Structural and biochemical assessment of the molecular binding of hexylresorcinol to insect immune phenoloxidase: A quest for a new insecticidal activity

Aloui Sarra,Ghazouani Tesnime,Raboudi Faten,Talbi Wafa,Vanden Broeck Jozef,Salghi Rachid,Fattouch Sami 한국곤충학회 2022 Entomological Research Vol.52 No.4

The enzyme phenoloxidase (PO) plays an essential role in insect immune defense. Phenolic compounds sharing structural homology with PO substrates could act as substrate analogues, and may interfere with insect physiological process, thus, leading to their control. Herein, the bioinformatic molecular docking was used to predict the interaction of the crystal 3D structure of the insect Manduca sexta PO (PDB: 3HHS) with the antiseptic 4 hexylresorcinol (4-Hr). The method was firstly validated using phenylthiourea (PTU) as reference ligand. Data demonstrated the ability of the 4-Hr to bind to M. sexta PO with binding energy score ΔG=372,285 Kcal/mol indicative of a plausible affinity to active site of the enzyme, nevertheless, the affinity of PTU was stronger with a binding energy of ΔG=462.173 Kcal/mol. Furthermore, biochemical in vitro assays confirmed the behavior of 4-Hr as substrate-analog when binding to the active site of the insect PO leading to its competitive inhibition. This is the first report demonstrating the molecular bases of the usefulness of hexylresorcinol as a promising insecticide. Further investigations could emphasize synergistic effects of 4-Hr with other insecticides in integrated pest management (IPM) programs.

Synthesis of a Minimum Functional State Observer Approach for Unperturbed/ Perturbed Dynamical Systems

Ridha Aloui,Naceur Benhadj Braiek 제어·로봇·시스템학회 2018 International Journal of Control, Automation, and Vol.16 No.4

In this paper, we investigate the synthesis of minimum functional state observer for unperturbed and perturbed linear time invariant systems. The principal contribution is the design of a minimum functional state observer, which can estimate directly the state feedback control law. Hence, for the linear time invariant systems, the existence conditions of a minimum functional state observer are obtained by verification of a special dimension condition on system matrices. As a matter of fact, the exact solution of the proposed approach is determined, and the minimum functional state observer that has the same dimension as the control vector is derived by solving a set of linear matrix inequality (LMI) constraints. Whereas, for perturbed linear systems, the proposed minimum functional state observer scheme is developed to ensure the robust quadratic stability of the augmented system. The robustness issue is given via the reconstructed control law designed using an LMI based H∞ method; so that the desired design matrices are derived through the resolution of an optimum LMI system. The effectiveness and usefulness of the proposed approach are validated through a flexible link robot example.

On the Optimal State Observer Synthesis for Discrete-time Linear Systems

Ridha Aloui,Naceur Benhadj Braiek 보안공학연구지원센터 2012 International Journal of Control and Automation Vol.5 No.3

Ultrasonic velocity as a tool for mechanical and physical parameters prediction within carbonate rocks

Abdelhedi, Mohamed,Aloui, Monia,Mnif, Thameur,Abbes, Chedly Techno-Press 2017 Geomechanics & engineering Vol.13 No.3

Physical and mechanical properties of rocks are of interest in many fields, including materials science, petrophysics, geophysics and geotechnical engineering. Uniaxial compressive strength UCS is one of the key mechanical properties, while density and porosity are important physical parameters for the characterization of rocks. The economic interest of carbonate rocks is very important in chemical or biological procedures and in the field of construction. Carbonate rocks exploitation depends on their quality and their physical, chemical and geotechnical characteristics. A fast, economic and reliable technique would be an evolutionary advance in the exploration of carbonate rocks. This paper discusses the ability of ultrasonic wave velocity to evaluate some mechanical and physical parameters within carbonate rocks (collected from different regions within Tunisia). The ultrasonic technique was used to establish empirical correlations allowing the estimation of UCS values, the density and the porosity of carbonate rocks. The results illustrated the behavior of ultrasonic pulse velocity as a function of the applied stress. The main output of the work is the confirmation that ultrasonic velocity can be effectively used as a simple and economical non-destructive method for a preliminary prediction of mechanical behavior and physical properties of rocks.

Behavior of sediment from the dam FERGOUG in road construction

Benaissa, Assia,Aloui, Zehour,Ghembaza, Moulay S.,Levacher, Daniel,Sebaibi, Yahia Techno-Press 2016 Advances in concrete construction Vol.4 No.1

In Algeria, wastes are often stored in such conditions that do not meet standards. Today and more than ever, we really must implement an environmentally management of wastes. Recovery of waste in Algeria has a considerable delay due to the absence of a policy favorable to the development of waste management. But many researchers have shown the possibility to reuse dredged sediments in road construction. Through Europe, recent research works have been already performed on dam sediments. Present study fits into the context of the valorization of dredged sediments from Fergoug dam. They are found in considerable quantities and mainly composed of mineral phases, organic matters and water. The reservoir sedimentation poses problems for the environment and water storage, dredging becomes necessary. Civil engineering is a common way of recycling for such materials. Dredged sediments have not the required mechanical characteristics recommended by the standards as GTR guide (LCPC-SETRA 1992). So as to obtain mechanical performance, dredged sediment can be treated with cement, lime, or replaced materials like quarry sand. An experimental study has been conducted to determine physical and mechanical characteristics of sediments dredged from dam. Then different mixtures of sediment and/or quarry sand with hydraulic binders are proposed for improving the grain size distribution of the mixes. Finally, according these mixtures, different formulations have been tested as alternative materials with dredged sediments.

Robust Adaptive Controller for the Diesel Engine Air Path with Input Saturation

Samia Larguech,Sinda Aloui,Olivier Pagès,Ahmed El Hajjaji,Abdessattar Chaari 제어·로봇·시스템학회 2019 International Journal of Control, Automation, and Vol.17 No.10

In this paper, we design an adaptive controller for the diesel engine air path with a priori consideration of actuator saturation effects to regulate the exhaust manifold pressure and the compressor flow rate. The originality of the proposed approach is the integration of an auxiliary system to compensate the saturation effects. Simulation results of the diesel engine air path are given to show the efficiency of the proposed approach.

Antioxidant Properties of Salvia officinalis Decoction Extract and Mechanism of Its Protective Effects on Ethanol-Induced Liver and Kidney Injuries

Saber Jedidi,Foued Aloui,Slimen Selmi,Houcine Selmi,Houcem Sammari,Ala Ayari,Chaabane Abbes,Hichem Sebai 한국식품영양과학회 2022 Journal of medicinal food Vol.25 No.5

This study assessed the hepato- and nephroprotective effects of Salvia officinalis flowers decoction extract (SODE) against ethanol (EtOH)-induced oxidative stress in rats as well as the possible mechanism implicated in such protection. Animals were divided into four groups: control, EtOH, and EtOH+SODE. Wistar rats were pretreated with SODE (50, 100, and 200 mg/kg, body weight [b.w.], p.o.) for 15 days and intoxicated during 2 h by acute oral administration of EtOH (4 g/kg, b.w.) 60 min after the last dose of SODE. We found that SODE pretreatment, in vivo, protected against EtOH-induced liver and kidney injuries evident by plasma transaminases activity and preservation of the hepatic tissue structure. Compared with the control group, the animals treated with the SODE showed a significant decrease (68.81 ± 6.89–50.65 ± 3.97 UI/L) of alanine aminotransferase (ALT) and aspartate aminotransferase (AST; 144.38 ± 6.58–113.64 ± 8.03 UI/L) in a dose-dependent manner. By contrast, the plant extract significantly and dose dependently increased (0.175 ± 0.077–0.302 ± 0.011 mmol/L) the uric acid. The SODE counteracted EtOH-induced liver and kidney lipoperoxidation, preserved sulfhydryl groups (–SH) and glutathione reduced (GSH) contents. Our extract prevented the depletion of antioxidant enzyme activities such as superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). We also showed that acute alcohol administration increased tissue and plasma hydrogen peroxide (H2O2), calcium and free iron levels. Of interest, SODE pretreatment reversed all EtOH-induced disturbances in intracellular mediators. More importantly, SODE treatment significantly protected against alcohol-induced inflammation by reducing C-reactive protein (CRP) and alkaline phosphatase (ALP) activities in plasma. It was concluded that the SODE exerted a potential protective effect against EtOH-induced inflammation and oxidative stress in the rat organs. This study recommends that the consumption of sage flowers is useful for patients who suffer from hepato- and nephrotoxicity.

Study of the regenerator constituting material influence on a gamma type Stirling engine

Ramla Gheith,Fethi Aloui,Sassi Ben Nasrallah 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.4

A gamma Stirling engine with compressed air as working fluid was investigated. This engine operates at a maximum charge pressure of 10 bar, runs at a maximum rotation speed of 600 rpm and can provide 500 W of brake power on the shaft. The engine is equipped with several pressure sensors and thermocouples. This experimental study concentrates on the regenerator constituting material (porous medium). Four different materials were investigated: stainless steel, copper, aluminum and Monel 400. The obtained experimental results provide guidance to Stirling engine enhancement and selection of the appropriate regenerator material. As a conclusion, the regenerator has an important role to enhance the heat exchange and to improve Stirling engine performance, which closely depends on its constituting material.

Measuring Risk of Portfolio: GARCH-Copula Model

( Samia Ben Messaoud ),( Chaker Aloui ) 세종대학교 경제통합연구소 2015 Journal of Economic Integration Vol.30 No.1

In this paper, we use the copulas functions in financial application, namely to examine the assumption of asymmetric dependence and to calculate some measures of risk. The first step consists of deducing filtered residuals for each return series by an asymmetric Glosten-Jagannathan-Runkle Generalized Autoregressive conditional Hetero skedasticity (GJR-GARCH) model. For the second step, we use an estimation of a Generalized Pareto Distribution for the upper and lower tails to determine the empirical semiparametric marginal Cumulative Distribution Function. In our approach, we propose to use a portfolio consisting of increments from five countries. The GJR-GARCH copula is then applied to the data and used to reduce correlation between the simulated residuals of each series. The marginal distributions of filtered residuals are fitted with a semi-parametric Cumulative Distribution Function using the copulas’ functions and Generalized Pareto Distribution for tails. For each series, we compute Value-at-Risk and Conditional Value-at-Risk.

Enhanced Polyhydroxyalkanoate and Astaxanthin Co-production by Cell Retention Culture of Paracoccus sp. LL1

Chanin KHOMLAEM,Hajer ALOUI,Beom Soo KIM 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10

A cell retention culture of Paracoccus sp. LL1 was performed in a membrane fermenter equipped with an internal ceramic filter module to reach high cell density and thus enhance the co-production of polyhydroxyalkanoate (PHA) and astaxanthin as growth associated products. This study showed that PHA accumulation increased with increasing dry cell weight (DCW) giving rise to a maximum of 43.87 ± 0.91 g/L (38.76% of DCW) at 48 h. A significant increase in both intra and extracellular astaxanthin concentrations was also recorded during the fermentation process achieving a maximum production of respectively 8.51 ± 0.20 and 10.2 ± 0.24 ㎎/L at 48 h. Based on gas chromatography, Fourier transform infrared spectroscopy, and ¹H nuclear magnetic resonance spectroscopy, the extracted PHA was identified as a copolymer of 3HB/3HV with a 3-hydroxyvalerate (3HV) content of 3.78 ㏖%. The thermal stability of the produced PHA was comparable to that of standard poly-3-hydroxybutyrate (PHB) and higher than that of standard poly-3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV) with 12 ㏖% 3HV.