Assessment of soil metals status in parts of Rivers State, Nigeria

The study evaluates levels of metals in soils of 9 locations in Port Harcourt and its environs in Rivers State in Nigeria. Composite samples were collected by random sampling from each of the 9 test locations, 3 control samples were also collected from each of the study areas. Concentration levels of (Lead) Pb, (Copper) Cu, (Cadmium) Cd, (Zinc) Zn, (Calcium) Ca, (Nickel) Ni, (Sodium) Na, (Potassium) K, (Chromium) Cr, (Magnesium) Mg, (Manganese) Mn, and (Sulphur) S in soil were measured using Atomic Absorption Spectrophotometry. The obtained mean levels of Pb, Cu, Cd, Zn, Ca, Ni, Na, K, Cr, Mn and Mg were 1.45±0.16, 0.22±0.04, 0.04±0.01, 2.61±0.51, 12.99±4.81, 0.75±0.08, 173.64±35.31, 6.06±1.58, 0.27±0.03, 4.21±0.61 and 11.87±2.10 ppm respectively. There were significant differences in levels of Pb among the test and control samples (p=.048). There was significant difference in levels of Cu among the test and control samples (p=0.001). There was significant difference in levels of Zn among the test and control samples (p=0.016). The study establishes that urbanization, industrialization and agricultural activities do affect the level of metals in the soils of the study areas. The pollution of soils with metals in the studied sites is within permissible limits, however, levels of Zn, Cd and Ni should be on close monitoring to in the industrial areas and urbanized areas. The study establishes that oil and gas activities variedly affect the levels of metal pollution in urbanized, industrialized and agricultural areas.Keywords: Anthropogenic activities, Metals, Impact, Ecosystem, Integrit

Intrinsic Vulnerability of Human-Water Contact Sites to Contamination with Schistosoma mansoni Ova in an Endemic Focus in Western Kenya

Human intestinal schistosomiasis caused by Schistosoma mansoni occurs in localized foci restricted to specific vector sub population areas. The molluscan vectors, Biomphalaria spp, have a widespread distribution within the lake region and elsewhere in Kenya, but the disease is endemic only in areas with certain physical characteristics and risk factors. A comprehensive study was conducted in Budalangi endemic focus of Western Kenya between May 2006 and June 2008 to determine the bionomics of intestinal schistosomiasis transmission with regards to proximity to various contact sites relative to contamination of ova of the worm in the vector breeding habitats with a view of instituting a deworming programme in primary schools. A survey of sanitation relative to presence, distribution and/or absence of latrines was conducted in the whole study area. The main human contact sites were identified and checked for the possibility of contamination with human stool. Distance of the main human water contact site from sampled homesteads without latrines was estimated and recorded within three categories. Vector snails were sampled from four permanent water habitats using standard procedures. Only 30.5% of the homesteads surveyed had pit latrines (c2; p<0.05) and 70.1% of them were situated less than 100m from various water contact sites. The actual density of vector snails and their mean counts per 10 scoops from the different sites in each type of breeding habitat varied widely (One way ANOVA; Lake Victoria: F = 8.11, df (5, 66), p<0.05; Dam: F = 3.65, df(7, 88), p<0.05; River Nzoia: F = 0.54, df (2, 33), p > 0.05; F = 6.76, df (3, 44), p<0.05) showing that their role in harbouring the vector snails and transmission of intestinal schistosomiasis was variable. However the mean vector snail count from all the different habitats showed no significant difference between them being suggestive of the fact that the four habitats were equally important for the purposes of vector breeding in the study area (One way ANOVA; F= 1.32, df(3, 17); p > 0.051). The study showed that there was a continuous low level of contamination of S. mansoni ova in area among the various other habitats in addition to the lake and that they were equally vulnerable. This information has a bearing on planning and implementing combined mass treatment of people who reside in the study area and vector control programmes in an integrated venture. Keywords: Vulnerability, Contact sites, Contamination, Schistosoma mansoni ov

Preparedness of Secondary School Management in the Planning, Supervision, Monitoring and Evaluation of School Projects in Gucha District, Kenya

Infrastructure developments in schools are a major factor towards realization of the Kenya’s vision 2030. Different stakeholders sponsor various school constructions; building of class rooms, school halls, laboratories, libraries, dormitories and so on.  This research sought to establish the factors influencing the implementation of construction projects in public secondary schools in Gucha South District, Kisii County. The study was guided by the following objectives: to establish the extent to which competency of principals in project management influence implementation of construction projects in public secondary schools in Gucha South District; to assess the extent to which stakeholders’ involvement influence the implementation of construction projects in public secondary schools in Gucha South District, to explore the extent to which availability of skilled labour influence the implementation of construction projects in public secondary schools in Gucha South District, Kisii County. Descriptive survey design was used in carrying out the study. All the forty two schools were used in the study. The respondents were 42 principals and 42 P.T.A chair persons representing the schools. The findings of the study showed that school principals lacked competency in planning, supervising and monitoring of school construction projects. The school chair persons similarly lacked the capacity to assist principals in project implementation. In conclusion school principals as managers of school constructions be trained and capacity build on project development, planning, management and supervision

Evaluation of the Effects of Cadmium in Soil on the LC50 of Soil Bacteria and Fungi for Environmental Monitoring

Contamination of soil with heavy metals by is currently of global concern. Cadmium (Cd) is one of the metals of concern. In the current study, LC50 of Cd to soil bacteria and fungi was used to assess the impact of anthropogenicactivity in development of Cd tolerance in soil microorganisms. Levels of Bio-physicochemical parameters in soil were determined. Results show that the concentration of Total Petroleum Hydrocarbon (TPH) and Cd in soil ranged between 5.09±0.33 to 9261.94±287.67, and 0.023±0.015 to 0.057±0.012 ppm respectively. There was significant difference (p = 0.001) in LC50 for fungi between the study and control samples. Pearson correlation showed that there was significant relationship (r = 0.30) between LC50 for bacteria and TPH. There was significant difference (p = 0.017) in LC50 values among the study and control samples for fungi. Anthropogenic activities influenced the concentrations of TPH soil but did not influence levels of Cd

Assessment of Ni Toxicity to Fungi and Bacteria in Oil Tainted Soils in Greater Port Harcourt Area, Nigeria

Intensified urbanization and industrialization are rapidly triggering the release of pollutants to the environment. This study determined the extent of soil contamination with Nickel (Ni) in oil mining areas and its effect on the levels of Ni tolerance by fungi and bacteria. The total CFUs/g of soil were enumerated after a culture period of 7 days at 28°C and LC50 was determined using probit and regression analysis. The mean values of Ni were 1.38±0.23 in industrial area, 1.41±0.36 ppm in agricultural area and 1.02±0.64 in urban area. The mean values of Total Petroleum Hydrocarbon (TPH) were 4,405.46 ppm in industrial area, 55.65 ppm in agricultural area and 1,304.53 ppm in urban area. Nickel’s peak concentration indicating growth of both fungi and bacteria at 150 ppm. There was significant difference (p ≤ 0.000) in the mean levels of LC50 for fungi among the study sites. There was no significant correlation between the concentration of TPH in soil and LC50 of fungi (r = -0.169) and bacteria (r = 0.042). In conclusion, TPH influenced the levels of fungi and bacteria tolerance to Ni in soils. Moreover, it was observed that LC50 can be a reliable method for monitoring chemically resistant microorganisms directly in the environment to improve the use of microorganisms for the bioremediation of oil contaminated soils and in monitoring of antibiotic resistant microorganisms in natural ecosystems

Metagenomic analysis of viruses associated with maize lethal necrosis in Kenya

Background: Maize lethal necrosis is caused by a synergistic co-infection of Maize chlorotic mottle virus (MCMV) and a specific member of the Potyviridae, such as Sugarcane mosaic virus (SCMV), Wheat streak mosaic virus (WSMV) or Johnson grass mosaic virus (JGMV). Typical maize lethal necrosis symptoms include severe yellowing and leaf drying from the edges. In Kenya, we detected plants showing typical and atypical symptoms. Both groups of plants often tested negative for SCMV by ELISA. Methods: We used next-generation sequencing to identify viruses associated to maize lethal necrosis in Kenya through a metagenomics analysis. Symptomatic and asymptomatic leaf samples were collected from maize and sorghum representing sixteen counties. Results: Complete and partial genomes were assembled for MCMV, SCMV, Maize streak virus (MSV) and Maize yellow dwarf virus-RMV (MYDV-RMV). These four viruses (MCMV, SCMV, MSV and MYDV-RMV) were found together in 30 of 68 samples. A geographic analysis showed that these viruses are widely distributed in Kenya. Phylogenetic analyses of nucleotide sequences showed that MCMV, MYDV-RMV and MSV are similar to isolates from East Africa and other parts of the world. Single nucleotide polymorphism, nucleotide and polyprotein sequence alignments identified three genetically distinct groups of SCMV in Kenya. Variation mapped to sequences at the border of NIb and the coat protein. Partial genome sequences were obtained for other four potyviruses and one polerovirus. Conclusion: Our results uncover the complexity of the maize lethal necrosis epidemic in Kenya. MCMV, SCMV, MSV and MYDV-RMV are widely distributed and infect both maize and sorghum. SCMV population in Kenya is diverse and consists of numerous strains that are genetically different to isolates from other parts of the world. Several potyviruses, and possibly poleroviruses, are also involved

Genetic diversity of provitamin a cassava in Uganda

Global efforts are being made towards developing provitamin A cassava (Manihot esculenta Cranz) varieties for sustainably addressing vitamin A malnutrition commonly noted in communities where cassava is a major staple. To elucidate the diversity in Uganda’s core collection of yellow root cassava germplasm, genetic variability was assessed for 64 yellow and white root cassava accessions including Ugandan landraces, and accessions introduced from the International Center for Tropical Agriculture (CIAT) and the International Institute of Tropical Agriculture (IITA). Phenotypic characterization was based on 12 morphological descriptors, total carotenoid content (TCC) and dry matter content (DMC). Variation of twenty six simple sequence repeat (SSR) markers was assessed and compared with morphological data. Total carotenoid content varied from 1.2 to 14.2 ?g/100 g and correlated negatively (R2 = -0.46) with dry matter content which ranged from 27.2 to 39.8 %. Genetic diversity was high in all accession groups with an average heterozygosity of 0.5583 ± 0.0182. Phenetic analyses using Unweighted Pair Group Method with Arithmetic Mean (UPGMA) and Principle Coordinate Analysis (PCoA) clustered the CIAT accessions into a distinct group, discriminating them from the landraces and IITA accessions. Based on the clustering pattern, it suffices to suggest limited gene flow between CIAT accessions and the landraces/IITA accessions which is an opportunity for broadening the genetic base through hybridization by exploiting the heterotic pool in the germplasm

Genetic diversity of cassava (Manihot esculenta Crantz) landraces and cultivars from southern, eastern and central Africa

Studies to quantify genetic variation in cassava germplasm, available within the national breeding programmes in Africa, have been limited. Here, we report on the nature and extent of genetic variation that exists within 1401 cassava varieties from seven countries: Tanzania (270 genotypes); Uganda (268); Kenya (234); Rwanda (184); Democratic Republic of Congo (DRC; 177); Madagascar (186); Mozambique (82). The vast majority of these genotypes do not exist within a formal germplasm conservation initiative and were derived from farmers' fields and National Agricultural Research Systems breeding programmes. Genotypes were assayed using 26 simple sequence repeat markers. Moderate genetic variation was observed with evidence of a genetic bottleneck in the region. Some differentiation was observed among countries in both cultivars and landraces. Euclidean distance revealed the pivotal position of Tanzanian landraces in the region, and STRUCTURE analysis revealed subtle and fairly complex relationships among cultivars and among landraces and cultivars analysed together. This is likely to reflect original germplasm introductions, gene flow including farmer exchanges, disease pandemics, past breeding programmes and the introduction of cultivars from the International Institute of Tropical Agriculture – Nigeria. Information generated from this study will be useful to justify and guide a regional cassava genetic resource conservation strategy, to identify gaps in cassava diversity in the region and to guide breeding strategies

Simple sequence repeat (SSR) diversity of cassava in South, East and Central Africa in relation to resistance to cassava brown streak disease

This study was conducted to: (1) determine the amount and structure of the genetic diversity of cassava in southern, eastern and central (SEC) Africa using simple sequence repeat (SSR) markers, (2) determine the frequency and distribution of alleles putatively associated with resistance to cassava brown streak disease (CBSD) derived from the variety ‘Namikonga’, and (3) examine the genetic relationships among some CBSD resistant genotypes. The major findings from this study were: (1) little genetic differentiation was confirmed among countries (7%) with the majority of variation distributed among individuals (93%), (2) the frequency of alleles putatively associated with resistance to CBSD was found to be generally low (0.2 to 0.5) but widely dispersed in the cassava germplasm of the SEC Africa region implying that if validated the markers will be useful for marker-assisted breeding on a broad scale, (3) several distinct putative sources of resistance to CBSD seem to be present in the cassava germplasm of SEC Africa offering the potential to pyramid genes for more effective and durable resistance and (4) it may be more informative to assess cassava diversity in the SEC Africa region based on pedigree (if known) or genetic relatedness, rather than geographical origin