Leveraging line features to improve localization accuracy of point-based visual-inertial SLAM (VI... more Leveraging line features to improve localization accuracy of point-based visual-inertial SLAM (VINS) is gaining interest as they provide additional constraints on scene structure. However, real-time performance when incorporating line features in VINS has not been addressed. This paper presents PL-VINS, a real-time and high-efficiency optimizationbased monocular VINS method with point and line features, developed based on the state-of-the-art point-based VINS-Mono [1]. We observe that current works use the LSD [2] algorithm to extract line features; however, LSD is designed for scene shape representation instead of the pose estimation problem, which becomes the bottleneck for the real-time performance due to its high computational cost. In this paper, we modify the LSD algorithm by studying a hidden parameter tuning and length rejection strategy. The modified LSD algorithm can run at least three times as fast as LSD. Further, by representing space lines with the Plücker coordinates, the residual error in line estimation is modeled in terms of the point-to-line distance, which is then minimized by iteratively updating the minimum four-parameter orthonormal representation of the Plücker coordinates. Experiments in a public benchmark dataset show that the localization error of our method is 12-16% less than that of VINS-Mono at the same pose update frequency.
Reliability of SLAM systems is considered one of the critical requirements in many modern autonom... more Reliability of SLAM systems is considered one of the critical requirements in many modern autonomous systems. This directed the efforts to developing many stateof-the-art systems, creating challenging datasets, and introducing rigorous metrics to measure SLAM system performance. However, the link between datasets and performance in the robustness/resilience context has rarely been explored. In order to fill this void, characterization the operating conditions of SLAM systems is essential in order to provide an environment for quantitative measurement of robustness and resilience. In this paper, we argue that for proper evaluation of SLAM performance, the characterization of SLAM datasets serves as a critical first step. The study starts by reviewing previous efforts for quantitative characterization of SLAM datasets. Then, the problem of perturbations characterization is discussed and the linkage to SLAM robustness/resilience is established. After that, we propose a novel, generic a...
To test the hypothesis that surface roughening and polishing of ceramics have no effect on their ... more To test the hypothesis that surface roughening and polishing of ceramics have no effect on their surface roughness and biofilm adhesion. Materials and Methods: Feldspathic ceramic Vitablocks™ TriLuxe forte (VTF), lithium disilicate glass IPS e.max Press™ (IPS) and zirconia reinforced lithium silicate Vita Suprinity™ (VS) ceramic blocks (n=27 per group) were prepared from sintered CAD blocks using a water-cooled saw. They were further subdivided into 3 subgroups according to the surface treatment protocols (n=9): as prepared, roughened and polished. The surface roughness of the ceramic blocks was measured using an electro-mechanical profilometer. The ceramic sections were inoculated with Streptococcus mutans and incubated for 48 h to form a biofilm. The ceramic surfaces with the biofilms were analyzed using Confocal Laser Scanning Microscopy to calculate the percentage of live bacteria and substratum coverage by the biofilm, and further visualized using scanning electron microscopy. Statistical analysis was done with SPSS software using two-way ANOVA, followed by post hoc Bonferroni test to identify significant differences between the groups. The level of significance was set at p = 0.05. Results: As prepared VTF showed significantly higher mean surface roughness values than as prepared IPS and VS. The mean percentage of live bacteria and biofilm coverage of the substrate were significantly higher in the roughened ceramic blocks than the as prepared and polished blocks for all three ceramic types (p < 0.05). Polished specimens of VS significantly lower percentage of biofilm coverage than the other groups (p < 0.05).
Biological tissues have complex electrical impedance related to the tissue dimension, the interna... more Biological tissues have complex electrical impedance related to the tissue dimension, the internal structure and the arrangement of the constituent cells. Since different tissues have different conductivities and permittivities, the electrical impedance can provide useful information based on heterogeneous tissue structures, physiological states and functions. In vivo bio-impedance breast measurements proved to be a dependable method where these measurements can be adopted to characterize breast tissue into normal and abnormal by a developed normalized coefficient of variation (NCV) as a numerical criterion of the bioimpedance measurements. In this study 26 breasts in 26 women have been scanned with a homemade Electrical Bio-impedance System (EBS). Characteristic breast conductivity and permittivity measurements emerged for Mammographically normal and abnormal cases. CV and NCV are calculated for each case, and the value of NCVs greater than 1.00 corresponds to abnormalities, partic...
Neonatal rat primary myocardial cells were subjected to heat stress in vitro, as a model for inve... more Neonatal rat primary myocardial cells were subjected to heat stress in vitro, as a model for investigating the distribution and expression of Hsp27 and aB-crystallin. After exposure to heat stress at 42uC for different durations, the activities of enzymes expressed during cell damage increased in the supernatant of the heat-stressed myocardial cells from 10 min, and the pathological lesions were characterized by karyopyknosis and acute degeneration. Thus, cell damage was induced at the onset of heat stress. Immunofluorescence analysis showed stronger positive signals for both Hsp27 and aB-crystallin from 10 min to 240 min of exposure compared to the control cells. According to the Western blotting results, during the 480 min of heat stress, no significant variation was found in Hsp27 and aB-crystallin expression; however, significant differences were found in the induction of their corresponding mRNAs. The expression of these small heat shock proteins (sHsps) was probably delayed or...
Women have historically been the most marginalised groups in South Africa, as their political, so... more Women have historically been the most marginalised groups in South Africa, as their political, social, and economic circumstances are precarious. South Africa's post-apartheid constitution has several provisions to protect women's human rights, however enforcing the constitutional responsibilities remains a difficulty owing to different constraints. This paper deals with the status of human rights of women in post apartheid South Africa. The purpose of this paper is to analyse constitutional and legal provisions for the protection of socio – economic and political human rights of women. It also attempts to explore the real situation of women’s rights in independent South Africa. The article concludes some suggestions to overcome the challenges against women’s human rights in South Africa particularly after the apartheid era.
Enterococcus faecalis as an important nosocomial pathogen is critically implicated in the pathoge... more Enterococcus faecalis as an important nosocomial pathogen is critically implicated in the pathogenesis of endocarditis, urinary tract and surgical wound infections. Its major virulence attributes (biofilm formation, production of proteases and hemolytic toxins) enable it to cause extensive host tissue damage. With the alarming increase in enterococcal resistance to antibiotics, novel therapeutics are required to inhibit E. faecalis biofilm formation and virulence. Trans-cinnamaldehyde (TC), the main phytochemical in cinnamon essential oils has demonstrated promising activity against a wide range of pathogens. Here, we comprehensively investigated the effect of TC on planktonic growth, biofilm formation, proteolytic and hemolytic activities, as well as gene regulation in E. faecalis. Our findings revealed that sub-inhibitory concentrations of TC reduced biofilm formation, biofilm exopolysaccharides as well as its proteolytic and hemolytic activities. Mechanistic studies revealed sign...
Current approaches towards subject-specific FE modelling and virtual testing would benefit from e... more Current approaches towards subject-specific FE modelling and virtual testing would benefit from easy-to-use personalization and positioning tools. The PIPER project aims to provide these tools for full human body FE models used in automotive safety as an open-source, easy-to-use software framework that is independent from both model and FE code. In this context the positioning of the spine is of particular interest, while remaining complex because of its high number of dofs. This abstract presents the development of a spline based spinal posture predictor tool relying on linear interpolation between known physiological postures, and its implementation within the PIPER tool.
Proceedings of the International Conference on Knowledge Engineering and Ontology Development, 2012
A formal treatment of conceptualization is essential and a fundamental aspect of knowledge repres... more A formal treatment of conceptualization is essential and a fundamental aspect of knowledge representation, Ontologies and information engineering. Several approaches have been proposed based on extensional logic and extensional reduction model. However, in this paper we highlight several limitations of their applicability for modelling conceptualizations in dynamic and open environments, due to several strong assumptions that are not adequate for dynamic and open environments. To this end we argue that intension based model is a natural and adequate model. We present a model based on the theory of Properties Relations and Propositions. This description takes the concepts and relations as primitives and, as such, irreducible. The proposed description is then extended to describe the world in more details by capturing the properties of the domain concepts.
Liver mesenchymal stem cells), and a combined treatment of Nilotinib and stem cell exosomes from ... more Liver mesenchymal stem cells), and a combined treatment of Nilotinib and stem cell exosomes from the 5 th week to the 9 th week of CCl 4 intoxication. Oxidative stress parameters (e.g. MDA, SOD, GSH, CAT, NO, and NOS) and hydroxyproline content were estimated for each group. Results: results showed a significant positive correlation between Hydroxyproline and MDA, NO and NOS. Also, there is a significant negative correlation between Hydroxyproline and GSH, SOD and CAT. Conclusion: There is a significant positive correlation between Hydroxyproline and MDA, NO and NOS. And there is a significant negative correlation between Hydroxyproline and GSH, SOD, CAT.
Quorum sensing (QS) is a cell-to-cell communication process that regulates major pathogenic attri... more Quorum sensing (QS) is a cell-to-cell communication process that regulates major pathogenic attributes in bacteria including biofilm formation, secretion of virulence factors, and antimicrobial resistance. The two-component Fsr-QS system of the nosocomial pathogen Enterococcus faecalis controls the production of extracellular gelatinase that contributes to biofilm development by enhancing the release of nucleic acids into the biofilm matrix. However, the contribution of this system to the deposition of other biofilm matrix components such as polysaccharides and proteins remains unknown. Using wild type and mutant strains, we discovered that biofilm formation was attenuated by inactivation of the Fsr system or its downstream gelatinase production. Inactivation of the Fsr system caused a modest, yet significant reduction in biofilm metabolic activity without affecting cell counts. Inactivation of the QS-signal sensor FsrC and response regulator FsrA resulted in decreased extracellular polysaccharides and proteins in biofilms in a temporal manner. Irrespective of biofilm age, eDNA levels were reduced in the gelatinase mutant strain. Our results collectively suggest that the Fsr system contributes to the temporal deposition of polysaccharides and proteins into the EPS of E. faecalis biofilm, without affecting bacterial viability. This understanding of the role of the Fsr-QS system in biofilm development may reveal a novel target to develop effective antibiofilm agents to tackle E. faecalis-mediated infections such as in dental root canals, heart valves and surgical sites. This article is protected by copyright. All rights reserved.
Providing a suitable shelter and delivering relief supplies to evacuees in the aftermath of a dis... more Providing a suitable shelter and delivering relief supplies to evacuees in the aftermath of a disaster is among the core responsibilities of relief efforts. Evacuation shelters provide housing to those whose primary residence has been affected by the disaster while basic supplies such as food and water are essential to maintain the safety of the affected population. Fulfilling those demands becomes the responsibility of relief agencies in the aftermath of a disaster due to the need for special transportation modes that can cope with a transportation infrastructure that might have been damaged during the onset of the disaster itself. In the aftermath of a disaster, a part of the population of the affected region are forced to move out of their homes that have been damaged during the onset of the disaster and to head to shelters provided by the relief agencies. Evacuees usually go the nearest shelter they could find without the knowledge of the available sheltering capacities at those shelters. This type of behavior could result in some shelters being overflown with evacuees while other shelters possess excess capacity. Furthermore, those shelters are usually pre-stocked with supplies in anticipation of a disaster but there is no guarantee that there would be a perfect match between the number of evacuees that head to a shelter and the amount of supplies that are present there (i.e. having too many evacuees and low levels of supplies or vice versa). This dissertation introduced a strategy for alleviating the effects of overcrowding in shelters, and of the mismatch between number of evacuees and amount of supplies in shelters in the aftermath of a disaster through the new concept of Relief Supplies and Evacuees Redistribution. This concept, to the extent of our knowledge, has not been addressed in the literature for disaster operations management. The Relief Supplies and Evacuees Redistribution problem consists of managing a fleet of vehicles to redistribute relief supplies and evacuees among shelters in the aftermath of a disaster in order to minimize shelter overcrowding and the impact of supply mismatches experienced by evacuees during the period they have to spend in shelters. A mathematical formulation of the Relief Supplies and Evacuees Redistribution problem is presented in the form of a Mixed Integer Linear Programming model which was used to solve small instances of the problem using commercial solvers. The results of these runs were used to analyze the effect of the new concept of allowing evacuees redistribution and investigate its value. The results of those tests confirmed the benefit of introducing the concept of evacuees redistribution and its potential in reducing overcrowding and shortages of relief supplies in shelters. A more efficient solution algorithm was developed to solve larger instances of the problem with an increased number of shelters and vehicles. This goal was achieved through the development of a problem specific solution procedure built upon the framework of Branch and Price methodology. The solution procedure developed was successful in solving instances of practical size to optimality and it was demonstrated that this approach for solving the problem has the potential to provide efficient solutions to even larger instances of the problem. The solution algorithm developed for the problem through the Branch and Price framework was expanded and used to solve even larger instances of the problem which considered multiple modes of transportation (i.e. boats and helicopters) in moving relief supplies and evacuees between shelters. The Branch and Price solution framework developed to solve the problem was expanded through an alternate solution approach to the pricing subproblem and different column management strategies. The developed solution framework provided efficient solutions to larger instances of the problem which consider a larger number of shelters and a larger and more diverse fleet of transporting vehicles. The main aim of this dissertation could be summarized as an attempt to demonstrate the viability of the concept of Relief Supplies and Evacuees Redistribution as a strategy for managing relief efforts in the aftermath of a disaster and to provide a practical solution methodology that would allow the implementation of such concept in real life disaster scenarios through the management of a fleet of different types of vehicles used to redistribute relief supplies and evacuees between shelters
Asset health monitoring continues to be of increasing importance on productivity, reliability, an... more Asset health monitoring continues to be of increasing importance on productivity, reliability, and cost reduction. Early Fault detection is a keystone of health management as part of the emerging Prognostics and Health Management (PHM) philosophy. This paper proposes a Hidden Markov Model (HMM) to assess the machine health degradation. using Principal Component Analysis (PCA) to enhance features extracted from vibration signals is considered. The enhanced features capture the second order structure of the data. The experimental results based on a bearing test bed show the plausibility of the proposed method.
The integrated dial-a-ride problem (IDARP) concerns of the optimal routes of a set of vehicles th... more The integrated dial-a-ride problem (IDARP) concerns of the optimal routes of a set of vehicles that serve the first and last miles of in combination journeys such that a fixed transport service may carry out the longest part of the journey. It implies some modeling and practical issues. Practical wise, it only integrates a single fixed line. It also does not accept any dial-a-ride problem (DARP) request. From the modeling perspective, the transfer node system enlarges quickly with each new request. It also requires more strengthening strategies to be adopted. The proposed integrated dial-a-ride problem fixed-route selection (IDARP-FRS) handles some of these issues. It extends the IDARP to include iterations over a two-line fixed service. An additional set of constraints is devised to easily switch the proposed model to the IDARP and even accommodate users from the dial-a-ride problem. The IDARP-FRS also introduces a set of newly constructed direction-based constraints, for controlli...
Hepatic fibrosis is a progressive disease with serious clinical complications that arise from abn... more Hepatic fibrosis is a progressive disease with serious clinical complications that arise from abnormal propagation and activation of multiple inflammatory pathways. Nilotinib is an oral tyrosine kinase inhibitor with antifibrotic activity. Mesenchymal stem cells (MSCs) are blank cells and can differentiate into specific cell types. They have the potential to repair and regenerate cells. MSCs have a special paracrine fashion where they produce special exosomes, microvesicles, and cytokines like IL-6, transforming growth factor-beta (TGF-β), and HGF as well as hepatic stellate cell suppressors. This paracrine fashion can decrease collagen deposition, enhance antifibrotic, anti-inflammatory, and angiogenic activity in vitro and in vivo. In our study, the rat’s hepatic stellate cells (HSCs) in addition to different normal cell lines were treated with Nilotinib alone and in combination with liver mesenchymal stem cells conditioned medium (LMSCs-CM) for 24 h. Mono and combined therapy ant...
Due to various issues such as lack of agility, low performance, security issues, and high mainten... more Due to various issues such as lack of agility, low performance, security issues, and high maintenance costs, the organization replaces its legacy information system (LIS). However, with the expansion of information technology, the security of the old system has received great attention. The protection of legacy data and information is critical to the organization. However, achieving safety through modernization, redevelopment, or redesign of LIS is a time-consuming and costly solution, especially in small and medium enterprises (SMEs). In addition, newly developed systems often lose inherent business rules, data integrity, and user trust. In this paper, we propose a Security Modernization Framework (SMF) to inject security measures into LIS without modernizing the existing solution. Fundamentally speaking, SMF is a collection of methods and technologies that enhance the security structure of LIS to protect applications and old data. SMF consists of two layers of security control: data audit trail and user access authorization. This contribution has two key advantages. First, it can help SMEs protect their data and applications from unauthorized access. Second, it is the lowest cost solution to implement security measures in LIS instead of modernizing or replacing the system. SMF has used the oracle technology for authentication, but the examples are also shown in pseudocode to facilitate easy positioning of other technologies.
BACKGROUND To evaluate the voids percentage and the retreatability by different supplementary irr... more BACKGROUND To evaluate the voids percentage and the retreatability by different supplementary irrigation techniques of a matched-taper single cone and epoxy resin-based sealer. METHODS A total of 72 single-rooted premolars were prepared and filled with gutta-percha and MM-Seal. The percentage of voids in the whole root canal and each anatomical part were evaluated by Micro-CT scans. After root filling removal, the teeth were randomly allocated (n=24) to group A, syringe irrigation; group B, Tornado Brush and group C, ultrasonically activated irrigation and rescanned to establish the volume of remnant root filling material. The data relative to voids and retreatment techniques were established by Kruskal-Wallis test. Differences in retreatment time were examined using one-way ANOVA and Tukey's test (P< .05). RESULTS No significant difference was found in the voids percentage between the different root-thirds and between the supplementary irrigation groups in the MM-Seal remnants for the whole root canal and each section. In all groups, the coronal region exhibited more remaining material than other sections. CONCLUSIONS MM-Seal showed low voids percentage and its removal was not significantly improved by supplementary irrigation techniques.
Funding The authors received no specific funding for this work. Conflict of interest Hadir Rostom... more Funding The authors received no specific funding for this work. Conflict of interest Hadir Rostom, Mohamed A. Elhawary and Islam N. Ali have no conflicts of interest related to the content of this manuscript. Ethics approval Not applicable because this article does not contain any studies with human or animal subjects. Consent to participate Not applicable. Consent for publication Not applicable. Availability of data and material Data sharing is not applicable to this article.
Leveraging line features to improve localization accuracy of point-based visual-inertial SLAM (VI... more Leveraging line features to improve localization accuracy of point-based visual-inertial SLAM (VINS) is gaining interest as they provide additional constraints on scene structure. However, real-time performance when incorporating line features in VINS has not been addressed. This paper presents PL-VINS, a real-time and high-efficiency optimizationbased monocular VINS method with point and line features, developed based on the state-of-the-art point-based VINS-Mono [1]. We observe that current works use the LSD [2] algorithm to extract line features; however, LSD is designed for scene shape representation instead of the pose estimation problem, which becomes the bottleneck for the real-time performance due to its high computational cost. In this paper, we modify the LSD algorithm by studying a hidden parameter tuning and length rejection strategy. The modified LSD algorithm can run at least three times as fast as LSD. Further, by representing space lines with the Plücker coordinates, the residual error in line estimation is modeled in terms of the point-to-line distance, which is then minimized by iteratively updating the minimum four-parameter orthonormal representation of the Plücker coordinates. Experiments in a public benchmark dataset show that the localization error of our method is 12-16% less than that of VINS-Mono at the same pose update frequency.
Reliability of SLAM systems is considered one of the critical requirements in many modern autonom... more Reliability of SLAM systems is considered one of the critical requirements in many modern autonomous systems. This directed the efforts to developing many stateof-the-art systems, creating challenging datasets, and introducing rigorous metrics to measure SLAM system performance. However, the link between datasets and performance in the robustness/resilience context has rarely been explored. In order to fill this void, characterization the operating conditions of SLAM systems is essential in order to provide an environment for quantitative measurement of robustness and resilience. In this paper, we argue that for proper evaluation of SLAM performance, the characterization of SLAM datasets serves as a critical first step. The study starts by reviewing previous efforts for quantitative characterization of SLAM datasets. Then, the problem of perturbations characterization is discussed and the linkage to SLAM robustness/resilience is established. After that, we propose a novel, generic a...
To test the hypothesis that surface roughening and polishing of ceramics have no effect on their ... more To test the hypothesis that surface roughening and polishing of ceramics have no effect on their surface roughness and biofilm adhesion. Materials and Methods: Feldspathic ceramic Vitablocks™ TriLuxe forte (VTF), lithium disilicate glass IPS e.max Press™ (IPS) and zirconia reinforced lithium silicate Vita Suprinity™ (VS) ceramic blocks (n=27 per group) were prepared from sintered CAD blocks using a water-cooled saw. They were further subdivided into 3 subgroups according to the surface treatment protocols (n=9): as prepared, roughened and polished. The surface roughness of the ceramic blocks was measured using an electro-mechanical profilometer. The ceramic sections were inoculated with Streptococcus mutans and incubated for 48 h to form a biofilm. The ceramic surfaces with the biofilms were analyzed using Confocal Laser Scanning Microscopy to calculate the percentage of live bacteria and substratum coverage by the biofilm, and further visualized using scanning electron microscopy. Statistical analysis was done with SPSS software using two-way ANOVA, followed by post hoc Bonferroni test to identify significant differences between the groups. The level of significance was set at p = 0.05. Results: As prepared VTF showed significantly higher mean surface roughness values than as prepared IPS and VS. The mean percentage of live bacteria and biofilm coverage of the substrate were significantly higher in the roughened ceramic blocks than the as prepared and polished blocks for all three ceramic types (p < 0.05). Polished specimens of VS significantly lower percentage of biofilm coverage than the other groups (p < 0.05).
Biological tissues have complex electrical impedance related to the tissue dimension, the interna... more Biological tissues have complex electrical impedance related to the tissue dimension, the internal structure and the arrangement of the constituent cells. Since different tissues have different conductivities and permittivities, the electrical impedance can provide useful information based on heterogeneous tissue structures, physiological states and functions. In vivo bio-impedance breast measurements proved to be a dependable method where these measurements can be adopted to characterize breast tissue into normal and abnormal by a developed normalized coefficient of variation (NCV) as a numerical criterion of the bioimpedance measurements. In this study 26 breasts in 26 women have been scanned with a homemade Electrical Bio-impedance System (EBS). Characteristic breast conductivity and permittivity measurements emerged for Mammographically normal and abnormal cases. CV and NCV are calculated for each case, and the value of NCVs greater than 1.00 corresponds to abnormalities, partic...
Neonatal rat primary myocardial cells were subjected to heat stress in vitro, as a model for inve... more Neonatal rat primary myocardial cells were subjected to heat stress in vitro, as a model for investigating the distribution and expression of Hsp27 and aB-crystallin. After exposure to heat stress at 42uC for different durations, the activities of enzymes expressed during cell damage increased in the supernatant of the heat-stressed myocardial cells from 10 min, and the pathological lesions were characterized by karyopyknosis and acute degeneration. Thus, cell damage was induced at the onset of heat stress. Immunofluorescence analysis showed stronger positive signals for both Hsp27 and aB-crystallin from 10 min to 240 min of exposure compared to the control cells. According to the Western blotting results, during the 480 min of heat stress, no significant variation was found in Hsp27 and aB-crystallin expression; however, significant differences were found in the induction of their corresponding mRNAs. The expression of these small heat shock proteins (sHsps) was probably delayed or...
Women have historically been the most marginalised groups in South Africa, as their political, so... more Women have historically been the most marginalised groups in South Africa, as their political, social, and economic circumstances are precarious. South Africa's post-apartheid constitution has several provisions to protect women's human rights, however enforcing the constitutional responsibilities remains a difficulty owing to different constraints. This paper deals with the status of human rights of women in post apartheid South Africa. The purpose of this paper is to analyse constitutional and legal provisions for the protection of socio – economic and political human rights of women. It also attempts to explore the real situation of women’s rights in independent South Africa. The article concludes some suggestions to overcome the challenges against women’s human rights in South Africa particularly after the apartheid era.
Enterococcus faecalis as an important nosocomial pathogen is critically implicated in the pathoge... more Enterococcus faecalis as an important nosocomial pathogen is critically implicated in the pathogenesis of endocarditis, urinary tract and surgical wound infections. Its major virulence attributes (biofilm formation, production of proteases and hemolytic toxins) enable it to cause extensive host tissue damage. With the alarming increase in enterococcal resistance to antibiotics, novel therapeutics are required to inhibit E. faecalis biofilm formation and virulence. Trans-cinnamaldehyde (TC), the main phytochemical in cinnamon essential oils has demonstrated promising activity against a wide range of pathogens. Here, we comprehensively investigated the effect of TC on planktonic growth, biofilm formation, proteolytic and hemolytic activities, as well as gene regulation in E. faecalis. Our findings revealed that sub-inhibitory concentrations of TC reduced biofilm formation, biofilm exopolysaccharides as well as its proteolytic and hemolytic activities. Mechanistic studies revealed sign...
Current approaches towards subject-specific FE modelling and virtual testing would benefit from e... more Current approaches towards subject-specific FE modelling and virtual testing would benefit from easy-to-use personalization and positioning tools. The PIPER project aims to provide these tools for full human body FE models used in automotive safety as an open-source, easy-to-use software framework that is independent from both model and FE code. In this context the positioning of the spine is of particular interest, while remaining complex because of its high number of dofs. This abstract presents the development of a spline based spinal posture predictor tool relying on linear interpolation between known physiological postures, and its implementation within the PIPER tool.
Proceedings of the International Conference on Knowledge Engineering and Ontology Development, 2012
A formal treatment of conceptualization is essential and a fundamental aspect of knowledge repres... more A formal treatment of conceptualization is essential and a fundamental aspect of knowledge representation, Ontologies and information engineering. Several approaches have been proposed based on extensional logic and extensional reduction model. However, in this paper we highlight several limitations of their applicability for modelling conceptualizations in dynamic and open environments, due to several strong assumptions that are not adequate for dynamic and open environments. To this end we argue that intension based model is a natural and adequate model. We present a model based on the theory of Properties Relations and Propositions. This description takes the concepts and relations as primitives and, as such, irreducible. The proposed description is then extended to describe the world in more details by capturing the properties of the domain concepts.
Liver mesenchymal stem cells), and a combined treatment of Nilotinib and stem cell exosomes from ... more Liver mesenchymal stem cells), and a combined treatment of Nilotinib and stem cell exosomes from the 5 th week to the 9 th week of CCl 4 intoxication. Oxidative stress parameters (e.g. MDA, SOD, GSH, CAT, NO, and NOS) and hydroxyproline content were estimated for each group. Results: results showed a significant positive correlation between Hydroxyproline and MDA, NO and NOS. Also, there is a significant negative correlation between Hydroxyproline and GSH, SOD and CAT. Conclusion: There is a significant positive correlation between Hydroxyproline and MDA, NO and NOS. And there is a significant negative correlation between Hydroxyproline and GSH, SOD, CAT.
Quorum sensing (QS) is a cell-to-cell communication process that regulates major pathogenic attri... more Quorum sensing (QS) is a cell-to-cell communication process that regulates major pathogenic attributes in bacteria including biofilm formation, secretion of virulence factors, and antimicrobial resistance. The two-component Fsr-QS system of the nosocomial pathogen Enterococcus faecalis controls the production of extracellular gelatinase that contributes to biofilm development by enhancing the release of nucleic acids into the biofilm matrix. However, the contribution of this system to the deposition of other biofilm matrix components such as polysaccharides and proteins remains unknown. Using wild type and mutant strains, we discovered that biofilm formation was attenuated by inactivation of the Fsr system or its downstream gelatinase production. Inactivation of the Fsr system caused a modest, yet significant reduction in biofilm metabolic activity without affecting cell counts. Inactivation of the QS-signal sensor FsrC and response regulator FsrA resulted in decreased extracellular polysaccharides and proteins in biofilms in a temporal manner. Irrespective of biofilm age, eDNA levels were reduced in the gelatinase mutant strain. Our results collectively suggest that the Fsr system contributes to the temporal deposition of polysaccharides and proteins into the EPS of E. faecalis biofilm, without affecting bacterial viability. This understanding of the role of the Fsr-QS system in biofilm development may reveal a novel target to develop effective antibiofilm agents to tackle E. faecalis-mediated infections such as in dental root canals, heart valves and surgical sites. This article is protected by copyright. All rights reserved.
Providing a suitable shelter and delivering relief supplies to evacuees in the aftermath of a dis... more Providing a suitable shelter and delivering relief supplies to evacuees in the aftermath of a disaster is among the core responsibilities of relief efforts. Evacuation shelters provide housing to those whose primary residence has been affected by the disaster while basic supplies such as food and water are essential to maintain the safety of the affected population. Fulfilling those demands becomes the responsibility of relief agencies in the aftermath of a disaster due to the need for special transportation modes that can cope with a transportation infrastructure that might have been damaged during the onset of the disaster itself. In the aftermath of a disaster, a part of the population of the affected region are forced to move out of their homes that have been damaged during the onset of the disaster and to head to shelters provided by the relief agencies. Evacuees usually go the nearest shelter they could find without the knowledge of the available sheltering capacities at those shelters. This type of behavior could result in some shelters being overflown with evacuees while other shelters possess excess capacity. Furthermore, those shelters are usually pre-stocked with supplies in anticipation of a disaster but there is no guarantee that there would be a perfect match between the number of evacuees that head to a shelter and the amount of supplies that are present there (i.e. having too many evacuees and low levels of supplies or vice versa). This dissertation introduced a strategy for alleviating the effects of overcrowding in shelters, and of the mismatch between number of evacuees and amount of supplies in shelters in the aftermath of a disaster through the new concept of Relief Supplies and Evacuees Redistribution. This concept, to the extent of our knowledge, has not been addressed in the literature for disaster operations management. The Relief Supplies and Evacuees Redistribution problem consists of managing a fleet of vehicles to redistribute relief supplies and evacuees among shelters in the aftermath of a disaster in order to minimize shelter overcrowding and the impact of supply mismatches experienced by evacuees during the period they have to spend in shelters. A mathematical formulation of the Relief Supplies and Evacuees Redistribution problem is presented in the form of a Mixed Integer Linear Programming model which was used to solve small instances of the problem using commercial solvers. The results of these runs were used to analyze the effect of the new concept of allowing evacuees redistribution and investigate its value. The results of those tests confirmed the benefit of introducing the concept of evacuees redistribution and its potential in reducing overcrowding and shortages of relief supplies in shelters. A more efficient solution algorithm was developed to solve larger instances of the problem with an increased number of shelters and vehicles. This goal was achieved through the development of a problem specific solution procedure built upon the framework of Branch and Price methodology. The solution procedure developed was successful in solving instances of practical size to optimality and it was demonstrated that this approach for solving the problem has the potential to provide efficient solutions to even larger instances of the problem. The solution algorithm developed for the problem through the Branch and Price framework was expanded and used to solve even larger instances of the problem which considered multiple modes of transportation (i.e. boats and helicopters) in moving relief supplies and evacuees between shelters. The Branch and Price solution framework developed to solve the problem was expanded through an alternate solution approach to the pricing subproblem and different column management strategies. The developed solution framework provided efficient solutions to larger instances of the problem which consider a larger number of shelters and a larger and more diverse fleet of transporting vehicles. The main aim of this dissertation could be summarized as an attempt to demonstrate the viability of the concept of Relief Supplies and Evacuees Redistribution as a strategy for managing relief efforts in the aftermath of a disaster and to provide a practical solution methodology that would allow the implementation of such concept in real life disaster scenarios through the management of a fleet of different types of vehicles used to redistribute relief supplies and evacuees between shelters
Asset health monitoring continues to be of increasing importance on productivity, reliability, an... more Asset health monitoring continues to be of increasing importance on productivity, reliability, and cost reduction. Early Fault detection is a keystone of health management as part of the emerging Prognostics and Health Management (PHM) philosophy. This paper proposes a Hidden Markov Model (HMM) to assess the machine health degradation. using Principal Component Analysis (PCA) to enhance features extracted from vibration signals is considered. The enhanced features capture the second order structure of the data. The experimental results based on a bearing test bed show the plausibility of the proposed method.
The integrated dial-a-ride problem (IDARP) concerns of the optimal routes of a set of vehicles th... more The integrated dial-a-ride problem (IDARP) concerns of the optimal routes of a set of vehicles that serve the first and last miles of in combination journeys such that a fixed transport service may carry out the longest part of the journey. It implies some modeling and practical issues. Practical wise, it only integrates a single fixed line. It also does not accept any dial-a-ride problem (DARP) request. From the modeling perspective, the transfer node system enlarges quickly with each new request. It also requires more strengthening strategies to be adopted. The proposed integrated dial-a-ride problem fixed-route selection (IDARP-FRS) handles some of these issues. It extends the IDARP to include iterations over a two-line fixed service. An additional set of constraints is devised to easily switch the proposed model to the IDARP and even accommodate users from the dial-a-ride problem. The IDARP-FRS also introduces a set of newly constructed direction-based constraints, for controlli...
Hepatic fibrosis is a progressive disease with serious clinical complications that arise from abn... more Hepatic fibrosis is a progressive disease with serious clinical complications that arise from abnormal propagation and activation of multiple inflammatory pathways. Nilotinib is an oral tyrosine kinase inhibitor with antifibrotic activity. Mesenchymal stem cells (MSCs) are blank cells and can differentiate into specific cell types. They have the potential to repair and regenerate cells. MSCs have a special paracrine fashion where they produce special exosomes, microvesicles, and cytokines like IL-6, transforming growth factor-beta (TGF-β), and HGF as well as hepatic stellate cell suppressors. This paracrine fashion can decrease collagen deposition, enhance antifibrotic, anti-inflammatory, and angiogenic activity in vitro and in vivo. In our study, the rat’s hepatic stellate cells (HSCs) in addition to different normal cell lines were treated with Nilotinib alone and in combination with liver mesenchymal stem cells conditioned medium (LMSCs-CM) for 24 h. Mono and combined therapy ant...
Due to various issues such as lack of agility, low performance, security issues, and high mainten... more Due to various issues such as lack of agility, low performance, security issues, and high maintenance costs, the organization replaces its legacy information system (LIS). However, with the expansion of information technology, the security of the old system has received great attention. The protection of legacy data and information is critical to the organization. However, achieving safety through modernization, redevelopment, or redesign of LIS is a time-consuming and costly solution, especially in small and medium enterprises (SMEs). In addition, newly developed systems often lose inherent business rules, data integrity, and user trust. In this paper, we propose a Security Modernization Framework (SMF) to inject security measures into LIS without modernizing the existing solution. Fundamentally speaking, SMF is a collection of methods and technologies that enhance the security structure of LIS to protect applications and old data. SMF consists of two layers of security control: data audit trail and user access authorization. This contribution has two key advantages. First, it can help SMEs protect their data and applications from unauthorized access. Second, it is the lowest cost solution to implement security measures in LIS instead of modernizing or replacing the system. SMF has used the oracle technology for authentication, but the examples are also shown in pseudocode to facilitate easy positioning of other technologies.
BACKGROUND To evaluate the voids percentage and the retreatability by different supplementary irr... more BACKGROUND To evaluate the voids percentage and the retreatability by different supplementary irrigation techniques of a matched-taper single cone and epoxy resin-based sealer. METHODS A total of 72 single-rooted premolars were prepared and filled with gutta-percha and MM-Seal. The percentage of voids in the whole root canal and each anatomical part were evaluated by Micro-CT scans. After root filling removal, the teeth were randomly allocated (n=24) to group A, syringe irrigation; group B, Tornado Brush and group C, ultrasonically activated irrigation and rescanned to establish the volume of remnant root filling material. The data relative to voids and retreatment techniques were established by Kruskal-Wallis test. Differences in retreatment time were examined using one-way ANOVA and Tukey's test (P< .05). RESULTS No significant difference was found in the voids percentage between the different root-thirds and between the supplementary irrigation groups in the MM-Seal remnants for the whole root canal and each section. In all groups, the coronal region exhibited more remaining material than other sections. CONCLUSIONS MM-Seal showed low voids percentage and its removal was not significantly improved by supplementary irrigation techniques.
Funding The authors received no specific funding for this work. Conflict of interest Hadir Rostom... more Funding The authors received no specific funding for this work. Conflict of interest Hadir Rostom, Mohamed A. Elhawary and Islam N. Ali have no conflicts of interest related to the content of this manuscript. Ethics approval Not applicable because this article does not contain any studies with human or animal subjects. Consent to participate Not applicable. Consent for publication Not applicable. Availability of data and material Data sharing is not applicable to this article.
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