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: Ekstraksi Minyak Ikan dari Jeroan Ikan Air Laut serta Potensinya sebagai Imunostimulan
Abstrak: Minyak ikan diketahui memiliki kandungan omega-3 yang tinggi dan baik untuk kesehatan. Kandungan poly unsaturated fatty acids (PUFA) seperti omega-3 pada minyak ikan memiliki efek imunomodulator yang potensial. Penelitian ini bertujuan untuk mengetahui profil asam lemak serta potensi minyak ikan dari jeroan ikan air laut sebagai imunostimulan. Minyak ikan diekstraksi dari 7 jenis jeroan ikan air laut dengan metode bligh and dyer. Pengujian aktivitas imunostimulan dilakukan dengan melihat proliferasi sel splenosit mencit menggunakan metode MTT assay. Asam lemak dominan pada jeroan ikan bawal hitam, kakap merah, makarel, kembung dan selar kuning adalah asam palmitat, sedangkan asam lemak dominan pada jeroan ikan tongkol abu dan mahi-mahi adalah docosahexaenoic acid (DHA). Jeroan ikan makarel dan tongkol abu mengandung PUFA tertinggi sehingga digunakan pada pengujian aktivitas proliferasi sel splenosit. Hasil pengujian aktivitas proliferasi sel splenosit menunjukkan ekstrak kasar minyak jeroan ikan makarel dan tongkol abu dapat meningkatkan proliferasi sel splenosit sehingga berpotensi sebagai imunostimulan., Fish oil is known to have high omega-3 content and also good for health. The content of poly unsaturated fatty acids (PUFA) such as omega-3 in fish oil has a potential immunomodulatory effect. This study aims to determine the fatty acid profile and the potential of fish oil from the viscera of seawater fishes as an immunostimulant. Fish oil was extracted from 7 types of seawater fish viscera using the bligh and dyer method. Testing of immunostimulant activity was carried out by observing the proliferation of splenocyte cells of mice using the MTT assay method. The dominant fatty acid in black pomfret, red snapper, chub mackerel, indian mackerel and yellowstripe scad visceras were palmitic acid, while the dominant fatty acid in longtail tuna and dolphinfish visceras were docosahexaenoic acid (DHA). Chub mackerel and longtail tuna fish oil contained the highest PUFA, so they were used in testing the proliferative activity of splenocytes. The results of the splenocyte cell proliferation activity test showed that crude extract of chub mackerel and longtail tuna viscera fish oil increased the proliferation of splenocyte cells so that they have potential as immunostimulants.
Keyword: Immunostimulan, Minyak ikan, MTT assay, Omega-3, Splenosit

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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