Judul: Aplikasi Probiotik Amilolitik NB21b dan Proteolitik L1k Melalui Pakan untuk Pengendalian Streptococcosis pada Ikan Nila Oreochromis niloticus
Abstrak: Intensive culture activity of tilapia can be affected by bacterial illness attack like streptococcosis, so in this research it was used probiotic bacteria into tilapia feed to overcome it. There were 5 feed treatment that were NB21b probiotic 1% (v/w), L1k probiotic 1% (v/w) and NB21b probiotic 0.5% (v/w) + L1k probiotic 0.5% (v/w), positive control, and negative control. Here tilapia has average weight 24.9±2.20 g/fish and was gived treatment feed during 21 days before challenge test. After that, the fish was challenged by cohabitation, where cohabitation fish was injected Streptococcus agalactiae with density 104 CFU/ml. The results showed that L1k 1% (v/w) probiotic bacteria can increase survival rate and immune system especially in phagocytosis activity, which prevented the infection of Streptococcus agalactiae effectively.
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Judul: Aplikasi sinbiotik melalui pakan pada Ikan Nila Merah Oreochromis niloticus yang diinfeksi Streptococcus agalactiae
Abstrak: One of the constraint on tilapia cultivation is presence of streptococcosis disease caused by Streptococcus agalactiae. Application of synbiotic is one of alternative in controlling the streptococcosis disease in red tilapia. The aims of this research were to compare the effectiveness of synbiotic application in feed fish in artificial feed (PB) and commercial feed (PK) to study the growth performance and to prevent the streptococcosis in red tilapia. Probiotic strain used in this research was NP5, whereas the prebiotic was prepared from extract of sweet potato from sukuh variety. Treatments in this research were positive control with feeding without supplementation of synbiotic & infected by S. agalactiae, negative control with feeding without supplementation of synbiotic & injected by PBS (Phosphate Buffer Saline), and feeding with the addition synbiotic & infected by S. agalactiae. Each treatment was tested on artificial feed (containing protein of 23%) and commercial feed (containing protein of 38%). Feeding treatment was given within first 30 days and on 31st day all fish (except negative control treatment) were challanged by intramuscularly injection of S. agalactiae (109 cfu/ml). The mortality rate was observed daily within 6 days. Result showed that the growth and the feed efficiency of fish fed by commercial feed was higher than that of artificial feed. Application of synbiotic could increase the feed efficiency in both of artificial feed and commercial feed although have not resulted the better growth. Moreover, the synbiotic could increase immune response and the survival rate of tilapia post challenge test. Treatment of synbiotic in commercial feed and artificial feed resulted survival rate of 83.33%, whereas the survival rate of positive control was only 25% (P<0.05).
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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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