283 research outputs found
Democratization in the post-colonial era: shortcomings
During colonialism, African countries were exposed to severe living circumstances and human rights abuses. African nations earned their independence and transitioned to democracy in the post-colonial period. Democracy was touted as a method of creating security, stability, and wealth in African countries, as well as demonstrating Africa's independence. The transition to democratic states was viewed as a necessary step for African countries in order to meet the needs of citizens who had previously been enslaved and whose rights had been violated by colonizers. This article examines the current position of democracy in African States post colonialization. This article argues that African leaders have failed to deliver on their promises of democracy, as evidenced by the fact that African countries are characterized by political instability, corruption, poverty, poor public service delivery, inequality, and low economic growth. Only the political elites in Africa have reaped the benefits of democracy, while the rest of the population has fared less favorably. The authors contend that the process of democratization has not afforded democratic African states the opportunity to acquire solutions. The authors acknowledge the progress, made by democratic states; nevertheless, in spite of this progress, a greater number of Africans continue to live below the poverty line. Those who are elected to positions of power have the appearance of being there to serve the people, but in reality, they only serve themselves and their own interests
Needles in the EST Haystack: Large-Scale Identification and Analysis of Excretory-Secretory (ES) Proteins in Parasitic Nematodes Using Expressed Sequence Tags (ESTs)
Excretory-secretory (ES) proteins are an important class of proteins in many organisms, spanning from bacteria to human beings, and are potential drug targets for several diseases. In this study, we first developed a software platform, EST2Secretome, comprised of carefully selected computational tools to identify and analyse ES proteins from expressed sequence tags (ESTs). By employing EST2Secretome, we analysed 4,710 ES proteins derived from 0.5 million ESTs for 39 economically important and disease-causing parasites from the phylum Nematoda. Several known and novel ES proteins that were either parasite- or nematode-specific were discovered, focussing on those that are either absent from or very divergent from similar molecules in their animal or plant hosts. In addition, we found many nematode-specific protein families of domains “transthyretin-like” and “chromadorea ALT,” considered vaccine candidates for filariasis in humans. We report numerous C. elegans homologues with loss-of-function RNAi phenotypes essential for parasite survival and therefore potential targets for parasite intervention. Overall, by developing freely available software to analyse large-scale EST data, we enabled researchers working on parasites for neglected tropical diseases to select specific genes and/or proteins to carry out directed functional assays for demystifying the molecular complexities of host–parasite interactions in a cell
In silico analysis of expressed sequence tags from Trichostrongylus vitrinus (Nematoda): comparison of the automated ESTExplorer workflow platform with conventional database searches
<p>Abstract</p> <p>Background</p> <p>The analysis of expressed sequence tags (EST) offers a rapid and cost effective approach to elucidate the transcriptome of an organism, but requires several computational methods for assembly and annotation. Researchers frequently analyse each step manually, which is laborious and time consuming. We have recently developed ESTExplorer, a semi-automated computational workflow system, in order to achieve the rapid analysis of EST datasets. In this study, we evaluated EST data analysis for the parasitic nematode <it>Trichostrongylus vitrinus </it>(order Strongylida) using ESTExplorer, compared with database matching alone.</p> <p>Results</p> <p>We functionally annotated 1776 ESTs obtained <it>via </it>suppressive-subtractive hybridisation from <it>T. vitrinus</it>, an important parasitic trichostrongylid of small ruminants. Cluster and comparative genomic analyses of the transcripts using ESTExplorer indicated that 290 (41%) sequences had homologues in <it>Caenorhabditis elegans</it>, 329 (42%) in parasitic nematodes, 202 (28%) in organisms other than nematodes, and 218 (31%) had no significant match to any sequence in the current databases. Of the <it>C. elegans </it>homologues, 90 were associated with 'non-wildtype' double-stranded RNA interference (RNAi) phenotypes, including embryonic lethality, maternal sterility, sterile progeny, larval arrest and slow growth. We could functionally classify 267 (38%) sequences using the Gene Ontologies (GO) and establish pathway associations for 230 (33%) sequences using the Kyoto Encyclopedia of Genes and Genomes (KEGG). Further examination of this EST dataset revealed a number of signalling molecules, proteases, protease inhibitors, enzymes, ion channels and immune-related genes. In addition, we identified 40 putative secreted proteins that could represent potential candidates for developing novel anthelmintics or vaccines. We further compared the automated EST sequence annotations, using ESTExplorer, with database search results for individual <it>T. vitrinus </it>ESTs. ESTExplorer reliably and rapidly annotated 301 ESTs, with pathway and GO information, eliminating 60 low quality hits from database searches.</p> <p>Conclusion</p> <p>We evaluated the efficacy of ESTExplorer in analysing EST data, and demonstrate that computational tools can be used to accelerate the process of gene discovery in EST sequencing projects. The present study has elucidated sets of relatively conserved and potentially novel genes for biological investigation, and the annotated EST set provides further insight into the molecular biology of <it>T. vitrinus</it>, towards the identification of novel drug targets.</p
Laser surface colouring of titanium for contemporary jewellery
This paper describes work which emerged through a need to understand more about the potential of laser surface engineering for use in the creative industries. The method of creation of contemporary jewellery pieces and the resultant 'Ocular' jewellery series are described from the creative point of view. The work demonstrates how laser controlled oxide growth on Ti–6Al–4V alloy under ambient conditions can be used as an artistic tool by producing precisely defined colours. Use of the method to produce regular areas of even colour and to reproduce freehand drawings on a titanium alloy surface is described. Analysis highlights interference as the main colouring mechanism and suggests a graded surface layer, progressing from an outer layer of TiO2 to lower layers rich in TiO and Ti2O. The model of research by practice presented in this paper offers a contribution to the current debate on partnerships between art and science and engineering
Investigations on the creeks of Saurashtra
Gujarat has a rich estuarine system supported by run-off from five
major rivers, viz., Narmada, Mahi, Tapti, Banas and Sabarmati. The branches
of these rivers form several small creeks which act as outlets to the sea.
These creeks are known to have supported traditional fisheries for a variety
of shrimps and fishes over the years. However, these fisheries are now on
a declining phase. With reduced rainfall in recent years, these creeks remain
saline for a major part of the year. Natural flushing is further obstructed
by the numerous check dams and small impoundments constructed across
the rivers and rivulets flowing into these creeks
A transcriptomic analysis of the adult stage of the bovine lungworm, Dictyocaulus viviparus
<p>Abstract</p> <p>Background</p> <p>Lungworms of the genus <it>Dictyocaulus </it>(family Dictyocaulidae) are parasitic nematodes of major economic importance. They cause pathological effects and clinical disease in various ruminant hosts, particularly in young animals. <it>Dictyocaulus viviparus</it>, called the bovine lungworm, is a major pathogen of cattle, with severe infections being fatal. In this study, we provide first insights into the transcriptome of the adult stage of <it>D. viviparus </it>through the analysis of expressed sequence tags (ESTs).</p> <p>Results</p> <p>Using our EST analysis pipeline, we estimate that the present dataset of 4436 ESTs is derived from 2258 genes based on cluster and comparative genomic analyses of the ESTs. Of the 2258 representative ESTs, 1159 (51.3%) had homologues in the free-living nematode <it>C. elegans</it>, 1174 (51.9%) in parasitic nematodes, 827 (36.6%) in organisms other than nematodes, and 863 (38%) had no significant match to any sequence in the current databases. Of the <it>C. elegans </it>homologues, 569 had observed 'non-wildtype' RNAi phenotypes, including embryonic lethality, maternal sterility, sterility in progeny, larval arrest and slow growth. We could functionally classify 776 (35%) sequences using the Gene Ontologies (GO) and established pathway associations to 696 (31%) sequences in Kyoto Encyclopedia of Genes and Genomes (KEGG). In addition, we predicted 85 secreted proteins which could represent potential candidates for developing novel anthelmintics or vaccines.</p> <p>Conclusion</p> <p>The bioinformatic analyses of ESTs data for <it>D. viviparus </it>has elucidated sets of relatively conserved and potentially novel genes. The genes discovered in this study should assist research toward a better understanding of the basic molecular biology of <it>D. viviparus</it>, which could lead, in the longer term, to novel intervention strategies. The characterization of the <it>D. viviparus </it>transcriptome also provides a foundation for whole genome sequence analysis and future comparative transcriptomic analyses.</p
STAT3 Transcription Factor Promotes Instability of nTreg Cells and Limits Generation of iTreg Cells during Acute Murine Graft-versus-Host Disease
SummaryAcute graft-versus-host disease (GvHD) is a major cause of mortality in allogeneic bone marrow transplantation (BMT), for which administration of FoxP3+ regulatory T (Treg) cells has been proposed as a therapy. However, the phenotypic stability of Treg cells is controversial, and STAT3-dependent cytokines can inhibit FoxP3 expression. We assessed whether the elimination of STAT3 in T cells could limit the severity of GvHD. We found STAT3 limited FoxP3+ Treg cell numbers following allogeneic BMT by two pathways: instability of natural Treg (nTreg) cells and inhibition of induced Treg (iTreg) cell polarization from naive CD4+ T cells. Deletion of STAT3 within only the nTreg cell population was not sufficient to protect against lethal GvHD. In contrast, transfer of STAT3-deficient naive CD4+ T cells increased FoxP3+ Treg cells post-BMT and prevented lethality, suggesting that the consequence of STAT3 signaling may be greater for iTreg rather than nTreg cells during GvHD
Unusal landings of large-sized Sepia pharaonis from the coastal waters of Saurashtra
Fishing grounds for cuttlefishes are beyond 50m depth zone, off Dwaraka. This report is on unsual landings of Sepia pharaonis from the coastal waters off Saurashtra. The total landing of S. pharaonis was estimated to be around 20 tonnes. It is revealed that minor upwelling has been the reason for this unusual catch
FGF Signaling Regulates the Number of Posterior Taste Papillae by Controlling Progenitor Field Size
The sense of taste is fundamental to our ability to ingest nutritious substances and to detect and avoid potentially toxic ones. Sensory taste buds are housed in papillae that develop from epithelial placodes. Three distinct types of gustatory papillae reside on the rodent tongue: small fungiform papillae are found in the anterior tongue, whereas the posterior tongue contains the larger foliate papillae and a single midline circumvallate papilla (CVP). Despite the great variation in the number of CVPs in mammals, its importance in taste function, and its status as the largest of the taste papillae, very little is known about the development of this structure. Here, we report that a balance between Sprouty (Spry) genes and Fgf10, which respectively antagonize and activate receptor tyrosine kinase (RTK) signaling, regulates the number of CVPs. Deletion of Spry2 alone resulted in duplication of the CVP as a result of an increase in the size of the placode progenitor field, and Spry1−/−;Spry2−/− embryos had multiple CVPs, demonstrating the redundancy of Sprouty genes in regulating the progenitor field size. By contrast, deletion of Fgf10 led to absence of the CVP, identifying FGF10 as the first inductive, mesenchyme-derived factor for taste papillae. Our results provide the first demonstration of the role of epithelial-mesenchymal FGF signaling in taste papilla development, indicate that regulation of the progenitor field size by FGF signaling is a critical determinant of papilla number, and suggest that the great variation in CVP number among mammalian species may be linked to levels of signaling by the FGF pathway
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