Distribution and risk assessment of trace metals in Leptodius exarata, surface water and sediments from Douglas Creek, Qua Iboe estuary

Five trace metals in Leptodius exarata, epipellic sediments and surface water from an intertidal ecosystem in Niger Delta (Nigeria) were investigated to evaluate their spatial distribution, degree of contamination, ecological and health risks. Results show Cd (cadmium), Cr (chromium), Ni (nickel), Pb (lead) and Zn (zinc) concentrations in sediment ranged between 0.550 – 1.142, 9.57 – 15.95, 9.15 – 13.96, 2.00 – 8.90 and 91.5 – 121.6 mg/kg dw, respectively; while L. exarata tissue metal content vary from 0.162 – 0.931, 3.81 – 8.62, 4.45 – 17.15, 1.90 – 7.35, and 125.55 – 269.75 mg/kg, dw, respectively. The bioconcentration factor ranking for trace metals followed the sequence Zn>Ni>Pb >Cr>Cd. High biota to sediment accumulation factor (BSAF) in L. exarata reveals a sentinel metal bioindicator. Sediments from most sites were uncontaminated to moderately contaminated (geoaccumulation, Igeo > 0) with Cd and Zn associated with anthropogenic intrusions. Low mean-ERM (effect range-median) and mean-PEL (probable effect level) quotients of sediments are observed, indicating low–medium degree of contamination with 30% and 21% probability of being toxic. The multi-metal potential ecological risk index (RI) for the intertidal ecosystem indicates low–moderate risk. Health risks associated with crabs (L. exarata) consumption are significant in children than adults

The Effect of Sewage Concentrations and Materials of Construction of Sewage Digester on Biogas Production

The effects of two sewage concentrations and bioreactor types on biogas generation capacity have been investigated. Different bioreactors including plastic, mild and galvanised steel were used. Results obtained show that more than 10 litres of biogas was generated from 0.4kg/l of 15 litres sewage as against 4.6 litres generated from equal volume of sewage of 0.5kg/l concentration. This indicated that an optimum sewage concentration exists, which favours biogas production. Also, while the metallic bioreactors such as mild and galvanised steel as used in this study inhibited biogas production, the transparent plastic bioreactors enhanced its production. Furthermore, it was noticed that increasing ambient temperatures from 28 to 31oC increased the biogas output from the two sewage concentrations

Petroleum hydrocarbons and limiting nutrients in Macura reptantia, Procambarus clarkii and benthic sediment from Qua Iboe Estuary, Nigeria

The levels of total petroleum hydrocarbons in two commonly consumed benthopelagic shellfishes, Macura reptantia and Procambarus clarkii, harvested from benthic sediment of Qua Iboe Estuary were determined using a gas chromatography with flame-ionization detector. Seventy-two (72) samples each of benthic sediment and the shellfishes were collected monthly between June 2003 and February 2004 covering the peak periods of the wet and dry seasons. Concentrations of hydrocarbons were highly variable and ranged between 5.00 and 232.00 μg/g dry weight of benthic sediment, 3.05 and 11.30 μg/g dry weight of M. reptantia, 1.62 and 9.00 μg/g dry weight of P. clarkii. Pearson’s correlation analysis of total hydrocarbon concentrations in subtidal sediments with levels in the fauna species yielded positive significant (P < 0.05) correlations in M. reptantia (r = 0.737) and P. clarkii (r = 0.924). This is indicative of a long term and chronic accumulation of hydrocarbons in the estuarine ecosystem, reflecting the potential for exposure of the resident biota and the risk to human health

Petroleum Hydrocarbons Accumulation Potential of Shellfishes from Littoral Waters of the Bight of Bonny, Niger Delta, Nigeria.

Total hydrocarbons concentration in four commercially available shellfishes (Ocypoda africanus, Macura reptantia, Procambarus clarkii and Penaeus notialis) from coastal waters of the Niger Delta region of Nigeria were investigated between June 2003 and February 2004 using standard methods. Levels of total hydrocarbons varied significantly depending on biota species, feeding habit and season. The seasonal mean concentrations reported were: 3.98±0.69, 7.95±1.18, 2.24±0.39 and 5.85±0.57 μg g -1 dry weight for M. reptantia, O. africanus, P. clarkii and P. notialis respectively during the wet season. Enhanced concentrations recorded during the dry season were 7.81±2.32, 11.59±2.63, 6.16±2.12 and 9.69±1.90 μg g-1 dry weight for M. reptantia, O. africanus, P. clarkii and P. notialis, respectively. The results obtained indicated seasonal variations which might have been associated with an incidental crude oil spill recorded during the investigation. In general, O. africanus showed higher levels of total hydrocarbons than other species investigated. However, biota species demonstrated hydrocarbon bioaccumulation potential. Regression between the monthly concentrations of total hydrocarbons in each of the biospecimens with the levels in the surface water and sediments indicated statistically significant (p&lt;0.05) relationships. Moreover, comparison of the seasonal mean concentrations using paired sample t-test at 95% confidence level indicated that the concentrations between the dry and wet seasons were statistically significant

Economic implication of foreign reserves management on the performance of the Nigerian economy, 1995 to 2013

The focus of this study has been on the economic implications of foreign reserves management on the performance of the Nigerian economy. Despite declaration of huge external reserves, the reserves had depleted drastically and economic indicators have not significantly improved, as they have always been highly fluctuating with marginal growth levels. This study aimed to establish relationships among economic performance indicators (capacity utilization rate, manufacturing output, growth rate of gross domestic product) and foreign reserves management variables (foreign reserves position, exchange rate, imports, exports). Relevant studies have been reviewed and the methodology implied desk and empirical research. The ordinary least square multiple regression model was used to analyze the data and it helped discover inverse relationships that exist among exchange rate, imports, exports and capacity utilization rate in Nigeria. The analysis found that exchange rate exerts significant impact on manufacturing output in Nigeria, and that there is an inverse relationship among manufacturing output, foreign reserve position, imports and exports. Moreover, positive relationships exist between foreign reserve position and both capacity utilization rate and growth rate of gross domestic product. Discoveries showed that if greater parts of Nigeria’s foreign reserves were channeled to the productive sectors of its economy, capacities of productive machines would be fully utilized, domestic industries would perform well, real value of manufacturing output would increase, the domestic market would have significant positive improvements, and the growth rate of gross domestic product would be improved. On these grounds, proposed recommendations encompassed that the Nigerian government should redirect foreign exchange earnings and reserves in the productive sectors of the economy. Also, they should encourage more exports and discourage or reduce to minimum imports by reviving ailing domestic industries. The exchange rate should be properly controlled and managed by monetary authorities to aid local producers in acquiring productive facilities at cheaper rates and enhance domestic production. Keywords: Economic Implications, Foreign Reserves, Foreign Reserves Management, Nigerian Economy, Gross Domestic Product, Capacity Utilization Rate, Manufacturing Outpu

Effect of P-alaxin on some neurobehavioural parameters in Swiss white mice

The effect of P-alaxin on some neurobehavioural parameters was studied in Swiss white mice. 21 mice were randomly assigned to three groups (n=7) namely; control group, clinical dose group and high dose group. Animals in control group received normal rat chow and standard feed ad libitum. Animals in the clinical dose group were given P-alaxin at a dose of 0.01mg/kg body weight while animals in the high dose group were given P-alaxin at a dose of 0.02mg/kg body weight. The results obtained showed that, in the open field maze test, the clinical dose and high dose groups showed significant increase (P&lt;0.05) in stretch attend posture compared to control. Conversely, there was a significant decrease (P&lt;0.05) in line crossings of high and clinical dose groups when compared to control. In the light/dark transition box test, the clinical and high dose groups showed a significant decrease (P&lt;0.05) in the frequency of line crossings when compared to control. In the morris water maze test, the high and clinical dose groups showed a significant inncrease in frequency of swimming latency when compared to control group. From the total analysis obtained, P-alaxin decreases locomotion and exploratory activities, it impairs motivation and the tendency to investigate the environment as well as reduction in visuospartial learning and memory

Geochemical fractionation and ecological risks assessment of benthic sediment-bound heavy metals from coastal ecosystems off the Equatorial Atlantic Ocean

This studydeterminesthepollution,fractionation,andecologicalrisksofsediment-boundheavymetals from coastalecosystemsofftheEquatorialAtlanticOcean.ContaminationFactor(CF),pollutionload index(PLI),andgeoaccumulationindex(Igeo) wereusedtoassesstheextentoftheheavymetalpol- lution, whilethepotentialecologicalriskwasevaluatedusingtherisksassessmentcode(RAC)and Håkanson potentialecologicalrisk.Theanalysisrevealedconcentrations(mg/g,dw)ofthecadmium(Cd), chromium (Cr),copper(Cu),nickel(Ni),andlead(Pb)insedimentsforwetanddryseasonsvaryfrom 4.40–5.08, 14.80–21.09,35.03–44.8,2.14–2.28, and172.24–196.39,respectively.Theresultsalsoshowed that themetalfractionationpercentagesintheresidual,oxidizable,andreduciblefractionsarethemost significant, whiletheexchangeableandcarbonateboundtracemetalsarerelativelylow.TheRACvalues indicate noriskforCdandNiandlowriskforothermetalsatallthestudiedsitesduringbothseasons. PotentialecologicalriskanalysisoftheheavymetalconcentrationsindicatesthatCdhadhighindividual potentialecologicalrisk,whiletheothermetalshavelowriskatallinvestigatedsites.Themulti-ele- mental potentialecologicalriskindices(R1) indicatehighecologicalriskinalltheecosystem

Durational exposure-dependent effect of carbamate treated net on hepatic and renal functions in Wistar rats

Assessment of the duration exposure-dependent effect of carbamate treated net on hepatic and renal functions of albino Wistar rats after 30 and 60 days was carried out. Serum ALT, AST and ALP levels were determined to assess liver function while serum creatinine and urea levels were measured for kidney function. Eighteen (18) male albino Wstar rats weighing 138-146g were divided into 3 groups of 6 rats each. Group 1 served as control, group 2 animals were exposed to carbamate treated net for 30 days and group 3 animals exposed for 60 days. The results showed that the levels of serum AST and ALT increased in all the experimental groups exposed when compared to the control group. ALT increased significantly (p&lt;0.05) in the rats exposed for 60 days (203.83±0.307) while AST increased highest in experimental groups exposed for 30 days (203± 1.613)and 60 days (362± 0.365) respectively when compared to the control (150.5±0.34). ALP increased significantly (p&lt;0.05) only in the group exposed for 30 days (17.67±0.21),but decreased in the group exposed for 60 days when compared to the control group. Serum creatinine increased insignificantly (p&gt;0.05) in the group exposed for 30 days but decreased in the group exposed for 60 days while serum urea level in the group exposed for 30 days remain unchanged but decreased after 60 days when compared to the control group. Statistically, there was a significant increase (p&lt;0.05) in body weight and organ weight of the animals exposed for 30 and 60 days. Therefore, this present study demonstrates that exposure to carbamate treated net may alter the integrity and function of liver thereby causing hepatotoxicity while the exposure of rats to carbamate treated net may not pose any significant nephrotoxicity in rats

A Survey of Gastrointestinal Helminthes of Local Chickens in Abak Local Government Area of Akwa Ibom State

Rural Poultry as practiced by the rural population is both for consumption and for income generation during festive seasons. The practice of allowing the birds to scavenge for food in the neighbourhood exposes them to disease. This research was an active surveillance of worms which parasitize these rural birds using saturated the salt floatation method. Two hundred sterile samples of the faeces of 200 rural birds were collected randomly from 10 villages in Abak Local government Area. These were transported immediately for analysis in the laboratory using floatation method with saturated salt solution. Viewing with X10 microscope it was discovered that out of the 200 samples examined for helminthes, Ascaris gallinarium was found in 92 samples or (46%), Heterakis Spp was seen with 62 0r 31% positions, Capillaria Spp was 58 or 29% and Strongyles Spp was 46 or 23%. The least was Raillietina Spp which was found in only 22 (11%). This study to the best of my knowledge is the first attempt to research into the types of worm parasites found in local birds, though it has been conducted in other parts of Nigeria and the World over. It was concluded that there is a light prevalence of helminthes in Abak in rural birds, which will lead to high loses. This we advice for educate the rural community in better husbandry practice to preserve the rural poultry population