Judul: Sex Reversalikan nila menggunakan madu dan analisis ekspresi gen aromatase
Abstrak: The use of synthetic steroid hormones to produce monosex populations of tilapia for intensive productive systems may lead to environmental and public health concerns. Such a situation is derived from the fact that female tilapine species have a high fecundity, generally reproducing at a small size and exhibiting stunted somatic growth at higher densities, while male tilapias exhibit faster growth rates and are often the preferred gender for monosex aquaculture.The study was conducted to determine the effect of immersion Nile tilapia larvae in water containing different honey source on male fish percentage and aromatase gene expression. In the first experiment, in a total of 30 tilapia larvae at 12 days posthatch were immersed in the water containing honey derived from the forest, cultured and mangrove bees, with a dose of 10 mL/L water for 10 hours. Fish were then maintained in the same condition for 2 months. The results showed that percentage of male fish immersed by different honey was similar (p>0.05), and all treatment was significantly different with the control (p<0.05). In the second experiment tilapia larvae were immersed in two bioactive compounds of honey, namely chrysin and potassium solution in a dose of 20 mg/L and 0.026 g/L, respectively, to verify the materials of honey that affects sex differentiation in Nile tilapia. The results showed that both compounds increased male fish percentage compared to that of control (p<0.1). This indicated that chrysin and potassium were involved in Nile tilapia sex reversal. Growth, survival and biomass of honey bee treated fish were similar with the control (p>0.05), while chrysin and potassium treated fish have lower survival rate than that of control (p<0.1). The lower survival rate maybe caused slightly higher specific growth in the chrysin and potassium treated fish compared to control (p<0.1). Furthermore, RT-PCR analysis showed that honey bee, chrysin and potassium down-regulated gonadal-type aromatase gene expression at 12 hours post immersion. Thus, honey can be use to sex reverse of Nile tilapia, and evolved the gonadal-type aromatase expression.
Keyword: 

Judul: Effectiveness of Sex Reversal of Red Tilapia (Oreochromis niloticus) through Immersion with Randu Honey at Different Concentrations
Abstrak: Ikan nila merah (Oreochromis niloticus) jantan merupakan komoditas ikan air tawar unggulan Indonesia yang memiliki pertumbuhan cepat, mudah berkembang biak, dan tahan terhadap perubahan lingkungan. Budidaya monoseks jantan sangat efektif dan efisien untuk memaksimalkan produksi. Populasi monoseks jantan dapat diperoleh dengan melakukan seks reversal menggunakan steroid alami yang aman dan ramah lingkungan yaitu madu. Penelitian ini bertujuan untuk mengevaluasi penggunaan jenis madu randu dan dosis efektif untuk seks reversal ikan nila menjadi jantan melalui perendaman larva. Rancangan acak lengkap dengan 3 perlakuan dan 3 ulangan dosis madu terdiri dari 0 mL/L, 15 mL/L, dan 30 mL/L selama 24 jam perendaman pada larva berumur 7 hari dan masa pemeliharaan 90 hari. Nisbah kelamin jantan tertinggi dihasilkan dari perlakuan perendaman dalam larutan madu 30 mL/L yaitu sebesar 90±4,08% dan laju pertumbuhan spesifik 7,36%., Male red tilapia (Oreochromis niloticus) is Indonesia's leading freshwater fish commodity which has fast growth, easy to breed, and resistant to environmental changes. Male monosex cultivation is very effective and efficient to maximize production. The male monosex population can be obtained by performing reversal sex using honey as natural steroids that are safe and environmentally friendly. The aim of this study was to evaluate the use of randu honey and the effective dose for reversal sex of tilapia into males through immersion of larvae. Completely randomized design with 3 treatments and 3 doses of honey consisting of 0 mL/L, 15 mL/L, and 30 mL/L for 24 hours of immersion using 7 day old larvae and 90 days of maintenance. The highest male sex ratio resulted from the treatment of immersion in 30 mL/L honey solution, which was 90±4.08% and specific growth rate was 7.36%.
Keyword: Honey, Oreochromis niloticus, Sex ratio, Sex reversal

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