Judul: Kualitas semen beku kambing peranakan etawah menggunakan modifikasi pengencer tris soya dan tris kuning telur
Abstrak: Reproduction of goats in Indonesia mostly managed by natural mating, while the Artificial Insemination (AI) has been limited. The success rate of AI in goats has been low because of some factors, one of those has been identified as the low quality of extender. Tris Egg Yolk (TEY) and AndroMed® have been widely used for extenders of frozen semen in goats. Effect of Tris Soya (TS) that have lesitin nabati and studies to describe the profiles of each extenders to the sperm quality have been quite limited. The aim of this study was to compare TEY, AndroMed® and TS extenders on sperm motility and viability before and after freezing of goats semen. Semen was collected from three sexually mature Etawah Crossbreed goats twice a week, each semen sample was divided into three tubes to be mixed with TEY, AndroMed® or TS before those got frozen. Sperm motility and viability were evaluated macroscopically before freezing and microscopically before and after freezing. The result of this study revealed that TEY and AndroMed® gave higher sperm motiliy (68.52±0.64% and 68.71±1.95%) than TS (37.03±4.25%). The viability of sperm was also higher in TEY and AndroMed® (73.45±1.52% and 73.94±1.31%) compared TS (46.76±4.76%). It was concluded that TEY and AndroMed® were better extenders to protect goats sperm compared TS.
Keyword: AndroMed®, Etawah Crossbreed, frozen semen, Tris Egg Yolk, Tris Soya.

Judul: Kriopreservasi Semen Kambing Peranakan Etawah (PE) Menggunakan Pengencer Tris-kuning telur dan Tris-soya dengan Modifikasi Karbohidrat dan Krioprotektan Berbeda
Abstrak: Artificial Insemination (AI) is known as a technology to improve the genetic quality of goats in Indonesia. AI in goat is still limited in its practical use; this is related to a variety of constraints, which one of those would be the guarded quality of frozen semen. The quality of frozen semen is determined by various factors, including the freezing techniques, the diluents and cryoprotectants. Buck frozen semen produced by AI centers usually use Tris-egg yolk (TEY) diluent. Egg yolk of animal origin has been recognized as a highly potential media allowing transfer microorganism to female tract through AI. Therefore, some research studies have been focusing to find another diluents using soy extract as an alternative of diluent. Preservation of buck semen using soy extract contains plant phospolipid has not been well studied. Dissacharide (trehalose) or trissacharide (raffinose) acts as an energy source as well as an extracellular cryoprotectants in diluents of frozen semen; these would aid in protecting the sperm during freezing process. Dimethylformamide (DMF) has smaller molecules than glycerol may act as a beneficial cryoprotectant when it is added into the diluents, showing a better effect in protecting the sperm membrane during freezing. This study was conducted in two steps: 1) Preserved liquid semen using tris-egg yolk (TEY) and tris-soya (TS) diluents with either trehalose and raffinose supplementation; 2) Produced frozen semen using TEY and TS with supplementation of the combination showing the best results in step 1. Both diluents used DMF and glycerol as the cryoprotectants. Semen were collected from three sexually mature bucks using artificial vagina, evaluated and divided into six aliquot treatment groups. Each of aliquot diluted with TEY and TS supplemented with 50 mM trehalose or raffinose, which contain 50x106 sperm concentration per 0.2 mL volume. All of them kept in refrigerator in 5°C. The progressive motility, viability and plasma membrane intact (PMI) were evaluated every 12 hours up to the time when only 50% of sperm display motility. The combination of trehalose or raffinose based showing the best results in analysis during the step 1 was added with TEY and TS diluents, supplemented with glycerol and DMF cryoprotectants in frozen semen process. Extended semen were kept in minitub straw, containing 100x106 sperm/0.25 mL. Equilibration time was 4 hours in 5°C, then freeze in N2 vaporated for 10 minutes in styrofoam box. The result showed that semen quality from three bucks were good, such as the average of volume was 1.29±0.21 mL, creamy and thick in consistency. The concentration was 3608.33±657.70x106/mL, motility was 77.78±2.56%, viability was 85.13±4.38%, PMI was 77.72±3.52% and abnormality was 7.51±2.88%. The motility of sperm kept in liquid semen diluents, TEY supplemented with trehalose or raffinose gave better result, it can be maintained sperm motility up to 50% for 72-84 hours, compared to TS diluent (48-60 hours) (P<0.05). TEY diluent supplemented with trehalose can maintained sperm motility longer (52.82±3.21%) for 84 hours, compared to raffinose supplementation (51.78±4.41%) and control (51.11±4.86%) for 72 hours. The viability of sperm evaluation showed 6-9% higher than sperm motility percentage, while the percentage of PMI gave similar percentage
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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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