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This paper investigates the petrogenesis of the Seqi Ultramafic Complex, which covers a total area of approximately 0.5 km2. The ultramafic rocks are hosted by tonalitic orthogneiss of the ca. 3000 Ma Akia terrane with crosscutting granitoid sheets providing an absolute minimum age of 2978 ± 8 Ma for the Seqi Ultramafic Complex. The Seqi rocks represent a broad range of olivine-dominated plutonic rocks with varying modal amounts of chromite, orthopyroxene and amphibole, i.e. various types of dunite (s.s.), peridotite (s.l.), as well as chromitite. The Seqi Ultramafic Complex is characterised primarily by refractory dunite, with highly forsteritic olivine with core compositions having Mg# ranging from about 91 to 93. The overall high modal contents, as well as the specific compositions, of chromite rule out that these rocks represent a fragment of Earth’s mantle. The occurrence of stratiform chromitite bands in peridotite, thin chromite layers in dunite and poikilitic orthopyroxene in peridotite instead supports the interpretation that the Seqi Ultramafic Complex represents the remnant of a fragmented layered complex or a magma conduit, which was subsequently broken up and entrained during the formation of the regional continental crust. Integrating all of the characteristics of the Seqi Ultramafic Complex points to formation of these highly refractory peridotites from an extremely magnesian (Mg# ~ 80), near-anhydrous magma, as olivine-dominated cumulates with high modal contents of chromite. It is noted that the Seqi cumulates were derived from a mantle source by extreme degrees of partial melting (>40%). This mantle source could potentially represent the precursor for the sub-continental lithospheric mantle (SCLM) in this region, which has previously been shown to be ultra-depleted. The Seqi Ultramafic Complex, as well as similar peridotite bodies in the Fiskefjord region, may thus constitute the earliest cumulates that formed during the large-scale melting event(s), which resulted in the ultra depleted cratonic keel under the North Atlantic Craton. Hence, a better understanding of such Archaean ultramafic complexes may provide constraints on the geodynamic setting of Earth’s first continents and the corresponding SCLM

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Against the backdrop of a high prevalence of the human immunodeficiency virus infection in Zimbabwe, this paper analyses data from the 1997 Zimbabwe Sexual Behaviour and Condom Use Survey to throw light on the degree to which sexually active adults consistently use condoms in high-risk sexual situations. The multivariate results indicate that at the time of the survey, consistent condom use in non-marital relationships is significantly higher for males than females, higher among those who had access to information about condoms from multiple sources than among those with limited access, and higher among those who have positive attitudes to condoms than among those with negative attitudes. Even though consistent condom use with non-marital partners is higher for those who know a source where condoms can be obtained, this effect is due to the fact that these respondents have more positive attitudes towards condoms. Likewise, the higher levels of consistent condom use exhibited by those who are aware of the efficacy of condoms are due to the fact that men have higher awareness of this, and men use condoms more consistently than women. In sum, the results suggest that the effects of the respondents' sex and their knowledge of the prophylactic importance of condoms and where condoms might be obtained are a function of other socioeconomic advantages they have. It is, therefore, concluded that programmes that use mass media information, education and communication campaigns to reduce shyness, embarrassment and stigma about condom use can help increase consistent use of condoms in non-marital relationships in Zimbabwe. 122J. Adetunji and D. Meekers (CDC, 1993, p. 590). Consistent use of condoms requires a high level of commitment and discipline among users, especially men. Hence, the question that arises is whether men and women who engage in high-risk sexual behaviour in Zimbabwe consistently use condoms. Furthermore, it is important to identify the factors that are associated with consistent condom use. Theoretical models of behaviour change predict that the adoption of healthy behaviour is a function of several factors, including perceptions about the severity of the disease, the efficacy of preventive measures, barriers to use of preventive measures, personal risk perception and self-efficacy (

Expanding access to family planning (FP) is a driving aim of global and national FP efforts. The definition and measurement of access, however, remain nebulous, largely due to complexity. This article aims to bring clarity to the measurement of FP access. First, we synthesize key access elements for measurement by reviewing three well-known frameworks. We then assess the extent to which the Demographic and Health Surveys (DHS)-a widely used data source for FP programs and research-has information to measure these elements. We finally examine barriers to access by element, using the latest DHS data from four countries in sub-Saharan Africa. We discuss opportunities and limitations in the measurement of access, the importance of careful interpretation of data from population-based surveys, and recommendations for collecting and using data to better measure access.