Judul: Analisis Transkriptomik Pohon Sengon (Falcataria moluccana Miq.) Rentan dan Resisten terhadap Hama Boktor (Xystrocera festiva Pascoe).
Abstrak: Sengon (Falcataria moluccana Miq.) plantations in monoculture system has increases boktor (Xystocera festiva Pascoe) pest population and distribution, however there is no effective and efficient control method yet. This study aims to analyze sengon transcriptomic data and identify expressed genes involved in sengon resistance to boktor pests, also other genes related to abiotic and biotic stresses. Unpublishe de novo transcriptomic data was acquired using the RNAseq and deposited in the DDBJ repository with accession number DRA008389. DEG analysis was perfomed using R program with edgeR package. The results of gene screening were then annotated using genes analog with the Swissprot database. DEG analysis produced 6859 upregulated contigs, genes in resistant tree were Heat shock cognate 70 kDA protein, Trypsin inhibitor, and Chalcone synthase. Based on previous research, trypsin inhibitor is a defensive mechanism of sengon against boktor pests, while other genes are known to be involved in the abiotic and biotic stress response.
Keyword: de novo transcriptomic, Falcataria moluccana Miq, trypsin inhibitor, Xystocera festiva Pascoe

Judul: Ekspresi Gen Trypsin Inhibitor Sengon (Falcataria moluccana Miq.) yang Sehat dan Terserang Hama Boktor
Abstrak: Sengon (Falcataria moluccana Miq.) merupakan salah satu jenis cepat tumbuh yang kayunya banyak dimanfaatkan sehingga sering dibudidayakan terutama di Pulau Jawa. Adanya serangan hama penggerek batang boktor (Xystrocera festiva Thombs) terhadap sengon menyebabkan kerugian yang besar karena dapat menurunkan kualitas kayu dan menurunkan nilai jual kayu sengon. Secara alami tanaman sengon memiliki gen ketahanan terhadap serangan hama boktor, salah satunya adalah trypsin inhibitor. Tujuan penelitian ini adalah membandingkan tingkat ekspresi gen trypsin inhibitor pada kambium pohon sengon resisten dan terserang hama boktor secara kuantitatif dengan teknik Quantitative Real Time PCR. Gen target yang digunakan yaitu trypsin inhibitor (TI) dan gen Actin sebagai internal kontrol dirancang dari analisa data transkriptom sengon. Data Threshold cycle (CT) yang diperoleh kemudian dikuantifikasi menggunakan metode comparative CT method (2 -ΔΔCT). Hasil kuantifikasi menunjukkan tingkat ekspresi gen trypsin inhibitor pada ketiga sampel sengon resisten yaitu sebesar 1.90, 2.20, dan 2,85 sedangkan sengon terserang boktor sebesar 4.07, 2.05, dan 4.08. Rata-rata ekspresi gen trypsin inhibitor pada sengon terserang hama boktor lebih tinggi dibandingkan sengon yang resisten. Kata kunci: Falcataria moluccana, Trypsin Inhibitor, Quantitative Real Time PCR, Sengon (Falcataria moluccana Miq.) is highly demanded fast growing tree species which leads to the increasing sengon cultivation especially in Java. Boktor pest (Xystrocera festiva Thombs) decrease the quality of sengon wood, causing a high loss due to lower selling price of the log. Naturally sengon has resistance gene to defend itself from boktor pest attacks, and one of these genes is trypsin inhibitor. This study aimed to comparing the level of trypsin inhibitor gene expression in sengon’s cambium that is resistant and attacked by boktor pests. The analysis of gene expression level was carried out using the Real Time PCR technique. Primers of trypsin inhibitor (TI) gene as the target gene and Actin gene as the internal control were designed from sengon’s transcriptomic data analysis. Threshold cycle (CT) that obtained then quantified using comparative CT method (2 -ΔΔCT). Quantification results showed that the expression level of trypsin inhibitor from three resistant samples are 1.90, 2.20, and 2,85 while in sengon attacked by boktor are 4.07, 2.05, and 4,08. The average trypsin inhibitor gene expression in sengon attacked by boktor pest was higher than resistant ones. Keywords: Falcataria moluccana, Trypsin Inhibitor, Quantitative Real Time PCR
Keyword: Falcataria moluccana, Trypsin Inhibitor, Real Time PCR

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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