42 research outputs found

    APPLICATION OF KALMAN FILTER TO ARTIFICIAL NEURAL NETWORKS PREDICTION FOR FOREIGN EXCHANGE RATES

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    In recent years, artificial neural networks have received increasing attention as a decision making tool when prediction of financial time series is concerned. Modeling issues associated with artificial neural network model like the size of sample data and the general architecture of the model affect the performance of the model. For this reason, artificial neural networks outputs are prone to over-fitting or under-learning resulting to large mean squared errors which affect the accuracy of the prediction. In this paper, we investigate if the application Kalman filter algorithm to artificial neural networks model output can improve the model accuracy through the reduction of the mean squared error. Performance measures for prediction accuracy were used to compare the two models over the datasets for dollar, Euro and Pound exchange rates in Kenya Shilling for a period of five years. In the entire cases artificial neural networks model performed better than artificial neural networks with Kalman filter model. Keywords: Artificial Neural Networks, Currency, Exchange Rates, Kalman Filter, Multi-Layer Perceptro

    Molecular Characterization of Human Enteroviruses Detected in Children Under Five Years Old in Kenya 2009 - 2015

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       Introduction:  Human enterovirus (HEVs) infection is common, with an extensive array of clinical displays ranging from asymptomatic to life-threatening. Presentation include nonspecific febrile illness often accompanied by muscle pain, sore throat, abdominal discomfort, rash, headache, encephalitis, aseptic meningitis and acute flaccid paralysis [2]. Objectives: The study objective was to investigate the natural selection and genetic variability of HEVs and to identify HEV serotypes in circulation among children below 5 years old with diarrhea in an informal settlement(Kibera) in Kenya. Methodology: Specimens (n=628) from a prospective cohort study assessing the incidence and etiology of diarrhea from 2009-2015 were analyzed. Enteric Taqman array cards (TAC) were used for initial screening where two hundred and nine (78%) tested positive for HEVs. Of these specimens, 72 (42%) had a cycle threshold (Ct) ≤30 and were tested by conventional PCR targeting the 3’ regions of the viral protein 1 (VP1) gene. A total of 48 (67%) underwent sequencing; 11 (23%) of which yielded nucleotide sequences. Phylogenetic analyses clustered the Kenyan serotypes to HEVs groups C, B and A. Evaluation of the VP1 amino acid sequences revealed numerous amino acid substitutions in relation to reference strains, which were confirmed to be due to natural selection by negative or positive selection. Conclusion: The Heterogeneous nature of stool samples is known to influence disparities in viral nucleic acid yields. TAC detected 209 of which 171 (82%) were confirmed positive for HEVs by real-time reverse transcription polymerase chain reaction (RRT-PCR), targeting the 5’ NTR regions. Therefore, the results may not be a representative of all circulating HEVs in the study area. Since this was a retrospective study of previously collected samples, it is possible that some HEVs strains may have failed to amplify

    Molecular characterization of fluoroquinolone resistance genes in isolates obtained from patients with diarrhea in Machakos District Hospital, Kenya

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    Background: Diarrhea caused by Enterobacteriaceae such as Shigella species and Escherichia coli (E. coli) is endemic throughout the world, and is one of the most important causes of global childhood mortality and morbidity. There is a range of antibiotics that can be used for treatment among them quinolones. However, there is emerging increase in microbial resistance to quinolones use, with E. coli and Shigellae among the species of bacteria commonly associated with quinolone resistance. Objective: To investigate the prevalence of quinolone resistance genes in Shigellae and E. coli from patients presenting with diarrhea in Machakos District Hospital. Methods: Bacteria isolates were identified to species level by biochemical methods and serology and thereafter tested for 12 different antibiotics including quinolones, cephalosporins and aminoglycosides. Those resistant to quinolones with a zone diameter of ≤20 mm were tested for the presence of quinolone resistance genes using PCR. The gyrA resistance genes were further analyzed by sequencing to determine mutations within the quinolone resistance regions. Results: There were different E. coli pathotypes and Shigellae spp.  They resisted more than four antibiotics: Ciprofloxacin (4%), (Chloramphenical (28%), Cotrimoxazole (78%), Co-amoxilav (70%) Erythromycin (98%) Cefotoxime (18%) and Tetracycline (56%). Mutations responsible for fluoroquinolone resistance in the gyrA, gyrB, parC, and parE genes of E. coli and Shigella spp were: gyrA (17/30, 36%) gyrB (7/30, 23.3%) topoisomerase (parC 3/30, 10%) parE (3/30, 10%). Discussion: There is an increase in fluoroquinolone resistance in Shigellae and E.coli which points to a major challenge in current treatment strategies. In addition, detection of high resistance found to commonly used antibiotics should serve as a warning call for close surveillance and understanding of the epidemiology of the resistance. Key words: Quinolone antibiotics, resistance, Shigella, Escherichia col

    E-learning for research capacity strengthening in sexual and reproductive health: the experience of the Geneva Foundation for Medical Education and Research and the Department of Reproductive Health and Research, World Health Organization

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    Abstract: Technological advancement has resulted in the increasing use of e-learning and online education, initially in high-income countries and increasingly in low- and middle-income countries. Background: In 2010, the Geneva Foundation for Medical Education and Research, in collaboration with the World Health Organization and partner institutions, developed an online postgraduate course “From Research to Practice: Training Course in Sexual and Reproductive Health Research”. This course takes advantage of the advancing Internet technology to provide training opportunities to health professionals mostly from low- and middle-income countries whose access to quality education is constrained by time, financial resources, or both. Case presentation: To assess the outcomes of the course, an evaluation was conducted by sending a self-administered questionnaire to graduates of the 2010–2012 programme. The objectives were to determine if the graduates had applied the knowledge gained from the course to their work and whether they had implemented their research project developed during the course. The evaluation also appraised the number of graduates who participated in the design or implementation of a new research project since the course concluded and whether the course had contributed to advancement in their careers. A total of 175 of 219 course graduates answered the questionnaire. The evaluation revealed that the majority of respondents (98%) had utilized the knowledge acquired, with nearly half of them (47%) having published a scientific paper as author or co-author. About a third of respondents (39%) had implemented their course research project and about three quarters of them (74%) have been involved in the design or implementation of a research project after completing the course. Over three quarters (81%) of respondents opined that the course had contributed to their career advancement and almost half of them (46%) had a career promotion as a direct or indirect benefit of the course. Conclusion: We surmise that the course positively impacted the participants’ knowledge and understanding of sexual and reproductive health, which they applied in their professional work, as well as strengthened their research capacity. Success factors for the e-learning programme include tailor-made content to meet participants’ needs, flexibility of access, and ongoing engagement/personal interactivity with course coaches

    Dengue and chikungunya virus infections among young febrile adults evaluated for acute HIV-1 infection in coastal Kenya

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    Background Fever is common among patients seeking care in sub-Saharan Africa (sSA), but causes other than malaria are rarely diagnosed. We assessed dengue and chikungunya virus infections among young febrile adults evaluated for acute HIV infection (AHI) and malaria in coastal Kenya. Methods We tested plasma samples obtained in a cross-sectional study from febrile adult patients aged 18±35 years evaluated for AHI and malaria at urgent care seeking at seven health facilities in coastal Kenya in 2014±2015. Dengue virus (DENV) and chikungunya virus (CHIKV) were amplified using quantitative real-time reverse-transcription polymerase chain reaction. We conducted logistic regression analyses to determine independent predictors of dengue virus infection. Results 489 samples that were negative for both AHI and malaria were tested, of which 43 (8.8%, 95% confidence interval [CI]: 6.4±11.7) were positive for DENV infection. No participant was positive for CHIKV infection. DENV infections were associated with clinic visits in the rainy season (adjusted odds ratio (AOR) = 3.0, 95% CI: 1.3±6.5) and evaluation at a private health facility (AOR 5.2, 95% CI: 2.0±13.1) or research health facility (AOR = 25.6, 95% CI: 8.9± 73.2) instead of a public health facility. Conclusion PA high prevalence of DENV infections was found in febrile young adult patients evaluated for AHI. Our data suggests that DENV, along with AHI and malaria, should be considered in the differential diagnosis of the adult patient seeking care for fever in coastal Kenya.</p
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