Judul: THE HEALTH STATUS OF SHRIMP (Litopenaeus vannamei) REARING WITHIN AND WITHOUT NURSERY METHODS
Abstrak: Udang vaname merupakan salah satu komoditas budidaya ekspor unggulan Indonesia. Rendahnya Survival Rate (SR) adalah salah satu kendala yang masih sering dijumpai sampai sekarang. Metode pendederan mengkondisikan udang supaya lebih sehat karena minim kontak langsung dengan suspensi limbah yang berada di dasar wadah budidaya, akumulasi limbah, dan pengadukan air lebih sedikit. Tujuan penelitian ini menganalisis dan membandingkan kinerja produksi dan status kesehatan udang vaname (Litopenaeus vannamei) pada pembesaran dengan metode pendederan dan tebar langsung. Penelitian ini dilakukan selama 84 hari. Penggunaan pendederan terbukti memiliki hasil produksi dan parameter respon imun yang lebih baik dengan rata-rata SR sebesar 92,70 % dan parameter respon imun yakni Aktivitas Fagositik (AF) dan Total Haemocyte Count (THC) yang lebih tinggi dan berbeda nyata yang secara berturut-turut nominalnya adalah 57,67 ± 2,51 % dan 11,53 x 106 ± 0,80 sel/ml. Nilai Respiratory Burst (RB) dan Phenoloxidase (PO) juga lebih tinggi meskipun tidak berbeda nyata. Selain itu, pada akhir penelitian, perlakuan pendederan mendapatkan hasil parameter kualitas air yang lebih baik, khususnya nitrit serta memiliki warna air yang lebih kehijauan. Penggunaan metode pendederan sebelum dilakukan penebaran dalam petak budidaya pada segmen pembesaran, dapat meningkatkan status kesehatan udang dan menekan kematian., Vaname shrimp is one of Indonesia's leading export cultivation commodities. Low Survival Rate (SR) is one of the obstacles that are still often encountered today. The nursery method conditions the shrimp to be healthier because there is minimal direct contact with the waste suspension at the bottom of the cultivation container, waste accumulation, and less water stirring. The purpose of this study was to observe, analyze, and compare the production performance and health status of vaname shrimp (Litopenaeus vannamei) on enlargement with nursery and direct stocking methods. The study was conducted for 84 days. The use of nursery proved to have better production results and immune response parameters with an average Survival Rate of 92.70 % and immune response parameters, like Fagositic Activity (FA) and Total Haemocyte Count (THC), which were higher and significantly different, respectively, the nominal was 57,67 ± 2,51 % and 11,53 x 106 ± 0,80 cells/ml. Value of Respiratory Burst (RB) and Phenoloxidase (PO) also higher but not significantly different. In addition, at the end of the research, the nursery method treatment obtained better water quality parameters, especially nitrites and had a greener water color. The use of nursery methode before stocking on enlargement rearing pond can improve health status and reduce mortality.
Keyword: Enlargement, health, imune, nursery, vannamei

Judul: Correlation of Water Quality and Production Performance in Vaname Shrimp Breeding (Litopenaeus vannamei) at PT Dewi Laut Aquaculture, Garut
Abstrak: Udang vaname (Litopenaeus vannamei) merupakan komoditas unggulan perikanan yang bernilai ekonomis tinggi. Salah satu faktor yang mempengaruhi keberhasilan budidaya udang vaname yaitu faktor kualitas air. Penelitian ini bertujuan untuk menghitung korelasi kualitas air selama pemeliharaan dan kinerja produksi udang vaname di Dewi Laut Aquaculture, Garut, Jawa Barat. Penelitian ini dilakukan dengan pengamatan secara langsung di tambak udang vaname pada tambak pemeliharaan dengan sistem intensif. Metode yang digunakan pada penelitian ini adalah analisis principal component analysis (PCA) dan uji korelasi. Parameter penelitian yang diamati adalah kualitas air (kecerahan, pH, DO, suhu, salinitas, amonia, nitrit, nitrat, alkalinitas, kesadahan, TOM, plankton, dan bakteri), survival rate (SR), average daily growth (ADG), feed conversion ratio (FCR). Hasil uji korelasi menunjukkan parameter nitrit, dan nitrat menjadi parameter yang paling banyak berkorelasi dengan parameter kinerja produksi. Parameter nitrit -0,414 dan nitrat -0,496 berkorelasi negatif sedang dengan parameter SR. Parameter nitrit dan nitrat sama-sama berkorelasi negatif sedang dengan ADG yaitu masing-masing sebesar -0,416 dan -0,424. Sementara itu, parameter nitrit dan nitrat berkorelasi positif sedang dengan parameter FCR yaitu masing-masing sebesar 0,419 dan 0,427., Whiteleg shrimp (Litopenaeus vannamei) is a leading fishery commodity with high economic value. One of the factors that affect the success of vannamei shrimp farming is the water quality factor. This study aims to calculate the correlation of water quality during rearing and production performance of vannamei shrimp in Dewi Laut Aquaculture, Garut, West Java. This study was conducted by direct observation in vannamei shrimp ponds in ponds with intensive system maintenance. The method used in this study was principal component analysis (PCA) and correlation test. The research parameters observed were water quality (brightness, pH, DO, temperature, salinity, ammonia, nitrite, nitrate, alkalinity, hardness, TOM, plankton, and bacteria), survival rate (SR), average daily growth (ADG), feed conversion ratio (FCR). Correlation test results showed that nitrite and nitrate parameters were the most correlated with production performance parameters. Nitrite -0.414 and nitrate -0.496 were moderately negatively correlated with SR parameters. The nitrite and nitrate parameters were both moderately negatively correlated with ADG at -0.416 and -0.424, respectively. Meanwhile, the nitrite and nitrate parameters were moderately positively correlated with the FCR parameter at 0.419 and 0.427.
Keyword: correlation, pond, production performance, shrimp vannamei, water quality

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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