Judul: Suksesi alami paska kebakaran pada hutan sekunder di Desa Fatuquero, Kecamatan Railaco, Kabupaten Ermera-Timor Leste
Abstrak: Forest is an invaluable natural resource because inside of forest there are biodiversity as germplasm source, forest product source like wood and non-wood, water system regulator, and flood and erosion preventive. Disturbance of forest resource is keep going on, even it intensity is increasing year to year. One of causal factors of forest damage is forest fire which is one of disturbances is increasingly happen. Negative impact is appear by forest fire is big enough include ecology damage, decreasing of biodiversity, reduced forest economic value and soil productivity, change of micro and global climate. This study is purposed to know dominant structure of type composition in natural succession formed post-fire in secondary forest. To get description of structure and composition of vegetation type grow in post-fire secondary forest, then it is made research plot using transect method or track with 100m track long and 20m width. To know stand type structure and composition is conducted vegetation analysis through Nested Sampling way in large plot containing smaller plots. Critical value of collecting result data in post-fire natural forest and un-burnt natural forest on secondary forest is processed and counted based on each exist type level. Index of critical value is determined through summation of relative density value, relative domination, and relative frequent in plant type. Based on research is related to post-fire natural succession in secondary forest shows during succession, structure of composition type dominate post-fire secondary forest is changing in every level of seedling, stake, pole, and tree growth. Species that tend to occupy post-fire natural forest in seedling and stake level is from Adina sp, Eucalyptus urophylla, species to occupy pole and tree level of Eucalyptus urophylla, Eucalyptus alba. In un-burnt secondary forest tend to occupy seedling and stake level is from Neolitsea sp, Macaranga sp, Vitex sp, Peperamia sp which is all these types are dominant in seedling and stake level, tree and pole level are tend to occupied Eucalyptus urophylla, Fagraea sp, Vitex sp, dan Podocarpus sp that occupy un-burnt secondary forest. Dominant type on seedling, stake, pole, and tree level is seen difference. Dominant index in both forest appear difference in seedling, stake, and pole level. This is thought that spreading of these types are carried by wind, bird, and other animals which eat seed or fruit so particular type is not appear in post-fire forest or un-burnt forest condition.
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Judul: Komposisi Vegetasi pada Lahan Bekas Terbakar di Hutan Pendidikan Gunung Walat
Abstrak: The resiliency of the ex-burnt forest area will following the forest succession stages and resulted to secondary forest. This study was conducted to identifies: (1) type and cause of forest fire on September 2012 at Hutan Pendidikan Gunung Walat (HPGW), (2) differences of the vegetation composition of stands, (3) undergrowth succession, as well as (4) differences of soil chemical properties in the ex-burnt and unburnt stands. Fire in HPGW was mainly due to the careless use of fire by local communities when they used fire to burn thatch on their land. Highest index of similarity is found on tree stage at all plots, while the most significant differences found on undergrowth stage. This may related to the vulnerability of the undergrowth to evey changes that occur, one of which is the change on soil chemical properties. Generally, the soil chemical properties at 11th month after fire is better than 6th month after fire.
Keyword: undergrowth, succession, soil chemical properties, forest fire, composition of vegetation

Judul: Optimization of Alginate-Chitosan Microcapsules Formation for Leydig Cells Encapsulation
Abstrak: Hypogonadism is a clinical condition characterized by low concentrations of testosterone. It is caused by malfunction of Leydig cells in producing testosterone. Encapsulation method will protect the transplanted cells from the immune system rejection. The aims of this study was to optimize the formation of microcapsules for Leydig cells encapsulation. The microcapsules were made of alginate and chitosan as the first and the second coating agents, respectively. The result showed that the minimum concentration of alginate was 1.5% (w/v) with a viscosity of 33.8 cPs, resulted spherical microcapsules with diameters of 230-270 µm. The optimum concentration of chitosan as the second coating agent was 0.5% (w/v), resulted spherical microcapsule with mechanical stability in 4 hours. Leydig cells can be trapped inside the capsule with a density that proportional with concentration of cells used in the encapsulation.
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