Judul: Activities of Tropical Plants Leaves Extract For Inhibiting Growth of Streptococcus pneumoniae
Abstrak: Resistansi Streptococcus pneumoniae terhadap beberapa antibiotik menjadi permasalahan yang belum dapat terselesaikan. Tanaman obat di Indonesia berpotensi menggantikan keberadaan antibiotik penyebab resistansi karena memilik aktivitas antibakteri pada daunnya. Penelitian ini bertujuan membuktikan aktivitas ekstrak daun sirih hijau (Piper betle L.), daun sirsak (Annona muricata L.), daun binahong (Anredera cordifolia (Ten.) Steenis), daun kumis kucing (Orthosiphon stamineus), daun kersen (Muntingia calabura L.), daun jarak pagar (Jatropha curcas L.), dan daun sirih merah (Piper crocatum) sebagai antibakteri Streptococcus pneumoniae. Hasil penelitian menunjukkan bahwa ekstrak tersebut berpotensi sebagai antibakteri terhadap Streptococcus pneumoniae ATCC 49619 secara in vitro pada konsentrasi 25%, 50%, 75%, dan 100%. Ekstrak daun sirih hijau, daun sirih merah, daun kersen, daun binahong, daun kumis kucing, dan daun jarak pagar mempunyai potensi untuk menghambat pertumbuhan Streptococcus pneumoniae yang sudah resistan. Uji lebih lanjut diperlukan terhadap ekstrak daun sirih hijau untuk dapat digunakan sebagai alternatif untuk mengatasi resistansi antibiotik.
Keyword: Bogor Agricultural University, Institut Pertanian Bogor, IPB, Antibacteria, Leaf extract, Resistance, Streptococcus pneumoniae, Resitansi, Uji optochin, Ekstrak daun tanaman obat

Judul: Aktivitas Antibakteri Ekstrak Daun Sirih Hijau (Piper betle L.) terhadap Bakteri Patogen dari Susu Segar
Abstrak: Efek antibakteri pada tanaman sirih (Piper betle L) telah lama diketahui. Penelitian ini bertujuan untuk mengidentifikasi aktivitas antibakteri ekstrak daun sirih hijau (Piper betle L) terhadap bakteri patogen yang berasal dari susu segar. Bakteri patogen yang diteliti terdiri dari 3 jenis bakteri yaitu Streptococcus dysgalactiae, Staphylococcus epidermidis dan Coliform. Penelitian ini menggunakan metode difusi cakram untuk menguji zona hambat dengan menggunakan 5 taraf perlakuan yaitu 50%, 25%, 12.5% dan 6.25% serta kontrol positif menggukan antibakteri. Data dianalisis menggunakan RAL (Rancangan Acak Lengkap) dan dilanjutkan dengan uji banding menggunakan Tukey test. Hasil penelitian menunjukan bahwa ekstrak daun sirih hijau (Piper betle L.) dapat digunakan sebagai antibakteri pada konsentrasi 50%, 25% dan 12.5% untuk bakteri Streptococcus dysgalactiae sedangkan pada bakteri Staphylococcus epidermidis dan Coliform dapat digunakan pada semua konsentrasi yang diujikan.
Keyword: Coliform, ekstrak daun sirih hijau, Staphylococcus epidermidis, Streptococcus dysgalactiae

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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