Judul: The physiological Impact of Microplastics on Holothuria leucospilota
Abstrak: Nowadays plastic debris are found in oceans.Various processes lead to a transformation of macroplastics into microplastics (i.e. particles < 5mm). Sunlight and the action of the waves can degrade plastic and shred the material over time into smaller pieces. Furthermore, they can be found as ingredients of different products e.g. cosmetics and therefore enter the marine environment. Microplastics could have negative effects on marine organisms, especially for benthic organisms but up to now little is known about potential consequences. This study aims to investigate the physiological impact of microplastics on marine deposit-feeding invertebrates like sea cucumber Holothuria leucospilota. Polyvinylchloride (PVC) and fluoranthene was selected as a representative model plastic and model pollutant. The size range of PVC particles were 50-200 μm and have been previously polluted with fluoranthene. In laboratory, groups of sea cucumbers (n=15) were exposed to 6 different pollution scenarios (i.e. 0%; 0.03%; 0.3%; 1%; 3% and 3% non polluted with fluoranthene) which differed regard to the microplastics density (% by weight of sediment). Futhermore, after exposed from PVC particles polluted and non polluted with fluoranthene, H. leucospilota would faced hypoxia condition used as a common response variable to investigate if H. leucospilota has a lower resistance to environmental stress due to previous microplastics ingestion. The study revealed that after 60 days exposure to microplastic PVC particles polluted and non polluted with fluoranthene is not given any negatively influence on physiological parameters (respiration rate, faeces production and survival rate) of black sea cucumber H. leucospilota. This study clearly indicates that H. leucospilota is susceptible to oxygen depletion. Probably, long-term experiments will reveal negative impacts that were not detected in the present study. Another aspects from this study, microplastics particles were collected and found in all sediment samples, depths and sampling locations at Rambut Island which also took H. leucospilota but in different site. The diverse composition of microplastics particularly on type at the sampling location Rambut Island were found fibers, foamed particles, films and fragments. Further, these findings revealed a possible threshold of marine organisms on the marine biodiversity especially in Rambut Island, one of closest island to Jakarta Bay.
Keyword: Microplastic, PVC, fluoranthene, holothurian, behavioral, survival, Rambut Island

Judul: Respon Kerang Hijau (Perna viridis) Terhadap Mikroplastik dan Mikro Partikel Alami
Abstrak: Penelitian mengenai dampak mikroplastik bagi hewan laut sudah banyak dilaporkan, namun hampir semua penelitian tersebut tidak membandingkan dampak yang diberikan mikroplastik dengan mikro partikel alami yang ada di alam yang juga dapat menjadi stressor bagi hewan laut. Hal ini dapat menyebabkan kesalahan interpretasi atas dampak yang diberikan mikroplastik kepada hewan. Maka kami melakukan penelitian ini untuk melihat apakah dampak yang diberikan mikroplastik dan mikro partikel alami benar-benar berbeda terhadap kerang hijau. Penelitian ini dilakukan di laboratorium selama 21 hari. Kerang hijau diberi paparan mikroplastik PVC dan mikro partikel alami red clay dengan tingkat konsentrasi yang berbeda (1.5 mg / l, 15 mg / l and 150 mg / l). Variabel yang diamati yaitu survival rates, clearance rates, and BCI index. Hasilnya untuk clearance rates dan survival rates secara statistik tidak berbeda nyata, sementara hasil BCI memperlihatkan dampak dari paparan PVC dan red clay pada tiap konstentarsi kurang dari 10%. Hal ini menunjukkan bahwa dampak dari paparan PVC dan red clay masih serupa. Sehingga sangat penting bagi penelitian mikroplastik selanjutnya untuk memasukkan pembanding mikro partikel alami sebagai indikator tingkat stress bagi hewan yang diamati., The impact of microplastics on marine animals has been widely reported, but almost all of them do not compare the effect of microplastics with natural micro particles, which can also be a stressor for the animals. This can lead us to look overestimated effect of microplastics on marine animals. Here we conducted a study to see whether the effect of microplastics was the same as the effect of natural micro particles on green mussels (Perna viridis). This research was conducted experimentally in the laboratory for 21 days. Green mussels were exposed to PVC as microplastics and red clay as natural micro particles with three different concentrations (1.5 mg/l, 15 mg/l, and 150 mg/l). We observed survival rates, clearance rates, and BCI index. Clearance rates and survival rates were not statistically significant, while the BCI results showed that the effects of PVC and red clay at each concentration were less than 10%. This suggests that the effect of microplastics and natural micro particles is similar, and it is necessary to include natural micro particles as a comparison in research related to microplastics.
Keyword: microplastics, natural micro particles, green mussel, survival rates, clearance rates, body condition index

Judul: Konstruksi aritmetika kurva eliptik F(2m) supersingular dan non-supersingular untuk skema kunci publik ElGamal
Abstrak: Algoritme ElGamal adalah salah satu algoritme kunci publik dengan aritmetik modular p yang mempunyai struktur grip siklik Z(p). Tingkat keanaman algoritme ini terletak pada pemecahan masalah logaritme diskret dari Z(p). Akan tetapi, tingkat keamanan tadi tahun ke tahun semakin menurun yang disebabkan kemampuan pemecahan algoritme diskret semakin meningkat. Untuk memenuhi tingkat keamanan yang memadai dibutuhkan p yang cukup besar yang menyebabkan proses enkripsi dan dekripsi menjadi lambat.
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