Judul: Efficacy of pelawan leaf infusion (Tristaniopsis merguensis) as  an antidiarrheal in mice (Mus musculus)
Abstrak: Pelawan merah (Tristaniopsis merguensis) merupakan tanaman yang banyak ditemukan di pulau Bangka. Bagian dari tanaman pelawan seperti akar, batang, daunnya banyak dimanfaatkan oleh masyarakat secara turun-temurun sebagai bahan obat untuk berbagai penyakit, salah satunya adalah diare. Daun pelawan merah mengandung metabolit sekunder seperti alkaloid, tanin, dan saponin yang dikenal sebagai zat aktif yang berkhasiat sebagai antidiare. Penelitian ini bertujuan untuk mendapatkan informasi dan data ilmiah mengenai efektivitas antidiare dari infusa daun pelawan merah (Tristaniopsis merguensis) dengan menggunakan metode proteksi intestinal dan transit intestinal. Penelitian ini juga dilakukan untuk menentukan konsentrasi efektif yang memberikan efek antidiare terbaik pada mencit. Penelitian ini menggunakan 25 ekor mencit yang dibagi menjadi lima kelompok yaitu kontrol negatif, kontrol positif, dan tiga kelompok perlakuan yang diberi infusa daun pelawan merah dengan konsentrasi 50%, 75%, dan 100% secara oral. Parameter yang diamati pada metode proteksi intestinal yaitu frekuensi dan konsistensi feses. Parameter yang diamati pada metode transit intestinal yaitu rasio panjang lintasan penanda. Penelitian ini menunjukkan kelompok perlakuan konsentrasi 75% dan 100% memiliki efek antidiare pada kedua metode uji. Efek antidiare terbaik ditunjukkan pada kelompok perlakuan konsentrasi 100% pada kedua metode uji., Pelawan (Tristaniopsis merguensis) is a plant that can be found in the island of Bangka. The parts of pelawan plant, such as the roots, stems, and leaves have been used by the community for generations as medicinal ingredients for various diseases, one of which is diarrhea. Pelawan leaves (Tristaniopsis merguensis) contain secondary metabolites such as steroids, saponins, quinones, and tannins which are known as active substances that are efficacious as anti-diarrhea. This study aims to obtain information and scientific data regarding the antidiarrheal effectiveness of pelawan leaf infusion using intestinal protection and intestinal transit methods. This research was also conducted to determine the effective concentration that give the best anti-diarrheal effect in mice. This study used 25 mice which were divided into five groups: negative control, positive control, and three treatment groups which were given pelawan leaf infusion with concentrations of 50%, 75%, and 100% orally. The observed parameters in the intestinal protection method were the frequency and consistency of the stool. The parameter observed in the intestinal transit method was the ratio of the marker path length. This study showed that the treatment group with a concentration of 75% and 100% have an antidiarrheal effect in both test methods. The best antidiarrheal effect was shown by100% concentration treatment group in both test methods.
Keyword: anti-diarrhea, pelawan, infusion, herbal

Judul: Effectiveness of Combined Leaf Decoction of Keji Beling (Strobilanthes crispa (L.) Blume) and Kentutan (Paederia foetida) Plants as Antidiarrheals in Mice
Abstrak: Diare masih menjadi masalah kesehatan utama di negara berkembang. Keanekaragaman hayati yang tinggi di Indonesia, menjadi peluang penggunaan herbal sebagai salah satu solusi pengobatan diare. Herbal memiliki banyak kandungan nutrisi, mineral, dan senyawa aktif yang memiliki efek antidiare seperti tumbuhan keji beling dan kentutan. Penelitian ini bertujuan mengetahui efek dan konsentrasi terbaik antidiare dari kombinasi dekok daun keji beling dan kentutan. Kelompok perlakuan terdiri dari kelompok kontrol negatif, kelompok kontrol positif (loperamid) dan kombinasi dekok (konsentrasi 100%, 50%, 25%, dan 12,5%). Metode yang digunakan adalah proteksi dan transit intestinal pada mencit. Induksi diare menggunakan oleum ricini. Hasil penelitian menunjukkan bahwa kombinasi dekok kedua tanaman dapat menurunkan motilitas usus, mempertahankan konsistensi feses, dan memiliki nilai rasio transit intestinal yang baik. Konsentrasi 50% memiliki hasil terbaik., Diarrhea is still a major health problem in developing countries. The high biodiversity in Indonesia is an opportunity for the use of herbal plants as a solution for treating diarrhea. Herbal plants contain many nutrients, minerals, and active compounds that have anti-diarrheal effects, such as keji beling and kentutan plant. This study aims to determine the effect and the best concentration of antidiarrheals from the combination of leaf decoction of keji beling and kentutan. The group consisted of a negative control group, a positive control group (loperamide), and decoction combination (100%, 50%, 25%, and 12,5% concentrations). The method used is intestinal protection and transit in mice. Diarrhea is induced using oleum ricini. The results showed that the combination of decoction of the two plants could reduce intestinal motility, maintain stool consistency, and have a good intestinal transit ratio. The decoct concentration of 50% has the best results.
Keyword: diarrhea, keji beling, kentutan, intestinal protection, intestinal transit

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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