Judul: Chemical Composition and Identification of Antioxidant Compounds from the Extracts of Tambelo (Bactronophorus thoracites)
Abstrak: Tambelo (Teredinidae) is consumed freshly by local people in Papua without removing the digestive tracts. This study aimed to investigate the chemical composition of fresh tambelo, to conduct antioxidant and phytochemistry tests, and to identify the compound of active antioxidant obtained from selected fractionated extract. The research consisted of two stages. The first stage involved the analyses of proximate, fatty acid, amino acid and mineral. The second stage was the extraction of active materials by means of maceration. The maceration result was evaporated and partitioned with a solvent of n-hexane and ethyl acetate. Next, the extract underwent phytochemical and antioxidant tests (20, 40. 60, and 80 ppm) with DPPH method applying BHT and vitamin super ester C as the standard with a concentration of 4, 6, 8 and 10 ppm. Finally, the identification of fresh antioxidant compound was carried out using LC-MS. The composition of fresh tambelo divided into moisture 82,72±0,01%, protein 7,21±0,31%, fat 0,28±0,04%, ash 2,07±0,27%, and carbohydrate (by difference) 7,72±0,62%. The composition of dried tambelo was moisture 6,63±0,01%, protein 42,77±2,01%, fat 14,27±0,22%, ash 5,88±1,04%, carbohydrate (by difference) 30,45±2,83%. The protein of tambelo contained nine essential amino acids and eight non essensial amino acids. It had seven saturated fatty acids and eight unsaturated fatty acids. It contained calcium of 3532,46 ppm and phosfor of 2363,06 ppm. The highest antioxidant activity was found in the crude extract of ethyl acetate with IC50 of 15 ppm. The highest antioxidant activity obtained by column fractionation was the 9th fraction with IC50 of 8.87 ppm. Phytochemical test, described the crude extract of tambelo contained a group of alkaloid, flavonoid, steroid and triterpenoid. MarinLit database (Blunt and Blunt 2008), 9th fraction was similar to farnesic acid glyceride, sesquiterpenoic acid glyceride and labdane diterpenoid.
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Judul: Aktivitas Ekstrak Tambelo (Bactronophorus Sp.) Dan Selulolitik Mikroorganisme Simbionnya
Abstrak: Tambelo merupakan moluska yang hidup di dalam kayu mangrove telah digunakan untuk tujuan pengobatan oleh masyarakat pesisir. Tujuan penelitian ini adalah menentukan aktivitas biologis yaitu aktivitas antioksidan, inhibitor - glukosidase, dan antibakteri, serta mendapatkan mikroorganisme simbion yang diisolasi dari tambelo, dan menentukan aktivitas selulolitik mikroorganisme simbion. Tambelo diekstrak menggunakan tiga pelarut yaitu metanol, etil asetat, dan heksana. Aktivitas antioksidan ekstrak diuji berdasarkan kemampuan ekstrak dalam mereduksi radikal bebas (DPPH) dengan menggunakan konsentrasi ekstrak 50, 100, 500, 1000, dan 5000 μg/mL. Aktivitas inhibisi -glukosidase ekstrak dengan konsentrasi ekstrak 25, 50, 100, 500, dan 1000 μg/mL. Aktivitas antibakteri ekstrak diukur menggunakan metode difusi agar dengan konsentrasi ekstrak 0.5, 1, dan 2 mg/sumur terhadap bakteri Escherichia coli dan Staphylococcus aureus. Mikroorganisme yang berasosiasi dengan tambelo diisolasi dari saluran pencernaannya. Isolat yang diperoleh diuji aktivitas selulolitik dengan media yang mengandung selulosa. Rendemen daging dan jeroan tambelo yang dihasilkan sebesar 93.98%. Kadar air, abu, lemak, dan protein masing-masing sebesar 73.93%, 1.24%, 0.47%, dan 6.22%. Rendemen ekstrak metanol sebesar 3.12% ± 0.62, etil asetat 0.68% ± 0.07, dan heksana 0.41% ± 0.13. Aktivitas antioksidan tertinggi pada ekstrak etil asetat dengan nilai IC50 sebesar 1072.19 μg/mL. Aktivitas inhibisi - glukosidase ekstrak menurun pada konsentrasi yang semakin tinggi. Aktivitas antibakteri tertinggi diperoleh pada ekstrak etil asetat dengan zona hambat sebesar 10.5 mm terhadap bakteri E. coli pada konsentrasi 2 mg/sumur. Ekstrak terpilih adalah ekstrak etil asetat yang mengandung flavonoid, tanin, saponin dan steroid. Ekstrak tersebut tergolong toksik dengan nilai LC50 sebesar 425.908 μg/mL. Mikroorganisme yang terisolasi terdiri dari 8 kapang dan 9 bakteri. Indeks selulolitik tertinggi ditunjukkan oleh isolat kapang TJ21 dengan indeks 4.53, serta isolat bakteri S3B sebesar 2.25.
Keyword: antibakteri, antioksidan, Bactronophorus sp., inhibitor -glukosidase, mikroorganisme simbion.

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