Judul: Distribusi Lamun dan Mangrove menggunakan Citra Satelit Worldview-2 di Gugus Pulau Pari, Kepulauan Seribu
Abstrak: Teknologi satelit penginderaan jauh mempunyai kemampuan untuk mengidentifikasi dan memantau sumberdaya alam dan lingkungan wilayah pesisir. Tujuan penelitian ini adalah mengetahui distribusi lamun dan mangrove menggunakan citra Satelit WorldView-2 di Gugus Pulau Pari, Kepulauan Seribu. Pengolahan citra menggunakan algoritma NDVI untuk mendeteksi vegetasi lamun dan mangrove, yang menghasilkan nilai NDVI dari -0,987 sampai 0,936. Survei lapang di padang lamun menggunakan transek 1 m x 1 m yang diletakkan secara acak, sedangkan untuk mangrove menggunakan transek 10 m x 10 m. Jenis lamun yang ditemukan adalah Cymodocea rotundata, Enhalus acoroides, dan Thalassia hemprichii, sedangkan jenis mangrove yang ditemukan adalah Rhizophora mucronata. Di Pulau Karang Kudus, Pulau Biawak, dan Pulau Pari jenis lamun yang dominan adalah Enhalus acoroides, sedangkan di Pulau Burung jenis lamun yang dominan adalah Thalassia hemprichii. Kerapatan rata-rata mangrove di Pulau Biawak adalah 13 ind/100 m2 dan Pulau Burung memiliki Rhizophora mucronata dengan kerapatan rata-rata 43 ind/100 m2. Rhizophora mucronata di Pulau Pari memiliki kerapatan rata-rata 22 ind/100 m2. Hasil klasifikasi citra WorldView-2 menunjukkan luas lahan untuk lamun sebesar 324.200 m2, sedangkan untuk mangrove jarang adalah 12.500 m2, mangrove sedang sebesar 32.700 m2 dan mangrove lebat sebesar 47.800 m2., Satellite remote sensing technology has the ability to identify and monitor natural resources and environment in coastal areas. The purpose of this research was to determine the distribution of seagrasses and mangroves using WorldView- 2 imagery in Pari Island, Kepulauan Seribu. NDVI image processing algorithm for detecting seagrasses and mangroves vegetation was applied, resulting in NDVI values of -0.987 to 0.936. Groundtruth survey on seagrasses was conducted haphazardly using transect plot of 1 m x 1 m, while for mangroves was 10 m x 10 m. Observed seagrass species were Cymodocea rotundata, Enhalus acoroides, and Thalassia hemprichii, while mangrove was Rhizophora mucronata. Karang Kudus Island, Biawak Island and Pari Island had dominant seagrass species of Enhalus acoroides, while in Burung Island was dominated by Thalassia hemprichii. Average mangroves density in Biawak Island was 13 ind/100 m2 and Burung Island has Rhizophora mucronata with average density of 43 ind/100 m2. Rhizophora mucronata in Pari Island had an average density was 22 ind/100 m2. Classification results of WorldView-2 showed the extent area for seagrasses was 324.200 m2, while for sparse mangrove was 12.500 m2, medium 32.700 m2 and dense 47.800 m2.
Keyword: penginderaan jauh, distribusi, lamun, lamun, Pulau Pari

Judul: Monitoring Mangrove Area and Density Using Landsat Satellite on Lancang Island, Kepulauan Seribu
Abstrak: Mangrove adalah tumbuhan yang hidup di lingkungan pesisir dengan salinitas rendah. Ekosistem mangrove dapat tumbuh di zona intertidal dan zona supratidal. Monitoring ekosistem mangrove secara langsung tidak mudah karena sulitnya memetakan kawasan mangrove sehingga dibutuhkannya teknologi penginderaan jauh sebagai metode alternatif. Penelitian ini bertujuan mengkaji perubahan luasan dan kerapatan mangrove secara temporal menggunakan citra Landsat. Metode yang digunakan adalah klasifikasi terbimbing dengan algoritma maximum likelihood classification dan indeks vegetasi Normalized Difference Vegetation Index (NDVI). Pada tahun 2000 hingga 2010, luasan ekosistem mangrove mengalami peningkatan seluas 5,31 ha atau 131,11% dari luasan sebelumnya. Pada rentang waktu berikutnya yaitu tahun 2010 hingga 2021, luasan ekosistem mangrove mengalami peningkatan kembali seluas 6,3 ha atau 67,30% dari luasan sebelumnya. Hasil klasifikasi kerapatan mangrove di Pulau Lancang terbagi menjadi tiga kelas yaitu jarang, sedang, dan rapat. Pada tahun 2000, 2010, dan 2021 kerapatan mangrove kelas jarang dan sedang mengalami penurunan, sedangkan kerapatan mangrove kelas rapat mengalami peningkatan. Peningkatan luasan dan kerapatan mangrove di Pulau Lancang, Kepulauan Seribu dikarenakan tidak adanya gangguan secara berlebihan dari masyarakat setempat, adanya unsur hara yang menyuplai ekosistem mangrove, dan memiliki jenis substrat berlumpur yang optimal bagi habitat mangrove. Hasil uji akurasi klasifikasi citra tutupan lahan sebesar 85,45%., Mangroves are plants that live in coastal environments with low to mid range salinity. Mangrove ecosystems can grow in the intertidal zone and supratidal zone. Monitoring mangrove ecosystems directly is not easy because of the difficulty of mapping mangrove areas. So, remote sensing technology is needed as an alternative method. This research purposed to examine temporary changes in an area and density of mangroves using Landsat imagery. Method that used in this research was supervised classification with the maximum likelihood classification algorithm and Normalized Difference Vegetation Index (NDVI) vegetation index. In 2000 to 2010, mangrove ecosystem area expanded by 5.31 ha or 131,11% from previous area. In the next time span between 2010 to 2021, mangrove ecosystem area expanded by 6.3 ha or 67,30% from previous area. Mangrove density on Lancang Island specified into three classes that was sparse, moderate, and concentrated. In 2000, 2010, and 2021, sparse and moderate density of mangroves area has been degradated, while concentrated mangroves area has been expanded. The expanding area and density of mangroves on Lancang Island, Kepulauan Seribu Regency was due to the absence of excessive disturbance from local community, the presence of nutrients that supplied the mangrove ecosystem, and optimal type of muddy substrate for mangrove habitat. The results of accuracy test on land cover image classification were 85.45%.
Keyword: Area, Canopy Cover, Density, Mangrove, NDVI

Judul: The Dynamic of HIV Virus Infection as a Result of Protease Inhibitor Therapy.
Abstrak: Acquired immunodeficiency syndrome (AIDS) is defined as symptoms of deterioration human immune system caused by human immunodeficiency virus (HIV). The virus damages the leucocytes; therefore, once a person infected by the HIV, his/her immune system will be paralyzed and eventually will not be able to survive from any disease. HIV is transmitted in many ways, such as having unsafe sex, using unsterilized syringe, blood transfusion, and many more. So far, there has not been discovered yet a way or a medicine that can totally cure this disease. However, reverse transcriptase inhibitor therapy, protease inhibitor, or combination of those two can decline the growth of virus inside the body of the infected person. Therefore, the immune system will be enhanced back to normal phase. In this paper, will analyze the effect of protease inhibitor therapy on the dynamics of virus inside the blood with different value of effectiveness. There are two mathematical models of protease inhibitor therapy to consider, i.e. perfect and imperfect protease inhibitor. The perfect protease inhibitor therapy hinders the virus to grow well and not to infect healthy leucocytes. On the other hand, the imperfect one cannot completely detained the virus growth.
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