24 research outputs found

    Energy Exploitation And Environmental Impact In Nigeria: The Way Forward.

    Get PDF
    Energy is the basis of industrial civilisation; without energy, modern life would be difficult to live. However, the exploitation and utilisation of energy in this case non-renewable energy (oil, gas and coal) comes with effects that impact negatively on the environment such as environmental pollution which affects weather conditions, soil fertility, aquatic habitats and wildlife animals. This paper, after highlighting the various environmental impact of energy exploitation, emphasizes on the need for the stakeholders, in this context, government, engineers, scientist, investors and community leaders to rise up to the challenges and ensure that the impacts of energy to the environment are addressed. It advocates for interdisciplinary approach and strict adherence to professional ethics by engineers and scientists to address the problems while the appropriate government agencies should enforce the various environmental laws. And judging by the threat the non-renewable energy exploitation poses to humans and the environment, the paper suggests a gradual shift to clean energy technology for sustainable development.Key words: Energy Exploitation, Environment Pollution, Modern Technologies, Sustainable Development

    Hydrogeological and Engineering Investigations of Gully Sites in Zing and Environs, Northeastern Nigeria

    No full text
    The research area is characterized by problems of gully erosion which have resulted in the destruction of roads and uprooting trees of economic importance. Reduction in the area of arable and other agricultural land, which become divided into smaller parcels and leads to increased farming cost. Hydrogeological and engineering investigations were conducted in Zing and environs, Taraba State of Nigeria to characterize the rock materials that aid gully erosion in the area. The methods involve three (3) stages, reconnaissance survey, detailed field mapping and laboratory analysis. The area is underlain by porphyritic granite and Biotite granite. The geologic structures include fractures, dykes, and veins which trend NNW to SSE, NW-SE and NNE to SSW. The results of geotechnical parameters indicate that the plastic limit ranges between 0 to 24.2%, liquid limit ranges from 20.1% to 43.9%, plasticity index ranges between 11.2 to 19.7%. The coefficient of uniformity ranges between 4.2 and 11.5 while the coefficient of curvature ranged between 0.53 and 1.99. The optimum moisture content was from 8.3 to 9.8%, while maximum dry density is from 1.75 to 1.91mg/m³. The angle of internal friction was between 28° to 40°, while the cohesion is between 0 to 54KN/m². The statistical grain size methods gave hydraulic conductivity values ranging from 2.35 x 10-3m/s to 8.64 x 10-5m/s. The hydraulic head distribution map indicates that the gully sites are located in the discharge areas. The discharge areas are characterized by high hydrostatic pressure which decreases effective stress and in turn reduces the shear strength of materials, enhance, internal erosion in form of piping and cave ins in the discharge areas. From the results of the study, recommendations such as sand mining/excavation along the rivers should be avoided, ridging perpendicular to river bank are reduced, dumping of refuse on the river channels and floodplains should be discouraged and houses should not be constructed along the river bank

    Smoothened-dependent and -independent pathways in mammalian noncanonical Hedgehog signaling

    No full text
    Hedgehog proteins are pivotal morphogens acting through a canonical pathway involving first activation of ligand binding to Patched followed by alleviation of Smoothened receptor inhibition, leading to activation of Gli transcription factors. Noncanonical Hedgehog signaling remains poorly characterized but is thought to be mainly dependent on Smoothened. However, Smoothened inhibitors have yielded only partial success in combating Hedgehog signal transduction-dependent cancer, suggesting that noncanonical Smoothened-independent pathways also are clinically relevant. Moreover, several Smoothened-dependent effects (e.g. neurite projection) do not require transcriptional activation, further suggesting biological importance of noncanonical Smoothened-dependent pathways. We comprehensively characterized the cellular kinome in Hedgehog-challenged murine WT and Smoothened(-/-) fibroblasts as well as Smoothened agonist-stimulated cells. A peptide assay-based kinome analysis (in which cell lysates are used to phosphorylate specific kinase substrates), along with endocytosis, Lucifer Yellow-based, and immunoblotting assays, identified an elaborate signaling network of both Smoothened-dependent and -independent pathways that mediates actin reorganization through Src-like kinases, activates various proinflammatory signaling cascades, and concomitantly stimulates Wnt and Notch signaling while suppressing bone morphogenetic protein (BMP) signaling. The contribution of noncanonical Smoothened-independent signaling to the overall effects of Hedgehog on cellular physiology appears to be much larger than previously envisioned and may explain the transcriptionally independent effects of Hedgehog signaling on cytoskeleton. The observation that Patched-dependent, Smoothened-independent, noncanonical Hedgehog signaling increases Wnt/Notch signaling provides a possible explanation for the failure of Smoothened antagonists in combating Hedgehog-dependent but Smoothened inhibitor-resistant cancer. Our findings suggest that inhibiting Hedgehog-Patched interaction could result in more effective therapies as compared with conventional Smoothened-directed therapies
    corecore