6 results on '"Shagari, Shehu"'
Search Results
2. Countermeasure to Structured Query Language Injection Attack for Web Applications using Hybrid Logistic Regression Technique.
- Author
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Shagari, Shehu Magawata, Gabi, Danlami, Dankolo, Nasiru Muhammad, and Gana, Noah Ndakotsu
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REPRISALS (International relations) , *WEB-based user interfaces , *LOGISTIC regression analysis , *SQL , *DATABASE management - Abstract
The new generation of security threats has been promoted by real-time applications, where several users develop new ways to communicate on the internet via web applications. Structured Query Language injection Attacks (SQLiAs) is one of the major threats to web application security. Here, unauthorised users usually gain access to the database via web applications. Despite the giant strides made in the detection and prevention of SQLiAs by several researchers, an ideal approach is still far from over as most existing techniques still require improvement, especially in the area of addressing the weak characterisation of input vectors which often leads to low prediction accuracy. To deal with this concern, this paper put forward a hybrid optimised Logistic Regression (LR) model with Improved Term Frequency Inverse Document-Frequency (ITFIDF-LR). To show the effectiveness of the proposed approach, attack datasets is used and evaluated using selected performance metrics, i.e., accuracy, recall, specificity and False Positive Rate. The experimental results via simulation when compared with the benchmarked techniques, achieved performance record of 0.99781 for accuracy, recall and F1-score as well as 0.99782, 0.99409 and 0.00591 for precision, specificity and False Positive Rate (FPR) respectively. This is an indication that the proposed approach is efficient and when deployed is capable of detecting SQLiA on web applications. [ABSTRACT FROM AUTHOR]
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- 2022
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3. The Impact of Hotspot-Targeted Interventions on Malaria Transmission in Rachuonyo South District in the Western Kenyan Highlands: A Cluster-Randomized Controlled Trial
- Author
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Bousema, Teun, Stresman, Gillian, Baidjoe, Amrish Y., Bradley, John, Knight, Philip, Stone, William, Osoti, Victor, Makori, Euniah, Owaga, Chrispin, Odongo, Wycliffe, China, Pauline, Shagari, Shehu, Doumbo, Ogobara K., Sauerwein, Robert W., Kariuki, Simon, Drakeley, Chris, Stevenson, Jennifer, and Cox, Jonathan
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Anopheles -- Health aspects -- Research ,Disease transmission -- Research ,Malaria -- Risk factors -- Research ,Biological sciences - Abstract
Background Malaria transmission is highly heterogeneous, generating malaria hotspots that can fuel malaria transmission across a wider area. Targeting hotspots may represent an efficacious strategy for reducing malaria transmission. We determined the impact of interventions targeted to serologically defined malaria hotspots on malaria transmission both inside hotspots and in surrounding communities. Methods and Findings Twenty-seven serologically defined malaria hotspots were detected in a survey conducted from 24 June to 31 July 2011 that included 17,503 individuals from 3,213 compounds in a 100-km.sup.2 area in Rachuonyo South District, Kenya. In a cluster-randomized trial from 22 March to 15 April 2012, we randomly allocated five clusters to hotspot-targeted interventions with larviciding, distribution of long-lasting insecticide-treated nets, indoor residual spraying, and focal mass drug administration (2,082 individuals in 432 compounds); five control clusters received malaria control following Kenyan national policy (2,468 individuals in 512 compounds). Our primary outcome measure was parasite prevalence in evaluation zones up to 500 m outside hotspots, determined by nested PCR (nPCR) at baseline and 8 wk (16 June-6 July 2012) and 16 wk (21 August-10 September 2012) post-intervention by technicians blinded to the intervention arm. Secondary outcome measures were parasite prevalence inside hotpots, parasite prevalence in the evaluation zone as a function of distance from the hotspot boundary, Anopheles mosquito density, mosquito breeding site productivity, malaria incidence by passive case detection, and the safety and acceptability of the interventions. Intervention coverage exceeded 87% for all interventions. Hotspot-targeted interventions did not result in a change in nPCR parasite prevalence outside hotspot boundaries (p [greater than or equal to] 0.187). We observed an average reduction in nPCR parasite prevalence of 10.2% (95% CI -1.3 to 21.7%) inside hotspots 8 wk post-intervention that was statistically significant after adjustment for covariates (p = 0.024), but not 16 wk post-intervention (p = 0.265). We observed no statistically significant trend in the effect of the intervention on nPCR parasite prevalence in the evaluation zone in relation to distance from the hotspot boundary 8 wk (p = 0.27) or 16 wk post-intervention (p = 0.75). Thirty-six patients with clinical malaria confirmed by rapid diagnostic test could be located to intervention or control clusters, with no apparent difference between the study arms. In intervention clusters we caught an average of 1.14 female anophelines inside hotspots and 0.47 in evaluation zones; in control clusters we caught an average of 0.90 female anophelines inside hotspots and 0.50 in evaluation zones, with no apparent difference between study arms. Our trial was not powered to detect subtle effects of hotspot-targeted interventions nor designed to detect effects of interventions over multiple transmission seasons. Conclusions Despite high coverage, the impact of interventions targeting malaria vectors and human infections on nPCR parasite prevalence was modest, transient, and restricted to the targeted hotspot areas. Our findings suggest that transmission may not primarily occur from hotspots to the surrounding areas and that areas with highly heterogeneous but widespread malaria transmission may currently benefit most from an untargeted community-wide approach. Hotspot-targeted approaches may have more validity in settings where human settlement is more nuclear. Trial registration ClinicalTrials.gov NCT01575613, Author(s): Teun Bousema 1,2,*, Gillian Stresman 2, Amrish Y. Baidjoe 1, John Bradley 3, Philip Knight 4, William Stone 1, Victor Osoti 5, Euniah Makori 5, Chrispin Owaga 5, Wycliffe [...]
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- 2016
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4. Factors associated with high heterogeneity of malaria at fine spatial scale in the Western Kenyan highlands.
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Baidjoe, Amrish Y., Stevenson, Jennifer, Knight, Philip, Stone, William, Stresman, Gillian, Osoti, Victor, Makori, Euniah, Owaga, Chrispin, Odongo, Wycliffe, China, Pauline, Shagari, Shehu, Kariuki, Simon, Drakeley, Chris, Cox, Jonathan, and Bousema, Teun
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MALARIA transmission ,AGE groups ,INFECTIOUS disease transmission ,PARASITES ,IMMUNOGLOBULINS ,REMOTE-sensing images ,DISEASE prevalence - Abstract
Background: The East African highlands are fringe regions between stable and unstable malaria transmission. What factors contribute to the heterogeneity of malaria exposure on different spatial scales within larger foci has not been extensively studied. In a comprehensive, community-based cross-sectional survey an attempt was made to identify factors that drive the macro- and micro epidemiology of malaria in a fringe region using parasitological and serological outcomes. Methods: A large cross-sectional survey including 17,503 individuals was conducted across all age groups in a 100 km
2 area in the Western Kenyan highlands of Rachuonyo South district. Households were geo-located and prevalence of malaria parasites and malaria-specific antibodies were determined by PCR and ELISA. Household and individual risk-factors were recorded. Geographical characteristics of the study area were digitally derived using high-resolution satellite images. Results: Malaria antibody prevalence strongly related to altitude (1350-1600 m, p < 0.001). A strong negative association with increasing altitude and PCR parasite prevalence was found. Parasite carriage was detected at all altitudes and in all age groups; 93.2 % (2481/2663) of malaria infections were apparently asymptomatic. Malaria parasite prevalence was associated with age, bed net use, house construction features, altitude and topographical wetness index. Antibody prevalence was associated with all these factors and distance to the nearest water body. Conclusion: Altitude was a major driver of malaria transmission in this study area, even across narrow altitude bands. The large proportion of asymptomatic parasite carriers at all altitudes and the age-dependent acquisition of malaria antibodies indicate stable malaria transmission; the strong correlation between current parasite carriage and serological markers of malaria exposure indicate temporal stability of spatially heterogeneous transmission. [ABSTRACT FROM AUTHOR]- Published
- 2016
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5. Combined DNA extraction and antibody elution from filter papers for the assessment of malaria transmission intensity in epidemiological studies.
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Baidjoe, Amrish, Stone, Will, Ploemen, Ivo, Shagari, Shehu, Grignard, Lynn, Osoti, Victor, Makori, Euniah, Stevenson, Jennifer, Kariuki, Simon, Sutherland, Colin, Sauerwein, Robert, Cox, Jonathan, Drakeley, Chris, and Bousema, Teun
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MALARIA transmission ,DNA ,IMMUNOGLOBULINS ,PLASMODIUM ,POLYMERASE chain reaction ,ENZYME-linked immunosorbent assay - Abstract
Background: Informing and evaluating malaria control efforts relies on knowledge of local transmission dynamics. Serological and molecular tools have demonstrated great sensitivity to quantify transmission intensity in low endemic settings where the sensitivity of traditional methods is limited. Filter paper blood spots are commonly used a source of both DNA and antibodies. To enhance the operational practicability of malaria surveys, a method is presented for combined DNA extraction and antibody elution. Methods: Filter paper blood spots were collected as part of a large cross-sectional survey in the Kenyan highlands. DNA was extracted using a saponin/chelex method. The eluate of the first wash during the DNA extraction process was used for antibody detection and compared with previously validated antibody elution procedures. Antibody elution efficiency was assessed by total IgG ELISA for malaria antigens apical membrane antigen-1 (AMA-1) and merozoite-surface protein-1 (MSP-1
42 ). The sensitivity of nested 18S rRNA and cytochrome b PCR assays and the impact of doubling filter paper material for PCR sensitivity were determined. The distribution of cell material and antibodies throughout filter paper blood spots were examined using luminescent and fluorescent reporter assays. Results: Antibody levels measured after the combined antibody/DNA extraction technique were strongly correlated to those measured after standard antibody elution (p < 0.0001). Antibody levels for both AMA-1 and MSP-142 were generally slightly lower (11.3-21.4%) but age-seroprevalence patterns were indistinguishable. The proportion of parasite positive samples ranged from 12.9% to 19.2% in the different PCR assays. Despite strong agreement between outcomes of different PCR assays, none of the assays detected all parasite-positive individuals. For all assays doubling filter paper material for DNA extraction increased sensitivity. The concentration of cell and antibody material was not homogenously distributed throughout blood spots. Conclusion: Combined DNA extraction and antibody elution is an operationally attractive approach for high throughput assessment of cumulative malaria exposure and current infection prevalence in endemic settings. Estimates of antibody prevalence are unaffected by the combined extraction and elution procedure. The choice of target gene and the amount and source of filter paper material for DNA extraction can have a marked impact on PCR sensitivity. [ABSTRACT FROM AUTHOR]- Published
- 2013
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6. Impact of metric and sample size on determining malaria hotspot boundaries.
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Stresman, Gillian H., Giorgi, Emanuele, Baidjoe, Amrish, Knight, Phil, Odongo, Wycliffe, Owaga, Chrispin, Shagari, Shehu, Makori, Euniah, Stevenson, Jennifer, Drakeley, Chris, Cox, Jonathan, Bousema, Teun, and Diggle, Peter J.
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The spatial heterogeneity of malaria suggests that interventions may be targeted for maximum impact. It is unclear to what extent different metrics lead to consistent delineation of hotspot boundaries. Using data from a large community-based malaria survey in the western Kenyan highlands, we assessed the agreement between a model-based geostatistical (MBG) approach to detect hotspots using Plasmodium falciparum parasite prevalence and serological evidence for exposure. Malaria transmission was widespread and highly heterogeneous with one third of the total population living in hotspots regardless of metric tested. Moderate agreement (Kappa = 0.424) was observed between hotspots defined based on parasite prevalence by polymerase chain reaction (PCR)- and the prevalence of antibodies to two P. falciparum antigens (MSP-1, AMA-1). While numerous biologically plausible hotspots were identified, their detection strongly relied on the proportion of the population sampled. When only 3% of the population was sampled, no PCR derived hotspots were reliably detected and at least 21% of the population was needed for reliable results. Similar results were observed for hotspots of seroprevalence. Hotspot boundaries are driven by the malaria diagnostic and sample size used to inform the model. These findings warn against the simplistic use of spatial analysis on available data to target malaria interventions in areas where hotspot boundaries are uncertain. [ABSTRACT FROM AUTHOR]
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- 2017
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- View/download PDF
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