Judul: Bioecology and population dynamic as a basis in the management of pokea (Batissa violacea var. celebensis von Martens, 1897) exploited in Pohara River Southeast Sulawesi
Abstrak: Poke a population in Pohara River is decreasing in terms of specifically its stock ability to recover due to increasing exploitation and declinign of habitat / environment quality. The aims of this research are to study the spatial and temporal density, growth potencials (somatic and reproductive), and the exploitation level and stock ability to recover as basis/ground in the freshwater clam (pokea) management.
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Judul: Ecobiology and stock dinamic as a base on management of endemic fish bonti-bonti (Paratherina striata Aurich) in Towuti Lake, South Sulawesi
Abstrak: Bonti-bonti (Paratherina striata), is one of endemic and vulnerable fish in Towuti and Mahalona Lake. It should be protected from decreasing of it population due to habitat quality decline and increasing of exploitation. The objectives of this research is to study the spatial and temporal distribution, growth potency (somatic and reproductive), and relationship between exploitation level and stock ability to recover as base management of the fish. This research was conducted in Towuti Lake, South Sulawesi from May 2006 to April 2007. Samples were collected at five stations using experimental gillnet sized 0.625, 0.75, 1.0, and 1.25 inches and bagan (dipnet). The results show that bonti-bonti is dispersing widely from lakeside to the middle of the lake. The highest abundance of the fish are in inlet with sand, gravel, and stone substrat. The highest temporal distribution of the fish abundance in November and December influenced by dissolved oxygen and high water level. The result of covarian and cluster analysis towards standard morphometric character, could be said that male and female at I, II, III, IV, and V stations is similar tendency or predicted from one fish population. Bonti-bonti is kind of partial spawner fish with peak spawning in May and November. Spawning site, nursery site, and feeding site of the fish are in inlet station. Recruitment of the fish each month with the peak estimated in September, October, and November. Growth pattern of male is Lt=20.05 [1-e-1.7(t+0.02)], while female is Lt=20.45 [1-e-2.0(t+0.01)]. Total length of male and female mature gonad (50%) were 16.78 and 14.61 cm, respectively. Pursuant to growth parameters value and matured fish (50%), growth potency of bonti-bonti is still in good condition. Exploitation level of bonti-bonti stock in Towuti Lake indication to over-fishing (male E=0.54 and female E=0.56). The increasing catch effort (unit/month) of bagan tend to reduce the catch productivity. Decreasing of ability of bonti-bonti stock to recover is not caused by the environmental variables, but caused by over exploitation activity.
Keyword: environmental variables, exploitation activity, catch productivity

Judul: Solusi Geometri Schwarzschild untuk Dimensi 4+1 dengan Invarian Rotasi Isotropik
Abstrak: Metrik Schwarzschild merupakan solusi eksak pertama dari persamaan medan Einstein dengan mangasumsikan metrik statik dan simetris. Metrik Schwarzschild yang ditemukan oleh Karl Schwarzschild masih dalam dimensi 3+1, namun seiring dengan teori-teori terbaru yang menunjukkan bahwa alam semesta tidak hanya di dimensi 3+1. Maka melalui penambahan dimensi, tujuan penelitian ini memperoleh solusi pada geometri Schwarzschild untuk dimensi 4+1 dengan memodifikasi koordinat bola yang invarian rotasi isotropik dan melalui penurunan rumus seperti koordinat bola, simbol Christoffel, dan tensor Ricci. Selain mendapatkan solusi ini, metrik Schwarzschild dimensi 4+1 dapat digunakan sebagai metrik dasar untuk memperoleh solusi blackhole dan wormhole pada dimensi 4+1. Hasil akhirnya, dengan memanfaatkan modifikasi koordinat bola, metrik Schwarzschild dapat dibentuk sehingga diperoleh solusi geometri Schwarzschild untuk dimensi 4+1.
Keyword: metrik Schwarzschild, persamaan medan Einstein, modifikasi koordinat bola, penambahan dimensi, invarian rotasi isotropik