Judul: Keanekaragaman Fungi Mikoriza Arbuskula di bawah Tegakan Jabon (Anthocephalus cadamba) di Madiun, Jawa Timur
Abstrak: Plants can grow well when it was supported by the available of soil microbes, one of them was arbuscular mycorrhyzal fungi (AMF). AMF was symbiotic mutualism that it was between fungi and roots. AMF could be symbiotic almost 90% of the high levels of plants, one of them was jabon (Anthocephalus cadamba). The research purposes to identify the diversity of AMF under the jabon stands. The methods which used in this research was the root coloring and decanthing methods. Preservation of spores to identify genus carried on by using polyvinil alcohol lactid acid glyserol (PVLG). The result of this research showed that the chemical content of soil didn’t have effect to the differences of root colonization on each research location. The various genus under jabon stands which are located in Durenan dry land and Sudimoroharjo dry land, such as Glomus, Acalauspora dan Enterospora, meanwhile Sudimoroharjo former rice fields could only be found 2 genus, such as Glomus and Acalauspora. Glomus had very wide spreading and dominate in the research location.
Keyword: jabon, genus, growth, diversity, arbuscular mycorrhizal fungi

Judul: Keanekaragaman Fungi Mikoriza Arbuskula di bawah Tegakan Tanaman Agroforestri Jabon (Anthocephalus cadamba Miq.) di Purwakarta, Jawa Barat
Abstrak: Anthocephalus cadamba is a one of tree species from Rubiaceae family that may symbiotic with arbuscular mycorrhizal fungi (AMF). The presence of AMF is very important for the soil nutrient existence, such as P, K, Mg, Fe, and also Mn to increase the growth of plants. The purpose of this research is to identify the diversity of AMF spores under stand of jabon agroforestry plants and to analyze the AMF status on various jabon planting patterns. Spores isolation was taken from soil sample using wet sieving method and decanthing method. Spores from the isolation morfologically identified by observing spores reaction through Melzer’s liquid. The result of this research indicated that soil chemical characteristic on three planting patterns of jabon do not give any concrete effects to the percentage of AMF’s root colonization. There are three genus of AMF found on the research location consist of Glomus sp., Acalauspora sp., and Scutellospora sp. Based on statistical analysis result, the jabon intercropping planting patterns which combining cucumber plants resulting the highest value of both diameter and height growth on various jabon planting patterns.
Keyword: root colonization, planting pattern, arbuscular mycorrhizal fungi

Judul: Truncated Stop Loss as a Optimal Solution of Reinsurance Agreement in One-Period Model
Abstrak: Reinsurance is one of risk management efforts of an insurance company, which is called the cedent. Similar with insurance, reinsurance constitutes the cedent to pay the premium. We consider one-period reinsurance model and derive a rule which minimizes the ruin probability of the cedent for a fixed reinsurance premium. Therefore, it is needed to construct an optimal reinsurance agreement for the cedent. The premium is calculated according to four different principles, i.e. economic, generalized zero-utility, Esscher, and mean-variance principles. Stop loss is a reinsurance contract which protect the insurance company for losses that exceed a certain amount. The result of this research shows that a truncated stop loss is an optimal agreement in the class of all reinsurance contracts with various premiums calculated using above mentioned principles.
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