MSA Repository "MSAR"

MSAR University's Digital Repository is a documentation and digitization of all university outcomes that are of effective value in the scientific and academic community and reflects the university's image, work, and effective contribution to society Through MSAR Digital Repository, the university managed to collect, store, archive and publish digital content - including documents, audio files, images and data sets - all in a safe place. MSAR is one of the strongest University Digital Repositories in Egypt and documented in the DSPACE community with its latest versions.

Error fetching top-level communities

Recent Submissions

ISoP MENA Chapter: Strategic Development and Future Directions Following a Decade of Strengthening Pharmacovigilance in the Middle East and North Africa
(Springer Nature, 2026-09-02) Hadir Rostom; Mohamed A. Elhawary; Mayada Alkhakany; Manal M. Younus; Thamir Alshammari; Felipe Villalobos; Omar Aimer
Pharmacovigilance (PV) in the Middle East and North Africa (MENA) region has advanced substantially over the past decade, driven by diverse surveillance methodologies, expanded pharmacological knowledge and innovative approaches, including artificial intelligence (AI) and real-world data and real-world evidence, to enhance medicine safety and prevent patient harm . Many national PV centres across the MENA region joined the World Health Organization (WHO) Programme for International Drug Monitoring during the 1990 s and early 2000 s and subsequently established national PV systems . However, considerable heterogeneity remains across the region, with PV systems that range from well-established programmes to initiatives that are still in the early stages of development . Ensuring the safe and effective monitoring of medicines in routine clinical practice remains challenging and requires collaboration among a broad range of stakeholders, including medicines regulatory authorities, pharmaceutical companies, academic institutions, healthcare professionals, policymakers and patient organisations . Recognising the need to strengthen regional collaboration, build capacity and promote stakeholder engagement in PV, the International Society of Pharmacovigilance (ISoP), with the support of its Executive Committee (2012–16), launched the Middle East Chapter during its Annual Meeting in Prague, Czech Republic, in October 2015 .
Earnings management and short-term market reaction: does narrative impression management matter in Egypt?
(Emerald Publishing, 2026-08-31) Tariq Ismail; Mohamed Samy El-Deeb; Mohamed H. El-Ashwal
Purpose: This study aims to investigate the joint effect of discretionary accrual-based earnings management (DABEM) and narrative impression management (IM) on short-term market reactions (STMR) and asks whether favourable narrative framing can offset investors' negative reactions to aggressive accruals in the Egyptian capital market. Design/methodology/approach: This study uses a sample of 200 firm-years from 40 non-financial companies listed on the Egyptian Stock Exchange (EGX) between 2020 and 2024. Descriptive statistics, OLS regressions with heteroskedasticity-robust standard errors, robustness checks, and potential relationships among the variables form the basis of the discussion. Findings: Discretionary accruals have a statistically significant negative influence on short-term market reactions. Thus, investors respond negatively to accrual management practices. Impression management does not significantly moderate the negative influence of discretionary accruals on market reaction. Practical implications: Adverse investors' reactions to discretionary accruals can be considered evidence of an effective market discipline mechanism and increased investor attention to earnings quality, considering the regulations introduced in 2020. However, it is essential to acknowledge that discretionary accruals may also be associated with regulatory pressure, changes in investor behavior, or economic instability unrelated to improvements in the analytical ability of the investor. Therefore, more emphasis should be placed on regulatory enforcement, increased audit efforts and narrative disclosures. Originality/value: This study adds to the literature on disclosure in emerging markets by providing empirical evidence on the working mechanism of financial and narrative manipulation in the context of the Egyptian transition after 2020. It also enhances the explanatory power of narrative signals and signaling and attribution theory in the context of low enforcement by thereby potentially undercutting the authority of narrative signals, even to complement financial manipulation.
Thermo-mechanical loading of innovative “Mini-skirt” preparation design versus conventional full-coverage maxillary central incisor preparation design: an in vitro study
(BioMed Central Ltd, 2026-09-02) Mohammad Rayyan; Rana Walid Tawil; Dana El Ballouli; Ehab A. Farghaly; Radwa Ibrahim Eltahawi; Mohamed B. A. Badawy; Omar Badran; Omayma Tantawy Said Mohammed; Alaa Mohamed Naguib; Nasser Hussein Shaheen; Mohamed Sayed; Sahar Mokhtar; Mohammed Moustafa Shalaby; Hatem M. Ibrahim; Maha Fouad
Background: Conventional full-coverage anterior crown preparations for zirconia often require substantial enamel and dentine reduction and may concentrate palatal-cervical stresses, risking marginal discrepancy and compromised seal. A conservative “Mini-skirt” (MS) design that positions the palatal finish line coronally (above the cingulum) could preserve tooth structure and enhance adhesive support, but its thermo-mechanical performance under thermal cycling and fatigue loading remains unclear. Purpose: To evaluate whether a conservative MS anterior preparation, with a palatal finish line above the cingulum, improves the thermo-mechanical behavior of generation-5 zirconia crowns compared with a conventional full-coverage (CF) design. Methods: Sixty extracted maxillary central incisors were randomly assigned to MS or CF groups (n = 30). Monolithic 4Y zirconia crowns were CAD/CAM-manufactured, air-abraded and adhesively luted. Specimens were thermocycled 10,000 times between 5 °C and 55 °C, then obliquely loaded at 45° for 1.7 × 10⁶ cycles (50 N, 2 Hz); survivors underwent static fracture testing (0.5 mm·min⁻¹). Marginal gaps were quantified from silicone replicas; failures were classified Grades I–IV (restorable = I–III). Finite-element models (~ 1.3 M elements) reproduced boundary conditions to map stress. Results: The MS preparation endured thermo-mechanical ageing markedly better than CF: 93.3% (28/30) versus 53.3% (16/30) of crowns completed the fatigue protocol (χ² = 9.01, p = 0.003). Post-fatigue, median fracture load increased from 860 N (IQR 780–930 N) in CF to 1,140 N (1,030–1,260 N) in MS (p < 0.05). Mean marginal gap contracted from 112 ± 21 μm to 67 ± 14 μm (40% reduction, p < 0.001). Restorable fractures predominated in MS (83%) but were minority in CF (37%); catastrophic Grade IV failures fell from 63% to 17% (χ² = 13.6, p < 0.001). Finite-element analysis corroborated the laboratory data, showing a 40% drop in peak palatal-cervical von Mises stress (415 to 250 MPa) and parallel reductions in tensile dentine stress and cement-shear hotspots. Conclusions: Within the limitations of this in vitro study, the MS preparation showed favorable biomechanical performance under simulated thermo-mechanical loading. These findings provide a preclinical rationale for further investigation of the MS design, although long-term clinical studies are required before definitive clinical recommendations can be made.
A Systematic Multi-Dataset, Multi-Seed Evaluation of Preprocessing Strategies for Retinal Optic Disc and Cup Segmentation
(Multidisciplinary Digital Publishing Institute (MDPI), 2026-09-07) Abdullah Alajmi; Youssef Elnahal; Mohamed Othman; Manal Aljuhani; Amani Alharbi; Ghada Abdelhady
Background/Objectives: Accurate delineation of the optic disc and optic cup in retinal fundus photographs is a prerequisite for automated glaucoma screening. While encoder–decoder segmentation models have advanced considerably, the contribution of upstream preprocessing to segmentation accuracy, and the stability of that contribution across repeated training runs, remain insufficiently characterized. Methods: Five preprocessing pipelines, baseline, Contrast Limited Adaptive Histogram Equalization (CLAHE), Region of Interest (ROI) cropping, ROI+CLAHE, and CLAHE with heavy augmentation, were benchmarked under a fixed EfficientUNet++ model with an EfficientNet-B7 encoder on three publicly available fundus datasets (REFUGE, ORIGA, and Drishti-GS). Every configuration was retrained under three independent random seeds (42, 15, and 89) to assess run-to-run variability. Seed-level standard deviations accompany every reported mean and define the confidence limit on each ranking. Results: On REFUGE, CLAHE with augmentation (Config 5) achieved the strongest mean Dice (disc (Formula presented.) ; cup (Formula presented.) ). On ORIGA, all five configurations clustered within 0.0067 disc Dice; ROI+CLAHE (Config 4) was marginally ahead on disc ( (Formula presented.) ) and augmentation led on the cup ( (Formula presented.) ). On Drishti-GS, all five configurations converged successfully once optimizer and loss settings were corrected; the near-total failures seen in earlier single-run experiments reflected a configuration problem, not the small (81-image) training set. Conclusions: CLAHE applied to full-resolution images is the single most consistently beneficial preprocessing choice across all three datasets. ROI+CLAHE showed a small, initialization-stable advantage on ORIGA, but ROI crop centres were derived from ground-truth centroids, an oracle localization setting, and these results should not be interpreted as achievable by a fully automated pipeline. Data augmentation showed a consistent reduction in initialization sensitivity on small datasets and may be beneficial as a default strategy.
Accuracy of a deep learning–based model for treatment recommendation in adult patients with skeletal Class III malocclusion
(Elsevier Inc., 2026-09) Maha Swelam; Ahmed S. Fouda; Mostafa El Dawlatly; Farid Ali; Mona M. Salah Fayed
Introduction: Treatment planning for adult patients with skeletal Class III malocclusion remains challenging because of overlapping diagnostic criteria and subjective weighting of skeletal vs soft-tissue considerations. This retrospective study aimed to develop and evaluate the accuracy of a convolutional neural network (CNN)-based image classification in predicting treatment approach and supporting orthodontists in deciding between orthodontic camouflage and orthognathic surgery. Methods: Using 1826 pretreatment images of 166 adult patients with skeletal Class III malocclusion (86 camouflage and 80 surgical), a hybrid model was developed that combines both deep learning and machine learning. These images included lateral cephalometric and panoramic radiographs and 9 intraoral and extraoral photographs. Of note, 11 CNN models processed each image type to generate binary predictions that were combined into an 11-dimensional vector and classified using 7 conventional machine learning algorithms. Results: Support vector machine, multilayer perceptron, logistic regression, k-nearest neighbor, and naive Bayes showed no statistically significant difference compared with random forest (P >0.05). Decision tree exhibited statistically significant inferior performance compared with random forest (P <0.01). Significance analysis indicated that soft-tissue photographs had a higher correlation with treatment decisions than that of cephalometric radiographs, although clinical validity requires expert confirmation. Conclusions: A CNN-based ensemble model demonstrated high diagnostic accuracy for predicting camouflage vs surgical treatment in adult patients with skeletal Class III malocclusion within a single-center dataset.