Jurnal ILMU DASAR
Not a member yet
416 research outputs found
Sort by
Cytotoxicity Effect of Methanolic Extract of Buni’s Fruits (Antidesma bunius (L) Spreng) against Hela Cells
Get PDF Antidesma bunius (L) Spreng., also known as buni, has traditionally been used as hypoglycemic, anemia, siphilis and anticancer materials. Buni contains alkaloid, saponin, flavonoid and tannin. The fruit extract of buni was tested for its biological activity using BST (Brine Shrimp Lethality Test). Result showed toxic effect of methanolic extract of fruit. In the present study, the fruit was extracted with methanol and then used for cytotoxicity test based on direct counting method against HeLa cell line. By probit analysis, it is known that the IC50 of the methanolic crude extract is 3.117 μg/ml. The lack of its IC50 is caused by the cytotoxic compound that is less extracted and there are many other compounds are extracted by methano
Tetraoksigenasi Santon dari Kulit Batang Garcinia nigrolineata Tetraoxygenated Xanthone from The Stem Bark of Garcinia nigrolineata
Get PDFA tetraoxygenated xanthone, 1,7-dihidroxy-3-methoxy-4-(3methylbut-2-enyl),6’,6’ –dimethylpyrano (2’ , 3’ : 5, 6) xanthone had been isolated from the ethyl acetate extract of the stem bark of Garcinia nigrolineata Planch Ex T. Anders. The structure of these compounds were determined on the basis of spectroscopic NMR 1D and 2D
Effectiveness of Added L-Ascorbyl Palmitate Antioxidant Synthezed Enzymatically in Coconut Oil
Get PDFL-ascorbyl palmitate (AsA-Pal-Enz) was synthesized by using the immobilized lipase from Aspergillus niger. The antioxidative activity of AsA-Pal-Enz was investigated in coconut oil at different temperatures within a range of 30(RT)-120oC. The effectiveness of AsA-Pal-Enz in coconut oil was monitored by the rate of formation of hydroperoxides, conjugated dienes (K232) and decomposition of hydroperoxides (K270). Samples in storage experiments were periodically removed and analyzed for peroxide value, K232, K270 and radical scavenging activity (DPPHr). Application of AsA-Pal-Enz have markedly reduced the rate of peroxidation in coconut oil during incubation time at RT, 60 and 80oC but at 120oC the rate of peroxidation slightly increased. It has shown that the effectiveness of AsA-Pal-Enz antioxidant in coconut oil was strongly depend on temperature and the time of incubation
‘Propolis’ Protective Effect to Prevent Oxidative Stress Caused by Strenous Physical Activity (Swimming Stress)
Get PDFStrenous physical activity may give not only a possitive impact but also the negative one. One of the factors that produce negative impact is the increasing formation of oxydant that may cause tissues’ damages. In this kind of circumstances, the oxydant could make damages to the various components in the body, it calls oxydative stress. The effect of the oxydant to the unsaturated fatty acid cause a chain reaction that will break the fatty acid to become different kinds of substances, such as malondialdehid (MDA). The MDA produced then released into the circulatory system, made the serum level of MDA increasing. The influence of propolis as antioxidant may be prevent this problem. This study is a laboratory experiment using posttest-only control group design. The samples of the experiment are 3-month male white rat with average weight between 180-220 grams. These samples are divided to three groups: (1) control group (2) exposure group that have to do strenous activity (30 days swimming stress) and (3) exposure group that have to do strenous activity (30 days swimming stress) and given propolis, each group consists of eight rats. The result of the study showed a higher average serum MDA level in exposure group (89.63 nmol/mL) than the control group (42.38 nmol/ml) significantly (p = 0.000). The influence of propolis could prevent oxidative stress wich was indicated by lower average serum MDA level (32.35 nmol/ml) significanly (p = 0.000)
Estimating Parameters of Logit Model on Multivariate Binary Response Using Mle and Gee
Get PDFIn this paper, we discuss binary multivariate response modeling based on extreme value distribution. Independent variables used in these models are some attributes of the alternative (labeled Zijt) and some attributes of the decision maker (labeled Xi). We assumed that n the decision maker observed with T response. Yit is tnd response variables from decision maker i and value Yit is binary. Response of decision maker i can be expressed as Yi = (Yi1,...,YiT). In each of the decision maker, we have data (Yi, Xi, Zi). Models are derived by the assumption that maximum random utility which the decision maker i choose one of the alternatives having greatest utility. Methods of parameter estimation are Maximum Likelihood Estimator (MLE) method and Generalized Estimating Equation (GEE). First discussion in this study is the estimation by MLE with independent assumption among response and then the MLE estimation using joint distribution by Bahadur’s representation. By MLE and GEE, estimating equations are obtained and solved by numerical (like’s Newthon-Rahpson method) in the condition that not all of the parameters of individual attributes can be estimated (identified). Based on testing simulation data with R.2.5.0, we recommend (a) in low correlation, GEE is better than MLE (b) in moderate correlation, MLE is most efficient but not stable (c) in high or moderate correlation, MLE and GEE should be used (d) correlation estimators cannot explain the real correlation because of its bias
Embedding K2,3,m Graphs on Torus
No full text This script aim to determine the maximal value of m of K2,3,m graph so that can be redrawn on torus without intersection of edges. Hereinafter, will be determined the toroidal crossing number of  K2,3,m which nontoroidal by the m minimize. To determined if the K2,3,m graph is toroidal, it is enough with drawn the graph on torus without intersection of edges, whereas, to determined if it is nontoroidal, besides with drawn, is also needed by theorem about properties of graph that containing K5-subdivision. Then to determined the toroidal crossing number was used the technique by proof of the crossing number of  K2,2,3 and looked for of all probabilities of the edges is going to intersect. In this research, was obtained the result that maximal value of m of  K2,3,m so that can be drawn on torus without intersection of edges is 3, while the toroidal crossing number of  K2,3,4 is 2, and our conjecture is tcr()
Characterization of Crude Protease Bacillus sp 31
Get PDFBacillus sp 31 was bacteria which produce protease. Characterization of protease from Bacillus sp 31 i.e. pH, temperature, influence of metal ion, enzyme kinetic and enzyme termostability is important to get optimal enzyme activity. Protease activity showed values 146.40 U/ml on pH 9 and optimal temperature 60°C by value. Protease activity increased by addition of 159.50 U/ml Fe2+, but its activity decreased by addition of Mg2+, Cu2+, Ca2+, Al2+, Zn2+ dan Mn2+. Maximal velocity (Vmax) of enzyme-catalysed reactions was 21.32 U/ml with Km 1.5x10-3 mg/ml (Michaels-Menten Kinetic). Protease was very stable at 60°C for 4 hours of incubation and 7 hours of half-time
Several Compounds Isolated from Stem Bark of Kedoya (Dysoxylum gaudichaudianum (A. Juss.) Miq.) (Meliaceae)
Get PDFSeveral compounds, p-hydroxyacetophenone, b-sitosterol and stigmasterol had been isolated from hexane and chloroform extracts of stem bark of kedoya (Dysoxylum gaudichaudianum (A. Juss.) Miq.) (Meliaceae) respectively. These structures had been established based on spectroscopic data (IR and NMR) and by comparison with spectroscopic data of related compounds that had been reported
New Procedures for Model Selection in Feedforward Neural Networks for Time Series Forecasting
Get PDFThe aim of this paper is to propose two new procedures for model selection in Neural Networks (NN) for time series forecasting. Firstly, we focused on the derivation of the asymptotic properties and asymptotic normality of NN parameters estimator. Then, we developed the model building strategies based on statistical concepts particularly statistics test based on the Wald test and the inference of R2 incremental. In this paper, we employ these new procedures in two main approaches for model building in NN, i.e. fully bottom-up or forward scheme by using the inference of R2 incremental, and the combination between forward (by using the inference of R2 incremental) and top-down or backward (by implementing Wald test). Bottom-up approach starts with an empty model, whereas top-down approach begins with a large NN model. We used simulation data as a case study. The results showed that a combination between statistical inference of R2 incremental and Wald test was an effective procedure for model selection in NN for time series forecasting
Status Analysis of Flora from â€Cagar Alam – Pulau Sempuâ€, Malang
Get PDFThe Natural reserve of Sempu Island is one of protected areas in East Java. There are many endemic flora and fauna of Tropical Rain Forest. However, there is a rumor that the government will use this protected area as a County Jail. Based on this condition, it is important to investigate specifically the flora status of Sempu Island. The result can be used to give a lot of information about the endemic, existence, list of endangered, uniqueness, and also qualification values of the flora of Sempu Island as Biodiversity Species Richness of East Java and Indonesia. The plotting method of 1×1m2 , 5×5m2, and 10×10m2 were used to get the sample data of herbs, shrubs, and trees. The plots were placed systematically along transects. The result shows that 54.54% qualification values among the fifty five flora of Sempu Island were unique, 32.73% were very unique, and the rest were enough. Meaning, most of the flora was species that have high endangered and endemicness levels. Based on the IUCN (International Union for Conservation of Nature and Natural Resources) procedure conservation, therefore entire flora must be protected and conserved. Furthermore, the reserved island could not be converted as a County Jail.Â