Judul: Ekstrak Kulit Bawang Merah (Allium ascalonicum) sebagai Antibakteri untuk Pengobatan Udang Vaname yang Diinfeksi Vibrio parahaemolyticus
Abstrak: Penanganan penyakit pada budidaya udang menggunakan antibiotik dapat memicu sifat resistensi pada patogen. Alternatif upaya penanganan penyakit pada udang vaname (Litopenaeus vannamei) akibat patogenitas bakteri Vibrio parahaemolyticus dapat dilakukan dengan cara pengobatan menggunakan bahan fitobiotik seperti kulit bawang merah (Allium ascalonicum). Tujuan penelitian ini adalah untuk mendapatkan dosis efektif dari ekstrak kulit bawang merah sebagai upaya pengobatan pada udang vaname yang diinfeksi V. parahaemolyticus. Udang vaname yang digunakan memiliki bobot rata-rata 3,41±0,73 g/ekor dan dipelihara selama 14 hari. Perlakuan ini terdiri dari lima perlakuan dengan tiga ulangan yang meliputi kontrol negatif (K-), kontrol positif (K+), dosis pengobatan metode dipping ekstrak kulit bawang merah sebesar 6,25%, 12,5% dan 25%. Pengobatan metode dipping ekstrak kulit bawang merah 6,25% menunjukkan gambaran darah dan kelangsungan hidup lebih baik serta mampu menekan bakteri V. parahaemolyticus di dalam tubuh udang vaname. Kata kunci: ekstrak kulit bawang merah, udang vaname, Vibrio parahaemolyticus, Handling diseases in shrimp culture using antibiotic can trigger resistance to pathogens. Alternative effort to treat disease in white shrimp (Litopenaeus vannamei) due to the pathogenicity of Vibrio parahaemolyticus bacteria can through of treatment using phytobiotic ingredients such as onion skin (Allium ascalonicum). The purpose of this study aimed to examine an effective dose of onion skin extract as treatment for vaname shrimp infected with V. parahaemolyticus. The vaname shrimp used had an initial weight of 3,41±0,73 g/shrimp and was reared for 14 days. This treatment consisted of five treatments with three replications which included negative control (K-), positive control (K+), onion skin extract dipping doses of 6,25%, 12,5% and 25%. Treatment with the dipping method dose of 6,25% shallot skin extract showed a better properties from haematology and survival rate as well as able to suppress V. parahaemolyticus bacteria in the vannamei shrimp body. Keywords: onion skin extract, vaname shrimp, Vibrio parahaemolyticus
Keyword: onion skin extract, vaname shrimp, Vibrio parahaemolyticus, ekstrak kulit bawang merah, udang vaname

Judul: Immunostimulating Effect of Oral Banana Stem Powder on Vaname Shrimp Litopenaeus vannamei for Prevention of Vibrio parahaemolyticus Infection
Abstrak: Udang vaname (Litopenaeus vannamei) merupakan salah satu komoditas unggulan yang dibudidayakan secara intensif dan memiliki peluang terserang penyakit. Pengendalian penyakit yang efektif, efisien dan ramah lingkungan adalah dengan fitofarmaka, salah satunya batang pisang. Penelitian ini bertujuan untuk membuktikan efektivitas penambahan serbuk batang pisang melalui pakan sebagai imunostimulan untuk pengendalian infeksi bakteri V. parahaemolyticus pada udang vaname. Penelitian dilakukan menggunakan rancangan acak lengkap yang terdiri atas lima perlakuan dengan masing-masing empat ulangan meliputi perlakuan K+: pemeliharaan udang tanpa serbuk batang pisang dan diuji tantang K-: pemeliharaan udang tanpa serbuk batang pisang dan tanpa uji tantang, P0,5: pemeliharaan udang dengan serbuk batang pisang 0,5 g kg-1 pakan dan diuji tantang, P0,6: pemeliharaan udang dengan serbuk batang pisang 0,6 g kg-1 pakan dan diuji tantang. P0,75: pemeliharaan udang dengan serbuk batang pisang 0,75 g kg-1 pakan dan diuji tantang. Dosis uji tantang V. parahaemolyticus yaitu 107 CFU mL-1. Udang dengan bobot 1,7±0,17 g dipelihara selama 30 hari, kemudian diuji tantang pada hari ke 31 dan dipelihara sampai hari ke 44. Hasil penelitian menunjukkan pemberian serbuk batang pisang 0,75 g kg-1 melalui pakan dengan durasi pemberian 30 hari mampu meningkatkan respons imun udang vaname sebagai pencegahan infeksi V. parahaemolyticus., Whiteleg shrimp (Litopenaeus vannamei) is one of the superior commodities that is cultivated intensively, with a risk of disease. Effective, efficient, and environmentally friendly disease control utilises phytopharmaceuticals, one of which is banana stems. This research aims to investigate the impact of adding 0.75% banana stem powder to feed as an immunostimulant to control bacterial infection of V. parahaemolyticus on whiteleg shrimp. The research was carried out using a completely randomized design consisting of five treatments with four replications each including treatment K+: shrimp reared without banana stem powder and challenged with V. parahaemolyticus, K-: shrimp reared without banana stem powder and without challenge test, P0,5: shrimp reared with 0,5 g kg-1 of banana stem powder as feed and challenged with V. parahaemolyticus, P0,6: shrimp reared with 0,6 g kg-1 of banana stem powder as feed and challenged with V. parahaemolyticus, P0,75: shrimp reared with 0,75 g kg-1 of banana stem powder as feed and challenged with V. parahaemolyticus. Challenge dose of V. parahaemolyticus is 107 CFU mL-1. Shrimp weighing 1.7 ± 0.17 g were reared for 30 days, then challenged on the 31 day and kept until the 44 day. The results of the study showed that administering 0,75 g kg-1 banana stem powder through feed with a duration of 30 days was able to increase the immune response of whiteleg shrimp as a prevention of V. parahaemolyticus.
Keyword: udang vaname, Vibrio parahaemolyticus, imunostimulan, respons imun, serbuk batang pisang, Vibrio parahaemolyticus, banana stem powder, immune response, immunostimulant, whiteleg shrimp

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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