Judul: Upaya maskulinisasi induk ikan lele dumbo Clarias sp. yang telah diovariektomi parsial dengan metode implantasi hormon 17a-Metiltestosteron
Abstrak: Fakta di lapangan yang menunjukkan bahwa ikan lele betina tumbuh lebih cepat dari pada ikan lele jantan, sehingga agar produksi ikan lele untuk konsumsi (100-150g) dapat lebih efisien dan efektif perlu dilakukan sistem budidaya monoseks betina.
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Judul: Maskulinisasi Ikan Lele Clarias sp. Melalui Suplementasi Serbuk Sari Pinus dalam Pakan
Abstrak: Ikan lele (Clarias sp.) merupakan ikan konsumsi yang banyak dibudidayakan di Indonesia. Pemijahan buatan pada ikan lele mengharuskan membunuh ikan jantan karena tidak dapat distripping, kondisi tersebut mengakibatkan ketersediaan jantan semakin lama semakin berkurang sehingga ketersediaan ikan jantan sangat penting untuk pemenuhan kebutuhan tersebut. Sex reversal (maskulinisasi) merupakan metode yang dilakukan untuk membuat jumlah ikan lele jantan lebih banyak yang kemudian dipersiapkan sebagai calon induk. Tujuan penelitian ini adalah menentukan dosis optimal serbuk sari pinus untuk maskulinisasi ikan lele. Benih ikan lele yang digunakan berumur 7 hari dengan kepadatan 30 ekor per 50 liter air dan diberi perlakuan selama 60 hari. Terdapat empat perlakuan berbeda, kontrol (tanpa penambahan serbuk sari pinus), serbuk sari pinus 0,3 g/kg pakan, serbuk sari pinus 0,5 g/kg pakan, dan serbuk sari pinus 0,7 g/kg pakan. Hasil penelitian menunjukkan bahwa persentase kelamin jantan pada perlakuan 0,3 g/kg sebesar 66,67±11,55%, dosis 0,5 g/kg sebesar 76,67±11,55%, dosis 0,7 g/kg sebesar 73,33±5,77 %, dan perlakuan kontrol sebesar 50±10%. Berdasarkan data hasil persentase kelamin jantan diketahui bahwa perlakuan terbaik terdapat pada dosis 0,5 g/kg (P<0,05). Suplementasi serbuk sari pinus dengan dosis yang berbeda dalam pakan dapat memaskulinisasi benih ikan lele., Catfish (Clarias sp.) is a consumption fish that is widely cultivated in Indonesia. Artificial spawning in catfish requires killing male fish because they cannot be stripped, this condition results in the availability of males decreasing over time so that the availability of male fish is very important to meet these needs. Sex reversal (masculinization) is a method used to make a larger number of male catfish which are then prepared as prospective broodstock. The purpose of this study was to determine the optimal dose of pine pollen for masculinization of catfish. The catfish seeds used were 7 days old with a density of 30 fish per 50 liters of water and were treated for 60 days. There were four different treatments, control (without the addition of pine pollen), pine pollen 0,3 g/kg feed, pine pollen 0,5 g/kg feed, and pine pollen 0,7 g/kg feed. The results showed that the percentage of male sex in the 0,3 g/kg treatment was 66,67 ± 11,55%, the dose of 0,5 g/kg was 76,67 ± 11,55%, the dose of 0,7 g/kg was 73,33 ± 5,77%, and the control treatment was 50 ± 10%. Based on the data on the percentage of male sex it is known that the best treatment is at a dose of 0,5 g/kg (P<0,05). Supplementation of pine pollen with different doses in feed can masculinize catfish seeds.
Keyword: male, pine pollen, sex reversal

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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