Judul: Pembuahan in Vitro pada Sapi, Manfaat dan Hambatannya
Abstrak: Pembuahan in vitro yaitu pembuahan sel telur oleh spermatozoa dilauar tubuh merupakan salah satu upaya manusia dalam meningkatkan produksi peternakan melalui efiseinsi reproduksi, khususnya sapi. Pembuahan in vitro dilakukan melalui persiapan sel telur dan spermatozoa. Sel telur diperoleh dari betina yang disuperovulasikan (matang in vivo) ataupun dari material abatoir setelah mengalami pematangan secara in vitro. Spermatozoa yang diejakulasikan harus melalui proses kapasitasi dulu baik secara in vivo maupun in vitro sebelum bertemu dengan sel telur.
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Judul: Fertilisasi in vitro pada hewan percobaan dan hewan ternak
Abstrak: Fertilisasi in vitro yaitu suatu peristiwa penetrasi sel telur (ovum) oleh spermatozoa di luar tubuh (Trounson, Willadsen dan Rowson, 1977), tepatnya di da lam suatu sistem kultur. Pada ternak, teknik ini merupakan salah satu upaya manusia dalam meningkatkan produksi peternakan melalui efisiensi reproduksi dan sebagai usaha untuk menyelamatkan bibit unggul yang tidak dapat dilaksanakan dengan cara fertilisasi in vivo. Sedangkan pada hewan percobaan teknik ini digunakan se bagai suatu cara untuk meneliti kemungkinan terjadinya pembuahan (fertilisasi) di luar tubuh yang dapat menghasilkan individu baru. Fertilisasi in vitro dilakukan setelah terlebih dahulu melalui proses persiapan sel telur dan sperma- tozoa. Khususnya pada sapi, sel telur diperoleh dari betina yang disuperovulasikan (matang in vivo) ataupun dari material rumah potong yang telah mengalami pematangan secara in vitro (Wright dan Bondioli, 1981). Sperma yang diejakulasikan harus mengalami proses kapasitasi terlebih dahulu baik secara in vivo maupun in vitro sebelum dipertemukan dengan sel telur. ...
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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