Judul: Tipologi Fungsional Mangrove Dan Keterkaitannya Dengan Komunitas Iktiofauna Di Pulau Lentea Kecamatan Kaledupa Selatan Kabupaten Wakatobi Sulawesi Tenggara.
Abstrak: Sebagai sumberdaya pesisir, ekosistem mangrove memiliki multi-fungsi untuk menunjang sistem kehidupan. Kurangnya informasi tentang fungsi mangrove sebagai habitat iktiofauna mengilhami kami untuk mencermati masalah ini sebagai suatu penelitian. Penelitian ini bertujuan untuk mengkaji kondisi ekosistem mangrove, struktur komunitas iktiofauna dan sebarannya berdasarkan kondisi perairan serta keterkaitan antara mangrove dan komunitas iktiofauna. Penelitian ini dilaksanakan pada bulan April sampai Juni 2007 di Pulau Lentea Kecamatan Kaledupa Selatan Kabupaten Wakatobi Sulawesi Tenggara. Pengambilan sampel untuk analisis vegetasi mangrove menggunakan metode plot transek garis. Analisis data vegetasi mangrove meliputi: Kerapatan Jenis, Kerapatan Relatif, Frekuensi Jenis, Frekuensi Relatif, Basal area, Penutupan Jenis atau Dominasi Jenis, Dominasi Relatif dan Nilai Penting (NP). Komunitas iktiofauna ditangkap dengan menggunakan alat tangkap gillnet, dengan ukuran panjang jaring 30 meter dan lebar 1,5 meter dengan tiga ukuran mata jaring yaitu 2.54 cm, 3.29 cm dan 5.08 cm. Untuk menentukan variasi kondisi biofisik perairan dan sedimen antar stasiun pengamatan digunakan analisis Analisis Komponen Utama (Principal Component Analysis, PCA). Untuk mengetahui distribusi iktiofauna berdasarkan stasiun penelitian dan hubungan keterkaitan iktiofauna dengan kondisi mangrove digunakan Analisis Faktorial Koresponden (Correspondence Analysis, CA).
Keyword: 

Judul: Ecosystem characteristics of mangrove at small islands of wakatobi national park, Southeast Sulawesi Province
Abstrak: The study was aimed to elaborate structure and composition of mangrove vegetation and to examine relationship between mangrove vegetation pattern and abiotic factors in Kaledupa, Derawa and Hoga Islands in Wakatobi National Park. Sampling of vegetation was done continuously across mangrove community, starting from front (seaward) vegetation formation to the inner formation (landward) by line transect and plot methods. Structure and composition of were determined through vegetation analysis with parameter including frequency, relative frequency, density, relative density, dominance, relative dominance, importance value, zonation determination, natural regeneration, distribution of stem diameter (diameter et breast high) and status of mangrove community. Species diversity was analyzed using Shannon Wiener Index. Analysis of Variance (ANOVA) was used to see difference of abiotic factors among islands and Duncan-test to examine abiotic factors having significantly different responses (p = 0,05). 20 species of true mangrove were found and the largest species was found in Kaledupa Island. Distribution of mangrove vegetation species in the study areas was supposed to be related to wave protection, siltation, and freshwater input. The highest total individual density was found in Kaledupa Island and the lowest one was found in Derawa Island. Species of Bruguiera gymnorrhiza (L.) Lamk., and Rhizophora mucronata Lamk with the highest density was found in Derawa Island. Diversity Index of mangrove vegetation species was chategorized as low. Species having a good natural regeneration was found at Ceriops tagal (Perr.) C.B. Rob., and Ceriops decandra (Griff.) Kaledupa Island, and Osbornia octodonta F.v.M Hoga Island. For genus of Rhizophora besides reproduce through seed/propagule, it is also reproduce vegetatively through branches. Environmental factors of soil having significant relationship with the community pattern in this study were: pH, Kalium (available), and Salinity. Content of soil organic material, Nitrogen (total), Phosphate (available) and soil texture (silt, clay and sand) did not show a significant relationship with the community pattern of mangrove vegetation community. Zonation pattern of mangrove vegetation was only found in Kaledupa Island. Mangrove zonation Kaledupa Island consisted of four zones. Successively, from the seaward to the landward were Rhizophora mucronata Lamk., Rhizophora apiculata Bl., Ceriops tagal (Perr.) C.B. Rob., Ceriops decandra (Griff.) Ding Hou zone. Height of seawater inundation was factor having significant relationship with zonation pattern. Distribution of diameter classes was chategorized as J-shaped graph model. Status of mangrove community in this national park was classified as damaged class due to human activities.
Keyword: 

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model