Judul: Evaluation of the Effectivity of Patin Brain Extract to Induce Spawning of Sangkuriang Catfish, Clarias sp.
Abstrak: The availability of fish juvenile with high quality and quantity is a key factor in aquaculture. Important development in fish breeding has been developed. Patin, Pangasianodon hypopthalmus brain extract has been known to contain GnRH that could stimulate the pituitary gland to secrete gonadotropin hormone. The aim of this research is to evaluate the effectivity of Patin brain extract to induce Sangkuriang catfish, Clarias sp. Spawning. This research showed that the dose of Patin brain extract with 200 mg/kg of brood catfish was the lowest dose to give the best result of Sangkuriang catfish, Clarias sp. spawning with the degree of spawning of 66,66%, spawning latency time of 9,25 ± 1,06 hour, egg diameter of 1,51± 0,09 mm, spawning fecundity of 11,38 ± 0,87%, fertility rate of 90,63 ± 9,50 and hatching rate of 76,3 ± 6,14%. The degree of spawning had the highest value (P<0,05) which was 100% when female brood catfish was injected with synthetic hormon (ovaprim as much as 0,3 ml/kg) and the hypofisis extract of Pangasius compared to other treatments.
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Judul: Induction of Ovulation and Spawning in Catfish (Pangasianodon hypopthalmus) with Hormonal Manipulation
Abstrak: Striped catfish is a species introduced from Thailand, has economically important because the meat is preferred by Indonesian society. Fish farming is growing rapidly, thus increasing the need for seed. Spawning of these fish can only be done by artificial spawning by stripping, which can lead to decreased quality of broodstock, gametes and seeds. The purposeof this study is to hormonally induce ovulation and spawning of seminatural for catfish and evaluate the effectiveness and efficiency of the use of hormone LHRH, antidopamin (AD), aromatase inhibitors (AI), prostaglandin(PGF2a), oxytocin and ovaprim to induce ovulation and spawning on this fish. Mature fish (1.5 - 3.5 kg per fish), was treated by hormonal injection with: LHRHa + AI (Spawnprime 1); AD + AI (Spawnprime 2); LHRHa + AD + AI + PGF2α (Spawnprime 3); LHRHa + AD + AI + PGF2α + oxytocin (Spawnprime 4); LHRHa + AD + oxytocin (Spawnprime 5); LHRHa + AD + PGF2α (spawnprime 6), AI + oxytocin (spawnprime 7), AI + PGF2α (spawnprime 8); ovaprim, and NaCl (0.90%). The results showed that spawnprime has faster latency period (6-8 hours) compared ovaprim (12 hours). spawnprime 1, 2, 5, and 6 can be spawned artificially by stipping, while spawnprime 3,4,7 and 8 naturally. The best results were shown by spawnprime 4 which causes ovulation rate of 100%. The latency period in spawnprime 4 is 6 hours and 33 minutes, the amount of egg in ovulation time is 195.000 ± 41079.19 eggs, the fertilization rate is 91.87% ± 3.03, the hatching rate is 92.33% ± 5.86, the survival rate of larvae 93.91% ± 2.96, diameter egg is 1.05 ± 0.04 mm and concentrations of estradiol 0.7 pg / ml. spawnprime can induced for ovulation and ntural spawning (without stripping) on stripped catfish. Spawnprime can be used as an alternative in the artificial propagation.
Keyword: catfish (Pangasianodon hypopthalmus), ovaprim, spawnprime

Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik.
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik