Judul: Immunostimulant Activity of Fish Oil from the Viscera of Gindara Fish, Gindara Kulit Duri, Layur, and Cucut
Abstrak: Minyak ikan menjadi sumber alami asam lemak tak jenuh (PUFA) omega-3 utamanya Docosahexaenoic acid (DHA) dan Eicosapentaenoic acid (EPA) yang diketahui mampu mengatur sistem imun dalam tubuh. Viscera dapat dijadikan alternatif bahan baku produksi minyak ikan guna meningkatkan nilai tambah Penelitian ini bertujuan untuk menentukan asam lemak yang terkandung pada viscera ikan air laut dalam serta potensi minyak ikan yang dihasilkan sebagai imunostimulan terhadap sel plenosit mencit secara in vitro. Ekstraksi minyak ikan air laut dalam dilakukan menggunakan metode bligh and dyer. Pengujian kapasitas proliferasi sel splenosit pada mencit dilakukan secara in vitro menggunakan pengujian MTT. Asam lemak paling dominan pada masing-masing viscera ikan air laut dalam antara lain asam palmitat pada viscera ikan layur dan ikan cucut, asam dokosaheksaenoat pada viscera ikan gindara, serta asam oleat pada viscera ikan gindara kulit duri. Minyak ikan air laut dalam yang digunakan dalam pengujian kapasitas proliferasi sel splenosit adalah minyak ikan gindara, minyak ikan gindara kulit duri, dan minyak ikan cucut. Keseluruhan sampel minyak ikan air laut dalam memiliki potensi sebagai agen imunostimulan., Fish oil is a natural source of omega-3 unsaturated fatty acids (PUFA), especially Docosahexaenoic acid (DHA) and Eicosapentaenoic acid (EPA), which are known to regulate the immune system in the body. Fish viscera can be used as an alternative raw material for fish oil production to increase added value. This study aims to determine the fatty acids contained in the viscera of deep sea fish and the potential of fish oil produced as an immunostimulant to plenocyte cells of mice in vitro. Extraction of deep sea fish oil was carried out using bligh and dyer method. Testing of the proliferative capacity of splenocytes in mice was carried out in vitro using the MTT assay. The most dominant fatty acids in each deep sea fish viscera include palmitic acid in the viscera of Layur and cucut fish, docosahexaenoic acid in gindara fish viscera, and oleic acid on the viscera of gindara fish with spines. The deep-sea fish oil used in testing the proliferative capacity of splenocyte cells were gindara fish oil, thorn skin gindara fish oil, and cucut fish oil. All samples of deep sea fish oil have potential as immunostimulant agents.
Keyword: asam lemak, concanavalin A, imunostimulan, minyak ikan

Judul: Virgin Deep Sea Fish Oil Lepidocybium flavobrunneum dan Ruvettus pretiosus serta Potensinya sebagai Imunostimulan
Abstrak: Ikan gindara dan gindara kulit duri merupakan ikan hasil tangkapan sampingan (by catch) dari ikan tuna yang dapat hidup pada kedalaman 200 meter dibawah permukaan air laut. Penelitian ini bertujuan menentukan nilai proksimat, rendemen minyak, profil asam lemak, parameter oksidasi dan potensi minyak ikan laut dalam sebagai agen imunostimulan secara in vitro. Ekstraksi minyak ikan laut dalam dilakukan dengan metode wet rendering suhu rendah (40, 50, 60, 70 ℃) dan pengujian proliferasi sel splenosit dengan uji MTT assay. Asam lemak yang dominan pada ikan gindara dan gindara kulit duri adalah asam oleat (C18:1n-9c) dengan nilai 26,85% (b/b) ikan gindara dan 23,02% (b/b) ikan gindara kulit duri. Minyak ikan gindara dan gindara kulit duri mengandung asam oleat yang tinggi. Hasil pengujian aktivitas proliferasi sel splenosit menunjukkan minyak ikan gindara dan gindara kulit duri suhu ekstraksi 70℃ dapat meningkatkan proliferasi sel splenosit sehingga berpotensi sebagai imunostimulan., Gindara and thorn skin gindara are by-catch fish from tuna which can live at a depth of 200 meters below sea level. This study aims to determine the proximate value, oil yield, fatty acid profile, oxidation parameters and the potential of deep sea fish oil as an immunostimulating agent in vitro. Extraction of deep sea fish oil was carried out using the low temperature wet rendering method (40,50,60,70℃) and splenocyte cell proliferation testing with the MTT assay test. The dominant fatty acid in gindara fish and thorn skin gindara was oleic acid (C18:1n-9c) with a value of 26.85% (w/w) for gindara fish and 23.02% (w/w) for gindara thorn fish. Gindara fish oil and gindara thorn skin contained high oleic acid. The results of testing the proliferative activity of splenocyte cells showed that gindara fish oil and gindara spines at an extraction temperature of 70℃ could increase splenocyte cell proliferation thus that they had the potential as immunostimulants.
Keyword: asam lemak, ikan laut dalam, imunostimulan

Judul: Bifurkasi Hopf pada Model Siklus Bisnis Kaldor Kalecki tanpa dan dengan Waktu Tunda
Abstrak: Business cycle model is one of dynamical system models in economic. One of the business cycles model is Kaldor-Kalecki model. Kaldor-Kalecki business cycle model that is written in delayed defferential equations, is a business cycle model that involves gross product and capital stock of a company. In this paper Kaldor-Kalecki business cycle model is analyzed using both nondelay and delay in time of capital stock. By Taylor expansion for the time delayed model, an analysis of stability around the fixed points has been done. Furthermore, by using Hopf bifurcation theorem, it can be shown that there exists periodic orbits and limit cycle. In the nondelayed model, changing the parameter of goods market could lead to the occurrence of Hopf bifurcation and the existence of limit cycle. Similarly, for the delayed model, it has been shown that changing the time delay parameter may result in the occurrence of Hopf bifurcation and limit cycle.
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