Effect of irrigation on heavy metals content of wastewater irrigated fluvisols along River Tatsewarki, Kano, Nigeria

There is an urgent need to educate farmers on the dangers of the presence of heavy metals in soils as well as the quality of irrigation water especially if it comes from tanning industries for increased crop production. Accordingly, soil and irrigation wastewater study was conducted to assess the concentrations of heavy metals in wastewater irrigated Fluvisols and in the irrigation wastewater itself as well as the relationship between the two. Composite surface soil and water samples including controls were collected and analyzed using standard methods. Analytical results were compared with the controls, the EU and FAO standards. Results indicated that the concentrations of Cu (30.556 to 41.667 mgkg-1), Cd (10.269 to18.687 mgkg-1), Zn (18.687 to 26.010 mgkg-1), Cr (8.848 to 12.14 mgkg-1) and Pb (3.953 to 4.787 mgkg-1) in the soil were non-toxic across the river sections. Results also indicated that the irrigation water contained toxic levels of Cu (0.85 to1.25 mgl-1), Cd (0.36 to 0.72 mgl-1) and Cr (0.47 to 0.67 mgl-1) and is therefore considered unsafe for use. However, it did not contain toxic levels of Zn (0.58 1.06 mgl-1) and Pb (0.22 to 0.25 mgl-1) and it is considered safe for use accordingly. Results also revealed that the irrigation water was responsible for the accumulation of Cr (r = 0.019), Cu (r = 0.151), Cd (r = 0.190) and Pb (r = 0.202) in the irrigated soils but not Zn (r = - 0.214). It is recommended that  periodic  appraisal of the soils should be embarked upon so as to monitor the toxicity level of the soil to keep it within the present non-toxic level. It is also recommended that the wastewater should be remediated to minimize and control the heavy metal contamination through phytoremediation. These measures are expected to enhance increased and sustainable crop production in the study area.Key words: Fluvisols, Heavy metals, Irrigation, Wastewater

Asymptomatic Plasmodium falciparum malaria and gametocyte carriage are common in Coastal Kenya

Adequate malaria diagnosis and treatment remain a major problem in rural sub Saharan Africa. Molecular parasite detection has shown that submicroscopic Plasmodium falciparum asexual and gametocytes are common in patients, and can infect mosquitoes in low endemic areas. The significance of the infectious reservoir of malaria in the general population remains unknown. In this study we investigated submicroscopic asexual parasitaemia and gametocytaemia in inhabitants of areas of hypo-endemic and seasonal malaria in which no molecular analysis on malaria survey has been done before. Cross-sectional stuies during the staging of two clinical trials clinical trial in Mokowe and Lamu, Coastal Kenya were conducted in the dry and wet seasons of 2010. Finger prick blood samples used to determine the prevalence of Plasmodium falciparum parasites by microscopy, Fluorescence In-situ hybridization (FISH), rapid diagnostic test and real time nucleic acid sequence-based amplification (QT-NASBA). A total of 450 individuals participated in the surveys of whom, 2.7% had microscopically confirmed asexual parasites while 2.4% had gametocytes. In contrast, FISH revealed that 8.9% (29/327) and QT-NASBA 24.6% (59/240) of the individuals harbored asexual parasites and 29.2% (70/240) gametocytes. There were a few cases of mixed infection with Plasmodium malariae, 1.8% (8/ 450) by microscopy and 4% (13/327) by FISH. No age dependency or seasonality was observed in the submicroscopic parasite carriage. In conclusion, molecular detection techniques disclose that carriage of submicroscopic asexual parasite and gametocyte is relatively common in these low transmission areas and that submicroscopic gametocytaemia is likely to be responsible for maintaining malaria transmission in the study area.Keywords: submicroscopic, gametocytaemia, FISH, rapid diagnostic test, QT-NASBAAfr J Health Sci. 2013; 26:314-32

An in vitro genotoxicity study of silver amalgam on Ames test

Silver amalgam/Silverfil Argentum® is a ‘Malaysian made amalgam’ has already been approved to be free from cytotoxicity, however its genotoxic effect has not been explored yet as biocompatible material. The objective of this study was to identify the genotoxic characteristic of silver amalgam by using Bacterial Reverse Mutation Assay (Ames test). This was a descriptive experimental study involving one strain of mutated Salmonella. The test material was evaluated in one mutated strain of Salmonella typhimurium TA1538 with and without an external metabolic activation system (S9 Mix). The bacteria were incubated for 48 hours at 37±0.5ºC before the colony growth or revertant colonies were counted. Data obtained were analyzed by using non-statistical method. The investigation of the genotoxic reaction on the test material revealed thatthe number of revertant colonies in both strains with and without S9 Mix were less than twice of the negative control even in the presence of high silver amalgam concentrations (5.0μg/ml). This study demonstratedthat the test material did not exhibit any mutagenic activity under the chosen conditions. Thus, silver amalgam could be considered to have no genotoxicity effect

Indirect Extrusion: A Multifaceted Approach of Sub-surface Tubular Expansion

Extrusion and indirect extrusion is a very old manufacturing process used in multitudes of applications mainly focused on transportation, household and power industries. Indirect extrusion has found an interesting application in petroleum industry, which resulted in resolving many unsolvable issues over the last few decades. The current and expected future global demand for hydrocarbons became a driving force for researchers to find new comprehensive and cheaper solutions for hydrocarbon production. The challenges faced in oil and gas fields, while drilling, constructing and operating new and old vertical/horizontal wells, are many. The use of indirect extrusion for in-situ expansion of sub-surface tubulars used in wells revolutionized the drilling and completion as opposed to one and half decade back. The emergence of solid expandable tubular technology has changed the basics of how we design and construct wells. The original development of the technology was to overcome the challenges faced by the petroleum industry to reach ultra-deep reservoirs, off-shore drilling, drilling in high-pressure/difficult zones and repair/maintenance of old/ageing wells. However, it gained significant interest of researchers and operators in providing solutions to wide-range problems. The development of a computational framework using finite element method (FEM) enabled to determine the force required for expansion and resulting dimensional changes in final product, which is of direct assistance to the field engineers. The effect of friction and stress variations along contact surface is also determined

Industrial Training as Gateway to Engineering Career: Experience Sharing

AbstractToday's engineering education demands in-depth theoretical knowledge as well as hands-on exposure to the profession. Traditionally, theoretical engineering education is achieved in campus through direct teaching and laboratory learning. However, hands-on exposure or real world confrontation provides engineering students with on-the-job experience. This helps them to decide whether their skills and industry are a good match. For specialised industries, such as manufacturing, aerospace and electronics, industrial training provides the opportunity for students to gain the most rewarding and enlightening working experience in related companies. This paper examines the industrial training experience gained by the students through a 12-week attachment period specifically looking at whether the companies have been successful in providing a relevant engineering workplace experience. A few industrial training experiences by students will be shared highlighting the positive and negative aspects. This study also suggests some steps that can be taken to ensure companies run industrial training programs that do meet the faculty's expectation

Determination of pharmaceuticals in freshwater sediments using ultrasonic-assisted extraction with SPE clean-up and HPLC-DAD or LC-ESI-MS/MS detection

A robust and sensitive analytical method is presented for the extraction and determination of six pharmaceuticals in freshwater sediments. The pharmaceuticals were extracted from sediment using ultrasonic extraction with 2% NH4OH in methanol (MeOH), followed by extraction into 2% formic acid in MeOH and then MeOH only. The resulting extracts were then analysed, after clean-up on HLB solid phase extraction cartridges, using a single gradient run using a Zorbax Eclipse XDB-C18 (150 × 4.6 mm, 5 μm) column and a mobile phase consisting of 10 mM ammonium acetate and MeOH (pH = 4.8). Analytes were detected and quantified using either Diode Array Detector (DAD) or tandem mass spectrometry (MS/MS) with electrospray ionization in positive mode. Validation studies were carried out using ten sediments sampled from the UK and Iraq with a wide range of characteristics. The mean calculated recoveries for fortified samples in all studied sediments ranged from 74.5 to 114.6% for atenolol, 72.3 to 124.9% for amitriptyline, 76.5 to 105% for mefenamic acid and 70.1 to 102% for diltiazem. Cimetidine and ranitidine showed lower recoveries which ranged from 40.2 to 68.4% and 30.4 to 55.2% respectively. Relative standard deviations (RSD) of recoveries for all sediment-pharmaceutical combinations ranged from 1.6 to 15.8%. The detection limits in sediments for the six analytes ranged from 15 to 58.5 ng g-1 and 0.03 to 3.5 ng g-1, dry weight, for HPLC-UV and LC-ESI-MS/MS respectively. Overall the results indicate that the developed method is effective for use in monitoring the concentrations of pharmaceuticals in aquatic sediments in different regions

Effects of natural selection and gene conversion on the evolution of human glycophorins coding for MNS blood polymorphisms in malaria-endemic African populations

Malaria has been a very strong selection pressure in recent human evolution, particularly in Africa. Of the one million deaths per year due to malaria, more than 90% are in sub-Saharan Africa, a region with high levels of genetic variation and population substructure. However, there have been few studies of nucleotide variation at genetic loci that are relevant to malaria susceptibility across geographically and genetically diverse ethnic groups in Africa. Invasion of erythrocytes by Plasmodium falciparum parasites is central to the pathology of malaria. Glycophorin A (GYPA) and B (GYPB), which determine MN and Ss blood types, are two major receptors that are expressed on erythrocyte surfaces and interact with parasite ligands. We analyzed nucleotide diversity of the glycophorin gene family in 15 African populations with different levels of malaria exposure. High levels of nucleotide diversity and gene conversion were found at these genes. We observed divergent patterns of genetic variation between these duplicated genes and between different extracellular domains of GYPA. Specifically, we identified fixed adaptive changes at exons 3-4 of GYPA. By contrast, we observed an allele frequency spectrum skewed toward a significant excess of intermediate-frequency alleles at GYPA exon 2 in many populations; the degree of spectrum distortion is correlated with malaria exposure, possibly because of the joint effects of gene conversion and balancing selection. We also identified a haplotype causing three amino acid changes in the extracellular domain of glycophorin B. This haplotype might have evolved adaptively in five populations with high exposure to malaria

Links between surface productivity and deep ocean particle flux at the Porcupine Abyssal Plain sustained observatory

In this study we present hydrography, biogeochemistry and sediment trap observations between 2003 and 2012 at Porcupine Abyssal Plain (PAP) sustained observatory in the Northeast Atlantic. The time series is valuable as it allows for investigation of the link between surface productivity and deep ocean carbon flux. The region is a perennial sink for CO2, with an average uptake of around 1.5 mmol m?2 day?1. The average monthly drawdowns of inorganic carbon and nitrogen were used to quantify the net community production (NCP) and new production. Seasonal NCP and new production were found to be 4.57 ± 0.85 mol C m?2 and 0.37 ± 0.14 mol N m?2, respectively. The C : N ratio was high (12) compared to the Redfield ratio (6.6), and the production calculated from carbon was higher than production calculated from nitrogen, which is indicative of carbon overconsumption. The export ratio and transfer efficiency were 16 and 4 %, respectively, and the site thereby showed high flux attenuation. Particle tracking was used to examine the source region of material in the sediment trap, and there was large variation in source regions, both between and within years. There were higher correlations between surface productivity and export flux when using the particle-tracking approach, than by comparing with the mean productivity in a 100 km box around the PAP site. However, the differences in correlation coefficients were not significant, and a longer time series is needed to draw conclusions on applying particle tracking in sediment trap analyses

Influence of Platelets Rich Plasma on Repair of Superficial Digital Flexor Tendon Rupture in Donkeys (An Experimental Study)

This study was planned to prospectively evaluate the influence of platelets rich plasma (PRP) on the restoration of superficial digital flexor tendon (SDFT) in donkeys. Eighteen apparently clinically healthy male donkeys of 3-6 years old, weighing 150-200 kg, were used. The animals were classified into two equal groups; control group and PRP group. One cm transection of the full thickness of middle portion of the SDFT was made in all animals. First, all animals were subjected to sedation via xylazine HCl injection in a dose of 1 mg/kg body weight then the animals were deeply narcotized with chloral hydrate 10% in a dose of 5 gm/50 kg body weight. A linear skin incision in the palmar aspect of the right fore limb at the mid cannon region was performed in all operated animals. The animals in PRP group were subjected to intratendinous injections of 4 mL PRP with weekly interval (day 0, w1, w2, w3) under the guidance of ultrasonography. Representative tendon specimens from all animals were collected 30, 60, and 90 days post operation (PO) for histopathological examination. The obtained clinical and histopathological results reveled that PRP application improved the healing of SDFT compared to the control group, through increasing and acceleration of angiogenesis, fibrogenesis, collagen deposition and remodeling in the injured tendon matrices

Antimalarial activity and toxicity evaluation of Kenyan Hugonia castaneifolia Engl. Teclea nobilis Del. and Turraea mombassana C.DC

The aqueous and methanol extracts of three medicinal plants, Hugonia castaneifolia, Teclea nobilis and Turrae mombassana were evaluated for in vitro antiplasmodial activity against a chloroquine sensitive Plasmodium falciparum strain (D6) and in vivo, against a P. berghei ANKA strain in mice. The extracts were also assessed for cytotoxicity in Vero cell lines and acute toxicity in mice. The water extracts were moderately active with IC50 of 33.07 3g/ml for T. mombassana and 23.92 3g/ml for H. castaneifolia while the methanol extracts of T. mombassana, H. castaneifolia and T. nobilis were highly active in vitro with IC50 of 6.1 3g/ml, 8.86 3g/ml and 8.61 3g/ml respectively. The methanol extract of T. mombassana had the highest chemosupppression followed by the methanol extract of H. castaneifolia in vivo. Aqueous extract of H. casteinofolia was weakly cytotoxic against Vero cells CC50 =22.00 3g/ml. No toxic effect or mortality was observed in mice treated orally with any of the extracts at the highest concentration of 5000mg/kg. These results demonstrate antimalarial potential and safety of the three medicinal plants tested, which are used traditionally for the treatment of malaria in Kenya. Keywords: Antiplasmodial; Malaria; Toxicity; Meliaceae; Rutaceae; Linacea