Judul: Identifikasi dan Ekspresi Gen Elongase-Like 5 Ikan Gurami yang Diberi Jenis Pakan Berbeda
Abstrak: Nukleotida adalah prekursor replikasi DNA yang berperan dalam setiap sistem biokimia dalam tubuh seperti metabolisme dan imunitas. Penelitian ini bertujuan mengevaluasi penambahan nukleotida pada pakan terhadap kinerja pertumbuhan larva ikan nila (Oreochromis niloticus). Penelitian menggunakan 5 perlakuan, yaitu pakan komersil yang ditambah nukleotida sebanyak 0%, 0.25%, 0.5%, 0.75%, dan 1%. Larva ikan nila berat 14 mg dan panjang 9,0 ± 0,8 mm ditebar dalam akuarium 50 x 40 x 35 cm dengan ketinggian air 20 cm. Setiap akuarium diisi 75 ekor larva ikan nila. Ikan dipelihara selama 30 hari. Selama masa pemeliharaan, ikan diberi pakan sesuai perlakuannya secara at satiation. Hasil penelitian menunjukkan penambahan nukleotida dapat meningkatkan kinerja pertumbuhan larva ikan nila, yakni meningkatkan bobot ikan, kelangsungan hidup, protein efisiensi rasio (PER), serta menurunkan nilai konversi pakan (FCR). Tingkat kelangsungan hidup dan bobot ikan pada perlakuan 0,5 % tidak berbeda nyata dengan perlakuan 1,0 %. Dengan demikian bisa disimpulkan bahwa dosis nukleotida optimal untuk ditambahkan pada pakan adalah 0,5 %.
Keyword: nukleotida, larva, ikan nila, pertumbuhan

Judul: Kinerja Pertumbuhan Ikan Nila Yang Diberi Pakan Dengan Kadar Protein Berbeda Dan Diperkaya Hormon Pertumbuhan Rekombinan Ikan Kerapu Kertang
Abstrak: Komponen biaya produksi terbesar dalam budidaya ikan adalah pakan. Penggunaan pakan berprotein rendah yang relatif murah umumnya berdampak pada terhambatnya laju pertumbuhan ikan. Penambahan hormon pertumbuhan rekombinan ikan kerapu kertang (rElGH) pada pakan berkadar protein rendah diharapkan dapat menanggulangi terhambatnya pertumbuhan ikan sehingga produktivitas budidaya meningkat. Penelitian ini bertujuan mengevaluasi kinerja pertumbuhan ikan nila yang diberi rElGH melalui pakan dengan kadar protein berbeda. Benih ikan nila sebanyak 25 ekor per perlakuan dipelihara selama 50 hari dalam hapa berukuran 2x1x1 m3 yang dipasang dalam kolam beton ukuran 20x10x1 m3. Ikan diberi pakan secara at satiation dengan frekuensi 3 kali sehari. Pakan mengandung hormon pertumbuhan rekombinan diberikan 2 kali per minggu pada hari Senin dan Kamis. Bobot pakan harian ditimbang untuk menentukan nilai konversi pakan. Hasil penelitian menunjukkan pengaruh rElGH yang signifikan (p<0,05) terhadap peningkatan biomassa, bobot rerata, laju pertumbuhan harian, dan konversi pakan. Tidak ada pengaruh signifikan (p>0,05) dari rElGH, kadar protein pakan, maupun interaksi antara keduanya terhadap kelangsungan hidup semua perlakuan dan kontrol. Kinerja pertumbuhan perlakuan pakan diperkaya rElGH dengan pakan kadar protein 20% dan 15% tidak berbeda nyata (p>0,05). Berdasarkan analisis ekonomi, pakan yang paling efisien adalah pakan diperkaya rElGH dengan kadar protein 15%.
Keyword: Oreochromis niloticus, rElGH, protein, pakan, pertumbuhan

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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