Judul: Aktivitas antibakteri Daun Senggugu (Clerodendron serratum [L.] Spr.)
Abstrak: Salah satu tanaman obat yang sering digunakan masyarakat untuk mengobati penyakit adalah senggugu. Seluruh bagian tanaman senggugu hampir semuanya digunakan untuk mengobati penyakit. Penelitian ini mempelajari aktivitas antibakteri dari daun senggugu tehadap bakteri uji (Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa), menentukan Konsentrasi Hambat Tumbuh Minimumnya (KHTM), serta melakukan uji kualitatif fitokimia. Daun senggugu dimaserasi dengan menggunakan pelarut metanol, aseton, dan heksana. Konsentrasi yang digunakan untuk menentukan KHTM bervariasi dari 500 mg/mL sampai 1 mg/mL. Ampisilin 0.4 mg/mL digunakan sebagai pembanding. Uji kualitatif fitokimia dilakukan untuk mengetahui golongan senyawa aktif yang diharapkan berpotensi sebagai antibakteri. Senyawa aktif yang diduga berpotensi sebagai antibakteri yang dimiliki oleh daun senggugu adalah alkaloid dan steroid. Ekstrak aseton memiliki aktivitas antibakteri paling besar. Konsentrasi terkecil ekstrak aseton daun senggugu yang masih bisa menghambat bakteri P. aeruginosa adalah 3 mg/mL, sedangkan pada S. aureus, B. subtilis, E. coli adalah 2 mg/mL. Hubungan konsentrasi dengan zona hambat pada semua bakteri uji berbanding lurus, yaitu semakin tinggi konsentrasi ekstrak daun senggugu maka semakin tinggi zona hambat yang dihasilkan. Potensi antibakteri yang dimiliki oleh ekstrak daun senggugu adalah lemah.
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Judul: Aktivitas antibakteri ekstrak Daun Jawer Kotok (Coleus scutellaroides [L.] Benth.)
Abstrak: Penelitian ini mempelajari aktivitas antibakteri dan Konsentrasi Hambat Tumbuh Minimum (KHTM) dari ekstrak daun jawer kotok terhadap bakteri Gram positif (Staphylococcus aureus & Bacillus subtilis) dan bakteri Gram negatif (Escherchia coli & Pseudomonas aeruginosa), serta penentuan senyawa metabolit pada jawer kotok. Filtrat daun muda dan tua diuji aktivitas antibakterinya. Daun jawer kotok tua secara umum memiliki aktivitas antibakteri yang lebih besar. Daun jawer kotok tua diekstraksi menggunakan tiga pelarut, yaitu heksana, air, dan aseton. Ekstrak daun jawer kotok diuji aktivitas antibakterinya. Ekstrak aseton memiliki zona hambat paling besar terhadap bakteri uji. Ampisilin 0.4 mg/mL digunakan sebagai kontrol positif. Uji kualitatif fitokimia ekstrak aseton menunjukkan hasil positif untuk uji senyawa alkaloid dan steroid. Zona hambat yang dihasilkan memiliki korelasi positif dengan konsentrasi ekstrak daun jawer kotok. Konsentrasi Hambat Tumbuh Minimum ekstrak daun jawer kotok terhadap bakteri B. Subtilis, S. aureus, E. coli, dan P. aeruginosa adalah 0,1 mg/mL dengan zona hambat berturut-turut adalah 6.6438, 6.5, 6.8062, dan 6.6188 mm. Zona hambat ampisilin 0.4 mg/mL terhadap B. subtilis, S. aureus, E. coli, dan P. aeruginosa masing-masing sebesar 26.2, 25.6042, 24.7708, dan 25.5292 mm.
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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