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: eanekaragaman Fungi Mikoriza Arbuskula (FMA) di bawah Tegakan Tanaman Jabon (Anthocephalus cadamba Miq.) di Pemalang Jawa Tengah
Abstrak: Mycorrhiza is a form of symbiosis mutualism between fungi and the roots of plants. Arbuscular mycorrhizal fungi (AMF) has some functions, one of them is increasing nutrients absorption, especially P. The sample of root and soil used in this research taken from a stand of jabon plants in Pemalang, at the coastal and mountainous area. Observation colonization on plant roots carried out through staining roots and isolation of spores from soil samples is done by using the wet sieving and decanting method. Spores were identified by looking at the spores reaction after etched with a Melzer solution. The result of the research show that the biggest average of root colonization, is found at PML 2.2 is 73.33%. Where as the lowest average of root colonization is found at PML 2.5, is 46.89. In this research is found 3 type of Genus that is Glomus, Acaulospora and Scutellospora. Glomus is the most dominant and are found in all location. The highest density of spores population is at PNK 1. The growth of plants in a coastal area better than a mountainous region.
Keyword: spore density, diversity, colonization, 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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