Judul: Analisis kebutuhan draft pengolahan tanah sawah pasang surut dengan menggunakan soil-bin
Abstrak: Draft pengolahan tanah dipengaruhi oleh alat yang digunakan, cara bergeraknya alat dan keadaan tanah. Kondisi tanah sawah pasang surut yang tergenang di musim hujan dan kekeringan di musim kemarau kemungkinan akan membentuk tanah dengan sifat-sifat yang berbeda dengan tanah sawah dan tanah kering. Penelitian pengolahan tanah sawah pasang surut dengan menggunakan soil-bin system dilaksanakan di Laboratorium Budidaya, Fakultas Teknologi Pertanian, IPB. Tujuan penelitian adalah untuk mengetahui pengaruh pemadatan, kadar air dan kecepatan pemotongan tanah terhadap draft pengolahan tanah serta menentukan model hubungan matematis antara draft dan faktor yang mempengaruhinya melalui analisis nondimensi. ...
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Judul: Draft dan pergerakan tanah pada pengolahan tanah dengan menggunakan "Linier Blade" pada "Soil Bin System" dengan analisis soehne
Abstrak: Tujuan dari penelitian ini adalah untuk menentukan hubungan draft dengan menggunakan persamaan analisis rumus Soehne dan untuk mengamati pergerakan tanah dan membandingkannya dengan hasil pengukuran pada perubahan kecepatan dan kedalaman pengolahan. Secara keseluruhan gaya yang diperlukan dalam pengolahan tanah meliputi gaya untuk pemotongan tanah, tenaga yang diperlukan untuk mengatasi gaya kohesi dan gaya geser termasuk pemampatan, pergeseran pembalikan dan penghancuran tanah dan tenaga untuk mengatasi gaya gesek antara tanah dan bajak. Kohesi tanah sangat dipengaruhi oleh kadar air tanah dan tekanan. Pada kadar air Q1 (40-50%) rata-rata kohesi tanah sebesar 1.212 kg/cm² sedang untuk selang kadar air Q2 (30-40%) 0.341 kg/cm². Dari kondisi ini terlihat bahwa penurunan kadar air akan menurunkan kohesi tanah. Pada pemampatan tanah dengan tekanan 300 kPa selama 80 detik, besar takanan yang tercatat lebih besar pada permukaan tanah dari pada dasar bin. Pada kadar air Q1 (40-50%) nilai kompaksi pada permukaan sebesar 202.431 kPa dan 119.234 kPa di dasar bin. Sedangkan untuk kadar air Q2 (30-40%) nilai kompaksi pada permukaan tanah sebesar 221.355 kPa dan 128.399 kPa untuk dasar bin…dst
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Judul: Development of DNA Vaccine Encoding Glycoprotein of Koi Herpes Virus Using Local Isolate.
Abstrak: The aim of this research was to develop DNA vaccine of Koi Herpesvirus in carp. Glycoprotein gene originated from ORF 25 KHV virus that is 1.8 kbp in size, is a potential gene in DNA vaccine construction. The sequencing and similarity analysis of the gene using BLAST software showed that this gene is a GP25 gene and was found to be very similar (99%) to GP25 of KHV virus from the USA and Israel. When this GP25 gene was ligated with pGEMT Easy (pT, 3 kbp in size) vector, plasmid size was increasing up to 5 kb. Following this, a digestion of pT-GP25 plasmid using Sal I enzyme was applied resulted in a GP25 fragment (1.8 kbp). Subsequently, pAct-D6 with a size of 8.5 kbp was also cut using the same enzyme to eleminate a D6 gene with a size of 1.6 kbp. GP25 gene was then ligated with pAct resulted a pAct-GP25 plasmid with a size of 8.8 kbp. As there was only one restriction site applied, ligation can be occurred in two different directions. Thus, in order to determine the plasmid with the desired direction PCR analysis was carried out, and plasmid with the right direction was the one that sized approximately 2.1 kbp (no. 6, 17 and 20). High level of GFP gene expression was detected in all tissues analyzed, i.e. kidney, gil, spleen, and muscle 24 hours after injection which indicated that β-actin promoter of Japanese medaka could be active in common carp. Although not as high as on 24 hours, expression was still detected until day 7 and disappeared after day 28 post injection indicating that pAct-GFP can be remained and β-actin promoter of Japanese medaka can be active in muscle, gills and kidney at least a week after injection. The result of RT-PCR analysis on pAct-GP25 injected common carp showed that GP25 gene expression can be detected 14 days after injection in all tissues observed. The expression level differences between GFP and GP25 genes possibly related to the primer sensitivity on annealing process to cDNA template and the size of PCR targeted DNA fragment, as smaller PCR targeted product will be easier to be amplified than a bigger one. The length of PCR targeted DNA with GP25 primer was 1.8 kbp whereas GFP gene was 0.6 kbp.The challenge test on common carp results showed that all unvaccinated and negative control (not infected with KHV) was alive until the end of the experiment. Whereas, the survival of fish vaccinated with a dose of 12.5 was ranged from 60.9 and 96.7%. In relation to the activity of β-actin promoter that was used in this DNA vaccine, gene expression was occured 24 hours after vaccination and remained until 2 weeks. The control fish that was not injected by GP25 showed no GP25 expression either in the observed tissues or organs and resulted in a lower survival, i.e. 23.3%. The challenge test results has indicated that the fish vaccinated with GP25 at doses of 7.5 and 12.5 μg/100μL were able to produce KHV glycoprotein in their body which would be
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