Judul: Isolasi kapang endofit rimpang temulawak dan uji potensi antibakteri xanthorrizol yang dihasilkan
Abstrak: Temulawak (Curcuma xanthorhiza Roxb.) memiliki banyak manfaat untuk kesehatan manusia, seperti efek analgesik, menurunkan kadar gula darah, antitumor, dan agen antibakteri. Penelitian ini dilakukan untuk mengisolasi kapang endofit rimpang temulawak yang berpotensi menghasilkan xanthorrizol sebagai antibakteri. Ekstrak xanthorrizol diperoleh dari kultur isolat kapang secara ekstraselular. Pendugaan xanthorrizol dilakukan dengan melihat aktivitas penghambatan ekstrak terhadap Streptococcus mutans. Aktivitas antibakteri ditentukan melalui metode difusi lubang terhadap bakteri uji, yaitu, Salmonella thypi, Staphylococcus aureus, dan Escherichia coli. Terdapat 7 isolat kapang yang diperoleh dari rimpang temulawak umur 15 bulan dan 3 isolat kapang yang diperoleh dari rimpang temulawak umur 5 bulan. Isolat Tb, Tc, Td, Tf, Tg, dan Mb diduga menghasilkan xanthorrizol. Ekstrak isolat Tb dan Td memiliki aktivitas penghambatan terhadap S. aureus dengan diameter zona hambat masingmasing 20 mm. Ekstrak isolat Tc menunjukkan aktivitas penghambatan terhadap E.coli dengan diameter 11 mm. Namun tidak ada satupun ekstrak yang menunjukkan aktivitas penghambatan terhadap Salmonella thypi. Hasil penelitian menunjukkan bahwa kapang endofit berpotensi sebagai agen antibakteri
Keyword: Curcuma xanthorriza Roxb, Streptococcus mutans, Escherichia coli, Salmonella typhi, Staphylococcus aureus

Judul: Xanthorrhizol Content and Antibacterial Activity of Temulawak (Curcuma xanthorrhiza Roxb.) Cultivated with N, P, and K Fertilizer
Abstrak: Temulawak merupakan tanaman obat yang mengandung senyawa xantorizol yang berkhasiat sebagai antibakteri. Komposisi pupuk yang sesuai meningkatkan produktivitas xantorizol temulawak. Penelitian ini bertujuan menentukan pengaruh pupuk tunggal N, P dan K serta kombinasinya terhadap produktivitas xantorizol dan aktivitas antibakteri dari rimpang temulawak. Terdapat 8 variabel yang diamati; temulawak tanpa pupuk, temulawak dengan pupuk N, P dan K tunggal, kombinasi NP, NK, PK serta NPK. Kandungan xantorizol diukur menggunakan HPLC dan aktivitas antibakteri diuji meggunakan metode difusi cakram. Analisis statistik dilakukan menggunakan uji Anova dan lanjutan dengan uji Duncan pada p < 0,05. Kadar xantorizol tertinggi terkandung pada temulawak dengan kombinasi pupuk PK sebesar 37,56 mg/g DW. Temulawak yang dibudidaya dengan pupuk NPK memiliki kemampuan antibakteri terbaik, dengan zona hambat sebesar 4,65 mm terhadap S. aureus dan 3,64 mm terhadap E. coli. Besarnya zona hambat berbanding lurus dengan kadar xantorizol ekstrak yang diujikan. Hasil penelitian ini dapat dijadikan acuan budidaya temulawak untuk menghasilkan temulawak dengan kadar xantorizol yang tinggi
Keyword: antibakteri, pupuk NPK, temulawak, xantorizol

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