Judul: Ekspresi Gen inaZ pada Beberapa Galur Bradyrhizobium japonicum Toleran Asam-Al
Abstrak: Penelitian terdahulu yang berlangsung di Laboralorium Mikrubiologi Jurusan Biologi, F.MIPA, IPB, lelah berhasil menyeleksi beberapa galur Bradyrhizobium japonicum toleran asam-Al yang diharapkan dapat dimanfaatkan sebagai simbion kedelai pada lattah asam. Untuk telaah kemampuan hidup bakteri tersebut di lingkungan alami dibutuhkan suatu penanda yang bersifat stabil.
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Judul: Aspek Fisiologi dan Analisis DNA Genom Beberapa Galur Bradyrhizobium japonicum Toleran Asam-Al
Abstrak: Uji fisiologi dan schizotyping telall dilakukan untuk menganalisis keragaman beberapa galur Bradyrhizobium japonicum toleran asam-Al. Duapuluh satu galur B. japonicum toleran asam-Al digunakan sebagai sumber galur untuk uji fisiologi dan enam diantaranya untuk analisis DNA genom. Uji fisiologi yang digunakan adalah uji produksi penisilinase, uji toleransi NaCI 1%, uji produksi H,S, uji produksi 3-ketolaktosa, dan uji aktivitas gelatinase. Analisis DNA genom dilakukan dengan memanfaatkan enzim restriksiAseI,Asnl, Spel, Xbal dan teknik elektroforesis medan berpulsa (pFGE). Dari hasil uji fisiologi, temyata semua galur uji tidak toleran terhadap 1% NaCI, tidak menghasilkan enzim-enzim sisteina desulfurase dan gelatinase, dan tidak mengoksidasi laktosa, namun 95,2% galur uji menghasilkan enzim penisilinase pada konsentrasi Penisilin 100 unit/mi. Dari analisis DNA genom diketahui bahwa ke enam galur uji tidak memiliki plasmid sedangkan urutan enzim restriksi yang memotong jarang adalah Xbal, Spel dan Asnl, Asei. Meskipun galur uji menunjukkan ciri fisiologi yang sarna namun secara genotipe berbeda kecuali dua dari enam galur uji yaitu galur 11 dan 15 yang menunjukkan kemiripan profil DNA.
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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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