Journal of Mathematical and Fundamental Sciences
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Variability Survey of Southern Open Clusters NGC 6134, NGC 6416, Collinder 394, and Alessi 10
No full textWe present the results of a brightness variability survey of four southern open clusters, namely NGC 6134, NGC 6416, Collinder 394, and Alessi 10, which were observed using three telescopes following a time series photometric scheme during the dry season in 2022. The purpose of these observations was to detect variability events and their types of variability in star members of these four clusters. Data analysis was performed using a differential photometry method to produce light curves. Several new variable star candidates were discovered in the observed clusters. More observational data are needed to examine the consistency of the variabilities, estimate relevant periodicity, and determine the type of variable star
Density Functional Theory Investigation on Muon Hyperfine Interaction in Methylated Guanine-Cytosine Double-Strand DNA
Full text linkThe aims of this study were to determine the most likely Mu trapping sites based on total energy consideration as well as identifying the associated muon hyperfine coupling constant of 1, 2, and 3 methylated guanine-cytosine base pair double-strand DNA. The Density Functional Theory method was used at B3LYP/6-31G level of theory to accomplish the objectives of the investigation. The relative energy in the 3 methylated guanine-cytosine base pair double-strand DNA molecule showed that N7 sites in the guanine base have the lowest energy, followed by N3, and C8 sites. It was found that the addition of a methyl group at the C5 atom in the cytosine base does change the stability of the C8 sites in the 3 methylated guanine-cytosine base pair double-strand DNA molecule, but the associated muon hyperfine coupling constant (HFCC) is not affected. The results of this study indicate that there will be no overlaps in the resonance dips due to N7, N3, and all C8 sites of the guanine bases and N3, C5, and C6 sites of the cytosine bases in the Avoided Level Crossing Muon Spin Resonance spectrum
Forecasting Climate-driven Dengue Incidence in Penang, Malaysia
Full text linkDengue continues to pose a major public health challenge in Malaysia, with no definitive cure currently available. Although the Ministry of Health of Malaysia has implemented various measures to control outbreaks, the number of cases keeps rising and is likely to worsen due to the impacts of climate change. Hence, early detection and prediction of dengue outbreaks are vital for the implementation of risk mitigation measures. This study applied and assessed the performance of a coupled ARIMAX and SI-SIR model for forecasting dengue incidence in Penang, Malaysia. Data from 2014 to 2020, including reported dengue cases and climate variables (rainfall and average temperature), were used. Previous research has demonstrated a strong correlation between climate factors and dengue transmission. Granger causality tests also indicated that the time series of rainfall and average temperature are significant predictors of the mosquito biting rate, which is closely linked to dengue transmission. Therefore, these climate variables were incorporated into the coupled model to enhance its forecasting performance. Through multiple simulation rounds with a four-week forecasting period, the coupled model achieved an average forecasting accuracy of around 80% in predicting dengue cases in Penang
Modelling the Dynamics of Tuberculosis A Multi-Stage Compartmental Approach
No full textWe propose a robust multi-stage compartmental model to studytuberculosis (TB) transmission dynamics in Namibia, incorporating multiple stagesof latent infection, along with undiagnosed and diagnosed active cases. The modeldistinguishes between early and late latent stages, allowing for a more accuraterepresentation of TB progression. By capturing the complex interactions betweendisease progression, diagnosis, treatment, and relapse, the model provides valuableinsights into TB dynamics. Mathematical analyses and key simulation parametersare discussed, offering a framework that can inform public health strategies foreffective TB control and intervention in Namibia
Molecular Docking and In Vitro Studies of Synthesized Oxadiazole Derivatives as Urease Inhibitors
Full text linkA novel sequence of 1,3,4-oxadiazoles (7a–h) was synthesized. The compounds were characterized by IR, ¹H NMR, and MS analyses. They were also examined to determine whether they could prevent urease from functioning. Molecular docking was done with AutoDock Vina, and the findings were visualized in Discovery Studio. The H NMR spectra showed peaks at δ 10.20 to 10.69 ppm for NH protons, δ 7.16 to 8.01 ppm for aromatic protons, and δ 4.21 to 4.37 ppm for 2H and CH₂ groups, confirming the structural details. The EI-MS spectra showed molecular ion peaks at 337 m/z with an intensity of 14-67%. Among the bioactivity-tested compounds, 7d resulted in robust activity with IC50 values of 161.6 ± 5.8 µM; compound 7e exhibited the weakest activity, at 453.6 ± 5.8 µM; and no inhibition was discovered by the 7a, 7f, and 7h compounds when compared to the Thiourea, at 21.8 ± 1.51 µM. Molecular dockings confirmed compound 7d as the best-docked complex, with a minimum energy of -7.4 kcal/mol, an RMSD value of 1.573 Å, and hydrogen interactions at His593 with the active site residue, confirming the experimental results. It was determined that 1,3,4-oxadiazoles can be employed as urease inhibitors
Mangosteen Peel Extract (Garcinia mangostana L.) as a Potential Complementary of Leukemia Therapy: In Vitro and In Silico Studies
Full text linkLeukemia is caused by abnormal white blood cell proliferation that leads to disruption of conventional blood cell functions. Mangosteen (Garcinia mangostana L.) contains phytochemical compounds with strong anticancer properties, according to various cancer studies. This study investigated the potential of mangosteen peel extract (MPE) as an anti-leukemia agent through molecular docking of LC-MS-identified compounds against FLT-1 and AKT proteins, followed by in vitro evaluation on HL-60 cells, namely cytotoxic (WST-8 assay), ROS levels and senescence (flow cytometry), and then FLT1 and AKT gene expression (qRT-PCR). LC-MS identified α-mangostin, β-mangostin, γ-mangostin, mangostinone, and epicatechin as the main compounds. Molecular docking revealed strong binding affinities from −8.5 to −9.9 kcal/mol against AKT, and from −9.0 to −9.9 kcal/mol against FLT-1. MPE (500 µg/mL) decreased cell viability and increased inhibition of HL-60 cells. Intracellular ROS levels decreased significantly at 0.6, 1.2, and 2.4 µg/mL MPE. MPE induced cell senescence especially at 1.2 and 2.4 µg/mL. Gene expression analysis revealed downregulation of AKT at 1.2 and 2.4 µg/mL and FLT1 at 2.4 µg/mL. These findings suggest that MPE may exert multifactorial anti-leukemic mechanisms, including apoptosis, ROS modulation, senescence induction, and regulation of AKT and FLT1 expression
Synthesis of Ternary Nanocomposites of MnO2/PANI/Maxsorb and their Performance as an Electrode Material for Supercapacitors
Full text linkIncreasing performance of supercapacitors can be achieved by using a composite of electrode materials. Nevertheless, selecting appropriate materials and determining the optimal combination composition remain significant challenges. In this research, a ternary composite of MnO2/polyaniline (PANI)/Maxsorb was studied. The combination of Maxsorb, PANI, and MnO₂ is a unique feature of this research, with Maxsorb acting as a porous structural framework; PANI enhancing electrical conductivity; and MnO₂ providing high pseudocapacitance. The ternary material was prepared by impregnation of MnO2 and PANI into the pores of Maxsorb carbon in a two-sequence procedure, i.e., (i) incipient wetness impregnation of Mn(NO3)2 into porous carbon followed by calcination to obtain MnO2/Maxsorb, and (ii) in situ polymerization of aniline monomer in the MnO2/Maxsorb, hence obtaining the final ternary nanocomposite of MnO2/PANI/Maxsorb. The electrochemical test using H2SO4 electrolyte (1 M) revealed that the ternary material outperformed single porous carbon or PANI as well as their binary nanocomposite in terms of properties such as energy density, power density, and capacitance. The ternary material had a specific surface area of around 2,078 m2 g-1, containing microporous and mesoporous structures. The material featured a specific capacitance up to 500 F g-1 and a power density of 37.6 kW kg-1 as well as an energy density of 62.69 Wh kg-1
Isolation and Identification of Endophytic Yeast from Sugarcane Juice (Saccharum officinarum L.) as a Bread Leavening Agent
Full text linkBaker’s yeast naturally occurs in plant materials with high glucose content, including sugarcane (Saccharum officinarum L.). This study aimed to isolate and identify yeast from sugarcane juice and evaluate its safety and potential application as baker’s yeast. The methodological workflow included isolation, purification, macroscopic and microscopic characterization, and molecular identification. Safety assessments consisted of hemolysis testing and the evaluation of phospholipase and protease enzyme activities. The technological potential of the isolates was examined through carbohydrate fermentation, tolerance to 50% glucose, flocculation capacity, and hydrogen sulfide production. Two isolates, designated SO1 and SO2, were successfully obtained. Molecular characterization revealed that SO1 shared 99.20% similarity with Hanseniaspora opuntiae, while SO2 showed 99.98% similarity with Candida akabanensis. Both isolates exhibited non-pathogenic characteristics, indicated by a hemolysis index (Hi) of 1 and phospholipase activity represented by a precipitation zone (Pz) of 1. Protease activity assay showed Pz values of 1 for H. opuntiae and 0.58 for C. akabanensis. Potency testing demonstrated that both species performed well in bread dough development, confirming promising leavening capabilities. Overall, H. opuntiae and C. akabanensis isolated from sugarcane juice are food-grade yeasts and are safe for use in bread production
Normal Form of Periodic FPU Chain of Four Particles with Alternating Masses
Full text linkThe periodic Fermi-Pasta-Ulam (FPU) chain is a Hamiltonian system modeling a one-dimensional chain of oscillators with a periodic boundary condition and nearest-neighbor interactions. While previous studies typically restricted the potential function in the Hamiltonian to cubic or quartic terms, this work considers a more general setting. Our aim is to demonstrate how Birkhoff-Gustavson normalization, combined with symplectic transformations, can be systematically applied to study the dynamics of Hamiltonian systems. We focus on the periodic FPU chain of four particles with alternating masses . The presence of discrete symmetries in phase space simplifies the resulting normal form and reduces the system to one degree of freedom. The dynamics of this system depend on the parameter . We focus on two cases, and , which correspond to different classes of resonances. These cases exhibit topologically distinct phase space structures, which are classified in the final analysis. The results highlight the periodic FPU chain as a rich and tractable model for studying resonances and Hamiltonian dynamics in systems with symmetry and variable mass configurations
On the Interaction between Trichogramma chilonis and Jatiroto Flies with Stem Borer Pests in Sugarcane Plantation
Full text linkPests in sugarcane plantations are a major cause of damage, which could lead to severe damage to the crop, reduction of sugar quality, and significant economic loss. One of the major pests known in sugarcane plantations is stem borer (Chilo sacchriphagus), which attacks the canes. Two primary parasitoids, Trichogramma chilonis, which predates the stem borer eggs, and the Jatiroto fly (Diatraeophaga striatalis), which predates the stem borer larvae, are discussed here. This paper presents a time-dependent ten-dimensional dynamical mathematical model consisting of four-stage stem borer compartments, three-stage Trichogramma compartments, and three-stage Jatiroto compartments. Simulations are presented to describe the phenomenon of Trichogramma predation, Jatiroto predation, and simultaneous predation of both predators. It is shown that the release rate of each predator and a combined release of two predators can significantly reduce the infestation levels to a tolerable level for sugarcane production. The oscillatory dynamics of the stem borers and the Jatiroto flies affected the release timing strategy based on the level of infestation in the field. The results are expected to help us better understand the predator-prey phenomenon in the field and improve the forecasting of infestations in the field