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World Journal of Gastroenterology 2009年第23期15卷 2887-2892页

作者： Angèle PM Kerckhoffs Melvin Samsom Michel E van der Rest Joris de Vogel Jan Knol kaouther ben-amor Louis MA Akkermans Gastrointestinal Research Unit Department of Gastroenterology and Surgery University Medical Center Utrecht Heidelberglaan 100 F02.618 3584CX Utrecht The Netherlands BioVisible BV LJ Zielstraweg 1 9713 GX Groningen The Netherlands Danone Research-Centre for Specialized Nutrition Bosrandweg 20 6704PH Wageningen The Netherlands

AIM: To determine the composition of both fecal and duodenal mucosa-associated microbiota in irritable bowel syndrome (IBS) patients and healthy subjects using molecular-based techniques. METHODS: Fecal and duodenal mucosa brush samples were obtained from 41 IBS patients and 26 healthy subjects. Fecal samples were analyzed for the composition of the total microbiota using fluorescent in situ hybridization (FISH) and both fecal and duodenal brush samples were analyzed for the composition of bif idobacteria using real-time polymerase chain reaction. RESULTS: The FISH analysis of fecal samples revealed a 2-fold decrease in the level of bifidobacteria (4.2 ± 1.3 vs 8.3 ± 1.9, P < 0.01) in IBS patients compared to healthy subjects, whereas no major differences in other bacterial groups were observed. At the species level, Bifidobacterium catenulatum levels were significantly lower (6 ± 0.6 vs 19 ± 2.5, P < 0.001) in the IBS patients in both fecal and duodenal brush samples than in healthy ***: Decreased bifidobacteria levels in both fecal and duodenal brush samples of IBS patients compared to healthy subjects indicate a role for microbiotic composition in IBS pathophysiology.

关键词： Irritable bowel syndrome Gut microbiota Bifidobacteria Bifidobacterium catenulatum

Does oil price affect the value of firms？ Evidence from Tunisian listed firms

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Frontiers in Energy 2016年第1期10卷 1-13页

作者： kaouther ZAABOUTI Ezzeddine ben MOHAMED Abdelfettah BOURI Faculty of Economics and Management of Sfax University of SfaxMonastir 5046 Tunisia Department of Accounting College of Business & Economics QassimUniversity Buraidah 51431 Kingdom of Saudi Arabia

A new debate on the potential impact of oil price changes on the value of firms was initiated in this paper. Using a stochastic frontier approach, an attempt was made to derive the optimal value Q＊ of firms and calculate the Q value observed. Then the shortfall （Q＊-Q） which represents the inefficiency term was explained. Starting from 19 industrial Tunisian firms listed on the Tunis Stock Exchange between 2007 and 2011, the fact that variation of oil prices can largely explain distortions in the value of firms was empirically demonstrated.

关键词： oil price value of firm stochastic frontier approach industrial Tunisian firms

EXISTENCE OF POSITIVE SOLUTIONS FOR A CLASS OF PARABOLIC EQUATIONS WITH NATURAL GROWTH TERMS AND L^1 DATA

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Acta Mathematica Scientia 2014年第4期34卷 1127-1144页

作者： kaouther AMMAR Hicham REDWANE Department of Mathematics Faculty of sciencesTaibah UniversityP.O. Box 344 Al MadinahSaudi Arabia Facult'e des Sciences Juridiques Economiques et SocialesUniversit'e Hassan 1B.P. 784SettatMorocco

We study a class of nonlinear parabolic equations of the type：δb（u）/δt-div（a（x,t,u）△u）＋y（u）｜△u｜^2=f,where the right hand side belongs to L^1（Q）, b is a strictly increasing C^1-function and -div（a（x, t, u）△u） is a Leray-Lions operator. The function g is just assumed to be continuous on R and to satisfy a sign condition. Without any additional growth assumption on u, we prove the existence of a renormalized solution.

关键词： renormalized solutions natural growth terms L^1 data

Antimicrobial activity of Tunisian Euphorbia paralias L.

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Asian Pacific Journal of Tropical Biomedicine 2017年第7期7卷 629-632页

作者： Malek Besbes Hlila kaouther Majouli Hichem ben Jannet Mahjoub Aouni Maha Mastouri Boulbaba Selmi Laboratory of Transmissible Diseases and Biological Active Substances Department of Pharmaceutical Sciences Faculty of Pharmacy University of Monastir Avenue Avicenne 5000 Monastir Tunisia Laboratory of Biochemistry Research Unit:UR 12ES08'Cell Signaling and Pathologies' Department of Biology Faculty of Medicine University of Monastir Monastir Tunisia Laboratory of Heterocyclic Chemistry Natural Products and Reactivity Team:Medicinal Chemistry and Natural Products Department of Chemistry Faculty of Sciences of Monastir University of Monastir Monastir Tunisia Laboratory of Bioresources:Integrative Biology and Exploiting Higher Institute of Biotechnology of Monastir Department of Molecular Biology Cellular and Biotechnology University of Monastir Monastir Tunisia

Objective: To examine the potential antimicrobial activity of Euphorbia paralias L. (Euphorbiaeae) leaves and stems extracts. Methods: The antimicrobial activity was tested against six microbial strains:Escherichia coli ATCC 8739, Bacillus subtilis ATCC 6633, Salmonella enterica CIP 8039, Staphy-lococcus aureus ATCC 6538, Pseudomonas aeruginosa ATCC 9027 and Candida albicans ATCC 90028 by two different methods, the disk method and the dilution method. Results: Our results showed the important antimicrobial activity of the chloroform extract of the stems towards the majority of the strains by using both methods. Bacillus subtilis was the most sensitive strain (MIC=MBC=15μg/mL). Conclusion: Thus, some extracts of Euphorbia paralias can be used in the treatment of infectious diseases caused by microbes.

关键词： Euphorbia paralias L. Antimicrobial activity MIC MBC

Stabilizing Sets of PI/PID Controllers for Unstable Second Order Delay System

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International Journal of Automation and computing 2014年第2期11卷 210-222页

作者： Rihem Farkh kaouther Laabidi Mekki Ksouri Laboratory for Analysis Conception and Control of SystemsLR-11-ES20Department of Electrical EngineeringNational Engineering School of TunisTunis El Manar University

In this paper, the problem of stabilizing an unstable second order delay system using classical proportional-integralderivative(PID) controller is considered. An extension of the Hermite-Biehler theorem, which is applicable to quasi-polynomials, is used to seek the set of complete stabilizing proportional-integral/proportional-integral-derivative(PI/PID) parameters. The range of admissible proportional gains is determined in closed form. For each proportional gain, the stabilizing set in the space of the integral and derivative gains is shown to be a triangle.

关键词： Hermite-Biehler theorem stability PI/PID controllers second order unstable delay system stability region.

Solid solution evolution during mechanical alloying in Cu–Nb–Al compounds

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International Journal of Minerals,Metallurgy and Materials 2019年第9期26卷 1129-1139页

作者： kaouther Zaara Mahmoud Chemingui Virgil Optasanu Mohamed Khitouni Laboratory of Inorganic Chemistry UR 11-ES-73University of SfaxB.P. 1171Sfax 3018Tunisia ICB UMR 6303 CNRSUniversity of Bourgogne Franche Comté9 av. Alain Savary21078 Dijon CedexFrance

This work concerns the structural evolution of Cu70Nb20Al10(at%) alloy processed by mechanical alloying using a planetary ball mill in air atmosphere for different times(4 to 200 h). The morphological, structural, microstructural, and thermal behaviors of the alloy were investigated by scanning electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and differential scanning calorimetry. X-ray diffraction patterns were examined using the Rietveld refinement technique with the help of the MAUD software. A disordered FCC-Cu(Nb,Al) solid solution was formed after 8 h of milling. The crystallite size, microstrain, and lattice parameter were determined by the Rietveld method. With increasing milling time, the crystallite size of the final product-ternary-phase FCC-Cu(Nb,Al)-is refined to the nanometer scale, reaching 12 nm after 200 h. This crystallographic structure combines good mechanical strength and good ductility. An increase in microstrain and partial oxidation were also observed with increasing milling time.

关键词： powder metallurgy mechanical alloying nanomaterials copper-based alloy solid solution

Time Series Facebook Prophet Model and Python for COVID-19 Outbreak Prediction

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Computers, Materials & Continua 2021年第6期67卷 3781-3793页

作者： Mashael Khayyat kaouther Laabidi Nada Almalki Maysoon Al-zahrani Department of Information Systems and Technology Collage of Computer Science and EngineeringUniversity of JeddahJeddah23218Saudi Arabia Department of Computer and Network Engineering Collage of Computer Science and EngineeringUniversity of JeddahJeddah23218Saudi Arabia and University of TunisElmanarTunisia

COVID-19 comes from a large family of viruses identied in 1965;to date,seven groups have been recorded which have been found to affect *** the healthcare industry,there is much evidence that Al or machine learning algorithms can provide effective models that solve problems in order to predict conrmed cases,recovered cases,and *** researchers and scientists in the eld of machine learning are also involved in solving this dilemma,seeking to understand the patterns and characteristics of virus attacks,so scientists may make the right decisions and take specic ***,many models have been considered to predict the Coronavirus outbreak,such as the retro prediction model,pandemic Kaplan’s model,and the neural forecasting *** research has used the time series-dependent face book prophet model for COVID-19 prediction in India’s various ***,we proposed a prediction and analysis model to predict COVID-19 in Saudi *** time series dependent face book prophet model is used to t the data and provide future *** study aimed to determine the pandemic prediction of COVID-19 in Saudi Arabia,using the Time Series Analysis to observe and predict the coronavirus pandemic’s spread daily or *** found that the proposed model has a low ability to forecast the recovered cases of the COVID-19 *** contrast,the proposed model of death cases has a high ability to forecast the COVID-19 ***,obtaining more data could empower the model for further validation.

关键词： COVID-19 time series analysis prediction face book prophet model python

Phytochemical analysis and biological activities of Hertia cheirifolia L. roots extracts

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Asian Pacific Journal of Tropical Medicine 2017年第12期10卷 1134-1139页

作者： kaouther Majouli Assia Hamdi Malek Besbes Hlila Laboratory of Biochemistry Research Unit:UR 12ES08 “Cell Signaling and Pathologies”Faculty of MedicineUniversity of MonastirTunisia Laboratory of Chemical Galenic and Pharmacological Development of DrugsFaculty of PharmacyUniversity of MonastirTunisia Laboratory of Transmissible Diseases and of Biologically Active Substances MDT01Faculty of PharmacyUniversity of MonastirTunisia

Objective: To test the antioxidant, antimicrobial and a-glucosidase inhibitory activities of the roots extracts from Hertia cheirifolia(H. cheirifolia) ***: Total phenolics and total flavonoids content of the different extracts were determined by colorimetric methods and reverse phase high-performance liquid chromatography(RP-HPLC) was performed to identify various chemical *** different extracts were evaluated for antioxidant activities by 2,2-diphenyl-1-picrylhydrazyl(DPPH), 2,2-azino-bis-3-ethylenebenzothiozoline-6-sulfonic acid(ABTS·^+) and β-carotene bleaching tests and α-glucosidase inhibitory properties. The antimicrobial activity was carried out in vitro by the broth dilution ***: Trans-cinnamic acid, rutin hydrate, naringin and quercetin were the main compounds of the ethyl acetate extract from H. cheirifolia L. This extract has significant scavenging activity to decrease free radicals especially for DPPH and ABTS radicals. As well as, the ethyl acetate extract exhibited an antimicrobial property against bacterial strains. Bacillus licheniformis and Salmonella enterica were the most sensitive strains with minimum inhibitory concentration values of 0.156 mg/***: The ethyl acetate extract was found to be selectively antioxidant and antimicrobial.

关键词： Hertia cheirifolia Phytochemical analysis Antioxidant Antimicrobial α-Glucosidase inhibitory

In Vitro Picloram-lnduced Somatic Embryogenesis from Leaflets of Cherry （Prunus incisa Thunb,）

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Journal of Life Sciences 2011年第11期5卷 913-920页

作者： ben Mahmoud kaouther Elloumi Nadhra Chakroun Ahlem Ahmed Jemmali Philippe Druart Institut National Agronomique de Tunisie Cite El Mahrajene Tunis 1082 Tunisie Departement Biotechnologie et Physiologie Vegetale Institut National de la Recherche Agronomique de Tunisie Rue Hedi KarrayAriana 2080 Tunisie Unite ＂Genie Biologique ＂ Departement Sciences du Vivant Centre Wallon de Recherches Agronomiques Chaussee de Charleroi234 Gembloux 5030 Belgique

Cherry regeneration via somatic embryogenesis is a powerful tool to breeding. In this way, the embryogenic capacity of Prunus incisa specie has been tested from leaves under different interactions of picloram concentrations and darkness exposures. Induction culture was achieved on MS medium supplemented with picloram concentrations at 0.5, 1 and 1.5 mg.L1 and submitted to 10, 20, 30 and 40 days of darkness. The best rate of embryogenic leaves was obtained with the interaction of 30 days darkness exposure＊ 1 mg.L^-1 picloram. According to their age, leaves were differently reacted to somatic embryogenesis; indeed, the 2nd expanded leaf from the apex was the most embryogenic one. Concerning the effect of additional auxin to picloram （1 mg·L^-1）, IAA at 0.1 mg·L^-1 and IBA at 0.1 mg·L^-1 gave significantly higher induction rates than all other concentrations, but regenerating somatic embryos showed some teratological abnormalities probably due to seconda;y embryogenesis. At the opposite, NAA at 0.5 mg·L^-1 didn＇t improve embryogenic rate but affected positively embryo development. Furthermore, embryogenesis preferentially took place on the basal part of leaf. Satisfactory rates of somatic embryogenesis are obtained but further improvement remains possible.

关键词： Auxin picloram somatic embryogenesis leaf explants Prunus incisa

Front-Face Fluorescence Using UV-LED Coupled to USB Spectrometer to Discriminate between Virgin Olive Oil from Two Cultivars

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Food and Nutrition Sciences 2019年第2期10卷 119-127页

作者： Gilbert Yvon Mbesse Kongbonga kaouther ben Hassine Hassen Ghalila Dhafer Malouche Faculty of Science University of Bangui Bangui Central African Republic Laboratoire de Spectroscopie Atomique Moléculaire et Applications (LSAMA) Faculty of Sciences University of Tunis El Manar Tunis Tunisia Centre for Atomic Molecular Physics and Quantum Optics (CEPAMOQ) Faculty of Science University of Douala Douala Cameroon Laboratory of Biochemistry UR: Human Nutrition and Metabolic Disorder Faculty of Medicine Monastir Tunisia Institut de l’Olivier Unité Technologie et Qualité Sfax Tunisia National Institute for Applied Sciences and Technologies Tunis Tunisia Higher School of Agriculture of Mograne Mograne Tunisia Engineering School of Statistics and Information Analysis University of Carthage Tunis Tunisia

A simple setup using a 365 nm LED coupled to a USB spectrometer through an optical fibre, in a front-face fluorescence configuration, was used to investigate the ability of fluorescence spectroscopy technique to discriminate between varieties of olive oil. To achieve this task, Virgin Olive Oils (VOO) from two major Tunisian olive cultivars known as Chetoui and Chemlali were used. Spectral analysis showed a clear separation between these two VOO varieties. A one-way ANOVA attests that this discrimination is significant. The Principal Components Analyses (PCA) showed that the normalized fluorescence intensities are the good parameters for this discrimination. This observation strengthens the potential of our spectral parameters to perform reliable analysis.

关键词： Chemometrics Fluorometry Oils Olive Oil PCA UV/Visible