Judul: Growth, survival rate, gamet development, and extract and fraction bioactivity from sponge aapfos Aaptos SCHMIDT transplanted to different environment
Abstrak: This expahent aimed to (a) examine the growth and survival rate from Aaptos aapfos (AA) sponge transplanted to different location (Barrang Lompo island/PBL dan Samalona island/PSL) and to different habitat (sand, rubble, dm coral); (b) examine the gamet development and some reproductive aspects. Analysis used in this experiment were t - Paired test, Mann - Whitney test, Kruskal - Wallis tesf and by description. The result i n d i d that the average growth of AA sponge fragment bansplanted to PBL ( 7 mile 6om the continent) were not significant to PSL (3 mile fiom the continent), but the survival rate at PBL were higher than PSL. Average growth at PBL and PSL in coral habitat (BKR habitat) were higher than sand habitat (BPR habitat) and rubble habitat (RBL habitat). Swival rate at PBL in RBL habitat were higher than REL habitat and BKR habita.
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Judul: Kajian Pertumbuhan dan Bioaktivitas Antibakteri Spons Laut Petrosia nigricans yang Ditransplantasikan pada Lingkungan Perairan yang Berbeda
Abstrak: Sponges are marine animals known to produce bioactive compounds that are useful as antibiotics, antifungal, antivirus, anticancer, antiinflammation, antioxidant that has continued to be explored. The purpose of this study were (1) to analyze the growth rate and survival rate of transplanted sponges P. nigricans in different water conditions, and (2) to analyze the antibacterial bioactivities of sponges P. nigricans (including chemistry antibacterial component) from nature and transplanted sponges in different water condition. Analysis of variance showed that the survival rate of sponges P.nigricans showed a significant difference between the depth of the location and time of observation. P. nigricans sponge survival rate ranged 90.0-100.0%. The average of survival sponges rate in Pari Island waters higher than in Pramuka Island waters. Average of length growth rate sponge P. nigricans is 4.42±0.066-6.15±0.88% per month. The average of survival sponge rate at 15 meters depth was higher than in 7 meters depth. P. nigricans sponge survival rate was high compared to some sponge transplant research before. Based on toxicity tests with brine shrimp lethsality method (LC50), the result was range between 36.95-73.76 μg/ml. This P. nigricans was toxic sponges and have the potential development for pharmaceutical ingredients. P. nigricans crude extracts sponges naturally from Pari Island waters was larger inhibition zone than in Pramuka Island waters. Analysis of inhibition zone variance bacteria showed very different results in different locations Pramuka and Pari and not significantly different month observation. P. nigricans bioactivity sponges have the higher inhibition potential to Staphylococcus aureus and Escherichia coli on total organic matter rich waters. The results of inhibition analysis showed the sponge transplants E. coli and S. aureus was different results and significantly differences in location and depth, both Pari and Pramuka sponges observation. Inhibition zone average sponge transplants of E. coli bacteria content 15 mg/ml ranged from 4.53±1.01- 5.81±1.21mm and S. aureus bacteria between 8.31±2.12-12.08±2.32 mm. Bioactivity of transplants sponge is lower than natural sponges. Research result showed that there were tight relation between age of sponge P. nigricans and bioactive compound from sponges’s crude extract in different depth at Pari and Pramuka Island seawater with high correlation coefficient value. Correlation value of age and bioactive compound from sponges’s crude extract was about 0.953- 0.981. Identification of active compounds based on Gas Chromatography analysis from transplants sponge retention time 5.84 of 7.82% presentations area be fathomed compounds from 2-pentanone, 4-hydroxy-4-méthyl (CAS) and for natural with a retention time 8.59 of 11.54% presentations area be fathomed compounds from cyclohexan-2-1-one, 3,5,5-trimethyl. High growth rate and survival, and the contents of bioactive compounds indicate that P. nigricans sponge is promising candidates for further cultivation in natural habitats and ponds.
Keyword: Growth rate, survival rate, antibacterial bioactivity, transplantation, Petrosia nigricans

Judul: Invers dari Matriks Tridiagonal Jacobi
Abstrak: Suatu matriks berukuran n×n dinamakan matriks tridiagonal jika untuk . Karya ilmiah ini memberikan algoritma yang mudah untuk menemukan invers ( dari matriks tridiagonal Jacobi yang simetrik dan nonsimetrik. Setiap elemen pada matriks tridiagonal ini adalah bilangan real. Terdapat 3 lema dan 2 teorema untuk menentukan . Lema pertama menunjukkan persamaan utama dalam membuktikan lema-lema dan teorema-teorema selanjutnya. Invers dari matriks yang simetrik dibuktikan oleh lema kedua yang menunjukkan elemen-elemen baris ke- dari . Selanjutnya, lema kedua dilengkapi dengan teorema pertama yang menunjukkan elemen-elemen dengan . Invers dari matriks yang nonsimetrik dibuktikan oleh lema ketiga yang menunjukkan elemen-elemen dengan dan elemen-elemen dengan dibuktikankan oleh teorema kedua.
Keyword: symmetric, nonsymmetric, matrix