Judul: Pengaruh Serangan Kutulilin Pinus (Pineus boerneri) Terhadap Kualitas Getah Tusam (Pinus merkusii Jungh, at de Vriese)
Abstrak: Pine (Pinus merkusii Jungh, at de Vriese) is one type of Indonesia native plant which grows fast and produces lumber and resin. Pine wood is a type of trade timber in Indonesia and its latex can be processed as rosin and turpentine. Since 1997, in Indonesia P. merkusii has been attacked by Pineus boerneri (Pine Woolly Adelgide) which can cause damage and even death of the plant. This research has purpose to know the effect of P. boerneri on the quality of P. merkusii latex. The sample trees were determined by purposive sampling and with five replications for each attack criterion (no attack, mild, moderate and severe). The latex was obtained by tapping directly with “Koakan” method. The harvesting of latex every three days for three times the collection. The parameters observed are color, water content, dirt level, acid number and base number of the latex. The result of this research shows that the Pine Woolly Adelgide attacks can affect the color, dirt level, water content, acid number and base number of the latex. The mild, moderate and severe attack levels of Pine Woolly Adelgide can make the dirt level of the latex become higher than normal one, while the color, moisture content, acid number and base number of the latex are only affected by moderate and severe attacks of Pine Woolly Adelgide.
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Judul: Distribution of attack by wooly adelgid (Pinus boerneri) on pine stand (Pinus merkusii) (Case study in KPH Sumedang, Perum Perhutani Unit III, West Java and Banten)
Abstrak: Pine tree is known as one of the Indonesian commercial timber. Timber produced by pine tree has clear yellowish white color, which make it very attractive to be used for various furniture, house building, floor, furniture and various other products. Pine trees which are abundantly planted as plantation forest have some risk to be attacked by pest and disease. Monoculture condition of plantation forest which tends to be homogeneous, increases the tendency of attack by pest and diseases. At present, there is found pest species of the order Hemiptera which is known by the term wooly adelgid (Pineus boerneri). Pest wooly adelgid which attacks P. merkusii in Indonesia constitutes a new pest which was originated from outside Indonesia (exotic) and at present has not been found in other kinds of pine trees. Knowledge on distribution and condition of attack by wooly adelgid in pine stand is needed to determine the natural control action through environmental modification to create environment which is unfavorable for the wooly adelgid pest.
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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