Lessons and challenges from software quality assessment: The case of space systems software

Software development activities have continued to be plagued by a number of problems even with the availability of so many esoteric software technologies and paradigms such as object oriented development, etc.Several studies can be traced back to the software processes adopted. Other contributing factors include lack of knowledge of available systems standards, tools and techniques employed by system practitioners. This paper presents lessons and challenges gained over the last 10 years of experience as software system administrator as well as lecturers in the computer science department. Over this period of time, we have managed a number of in-house and purchased project software amongst them are banking, airtime billing, human resource, result computation etc. We discussed these lessons and challenges across two measurable  characteristics namely quality of design (life cycle stages) and quality of conformance. Finally, we also recommended the lessons and challenges from software quality management for space system software

An Evaluation Study Of Principal’s Instructional Programme Management Performance As Perceived By Teachers

A journal article.This study is both evaluative and comparative in nature. It elicits data from teachers on their respective instructional programmes. One research objective was determined using descriptive statistics (frequencies, percentages, mean scores and standard deviation) and two null hypotheses were tested using the t-test at the 0.05 level of significance. The results show the principals mean performance ratings (by teachers) in the overall management of instructional programmes to be high. Furthermore, there is no significant difference in instructional programme management ratings between male and female principals. However, significant difference exists in the instructional management performance ratings between democratic and nondemocratic principals, with undemocratic principals being rated more highly than principals who exhibited democratic leadership style in overall instructional programme management

Kinetics and Thermodynamics of Oil Extracted from Amaranth

This chapter deals with the kinetics of solvent extraction of oil from Amaranth, as well as the thermodynamics of the extraction process. Brief introduction of Amaranth and Amaranth oil yields and compositions were given. The justifications of the choice of extraction method, as well as the solvent used in the kinetics and thermodynamic studies, were discussed. Known kinetic models used to model vegetable oils extraction process, were discussed, with the view of evaluating the feasibility of fitting the obtained experimental data into the models. The extraction kinetic models considered are the parabolic diffusion, power law, hyperbolic, Elovich’s and pseudo second order models. The thermodynamics of oil extraction process were also considered. Hence, the thermodynamic parameters, enthalpy, entropy and Gibb’s free energy change of the process were also discussed

Development of a Patient-Specific Multi-Scale Model to Understand Atherosclerosis and Calcification Locations: Comparison with In vivo Data in an Aortic Dissection

Vascular calcification results in stiffening of the aorta and is associated with hypertension and atherosclerosis. Atherogenesis is a complex, multifactorial, and systemic process; the result of a number of factors, each operating simultaneously at several spatial and temporal scales. The ability to predict sites of atherogenesis would be of great use to clinicians in order to improve diagnostic and treatment planning. In this paper, we present a mathematical model as a tool to understand why atherosclerotic plaque and calcifications occur in specific locations. This model is then used to analyze vascular calcification and atherosclerotic areas in an aortic dissection patient using a mechanistic, multi-scale modeling approach, coupling patient-specific, fluid-structure interaction simulations with a model of endothelial mechanotransduction. A number of hemodynamic factors based on state-of-the-art literature are used as inputs to the endothelial permeability model, in order to investigate plaque and calcification distributions, which are compared with clinical imaging data. A significantly improved correlation between elevated hydraulic conductivity or volume flux and the presence of calcification and plaques was achieved by using a shear index comprising both mean and oscillatory shear components (HOLMES) and a non-Newtonian viscosity model as inputs, as compared to widely used hemodynamic indicators. The proposed approach shows promise as a predictive tool. The improvements obtained using the combined biomechanical/biochemical modeling approach highlight the benefits of mechanistic modeling as a powerful tool to understand complex phenomena and provides insight into the relative importance of key hemodynamic parameters

Effects Of Intercropping On Root-Gall Nematode Disease On Soybean (Glycine max (L) Merril)

ABSTRACT: Six intercrops (maize, melon, okra, Telfairia, Amaranthus and pepper) were tested for control of root-gall nematode disease on soybean in a loamy sand soil naturally infested with Meloidogyne javanica. The experiment was laid out in a randomized complete block design replicated four times. Results based on root-gall indices and number of juveniles (J 2 ) recovered from roots and rhizospheric soil showed that intercropping soybean with Telfairia, pepper and Amaranthus effectively suppressed infection on soybean roots. Okra, maize and melon intercropped with the soybean aggravated root-gall damage and caused yield reductions

Physicochemical Quality and Genotoxic Potential of Wastewater Generated by Canteen Complex

Canteens generate high volumes of wastewater that should constantly be subjected to physicochemical and genotoxicity screening. In this study, the wastewater generated by a canteen complex was screened for physicochemical properties and genotoxic potential using standard procedures and Allium cepa chromosome assay. Results showed that the wastewater had total suspended solids, total dissolved solids, and total hardness concentrations of 120.70 mg/l, 554.50 mg/l, and 500.00 mg/l, respectively. The chloride concentration of the wastewater (7873.60 mg/l) was much higher than the recommended limit of 250 mg/l. The wastewater inhibited root growth in A. cepa at 0.1%, 1%, 10%, 25%, 50%, and 100% concentrations but promoted root growth at 2% and 5% concentrations. The wastewater was highly mitodepressive, with mitotic inhibition generally increasing with rising concentrations. The major chromosomal aberrations observed in A. cepa exposed to different concentrations of canteen wastewater were vagrant, sticky, and bridged chromosomes. No chromosomal aberration was observed in onion roots exposed to water (control). The differences in total chromosomal aberrations across wastewater concentrations were not statistically significant (P > 0.05). In view of these results, the practice of discharging untreated canteen wastewater into drainage canals may not be environmentally sustainable

Aortic dissection simulation models for clinical support: fluid-structure interaction vs. rigid wall models

BACKGROUND: The management and prognosis of aortic dissection (AD) is often challenging and the use of personalised computational models is being explored as a tool to improve clinical outcome. Including vessel wall motion in such simulations can provide more realistic and potentially accurate results, but requires significant additional computational resources, as well as expertise. With clinical translation as the final aim, trade-offs between complexity, speed and accuracy are inevitable. The present study explores whether modelling wall motion is worth the additional expense in the case of AD, by carrying out fluid-structure interaction (FSI) simulations based on a sample patient case. METHODS: Patient-specific anatomical details were extracted from computed tomography images to provide the fluid domain, from which the vessel wall was extrapolated. Two-way fluid-structure interaction simulations were performed, with coupled Windkessel boundary conditions and hyperelastic wall properties. The blood was modelled using the Carreau-Yasuda viscosity model and turbulence was accounted for via a shear stress transport model. A simulation without wall motion (rigid wall) was carried out for comparison purposes. RESULTS: The displacement of the vessel wall was comparable to reports from imaging studies in terms of intimal flap motion and contraction of the true lumen. Analysis of the haemodynamics around the proximal and distal false lumen in the FSI model showed complex flow structures caused by the expansion and contraction of the vessel wall. These flow patterns led to significantly different predictions of wall shear stress, particularly its oscillatory component, which were not captured by the rigid wall model. CONCLUSIONS: Through comparison with imaging data, the results of the present study indicate that the fluid-structure interaction methodology employed herein is appropriate for simulations of aortic dissection. Regions of high wall shear stress were not significantly altered by the wall motion, however, certain collocated regions of low and oscillatory wall shear stress which may be critical for disease progression were only identified in the FSI simulation. We conclude that, if patient-tailored simulations of aortic dissection are to be used as an interventional planning tool, then the additional complexity, expertise and computational expense required to model wall motion is indeed justified

PREVALENCE OF DIARRHOEA AGENTS AND THE IN-VITRO EFFECTS OF THREE PLANT EXTRACTS ON THE GROWTH OF THE ISOLATES

ABSTRACT Isolation of bacteria associated with diarrhoea in young children below the age of five years and the antibacterial efficacy of Dioscorea dumetorum, Oscimum suave, and Ancistracarpus densispinosus were investigated. Leaves of these plants were dried and powdered before being soaked in 70% ethanol for 3 days. The stools were cultured and isolates were identified according to standard bacteriological methods . Agar diffusion method was employed in determining the inhibitory effects of the extracts on growth of the bacterial isolates. Out of 100 samples collected, 97% showed growth of different bacterial species. These include Escherichia coli (28%), Salmonella (21%), Klebsiella (16%), Shigella (15%), Proteus mirabilis (1%), and Staphylococcus aureus (7%). Klebsiella, Proteus and Escherichia coli were susceptible to the inhibitory effect of the three extracts at varying concentrations except for Proteus mirabilis which did not respond at all to Ancistracarpus densispinosus. Statistically, Dioscorea dumetorum proved to be more effective than Oscimum suave (p<o.o5). . Hence, Dioscorea dumetorum and Ocimum suave could serves as an alternative to orthodox drugs in the treatment of diseases due to Klebsiella, Escherichia coli, and Proteus mirabilis