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Item Determination of natural radioactivity in soils of Henties Bay, Namibia(University of Namibia, 2015) Shimboyo, Simon A.; Oyedele, JamesThe concentrations of naturally occurring radionuclides 40K, 238U and 232Th in soil samples collected across the town of Henties Bay in Western Namibia have been determined and used to estimate a baseline natural radiation level in the town. These concentrations were measured using an HPGe detector and found to vary from 790.2±31.6 Bq kg−1 to 1039.0±38.7 Bq kg−1 with a mean of 936.1±68.5 Bq kg−1 for 40K, 36.2±2.6 Bq kg−1 to 153.4±4.8 Bq kg−1 with a mean of 62.2±20.0 Bq kg−1 for 238U and 50.4±4.5 Bq kg−1 to 323.6±12.7 Bq kg−1 with a mean of 97.1±44.7 Bq kg−1 for 232Th. The corresponding effective dose rate obtained from the radionuclides is 0.16±0.04 mSv y−1. This dose rate is well below the limit of 1.0 mSv y−1 recommended for the public by the International Commission on Radiological Protection (ICRP) and indicates that the town has a normal background radiation.Item The effect of tourist roads development on road-side vegetation and soils within the Etosha national park(University of Namibia, 2015) Nakanyala, Jesaya; Hipondoka, Martin; Graz, Patrick F.Management of tourism-based protected areas is often faced with a challenge of balancing nature conservation and tourism development. Understanding such interactions is crucial for resources management in tourism-based conservation hotspots such as Etosha National Park (ENP). This study assessed how roads, being part of tourism development, impacts on conservation efforts in ENP, focusing specifically on the roadside landscape, vegetation and soils. Data was collected at at 30 selected sites in major vegetation communities within the park. Herbaceous biomass was assessed using a Disk Pasture Meter based on field calibration from ENP. Soil samples were collected using a soil auger and analyzed. Results show that a substantial network of tourist roads has been developed for Etosha National Park, translating in a road density of 0.2 km/km2. The development of this road network has left more than 180 unrestored gravel pits, or an average of one gravel pit for every 4 km. Similarly, results demonstrated that roads and related vehicular activities have significant impact on the foliage cover and biomass yield of herbaceous species adjacent to the roads, with foliage cover decreasing with increasing proximity to roads. No conclusive evidence emerged to suggest that roads and vehicular emission have a significant impact on roadside soil chemical properties. An exception is made to elevated calcium, carbonate and high cation exchange capacity which is speculated to have been sourced from the Etosha limestone. This study concluded that an unrestricted development of roads and the accompanying quarrying of gravels have a potential to degrade the landscape of Etosha National Park. As a first attempt, this study serves as a baseline for monitoring tourism related ecological disturbances in the park.Item Avian diversity and assemblages around Ruacana Waterfall, north-western Namibia(University of Namibia, 2015) Kopij, GrzegorzIn 2011-2012, the line transect method was employed to study avian assemblages in the Koakoland (Mopane) Savanna around the Ruacana waterfall in the Kunene Region, north-western Namibia. In total 64 resident species were recorded, a number which was high in comparison with other bushy habitats. Simpson’s Diversity Index was also high (S = 0.96). Group of dominant species (32.4%) comprised Streptopelia capicola, Tockus erythrorhynchus, Plocepasser mahali, Pycnonotis nigricans and Lanioturdus torquatus. The following species recorded as resident around Ruacana Waterfall were endemic to Namibia: Poicephalus rueppellii, Phoeniculus damarensis, Lanioturdus torquatus, Tockus damarensis and Parus carpi. Although the difference between the riparian and dry variety of the Mopane Savanna was insignificant in terms of biodiversity (S = 0.97 and S = 0.92 respectively), the number of species in dry bush was much lower than in the riparian bush ( 2-test = 4.76; p < 0.05). Also the S¨orensen similarity coefficient was unexpectedly low between the two habitat varieties (I = 0.48).Item Namibian marine algae as a potential source of novel bioactive natural products(University of Namibia, 2015) Knott, Michael G.; Ishola, AnthonyA literature review shows that the medicinal chemistry and bioactivity of very few Namibian species has ever been investigated. In southern Africa, marine red algae such as species of Plocamium, Laurencia and Portieria are known to contain bioactive natural products. Of these three species, only Plocamium species are currently found in Namibia. In vitro testing of secondary metabolites from South African Plocamium species have demonstrated antibacterial, cytotoxic, antiplasmodial, and anti-fouling properties. Whilst the commercial benefits of some Namibian marine algae are well established, this review highlights the shortage of knowledge and research related to the pharmaceutical potential of Namibian marine algae, and how marine algae could possibly benefit the health and wellbeing of Namibians in the future.Item Does Mycobacterium bovis contribute to the case load of human tuberculosis in Namibia(University of Namibia, 2015) Kahler, BarbaraNamibia has one of the highest infection rates of human tuberculosis (TB) in the world. The causative agent is generally asserted to be Mycobacterium tuberculosis. Renewed concerns have been raised globally in the last decades regarding the emergence of Mycobacterium bovis as a contributor to human TB. The pathogen is harbored by a number of mammalian animal species and, hence has a high zoonotic potential. Numerous investigations in recent years show evidence of the spread of M. bovis from the wildlifelivestock interface to humans in southern African countries. Rural communities in these regions are most at risk since livestock can easily be infected. Namibia is considered to be free of bovine TB in cattle because no cases have been reported since 1995. However the disease may be under-diagnosed in single cases especially in remote areas because of the slow and chronic course. Weakened animals might be slaughtered privately, with contaminated meat and raw milk from infected cows or goats being consumed. The aim of this review is to discuss the complex issues of diagnosis and epidemiology, and to highlight the importance of the differentiation of mycobacteria species in the medical laboratory for the outcome of patient treatment. M. bovis is clinically indistinguishable from human TB, possesses intrinsic resistance to at least one of the four first-line anti TB drugs, and shows a tendency to develop multidrug resistance. It poses a high risk predominantly for immuno-compromised individuals, as HIV-patients for example. Since Namibia has both - a high case load of HIV and TB - the occurrence and risk of zoonotic M. bovis in southern Africa should be discussed.Item Prevalence and aetiological agents of parasitic infestation among population in northern Namibia(University of Namibia, 2015) Chikukwa, Sydney; Lukas, T.Intestinal parasitic infestations continues to be a public health burden in many developing countries. A hospital based cross-sectional retrospective study was conducted for the period June to December 2013 at Intermediate Hospital Oshakati (IHO), northern Namibia, to assess the prevalence of parasitic infestation. A total of 1000 stool specimens were analysed for intestinal parasites at Namibia Institute of Pathology (NIP) Oshakati laboratory based on all patients who submitted specimen during the study period. Data on age, gender, species of parasites and dual infection were tallied on the data collection sheet from microbiology stool bench work cards and laboratory information system, and was imported to and analysed by Microsoft Excel. Of the 1000 patients under review 138 (13.8%) patients had either dual or mono infestation by different species of parasites, of which 128 (12.8%) had mono parasitic infection, while 10 (1%) had dual infection. Entamoeba coli was the most (5.5%) prevalent intestinal parasites, followed by Giardia lamblia (4.4%) and Entamoeba histolytic (1.7%). The most affected age group was the 76-90 years old due to personal hygiene and the rural environment where most live under poor sanitation and portable water problems. Females (18.6%) were twice as much at risk of intestinal parasites infection than their male (9.7%) counter parts. Communal hand washing, absence of proper human waste disposal in rural areas and informal urban settlements may be attributed as predisposing factors. Drastic public health measures as provision of pit latrines and health education on intestinal parasites will go a long way in reducing these high prevalence rates. The mass deworming exercises currently being undertaken among school children should be expanded to cover older people.Item Qualitative and quantitative analysis of phytochemical compounds in Namibian Myrothamnus flabellifolius(University of Namibia, 2015) Cheikhyoussef, Ahmad; Summers, Rowan Wayne; Kahaka, Gladys K.The phytochemical content and antioxidant activity of the Namibian resurrection plant, Myrothamnus flabellifolius, which is traditionally used in the management and treatment of various diseases was determined. Samples were collected from Remhoogte pass, 130 km south west of Rehoboth. Solvent extraction using ethanol, methanol, water on powdered extracts (leaves and twigs) were done by soxhlet extraction and maceration. Twelve classes of phytochemicals tested positively; flavonoids, anthocyanins, alkaloids, steroids, terpenoids, triterpenes, cardiac glycosides, saponins, phlobatanins, tannins, polyphenols and reducing sugars in the leaves extracts. However, anthraquinones, anthranoids, iridoids, leucoanthocyanins, proteins and amino acids tested negatively in all three solvent extracts from both leaves and twigs. The quantitative antioxidant activity analysis namely; the total phenolic content (TPC) and total flavonoid content (TFC) of the solvent extracts from M. flabellifolius were also determined. The TPC and TFC ranged from 372.42±0.21 to 375.14±0.21 mg gallic acid equivalent (GAE)/g and 1.43±0.03 to 3.49±0.15 mg equivalents for quercetin (QE)/g respectively. The high TPC in M. flabellifolius makes it suitable for potential application as a potent natural source of antioxidants and validates the ethnobotanical uses of this plant in the traditional healing system in Namibia.Item Psychology and adherence of tuberculosis patients: Do illness perceptions predict poor adherence to TB management?(University of Namibia, 2015) Rennie, Timothy; Bates, IanTo quantitatively explore illness and medication perceptions of tuberculosis patients and to examine their impact on patient adherence to medical management. A questionnaire eliciting illness and medicines perceptions and socio-demographic data was designed. TB patients in three TB services in North East London were recruited and completed the questionnaire. Further data, including the outcome measure of clinic attendance, were collected from clinical notes. Bivariate data analysis was conducted and variables most associated with the outcome measure were entered for regression analysis. Recruited patients were characteristic of TB patients in North East London (n = 109). Patients reported perceptions of short timeline, greater personal control and treatment control over their illness, somewhat incoherent and negative emotional perceptions of their TB, and general perceptions of the benefit of their medicines. Correlations were observed between illness and medicines perceptions, and with self-reported and outcome adherence measures. Regression analysis identified that patients speaking English as a first language and patients with negative emotional representations were more likely to miss scheduled clinic appointments. Illness perceptions may present modifiable factors for use in interventions designed to promote TB patient adherence. Further research needs to clarify the relationship between illness/medication perceptions and adherence.