Judul: Penapisan Fitokimia, Antioksidan, dan Antifungal Endofit yang Berasosiasi dengan Pohon Penghasil Gaharu (Aquilaria malacensis dan A. microcarpa).
Abstrak: Endofit merupakan fungi yang sepanjang hidupnya berasosiasi di dalam jaringan tumbuhan dan dapat menghasilkan senyawa yang mirip dengan yang dihasilkan pohon inang. Sebanyak 3 isolat fungi dari Aquilaria malacensis dan 12 isolat fungi dari A. microcarpa yang telah diisolasi ditumbuhkan pada 3 media yang berbeda, yaitu PDA (potato dextrose agar), MYGA (malt yeast glucose agar), dan MYGPA (malt yeast glucose peptone agar). Selanjutnya, fungi dibiakkan di media cairnya, kemudian diekstraksi menggunakan etil asetat. Ekstrak etil asetat yang sudah dipekatkan selanjutnya diuji fitokimia, antioksidan, dan antifungal. Uji fitokimia yang diperoleh menunjukkan beragamnya kandungan senyawa golongan fenol, terpenoid, dan steroid pada isolat fungi. Sebanyak 3 isolat menunjukkan aktivitas sebagai antioksidan dengan nilai IC50 paling rendah, yaitu 61 ppm. Aktivitas antifungal menunjukkan semua isolat dapat menghambat pertumbuhan fungi patogen Fusarium solani dengan kisaran persen penghambatan 9−70%.
Keyword: antifungal, antioksidan, fitokimia, fungi endofit

Judul: Toksisitas dan Aktivitas Antioksidan Ekstrak Daun Pohon Penghasil Gaharu Hasil Inokulasi
Abstrak: Gaharu leaves are expected to contain many secondary metabolic compounds as a response against fungal infection on gaharu-producing trees. This study aimed to determine the phytochemical components, cytotoxic and antioxidant activities of Aquilaria microcarpa and A. malaccensis leaves with and without fungal inoculation. Gaharu leaves were extracted by using methanol. The phytochemical assay of the crude extract revealed the presence of tannins, steroids, phenols, and flavonoids. The toxicity evaluation with brine shrimp showed that all samples were potencial as active ingredient, but only the juvenile leaves of A. microcarpa inoculated by fungi from Papua and Gorontalo had the potency as anticancer due to their LC50 value < 30 μg/mL. Free radical scavenging activity of the extracts against 2,2-diphenyl-1-picrylhydrazyl showed strong antioxidant activities with IC50 value of < 200 μg/mL. The highest antioxidant activity was exhibited by juvenile leaves of A.microcarpa inoculated by fungi from Timor and uninoculated mature leaves of A. malaccensis.
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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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