Browsing by Subject "Namibia"
Now showing items 1-7 of 7
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Brierley, Andrew S.; Axelson, Bjorn Erik; Buecher, Emmanuelle; Sparks, Conrad A.J.; Boyer, Helen; Gibbons, Mark J. (Inter-Research, 2001)[more][less]
Abstract: Multi-frequency acoustic data (18, 38 and 120 kHz) were collected in conjunction with pelagic trawl sampling for gelatinous macrozooplankton during a cruise to the Namibian Benguela in September 1999. Sampling focused specifically on the scyphozoan Chrysaora hysoscella and the hydrozoan Aequorea aequorea, both of which occur in large numbers, are probably of major ecological importance, and physically hamper pelagic fishing and diamond extraction activities. C. hysoscella was detected predominantly at an inshore station and A. aequorea was found in greatest abundance further offshore in deeper water. Echo-sounder observations were linked directly to net catches, and relationships between catch density (number of individuals m–3) and nautical area scattering coefficients (sA) at each frequency were determined for both species in order to estimate target strength (TS) using the comparison method. TS for C. hysoscella (mean umbrella diameter 26.8 cm) was –51.5 dB at 18 kHz, –46.6 dB at 38 kHz and –50.1 dB at 120 kHz; for A. aequorea (mean central umbrella diameter 7.4 cm) TS was –68.1 dB at 18 kHz, –66.3 dB at 38 kHz and –68.5 dB at 120 kHz. These TS values compared favourably with previously published estimates for related species. Jellyfish were caught at high numerical densities (maxima 3 C. hysoscella per 100 m3, 168 A. aequorea per 100 m3). These high densities, combined with the not unsubstantial TS at frequencies used for fisheries surveys, imply that jellyfish could potentially bias acoustic estimates of fish abundance. We suggest a simple multifrequency approach that could be used to discriminate between echoes from jellyfish and some commercially important pelagic fish in the northern Benguela ecosystem. URI: http://hdl.handle.net/10566/246 Files in this item: 1
BrierleyAcoustic 2001.pdf (799.2Kb) -
Sloth-Nielsen, Julia; Wakefield, Lorenzo; Murungi, Nkatha L. (Cambridge University Press, 2011)[more][less]
Abstract: The right to non-discrimination for all children is established in international human rights law. International children’s rights law further provides for the common responsibility of parents for the maintenance of their children. African customary law and common law have always made a distinction between children born in and out of wedlock so far as the duty to maintain them is concerned. The resilience of this customary and common law approach is evident in statutory provisions of the countries discussed in this article. This is despite international obligations under children’s rights treaties ratified by these countries. On the face of it, the distinction of responsibility based on marital status seems harmless. However, in view of gender inequities and resource distribution between men and women in society, such a distinction has serious implications for the rights of affected children. URI: http://hdl.handle.net/10566/577 Files in this item: 1
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Odendaal, Willem (PLAAS, University of the Western Cape, 2011)[more][less]
Abstract: This brief examines some emerging trends and dynamics in changing power relations in rural Namibian communities due to emerging new elites and the threats to subsistence farmers’ access to communal land and natural resources. URI: http://hdl.handle.net/10566/601 Files in this item: 1
PB 33.pdf (263.8Kb) -
Ntumba, Alexis; Scott, Vera; Igumbor, Ehimario U. (OpenJournals Publishing, 2012)[more][less]
Abstract: Background: Namibia bears a large burden of Human Immunodeficiency Virus (HIV), and the youth are disproportionately affected. Objectives: To explore the current knowledge, attitudes and behaviour of female adolescents attending family planning to HIV prevention. Methods: A cross-sectional study design was used on a sample 251 unmarried female adolescents aged from 13 years to 19 years accessing primary care services for contraception using an interviewer-administered questionnaire. Data were analysed using Epi Info 2002. Crude associations were assessed using cross-tabulations of knowledge, attitude and behaviour scores against demographic variables. Chi-square tests and odds ratios were used to assess associations from the cross-tabulations. All p-values < 0.05 were considered statistically significant. Results: A quarter of sexually active teenagers attending the family-planning services did not have adequate knowledge of HIV prevention strategies. Less than a quarter (23.9%) always used a condom. Most respondents (83.3%) started sexual intercourse when older than 16 years, but only 38.6% used a condom at their sexual debut. The older the girls were at sexual debut, the more likely they were to use a condom for the event (8% did so at age 13 years and 100% at age 19 years). Conclusions: Knowledge of condom use as an HIV prevention strategy did not translate into consistent condom use. One alternate approach in family-planning facilities may be to encourage condom use as a dual protection method. Delayed onset of sexual activity and consistent use of condoms should be encouraged amongst schoolchildren, in the school setting. URI: http://hdl.handle.net/10566/515 Files in this item: 1
NtumbaHIVFemaleAdolescents2012.pdf (438.9Kb) -
Clarke, Dylan T.; Paterson, Gordon L. J.; Florence, Wayne K.; Gibbons, Mark J. (Iziko Museums of Cape Town, 2010)[more][less]
Abstract: A new species of Magelonidae, Magelona debeerei sp. nov., is described and illustrated from grab-samples collected at <100moff the southwest coast of Africa. Magelona debeerei sp. nov. has previously been identified from the region as M. papillicornis (Müller, 1858) by Day (1955, 1961, 1967) but differs from M. papillicornis sensu stricto by possessing dorsal medial lobes on chaetigers 4–8 and lateral pouches (Σ configuration) between chaetigers 10 and 11. Three species of Magelona have now been recorded from southern Africa (M. capensis Day, 1961, M. cincta Ehlers, 1908 and M. debeerei sp. nov.), and a key to Magelona from this region is provided. URI: http://hdl.handle.net/10566/245 Files in this item: 1
Clarke et al 2010.pdf (455.5Kb) -
Brierley, Andrew S.; Boyer, David C.; Axelson, Bjorn Erik; Lynam, Christopher P.; Sparks, Conrad A.J.; Boyer, Helen; Gibbons, Mark J. (Inter-Research, 2005)[more][less]
Abstract: Acoustic target strengths (TSs) of the 2 most common large medusae, Chrysaora hysoscella and Aequorea aequorea, in the northern Benguela (off Namibia) have previously been estimated (at 18, 38 and 120 kHz) from acoustic data collected in conjunction with trawl samples, using the ‘comparison method’. These TS values may have been biased because the method took no account of acoustic backscatter from mesozooplankton. Here we report our efforts to improve upon these estimates, and to determine TS additionally at 200 kHz, by conducting additional sampling for mesozooplankton and fish larvae, and accounting for their likely contribution to the total backscatter. Published sound scattering models were used to predict the acoustic backscatter due to the observed numerical densities of mesozooplankton and fish larvae (solving the forward problem). Mean volume backscattering due to jellyfish alone was then inferred by subtracting the model-predicted values from the observed water-column total associated with jellyfish net samples. Zooplankton-corrected echo intensity/jellyfish density data pairs were in close agreement with linear relationships determined previously from uncorrected data. Small sample sizes precluded recalculation of TS, but nonparametric pair-wise tests failed to detect any significant differences between echo intensities for jellyfish densities observed in the present study and echo intensities predicted for those densities by density–intensity relationships arising from the previous study. Previous linear density–intensity relationships had y-axis intercepts greater than zero. On the assumption that the positive intercepts were due to backscatter from unsampled mesozooplankton, new TS relationships were calculated from downward-adjusted density–intensity relationships. New values agreed closely with TS estimates determined elsewhere using single-target echo detection techniques. Given that estimates of jellyfish TS appear robust, it should now be feasible to identify jellyfish acoustically at sea and to assess their abundance, even in the presence of mixed mesozooplankton assemblages. URI: http://hdl.handle.net/10566/247 Files in this item: 1
BrierleyAcoustic2005.pdf (103.7Kb) -
Akuupa, Michael (Forum Press, 2010)[more][less]
Abstract: Social scientists who have written about the dynamics of festival rituals have analysed such practices variously as celebrations of commonality, as the enhancement of social cohesion, or as expressions of nostalgia. Festivals have also been studied as spaces, where information is disseminated to the public. This paper demonstrates that in postcolonial Namibia, cultural festivals have become avenues where discourses of difference and belonging are emphasised and contested by local people, festival participants and state officials through a range of ethnic-cultural presentations. The paper is primarily concerned with the ‘making’ of Kavango identity as distinctively different from that of other ethnic groups in postcolonial Namibia. This process takes place in a particular political space, that of the culture festivals, which the state has organised and staged since the mid-1990s. Every year during the Annual National Culture Festivals representatives of Namibia’s various ethnic groups gather to ‘showcase’ and express their diversity. Representatives of the state have time and again emphasised, couched in a discourse of ‘unity in diversity’, the importance of bringing together the country’s previously segregated population groups. The paper shows that while the performers act out diversity through dance and other forms of cultural exhibition, the importance of belonging to the nation and a larger constituency is simultaneously highlighted. URI: http://hdl.handle.net/10566/639 Files in this item: 1
AkuupaCulturalFestivals2010.pdf (248.7Kb)
Now showing items 1-7 of 7