32 research outputs found

    Examining the Physio, Psycho and Socio-Economic Implications of Non- Residential Policy on Imo State University Students

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    The Imo State University (IMSU), is running a nonresidential policy despite her growing student population. Although her policy has led to tremendous development of Ugwuorji layout and other close neighbourhoods, its implications on students have been neglected by the institution. This paper examines the effects of this policy on the student performances. The result upheld the alternative hypothesis that off-campus system has effect on the student’s success. The paper observed that all the students live off-campus, in mostly purpose-built and modified hostels, owned by individuals. They pay very high rents and struggle for accommodation with other home-seekers. They also lack regular and direct access to water supply and electricity in their accommodation to support their studies. Security in these off-campus accommodation were observed to be porous. There were other challenges as indicated by these students. These findings have negative physiological, psychological, and socio-economic implications on the performance of the students. It concluded that the students cannot attain optimal academic performance, living under the observed conditions. The paper therefore advocates for assistance from the Imo State government to facilitate the development of high-rise hostels within the campus, provision of necessary infrastructure and adequate security personnel to support improved academic performance.Key words: Imo State University (IMSU); Accommodation; Nigerian university students; Nigeria; Imo State governmentRésumé L’Université de l’Etat d’Imo (IMSU), est en cours d'exécution d’une politique non-résidentielle en dépit de sa population étudiante croissante. Bien que sa politique a conduit au développement considérable de mise en page Ugwuorji et d’autres quartiers proches, ses implications sur les élèves ont été négligés par l’institution. Ce document examine les effets de cette politique sur les performances des élèves à l’art. Le résultat a confirmé l’hypothèse alternative que hors campus système a un effet sur la réussite de l’élève. Le document fait remarquer que tous les étudiants vivent hors campus, dans la plupart des auberges de but-construits ou modifiés, appartenant à des particuliers. Ils paient des loyers très élevés et de la lutte pour le logement avec d’autres maisons d’asile. Ils manquent également d’un accès régulier et direct à l’approvisionnement en eau et d’électricité dans leur logement pour financer leurs études. Sécurité dans les hébergements hors campus ont été observés à être poreux. Il y avait d’autres défi s, comme indiqué par ces étudiants. Ces constatations ont des répercussions négatives sur physiologiques, psychologiques et socio-économique sur la performance des élèves. Il a conclu que les étudiants ne peuvent pas atteindre des performances optimales scolaire, de logement dans les conditions observées. Le document préconise donc à l’aide du gouvernement l’État d'Imo à faciliter le développement des gratte-ciel auberges au sein du campus, la fourniture de l'infrastructure nécessaire et le personnel de sécurité adéquates pour soutenir un meilleur rendement scolaire.Mots clés: Université de l’État d’Imo; accomodation; Étudiants Nigériens; Nigeria; Gouvernement de l’État d’Im

    Effects of deposition time and post-deposition annealing on the physical and chemical properties of electrodeposited CdS thin films for solar cell application

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    CdS thin films were cathodically electrodeposited by means of a two-electrode deposition system for different durations. The films were characterised for their structural, optical, morphological and compositional properties using x-ray diffraction (XRD), spectrophotometry, scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) respectively. The results obtained show that the physical and chemical properties of these films are significantly influenced by the deposition time and post-deposition annealing. This influence manifests more in the as-deposited materials than in the annealed ones. XRD results show that the crystallite sizes of the different films are in the range (9.4 – 65.8) nm and (16.4 – 66.0) nm in the as-deposited and annealed forms respectively. Optical measurements show that the absorption coefficients are in the range (2.7×104 – 6.7×104) cm-1 and (4.3×104 – 7.2×104) cm-1 respectively for as-deposited and annealed films. The refractive index is in the range (2.40 – 2.60) for as-deposited films and come to the value of 2.37 after annealing. The extinction coefficient varies in the range (0.1 – 0.3) in asdeposited films and becomes 0.1 in annealed films. The estimated energy bandgap of the films is in the range (2.48 – 2.50) eV for as-deposited films and becomes 2.42 eV for all annealed films. EDX results show that all the films are S-rich in chemical composition with fairly uniform Cd/S ratio after annealing. The results show that annealing improves the qualities of the films and deposition time can be used to control the film thickness. Keywords: Electrodeposition; two-electrode system; CdS; annealing; deposition time; thin-film

    Apobec 3G Efficiently Reduces Infectivity of the Human Exogenous Gammaretrovirus XMRV

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    The human exogenous gammaretrovirus XMRV is thought to be implicated in prostate cancer and chronic fatigue syndrome. Besides pressing epidemiologic questions, the elucidation of the tissue and cell tropism of the virus, as well as its sensitivity to retroviral restriction factors is of fundamental importance. The Apobec3 (A3) proteins, a family of cytidine deaminases, are one important group of host proteins that control primary infection and efficient viral spread.Here we demonstrate that XMRV is resistant to human Apobec 3B, 3C and 3F, while being highly susceptible to the human A3G protein, a factor which is known to confer antiviral activity against most retroviruses. We show that XMRV as well as MoMLV virions package Apobec proteins independent of their specific restriction activity. hA3G was found to be a potent inhibitor of XMRV as well as of MoMLV infectivity. In contrast to MoMLV, XMRV infection can also be partially reduced by low concentrations of mA3. Interestingly, established prostate cancer cell lines, which are highly susceptible to XMRV infection, do not or only weakly express hA3G.Our findings confirm and extend recently published data that show restriction of XMRV infection by hA3G. The results will be of value to explore which cells are infected with XMRV and efficiently support viral spread in vivo. Furthermore, the observation that XMRV infection can be reduced by mA3 is of interest with regard to the current natural reservoir of XMRV infection

    A connectome of the adult drosophila central brain

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    The neural circuits responsible for behavior remain largely unknown. Previous efforts have reconstructed the complete circuits of small animals, with hundreds of neurons, and selected circuits for larger animals. Here we (the FlyEM project at Janelia and collaborators at Google) summarize new methods and present the complete circuitry of a large fraction of the brain of a much more complex animal, the fruit fly Drosophila melanogaster. Improved methods include new procedures to prepare, image, align, segment, find synapses, and proofread such large data sets; new methods that define cell types based on connectivity in addition to morphology; and new methods to simplify access to a large and evolving data set. From the resulting data we derive a better definition of computational compartments and their connections; an exhaustive atlas of cell examples and types, many of them novel; detailed circuits for most of the central brain; and exploration of the statistics and structure of different brain compartments, and the brain as a whole. We make the data public, with a web site and resources specifically designed to make it easy to explore, for all levels of expertise from the expert to the merely curious. The public availability of these data, and the simplified means to access it, dramatically reduces the effort needed to answer typical circuit questions, such as the identity of upstream and downstream neural partners, the circuitry of brain regions, and to link the neurons defined by our analysis with genetic reagents that can be used to study their functions. Note: In the next few weeks, we will release a series of papers with more involved discussions. One paper will detail the hemibrain reconstruction with more extensive analysis and interpretation made possible by this dense connectome. Another paper will explore the central complex, a brain region involved in navigation, motor control, and sleep. A final paper will present insights from the mushroom body, a center of multimodal associative learning in the fly brain

    A connectome and analysis of the adult Drosophila central brain

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    The neural circuits responsible for animal behavior remain largely unknown. We summarize new methods and present the circuitry of a large fraction of the brain of the fruit fly Drosophila melanogaster. Improved methods include new procedures to prepare, image, align, segment, find synapses in, and proofread such large data sets. We define cell types, refine computational compartments, and provide an exhaustive atlas of cell examples and types, many of them novel. We provide detailed circuits consisting of neurons and their chemical synapses for most of the central brain. We make the data public and simplify access, reducing the effort needed to answer circuit questions, and provide procedures linking the neurons defined by our analysis with genetic reagents. Biologically, we examine distributions of connection strengths, neural motifs on different scales, electrical consequences of compartmentalization, and evidence that maximizing packing density is an important criterion in the evolution of the fly’s brain

    Deaminase-Independent Inhibition of Parvoviruses by the APOBEC3A Cytidine Deaminase

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    The APOBEC3 proteins form a multigene family of cytidine deaminases with inhibitory activity against viruses and retrotransposons. In contrast to APOBEC3G (A3G), APOBEC3A (A3A) has no effect on lentiviruses but dramatically inhibits replication of the parvovirus adeno-associated virus (AAV). To study the contribution of deaminase activity to the antiviral activity of A3A, we performed a comprehensive mutational analysis of A3A. By mutation of non-conserved residues, we found that regions outside of the catalytic active site contribute to both deaminase and antiviral activities. Using A3A point mutants and A3A/A3G chimeras, we show that deaminase activity is not required for inhibition of recombinant AAV production. We also found that deaminase-deficient A3A mutants block replication of both wild-type AAV and the autonomous parvovirus minute virus of mice (MVM). In addition, we identify specific residues of A3A that confer activity against AAV when substituted into A3G. In summary, our results demonstrate that deaminase activity is not necessary for the antiviral activity of A3A against parvoviruses

    A connectome and analysis of the adult Drosophila central brain

    Get PDF
    The neural circuits responsible for animal behavior remain largely unknown. We summarize new methods and present the circuitry of a large fraction of the brain of the fruit fly Drosophila melanogaster. Improved methods include new procedures to prepare, image, align, segment, find synapses in, and proofread such large data sets. We define cell types, refine computational compartments, and provide an exhaustive atlas of cell examples and types, many of them novel. We provide detailed circuits consisting of neurons and their chemical synapses for most of the central brain. We make the data public and simplify access, reducing the effort needed to answer circuit questions, and provide procedures linking the neurons defined by our analysis with genetic reagents. Biologically, we examine distributions of connection strengths, neural motifs on different scales, electrical consequences of compartmentalization, and evidence that maximizing packing density is an important criterion in the evolution of the fly's brain

    Host restriction factors in retroviral infection: promises in virus-host interaction

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    Exosomes: Implications in HIV-1 Pathogenesis

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    Exosomes are membranous nanovesicles of endocytic origin that carry host and pathogen derived genomic, proteomic, and lipid cargos. Exosomes are secreted by most cell types into the extracellular milieu and are subsequently internalized by recipient cells. Upon internalization, exosomes condition recipient cells by donating their cargos and/or activating various signal transduction pathways, consequently regulating physiological and pathophysiological processes. The role of exosomes in viral pathogenesis, especially human immunodeficiency virus type 1 [HIV-1] is beginning to unravel. Recent research reports suggest that exosomes from various sources play important but different roles in the pathogenesis of HIV-1. From these reports, it appears that the source of exosomes is the defining factor for the exosomal effect on HIV-1. In this review, we will describe how HIV-1 infection is modulated by exosomes and in turn how exosomes are targeted by HIV-1 factors. Finally, we will discuss potentially emerging therapeutic options based on exosomal cargos that may have promise in preventing HIV-1 transmission
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