Judul: Preventation of Bacterial Diseases Aeromonas hydrophila on Tilapia with Shallot Skin, Commercial Vaccines, and their Combinations
Abstrak: Budidaya intensif berpotensi menimbulkan penyakit pada ikan nila. Upaya pencegahan agar benih ikan nila sehat dan tidak terinfeksi bakteri Aeromonas hydrophila yaitu dengan penggunaan fitofarmaka dan vaksin. Penelitian ini bertujuan mengevaluasi efektivitas tepung kulit bawang merah dan vaksin komersil untuk pencegahan penyakit akibat bakteri A. hydrophila. Ikan nila yang digunakan memiliki panjang ikan rata-rata 8,17±0,34 cm dengan bobot rata-rata 8,34±1,00 g yang dipelihara selama 14 hari dengan perlakuan pemberian pakan, kemudian diuji tantang selama 14 hari. Perlakuan yang diberikan yaitu kontrol positif (K+), kontrol negatif (K-), tepung kulit bawang merah (KBM), vaksin komersil (VAK), dan gabungan dari tepung kulit bawang merah dan vaksin (KBM+V). Perlakuan KBM, VAK, dan KBM+V memberikan hasil yang lebih baik dibandingkan dengan kontrol positif pada parameter kelangsungan hidup, total eritrosit, total leukosit, kadar hemoglobin, kadar hematokrit, aktivitas fagositik, respiratory burst, aktivitas lisozim, titer antibodi, dan gejala klinis Perlakuan dengan gabungan tepung kulit bawang merah dan vaksin komersial dapat meningkatkan kelangsungan hidup ikan nila dengan selisih tingkat kelangsungan hidup 34% lebih tinggi dari kontrol positif., Intensive cultivation has the potential to cause disease in tilapia. Preventation efforts so that tilapia fish seeds are healthy and not infected with bacteria Aeromonas hydrophila namely by using phytopharmaca and vaccines. This study aimed to evaluate the effectiveness of onion skin flour and commercial vaccines for preventing bacterial disease A. hydrophila. The tilapia fish used had an average fish length of 8,17 ± 0,34 cm with an average weight of 8,34 ± 1,00 g which were maintened for 14 days with feeding treatment, then challenged for 14 days. The treatments given were positive control (K+), negative control (K-), shallot skin flour (KBM), commercial vaccine (VAK), and combination of shallot skin flour and vaccine (KBM+V). The KBM, VAK, and KBM+V treatments gave better results compered to the positive control in terms of survival rates, total erythrocytes, total leukocytes, hemoglobin levels, hematocrit levels, phagocytic activity, respiratory burst, lysozim activity, antibody titer, and clinical symptoms. Treatment with a combination of shallot skin flour and commercial vaccine can increase survival in tilapia with a survival rate of 34% higher than the positive control.
Keyword: fitofarmaka, ikan nila, respon imun, tepung kulit bawang merah, vaksin

Judul: Application of Bacillus cereus BR2, Honey, and the combination of both for prevention of Streptococcus agalactiae infection in saline nile tilapia (Oreochromis niloticus)
Abstrak: Ikan nila merupakan komoditas unggulan yang dibudidayakan secara intensif dan berpeluang terserang penyakit Streptococcus agalactiae. Upaya pencegahan yang dapat dilakukan untuk mengurangi dampak serangan bakteri S. agalactiae adalah dengan pakan suplementasi menggunakan probiotik, prebiotik, dan sinbiotik. Penelitian ini bertujuan untuk menguji pengaruh pemberian probiotik Bacillus cereus BR2, prebiotik madu randu, dan gabungan keduanya melalui pakan untuk pencegahan infeksi S. agalactiae. Penelitian ini terdiri atas lima perlakuan dan tiga ulangan yaitu A (B. cereus BR2 109 CFU mL-1 1%), B (madu randu 1%), C (B. cereus BR2 109 CFU mL-1 1% + madu randu 1%), K+ dan K- (tanpa suplementasi). Ikan uji yang digunakan adalah ikan nila nirwana 3 dengan bobot rata-rata 15,13±1,74 g. Ikan diaklimatisasi terlebih dahulu ke air payau secara bertahap hingga salinitas 10 ppt dalam akuarium berukuran 60×30×40 cm3 dengan kepadatan 10 ekor per akuarium (450 ekor m-3 ). Selama 30 hari pemeliharaan, ikan diberi pakan komersil yang telah disuplementasi sebanyak 3 kali sehari sekenyangkenyangnya. Hasil penelitian menunjukkan bahwa tingkat kelangsungan hidup, kinerja pertumbuhan, dan respon imun ikan nila salin yang diberi perlakuan suplementasi pakan probiotik B. cereus BR2 dan prebiotik madu randu lebih baik dan berbeda nyata (P<0,05) dibandingkan perlakuan kontrol. Pemberian sinbiotik B. cereus BR2 dan madu melalui suplementasi pakan dapat meningkatkan kinerja pertumbuhan dan respons imun ikan ikan nila salin., Tilapia is the main commodity that is cultivated intensively and has the potential to be infected by Streptococcus agalactiae. Prevention efforts that can be done to reduce the impact of S. agalactiae attack are by supplementing feed using probiotics, prebiotics, and synbiotics. This study aimed to examine the effect of giving Bacillus cereus BR2 probiotic, honey prebiotic, and a combination of both through the feed for the prevention of S. agalactiae infection. This study consisted of five treatments and three replications, namely A (B. cereus BR2 109 CFU mL-1 1%), B (kapok honey 1%), C (B. cereus BR2 109 CFU mL-1 1% + kapok honey 1 %), K+ and K- (without supplementation). The test fish used were nile tilapia with an average weight of 15.13±1.74 g. The fish were first acclimatized to brackish water gradually to 10 ppt. salinity in an aquarium measuring 60×30×40 cm9 with a density of 10 fish per aquarium (450 fish m-3 ). During the 30 days of rearing, the fish were given commercial feed which had been supplemented 3 times a day as full as possible. The results showed that the survival rate, growth performance, and immune response of saline tilapia which were treated with B. cereus BR2 probiotic feed supplementation and prebiotic kapok honey were better and significantly different (P<0.05) than the control treatment. The application of B. cereus BR2 and kapok honey synbiotic through feed supplementation can improve growth performance and immune response of saline tilapia.
Keyword: Bacillus cereus BR2, honey, Streptococcus agalactiae, tilapia, ikan nila salin, madu

Judul: Metrik Einstein (Anti-) Self-Dual Berdimensi Empat dengan Metode Cartan
Abstrak: Gravitational field equation can be formulated in differential forms (differential geometry), which describes gravity as a manifestation of the curvature of space-time. Curvature of space-time is characterized by a metric that satisfies the gravitational field equation. With differential forms it can be formulated the (anti-) self-dual Einstein equation, which is a modification of the Cartan structure in (anti-) self-dual basis. Calculation of (anti-) self-dual metric with (anti-) self-dual Einstein equation is simpler than the calculation using Christoffel symbols.
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