Interworking Architectures in Heterogeneous Wireless Networks: An Algorithmic Overview

The scarce availability of spectrum and the proliferation of smartphones, social networking applications, online gaming etc., mobile network operators (MNOs) are faced with an exponential growth in packet switched data requirements on their networks. Haven invested in legacy systems (such as HSPA, WCDMA, WiMAX, Cdma2000, LTE, etc.) that have hitherto withstood the current and imminent data usage demand, future and projected usage surpass the capabilities of the evolution of these individual technologies. Hence, a more critical, cost-effective and flexible approach to provide ubiquitous coverage for the user using available spectrum is of high demand. Heterogeneous Networks make use of these legacy systems by allowing users to connect to the best network available and most importantly seamlessly handover active sessions amidst them. This paper presents a survey of interworking architectures between IMT 2000 candidate networks that employ the use of IEFT protocols such as MIP, mSCTP, HIP, MOBIKE, IKEV2 and SIP etc. to bring about this much needed capacity

Self Reported Symptoms associated with Coffee Consumption among University Students in Nigeria

This paper examined the psycho physiological effects of coffee consumption as reported by University students. The relationship between coffee consumption and anxiety was also explored. It was hypothesized that heavy caffeine users would report significantly higher anxiety and more psychophysical symptoms of caffenism more than non-users. A sample size of 447-university students made up of 239 males and 208 females within ages 16-36 years (M = 22.7; SD = 2.92) participated in the study. All respondents completed an adapted version of STAI forms Y-1 and Y-2 which measures state-trait anxiety. Analysis of data revealed significant difference between coffee users and non-users on state anxiety. The quantity and frequency of daily coffee consumption were found to be related to the symptoms exhibited on state anxiety. There was no significant sex difference on the frequency and quantity of coffee consumption but a significant age difference in favour of younger respondent was recorded on frequency of coffee consumption. Various symptoms reported by the respondents confirmed the stimulating properties of caffeine.African Research Review Vol. 2 (2) 2008 pp. 13-3

Review of Business Strategies for Environmental Leadership and Sustainability Matters

Environmental leadership and sustainability has not much been pursued by most business organization in that, the main focus of most business organizations today is to make profit and to satisfy the customer. Modern business strategies demand the protection of the natural environment. Many people are now expecting corporate institutions to be socially responsible. Environmental deterioration caused by corporate activities is reducing the quality state of our environmental. Institutions must now develop strategies that can help protect and sustain the environment. There are many strategies firms can practice to sustain the environment. These strategies are known as Environmental business strategy. In the literature review two of these strategies were reviewed: Purchasing environmental strategy and Marketing environmental strategy. Keywords: Sustainability, Strategies, marketing, Business Models, Environmental leadership DOI: 10.7176/JESD/12-2-04 Publication date: January 31st 202

Incidence of Bacterial Septicaemia in Ile-Ife Metropolis, Nigeria

A retrospective study of septicaemia was conducted in Ile-Ife metropolis with a view to determine its incidence and changes in the predominant aetiological agents. Six hundred and fifty (650) subjects, aged from one day to seventy years and above were examined. They all had clinical features suggestive of septicaemia and were on admission at the Obafemi Awolowo University hospital Complex, Ile-Ife, Nigeria. Their blood specimens were seeded into thioglycolate and glucose broths and incubated at 37 °C for 7 days. Subcultures were performed after 1, 2, 3, 4 and 7 days respectively. Growth (positivity) in the broths was assessed using conventional diagnostic methods namely macroscopy (visualization), Gram filming (microscopy) and culture. The bacterial isolates harvested were subjected to in-vitro antibiotic susceptibility tests using the disc diffusion method. Etiology was established in 204 out of 650 subjects indicating an incidence of 31.4%. This difference in prevalence among different age groups was statistically significant (P < 0.01). The males (112/650, 17.2%) appeared to be more susceptible to septicaemia than the females (94/650, 14.5%) in all the age groups. This variation had no statistical significance (P > 0.01). Monomicrobial septicaemia had a higher prevalence (92.2%) than polymicrobial septicaemia (7.8%). Staphylococcus aureus and Escherichia coli constituted 43.8%. Most of the offensive microbes were facultative anaerobes (91.7%) while very few were strict aerobes (6.8%) and strict anaerobes (1.5%). The isolated anaerobes were Peptostreptococcus sp. (0.5%) and Bacteroides fragilis (1%). The in vitro susceptibility of the bacterial isolates to antibiotics indicated 76.4-95.6% sensitivity to vancomycin, zinnat, peflacin and fortum. However, they were 60 – 90% resistant to penicillin, ampicillin, tetracycline and septrin. This study confirmed the diverse nature of bacterial etiologies of septicaemia in the area; the need for the use of thioglycolate broths, first subcultures on or before 24 h instead of starting off for after 48 h of incubation, complementary application of macroscopy, Gram filming and culture including antibiotic susceptibility test as an integral part of diagnosis and management of septicaemia is hereby advocated, most especially in the developing countries of the world

A Study of Valuation Clients Perception on Mortgage Valuation Reliability

The effect of overvaluation and undervaluation cannot be over emphasized in any economy. Valuation opinions are very crucial to the operations and business dealings of the clients that seek valuer’s advice in decision making. Wrong opinion of value has caused strain in many business dealings. This paper studies the perception of clients on reliability of mortgage valuation in Nigeria. A sample size of 50 lending institutions was randomly chosen representing 57.5% of the target population in Lagos State, the study area. The study used descriptive statistic to analyse the data. The study reveals that clients are of the opinion that valuations produced by valuers were not reliable. This is as a result of the experiences they were having with large disparity between the final opinion of values of those properties on default mortgage that were foreclosed and the final sales price. The study therefore concludes that the estate surveyors and valuers in the country owe their clients a duty of care by presenting accurate and reliable valuation reports since other stakeholders of the real property investors depend on these reports for their investment decision

Navigating Metaphorical Expressions through Design Problem Solving: A Perspective of Design Critic in a Creative Economy

In the school of creativity, Metaphors are tools and weapons that designers employs during intellectual navigation to understand unfamiliar design problems and are as useful as criticism to an art-teacher in portfolio grading, assessment and examination. A connecting thread is found by juxtaposing metaphor and criticism in which a creative end is reached for both the Art-teachers and students in academe and practice. Thus in a developing economy where design endeavor gains nobility, a creative product emerges and retrieving concepts from metaphors necessitates creative thinking. While the importance of these creative tools has been acknowledged in design, more research work is needed to appreciate its contribution to design practice. This investigation is aimed at building a connecting thread resilient enough to create a synergy between the uses of metaphor in design criticism and meaningful design problem solving with a particular focus on design creativity. Overt meaning of metaphorical expressions, factors of creativity and constructive criticism were interpolated into a holistic value. Critical evaluation showed that the connection of metaphor and criticism is the most significant factor characterizing design evolution and creativity. On the other hand, the synthesis of design solutions is the stronger factor of the use of metaphors. Evaluation in this paper demonstrates that correct use of metaphorical expressions play an important role in design creativity. Theoretical discourse analysis of metaphorical expressions in design problems was the screen that showed unique contributions of criticism to individual potential discoveries and general creativity by design problem solving in a dynamic econom

RELEVANCE OF REAL ESTATE EDUCATION TO PRACTICE IN NIGERIA

Attempts to define a common body of knowledge for real estate education have generated a lot of debate in recent years. Some people see estate management as an academic discipline, while others see it as an environmental discipline. This study therefore seeks to research into complaints over the quality of estate management graduates being sent into the labour market yearly, the shortfalls of the current curriculum and effectiveness of the current teaching techniques. The target population was the stakeholders comprising practicing estate surveyors, lecturers and final year students in the Department of Estate Management of three federal tertiary institutions. Two sets of questionnaires were administered in addition to in-depth interviews. The study found out that young graduates of estate management are deficient in valuation, agency, feasibility and viability appraisal, and property management. The study recommended th

Effect of Interaction of Methanol Leaf Extract of Spondias mombin (Linn) and Amoxicillin on Some Diarrheagenic Escherichia coli

Purpose: To study the effect of interaction between methanol leaf extract of Spondias mombin and amoxicillin on diarrheagenic Escherichia coli (DEC).Methods: Cold methanol extraction of Spondias mombin leaf and its phytochemical screening were carried out. Isolated, characterized and identified strains of enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), and enterohemorrhagic E. coli (EHEC) from watery stool, mucoid bloody stool and watery bloody stool of diarrheal patients, respectively, were confirmed and typed by conventional and molecular methods. The minimum inhibitory concentration (MIC) and ½ MIC at which the extract and amoxicillin interacted were determined.Results: Spondias mombin extract showed remarkable antibacterial activity at extract concentration of 50 - 200 mg/mL with a mean zone of inhibition (MZ) ≥ 11.1 and activity index (AI) of 0.8 - 1.1. MIC of 12.5 mg/mL was observed for both ETEC and EIEC while it was 6.25 mg/mL for EHEC. The extract showed synergistic interaction at various concentrations (50 – 200, 12.5 and 6.25 mg/mL, respectively) with amoxycillin against ETEC, EHEC and EIEC. Synergy across a wide range of concentrations compared favourably with the ½ MIC and MIC of both extract and amoxycillin for ETEC. The extract contained moderate levels of alkaloids, flavonoids and tannins, as well as a lot of saponins, and low levels of phenol. The activity of the extract of Spondias mombin compares well with that of amoxicillin with AI ≥ 1 in some cases.Conclusion: A synergistic interaction between the leaf extract of S. mombin and amoxicillin confirms the extract as potential antibacterial agent but further studies are required to ascertain this.Keywords: Diarrheagenic E. coli, Drug interaction, Spondias mombin, Amoxicillin, Time-kill, Activity inde

Improved Colorimetric Determination of Reserpine in Tablets Using 4-Caboxyl-2,6-dintrobenzene diazonium ion (CDNBD)

Purpose: To develop a simple, rapid and improved colorimetric method for the assay of reserpine in tablets Method: The method is based on the aromatic ring coupling of reserpine with 4-carboxyl-2,6-dinitrobenzene diazonium ion with the consequent formation of an azo adduct. Optimization of reaction conditions and validation were carried out and the method applied to assay of reserpine in tablets. Result: Reserpine coupled readily with CDNBD and optimization of experimental conditions showed the reaction to be completed in 10 min at room temperature. A 1:1 drug to reagent stoichiometric ratio was obtained for the azo adduct formed. The adduct exhibited a bathochromic shift with respect to the drug and pronounced hyperchromic shift with respect to the reagent. Sample analyses were done using a colorimeter at 470 nm. The assays were linear and reproducible over the concentration range of 2.25 -24 µg/mL. The new method was successfully applied in the assay of reserpine in tablets with a performance similar to the official (USP) spectrophotometric method (p > 0.05). This method represents a profound improvement on the previously reported colorimetric method for reserpine. Conclusion: The method developed is rapid and could find application in in-process quality control of reserpine. Keywords: Reserpine, colorimetry, 4-Caboxyl-2,6-dintrobenzene diazonium ion (CDNBD), diazo coupling > Tropical Journal of Pharmaceutical Research Vol. 6 (2) 2007: pp. 695-70