Judul: Processing data radar cuaca C-Band Doppler untuk curah hujan: studi kasus Jabodetabek
Abstrak: Rainfall is one of the most important element of the weather in a region. The study of rainfall has be done with a lot of method. One of them is by using the weather radar. The weather radar is classifeid in many group according to its frequency. This radar using the Doppler Concept in its process. This research is indicated to learn the processing of weather radar C-Band Doppler including its software to get the rainfall data in Jabodetabek region and to see the movement of rain fall region with weather radar data. The processing of this radar is in the computer with Linux Operating System with many software must be included, C, Fortran, Perl, and NetCDF. The processing needs some of script which can turn the primary data which is RAW format into the rain fall data (mm/hr). Cressman modification was used in the process, in order to turn the Raw format into reflectivity. The process needs the equivalence of Marshall-Palmer, in order to turn the reflectivity into CAPPI data format and Image CAPPI format. The result of this process is in text format, which is contain longitude, altitude, height, and rain fall. This rainfall value will be able to create many weather and climate infomation, such as rain fall region, floods, and more. In this research, the aplication of rainfall data is limited into the condition of rainfall region. The rain fall data will show the movement of the rain fall in a region. Jakarta, Bogor, Depok, Tangerang, and Bekasi were area case of study. According to result, the maximum of rainfall region is happening in the east and south of Jabodetabek, one of them is Bogor. Results data also showed the decrease in altitude, precipitation will be smaller.
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Judul: Perbandingan Metode Koreksi Data Radar Cuaca Dengan Penakar Hujan Wilayah Bengkulu
Abstrak: Weather radar data can provide spatio temporal rainfall forecast at high- resolution. Radar covers a large area and captures the spatial variability of rainfall that increases a short-term predictability of rain. However, the rainfall derived from radar is inherently an estimated value that may contain bias. Also, the estimated value is derived indirectly from the radar reflectivity equation. Therefore, adjusting the estimated rainfall value based on the local observed rain gauge remains a research challenge. This study employed Bengkulu weather radar data and combined with the rainfall from automatic weather station at the Bengkulu Climatology Station. Observed rainfall datasets from 34 rain gauges over Bengkulu for 2015 to 2020 were used for the analysis, we selected December-February as representative of wet season, whereas June-August was for the dry season. Correction of radar data with rain gauge is calculated using the Mean Field Bias (MFB), Local Bias Correction (LBC), and Quantile Mapping (QM) approaches. MFB is a method for estimating the overall bias (average) for radar in a large domain. The LBC correction is a correction by considering the distance factor of the rain gauge to the radar location. Correction of bias QM corrects the data distribution using the probability approach. The Conversion of reflectivity to intensity using three different Z-R relationship, namely Marshall Palmer, Rosenfeld, and the new Z-R equation refers to previous research on the island of Sumatra. The results of analyses in the present study strongly indicated an improvement in radar data quality after the correction method was applied. The Local Bias Correction (LBC) method gives the best results compared to the MFB and QM methods for the Bengkulu region, with the highest correlation of 0.51. The best Z-R relationship is obtained from the Marshall Palmer equation. Bias correction performance in the wet season (DJF) has better results than in the dry season (JJA).
Keyword: Reflectivity, radar, correction, rain, method

Judul: Kerentanan Strain Ikan Nila Terhadap Infeksi Streptococcus Agalactiae Penyebab Penyakit Streptococcosis
Abstrak: Strain ikan nila (Oreochromis niloticus) unggulan hasil pemuliaan telah banyak dilepas untuk meningkatkan produksi perikanan budidaya di Indonesia. Namun ada kendala yang dihadapi yaitu kasus kematian ikan akibat penyakit Streptococcosis yang dikhawatirkan akan menjadi penghambat keberhasilan budidaya ikan nila. Penyakit ini disebabkan oleh infeksi bakteri Streptococcus agalactiae. Penanganan yang kurang baik, padat tebar yang tinggi, lingkungan pemeliharaan yang buruk, manajemen pemberian pakan yang kurang baik menyebabkan terjadinya ketidakseimbangan lingkungan dan akhirnya ketahanan tubuh ikan menjadi menurun sehingga rentan terhadap serangan penyakit. Bakteri S. agalactiae memiliki kisaran inang (host range) yang luas dan kemampuan adaptasi lingkungan yang cukup baik. Berdasarkan potensi infeksi S. agalactiae yang cukup tinggi dan potensial inang yang besar, maka diperlukan informasi mengenai kerentanan antar strain ikan nila unggulan dan variasi respon imun antara ikan nila (cichlidae) dan ikan mas (non-cichlidae). Pertama, melakukan uji kerentanan empat strain ikan nila terhadap infeksi S. agalactiae NK1. Strain ikan nila yang dipergunakan adalah ikan Nila Srikandi, ikan Nila Nirwana, ikan Nila BEST dan ikan Nila Sultana. Keempat strain nila diinfeksi dengan S. agalactiae NK1 pada dosis kepadatan bakteri 103, 104, 105, 106 CFU/ekor dan satu kontrol yang diinjeksi dengan PBS, masing-masing 2 kali ulangan. Nilai LD50 yang diperoleh berkisar antara 103,20-103,45 CFU/ekor . Kedua, melakukan analisis parameter imunologis strain ikan nila dan ikan mas terhadap infeksi S. agalactiae NK1. Dipergunakan ikan Nila Srikandi yang memiliki nilai LD50 tertinggi dan ikan mas yang mewakili kelompok noncichlidae (sebagai kontrol). Ikan diinfeksi dengan S. agalactiae NK1 menggunakan dosis 103 CFU/ekor. Hasil penelitian menunjukkan bahwa ikan nila memperlihatkan perubahan pola renang (berdiam didasar, berenang tidak beraturan dan berenang berputar), perubahan anatomi makroskopis (pigmentasi, eksoptalmi, mata keruh, operkulum jernih, hemoragi pada pangkal sirip). Sintasan ikan Nila Srikandi sebesar 50% dan ikan mas 100% pada 15 hari masa pemeliharaan. Ikan mas tidak menunjukkan perubahan pola renang dan perubahan anatomi. Kematian tercepat terjadi pada ikan Nila Srikandi terjadi pada 96 jam pasca infeksi. Aktivitas lisozim menunjukkan perbedaan yang signifikan antara ikan Nila Srikandi dan ikan mas. Berdasarkan pengamatan terhadap preparat histopatologi diketahui bahwa otak ikan Nila Srikandi yang terinfeksi S. agalactiae mengalami meningoensefalitis, sedangkan pada ikan mas hanya mengalami meningitis. Streptococcus agalactiae merupakan patogen spesifik pada ikan nila, hal ini terbukti dengan sintasan ikan mas yang mencapai 100%.
Keyword: Kerentanan, strain nila, Streptococcus agalactiae