Judul: Regenerasi talus Kappaphycus alvarezii (Doty) transgenik sitrat sintase (PaCS) secara in vitro
Abstrak: Seaweed is one of Indonesian aquaculture commodities. One type of seaweed that widely produced in Indonesia is Kappaphycus alvarezii (Doty). The amount of national and international market demand of seaweed encourage people to cultivate extensively regardless of environmental factors. Citric acid secretion in plants plays an important role in stress tolerance to heavy metals, especially aluminum. Citrate syntase encoding genes (PaCS) has been successfully introduced into K.alvarezii. This research aimed to compare in vitro regeneration of transgenic citrate synthase (PaCS) K.alvarezii thallus with non-transgenic K.alvarezii thallus and to determine the effect of growth regulators addition in solid culture media. Regeneration parameters such as wet weight gain and the length of the thallus was measured every two weeks for ten weeks. The measurement results were analyzed using t-test analysis. Based on t-test analysis result, there was no significant difference in vitro regeneration of transgenic citrate synthase gene (PaCS) K.alvarezii thallus with non-transgenic K.alvarezii thallus. The results of t-test analysis also showed no significant difference in vitro regeneration of transgenic K.alvarezii thallus cultured on solid PES media before to liquid medium. In addition, provision of ZPT on solid PES culture media did not have a significant effect on transgenic thallus in vitro regeneration.
Keyword: Bogor Agricultural University (IPB), t-test analysis., thallus regeneration, PaCS, Kappaphycus alvarezii

Judul: Acclimatization and field cultivation test of an in vitro propagated seaweed (Kappaphycus alvarezii Doty) seed in the sea
Abstrak: In traditional aquaculture, propagation seeds of seaweed are usually obtained through vegetative technique. Nowadays, in vitro technique is applicable to get high-grade seaweed seeds. This study aimed to determine the best medium for micropropagule and fertilizer effect on young plantlets of Kappaphycus alvarezii. This study also performed to compare growth of seaweeds between vegetative and in vitro technique. The results showed that seawater medium with 20 ml l-1 provasoli enriched seawater fertilizer showed significant specific growth rate (4.65%) over three other medium treatment during culture in laboratory. However, during culture in greenhouse, seawater medium with 5 ml l-1 PES and 1.2 mg l-1 Growmore, a commercial fertilizer showed significant over two other medium treatment. In the last study, seaweeds from provasoli enriched seawater fertilizer treatment during acclimatization showed the highest growth (108,00 g) compared to the others when cultured in the sea. However, cultivation seaweeds from in vitro technique has better growth than vegetative technique.
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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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