670 research outputs found

    Lipohypertrophy in children and adolescents with type 1 diabetes and the associated factors

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    <p>Abstract</p> <p>Background</p> <p>Despite the important implications of lipohypertrophy for diabetes control, there is a dearth of information and research about the subject in children. The aim of this study was to study the prevalence of lipohypertrophy in children with type 1 diabetes, and to evaluate the associated factors.</p> <p>Findings</p> <p>119 children coming for regular follow up in the diabetes clinic were examined for the presence of lipohypertrophy by inspection and palpation. The last 4 readings of glycated hemoglobin (HbA1c) levels and other factors that may affect lipohypertrophy were documented. RESULTS: The patient's age ranged from 2 months to 21 years with a median of 10 years (inter-quartile range = 6). Lipohypertrophy occurred in 54.9% of patients, more commonly in males (62.7%) vs. females (48.4%) (P = 0.074). Grade 1 lipohypertrophy occurred in 42.5% and grade 2 in 12.4%. Lipohypertrophy was related significantly to the dose of insulin units per kg of body weight (Odds ratio [OR] = 16.4; 95% CI, 2.2 - 124.6; P = 0.007), the duration of diabetes, [OR] = 1.16; 95% CI, 1.05 - 1.32; P = 0.004)), and the body mass index (BMI) [OR] = 1.68; 95% CI, 1.25 - 2.15; P = 0.006). The mean HbA1c levels of patients with grade 1 and grade 2 lipohypertrophy did not differ from diabetics without lipohypertrophy (F = 0.178, P = 0.837)</p> <p>Conclusions</p> <p>The presence of lipohypertrophy was significantly associated with the duration of diabetes and the body mass index. Children with lipohypertrophy needed a significantly higher dose of insulin units/kg of body weight to achieve fair control compared to children without lipohypertrophy. Further studies are needed to ascertain the clinical meaning of these findings.</p

    Torsional Behavior of Hollow-Core FRP-Concrete-Steel Bridge Columns

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    This paper presents the behavior of hollow-core fiber reinforced polymer-concrete-steel (HC-FCS) column under pure torsion loading with constant axial load. The HCFCS consists of outer FRP tube and inner steel tube with concrete shell sandwiched between the two tubes. The FRP tube was stopped at the surface of the footing and provided confinement to the concrete shell from outer direction. The steel tube was embedded into the footing to a length of 1.8 times to the diameter of the steel tube. The longitudinal and transversal reinforcements of the column were provided by the steel tube only. A large-scale HC-FCS column with a diameter of 610 mm and height of applied load of 2,438 mm with aspect ratio of 4 was investigated during this study. The study revealed that the torsional behavior of HC-FCS column mainly depended on the stiffness of the steel tube and the interactions among the column components (concrete shell, steel tube, and FRP tube)

    Hollow-Core FRP-Concrete-Steel Bridge Columns under Torsional Loading

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    This paper presents the behavior of hollow-core fiber-reinforced polymer-concrete-steel (HC-FCS) columns under cyclic torsional loading combined with constant axial load. The HC-FCS consists of an outer fiber-reinforced polymer (FRP) tube and an inner steel tube, with a concrete shell sandwiched between the two tubes. The FRP tube was stopped at the surface of the footing, and provided confinement to the concrete shell from the outer direction. The steel tube was embedded into the footing to a length of 1.8 times the diameter of the steel tube. The longitudinal and transversal reinforcements of the column were provided by the steel tube only. A large-scale HC-FCS column with a diameter of 24 in. (610 mm) and applied load height of 96 in. (2438 mm) with an aspect ratio of four was investigated during this study. The study revealed that the torsional behavior of the HC-FCS column mainly depended on the stiffness of the steel tube and the interactions among the column components (concrete shell, steel tube, and FRP tube). A brief comparison of torsional behavior was made between the conventional reinforced concrete columns and the HC-FCS column. The comparison illustrated that both column types showed high initial stiffness under torsional loading. However, the HC-FCS column maintained the torsion strength until a high twist angle, while the conventional reinforced concrete column did not

    Evaluating Teaching Performance in View of Learning and Innovation Skills among Saudi University Instructors

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    This novel study evaluated Saudi university instructors’ teaching performance at King Khalid University, College of Education, in view of learning and innovation skills from their students’ perspectives in postgraduate programs. The study adopted descriptive analytical method. A checklist of appropriate teaching performance was prepared in view of learning and innovation skills. Based on the checklist, an electronic questionnaire was prepared and distributed on line in the form of a five-point rating scale. The participants consisted of (136) male and female students, enrolled in master and doctoral programs in six majors. The study tool was applied during the academic year 2018/209AD. The results revealed that Saudi university instructors’ level of teaching performance was high with a rate of (78.8%), and there was no statistically significant difference at (0.05) between the level of teaching performance and the competence level, specified educationally at (80%) in overall performance. The results also indicated that there were no statistically significant differences at (0.05) within the instructors’ teaching performance degree in the light of learning and innovation skills regarding the demographic variables of the participants. Briefly, many applications are suggested for the university beneficiaries

    Verifix: Verified Repair of Programming Assignments

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    Automated feedback generation for introductory programming assignments is useful for programming education. Most works try to generate feedback to correct a student program by comparing its behavior with an instructor's reference program on selected tests. In this work, our aim is to generate verifiably correct program repairs as student feedback. The student assignment is aligned and composed with a reference solution in terms of control flow, and differences in data variables are automatically summarized via predicates to relate the variable names. Failed verification attempts for the equivalence of the two programs are exploited to obtain a collection of maxSMT queries, whose solutions point to repairs of the student assignment. We have conducted experiments on student assignments curated from a widely deployed intelligent tutoring system. Our results indicate that we can generate verified feedback in up to 58% of the assignments. More importantly, our system indicates when it is able to generate a verified feedback, which is then usable by novice students with high confidence

    Facies analysis, glauconite distribution and sequence stratigraphy of the middle Eocene Qarara Formation, El-Minya area, Egypt

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    AbstractThe Qarara Formation consists mainly of shale at the base and overlain by limestone at the top. The formation is Middle Eocene (Lutetian) in age. Three sections located at the eastern bank of the Nile River in El-Minya Province have been measured, described, and sampled. These sections from north to south are: Gebel Qarara, El-Sheikh Fadl, and Gebel El-Ahmar.The main microfacies identified in the studied sections are: silty claystone, silty shale, fossiliferous glauconite, glauconitic (green) sand, glauconitic fossiliferous ironstone, glauconitic bioclastic wacke-packstone, glauconitic bioclastic lime-mudstone-wackestone. These microfacies have been deposited in shallow open marine environment.Collectively the studied rocks contain two principal facies: lower argillaceous facies and upper carbonate facies that separated by glauconitic fossiliferous ironstone bed. The lower argillaceous part represents highstand systems tract (HST), whereas the upper carbonate part represents transgressive systems tract (TST). The glauconitic fossiliferous ironstone bed is recognized as a sequence boundary (SB)

    Application of a Novel Synergetic Control for Optimal Power Extraction of a Small-Scale Wind Generation System with Variable Loads and Wind Speeds

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    © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).The synergetic control technique (SCT) has the solution for understanding the symmetry inherent in the non-linear properties of wind turbines (WTs); therefore, they achieve excellent performance and enhance the operation of the WT. Small-scale WTs are efficient and cost-effective; they are usually installed close to where the generated electricity is used. This technology is gaining popularity worldwide for off-grid electricity generation, such as in rural homes, farms, small factories, and commercial properties. To enhance the efficiency of the WT, it is vital to operate the WT at its maximum power. This work proposes an efficient and fast maximum power point tracking (MPPT) technique based on the SCT to eradicate the drawbacks of the conventional methods and enhance the operation of the WT at the MPP regardless of wind speed and load changes. The SCT has advantages, such as robustness, simplified design, fast response, no requirement for knowledge of WT characteristics, no need for wind sensors or intricate power electronics, and straightforward implementation. Furthermore, it improves speed convergence with minimal steady-state oscillations at the MPP. The investigated configuration involves a wind-driven permanent magnet synchronous generator (PMSG), uncontrolled rectifier, boost converter, and variable load. The two converters are used to integrate the PMSG with the load. Three scenarios (step changes in wind speed, stochastic changes in wind speed, and variable electrical load) are studied to assess the SCT. The results prove a high performance of the suggested MPPT control method for a fast convergence speed, boosted WT efficacy, low oscillation levels, and applicability under a variety of environmental situations. This work used the MATLAB/Simulink program and was then implemented on a dSPACE 1104 control board to assess the efficacy of the SCT. Furthermore, experimental validation on a 1 kW Darrieus-type WT driving a PMSG was performed.Peer reviewe

    MTA1 Expression Correlates Significantly with Histologic Grade in Salivary Mucoepidermoid Carcinoma

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    Background: Metastasis associated protein-1 (MTA1) has been a recently identified as a unique gene playing important role in tumorigenesis and progression of cancer cells. Objective:To evaluate MTA1 expression and its predictive value in determining histologic grade of salivary mucoepidermoid carcinoma (MEC).   Patients and Methods: MTA1 expression was evaluated by immunohistochemistry in paraffin-embedded tumor specimens blocks from 22 patients. Assessment of MTA1 immunostaining was achieved by counting the proportion of positively-stained tumor cells in 5 high power microscopic fields; and staining was analyzed in relation to clinicopathological variables.  Results: MTA1 show nuclear and cytoplasmic expression in varying intensity in 95% of cases. No significant correlation was found between MTA1expression and age, gender, site of the tumor (p>0.05). However, statistically significant correlation was found between MTA1expression and clinical stage, nodal involvement (p=0.009 and 0.007; respectively). Regarding histologic grade, high MTA1 level was significantly associated with grade of tumors categorized by Auclair and Brandwein systems (<0.001 and 0.009; respectively). Conclusion:MTA1 expression significantly correlates with tumor grade and progression, and has a potential role in diagnosis and prediction of behavior in salivary MEC

    A comprehensive review on the exergy analysis of combined cycle power plants

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    The arriving optimum improvement of a thermodynamic system of energy conversion such as a combined cycle power plant (CCPP) is complicated due to the existence of different factors. Energy and exergy analysis is utilized as effective methods to determine both the quantity and quality of the energy sources. This paper reviews the latest thermodynamics analysis on each system components of a CCPP independently and determine the exergy destruction of the plant. A few layouts of the CCPP plant from different locations considered as case studies. In fact, the most energy losses occurred in the condenser compared with the plant components. It found that in the combustion chamber (CC) the highest exergy destruction occurred. The ambient temperature causes an evident decrement in the power production by the gas turbine (GT). The result has proved that besides energy, exergy analysis is an efficient way to the assessment of the performance of the CCPP by recommending a more advantageous configuration of the CCPP plant, which would lead to reductions in fuel required and emissions of air pollutants

    Effect of different concentrations of chitosan coating on storage life and quality characteristics of Papaya (Carica Papaya L.)

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    Mature green stage of papaya fruits were treated with different concentrations of chitosan at 0, 0.5, 0.75 and 1%, and stored at 13±1 °C for 28 days to study the effect of these concentrations on the storage life and maintaining quality of papaya. Chitosan concentrations 0.75 and 1% showed the best control effect on decay compared with 0% (Control) and 0.5%. At 0.75 and 1% of chitosan, flesh firmness maintained resulted in prolonging in storage life of 28 and 26 days compared with 21 and 19 days, respectively for 0.5 and 0%. Furthermore, they were significantly decreased the weight loss of fruit. All of the treatments inhibited increase of soluble solid contents and pH values of pulp fruits after 21 days of storage at 13 ± 1°C. Titratable acidity and ascorbic acid were higher for coated fruits (0.5, 0.75 and 1%) compared with uncoated fruits. Concern treatments of chitosan at 0.75 and 1% improve papaya fruit quality and resistance to decay
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