Browsing by Title
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Mutanyatta, J.; Bezabih, M.; Abegaz, B.; Dreyer, M.; Brun, R.; Kocher, N.; Bringmann, G (Elsevier Ltd.http://www.elsevier.com/wps/find/journaldescription.cws_home/942/description#description, NaN, 2005)[more][less]
Abstract: From the roots of Bulbine frutescens, the first sulfated phenylanthraquinones were isolated, together with their known sulfate-free analogs. Their structures were elucidated by spectroscopic and chiroptical methods, by acid hydrolysis or by partial synthesis. The new compounds have the usual stereo-orientation at the biaryl axis (i.e., with the acetyl portion above the anthraquinone plane) except for sodium ent-knipholone 60-O-sulfate (and thus, also its hydrolysis product, ent-knipholone), which exhibit an opposite axial configuration. We also describe the first stereoanalysis of natural phenylanthraquinones, some of which were found to be not enantiomerically pure, some even nearracemic. We furthermore, report on the first X-ray structure analysis of a phenylanthraquinone, viz. 40-O-demethylknipholone. URI: http://hdl.handle.net/10311/246 Files in this item: 2
license.txt (1.998Kb) -
Onyewadume, I.U. (Human Kinetics http://www.humankinetics.com, July NaN, 2006)[more][less]
Abstract: This study compared the fitness of Black African early adolescents with and without mild mental retardation. Participants included 30 purposively selected early adolescent Black Africans with mild mental retardation aged 11-14 from three schools for children with mild mental retardation in Southern Botswana and 30 randomly selected early adolescents of similar ages without mental retardation. Participants were assessed on a number of standard fitness variables including the Rockport Walk Test. In general, when compared to participants without mental retardation, participants with mild mental retardation exhibited low levels of fitness. Based on study results, the Ministry of Education is called upon to urgently put in place policies and programs that would reverse the low level of fitness among adolescents with mild mental retardation. URI: http://hdl.handle.net/10311/709 Files in this item: 1
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Omari, K.; Mubyana, T.; Matsheka, M.I.; Bonyongo, M.C.; Veenendaal, E. (South African Journal of Botany http://www.elsevier.com/wps/find/journaldescription.cws_home/707238/description#description, NaN, 2004)[more][less]
Abstract: Effects of flooding on soil nitrogen (N), and asymbiotic nitrogen fixing bacterial (diazotroph) populations of the Okavango Delta were investigated. Diazotrophs from the rhizosphere of dominant annual and perennial grasses of the Okavango Delta were isolated on N-free composite media and identified applying morphological and biochemical criteria and Restriction Fragment Length Polymorphism (RFLP). Azotobacter species were found associated mostly with the grasses Andropogon guyanus and Vetevaria nigritiana (103CFU g–1 rhizosphere soil). Annual grasses such as Eragrostis inamoena, Setaria sphacelata as well as perennials showed insignificant populations (<101CFU g–1 soil). On the contrary, Azospirillum spp. was found associated with most of the grasses. Highest population densities (above 104MPN g–1 soil) were observed in rhizospheres of E. inamoena, Cympogon excavatus, Sporobolus acinifolis, Eragrostis lapila and Eragrostis rigidor and lowest population densities (below 102MPN g–1 soil) in rhizospheres of Andropogon guyanus and Panicum repens. Flooding increased the Azotobacter populations, while Azospirillum spp. populations were significantly reduced. Nitrogen-fixing sulphur reducers were observed in the rhizosphere of annuals (A. guyanus and P. repens) and only in perennials growing in flooded soils. No Beijerinckia species were found associated with any of the grasses. The highest soil nitrogen levels were detected in flooded soils (<0.20% N) while no N was detected in the rhizosphere soil of grasses growing in very dry soils (<5% moisture content). The results indicate that in the Okavango Delta, total soil nitrogen varies with flooding regime. With flooding, the diazotroph population shifts towards Azotobacter and Nfixing sulphur reducers while Azospirillum spp. are widespread in non-flooded soils. RFLP analysis of the 1 450bp amplicon using the restriction endonuclease Alu1, showed three different banding profiles, suggesting the occurrence of three different species of Azospirillum. URI: http://hdl.handle.net/10311/294 Files in this item: 1
Flooding and its influence.pdf (2.253Mb) -
Setshogo, M.P.; Mbereki, C.M. (Global Science Books, http://www.globalsciencebooks.info/, NaN, 2011)[more][less]
Abstract: The sale of herbal medicine, either as concoctions or single plant specimens, has become common in the streets and main shopping centres of major towns and cities in Botswana. A study was undertaken to collect information on the uses of medicinal plants sold by street vendors in Gaborone, Botswana during June 2008 to December 2008. The indigenous knowledge of the street vendors and the plants used for medicinal purposes were collected through questionnaire and personal interviews during field trips. The survey showed that the street vendors used 47 species of plants distributed in 45 genera belonging to 29 families to treat various diseases and health conditions. The documented medicinal plants were mostly used to cure skin sores, sexually transmitted diseases (STD) and asthma. In this study, the most dominat families are the Asteraceae and Fabaceae, each with 5 species and roots were most frequently used for the treatment of diseases accounting for 62% of the medicines sold. This study showed that many people in Botswana still continue to depend on medicinal plants for primary healthcare. URI: http://hdl.handle.net/10311/922 Files in this item: 1
Setshogo_AJPSB_2011.pdf (876.4Kb) -
Mabbs, R.; Nijegorodov, N.; Downey, W.S. (Elsevier Science Ltd. www.elsevier.com/locate/saa, NaN, 2003)[more][less]
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Kwaambwa, H.M.; Maikorera, R. (Elsevier B.V. www.elsevier.com/locate/colsurfb, NaN, 2007)[more][less]
Abstract: The fluorescence studies of coagulating protein extracted from Moringa oleifera seeds have been studied using steady-state intrinsic fluorescence. The fluorescence spectra are dominated by tryptophan emission and the emission peak maximum ( max = 343±2 nm) indicated that the tryptophan residue is not located in the hydrophobic core of the protein. Changes in solution pH affected the protein conformation as indicated by changes in the tryptophan fluorescence above pH 9 whereas the ionic strength had minimal effect. The exposure and environments of the tryptophan residue were determined using collisional quenchers. URI: http://hdl.handle.net/10311/323 Files in this item: 1
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Weiser, S.D.; Leiter, K.; Bangsberg, D.R.; Butler, L.M.; Percy-de Korte, F.; Hlanze, Z.; Phaladze, N.; Iacopino, V.; Heisler, M. (Plos Medicine. www.plosmedicine.org, NaN, 2007)[more][less]
Abstract: Background: Both food insufficiency and HIV infection are major public health problems in sub-Saharan Africa, yet the impact of food insufficiency on HIV risk behavior has not been systematically investigated. We tested the hypothesis that food insufficiency is associated with HIV transmission behavior. Methods and Findings: We studied the association between food insufficiency (not having enough food to eat over the previous 12 months) and inconsistent condom use, sex exchange, and other measures of risky sex in a cross-sectional population-based study of 1,255 adults in Botswana and 796 adults in Swaziland using a stratified two-stage probability design. Associations were examined using multivariable logistic regression analyses, clustered by country and stratified by gender. Food insufficiency was reported by 32% of women and 22% of men over the previous 12 months. Among 1,050 women in both countries, after controlling for respondent characteristics including income and education, HIV knowledge, and alcohol use, food insufficiency was associated with inconsistent condom use with a nonprimary partner (adjusted odds ratio [AOR] 1.73, 95% confidence interval [CI] 1.27–2.36), sex exchange (AOR 1.84, 95% CI 1.74–1.93), intergenerational sexual relationships (AOR 1.46, 95% CI 1.03–2.08), and lack of control in sexual relationships (AOR 1.68, 95% CI 1.24–2.28). Associations between food insufficiency and risky sex were much attenuated among men. Conclusions: Food insufficiency is an important risk factor for increased sexual risk-taking among women in Botswana and Swaziland. Targeted food assistance and income generation programs in conjunction with efforts to enhance women’s leg URI: http://hdl.handle.net/10311/556 Files in this item: 1
Food insufficiency.pdf (2.245Mb) -
Gumbricht, T.; Wolski, P.; Frost, P.; McCarthy, T.S. (Elservier, www.elsevier.com, NaN, 2004)[more][less]
Abstract: The pristine Okavango Delta wetland of northern Botswana is potentially under threat due to water abstraction from its tributaries. We have developed a statistical model which makes it possible to predict the extent of wetland loss which will arise from water abstraction. The model also permits prediction of the maximum area of flooding, and its spatial distribution, three months in advance of the flood maximum. The model was calibrated using maximum areas of seasonal inundation extracted from satellite imagery covering the period 1985-2000, which were correlated with rainfall and total flood discharge. A technique was developed to translate the modelled flood area into a flood map. The methodology can predict maximum area of flooding and its distribution with better than 90% accuracy. An important, although relatively minor, source of error in the spatial distribution of the flood arises from a secular change in flood distribution in the distal Delta which has taken place over the last 15 years. Reconstruction of flooding history back to 1934 suggests that the Delta may be subject to a quasi 80 year climatic oscillation. If this oscillation continues, the extent of flooding will increase in the coining decades. URI: http://hdl.handle.net/10311/948 Files in this item: 1
Gumbricht JOH 2004.pdf (2.449Mb) -
Gumbricht, T.; Wolski, P.; Frost, P.; McCarthy, T.S. (Elsevier http://www.doi:10.1016/j.jhydrol.2003.11.010, NaN, 2004)[more][less]
Abstract: The pristine Okavango Delta wetland of northern Botswana is potentially under threat due to water abstraction from its tributaries. We have developed a statistical model which makes it possible to predict the extent of wetland loss which will arise from water abstraction. The model also permits prediction of the maximum area of flooding, and its spatial distribution, three months in advance of the flood maximum. The model was calibrated using maximum areas of seasonal inundation extracted from satellite imagery covering the period 1985–2000, which were correlated with rainfall and total flood discharge. A technique was developed to translate the modelled flood area into a flood map. The methodology can predict maximum area of flooding and its distribution with better than 90% accuracy. An important, although relatively minor, source of error in the spatial distribution of the flood arises from a secular change in flood distribution in the distal Delta which has taken place over the last 15 years. Reconstruction of flooding history back to 1934 suggests that the Delta may be subject to a quasi 80 year climatic oscillation. If this oscillation continues, the extent of flooding will increase in the coming decades. URI: http://hdl.handle.net/10311/428 Files in this item: 1
Gumbricht_JH_2004.pdf (1.267Mb) -
Southworth, J.; Nagendra, H.; Cassidy, L. (Taylor & Francis, June 3, 2011)[more][less]
Abstract: Tropical forest habitat continues to decline globally, with serious consequences for environmental sustainability. The South/Southeast Asian landscapes represent one of the most challenging parts of the world to study issues of landscape change. High population densities in the region pose major threats to forest cover. Despite presentations of supposedly catastrophic declines in forest cover, substantial areas have been observed to maintain or increase forest cover in recent years. This research draws on data from Nepal, India, Thailand, and Cambodia to examine trajectories of forest-cover change along gradients of deforestation and reforestation. The gradients we observe extend from Cambodia, a still predominantly forested landscape, with development and change at initial stages, to Nepal which, despite having experienced large-scale forest clearing in the past, has considerable reforestation in recent years. Understanding these processes is critical for policymakers working on climate change and adaptation. This research allows us to link national-scale and local-scale analyses, in terms of both their similarities and differences, and also to see changes still in progress via the inclusion of regrowth and degradation classes, not just reforestation and deforestation. URI: http://hdl.handle.net/10311/826 Files in this item: 1
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Uziak, J.; Foster, J.D.G. (University of Botswana, Faculty of Engineering and Technology, http://ajol.info/index.php/bjt, October NaN, 2001)[more][less]
Abstract: In this paper a method is presented which enables the solution of the equation of motion of the slider-crank mechanism. Expansion of functions into Fourier series is used in this method, whereby the solution of the equation of motion is also obtained in the form of Fourier series. This method enables also the determination of the coefficient of speed fluctuation of the slider-crank mechanism. The method creates the basis for an analysis of the influence of various factors, e.g. the working conditions or the construction parameters of the system, on the coefficient of speed fluctuation. URI: http://hdl.handle.net/10311/665 Files in this item: 1
Uziak_BJT_2001.pdf (2.257Mb) -
Uziak, J.; Foster, J.D.G. (University of Botswana, NaN, 2001)[more][less]
Abstract: In this paper a method is presented which enables the solution of the equation of motion of the slider-crank mechanism. Expansion of functions into Fourier series is used in this method, whereby the solution of the equation is also Fourier series. This method enables also the determination of the coefficient of speed fluctuation of the slider-crank mechanism. The methods create the basis for an analysis of the influence of various factors, e.g. the working conditions or the construction parameters of the system, on the coefficient of speed fluctuation. URI: http://hdl.handle.net/10311/702 Files in this item: 1
Uziak_BJT_2001.pdf (999.6Kb) -
Ddamba, W.A.A.; Ngila, J.C.; Mokoena, T.T.; Motlhagodi, K. (South African Journal of Chemistry. <http://ejour.sabinet.co.za/images/ejour/chem/chem_v55_a1.pdf>., NaN, 2002)[more][less]
Abstract: The copolymerization of difurylmethane with maleic anhydride in the presence of azobisisobutyronitrile as an initiator has been investigated at 65 °C, 72 °C and 85 °C in different solvents. Reaction feeds containing 85 mol % and higher of difurylmethane yielded a soluble alternating copolymer in which the furan residue entrained in the polymer chain formed 2,5 linkages and had 3,4 unsaturation. The 1:1 difurylmethane– maleic anhydride adduct was readily prepared, and at the above temperatures and in the presence of the radical initiator partially underwent retro-Diels–Alder reaction. Copolymerization of the difurylmethane and maleic anhydride thus formed yielded the unsaturated alternating copolymer. Copolymers prepared from reaction feeds with proportions of difurylmethane lower than 85 mol % had higher cross-link density and exhibited higher thermodecomposition temperatures. URI: http://hdl.handle.net/10311/305 Files in this item: 1
Free radical.pdf (2.417Mb) -
Mutula, S.M. (Emerald, NaN, 2006)[more][less]
Abstract: Abstract Purpose – To argue that developing countries in the Southern African Development Community (SADC) region should embrace the concept of freedom of information to enable better human rights and economic development. Design/methodology/approach – The paper reviews the current situation through discussion of current legislation and proposed policies. Findings – Whereas several theories abound as to why there has been little development in sub- Saharan Africa, this paper discusses the status of freedom of information legislations within the SADC region and the implications for accountability and transparency in the management of public resources. Research limitations/implications – The paper suggests the importance of further research into the importance of freedom of information legislation for economic and human rights development. Practical implications – The paper has practical implication for those considering the potential of freedom of information legislation in developing countries. Originality/value – Freedom of information has largely taken a back seat amidst several social, economic and political reforms that have been instituted collectively or by individual countries. It is the view of this paper that freedom of information provides an important link for the economic, social and political reform initiatives URI: http://hdl.handle.net/10311/438 Files in this item: 1
Mutula_LR_2006.pdf (917.1Kb) -
Sebina, P. (Routledge (Taylor and Francis) www.routledge.com, NaN, 2009)[more][less]
Abstract: The passing of the Promotion of Access to Information Act (PAIA) in South Africa in 2000 ushered in a new era in accessing government records. Members of the public no longer have to wait for 20 years for government records to become archives in order to gain access to them. PAIA gave the public the right of access to all records irrespective of age except for those exempted under the provisions of the Act. This chapter evaluates the impact that Freedom of Information (FOI) legislation in general and PAIA in particular have had on access policies and practices in South Africa, and examines the extent to which this legislation has been used successfully by historians, journalists and other researchers. While the focus is on South Africa, the chapter further examines the lessons that the rest of sub-Saharan Africa could draw from the implementation and use of PAIA. URI: http://hdl.handle.net/10311/755 Files in this item: 1
Sebina_JSA_2009.pdf (1.558Mb) -
Bwire, R N; Majinda, R R; Masesane, I B; Steel, P G (International Union of Pure and Applied Chemistry. http://stage.iupac.org/publications/pac/, NaN, 2009)[more][less]
Abstract: The Diels–Alder adducts of ethyl (E)-3-nitroacrylate and furan provided a common and versatile template for the stereocontrolled synthesis of an isomer of the natural product oryzoxymycin and polyhydroxylated cyclohexyl β-amino acid derivatives. The strategy for the synthesis of the polyhydroxylated cyclic β-amino acid derivatives involved base-induced fragmentation of the oxanorbornene skeleton and face selective oxidation reactions. A Pd-catalyzed transfer hydrogenation reaction in the presence of organic acids is also described. This reaction is amenable to being enantioselective through use of optical pure chiral organic acids. URI: http://hdl.handle.net/10311/301 Files in this item: 1
From nature.pdf (2.826Mb) -
Temtime, Z.T. (WileyInterscience, http://www.wileyinterscience.com, NaN, 2008)[more][less]
Abstract: Today’s business environment is characterized by stiff competition, rapid technological advancements, and changing requirements of customers and employees. To grow and survive in this turbulent environment, Small and Medium Enterprises (SMEs) must balance the emphasis they put on the improvement of short-term operational efficiency and long-term competitiveness. Due to the apparent lack of resources and expertise, most SMEs pay very little attention to long-term competitiveness and dynamism. Preoccupied with operational bits and pieces, SMEs lack strategic awareness and orientation. Strategic awareness is a mental process of continually evaluating organizational and environmental factors and improving on how they are identified, recognized, influenced, and interpreted, and consequently used in making strategic business decisions. The widespread use of short-term oriented, non-formal business planning practices indicates lack of strategic awareness and competitiveness among SMEs. This paper examines the degree of emphasis attached by SMEs, during their business planning, to the achievement of long-term competitive advantages by presenting evidence from a recent empirical study based on data collected from 91 SMEs and analyzed using descriptive statistics such as mean and standard deviation. The findings indicated that SMEs put greater emphasis on short-term profitability and operational efficiency than developing strategic awareness and long-term competitiveness. Although this could be attributed to the relative lack of resources required for the implementation of strategic planning, policy deployment, and positioning, SMEs should be assisted to think and act strategically if they are to survive and grow in today’s turbulent and dynamic markets. Government agencies, policy-makers, consultants, non-governmental organizations, and other small business support agencies must redirect their efforts toward bridging the gap between short-term operational efficiency and strategic competitiveness and sustainability. This paper provides managerial and policy implications for SMEs, SME support agencies, government and non-government agencies, and future research. URI: http://hdl.handle.net/10311/841 Files in this item: 1
Temtime_SC17_2008.pdf (1.252Mb) -
Fynn, R.W.S.; Bonyongo, M.C. (Wiley, November NaN, 2010)[more][less]
Abstract: Ungulate populations in African conservation areas (CAs) are in widespread decline, which can largely be attributed to a lack of functionality of the area encompassed by the CAs themselves. We present evidence from a wide range of African CAs showing that they do not encompass both the functional wet- and dry-season resources that ungulates traditionally migrated between. Before human populations and economic development had grown to levels where they interfered with migrations outside the CAs, ungulates were able to make use of their traditional seasonal resources but this is becoming increasingly difficult and we are now seeing the effects of this restriction of movement on ungulate population numbers. New innovative strategies are required for the conservation of African wildlife. An urgent Africa-wide survey is needed to establish past and present functional resources in and around CAs and to prioritize conservation regions that are most functional. In addition, innovative attempts need to be made to reconsolidate functional seasonal resources within revised expanded protected areas. URI: http://hdl.handle.net/10311/781 Files in this item: 1
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Bagwasi, M.M. (Multilingual Matters and Channel View Publications, http://www.multilingual matters.com, NaN, 2003)[more][less]
Abstract: In multilingual societies such as Botswana, language use is an extremely complex matter, further compounded by the fact that the languages involved are themselves dynamic phenomena that often elude the planned outcomes of policies which try to shape and constrain them. The paper describes the functional distribution of the national language Setswana, spoken as a mother tongue by 80% of the population, and English, the official language in Botswana. The role of the two languages is outlined, with particular regard to cultural identity, on the one hand, and social and economic status on the other. URI: http://hdl.handle.net/10311/831 Files in this item: 1
Bagwasi_LCC_2003.pdf (692.5Kb) -
Khartchenko, N.V.; Oladiran, M.T.; Douglass, G.W. (University of Botswana, http://www.ub.bw, NaN, 1999)[more][less]
Abstract: Coal is plentiful in many parts of the world but its combustion can create severe environmental and aesthetic problems.In the past three decades, the cost of crude oil and natural gas has been unstable and the reserves of these fuels are exhaustible. Other non-conventional energy resources, for example, solar, wind and tidal energy are only making a small contribution to the energy mix in few countries. Consequently, coal still has an important role to play to satisfy the energy demand, especially when it can be converted before combustion to other less environmentally objectionable forms, e.g. coal gas/producer gas. This paper describes the basic principles of coal gasification process and compares the performance of different gasifiers. The fundamentals of the raw gas cleaning methods are presented and experience to date of coal gasification in Botswana is discussed.It seems certain that coal gasification in tanderm with combined cycle power plant will be a principal technique for electricity generation in the next century. The paper recommends that Botswana takes necessary actions to gain maximum advantage from these developments. URI: http://hdl.handle.net/10311/710 Files in this item: 1
Khartchenko_BJT_1999.pdf (1.810Mb)