Judul: The Effectiveness of Estradiol-17β and Soy Flour for Controlling the Cannibalism in Catfish Fingerlings (Clarias gariepinus)
Abstrak: Ikan lele (Clarias gariepinus) adalah salah satu komoditas ikan air tawar favorit. Produksinya selalu meningkat sejalan dengan meningkatnya permintaan konsumen setiap tahunnya. Beberapa hal masih menjadi kendala yang ditemukan pada kegiatan produksi benih lele, diantaranya adalah tingginya mortalitas akibat kebiasaan kanibal benih pada benih lele. Pengendalian kanibalisme dapat dilakukan dengan pendekatan terapi hormon menggunakan hormon estradiol-17β dan tepung kedelai. Penelitian ini dilakukan dengan tujuan untuk menguji efektivitas penambahan hormon estradiol-17β dan tepung kedelai dalam menekan serta mengendalikan tingkat kanibalisme pada benih ikan lele. Penelitian terdiri atas tiga perlakuan dengan tiga ulangan yang meliputi penambahan 30 mg estradiol-17β.kg-1, penambahan 50 g tepung kedelai.kg-1 dan perlakuan kontrol (tanpa penambahan hormon estradiol-17β dan tepung kedelai) pada pakan benih lele. Benih ikan lele berukuran panjang rata-rata 4.97±0.47 cm dan bobot rata-rata 0.87±0.05 g. Ikan lele dipelihara dengan kepadatan 1000 ekor.m-2 pada kolam terpal (2×1×0.5 m3) selama 30 hari masa pemeliharaan. Hasil penelitian menunjukkan bahwa penambahan tepung kedelai dan hormon estradiol-17β ke dalam pakan mampu menekan kanibalisme tipe-I dibandingkan dengan kontrol, namun tidak memberikan pengaruh nyata terhadap tingkat kelangsungan hidup benih lele, karena mungkin dipengaruhi oleh penyakit infeksi yang belum diidentifikasi., Catfish (Clarias gariepinus) is one of the favourite freshwater aquaculture commodities. Its production continues to increase as the consumer demand raises, every year. One of the obstacles found in catfish fry production activity is the high mortality due to the cannibalism behaviour in the catfish fry. The cannibalism can be controlled with hormonal therapy approaches using the hormone estradiol-17β and soy flour. This study aimed to evaluate effectiveness of the addition of hormone estradiol-17β and soy flour in suppressing and controlling the level of cannibalism in catfish fry. The study consisted of three treatments, each with three replications which included the addition of 30 mg of estradiol-17β kg-1, addition of 50 g of soy flour kg-1 and control treatment (without addition of the hormone estradiol-17β and soy flour) in catfish fry feed. Average length of catfish fry used in this study was 4.97 ± 0.47 cm with average weight of 0.87 ± 0.05 g. Catfish were reared with a density of 1000 m-2 in a tarpaulin pond (2×1×0.5 m3) for 30 days. The results showed that the addition of soy flour and the hormone estradiol-17β in the feed was significantly suppressed type-I cannibalism compared to the control, but did not have a significant effect on the survival rate of catfish seeds probably was due to unknown infectious disease.
Keyword: cannibalism, Clarias gariepinus, estradiol-17β, soy flour

Judul: Efektivitas dan  Efisiensi Penggunaan Tepung Kedelai dalam Pengendalian Kanibalisme Benih  Ikan Lele (Clarias sp.) pada Skala Lapang
Abstrak: Ikan lele (Clarias sp.) merupakan ikan primadona perairan tawar yang setiap tahun mengalamani peningkatan baik produksi dan permintaan konsumen. Tetapi, terdapat kendala yaitu tingginya kematian akibat kanibalisme. Untuk mengatasi dilakukan pendekatan terapi hormon menggunakan tepung kedelai dalam mengendalikan kanibalisme. Penelitian ini bertujuan untuk menentukan dosis tepung kedelai yang efektif dan efisien dalam pengendalian kanibalisme benih ikan lele pada skala lapang. Terdapat empat perlakuan dengan satu kali ulangan dalam penelitian ini, mencakup penambahan tepung kedelai dalam pakan dengan dosis berbeda yaitu 50 g kg-1, 100 g kg-1, dan 150 g kg-1 pakan serta perlakuan kontrol tanpa penambahan tepung kedelai. Benih ikan lele yang digunakan memiliki panjang rata-rata 5,43 ± 0,29 cm/ekor dengan bobot 1,69 ± 0,28 g/ekor. Ikan lele dipelihara dalam kolam beton dengan kepadatan 1000 ekor/kolam dengan ukuran 2 x 1 x 0,5 m selama 30 hari masa pemeliharaan, pemberian pakan dilakukan secara restricted sebanyak 5% dari biomassa ikan dengan frekuensi pemberian pakan 3 kali sehari. Hasil penelitian menyatakan penambahan tepung kedelai 50 – 150 g kg-1 pakan dapat menurunkan tingkat kanibalisme benih ikan lele pada ukuran rata-rata 5,43 ± 0.28 cm/ekor. Dosis terbaik penambahan tepung kedelai adalah 100 g kg-1 pakan dengan tingkat kelangsungan hidup 72,5% dan keuntungan Rp. 133.300/725 ekor., Catfish (Clarias sp.) is a favorite freshwater fish that experiences an increase in both production and consumer demand every year. However, there is an obstacle, namely the high number of deaths due to cannibalism. To overcome this, a hormone therapy approach was used using soybean flour to control cannibalism. This research aims to determine the effective and efficient dose of soybean flour in controlling cannibalism of catfish seeds on a field scale. There were four treatments with one replication in this study, including the addition of soy flour to the feed at different doses, namely 50 g kg-1, 100 g kg-1, and 150 g kg-1 feed as well as a control treatment without the addition of soy flour. The catfish seeds used had an average length of 5.43 ± 0.29 cm/fish with a weight of 1.69 ± 0.28 g/fish. Catfish are kept in concrete ponds with a density of 1000 fish/pond with dimensions of 2 x 1 x 0.5 m for a 30 day rearing period, feeding is restricted to 5% of the fish biomass with a feeding frequency of 3 times a day. The results of the study stated that the addition of soybean flour 50 – 150 g kg-1 feed could reduce the level of cannibalism of catfish fry at an average size of 5.43 ± 0.28 cm/fish. The best dose for adding soy flour is 100 g kg-1 feed with a survival rate of 72.5% and a profit of IDR. 133,300/725 fish.
Keyword: cannibalism, cannibalism control, catfish (Clarias sp.), doses, soybean flour

Judul: Penggunaan Teorema Homeomorphy 2-Manifold dan Teorema Euler Poincare pada Torus 𝑇�� dan Simplicial Complex 𝐾��
Abstrak: Two dimensional topological spaces are said to be homeomorphic if they have the same topological invariant, where one of topological invariant used is an Euler characteristic. Homeomorphy 2-Manifold’s Theorem and Euler Poincare’s Theorem are used to distinguish two topological spaces. Homeomorphy 2-Manifold’s Theorem uses Euler characteristic to identify two dimensional topological spaces. Euler Poincare’s Theorem is an alternative way to find Euler characteristic with Betti number, which is topological invariant as well. The objective of this paper is to investigate the homeomorphism of torus 𝑇����� and simplicial complex 𝐾�����. Topological space torus and simplicial complex 𝐾����� have the same Euler characteristic, which is two. Based on Homeomorphy 2-Manifold’s Theorem topological space torus 𝑇����� and simplicial complex 𝐾����� is homeomorphic.
Keyword: simplicial, torus, Euler, homeomorphism, topology