The distribution and concentration levels of trace metals in water and sediments of Lake Victoria, Kenya

The water and bottom sediments of Lake Victoria (Kenya) were analysed for A1, Fe, Mn, Zn, Pb, Cu, Cr and Cd. The total metal concentrations were determined and their mean variations and distributions discussed. The bottom lake waters showed higher concentration levels than the surface waters. The range of values (in mg/l) in the bottom and surface lake waters were as follows: Surface Waters: A1(0.08 - 3.98), Fe(0.09 - 4.01), Mn(0.02 - 0.10). Zn(0.01 -0.07), Pb(0.001- 0.007), Cu(not detected - 0.006), Cr(not detected - 0.004). Bottom Waters: A1(0.1 0 - 6.59), Fe(0.23 - 9.64), Mn(0.04 - 0.39), Zn(0.01- 0.08), Pb(0.002 - 0.009), Cu(not detected - 0.03). Cr(not detected -0.002). River mouths and shallow areas in the lake showed higher total metal concentrations than offshore deeper areas. Apart from natural metal levels, varied urban activities and wastes greatly contribute to the lake metal pollution as shown by high Pb and Zn levels in sediments, around Kisumu and Homa Bay areas. Other comparatively high values and variations could be attributed to the varied geological characteristics of the lake and its sediments. Compared to the established W.H.O (1984) drinking water standards manganese, aluminium and iron levels were above these limits whereas zinc, lead, chromium, copper and cadmium were below

A Conversation with Onyango Oloo at the WSF Nairobi 2007

Onyango Oloo, National Coordinator for the Kenyan Social Forum 2006 and who also served on the Nairobi Organizing Council for the World Social Forum Nairobi 2007, has gained notoriety as an outspoken advocate for women’s leadership at the World Social Forum. His widely circulated article, “Gendering WSF Nairobi 2007 - Conceptual Underpinnings,” raised expectations among some readers about the role women would play at the Nairobi forum. In this interview, completed in the midst of that event, Onyango reflects on the evolution of his own feminist consciousness and the tactics he feels need to be implemented in order to infuse the WSF with feminist principles

Blood transfusions for severe malaria-related anemia in Africa: a decision analysis

Severe childhood malarial anemia is commonly treated using blood transfusion. Although transfusion may decrease short-term mortality, the risk of human immunodeficiency virus (HIV) transmission is considerable in Africa. We constructed a decision tree to weigh the short-term mortality benefit of transfusion against HIV infection risk. Probability estimates were derived from published studies. The base-case was a two-year-old child with a 13.5% mortality risk to be transfused with screened or unscreened blood (1% or 13% HIV contamination risk, respectively), with reduction of mortality to 5.5% by transfusion (odds ratio=2.7), and a 2.4% risk of fatal transfusion complications. A sensitivity analysis was performed to assess the influence of variation in these estimates. If a child developed acquired immunodeficiency syndrome, survival was weighed as one-tenth of normal survival. For the base-case, we found that transfusion with screened blood provided a survival benefit of 5%. In contrast, transfusion with unscreened blood decreased survival by 2%. Patients with a mortality risk < 5% derived no benefit from a transfusion with screened blood. Other important factors for the benefit of transfusion were the effectiv

Sensor-Driven, Spatially Explicit Agent-Based Models

Conventionally, agent-based models (ABMs) are specified from well-established theory about the systems under investigation. For such models, data is only introduced to ensure the validity of the specified models. In cases where the underlying mechanisms of the system of interest are unknown, rich datasets about the system can reveal patterns and processes of the systems. Sensors have become ubiquitous allowing researchers to capture precise characteristics of entities in both time and space. The combination of data from in situ sensors to geospatial outputs provides a rich resource for characterising geospatial environments and entities on earth. More importantly, the sensor data can capture behaviours and interactions of entities allowing us to visualise emerging patterns from the interactions. However, there is a paucity of standardised methods for the integration of dynamic sensor data streams into ABMs. Further, only few models have attempted to incorporate spatial and temporal data dynamically from sensors for model specification, calibration and validation. This chapter documents the state of the art of methods for bridging the gap between sensor data observations and specification of accurate spatially explicit agent-based models. In addition, this work proposes a conceptual framework for dynamic validation of sensor-driven spatial ABMs to address the risk of model overfitting

Implications of the 2015 World Health Organization isoniazid preventive therapy recommendations on tuberculosis prevention efforts in Namibia

The World Health Organization recently released guidelines recommending 36-month use of isoniazid preventive therapy in adults and adolescents living with HIV in  resource-limited settings. Namibia continues to grapple with one of the highest   incidences of tuberculosis (TB) worldwide. Implementation of these guidelines requires considerations of TB epidemiology, health infrastructure, programmatic priorities and patient adherence. This article explores the challenges Namibia currently faces in its fight against TB and the implications of the new guidelines on Namibian TB prevention efforts

Equivariant Intersection Cohomology of BXB Orbit Closures in the Wonderful Compactification of a Group

This thesis studies the topology of a particularly nice compactification that exists for semisimple adjoint algebraic groups: the wonderful compactification. The compactifica- tion is equivariant, extending the left and right action of the group on itself, and we focus on the local and global topology of the closures of Borel orbits. It is natural to study the topology of these orbit closures since the study of the topology of Borel orbit closures in the flag variety (that is, Schubert varieties) has proved to be inter- esting, linking geometry and representation theory since the local intersection cohomology Betti numbers turned out to be the coefficients of Kazhdan-Lusztig polynomials. We compute equivariant intersection cohomology with respect to a torus action because such actions often have convenient localization properties enabling us to use data from the moment graph (roughly speaking the collection of 0 and 1-dimensional orbits) to compute the equivariant (intersection) cohomology of the whole space, an approach commonly re- ferred to as GKM theory after Goresky, Kottowitz and MacPherson. Furthermore in the GKM setting we can recover ordinary intersection cohomology from the equivariant inter- section cohomology. Unfortunately the GKM theorems are not practical when computing intersection cohomology since for singular varieties we may not a priori know the local equivariant intersection cohomology at the torus fixed points. Braden and MacPherson address this problem, showing how to algorithmically apply GKM theory to compute the equivariant intersection cohomology for a large class of varieties that includes Schubert varieties. Our setting is more complicated than that of Braden and MacPherson in that we must use some larger torus orbits than just the 0 and 1-dimensional orbits. Nonetheless we are able to extend the moment graph approach of Braden and MacPherson. We define a more general notion of moment graph and identify canonical sheaves on the generalized moment graph whose sections are the equivariant intersection cohomology of the Borel orbit closures of the wonderful compactification

Quality Assurance of University Education in Alberta and Kenya: Policies and Practices

Since the introduction of degree granting institutions, Alberta and Kenya have persistently made efforts to manage and improve the quality of university education. While contexts, stakeholders, and quality assurance regimes have changed over time, debate on academic quality in both jurisdictions has continued bringing to the fore disagreements about the exact meaning of the phrase. However, many observers appreciate the importance of quality assurance and enhancement of degree programming. In this paper, we review policies and practices in quality assurance of degree education in the Canadian Province of Alberta and Kenya and the roles of Campus Alberta Quality Council and the Kenya Commission for Higher Education in assuring and enhancing quality of higher education in the two jurisdictions. Possible lessons for Kenya and other developing countries are presented.Keywords: quality assurance, higher education, Alberta, Canada, Keny

Colonial Crop, Maize: Land Appetite and Economic Subsidies in Colonial Kenya: 1895 - 1965.

Kenya depends on agriculture for food production. It is an industry that is currently occupied by smallholder farmers, unlike the colonial era. The smallholder farmers averagely cultivate less than one hectare of land. For the smallholder farmers, farming is a household activity implemented at the subsistence level. However, because the Kenyan economy depends mostly on agriculture, national food security is pegged on the availability of adequate maize supply to meet the food demand.This primarily historical study aims at examining the successful introduction of the food staple maize crop in Kenya, drawing selectively from an extensive published scholarly literature about crop changes and related policies that were put in place to boost maize productivity. The thesis focuses on land acquisition by European settlers in the early 1900s, the development of White Highlands, Kitale, and other significant areas where maize production made an essential impact on the food economy. The thesis concentrated on the development of the maize crop between 1895 to 1965, the period when maize became the dominant food crop in Kenya, the use of technology, and other public investments like seed company that led to the legacy of maize growing in the post-independent Kenya. The period of 1985 – 1965 is significant in understanding the introduction of white maize and transition from traditional crops like sorghum and millet to maize. It is essential for understanding why white maize is preferred in Kenya, how maize farming changed Kenya’s economy to an agriculture economy and the evolution of maize politics in Kenya