30 research outputs found

    Business Strategies and Competitive Advantage: Evidence from Flour Mill Companies in Lagos State, Nigeria

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    The authors argued from business strategies perspective to understand competitive advantage among homogenous producers. The population consisted of top and functional managers of flour mill companies in Lagos State, Nigeria. Cross sectional survey research design was adopted and primary data were collated and used. The research instrument was an adapted questionnaire. Its validity and reliability were statistically determined. Six hundred and twenty copies of the questionnaire were administered and 605 retrieved. Econometric equation was formulated and multiple regression analysis was employed for data analysis. Business strategies were found to have significantly affected competitive advantage. The study recommended product differentiation and portfolio diversification in order to achieve competitive advantage

    Prevalence of Extended Spectrum Beta Lactamases (ESBL) Producing Escherichia coli and Klebsiella pneumoniae in Tuberculosis Patients in Kano, Nigeria

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    Resistance to broad spectrum β lactams, mediated by extended spectrum beta lactamase (ESβL) is an increasing problem worldwide. Production of these enzymes in clinical infections can result in treatment failure if one of the second or third generation cephalosporins is used. This study investigates the incidence of ESBL among E. coli and K. pneumoniae which were isolated from tuberculosis patients with secondary opportunistic bacterial infection attending Aminu Kano Teaching Hospital (AKTH), Kano and Infectious Disease Hospital (IDH), Kano. A total of 37 E. coli and 33 K. pneumoniae obtained from their sputum were screened for ESBL production by Double disk synergy test method (DDST). Prevalence of 37.3% (14/37) and 36.4% (12/33) was recorded for Escherichia coli and Klebsiella pneumoniae respectively. Furthermore, a slight high prevalence of 39.4% (13/33) was recorded with the female tuberculosis patients when compared with their male counterpart 35.1% (13/37). Escherichia coli harboring ESBL were more encountered among the elderly patients aged 31-50 (13/51 or 25.5%) when compared with K. pneumoniae with (9/51 or 17.6%). The study shows alarming rise in ESBL production among Klebsiella pneumoniae and Escherichia coli among immunocompromised patients raising fear of possible emergence of multiple drug resistant bacteria that will be hard to treat. Thereby early detection of ESBL in these patients is recommended to curb the spread. Keywords: Extended spectrum beta lactamase (ESBLs), Escherichia coli, Klebsiella pneumoniae, Tuberculosis

    Prevalence of Cysticercus tenuicollis cysts in sheep slaughtered at Sokoto abattoir, Sokoto state, Nigeria

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    A prospective study was conducted based on the principle of post mortem examination on sheep slaughtered at Sokoto abattoir for the presence of Cysticercus tenuicollis cysts. A total of 261 sheep were examined with 34 (13.03%) infected. Prevalence of infection increased with the age of the  animals. Males had relatively higher prevalence than females. Infection was recorded in several visceral organs with omentum having the highest  prevalence (35.29%) and the lungs the least(11.76%). The results suggest that C. tenuicollis is common and may constitute a health problem in sheep and a source of economic loss in the meat industry, thus emphasizing the need for proper meat inspection and handling of offals in the study area

    The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes

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    Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics

    Optimal location and signal selection of upfc device for damping oscillation

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    Unified power flow controller (UPFC) is used for controlling the real and reactive power in transmission line and bus voltage simultaneously and independently. An additional task of UPFC is to increase transmission capacity as result of power oscillation damping. The effectiveness of this controller depends on its optimal location and proper signal selection in the power system network. A residue factor has been proposed to find the optimal location of the UPFC controllers and eigenvalue analyses are used to assess the most appropriate input signals (stabilizing signal) for supplementary damping control of UPFC to damp out the inter-area mode of oscillations. The proposed residue factor is based on the relative participation of the parameters of UPFC controller to the critical mode. A simple approach of computing the residue factor has been proposed, which combines the linearized differential algebraic equation model of the power system and the UPFC output equations. While for signal selection a right-half plane zeros (RHP zeros) and Hankel singular value (HSV) is used as tools to select the most receptive signal to a mode of the inter-area oscillation. The placements of UPFC controllers have been obtained for the base case and for the dynamic critical contingences. The effectiveness of the proposed method of placement and selection of signals are demonstrated on practical network of TNB 25 bus system of south Malaysian network and New England 39 bus system

    TCSC damping controller design based on self-learning fuzzy controller techniques

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    Application of self learning fuzzy (SLFLC) controller to TCSC device for improving damping inter-area modes of oscillations is investigated. The SLFLC plus integral term utilizing sensitivity technique is synthesized by learning that is actuated after completion of the main learning algorithm. The paper considers the conventional PID controller and compares its performance with respect to the proposed SLFLC controller. numerous abnormal conditions like fault and load disturbance simulation results are presented to emphasize the efficiency of the proposed TCSC controller in a TNB 25 bus system

    Optimal thyristor control series capacitor neuro-controller for damping oscillations

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    This study applies a neural-network-based optimal TCSC controller for damping oscillations. Optimal neural network controller is related to model-reference adaptive control, the network controller is developed based on the recursive “pseudo-linear regression. Problem statement: The optimal NN controller is designed to damp out the low frequency local and inter-area oscillations of the large power system. Approach: Two multilayer-perceptron neural networks are used in the design-the identifier/model network to identify the dynamics of the power system and the controller network to provide optimal damping. By applying this controller to the TCSC devices the damping of inter-area modes of oscillations in a multi-machine power system will be handled properly. Results: The effectiveness of the proposed optimal controller is demonstrated on two power system problems. The first case involves TCSC supplementary damping control, which is used to provide a comprehensive evaluation of the learning control performance. The second case aims at addressing a complex system to provide a very good solution to oscillation damping control problem in the Southern Malaysian Peninsular Power Grid. Conclusion: Finally, several fault and load disturbance simulation results are presented to stress the effectiveness of the proposed TCSC controller in a multi-machine power system and show that the proposed intelligent controls improve the dynamic performance of the TCSC devices and the associated power network
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