42 research outputs found

    Stabilization of Laterite Soil with Eggshell Powder and Sodium Silicate used as fill Material in Road Construction

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    The investigation carried out in this paper was to evaluate the effect of eggshell powder and sodium silicate as stabilizers to laterite soil used as fill material for the purpose of constructing light traffic pavement. The laterite soil used in this study was collected from Ikorodu North Local Government Area in Lagos State, Nigeria and treated with eggshell powder (ESP) and sodium silicate (SS) blend in stepped concentrations of 3% ESP + 2% SS, 6% ESP + 4% SS, 9% ESP + 6% SS, 12% ESP + 8% SS and 15% ESP + 10% SS by dry weight of the soil. Results from the tests carried out showed a general improvement on the engineering properties of the laterite treated with ESP and SS blend. Optimum California Bearing Ratio (CBR) tests results for un-soaked and soaked samples were recorded as 51% and 22% at 12% ESP + 8%SS content. Peak Unconfined Compressive Strength (UCS) values of 355 KN/m2 and 570 KN/m2 were recorded at 7- and 28-days curing periods respectively at an optimum blend of 12% ESP + 8%SS content.  From the results obtained in this research, an optimum blend of 12% ESP and 8% SS using the West African Standard (WAS) compactive effort can be used to stabilize laterite soil material for use as fill material for the construction of light traffic roads. An advantage of applying the ESP is the decrease in the deleterious environmental impact of eggshell waste

    Growth and nutritional composition of Spinacia oleracea L. harvested from soil treated with urine in comparison with other organic and inorganic soil amendments

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    The challenge of feeding the ever growing population is largely dependent on using the limited land and improving soil fertility. The study compared the effectiveness of using human urine as a source of soil nutrients in comparison with the commonly used soil amendments [chemical fertilizers (NPK) and biosolids] on the growth and nutritional composition of Spinacia oleracea. An enclosed plot was treated with different soil amendments before the introduction of Spinacia oleracea seedlings. After harvesting, the results showed a significant difference (P < 0.05) in the mean total biomass for the leaves of the plants harvested from all the plots and the values ranged from 1322.77 ± 0.88 g – 5528.28 ± 3.47 g. The differences in the result obtained for the mean leaf 2 2 areas were also significant (P < 0.05) and with values ranging from 366.57 ± 10.9 cm – 945.24 ± 31.3 cm . The concentrations of total N from the leaves followed the trend NPK > Urine > Control > Biosolids. The total P from the leaves showed equal amount for urine and NPK, followed by biosolids and the control having the least values. The levels of Ca recorded from the leaves followed the order biosolids > urine > NPK > control. In general, the study showed that the urine used as a soil amendment for this study competed favorably well with other amendments

    Trace Metals Bioaccumulation Potentials of Three Indigenous Grasses Grown on Polluted Soils Collected Around Mining Areas in Pretoria, South Africa

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    The rapid increase in the number of industries may have increased the levels of trace metals in the soil. Phytoremediation of these polluted soils using indigenous grasses is now considered an alternative method in remediating these polluted soils. The present study investigated and compared the ability of three indigenous grasses as bioaccumulators of trace metals from polluted soils. Seeds of these grasses were introduced into pots containing polluted soil samples after the addition of organic manure. The seeds of the grasses were allowed to germinate and grow to maturity before harvesting. The harvested grasses were later separated into shoots and roots and the trace metal contents were determined using ICP –MS. From all the grasses, the concentrations of trace metals in the roots were more than those recorded in the shoot with a significant difference (P < 0.05). The transfer factor (TF) showed that Zn was the most bioaccumulated trace metals by all the grasses followed by Pb, Mn, and Cu respectively. Chromium concentration from the shoot of the grasses was in the order Urochlora moasambicensis > Themeda trianda > Cynodon dactylon. The study concluded that the three grasses used were all able to bioaccumulate trace metals in a similar proportion from the polluted soils. However, since livestock feed on these grasses, they should not be allowed to feed on the grasses used in this study especially when harvested from a polluted soil due to their bioaccumulative potentials

    Bioaccumulation of Heavy Metals by Moringa Oleifera in Automobile Workshops from three Selected Local Governments Area, Ibadan, Nigeria

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    Plants accumulate minerals essential for their growth from the environment alongside with heavy metals from contaminated areas.This study investigated bioaccumulation of heavy metals by Moringa oleifera in automobile workshops in three selected local government areas in Ibadan. This was done with a view to determining the concentration and type of heavy metals accumulated in the tissues of Moringa oleifera grown around automobile workshops. Barks, leaves and seeds of M. oleifera were collected from three automobile workshops in each of the local government area and from a control site. The samples were dried, ground and analyzed for heavy metals content (Cu, As, Pb, Cd, Cr, Mn and Zn) using ICP-MS. The mean level of heavy metals obtained ranged from 0.018 ± 0.001 to 0.356 ± 0.021 in the leaves, 0.012 ± 0.001 to 0.255 ± 0.016 in the seed and 0.048 ± 0.003 to 0.989 ± 0.003 in the bark. The concentration of heavy metals recorded followed the trend of Cu > Zn > Mn > Pb > Cr > As > in the leaves; Zn > Cu > Pb > Cr = Mn > As in the seeds and Zn > Cu > Mn > Pb > Cr > As> in the barks. The overall concentration of heavy metals bioaccumulated by this plant follows the trend; bark > leaves > seeds. The increase in the concentrations of heavy metals observed in the barks, leaves and seeds of M. oleifera collected from automobile workshops to that of control site indicated the impact of mechanical activities in introducing trace metals to the environment.The study further suggested that Moringa olifera in polluted sites may accumulate trace metals in any of its parts; hence care should be taken when harvesting the plant for medicinal purpose

    An assessment of university students and staff perceptions regarding the use of human urine as a valuable soil nutrient in South Africa

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    Background: The declines in soil fertility associated with insufficient commercial fertilizers have resulted in the use of organic manure (human urine and faeces) as a source of fertilizers for production and cultivation of crop plants. The aim of this study was to assess perceptions of students and workers at the University of Limpopo (Medunsa Campus) regarding the fertilizing effect of urine. Methods: A total of 225 questionnaires were administered to staff and students. The questionnaire sought to establish the knowledge, attitude and behavioural changes as regards the use of urine as a fertilizer for the cultivation of vegetables. Results: Descriptive statistical analysis of the data indicated that 86.8% of the respondents were unaware of any human urine use as a fertilizer, 82.7% and 81.1% would not eat spinach and maize fertilized with urine respectively. Only 38.3% said they would eat vegetables fertilized with animal urine making it more tolerable as compared to human urine. Health reasons were given as the main reasons why respondents were unwilling to eat crops fertilized with human urine. However, 69.9% of the respondents [74.3% females, 69.9% students, 75.0% (27-36) age group] were willing to change their attitudes and unwillingness if they were better informed about the safety of human urine use for agricultural purposes. Conclusion: Education, awareness and reassurance on the importance and safety of urine would have to be done so that urine for agricultural purposes could become more acceptable to people

    Wildlife species diversity indices and seasonal distribution assessment in road-side markets of South-west Nigeria

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    Wildlife species are under serious exploitation by the rural populace in Nigeria because hu­man beings have understood their ecology. The need to update the existing knowledge of wildlife population is therefore essential. Twenty-three games markets along five Roads in South-west Nigeria were visited to document the wildlife displayed for sale. Two hundred and fifty copies of structured questionnaire were administered using systematic random sampling (odd) method for wildlife species information from market stakeholders. Direct method was counting for species and their numbers. Data generated were analysed through Species Diver­sity Indices Assessment. All emergent species were compared with International Union for Conservation of Nature (IUCN) abundance rating. Road seasonal distribution of the marketed wildlife was determined by percentages, standard deviation, standard error of mean, mean differences, t-test, and tests of significance and Diversity Indices. Results revealed that 69,398 wild animals were displayed. Also more wildlife were sold during rainy than dry seasons. Appropriate recommendations of government sensitization of rural and urban settlers against over-utilization of wildlife resources, encouragement of the public towards animal domesti­cation and others were made

    Lead exposure in adult males in urban Transvaal Province, South Africa during the apartheid era

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    Human exposure to lead is a substantial public health hazard worldwide and is particularly problematic in the Republic of South Africa given the country’s late cessation of leaded petrol. Lead exposure is associated with a number of serious health issues and diseases including developmental and cognitive deficiency, hypertension and heart disease. Understanding the distribution of lifetime lead burden within a given population is critical for reducing exposure rates. Femoral bone from 101 deceased adult males living in urban Transvaal Province (now Gauteng Province), South Africa between 1960 and 1998 were analyzed for lead concentration by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Of the 72 black and 29 white individuals sampled, chronic lead exposure was apparent in nearly all individuals. White males showed significantly higher median bone lead concentration (ME = 10.04 µg·g−1), than black males (ME = 3.80 µg·g−1) despite higher socioeconomic status. Bone lead concentration covaries significantly, though weakly, with individual age. There was no significant temporal trend in bone lead concentration. These results indicate that long-term low to moderate lead exposure is the historical norm among South African males. Unexpectedly, this research indicates that white males in the sample population were more highly exposed to lead

    Novel functional insights into ischemic stroke biology provided by the first genome-wide association study of stroke in indigenous Africans

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    \ua9 The Author(s) 2024. Background: African ancestry populations have the highest burden of stroke worldwide, yet the genetic basis of stroke in these populations is obscure. The Stroke Investigative Research and Educational Network (SIREN) is a multicenter study involving 16 sites in West Africa. We conducted the first-ever genome-wide association study (GWAS) of stroke in indigenous Africans. Methods: Cases were consecutively recruited consenting adults (aged > 18 years) with neuroimaging-confirmed ischemic stroke. Stroke-free controls were ascertained using a locally validated Questionnaire for Verifying Stroke-Free Status. DNA genotyping with the H3Africa array was performed, and following initial quality control, GWAS datasets were imputed into the NIH Trans-Omics for Precision Medicine (TOPMed) release2 from BioData Catalyst. Furthermore, we performed fine-mapping, trans-ethnic meta-analysis, and in silico functional characterization to identify likely causal variants with a functional interpretation. Results: We observed genome-wide significant (P-value < 5.0E−8) SNPs associations near AADACL2 and miRNA (MIR5186) genes in chromosome 3 after adjusting for hypertension, diabetes, dyslipidemia, and cardiac status in the base model as covariates. SNPs near the miRNA (MIR4458) gene in chromosome 5 were also associated with stroke (P-value < 1.0E−6). The putative genes near AADACL2, MIR5186, and MIR4458 genes were protective and novel. SNPs associations with stroke in chromosome 2 were more than 77 kb from the closest gene LINC01854 and SNPs in chromosome 7 were more than 116 kb to the closest gene LINC01446 (P-value < 1.0E−6). In addition, we observed SNPs in genes STXBP5-AS1 (chromosome 6), GALTN9 (chromosome 12), FANCA (chromosome 16), and DLGAP1 (chromosome 18) (P-value < 1.0E−6). Both genomic regions near genes AADACL2 and MIR4458 remained significant following fine mapping. Conclusions: Our findings identify potential roles of regulatory miRNA, intergenic non-coding DNA, and intronic non-coding RNA in the biology of ischemic stroke. These findings reveal new molecular targets that promise to help close the current gaps in accurate African ancestry-based genetic stroke’s risk prediction and development of new targeted interventions to prevent or treat stroke
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