Judul: Sistem Dinamik Model Pengurangan Biomassa Hutan Akibat Penumpukan Industrialisasi
Abstrak: Forests are lungs of the earth which regulate ecological stability and it is important in cycles of oxygen (O2) and carbon dioxide (CO2). Forests give many benefits for supporting human life. The sustainability of forests for life of human are determined by consciousness of society in using them. Uncontrolled exploitations have effects for depletion of forest biomass. In this research, we present a nonlinear mathematical model, which has been analyzed to study the depletion of forest biomass. Moreover, this research also considers the implication of crowding by industrialization on forest biomass. A mathematical model is formulated to investigate the depletion of forest biomass. There are four variabels to consider, namely, the density of forest biomass (��), population of human (��), population pressure (��), and density of industrialization (��). In this research, we get four nonnegative equilibria, namely, ��1, ��2, ��3, and ��4. The equilibria ��1, ��2, and ��3 are analyzed by linierizing the system. Then, we determine the eigenvalues of the Jacobian matrix for those equilibria. The equilibrium ��4 is analyzed by use stability theory of Liapunov. The analysis of the model showed that under certain condition, ��1, ��2, and ��3 are unstable saddle point. Whereas the equilibrium ��4 is globaly asymtotically stable. The numerical simulations show that the equilibrium level of forest biomass density decrease as the equilibrium level of the human population, population pressure, and density of industrialization increase. It is lower than its original carrying capacity. Moreover, if the rate of crowding by industrialization increases, then the forest biomass density decreases. In all simulations, we conclude that if conditions of stability theorems are satisfied, then dynamics of the system always attain their corresponding equilibrium level.
Keyword: dynamical system, forest biomass, industrialization, stability

Judul: Analisis penawaran dan permintaan kayu bulat: kebijakan pengaturan bahan baku untuk industry pengolahan kayu primer
Abstrak: The role of forestry sector in national economies show a declining trend. This decrease was caused by various factors. One of them is the occurrence of an imbalance between supply and demand for logs in which there is excess demand for primary wood processing industry. Many efforts have been made such as the arrangement of primary wood processing industry and implementation of a log export ban, but has not given encouraging results yet. This research is applying a simultaneous equations model of the Indonesian timber market system that are more detailed than previous studies. On the supply side, the behavioral model of timber supply from various sources (natural forests, plantation forests and community forests) is constructed. Meanwhile, on the demand side, this research constructed demand behavior of sawntimber, plywood, and pulp industries. The model developed is intended to answer questions relating to (1) the factors that influence production of roundwood production and its derivatives, (2) forms of government policies that ensure the sustainability of the forest industry (upstream-downstream), and (3) policies that can reduce the gap of supply and demand of logs. 2SLS method was used for model parameter estimation. The results show that the decision to determine the extent of timber harvesting area in natural forest and plantation forest are influenced by previous cutting experience in addition to the demand by the industrial roundwood, roundwood prices, taxes and levies and wage rates. Roundwood production from natural and plantation forests are influenced by land productivity, while for community forest production is more affected by extensive logging. Level of demand by the industry is affected by the production of primary wood processing industry, the world price of processed wood products, and the price of logs. Efforts to accelerate the decline in the gap can be done through increased productivity of natural forests through the implementation of intensive silviculture. Other efforts that could be implemented are acceleration of development of community’s plantation forests (HTR) in production forests are not burdened with rights, implementation of compensation fee for the people who developing HTR as much as their opportunity cost if they reduce cash crops in HTR area simplify the procedure so that the community can meet the required conditions, granting access to financing credit, encouraging participants to plant perennials HTR; application of multi-system silviculture. Increased production of logs per unit area as described above is expected to increase the contribution of the forestry sector, through increased taxes and charges up to certain limits. Application of the use of efficient wood processing technology, especially in the application of new industrial units, to offset rising production costs, for example increase the wage rate.
Keyword: Forestry sector, Multi-system silviculture

Judul: Penggunaan Trypan Blue pada Evaluasi Spermatozoa Kucing Asal Cauda Epididymis dan Ductus Deferens setelah Penyimpanan pada Suhu 4OC.
Abstrak: Pada penelitian ini digunakan Trypan Blue untuk evaluasi spermatozoa kucing sebagai kontrol digunakan pewarna Eosin-Nigrosin. Evaluasi dilakukan untuk mengetahui viabilitas dan abnormalitas spermatozoa yang dikoleksi dari cauda epididymis dan ductus deferens setelah penyimpanan jaringan pada suhu 4°C. Pada penelitian ini digunakan jaringan epididyrnis dan ductus deferens dari 21 ekor kucing jantan yang telah dikastrasi.
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