College of Education, University of Rwanda
Kigali, Rwanda
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More V.S.,MSRCASC | Tallur P.N.,Government Arts and Science College | Niyonzima F.N.,College of Education, University of Rwanda | More S.S.,University Graduate Center
3 Biotech | Year: 2015

A bacterium capable of degrading pendimethalin was isolated from the contaminated soil samples and identified as Bacillus lehensis XJU based on 16S rRNA gene sequence analysis. 6-Aminopendimethalin and 3,4-dimethyl 2,6-dinitroaniline were identified as the metabolites of pendimethalin degradation by the bacterium. The biodegradation of pendimethalin by freely suspended and the immobilized cells of B. lehensis on various matrices namely agar, alginate, polyacrylamide, and polyurethane foam was also investigated. The batch degradation rate was nearly the same for both free and immobilized cells in agar and alginate, whereas polyacrylamide- and PUF-immobilized cells degraded 93 and 100 of 0.1 % pendimethalin after 96 and 72 h, respectively. At higher concentration, the degradation rate of freely suspended cells decreased; whereas the same immobilized cells on polyurethane foam completely degraded 0.2 % pendimethalin within 96 h. The repeated batch degradation with the polyurethane foam-immobilized cells was reused for 35 cycles without losing the 0.1 % pendimethalin degrading ability. In contrast, agar-, alginate- and polyacrylamide-immobilized cells could be reused for 15, 18, and 25 cycles, respectively. When the pendimethalin concentration was increased to 0.2 %, the immobilized cells could be reused but the pendimethalin degradation rate was decreased. Polyurethane foam-immobilized cells exhibited better tolerance to pH and temperature alterations than freely suspended cells and could be stored for more than 3 months without losing pendimethalin degrading ability. The immobilization of cells capable of degrading pendimethalin may serve as an ideal technique for the complete degradation of the herbicide in the environment. © 2015, The Author(s).

Tsinda A.,College of Education, University of Rwanda | Abbott P.,University of Aberdeen | Chenoweth J.,University of Surrey
Habitat International | Year: 2015

This article analyses sanitation markets in the informal settlements of three case study cities, namely Kigali (Rwanda), Kampala (Uganda) and Kisumu (Kenya), to identify how sanitation markets in East Africa can be made to function more effectively. It is based on a mixed method approach where 1794 households from Kigali, 1666 households from Kampala and 1927 households from Kisumu were surveyed. This was complemented by qualitative research involving 83 focus group discussions, 99 interviews and 3 deliberative forums. Findings reveal similarities and strong differences between the cities in terms of sanitation markets. While construction and emptying services are more available in Kampala and to lesser extent in Kisumu, organic solutions are mostly available in Kigali. However, the purchase of products and services is generally low. One of the reasons is that households are provided with products they do not want to buy. The sanitation intervention should be focused on the households rather than the suppliers of sanitary products. This involves understanding consumers' needs, desires, habits and the circumstances required for a facility to be acceptable and meet the needs of users rather than what fits the supplier. © 2015 Elsevier Ltd.

Muhire I.,University of Johannesburg | Muhire I.,College of Education, University of Rwanda | Ahmed F.,University of Witwatersrand | Abutaleb K.,University of Johannesburg
Theoretical and Applied Climatology | Year: 2015

This study aims primarily at investigating the relationships between Rwandan seasonal rainfall anomalies and El Niño-South Oscillation phenomenon (ENSO) events. The study is useful for early warning of negative effects associated with extreme rainfall anomalies across the country. It covers the period 1935–1992, using long and short rains data from 28 weather stations in Rwanda and ENSO events resourced from Glantz (2001). The mean standardized anomaly indices were calculated to investigate their associations with ENSO events. One-way analysis of variance was applied on the mean standardized anomaly index values per ENSO event to explore the spatial correlation of rainfall anomalies per ENSO event. A geographical information system was used to present spatially the variations in mean standardized anomaly indices per ENSO event. The results showed approximately three climatic periods, namely, dry period (1935–1960), semi-humid period (1961–1976) and wet period (1977–1992). Though positive and negative correlations were detected between extreme short rains anomalies and El Niño events, La Niña events were mostly linked to negative rainfall anomalies while El Niño events were associated with positive rainfall anomalies. The occurrence of El Niño and La Niña in the same year does not show any clear association with rainfall anomalies. However, the phenomenon was more linked with positive long rains anomalies and negative short rains anomalies. The normal years were largely linked with negative long rains anomalies and positive short rains anomalies, which is a pointer to the influence of other factors other than ENSO events. This makes projection of seasonal rainfall anomalies in the country by merely predicting ENSO events difficult. © 2014, Springer-Verlag Wien.

Muhire I.,University of Johannesburg | Muhire I.,College of Education, University of Rwanda | Ahmed F.,University of Witwatersrand | Abutaleb K.,University of Johannesburg | Kabera G.,South African Medical Research Council
International Journal of Plant Production | Year: 2015

This paper investigated the response of major food crop yields namely beans, cassava, Irish potatoes, maize and sweet potatoes to ongoing changes in climate in Rwanda. The projected daily precipitation and temperature data for the period 2000-2050 used in this study were generated by stochastic weather generator (LARS-WG) from daily raw data for the period 1961-2000. These data were collected from Rwandan Meteorological Center based in Kigali, while the agricultural records for the period 2000-2010 used to project yields of major food crops for 2011-2050 were obtained from the National Institute of Statistics of Rwanda and the Ministry of Agriculture and Animal Resources. A number of statistical techniques were applied in projecting the major food crops yields and attempting to quantify their magnitude trends in response to projected precipitation and temperature data. The climate and soil suitability analysis revealed that the central plateau and south-west regions of the country will be the most suitable regions for cultivation of major food crops except Irish potatoes which can be grown in the north-western highlands. The central plateau region is the only region that is expected to experience an increase in yields for most of the major food crops under investigation. The south-west region will have increased beans, cassava and sweet potatoes yields in season A (September-January). The eastern lowlands are expected to register a decreasing trend in most of crops yields in season A, corresponding to the anticipated decline in mean rainfalls and number of rainy days. The envisaged yields increase in season B (February-June) for beans, maize and Irish potatoes will be in response to a rise in mean rainfall and number of rainy days. Heavy rainfall in the north-western region is likely to have a negative impact on crop yields. The rain might cause waterlogging, flooding events and landslides which may damage and destroy the crops. © 2015, Gorgan univ agricultural sciences and natural resources. All right reserved.

Muhire I.,University of Johannesburg | Muhire I.,College of Education, University of Rwanda | Ahmed F.,University of Witwatersrand
Theoretical and Applied Climatology | Year: 2016

This study aims at quantifying the trends in mean temperatures and aridity index over Rwanda for the period of 1961–1992, based on analysis of climatic data (temperatures, precipitations, and potential evapotranspiration). The analysis of magnitude and significance of trends in temperatures and aridity index show the degree of climate change and mark the level of vulnerability to extreme events (e.g., droughts) in different areas of the country. The study reveals that mean temperatures increased in most parts of the country, with a significant increase observed in the eastern lowlands and in the southwestern parts. The highlands located in the northwest and the Congo-Nile crest showed a nonsignificant increase in mean temperatures. Aridity index increased only in March, April, October, and November, corresponding with the rainy seasons. The remaining months of the year showed a decreasing trend. At an annual resolution, the highlands and the western region showed a rise in aridity index with a decreasing pattern over the eastern lowlands and the central plateau. Generally, the highlands presented a nonsignificant increase in mean temperatures and aridity index especially during the rainy seasons. The eastern lowlands showed a significant increase in mean temperatures and decreasing trends in aridity index. Therefore, these areas are bound to experience more droughts, leading to reduced water and consequent decline in agricultural production. On the other hand, the north highlands and southwest region will continue to be more productive. © 2015, Springer-Verlag Wien.

Nsengimana V.,College of Education, University of Rwanda | Weihler S.,College of Arts and Social Sciences, University of Rwanda | Kaplin B.A.,College of Science and Technology, University of Rwanda
Society and Natural Resources | Year: 2016

This research presents a case study on perceptions of local people on the use of Nyabrongo river wetland and its conservation in Rwanda. It critically examines the potential implications of a shift in wetland use and management practices for local people and presents empirical data from a household survey, group discussions, and observations from transect walks. Results showed that the change in the use and management regime of Nyabarongo river wetland poses substantial loss for local people in terms of provision of resources, income, and access to the wetland, so that the majority of the participants are not happy with the current use of the wetland. Research concluded that there should be participation of all stakeholders, including local people, during policy development in order to shift from command-and-control toward local stakeholder integration in decision making. 2016 Copyright © Taylor & Francis Group, LLC

Muhire I.,University of Johannesburg | Muhire I.,College of Education, University of Rwanda | Ahmed F.,University of Witwatersrand
South African Geographical Journal | Year: 2015

This study applies a number of statistical techniques in an attempt to quantify the magnitude, and to determine the significance of trends in the number of rainy days and mean rainfall over Rwanda on a monthly, seasonal and annual timescale. Trend analysis of the number of rainy days (1961-1992) was performed on daily values collected from 25 weather stations and the rainfall trends (1935-1992) were analysed using aggregated mean monthly data from 28 weather stations. The magnitude and significance of trends at 95% interval level derived from the slopes of the regression lines are presented spatially with the help of maps. It was observed that on average, there was a steady decline in the frequency of rainfall across the country. A significant incline was registered mainly over the northern region and the number of rainy days decreased significantly over the eastern and central plateau. The mean rainfall was found to increase sharply in most parts, especially in the regions around Kivu Lake during the short rainy seasons. The central region of Rwanda displayed a diminishing trend in rainfall totals in January and February. At the same time, the wet areas located in the highlands and around Kivu Lake are becoming wetter compared to the rest of the country. The highlands were consequently experiencing more flooding, with the eastern lowlands and the central plateau becoming warmer. These phenomena have an adverse effect on crop production, as they cause failure and/or destruction. © 2014 Society of South African Geographers.

Kampire E.,Nelson Mandela Metropolitan University | Kampire E.,College of Education, University of Rwanda | Rubidge G.,Nelson Mandela Metropolitan University | Adams J.B.,Nelson Mandela Metropolitan University | Human L.,Nelson Mandela Metropolitan University
Water SA | Year: 2016

This study investigated the effect of freshwater as a point source of PCBs contributing to a marine outfall region. Inflowing and outflowing water from the North End Lake, Port Elizabeth, was collected to determine the contamination levels of polychlorinated biphenyls (PCBs). Mussels at the outflow to the sea were also sampled. The samples were analysed by an internal standard method for 6 indicator PCB congeners using gas chromatography/mass spectrometry (GC/MS) in selected ion monitoring (SIM) mode. The total PCB concentrations in the water (dissolved plus particulate phases) ranged from 0.180 to 0.355 ng∙L-1 and from 20.84 to 31.34 ng∙g-1 wet weight (ww) in mussels. Lighter PCB congeners exhibited highest concentrations in the water samples while heavier PCBs were dominant in mussels. PCB-52 was the most abundant in the water samples while PCB-153 was abundant in mussels. To protect human health from the possible effects of eating fish and shellfish contaminated with PCBs, the Environmental Protection Agency regulates that the level of PCBs in water be no greater than 0.17 ng∙L-1 of water. The levels of PCBs in water from the NorThend Lake were found to be high (0.180-0.355 ng∙L-1) compared to the levels recommended by EPA. © 2016, South African Water Research Commission. All rights reserved.

Uwamahoro J.,College of Education, University of Rwanda | Habarulema J.B.,The South African National Space Agency | Habarulema J.B.,Rhodes University
Earth, Planets and Space | Year: 2014

This paper describes a neural network-based model developed to predict geomagnetic storms time K index as measured at a magnetic observatory located in Hermanus (34°25 S; 19°13 E), South Africa. The parameters used as inputs to the neural network were the solar wind particle density N, the solar wind velocity V, the interplanetary magnetic field (IMF) total average field B t as well as the IMF B z component. Averaged hourly OMNI-2 data comprising storm periods extracted from solar cycle 23 (SC23) were used to train the neural network. The prediction performance of this model was tested on some moderate to severe storms (with K ≤ 5) that were not included in the training data set and the results are compared to the prediction of the global geomagnetic Kp index. The model results show a good predictability of the Hermanus storm time K index with a correlation coefficient of 0.8. © 2014 Uwamahoro and Habarulema; licensee Springer.

PubMed | College of Education, University of Rwanda and Lille University of Science and Technology
Type: | Journal: TheScientificWorldJournal | Year: 2015

The Cichorium intybus flower development in fertile, cytoplasmic male sterility (CMS 524) and various phenotypes carrying the 524 male sterile cytoplasm was investigated macroscopically and by light microscopy. The development was similar in fertile and in male sterile florets up to meiosis, and then it was affected in anther wall structure and pollen grain development in male sterile floret. In the male sterile plants, the tapetum intrusion after meiosis was less remarkable, the microspores started to abort at vacuolate stage, the connective tissue collapsed, and endothecium failed to expand normally and did not undergo cell wall lignification, which prevented anther opening since the septum and stomium were not disrupted. Crosses undertaken in order to introduce the CMS 524 into two different nuclear backgrounds gave rise to morphologically diversified progenies due to different nuclear-mitochondrial interactions. Macroscopic and cytological investigations showed that pollen-donor plants belonging to Jupiter population had potential capacity to restore fertility while the CC line could be considered as a sterility maintainer.

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