Judul: Viability and effectivity test of formula talc a8 in packaging on infected rice plants by blast disease
Abstrak: Formula A8 yang terdiri atas bakteri Bacillus firmus E65, Bacillus cereus II.14, Pseudomonas aeruginosa C32b, dan Seratia marcescens E31 telah teruji memiliki potensi dalam menghambat pertumbuhan cendawan Pyricularia oryzae secara in vivo dan in vitro. Penelitian ini bertujuan mengamati ketahanan formula A8 sebagai agens hayati potensial melalui uji viabilitas sel bakteri dengan menggunakan bahan pembawa talek, pada suhu ruang (26-27oC) dan suhu kulkas (4oC) dengan pengemasan plastik dan aluminium foil hingga masa penyimpanan 2 bulan dan menguji efektivitas pada tanaman padi yang terserang penyakit blas. Formula A8 menggunakan bahan pembawa dengan perlakuan suhu dan pengemasan dengan kode suhu kulkas aluminium foil (SKA), suhu kulkas plastik (SKP), suhu ruang aluminium foil (SRA), dan suhu ruang plastik (SRP) secara berurutan memiliki persentase uji antagonisme sebesar 68.33 %, 83.33 %, 77.77% dan 77.77%. Perlakuan yang mengalami kestabilan jumlah log sel yaitu SRP dengan penurunan jumlah log sel selama tiga bulan sebesar 0.39 %. Berdasarkan uji in vivo, terlihat adanya aktivitas penekanan formula A8 terhadap penyakit blas. Persentase penghambatan tertinggi dimiliki oleh padi yang diberi perlakuan suhu ruang dengan kemasan aluminium foil (SRA) sebesar 86.4 % pada 10 hsi dan 70.08 % pada 14 hsi., Formula A8 consisted of Bacillus firmus E65, Bacillus cereus II.14, Pseudomonas aeruginosa C32b, and Seratia marcescens E31 was tested its effectivity to suppress blast disease on rice fields in vitro and in vivo . The objectives of this research are to know the viability and effectivity of formula A8 as biocontrol with temperature and packaging factor for effectiveness in controlling blast disease, with carrier agent of formulation was used talc, at room (26-27oC) and refrigerator (4oC) temperature. Formula A8 with temperature and packaging treatment which code refrigerator temperature with aluminium foil packaging (SKA), refrigerator temperature with plastic packaging (SKP), room temperature with aluminium foil packaging (SRA), and room temperature with plastic packaging (SRP). The result of in vitro treatment each showed precentage 68.33 %, 83.33 %, 77.77% dan 77.77%. The precentage of best viability was SRP with decrease 0,39 %. Based on in vivo test, preventive application of formula A8 to Inpari 13 rice plant suppressed the growth of blast. The highest inhibition of formula A8 against the blast was SRA reached 86.4 % at 10 day after inoculation and 70.08 % at 14 day after inoculation. Key words : Biological agents, P. oryzae, formula A8, blast disease, temperature and packaging factor.
Keyword: agens hayati, formula A8, P. oryzae, penyakit blas, pengemasan dan suhu penyimpanan

Judul: Uji Viabilitas Formula Biofilm A8 dan Pengujian pada Penyakit Blas Padi
Abstrak: Blast disease caused by Pyricularia oryzae is a serious rice disease causing yield lost. This study aims to study the viability test of the bacterial consortium biofilm carrier by in vitro and in vivo. The method was performed, by antagonist test, viability, in vivo test on consortium of the A8 and A8 formula treatment using Plastic Refigerator’s Temperature (SKP), Alumunium foil’s Refigeratore’s Temperature (SKA), Plastic Room Termperature (SRP), and Alumunium foil’s Room Temperature (SRA) against Pyricularia oryzae. The results of SKP treatment showed the best inhibition percentage of 63%. Viability test of A8 formula biofilm was carried out during three months of storage. The results showed a decline in log cells at third month, except the SRP treatment. The best in vivo test results was obtained by SRA treatment as a percentage inhibition of 58.89% and 44.89% after 10 and 14 day after inoculation (dai).
Keyword: Bogor Agricultural University (IPB), blast disease, Pyricularia oryzae, biocontrol, bacterial consortium A8, Biofilms

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