Judul: Konservasi Tumbuhan Pasak bumi (Eurycoma longifolia Jack.) melalui Kultur In Vitro
Abstrak: Tumbuhan pasak bumi (Eurycoma longifolia Jack.) banyak dimanfaatkan oleh masyarakat sebagai afrodisiak dan antimalaria karena kandungan senyawa turunan eurycomanone di dalamnya. Populasi pasak bumi di alam terus menurun dan statusnya langka menurut Rifai (1992), sehingga dibutuhkan upaya konservasi spesies melalui perbanyakan tanaman. Kultur in vitro dilakukan menggunakan eksplan berupa jaringan titik tumbuh, daun dan biji. Persentase kelangsungan hidup tertinggi (37.5%) diperoleh dengan media Murashige dan Skoog (MS) dengan metode sterilisasi menggunakan larutan bakterisida dan fungisida 2 g/ 100 ml selama 1 jam, kemudian direndam dalam amoxicillin 100 mg/ ml selama 45-60 menit di luar Laminar Air Flow dan sterilisasi dalam menggunakan larutan HgCl2 0.02 g/ 100 ml selama 15 menit, lalu eksplan direndam menggunakan larutan chlorox dengan konsentrasi 10% selama 15 menit dilanjutkan dengan pembilasan menggunakan air steril sebanyak empat kali. Proses penyelamatan eksplan yang dilakukan memiliki persentase keberhasilan sebesar 8.3%. Upaya konservasi pasak bumi secara generatif melalui perkecambahan biji memiliki persen hidup kecambah sebesar 60%. Perbanyakan secara vegetatif melalui cangkok belum berhasil dilakukan. Karantina dan perlakuan pendahuluan yang dilakukan berhasil menimbulkan respon berupa pertumbuhan tunas pucuk yang dapat digunakan sebagai bahan eksplan titik tumbuh.
Keyword: Eksplan, Eurycoma longifolia, Kultur in vitro, sterilisasi

Judul: Teknik Perbanyakan dan Kekerabatan Genetik Pasak Bumi (Eurycoma longifolia Jack)
Abstrak: Pasak bumi (Eurycoma longifolia Jack) is a shrubs growing wildly in the forests of Southeast Asia and widely used throughout the region because of its medicinal properties. Uncontrolled harvesting of wild-grown trees has led to rapid decrease of natural populations, as well as causing a potential decrease in genetic diversity. The objectives of this research were 1). To get information about propagation technique of pasak bumi by seed and stem cutting and its suitable growing medium and 2). To estimate genetic relatedness of pasak bumi propagated by seed collected from Jambi using RAPD marker. Propagation by seed produced low germination percentage (14-34%) at different media. Seedling planted in pure carbonized rice husk medium produced the best growth variabel on vigority, primary root number, secondary root number, primary root length and secondary root length. Result from stem cutting showed that medium significantly improved secondary root length, while rooting percentage, primary root length and the number of root significantly was affected by Rootone F treatment. Genetic relatedness by RAPD marker showed that pasak bumi propagated by seed has high value of genetic diversity within population (He = 0,3076) and 78,57% all the loci tested were polimorphic, clustering analysis showed that the plant can be grouped into two group.
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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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