Judul: Konsentrasi MDA Darah, Hati, dan Telur serta Profil Darah Puyuh Petelur yang Diberi Ekstrak Gambir (Uncaria gambir Roxb).
Abstrak: Gambir mengandung katekin yang merupakan sumber antioksidan alami. Antioksidan dapat mencegah stress oksidasi yang ditunjukkan oleh persentase MDA (malondialdehida). Penelitian ini bertujuan untuk mengetahui pengaruh penambahan ekstrak gambir yang mengandung antioksidan dicampur dengan ransum terhadap kadar MDA darah, hati, dan telur serta profil darah puyuh petelur. Penelitian ini menggunakan 200 ekor puyuh yang dipelihara selama 6 minggu. Rancangan penelitian ini adalah Rancangan acak lengkap (RAL) dengan 5 perlakuan dan 4 ulangan. Peubah yang diamati adalah profil darah, serta kadar MDA di darah, hati, dan kuning telur. Data dianalisa dengan ANOVA dan uji Duncan. Perlakuan yang diberikan adalah P0= ransum kontrol, P1= ransum kontrol + 0.1% ekstrak gambir, P2 = ransum kontrol + 0.2% ekstrak gambir, P3 = ransum kontrol + 0.3% ekstrak gambir, P4 = ransum kontrol + vitachick (5gram/7liter air minum). Suplementasi ekstrak gambir sebesar 0.3% pada pakan puyuh menurunkan hemoglobin, eritrosit, dan leukosit dibanding perlakuan lain namun masih dalam taraf normal.
Keyword: Uncaria gambir Roxb, malondialdehida, profil darah, puyuh, petelur

Judul: Suplementasi Ekstrak Gambir (Uncaria gambir Roxb) dalam Air Minum Sebagai Antioksidan terhadap Kualitas dan Kandungan MDA Telur Ayam Petelur Isa-Brown.
Abstrak: Gambier extract contains a polyphenols chemical compound that act as antioxidant. This study aimed to evaluate the effect of supplementation gambier extract on the quality and MDA (malondialdehyde) content of eggs. A completely randomized design was used in this experiment. The variables observed were egg quality (egg weight, albumin percentage, yolk percentage, yolk color, egg shell percentage, egg shell color, average shell thickness, egg shape index, albumin high, and Haugh Unit) and MDA content of yolk. This study used 90 of 38 weeks old of Isa Brown layer hen reared until 43 weeks old. The treatments were R0 = kontrol water, R1 = drinking water contained gambier extract 20 mg kg-1 BB), R2 = drinking water contained gambier extract 40 mg kg-1 BB. The results showed that supplementation of gambier extract decreased MDA content of yolk. Gambier extract supplementation significantly (P<0.05) increased eggshell color score, high of albumin, and Haugh Unit. The conclusion of the study was that gambier extract increased quality of egg and potential as antioxidant for the laying hen.
Keyword: egg quality, MDA, Uncaria gambier Roxb, yolk

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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