Judul: Sebaran radiasi dan efisiensi penggunaan radiasi surya pada tanaman kentang generasi-O (Solanum tuberosum L.) dan interaksinya terhadap pertumbuhan dan produksi
Abstrak: Interaksi radiasi surya dengan klorofil dalam proses fotosintesis akan menghasilkan assimilat yang digunakan untuk membentuk bagian-bagian dari tanaman, terdapat hubungan yang linier antara laju pertumbuhan dengan radiasi yang diintersepsi oleh tanaman. Dalam penelitian ini dipelajari prilaku sebaran radiasi (intersepsi radiasi (%), transmisi radiasi (%), absorbsi PAR (%), koefisien penyirnaan), efisiensi penggunaan radiasi, laju pertumbuhan taraman dan laju assimilasi bersih selama pertumbuhan tanaman pada jarak tanam yang berbeda. Analisis data menggunakan analisis regresi dan rancangan acak lengkap dengan satu faktor yaitu jarak tanam. Persen intersepsi dan absorbsi PAR semakin meningkat dengan bertambahnya ILD sampai mencapai ILD maksimum, kemudian turun menjelang panen. Sedangkan persen transmisi radiasi semakin menurun dengan bertambahnya ILD. Adanya perlakuan jarak tanam menyebabkan pengaruh yang nyata terhadap persentase intersepsi, persentase transmisi dan persentase absorbsi PAR. Intersepsi radiasi dan absorbsi radiasi PAR yang tinggi akan meningkatkan produksi bahan kering tanaman dan juga laju pertambahan berat kering tanaman serta laju assimilasi bersih, dan sebaliknya dengan transmisi radiasi. Adanya perlakuan jarak tanam menyebabkan pengaruh yang nyata terhadap ILD, produksi berat kering tanaman dan laju pertambahan berat kering tanaman. Pada jarak tanam yang rapat akan menyebabkan intersepsi radiasi yang diterima tanaman lebih besar dibandingkan dengan jarak tanam y ing renggang, sehingga mempengaruhi produksi berat bahan kering dan laju pertambahan berat kering tanaman pada setiap jarak tanam. Efisiensi penggunaan radiasi tertinggi dalam luasan m² terbesar 16.4 g/l pada jarak tanam 10x10 cm atau 2.1 % dan terendah 2.1 g/MJ atau 0.6% pada jarak tanam 15x20 cm. Sedangkan efisiensi penggunaan radiasi per tanaman terbesar 0.5 g/MJ pada jarak tanam 15x20 cm dan terendah 0.1 g/MI pada jarak tanam 13x1: cm. Umur tanaman ta yang tidak sama ma pada setiap jarak tanam nam pada penelitian ini disebabkan adanya serangan hama dan peryakit tanaman sehingga tanaman cepat mengalami kekeringan dan mati. Produksi tertinggi terdapat pada jarak tanam 10x10 cm sebesar 32 ton/ha, sedangkan jumlah umbi pertanaman terbesar pada jarak tanam 15x20 cm yaitu 4.2 butir umbi/tanaman
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Judul: Efisiensi penggunaan radiasi surya pada tanaman kentang (Solanum tuberosum L.) varietas Granola di Galudra, Cianjur
Abstrak: The production of potatoes crop is influenced by solar radiation. Radiation use efficiency is a gradient of relationship between cumulative intercepted radiation and total dry matter. The aim of this experiment is to measure intercepted solar radiation and total dry matter to find out radiation use efficiency (RUE). An experiment was conducted in April-Juni 2010 at Galudra, Cianjur. The intercepted radiation was calculated by equation of Beer’s law, Qint = Qo (1-t), with t = 0,0393 e1,3718LAI and Qo = solar radiation measured at Stasiun Klimatologi Pacet. The result shows that the intercepted solar radiation by crop canopy increased with increased LAI, and therefore total crop dry matter. Radiation use efficiency of potato crop in Galudra was 1,55 gMJ-1 (above ground biomass), and 4,49 gMJ-1 (total biomass, including dry tuber).
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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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