Judul: Penentuan Salinitas Optimum untuk Pertumbuhan Benih Kepiting Bakau Scylla serrata dalam Sistem Resirkulasi
Abstrak: One of the abiotic factors that affects the growth and the survival of crabs is salinity. The optimum salinity media will give maximum impact on mangrove crabs because it is related with the osmoregulation process. This study aimed to examine the effect of salinity on the survival rate (SR) and spesific growth rate (SGR) of Mangrove Crab (Scylla serrata) through the reaction of physiological condition. This study consisted of the treatments with the salinity medium 15 ppt (A), salinity medium 20 ppt (B), salinity medium 25 ppt (C), and salinity medium 30 ppt (D). The crab’s maintenance in different salinity gave a significant effect (p < 0.05) on the survival rate of the crabs. The salinity treatments also gave a significant effect (p < 0.05) on the Spesific Growth Rate (SGR) of the crabs. The low level of crab’s stress at salinity 25 ppt was described by the total value of high hemocyte and the low osmotic load so that the salinity 25 ppt was the optimum condition for the crabs.
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Judul: Penentuan Suhu Optimum untuk Meningkatkan Kelangsungan Hidup dan Pertumbuhan Benih Kepiting Bakau Scylla serrata (Forskal) pada Media dengan Sistem Resirkulasi
Abstrak: Supply of mud crab depand on nature stock because crab culture activities and cultivation technology is still limited, so that the exploitation of natural crab was in uncontrolled. In addition, the high mortality due to cannibalism is still the dominant factor affecting the maintenance of mud crab production, both in the larvae and post-larvae stage. A research aimed to examine the effect of temperature on the survival rate and growth rate of mud crab. The research had been done on April 2014 in the Laboratory of Aquatic Animal Physiology, Faculty of Fisheries and Marine Science, Bogor Agricultural University. The treatments consisted of the temperature medium 25±0,21oC (A), 27±0,15oC (B), 29±0,21oC (C), and 31±0,21oC (D). The mud crabs measuring of 90±2,02 g/fish were reared in an container with circulation system with a density of 8 fish/container during 28 days. The results showed that the mud crab were reared on different temperatures had a significant effect (p <0.05) on the survival rate and growth rate of mud crab. The temperature of 29±0,21oC was the optimum temperature for mud crab.
Keyword: Bogor Agricultural University (IPB), Mud crab., Growth rate, Survival rate, Temperature

Judul: Invers Drazin dari Matriks Toeplitz Singular
Abstrak: Matriks Toeplitz adalah matriks yang setiap unsur pada diagonal utama bernilai sama dan setiap unsur pada subdiagonal yang bersesuaian dengan diagonal utama juga bernilai sama. Matriks singular adalah matriks yang tidak bisa ditentukan inversnya. Akan tetapi, dapat diupayakan untuk ditentukan inversnya menggunakan invers matriks yang diperumum. Invers Drazin merupakan salah satu jenis invers matriks yang diperumum. Pada karya ilmiah ini ditentukan invers Drazin dari matriks Toeplitz singular dengan menggunakan metode Leverrier Faddeev. Kemudian, ditentukan invers Drazin dari matriks Toeplitz singular yang direpresentasikan sebagai penjumlahan segitiga bawah dan segitiga atas matriks Toeplitz berdasar pada teorema Gohberg dan Semencul., Toeplitz matrix is a matrix in with element on the main diagonal has the same value and on the subdiagonal corresponding to the main diagonal also has the same value. Singular matrix is a matrix that has no inverse. However, it can be attempted to determine the inverse using a generalized inverse matrix. Inverse Drazin is a type of generalized matrix inverse. This paper discussed the inverse Drazin for a singular Toeplitz matrix using the Leverrier Faddeev method. Then, the Drazin inverse of the singular Toeplitz matrix which is represented as a sum of products of lower and upper triangular Toeplitz matrix based on Gohberg and Semencul theorem.
Keyword: inverse Drazine, singular Toeplitz matrix