30 research outputs found
Human longevity : crosstalk between the brain and periphery
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Although mortality in old age has significantly decreased over the last fifty years in the developed world, there still remains a large inter-individual variability in ageing trajectories, morbidity and mortality. In the three parts of this thesis, we examined three interacting systems that have been identified as contributing to a slower pace of ageing, namely glucose/insulin metabolism (part I), the thyroid axis (part II), and the autonomic nervous system (part III). We found that familial longevity is associated with a stronger association of insulin parameters with microstructural brain parameters, and by higher TSH secretion, in the absence of differences in basal energy metabolism or differences in heart rate and its variability. Using specialized MRI techniques, we showed that subtle changes in microstructural brain parenchymal homogeneity in relation to insulin can be detected, even in brain tissue that appears normal on conventional MR imaging sequences. Insulin (rather than glucose), seemed to be a stronger indicator of micro- structural brain integrity in normo-glycemic older adults. Furthermore, intranasal application of insulin improved brain perfusion in parietal and occipital gray matter and in the thalamus of older adults. These results deepen our understanding of the physiological mechanisms and processes that underlie the ageing process.
 European commission project Switchbox (FP7, Health-F2-2010-259772).LUMC / Geneeskund
An overview of the challenges and prospects in developing an aquaculture industry in Lagos State, Nigeria
Macroeconomic growth and the development of sustainable business activities are interrelated. In Lagos State, aquaculture is a marginal economic activity thriving mainly on a semi-intensive level. Notwithstanding the available potentials for the development of successful commercial aquaculture enterprises in the state, the transformation to a full-flagged industry continues to be undetermined by certain critical factors. Feasible development strategies may be sought in increasing all stakeholders' capacity in the formulation of policies, plans and regulations, a complete separation of aquaculture from the capture fisheries in administrative structure and policy; the adoption of precautionary approach; provision of economic incentives to enhance private investments and increase output,respectivel
Effects of Organic and Inorganic Fertilizers on the Growth of Senecio biafrae (WOROWO) OLIVE & HIERN
Soils have shown a negative balance in nutrient budget which poses a great threat to sustainable soil management for increase in growth and crop yield. This study thus investigated the effects of organic and inorganic fertilizers on the growth of Senecio biafrae (Oliv. &Hiern). Topsoil, organic (poultry manure) and inorganic fertilizers (NPK 15:15:15) were used. The fertilizers were weighed and applied to the soil at 5g, 10g, 15g each; control topsoil without application of fertilizers and were replicated five times. Growth parameters including height, number of leaves and stem diameter were taken weekly for the period of the experiment. Application ofpoultry manure and NPK fertilizer had significant effects on all the growth parameters considered. The application of poultry manure resulted into significant increase in the growth parameters towards the latter part of the study. This study has shown that organic manure has great potential for improving soil productivity and plant growth.
Keywords: Senecio biafrae, investigate, organic, inorganic, plant yiel
Growth Performance of Tetrapleura Tetraptera (Schum and Thonn) Seedlings to Green Manure and Inorganic Fertilizer
The use, types and method of fertilizers for agricultural and forest plants should be sustainable, ecofriendly and natural to the environment. Application of green manure is being used nowadays for soil nutrient management, growth and plant yields because of their natural effects. This study investigated the use of green manure andinorganicfertilizer on the growth performance of Tetrapleura tetraptera. Topsoil, leucaenana leucoephala (leave powder) and inorganic fertilizer (NPK 15: 15:15) were used. The fertilizer were weighed and applied to the 5kg of soils at 0g, 10g and 20g each and were replicated six times. Growth parameters such as seedling heights, number of leaf and stem diameter were assessed weekly for aperiod of three months. The application leucaenana leucoephala’s leave powder as green manure showed significantly high effects on the growth parametersof Tetrapleura tetraptera seedlings at p ≤ 0.05. This study has shown the efficacy of leucaenana leucoephala’s leave powder as green manure for optimum growth of Tetrapleura tetraptera seedlings
Reinforcement bar Corrosion - Causes and Management
Concretes are composite materials which decay as a result of steel corrosion in concrete
structures is mostly accelerated in environments laden with chlorides and industrial
effluent gases as well as harsh chemicals employed in and those generated from wastes
in agricultural industries. This review summarises the effects of various environmental
pollutants which promote deterioration of concretes with resultant corrosion of
reinforcing bar (rebar). An overview of traditional and current methods for significant
reduction of this mode of material deterioration is described. Discussions on
management tools for rebar corrosion in agricultural and marine environments have
been highlighted. Repair methods include the traditional application of patch repair
mortar which has been modified with polymeric materials to improve adhesion and
reduce porosity. The use of cathodic protection system to reduce rebar corrosion to its
barest minimum has gained currency. Attention should be directed at corrosion
reduction practices at the design and planning stages as well as modification concrete
mixes with modified agricultural wastes/products and polymers
Reinforcement bar Corrosion - Causes and Management
Concretes are composite materials which decay as a result of steel corrosion in concrete
structures is mostly accelerated in environments laden with chlorides and industrial
effluent gases as well as harsh chemicals employed in and those generated from wastes
in agricultural industries. This review summarises the effects of various environmental
pollutants which promote deterioration of concretes with resultant corrosion of
reinforcing bar (rebar). An overview of traditional and current methods for significant
reduction of this mode of material deterioration is described. Discussions on
management tools for rebar corrosion in agricultural and marine environments have
been highlighted. Repair methods include the traditional application of patch repair
mortar which has been modified with polymeric materials to improve adhesion and
reduce porosity. The use of cathodic protection system to reduce rebar corrosion to its
barest minimum has gained currency. Attention should be directed at corrosion
reduction practices at the design and planning stages as well as modification concrete
mixes with modified agricultural wastes/products and polymers
TOXICITY EVALUATION OF CRANKCASE OIL IN RATS
The aim of this study was to investigate the effect of crankcase oil on the cellular and func-tional integrity of rat skin. Thirty (30) rats were randomly grouped into six viz groups A–F. Group A (base-line control) received 2 ml of distilled water. 2.5 %, 5.0 %, 7.5 %, and 10.0 % v/v of the crankcase oil were prepared using unused oil as solvent and 2 ml of the concentra-tions were topically administered to groups C–F respectively for seven consecutive days. Group B served as positive control and received 2 ml of the unused oil. The rats were sacri-ficed 24 hours after the last administration, and blood and part of the skin were collected. Al-kaline phosphatase (ALP), acid phosphatase (ACP), superoxide dismutase (SOD) and malondialdehyde level in the blood and skin samples collected were evaluated. Elemental analysis of the crankcase oil was also carried out. The result revealed high lead, iron and chromium levels. Blood lead concentration of rats was significantly (P<0.05) high after seven days of administration. ALP level in skin and serum increased significantly (P<0.05) with the concentration of crankcase oil. There was a significant decrease (P<0.05) in skin ACP activity while it increased significantly (P<0.05) in the serum. Similar results were observed in the SOD levels of the serum and the skin. The level increased significantly (P<0.05) in groups D–F when compared with controls. The MDA concentration of both serum and skin were signif-icantly (P<0.05) elevated. This suggests toxic potential of used lubricating oil and its potential predisposition to cance
Valorized chicken feather as corrosion inhibitor for mild steel in drilling mud
Modified chicken feather reduced the corrosion rate of mild steel in drilling mud as deduced from electrochemical
potentiodynamic polarization technique, albeit, with observed infestation of the test environment by microbes
over protracted exposure period of 92 days. The corrosion rates with and without the addition of 0.3g of
hydrolyzed feather per 100 ml of drilling mud were 1.70 and 1.95 mm/yr, respectively; which corresponded to
inhibition efficiency of 13% over the immersion period. The corresponding charge transfer resistances, a measure
of corrosion rates were 1480.4 and 1780.0 Ω, respectively; in the uninhibited and hydrolyzed-feather inhibited
environments. The voltage over the double layer capacitor as obtained from the polarization studies numerically
increased from �0.907 to �0.948 V which indicated adsorption of moieties in the inhibitor and probably some
corrosion products on the surface of the mild steel specime
Human longevity : crosstalk between the brain and periphery
Â
Although mortality in old age has significantly decreased over the last fifty years in the developed world, there still remains a large inter-individual variability in ageing trajectories, morbidity and mortality. In the three parts of this thesis, we examined three interacting systems that have been identified as contributing to a slower pace of ageing, namely glucose/insulin metabolism (part I), the thyroid axis (part II), and the autonomic nervous system (part III). We found that familial longevity is associated with a stronger association of insulin parameters with microstructural brain parameters, and by higher TSH secretion, in the absence of differences in basal energy metabolism or differences in heart rate and its variability. Using specialized MRI techniques, we showed that subtle changes in microstructural brain parenchymal homogeneity in relation to insulin can be detected, even in brain tissue that appears normal on conventional MR imaging sequences. Insulin (rather than glucose), seemed to be a stronger indicator of micro- structural brain integrity in normo-glycemic older adults. Furthermore, intranasal application of insulin improved brain perfusion in parietal and occipital gray matter and in the thalamus of older adults. These results deepen our understanding of the physiological mechanisms and processes that underlie the ageing process.
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Gender differences in self-reported academic burnout among undergraduates
Academic burnout among tertiary level students has increased significantly in recent decades, thus galvanizing studies among behavioral scholars that have investigated the phenomenon. Most of these studies adopted an approach that evaluated social and environmental factors that are predictive of academic burnout, while the role of gender in academic burnout remains under-researched. This is so even in the light of a plethora of studies which suggest that gender may be related to the experience of burnout in general. The present study therefore extended the literature by examining whether gender predicted dimensions of academic burnout using a sample of undergraduates in the final level in school. The sample consisted of 273 participants made up of 129 male and 144 female undergraduates whose age ranged between 21 years and 34 years (Mean = 22.55; SD = 3.37). Participants were all in the final year of their study in the university. The instrument for data collection was a questionnaire that consisted of two sections which measured sex, and academic burnout, using a standardized scale. Result revealed no significant gender influence on dimensions of academic burnout. The findings suggested that gender influence on dimensions of academic burnout is contestable and where it is found to be significant, factors other than gender may account for such observed difference.Keywords: Gender differences, Academic Burnout, Undergraduate