Judul: Analisis keragaman genetik rizobakteri penghasil asam indol asetat asal Sukabumi menggunakan ARDRA Gen 16S rRNA
Abstrak: Rizobakteri merupakan mikroorganisme menguntungkan yang hidup berkoloni di lapisan tanah tipis sekitar zona perakaran yang memiliki kemampuan meningkatkan pertumbuhan tanaman dengan menghasilkan hormon asam indol asetat (AIA). Kestabilan dan keanekaragaman rizobakteri dapat terancam seiring penggunaan pupuk sintetis dan pestisida dalam frekuensi yang tinggi. Tujuan penelitian ini adalah mengidentifikasi keragaman genetik rizobakteri penghasil asam indol asetat yang diisolasi dari lahan pertanian Sukabumi menggunakan ARDRA (Amplified Ribosomal DNA Restriction Analysis). Hormon AIA tertinggi dimiliki oleh isolat asal tanah tanaman singkong daerah Makasari dengan konsentrasi 376.86 ppm. Hasil analisis ARDRA diharapkan dapat bermanfaat sebagai penambah kultur koleksi rizobakteri. Keragaman genetik rizobakteri dianalisis menggunakan ARDRA dengan enzim restriksi Rsal. Enzim ini membentuk 5 pola pita pada 8 isolat bakteri terpilih. Keragaman genetik yang dihasilkan dapat dinyatakan kurang beragam dilihat dari sedikitnya kelompok dan Filotipe yang terbentuk pada pohon filogenetik, namun memiliki kekerabatan yang cukup dekat. Berdasarkan hasil sekuensing gen 16S rRNA diketahui kedua isolat sampel rizobakteri yaitu SC 2 dan SM 1 termasuk dalam spesies yang sama, yaitu Bacillus amyloliquefaciens FZB42 and B. amyloliquefaciens MPA 1034.
Keyword: IAA, ARDRA, Keragaman genetikK, Rizobakteri, Plant growth hormone, Root-associated in, IAA, ARDRA, Fertilizer, Pesticide

Judul: Keragaman genetik Bacillus sp. Rizobakteri pemacu pertumbuhan tanaman berdasarkan sekuen gen 16S rRNA dan amplified rDNA restriction analysis
Abstrak: Sebelas isolat Bacillus sp. rizobakteri pemacu pertumbuhan tanaman telah berhasil diketahui keragaman genetiknya melalui metode sekuens gen 16s rRNA dan ARDRA. Hasil BlastN menunjukkan bahwa tidak terdapat dominansi spesies Bacillus sp. yang digunakan. Penggunaan empat enzim restriksi yaitu HaeIII, CfrI, dan Hinfl telah berhasil menunjukkan keragaman genetik pada Bacillus sp. Penggunaan enzim restriksi RsaI menunjukkan keseragaman pada semua isolat. Hasil dari ARDRA terdiri atas filotipe yaitu Filotipe I (Bacillus sp. Cr24, Cr33, Cr64, dan Cr68), filotipe I1 (Bacillus ps. '2131 dan Cr66), filotipe 111 (Bacillus sp. Cr44 dan Cr71), dan filotipe IV (Bacillus sp. Cr67, Cr 28, dan Cr69) yang dibuat pohon filogenetiknya dengan metode neighbor-joining menggunakan program Treecon 1.3b. Hasil filogenetik menggunakan sekuens gen 16s rRNA juga menunjukkan kekerabatan antar spesies yang digunakan. ARDRA dapat digunakan untuk melihat keragaman spesies berdasarkan situs pemotongannya.
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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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