Judul: Karakterisasi sifat fisika tanah yang berhubungan dengan sifat mineral liat pada berbagai jenis tanah
Abstrak: Perilaku mineral tanah umumnya bersifat spesifik, kekhususan ini baik secara sendiri maupun dalam interaksinya dengan komponen tanah lainnya, menentukan totalitas perilaku tanah yang bersangkutan. Penelitian ini dilakukan dengan tujuan untuk mengkaji hubungan antara sifat-sifat fisika tanah dengan sifat mineral liat pada berbagai tekstur dan jenis tanah. Dalam penelitian ini pengambilan contoh di lapang dari berbagai tempat di Jawa Barat, Jawa Tengah, dan Sumatera Selatan. Analisis sifat fisik tanah dengan metode baku, dilakukan di laboratorium Fisika dan Konservasi Tanah, lab Kimia dan Kesuburan Tanah, dan lab Genesis dan Mineralogi Tanah, Departemen Tanah. Fakultas Pertanian, Institut Pertanian Bogor, sedangkan analisis mineral liat di Balai Penelitian Tanah. Badan Litbang Pertanian, Departemen Pertanian, Bogor dari bulan Januari sampai Juni 2003. ...
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Judul: Karakterisasi kelembaban tanah dalam kaitannya dengan sifat fisika tanah pada berbagai tekstur dan jenis tanah
Abstrak: Karakteristik tanah yang berbeda sangat dipengaruhi oleh kelas tekstur tanah. Salah satu karakteristik tersebut adalah kelembaban tanah. Penelitian ini bertujuan untuk (a) menelaah secara mendalam karakter kelembaban tanah dan sifat-sifat fisika pada berbagai tekstur dan jenis tanah, (b) menganalisis hubungan antara berbagai sifat fisik dan kimia tanah dengan parameter kelembaban tanah. Metode yang dilakukan pada penelitian ini meliputi pengambilan contoh tanah di lapang dan analisis tanah di laboratorium yang berlangsung sejak bulan Januari sampai dengan Juni 2003. Pengambilan contoh tanah dilakukan pada berbagai tempat di Jawa Tengah, Jawa Barat dan Sumatera Selatan. Analisis tanah dilakukan di Laboratorium Departemen Tanah, Fakultas Pertanian, Institut Pertanian Bogor meliputi analisis tekstur 10 fraksi, bobot isi, bobot jenis partikel, kadar C-organik dan pengukuran retensi air tanah pada pF 1, 2, 2.54 dan 4.2 dengan menggunakan alat Pressure Plate. Peubah-peubah yang diamati dalam penelitian ini adalah kadar air kapasitas lapang, kadar air titik layu permanen, air tersedia dan pori air drainase sebagai peubah tak bebas, sedangkan bobot isi, porositas total, tekstur, indeks stabilitas agregat dan kadar bahan organik sebagai peubah bebas. Analisis statistik yang digunakan dalam penelitian ini adalah analisis regresi linear sederhana. Hasil penelitian menunjukkan bahwa tanah yang bertekstur liat (halus) mempunyai bentuk kurva pF yang agak tegak antara pF 1 sampai pF 2.54, kemudian agak mendatar antara pF 2.54 sampai pF 4.2. Tanah yang bertekstur kasar (pasir) mempunyai bentuk kurva pF yang agak mendatar antara pF 1 sampai pF 2.54, kemudian agak tegak antara pF 2.54 sampai 4.2. Tanah yang bertekstur sedang (lempung) mempunyai bentuk kurva pF di antara tanah yang bertekstur liat dan pasir. Persen pasir mempunyai pengaruh nyata terhadap kadar air pF 2, kadar air kapasitas lapang, kadar air titik layu permanen dan pori air drainase (r² = 0.496, r²= 0.588, r² 0.594 dan r²= 0.422). Persen liat mempunyai pengaruh nyata terhadap kadar air pF 2, kadar air kapasitas lapang, kadar air titik layu permanen dan pori air drainase (r² = 0.619, r² = 0.785, r²= 0.645 dan r²= 0.437). Bobot isi, porositas total dan bahan organik mempunyai pengaruh nyata terhadap air tersedia (r²= 0.627, r²= 0.609 dan r²= 0.598). Persen debu dan indeks stabilitas agregat (ISA) tidak berpengaruh nyata terhadap parameter-parameter kelembaban tanah.
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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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