Influence of Variation in the Composition of Fine Aggregate on the Properties of Sandcrete Blocks

Sandcrete block is predominantly used for the construction of walls.  Sandcrete block is made from a mixture of cement and fine aggregate (sharp sand). This study investigates the influence of variation in the composition of fine aggegate on the properties of sandcrete block. Laboratory experiments were conducted on the materials used as well as on the hollow sandcrete block samples. A total of 120 sandcrete block samples were produced using cement and sharp sand at different mix ratios of 1:6 or 1:8 mixes, as well as mixes containing partial replacement of sharp sand with fine sand or granite dust at 1:6:2, 1:5:3 and 1:4:4 by volume. Result revealed that the compressive strength at 21 and 28 days curing age for 1:6 mixes are 3.87 N/mm2 and 4.17 N/mm2 respectivelyand for the 1:8 mixes are 2.81 N/mm2 and 2.95 N/mm2 respectively. For cement, sharp sand and fine sand constituents of 1:6:2, 1:5:3 and 1:4:4; the compressive strength at 28 days curing is 2.24 N/mm2, 1.72 N/mm2 and 2.5 N/mm2 respectively. Similarly, for cement, sharp sand and granite dust constituents, 28 days compressive strength are 2.13 N/mm2, 1.61 N/mm2 and 1.42 N/mm2 respectively. The study recommends appropriate mix proportion for sandcrete block constituents to avoid huge lifecycle maintenance cost

Kinetic and Thermodynamic Studies of Chromium Ion Adsorption Using Chitosan from Mussel Shell

A study was carried out to investigate the removal of chromium (VI) ion from chromate solution using deacetylated chitin extracted from mussel shell. Mussel shells were obtained from Gubi dam in Bauchi, Nigeria and chemical method was used to extract chitin and then chitosan from these shells. A batch adsorption study was used to generate data for kinetic modelling. Out of the four kinetic models tested, the adsorption process was found to follow the pseudo-second order kinetic model with an R2-value of 0.9997; The process was physical with a free sorption energy of 0.224 kJ/mol. Also, the enthalpy of adsorption was -67.295 kJ/mol K and the Gibbs free energies were all negative, thus the process is spontaeneous and exothermic. Keywords: Kinetic, Chitosan, Mussel, Chromium, Adsorption, Thermodynami

Pathological conditions and lesions observed in slaughtered cattle

Disease prevalence in ruminants constitutes a serious impediment to livestock production in Nigeria. Records of common cattle diseases prevalent in Zaria are pertinent for effective control programmes. Knowledge of the extent to which the public is exposed to zoonotic diseases through meat consumption is useful in preventive medicine. The slaughter house in Zango-Zaria was visited between January and September, 2008 to obtain information on pathological conditions found in cattle slaughtered during the same period. A total of 7812 cattle were examined. Fascioliosis constituted 23.41%, haemonchosis 11.61%, pericarditis 17.06%, pneumonia 8.79%, liver cirrhosis 10.41%, fracture 6.50%, pulmonary emphysema 4.71% and abscesses in liver, lungs and kidneys 4.55% of the pathological conditions noted. Seasonality trend of some conditions was noted, that is streptothricosis was highest in July, abscesses in September, liver cirrhosis in April and emaciation and haemonchosis, pneumonia and pericarditis occurred mostly in June. Of the 5758 organs having lesions, 598 whole organs were totally condemned. The number of carcasses partially condemned was 5160. The results highlight the need for improved meat inspection practices at abattoirs and awareness of butchers and cattle traders

The Effect of Foreign Direct Investment on the Nigerian Manufacturing Sector

This study examined the effect of Foreign Direct Investment (FDI) on the Nigerian manufacturing sector spanning 1975 – 2008. Nigeria has embarked on several policy measures aimed at enhancing the manufacturing sector’s productivity coupled with the inflow of FDI to the country. The controversy is that the policy makers are not convinced that the potential benefits of FDI could be fully realized. The methodology adopted for the study is the Vector Auto Regression (VAR), co-integration and error correction techniques to establish the relationship between FDI and the growth of manufacturing sector. The findings from the study show that FDI has a negative effect on the manufacturing productivity and is statistically significant. Arising from the findings, it is recommended that government should create an enabling environment for foreign investment and the monitoring of FDI benefits, with particular focus of NEPAD and NEEDS through the instrumentality of the MDGs; thereby mustering the capacity for sustainable growth in the manufacturing sector.Key words: FDI; Manufacturing sector; Productivity; Growth, Polic

Anticonvulsant and sedative activities of aqueous leave extract of Leucas martinicensis (Jacq.) R. Br

Leucas martinicensis is a medicinal plant used in traditional medicine to treat convulsions and epilepsy. The present study was to evaluate the anticonvulsant and sedative effects of the aqueous leave extract of L. martinicensis in Wistar rats. The anticonvulsant activities of L. martinicensis (50, 100, 200 or 400 mg/kg i.p.) were evaluated using maximal electroshock seizure (MES) - and strychnine (STR) -induced seizure models while the sedative properties were evaluated using the diazepaminduced sleep model in Wistar rats. The 400 mg/kg of the extract protected rats (100%) against seizures in both models while at 200 mg/kg seizure protection (100%) was only in STR model. There was a significant (p<0.05) delay in the onset and reduction in the duration of seizure in the two models in unprotected rats. L. martinicensis exerted sedative effect by significantly reducing the onset (sleep latency) and increasing the total duration of sleep induced by diazepam. These results suggest that aqueous extract of L. martinicensis may possess anticonvulsant and sedative properties that might show efficacy against primary generalised seizures and secondarily generalised tonic -clonic seizures in humans. It also lends pharmacological credence to the use of the plant in traditional medicine for the management of epilepsy and convulsions.Keywords: Leucas martinicensis; Epilepsy; Traditional medicine; Anticonvulsant; slee

Perception of the Impact of Fuel Wood and Charcoal Productions on the Environment: A Case Study of Toro L.G.A of Bauchi State, Nigeria

Wood biomass felling for fuel negatively impacted on the structuring and functioning of ecosystem worldwide. Consequently, increasing soil erosion, reduction in soil moisture, content, fertility, and decline vegetation cover. The study area comprised four districts: Leme, Rimi, Jama’a and Tilden Fulani in Toro LGA, Bauchi State, purposively chosen because of their high fuel wood activity. Charcoal producers were sampled, using stratified sampling methods while traditional leadership and the department of Forestry officials were purposefully sampled for their involvement in fuelwood and forest management of the area. Fifty (50) fuel wood and charcoal producers were chosen per district. A total of two hundred (200) sampled respondents and four each of the traditional leaders and forestry officials in the four districts were investigated. Apparent collapse of traditional governance system correlated with fuelwood exploitation (especially for charcoal production) and remained a threat to sustainability of forest and forest products management. Poverty was the main driver to resource destruction, as only 34% were employed.67%, 71% and 59% indicated impact on environment, temperature, and erosion due to charcoal production.Charcoal producers obtained the trees and logs for charcoal production from the natural forest and 88% of them use life trees, cutting above 40cm above the ground level. This method of harvesting from the forest inhibits replenishment commensurate with the rate of extraction. The study showed that poverty, unemployment, ignorance and lack of education have great and direct negative impact on the environment as global warming, ozone layer depletion and climate change are evident

Assessment of Physicochemical Properties of Wastewater from Waste Stabilization Pond of a Refinery and Petrochemical Industry, Kaduna State, Nigeria

The wastewater released by refineries and petrochemical industries frequently contain a range of substances categorized as physical and chemical pollutants. The objective of this study was to assess the physicochemical properties of wastewater from waste stabilization pond of a refinery and petrochemical industry, Kaduna, Nigeria using appropriate standard methods. Results obtained showed that the wastewater had an average pH (8.18), temperature (26.29oC), dissolved oxygen (0.86 mg/L), total dissolved solids (195.33mg/L), electrical conductivity (159.71µs/cm) and chloride (40.08mg/L) which were in compliance with the limit set by the Federal Ministry of Environment, Nigeria. However, chemical oxygen demand (65.85mg/L), biological oxygen demand (32.32 mg/L), oil and grease (231.97mg/L), nitrate (16.95mg/L), turbidity (5.37NTU), phosphate (10.06mg/L) and sulphate (140.36mg/L) where found to exceed the permissible limit. The mean concentrations of arsenic (4.59mg/L), nickel (0.15mg/L), iron (0.62mg/L), lead (0.67mg/L), cadmium (0.04mg/L) and chromium (0.29mg/L) were higher than the acceptable limits. However, cobalt (0.16mg/L), zinc (0.30mg/L), manganese (0.56mg/L), copper (0.13mg/L) and magnesium (1.65mg/L) contents were within the acceptable limits. These results point the need for adequate treatment of wastewater from petrochemical and related industries using appropriate wastewater treatment technologies. Continuous release of this wastewater into the environment poses great threat to both the environment and public health

Microfluidic Microcirculation Mimetic as a Tool for the Study of Rheological Characteristics of Red Blood Cells in Patients with Sickle Cell Anemia

Sickle cell disorder (SCD) is a multisystem disease with heterogeneous phenotypes. Al- though all patients have the mutated hemoglobin (Hb) in the SS phenotype, the severity and frequency of complications are variable. When exposed to low oxygen tension, the Hb molecule becomes dense and forms tactoids, which lead to the peculiar sickled shapes of the affected red blood cells, giving the disorder its name. This sickle cell morphology is responsible for the profound and widespread pathologies associated with this disorder, such as vaso-occlusive crisis (VOC). How much of the clinical manifestation is due to sickled erythrocytes and what is due to the relative contributions of other elements in the blood, especially in the microcapillary circulation, is usually not visualized and quantified for each patient during clinical management. Here, we used a microfluidic microcirculation mimetic (MMM), which has 187 capillary-like constrictions, to impose deformations on erythrocytes of 25 SCD patients, visualizing and characterizing the morpho-rheological properties of the cells in normoxic, hypoxic (using sodium meta-bisulfite) and treatment conditions (using hydroxyurea). The MMM enabled a patient-specific quantification of shape descriptors (circularity and roundness) and transit time through the capillary constrictions, which are readouts for morpho-rheological proper- ties implicated in VOC. Transit times varied significantly (p < 0.001) between patients. Our results demonstrate the feasibility of microfluidics-based monitoring of individual patients for personalized care in the context of SCD complications such as VOC, even in resource-constrained setting

Diversity and antimicrobial resistance of Salmonella enterica isolated from fresh produce and environmental samples

In Nigeria, as in most developing countries, vegetable farmers depend largely on wastewater for irrigation and on untreated manure for soil enrichment. Salmonella is among the most important foodborne pathogens worldwide with fresh vegetables as major route of transmission to man. A total of 440 samples comprising vegetables and environmental samples (irrigation water and manure treated soil) were analyzed for the presence of Salmonella, resistance and virulence genes and diversity of isolates by genotyping. Samples were obtained from five irrigation fields in Kano and Plateau States and cultured using selective isolation with prior enrichment method. Presumptive isolates were identified and characterized using conventional biochemical methods and Microbact 24E (Oxoid, UK) identification kit. Amplification of virulence (invasive A and enterotoxin) genes by polymerase chain reaction (PCR) further confirmed Salmonella and its virulence potential. Enterobacterial repetitive intergenic concensus (ERIC) fingerprinting PCR showed genetic diversity of confirmed isolates. Confirmed isolates were evaluated for susceptibilities to eight commonly used antimicrobial agents. Sixty-one (13.9%) samples were positive for Salmonella. The distribution of serotypes included; Salmonella typhi (7.7%), Salmonella paratyphi (2.0%) and Salmonella typhimurium (4.1%). S. typhi had the highest isolation rate and was most commonly detected in vegetables. Simultaneous resistance to all antibiotics assayed was found amongst the salmonellae. Fingerprinting pattern of the Salmonella strains from the different samples showed marked similarities and close genetic relatedness. Cluster analysis at a coefficient of similarity of 0.82 grouped the fifteen strains of Salmonella assayed into five different groups. Our results indicate that irrigated vegetables are vehicles of transmission of potentially pathogenic Salmonella isolates that can contribute to the development of salmonellosis and other Salmonella related infections in Nigeria. This study provides data that support the potential transmission strains of Salmonella harboring virulence and resistance factors from vegetables and environmental sources to cause infections in humans