Judul: Protein Fraction of Rennet Extracted from Abomasum of Local Sheep by Gel Filtration Column Chromatography Method.
Abstrak: Pemisahan protein rennet yang diekstraksi dari abomasum domba lokal dilakukan dengan metode kromatografi kolom gel filtrasi untuk memisahkan enzim pepsin dan khimosin. Pada penelitian ini digunakan dua sampel abomasum domba lokal usia dewasa muda (5-12 bulan). Mukosa fundus dari kedua sampel abomasum diekstraksi menjadi rennet dan disimpan beku. Rennet ekstrak kasar kemudian diproses lebih lanjut untuk memisahkan kedua enzim melalui dua tahapan fraksinasi awal, yaitu presipitasi garam dengan amonium sulfat dan dialisa menggunakan kantong dialisa cut off 12 kD. Hasil dialisa rennet kemudian difraksinasi lebih lanjut menggunakan kromatografi kolom gel filtrasi dengan matriks berupa sephadex-G75. Rennet ekstrak kasar, hasil dialisa rennet, dan fraksi-fraksi hasil kromatografi dianalisa menggunakan uji aktivitas koagulasi susu dan SDS-PAGE untuk mengetahui keberadaan enzim pepsin dan khimosin. Fraksi-fraksi hasil kromatografi juga dianalisa menggunakan spektrofotometer 280 nm. Hasil dari penelitian ini menunjukkan bahwa pepsin dan khimosin terelusi pada fraksi-fraksi dimana total proteinnya tinggi. Fraksi-fraksi yang diperoleh dari penelitian ini dapat digunakan untuk purifikasi lebih lanjut enzim pepsin dan khimosin menggunakan metode purifikasi lain.
Keyword: 

Judul: Pemisahan Protein Dari Ekstrak Rennet Abomasum Domba Lokal Dengan Metode Liquid Isoelectric Focusing
Abstrak: Extract of abomasum fundic mucosae of lamb contains at least two kinds of protein including protease enzymes especially pepsin and chymosin. The purpose of this study was to fractinate protein from crude rennet extracted from fundic mucosae using liquid isoelectric focusing (IEF) and to analyze the fractinated protein in order to determine the existence of proteases enzymes based on its molecular weight. This study used each of two rennet samples represented under and above one year of age, were fractinated using IEF procedure followed by biologic examination using milk clotting activities and protein analysis using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). IEF separate proteins by its isoelectric point (pI). The results of fractination showed that chymosin was examined around pH 4.5- 5.0. Milk clotting activities showed that fractinated rennet provide less time to coagulate than crude rennet samples. It showed that the fractinated rennet resulting milk curd formation better than the crude rennet. The protein analysis of the fractinated samples contained bands of protein, and one was considered as chymosin related to its molecular weight (31 kDa). The conclusion is liquid isoelectric focusing method could possibly fractinate crude rennet samples. Further research is necessary to optimize the purification method.
Keyword: 

Judul: Characteristic of Overshooting Top (OT) Based on  Himawari  8  Satellite  as  a  Convective  Cloud  Feature  that  Generates  Extreme Weather in the Java Island Region
Abstrak: Overshooting Top (OT) is a feature at the top of a convective cloud that is associated with extreme weather. Research on OT in tropical Indonesia is still very limited. The existence of geostationary satellites with wide area coverage and fast frequency observations is useful for observing the fast dynamics of the OT life cycle. Therefore, this study intends to analyze the relationship between OT and extreme weather, updraft and thermodynamic conditions of OT when extreme weather occurs, the best objective method for detecting OT in the day time and night time, and the spatiotemporal distribution of OT in the tropical region of Java Island during the 2018-2021 period. Based on visual analysis using visible channel and Himawari 8 sandwich products, 87% of extreme weather events in Java were accompanied by the appearance of OT. It indicates that the presence of the OT pattern is a convection cloud pattern or feature that is closely related to extreme weather events for the Java Island region. The existence of a time lag between the appearance of OT and extreme weather events on Java Island indicates that the OT of convection cloud can be used as a precursor or nowcasting for the appearance of extreme weather. Most of the convective cloud OT features during extreme weather events on Java Island have altitude that were only able to exceed the altitude of the equilibrium level and few were able to exceed the tropopause level of 9 km – 16 km. The difference in atmospheric conditions during extreme weather events on Java Island, which is in the tropics and subtropics, is a strong and unstable convective energy condition characterized by a larger CAPE, as well as unstable KI, LI, SI and TTI values. It is offset by kinematic factors in the form of a weak vertical wind shear (bulk wind shear 0-6 km) and a higher freezing point height. The difference between extreme weather events in the Java Island region and other tropical regions compared to subtropical regions is the strong updraft speed of convection clouds. The IRW Texture COMB algorithm based on the IRW-Texture Gradient modification and the COMB algorithm shows a significant increase in quality for detecting OT and non-OT pixels in Java. Rainy days with rainfall > 50 mm/day are very common in areas with an altitude of > 500 m. On the other hand, the level of convection activity which is indicated by the presence of OT and lightning is significantly reduced in this area. OT of convective clouds appear more frequently during the DJF season and less frequently during the JJA season. OT often appears during the day time and rarely at night time. Most OTs appear in the central part, away from the south and north coasts of Java Island during the day, while OTs that appear near the south and north coasts of Java Island can appear in the morning or afternoon.
Keyword: convective clouds, extreme weather, Overshooting Tops, Himawari 8 Satellite