Judul: Study of Biofloc Technology for Controlling  Streptococcus agalactiae in Cultivated Tilapia Oreochromis niloticus
Abstrak: Sistem intensifikasi yang diterapkan dalam budidaya ikan nila saat ini semakin meningkat. Namun, seringkali ditemukan permasalahan pada teknologi budidaya dan infeksi patogen terutama bakteri dan virus penyebab penyakit. Salah satu jenis bakteri penyakit yang sering menyerang budidaya ikan nila adalah Streptococcus agalactiae. Untuk mengatasi masalah ini, peningkatan teknologi budidaya sangat penting untuk dapat memodulasi resistensi penyakit. Teknologi bioflok (BFT) saat ini terus disempurnakan karena kemampuannya dalam mencegah infeksi S. agalactiae. Efektivitas BFT telah dibuktikan dan dievaluasi secara luas oleh banyak penelitian dalam meningkatkan ketahanan respons imun dan kinerja pertumbuhan ikan nila. Tujuan dari studi literatur yangdilakukan adalah untuk merangkum dan membandingkan pengaruh penerapan BFT pada perlakuan dan kondisi yang berbeda terhadap respons imun ikan nila untuk mencegah infeksi S. agalactiae. Penelitian ini menggunakan kajian antar pustaka dan metode yang telah dipublikasikan dalam 20 tahun terakhir. BFT tidak hanya meningkatkan respons imun ikan nila budidaya, tetapi juga dapat memodulasi mikrobiota usus, meningkatkan ketahanan terhadap penyakit, meningkatkan pertumbuhan, dan menjaga kualitas air. BFT mampu meningkatkan respons imun non-spesifik sehingga mampu menurunkan angka kematian ikan nila yang disebabkan oleh bakteri S. agalactiae., Intensification system applied in tilapia cultivation is increasing tremendously. However, there are often problems encountered with cultivation technology and pathogenic infections especially bacterial and viral that cause disease. One species of bacterial disease that often attacks tilapia fish farming is Streptococcus agalactiae. To overcome this problem, an improved cultivation technology is crucial to be able to modulate the disease resistance. Biofloc technology (BFT) is currently continuing to be refined due to its ability to prevent S. agalactiae infection. The BFT effectiveness has been widely proven and evaluated by many studies in improving the immune response survival and growth performance of tilapia. The aim of the literatures study carried out was to summarize and compare the effect of the application of BFT in different treatments and conditions on the immune response of tilapia to prevent S. agalactiae infection. The study uses an inter library reviews and methods that has been published in the last 20 years. BFT is not only improve the immune response of farmed tilapia, but can also modulate the gut microbiota, increase the disease resistance, increase the growth, and maintain the water quality. BFT is able to increase non-specific immune responses so that it can reduce the death rate of tilapia caused by S. agalactiae bacteria.
Keyword: ikan nila, respons imun, immune response, nile tilapia, teknologi bioflok, S. agalactiae, studi pustaka, biofloc technology, literature study

Judul: Gene Expression and Blood Profiles of Nile Tilapia (Oreochromis niloticus) Resistant to Aeromonas hydrophila
Abstrak: Salah satu kendala yang sering terjadi dalam budidaya ikan nila adalah penyakit bakterial yang disebabkan oleh bakteri Aeromonas hydrophila. Usaha yang dapat dilakukan untuk mengurangi dampak infeksi bakteri patogen adalah dengan melakukan evaluasi respons imun secara molekuler. Penelitian ini bertujuan untuk mengevaluasi respons imun ikan nila (Oreochromis niloticus) terhadap infeksi bakteri A. hydrophila berdasarkan ekspresi gen mhc1, lisozim (lysc), dan interleukin (il1b) serta gambaran darah di jaringan hati ikan pascainfeksi. Perlakuan infeksi diberikan melalui penyuntikan ikan nila dengan 0,1 mL bakteri A. hydrophila dosis LD50 secara intramuskular, dan pada ikan kontrol dilakukan penyuntikan dengan 0,1 mL PBS. Selanjutnya dilakukan isolasi jaringan, analisis darah, ekstraksi RNA dan sintesis cDNA, serta analisis ekspresi gen. Hasil penelitian menunjukkan pada ikan yang diinfeksi A. hydrophila memiliki tingkat kelangsungan hidup sebesar 21,42%, sedangkan pada ikan kontrol tidak ditemukan kematian. Ekspresi gen mhc1,lysc dan il1b ikan nila resistan cenderung lebih tinggi daripada ikan nila yang rentan pascainfeksi A. hydrophila. Gambaran darah yang meliputi hematokrit, jumlah eritrosit, leukosit dan kadar hemoglobin pada ikan nila tahan infeksi (resistan) A. hydrophila menunjukkan kecenderungan lebih tinggi dibandingkan dengan ikan nila yang tidak tahan infeksi (rentan)., One of the obstacles that often occurs in tilapia cultivation is bacterial disease caused by the bacteria Aeromonas hydrophila. Efforts that can be made to reduce the impact of pathogenic bacterial infections include conducting a molecular evaluation of the immune response. This study aims to evaluate the immune response of tilapia (Oreochromis niloticus) to A. hydrophila infection based the expression of mhc1, lysozyme (lysc), and interleukin (il1b) genes and on blood profiles in the liver tissue after infection. Infection treatment was given by injecting tilapia fish with 0.1 mL of the LD50 dose of A. hydrophila bacteria intramuscularly, and control fish were injected with 0.1 mL of PBS. Then, tissue isolation, blood analysis, RNA extraction, cDNA synthesis, and gene expression analysis were carried out. The results of the study showed that fish infected with A. hydrophila had a survival rate of 21.42%, while no deaths were found in control fish. The expression of the mhc1, lysc, and il1b genes in resistant tilapia tended to be higher than in susceptible fish after A. hydrophila infection. Blood profiles including hematocrit, number of erythrocytes, leukocytes, and hemoglobin levels in resistant tilapia to A. hydrophila infection tends to have higher level compared to susceptible fish.
Keyword: Aeromonas hydrophila, Oreochromis niloticus, il1b, lysc

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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