Volume 3

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Characterization of An for n = 5, 6 by 3-centralizers
(University of Namibia, 2014) Ligonnah, A.
Let 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.
Science and technology: A call for action
(University of Namibia, 2014) Chinsembu, Kazhila C.
A synopsis of the polyvalent qualities of zeolite-clinoptilolite and the proposed uses within the Namibian medical, pharmaceutical, industrial and economical sectors: A proposal for an integrated research.
(University of Namibia, 2014) Kahler, Barbara
Zeolites are crystalline hydrated aluminosilicates of the alkaline and alkaline-earthmetals with unique properties in cation exchange, adsorption and catalysis. Due to these properties they have been increasingly used in a wide range of applications in industry, environmental protection, agriculture, animal production, veterinary- and human medicine. Their increasing integration in the health sector worldwide with recognized efficacy based on scientific researches, clinical trials and personnel experience of many therapists encouraged the author to write this review. Clinoptilolite, one of the natural zeolites, offers a variety of well documented appliances as medical drug for internal and external use in addition to its utilization as growth promoter in animal feed, potent binder of heavy metals and radionuclides along with ammonium exploited in industries, and the use in filter systems for waste water clearance and building and construction material. Since Namibia provides the climate and geological conditions for deposits containing abundant zeolite, it is worth to look at the options for an efficient exploitation. This could open new markets for the national as well as the international trade.The utilization of zeolites within the fields described in this article would offer inexpensive alternatives to cover some shortfalls in the domains of agriculture, building and construction, environment protection and public health. One objective of this literature study is to explore interdisciplinary cooperative efforts to integrate various available information and reports regarding this multipurpose zeolite material in the activities of Namibian educational and research institutions. Several starting points are addressed particularly in the fields of agriculture, animal sciences, pharmacy and human medicine, how natural zeolites could be incorporated into or combined with existing concepts respectively would contribute to develop new strategies, emphasizing the health sector.
Assessment of male infertility causes in Mozambique: A case study of working class patients by IVF at Medicos associados clinica Cruz Azul laboratory Maputo
(University of Namibia, 2014) Mausse, Francisco; Mabota, F.; Bugalho, A.
A total of 105 semen specimens from infertile patients from different economic backgrounds collected throughout the country, were analyzed at IVF laboratory Medicos Associados Clinica Cruz Azul, Maputo between 2008 and 2010. The semen from patients were collected at the laboratory and quality assessment was carried out through microscopic observation. The objective of this study was to: (a) evaluate semen specimen’s prior IFV; (b) provide appropriate prognosis; and (c) find out alternative reproductive techniques to apply. Results revealed 17.14% with normo spermia; 36.2% with moderate oligospermia; 24.8% with severe oligospermia; 9.5% with presence of crystals consisting epithelial and germ cells within the seminal plasma specimens and 21.9% with high semen specimen viscosity (HSSV). These results indicate a significant level of infertility caused by both moderate and severe oligospermia, while the rest of the observed infertility is attributed to HSSV, followed by possible coital disorders which affected 17.14% of patients with standard semen parameters. Introduction of Intra- Cytoplasmic Sperm Injection techniques and counseling measures in the IVF laboratory are advised given their contribution in achieving both fertilization and acceptable conception rates, concurrently with observation of health care, towards keeping active and functional reproductive organs and standard semen quality..
Determination of some hydraulic characteristics of bamboo (Bambusa vulgaris (Schrad)) pipe
(University of Namibia, 2014) Ogedengbe, Kola
The hydraulic characteristics (HCs) of any pipe are important in determining its acceptability for water conveyance. Bamboo culms made into pipes by drilling through their septa at the nodes have been in use for many years but very few documented researches have been reported on their HCs. The HCs of Bambusa vulgaris (Schrad) pipe were therefore investigated to contribute to knowledge of its potential usage in irrigation of agricultural land. Three drilling bits namely hole saw drilling bit (HSDB), Ethiopian drilling bit (EDB) and Tanzanian drilling bit (TDB) were studied and compared, in the removal of the septa at the nodes to make bamboo pipes (BPs) from the Bambusa vulgaris culms. Experimental set-ups were made using 9 m length of the BPs to determine hydraulic parameters such as the head loss due to the nodes and the internodes; friction factors and flow types. The data obtained were analyzed using one-way analysis of variance which were further tested using Duncan post-hoc test. The HSDB performed significantly better (p < 0:05) than the TDB and EDB in the smoothness of septa removal at the nodes with the average percentage head loss value of 0.36%, 0.42% and 0.46% respectively. Average friction factor obtained were 0.037, 0 047 and 0.049 for HSDB, TDB and EDB prepared BPs respectively. All these values are within the acceptable limits for a good hydraulic pipe. The flow type through the BPs was turbulent like for most manufactured pipes presently in use for water conveyance. Based on the determined values of its hydraulic characteristics, B.vulgaris pipe is suitable for usage in irrigation and drainage practices.
The covariance biplot to reveal relationships between different sets of variables
(University of Namibia, 2014) Oyedele, Opeoluwa; Gardner-Lubbe, Sugnet
The 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.
Structures of salivary and pancreatic amylase hydrolysates from processed starches
(University of Namibia, 2014) Nantanga, Komeine K.; Bertof, Eric; Seetharaman, Koushik
Digestion of starch in humans includes luminal and mucosal steps. Structures from the luminal phase of amylases hydrolysis can impact subsequent steps of digestion at the mucosa of the small intestine. However, structures of the starch digestion products along the gut from the mouth to the small intestines products that impact glucose homeostasis are not well understood. This submission focuses on the luminal step of starch digestion, i.e. impact of salivary and pancreatic amylases on the structure of hydrolysis products obtained from cooked starches from different botanical sources. Starch to water ratios of 1:0.7 (T0.7) or 1:2 (T2) were used to cook normal corn (NCS), wheat (NWS) and potato (NPS) starches. Comparatively, DMSO was used to disperse the starches to remove the effect of granular organisation. Cooked and dispersed starches were then subjected to salivary and pancreatic amylases hydrolysis for 20 min and 120 min. Extent of 20 min hydrolysis was lower at T0.7 compared to T2 and TD for all the starches. The molecular weight profiles of 20 min hydrolysates between the processing treatments were more different for NPS than for the other starches. Oligosaccharide composition of 120 min hydrolysates differed in amounts of DP 2, 3, 5, 6 and 7 between processing treatments and also between the starches. These differences, however, did not necessarily follow the intensity of cooking treatment. These differences in structures of hydrolysates, which are the substrate for mucosal hydrolysis in the small intestine, can potentially influence glucose homeostasis.
Optimization of indigenous Ganoderma lucidum
(University of Namibia, 2014) Ueitele, Isabella S.; Chimwamurombe, Percy M.; Kadhila-Muandingi, Nailoke P.
Ganoderma lucidum is a mushroom which shows antitumor, anti-inflammatory and cytoxic activity and grows prolifically in warm climates on decaying hardwood logs and stumps. An experiment was done at the University of Namibia to cultivate the indigenous G. lucidum; however, compared to results from other countries the mushroom took much longer to grow. The objective of this study was to shorten the cropping cycle of the indigenous G. lucidum under cultivation at the University of Namibia. The indigenous mushroom was cultivated according to the established protocol. A suitable indigenous Ganoderma mushroom was selected to make tissue culture, which was used to make the spawn that was inoculated into the woodchips substrate. New ideas were introduced to induce fast growth and optimum yield. The grains were inoculated with more pieces of tissue culture; the substrate was inoculated with increased layers of spawn and mixed with pearl millet husk instead of wheat bran to accelerate the colonization of the substrates. In addition to the hanging bag method used in the previous study, the buried wood log method was also introduced. Temperature and moisture were closely controlled during the experiment. A major highlight of this study was the significant reduction (p < 0:05) in the time it took for the substrate to reach fruiting stage. The substrate mixed with pearl millet husk was completely colonized by the mycelia, two weeks faster than the substrate that was mixed with wheat bran. Since Pearl millet is readily available in Northern Namibia, individuals and communities can substitute the wheat bran with pearl millet husk, which allows the substrate to be ready for fruiting faster, thus shortening the cropping cycle and also reducing the production cost as they no longer have to purchase wheat bran. The buried wood logs did not yield any fruiting bodies, but the hanging bags did produce G. lucidum. The study was successful in producing fruiting bodies in a shorter period. There was no significant improvement in the yield obtained.
Lead pollution: A growing concern along the Namibian coastal waters
(2014) Vellemu, Emmanuel C.; Omoregie, Edosa
The accumulation of lead within specific strata of the Namibian coastal waters during the winter and summer months (2012) of the Southern Hemisphere was investigated using inductively coupled plasma optical emission spectrometry (ICP-OES). The black mussel, Choromytilus meridionalis was used as indicator organism to ascertain levels of bioaccumulation. Accumulation levels in collected sediments and the water column were used as indicators for the partitioning of lead within the coastal water ecosystem. For this investigation, the Central Namibian coastline was demarcated into four sampling stations (Walvis Bay, Swakopmund, Henties Bay and Cape Cross). Results obtained indicated significantly higher levels of lead in sediment samples collected from the Walvis Bay harbour compared to the other sampling stations (p < 0:05), with Cape Cross and Henties Bay relatively in a more pristine stage in terms of lead pollution. Although not significant (p > 0:05), worrisome levels were observed in C. meridionalis tissues collected from Walvis Bay harbour. Maximum mean values of lead detected in sampled C. meridionalis collected from the Walvis Bay harbour was 0.70 mg/Kg of sample dry weight during the summer months. The mean values within the sediments ranged from 79.30 to 0.30 mg/Kg detected from the Walvis Bay harbour to Cape Cross respectively. Though C. meridionalis farmed in and around Walvis Bay harbour could be regarded safe for human consumption as observed lead levels did not exceed permissible WHO limits. However, industrial activities involving discharges of untreated effluent into the harbour could pose health concerns over the long term if these practices are not checked. The major outcome of this investigation is the need for continued monitoring of activities in and around the Walvis Bay harbour that could aggravate increased lead pollution to avoid human risks and irreversible ecosystem destruction.
Avian assemblages of urbanized habitats in north-central Namibia
(University of Namibia, 2014) Kopij, Grzegorz
Studies were conducted by means of the line transect method in 4 towns (Ondangwa, Ongwediva, Oshakati, Outapi) and 12 larger villages in Ovamboland, north-central Namibia. In overall, 59 residential bird species were recorded. In particular across settlement, the number varied from 6 to 34 (x = 20:2;sd = 9:99). The Simpson’s Diversity Index varied from D = 0:61 to D = 0:93. Overall, dominants comprised 68.1% of all pairs recorded (N = 2105), with Passer domesticus accounted for 32.2% (eudominant). Other dominant species included: Uraeginthus angolensis, Cypsiurus parvus, Corvus albus, Streptopelia senegalensis and Urocolius indicus. Subdominants (5 species) comprised 14.2%. Bird assemblage in Ruacana proved to be fairly distant from that in other Ovambo settlements. Latitudinal trends have been shown for the proportion between Pycnonotis tricolor and P. nigricans and Passer diffusus and P. domesticus species. Passer domesticus almost totally replaced Passer diffusus, while Streptopelia senegalensis almost totally replaced Streptopelia capicola in the urbanized habitats of the northStudies were conducted by means of the line transect method in 4 towns (Ondangwa, Ongwediva, Oshakati, Outapi) and 12 larger villages in Ovamboland, north-central Namibia. In overall, 59 residential bird species were recorded. In particular across settlement, the number varied from 6 to 34 (x = 20:2;sd = 9:99). The Simpson’s Diversity Index varied from D = 0:61 to D = 0:93. Overall, dominants comprised 68.1% of all pairs recorded (N = 2105), with Passer domesticus accounted for 32.2% (eudominant). Other dominant species included: Uraeginthus angolensis, Cypsiurus parvus, Corvus albus, Streptopelia senegalensis and Urocolius indicus. Subdominants (5 species) comprised 14.2%. Bird assemblage in Ruacana proved to be fairly distant from that in other Ovambo settlements. Latitudinal trends have been shown for the proportion between Pycnonotis tricolor and P. nigricans and Passer diffusus and P. domesticus species. Passer domesticus almost totally replaced Passer diffusus, while Streptopelia senegalensis almost totally replaced Streptopelia capicola in the urbanized habitats of the north-central Namibia.

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