GEOMORPHOLOGICAL MAPPING OF PART OF THE NIGER DELTA, NIGERIA USING DEM AND MULTISPECTRAL IMAGERY

This study utilised geo-information technology to carry out a geomorphological mapping of a part of the Niger Delta. Satellite image analysis was based on bi-annual seasonal approach using a combination of visual analysis of the geometry, site, situation, colour, and season for analysis of the non-topographic features. The study also utilised virtual and onsite fieldworks and existing geomorphologic information to interpret and analyse topographic and bathymetric features. First-order topographic features (elevation) and second level features including slope, aspect, curvature and mathematically exaggerated shaded relief were extracted from DEM. Relief classification was based on average elevation differences, hill shade, slope, and aspect. Three main non-topographic landforms were identified; the permanent rivers with stable meanders, perennially-active systems of creeks and fluvial landforms including scroll bars and oxbows. With the exception of higher elevation values towards the north-western fringe, the elevation ranges between mean sea level and 1 metre above sea level thus establishing a somewhat flat terrain. These areas were filled with meandering streams, sinuous creeks and watercourses flanked by mangrove vegetation.  In the north-western area, elevation rose close to approximately 4 metres in most of the area with a peak of 10 metres.  Generally, the cumulative area-slope analysis yielded a deltaic plain with generalised slope ≤ 20. Overall two elevation-based geographically differentiated morphological units were identified; tidal mudflats and saltmarshes. The study recommends that to provide needed information for resource planning and management, further investigation should be carried out with a view to modelling probable ecological and geomorphological changes in the entire Niger Delta.   &nbsp

Climate change, sea level rise and coastal inundation along part of Nigeria Barrier Lagoon Coast

The phenomenon of ocean surges and other morphological processes  along the Lagos coastline have generated serious public concern on the vulnerability of infrastructures and coastal services along the entire stretch of the Barrier-Lagoon coastline of Lagos State. This study examines  Badagry coastal environment inundations that arise from sea level rise. The study uses an iterative GIS-based simulation that mapped area  inundated based on Intergovernmental Panel on Climate Change - Special Report on Emissions Scenarios (IPCC –SRES) classification (A1, A1T, B2, A1B and A2) and Locally Oriented Economic Development Scenarios  (LOEDS). The results of IPCC-SRES scenario analysis show that area  inundated at the high emission and worse case sea level rise is less than 0.13% of the study area while the LOEDS inundation area starts having significant impacts as from 4 meter rise in sea level. Since it is only environmental catastrophism and anthropogenic activities that can attain such serious dimension at local, regional and global scales in sea level, it is recommended that coastal protection infrastructures should be   integrated in any major developmental activitie

Physicochemical assessment and bacteriological studies of hand-dug wells of major markets in south western, Nigeria

Rapid population in developing nations has imposed stress on groundwater resources, thus the need to assess physicochemical and bacteriological impact of microbes on hand-dug wells along some major markets in Ibadan Southwestern Nigeria. Water samples from hand-dug wells were measured sequentially, and total dissolved solute (TDS), pH, electrical conductivity (EC), salinity, and temperature were measured in situ. Water samples were analyzed at a Microbiology Laboratory. Most probable techniques used for micro-organism analysis were in three stages: presumptive test used for confirmation of Escherichia coli, confirmed test for total viable bacteria count (TVBC), and complete test to reconfirm the presence of coliform. Presumptive test showed high rate of E. coli in most of the hand-dug wells with (37.5 %). Confirmed test revealed Staphylococcus aureus to be 25 %, followed by Proteus vulgaris (14.6 %), Bacillus species (12.5 %), Pseudomonas aeruginosa (8.3 %), and Klebsiella spp. (2.1 %) respectively. Total viable bacteria counts are 500 to 192,000. Physicochemical results (total dissolved solute (TDS), pH, electrical conductivity (EC), salinity, temperature) when compared with WHO (2006) and SON (2007) revealed all the parameters to be within the permissible limits except pH (5.8 to 9.56), and high values of the parameters were caused by organic matter. High E. coli in the study area revealed influence of human and animal fecal that coul

The Human TPR Protein TTC4 Is a Putative Hsp90 Co-Chaperone Which Interacts with CDC6 and Shows Alterations in Transformed Cells

BACKGROUND: The human TTC4 protein is a TPR (tetratricopeptide repeat) motif-containing protein. The gene was originally identified as being localized in a genomic region linked to breast cancer and subsequent studies on melanoma cell lines revealed point mutations in the TTC4 protein that may be associated with the progression of malignant melanoma. METHODOLOGY/PRINCIPLE FINDINGS: Here we show that TTC4 is a nucleoplasmic protein which interacts with HSP90 and HSP70, and also with the replication protein CDC6. It has significant structural and functional similarities with a previously characterised Drosophila protein Dpit47. We show that TTC4 protein levels are raised in malignant melanoma cell lines compared to melanocytes. We also see increased TTC4 expression in a variety of tumour lines derived from other tissues. In addition we show that TTC4 proteins bearing some of the mutations previously identified from patient samples lose their interaction with the CDC6 protein. CONCLUSIONS/SIGNIFICANCE: Based on these results and our previous work with the Drosophila Dpit47 protein we suggest that TTC4 is an HSP90 co-chaperone protein which forms a link between HSP90 chaperone activity and DNA replication. We further suggest that the loss of the interaction with CDC6 or with additional client proteins could provide one route through which TTC4 could influence malignant development of cells

Comparison of gene expression during in vivo and in vitro postnatal retina development

Retina explants are widely used as a model of neural development. To define the molecular basis of differences between the development of retina in vivo and in vitro during the early postnatal period, we carried out a series of microarray comparisons using mouse retinas. About 75% of 8,880 expressed genes from retina explants kept the same expression volume and pattern as the retina in vivo. Fewer than 6% of the total gene population was changed at two consecutive time points, and only about 1% genes showed more than a threefold change at any time point studied. Functional Gene Ontology (GO) mapping for both changed and unchanged genes showed similar distribution patterns, except that more genes were changed in the GO clusters of response to stimuli and carbohydrate metabolism. Three distinct expression patterns of genes preferentially expressed in rod photoreceptors were observed in the retina explants. Some genes showed a lag in increased expression, some showed no change, and some continued to have a reduced level of expression. An early downregulation of cyclin D1 in the explanted retina might explain the reduction in numbers of precursors in explanted retina and suggests that external factors are required for maintenance of cyclin D1. The global view of gene profiles presented in this study will help define the molecular changes in retina explants over time and will provide criteria to define future changes that improve this model system

Hsp70 chaperones: Cellular functions and molecular mechanism

Hsp70 proteins are central components of the cellular network of molecular chaperones and folding catalysts. They assist a large variety of protein folding processes in the cell by transient association of their substrate binding domain with short hydrophobic peptide segments within their substrate proteins. The substrate binding and release cycle is driven by the switching of Hsp70 between the low-affinity ATP bound state and the high-affinity ADP bound state. Thus, ATP binding and hydrolysis are essential in vitro and in vivo for the chaperone activity of Hsp70 proteins. This ATPase cycle is controlled by co-chaperones of the family of J-domain proteins, which target Hsp70s to their substrates, and by nucleotide exchange factors, which determine the lifetime of the Hsp70-substrate complex. Additional co-chaperones fine-tune this chaperone cycle. For specific tasks the Hsp70 cycle is coupled to the action of other chaperones, such as Hsp90 and Hsp100

Expression of a malarial Hsp70 improves defects in chaperone-dependent activities in ssa1 mutant yeast

Plasmodium falciparum causes the most virulent form of malaria and encodes a large number of molecular chaperones. Because the parasite encounters radically different environments during its lifecycle, many members of this chaperone ensemble may be essential for P. falciparum survival. Therefore, Plasmodium chaperones represent novel therapeutic targets, but to establish the mechanism of action of any developed therapeutics, it is critical to ascertain the functions of these chaperones. To this end, we report the development of a yeast expression system for PfHsp70-1, a P. falciparum cytoplasmic chaperone. We found that PfHsp70-1 repairs mutant growth phenotypes in yeast strains lacking the two primary cytosolic Hsp70s, SSA1 and SSA2, and in strains harboring a temperature sensitive SSA1 allele. PfHsp70-1 also supported chaperone-dependent processes such as protein translocation and ER associated degradation, and ameliorated the toxic effects of oxidative stress. By introducing engineered forms of PfHsp70-1 into the mutant strains, we discovered that rescue requires PfHsp70-1 ATPase activity. Together, we conclude that yeast can be co-opted to rapidly uncover specific cellular activities mediated by malarial chaperones. © 2011 Bell et al

Shifting livelihood strategies in northern Nigeria - extensified production and livelihood diversification amongst Fulani pastoralists

Abstract This paper presents an in-depth investigation of the livelihood strategies of Fulani pastoralists in north central Nigeria. Results show a diversified crop-livestock system aimed at spreading risk and reducing cattle offtake, adapted to natural resource competition and insecurity by extensification, with further diversification into off-farm activities to spread risk, increase livelihood security and capture opportunities. However, significant costs were associated with extensification, and integration of crop and livestock enterprises was limited. Mean total income per capita in the study area was $554 or$1.52/person/day with 42% of households earning less than 1.25/person/day. Income levels were positively correlated with income diversity and price received per animal sold, rather than herd size. The outcomes of this livelihood strategy were favourable across the whole community, but when individual households are considered, there was evidence of moderate economic inequality in total income, cash income and herd size (Gini coefficient 0.32, 0.35 and 0.43 respectively). The poorest households were quite vulnerable, with low assets, income and income diversity. Implications for sustainability are discussed given the likelihood that the negative trends of reduced access to natural resources and insecurity will continue