Parallel-Vector Computation for Geometrically Nonlinear Frame Structural Analysis and Design Sensitivity Analysis

Parallel-vector algorithms are presented for solving the geometrically nonlinear structural problems and obtaining design sensitivity information. A new algorithm is also presented for parallel generation and assembly of the finite element stiffness and mass matrices. The presented assembly algorithm is based on a node-by-node approach rather than the more conventional element-by-element approach. Three different methods, Newton Raphson, Modified Newton Raphson, and the BFGS, are used in the analysis of the nonlinear structural problems. A study is made to determine the performance of each of the mentioned methods in a parallel-vector computer environment. Medium to large-scale, practical problems are solved to evaluate the performance of each method. A hybrid method combining the direct and iterative solvers for linear system of equations is also presented to solve the nonlinear finite element problems. The proposed hybrid method combines the use of the Choleski method and the use of the pre-conditioned conjugate gradient method, to solve the nonlinear structural problem using the piecewise linear approximation method. A different approach for achieving a parallel-vector speed for the Successive Over Relaxation method is also presented in this work. The new approach for the S.O.R method reduces the cost of communications between processors on shared memory computers. Multi-processor Cray Y-MP and Cray 2 supercomputers are used in this work

A Comparison of Force and Pressure Coefficients on Dome, Cube and Prism Shaped Buildings due to Straight and Tornadic Wind Using Three Dimensional Computational Fluids Dynamics

Tornadoes induce very different wind forces than a straight-line (SL) wind. A suitably designed building for a SL wind may fail when exposed to a tornado-wind of the same wind speed. It is necessary to design buildings that are more resistant to tornadoes. Most studies have been conducted to investigate tornado forces on cubic, gable-roof and cylinder buildings. However, little attention has been paid to investigate tornado force on dome buildings; hence, further research is conducted in this study. The forces on a dome, cube and prisms were analyzed and compared using Computational Fluid Dynamics (CFD) for tornadic and SL winds. One typical tornado parameter was considered for comparison. The conclusions drawn from this study were illustrated in visualizations. The tornado force coefficients on the cube and prisms were larger than those on the dome by at least 90% in the x-y directions, and 140% in the z direction. The tornado pressure coefficients on cube and prisms were greater at least 200%. The force coefficients on cube and prisms due to SL wind were higher than those on the dome due to tornado wind by about 100% in the z-direction. The ratio of tangential (Vθ) to translational (Vt) velocity reported in recent studies is 10 or greater, which is larger than the field observation ratios. The influence of Vθ/Vt ratios on the tornado force coefficient for a cubic, prism and dome buildings were compared using a systematic study. The Vθ/Vt ratios were considered to be 1, 3, 6, and 8 for comparison. These ratios were very much in agreement with field observation ratios. The magnitudes of the forces were found to be larger for slower translation speed or higher Vθ/Vt ratios. For faster translation speeds or, lower Vθ/Vt ratio, the maximum force coefficients shifted to the left of the time history

Intranasal insulin treatment improves memory and learning in a rat amyloid-beta model of Alzheimer’s disease

Recently, insulin has been used as a pro-cognitive agent for the potential treatment of Alzheimer’s disease (AD), because of its ability to cross the brain–blood barrier (BBB) by a saturable transport system. This study has been designed to evaluate the effects of intranasal insulin regimen, as a bypass system of BBB, on spatial memory in amyloid-beta (Aβ) model of AD in rat. Unilateral infusion of Aβ25–35 (10 nmol/2 µl/rat) into the lateral ventricular region of brain was used to produce a rat model of AD. After a 24-h recovery period, rats received insulin or vehicle via intraperitoneal or intranasal route (0.1, 0.2, and 0.3 IU) for 14 days. Memory function in rats was assessed by Morris water maze test, with 5 days of training and consequent probe test protocol. Different doses of intraperitoneal insulin did not have a significant effect on learning and memory in AD rats. However, intranasal insulin at doses of 0.2 and 0.3 IU improved the learning and memory in Aβ-received rats. In conclusion, intranasal insulin as a non-invasive strategy improves spatial learning and memory in AD model

Effect of diet supplemented with graded levels of garlic (Allium sativum L.) powder on growth performance, carcass characteristics, blood hematology, and biochemistry of broilers

Background: Recently, attention has been paid to using plants with medicinal efficacy as alternates to antibiotics and growth promoters. Garlic is a traditional plant used as a spice and herb in broilers. Aim: To investigate the effect of garlic powder on broiler performance, carcass characteristics, blood hematology, and biochemistry. Method: A total of 240 1-day-old broiler chicks (Cobb500) were purchased from a local hatchery and randomly distributed into four dietary treatments. Each treatment comprised 5 replicates with 12 chicks each. Garlic powder (Allium sativum) was supplemented as follows: 0.0%, 0.1%, 0.2%, and 0.3%. The diets were formulated to be approximately isocaloric and cover all nutrient requirements for broilers throughout two stages of growth periods: starter diets (1–21 days) and finisher diets (22–42 days). At the end of the experiment, one bird was chosen from each replicate to measure the carcass characteristics and blood was collected. Results: The findings showed that birds fed a diet supplemented by 0.3% garlic powder was significantly (p < 0.05) better in terms of body weight, body weight gain, and feed conversion ratio compared to those birds fed 0%, 0.1%, or 0.2% garlic powder. In addition, feeding 0.1% or 0.2% garlic powder significantly increased (p < 0.05) packed cell volume, total white blood cells, neutrophil, eosinophil, monocyte, and lymphocyte compared to the control group. Furthermore, garlic supplementation led to a decrease in alanine aminotransferase, total cholesterol, triglycerides, and low density lipoprotein compared to the control. At the same time, high density lipoprotein was significantly increased (p < 0.05) by garlic supplementation. Conclusion: It can be concluded that the supplementation of 0.3% garlic powder as a growth promoter leads to reducing the cost of production through improving growth performance and enhancing birds’ health

Towards a new solution of minority shareholder protection in Libya: letting the minority shareholders have a voice

The study develops a framework for improving corporate governance mechanisms in Libya that takes into account its specific environment of weak formal enforcement and its corporate ownership structure, which is based on concentrated state ownership. The central goal of the research is to establish an adequate protection system for minority shareholders that can contribute to the development of an efficient and healthy commercial environment in Libya. To do so, the study examines the current solution for dealing with the conflict of interests between shareholders adopted by Libyan law under art 159 of Libyan Economic Activity Act (LEAA 2010): the minority shareholders’ actions. Using a social and economic analysis and a black letter approach, this study presents a novel analytical framework that formulates an appropriate solution for controlling conflict of interests between shareholders in Libya. To that end, the study addresses the following questions: how effective is the current mechanism for dealing with the conflict of interest between shareholders in Libya? What are the economic and social implications of the different proposed approaches? What elements determine which approach is preferable in Libya? And, finally, what are the challenges that the proposed law reform may face? To answer these questions, firstly, it is necessary to consider the general framework of corporate governance in Libya, examine the country’s current position as an economy in the early stages of transformation and analyse the potential impact of this transformation on corporate governance. Following this, I locate the dimensions of the conflict of interest problem between the minority and majority shareholders in Libya through analysing literature of corporate governance with regard to the minority-majority shareholder problem and applying it to the case of Libya. After that, I examine the efficacy of the current mechanism available in Libyan law (minority shareholders actions) as a solution for dealing with the conflict of interests between the minority shareholders and the majority shareholders in Libyan companies. However, the current approach is not appropriate for Libya for several reasons that relate to either the efficiency of the approach itself or its application and enforcement in Libya. After examining other possible solutions (e.g. a prohibition strategy), I propose the self-enforcing model as the most appropriate solution since it contributes to companies being able raise capital from investors, and it also lowers the number of conflict of interest transactions and makes a company’s transactions more efficient. Finally, the self-enforcing model does away with the need for external monitoring. However, this is not the end of the story; adopting such a model will inevitably lead to some potential risks (such as the risk that the minority shareholders may abuse their rights), which will require the formulation and adoption of new and specific strategies of corporate governance that are appropriate to Libya

Relative influence of changes in hydraulic conductivity with depth and climate change on estimations of borehole yields

Understanding the impact of climate change on borehole yields from fractured aquifers is essential for future management of groundwater resources. Although the impact of changes in hydraulic conductivity with depth (VKD) on groundwater levels is well established, the relative significance of climate change and VKD on borehole yield estimates is poorly understood. We hypothesize that VKD exerts a significant additional control on borehole yields under climate change which has not been considered in yield assessments to date. We developed a radial groundwater flow model of an idealised pumping borehole in the fractured Chalk aquifer of south-east England, and applied 11 VKD profiles based on a simple conceptual representation of variability in hydraulic conductivity with depth in the Chalk. For each VKD profile, we applied 20 climate scenarios and six constant pumping rates for the period 1962 – 2014. We then estimated borehole yields based on the derived lowest pumping water levels during key drought years (e.g. 1976). We show that VKD is more significant (p 0.1) in controlling lowest pumping groundwater levels. Hydraulic conductivity is as significant a control as climate on borehole yields, although responses are highly non-linear associated with pumping water level-pumping rate curves intersecting key yield constraints (e.g. pump intake depth, major inflow horizons). It is recommended that variations in hydraulic conductivity with depth are taken into consideration in future assessments of borehole yields under climate change when developing integrated water resources management plans. The approach presented is generic and can be applied across different aquifers where vertical heterogeneity is present

Biofilm Formation and Methicillin Resistance of Staphylococcus aureus Isolated from Clinical Samples

Background: Staphylococcus aureus including methicillin resistant S. aureus (MRSA) is one of the most effective biofilm-forming organisms, biofilm contribute in protecting the microorganism from host defenses and prevent the effective penetration of antimicrobial agents. Biofilm formation is considered as an important contributing factor for the initiation and establishment of chronic infection by S. aureus and known as a major obstacle in the treatment of S. aureus infections is their ability to develop resistance to antimicrobials. Aims : To screen clinical Staphylococcus aureus including MRSA isolates for their biofilm forming abilities and their association with antimicrobial resistance. Methods: A total of 196 clinical isolates of S. aureus were obtained from different sample sources using standard microbiological techniques from three major hospitals in Gaza strip. Biofilm formation of these isolates was determined by tissue culture plate (TCP) method and tube adherence method (TM). Antimicrobial susceptibility test was performed using the modified Kirby–Bauer disk diffusion method as per Clinical and Laboratory Standards Institute guidelines. MRSA was detected using the cefoxitin disk test. Results: Biofilm formation was observed in 174 (88.8 %) and in 145 (74.0%) isolates of S. aureus via TCP method and TM, respectively. The highest resistance percent was for penicillin (92.9%), followed by cefoxitin (80.6%) and oxacillin (67.9%), while the lowest resistance percent was for linezolid and ceftaroline (1%). Among the 196 isolates 71.4% (N=140) were classified as MDR with a MAR index (≥ 0.2). A total of 158 isolates (80.6%) were identified as MRSA distributed as 90.4%, 79.4% and 70.9% from Al-Shifa, Al-Nasser pediatrics and Al-Aqsa hospitals respectively. Large proportions (82.1%) of biofilm producers were identified as MRSA. Biofilm-producing MRSA exhibited a higher percent (90.5%) when compared with the biofilm non-producer MRSA (9.5%). Importantly, 89.2% of biofilm-producing S. aureus were multidrug resistant. Conclusions: S. aureus isolates possessed high biofilm-forming ability. Biofilm-producing strains have very high tendency to exhibit antimicrobial resistance, multidrug resistance and methicillin resistance. Regular surveillance of biofilm formation by S. aureus and their antimicrobial resistance profile may lead more success in treating S. aureus infections.   Keywords: Biofilm, MDR, MRSA, TCP, TM, Gaza strip, Palestine

3D geological models and their hydrogeological applications : supporting urban development : a case study in Glasgow-Clyde, UK

Urban planners and developers in some parts of the United Kingdom can now access geodata in an easy-to-retrieve and understandable format. 3D attributed geological framework models and associated GIS outputs, developed by the British Geological Survey (BGS), provide a predictive tool for planning site investigations for some of the UK's largest regeneration projects in the Thames and Clyde River catchments. Using the 3D models, planners can get a 3D preview of properties of the subsurface using virtual cross-section and borehole tools in visualisation software, allowing critical decisions to be made before any expensive site investigation takes place, and potentially saving time and money. 3D models can integrate artificial and superficial deposits and bedrock geology, and can be used for recognition of major resources (such as water, thermal and sand and gravel), for example in buried valleys, groundwater modelling and assessing impacts of underground mining. A preliminary groundwater recharge and flow model for a pilot area in Glasgow has been developed using the 3D geological models as a framework. This paper focuses on the River Clyde and the Glasgow conurbation, and the BGS's Clyde Urban Super-Project (CUSP) in particular, which supports major regeneration projects in and around the City of Glasgow in the West of Scotland

Therapy for Thyroid Cancer Practice in King Abdulaziz University Hospital

Abstract Since 1940s, intake of Iodine 131 is a deeprooted postoperative therapy for malignant thyroid. However, clinical practice does differ significantly between hospitals. This paper presents a retrospective study of a clinical practice for patients diagnosed with thyroid cancer at King Abdulaziz University Hospital (KAUH). The aim of this study was to benchmark KAUH practice patterns against international guidelines. A total of 100 patients with thyroid cancer were included, 70% females and 30% males with median age of 42.5 and 43.5 years respectively. Cases were patients, diagnosed with thyroid cancer and treated with radioactive iodine at KAUH in Saudi Arabia between 2005 and 2011. Some additional patient's data were excluded from the study because of missing information or lost to follow-up. Medical records included patient's gender, age, clinical diagnoses, iodine dose, and the recurrence. Where, thirty-three percent (33%) of the patients had papillary carcinoma, (3%) had follicular carcinoma and (1%) had Hurtle cell tumors. All patients had their total/partial thyroidectomy at KAUH. Dose administered ranged from (50 to 300) mCi with the 61% receiving a dose of 100mCi. A statistical test, Chisquare test, were used to allow us to test for deviations of observed frequencies from expected frequencies. The medical record showed that 3% of the patient had died and 4% had a recurrence that was successfully treated by the time of the study. Moreover, the 5-year survival rates for patients with thyroid cancers was 93%. The thyroid cancer incidence and the I-131 practice in KAUH is consistent with international data and standards