Judul: Masculinization of Nile Tilapia (Oreochromis niloticus) By Immersion Technique in Purwoceng (Pimpinella alpina) Extract
Abstrak: Masculinization of in nile tilapia is very important in controlling reproduction and obtaining gender that have faster growth. Synthetic steroids which are commonly used to masculinize but has potential hazards and not recommended for aquaculture. The use of natural product is a potential alternative to be explored, especially from plant. The objective of this study was to determine the effect of immersion nile tilapia larval in extract of purwoceng in masculinizing nile tilapia. Doses used in this study are 10, 20, 30 mg/l of purwoceng extract with two control groups those are using 500 μg/l 17α-methiltestesterone and no immersion in purwoceng extract. Exposing 8h on 4 and 7 days post-hatching in extract of purwoceng and 17α-metiltestesterone, resulted in significantly skewed sex ratio of 73,3% males by immersion in 20 mg/l. Synthetic androgen, 17α-methiltestesterone gave better result than extract of purwoceng in this study. Further study on extract of purwoceng is needed to observe the best limit of short-time immersion and to find the best result in sex ratio.
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Judul: Efektivitas Ekstrak Tepung Testis Sapi Dalam Alih kelamin Ikan Nila, Oreochromis Niloticus L. Melalui Teknik Perendaman
Abstrak: Monosex fish stocks are desirable in aquaculture in order to control reproduction and select the gender that have faster growth characteristics in a particular species. Synthetic steroids are commonly used to sex-reverse tilapia but because of their potential hazards and not recommended in Indonesia; the use of new natural compound is a potential alternative to be explored. Bull testes meal extract (BTME) had knowed containing natural testosterone hormone which can used on sex reversal in fish. The objective of this study was to determine the efficacy of a short-term immersion procedure for masculinizing Nile tilapia,_Oreochromis niloticus. Two androgens hormone were evaluated: 17a-methyltestosterone as control part (synthetic androgens) and the other is BTME as natural androgen. Exposure (8 h) on 4 and again on 7 days post-fertilization to 17a-methyltestosterone at 500 μg/ l successfully masculinized fry in all replicated experiments, resulting in 81,11% respectively. Immersions in BTME at 1 ml/l (Experiments A) resulted in significantly skewed sex ratios in (68,89 %), and Experiments B (3 ml/l) resulted in 75,56 % males; and Experiments C (5 ml/l) resulted in 85,56 % males. Although further research and refinement is needed, immersion of Nile tilapia in BTME may provide a practical alternative to the use of natural steroid-treated immersion. Furthermore, when compared with current techniques for steroid-induced sex inversion of tilapia, short-term immersion reduces the period of time that workers are exposed to anabolic steroids.
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Judul: Closed Knight’s Tour pada Papan Catur Berbentuk Persegi Panjang dengan Ukuran Maksimal 8 × 8
Abstrak: Closed Knight’s Tour merupakan langkah kuda yang mengunjungi setiap kotak pada papan catur tepat satu kali dengan langkah kuda berawal dan berakhir pada kotak yang sama. Graf yang terbentuk dari closed knight’s tour dinotasikan sebagai graf G(m,n), dengan m adalah banyaknya baris dan n adalah banyaknya kolom. Graf tersebut memuat Hamiltonian cycle. Sebuah graf terhubung G adalah graf bipartite jika dan hanya jika graf tersebut tidak memiliki cycle dengan panjang ganjil. Papan catur yang memenuhi syarat cukup untuk memiliki closed knight’s tour adalah papan catur berukuran 5 × 6, 5 × 8, 6 × 6, 6 × 7, 6 × 8, 7 × 8, dan 8 × 8.
Keyword: bipartite, closed knight’s tour, hamiltonian cycle, knight’s tour, teori graf