay on the other part of the body. Besides Otodectes, fungi and cat lice were also identified on the skin scraping examination. Fungi and lice infestation caused similar symptoms to mite infestation on cat skin. These two agents should be considered as the differential diagnoses to mange caused by mites on cat. Otodectes can be transmitted to human through direct contact so people awareness should be taken seriously about this zoonotic disease
Keyword: cat, mites, mange, Otodectes sp.

Judul: Infestasi Pinjal dan Infeksi Dipylidium caninum pada Kucing Liar Di Kampus Institut Pertanian Bogor Dramaga
Abstrak: This study was conducted to investigate flea infestation and Dipylidium caninum infection on stray cat in Bogor Agricultural University Dramaga. The totals of 30 stray cats were collected from various places which found commonly in Bogor Agricultural University Dramaga. The stray cats were collected purposifelly which showed pruritus and alopecia. The whole body of cat powdered by gamexan powder, after that the fleas were collected by manual and examined microscopically. The D. caninum were examined from 30 fecal samples of stray cats used McMaster methode, flotation methode and observed by existence of proglotids. Fleas identification were conducted in Laboratory Entomology, while fecals were examined in Laboratory Helminthology, Faculty of Veterinary Medicine Bogor Agricultural University. The identification showed that was only one spesies of flea namely Ctenocephalides felis, while D. caninum were not found. Twenty one (70%) from thirty cats were infestated by the flea with density average of fleas per cat was 3.8±1.9.
Keyword: Ctenocephalides felis, Dipylidium caninum, Prevalence, Stray cat.

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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