245 research outputs found

    Gap sequences of 1-Weierstrass points on non-hyperelliptic curves of genus 10

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    In this paper, we compute the 1-gap sequences of 1-Weierstrass points on non-hyperelliptic smooth projective curves of genus 10. Furthermore, the geometry of such points is classified as flexes, sextactic and tentactic points. Also, an upper bounds for their numbers are estimated.Comment: 12 page

    The Role of Human α7-Nicotinic Acetylcholine Receptors in Mediating Neuroprotective Action of Curcumin

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    Curcumin is a polyphenolic compound isolated from the rhizomes of Curcuma longa. Curcumin has been demonstrated to have antioxidant, anti-inflammatory, and anticancer properties. Moreover, it has been shown to exhibit beneficial effects in the treatment of several neurodegenerative diseases including Alzheimer’s and Parkinson’s diseases. However, the molecular and cellular targets mediating the pharmacological actions of curcumin remain largely unknown. In this study, the effects of curcumin application on the functional properties of the nicotinic acetylcholine receptor, a prototype for ligand-gated ion channels were investigated. Using the two-electrode voltage clamp technique, the results showed that curcumin co-application caused a significant potentiation of the action of human α7-nicotinic acetylcholine receptors (α7-nAChR) expressed in Xenopus oocytes. Importantly, curcumin was found less effective on other nicotinic receptor subunit combinations and other members of ligand-gated ion channels. Curcumin significantly decreased desensitization of α7-nAChR suggesting that it acts as a type II PAM. High affinity-binding site for curcumin on α7-nAChR was also verified by molecular docking study. In the second part of this study, the neuroprotective effects of curcumin in an animal model of Parkinson’s disease were investigated. Stereotaxic micro-neurosurgery was successfully established (for the first time in our university) and used to induce the toxin based (6-hydroxydopamine; 6-OHDA) animal model of Parkinson’s disease. This was followed by testing the behavior of the animals, tissue collection, immunohistochemistry, striatal fiber density measurement, and stereological data analysis. Systemic administration of curcumin alleviated 6-OHDA-induced motor abnormalities and protected against substantia nigra pars compacta dopaminergic neuronal loss, through an α7-nAChRs-mediated mechanism. The protective effects of curcumin were completely reversed by the administration of the α7-nAChR-selective antagonist methyllycaconitine (MLA). In summary, the results of this study suggest that α7-nAChR-mediated activation is an important mechanism for the neuroprotective effects of curcumin in toxin-based (6-hydroxydopamine; 6-OHDA) animal model of Parkinson’s disease

    An Integrated Method for Optimizing Bridge Maintenance Plans

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    Bridges are one of the vital civil infrastructure assets, essential for economic developments and public welfare. Their large numbers, deteriorating condition, public demands for safe and efficient transportation networks and limited maintenance and intervention budgets pose a challenge, particularly when coupled with the need to respect environmental constraints. This state of affairs creates a wide gap between critical needs for intervention actions, and tight maintenance and rehabilitation funds. In an effort to meet this challenge, a newly developed integrated method for optimized maintenance and intervention plans for reinforced concrete bridge decks is introduced. The method encompasses development of five models: surface defects evaluation, corrosion severities evaluation, deterioration modeling, integrated condition assessment, and optimized maintenance plans. These models were automated in a set of standalone computer applications, coded using C#.net in Matlab environment. These computer applications were subsequently combined to form an integrated method for optimized maintenance and intervention plans. Four bridges and a dataset of bridge images were used in testing and validating the developed optimization method and its five models. The developed models have unique features and demonstrated noticeable performance and accuracy over methods used in practice and those reported in the literature. For example, the accuracy of the surface defects detection and evaluation model outperforms those of widely-recognized machine leaning and deep learning models; reducing detection, recognition and evaluation of surface defects error by 56.08%, 20.2% and 64.23%, respectively. The corrosion evaluation model comprises design of a standardized amplitude rating system that circumvents limitations of numerical amplitude-based corrosion maps. In the integrated condition, it was inferred that the developed model accomplished consistent improvement over the visual inspection procedures in-use by the Ministry of Transportation in Quebec. Similarly, the deterioration model displayed average enhancement in the prediction accuracies by 60% when compared against the most commonly-utilized weibull distribution. The performance of the developed multi-objective optimization model yielded 49% and 25% improvement over that of genetic algorithm in a five-year study period and a twenty five-year study period, respectively. At the level of thirty five-year study period, unlike the developed model, classical meta-heuristics failed to find feasible solutions within the assigned constraints. The developed integrated platform is expected to provide an efficient tool that enables decision makers to formulate sustainable maintenance plans that optimize budget allocations and ensure efficient utilization of resources

    THE USE OF PHYSICAL PHENOMENON AS AN INNOVATIVE SOURCE IN ART EDUCATION

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    It is undoubtable that there is a reciprocity relationship between the different sciences and fields of knowledge. The relation between art and science is one that extends ancient times since both of them use search and experimentation methods in pursuit of reaching the best results and satisfactory solutions which makes them in continuous development. Likewise, Art education draws its references and aesthetic values from all that is found neoteric whether it is in nature, heritage or other sciences. The idea of integration between art and science prompts on finding innovative ways towards creativity, because whenever the sources behind the design were of a scientific nature, the higher the visual connotations are closer to perception and mental receptivity. Hence, researchers are trying to create new experimental approaches through the study and analysis of some physical phenomena, such as energy, frequency and vibration, which produces precise and perfect artistic forms in harmonious rhythms and in accordance with formalized geometric and mathematical relations of scientific origin that can be used by art students to create innovative design works as intellectual starting points, can be consulted and relied on as technical references, with a formal logic, and mental legitimation, which contributes to the enrichment of the aesthetic values ​​of the art work. So, this study aims to take advantage of some physical phenomena such as energy and frequency and vibration and its formal output as an innovative source in teaching arts

    Role of Elastic Stable Intramedullary Nailing in Diaphyseal Fractures in Children

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    Background: All femoral or tibial fractures regardless of associated injuries, intramedullary nailing (IMN) has its more advantages in rapid rehabilitation, good effects on the child and his family and strong fixation. Objective: To assess the role of elastic stable IMN in union of diaphyseal fractures of long bones in children. Patients and Methods: A prospective and retrospective analytical study on ten children with isolated femoral or tibial fractures who were admitted to Orthopedic Department, Zagazig University Hospitals. They were divided equally into group I that included 5 patients with femoral shaft fracture managed with IMN and group II, which included 5 patients with tibial shaft fracture managed with IMN. Their mean age was 4.7 years old. Results: When the groups compared, the spica cast group was found to have a shorter duration of hospital stay compared to elastic nail group. The knee range of motion of the spica cast group was found to be better compared to the elastic nailing group. The elastic nailing group was found to have started walking earlier both with and without support. Patients with intramedullary nailing started to walk with aid after one month and  independently after 2 weeks. Patients with spica cast started to walk with aid after 2 months and independently after 12 weeks. Conclusion: None of the available treatment tools to fix diaphyseal long bones fractures in preschool children is perfect because each method has its own set of complications. However, constitute the motive for developing new techniques or changing the design of currently available devices
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