Judul: Pemetaan Perubahan Garis Pantai di Pesisir Manggar, Belitung Timur dengan Menggunakan Citra Sentinel-2A
Abstrak: Wilayah pesisir merupakan wilayah yang paling rentan terhadap perubahan karena masih dipengaruhi interaksi dari daratan dan lautan yang bergerak secara terus-menerus, seperti aktivitas arus dan gelombang yang dibangkitkan oleh angin, serta pasang surut. Perubahan garis pantai dianalisis menggunakan teknologi pengindraan jauh yang memiliki kemampuan khusus untuk menangani daya yang bereferensi keruangan (spasial) dalam waktu yang singkat terkait fenomena yang ada dimuka bumi. Penelitian ini bertujuan memetakan dan mengetahui laju perubahan garis pantai yang disebabkan oleh proses abrasi dan akresi di pesisir Kecamatan Manggar, Kabupaten Belitung Timur, Bangka Belitung, dengan menggunakan citra Sentinel-2A pada tahun 2015 – 2023. Metode Digital Shoreline Analysis System (DSAS) digunakan untuk menghitung jarak dan laju perubahan garis pantai secara statistik maupun geospasial, melalui Net Shoreline Movement (NSM) dan End Point Rate (EPR). Lokasi penelitian terbagi menjadi 11 sub-zona, yang mencakup 4 pantai di Belitung Timur. Abrasi tertinggi terjadi di Desa Lalang (sub-zona D2) dengan jarak kemunduran garis pantai sejauh 65,38 m dan laju kemundurannya 8,78 meter/tahun. Akresi tertinggi terjadi di Desa Baru (sub-zona B2) dengan jarak kemajuan garis pantai sejauh 56,68 m dan laju kemajuannya 7,61 meter/tahun. Kondisi abrasi dan akresi pesisir Manggar dipengaruhi oleh faktor darat dan laut, seperti sedimentasi muara sungai, topologi pantai yang berpasir dan landai, serta kondisi geografi Belitung Timur yang termasuk perairan terbuka., Coastal areas are extremely vulnerable to change due to the continuous interaction between land and ocean, including current and wave activity generated by wind and tides. Remote sensing technology is a powerful tool used to analyze shoreline changes, capable of quickly handling spatially-referenced data related to phenomena on Earth. This study confidently maps and determines the shoreline change rate caused by abrasion and accretion processes on the coast of Manggar Subdistrict, East Belitung Regency Bangka Belitung, using Sentinel-2A images from 2015 to 2023. The Digital Shoreline Analysis System (DSAS) method was applied with statistical and geospatial calculations using Net Shoreline Movement (NSM) and End Point Rate (EPR) to accurately calculate the distance and rate of shoreline change. The research site was divided into 11 sub-zones, covering 4 beaches in East Belitung. Lalang Village (D2) experienced the highest abrasion, with a shoreline retreat distance of 65.38 meters and a retreat rate of 8.78 meters/year. On the other hand, Baru Village (B2) saw the highest accretion, with a shoreline advance distance of 56.68 meters and an advance rate of 7.61 meters/year. Both land and sea factors influence Manggar coast abrasion and accretion. These factors comprise the sedimentation of river estuaries, sandy and sloping coastal topology, and the geography of East Belitung, which includes open waters.
Keyword: abrasion, accretion, DSAS, East Belitung

Judul: Shoreline Changes in the Coastal of Sungai  Limau Subdistrict, Padang Pariaman Regency, West Sumatra Province
Abstrak: Pesisir merupakan wilayah peralihan antara darat dan laut sehingga sangat potensial sebagai lokasi pembangunan. Pembangunan kawasan pesisir yang semakin pesat menyebabkan adanya perubahan tata guna lahan. Penelitian ini dilakukan untuk mendeteksi perubahan garis pantai Kecamatan Sungai Limau Kabupaten Padang Pariaman, Sumatra Barat tahun 2016-2020 menggunakan citra satelit sentinel. Laju perubahan garis pantai dihitung menggunakan metode Digital Shoreline Analysis System (DSAS). Parameter yang dibutuhkan dalam metode DSAS yaitu baseline, shoreline, dan transect. Perubahan garis pantai pada transek dihitung dengan perhitungan End Point Rate (EPR) dan Net Shorline Movement (NSM). Abrasi terjadi pada semua zona yang meliputi Desa Pilubang, Desa Kuranji Hilir, Desa Koto Tinggi dan Desa Guguak. Desa Pilubang mengalami abrasi terbesar dengan perubahan garis pantai 114,59 meter. Desa Kuranji Hilir mengalami abrasi sebesar 94,60 meter, Desa Koto Tinggi mengalami abrasi sebesar 86,93 meter dan Desa Guguak mengalmi perubahan garis pantai berupa abrasi sebesar 78,72 meter. Perubahan garis pantai yang terjadi di pesisir Pantai Sungai Limau dipengaruhi oleh arus (0,12 – 0,25 m/s), angin (5 – 2 m/s), gelombang (0,3 – 0,93 meter) dan pasang surut (-0,6 – 0,8 meter). Arus yang bergerak menyusuri pantai yang terbentuk akibat angin dan gelombang yang ada di pesisir Kecamatan Sungai Limau mengakibatkan terjadinya abrasi., The coast is a transitional area between land and sea so it is very potential as a location for construction. The rapid development of coastal areas causes changes in land use. This research was conducted to detect changes in the coastline of Sungai Limau Subdistrict, Padang Pariaman Regency, West Sumatra Province from 2016- 2020 using sentinel satellite imagery. The rate of shoreline change was calculated using the Digital Shoreline Analysis System (DSAS) method. The parameters needed in the DSAS method are baseline, shoreline, and transect. The shoreline change on the transect is calculated by the End Point Rate (EPR) and Net Shoreline Movement (NSM) formulas. Abrasion occurred in all zones which include Pilubang Village, Kuranji Hilir Village, Koto Tinggi Village, and Guguak Village. Pilubang Village experienced the biggest abrasion with a coastline change of 114.59 meters. Kuranji Hilir Village experienced an abrasion of 94.60 meters, Koto Tinggi Village experienced an abrasion of 86.93 meters and Guguak Village experienced a change in the coastline in the form of abrasion of 78.72 meters. Coastline changes that occur on the coast of Sungai Limau are influenced by currents (0.12 – 0.25 m/s), wind (5 – 2 m/s), waves (0.3 – 1.42 meters) and tides (-0.6 – 0.8 meters). Currents that move along the coast formed by wind and waves on the coast of Sungai Limau District cause abrasion.
Keyword: abrasi, akresi, citra sentinel, DSAS, garis pantai

Judul: Pemurnian dan karakterisasi protein inhibitor RNA helikase virus hepatitis C
Abstrak: Hepatitis C virus (HCV) infection is the second most common chronic viral infection in the world with global prevalence. This infection is contribution to chronic hepatitis and liver cirrhosis, often leading to hepatocellular carcinoma. There is no effective drug and vaccine available against HCV. The current standard treatment, a combination of pegylated interferon-α with ribavirin, is limited by its suboptimal response rate in a significant patient population, side effects, and affordability. Therefore, development of effective drug is needed. One approach to find out the candidate of antiviral drug is to discover the inhibitor of enzyme that essential for virus replication, such as RNA helicase. Streptomyces chartreusis 5-095 produce the inhibitor of HCV RNA helicase. The aim of this study was to purify the protein inhibitor which has inhibition activity against ATPase activity of RNA helicase HCV from S. chartreusis 5-095. The supernatant of culture S. chartreusis 5-095 exhibited high inhibiton activity against ATPase activity of RNA helicase HCV (approximately 72%) at 10 days of incubation. The extracellular protein inhibitor was partially purified by procedures of precipitation with ammonium sulfate to 65% saturation and gel filtration (Sephadex G50) using methanol water solution (4:6) as an eluen. The purity of protein inhibitor was monitored by SDS PAGE. The protein inhibitor showed a relative molecular mass were estimated to be 14 kDa and increased the purity 23,08 fold than those of the crude protein. The specific activity and IC50 after purification were 13,1338 U/mg and 0,0767 mg/mL, respectively. The activity of purified protein inhibitor showed its stability over pH range from 5-8 and optimum at pH 7,4. The inhibition activity showed its stability up to 70% at temperature 100 oC. The purified protein inhibitor relatively stable its activity at storage in the range of -20 oC to room temperature for 35 days.
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