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Landslide susceptibility mapping using machine learning algorithms and comparison of their performance at Abha Basin,Asir Region,Saudi Arabia

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Geoscience Frontiers 2021年第2期12卷 639-655页

作者： Ahmed mohamed youssef Hamid Reza Pourghasemi Geology Department Faculty of ScienceSohag UniversityEgypt Geological Hazards Department Applied Geology SectorSaudi Geological SurveyP.O.Box 54141Jeddah21514Saudi Arabia Department of Natural Resources and Environmental Engineering College of AgricultureShiraz UniversityShirazIran

The current study aimed at evaluating the capabilities of seven advanced machine learning techniques(MLTs),including,Support Vector Machine(SVM),Random Forest(RF),Multivariate Adaptive Regression Spline(MARS),Artificial Neural Network(ANN),Quadratic Discriminant Analysis(QDA),Linear Discriminant Analysis(LDA),and Naive Bayes(NB),for landslide susceptibility modeling and comparison of their *** machine learning algorithms with spatial data types for landslide susceptibility mapping is a vitally important *** study was carried out using GIS and R open source software at Abha Basin,Asir Region,Saudi ***,a total of 243 landslide locations were identified at Abha Basin to prepare the landslide inventory map using different data *** the landslide areas were randomly separated into two groups with a ratio of 70%for training and 30%for validating *** landslide-variables were generated for landslide susceptibility modeling,which include altitude,lithology,distance to faults,normalized difference vegetation index(NDVI),landuse/landcover(LULC),distance to roads,slope angle,distance to streams,profile curvature,plan curvature,slope length(LS),and *** area under curve(AUC-ROC)approach has been applied to evaluate,validate,and compare the MLTs *** results indicated that AUC values for seven MLTs range from 89.0%for QDA to 95.1%for *** findings showed that the RF(AUC=95.1%)and LDA(AUC=941.7%)have produced the best performances in comparison to other *** outcome of this study and the landslide susceptibility maps would be useful for environmental protection.

关键词： Landslide susceptibility Machine learning algorithms Variables importance Saudi Arabia

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Paleoecology of Benthic Foraminifera in Coral Reefs Recorded in the Jurassic Tuwaiq Mountain Formation of the Khashm Al-Qaddiyah Area, Central Saudi Arabia

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Journal of Earth Science 2015年第2期26卷 224-235页

作者： mohamed youssef Abdelbaset S.El-Sorogy Department of Geology and Geophysics College of Science King Saud University Department of Geology Faculty of Science South Valley University Department of Geology Faculty of Science Zagazig University

Thirty three benthic foraminiferal species belong to 23 genera and 16 families have been recorded from the coral reefs of the Callovian Tuwaiq Formation, Khashm AI-Qaddiyah area, Central Saudi Arabia. Three species： Astacolus qaddiyahensis, Nodosaria riyadhensis, Siderolites jurassica are believed to be new. Nearly all identified foraminifera are of Atlantie-Miditeranean affinity. The foraminiferal assemblage recorded in the present work is mixed of open marine, moderately deep marine conditions associations and shallow to deep lagoon. The reefal part of upper Twiaq Formation may have been deposited in shallow water of lower to middle shelf depth （20-50 m） as indicated by abundant corals and benthic foraminifera. The coral fauna and bearing benthic foraminifera indicated moderate water energy.

关键词： coral reef benthic foraminifera Jurassic Tuwaiq Formation Saudi Arabia.

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Fabrication,characterization,and electrical conductivity properties of Pr_6O_(11) nanoparticles

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Journal of Rare Earths 2013年第7期31卷 701-708页

作者： Bahaa M.Abu-Zied youssef A.mohamed Abdullah M.Asiri Chemistry Department Faculty of ScienceKing Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia Chemistry Department Faculty of ScienceAssiut University71516 AssiutEgypt Center of Excellence for Advanced Materials Research(CEAMR) King Abdulaziz UniversityP.O.Box 80203Jeddah 21589Saudi Arabia

PrrOll nanoparticles were obtained by subsequent thermal decomposition of the as-prepared precipitate formed under ambient temperature and pressure using NaOH as precipitant. The calcination process was affected, for 1 h in static air atmosphere, at 400-700 ℃ temperature range. The different samples were characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM）, field emission scanning electron microscopy （FE-SEM）, thermogravimetric analysis （TGA）, in situ electrical conductivity, and N2 adsorption/desorption. The obtained results demonstrated that nano-crystalline Pr6O11, with crystallites size of 6-12 nm, started to form at 500 ℃. Such value increased to 20-33 nm for the sample calcined at 700℃. The as-synthesized PrrOll nanoparticles presented high electrical conductivity due to electron hopping between Pr（III）-Pr（IV） pairs.

关键词： nanocrystalline praseodymium oxide Pr6O11 nano structured materials electrical conductivity rare earths

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Preparation and Reactions of 2-Methyl-7-（3-methyl-5-oxo-1- phenyl-2-pyrazolin-4-yl）-5-arylthiazolo[3,2-a]- pyrimido[4,5-d]oxazin-4（5H）-one

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Chinese Journal of Chemistry 2011年第7期29卷 1473-1482页

作者： youssef, mohamed Salah K. Abbady, mohamed S. Ahmed, Ragaa A. Omar, Ahmed A. Chemistry Department Faculty of Science Assiut University Assiut 71516 Egypt

Ethyl 7-amino-3-（3-methyl-5-oxo- 1-phenyl-2-pyrazolin-4-yl）-5-aryl-5H-thiazolo[3,2-a]pyrimidine-6-carboxy- late was hydrolyzed with an ethanolic sodium hydroxide and the sodium salt thus formed underwent cyclization with acetic anhydride to afford 2-methyl-7-（3-methyl-5-oxo-l-phenyl-2-pyrazolin-4-yl）-5-arylthiazolo[3,2-a]- pyrimido[4,5-d]oxazin-4（SH）-one. This compound was transformed to related heterocyclic systems via its reaction with various reagents. The biological activity of the prepared compounds was tested against Gram positive and Gram negative bacteria as well as yeast-like and filamentous fungi. They revealed in some cases excellent biocidal properties.

关键词： thiazolopyrimidooxazinone thiazolopyrimidopyrimidines antimicrobial activity

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Mapping the Mega Paleodrainage Basin Using Shuttle Radar Topography Mission in Eastern Sahara and Its Impact on the New Development Projects in Southern Egypt

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Geo-Spatial Information Science 2009年第3期12卷 182-190页

作者： Ahmed mohamed youssef Geological Engineering and GIS Geology Department Faculty of Science Sohag University

In the current study, the shuttle radar topography mission (SRTM) data, with～90 m horizontal resolution, were used to delineate the paleodrainage system and their mega basin extent in the East Sahara area. One mega-drainage basin has been detected, covering an area of 256 000 km2. It is classified into two sub mega basins. The Uweinate sub mega basin, which is composed of four main tributaries, collected water from a vast catchment region and drained eastward from the north, west, and southwest, starting at highland areas. The first subwatershed basin is in the northern plateau, south of the Abu-Balas area, with a total catchment area of 25 045 km2. The second subwatershed is in the Gilf Kebir plateau and has a total catchment area of 38 257 km2. The third subwatershed drains from the Uweinate highlands and has a catchment area of 46 154 km2. The fourth subwatershed, which is known in literature as Wadi Mokhtafi in its upper reach and Wadi Arid in its lower reach, drains the northwestern highlands of Sudan and has a total catchment area of 28 653 km2. The Tushka sub mega basin includes one watershed that drains from the northeast highlands of Sudan and has a total catchment area of 63 019 km2. The Uweinate and Tushka sub mega basins are joined together to the North of the Tushka depression, which drains northward toward the Kharga depression. This study indicates that the Eastern Sahara Mega Basin is a closed hydrological system independent of the other drainage systems, such as the Nile hydrosystem and the Qena Valley system. The present research illustrates the capability of the SRTM data in mapping the paleochannel networks, as well as estimate the catchment area and direction of the water flow. Finally, the study reveals that the four areas could be potentially used for different reclamation activities due to the ground water accumulations possibilities.

关键词： GIS paleodrainages SRTM hydro-tools groundwater potentiality

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Association analysis of FTO gene polymorphisms and obesity risk among Egyptian children and adolescents

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Genes & Diseases 2017年第3期4卷 170-175页

作者： Samar Samir Abdelmajed mohamed youssef Moushira Erfan Zaki Naglaa Abu-Mandil Hassan Somaia Ismail October University for Modern Sciences and Arts(MSA) GizaEgypt Organic chemistry Department Faculty of scienceCairo UniversityEgypt Biological Anthropology Department Medical Research DivisionNational Research CentreEgypt Medical Molecular Genetics Department Human Genetics and Genome Research DivisionNational Research CentreGizaEgypt

Obesity is a common disorder that has a significant impact on human health as it may lead to many serious diseases and sometimes *** genome-wide association studies(GWAS)confirmed that there is a relationship between some variants in the first intron of the fat mass and obesity associated(FTO)gene and obesity in adults and children in different ethnic *** our study,the association of the FTO rs9939609 and rs17817449 variants with obesity was investigated in Egyptian children and *** examined rs9939609 and rs17817449 polymorphisms in 100 control and 100 obese cases,we used the restriction fragment length polymorphism(RFLP)technique to genotype the *** current study showed that there were no significant differences(P>0.05)between the cases and controls in both variants of rs17817449 and rs9939609 ***,there were significant correlations between rs17817449 and cholesterol and between rs9939609 and *** Current Study although the two variants(rs9939609 and rs17817449)didn’t show an association with obesity,but there was a correlation between the lipid profile and these two variants.

关键词： Children Egyptians Fat mass and obesity associated gene(FTO) Obesity Variants

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Surgical Outcome of Fusion in Recurrent Lumbar Disc Herniation

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Open Journal of Modern Neurosurgery 2020年第1期10卷 157-166页

作者： Ahmed Taha mohamed youssef Neurosurgery Department Faculty of Medicine Al-Azhar University Damietta Egypt

Background Data: Recurrent lumbar disc herniation means re-herniation of disc on the same site and at the same level where a previous discectomy had been performed: recurrent lumbar disc herniation occurs in 7% to 24% of patient underwent discectomy. Tow mean surgical options after reherniated lumbar disc are revision discectomy alone or revision discectomy with fusion discectomy alone in recurrent lumbar disc herniation may not be an efficient treatment without fusion. Objective: To evaluate the efficacy and safety of revision discectomy with fusion in management of recurrent lumbar disc. Study Design: Retrospective study reviewed all patient underwent revision discectomy with fusion, they were 40 patients operated for recurrent lumbar disc from September 2014 to April 2018 in Al-Azhar University Hospital Damietta. Pre- and post-operative data collection and analysis of the outcome were completed based on the “Japanese Orthopedic Association score” (JOAs), and radiographic follow-up. Patients and Methods: 40 patients (30 male and 10 female) underwent revision discectomy with fusion as surgical management for reherniated lumbar disc from September 2014 to April 2018. All patients presented with low back pain and radicular pain with mean duration of 18 months. The patients were investigated by standard plain X-ray CT SCAN and MRI of the lumbar spine. All patients had a discectomy and postero-lateral fusion in revision surgery. These patients followed post operatively clinically for improving pain and neural function, and radiologically for disc removal stability and fusion. Results: The age ranged from 30 to 60 years, mean age was 45 years, male to female ratio 3:1. Follow-up ranged from 18 - 30 months with a mean follow-up 24 months. 30 patients had an excellent outcome, 6 patients had a good outcome, 2 patients had a fair outcome, and 2 patients had a poor outcome. Conclusion: Recurrent lumbar disc herniation occurs in 7% to 24% of patient underwent discectomy. Rev

关键词： Reherniated Lumbar Disc Postero-Lateral Fusion Revision Discectomy

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Surgical Results of Posterior Lumbar Interbody Fusion with Transpedicular Fixation in Management of Spondylolisthesis

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Open Journal of Modern Neurosurgery 2020年第1期10卷 146-156页

作者： Ahmed Taha mohamed youssef Neurosurgery Department Faculty of Medicine Al-Azhar University Damietta Egypt

Objective: To evaluate the surgical results of posterior lumber interbody fusion with transpedicular fixation with rod screw system in management of spondylolisthesis. Study Design: Retrospective study reviewed all patient treated by lumber interbody fusion with transpedicular fixation with rod screw system. Patients and Methods: They were 40 patients operated for lumber and lumbosacral spondylolisthesis from Feb 2014 to April 2017 in Al-Azhar university hospital. These patients followed postoperatively clinically for improved neural function and for fusion stability and hardware fixation by radiological investigation. Data about pain intensity (by Visual Analogue Scale) was collected pre- and postoperatively;and outcome was assessed by Oswetry disability index (ODI). Outcome was graded as excellent, good, fair, or poor. Pre- and Post-operative data were statistically compared. Results: The mean age was 45 years (range between 30 - 60 years) with female sex predominance (male:female = 1:3). They had lytic (n = 30) or degenerative (n = 10) spondylolisthesis;and all underwent PLIF (posterior lumbar interbody fusion). In lytic group, the level was L4/L5 in 19 patients and L5/S1 in 11 patients, while in degenerative group the level was L4/L5 in 4 patients, L5/S1 in 3 patients, L2/L3 in 2 and L3/L4 in one patient. The spondylolisthesis grade was grade I among 25 subjects, grade two among 11 subjects and retrolisthesis among 4 subjects. Sensory deficits reported in 22 subjects (19 had lytic and 3 had degenerative spondylolisthesis);while motor deficits reported among 10 subjects and reduced reflexes among 8 subjects. The outcome was excellent, good, and fair among 30, 7, and 3 subjects respectively. The return to previous levels of activity was reported among 32 patients. VAS was 3.5 ± 2.94 at the end of follow up, while ODI was 28% and 36.0% and 3 and 6 months respectively. Conclusion: PLIF associated with transpedicular rod screw fixation system for management of spondy

关键词： Spondylolisthesis Posterior Lumbar Interbody Fusion Transpedicular Fixation

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易测量非球面定义及应用（英文）

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中国光学 2017年第2期10卷 256-266页

作者： youssef Al-Khatib mohamed Fawaz Mousselly MAMOUN Naim 叙利亚应用科学与技术高等学校大马士革31983

本文提出了一种新型、易于用传统光学干涉仪测量的非球面。该非球面的检测主要基于Zemax光学程序软件设计的多重配置特性。第一配置为易于测量非球面,第二配置为采用平行平面玻璃板或单透镜作为零位校正器,用于检测第一配置的非球面。... 详细信息

本文提出了一种新型、易于用传统光学干涉仪测量的非球面。该非球面的检测主要基于Zemax光学程序软件设计的多重配置特性。第一配置为易于测量非球面,第二配置为采用平行平面玻璃板或单透镜作为零位校正器,用于检测第一配置的非球面。本文通过一些实例,说明了易测量非球面检测技术的应用和优势,证实了与圆锥或普通非球面相比,易测量非球面更易于操作与检测,同时有利于减小光学像差。

关键词：易测量非球面干涉仪零位检验

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Rod and Screw Fixation for Cranio-Cervical Instability

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Open Journal of Modern Neurosurgery 2020年第1期10卷 19-26页

作者： Hedaya Hendam Ahmed Taha mohamed youssef Department of Neurosurgery Al Azhar Faculty of Medicine Damietta Egypt

Background Data: Atlanto-occipital dislocation is a rare and fatal condition. Pain, limitation of movements, and weakness, were the main complaints of patients with upper cervical lesions. Internal fixation and fusion was indicated in all patients of Atlanto occipital dislocation with deficits. CT scan is the imaging modality of choice for evaluation. Objective: To evaluate the efficacy and safety of rod and screw fixation in cranio-cervical instability. Study Design: Retrospective study reviewed all patient treated by rod and screw fixation, they were 12 patient operated for atlanto-occipital instability from April 2013 to April 2016 in Alazher University Hospital Damietta. Pre and postoperative data collection and analysis of the outcome were completed based on the Frankel classification and grading. Patients and Methods: We operated 12 patients, 10 with traumatic and 2 with pathologically diagnosed Atlanto occipital instability. From April 2013 to April 2016. All patients presented with neck pain, limitation of neck movement, and neurological deficits. The patients were investigated by standard plain X ray to the cervical spine, CT scan and MRI of the cervical spine pre-operatively, and they operated thorough posterior Cranio-cervical fixation. These patients followed post-operatively clinically for improving neural functions and radiologically for alignment, stability, fusion and efficacy of hard ware fixation. Results: The mean age of the studied cases was 42.1 years, trauma was the cause of instability in 10 patients, and 2 patients one with rheumatoid arthritis and one with neoplastic lesion. The mean follows up period is 14.7 months. We used screw rod system in posterior craniocervical fixation with iliac bone graft without operative or post-operative complications. All our patients were improved neurologically post-operatively and no hardware failure during the follow up period. Conclusion: Craniocervical instability was rare condition, with miss diagnosis

关键词： Spine Atlanto-Axial Atlanto-Occipital Cranio-Cervical Internal Fixation

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