Judul: Effect of Saccharomyces cerevisiae (BY4741) on Intestinal Bacteria, Neurogenesis and Behavior in Mice (Mus musculus)
Abstrak: Microbiota-gut-brain axis memengaruhi proses neurogenesis di otak. Neurogenesis dapat ditingkatkan dengan pemberian probiotik. Saccharomyces cerevisiae memiliki peran sebagai probiotik. Penelitian ini bertujuan mengetahui pengaruh pemberian S. cerevisiae terhadap mikrobiota usus, neurogenesis pada hipokampus, serta perilaku. Penelitian ini terdiri atas kelompok kontrol, kelompok perlakuan 100µl (~103 cfu), 100µl (~106 cfu), dan 100µl (~109 cfu) S. cerevisiae (BY4741). Analisis mikroorganisme saluran pencernaan dilakukan dengan mengisolasi feses. Analisis perilaku yang dilakukan yaitu pembelajaran spasial dan perilaku kecemasan. Analisis neurogenesis dilakukan dengan membuat preparat histologi otak dengan menggunakan pewarna hematoksilin-eosin. Data diuji statistik melalui independent-samples t-test. Pemberian S. cerevisiae (BY4741) menjaga konsentrasi normal bakteri asam laktat dan E. coli. Neuron baru dan penyimpanan memori yang berada pada tingkat kematangan berbeda pada ~106 cfu/100µl tidak meningkatkan kinerja memori spasial. Perubahan konsentrasi bakteri saluran pencernaan mendukung peningkatan persentase neural progenitor cell (NPC) pada konsentrasi ~109 cfu/100µl sehingga sejalan dengan menurunnya perilaku kecemasan dan kinerja memori spasial yang meningkat. Peningkatan persentase densitas NPC yang secara tidak langsung berpengaruh pada penurunan perilaku kecemasan, serta peningkatan kinerja memori spasial., Microbiota-gut-brain axis influences the neurogenesis process. Neurogenesis can be increased by administering probiotics. Saccharomyces cerevisiae has a role as a probiotic. This study aimed to determine the effect of the provision of S. cerevisiae on the intestinal microbiota, behavior, and hippocampal neurogenesis. This study consisted of control group, the treatment group 100µl (~103 cfu), 100µl (~106 cfu), dan 100µl (~109 cfu) of S. cerevisiae (BY4741) with treatment for 4 weeks. Analysis of digestive tract microorganisms was carried out by from fecal samples. Anxiety behavior and memory performance analysis were carried out every week. Neurogenesis analysis was performed by making brain histological preparations using haematoxylin-eosin dye. The data were tested statistically through the independent-samples t-test. The provision of S. cerevisiae (BY4741) in this study maintained normal concentrations of lactat acid bacteria and E. coli. New neurons and memory stores that were at different maturity levels at ~ 106 cfu/100 µl did not improve spatial memory performance. The difference in the concentration of gastrointestinal bacteria supported the increase in the percentage of neural progenitor cell (NPC) at a concentration of ~ 109 cfu/100µl so that it was in line with decreased anxiety behavior and increased spatial memory performance. Increasing the percentage of NPC density indirectly affects the decrease in anxiety behavior, as well as an increase in spatial memory performance.
Keyword: Kecemasan, memori spasial, microbiota-gut-brain axis, NPC

Judul: The Effect of Clove Leaves Extract (Syzygium aromaticum L.) on Digestive Bacteria and Neurogenesis in Hippocampus on Mice (Mus musculus)
Abstrak: Neurogenesis adalah proses lahirnya neuron baru pada dentate gyrus di hipokampus. Mikrobiota saluran pencernaan dapat mempengaruhi neurogenesis melalui sistem komunikasi dua arah, yang terjadi antara otak dan saluran pencernaan (gut-brain axis). Cengkeh yang kaya akan polifenol dapat mempengaruhi neurogenesis. Penelitian ini bertujuan mengetahui pengaruh pemberian ekstrak daun cengkeh yang memiliki kandungan senyawa polifenol terhadap neurogenesis yang mempengaruhi kinerja memori dan tingkat kecemasan pada mencit dan bagaimana hubungannya dengan komposisi bakteri pada saluran pencernaan. Dalam penelitian ini, metode light-dark transition test dan y-maze alteration test digunakan untuk analisis perilaku. Mikrobiota feses mencit diisolasi dengan metode media selektif. Perbandingan jumlah koloni mikrobiota dihitung melalui metode total plate count. Dosis tinggi P400 memiliki kinerja memori spasial paling rendah setelah 4 minggu pemberian perlakuan (M4). Dosis tinggi P400 pada M4 juga menunjukkan tingkat kecemasan paling tinggi yang dialami oleh mencit. Sebaliknya pada kelompok perlakuan P100 dan P200 mencit menunjukkan tingkat kecemasan yang lebih rendah pada M4. Hasil analisis menunjukkan semakin rendah dosis yang diberikan tingkat neurogenesisnya juga semakin baik (NPC terbanyak P100). Kuantifikasi mikrobiota P400 meningkatkan konsentrasi bakteri Escherichia coli namun, menurunkan konsentrasi BAL. Hasil uji perilaku memperlihatkan tingkat dosis yang diberikan berkaitan dengan lama waktu pemberian perlakuan., Neurogenesis is the process of producing new neurons at the dentate gyrus in the hippocampus. The digestive tract microbiota can influence neurogenesis through the two-way communication system between the brain and the digestive tract (gut-brain axis). Cloves are rich in polyphenols that can affect neurogenesis. This study aims to determine the effect of giving clove leaf extract which contains polyphenol compounds on neurogenesis which affects memory performance and anxiety levels in mice and how it relates to the composition of bacteria in the digestive tract. Behavioral analysis was carried out using light-dark transition test and y-maze alternation test. The isolation of the fecal microbiota a was done using selective media method. The number of microbiota colonies was calculated using the total plate count method. The high dose of P400 has the lowest spatial memory performance following four weeks of treatment (M4). The high dose of P400 on M4 also showed the highest level of anxiety experienced by the mice. Whereas, in the treatment group P100 and P200 mice showed the lowest anxiety level at M4. Our data indicate that the lower of the dose given, the better of neurogenesis rate level (most NPC was P100). P400 treatment increased the concentration of Escherichia coli bacteria yet decreased the concentration of BAL. Behavioral test results shows that the dose level given is related to length of giving treatment time.
Keyword: kecemasan, neural progenitor cell, memori spasial, polifenol

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.
Keyword: