Judul: Bioprospecting of kerangas forest: analysis of Nepenthes gracilis Korth. as conservation stimuli
Abstrak: The heath forest or locally known as kerangas forest is a forest type that grows in site with limiting site factors, epecially the extremely unfavourable soil type for plants. There is an urgent call to conserve the kerangas forest due to it’s vulnerability and sound strategy needs to be well designed by utilizing its values and various functions and importances. Maintenance of functional biodiversity of kerangas forests and its sustainable utilization through biodiversity prospecting (bioprospecting) approach are two key factors that could be considered in the conservation efforts of kerangas forest. With this regard, Nepenthes gracilis as indicator species is well known for its uses such as ornamental plants, medicinal plants and could be used to stimulate the conservation actions. Therefore, a comprehensive research utilizing N.gracilis as conservation stimuli was conducted with objectives to : i) gain data and information on bio-prospecting N.gracilis and kerangas forest, ii) determine the potentials uses of N.gracilis and kerangas forest, iii) identify the enviromental settings of kerangas forest and N.gracilis d iv) determine the spatial genetic variation of N.gracilis, v) to determine the bio-active compounds of N.gracilis, and vi) identify the conservation attitude of community toward N.gracilis. Research methods used a combination of ecological and socio-economic surveys followoing standard procedures and laboratory works for genetic analysis,phytocehmistry analysis, and bioactivity analysis. In general, kerangas forests in the research sites are degraded under unmanaged condition. Therefore, composition and structure of the forests were significantly different in comparison to the reference forest sites. In particular, N.gracilis is found in open sites with following characteristics such as pH= ± 4,12, peat thickness= ± 5,6 cm, light intensity above ground= 270-300 lux, and the roots usually covered by seedling and sapling. Ecosystem services of kerangas forest were described by the following benefecial function, such as buffer area for water and buffering extreme weather impact, carbon sink and source, preference habitat for biological components above and below ground, sources of woods, food and medicinal plant. Functional of N.gracilis in relation to environment could be explained by capacity of plant to overcame limited water and nutrient (functional for physic-chemical environment). Existing symbiosis of x N.gracilis and other organisms reflected N.gracilis benefecial for bio-ecological environment of kerangas forest. Utilizing of N.gracilis as a medicine was also benefecial with respects to socio-economical dynamics of human dimension.It was found that plant diversity of kerangas were as sources for medicinal plants. 92,31% of kerangas plants (35 species from 39 species founded) were utilized as raw material for medicies for communities living around kerangas forest area. Genetic diversity of N.gracilis inside population and inter population are relatively high (He=0,25), indicating N.gracilis reproduction strategies. Many part of N.gracilis can be used for medicinal material based on information of phytochemistry and toxicities tests. The methanol extract of N.gracilis roots had highest toxicities (LC 50=151.53 ppm) than other parts of plant. The methanol extract from roots, stems, leaves, pockets and closed pocket liquid of N.gracilis effectively inhibited S.aures at concentration 62,5 ppm, 125 ppm, 125 ppm, 2000 ppm, 3000 ppm, respectively; while E.coli were inhibited at concentration 15.6 ppm,125 ppm, >2000
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Judul: Karakteristik Populasi Dan Potensi Bioprospeksi Keruing Gunung (Dipterocarpus Retusus Bl.) Di Taman Nasional Gunung Rinjani, Provinsi Ntb.
Abstrak: Taman Nasional Gunung Rinjani (TNGR) memiliki flora bernilai ekonomi tinggi, yaitu keruing gunung (Dipterocarpus retusus Bl.). Keruing gunung merupakan tumbuhan dengan habitus pohon yang berasal dari famili Dipterocarpaceae. Masyarakat sekitar hutan TNGR belum memanfaatkan potensi tumbuhan tersebut kecuali sebagai bahan bangunan dan kayu bakar. Penelitian ini bertujuan menganalisis vegetasi berupa semai, pancang, tiang, dan pohon. Selain itu, menguji ekstrak yang paling aktif sebagai antibakteri dan menguji kandungan kelompok metabolit sekunder pada ekstrak teraktif tersebut. Keruing gunung memiliki potensi sebagai obat. Oleh karena itu, diperlukan upaya untuk melindunginya dari kepunahan. Salah satu kriteria untuk menentukan prioritas dalam melindungi suatu spesies adalah dengan menentukan struktur vegetasi Keruing gunung. Parameter ekologi keruing gunung diamati dan diukur dengan menggunakan petak tunggal ukuran 100 m x 100 m (1 ha) sebanyak 25 plot pengamatan. Setiap plot berbentuk persegi dengan ukuran 20 m x 20 m. Berdasarkan pengamatan dan perhitungan bahwa keruing gunung memiliki 5.000 individu semai, 3.728 individu pancang, 88 individu tiang dan 60 individu pohon. Sampel berupa kulit batang dan daun yang diekstraksi dengan pelarut yang berbeda tingkat kepolarannya (etanol, etil asetat, n-heksana dan kloroform). Ekstrak kloroform pada daun dan ekstrak etil asetat pada kulit paling aktif dalam menghambat bakteri Staphylococcus aureus. Kedua ekstrak teraktif tersebut memiliki nilai daya hambat, yaitu ekstrakfraksi kloroform daunsebesar 17,5 mm dan ekstrak etil asetat kulitsebesar 17 mm. Nilai konsentrasi kedua ekstrak tersebut sama, yaitu 20.000 ppm.
Keyword: Konservasi, Bioprospeksi, TNGR, Dipterocarpus retusus Bl

Judul: Hamiltonian formulation for linear waves motion in two layers fluid
Abstrak: The surface wave could be considered as a wave that separates two fluids, namely water and air. Based on this assumption, it is introduced the interfacial wave, a wave between two layers of fluid with different density. The formulation of interfacial waves motion begins with deriving the base equation of irrotational ideal fluid. Furthermore, according to irrotational fluid assumption, the base equation can be stated in velocity potential. In this derivation, the fluids domain is assumed to be restricted by rigid lid boundary conditions, both at the upper and lower limit. Therefore, the interfacial waves motion can be explained in a hamiltonian formulation. In the hamiltonian formulation, total energy is defined as the sum of kinetic and potential energy. The hamiltonian system is obtained from reduction of kinetic energy by using the Dirichlet Neumann Operator. The resulted kinetic energy equation is nonlinear. Therefore, this form is linearized by first part of the Taylor expansion. This linearization gives a dispersion relation of linear wave. Based on this dispersion relation, the phase speed of the linear wave depends on the density ratio of the two layers fluid.
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