Judul: Identifikasi penyebab penyakit hawar daun tanaman buah merah (pandanus conoideus lamk.) dan pengendaliannya menggunakan bakteri rizosfer
Abstrak: Red Fruit (Pandanus conoideus Lamk.) is an endemic plant in Papua, which is used for food and as pharmaceutical substance. A leaf blight disease of red fruit is occurred in Manokwari District. The symptom begins with a small spot and gradually enlarges into brown blight with dark brown at the center and surrounded by a yellow “halo”. The causal agent of the disease was not yet identified. This study was conducted to identify the pathogen of leaf blight based on morphology and molecular characters, to observe the abundance of rhizosphere bacteria and its ability as biocontrol agent. Based on Koch’s Postulates, morphological characterization, PCR and sequencing of 28S rDNA, the causal agent of leaf blight is identified as Fusarium sp. The fungal pathogen shows different characters from that of other Fusarium isolated from watermelon, melon, tomato, banana and jackfruit. Some heat tolerant bacteria isolates, chitinolytic bacteria isolates and a fluorescence bacterium originated from the rhizosphere of red fruit show ability to inhibit the growth of the pathogen.
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Judul: Seleksi dan Identifikasi Bakteri Rizosfer yang Berpotensi sebagai Agens Antagonis Fusarium oxysporum pada Bawang Merah yang diberi Kombinasi Pupuk Organik dan Anorganik.
Abstrak: Penyakit layu fusarium merupakan salah satu penyakit penting tular tanah yang bisa menurunkan produksi bawang merah. Pupuk organik memiliki kelebihan diantaranya memperbaiki sifat fisik, kimia dan biologi tanah sehingga dapat meningkatkan aktivitas mikroba pada tanah yang berperan sebagai antagonis terhadap penyakit layu fusarium. Penelitian ini bertujuan mendapatkan isolat bakteri antagonis yang potensial mengendalikan penyakit layu fusarium (Fusarium oxysporum) dari pertanaman bawang merah yang diberi kombinasi pupuk organik dan anorganik. Sampel yang digunakan dalam penelitian berupa sampel tanah yang diperoleh dari Sukorejo, Nganjuk Jawa Timur. Hasil penelitian menunjukkan bahwa penggunaan pupuk organik dan kombinasinya dengan pupuk anorganik mempengaruhi populasi bakteri rizosfer. Sebanyak 71 isolat dari 512 isolat hasil isolasi, tidak bersifat fitotoksik dan patogenik terhadap mamalia setelah dilakukan uji hipersensitif pada daun tembakau dan uji hemolisis pada media agar darah. Uji daya hambat in vitro kandidat agens antagonis dilakukan dengan metode kultur ganda dan uji produksi senyawa volatil. Berdasarkan hasil uji in vitro diperoleh sebanyak 9 isolat yang berpotensi sebagai antagonis dan memiliki persentase daya hambat di atas 30%. Isolat yang paling tinggi penghambatannya adalah isolat bakteri P1A4B47. Identifikasi berdasarkan analisis sekuen nukleotida gen 16S rRNA hasil sekuensing produk PCR dengan primer 27F dan 1492R menunjukkan bahwa isolat bakteri P1A4B47 memiliki derajat kemiripan sebesar 99.26% dengan Pseudomonas aeruginosa.
Keyword: agens biokontrol, bakteri antagonis, bawang merah, PHT, Pseudomonas aeruginosa

Judul: The Construction of Greedy SVP LLL Algorithm
Abstrak: A lattice is a set of all integer linear combination of a set of linearly independent vectors in ℝ𝑛���. The independent vectors are called bases of lattice. Any lattice can be generated from many bases, and these bases have the same cardinality. In the lattice, the most fundamental and renowned problem is the Shortest Vector Problem (SVP). SVP is a tracking problem of the shortest nonzero vector in a lattice with equivalent bases. In two dimensions, SVP problem has resolved exactly by Gauss’ algorithm. When the lattice dimension is higher than two, A.K. Lenstra, H.W. Lenstra and L. Lovasz gave a LLL algorithm to compute approximation of nonzero shortest vector in the lattice. Reduced bases solution obtained from LLL algorithm still be an approximation and has polynomial running time of arbitrary dimension which large enough. In 1994, Schnoor and Euchner modified this LLL algorithm as a new variant which later was named deep insertion LLL algorithm. This algorithm is a modified version of the LLL algorithm to the terms of the exchange step to improve the accuracy of output of LLL reduced bases and applying it to the subset sum problem. The purpose of this research are: (1) Reconstruct the LLL algorithm and deep insertion LLL algorithm using a geometric approach. (2) Construct a greedy SVP LLL algorithm. (3) Implement the three algorithms in a symbolic programming language, and evaluate them experimentally. A bases ℬ=[𝐛���1,𝐛���2,…,𝐛���𝑛���] in ℝ𝑚��� is called reduced LLL with parameter 𝛿��� if satisfies: (a) |𝜇���𝑗���𝑖���|≤12, for every integer 𝑖���,𝑗��� with 1≤𝑖���<𝑗���<𝑛���. (b)𝛿���‖𝜋���𝑗���(𝐛���𝑗���)‖2≤‖𝜋���𝑗���(𝐛���𝑗���+1)‖2, for 𝑗���=1,2,…,𝑛���−1,where 𝛿��� is a reduced parameter of real numbers with 14<𝛿���<1. The first requirement is the reduced basis 𝛿��� must “nearly orthogonal” and in its computation case, this requirement can be reached out by using the Gram-Schmidt’s orthogonalization. While the second requirement is called exchange step, or used to called as Lovasz condition. By using both of these requirements, then they establish the LLL algorithm. Then, Schnoor and Euchner modify the LLL algorithm based on the requirements of the exchange step called the deep insertion LLL algorithm, where the exchange step is based on the comparison of the projected vector in orthogonal complement [𝐛���1,𝐛���2,…,𝐛���𝑘���−1]⊥ after j-th reduction. To construct greedy SVP LLL algorithm, the requirements of the exchange step is based on purely by comparing norm of lattice 𝐛���𝑗��� with norm lattice 𝐛���𝑖��� for 𝑖���=1,2,3…,𝑗���−1. The process of insertion reduced vector after the exchange step also has done greedily. Then, we calculate the number of arithmetic operation in greedy SVP LLL algorithm for further analysis. The result of our exprimentation for three algorithms on the certain matrix size shows that the running time of the three algorithms increases propotional to the size of the matrix. The result also shows that by using 𝛿���=34 for the LLL algorithm and the deep insertion LLL algorithm, and the greedy SVP LLL algorithm which is a new variant made by using no parameter of 𝛿���, outperform of the other of two previous algorithm in terms of speed with the same output.
Keyword: LLL algorithm, LLL deep insertion algorithm, greedy SVP LLL algorithm