Boiyo D.K.,Nelson Mandela Metropolitan University |
Kipnoo E.K.R.,University of Kabianga |
Gamatham R.R.G.,The Square Kilometre Array SKA Project |
Leitch A.W.R.,Nelson Mandela Metropolitan University |
Gibbon T.B.,Nelson Mandela Metropolitan University
Optical Switching and Networking | Year: 2017
We experimentally characterized and optimized link performance of a multi-node flexible spectrum network. The cheap and low power consuming and wavelength tunable vertical cavity surface-emitting lasers (VCSELs) have been used to create colourless and wavelength selective flexible transmitters to enable up to 10 Gb/s per channel/wavelength signals. With a −3.8 dBm VCSEL optical power and chromatic dispersion mitigation, a 25 km multi-node network has been experimentally demonstrated with a transmission penalty range of 0.2–3.2 dB. Moreover, an impairment-aware mathematical model has been created to predict signal continuity for crosstalk and dispersion penalties for a hop-to-hop signal transmission and a bit error-rate (BER) evaluation at the 10-9threshold level. This study is vital for creating routing and network algorithms for the next-generation optical fibre networks. © 2017 Elsevier B.V.
Owiti Y.J.,University of Kabianga |
Christopher M.,University of Kabianga
Jordan Journal of Biological Sciences | Year: 2017
Optimizing procedures for mass rearing mosquitoes for practices akin to the sterile insect techniques or routine laboratory activities is crucial. The present study evaluated the impact of nutrients, temperature, egg storage period and pH on egg hatchability and pupation rate, respectively, of Anopheles arabiensis mosquitoes. First, twenty eggs, collected from female mosquitoes and raised on different diet types (Rastrineobola argentea, Tetramin® Baby fish food and Bakers' active yeast) in their larval stages, were stored at different time periods at two temperature regimes; 22 - 23°C and 28 - 29°C and later dispensed in plastic cups (4.0 cm top × 3.5 cm bottom × 2.7 cm height) containing 25cm3 of water and left to hatch. Secondly, twenty L4s were placed individually in 100 Ml of larval rearing media of different pH regimes in plastic cups (7.5 cm top × 5.0 cm bottom × 8 cm height) and left to pupate and emerge as adults. The media were of pH 6, 6.8 (clean borehole water), 7, 8, 9 and cow dung solution. It was found that eggs incubated at 28-29°C were less viable than those incubated at 22-23°C (p < 0.05). Eggs remained hatchable for 8 days. Mean pupation time for L4 larvae maintained in untreated tap water (pH 6.8) differed significantly compared to other rearing media (p p < 0.05). Mean pupation time was neither influenced by sex (p = 0.124) or size (p = 0.801) of emerged mosquitoes. It was concluded that pH (6.8) and temperatures of 22-23°C were optimal for pupation and egg hatchability, respectively.
Rioba N.B.,University of Kabianga |
Stevenson P.C.,University of Greenwich |
Stevenson P.C.,Jodrell Laboratory
Industrial Crops and Products | Year: 2017
Ageratum conyzoides L. (Asteraceae) is an aromatic, annual herb and cosmopolitan weed commonly known as billygoat weed or goat weed and is typically found in cultivated fields and other disturbed ecosystems. The species has been studied widely owing to its biological properties and its potential application in medicine and agriculture. Due to its importance and use in the treatment of burns and wounds, arthrosis, malaria, asthma, leprosy and dermatitis, its medicinal properties have been reviewed. A. conyzoides, however, also has insecticidal activity against a range of major pests of field crops and stored products including Callosobruchus chinensis L. (Coleoptera: Chrysomelidae), Chilo partellus Swinhoe (Lepidoptera: Crambidae), Sitophilus oryzae L. (Coleoptera: Curculionidae), Panonychus citri McGregor (Tetranychidae: Panonychus), Sitophilus zeamais Motchulsky (Coleoptera: Curculionidae). , Plutella xylostella L. (Lepidoptera: Plutellidae) and Brevicoryne brassicae L. (Hemiptera: Aphididae). Evidence suggests that its efficacy is comparable to synthetic pesticides and that it is economically viable too while its impact on beneficial insects including ladybirds, hoverflies and spiders is much reduced compared to synthetics. Anti-microbial activity against important agricultural disease agents is also reviewed here including against Fusarium oxysporum Schltdl., (Hypochreales: Nectriaceae), Phytophthora citrophthora (R.E. Sm. & E.H. Sm.) Leonian, (Phythiales: Phythiaceae), Pythium aphanidermatum (Edson) Fitzp., (Peronosporales: Pythium), Fusarium solani Mart (Sacc.) (Hypochreales: Nectriaceae) and Gibberella zeae (Schwein.) Petch (Fusarium graminearum (Schwabe) (Hypochreales: Nectriaceae). These activities suggest a compelling multipurpose plant that has merit as a potential commercial species. Since earlier reviews have focused on medicinal properties of A. conyzoides and less on its potential value in agriculture, this review seeks to bridge this gap by reviewing research on the various properties of this species that are relevant to food production. The review presents updated information on the use of this species as an agricultural resource and emphasizes its potential as an industrial crop. © 2017 Elsevier B.V.
Wesolowski A.,Harvard University |
Wesolowski A.,Boston Dynamics |
Wesolowski A.,Flowminder Foundation |
Metcalf C.J.E.,Princeton University |
And 12 more authors.
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015
Changing patterns of human aggregation are thought to drive annual and multiannual outbreaks of infectious diseases, but the paucity of data about travel behavior and population flux over time has made this idea difficult to test quantitatively. Current measures of human mobility, especially in low-income settings, are often static, relying on approximate travel times, road networks, or cross-sectional surveys. Mobile phone data provide a unique source of information about human travel, but the power of these data to describe epidemiologically relevant changes in population density remains unclear. Here we quantify seasonal travel patterns using mobile phone data from nearly 15 million anonymous subscribers in Kenya. Using a rich data source of rubella incidence, we show that patterns of population travel (fluxes) inferred from mobile phone data are predictive of disease transmission and improve significantly on standard school term time and weather covariates. Further, combining seasonal and spatial data on travel from mobile phone data allows us to characterize seasonal fluctuations in risk across Kenya and produce dynamic importation risk maps for rubella. Mobile phone data therefore offer a valuable previously unidentified source of data for measuring key drivers of seasonal epidemics. © 2015, National Academy of Sciences. All rights reserved.
PubMed | University of Minnesota, Maseno University, University of Kabianga, Indiana University and 2 more.
Type: | Journal: PeerJ | Year: 2017
Malaria elimination campaigns are planned or active in many countries. The effects of malaria elimination on immune responses such as antigen-specific IFN- IFN- While one individual (0.4%) tested positive for Naturally acquired IFN-
Onyangore F.O.,University of Kabianga |
Were G.M.,University of Eldoret |
Mwamburi L.A.,University of Eldoret
African Journal of Food, Agriculture, Nutrition and Development | Year: 2016
The increased prevalence of iron deficiency among infants can be attributed to the consumption of an iron deficient diet or a diet that interferes with iron absorption at the critical time of infancy, among other factors. The gradual shift from breast milk to other foods and liquids is a transition period which greatly contributes to iron deficiency anaemia (IDA). The purpose of this research was to assess iron deficiency anaemia among infants aged six to nine months in Keiyo South Sub County. The specific objectives of this study were: to establish the prevalence of infants with iron deficiency anaemia and dietary iron intake among infants aged 6 to 9 months. The cross sectional study design was adopted in this survey. This study was conducted in three health facilities in Keiyo South Sub County. The infants were selected by use of a two stage cluster sampling procedure. Systematic random sampling was then used to select a total of 244 mothers and their infants. Eighty two (82) infants were selected from Kamwosor sub-district hospital and eighty one (81) from both Nyaru and Chepkorio health facilities. Interview schedules, 24-hour dietary recall and food frequency questionnaires were used for collection of dietary iron intake. Biochemical tests were carried out by use of the Hemo-control photochrometer at the health facilities. Infants whose hemoglobin levels were less than 11g/dl were considered anaemic. Further, peripheral blood smears were conducted to ascertain the type of nutritional anaemia. Data was analyzed using the Statistical Package for Social Sciences (SPSS) computer software version 17, 2009. Dietary iron intake was analyzed using the NutriSurvey 2007 computer software. Results indicated that the mean hemoglobin values were 11.3± 0.84 g/dl. Twenty one percent (21.7%) of the infants had anaemia and further 100% of peripheral blood smears indicated iron deficiency anaemia. Dietary iron intake was a predictor of iron deficiency anaemia in this study (t=-3.138; p=0.01). Iron deficiency anaemia was evident among infants in Keiyo South Sub County. The Ministry of Health should formulate and implement policies on screening for anaemia and ensure intensive nutrition education on iron rich diets during child welfare clinics.
Otiende M.A.,University of Kabianga |
Nyabundi J.O.,Maseno University |
Ngamau K.,Jomo Kenyatta University of Agriculture and Technology
Journal of Applied Horticulture | Year: 2016
Inadequate grafting take of some of the rose cultivars may cause economic losses. The study was conducted to determine the effects of cutting position (top, middle and bottom) of Rosa hybrida rootstocks ('Natal Briar' and 'Rosa Progress') and auxins (0 %, 0.4 % IBA and 0.2 % NAA) on rooting and grafting take of rose cultivar 'Inca'. Changes in endogenous carbohydrate content during rooting were measured on days 0, 3 and 7 after sticking. The experiment was factorial in a completely randomized design. Interaction between cutting position and rootstock was significant (P ≤ 0.05) for most of the parameters measured. The shoot height, root number, percent rooting and grafting take increased towards the basal position in 'Rosa Progress'. In 'Natal Briar', the shoot and root growth parameters increased towards the top though non significant except grafting take that significantly increased towards the basal position. The auxin treated cuttings recorded significantly (P ≤ 0.05) higher grafting take and rooting percentage than the control. 0.4 % IBA exhibited higher shoot height, leaf number and root number than 0.2 % NAA. The rootstock 'Natal Briar' recorded significantly (P ≤ 0.05) higher rooting percentage and grafting take than 'Rosa Progress'. Middle and top position cuttings of 'Rosa Progress' and 'Natal Briar' recorded higher carbohydrate content, respectively than bottom position cuttings. Bottom position recorded higher sucrose content on day 3 than days 0 and 7 after planting in 'Rosa Progress'. 'Natal Briar' exhibited significantly (P ≤ 0.05) higher carbohydrate content than 'Rosa Progress'. The increase in growth with top position cuttings of 'Natal Briar' could be attributed to high carbohydrate content. The high growth responses in bottom position cuttings of 'Rosa Progress' could be attributed to high sucrose content on day 3 after planting. The stem cuttings of rootstocks for top grafting rose cultivar 'Inca' should be taken from bottom position cuttings of both rootstocks, and auxins should be applied to increase rooting and grafting take.
Maina L.C.,Jomo Kenyatta University of Agriculture and Technology |
Karanja S.,Jomo Kenyatta University of Agriculture and Technology |
Kombich J.,University of Kabianga
Pan African Medical Journal | Year: 2013
Introduction: The institutionalization of strong immunization services over recent years has ensured that today more than 70% of the worlds' targeted population is reached. In Kenya, approximately 77% of children aged 12-23 months are fully vaccinated with some districts reporting even lower levels of coverage. However, low immunization coverage remains a challenge in low income and high population settings such as Kaptembwo Location, Nakuru district. Methods: A cross sectional community based survey was undertaken between January and March 2011. Cluster sampling method was employed. Data was collected using pretested interviewer guided structured questionnaires through house to house visits. Data was analyzed in SPSS using descriptive, bivariate and multivariate logistic regression to identify independent predictors of full immunization. Results: Complete immunization coverage was 76.6%. Coverage for specific antigens was; BCG (99.5%), OPV0 (97.6%), OPV 1(98.7%), OPV2 (96.6%), OPV3 (90.5%), Penta 1(98.9), Penta 2 (96.6%), Penta 3 (90.0%), Measles (77.4%). The drop-out rate between the first and third pentavalent vaccine coverage was 8.9%. Predictors of full immunization included number of children within the family, place of birth of the child, advice on date of next visit for growth monitoring and opinion on the health immunization services offered. Conclusion: Complete immunization coverage among children aged 12-23 months is still below target. Efforts to improve vaccination coverage must take into account the immunization determinants found in this study. There is need to focus on strengthening of awareness strategies. © Lilian Chepkemoi Maina et al.
Erima J.,Moi University |
Masai W.,InformAction |
Wosyanju M.G.,University of Kabianga
2016 IST-Africa Conference, IST-Africa 2016 | Year: 2016
The digital age has presented the academic society with new opportunities. Academic institutions are increasingly moving towards digital presentation of corporate Information, such as web sites that contain prospectuses, course guides and corporate policies. Most of the intellectual assets of academic institutions, including research content, are also increasingly being produced and held in digital form, thus demanding new approaches to their preservation to ensure long-Term value for teaching, research and development. This highlights the importance of an appropriate and effectively implemented digital preservation framework to ensure that these digital resources are properly maintained if their potential value is to be realized. This study endeavors to assess the current state of preservation of academic research content at Moi University (MU); the extent to which these materials have been digitized, with a view to proposing an appropriate strategy for their successful preservation. The specific objectives of the study are to: identify and classify the types of research content produced in MU; establish the different forms and categories in which these materials are stored; assess the existing digital preservation practices used to preserve these research assets; establish the challenges faced in the preservation of these materials; propose an appropriate preservation strategy to digitize and preserve these research content. This study has highlighted the need and importance of digitization and preservation of research content. It has also propose an applicable digital preservation strategy for MU. © 2016 IIMC.
PubMed | Kenya Medical Research Institute, Jomo Kenyatta University of Agriculture and Technology, University of Kabianga and University of Eldoret
Type: | Journal: BMC research notes | Year: 2015
Despite advances to targeted leishmanicidal chemotherapy, defies around severe toxicity, recent emergence of resistant variants and absence of rational vaccine still persist. This necessitates search and/or progressive validation of accessible medicinal remedies including plant based. The study examined both in vivo and in vitro response of L. major infection to combined therapy of Ricinus communis and Azadirachta indica extracts in BALB/c mice as the mouse model. A comparative study design was applied.BALB/c mice, treated with combination therapy resulted in significantly (p < 0.05) larger reduction of lesion than those treated with monotherapies. The spleno-somatic index was found to be significantly low with combination therapy than monotherapies. Antiparasitic effect of A. indica and R. communis on amastigote with a 50 % inhibitory concentration (IC50) was of 11.5 and 16.5 g mL(-1) respectively while combination therapy gave 9.0 g ml(-1) compared to the standard drugs, Pentostam and amphotericin B which had an IC50 of 6.5 and 4.5 g ml(-1) respectively. Optimal efficacy of A. indica and R. communis was 72 and 59.5 % respectively, combination therapy gave 88 %, while Pentostam and amphotericin B had 98 and 92 % respectively against amastigotes. Against promastigotes A. indica and R. Communis gave an IC50 of 10.1, 25.5 g mL(-1) respectively, while combination, 12.2 g mL(-1) against 4.1 and 5.0 g ml(-1) for Pentostam and amphotericin B respectively. The optimal efficacy of the compounds against promastigotes was 78.0, 61.5 and 91.2 % (A. indica, R. communis and A. indica + R. communis respectively) against 96.5 and 98 % for Pentostam and amphotericin B respectively. The concentrations at optimal efficacy were significantly different (p < 0.05) among the test compounds. An evaluation of the IC50 values of the combination therapies clearly reveals synergistic effects.Combination therapy of A. indica and R. communis had best antileishmanial activity than the monotherapies. The active ingredients of both R. communis and A. indica need to be fractionated, and studied further for activity against Leishmania parasites.