Judul: Respon konduktansi stomata terhadap defisit tekanan uap pada dua spesies hutan tropis, sapling randu (Ceiba petandra) dan damar (Shorea javanica)
Abstrak: Stomata merupakan elemen penting dalam fotosintesis. Faktor lingkungan yang masih diperdebatkan mengenai mekanisme pengaruhnya terhadap konduktansi stomata (pembukaan dan penutupan stomata), gs adalah defisit tekanan uap. Penelitian dilakukan pada sapling randu (Ceiba petandra) dan damar (Shorea javanica) yang diukur menggunakan Infrared Gas Analysis (IRGA). Untuk pengamatan diurnal dengan kondisi alamiah, data di analisis menggunakan metode ANOVA dari General Linear Model (GLM). Dari analisis tersebut diketahui ada tiga faktor utama yang mempengaruhi konduktansi stomata secara signifikan. Faktor tersebut adalah defisit tekanan uap (D), radiasi (Q) dan potensial air daun (4). Perilaku potensial air daun selama satu hari menunjukkan bahwa randu berperilaku isohidrik dan damar berperilaku anisohidrik. Perilaku pada randu menunjukkan bahwa tanaman ini lebih efisien dalam penggunaan air, terlihat dari rasio laju fotosintesis dengan transpirasinya (3,3 ± 0,4 µmol µmol') lebih tinggi dibandingkan damar (1,7 ± 0,3 µmol µmol'). Untuk kondisi cahaya buatan digunakan pendekatan analisis yang dilakukan Orën, et al. (1999) yaitu gs = bm InD yang merupakan persamaan linear biasa. Dari persamaan tersebut didapatkan gs 22882 InD untuk randu dan g. 131-37 InD untuk damar. Persamaan ini menunjukkan bahwa randu memiliki sensitifitas stomata yang besar terhadap perubahan D dilihat dari nilai m yang merupakan slope dari persaman linear tersebut. Hal ini diikuti dengan nilai potensial ambang batas (threshold) pada randu lebih tinggi dibandingkan damar. Pilareshold diduga dari nilai D, dimana nilai D, merupakan nilai D yang mengakibatkan semua stomata tertutup. Untuk randu nilai D, sekitar 16,3 kPa sedang untuk damar sekitar 34,6 kPa. Dari hasil di atas diduga bahwa randu merupakan tanaman yang tidak tahan terhadap kekeringan karena tingkat sensitifitas stomatanya yang tinggi dibandingkan damar.
Keyword: Stomata, sensitifitas stomata, defisit tekanan uap, cahaya matahari, potensial air daun, randu, damar, IRGA

Judul: Respon Konduktansi Stomata Potensial Air Daun Anakan Bayur  (Pterospermum javanicum Jungh.), Damar  (Shorea javanica Koord. & Valeton.), Duku (Lansium domesticum Corr.), Karet (Hevea brasilitensis Muell.Arg) dan Pulai (Alstonia scholaris (L.) R. Br.) Terhadap Kondisi Stres Air
Abstrak: Water is one of the most important factors that can influence the plant growth under agroforest ecosystem. In most cases, agroforests was built in an open area that has big potential to caused water stress. Increased light level, higher temperature, and lower relative humidity imply higher evaporative demand (and potentially higher water losses), leading to higher chances of water stress. Water stress is a natural phenomenon which happened when the availability of soil water become lower and can cause the decrease of leaf water potential on plant grown there.
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Judul: Pemurnian dan karakterisasi protein inhibitor RNA helikase virus hepatitis C
Abstrak: Hepatitis C virus (HCV) infection is the second most common chronic viral infection in the world with global prevalence. This infection is contribution to chronic hepatitis and liver cirrhosis, often leading to hepatocellular carcinoma. There is no effective drug and vaccine available against HCV. The current standard treatment, a combination of pegylated interferon-α with ribavirin, is limited by its suboptimal response rate in a significant patient population, side effects, and affordability. Therefore, development of effective drug is needed. One approach to find out the candidate of antiviral drug is to discover the inhibitor of enzyme that essential for virus replication, such as RNA helicase. Streptomyces chartreusis 5-095 produce the inhibitor of HCV RNA helicase. The aim of this study was to purify the protein inhibitor which has inhibition activity against ATPase activity of RNA helicase HCV from S. chartreusis 5-095. The supernatant of culture S. chartreusis 5-095 exhibited high inhibiton activity against ATPase activity of RNA helicase HCV (approximately 72%) at 10 days of incubation. The extracellular protein inhibitor was partially purified by procedures of precipitation with ammonium sulfate to 65% saturation and gel filtration (Sephadex G50) using methanol water solution (4:6) as an eluen. The purity of protein inhibitor was monitored by SDS PAGE. The protein inhibitor showed a relative molecular mass were estimated to be 14 kDa and increased the purity 23,08 fold than those of the crude protein. The specific activity and IC50 after purification were 13,1338 U/mg and 0,0767 mg/mL, respectively. The activity of purified protein inhibitor showed its stability over pH range from 5-8 and optimum at pH 7,4. The inhibition activity showed its stability up to 70% at temperature 100 oC. The purified protein inhibitor relatively stable its activity at storage in the range of -20 oC to room temperature for 35 days.
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