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1 – 3 of 3V.C. Uzomah and A.Y. Sangodoyin
Examines rainwater chemistry as it relates to atmospheric pollution in Southern Nigeria. Rainwater samples were collected and analysed for major cations and anions in Lagos…
Abstract
Examines rainwater chemistry as it relates to atmospheric pollution in Southern Nigeria. Rainwater samples were collected and analysed for major cations and anions in Lagos, Ibadan and Port Harcourt, these sites reflecting industrial, residential and oil flaring regions respectively. In general, water samples from Ibadan were about neutral. Correlation studies revealed that HCl and H2SO4 dominated the slightly acidic rainwater in the Lagos and Port Harcourt areas respectively. The effect of marine spray from the Gulf of Benin was observed with trace of NaCl. The reaction of the much emitted NH3 with the available SO42– in the atmosphere produced (NH4)2SO4 which acted as a neutralizer for samples from the Lagos area. The findings suggest that rainwater from most industrial cities of Nigeria are tending towards acidity and if oil flaring activities are not checked, there is a tendency of increasing acidic rainwater in the delta regions. The observation and findings are useful for preliminary assessments of the influence of rapid industrial and urban development on atmospheric pollution and indirectly rainwater constituents.
Humphrey Boogaerdt and Alistair Brown
The purpose of this study is to consider how a local government authority may present a tree asset register of street trees for the decision-making of the authority's stakeholders.
Abstract
Purpose
The purpose of this study is to consider how a local government authority may present a tree asset register of street trees for the decision-making of the authority's stakeholders.
Design/methodology/approach
Using the tenets of population density theory, urban form theory and social stratification theory, the approach of the study is to develop a tree asset register in a local government authority's setting that could be modelled using many different attributes to derive important information for decision-making purposes.
Findings
Tree asset registers represent a critical tool in managing street trees across local government authorities.
Research limitations/implications
Although the efficacy of an asset tree register may be curtailed by lack of internal audit or yearly updates, the practical consequence of an asset tree register is that local administrators may use the register to gather summarised, organised and parsimonious measures of a wide range of environmental, historical, cultural, aesthetic and scientific values of street trees.
Practical implications
Tree asset registers affords ratepayers, developers, tree managers and valuers a technology to plan, coordinate and manage street trees to support ecosystem services.
Social implications
Asset tree registers offer planners a means to bring about sustainable change management.
Originality/value
The originality of the study rests in introducing tree registers as a means to meet diverse strategies for street tree management by interested stakeholders.
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Keywords
Abedalmuhdi Almomany, Ahmad M. Al-Omari, Amin Jarrah and Mohammad Tawalbeh
The problem of motif discovery has become a significant challenge in the era of big data where there are hundreds of genomes requiring annotations. The importance of motifs has…
Abstract
Purpose
The problem of motif discovery has become a significant challenge in the era of big data where there are hundreds of genomes requiring annotations. The importance of motifs has led many researchers to develop different tools and algorithms for finding them. The purpose of this paper is to propose a new algorithm to increase the speed and accuracy of the motif discovering process, which is the main drawback of motif discovery algorithms.
Design/methodology/approach
All motifs are sorted in a tree-based indexing structure where each motif is created from a combination of nucleotides: ‘A’, ‘C’, ‘T’ and ‘G’. The full motif can be discovered by extending the search around 4-mer nucleotides in both directions, left and right. Resultant motifs would be identical or degenerated with various lengths.
Findings
The developed implementation discovers conserved string motifs in DNA without having prior information about the motifs. Even for a large data set that contains millions of nucleotides and thousands of very long sequences, the entire process is completed in a few seconds.
Originality/value
Experimental results demonstrate the efficiency of the proposed implementation; as for a real-sequence of 1,270,000 nucleotides spread into 2,000 samples, it takes 5.9 s to complete the overall discovering process when the code ran on an Intel Core i7-6700 @ 3.4 GHz machine and 26.7 s when running on an Intel Xeon x5670 @ 2.93 GHz machine. In addition, the authors have improved computational performance by parallelizing the implementation to run on multi-core machines using the OpenMP framework. The speedup achieved by parallelizing the implementation is scalable and proportional to the number of processors with a high efficiency that is close to 100%.
Details