Judul: Adaptation and tolerance of rice genotypes to phosphorus deficiency in paddy soil
Abstrak: Javanese Tree Frog (R. margaritifer 1837) is an endemic frog of Java Island. Population of this species is threatened due to human activity and the pathogenic fungus Batrachochytrium dendrobatidis (Bd). Therefor sterilization of Bd is needed as the first effort to protect of R. margaritifer outside their natural habitats. The research aims to assess: 1) frog behaviour after and before sterilization treatment; 2) best temperature for sterilization by heat treatment for Bd on frogs vitality; and 3) behaviour of frog’s adaptation in terrarium after sterilization. Research were conducted in Indonesian Safari Park I Cisarua, West Java includes specimen’s collection in Curug Jaksa and Rumah Dua. Sterilization were carried out using two methods, i.e (I) aquarium heater with hot steam and (II) aquarium heater with dry heat temperature. A total of 12 frogs were sterilized with 3 different temperature treatment for each heater. Ad libitum sampling methods was used in the observation of the behaviour of adaptation during captivity. In general the condition of frog captured for experiment and moved to temporary terrarium were good, in which most of them were active. All of frogs were resting before sterilization. The most effective sterilization temperature for R. margaritifer is 37˚C for 4 hours. Terrarium provided by Indonesian Safari Park were not sufficient for its movement as shown with the injured in snout part of frogs. There is only a small differences of temperature between natural habitats and terrarium which is not affecting R. margaritifer activity. Frogs were active in the evening from 18.00–23.00. During the daytime, frogs use different kind of a substrate to rest such as terrarium glass, hanjuang leafes, rocks, and fluorescent bulb. Overall, hanjuang leafes and terrarium glass was the most widely used by frogs to 23%. During 30 day period of captivity, in view from the number of feed consumption and unstable changes of body weight, frogs haven’t been able to adapt properly. Behaviour of R. margaritifer before and after sterilization suggesting that sterilization had not caused negative effect to R. margaritifer behaviour. The survival of frogs in captivity was 100% since no mortality were observed after sterilization.
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Judul: Peluang Hidup Telur dan Berudu Katak Pohon Jawa Rhacophorus margaritifer Schlegel 1837 di Taman Nasional Gunung Gede-Pangrango Provinsi Jawa Barat
Abstrak: Javan tree frog (Rhacophorus margaritifer) is an endemic species found in Java Island. The presence of javan tree frog habitat is threatened by the destruction of its habitats because of human activities such as forest encroachment and illegal felling of trees. This frog species is threatened not only during adults but also during tadpole phase. High chances of survival from tadpoles into frogs will sustain the existence of this species in its habitats. The purpose of this study was to see the percentage of eggs survived in natural habitats and the survivalof R. margaritifer tadpoles in translocation habitat to reach metamorphosis. Additional purpose is also to analyze the microhabiotat of of R. margaritifer eggs and tadpoles in Mount Gede-Pangrango National Park (MGPNP). Eggs and tadpoles data in natural habitats was collected from Cibeureum area. Translocation of tadpoles were carried out in Ciwalen and Cibodas in the Mount Gede- Pangrango National Park. Data collected includes number of successful and failed eggs hatched into tadpoles, the percentage of tadpole that survive in each stage of metamorphosis , habitat characteristics (water temperature, water quality, air temperature, substrate), and the total area of habitat and density of tadpoles in its natural habitat. The percentage of R. margaritifer eggs becoming tadpoles was high in their natural habitat, however in two occasions the survival was nil since all eggs decayed and failed to become tadpoles due to extreme temperature conditions. Based on observation, the survival probability of R. margaritifer tadpoles in age class I (st 25) to age class II (st 26-30) was only by 0.4 and continued to decline in subsequent age classes in following orders 0.26 (stage 31-40), 0.2 (stage 41-45) and 0.18 (stage 46). This indicated that tadpoles in its early growth phase are susceptible to death. Eggs clutch of R. margaritifer in their natural habitat at the MGPNP was found on water plants such as kecubung (Brugmansia suaveolens) and babakoan (Eupatorium sordidum) which situated above the flowing river. Tadpoles usually found in temporary pool or on the banks of the river basin with main substrate of mud. The average of diameter of the pools was approximately 150 cm, with average depth of less than 20 cm. The highest density of tadpoles found in its natural habitat is in Curug III (120 ind/m3 ) and the lowest is in the Curug I pool (3 ind/m3).
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Judul: Aproksimasi Fungsi Sinus dan Kosinus sebagai Kombinasi Linear dari Fungsi Eksponensial
Abstrak: Salah satu gagasan yang menarik dalam matematika adalah aproksimasi suatu fungsi oleh fungsi lain. Sebagai contoh, fungsi polinom dapat diaproksimasi menggunakan deret Taylor atau fungsi persamaan diferensial dapat diaproksimasi menggunakan deret Fourier. Adapun fungsi yang dapat mengaproksimasi fungsi lain salah satunya adalah fungsi eksponensial. Kemungkinan mengaproksimasi fungsi dengan kombinasi linear dari fungsi eksponensial dari bentuk eˣ, e²ˣ, ... dianggap sebagai perkembangan sejajar dengan gagasan Deret Taylor yang mengaproksimasi fungsi dengan kombinasi linear dari segi fungsi kuadrat. Fungsi sin x dan cos x digunakan sebagai target untuk menilai seberapa baik aproksimasi yang dilakukan oleh fungsi yang diberikan. Aproksimasi fungsi sinus dan kosinus menggunakan hampiran Taylor lebih akurat dibandingkan dengan aproksimasi menggunakan fungsi eksponensial.
Keyword: Aprosimaksi eksponensial, aproksimasi fungsi, aprosimaksi Taylor, fungsi eksponensial