Judul: Evaluasi Penambahan Ragi Bir Saccharomyces cerevisiae dalam Pakan terhadap Kinerja Pertumbuhan dan Daya Tahan Tubuh Ikan Mas Cyprinus carpio terhadap Infeksi Bakteri Aeromonas hydrophila
Abstrak: Penelitian ini bertujuan untuk mengetahui pengaruh penambahan ragi bir S. cerevisiae dalam pakan terhadap kinerja pertumbuhan dan daya tahan tubuh ikan mas C. carpio terhadap infeksi bakteri A. hydrophila. Penelitian dilakukan dengan tiga kali ulangan, ikan yang digunakan yaitu ikan mas dengan bobot awal rata-rata 7,61±0,07 g. Ikan dipelihara dalam 15 akuarium dengan dimensi 50x40x35 cm pada sistem resirkulasi, dengan padat penebaran 15 ekor/akuarium. Selama pemeliharaan ikan diberi pakan dengan penambahan ragi bir 0%, 3%,6%, serta penambahan bioyeast 3%. Pada hari ke-48 dilakukan uji tantang dengan A. hydrophila(106cfu/ml). Hasil penelitian menunjukkan bahwa penambahan ragi bir di dalam pakan memberikan pengaruh yang sama terhadap kinerja pertumbuhan ikan mas. Namun berdasarkan jumlah limbah yang dihasilkan akibat dari nilai efisiensi pakan, penambahan 6% ragi bir adalah perlakuan yang menghasilkan limbah budidaya paling sedikit. Disisi lain, penambahan ragi bir dan bioyeast pada seluruh kadar yang diujikan mampu menekan kematian ikan akibat infeksi bakteri Aeromonas hydrophila. Dengan demikian, ragi bir paling baik digunakan sebanyak 6% di dalam pakan ikan mas.
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Judul: Pengaruh penambahan ragi bir dalam pakan terhadap daya tahan tubuh ikan lele Clarias sp dari infeksi bakteri Aeromonas hydrophila
Abstrak: Motile aeromonad septicaemia caused by Aeromonas hydrophila, induced serious epidemics disease in freshwater fish, one of them is Clarias sp. This research was purposed to evaluate the feeding period of brewer's yeast Saccharomyces cerevisae on the resistance of Clarias sp against A. hydrophila infection. Clarias sp with an initial body weight of 5.33±0.5 g were cultured for 30 days in 50 x 40 x 35 cm aquarium. During rearing period, fish were fed on the diet contained either 0% or 3% of S. cerevisae. On day10, fishin the groups of K+10 (feeding with 0% S. cerevisae) and RB10 (feeding with 3% S. cerevisae), were infected with A. hydrophila; while those fish in the groups of K+20 and RB20 were infected on day 20. Fish in the group of K- were not infected with A. hydrophila. The results showed that on day-30, fish in the groups of K-, RB10, and RB20 had significantly higher survival than fish in K+10 and K+20. The survival of fish in K-, RB10, and RB20 were 100%, 76.7%, and 73.3%, respectively; while those in K+10 and K+20 were only 26,7% and 33.3%, respectively. Therefore, feeding on S. cerevisae in the period of ten days effectively reduce the mortality of fish due to the infection of A.hydrophila., Penyakit motile aeromonad septicaemia yang disebabkan oleh Aeromnas hydrophila menyebabkan wabah penyakit serius pada ikan air tawar, salah satunya ikan lele dumbo Clarias sp. Penelitian ini bertujuan untuk mengevaluasi efektivitas lama periode pemberian ragi bir Saccharomyces cerevisae sebagai pakan ikan yang dapat meningkatkan daya tahan tubuh ikan lele dumbo. terhadap infeksi bakteri A. hydrophila. Ikan lele ukuran 5,33±0,5 g dipelihara dalam akuarium ukuran 50 x 40 x 35 cm dengan padat tebar 10 ekor/akuarium, selama 30 hari. Selama masa budidaya, ikan diberi 3% ragi bir dalam pakan dan pakan tanpa ragi bir. Perlakuan yang diujikan adalah lama pemberian pakan yang berbeda sebelum ikan diinfeksi bakteri. Perlakuan tersebut adalah: RB10 (pakan formulasi dengan 3% ragi bir, ikan diinfeksi A. hydrophila pada hari ke-10); RB20 (pakan formulasi dengan 3% ragi bir, ikan diinfeksi A. hydrophila pada hari ke-20); K+10 (pakan formulasi tanpa ragi bir, ikan diinfeksi A. hydrophila pada hari ke-10); K+20 (pakan formulasi tanpa ragi bir; serta ikan diinfeksi A. hydrophila pada hari ke-20) dan perlakuan kontrol, yaitu K- (pakan formulasi tanpa ragi bir serta tanpa diinfeksi A. hydrophila). Hasil penelitian menunjukkan bahwa pada hari ke-30 masa budidaya, nilai kelangsungan hidup yang tinggi diperoleh pada perlakuan K-, RB10, dan RB 20, yakni masing-masing 100%, 76,7%, dan 73,3%. Sedangkan kelangsungan hidup ikan pada perlakuan K+10 dan K+20, masing-masing 26,7% dan 33,3%. Dengan demikian, pemberian ragi bir selama 10 hari dapat menekan kematian ikan lele akibat serangan bakteri A. hydrophila.
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Judul: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite