Judul: Microbe Isolation of Kaligesing Goat Rumen and It’s Inoculation effect to Goat Rumen on digestibility of Calliandra (Calliandra calothyrsus)
Abstrak: Research on the Isolation of tannin-digesting bacteria from the Kaligesing goat rumen and test its ability to digest tannin has been done. Isolates were obtained and then inoculated in the rumen systems goat who never consume calliandra. The study was conducted from February 1997 until September 1998. The study was conducted in four stages of research. First study, evaluating the potential of microbes in the rumen fluid of Kaligesing goats on digestibility of calliandra in vitro. A second study, bacteria isolated from Kaligesing goat rumen. A third study, evaluating the isolates in digesting tannin. The fourth study, inoculation of isolates into the rumen systems goat who never consume calliandra on digestibility calliandra in vitro. The first research results indicate that the microbes in the Kaligesing rumen goat capable of significantly better microbes digest calliandra of rumen fluid from calliandra adapted goats and goats who do not eat calliandra. The result of the second study yielded four isolates notated IK1, IK2, IK3, and IK4. The IK1 isolate die during the storage process. The third study results showed that all three isolates are able to digest condensed tannins in defined culture media. The fourth study showed that inoculation of goat rumen isolates in the system who never consume caliandra not meet expectations can enhance significantly on digestibility caliandra in vitro.
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Judul: Efektivitas Isolat Bakteri Rumen Kerbau Pencerna Serat dalam Fermentasi Hijauan Leguminosa dan Pemanfaatan Urea in vitro
Abstrak: Ruminants have ability to digest fiber component of feed due to the presence of cellulolitic bacteria in their rumen that secrete cellulase. Other bacteria have capability to digest protein by secreting protease and utilize non protein nitrogen. Fiber-digesting bacteria isolated from rumen of buffalo have not been confirmed in their ability to digest protein rich feed and utilize protein. This study aimed to evaluate the ability of fiber-digesting bacteria isolates in digesting leguminous herbage, degrading protein and utilizing non protein nitrogen. The first study was to compare the fermentability and coeficient digestibility of Calliandra callotyrsus, Leucaena leucocephala, Indigofera sp. and Gliricidia sepium by using bacteria in fresh rumen fluid and fiber-digesting bacteria isolates. The second study aimed to evaluate the ability of buffalo rumen bacterial isolates in the use of urea. Corn and cassava waste were used as carbohydrate sources with addition of urea as non protein nitrogen at level of 3%, 4,5%, and 6%. The first study showed that source of bacteria had no different effect on VFA concentration, and the coeficient digestibility of dry and organic matter of the herbage. The NH3 levels in the treatment of bacterial isolates was higher than that of fresh rumen fluid (P <0.05). The buffalo rumen bacterial isolates have the ability to degrade proteins and also showed that Indigofera sp., and Gliricidia sepium protein more susceptible to degradation than other legumes. The levels of NH3 in fermentaion media of feed added urea to 6% was in normal level. It was concluded that fiber-digesting rumen bacteria isolates were able to digest leguminous herbage and utilize the protein component of legume and capable of utilizing urea up to 6% in starchy feed.
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Judul: Solusi Numerik Persamaan Black-Scholes Kasus Opsi Jual Eropa dan Amerika dengan Fluktuasi Saham Berlintasan Brownian
Abstrak: Opsi merupakan instrumen keuangan turunan dari aset yang mendasarinya. Opsi jual memberikan hak bukan kewajiban kepada pemegang opsi untuk menjual sejumlah tertentu dari sebuah aset yang menjadi dasar kontrak tersebut. Opsi tipe Amerika memberikan kesempatan kepada pemegang opsi untuk mengeksekusi haknya setiap saat hingga waktu jatuh tempo. Sedangkan opsi tipe Eropa hanya memberikan kesempatan kepada pemegang opsi untuk mengeksekusi haknya pada saat waktu jatuh tempo. Model yang digunakan untuk menentukan harga opsi jual tipe Eropa dan Amerika adalah model Black-Scholes. Selanjutnya, model pergerakan saham dimodelkan menggunakan random generator di Matlab untuk menghasilkan lintasan Brownian pada harga saham. Model ini dapat diselesaikan dengan menggunakan metode eksplisit beda hingga.
Keyword: Black-Scholes, opsi jual, Gerak Brownian, metode eksplisit beda hingga