Judul: Sinekologi ekosistem padang lamun akibat tekanan antropogenik di kepulauan spermonde Provinsi Sulawesi Selatan
Abstrak: Anthropogenic pressures along coastal areas particularly in small islands have increased in accordance with increasing of human population. A study has been conducted in two small islands within Spermonde Archipelago, South Sulawesi i.e. Barranglompo and Bonebatang Islands to elaborate impacts of increased anthropogenic pressure to the assemblages of seagrass beds and their associated organisms. Combined field sampling and laboratory analysis were applied to provide data and information on the impacts of anthropogenic activities occurred in small islands to the seagrass ecosystem. In Barranglompo Island, there were two activities with high intensity i.e. ship/boat transportation and domestic sewage disposal. Analysis of carbon contents of seagrass Enhalus acoroides showed that this species contributed to carbon stocks as much as 0.49-1.05 ton/ha in Barranglompo Island, while in Bonebatang Island, the values ranged between 0.08-0.34 ton/ha. Meanwhile, nitrogen concentrations in Barranglompo Island were significantly higher than those in Bonebatang Island. This was supported by lower C:N ratios and higher N:P ratios in Barranglompo Island and significantly different nitrate contents of water column between both Islands (p  0.01). Potential anthropogenic activities affecting nutrient composition in Barranglompo Island were domestic sewage disposal and drainage of liquid household sewage. Based on the water quality parameter measured, It was concluded that anthropogenic activities in Barranglompo and Bonebatang Islands affected turbidity and Total Suspended Solid (TSS) only. Seagrass communities in Barranglompo and Bonebatang Islands were composed of eight and seven species, respectively, that grow in mixed community. Thalassia hemprichii was species with the highest important value index in both islands. Most of macroalgae found in both islands live as epilithic (litophytic) and epipelic (rhizophytic). Three positive and two negative associations in Barranglompo and one positive and five negative associations in Bonebatang were formed among pairs of macrophytes. Analysis of macrophyte structure in both islands classified Barranglompo in moderate ecological status, whereas Bonebatang had high ecological status. This status indicated that in Barranglompo was detected a change in macrophyte composition due to anthropogenic pressure. The highest similarity index was found among stations in the same island indicating that different islands have different macrophyte assemblages. Among all sea urchin species found in both islands, Tripneustes gratilla and Diadema setosum were two dominant species having the highest density. Index of Preponderance revealed that T. hemprichii was the largest seagrass diet within almost all sea urchin guts. Electivity index indicated that sea urchins prefer several seagrass species especially T. hemprichii.
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Judul: Interaksi landak laut dan lamun di Pulau Barrang Lompo,  Kepulauan Spermonde, Sulawesi Selatan
Abstrak: Sea urchin is an active grazer on seagrass. The grazing may have affected on the seagrass bed. The aim of this research was to study the interaction between the sea urchin and seagrass in the Barrang Lompo Island, South Sulawesi. The measurement of the seagrass and the sea urchin density were using a linier quadrant transect method. Correlation between the seagrass and the sea urchin were analyzed using Pearson‟s correlation. The results showed that the highest value of INP (Indeks Nilai Penting) were Thalassia hemprincii (129,39), Enhalus acoroides (88,92), Cyomodecea rotundata (36,10), Halodula uninervis (28,26), Halophila ovalis (9,23) and Syngirodium isoefolium (7,16), respectively. The community of sea urchin was dominated by Tripneustes gratilla (63.69 ind/m2), followed by Diadema setosum (23.10 ind/m2), Echinotrix calamaris (6.10 ind/m2), Echinotrix diadema (2.47 ind/m2), Echinometra matheai (1.33 ind/m2), and Mespilia globulus (1.33 ind/m2). No relationship beetwen seagrass and sea urchin was observed (r= -0.111, P= 0.485) since not all the sea urchin are grazer. Between seagrass on three age stages and sea urchin also showed no significant relationship since the stage pattern of seagrass and its tanin content may not preferred by the sea urchin. The present of T. gratilla and D. setosum as main grazer however showed no significant relationship with the seagrass. D. setosum is food adaptive and T. gratilla utilizes the seagrass leaf as food and protection from wave and predator.
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Judul: Construction of Strongly Optimal Binary Linear Code with Minimum Distance 9 and 11
Abstrak: A binary linear code of length n over q F is a subspace of n q F . A code has three parameters that attached to it, namely length, dimension, and minimum distance. A code with length n, dimension k and minimum distance d is often called [n, k, d ]-code. Usually, when two parameters are given, then we want to find a code that has the best value for the last parameter. Based on Gilbert- Varshamov bound, if a [n, k, d ]-code exists and can not be expanded, we call it a strongly optimal code. In this paper, we construct strongly optimal code with minimum distance 9 and 11. In constructing the code, we created a theorem and algorithm based on Gilbert-Varshamov bound before we implement the algorithm to MAPLE programming language. Because of computational limitations, the program can only construct up to k = 10 for d = 9 and k = 12 for d = 11.
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