Judul: Seleksi Bakteri Probiotik dari Saluran Pencernaan Untuk Meningkatkan Kinerja Pertumbuhan Ikan Jelawat Leptobarbus hoevent Blkr:
Abstrak: The effect of probiotics isolated from jelawat fish gut Leptobarbus hoeveni supplemented into the diet on enzym activities, growth performance of jelawat fish and digestibility was investigated. A triplicate experiment was conducted using 6-7 g jelawat fish. Each fish was fed on the diet supplemented with either probiotics produce amylase (U4), produce lypase (S1), produce protease (U12), produce protease, lypase and amylase (U7) or control (no supplementation of probiotics). Regardless of the strain, the application of probiotics significantly increased the bacteria population in the fish gut, thereby digestibility and protein retention, food conversion ratio and growth of fish significantly improved. On the other hand, fish fed on the diet supplemented with U4 probiotics had the best growth performance. Therefore, U4 is the best probiotics isolated from the jelawat fish gut to use as a supplementary diet for jelawat fish
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Judul: Penapisan bakteri probiotik dari saluran pencernaan dan media pemeliharaan ikan jelawat Leptobarbus hoeveni Blkr untuk pengendalian bakteri patogen
Abstrak: Ikan jelawat adalah ikan liar yang hidup di perairan sungai di Kalimantan Barat yang telah disomestikan dan saat ini telah berhasil dibudidayakan. Salah satu kendala dalam budidaya ikan jelawat adalah sifat ikan yang mudah mengalami stres serta tingginya mortalitas selama periode budidaya. Salah satu penyebab dari tingginya mortalitas tersebut diduga sebagai akibat infeksi penyakit. Namun patogen penyebab infeksi penyakit yang menyerang ikan jelawat hingga saat ini belum diketahui secara pasti. Karena itu digunakan beberapa jenis bakteri patogen yang sering menginfeksi ikan air tawar, sebagai langkah awal untuk menguji kerentanan ikan jelawat terhadap beberapa bakteri patogen.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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