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المنشورات العلمية

الرئيسية // المنشورات العلمية
Isolation and identification of fungi associated with some Libyan foods
Journal Article
  • Cereal and its products can be contaminated with fungi in the field, during drying, processing, transportation and subsequent storage, which may lead to secretion of mycotoxins under favourable condition. The aim of this study was the isolation and identification of some fungi associated with four kinds of Libyan food products of different trademarks. Twenty four (24) samples of couscous, macaroni, wheat flour and rice regularly used for human consumption by Libyan family were collected from local markets in the city of Alzawia, west of Tripoli, Libya. The results reveal isolation of 113 isolates belonging to nine genera: Penicillium, Aspergillus, Fusarium, Paecilomyces, Alternaria, Rhizopus, Mucor, Scopulariopsis and Cladosporum. Approximately 24 species were identified to belong to those isolated genera, several of which are known as main producer of mycotoxins especially A. flavus which are known to produce aflatoxins, Aspergillus niger, Aspergillus carbonarious, Penicillium chrysogenum and Penicillium verrucosum known to produce ochratoxin and Fusarium oxysporum and Fusarium chlamydosporum known to produce fumonisins and trichothecenes. Certainly, the occurrence of such types of mycotoxins can pose a health threatening risk for the consumer of those food items. Presence of these fungi in food products could be due to lack of good agriculture and food manufacturing practices throughout the food chain.
  • Key words: Couscous, macaroni, wheat flour, rice, fungi, Libya.


Mohamed Ahamed Alryani, (07-2015), academicjournal: African Journal of Food Science, 7

Female directors and earnings management: Evidence from UK companies
Journal Article

Since the gender diversity of boards and reporting of earnings are two most debated issues in the corporate world, the paper examined how the presence of women directors on the corporate board influence earnings management practices. We found that firms with a higher number of female and independent female directors are adopting restrained earnings management practices in the UK. We further made a distinction between complex (high debt) and simple (low debt) companies, and the outcomes reveal that female directors have a positive effect on the earnings management in simple companies. The paper contributes to the debate on gender diversity on boards, and its impact on the use of accounting discretion in financial reporting.

Yousf Ebrahem Abolgasem Almahrog, Thankom Arun, Zakaria Aribi, (05-2015), International Review of Financial Analysis: Elsevier Ltd, 39

ذاكرة المدى القصير وعلاقتها بالتحصيل الدراسي
مقال في مجلة علمية

هدفت هذه الدراسة الى معرفة العلاقة بين ذاكرة المدى القصير والتحصيل الدراسي لدى تلاميذ الصف السادس في مدارس التعليم الأساسي بمكتب التعليم بدر ببلدية باطن الجبل، والإجابة على فروض الدراسة المتمثلة في هل هناك فروق ذات دلالة احصائية في ذاكرة المدى القصير ترجع لمتغيرات (ذوي التحصيل العالي والمنخفض، الجنس). تكون مجتمع الدراسة من (198)تلميذ وتلميذة، تكونت عينة الدراسة من 68 تلميذ للعام الدراسي -2015 ،2016 تم تجميع بيانات الدراسة بواسطة اختبار الأرقام للذاكرة معد لذلك ومقارنة ذلك بدرجات التلاميذ في الإمتحان النصفي لمادة الرياضيات، وتوصلت النتائج الى وجود علاقة ذات دلالة احصائية بين درجات التحصيل الدراسي والذاكرة القصيرة المدى كذلك الى وجود فروق ذات دلالة إحصائية بين ذوي التحصيل المرتفع والتحصيل المنخفض لصالح ذوي التحصيل المرتفع والى عدم وجود فروق ذات دلالة احصائية بين الجنسين في الذاكرة قصيرة المدى.

عبدالخالق الاسود عمر الاصفر، (04-2015)، طرابلس: مجلة القلم، 10

نحو حلول تصميمية مستدامة للبيئات الجامعية القائمة في مصر : دراسة حالة جامعة المنصورة
مقال في مجلة علمية

نحو حلول تصميمية مستدامة للبيئات الجامعية القائمة في مصر : دراسة حالة جامعة المنصورة


خالد جمعة العجيلي عبدالله، (03-2015)، جامعة المنصورة / مصر: مجلة جامعة المنصورة، 1

BioQt an Integrated Bioinformatics Software Development Kit
Master Thesis

Bioinformatics is a multi-disciplinary science focusing on the applications of computational methods and mathematical statistics to molecular biology. Choosing bioinformatics as specialization gives an opportunity to get involved with the most interesting computational techniques dealing with biological data to contribute to cure and diagnose some of genetic disorders that affect biological machines. The purpose of this library (which defines namespace BioQt), is to provide a set of routines for handling biological sequence data for Qt/C++ users (the full source code available on https://github.com/alrawab/BioQt). This thesis will shed the light on some modules of BioQt SDK such as exact string matching problem, Microsatellite Repeats, Palindromic sequences and sequence alignment algorithms (Longest Common Subsequence, Needleman-Wunsch and Smith-Waterman). This thesis examines and evaluates these challenging problems in bioinformatics by using Qt/C++.

osamah shuhoub salim alrouwab, (01-2015), libya: الاكادمية الليبية,

The expression and activity of antioxidant enzymes in the liver of rats exposed to high-fructose diet in the period from weaning to adulthoo
PhD Thesis

Abstract

BACKGROUND: Increased fructose consumption correlateswith rising prevalence of variousmetabolic disorders, some of which

were linked to oxidative stress. The relationship between fructose consumption and oxidative stress is complex and effects of

a fructose-rich diet on the young population have not been fully elucidated. The aim of this study was to investigate whether

high-fructose diet applied in the period from weaning to adulthood induces oxidative stress in the liver, thus contributing to

induction or aggravation of metabolic disturbances in later adulthood. To that end we examined the effects of high-fructose

diet on expression and activity of antioxidant enzymes, markers of lipid peroxidation and protein damage in the liver as the

main fructose metabolizing tissue.

RESULTS: High-fructose diet increased only SOD2 (mitochondrial manganese superoxide dismutase) activity, with no effect on

other antioxidant enzymes, lipid peroxidation or accumulation of damaged proteins in the liver.

CONCLUSION: The results show that fructose-induced metabolic disturbances could not be attributed to oxidative stress, at

least not at young age. The absence of oxidative stress in the liver observed herein implies that young organisms are capable of

maintaining redox homeostasis when challenged by fructose-derived energy overload.

Alhadi Mohamed Ali Jelban, (11-2014), Serbian national center for biological research: journal of the science of food and agriculture,

Thermal stability, AC electrical conductivity and dielectric properties of N-(5-{[antipyrinyl-hydrazono]-cyanomethyl}-[1,3,4]thiadiazol-2-yl)-benzamide Author links open overlay panel
Journal Article

A novel organic compound containing antipyrine and thiadiazole moieties, N-(5-{[antipyrinyl-hydrazono]-cyanomethyl}-[1,3,4]thiadiazol-2-yl)-benzamide (ACTB) has been synthesized. The thermal properties, alternating current electrical conductivity (σAC) and electrical modulus of ACTB have been reported. The thermal properties were analyzed using differential scanning calorimetry and thermogravimetric measurements. The AC measurements of bulk ACTB were performed in frequency range 100 Hz–5 MHz and temperature range 303–503 K. The frequency dependence of AC conductivity is found to follow Jonscher’s universal power law with the applicability of the correlated barrier hopping model. The temperature dependence of σAC could be described in terms of Arrhenius relation with two activation energies. The activation energy decreases with increasing frequency. The dielectric relaxation behavior is explained in terms of electric modulus formalism. At relatively higher temperatures, the imaginary modulus spectra exhibit asymmetric maxima with peak-width much broader than that of the Debye peak and are skewed toward the high frequency sides of the maxima with increasing temperature. The relaxation time is calculated and exhibited thermally activated process with activation energy of 0.77 eV.


Hagar Hussien Hussien Nawar, (10-2014), Journal of alloys and compounds: Elsevier, -610

Earnings Management and Corporate Social Responsibility: The Case of UK
PhD Thesis

The primary focus of this study is to investigate the relation between Earnings Management (EM) and Corporate Social Responsibility (CSR) in the UK. While there are few studies in the existing literature that examined the relationship between EM and CSR, there is a lack of studies examining this relation in the UK. Furthermore, the existing academic literature appears to provide inconsistent results.

These considerations motivate this study to bridge this gap in the literature by providing evidence of whether or not EM and CSR are related in the UK. The present study carried out through three empirical stages based on the data obtained from the FTSE 350 Index between 2008 and 2010.

The first stage examined the EM practice using three EM models to estimate discretionary accruals as proxy for EM. The models were the Jones (1991), modified Jones (Dechow et al. 1995) and performance - matched (Kothari et al. 2005) models.

Firstly, these models were tested using multivariate analysis; the findings revealed that the performance - marched model has been identified as the model that could most accurately measure the presence of EM. Secondly, by applying univariate analysis, the study has found insignificant differences between the high and low EM practices in UK firms and that the highest and the lowest levels of EM were in 2008. Similar results were discovered when comparing the differences between income - increasing and income - decreasing EM.

The second stage tested CSR by applying both content analysis and disclosure index approaches to identify the level of Corporate Social Responsibility Disclosure (CSD) as proxy of CSR. The findings from the content analysis revealed that the employees (EMP) theme had the highest level of CSR information, followed by community (COM), environment (ENV), others (OTH), products and services (PRO), and customers (CUS). Similar results were obtained when the disclosure index approach was employed.

The relationship between EM and CSR was tested in the final stage by using univariate and multivariate analyses. The findings revealed that firms with more CSR information reported lower EM. Further tests were performed to investigate the link between EM and CSR themes and the findings revealed that firms with more information of EMP, COM, EVE and PRO reported lower EM. However, no evidence suggested that CUS and OTH information affect EM. Overall, the findings suggest that the level of CSR improve financial reports’ quality. This study aspires to contribute to our understanding and knowledge on the issue related to the role of CSR regarding the quality of reported earnings.

Yousf Ebrahem Abolgasem Almahrog, (09-2014), University of Central Lancashire: University of Central Lancashire,

Long-term fructose-enriched diet introduced immediately after weaning does not induce oxidative stress in the rat liver
Journal Article

Increased fructose consumption is correlated with the rising prevalence of obesity, metabolic

syndrome, and type 2 diabetes. It is believed that reactive oxygen species contribute to the

development and progression of metabolic disturbances, especially those associated with

insulin resistance. Dietary fructose produces both pro-oxidative and antioxidative effects,

depending upon the experimental conditions, dosage, duration of treatment, and

pathophysiological milieu. The effects of fructose overconsumption on young populations,

which have an increased risk of developing metabolic disorders in adulthood, have not been

fully elucidated.Wehavepreviously shownthat rats subjected toa long-termfructose-enriched

diet immediately after weaning display impaired hepatic insulin sensitivity. In this study, we

tested the hypothesis that long-term fructose consumption induces alterations in the redox

setting of the liver. Starting fromthe 21st day after birth,maleWistar ratsweremaintained for 9

weeks on a standard diet (control) or a fructose-enriched diet that consisted of standard food

and 10%fructose solution instead of drinkingwater. The expression and activity of antioxidant

enzymes aswell as lipid peroxidation and protein damagemarkersweremeasured. The results

showed that a fructose-enriched diet led to an increased expression of mitochondrial

manganese superoxide dismutase but did not affect antioxidant enzymes activity, lipid

peroxidation, thiol content, and the level of protein oxidation. Therefore, our results suggest

that the decrease in hepatic insulin sensitivity that was previously observed in rats that were

kept on the same diet regimemight be attributed to molecular mechanisms other than redox

disbalance. A possible fructose-related micronutrient deficiency should be examined.

  • © 2014 Elsevier Inc. All rights reserved.

Alhadi Mohamed Ali Jelban, (09-2014), Serbian national center for biological research: Elsevier, 34

EFFECT OF PYROLYSIS ON SHRINKAGE PROPERTIES OF SU-8 POLYMER
Master Thesis

Abstract

SU-8 has drawn a lot of attention during the last decades due to its promising mechanical and electrical properties. Extensive research regarding the mechanical properties of negative photoresists SU-8 has been carried out during the last decades. A lot of effort has been put into developing methods to properly characterize features such as effect of pyrolysis temperature and the pyrolysis time on shrinkage properties and morphology of SU-8. In this work photo patterned SU-8 were fabricated on silicon wafers by spin process for different speed steps (step (1) 250rpm and time 10sec, step (2) 450rpm and time 30sec, step (3) 0rpm and time 5sec), then Soft baked at 95°C for 4min before cooling for 10min. Exposure to ultraviolet (UV) light was necessary to obtain the shape of the mask, increase crosslinking degree in the irradiated areas and stabilizes them against the action of solvents during development step. The density of UV used was 6 mW/cm2 at 365 nm and exposure time was 5min, while the volume of SU-8 developer was 40cm3 at 10min. Samples were cut into 2cmx2cm dimensions. The pyrolysis was carried out in a closed quartz tube furnace in an inert nitrogen gas (N2) flow at 1500 standard cubic centimeters per minute (SCCM) and different parameter of temperature (350oC, 400oC, 450oC and 500oC) and time (10min and 20min). Peeling of the SU-8 occurs due to a poor adhesion of the resist to the substrate, thicker films or faster heating rates during the pyrolysis of SU-8. Increasing pyrolysis parameters (temperature and time) lead to larger vertical and horizontal shrinkage, lower sheet resistivity and roughness. The scanning electron microscope (SEM), atomic force microscopy (AFM) and profilometer were used to examine the shrinkage and roughness of SU-8, in order to gain an understanding of how it can affect the shrinkage properties and determine the optimized pyrolysis conditions. 


Waled Ashor Mftah Galy, (08-2014), جامعة برليس الماليزية: University Malaysia Perlise,