Judul: Ekstraksi dan Karakterisasi Kolagen Kulit Ikan Baronang (Siganus canaliculatus)
Abstrak: Kolagen merupakan protein paling berlimpah yang terdapat dalam tubuh makhluk hidup dan jumlahnya sekitar 30% dari total protein keseluruhan. Pemanfaatan limbah kulit ikan baronang menjadi kolagen adalah salah satu alternatif untuk meningkatkan nilai ekonomis limbah. Komposisi kimia kulit ikan baronang terdiri dari air 66,96%, protein 83,9%, lemak 9%, dan abu 1,46%. Ekstraksi kolagen dilakukan dengan metode kolagen larut asam (ASC) dengan variasi konsentrasi asam asetat (0,5 M, 0,75M, 1M). Hasil penelitian menunjukan bahwa rendmen kolagen masing- masing 15,55%, 20,01%, 12,08%. Nilai pH kolagen yaitu 6,92, 6,75, dan 5,25. Nilai Viskositas kolagen berkisar antara 51,83- 64,50 cP. Hasil FTIR kolagen menunjukan kelompok Amida( Amida A, B, I, II, III), Pola pita protein kolagen dengan pita α1, α2 dan β. Selain itu, metode terbaik (0,75M) menunjukan bahwa asam amino yang terkandung didalam kolagen seperti glisin, prolin, arginin, dan alanin.
Keyword: asam amino, kolagen, rendemen, viskositas

Judul: Ekstraksi dan Karakterisasi Kolagen dari Kulit Ikan Tongkol (Euthynnus affinis)
Abstrak: Collagen is the most abundant protein in the living body and comprising approximately 30% of the total protein content. Utilization of waste from the skin of eastern little tuna to produce collagen is one alternative to increase the economic value of its waste. Pretreatment process in extracting collagen affects the quality of collagen that obtained. The different concentration of NaOH (0.05; 0.1; and 0.2 M) and soaking time (2, 4, 6, 8, 10, and 12 hours) were used as the pretreatment step. The best result of pretreatment was obtained from soaking the skin in a solution of 0.05 M NaOH for 12 hours with the lowest of soluble non-collagen protein concentration was 0.140 mg/mL. The yield and pH of the best collagen were 7.459% and 5.29, respectively. The highest solubility of collagen was 90.80% at pH 3. Amino acid analysis showed that the collagen has a glycine, proline, arginine, and alanine were dominant. FTIR analysis showed the major absorption bands of amide A, B, I, II, and III were at wavenumber 3395 cm-1, 2929 cm-1, 1652 cm-1, 1543 cm-1, and 1237 cm-1, respectively.
Keyword: amino acid, collagen, eastern little tuna, FTIR, yield

Judul: A Continuous Vaccination Strategy in the SVIR Epidemic Model
Abstrak: Vaccination is conducted to minimize the spread of a disease. The vaccination is usually done several times within a fixed time interval. In the SVIR model, it is assumed that individuals do not get immediate immunity following a vaccination program. So according to process of vaccination on SVIR model, there are two strategies, i.e. the continuous vaccination strategy (CVS) and the pulse vaccination strategy (PVS). In this study, only the CVS strategy in epidemic model SVIR is considered. Results of the study indicate that dynamics of the CVS system depends on the basic reproductive number. If the basic reproductive number is less than one, then the disease-free fixed point is asymptotically stable. It means that the disease will eventually disappear from the population. Conversely, if the basic reproductive number is greater than one, then the endemic fixed point is asymptotically stable, which means that the disease will remain exist in the population. Simulation result shows that the vaccination would minimize the spread of disease by reducing the basic reproductive number. If the time for the vaccinated recipients to obtain the immunity, as well as a possibility of vaccinated recipients to be infected are neglected, then the disease will be eradicated. This condition is called an over-evaluating effect of vaccination.
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