UNAM Open Access Journal University of Namibia
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Characterization of An for n = 5, 6 by 3-centralizers
Get PDFLet G be a finite group containing a subgroup H isomorphic to an alternating group, An, such that G satisfies the 3-cycle property, namely ’for a 3-cycle x 2 H, if xg 2 H for any g 2 G, then g 2 H.’ It is proved that G is isomorphic to LK, an extension of an Abelian 2-group L by a group K isomorphic to either A5 for n = 5; or A6 or A7 for n = 6. If G is simple, we establish that G is isomorphic to A5 for n = 5; or G is isomorphic to A6 or A7 for n = 6
The importance of nuclear magnetic resonance in elucidating the chemical structures of active components found in medicinal plants indigenous to Namibia.
Get PDFNamibia has a vast plant biodiversity which, supported by strong Indigenous Knowledge Systems, could lead to the development of active drugs from one or more of the indigenous plants. This notification paper examines how Namibia is hampered from taking control of and developing its own natural product resources due to a lack of Nuclear Magnetic Resonance (NMR) technology
Searching for the rain
Get PDFSearching for the rain is an anthology of verse by Namibian poet Axaro W. Thaniseb who currently directs the National Theatre of Namibia (NTN). In this anthology, Thaniseb dares to address issues in post-independence Namibia that many would rather not hear nor talk about. He demonstrates bravery as he calls a spade a spade as he explores diff erent controversial themes. The same bravery is shown when he intelligently uses vernacular languages when he switches between languages in the book. In this realistic contemporary work, he shows both his great talent in writing and also his understanding and analysis of Namibian society, its passions, struggles and achievements and manages to do so impartially. Thaniseb’s style of writing is not only easy to read and thought provoking but it is also realistic. In this 46 poem anthology, Thaniseb covers themes raging from dreams, social inequalities, love, self-discovery, fear, pain, war to nationalism. As he travels not only across Namibia but across the world, he pens the poems we fi nd in Searching for the rain, the reader is therefore taken on a journey and into the thought life of the author as he writes with brutal honesty about his feelings, observation and judgements on life especially within Namibia. In this dominantly post-independence Namibian poetry, Thaniseb intricately uses many voices and as a result allows the reader an opportunity to hear not only his voice but many others’ such as that of a man in post-independence Namibia, a young man from the kasie, a man in love and a father who adores his daughter
The covariance biplot to reveal relationships between different sets of variables
Get PDFThe biplot has many advantages, including demonstrating the association between samples and (or) variables of a data set graphically. In this paper, the covariance biplot is used as a visual tool for exploring the relationships between different sets of variables
Today, tomorrow, forever
Get PDFEarly diagnosis and prompt treatment of febrile conditions is a key strategy towards control of the disease from progressing to severe or fatal stages. In this paper, we studied the timing of treatment among children with a history of diarrhoea and fever in Namibia, while simultaneously investigated socio-economic and spatial factors that influence the treatment seeking behaviour. A multinomial probit model with ordered categories was estimated, and results confirmed that there was significant spatial variation at regional level. Socio-economic factors also explain treatment seeking having controlled for spatial dependence. The spatial variation can be interpreted as representing unobserved heterogeneity not captured by the data or possible clustering inherent in nested survey data
On the electronic structure of AlS₂ and AlS₂⁻
Get PDFThe ground and low-lying excited states of AlS2and AlS−2have been studied using den-sity functional theory (DFT) and coupled cluster [CCSD(T)] approximations, in conjunc-tions with the 6-311+G(2df) one particle basis set. AlS2is linear with a2∏gground state.CCSD(T) predicts that the2A2state of the C2visomer is separated from the ground stateby less than 0.1 eV, while the2∏uand2∑+ustates in D∞hsymmetry are located at 0.67 eVand 1.40 eV, respectively, above the2∏gstate. The AlS−2anion possesses a1∑+ggroundstate with a very similar geometry with the neutral molecule. At the CCSD(T) level, adi-abatic electron detachment energies for the [AlS2(2∏g)←AlS−2(1∑+g)] transition is 4.03eV
Loop Space Homology of Some Homogeneous Spaces
Get PDFLet X be a simply-connected compact oriented manifold of dimension m. We show that the Gerstenhaber structure of the loop space homology H (map(S1;X);Q) can be computed in terms of derivations on the minimal Sullivan model of X. The technique is applied to compute brackets in the loop space homology of homogeneous spaces.loop space homology
Identification and selection of superior phenotypes of Uapaca Kirkiana Muell Arg. (Euphorbiaceae), a priority indengenous fruit tree of Zimbambwe.
Get PDFThe International Centre for Research in Agroforestry (ICRAF now known as the World Agroforestry Centre) initiated research and development work on at least 20 priority indigenous fruit trees in 5 countries in Southern Africa including Zimbabwe. The long term objective of this work was to improve food security and income generating capacities of local communities through domestication, marketing and commercialisation of indigenous fruit trees. Country specific priority species were identified based on consultations with a wide range of users. For Zimbabwe, Uapaca kirkiana emerged as a priority species with economic potential and has since become the focus of intensive research. A study aimed at identifying and selecting superior phenotypes of U. kirkiana was initiated in six districts of Murehwa (Natural Region I), Goromonzi (Natural Region II), Rusape (Natural Region II), Bindura (Natural Region II), Masvingo (Natural Region III) and Gokwe (Natural Region IV). Participatory Rural Appraisal (PRA) techniques in the form of group discussions amongst researchers, extensionists, school children, vendors and processors led to the identification of 48 trees of superior phenotypes. Tree location and altitude were recorded using the Geographical Positioning System (GPS). Fruit size, colour, shape were recorded. Total Soluble Solutes (TSS %) was measured using a hand refractometer. The largest fruits (42.3 g/fruit) were collected from Gokwe (ICR03GokZW41) whilst the smallest fruits (9.1 g/fruit) were collected from Rusape (ICR03RusZW53). Fresh fruit weight was strongly correlated to the seed weight (r = 0.813). Fruits with higher pulp content had a lower seed weight (r = −0.452). Fruits from Gokwe and Masvingo had higher TSS percentage. Basing on stakeholders’ selection criteria and laboratory analysis, 23 trees above the mean fruit weight (20.63 g/fruit) were classified as large, whilst 24 trees with pulp content above the mean of 45.18% were classed as pulpy and 22 trees with TSS above 19.53% were classed as sweet. Similarity of the phenotypes was determined through complete linkage in hierarchical cluster analysis. Clustering confirmed the characterisation by farmers using taste as a key method of selecting suitable phenotypes. In-situ conservation and establishment of clones from the selected trees is recommended for purposes of commercialising these superior phenotypes
Evaluation of drought indices using the 40-percentile threshold for the north-central regions of Namibia.
Get PDFDrought is not uncommon to the Southern African climate and it has become a matter of serious concern in Namibia. For that reason, almost all parts of Namibia have become vulnerable to drought occurrence. Whilst recognising agriculture as a pertinent component of the Namibian economy, it is imperative to underscore the importance of drought early warning products for short- and long-term decision making in various sectors of the country’s economy. Following the 1991/92 drought, which ravaged more than 80% of Southern Africa, Namibia now realise the value of meteorological information in weathersensitive decisions. This severe drought has been described as the worst in living memory. Five stations (Ombalantu, Oshakati, Rundu, Katima Mulilo and Tsumkwe) in the northern part of Namibia were assessed. The researcher used the rainfall decile method to assess drought conditions by evaluating whether the widely used 40-percentile threshold is appropriate for triggering a drought warning in Namibia. Results showed that the threshold might have been set too high to be of use in warning farmers of coming droughts. In order to determine the percentile that would be best serve as trigger for drought warnings, there is need for further examination at 30, 25 and 20 percentile mark thresholds. Based on the 40-percentile threshold, much of the drought and a decrease in rainfall accumulation in Ombalantu and Oshakati in the Omusati and Oshana regions respectively, occurred towards the end of the 20th century
Trace and heavy element distribution of the Hwange Coals in Zimbabwe
Get PDFThe study of heavy metals in the Hwange coals enhances knowledge of both the geological evolution of the coal-bearing horizons and the climates that prevailed during their deposition, as well as indicating likely trace and heavy elements that would affect the health of the miners and the environment at large. The Main Coal Seam of the Hwange coals are bracketed by the Lower Wankie Sandstones of Carboniferous to Permian that were deposited during the Dwyka epoch and the Upper Wankie Sandstones of Permian age. The Hwange coals of Zimbabwe are inferred to have been deposited in swamps associated with fresh water lakes lying on either side of a great elevated tract of Archean and Proterozoic basement during the early Permian. Initially the lake was shallow, as observed from sedimentological data, and eventually the lake became deeper during the continuation of the Karoo period of southern Africa. The sedimentation in Zimbabwe began with the melting of the Carboniferous ice cap of the then south and central Africa. The Karoo succession in the Mid-Zambezi Valley suggests that climatic cycles of glacial to semi-glacial and finally to post-glacial nature occurred, followed by very hot, humid and arid conditions towards the end of the sedimentation period. Four sedimentary successions are reflected at Hwange, the first being fluvial-glacial beds, followed by flooding and deposition of the Lower Wankie Sandstones. At the end of this phase, there followed a general increase in flora and fauna, responsible for the formation of coal now preserved in the Main Coal Seam. Above this succession is the Lower Carbonaceous Mudstones of the Wankie succession. The unconformity of the Upper Wankie Sandstones with the Lower Mudstones marks the end of the coal-bearing horizons. Above the Upper Wankie Sandstones further flooding at a large scale occurred, which is thought to have been rapid, as no coal seams are associated with this mudstone in the whole of the Zambezi valley. A systematic study of heavy elements, ash, moisture content and arsenic, shows that during the deposition of the Hwange coals of the Main Coal Seam there were significant amounts of gallium, germanium, niobium, vanadium and chromium in the source areas, together with metals of felsic affinity such as strontium, tin and lithium. There is a systematic relationship between ash content and heavy mineral content in the coal. For coals with a high heavy metal content, their ash contents are low in some samples, whereas others demonstrate the reverse. While we can easily attribute the source of the felsic affliated elements to the basement granites, heavy metals are interpreted to have been fixed under anoxic conditions when the organic matter was being converted to coal. It is suggested that the heavy elements may have acted as catalysts in the coalification processes