Judul: Inventarisasi dan Identifikasi Tungau Ektoparasit pada Cicak di Pasar dan Suaka Margasatwa Muara Angke, Jakarta
Abstrak: Ectoparasites are form of parasite that stick on the surface of organism, suck their blood or looking for feed on hair, fur, skin, or skin secretions. This study was aimed to inventory, identify, and analize mites infestation in the lizard ectoparasites on market and Muara Angke conservation area, Jakarta. Lizards were collected and preserved in 70% alcohol. The sticky sites on lizard which could be infested are head, ears, armpits, torso, thighs, forelimbs, hind limbs, and tail. All mites were prepared with PVA media. The results showed that there were four species of Geckos, Cosymbotus platyurus, Hemidactylus garnotii, Hemidactylus frenatus, and Gehira mutilata. Identification results based on characters of mites found six types of Geckobia (G1, G2, G5, G6, G10, G11). However based on chaetotaxy the G5 and G11 were grouped as G. indica, G2 in G. glebosum, G6 were in Geckobia group 1, G10 in group with G. gleadoviana, and unidentified G1 geckos. Hemydactylus garnotii was found to had the largest prevalence values at market and conservation, i.e 94.4% and 73.3%. Hemydactylus garnotii also was found to had the largest infestation intensity values at market and conservation, i.e 28.1 and 7.7
Keyword: lizard, Geckobia, chaetotaxy, ectoparasite mites

Judul: Inventarisasi dan Identifikasi Tungau Ektoparasit pada Cicak di Kawasan Taman Margasatwa Ragunan
Abstrak: Gecko interacts with various types of mites, both ectoparasite and endoparasite. Ectoparasite mites are parasitic organisms that live on the surface of its host, sucking the blood or feed on hair, fur, skin, or skin secretions. Many species of gecko were infested by Geckobia. The aim of this research was to inventory, identify, analyze mite’s leg chaetotaxy, calculate the prevalance and intensity of mite infestation, and learn the diversity of ectoparasites mites on gecko in the inside and outside of Taman Margasatwa Ragunan. Mites were prepared by whole mount method using polyvinyl alcohol media. Identification results based on characters of mites found twelve species of Geckobia (G1, G2, G4, G5, G6, G7, G10, G11, G12, G13, G18, and G19). However, based on chaetotaxy, the G2, G4, and G6 were grouped in Geckobia grup 1, G10 in group with G. gleadoviana, G11 in group with G. indica, G13 in group with G. keegani, and G19 in group with G. oedurae. The G1, G5, G7, G12, and G18 in the new group Geckobia. The highest of mite infestation intensity on gecko C. platyurus was mite G4. The highest of mite infestation intensity on gecko H. frenatus was mite G1, and gecko H. garnotii was mite G10. H. garnotii has the largest infestation intensity values.
Keyword: Bogor Agricultural University (IPB), Taman Margasatwa Ragunan, Geckobia, gecko, ectoparasite, chaetotaxy

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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