14 research outputs found

    Virtual learning process environment (VLPE): a BPM-based learning process management architecture

    Get PDF
    E-learning systems have significantly impacted the way that learning takes place within universities, particularly in providing self-learning support and flexibility of course delivery. Virtual Learning Environments help facilitate the management of educational courses for students, in particular by assisting course designers and thriving in the management of the learning itself. Current literature has shown that pedagogical modelling and learning process management facilitation are inadequate. In particular, quantitative information on the process of learning that is needed to perform real time or reflective monitoring and statistical analysis of students’ learning processes performance is deficient. Therefore, for a course designer, pedagogical evaluation and reform decisions can be difficult. This thesis presents an alternative e-learning systems architecture - Virtual Learning Process Environment (VLPE) - that uses the Business Process Management (BPM) conceptual framework to design an architecture that addresses the critical quantitative learning process information gaps associated with the conventional VLE frameworks. Within VLPE, course designers can model desired education pedagogies in the form of learning process workflows using an intuitive graphical flow diagram user-interface. Automated agents associated with BPM frameworks are employed to capture quantitative learning information from the learning process workflow. Consequently, course designers are able to monitor, analyse and re-evaluate in real time the effectiveness of their chosen pedagogy using live interactive learning process dashboards. Once a course delivery is complete the collated quantitative information can also be used to make major revisions to pedagogy design for the next iteration of the course. An additional contribution of this work is that this new architecture facilitates individual students in monitoring and analysing their own learning performances in comparison to their peers in a real time anonymous manner through a personal analytics learning process dashboard. A case scenario of the quantitative statistical analysis of a cohort of learners (10 participants in size) is presented. The analytical results of their learning processes, performances and progressions on a short Mathematics course over a five-week period are also presented in order to demonstrate that the proposed framework can significantly help to advance learning analytics and the visualisation of real time learning data

    Kinetics and thermodynamic studies of adsorption of malachite green onto unmodified and EDTA-modified groundnut husk

    Get PDF
    A batch experiment was applied to study the adsorption of malachite green from aqueous solution by unmodified and ethylene diamine tetraacetic acid (EDTA)-modified groundnut husk. The effect of initial dye concentration, temperature, contact time and pH on the sorption process was investigated. The Langmuir and Freundlich adsorption isotherms were applied to test the experimental data. The chemically modified groundnut husk agreed well with both the Langmuir and Freundlich models at the temperature below the room temperature (25°C) and above the room temperature. Unmodified groundnut husk showed poor agreement with the isotherm at temperature below the room temperature but fits well into the model at higher temperature. Kinetics of the adsorption with respect to the initial dye concentration and temperature was also investigated. The pseudo-first-order, pseudo-second-order and intraparticle diffusion models were used to test the kinetic data. Obtained data were fitted properly in the pseudo-second-order kinetic model. The thermodynamic parameters such as change in free energy (∆G°), enthalpy (∆H°) and entropy (∆S°) were also determined and the results obtained confirmed that the sorption process is feasible, spontaneous, and endothermic

    Immune thrombocytopaenic purpura in pregnancy: a case of near miss mortality in a Nigerian

    Get PDF
    Thrombocytopenia occurs in pregnancy like in the non-pregnant state and can be due to immune thrombocytopaenic purpura (ITP). The hyperoestrogenic state of pregnancy has been identified as a precipitating factor. This is a case report of a thirty year old Nigerian lady, who at a gestational age of 26 weeks developed ITP as a near miss mortality. Although, most literatures reported that the perinatal outcome is usually favourable in this condition, we report a case managed in our facility that had intrauterine death and non- remission until delivery; despite corticosteroid therapy and transfusion of eleven (11) units of blood. This report is relevant in a developing world where a rare condition almost caused a maternal death in spite of the high maternal mortality rates from other conditions. Baseline full blood count is advocated at booking to identify and monitor rare haematological disorders like this in pregnancy. (Immune thrombocytopaenic purpura, Nigeria, perinatal mortality, pregnancy)Trop J Obstet Gynaecol, 30 (1), April 201

    Farmer behavior and new agricultural technologies in the rainfed agriculture of southern Niger: A stochastic programming analysis

    No full text
    Agricultural production in Southern Niger is precarious and occurs in a fragile environment characterized by enormous rainfall variability, poor soil fertility, and large price and yield risks. Farmers have developed strategies of coping with the risks of crop production in this risky environment. Farmers make decisions sequentially throughout the season in order to adapt to stochastic events. An understanding of how farmer behavior affects choice of agricultural technologies is important for technology development programs. The specific objectives of this study are to evaluate sequential decision making of smallholder farmers in southern Niger and to determine how this affects adoption of agricultural technologies. The study determined: (a) the farm-level impacts of new agricultural technologies under five alternative rainfall scenarios. The technologies evaluated are early maturing cultivars, and improved cultivars at higher planting density and moderate levels of chemical fertilization: (b) the returns to labor under alternative technologies and weather patterns; (c) the impacts of a cereal price floor in good rainfall years when farmers have more cereal to sell. A discrete stochastic programming model was used to incorporate risk and to capture farmers\u27 sequential decisions. The empirical model was validated against observed farmer behavior. The results showed that (a) farmers adopted early maturing cultivars in low rainfall years but used late season cultivars in higher rainfall years. But carrying a portfolio of cultivars, farmers were able to respond to ensuing stochastic weather patterns. (b) Adoption of the technologies increased household nutritional positions, expected total farm incomes, and returns to labor. Total income estimates show that with adoption of agricultural technologies farmers can make between 42 and 57 percent higher than the rural wage rate. Moreover, in absolute terms, agricultural incomes are low even with agricultural technologies. (c) The adoption of early maturing varieties reduced the variability of incomes received by farmers. (d) A cereal price floor of 50 CFA/kg. has no effect on choice of agricultural technologies. Rather, it increases expected total returns to agriculture. (e) The initial liquidity position of the farmer influences adoption of agricultural technologies

    Detection of Lassa Virus-Reactive IgG Antibodies in Wild Rodents: Validation of a Capture Enzyme-Linked Immunological Assay

    No full text
    The aim of this study was to evaluate the use of a capture enzyme-linked immunosorbent assay (ELISA) for the detection of LASV-reactive IgG antibodies in Mastomys rodents. The assay was used for laboratory-bred Mastomys rodents, as well as for animals caught in the wild in various regions of West Africa. The ELISA reached an accuracy of 97.1% in samples of known exposure, and a comparison to an immunofluorescence assay (IFA) revealed a very strong agreement between the ELISA and IFA results (Cohen’s kappa of 0.81). The agreement is valid in Nigeria, and in Guinea and Sierra Leone where the lineages II and IV are circulating, respectively. Altogether, these results indicate that this capture ELISA is suitable for LASV IgG serostatus determination in Mastomys rodents as an alternative to IFA. This assay will be a strong, accurate, and semi-quantitative alternative for rodent seroprevalence studies that does not depend on biosafety level 4 infrastructures, providing great benefits for ecology and epidemiology studies of Lassa fever, a disease listed on the Research and Development Blueprint of the WHO

    Circulation of Lassa virus across the endemic Edo-Ondo axis, Nigeria, with cross-species transmission between multimammate mice

    Get PDF
    ABSTRACTWe phylogenetically compared sequences of the zoonotic Lassa virus (LASV) obtained from Mastomys rodents in seven localities across the highly endemic Edo and Ondo States within Nigeria. Sequencing 1641 nt from the S segment of the virus genome, we resolved clades within lineage II that were either limited to Ebudin and Okhuesan in Edo state (2g-beta) or along Owo-Okeluse-Ifon in Ondo state (2g-gamma). We also found clades within Ekpoma, a relatively large cosmopolitan town in Edo state, that extended into other localities within Edo (2g-alpha) and Ondo (2g-delta). LASV variants from M. natalensis within Ebudin and Ekpoma in Edo State (dated approximately 1961) were more ancient compared to those from Ondo state (approximately 1977), suggesting a broadly east-west virus migration across south-western Nigeria; a pattern not always consistent with LASV sequences derived from humans in the same localities. Additionally, in Ebudin and Ekpoma, LASV sequences between M. natalensis and M. erythroleucus were interspersed on the phylogenetic tree, but those from M. erythroleucus were estimated to emerge more recently (approximately 2005). Overall, our results show that LASV amplification in certain localities (reaching a prevalence as high as 76% in Okeluse), anthropogenically-aided spread of rodent-borne variants amidst the larger towns (involving communal accommodation such as student hostels), and virus-exchange between syntopic M. natalensis and M. erythroleucus rodents (as the latter, a savanna species, encroaches southward into the degraded forest) pose perpetual zoonotic hazard across the Edo-Ondo Lassa fever belt, threatening to accelerate the dissemination of the virus into non endemic areas

    Molecular taxonomy of **Crocidura** species (Eulipotyphla: Soricidae) in a key biogeographical region for African shrews, Nigeria

    No full text
    International audienceThe taxonomy of African shrew species is still unresolved due to their conserved morphology. This also affects knowledge concerning their geographic distribution. In Nigeria, using mitochondrial Cytochrome b gene sequences, we carried out a survey for shrews from the genus Crocidura across various ecological zones to determine taxa that are present and also to assess their phylogeographic structure. Our analyses include 183 specimens collected with Sherman traps from 19 localities around the country. We detected six taxa: Crocidura olivieri lineages II, III and IV, C. hildegardeae, C. jouvenetae, and C. foxi. Among these, C. hildegardeae and C. jouvenetae are reported in Nigeria for the first time. Phylogenetic comparison of our genetic sequences to those generated from other parts of Africa demonstrate that all species in our study, as currently defined, are in need of taxonomic revision. Geographically, Nigeria seems to represent the easternmost boundary for C. olivieri lineage II and C. jouvenetae, and the western distribution limit of C. olivieri lineage IV and C. hildegardeae. The Niger River appears to be the most significant topographical barrier restricting these taxa. This information is vital to preserving the diversity but also managing the epidemiological potential of these small mammals

    Widespread arenavirus occurrence and seroprevalence in small mammals, Nigeria

    No full text
    Abstract Background Lassa fever, killing thousands of people annually, is the most reported viral zoonotic disease in Nigeria. Recently, different rodent species carrying diverse lineages of the Lassa virus (LASV) in addition to a novel Mobala-like genetic sequence were detected within the country. Here, screening 906 small mammal specimens from 11 localities for IgG antibodies and incorporating previous PCR detection data involving the same populations, we further describe arenavirus prevalence across Nigeria in relation to host species and geographical location. Methods Small mammals were trapped during the period 2011–2015 according to geographical location (endemic and non-endemic zones for Lassa fever), season (rainy and dry seasons between 2011 and 2012 for certain localities) and habitat (indoors, peridomestic settings and sylvatic vegetation). Identification of animal specimens from genera such as Mastomys and Mus (Nannomys) was assisted by DNA sequencing. Small mammals were tested for LASV IgG antibody using an indirect immunofluorescence assay (IFA). Results Small mammals were infected in both the endemic and non-endemic zones for Lassa fever, with a wider range of species IgG-positive (n = 8) than those which had been previously detected to be PCR-positive (n = 3). IgG-positive species, according to number of infected individuals, were Mastomys natalensis (n = 40), Mastomys erythroleucus (n = 15), Praomys daltoni (n = 6), Mus baoulei (n = 5), Rattus rattus (n = 2), Crocidura spp. (n = 2), Mus minutoides (n = 1) and Praomys misonnei (n = 1). Multimammate mice (Mastomys natalensis and M. erythroleucus) were the most ubiquitously infected, with animals testing positive by either PCR or IgG in 7 out of the 11 localities sampled. IgG prevalence in M. natalensis ranged from 1% in Abagboro, 17–36 % in Eguare Egoro, Ekpoma and Ngel Nyaki, up to 52 % in Mayo Ranewo. Prevalence according to locality, season and age was not, however, statistically significant for M. natalensis in Eguare Egoro and Ekpoma, localities that were sampled longitudinally. Conclusions Overall, our study demonstrates that arenavirus occurrence is probably more widely distributed geographically and in extent of host taxa than is currently realized. This expanded scope should be taken into consideration in Lassa fever control efforts. Further sampling should also be carried out to isolate and characterize potential arenaviruses present in small mammal populations we found to be seropositive
    corecore