Judul: Evaluasi Penambahan Ragi Limbah Produksi Bir dalam Pakan terhadap Kinerja Pertumbuhan dan Daya Tahan Ikan Lele Clarias sp. akibat Infeksi Aeromonas hydrophila
Abstrak: The purpose of the study was to test on field-scale the addition of brewer’s yeast Saccharomyces cerevisiae which was considered as brewery by-product in feed on growth performance and immunity of catfish against the infection of Aeromonas hydrophila. Catfish weighed 2.09 ± 0.01 g with average length of 6.42 ± 0.07 cm were stocked in tarpaulin ponds 200 x 200 x 80 cm3 as much as 1.000 fish/pond with 2 treatments and 3 replications. Fish were fed commercial feed without brewer’s yeast addition (K), and brewer’s yeast added feed (RB) for 30 days and the growth response were observed. Fish were challenged in aquariums 60 x 30 x 25 cm3 using 3 treatments and 3 replications which consisted of K- (PBS injected fish), K+ (A. hydrophila injected fish), and RB (A. hydrophila injected fish). After injection, fish were fed K feed for 10 days and the mortality rate were observed. The results showed that feeding with RB feed increased the growth rate of the fish and decreased the feed conversion ratio. Cost analysis showed that RB treatment could decrease feed production cost toRp 33917 from Rp 39418 (control). Fish immunity were increased with increasing total blood leukocytes, suppressed A. hydrophila infection indicated by lighter clinical symptoms showed, and suppressed mortality rate (71.67%) compared to K+ (95.00%).
Keyword: Saccharomyces cerevisiae., growth, endurance, catfish, brewer's yeast, Aeromonas hydrophila

Judul: Pengaruh penambahan ragi bir dalam pakan pada dosis yang berbeda terhadap kinerja pertumbuhan dan daya tahan ikan lele Clarias sp. terhadap infeksi bakteri Aeromonas hydrophila
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh penambahan ragi bir Saccharomyces cerevisiae dalam pakan terhadap kinerja pertumbuhan, biaya produksi dari pakan dan kelangsungan hidup ikan lele Clarias sp. setelah diuji tantang dengan penyuntikan bakteri Aeromonas hydrophila. Ikan lele dengan bobot 110,75 ± 1,73 g ditebar dalam 15 akuarium masing- masing berdimensi 50 × 40 × 35 cm dengan kepadatan 15 ekor/akuarium. Ikan dipelihara selama 40 hari, serta diberi pakan yang mengandung ragi bir sebanyak 0%, 3%, 6%, atau 3% bioyeast. Hasil penelitian menunjuk kan bahwa penambahan ragi bir dan bioyeast dalam pakan tidak memberikan nilai yang berbeda nyata pada parameter jumlah konsumsi pakan, tingkat 4 kelangsungan hidup, laju pertumbuhan harian, efisiensi pakan dan konversi pakan. Namun, untuk menghasilkan 1 kg ikan, biaya pakan paling rendah diperoleh ketika menggunakan perlakuan ragi bir sebesar 3%. Hasil uji tantang dengan bakteri Aeromonas hydrophila memberikan nilai tingkat kelangsungan hidup yang tidak berbeda nyata pada semua perlakuan. Dengan demikian, ragi bir paling efisien digunakan di dalam pakan ikan lele sebanyak 3%.
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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