• Title/Summary/Keyword: MFO

Search Result 57, Processing Time 0.027 seconds

Activity of Mixed Function Oxidase in a few Insect Species in Relation to Their Food Source (먹이종류에 따른 몇가지 곤충의 MFO활성 비교)

  • 이정호;부경생
    • Korean journal of applied entomology
    • /
    • v.32 no.3
    • /
    • pp.291-299
    • /
    • 1993
  • Midgut tissues from 4 insect specIes were exammed for the activity of cytochrome P-450 monooxygenases, a major enzyme involved in chemical detoxification. When Helicoverpa assulta larvae were reared on an artificial d;et, the specific activity of the midgut cytochrome P-450 monooxygenases (MFO) was :3 times higher than that of the fat body, The specific activity of the midgut cytochrome P-450 monooxygenases was higher in H. assul/a larvae when reared on Nicotiana tabacum leaves than when on CapsIcum annuum fruits or an artificial diet. In the case of Hyphantria cunea larvae, Tilia megaphyllo leaves were the best in inducing midgut cytochrome P-450 monooxygenases activity. When larvae of H. assulta, Spodoptera exigua, H. cunea and Spodoptera litura were reared on their own artificial diet, the highest activity was seen in S. exigua larvae which is a polyphagous and insecticide-resistant strain.

  • PDF

Ecotype-Dependent Genetic Regulation of Bolting Time in the Arabidopsis Mutants with Increased Number of Leaves

  • Lee, Byeong-Ha
    • Journal of Microbiology and Biotechnology
    • /
    • v.19 no.6
    • /
    • pp.542-546
    • /
    • 2009
  • Leaves are the major biomass-producing organs in herbaceous plants and mainly develop during vegetative stage by activities of shoot apical meristem. There is a strong correlation between leaf number and bolting, a characteristic phenotype during the transition to reproductive phase in Arabidopsis thaliana. In order to study interactions between leaf number and bolting, we isolated a Landsberg erecta-derived mutant named multifolial (mfo1) that produces increased number of leaves and bolts at the same time as the wild type. Through positional cloning and allelism test, mfo1 was found to be an allele of a previously reported mutant, altered meristem program1-1 (amp1-1) that is defective in a glutamate carboxypeptidase and bolts earlier than its wild type, Columbia ecotype, with the increased number of leaves. The bolting time differences between mfo1 and amp1, despite the same phenotype of many leaves, suggest the existence of genetic factor(s) differently function in each ecotype in the presence of mfo1/amp1 mutation.

Illumination correction via improved grey wolf optimizer for regularized random vector functional link network

  • Xiaochun Zhang;Zhiyu Zhou
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.17 no.3
    • /
    • pp.816-839
    • /
    • 2023
  • In a random vector functional link (RVFL) network, shortcomings such as local optimal stagnation and decreased convergence performance cause a reduction in the accuracy of illumination correction by only inputting the weights and biases of hidden neurons. In this study, we proposed an improved regularized random vector functional link (RRVFL) network algorithm with an optimized grey wolf optimizer (GWO). Herein, we first proposed the moth-flame optimization (MFO) algorithm to provide a set of excellent initial populations to improve the convergence rate of GWO. Thereafter, the MFO-GWO algorithm simultaneously optimized the input feature, input weight, hidden node and bias of RRVFL, thereby avoiding local optimal stagnation. Finally, the MFO-GWO-RRVFL algorithm was applied to ameliorate the performance of illumination correction of various test images. The experimental results revealed that the MFO-GWO-RRVFL algorithm was stable, compatible, and exhibited a fast convergence rate.

Moth-Flame Optimization-Based Maximum Power Point Tracking for Photovoltaic Systems Under Partial Shading Conditions

  • Shi, Ji-Ying;Zhang, Deng-Yu;Xue, Fei;Li, Ya-Jing;Qiao, Wen;Yang, Wen-Jing;Xu, Yi-Ming;Yang, Ting
    • Journal of Power Electronics
    • /
    • v.19 no.5
    • /
    • pp.1248-1258
    • /
    • 2019
  • This paper presents a moth-flame optimization (MFO)-based maximum power point tracking (MPPT) method for photovoltaic (PV) systems. The MFO algorithm is a new optimization method that exhibits satisfactory performance in terms of exploration, exploitation, local optima avoidance, and convergence. Therefore, the MFO algorithm is quite suitable for solving multiple peaks of PV systems under partial shading conditions (PSCs). The proposed MFO-MPPT is compared with four MPPT algorithms, namely the perturb and observe (P&O)-MPPT, incremental conductance (INC)-MPPT, particle swarm optimization (PSO)-MPPT and whale optimization algorithm (WOA)-MPPT. Simulation and experiment results demonstrate that the proposed algorithm can extract the global maximum power point (MPP) with greater tracking speed and accuracy under various conditions.

Effect of Aflatoxin B1 on the Function of Peritoneal Macrophage from Mule Duck

  • Cheng, Yeong-Hsiang;Shen, Tian-Fuh;Pang, Victor Fei;Chen, Bao-Ji
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.15 no.3
    • /
    • pp.438-444
    • /
    • 2002
  • This study was conducted to investigate the effect of aflatoxin $B_1$ ($AFB_1$) alone or mixed function oxidase (MFO)-activated $AFB_1$ on various functions of mule duck peritoneal macrophages. Duck peritoneal macrophages were incubated with $AFB_1$ 0, 5, 10, 20, 50 and $100 {\mu}g/ml$ for 12 h. The cell viability significantly declined as the concentration of $AFB_1$ increased and more obviously detrimental effects was noticed in MFO-metabolized $AFB_1$ treatments. Either in opsonized or unopsonized Candida albicans, phagocytotic ability of macrophages was decreased with the elevation of the concentration of $AFB_1$. Significantly higher levels of macrophages were damaged in MFO-metabolized $AFB_1$ than $AFB_1$ alone in concentrations above $20{\mu}g/ml$. The cytotoxicity activity was in the range of 41 to 33% after exposure to $AFB_1$ 5 to $100{\mu}g/ml$, and a significant higher TNF-like substance secretion by lipopolysaccharide (LPS) stimulation was obtained. When LPS was present in the medium, the percentage of cytotoxicity was higher than all treatments of $AFB_1$ both with and without MFO-activation in the absence of LPS. The results suggest that MFO-metabolized $AFB_1$ can alter cell viability and morphology of duck macrophages more than $AFB_1$ administered alone. Both with and without MFOactivation, $AFB_1$ has detrimental effects on phagocytotic ability and TNF-like substance secretion, increasing with level of $AFB_1$.

Time-course Responses of Hepatic Xenobiotic Metabolizing Enzymes and Stress in Olive Flounder (Paralichthys olivaceus) Exposed to Formalin (Formalin에 약욕시킨 넙치(Paralichthys olivaceus)의 스트레스 반응과 간장 약물대사효소의 경시적 반응)

  • Lee Ji-Seon;Kim Pyong-Kih;Lee Kyoung-Seon;Jeon Joong-Kyun
    • Journal of Aquaculture
    • /
    • v.19 no.2
    • /
    • pp.90-94
    • /
    • 2006
  • The effects of formalin on mixed function oxygenase (MFO) system and stress-response were investigated in olive flounder (Paralichthys olivaceus). Olive flounder was exposed to formalin at the concentration of 300 ppm for 1, 2, 4 and 16 h. Levels of stress-response enzymes together with total protein, glucose and osmolality were quantitatively determined in blood, and the activities of phase I (cytochrome P450, ethoxyresorufin deethylase) and phase II (glutathione S-transferase) hepatic enzymes were also determined. Since the formalin-exposure for 16 h resulted no significant changes in aspartate aminotransferase and alanine aminotransferase, specific enzymes for liver damage, it was thought that it did not cause hepatic tissue damage at the concentration of 300 ppm. However, hepatic MFO system was induced at 1 to 4 h, and stress response was induced after 16 h of exposure. Moreover, it is considered that the depression of MFO activity after 16 h of exposure may not be adaptation to formalin, but toxic response. These results suggest that low concentration of formalin does not cause hepatic tissue damage of fish, but could induce MFO and stress response.

Structural damage detection based on MAC flexibility and frequency using moth-flame algorithm

  • Ghannadi, Parsa;Kourehli, Seyed Sina
    • Structural Engineering and Mechanics
    • /
    • v.70 no.6
    • /
    • pp.649-659
    • /
    • 2019
  • Vibration-based structural damage detection through optimization algorithms and minimization of objective function has recently become an interesting research topic. Application of various objective functions as well as optimization algorithms may affect damage diagnosis quality. This paper proposes a new damage identification method using Moth-Flame Optimization (MFO). MFO is a nature-inspired algorithm based on moth's ability to navigate in dark. Objective function consists of a term with modal assurance criterion flexibility and natural frequency. To show the performance of the said method, two numerical examples including truss and shear frame have been studied. Furthermore, Los Alamos National Laboratory test structure was used for validation purposes. Finite element model for both experimental and numerical examples was created by MATLAB software to extract modal properties of the structure. Mode shapes and natural frequencies were contaminated with noise in above mentioned numerical examples. In the meantime, one of the classical optimization algorithms called particle swarm optimization was compared with MFO. In short, results obtained from numerical and experimental examples showed that the presented method is efficient in damage identification.

A Study on the Modified Fenton Oxidation of MTBE in Groundwater with Permeable Reactive Barrier using Waste Zero-valent Iron (폐영가철 투수성반응벽체를 이용한 Modified Fenton 산화에 의한 MTBE 처리연구)

  • Moon, So-Young;Oh, Min-Ah;Lee, Jai-Young
    • Journal of Soil and Groundwater Environment
    • /
    • v.17 no.2
    • /
    • pp.15-21
    • /
    • 2012
  • MTBE (Methyl tertiary-butyl ether) has been commonly used as an octane enhancer to replace tetraethyl lead in gasoline, because MTBE increases the efficiency of combustion and decreases the emission of carbon monoxide. However, MTBE has been found in groundwater from the fuel spills and leaks in the UST (Underground Storage Tank). Fenton's oxidation, an advanced oxidation catalyzed with ferrous iron, is successful in removing MTBE in groundwater. However, Fenton's oxidation requires the continuous addition of dissolved $Fe^{2+}$. Zero-valent iron is available as a source of catalytic ferrous iron of MFO (Modified Fenton's Oxidation) and has been studied for use in PRBs (Permeable Reactive Barriers) as a reactive material. Therefore, this study investigated the condition of optimization in MFO-PRBs using waste zero-valent iron (ZVI) with the waste steel scrap to treat MTBE contaminated groundwater. Batch tests were examined to find optimal molar ratio of MTBE : $H_2O_2$ on extent to degradation of MTBE in groundwater at pH 7 with 10% waste ZVI. As the results, the ratio of optimization of MTBE to hydrogen peroxide for MFO was determined to be 1:300[mM]. The column experiment was conducted to know applicability of MFO-PRBs for MTBE remediation in groundwater. As the results of column test, MTBE was removed 87% of the initial concentration during 120days of operational period. Interestingly, MTBE was degraded not only within waste ZVI column but also within sand column. It means the aquifer may affect continuously the MTBE contaminated groundwater after throughout the waste ZVI barrier. The residual products showed acetone, TBF (Tert-butyl formate) and TBA (Tert-butyl acetate) during this test. The results of the present study showed that the recycled materials can be effectively used for not only a source of catalytic ferrous iron but also a reactive material of the MFO-PRBs to remove MTBE in groundwater.