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Masinde N.W.,Jaramogi Oginga Odinga University of Science and Technology | Fatima S.S.,Osmania University
Proceedings of the 2nd Pan African International Conference on Science, Computing and Telecommunications, PACT 2014 | Year: 2014

The use of recommender systems have become the de-facto standard in e-commerce systems. The most popular recommendation techniques are the collaborative filtering techniques. Their open nature of collaborative recommender systems however allow attackers who inject biased profile data to have an impact on the recommendations produced. The standard memory-based collaborative filtering algorithms, such as k-nearest neighbor, have been shown to be quite vulnerable to such attacks. In this paper, we examine the robustness of model-based recommendation algorithms in the face of profile injection attacks. Specifically, two recommendation algorithms under the Slope One class of algorithms, namely, Weighted Slope One and Improved Slope One, are considered. Additionally, we propose a modified Slope One based algorithm which we call the Robust Weighted Slope One (RWSO) algorithm. Empirically, we show that the Robust Weighted Slope One performs better under profile injection attacks. We also show that the Improved Slope One performs poorly under pre-attack conditions contrary to expectations. © 2014 IEEE. Source

Ayalew M.,African Climate Policy Center | Chenoweth J.,University of Surrey | Malcolm R.,University of Surrey | Mulugetta Y.,University of Surrey | And 2 more authors.
Journal of Environmental Law | Year: 2014

The Millennium Development Goals (MDGs) included a target to halve the proportion of people without sustainable access to safe drinking water by 2015-a right recognised as fundamental to human needs. Small independent water vendors are often the only water supply option in peri-urban neighbourhoods in developing countries and fill a critical gap in the municipal system, but there is concern about the quality and price of their water. Such vendors need to be recognised and regulated due to their role in meeting basic water needs. This article reflects on the lack of regulation and discusses a recent multidisciplinary research project in Kenya and Ethiopia that considered whether there is a case for regulation of competition, price and quality. It concludes that recognising small independent water vendors as part of a regulatory framework will result in increased access to water for the poor and assist in the realisation of the MDGs, the right to water and intergenerational equity. © The Author 2013. Published by Oxford University Press.All rights reserved. Source

Oyugi D.O.,Jaramogi Oginga Odinga University of Science and Technology | Mavuti K.M.,University of Nairobi | Aloo P.A.,Karatina University | Ojuok J.E.,Kenya Marine and Fisheries Research Institute | Britton J.R.,Bournemouth University
Hydrobiologia | Year: 2014

Habitat suitability indices indicate how fish species respond to different habitat types. We assessed effects of habitat characteristics on fish distribution in an equatorial lake, Lake Naivasha, Kenya, where habitats vary according to substrate, depth and turbidity. Using monthly data between 2008 and 2010 using multi-mesh gill nets, catch per unit effort was used as a relative abundance measure to identify how habitat variables drive fish distribution. The focus was on commercial fishes: two introduced species (Cyprinus carpio and Micropterus salmoides) and two naturalised species (Oreochromis leucostictus and Tilapia zillii). Analyses revealed distinct preferences for different habitat variables by all commercial species except for C. carpio. For example, O. leucostictus preferred shallow waters with silt-clay substrates whilst M. salmoides preferred deeper waters with sandy/rocky substrates. Conversely, C. carpio showed no specialised habitat requirements. Niche overlaps were significantly lower between O. leucostictus and its respective sympatric species than between other species, a likely result of its territorial behaviour. The continued environmental degradation of Lake Naivasha may imperil the preferred habitats of the niche restricted M. salmoides, O. leucostictus and T. zillii. By contrast, the ubiquity of C. carpio may facilitate their invasion, and consequently sustain their dominance in the lake's commercial fishery. © 2014 The Author(s). Source

Njaanake K.H.,University of Nairobi | Simonsen P.E.,Copenhagen University | Vennervald B.J.,Copenhagen University | Mukoko D.A.,Ministry of Public Health and Sanitation | And 4 more authors.
BMC Infectious Diseases | Year: 2014

Background: Pathological changes due to infection with Schistosoma haematobium include cytokine-mediated urinary tract inflammation. The involved cytokines may be excreted in urine and their presence in urine may therefore reflect S. haematobium-related urinary tract pathology. The present study, for the first time, reports on the relationship between selected cytokines in urine and infection with S. haematobium in children from an area highly affected by this parasite.Methods: Children aged 5-12 years from two primary schools in Tana Delta District of Kenya were examined for S. haematobium eggs using urine filtration technique, for haematuria using dipstix and for eosinophil cationic protein (ECP), IL-6, IFN- γ, TNF-α and IL-10 levels using ELISA, and for S. haematobium-related urinary tract pathology using ultrasonography. In addition, venous blood was examined for serum IL-6, IFN- γ, TNF-α and IL-10 levels using ELISA.Results: There was no significant correlation between urinary and serum levels of IL-6, IFN- γ, TNF-α or IL-10. There was no significant difference in geometric mean intensity (GMI) in any of the serum cytokines, or in urinary TNF-α or IFN-γ, between children with light and heavy S. haematobium infections. However, children with heavy S. haematobium infections had significantly higher GMI of urinary IL-6 (p < 0.001) and lower GMI of urinary IL-10 (p = 0.002) than children with light infections. There was also a significant positive correlation between urinary IL-6 and urinary ECP (p < 0.001) and a significant negative correlation between urinary IL-10 and urinary ECP (p = 0.012).Conclusion: Urinary IL-6 was positively correlated to and IL-10 was negatively correlated to infection intensity and urinary tract inflammation in S. haematobium-infected children. Urinary IL-6 and IL-10 ELISA may be a useful non-invasive tool to complement the already available tools for studying S. haematobium-related urinary tract pathology in children. © 2014 Njaanake et al.; licensee BioMed Central Ltd. Source

Obonyo G.O.,Maseno University | Ayieko M.A.,Jaramogi Oginga Odinga University of Science and Technology | Kambona O.O.,Maseno University
Tourism and Hospitality Research | Year: 2012

Tourism development has principally focused on the tangible tourism products thereby overlooking the intangible element such as service. This study aimed to evaluate food service attributes in gastro-tourism development in the Western Tourist Circuit, Kenya. A total of 166 top and middle level managers were selected from 62 hotels for this study using multi-stage sampling method. Several food service attributes were identified and used to structure self-administered questionnaires. The data collected were analyzed using descriptive statistics, Factor, regression and importance-performance analysis. The findings indicate that perceived importance-performance of food service attributes in gastro-tourism development varied considerably. Three factors identified were food service output, food service input both perceived to be important with good performance; and food service process perceived important but hoteliers' performance on the same was poor. The findings provide intuitively appealing strategies for hoteliers and tourism promoters in Western Tourist Circuit, Kenya to set priorities for developing gastro-tourism through food service attributes. © The Author(s) 2013. Source

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