Judul: Struktur dan Keragaman Genetik Populasi Hama Boktor (Xystrocera festiva) pada Hutan Rakyat Sengon (Falcataria moluccana) di Jawa.
Abstrak: Boktor (Xystrocera festiva) is the most destructive sengon pests, because the larvae feeding activity is done by broaching the woody tissue inside sengon trees. The objective of this research was to study population structure and genetic diversity of boktor pests in Java using RAPD markers. Boktor larvae were sampled from 10 susceptible trees in eight districts in Jawa, and then census was done to calculate the total individuals found in each tree, before taking measurements of body length and diameter of its head. Having been census a number of 10 larvae per tree of various sizes were picked up as sample for DNA analysis. DNA extraction was done using CTAB (Cetyl Trimethil Ammonium Bromide) method, and the PCR (Polymerase Chain Reaction) was done using OPP 9, OPP 15, and OPP 19 primers to get RAPD (Random Amplified Polymophic DNA) fragment. Scored fragment data was analyzed using software POPGENE 1.31 version 32 and NTSYS version 2.0. The results showed the heterogeneity of the population structure according to the diameter and body length of each population. Result of RAPD analysis showed that the highest heterozigosity (He) value was from Tasikmalaya (0.2525) and the lowest heterozigosity (He) was 0.1039 from Magelang. Dendrogram based on genetic distance showed that Kediri population was closely related with Temanggung while Ciamis population is farthest.
Keyword: CTAB, RAPD, sengon, population structure, Xystrocera festiva

Judul: Analisis Keragaman Genetik Dan Filogenetik Populasi Hama Boktor Xystrocera Festiva (Coleoptera: Cerambycidae) Di Jawa
Abstrak: Banyak studi yang telah dilakukan untuk mencari sistem pengendalian hama boktor (Xystrocera festiva), yaitu hama utama pada tegakan sengon. Namun hingga saat ini sistem pengendalian yang ditemukan belum berhasil menangani serangan hama boktor. Hal ini disebabkan oleh minimnya informasi mengenai hama tersebut, salah satunya informasi mengenai variasi genetik pada hama boktor. Penelitian ini bertujuan untuk menganalisis pola sebaran serangan hama boktor pada delapan populasi sengon di Jawa, dan menganalisis variasi genetik larva yang ada di Jawa. Sampling dilakukan menggunakan metode purposive pada 8 populasi, yaitu Sukabumi, Cianjur, Tasikmalaya, Ciamis, Temanggung, Magelang, Kediri dan Malang. Variasi genetik boktor disekuen pada gen Cytochrome Oxidase subunit I (COI). Pola sebaran hama boktor di Jawa bervariasi di masing-masing populasi, yaitu beragamnya ukuran larva berdasarkan diameter kepala dan panjang tubuh yang mengindikasikan larva melakukan serangan berulang pada suatu populasi. Sekuen gen COI larva boktor yang berasal dari Jawa diperoleh sepanjang 605 pb yang terdiri dari 9 haplotipe yaitu 4 haplotipe diperoleh dari Jawa Barat, 3 haplotipe dari Jawa Tengah, dan 2 haplotipe dari Jawa Timur. Keragaman genetik X. festiva di Jawa termasuk kategori tinggi, yaitu Hd=0.772. Berdasarkan hasil analisis jarak genetik menunjukkan ilustrasi pohon filogenetik menunjukkan jarak genetik suatu populasi berbeda dipengaruhi oleh jarak geografis masing-masing populasi. Pohon filogenetik juga menunjukkan semua sekuen X. festiva berkelompok, dan berbeda dengan sekuen kelompok X. globosa yang diperoleh dari basis data Genbank. Hasil sekuen tersebut dapat digunakan sebagai barcode untuk membedakan spesies dari genus Xystrocera.
Keyword: Boktor, COI, populasi, sengon, variasi genetik

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: