Letters and Viewpoints Potentials of Using Waste Burnt Clay as a Pozzolanic Material in Kenya

Samples of waste burnt clay were collected from various parts of the country to study their pozzolanic properties. The samples were ground into fine powder and taken for chemical tests. Results from the chemical tests on all the samples showed high silica content. In fact the combined percentages of Silica (SiO2), Alumina (Al2O3) and Iron Oxide (Fe2O3) was more than 70%, a requirement by the Kenyan standard for a suitable pozzolanic material. One sample from a major factory (being a large quantity) was mixed with various proportions of Ordinary Portland cement (OPC) and used for physical tests. Results showed compressive strengths way above the recommended for masonry cement when up to 50% OPC was replaced with burnt clay. For masonry works 50% OPC replacement with burnt clay will still give satisfactory results and reduce cost of binder by at least 20%. Discovery and Innovation Vol. 13 no. 3/4 December (2001) pp. 114-118 KEY WORDS: waste burnt clay, pozzolanic material, masonry clement, building standard

Spiny mice of the Zambezian bioregion – phylogeny, biogeography and ecological differentiation within the Acomys spinosissimus complex

Mammalian Biology, 91 (2018): 79-90Despite the high degree of biological diversity in the Zambezian region, little information is available regarding the evolutionary history of its biota, and this is especially true for the fauna and flora of non-forested habitats. Here we use the most comprehensive multi-locus genetic dataset available to (1) reconstruct the phylogeny of spiny mice of the Acomys spinosissimus complex and to describe the spatial distribution of its genetic diversity; (2) to assess the level of reproductive isolation between genetic clades; (3) to analyse differences in climatic niche between potential species; and (4) to model their current and past distribution. The complex comprises four main genetic clades that correspond to four nominal species living in the east of the Zambezian region. Their distribution is delimited by important geographical divides including the Eastern Arc Mountains, Lake Malawi and the Zambezi River. Two species considered Tanzanian endemics, A. ngurui and A. muzei, are now known to be more widespread than previously thought and they have their centres of genetic diversity just north of the Zambezi. The first split between the extant members of the A. spinosissimus complex is estimated at 3 Mya. Most intraspecific diversification events are thought to have occurred in the Pleistocene, suggesting that climatic oscillations played an important role in their diversification. The climatic niches of parapatric taxa differ significantly; hence, local adaptations have likely played an important role in reproductive isolation. Species distribution modelling predicts a dramatic reduction of occurrence probability across the area during the last interglacial period, facilitating allopatric diversification of fragmented populations. Our results strongly suggest the combined role of Pleistocene climatic change, biogeographical barriers and local adaptation in forming current taxa diversity in east African savannah-like habitats. While such processes have frequently been observed in forest-living organisms (theory of allopatric diversification in forest refugia), similar mechanisms were likely also working in open ecosystems ("savannah refugia")

Happily together forever: temporal variation in spatial patterns and complete lack of territoriality in a promiscuous rodent

Population Ecology, 2014; 56 (1): 109-118The availability of resources, their effect on population density and territoriality, and the ways in which these factors are interwoven with mating systems are important determinants of small mammal space use. It is often difficult to study these patterns in an integrated way, however, especially because long-term data are needed but not readily available. In this paper, we investigate effects of population density, season and breeding status on home range patterns of the promiscuous rodent Mastomys natalensis using monthly capture-mark-recapture data collected over 17 years in a 3-ha grid. Home ranges were estimated using minimum convex polygons bounded by trap locations, and home range overlap and visitation rates were calculated as a measure of territoriality. As higher population densities coincide with increased resource availability, we predicted that home range sizes would correlate negatively with density. Furthermore, as M. natalensis is promiscuous and population densities are generally high, we predicted that territoriality would be low, and home range overlap would therefore be high. Contrary to expectations the home ranges of female adults increased with population density, although those of male adults and subadults followed the expected decrease. Home range overlap and visitation rates were generally high, and increased significantly with population density. More importantly, they were never lower than those of simulated datasets consisting of randomly moved home ranges. These results therefore suggest that M. natalensis displays a complete lack of territoriality that is rarely seen in small mammals but still meets predictions based on knowledge of density and mating system

Happily together forever: temporal variation in spatial patterns and complete lack of territoriality in a promiscuous rodent

Population Ecology, 2014; 56 (1): 109-118The availability of resources, their effect on population density and territoriality, and the ways in which these factors are interwoven with mating systems are important determinants of small mammal space use. It is often difficult to study these patterns in an integrated way, however, especially because long-term data are needed but not readily available. In this paper, we investigate effects of population density, season and breeding status on home range patterns of the promiscuous rodent Mastomys natalensis using monthly capture-mark-recapture data collected over 17 years in a 3-ha grid. Home ranges were estimated using minimum convex polygons bounded by trap locations, and home range overlap and visitation rates were calculated as a measure of territoriality. As higher population densities coincide with increased resource availability, we predicted that home range sizes would correlate negatively with density. Furthermore, as M. natalensis is promiscuous and population densities are generally high, we predicted that territoriality would be low, and home range overlap would therefore be high. Contrary to expectations the home ranges of female adults increased with population density, although those of male adults and subadults followed the expected decrease. Home range overlap and visitation rates were generally high, and increased significantly with population density. More importantly, they were never lower than those of simulated datasets consisting of randomly moved home ranges. These results therefore suggest that M. natalensis displays a complete lack of territoriality that is rarely seen in small mammals but still meets predictions based on knowledge of density and mating system

Happily together forever: temporal variation in spatial patterns and complete lack of territoriality in a promiscuous rodent

Population Ecology 2014, Vol. 56: pp109–118The availability of resources, their effect on population density and territoriality, and the ways in which these factors are interwoven with mating systems are important determinants of small mammal space use. It is often difficult to study these patterns in an integrated way, however, especially because long-term data are needed but not readily available. In this paper, we investigate effects of population density, season and breeding status on home range patterns of the promiscuous rodent Mastomys natalensis using monthly capture-mark-recapture data collected over 17 years in a 3-ha grid. Home ranges were estimated using minimum convex polygons bounded by trap locations, and home range overlap and visitation rates were calculated as a measure of territoriality. As higher population densities coincide with increased resource availability, we predicted that home range sizes would correlate negatively with density. Furthermore, as M. natalensis is promiscuous and population densities are generally high, we predicted that territoriality would be low, and home range overlap would therefore be high. Contrary to expectations the home ranges of female adults increased with population density, although those of male adults and subadults followed the expected decrease. Home range overlap and visitation rates were generally high, and increased significantly with population density. More importantly, they were never lower than those of simulated datasets consisting of randomly moved home ranges. These results therefore suggest that M. natalensis displays a complete lack of territoriality that is rarely seen in small mammals but still meets predictions based on knowledge of density and mating system

Happily together forever: temporal variation in spatial patterns and complete lack of territoriality in a promiscuous rodent

Population Ecology 2014, Vol. 56: pp109–118The availability of resources, their effect on population density and territoriality, and the ways in which these factors are interwoven with mating systems are important determinants of small mammal space use. It is often difficult to study these patterns in an integrated way, however, especially because long-term data are needed but not readily available. In this paper, we investigate effects of population density, season and breeding status on home range patterns of the promiscuous rodent Mastomys natalensis using monthly capture-mark-recapture data collected over 17 years in a 3-ha grid. Home ranges were estimated using minimum convex polygons bounded by trap locations, and home range overlap and visitation rates were calculated as a measure of territoriality. As higher population densities coincide with increased resource availability, we predicted that home range sizes would correlate negatively with density. Furthermore, as M. natalensis is promiscuous and population densities are generally high, we predicted that territoriality would be low, and home range overlap would therefore be high. Contrary to expectations the home ranges of female adults increased with population density, although those of male adults and subadults followed the expected decrease. Home range overlap and visitation rates were generally high, and increased significantly with population density. More importantly, they were never lower than those of simulated datasets consisting of randomly moved home ranges. These results therefore suggest that M. natalensis displays a complete lack of territoriality that is rarely seen in small mammals but still meets predictions based on knowledge of density and mating system

Swedish exceptionalism, herd immunity and the welfare state : A media analysis of struggles over the nature and legitimacy of the COVID-19 pandemic strategy in Sweden

Compared to many other countries, Sweden has managed the COVID-19 pandemic with no lockdowns, less regulation and more voluntary action expected of citizens and organizations. In this article, the authors explore media representations of national preventative strategies and how they were anchored in broader discourses. The article aims to analyse the development of crisis narratives and struggles over legitimacy during the first phase of the COVID-19 pandemic in Sweden. Employing a critical discourse analysis, the authors investigate the editorials and opinion articles in Sweden’s largest morning newspaper, Dagens Nyheter, during the spring of 2020. The authors combine descriptive analyses of the development of the crisis narratives with discursive analyses of conflicting ideologies in the debate. The study indicates that three crisis narratives dominated the debates: health, the economy and democracy. Within and between these narratives, struggles over legitimacy in the handling of COVID-19 were captured in several conflicting perspectives or paradoxes: Swedish exceptionalism versus the world, centralization versus decentralization and herd immunity versus herd humanism.

Socio-cultural determinants of health-seeking behaviour on the Kenyan coast: a qualitative study

Abstract: Background: Severe childhood illnesses present a major public health challenge for Africa, which is aggravated by a suboptimal response to the child’s health problems with reference to the health-seeking behaviour of the parents or guardians. We examined the health-seeking behaviour of parents at the Kenyan coast because understanding impediments to optimal health-seeking behaviour could greatly contribute to reducing the impact of severe illness on children’s growth and development. Methods and Results: Health-seeking behaviour, and the factors influencing this behaviour, were examined in two traditional communities. We held in-depth interviews with 53 mothers, fathers and caregivers from two rural clinics at the Kenyan Coast. Biomedical medicine (from health facilities and purchased over the counter) was found to be the most popular first point of treatment. However, traditional healing still plays a salient role in the health care within these two communities. Traditional healers were consulted for various reasons: a) attribution of causation of ill-health to supernatural sources, b) chronic illness (inability of modern medicine to cure the problem) and c) as prevention against possible ill-health. In developing an explanatory model of decision-making, we observed that this was a complex process involving consultation at various levels, with elders, but also between both parents, depending on the perceived nature and chronicity of the illness. However, it was reported that fathers were the ultimate decision makers in relation to decisions concerning where the child would be taken for treatment. Conclusions: Health systems need to see traditional healing as a complementary system in order to ensure adequate access to health care. Importantly, fathers also need to be addressed in intervention and education programs