Judul: Karakterisasi dan Identifikasi Senyawa Aktif Ekstrak Pigmen Telur Keong Mas (Pomacea canaliculata)
Abstrak: Keong mas (Pomacea canaliculata) diketahui menjadi hama bagi tanaman padi karena kemampuan adaptasi dan daya reproduksi yang tinggi. Salah satu upaya untuk memberantas hama keong mas dengan memanfaatkan telor keong mas untuk bahan baku produk dalam bidang industri pangan maupun kesehatan. Tujuan penelitian ini yaitu mengidentifikasi senyawa aktif yang terkandung dalam ekstrak pigmen telur keong mas. Metode penelitian yang digunakan meliputi ekstraksi pigmen menggunakan aseton dan metanol, analisis fitokimia, penentuan pigmen secara kualitatif dengan KLT dan penentuan senyawa aktif secara semi kuantitatif dengan LC-MS/MS. Hasil identifikasi pada ekstrak metanol pigmen telur keong mas menunjukkan adanya senyawa aktif berupa pigmen yaitu 11 pigmen karotenoid golongan xantofil, 2 pigmen karotenoid golongan karoten, dan 7 senyawa aktif berupa non pigmen, sedangkan pada ekstrak aseton menghasilkan 11 pigmen karotenid golongan xantofil dan 6 senyawa aktif berupa non pigmen.
Keyword: karotenoid, LC-MS/MS, senyawa aktif, telur keong mas (Pomacea canaliculata)

Judul: Aktivitas Antioksidan Fraksi Biopigmen Telur Keong Mas.
Abstrak: Biopigmen merupakan zat warna alami yang tidak menimbulkan efek toksik, dapat diperbarui dan ramah lingkungan. Telur keong mas berpotensi sebagai sumber biopigmen. Golongan pigmen alami yang banyak ditemukan pada telur keong mas yaitu golongan karotenoid salah satunya pigmen astaxanthin. Tujuan penelitian ini adalah untuk menentukan aktivitas antioksidan ekstrak telur keong mas dan menentukan fraksi biopigmen terbaik antara pelarut aseton dan metanol untuk dimanfaatkan sebagai antioksidan dengan berbagai uji in-vitro. Ekstrak kasar biopigmen telur keong mas dengan perlakuan aseton memiliki aktivitas antioksidan terbaik dengan nilai IC50 metode DPPH sebesar 130,52+3,07 μg/mL dan ABTS sebesar 125,89+1,70 μg/mL. Nilai kapasitas antioksidan FRAP sebesar 184,11+3,92μmol Fe2+/g ekstrak dan CUPRAC sebesar 29,17+3,58 μg/mL Asam Askorbat/g ekstrak. Fraksi aseton 2 memiliki aktivitas antioksidan paling baik dibandingkan fraksi lainnya dengan nilai IC50 metode DPPH sebesar 92,08+2,85 μg/mL dan metode ABTS sebesar 144,80+3,33 μg/mL. Nilai kapasitas antioksidan FRAP sebesar 259,11+3,93 μmol Fe2+/g ekstrak. Identifikasi senyawa secara semi kualitatif dengan LC-MS/MS pada fraksi aseton 2 ditemukan adanya senyawa pigmen astaxanthin dan lima senyawa pigmen lainnya.
Keyword: astaxanthin, karotenoid, LC-MS/MS, Pomacea canaliculata

Judul: The Effects of Variance of Interest rate to Variance of Annuity Future Values
Abstrak: Time value of money is a concept that refers to the difference of the value of money due to time difference. The value of money for present time would not be the same as the value of money in the future. The value of money for present time is called as Present Value (PV) of the money and the value of money for future time is called Future Value (FV) of the money. Determination the value of money, for present and future time, depends on the time and rate of return. The value of money is determined by several factors such as inflation, fluctuation of interest rates, and government policy in securities and taxation. Due to fluctuation of the value of money we need a FV formulation, it is useful for knowing whether an investment can be profitable or not, and this information is useful also in budget analysis. Annuity is defined as a series of payments made for a specific period. The payment, fixed or varied, can be made at the beginning or at the end of the period. Annuity paid at the beginning of the period is called annuity-due and annuity paid at the end of the period is called immediate annuity-certain. The accumulated value of the annuity after few years later is called as a final value or a future value. Burnecki et al. (2003) have discussed about the FV of a fixed-rate annuity in which payments are made according to the arithmetic or geometric series. They have also examined FV for annuities in which payments are made according to arithmetic or geometric series with random rates of interest. This paper examines FV for annuity-due in which payments are made according to arithmetic or geometric series with interest rates as a random variable, which is normal distribution ,  . Future value formula is expressed in recursive form. FV for annuity-due which payments are made according to the arithmetic or geometric series with random rates of interest is calculated by theoretical way and simulation way. The random rates of interest is denoted as k k i  i  , where k i an independent random variable; i is a constant and k  is a random variable which has normal distribution ,  . By using the determined parameters, a sequence of random rates of interest are generated for theoretical calculation. Meanwhile for the simulation, the random rates of interest is generated 1000 times for the simulation. The generated data give mean value, variance, and standard deviation. Moreover, error of mean value, variance, and standard deviation from the theoretical and simulation results are calculated. Error calculation uses Symmetric Mean Absolute Percentage Error (SMAPE). The smaller the value of SMAPE is the more accurate the simulation. The interest rate variances are varied from 0.000036 to 0.0001 to study the relationship between variance of rates of interest and variance of future value. The theoretical and simulation results show that when the variance of random rates of interest increases, then the variance of FV increases linearly. FV of the annuity-due in
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