Judul: Gambaran Histopatologi Organ Otak Monyet Ekor Panjang (Macaca fascicularis) dengan Gangguan Memori Terindikasi Penyakit Neurodegeneratif Tipe Alzheimer
Abstrak: Monyet ekor panjang (Macaca fascicularis) adalah hewan yang dapat mengalami penimbunan amiloid beta secara alamiah, seperti kondisi penyakit neurodegeneratif pada manusia. Studi ini dilakukan untuk mempelajari aspek histopatologi pada jaringan otak 9 monyet ekor panjang dengan latar belakang penurunan kognitif dan positif uji ELISA terhadap amiloid beta 42. Pengamatan histopatologis jaringan otak dilakukan pada preparat dengan pewarnaan Hematoksilin Eosin. Temuan lesio kemudian dianalisa secara kualitatif dan semikuantitatif. Berdasarkan pengamatan yang dilakukan, ditemukan lesio patologis yang menyerupai biomarker penyakit Alzheimer, yaitu neurofibrillary tangle (NFT), granulovacuolar disease (GVD), senile plaque (SP) dan apoptosis pada organ otak monyet ekor panjang tersebut. Lesio NFT dan GVD ditemukan pada tujuh dari sembilan individu, sedangkan lesio SP dan apoptosis masing-masing ditemukan pada satu individu dari sembilan individu yang diamati. Seluruh temuan histopatologi didapatkan dari lobus otak yang sama. Temuan ini diharapkan dapat melengkapi informasi mengenai penggunaan monyet ekor panjang sebagai hewan model penyakit Alzheimer.
Keyword: hewan model, histologi, monyet ekor panjang, otak, penyakit Alzheimer

Judul: Study of the BACE1 Gene Expression as Molecular Marker for Alzheimer's Disease in Long-tailed Macaques (Macaca fascicularis) Brain
Abstrak: Penyakit Alzheimer adalah gangguan neurodegenerative yang menyebabkan penurunan daya ingat dan fungsi kognitif pada penderitanya. Penggunaan monyet ekor panjang dilakukan karena secara anatomis maupun fisiologis memiliki kemiripan dengan manusia dibandingkan hewan coba lainnya. Penelitian ini menganalisis ekspresi gen Β-site Amyloid Precursor Protein Cleaving Enzyme 1 (BACE1) di otak sebagai marka molekuler penyakit Alzheimer. Sampel diekstraksi dan diolah menggunakan Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR) berdasarkan regio otak hipokampus dan korteks prefrontal pada 6 monyet ekor panjang betina dengan kelompok usia dewasa dan tua. Level ekspresi mRNA gen BACE1 dibandingkan dengan gen housekeeping yaitu beta-actin (ACTB). Hasil analisis data statistik menunjukan tidak adanya perbedaan nyata antara ekspresi mRNA gen BACE1 pada perbedaan kelompok usia maupun regio otak. Namun, hasil perhitungan menunjukan kecenderungan lebih tinggi pada regio hipokampus dan kelompok usia dewasa dibandingkan korteks dan kelompok usia tua pada monyet ekor panjang., Alzheimer’s disease is is a neurodegenerative disorder that cause decline in memory, and cognitive function in the patient’s. The use long-tailed macaques is conducted due to their anatomical and physiological similarities to humans compared to other experimental animals. This study analyzed the expression of the Β-site Amyloid Precursor Protein Cleaving Enzyme 1 (BACE1) gene in the brain as molecular marker of Alzheimer's disease. Samples were extracted and processed using Reverse Transcription quantitative Polymerase Chain Reaction (RT-qPCR) from the hippocampus and prefrontal cortex regions of six female long-tailed macaques with adult and old age groups. The mRNA expression levels of the BACE1 gene were compared to the beta-actin (ACTB) as housekeeping gene. The data analysis showed no significant differences in the mRNA expression of the BACE1 gene between different age groups or brain regions. However, there was a tendency that mRNA expression levels in the hippocampus region and the adult age group higher than the cortex region and the old age group in the long-tailed macaques.
Keyword: BACE1, monyet ekor panjang, otak, penyakit Alzheimer, RT-qPCR, Alzheimer’s disease, BACE1, brain, long-tailed macaques, RT-qPCR

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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