Looking Inwards for Sustainability: Nigerian Cities and Building Demolition-waste or wealth?

Cities could generally be described as sustainable before the replacement of manual labour with machines known as the industrial revolution of the 18th century in Europe. Nevertheless, the Industrial Revolution has been associated with environmental degradation and other negative impacts. The trend continued for two centuries until it was realised that there is a limit to the capacity of the earth to withstand such impacts. The damage to the earth needs to be halted by choice or forced by natural consequences. The idea of pursuing economic development with minimum negative socio-economic and environmental impacts comes to be known as Sustainability. The built environment becomes at the centre of the sustainability agenda due to the enormous negative impact to the environment. Moreover, it was reported that 90% of all materials resources ever extracted might be used in the built environment. Unfortunately, many of these materials, including 10% unused are discarded as wastes. In the UK example, 90-120 million tonnes of construction and demolition (C&D) waste is generated annually. This makes C&D wastes even more critical to the sustainability agenda; and in search for solution, in the words of Janine Benyus, it may even involve the urban westerners learning from the wisdom of the preindustrial societies that have been living in harmony with the nature. In the preindustrial community of Kano in Nigeria, there is virtually zero C&D waste; rather it is merchandise. The different categories of the stakeholders were interviewed to establish how the system works, the conditions that led to its emergence, and limitations. It was discovered that the end-of-life management of buildings in Kano is a naturally evolved industrial ecology analogous to the natural ecological system, whereby the bye-product of one process becomes the raw material for another with no waste. Furthermore, a conceptual model of the system was developed using the biomorphic adaptation of the shell of an African snail. It was therefore argued that sustainability practices are inherent within the African traditions rather than to be learnt from outside

Empirical properties of duality theory

This research examines selected empirical properties of duality relationships. Monte Carlo experiments indicate that Hessian matrices estimated from the normalised unrestricted profit, restricted profit and production functions yield conflicting results in the presence of measurement error and low relative price variability. In particular, small amounts of measurement error in quantity variables can translate into large errors in uncompensated estimates calculated via restricted and unrestricted profit and production functions. These results emphasise the need for high quality data when estimating empirical models in order to accurately determine dual relationships implied by economic theory.Research Methods/ Statistical Methods,

AN EXAMINATION OF THE EMPIRICAL PROPERTIES OF DUALITY BETWEEN THE RESTRICTED PROFIT, UNRESTRICTED PROFIT, AND PRODUCTION FUNCTIONS

This research examines the empirical properties of duality theory. A comparison of the Hessian matrices calculated from the normalized unrestricted and restricted profit, and production functions indicate that duality is highly sensitive to measurement error and relative price variability. Keywords: duality, restricted and unrestricted profit functionsduality, restricted and unrestricted profit functions, Demand and Price Analysis, Production Economics,

A 10B-based neutron detector with stacked Multiwire Proportional Counters and macrostructured cathodes

We present the results of the measurements of the detection efficiency for a 4.7 \r{A} neutron beam incident upon a detector incorporating a stack of up to five MultiWire Proportional Counters (MWPC) with Boron-coated cathodes. The cathodes were made of Aluminum and had a surface exhibiting millimeter-deep V-shaped grooves of 45{\deg}, upon which the thin Boron film was deposited by DC magnetron sputtering. The incident neutrons interacting with the converter layer deposited on the sidewalls of the grooves have a higher capture probability, owing to the larger effective absorption film thickness. This leads to a higher overall detection efficiency for the grooved cathode when compared to a cathode with a flat surface. Both the experimental results and the predictions of the GEANT4 model suggests that a 5-counter detector stack with coated grooved cathodes has the same efficiency as a 7-counter stack with flat cathodes. The reduction in the number of counters in the stack without altering the detection efficiency will prove highly beneficial for large-area position-sensitive detectors for neutron scattering applications, for which the cost-effective manufacturing of the detector and associated readout electronics is an important objective. The proposed detector concept could be a technological option for one of the new chopper spectrometers and other instruments planned to be built at the future European Spallation Source in Sweden. These results with macrostructured cathodes generally apply not just to MWPCs but to other gaseous detectors as well.Comment: 14 pages, 9 figure

A Framework for Enhancing Contractor-Subcontractor Relationships in Construction Projects in Nigeria

The delivery capability of main contractors depends largely on the quality of their subcontractors and the harmonious relationships that exist between them. Research work was therefore conducted to identify the mechanisms to facilitate the understanding between these pairs and also develop a model that puts emphasis on the factors. To achieve this aim, one hundred questionnaires each were administered randomly to main contractors and labor-only subcontractors in the study area. Seventy-five and eighty-eight questionnaires were respectively filled and returned in this regard. The application of total weight value and rating index techniques shows that type of contract, scope of contract, payment terms, cooperative attitudes, third-party involvement are the main factors that influence this relationship and this was further validated by a model. The paper concludes that this methodology could culminate into a useful decision making tool for both main contractors and subcontractors during the development and execution stages of construction projects in the study area

Pneumococcal carriage in sub-Saharan Africa--a systematic review.

BACKGROUND: Pneumococcal epidemiology varies geographically and few data are available from the African continent. We assess pneumococcal carriage from studies conducted in sub-Saharan Africa (sSA) before and after the pneumococcal conjugate vaccine (PCV) era. METHODS: A search for pneumococcal carriage studies published before 2012 was conducted to describe carriage in sSA. The review also describes pneumococcal serotypes and assesses the impact of vaccination on carriage in this region. RESULTS: Fifty-seven studies were included in this review with the majority (40.3%) from South Africa. There was considerable variability in the prevalence of carriage between studies (I-squared statistic = 99%). Carriage was higher in children and decreased with increasing age, 63.2% (95% CI: 55.6-70.8) in children less than 5 years, 42.6% (95% CI: 29.9-55.4) in children 5-15 years and 28.0% (95% CI: 19.0-37.0) in adults older than 15 years. There was no difference in the prevalence of carriage between males and females in 9/11 studies. Serotypes 19F, 6B, 6A, 14 and 23F were the five most common isolates. A meta-analysis of four randomized trials of PCV vaccination in children aged 9-24 months showed that carriage of vaccine type (VT) serotypes decreased with PCV vaccination; however, overall carriage remained the same because of a concomitant increase in non-vaccine type (NVT) serotypes. CONCLUSION: Pneumococcal carriage is generally high in the African continent, particularly in young children. The five most common serotypes in sSA are among the top seven serotypes that cause invasive pneumococcal disease in children globally. These serotypes are covered by the two PCVs recommended for routine childhood immunization by the WHO. The distribution of serotypes found in the nasopharynx is altered by PCV vaccination

Serum homocysteine level in hormonal contraceptive users in Kano Metropolis

Background: Homocysteine is a sulfur containing amino acid that is normally present in all cells of the body. The homocysteine level is linked to folate and Vitamin B-12 levels. Aim: The aim of this study was to investigate the effect of hormonal contraceptives (HCPs) on homocysteine levels among healthy women using the HCPs. Method: A total of 90 participants were recruited in this study; 60 women on hormonal contraceptives served as the case group and 30 non-HCP users were considered as control. Blood samples were collected, and serum was analyzed for homocysteine levels in both groups. The mean ± standard deviation of the homocysteine levels were then determined and compared using student t-test. Results: The mean ± standard deviation of Serum Homocysteine in the case group, (14.14 ± 7.56μmol/L, was found to be significantly higher than the mean ± standard deviation of the control group which was 9.59 ± 5.87μmol/L (p-value of 0.005). The study also found statistically significant positive correlation (r<1) between duration of hormonal contraceptives use and serum homocysteine levels of HCPs users with r-value of 0.058. Conclusion: This study observed significant relationship between HCPs and increased serum homocysteine. Significantly increased homocysteine levels were observed in HCPs users compared to non-users. There was also positive correlation between the duration of HCP usage and increased homocysteine levels. Keywords: Contraception; Folate; Homocystinuria; Oral contraceptive

Living with diversity and change: Intergenerational differences in language and identity in the Somali community in Britain

The Somali community in Britain has been portrayed as largely homogenous and rather problematic, unwilling to integrate into mainstream British society, a perception that is reinforced by the media and government policies. The government policies tend to ignore the internal diversity and change that the community is experiencing. Drawing on data from a family language policy project, this paper aims to explore intergenerational changes in language preference and use and associated issues of identity within the Somali community in Britain. We look at how the changes in language preference and practice manifest themselves through reported language use and language policies at home, how the changes are affecting the British Somali youths in particular, and how ideas of Somaliness and Britishness are negotiated on an individual level, as well as on a community-wide level through Somali-led organisations. And we highlight the work that the community is doing to tackle issues of intergenerational language shift and Somali identity building. The study aims to contribute to a better understanding of the struggles of the Somali community in Britain in dealing with diversity and change, an understanding that is crucial to the development of appropriate policies regarding the community