Judul: Hubungan beberapa sifat fisik, kimia dan aktivitas mikroorganisme tanah dengan kemantapan agregat
Abstrak: Penelitian ini bertujuan untuk membandingkan hubungan beberapa sifat fisik, kimia dan aktivitas mikroorganisme tanah dengan kemantapan agregat dan menentukan faktor yang paling berperanan dalam kemantapan agregat. Untuk ini digunakan 5 jenis tanah, diambil pada kedalaman O 20 cm dan 40 60 cm. Indeks stabilitas agregat ditetapkan dengan metode pengayakan kering dan basah. Parameter lain yang dianalisis meliputi tekstur, nilai SAR, kandungan bahan organik, nilai COLE, aktivitas mikroorganisme, kandungan oksida Al dan Fe, porositas total dan distribusi ukuran pori. Liat, bahan organik dan oksida Al dan Fe diperlukan untuk pemantapan agregat, tetapi peningkatan secara individu bahan tersebut tidak menjamin terbentuknya agregat yang lebih stabil. Hasil analisis regresi sederhana diperoleh korelasi sangat nyata antara persentase pasir dan nisbah bahan organik terhadap liat dengan ISA, serta diperoleh korelasi nyata untuk nisbah oksida Al dan Fe terhadap liat, dan persentase liat. Untuk analisis regresi linier berganda diperoleh korelasi nyata antara persentase pasir, persentase liat, PDL, nilai COLE, oksida Al dan Fe serta kandungan bahan organik dengan ISA.
Keyword: 

Judul: Hubungan Nisbah Liat dan Stabilitas Agregat Serta Pengaruhnya Terhadap Erodibilitras Tanah Podsolik Merah Kekuningan, Latosol Coklat Kemerahan dan Mediteran Coklat
Abstrak: Tujuan Penelitian ini untuk mengetahui besarnya nilai- nilai erodibilitas tanah (K) pada beberapa jenis tanah yang berbeda dan melihat hubungan antara nisbah liat dan stabilitas agregat serta pengaruhnya terhadap erodibilitas tanah. Hubungan tersebut dianalisa untuk mengetahui sifat-sifat fisik tanah yang paling berpengaruh terhadap erodibilitas tanah. Dalam penelitian ini dipergunakan nilai erodibilitas ta- nah hasil prediksi dengan metoda Wischmeier et al. 1971. Hasil penelitian menunjukkan bahwa tanah semakin peka terhadap erosi, bila kadungan debu dan pasir halus tinggi, kandungan liat dan bahan organik rendah, dan stabilitas agregat tinggi. Nilai nisbah liat untuk tanah Podsolik, Latosol dan Me- diteran masing-masing sebesar 0,49; 1,01; dan 3,55. Nilai Indeks stabilitas agregat untuk tanah Podsolik, Latosol, Me- diteran msing-masing sebesar 119, 67, dan 38. Nilai erodi- bilitas untuk tanah Podsolik, Latosol, dan Mediteran masing- masing sebesar 0,105; 0,190; dan 0,291. Hubungan nisbah liat dan erodibilitas tanah mempunyai korelasi positip, sedangkan hubungan indeks stabilitas agre- gat dan erodibilitas tanah serta hubungan indeks stabilitas agregat dan nisbah liat mempunyai korelasi negatip. Hasil pendugaan erosi pada petak kecil di daerah Cita- yam, Kentrong dan Tonjong masing-masing sebesar 16,66; 132,12 dan 465,14 ton/ha/tahun. Pendugaan erosi tersebut menggunakan metoda USLE….
Keyword: 

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
Keyword: