73 research outputs found

    Regional 3D geophysical investigation of the Sudbury Structure

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    This paper is © 2019 Society of Exploration Geophysicists. The posting is available free of charge and its use is subject to the SEG terms and conditions: https://seg.org/Terms-of-UseThe 3D geologic and structural setting of the Sudbury Structure was predicted by an integration of surface and subsurface geologic data with 2.5D modeling of high-resolution airborne magnetic and gravity data using 3D GeoModeller software. Unlike other CAD-based 3D software, GeoModeller uses the field interpolator method, whereby contacts of rock units are assumed to be equipotential surfaces, whereas orientation data determine the gradient and direction of the surfaces. Contacts and orientation variables are cokriged to generate 3D continuous surfaces for each geologic unit. Our 3D geologic model was qualitatively evaluated by forward computing the predicted gravity response at 1 m above topography and by comparing this response to the measured gravity field. Large-scale structures within the Onaping Formation and Archean basement, which overlie and underlie the Sudbury Igneous Complex (SIC), respectively, were not the cause of the linear gravity high in the center of the Sudbury Structure. We suggested that the deformation of the initial circular SIC may have commenced under the Sudbury Basin due to the reversal of the normal faults related to the Huronian rift system during the Penokean orogeny, therefore resulting into a north verging fold at the base of the SIC in the south range. This new interpretation was consistent with the magnetic and gravity data and honoured most of the significant seismic reflectors in the Lithoprobe seismic sections.NSERC, Vale, Sudbury Integrated Nickel Operations, KGHM International, Wallbridge Min- ing, and the Centre for Excellence in Mining Innovatio

    Effect of optimizing process variables on the quality characteristics of cassava-wheat composite bread

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    The optimisation of bread-making process can have a positive impact in ramping up the quality characteristics of cassava-wheat bread to  that of whole wheat bread. In this study, a threevariable Box-Behnken design response surface methodology was employed to investigate and optimise independent variables namely cassava flour composition, water content and proofing time in relation to response variables namely dough yield, loaf specific volume and loaf protein of cassava-wheat-composite bread. The data from the experimental design were fitted into second-order regression models and their validity and reliability were confirmed by analysis of variance. Optimal cassava flour composition, water content and proofing time were derived as; 100 g/kg, 589 g/kg and 90 min, respectively. It was revealed that cassava flour composition had the most effect on the quality characteristics of cassava-wheat-composite bread. At constant cassava flour  composition, increase in water content and proofing time had a positive effect on all the studied quality characteristics of cassava-wheat composite bread. Increase cassava flour composition regardless of proofing time and water content had a negative effect on loaf specific volume and protein. This study has provided bread-making conditions which can be utilised in enhancing the consumer acceptability of cassava-wheat composite bread. &nbsp

    Lamivudine-Induced Liver Injury

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    BACKGROUND: Lamivudine is a nucleoside analogue antiretroviral drug, known for its low toxicity at clinically prescribed dose. However, the toxicity or mechanism of toxicity and target tissue effects during prolonged administration of higher doses were hardly given sufficient laboratory attention. AIM: The present work was designed to investigate the biochemical and histopathological changes in the liver of rat administered with prolonged doses of lamivudine. MATERIAL AND METHODS: Lamivudine in multiple doses of five ranging from 4 mg/kg to 2500 mg/kg were administered, in vitro, by injection into the air-sac of 10–day old fertile embryonated eggs of Gallus domesticus. Also, female rats of the Wistar strain received oral doses, up to 500 mg/kg singly or repeatedly for 15 or 45 days, respectively. Spectrophotometric techniques were employed to monitor activities of the aminotransferases (ALT and AST), γ–glutamyltransferase (GGT) and total protein concentration in serum while activities of glutathione S–transferase (GST), GGT and superoxide dismutase (SOD) as well as concentrations of malondialdehyde (MDA) and protein were determined in liver. Histopathological studies were carried out on liver. Data were analysed using ANOVA and were considered significant when p < 0.05. RESULTS: The LD50 for the drug calculated from the incubation experiment was 427 mg/kg. Total serum protein concentration significantly reduced while enzymes activities significantly increased at 500 mg/kg only among the repeat-dosed rats. Hepatic GGT, GST and SOD activities as well as MDA concentration were significantly elevated at 20 mg/kg. Histopathological studies showed multifocal lymphoid cell population in the liver sinusoid of the chicken and hydropic degeneration of hepatocytes were recorded among rats repeatedly exposed to the drug respectively at doses ≥ 100 mg/kg

    APPLICATIONS OF ARTIFICIAL NEURAL NETWORKS AND GENETIC ALGORITHMS IN DRYING OF FRUITS AND VEGETABLES : A REVIEW

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    oai:ojs2.laujet.com:article/1Fruits and vegetables play an important role in the diet of human beings and economic development of a country. They are cheapest and most available sources of important proteins, vitamins, minerals and essential amino acids. Considering the perishable nature of fruits and vegetables it is necessary to preserve them and drying is one such method to do it. The drying of fruits and vegetables is a complex operation that demands much energy and time. Due to this complexity, the use of drying mathematical models in estimating the drying kinetics, the behaviour and the energy needed in the drying of fruits and vegetables becomes indispensable. Numerous mathematical models, empirical and semi-empirical, have been proposed to estimate the drying characteristics of fruits and vegetables. But these models are generally solutions of simultaneous heat and mass transfer differential equations and the final result may be very complicated and difficult to use in actual drying systems. This article present a comprehensive review on the applications of artificial neural networks and genetic algorithms in drying of fruits and vegetables. The paper starts with the drying of fruits and vegetables, the introduction of basic theoretical knowledge of ANN and GA. Then summarize their application on modeling, predicting, and optimization of heat and mass transfer, thermodynamic performance parameters, and quality indicators as well as physicochemical properties of dried fruits and vegetables. Conclusively, opportunities and limitations of ANN and GA technique in are outlined to provide more ideas for research and development in this field

    Evaluation of neuronal inflammation and oxidative DNA damage in different haptoglobin phenotypes of Nigerian type-2 diabetes mellitus population

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    Background: Oxidative stress is a major factor in the pathogenesis and progression of the clinical condition type 2 Diabetes Mellitus (DM) related to adverse biochemical/molecular interactions. Aim and Objectives: To determine whether haptoglobin phenotypes predispose DM patients to vascular complications and neuronal damage. Material and Methods: A total of 74 subjects were assessed out of which 31 had treated and untreated diabetes complicated with hypertension, 26 had treated and untreated uncomplicated DM and 17 were apparently healthy subjects who served as controls. Body Mass Index (BMI), Systolic Blood Pressure (SBP) and Diastolic Blood Pressure (DBP), serum Glucose (GLU), protein S100B and 8-Hydroxy-2-deoxyguanosine (8-OHdG) were determined in all subjects alongside the characterization of Haptoglobin (Hp) phenotypes. Results: BMI, SBP, DBP, GLU, protein S100B and 8-OHdG in treated and untreated complicated and uncomplicated DM patients were higher when compared to controls (p < 0.05). Hp 2 allele (Hp 2-1 and Hp2-2) was seen to be associated with poor glucose control, higher blood pressure and increased neuronal damage in both complicated and uncomplicated DM. It was also seen that the possession of Hp 2 gene was associated with a lower response to treatment. Conclusion: The Hp 2 allele could be a predisposing factor in developing diabetes related complications like hypertension and neuronal damage

    Performance of tropical maize hybrids under conditions of low and optimum levels of nitrogen fertilizer application – grain yield, biomass production and nitrogen accumulation

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    Nitrogen (N) is the most limiting mineral nutrient in the soils of the major maize producing areas of West and Central Africa. Low soil N and sub-optimal application of N fertilizers lead to N deficiency and poor grain yield (GY) in maize. Maize varieties with improved grain yield under low soil N and increased performance under optimal N availability could be beneficial to low input agriculture. This study evaluated the performance of a selection of experimental and commercial hybrids under suboptimal and optimal N fertilizer applications. Significant differences were observed among the hybrids, as well as significant interactions between hybrid and N level for GY and other measured attributes, with the severity of variation increasing as the level of N decreases. Mean GY reductions across the years was 76.5% at no-N and 35.4% at low-N. Depending on N treatment, GY varied from 0.48 to 4.42 Mg ha-1, grain N content from 0.17 to 1.26 g plant-1, total N content at harvest from 0.33 to 2.00 g plant-1, above ground biomass at silking from 30.6 to 91.2 g plant-1 and at maturity from 39.9 to 191.1 g plant-1. Number of kernels was the GY component most severely reduced by N stress and had significant (p = 0.001) positive correlation with GY at all N levels. Six hybrids (4001/4008, KU1409/4008, KU1409/9613, 4008/1808, 4058/Fun 47-4, and 1824/9432) which showed consistent above average grain yields under no-N, low-N, high-N and across N levels were found and their use could further be investigated

    Influence of Spirituality and Modesty on Acceptance of Self-Sampling for Cervical Cancer Screening.

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    INTRODUCTION: Whereas systematic screening programs have reduced the incidence of cervical cancer in developed countries, the incidence remains high in developing countries. Among several barriers to uptake of cervical cancer screening, the roles of religious and cultural factors such as modesty have been poorly studied. Knowledge about these factors is important because of the potential to overcome them using strategies such as self-collection of cervico-vaginal samples. In this study we evaluate the influence of spirituality and modesty on the acceptance of self-sampling for cervical cancer screening. METHODOLOGY: We enrolled 600 participants in Nigeria between August and October 2014 and collected information on spirituality and modesty using two scales. We used principal component analysis to extract scores for spirituality and modesty and logistic regression models to evaluate the association between spirituality, modesty and preference for self-sampling. All analyses were performed using STATA 12 (Stata Corporation, College Station, Texas, USA). RESULTS: Some 581 (97%) women had complete data for analysis. Most (69%) were married, 50% were Christian and 44% were from the south western part of Nigeria. Overall, 19% (110/581) of the women preferred self-sampling to being sampled by a health care provider. Adjusting for age and socioeconomic status, spirituality, religious affiliation and geographic location were significantly associated with preference for self-sampling, while modesty was not significantly associated. The multivariable OR (95% CI, p-value) for association with self-sampling were 0.88 (0.78-0.99, 0.03) for spirituality, 1.69 (1.09-2.64, 0.02) for religious affiliation and 0.96 (0.86-1.08, 0.51) for modesty. CONCLUSION: Our results show the importance of taking cultural and religious beliefs and practices into consideration in planning health interventions like cervical cancer screening. To succeed, public health interventions and the education to promote it must be related to the target population and its preferences

    DEVELOPMENT AND EVALUATION OF AN IMPROVED ELECTRO-MECHANICAL YAM POUNDING MACHINE

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    Yam is one of the oldest known recipes to man, which belongs to the class of carbohydrate and has been a part of the African meals for centuries. Pounded yam is generally accepted food prepared from yam tuber using indigenous method or equipment. Replacing such energy in cooking and yam pounding operation became expedient due to many reasons including tedious, laborious and very difficult. Materials to be used for construction of the electro-mechanical pounding machine were sourced locally and three different varieties of yam were used for its performance evaluation. It was observed from the result that the efficiency of the machine is high [98.75% (white yam), 99.70% (yellow yam), and 99.10% (water yam)]. The percentage lump and pounding capacity for white yam, yellow yam and water yam were 1.25, 3.49, 0.90 and 31.71, 29.68, 27.73g/s respectively
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