809 research outputs found

    WOAIP: Wireless Optimization Algorithm for Indoor Placement Based on Binary Particle Swarm Optimization (BPSO)

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    تحسين نشر نقطة الوصول (AP) له دور كبير في التطبيقات اللاسلكية بسبب الحاجة إلى توفير اتصال فعال بتكاليف نشر منخفضة. تقترح هذه الدراسة التحقيق في خوارزمية تحسين متعددة المستويات تسمى خوارزمية التحسين اللاسلكي للوضع الداخلي (WOAIP) استنادًا إلى تحسين حشد الجسيمات الثنائية (BPSO). يهدف WOAIP إلى الحصول على وضع AP الأمثل متعدد الطوابق مع تغطية فعالة تجعله أكثر قدرة على دعم جودة الخدمة (QoS). تم أخذ خمسة أزواج (التغطية ، نشر AP) من الأوزان ، عتبات الإشارة وقياسات قوة الإشارة المستقبلة (RSS) المحاكية باستخدام برنامج Wireless InSite (WI) في دراسة حالة الاختبار. من خلال مقارنة النتائج التي تم جمعها من WI مع نشر AP المادي المحاكي اللاسلكي الحالي للمبنى المستهدف - قسم علوم الحاسوب في جامعة بغداد. يُظهر تقييم أداء WOAIP زيادة من حيث موضع AP والتحسين المميز من أجل زيادة نسبة التغطية اللاسلكية إلى 92.93٪ مقارنة بـ 58.5٪ من تغطية AP الحالية (أو تحسين التغطية بنسبة 24.5٪ في المتوسط).Optimizing the Access Point (AP) deployment has a great role in wireless applications due to the need for providing an efficient communication with low deployment costs. Quality of Service (QoS), is a major significant parameter and objective to be considered along with AP placement as well the overall deployment cost. This study proposes and investigates a multi-level optimization algorithm called Wireless Optimization Algorithm for Indoor Placement (WOAIP) based on Binary Particle Swarm Optimization (BPSO). WOAIP aims to obtain the optimum AP multi-floor placement with effective coverage that makes it more capable of supporting QoS and cost-effectiveness. Five pairs (coverage, AP deployment) of weights, signal thresholds and received signal strength (RSS) measurements simulated using Wireless InSite (WI) software were considered in the test case study by comparing the results collected from WI with the present wireless simulated physical AP deployment of the targeted building - Computer Science Department at University of Baghdad. The performance evaluation of WOAIP shows an increase in terms of AP placement and optimization distinguished in order to increase the wireless coverage ratio to 92.93% compared to 58.5% of present AP coverage (or 24.5% coverage enhancement on average)

    Degradation of crude oil and pure hydrocarbon fractions by some wild bacterial and fungal species

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    The use of biodegradation as a method for cleaning up soil that has been contaminated by spilt petroleum can be an effective strategy. So, this study investigated the existence of the wild microorganism in soil contaminated with oil and study their ability to degrade petroleum in vitro. Nineteen samples were collected from various locations near Taq Taq (TTOPCO) natural seeps in the Kurdistan Region of Iraq. Morphological, cultural, biochemical tests and molecular identification were used to identify the microbial communities, in addition, spore texture and the colour of the fungal isolates were investigated on the fungal isolates. Out of the19 samples, 17 indigenous bacterial strains and 5 fungal strains were successfully isolated. From the absorption spectrophotometry, Bacillus anthracis, Bacillus cereus, Achromobacter sp. and Pseudomonas aeruginosa for the bacterial isolates grew well on a minimal salt medium supplemented with 1% crude oil. Results showed that these isolates mentioned above had a strong ability to degrade crude oil by reducing the colour of 2,6-dichlorophenol indophenol (DCPIP) from deep blue to colourless. However, for the fractions of hydrocarbon, the bacterial isolates failed and did not affect the colour of any of the fractions. The results for fungi showed that Aspergillus lentulus and Rhizopus arrhizus had a strong ability to degrade both crude oil and fraction F1 by reducing the colour of DCPIP. Each fungal isolates also had a great tolerance to different concentrations of crude oil when grown on solid MSM. This study showed these microorganisms have a strong ability to degrade crude oil and can be used to clean up soil and the environment

    Portal vein thrombosis and arterioportal shunts : effects on tumor response after chemoembolization of hepatocellular carcinoma

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    AIM: To evaluate the effect of portal vein thrombosis and arterioportal shunts on local tumor response in advanced cases of unresectable hepatocellular carcinoma treated by transarterial chemoembolization. METHODS: A retrospective study included 39 patients (mean age: 66.4 years, range: 45-79 years, SD: 7) with unresectable hepatocellular carcinoma (HCC) who were treated with repetitive transarterial chemoembolization (TACE) in the period between March 2006 and October 2009. The effect of portal vein thrombosis (PVT) (in 19 out of 39 patients), the presence of arterioportal shunt (APS) (in 7 out of 39), the underlying liver pathology, Child-Pugh score, initial tumor volume, number of tumors and tumor margin definition on imaging were correlated with the local tumor response after TACE. The initial and end therapy local tumor responses were evaluated according to the response evaluation criteria in solid tumors (RECIST) and magnetic resonance imaging volumetric measurements. RESULTS: The treatment protocols were well tolerated by all patients with no major complications. Local tumor response for all patients according to RECIST criteria were partial response in one patient (2.6%), stable disease in 34 patients (87.1%), and progressive disease in 4 patients (10.2%). The MR volumetric measurements showed that the PVT, APS, underlying liver pathology and tumor margin definition were statistically significant prognostic factors for the local tumor response (P = 0.018, P = 0.008, P = 0.034 and P = 0.001, respectively). The overall 6-, 12- and 18-mo survival rates from the initial TACE were 79.5%, 37.5% and 21%, respectively. CONCLUSION: TACE may be exploited safely for palliative tumor control in patients with advanced unresectable HCC; however, tumor response is significantly affected by the presence or absence of PVT and APS

    Role of Stem Cells in Orthopaedic Surgery: Theoretical Survey

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    This study aims at analyzing the Stem cell application is a burgeoning field of medicine that is likely to influence the future of orthopaedic surgery. Stem cells are associated with great promise and great controversy. For the orthopaedic surgeon, stem cells may change the way that orthopaedic surgery is practiced and the overall approach of the treatment of musculoskeletal disease. Stem cells may change the field of orthopaedics from a field dominated by surgical replacements and reconstructions to a field of regeneration and prevention. This review will introduce the basic concepts of stem cells pertinent to the orthopaedic surgeon and proceed with a more in depth discussion of current developments in the study of stem cells in orthopaedic surgery. Keywords: Stem cell, orthopaedic, surgery

    Myxovirus resistance 1 (MX1) is an independent predictor of poor outcome in invasive breast cancer

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    Background: Breast cancer (BC) is a disease with variable morphology, clinical behaviour and response to therapy. Identifying factors associated with the progression of early stage BC can help understand the risk of metastasis and guide treatment decisions. Myxovirus resistance 1 (MX1), which is involved in the cellular antiviral mechanism, plays a role in some solid tumours; however, its role in invasive BC remains unknown. In this study, we aimed to explore the clinicopathological and prognostic significance of MX1 in BC.Methods: MX1 was assessed at the protein level using tissue microarrays from a large well-annotated BC cohort (n=845). The expression of MX1 mRNA was assessed at the transcriptomic level using the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC; n=1980) and validated using three publicly available cohorts on Breast Cancer Gene-Expression Miner (bc-GenExMiner version 4.4). The associations between MX1 expression and clinicopathological factors, and outcome were evaluated.Results: High MX1 protein expression was associated with features of aggressiveness, including large tumour size, high tumour grade, high Nottingham prognostic index scores, hormone receptor negativity and high Ki67 expression. High MX1 expression showed an association with poor patient outcome and it was an independent predictor of short BC- specific survival (p=0.028; HR=1.5; 95%CI=1.0–2.2). Consistent with the protein results, high MX1 mRNA levels showed an association with features of aggressive behaviour and with shorter survival.Conclusion: This study identified MX1 as an independent predictor of poor outcome in patients with BC. Further functional studies are needed to investigate the biological role of MX1 in BC and its potential value as a therapeutic target

    The infection with HBV and HCV and their relationship to ABO blood group among blood donors

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    Background: Hepatitis B virus (HBV) and C virus (HCV) known to be transmitted through blood and blood products and has been implicated as a major cause of chronic liver disease and hepatocellular carcinoma worldwide. Objective: This study aim to detect the relationship between the HBV and HCV infections with ABO blood groups and age of blood donor in Al- Ramadi city. Patients & Methods: We conducted Hepatitis B surface antigen test strip (ACON Laboratories) (USA) and HCVAb, as step to detect the infections among blood donors at the laboratories for central blood bank in Alanbar health directory, M.O.H. The results of this study were analyzed statistically using the T-test to find the significance of probability level according to SPSS ver12 program. (P) Value < 0.05 were considered significant. Results: Among (430) volunteer blood donors, there were 71(16.511%) positive for HBs Ag and 12(2.790%) for HCVAb. Hepatitis B and C infections were significantly associated with blood group of the donors; percentage of HBs Ag and HCVAb were found to be higher in donors who has blood group O and lowest in blood group AB donors, while the distribution of Rh in hepatitis infected donors was higher among Rh positive donors. HCV infections show a high percentage at age group (26–35) years old, while the percentage of HBV infections increase with progress of age group among blood donors. Conclusion: There were a significant association between blood group of donors and hepatitis infections and the infections of HCV increase among (26-35) years old blood donors while the HBV infections increase with progress of age groups

    INVESTIGATIONS ON THIXOJOINING PROCESS OF STEEL COMPONENTS

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    This research is to develop a carbon composite prepared from carbon coir fibers that is reinforced with epoxy resin. Carbon coir fibers were taken from three types of coir fiber specifically designated as CKCF, CYCF and CRCF. The samples were prepared using epoxy resin reinforced with carbon at different weight percentages for three types of coir fiber starting with 0wt.%, 2wt.%, 4wt.%, 6wt.%, 8wt.% and 10wt.%. The mechanical properties such as tensile stress and impact strength were used to characterize all the samples. The morphological study of reinforced samples was also conducted in this research using a SEM machine. The characteristics of all the composite materials were also investigated and discussed. It was determined that the CKCF sample exhibited better mechanical properties than the other coir fiber composites, having a higher average tensile stress value at 11.80MPa and higher impact strength values ranging from 268J to 276J at different carbon content. CKCF with 10wt% AC content had a tremendous impact strength compared with CYCF and CRCF
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