Judul: Validation of the Red-Eared Slider Turtle Trachemys scripta elegans (Wied-Neuwied, 1839) Traded in Bogor Based on Cytochrome Oxydase Subunit I (COI) Gene Markers
Abstrak: Kura-kura Brazil Trachemys scripta elegans (Wied-Nuwied, 1839), termasuk hewan introduksi semi akuatik di Indonesia. Namun, keberadaannya dikhawatirkan dapat mengancam spesies lokal akibat pelepasliaran di perairan bebas. Tujuan penelitian ini adalah untuk validasi secara molekuler spesies kura-kura Brazil (Trachemys scripta elegans) di wilayah Bogor, Jawa Barat yang didasarkan pada marka gen COI. Metode yang digunakan meliputi isolasi dan ekstraksi DNA, elektroforesis, amplifikasi, serta sekuensing. Analisis data berupa analisis morfologi, pensejajaran nukleotida, validasi fragmen COI, perhitungan jarak genetik, konstruksi pohon filogenetik, dan keragaman haplotype. Hasil didapat berupa 11 DNA target yang memiliki jarak genetik < 3% dengan Trachemys scripta elegans, hubungan kekerabatan yang dekat dengan Trachemys scripta elegans, serta keragaman haplotype yang sedang. Dapat disimpulkan bahwa sampel berpotensi menjadi invasif jika dilepasliarkan secara bebas dan tervalidasi dengan Trachemys scripta elegans berdasarkan identifikasi molekuler.
Keyword: gen COI, identifikasi molekuler, T. scripta elegans

Judul: Validasi Kura-Kura Brazil Trachemys scripta elegans (WiedNeuwied, 1839) yang DiperjualBelikan di Bogor Berdasarkan Marka Gen 16S rRNA.
Abstrak: Kura-kura Brazil Trachemys scripta elegans (Wied-Nuwied, 1839) merupakan kura-kura semi akuatik introduksi yang berasal dari Amerika bagian tengah atau selatan yang banyak diminati masyarakat Indonesia sebagai hewan peliharaan. Keberadaan spesies ini dikhawatirkan dapat mengancam spesies lokal akibat pelepasan secara liar di perairan bebas. Tujuan penelitian ini adalah untuk memvalidasi secara molekuler spesies kura-kura Brazil (Trachemys scripta elegans) di tiga wilayah Bogor, Jawa Barat sebagai informasi hubungan kekerabatannya berdasarkan marka gen 16S rRNA. Metode yang digunakan yaitu isolasi dan ekstraksi DNA, elektroforesis, amplifikasi dan visualisasi, dan sekuensing gen 16S rRNA. A nalisis data berupa analisis morfologi, validasi fragmen 16S rRNA, pensejajaran nukleotida, perhitungan jarak genetik, dan konstruksi pohon filogenetik. Hasil PCR kesebelas sampel menunjukkan pita DNA tunggal yang terang dan tebal. Validasi seluruh sampel merujuk pada Trachemys scripta elegans dengan nilai persen identifikasi ≥ 99,50%, dan diperoleh hasil jarak genetik < 3% dengan Trachemys scripta elegans, serta hubungan kekerabatan yang dekat dengan Trachemys scripta elegans. Kesimpulan yang diperoleh yaitu sampel tervalidasi dengan Trachemys scripta elegans berdasarkan identifikasi molekuler dan berpotensi menjadi invasif jika dilepas secara liar dan bebas di perairan., The Brazilian tortoise Trachemys scripta elegans (Wied-Nuwied, 1839) is an introduced semi-aquatic turtle originating from Central or South America that is in great demand by Indonesian people as pets. The existence of this species is feared to threaten local species due to release in free waters. The aim of this study was to molecularly validate the species of Brazilian turtle (Trachemys scripta elegans) in three areas of Bogor, West Java as information on their kinship based on 16S rRNA gene markers. The methods used were DNA isolation and extraction, electrophoresis, amplification and visualization, and 16S rRNA gene sequencing. A data analysis in the form of morphological analysis, validation of 16S rRNA fragments, nucleotide alignment, calculation of genetic distances, and construction of phylogenetic trees. The PCR results of the eleven samples showed a single bright and thick DNA band. The validation of all samples referred to Trachemys scripta elegans with a percent identification value of ≥ 99.50%, and the results obtained were <3% genetic distance with Trachemys scripta elegans, as well as close kinship with Trachemys scripta elegans. The conclusion obtained is that the samples were validated with Trachemys scripta elegans based on molecular identification and have the potential to become invasive if released wildly and freely into the waters.
Keyword: 16S rRNA, genetic, Trachemys scripta elegans

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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