107 research outputs found

    Genetic Diversity of Selected Upland Rice Genotypes (Oryza sativa L.) for Grain Yield and Related Traits

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    Seventy-seven upland rice genotypes including popular cultivars in Nigeria and introduced varieties selected from across rice-growing regions of the world were evaluated under optimal upland ecology. These genotypes were characterised for 10 traits and the quantitative data subjected to Pearson correlation matrix, Principal Component Analysis and cluster analysis to determine the level of diversity and degree of association existing between grain yield and its related component traits. Yield and most related component traits exhibited higher PCV compared to growth parameters. Yield had the highest PCV (41.72%) while all other parameters had low to moderate GCV. Genetic Advance (GA) ranged from 9.88% for plant height at maturity to 41.08% for yield. High heritability estimates were recorded for 1000 grain weight (88.71%), days to 50% flowering (86.67%) and days to 85% maturity (71.98%). Furthermore, grain yield showed significant positive correlation with days to 50% flowering and number of panicles m-2. Three cluster groups were obtained based on the UPGMA and the first three principal components explained about 64.55% of the total variation among the 10 characters. The PCA results suggests that characters such as grain yield, days to flowering, leaf area and plant height at maturity were the principal discriminatory traits for this rice germplasm indicating that selection in favour of these traits might be effective in this population and environment

    Field Evaluation of Yield and Yield Component Traits of Breeding Lines of Maize over Two Seasons in Derived Savannah Agro-Ecology

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    The understanding of yield and the interaction with its components is very important for selection in early generations of crop breeding. Twelve maize genotypes were collected from International Institute for Tropical Agriculture (IITA) along with seven landraces in order to identify the contribution of different traits to yield improvement. The experiments were carried out in two different seasons (March/April-early and July/August- late) in a randomized complete block design with three replications. Early season planting had a higher grain yield than late season planting. The difference in grain yield between early and late season was 3.92 tons/ha. This represents a 27.8% increase in grain yield during the early season over the late season planting. Number of ears per plant and shelling percentage were not influenced by seasonal effects. Ear weight and days to tasselling showed the highest direct positive effects of 0.972 and 0.665, respectively on grain yield, during early season. Furthermore, ear weight, followed by shelling percentage, exerted the highest direct positive effect on grain yield in late season. Higher indirect positive effects were obtained for ear diameter, ear length, ear height and plant height via ear weight in both seasons. Ear weight, days to tasselling and ear length were identified as the major traits affecting yield of maize in both seasons in the derived Savannah agro-ecology

    Ameliorative Potentials of Camellia sinensis on Petrol Fumes- induced Oxidative Stress in Rats

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    Volatile organic compounds found in petrol include benzene, toluene, ethylbenzene, and xylene (BTEX). Extract of Camellia sinensis (tea plant) leaf contains some secondary metabolites such as flavonoids, alkaloids, terpenoids saponins, anthraquinones, and tannins. Polyphenols in Camellia sinensis possess anti-atherosclerosis and cardioprotective, neuroprotective, anti-inflammatory, anti-carcinogenic, antibacterial, anti-diabetic, anti-tumor, anti-hypertensive, and hepato-protective effects. The study aimed to investigate the potential of Camellia sinensis in ameliorating lung damage, oxidative stress, and inflammation caused by petrol fumes. Forty-eight Wistar albino rats weighing between 140g-230g  were randomized into 8 groups of 6 rats each consisting of control, petrol fumes only group, three aqueous drink groups of different doses, and three methanol extract groups of different doses respectively. The oxido-inflammatory responses and histopathological alterations in rat lungs following 6 hours of daily exposure for 30 and 60 days were recorded. Oxidative stress (superoxide dismutase (SOD), reduced glutathione (GSH), catalase (CAT)) and inflammatory biomarkers namely: Tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6) were evaluated. The biochemical analyses showed that petrol fumes exposure resulted in significant (P<.05) increases in biomarkers of oxidative stress, pro-inflammation cytokines, and reduced GSH levels in rats as well histopathological alteration in lungs. The treated groups showed anti-oxidant properties by the elevation of antioxidant enzymes (CAT, SOD) and non-enzymatic antioxidant (gluthathione) and reduction of MDA levels as well as reversal of alterations in the lungs after histopathological analysis. This study showed that Camellia sinensis leaf aqueous and methanol extract have the potential to attenuate petrol fumes-induced oxidative stress due to its natural bioactive constituents

    Ab-initio calculation of Kerr spectra for semi-infinite systems including multiple reflections and optical interferences

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    Based on Luttinger's formulation the complex optical conductivity tensor is calculated within the framework of the spin-polarized relativistic screened Korringa-Kohn-Rostoker method for layered systems by means of a contour integration technique. For polar geometry and normal incidence ab-initio Kerr spectra of multilayer systems are then obtained by including via a 2x2 matrix technique all multiple reflections between layers and optical interferences in the layers. Applications to Co|Pt5 and Pt3|Co|Pt5 on the top of a semi-infinite fcc-Pt(111) bulk substrate show good qualitative agreement with the experimental spectra, but differ from those obtained by applying the commonly used two-media approach.Comment: 32 pages (LaTeX), 5 figures (Encapsulated PostScript), submitted to Phys. Rev.

    Magnetic properties of X-Pt (X=Fe,Co,Ni) alloy systems

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    We have studied the electronic and magnetic properties of Fe-Pt, Co-Pt and Ni-Pt alloy systems in ordered and disordered phases. The influence of various exchange-correlation functionals on values of equilibrium lattice parameters and magnetic moments in ordered Fe-Pt, Co-Pt and Ni-Pt alloys have been studied using linearized muffin-tin orbital method. The electronic structure calculations for the disordered alloys have been carried out using augmented space recursion technique in the framework of tight binding linearized muffin-tin orbital method. The effect of short range order has also been studied in the disordered phase of these systems. The results show good agreements with available experimental values.Comment: 21 pages, 4 eps figures, accepted for publication in Journal of Physics Condensed Matte

    Isolation, Growth and Identification of Chlorpyrifos Degrading Bacteria from Agricultural Soil in Anambra State, Nigeria

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    Abstract The extensive use of pesticides is one of the major causes of pollution of soil and water environments. The current method for removing such contaminants from the environment through biodegradation has been shown to be more effective than any other method. Three pesticide degrading bacteria were isolated and identified through cultural and biochemical tests as strains of Pseudomonas aeruginosa, Serretia marcescens and Klebsiella oxytoca. Their growth in mineral salt medium supplemented with 20mg/l of Chlorpyrifos was monitored at optical density of 600nm. The result showed that Pseudomonas aeruginosa had maximum growth in ten days, while Serretia marcescens and Klebsiella oxytoca recorded highest growth after six days of incubation. HPLC analysis of the residual Chlorpyrifos after 14 days incubation showed that Pseudomonas aeruginosa was able to degrade 60% of the pesticide; Klebsiella oxytoca degraded 54%, while Serretia marcescens had 53% reduction of the pesticide concentration in the mineral salt medium. The results of this research indicated that the isolated bacteria can be used for bioremediation of Chlorpyrifos contaminated soil and water ecosystems

    Leadership and Entrepreneurship: Preliminary Validation of Covenant Entrepreneurial Effectiveness Scale

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    Attaining and maintaining leadership in any field of human endeavour requires regular valid measurement and evaluation. The latter is the quest of Psychometrics. The core objective of this study, therefore, was to develop and attempt preliminary validation of the Covenant Entrepreneurial Effectiveness Scale [CEES], a monitoring device for entrepreneurs. The CEES was based on Schumpeter’s theory of Innovation in entrepreneurship and Leibenstein’s theory of entrepreneurship, combined with current observations of SMEs in a developing economy. The core research questions were: What are the internal consistency reliabilities of the CEES? What are the discriminant validity indices of the CEES? One hundred and ninety-four (194) small scale entrepreneurs were randomly sampled from Ado-Odo Ota local government area in Ogun State, Nigeria. There were 128 males and 66 females with age ranging from 20-65 years. The mean and standard deviation of their age were 38.05 and 8.56 respectively. The responses to the CEES were analysed with Cronbach alpha, Guttman Split-half and Spearman-Brown coefficients and independent student t-test. The results showed that the CEES has significant internal consistency reliability (0.755), splithalf reliability (0.742) and discriminant validities for entrepreneurs who were differentiated on Gender (t=2.75, p=0.007), Age (t=2.003, p=0.048), House (t=5.68, p=0.0) Car (5.89, p=0.0) and Annual Profit (t=3.432, p=0.001). It was recommended that the CEES be administered on SMEs in other parts of the globe to further ascertain its reliability and validity for regular monitoring and evaluation, to catalyse entrepreneurial leadership

    Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers

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    https://deepblue.lib.umich.edu/bitstream/2027.42/138963/1/12987_2017_Article_71.pd
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