Judul: Ketahanan Bakteri Kandidat Probiotik Lactobacillus casei strain NS yang Dienkapsulasi Nano-Alginat terhadap pH Rendah dan Garam Empedu.
Abstrak: Bakteri asam laktat, Lactobacillus casei strain NS dilapisi dengan kitosan, kemudian dienkapsulasi dengan nanopartikel alginat menggunakan teknik gelasi ionik. Tujuan dari perlakuan ini adalah untuk meningkatkan ketahanannya terhadap pH rendah dan garam empedu. Ketahanan bakteri ditunjukkan dengan jumlah populasi bakteri yang bertahan (log). Ukuran partikel bakteri terenkapsulasi dan muatan partikel diukur dengan teknik laser difraksi. Hasil pengukuran didapat rentang ukuran partikel antara 291-1213 nm. Perbedaan ukuran tersebut dipengaruhi oleh konsentrasi CaCl2 dan Na-alginat yang ditambahkan. Enkapsulasi bakteri terlapis kitosan dengan nanopartikel alginat menunjukkan ketahanan yang lebih baik pada pH rendah maupun garam empedu dibanding tanpa enkapsulasi dengan jumlah populasi bertahan sebesar 10 log cfu/mL setelah penyimpanan selama 7 hari.
Keyword: alginat, kitosan, Lactobacillus casei, nanoenkapsulasi

Judul: Ketahanan Bakteri Probiotik Bifidobacterium Longum Bf-1 Yang Dienkapsulasi Nano Alginat Terhadap Cairan Lambung Dan Usus Halus Simulasi.
Abstrak: Nanoenkapsulasi merupakan salah satu metode dalam mempertahankan viabilitas probiotik di kondisi saluran pencernaan manusia. Tujuan dari penelitian ini adalah untuk mempertahankan populasi bakteri probiotik Bifidobacterium longum BF-1 berlapis kitosan dan nano alginat dalam cairan lambung dan usus halus simulasi. Penggunaan kitosan 2 mg/mL pH 6 menghasilkan probiotik dengan populasi tertinggi (14.27 log cfu/ml), zeta potensial positif, dan ukuran partikel terkecil (1351 nm) dibandingkan dengan perlakuan lainnya (P<0.05). Pembuatan nano alginat dengan RAL 3x ulangan menggunakan konsentrasi larutan alginat 1 mg/mL dan CaCl2 dengan berbagai konsentrasi (0.5-1.5 mg/ml). CaCl2 dengan konsentrasi 0.5 mg/mL menghasilkan nanopartikel alginat terkecil (339.4 nm) dibandingkan perlakuan lainnya (P<0.05). Proses enkapsulasi dilakukan dengan mengoptimasi probiotik berlapis kitosan dan nano alginat terpilih, lalu diuji ketahanannya dalam cairan lambung dan usus halus simulasi. Proses enkapsulasi dengan nano alginat dan coating kitosan dapat mempertahankan viabilitas probiotik yang lebih baik dibandingkan dengan sel probiotik bebas tanpa enkapsulasi (P<0.05) dengan populasi akhir >7 log cfu/ml.
Keyword: nanoenkapsulasi, Bifidobacterium longum, alginat, kitosan

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