Jurnal ILMU DASAR
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The Utilization of Serratia marcescens to Increase Phosphate-Availability and Production of Cucumber in Alfisols
Full text linkSerratia marcescens is a bacterium that can dissolve phosphate (P) in soil, increasing phosphate availability and allowing plants to use it to support plant growth. P-available in the soil is generally low, including in Alfisols, due to the formation of bonds with Al, Fe, Ca, Mg, and other cations, which is influenced by soil pH or clay mineral adsorption. Cucumber plants require adequate nutrients, including P nutrients, for optimal growth and production. The study was carried out in a greenhouse using a completely randomized design (CRD) with four treatments and five replications. The treatments were S. marcescens bacterial solution concentrations of P0 (0 ml); P1 (20 ml); and P2 (20 ml); P3 (60 ml) bacterial colony density: 33x109 cfu/ml. According to the findings of the study, S. marcescens inoculation had a significant effect on increasing soil pH by 6,16, P-total concentration of 41,62 mg/100g, P-available concentration of 28,39 ppm, P-tissue concentration shoot and root were 0,30% and 0,78%, respectively, and P-root uptake of 2,27 g/pot. Similarly, S. marcescens inoculation significantly affected the plant height of 138,72 cm, root volume of 43 ml, and root length of 59,92 cm compared to the control treatment
Implementation of Discrete Time Markov Chain Method to Estimate The Transition of Smartphone Brands Usage in Balikpapan
Full text linkThe increasingly rapid competition in the industrial world today encourages all companies to be able to compete by prioritizing the products they offer, one of which is smartphones. Indonesia is one of the countries with the largest smartphone market share in Asia, with the number of active smartphone users in Indonesia reaching 177 million people in 2021 according to data released by the Statista research institute in March 2022. With these conditions, many smartphone companies always follow the direction of development of sophisticated communication technology media and offer a variety of complete and attractive facilities to encourage people to buy these products. One method that can be used to model this uncertainty is Discrete Time Markov chain which can be implemented as a tool for decision making and predicting future events. Therefore, this study was conducted to know the shifting pattern of smartphone use by consumers and predict the shift in smartphone market share for the coming period. The results of the study found that the steady state or equilibrium condition was achieved in the 10th period or in 2032 with the steady state percentage of each brand, namely Samsung = 22.49%, Oppo = 20.82 %, Xiaomi = 17.01%, Realme = 11.54%, Vivo = 11.41%, Apple = 10.27%, and other brands = 6.46%. The increase in market share is predicted to occur in the Oppo, Realme, and Vivo brands, while the decrease in market share will occur in the Apple, Samsung, Xiaomi and other brands
Construction and expression of Wee1 recombinant protein in Escherichia coli strain BL21 (DE3)
Full text linkWee1 is a gene encoding for protein kinase that is located in the nucleus and it plays an essential role in determining the timing of mitosis. Overexpression of Wee1 in rice is resulting in increased plant size. However, the increasing plant size due to the increase of Wee1 protein expression is not elucidated. Immunodiagnostic using specific antibodies against Wee1 protein should be conducted to determine the role of the protein on cell division. This experiment was directed to construct Wee1 in an expression vector for synthesis of recombinant Wee1 protein using three strategies of construction. The three strategies were construction of full length (FL), deletion of putative binding site (BS), and deletion of N-terminal domain (ΔN) of Wee1. Restriction analysis with BamH1/Sal1 of FL-Wee1, BS-Wee1, and ΔN-Wee1 construct resulted in the different DNA fragments with molecular size at 1239, 1176, and 960bp, respectively. This result indicated that the Wee1 fragments have been successfully inserted in the expression plasmid which was further confirmed using DNA sequencing. Colony PCR analysis showed that Escherichia coli strain BL21 (DE3) has been transformed with the constructs. The protein analysis using SDS-PAGE revealed that the recombinant protein of Wee1 synthesized in the E.coli containing ΔN-Wee1 construct, but not in FL-Wee1 and BS-Wee1 constructs. The ΔN-Wee1 protein was synthesized in an insoluble fraction with a molecular size of 38.8 kDa which is the same as the size estimated using the software ExPASy. Interestingly, the level of synthesized ΔN-Wee1 protein was not induced by IPTG concentration. Collectively, the results indicated that the DNA construct of ΔN-Wee1 is suitable for recombinant protein production
Effects of Carbonization Temperature from Activated Carbon of Water Hyacinth on the Flux and Its Ability on Iron Removal
Full text linkThe synthesis of activated carbon derived from water hyacinth has been successfully carried out as an iron adsorbent in a laboratory-scale water filter design system. In this article, activated carbon derived from water hyacinth is made through a carbonization process at 400°C and 500°C with NaOH as an activating agent. This activated carbon derived from water hyacinth acts as a filter media for purifying well water by assessing the flux, pH and iron removal efficiency before and after filtration. The results showed that the use of activated carbon derived from water hyacinth with a carbonization temperature of 500°C resulted in a water flux value greater than the carbonization temperature of 400°C. The pH value showed no difference between the use of activated carbon derived from water hyacinth (at a carbonization temperature 400°C and 500°C) before and after the filtration process, which was 7.5. Meanwhile, the effectiveness of activated carbon derived from water hyacinth at a carbonization temperature of 500°C as a filtration medium is more optimal in reducing iron levels compared to the use of activated carbon at a carbonization temperature of 400°C with percentage efficiency up to 98.09%
Characterization of Protease from Endophytic Fungi Fusarium sp. JE-DP4a
Full text linkProtease is a catalytic enzyme that catalyzes a proteolysis process and breaks down a protein into smaller polypeptides or amino acids. Endophytic fungi can produce bioactive compounds, one of which is protease enzymes. The papaya leaf endophytic fungi used in this study was Fusarium sp. strain JE-DP4a. This study was conducted to determine the characterization of protease from endophytic fungi Fusarium sp. strain JE-DP4a with variations in incubation temperature of 30, 37, and 44oC and pH variation of 5.5-8. Measurement of protease enzyme activity using a spectrophotometer UV-Vis at 280 nm. Based on the research results, the highest protease activity produced at a temperature of 44oC is 53.78 U/mL, and specific activity is 17.31 U/mg protein. Protease activity at pH 7 shows the highest was 46.72 U/mL.Thus it is ably concluded that the protease produced by Fusarium sp. strain JE-DP4a belongs to the neutral protease group
A Review on Physical, Chemical and Optical Properties of Liquid Crystal
Full text linkThe foundation of the upcoming generation of cutting-edge gadgets and digitally augmented technologies is expected to be smart soft materials. Because of their responsiveness and adaptability, liquid crystals (LCs) are promising smart soft materials. In the 20th century, LCs were crucial to changing the information display sector. However, several beyond-display uses for LCs have been proven at the turn of the twentieth century, neatly using their controlled stimuli-responsive and adaptable properties. New LC materials have been developed and engineered for such applications. The review comes close with a summary and viewpoints on the potential and problems facing LCs as smart soft materials. This review is expected to inspire a wide range of concepts for the application of nature's delicate phase of matter in the generation and beyond of smart and augmented devices
Characterization of The essential oil of Eucalyptus Leaves (Melaleuca leucadendra) from Pontianak City and Its Activity Against Streptococcus mutans
Full text linkEucalyptus plants can grow in the city of Pontianak, which is an area with peat soil, although in fact, this plant can grow well in swamps, sandy areas, and mangroves. The difference in the location where eucalyptus grows, causes a difference in the composition of the compounds contained in it, especially 1.8 cineol which is a potential compound to prevent dental caries. This study aims to isolate and characterize the essential oil of eucalyptus leaves from the city of Pontianak and determine its activity in inhibiting the S. mutans bacteria. This research was carried out in two stages: isolating, characterizing, and determining the chemical content of eucalyptus leaf essential oil from Pontianak using Gas Chromatography-Mass Spectroscopy (GC-MS). The second stage was to test the antibacterial activity in inhibiting the growth of S. mutans bacteria using the well diffusion method. The results of the isolation of essential oils obtained a yield of 0.58% (w/w) with a specific gravity characteristic of 0.9288 g/mL, a clear greenish-yellow color, and a characteristic smell of eucalyptus oil, and is soluble in 70% ethanol. GC-MS analysis showed that there were 29 compounds, with the main compound being 1.8 cineol as much as 55.71%. The results of the antibacterial activity test against S. mutans showed that the samples at all test doses were antibacteria with inhibition values of 9.03 mm (1.393 mg/well), 6.76 mm (0.697 mg/well), 6.53 mm (0.348 mg/well), and 5.39 mm (0.174 mg/well). The follow-up test showed that at all doses of the essential oil, it was bacteriostatic against S. mutans bacteria. From the study results, it can be concluded that Pontianak eucalyptus oil meets the standards of SNI 06-3954-2006 with 1.8 cineol as the main compound and has antibacteria properties against S. mutans
Application of Fuzzy TOPSIS Method as a Decision Support System for Achievement Student Selection
Full text linkAchievement student selection aims to appreciate students who have achieved an achievement, both in the academic and non-academic fields. This activity is carried out in stages, starting from departments, faculties, and universities, to the national level. In the selection process, several criteria were used: GPA, scientific work, presentation, English, and achievements were featured and involved several juries to avoid subjectivity in the assessment. This study aims to get the best results from the decision support system in Achievement student election in the Mathematics Department of Jember University. Therefore, we need the fuzzy TOPSIS method to avoid and minimize problems and to make multi-criteria decision-making easier. This study's ranking results were obtained from the fuzzy TOPSIS method and standardized assessment method (based on higher education guidelines). From the four candidates who participated in this selection, the two methods give different results in the last two ranks. The fuzzy TOPSIS method ranking shows the results sequentially for candidates B, C, A, and D. In contrast, and the standardized assessment method ranking shows the results sequentially for candidates B, C, D, and A. This difference is caused by the value of the criteria factor and the weight of the candidate criteria, but the fuzzy TOPSIS method is simpler than the standardized assessment method. So that it can be recommended for the next period achievement student election at the department, faculty, or university level
Analysis of Mangrove Forest Resource Depletion Models due to The Opening of Fish Pond Land with Time Delay
Full text linkMangrove forest is an ecosystem with many resources and high biological diversity that contain many species of animal, such as proboscis monkeys. One of the problems that keep happening on mangrove forest is the opening of fish pond. Opening of fish pond can damage mangrove resource by the degradation of the mangrove habitat. This study aims to analyze the depletion stability model of mangrove forest resources with time delay, and to show effect of time delay and the presence of change in the equilibrium point (Hopf bifurcation) on depletion stability model of mangrove forest resources due to fish pond openings. The depletion stability model of mangrove forest resources can be modeled as a system of nonlinear differential equations. In the numerical simulation results, critical value of delay (Ï„0) is 7.05 and the transverse conditions are not fulfilled. This mean there is no change in stability and the delay time parameter (Ï„) does not affect the stability of the system. System will remain stable when the mangrove forests, proboscis monkeys, and fish ponds are in equilibrium. In other words, mangrove forests, proboscis monkeys, and fish ponds can coexist even though time delays, and the analysis using the Hopf bifurcation cannot be carried out