Judul: The Influence of Serum and or DNase in Dissociation Medium on the Number and Viability of Giant Gouramy (Osphronemus gouramy Lac.)
Abstrak: Disosiasi adalah langkah awal yang diperlukan untuk mendapatkan jumlah spermatogonia yang cukup sebagai sel donor untuk transplantasi. Teknik disosiasi dilakukan dengan metode mekanik dan enzimatik untuk mempercepat pemisahan sel dan jaringan. Penelitian ini bertujuan untuk mengetahui pengaruh penambahan serum dan atau DNase pada medium disosiasi terhadap jumlah dan viabilitas spermatogonia. Testes diambil dari ikan gurame yang berukuran 500 sampai 800 gram/ekor dengan bobot gonad  20 mg. Disosiasi dilakukan menggunakan empat medium yang berbeda yaitu menggunakan PBS yang mengandung: (1) tripsin 0.5% (2) tripsin 0.5% + serum 5%, (3) tripsin 0.5% + DNase 10 IU/μL, dan (4) tripsin 0.5% + serum 5% + DNase 10 IU/μL, dengan volume total 500 μl. Jumlah spermatogonia dihitung setiap jam selama lima jam disosiasi dengan menggunakan hemositometer, dan viabilitas sel diidentifikasi menggunakan pewarna Trypan Blue (TB). Data kuantitatif yang diperoleh dianalisis menggunakan metode analisis General Linier Model (GLM) dan uji lanjut Duncan’s jika terdapat perbedaan nyata. Penambahan serum dalam medium disosiasi tidak menunjukkan pengaruh yang nyata terhadap jumlah rata-rata spermatogonia, namun meningkatkan secara nyata persentase viabilitas spermatogonia. Penambahan DNase maupun kombinasi serum dan DNase mampu menghasilkan rata-rata jumlah spermatogonia dan persentase viabilitas spermatogonia paling tinggi selama disosiasi, dengan jumlah spermatogonia hidup yang meningkat secara nyata setelah disosiasi selama tiga jam untuk penambahan DNase dan dua jam untuk kombinasi serum dan DNase
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Judul: Xenotransplantation of giant gourami testicular germ cells into larvae of nile tilapia
Abstrak: We were attempting to develop testicular germ cell (TGC) transplantation as a tool to produce surrogate broodstock of commercially valuable fish and long generation time species. Giant gourami testis had been used as a model for donor and Nile tilapia larvae as recipient. The research was conducted to study the competency of giant gourami TGC as donor and Nile tilapia larvae as recipient for xenotransplantation of giant gouramy TGC into larvae of Nile tilapia. We developed TGC xenotransplantation system by some steps as follow : 1) The characterization of spermatogonia to identify optimal donor of giant gourami based on body weight using histological approach, 2) The determination of dissociation method for giant gourami testicular tissue by comparing two different composition of dissociation medium with 5 hours incubation time, 3) Optimizing the timing of intraperitoneal TGC transplantation into peritoneal cavity of 1, 3, 5 and 7 days post hatching (dph) recipient by investigating the colonization efficiency of donor cell labelled PKH 26 fluorescent membrane dye under fluorescent microscope and of molecular technique using growth hormone of giant gourami specific primer, 4 ) Analyzing the proliferation of spermatogonia colonized in recipient gonad using molecular approach, and 5) The evaluation of TGC isolated from testis of giant gourami which preserved at 4 oC using NaCl 0.7% for 6, 12, 24 and 48 hours and then transplanted into peritoneal cavity of recipient. The result showed that the donor with abundant spermatogonia stem cell and A type spermatogonia (cell diameter = 14.43–20.53 μm) were found in giant gourami with body weight ranged from 500–1000 g. The dissociation method produced high number of spermatogonia with high viability was one used medium PBS containing trypsin, DNase, CaCl2, HEPES, FBS and incubated for 3 hours. The highest colonization efficiency was observed at 3 dph recipient (61.1±34.71%) suggesting that 3 dph Nile tilapia larvae was the optimum recipient for transplantation. Intraperitoneally transplanted xenogenic spermatogonia efficiently colonized the ovary as well with sex ratio male out of female was 1:1, and possibly proliferated indicated by cell cluster forming and the increase of DNA concentration of donor in recipient testis during time interval 1 month to 2 or 3 month pt. The successful colonization of spermatogonia isolated from preserved testis were also observed with colonization efficiency not differed significantly as from non preserved testis. In conclusion : the testis of giant gouramy was composed of cells that had competency as donor for xenotransplantation using Nile tilapia larvae as recipient.
Keyword: Sel Testikular, Osphronemus goramy, Ikan Gurami, ikan nila, kolonisasi, proliferasi, preservasi

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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