Kariuki S.M.,KEMRI Wellcome Trust Collaborative Research Programme |
Abubakar A.,KEMRI Wellcome Trust Collaborative Research Programme |
Abubakar A.,Pwani University |
Abubakar A.,University of Oxford |
And 7 more authors.
The Lancet Psychiatry | Year: 2017
Background Three-quarters of the burden of mental health problems occurs in low-and-middle-income countries, but few epidemiological studies of these problems in preschool children from sub-Saharan Africa have been published. Behavioural and emotional problems often start in early childhood, and this might be particularly important in Africa, where the incidence of perinatal and early risk factors is high. We therefore aimed to estimate the prevalence and risk factors of behavioural and emotional problems in young children in a rural area on the Kenyan coast. Methods We did a population-based epidemiological study to assess the burden of behavioural and emotional problems in preschool children and comorbidities in the Kilifi Health and Demographic Surveillance System (KHDSS, a database formed of the population under routine surveillance linked to admissions to Kilifi County Hospital). We used the Child Behaviour Checklist (CBCL) to assess behavioural and emotional problems. We then determined risk factors and medical comorbidities associated with behavioural and emotional problems. The strength of associations between the risk factors and the behavioural and emotional problems was estimated using generalised linear models, with appropriate distribution and link functions. Findings 3539 families were randomly selected from the KHDSS. Of these, 3273 children were assessed with CBCL. The prevalence of total behavioural and emotional problems was 13% (95% CI 12–14), for externalising problems was 10% (9–11), and for internalising problems was 22% (21–24). The most common CBCL syndrome was somatic problems (21%, 20–23), whereas the most common DSM-IV-oriented scale was anxiety problems (13%, 12–14). Factors associated with total problems included consumption of cassava (risk ratio 5·68, 95% CI 3·22–10·03), perinatal complications (4·34, 3·21–5·81), seizure disorders (2·90, 2·24–3·77), and house status (0·11, 0·08–0·14). Seizure disorders, burn marks, and respiratory problems were important comorbidities of behavioural and emotional problems. Interpretation Behavioural and emotional problems are common in preschool children in this Kenyan rural area and are associated with preventable risk factors. Behavioural and emotional problems and associated comorbidities should be identified and addressed in young children. Funding Wellcome Trust. © 2017 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY license
BULL P.C.,Roosevelt University |
ABDI A.I.,Pwani University
Parasitology | Year: 2016
The Plasmodium falciparum erythrocyte membrane protein 1 antigens that are inserted onto the surface of P. falciparum infected erythrocytes play a key role both in the pathology of severe malaria and as targets of naturally acquired immunity. They might be considered unlikely vaccine targets because they are extremely diverse. However, several lines of evidence suggest that underneath this molecular diversity there are a restricted set of epitopes which may act as effective targets for a vaccine against severe malaria. Here we review some of the recent developments in this area of research, focusing on work that has assessed the potential of these molecules as possible vaccine targets. Copyright © Cambridge University Press 2016 This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.
Olwendo O.J.,Pwani University |
Cesaroni C.,Italian National Institute of Geophysics and Volcanology
Journal of Atmospheric and Solar-Terrestrial Physics | Year: 2016
NeQuick 2 is an ionospheric electron density model which provides electron density for a given location. Its output depends on solar activity expressed by 12-month running average sunspot number (R12) or solar radio flux (F10.7). To improve the model capabilities to reproduce electron density, data ingestion techniques have been implemented which replace the standard solar activity indices input with effective parameters that allow adapting a model to a certain data sets. In regions like the Sub-Saharan Africa where few observational data were available until recently, the performance of the ingested model needs some validation. This study investigates the performance of NeQuick 2 in the Kenya region. , a low latitude region by assisting the model with total electron content measurement from a single GNSS station. These measurements are used to calculate effective ionization level parameters, which enable the difference between the measured and modeled TEC over the station to be less or equal to 0.5 TECU. The results show that by using computed effective parameters values as inputs in nearby stations, the model performance is greatly improved for both the low and moderate solar activity. This work has also demonstrated the capability of the model to describe spatial distribution of the total electron content in the low- latitude ionosphere. © 2016 Elsevier Ltd.
Baluku T.K.,Pwani University |
Hellberg M.A.,University of KwaZulu - Natal
Physics of Plasmas | Year: 2015
Using a kinetic theory approach, dust ion acoustic (DIA) waves are investigated in an unmagnetized collisionless plasma with kappa-distributed electrons and ions, and Maxwellian dust grains of constant charge. Both analytical and numerical results, the latter following from the full solution of the associated dispersion relation, are presented, and a comparison is made. The effects of the ion and electron spectral indices, as well as the species' density (ne/ni) and temperature (Te/Ti) ratios, on the dispersion and damping of the waves are considered. In the long wavelength regime, increases in both the electron spectral index (κe) and the dust density fraction (reduced f=ne/ni) lead to an increase in phase velocity. The range in wavelength over which modes are weakly damped increases with an increase in Te/Ti. However, the ion spectral index, κi, does not have a significant effect on the dispersion or damping of DIA waves. © 2015 AIP Publishing LLC.
D'Ujanga F.M.,Makerere University |
Baki P.,University of Nairobi |
Olwendo J.O.,Pwani University |
Twinamasiko B.F.,Makerere University
Advances in Space Research | Year: 2013
The equatorial ionosphere has been known to become highly disturbed and thus rendering space-based navigation unreliable during space weather events, such as geomagnetic storms. Modern navigation systems, such as the Global Positioning System (GPS) use radio-wave signals that reflect from or propagate through the ionosphere as a means of determining range or distance. Such systems are vulnerable to effects caused by geomagnetic storms, and their performance can be severely degraded. This paper analyses total electron content (TEC) and the corresponding GPS scintillations using two GPS SCINDA receivers located at Makerere University, Uganda (Lat: 0.3o N; Lon: 32.5o E) and at the University of Nairobi, Kenya (Lat: 1.3o S; Lon: 36.8 o E), both in East Africa. The analysis shows that the scintillations actually correspond to plasma bubbles. The occurrence of plasma bubbles at one station was correlated with those at the other station by using observations from the same satellite. It was noted that some bubbles develop at one station and presumably "die off" before reaching the other station. The paper also discusses the effects of the geomagnetic storm of the 24-25 October 2011 on the ionospheric TEC at the two East African stations. Reductions in the diurnal TEC at the two stations during the period of the storm were observed and the TEC depletions observed during that period showed much deeper depletions than on the non-storm days. The effects during the storm have been attributed to the uplift of the ionospheric plasma, which was then transported away from this region by diffusion along magnetic field lines. © 2012 COSPAR. Published by Elsevier Ltd. All rights reserved.
Kelvin K.,Kenya Industrial Research and Development Institute KIRDI |
Tole M.,Pwani University
Water, Air, and Soil Pollution | Year: 2011
Constructed wetlands have recently received considerable attention as low cost and efficient means of cleaning up many different types of wastewaters at secondary and tertiary levels. This is an environmentally sound method of wastewater treatment that does not use hazardous chemicals, and is based on the high productivity and nutrient removal capability of the wetland that strongly relies on its intricate ecosystem structure and function. Research work was conducted on a tropical constructed wetland to establish its capability to treat wastewater during the dry season. A comparison of its efficacy with that of conventional wastewater treatment plants was made on the basis of the measured water quality parameters. Temperature, pH, dissolved oxygen, and conductivity were measured in situ. Total suspended solids (TSS), total dissolved solids (TDS), biochemical oxygen demand (BOD5), chemical oxygen demand (COD), phosphorus, ammonia, and nitrites were analyzed in the laboratory. Fecal coliforms were enumerated and Escherichia coli counts were determined. The TSS values reduced from a mean of 102 mg/l at the influent point to 16 mg/l at the effluent point, depicting a reduction of 84.3%. Influent TDS averaged 847 mg/l, while the effluent averaged 783 mg/l. Dry season BOD5 levels were reduced from an average of 286 at the inlet point to 11 mg/l at the outlet representing a reduction efficiency of 96.2%. COD levels were reduced from a mean of 2,002.5 to 47.5 mg/l depicting a removal efficiency of 97.6%. Phosphorus was reduced from a mean of 14 to 11 mg/l representing a percentage removal of 21.4%. Levels of ammonia reduced from a mean of 61 at the influent point to 36 mg/l at the effluent point representing a percent reduction of 41.0%. There was a 99.99% reduction for both the fecal coliforms and E. coli counts. Conductivity of wastewater increased from 1.08 to 1.98 mS, while the pH increased from 6.23 at the inlet point to 7.99 at the outlet of the system. Temperature and dissolved oxygen measurements showed a diurnal variation. The dry season wastewater heavy metal concentrations were in the following ranges: Pb (0.7-6.9 ppm), Cr (0.2-0.5 ppm), Zn (0.1-2.3 ppm), Ni (0.1-1.3 ppm) with Cd and Cu not being detected in the wastewater streams. Overall, tropical constructed wetlands are effective in treating wastewater streams and they perform a lot better than the popularly used waste stabilization ponds. This paper recommends that they can be widely used within the tropics. © 2010 Springer Science+Business Media B.V.
Gikandi J.W.,University of Canterbury |
Gikandi J.W.,Pwani University |
Morrow D.,University of Canterbury |
Davis N.E.,University of Canterbury
Computers and Education | Year: 2011
As online and blended learning has become common place educational strategy in higher education, educators need to reconceptualise fundamental issues of teaching, learning and assessment in non traditional spaces. These issues include concepts such as validity and reliability of assessment in online environments in relation to serving the intended purposes, as well as understanding how formative assessment functions within online and blended learning. This article provides a systematic qualitative review of the research literature on online formative assessment in higher education. As an integrative narrative review, the method applied in this review entailed systematic searching, reviewing, and writing this review of the literature to bring together key themes and findings of research in this field. The authors applied qualitative thematic criteria in selecting and reviewing the available literature from which they focused on identifying and analyzing the core themes that are central to the concept of formative assessment with a key focus on application of formative assessment within blended and online contexts. Various techniques were identified for formative assessment by the individual, peers and the teacher, many of which were linked with online tools such as self-test quiz tools, discussion forums and e-portfolios. The benefits identified include improvement of learner engagement and centrality in the process as key actors, including the development of a learning community. The key findings are that effective online formative assessment can foster a learner and assessment centered focus through formative feedback and enhanced learner engagement with valuable learning experiences. Ongoing authentic assessment activities and interactive formative feedback were identified as important characteristics that can address threats to validity and reliability within the context of online formative assessment. © 2011 Elsevier Ltd. All rights reserved.
Mlewa C.M.,Pwani University
African Journal of Ecology | Year: 2013
The taxonomy of the two established barbus species: Barbus neumayeri and Barbus pellegrini has presented problems due to their close relationship and pronounced character variation within and between their populations. In this study, morphomeristic methods were used to investigate Barbus specimens from several populations in the Lake Kivu - Lake Edward area. Meristic and morphometric data on specimens in the RMAC collection from lakes Kivu and Edward, and the Nyabarongo and Mpanga river systems were analysed using principal component analysis in the PAST software programme. The results revealed additional morphomeristic characters useful in distinguishing the two closely related barbus species; hence, both B. pellegrini and B. neumayeri are redescribed incorporating additional characters to their respective original descriptions. Specimens from Nyabarongo river system were significantly different to warrant recognition as new species; thus, a new species B. new species is proposed and described. Meristically, the B. new species and the two established species are distinguished by lateral line scale counts; while predorsal length, head length and body depth at operculum, expressed as percentage of standard length, are the most diagnostic morphometric characters. © 2013 Blackwell Publishing Ltd.
Maua M.,Pwani University |
Mwiti T.,Pwani University
2013 IST-Africa Conference and Exhibition, IST-Africa 2013 | Year: 2013
The paper seeks to demystify the misty of selected software by explaining the skills, facilities, equipment and economic sustainability required for the University library to realize the acquisition, installation, and implementation of the open source software, challenges and how to minimize these challenges. In the face of budget cuts and increased accountability, University libraries faced a challenge to prove their value and remain visible and to remain as a catalyst in supporting the teaching, learning and research missions of their Universities. University libraries must demonstrate their ability to lead and to adapt their roles in response to changing circumstances. Libraries are increasingly being asked to play an important role in the development of more effective arrangements for managing, sharing and preserving data created or gathered by researchers. In an ever-changing technology landscape, the capacity to learn constantly and quickly is more relevant than ever, and is the primary motivation of this paper. © 2013 The Authors.
Agency: European Commission | Branch: FP7 | Program: MC-IIFR | Phase: FP7-PEOPLE-2011-IIF | Award Amount: 15.00K | Year: 2014
The filamentous marine cyanobacterium, Lyngbya majuscula (order Oscillatoriales) is a prolific source of modular natural products, some of which have shown promise for the treatment of cancer, diabetes, HIV and Alzheimers disease. However, the failure to grow its axenic cultures (because of the lack of the nifH gene) suggests that obtaining the natural products from the cyanobacterium in sustainable yields is enigmatic. My investigations into the Kenyan L. majuscula molecular diversity established it to be encapsulated by a sheath of brightly coloured epibiotic bacteria (EB) species, representative of a group of phyla that are an especially important source of novel natural products in drug discovery. Consistent with the paucity of natural product genes (a mere 3%) observed in the L. majuscula 3L draft genome sequence, there are serious concerns on whether the nearly 300 compounds isolated pan-tropically from L. majuscula originate from the cyanobacterium or EB cohabiting with it or both. This study therefore aims to investigate the heterologous cytochrome P450 (cyp450) mediated biosynthesis of L. majuscula natural products from EB cohabiting with it. The Kenyan L. majuscula is the source of the modular homodolastatin 16 (HMDS 16) and antanapeptin A (ANTAP A). Specifically, EB will be screened for polyketide synthase (PKS)/nonribosomal peptide synthetase (NRPS) megasynthase gene clusters targeting HMDS 16 and ANTAP A. Gene clusters encoding for HMDS 16, ANTAP A and cyp450 flanking the clusters will be amplified from cDNA using specific primers for the gene models. PCR amplification products will be cloned and resulting plasmids transformed into a Saccharomyces cerevisiae shuttle vector for co-expression with cyp450. Methanolic extracts of the recombinant cultures will be analysed for modular natural products and the results compared with those of EB in direct culture and of L. majuscula. Structural elucidation of natural products will utilise LC/MS/NMR spectrometry.