Judul: Aktivitas Antibakteri Fraksi Etanol Kulit Batang Tumbuhan Berenuk (Crescentia cujete L.).
Abstrak: Berenuk termasuk salah satu tumbuhan yang dapat dijadikan obat herbal. Kulit batang berenuk mempunyai kemampuan sebagai antibakteri. Penelitian ini bertujuan menentukan aktivitas antibakteri kulit batang berenuk pada fraksi n-heksana, diklorometana, etil asetat dan air menggunakan metode difusi agar dan metode kromatografi lapis tipis (KLT) bioautografi. Uji aktivitas antibakteri difusi agar menunjukkan bahwa fraksi air mampu menghambat pertumbuhan bakteri Escherichia coli sedangkan fraksi diklorometana dan fraksi etil asetat mampu menghambat pertumbuhan bakteri Staphylococcus aureus. Fraksi diklorometana memiliki aktivitas antibakteri pada KLT Bioautografi pada Rf 0.88, 0.84, dan 0.78 yang mampu menghambat pertumbuhan bakteri S. aureus.
Keyword: antibakteri, berenuk, bioautografi

Judul: Potensi Ekstrak Etanol Kulit Batang dan Daun Berenuk (Crescentia cujete L.) sebagai Antibakteri
Abstrak: Berenuk (Crescentia cujete L.) memiliki berbagai senyawa aktif yang dapat berfungsi sebagai antibakteri. Tujuan penelitian ini adalah mengidentifikasi senyawa aktif yang terdapat pada ekstrak etanol kulit batang dan daun berenuk, menentukan aktivitas antibakteri terhadap bakteri S. aureus dan E. coli, dan konsentrasi hambat minimum (KHM) pada bakteri S. aureus. Senyawa aktif pada kedua ekstrak diidentifikasi dengan uji fitokimia. Uji aktivitas antibakteri dilakukan dengan metode difusi cakram dengan konsentrasi bakteri 106 cfu/mL. Penentuan KHM dilakukan dengan metode kontak. Hasil uji fitokimia menunjukkan bahwa ekstrak etanol kulit batang dan daun berenuk mengandung alkaloid, flavonoid, saponin, tanin, dan steroid. Hasil uji aktivitas antibakteri menunjukkan kedua ekstrak memiliki aktivitas penghambatan yang lebih besar terhadap S. aureus dan menghasilkan zona hambat terbesar pada konsentrasi 100%. Persentase penurunan jumlah koloni bakteri pada kedua ekstrak kurang dari 90% sehingga KHM kedua ekstrak terhadap S. aureus belum dapat ditentukan.
Keyword: antibakteri, berenuk, daun, ekstrak etanol, kulit batang

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