Judul: Effect of Injection of Karamunting Melastoma malabathricum Leaf Extract on Sperm Quality of Male Vannamei Shrimp Litopenaeus vannamei Broodstock
Abstrak: Induk udang vaname jantan dengan kualitas sperma yang optimal sangat diperlukan untuk menunjang produktivitas pasokan benih unggul. Salah satu tanaman yang berpotensi untuk meningkatkan kualitas sperma pada udang adalah karamunting (Melastoma malabathricum L.). Penelitian ini bertujuan menguji pengaruh injeksi ekstrak daun karamunting terhadap kualitas sperma induk udang vaname jantan. Induk udang vaname jantan diberi perlakuan dengan diinjeksi akuades sebagai kontrol, serta injeksi ekstrak daun karamunting dengan dosis 7,5 mg/kg bobot tubuh (DK7,5), 10 mg/kg bobot tubuh (DK10,0), dan 12,5 mg/kg bobot tubuh (DK12,5). Injeksi dilakukan setiap lima hari sekali selama 20 hari pemeliharaan. Perlakuan injeksi ekstrak daun karamunting mengalami peningkatan jumlah sel sperma relatif dibandingkan kontrol. Abnormalitas sel sperma terendah diperoleh pada perlakuan DK7,5 hari ke-20 sebesar 2,04 ± 0,93%. Persentase melaninasi pada spermatofor induk udang vaname jantan terendah diperoleh pada perlakuan DK7,5 dan DK10,0 yaitu sebesar 27% dan 20%. Injeksi ekstrak daun karamunting yang dilakukan lima hari sekali berpengaruh terhadap kualitas sperma induk udang vaname jantan. Hasil terbaik diperoleh pada dosis 7,5 mg/kg bobot tubuh setelah empat kali injeksi., Male vaname shrimp broodstock with optimal sperm quality is needed to support the productivity of superior seed supply. One of the plants that has potential to improve sperm quality in shrimp is karamunting (Melastoma malabathricum L.). This study aims to examine the effect of karamunting leaf extract injection on sperm quality of male vaname shrimp broodstock. Male vaname shrimp broodstock were treated by injecting distilled water as a control, as well as injections of karamunting leaf extract at following doses: 7,5 mg/kg body weight (DK7,5), 10 mg/kg body weight (DK10,0), and 12,5 mg/kg body weight (DK12,5). The extract was injected every five days for 20 days. Treatments injected with karamunting leaf extract increased the number of relative sperm counts compared to control. The lowest sperm cell abnormality was observed in DK7,5 treatment on day 20 at 2,04 ± 0,93%. The lowest percentage of melanized spermatophore was obtained in DK7,5 and DK10,0 treatments, at 27% and 20%, respectively. The injection of karamunting leaf extract which is done every five days affects the sperm quality of male vaname shrimp. The best results were obtained at a dose of 7,5 mg/kg body weight after four injections.
Keyword: udang vaname, karamunting, kualitas sperma

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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