Judul: Respon Pertumbuhan Anakan Shorea leprosula Miq, Shorea mecistopteryx Ridley, Shorea ovalis (Korth) Blume, dan Shorea selanica (Dc) Blume terhadap Tingkat Intensitas Cahaya Matahari
Abstrak: Meranti is one of the commercial wood that has been recognized by many countries of Southeast Asia with a variety of trade names, especially the kind of red meranti (Shorea spp.). Red Meranti, including endemic species in Indonesian including threatened extinct namely Shorea leprosula (Kalimantan), Shorea ovalis (Kalimantan) and Shorea selanica (Maluku) are entered into the IUCN Red List (Ashton 2011). The giving of shade on meranti saplings is very important in both the field and in the nursery. The giving of shade plants performed as meranti is the kind of gap opportunist in where light is a limiting factor for early growth. This research observe the growth response of red meranti saplings of Shorea leprosula, Shorea mecistopteryx, Shorea ovalis and Shorea selanica with treatment shade 0% (light intensity 100%), 20% shade (light intensity 80%), 40% shade (light intensity 60 %), 60% shade (light intensity 40%). The experiments did with two factorial completely randomized design. The results of research treatment shade showed that red meranti saplings of Shorea leprosula, Shorea mecistopteryx, Shorea ovalis, and Shorea selanica real influential. The treatment shade 60% (light intensity 40%) give the best response to the growth of Shorea leprosula, Shorea mecistopteryx, Shorea ovalis, and Shorea selanica.
Keyword: 

Judul: Respon pertumbuhan meranti merah terhadap lebar jalur tanam dan intensitas cahaya matahari dalam sistem silvikultur TPTJ (Studi kasus di areal PT. Sarpatim, Kalimantan Tengah)
Abstrak: Shorea leprosula merupakan salah satu jenis meranti merah yang termasuk kedalam spesies target dan menjadi unggulan dalam teknik silvikultur intensif (SILIN), serta memiliki prospek yang baik untuk dikembangkan dalam membangun hutan tanaman meranti di Indonesia. Penelitian ini bertujuan untuk mengetahui pertumbuhaan S. leprosula dalam sistem silvikultur TPTJ dan pengaruh lebar jalur tanam, penutupan tajuk, dan intensitas cahaya matahari terhadap pertumbuhannya. Penelitian ini dilakukan pada sistem silvikultur TPTJ yang terdapat pada plot TPTJ 2005, 2006, 2007, 2008, 2009, 2010, dan 2011. Masing-masing plot dibuat petak berukuran 100 x 100 m dan dipilih 4 jalur sebagai jalur pengamatan dan pengukuran. Data yang dikumpulkan berupa diameter dan tinggi tanaman, lebar jalur, penutupan tajuk, dan intensitas cahaya matahari. Hasil penelitian menunjukkan bahwa pertumbuhan S. leprosula yang ditanam dalam sistem silvikultur TPTJ tergolong dalam pertumbuhan yang cepat dengan rata-rata riap diameter 1,32 cm/tahun, riap tinggi 1,61 cm/tahun, dan persentase hidup 86,57%. Lebar jalur tanam berpengaruh nyata terhadap riap diameter dan tinggi tanaman pada taraf nyata 5%. Hasil regresi menunjukkan bahwa penutupan tajuk berpengaruh nyata terhadap pertumbuhan riap diameter dan tinggi tanaman S. leprosula dan intensitas cahaya matahari berpengaruh nyata terhadap pertumbuhan riap diameter. Pertumbuhan riap terbaik terdapat pada plot TPTJ 2009 dengan riap diameter 1,63 cm/tahum dan riap tinggi 1,91 m/tahun pada lebar jalur 5 m, penutupan tajuk 77,71% dan intensitas cahaya matahari 10.632 lux. Kata kunci: pertumbuhan, Shorea leprosula Miq., lebar jalur tanam, intensitas cahaya matahari, TPTJ
Keyword: Growth, Shorea leprosula Miq., width of planting line, Light intensity, TPTJ

Judul: Dynamical System of Hepatitis B in Three Groups with Vaccination
Abstrak: The aim of this study is to modify the hepatitis B transmission model in three age groups involving vaccination from the model conducted by Zhoe and Zhang.The method used is to analyze the stability of the fixed point and its basic reproduction number (R_0). Performed stability analysis and numerical simulation to see population dynamics. Next, a sensitivity analysis of the parameters was carried out to see its effect on R_0. From the analysis obtained two fixed points, namely non-endemic and endemic fixed points. Non-endemic fixed points are locally asymptotically stable if R_0 <1 Meanwhile, the endemic fixed point is locally asymptotically stable if R_0 > 1. Hepatitis vaccination affects the number of susceptible population, because the more successful the vaccination, the smaller the number of susceptible populations so that the smaller the population will be infected.
Keyword: Dynamic, Hepatitis B, Vaccine, Mathematical model