Judul: Analisis komunitas padang lamun dan kandungan zat hara di perairan Pulau Barrang Lompo, Kepulauan Spermonde, Sulawesi Selatan
Abstrak: Lamun adalah tumbuhan berbunga yang hidup dan tumbuh di perairan pesisir subtidal. Daur hidup dan pertumbuhan lamun umumnya ditentukan oleh ketersediaan zat hara fosfat, nitrat, dan amonium. Tujuan penelitian ialah menganalisis struktur komunitas vegetasi lamun serta hubungannya dengan kandungan zat hara di perairan kepulauan Spermonde, Sulawesi Selatan. Analisis kandungan zat hara dilakukan dengan pengambilan sampel air antara dan air kolom di stasiun pengamatan tersebut. Kandungan zat hara fosfat, nitrat, dan amonium pada lokasi pengamatan sangat rendah. Konsentrasi zat hara pada air kolom lebih rendah dibandingkan air antara di padang lamun tersebut. Pengukuran kepadatan lamun dilakukan menggunakan metode transek linier kuadrat di 3 stasiun pengamatan (utara, barat, dan selatan pulau Barrang Lompo). Analisis vegetasi lamun diperoleh INP (Indeks Nilai Penting) terbesar pada Thalassia hemprichii (129,39), kemudian diikuti oleh Enhalus acoroides (88,92), Cyomodecea rotundata (36,10), Halodula uninervis (28,26), Halophila ovalis (9,23) dan Syringodium isoetifolium (7,16).
Keyword: Analysis of Seagrass, In the water of Pulau Barrang Lompo

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: Penentuan Nilai Eigen dan Vektor Eigen dari Matriks Tridiagonal 2-Toeplitz dengan Pendekatan Polinomial Chebyshev
Abstrak: The eigenvalues and eigenvectors of a matrix can be determined by finding its characteristic polynomials. The characteristic polynomials of a tridiagonal 2-Toeplitz matrix is shown to be closely connected to polynomials which satisfy the Chebyshev recurrence relationship. If the order of the matrix is odd, then the eigenvalues are found explicitly in terms of the Chebyshev zeros and the eigenvectors are found in terms of the polynomials satisfying the recurrence relationship. For even ordered matrices, the situation is more complicated. The problem in these cases is that although the Chebyshev recurrence formula is still applied, its initial values are not generating Chebyshev polynomials
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