1,234 research outputs found

    Design and Simulation of Worldwide Interoperability for Microwave Access Computer Network for 3×3 Km Universal Sample of Building Campus

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    The aim of this study to design a wireless computer network of a particular network as a large-scale company or university to improve mobility and to let the teachers and students of the university, for example, stay interacted and connected at any time in any campus location or site. Therefore, This study needed to cover the overall area of this campus with efficient wireless coverage that exceeds the university boundaries to maintain wireless signal strength. To do that, the researchers thought that it is very significant to design a Worldwide Interoperability for Microwave Access (WiMax) computer network with the most powerful and advanced hardware component capabilities to full fit teachers’ and students’ requirements of fast net browsing and files’ download. After designing the university campus of computer network, simulation has done by OPNET 14 Modular to determine the WiMax network design parameters. The purpose of the current research is to find if the design of the campus network is efficient or not and also to determine the performance of theimplemented network

    Lymphatic expression of CLEVER-1 in breast cancer and its relationship with lymph node metastasis

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    BACKGROUND Mechanisms regulating breast cancer lymph node metastasis are unclear. Staining of CLEVER-1 (common lymphatic endothelial and vascular endothelial receptor-1) in human breast tumors was used, along with in vitro techniques, to assess involvement in the metastatic process. METHODS 148 sections of primary invasive breast cancers, with 10 yr follow-up, were stained with anti-CLEVER-1. Leukocyte infiltration was assessed, along with involvement of specific subpopulations by staining with CD83 (mature dendritic cells, mDC), CD209 (immature DC, iDC) and CD68 (macrophage, Mϕ). In vitro expression of CLEVER-1 on lymphatic (LEC) and blood endothelial cells (BEC) was examined by flow cytometry. RESULTS In vitro results showed that although both endothelial cell types express CLEVER-1, surface expression was only evident on LEC. In tumour sections CLEVER-1 was expressed in blood vessels (BV, 61.4% of samples), lymphatic vessels (LV, 18.2% of samples) and in Mϕ/DCs (82.4% of samples). However, only CLEVER-1 expression in LV was associated with LN metastasis (p = 0.027) and with Mϕ indices (p = 0.021). Although LV CLEVER-1 was associated with LN positivity there was no significant correlation with recurrence or overall survival, BV CLEVER-1 expression was, however, associated with increased risk of recurrence (p = 0.049). The density of inflammatory infiltrate correlated with CLEVER-1 expression in BV (p < 0.001) and LV (p = 0.004). CONCLUSIONS The associations between CLEVER-1 expression on endothelial vessels and macrophage/leukocyte infiltration is suggestive of its regulation by inflammatory conditions in breast cancer, most likely by macrophage-associated cytokines. Its upregulation on LV, related surface expression, and association with LN metastasis suggest that it may be an important mediator of tumor cell metastasis to LN

    HAND WRITTEN RECOGNITION USING NEURAL NETWORK ALGORITHM

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    Hand written recognition problem can be done in two major steps, first by separating each character alone and second by detecting the separated shape to its corresponding like alphabetic letter. A backpropagation neural network found to be a good artificial intelligence algorithm in facing character recognition problem.In this work, backpropagation neural network is used with 3-layers to detect and separate 26 English letter from (A to Z). In addition, a previous steps should be taken to detect the boundaries of each single written letter. Detecting a complete text can be done by separating each character through finding its boundaries, resizing the separated character to be suitable for pre-trained neural network, detecting the hand-written letter and finally saving the guessed letter to a text file. This work is developed using Matlab 2008 version 7.6. The obtained results show good representations of letter contaminated by noise and non-trained letters

    Development and Validation of a Kinetic Model for Enzymatic Hydrolysis Using \u3ci\u3eCandida rugosa\u3c/i\u3e Lipase

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    Biochemical processing involving enzymatic catalysis of hydrolysis reactions of oils and fats must overcome significant technological barriers before the full benefits of the technology can be realized. Owing to their selectivity and mild reaction conditions, lipases are becoming increasingly important as biocatalysts provided that their kinetics and optimum reaction conditions are well-understood. In this study we report on the development and validation of a kinetic model for the degradation of oils using Candida rugosa lipase, from which a better understanding of the influence of different reaction conditions on hydrolysis kinetics is elucidated. Variations of reaction temperature, mixing speed, enzyme loading and substrate concentrations yielded a maximum lipase activity of 25.67 lipase units (LU), and an activation energy of 4.32 Kcal/gmol. Significantly higher enzyme loading at 0.7 mg/ml was achieved, a 169% increase over most recently reported loading by other investigators. Optimum operating ranges for medium pH and substrate concentration were established to be 7.5 to 8.5, and 30 to 55%, respectively. Reported findings mark a significant improvements over previously reported much narrower ranges of 8.0 for pH and 30 to 43% for the substrate concentration under similar experimental conditions. Developed kinetics model closely predicted and matched experimental results, rendering it suitable for biochemical engineering design application

    COMPLEXITY REDUCTION OF CYCLOSTATIONARY SENSING TECHNIQUE USING IMPROVED HYBRID SENSING METHOD

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    In cognitive radio system, the spectrum sensing has a major challenge in needing a sensing method, which has a high detection capability with reduced complexity. In this paper, a low-cost hybrid spectrum sensing method with an optimized detection performance based on energy and cyclostationary detectors is proposed. The method is designed such that at high signal-to-noise ratio SNR values, energy detector is used alone to perform the detection. At low SNR values, cyclostationary detector with reduced complexity may be employed to support the accurate detection. The complexity reduction is done in two ways: through reducing the number of sensing samples used in the autocorrelation process in the time domain and through using the Sliding Discrete Fourier Transform (SDFT) instead of the Fast Fourier Transform (FFT). To evaluate the performance, two versions of the proposed hybrid method are implemented, one with the FFT and the other with the SDFT. The proposed method is simulated for cooperative and non-cooperative scenarios and investigated under a multipath fading channel. Obtained results are evaluated by comparing them with other methods including: cyclostationary feature detection (CFD), energy detector and traditional hybrid. The simulation results show that the proposed method with the FFT and the SDFT successfully reduced the complexity by 20% and 40% respectively, when 60 sensing samples are used with an acceptable degradation in the detection performance. For instance, when Eb/N0 is 0 dB , the probability of the detection of Pd is decreased by 20 % and 10% by the proposed method with the FFT and the SDFT respectively, as compared with the hybrid method existing in the literature

    Relationship between biomarkers of muscle damage and redox status in response to a weightlifting training session: effect of time-of-day

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    The aims of the present study were to: (1) investigate the effect of a weightlifting training session and time-of-day (TOD) upon biological parameters (i.e., oral temperature, hematological, C-reactive protein (CRP), and oxidative stress) and (2) assess their possible link with muscle damage responses. Nine weightlifters (21 ± 0.5 years) performed, in a randomized order, three Olympic-Weightlifting sessions (i.e., at 08:00, 14:00, and 18:00). Blood samples were collected at rest, 3 min and 48 h after each training session. Between pre- and post-training session, ANOVA showed significant increases in oxidative stress markers at the three TODs (p < 0.01) and significant increases for creatine kinase (CK) and lactate dehydrogenase (LDH) only at 08:00 and 18:00 (p < 0.05). At rest, the results showed a significant diurnal variation for the majority of the selected parameters except for malondialdehyde (MDA), total bilirubin, and CRP with higher values observed at 18:00 (p < 0.05). After the training session, given the higher rate of increase during the morning session, these diurnal variations persisted for temperature and WBC (p < 0.01) and were suppressed for CK, LDH, uric acid (UA), catalase, and glutathione peroxidase. The main significant correlations (p < 0.001) were observed between: (1) CK and MDA (r = 0.6) and CK and UA (r = 0.66 and r = 0.82) during the morning and evening training sessions; (2) CK and CRP only during the morning session (r = 0.5); and (3) CRP and WBC during the three training sessions (r = 0.8). In conclusion, the present findings: (1) confirm that the muscle damage responses could be induced by a high level of oxidative stress and (2) suggest to avoid scheduling training sessions in the morning given the higher muscle damage, inflammatory, and oxidative responses at this TOD

    Effect of hybridization on the mechanical properties of pineapple leaf fiber/kenaf phenolic hybrid composites

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    In this study, pineapple leaf fiber (PALF), kenaf fiber (KF) and PALF/KF/phenolic (PF) composites were fabricated and their mechanical properties were investigated. The mechanical properties (tensile, flexural and impact) of the PALF/KF/PF hybrid composites were investigated and compared with PALF/KF composites. The 3P7K exhibited enhanced tensile strength (46.96 MPa) and modulus (6.84 GPa), flexural strength (84.21 MPa) and modulus (5.81 GPa), and impact strength (5.39 kJ/m2) when compared with the PALF/PF and KF/PF composites. Scanning electron microscopy (SEM) was used to observe the fracture surfaces of the tensile testing samples. The microstructure of the 7P3K hybrid composite showed good interfacial bonding and the addition of KF improved the interfacial strength. It has been concluded that the 3P7K ratio allowed obtaining materials with better mechanical properties (tensile, flexural and impact strengths) than PALF/PF and KF/PF composites. The results obtained in this study will be used for further comparative study of untreated hybrid composites with treated hybrid composites
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