Judul: The use of a combination of pine (Pinus merkusii) extract and powder in masculinization of red tilapia (Oreochromis sp.)
Abstrak: Ikan nila jantan memiliki pertumbuhan yang lebih cepat dibandingkan dengan ikan nila betina. Maskulinisasi pada ikan nila dilakukan untuk mempercepat masa produksi ikan dengan metode budidaya monoseks. Proses maskulinisasi dapat dilakukan dengan pemberian hormon androgen untuk menginduksi pengarahan kelamin jantan pada ikan. Penelitian ini bertujuan untuk mengetahui efektivitas penggunaan ekstrak dan serbuk buah pinus dengan metode perendaman dan suplementasi dalam pakan pada larva ikan nila berumur 5 hari selama 60 hari pemeliharaan. Terdapat empat perlakuan yaitu perendaman dengan ekstrak buah pinus dosis 0,2 ml.L-1 air selama 10 jam (I), perendaman dengan ekstrak buah pinus dan suplementasi serbuk buah pinus dalam pakan dosis 0,5 g/kg pakan (IS0,5), perendaman dengan ekstrak buah pinus dan suplementasi serbuk buah pinus dalam pakan pakan dosis 1g/kg pakan (IS 1,0) dibandingkan dengan perlakuan kontrol tanpa penggunaan ekstrak maupun serbuk buah pinus (K). Nilai nisbah kelamin jantan tertinggi yang dihasilkan yaitu pada perlakuan IS 1,0 sebesar 74,17±1,67%, dibandingkan dengan perlakuan IS 0,5 sebesar 66,67±7,20%, perlakuan I sebesar 61,67 ± 4,30% dan perlakuan kontrol sebesar 55,00±7,93 %. Berdasarkan penelitian ini, perlakuan terbaik terdapat pada perlakuan IS 1,0 dengan perbedaan sebesar 19.17% dibandingkan perlakuan kontrol. Sintasan ikan tertinggi yang didapatkan pada perlakuan IS 1,0 memiliki nilai sebesar 95,5±1,0 %, Male tilapia fish have faster growth compared to female tilapia. Masculinization in tilapia is performed to accelerate fish production using the monosex culture method. The masculinization process can be achieved by administering androgen hormones to induce male sex determination in the fish. This study aims to determine the effectiveness of using pine fruit extract and powder through immersion and supplementation methods in the diet of 5-day-old tilapia larvae for a 60-day rearing period. There are four treatments: immersion with pine fruit extract at a dosage of 0.2 ml/L of water for 10 hours (I), immersion with pine fruit extract and supplementation of pine fruit powder in the diet at a dosage of 0.5 g/kg of feed (IS 0.5), immersion with pine fruit extract and supplementation of pine fruit powder in the diet at a dosage of 1 g/kg of feed (IS 1.0), compared to the control treatment without the use of extract or pine fruit powder (K). The highest male sex ratio obtained was in the IS 1.0 treatment, which amounted to 74.17 ± 1.67%, compared to the IS 0.5 treatment at 66.67 ± 7.20%, the I treatment at 61.67 ± 4.30%, and the control treatment at 55.00 ± 7.93%. Based on this study, the best treatment was found in the IS 1.0 treatment with a difference of 19.17% compared to the control treatment. The highest fish survival rate obtained in the IS 1.0 treatment was 95.5 ± 1.0%.
Keyword: Nila, maskulinisasi, buah pinus, pertumbuhan

Judul: Pemberian ekstrak buah pinus merkusii  dalam maskulinisasi benih nila melalui metode yang berbeda
Abstrak: Maskulinisasi dilakukan dengan tujuan memperoleh benih ikan nila monoseks jantan untuk mempercepat pertumbuhan ikan nila. Hormon sintetik yang sering digunakan dalam proses maskulinisasi ikan yaitu 17α-Methyltestosterone (MT), akan tetapi saat ini penggunaannya sudah dibatasi karena dapat meninggalkan residu. Sehingga diperlukan bahan alami yang dapat menjadi subtitusi dalam kegiatan tersebut. Penelitian ini bertujuan mengetahui pengaruh pemberian ekstrak buah pinus dengan metode berbeda. Larva yang digunakan berumur 5 hari dan dipelihara selama 60 hari dengan kepadatan 100 ekor setiap akuarium. Terdapat tiga perlakuan yang digunakan, yaitu kontrol (K), imersi EBP dosis 0,20 mL L -1 (I), serta kombinasi imersi dosis 0,20 mL L -1 dan suplementasi 2 mL kg-1 pakan (IS). Nilai nisbah kelamin jantan tertinggi terdapat pada perlakuan IS sebesar 83,33±5,09%, sedangkan perlakuan I dan K berturut-turut sebesar 71,11±6,67% dan 50,00±3,33%. Berdasarkan penelitian ini, perlakuan terbaik terdapat pada perlakuan IS dibandingkan dengan perlakuan kontrol dengan peningkatan 33,33%. Kata kunci: EBP, ikan nila, monoseks, perendaman, suplementasi., Masculinization was carried out with the aim of obtaining male monosex tilapia seeds to accelerate the growth of tilapia. The synthetic hormone that is often used in the process of masculinizing fish is 17α-Methyltestosterone (MT), but currently its use is limited because it can leave residues. So we need natural materials that can be substitutes in these activities. This study aims to determine the effect of giving pinecone extract with different methods. The larvae used were 5 days old and reared for 60 days at a density of 100 individuals in each aquarium. There were three treatments used, namely control (K), EBP immersion dose of 0.20 mL L-1(I), and a combination of immersion dose of 0.20 mL L-1 and supplementation of 2 mL kg-1 feed (IS). The highest male sex ratio was found in the IS treatment of 83.33 ± 5.09%, while in treatments I and K were 71.11 ± 6.67% and 50.00 ± 3.33%, respectively. Based on this study, the best treatment was in the IS treatment compared to the control treatment with an increase of 33.33%. Keywords: EBP, immersion, monosex, tilapia, supplementation.
Keyword: EBP, immersion, monosex, tilapia, supllementations

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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