Distribution of heavy metals in sediments of Igbede, Ojo and Ojora rivers of Lagos, Nigeria

The distribution of some heavy metals, namely Cd, Pb, Zn, Fe, Cu, Cr and Mn in epipellic sediments of Igbede, Ojo and Ojora rivers of Lagos was studied weekly in the early summer (November) of 2003. The levels of selected trace metals were determined using Atomic Absorption Spectrophotometer (UNICAM 969 AAS SOLAR). Trends in heavy metal burdens in the sediments revealed weekly variations in all the rivers assessed. Statistical analyses also showed different mean levels of trace metals in the aquatic environments, the distribution of which followed the sequence Fe > Zn > Mn > Pb > Cu > Cr > Cd, Fe > Zn > Cu > Mn > Pb > Cr > Cd and Fe > Zn > Mn > Cu > Cr > Pb > Cd in Igbede, Ojo and Ojora rivers respectively. Fe recorded the highest concentration levels (1,582.95 ± 96.57 μg/g–1,910.34 ± 723.19 μg/g) in all the sediments investigated while the Cd levels (0.06 ± 0.10 μg/g–0.47 ± 0.36 μg/g) were the lowest. Expectedly, trace metal concentrations in fine grain muddy sediments of the Igbede and Ojo coastline were much higher than those of Ojora which consist of coarse and sandy deposits covering the near shore area. Generally, the results obtained fell within toler-able limits stipulated by World Health Organization (WHO)

Stigma Hurts: Exploring Employer and Employee Perceptions of Tattoos and Body Piercings in Nigeria

Purpose – This study draws on social stigma and prejudice to examine the perceptions and beliefs of managers and employees regarding visible tattoos and body piercings, as well as the impact they have on potential employment and human resource management in the global South, using Nigeria as the research context. Design/methodology/approach – The study uses a qualitative research approach, drawing on data from forty-three semi-structured interviews with managers and employees in Nigeria. Findings – Contrary to the popular opinion that tattoos and body piercings are becoming more accepted and mainstream in society, this study finds that some Nigerian employers and employees may stigmatise and discriminate against people with visible tattoos and body piercings. The findings of this study suggest that beliefs about tattoos are predicated on ideologies as well as religious and sociocultural values, which then influence corporate values. Practical Implications – Religious and sociocultural preconceptions about people with visible tattoos and body piercings have negative implications for the recruitment and employment of such people and could prevent organisations from hiring and keeping talented employees. This implies that talented employees might experience prejudice at job interviews, preventing them from gaining employment. Furthermore, stigmatising and discriminating against people with visible tattoos and body piercings may lead to the termination of employment of talented employees, which could negatively affect organisational productivity and growth. Originality/value – This study provides an insight into employment relations with regards to tattoos and body piercings in Nigeria. It also makes some contributions to the social psychology of workplace prejudice and highlights the reasons for the stigma and prejudice against individuals with visible tattoos and body piercings

Modern-Day Slavery? The Work-Life Conflict of Domestic Workers in Nigeria

Purpose – The trend of domestic employment thrives almost in every society. It is most common in developing countries, and Nigeria is no exception. This article examines the nature of the role of a domestic worker in Nigeria and the work-life conflict issues involved in such work. Design/Methodology/Approach – This study uses a qualitative research approach to examine the nature of the role of domestic workers and the associated work-life conflict issues. Findings – The findings show that the nature of the jobs of domestic workers in Nigeria gives rise to a situation of modern-day slavery in which an employee works without a formal employment contract, with little or no rights to private time. Long and unstructured working hours, employers’ perceptions about domestic workers, and an enormous workload fuel and exacerbate work-life conflict among domestic workers in Nigeria. Research Limitations/Implications – The extent to which the findings of this research can be generalised is constrained by the limited and selected sample of the research and the research context. Practical Implications – The primacy of the employer over the employee in domestic employment means that both time and work-based conflicts continue to buffer work-life conflict if domestic workers’ working hours remain unscheduled and their employers’ perceptions about them remain unchanged. This invariably has a negative impact on the domestic workers’ health and productivity. Therefore, domestic employment should be regulated by law, and domestic workers should be treated like other formal employees. Originality/Value – This research contributes to the debates on work-life conflict by highlighting the nature of the role of domestic workers in a non-western context, Nigeria, and provides a nuanced insight into the work-life conflict issues involved in such work. The findings add conceptual thought and empirical evidence to the debate on work-life conflict

The Work-Family Balance of British Working Women During the Covid-19 Pandemic

Purpose – The COVID-19 pandemic has affected women in unique gender-specific ways, particularly their traditional status as home managers. This study draws on role theory to examine the impact of the COVID-19 pandemic on women’s work-family balance during the lockdown. Design/methodology/approach – The current COVID-19 pandemic, which has altered the ways in which we live and work, requires specific methodological tools to be understood. We therefore opted for a interpretive-constructivist and constructivist-phenomenologist approach. The dataset thus comprises of semi-structured interviews with twenty-six working women in the UK. Findings – The findings illustrate how the COVID-19 lockdown has intensified British women’s domestic workload and has thus caused unbridled role conflict, which has further been exacerbated by structural and interactional roles undertaken by women especially during the lockdown. Remote working has contributed to women’s role congestion and role conflict and poses severe challenges to role differentiation. Furthermore, we found that the lockdown has facilitated the rediscovery of family values and closeness, which is connected to the decline in juvenile delinquency and low crime rate that has resulted from the lockdown. Originality/value – Through the lens of the role theory, this study concludes that the cohabitation of work and family duties within the domestic space undermines the ability to achieve work-family balance and role differentiation due to the occurrence of inter-role conflicts. This study enriches our understanding of the effect of remote working on female employees’ work-family balance during the unprecedented COVID-19 pandemic lockdown

Synthesis, characterization, antimicrobial activity and toxicology study of some metal complexes of mixed antibiotics

Mixed ligand metal complexes of ampicillin and chloramphenicol prepared by using Ni(II), Co(II) and Fe(III) metal chloride hexahydrate were reported and characterized based on some physical properties and spectroscopic analysis such as AAS, UV, and IR spectroscopy. The complexes were proposed to have the formulae [ML1L2](Cl)n ( where M= Ni(II), Co(II), Fe(III); L1 = ampicillin, L2 = chloramphenicol, and n=2-3). IR spectra suggested that both L1 and L2 coordinated to the metal ions in a terdentate manner with �(O-H), �(C=O) and �(N-H) as donor sites in each of the ligands. From analytical and spectroscopic data obtained, the complexes were proposed to be of octahedral. The synthesized complexes, in compares to their ligands, were also screened for their antibacterial activity against isolated strains of Escherichia coli, Staphylococcus aureus and Klebsiella pneumonia by using agar diffusion method. The activity data showed the metal complexes to be more potent antibacterial than the parent drugs against the three bacteria species. However, toxicology tests against some tissues of albino rat (Rattus novergicuss) revealed toxicity of the complexes as compared to the parent drugs because the complexes were found to significantly increase (P<0.05) alkaline phosphatase from homogenates of liver and kidney tissues of the tested doses. However, there was no significant difference (P>0.05) in ALP of rat serum. The results generally indicated that more potent compounds with better physical properties and enhanced antimicrobial activities upon complexation have been prepared

Understanding Spark System Performance for Image Processing in a Heterogeneous Commodity Cluster

In recent years, Apache Spark has seen a widespread adoption in industries and institutions due to its cache mechanism for faster Big Data analytics. However, the speed advantage Spark provides, especially in a heterogeneous cluster environment, is not obtainable out-of-the-box; it requires the right combination of configuration parameters from the myriads of parameters provided by Spark developers. Recognizing this challenge, this thesis undertakes a study to provide insight on Spark performance particularly, regarding the impact of choice parameter settings. These are parameters that are critical to fast job completion and effective utilization of resources. To this end, the study focuses on two specific example applications namely, flowerCounter and imageClustering, for processing still image datasets of Canola plants collected during the Summer of 2016 from selected plot fields using timelapse cameras in a heterogeneous Spark-clustered environments. These applications were of initial interest to the Plant Phenotyping and Imaging Research Centre (P2IRC) at the University of Saskatchewan. The P2IRC is responsible for developing systems that will aid fast analysis of large-scale seed breeding to ensure global food security. The flowerCounter application estimates the count of flowers from the images while the imageClustering application clusters images based on physical plant attributes. Two clusters are used for the experiments: a 12-node and 3-node cluster (including a master node), with Hadoop Distributed File System (HDFS) as the storage medium for the image datasets. Experiments with the two case study applications demonstrate that increasing the number of tasks does not always speed-up job processing due to increased communication overheads. Findings from other experiments show that numerous tasks with one core per executor and small allocated memory limits parallelism within an executor and result in inefficient use of cluster resources. Executors with large CPU and memory, on the other hand, do not speed-up analytics due to processing delays and threads concurrency. Further experimental results indicate that application processing time depends on input data storage in conjunction with locality levels and executor run time is largely dominated by the disk I/O time especially, the read time cost. With respect to horizontal node scaling, Spark scales with increasing homogeneous computing nodes but the speed-up degrades with heterogeneous nodes. Finally, this study shows that the effectiveness of speculative tasks execution in mitigating the impact of slow nodes varies for the applications

Cu(II) and Fe(III) complexes of sulphadoxine mixed with pyramethamine: Synthesis, characterization, antimicrobial and toxicology study

Two new mixed ligands metal complexes of sulphadoxine and pyramethamine were prepared by using CuCl2.6H2O and FeCl3.6H2O. The complexes were characterized by elemental analysis, melting point determination, molar conductivity, metal content analysis (AAS), IR, magnetic susceptibility measurements and UV-Visible spectroscopy. Based on the analytical and spectroscopic data, the complexes were proposed to have the formulae [M1L1L2(Cl)2] and [M2L1L2(Cl)3] (where M1 = Cu(II), M2 = Fe(III)), L1 = sulphadoxine, L2 = pyramethamine). The spectroscopic data proposed L1 to be a monodentate ligand and coordinated through N atom of the NH2 group in both complexes. Also, L2 was proposed to be tridentate ligand and coordinated through N atom of the NH2 groups and through N atom of imine group. However, [M1L1L2(Cl)2] and [M2L1L2(Cl)3] were proposed to possess distorted octahedral geometry. Conductivity measurement values supported the non-electrolytic nature of the complexes. The complexes have been tested in vitro against a number of pathogenic bacteria [g(+) Escherichia coli, g(+) Proteus species, g(+) Pseudomonas aeruginosa and g(+) Salmonella typhi] by using disc diffusion method. Obtained results indicated that the metal complexes exhibited better antibacterial activities as compared to the ligands. Toxicology tests against some tissues of albino rat (Rattus novergicuss) revealed toxicity of the complexes in the kidney as compared to the parent drugs. [M1L1L2(Cl)2] was found to be toxic to the sera, livers and kidneys of the rats used, while [M2L1L2(Cl)3] was found to be non-toxic to the sera, livers and kidneys of the rats as their alkaline phosphatase (ALP) values showed non-significant difference to the control value

Primary spontaneous pneumothorax in a term neonate

Pneumothorax is a rare but recognized cause of respiratory distress in the newborn. It can occur spontaneously or post-traumatic.We report our experience in a term male neonate who had primary spontaneous pneumothorax. He had no surgical intervention but completely recovered with conservative management and supplemental oxygen

Phytochemical analysis, cytotoxicity and genotoxicity of Psidium guajava L. (Myrtaceae) leaf extracts

Psidium guajava is one of the oldest and widely used medicinal plants in the world. The leaves, bark, roots and immature fruits are used in African ethno-medicine because of their anti-inflammatory, anti-diarrhoeal and anti-microbial properties amongst others. The aim of this work was to determine the phytochemical profile of locally sourced mature Psidium guajava leaves and to also evaluate the cytotoxic and genotoxic properties of aqueous extracts of Psidium guajava leaves. Ethanol extracts of Psidium guajava leaves were subjected to analysis using GC-MS. Aqueous extracts were prepared by boiling pre-weighted fresh leaves in tap water and subsequently used in the Allium cepa assay. Analysis revealed terpene compounds (80.6%) as the most abundant phytochemical in ethanol extracts of the leaves. The results also revealed an overall significant concentration and time-dependent reduction in mitotic index (p ≤ 0.05). The value of EC50 was estimated to be 54.4 g/l. Examination of treated Allium cepa root tip cells revealed chromosomal aberrations including binucleation, bridges, distorted anaphase, clumping, vagrant chromosomes and c-mitosis. Aqueous leaf extracts of Psidium guajava leaves have genotoxic and cytotoxic potentials which should be seriously considered in its therapeutic applications

Analysis of acidic properties of distribution transformer oil insulation: a case study of Jericho (Nigeria) distribution network

This paper examined the acidic properties of distribution transformer oil insulation in service at Jericho distribution network Ibadan, Nigeria. Five oil samples each from six distribution transformers (DT1, DT2, DT3, DT4 and DT5) making a total of thirty samples were taken from different installed distribution transformers all from the Jericho distribution network. 10 g of the oil sample were dissolved in 40 ml of solvent ethanol in a ratio of 5 to 4. Then 0.1mol/litre of Potassium hydroxide (KOH) was added as titre with volume increments of 0.001 ml. The system detects when the acidbase- equivalence-point is reached by a voltage measurement in the solution. A transformer insulating oil passes acidity test if the acidity content is not more than 0.2 mg KOH/g oil according to the guideline from the American Society of testing Materials (ASTM). It was observed that twenty test samples of transformer insulating oil from four distribution transformers passed acidity test while ten samples from the remaining two failed the test, showing the later were in conditions. With the acidic content beyond the prescribed minimum value present in the transformer oil, transformer winding is at the risk excessive heat due to internal conduction that could cause explosion or fire outbreak in the transformerKeywords: Acidity, Mineral Oil, Oxidation, Transformer, Distribution network