International Science and Technology Journal of Namibia (ISTJN)

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Aims and Scope of ISTJN Introduction International Science and Technology Journal of Namibia (ISTJN) is a free, expedited, print and online journal of peerreviewed research and commentary in pure, applied and allied sciences and technology published by the Faculty of Science, University of Namibia. Aims and Scope The journal reflects the multidisciplinary nature of the field of science and technology. It addresses the needs of multiple, interlocking communities, including methodologists in mathematics, statistics and econometrics; as well as basic and applied scientists in biology, chemistry, physics, public health, medicine, education, mining, geology, computing, food, agriculture and engineering. The journal will strive to enhance the level of methodological rigour in pure and applied sciences and will contribute to the development of methodological standards in the fields of science and technology in Namibia. In pursuing its main objective, the journal will also provide a meeting ground for researchers from a number of traditional disciplines and will foster the development of scientific research and publication especially among younger practitioners. Interview corner. Editorial Setup The journal has a dedicated team of editors, who would be academic editors (AE) and experts in the field. Founding Editors: Prof LN Kazembe, Statistics Prof EF Archibong, Chemistry Dr KC Chinsembu, Biological Sciences Prof PM Chimwamurombe, Biological Sciences Prof S. Singh, Physics Advisory Editorial Board: Prof O. Mwandemele, PVC (Academic Affairs and Research), University of Namibia Dr F. Gideon, Dean of Science, University of Namibia Mr A. van Kant, Department of Science and Technology, Ministry of Education Mr E. Shivolo, Ministry of Mines and Energy, Namibia Dr E. Mvula, National Commission on Research, Science & Technology Dr R. Steenkamp, HESS Prof R. Auala, Faculty of Education, UNAM Prof J. Lyaku, Faculty of Agriculture, UNAM Prof P. Odonkor, Faculty of Health Sciences, UNAM Prof I. Davidson, Faculty of Engineering & IT, UNAM Prof C. Esterhuysen, Stellenbosch University, South Africa Prof T. Chirwa, Faculty of Health Sciences, Witwatersrand University, South Africa Prof E. Mwenje, Bindura University of Science Education, Zimbabwe Dr O. Ruzvidzo, North West University, South Africa Prof Ponnadurai Ramasami, University of Mauritius

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An activity theory analysis of factorsm influencing information security practices in software organisations
(University of Namibia, 2016) Iyawa, Gloria E.; Mufeti, Tulimeveva K.
Information is an asset to any organisation. As a result, different organisations strive to ensure that information is well protected. This has led to organisations creating information security policies Despite this approach, employees play a vital role to ensure that these policies are implemented. Information security has been studied in different contexts. However, in the existing literature, there is limited research which investigates the factors that influence information security practices in the context of software organisations. Similar to other business contexts, information is an important tool within software organisations. The purpose of this study was to investigate the factors that influence information security practices in software organisations using a Namibian software organisation as a case study. The use of Activity Theory as a lens helped to investigate the factors that influence information security practices in software organisations which are often overlooked. From the analysis of the findings, it is evident that factor such as employee structure, work context, information sensitivity, reputation, responsibility, accountability and policies influence information security practices in software organisations. The findings revealed that information security policies have to been forced at different levels and units in software organisations. The findings from this study may assist software organisations when implementing information security policies.
Analysis of the basic Ross-MacDonald Malaria model parameters
(University of Namibia, 2017) Iiyambo, David S.
We consider a basic finite dimensional Ross-Macdonald malaria mathematical model on interaction of the infected humans and the infected mosquitoes. We study this system for consistence of the equations to the real biomedical situation that they model. Local and global well-posedness of the system is proven and the analysis of the equilibrium points is carried out. Numerical analysis show that mathematical analysis is very powerful for understanding such systems.
Analytical evaluation of eight-cell cow embryos structure, outwards water and inwards cryo-protectants to ensure successful cryopreservation
(University of Namibia, 2013) Mausse, Francisco; Bezugly, N.
Modern reproductive techniques use cow embryos at different stages of development. Eight-cell embryos feature a layer comprising seven cells (blastomeres), surrounding the inner cell, making a total of eight. This article analyses outwards water paths and inwards cryo-protectants, within the eight-cell cow embryos and effectiveness of their cryopreservation. Reproductive cycles and superovulation in cows were triggered through reproductive hormones injection. After slaughter, oocytes were harvested and eight-cell embryos were produced in vitro fertilization and through embryo culture. The study included morphological observations to visualize embryo structure, distribution of blastomeres, cell-layers and analytical evaluation as well, to assess distribution of penetrating cryoprotectants within the inner-cell mass. Findings based on the eight-cell embryo structure suggest that the quantity of outwards water and inwards cryo-protectants is symmetrically distributed. Although, the characteristic of water and cryo-protectants movement is expected to be much better in eight-cell embryos, cryo-protectants properties and the modality of cryo-protectants should differ from procedures applied in other class of embryos. Survival rate of cryopreserved eight cell embryos was lower (6.3%) as compared to the results for 7–8 days embryos. Obviously, a successful cryopreservation of eight-cell cow embryos can only be achieved through a combination of both technical and biological parameters.
Are there bubbles in the housing market of Namibia?: An analysis of historical evidence
(University of Namibia, 2017) Nyambe, Crever; Vijayakumar, Kandaswamy R.; Gnitchogna, Rodrique
The dividend yield ratio in the stock markets is, to an extent, comparable to the rent price ratio in the housing market. Taking advantage of this definitional similarity, one can then use the traditional unit root test for log dividend yield in this case, the log rent-price ratio to test for the existence of real estate bubbles. Such unit root tests are conducted for the whole of Namibia. We develop a continuous and monthly rent price information-based method to track the periods when real estate prices diverge from their fundamental levels. The effect of those investigations would suggest the existence of pockets of bubbles in the real estate market. We finally get to distinguish of the pockets of bubbles observed, which minor, intermediate and major bubbles are.
Assessment of background radiation fin playgrounds of selected basic schools in the GA east municipal district, Accra, Ghana
(University of Namibia, 2017) Taapopi, Erastus E.; Faanu, A.; Dampare, S.B.
A study has been carried out in the play grounds of selected basic schools in the Ga East municipal district of Accra, Ghana, to determine the exposure of school children to the radiation emitted by Naturally Occurring Radionuclide Materials and trace elements. The activity concentrations of different radionuclides were determined using high purity germanium (HPGe) detector. The average activity concentrations of 238U, 232Th and 40K were found to be19.8±8.7, 29.1±16.3 and119.4±97.9 Bq ·kg−1 respectively. The average annual effective dose calculated from these activity concentrations was 0.04mSv which is below the dose limit of1 mSv/year recommended by the International Commission on Radiological Protection (ICRP) for public exposure control. Radiological hazard assessments were carried out and the Rn−222 concentration and exhalation rate were estimated to be 32.13 kBg ·m−3 and 0.016 Bg ·m−2 · s−1 respectively. These values are with in the world average values..
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..
Assessment of natural radioactivity levels and radiation hazards in shore sediments from the Zambezi River, Namibia
(University of Namibia, 2019) Amwaalanga, Maria N.; Onjefu, Sylvanus A.; Zivuku, Munyaradzi; Hamunyela, Roswita H.
In this study, the radioactivity concentrations and the potential health hazards of primordial radionuclides; 238U, 232Th and 40K were measured using a gamma ray spectrometer in 30 soil samples collected from the Zambezi River, Namibia. The average activity concentrations for 238U, 232Th and 40K was found to be 18.91 Bq/kg, 15.58 Bq/kg and 79.17 Bq/kg respectively. The activity concentrations of the measured radionuclides were used to calculate the radiological hazards in soil samples i.e. absorbed dose rate, annual effective dose equivalent, radium equivalent activity and hazard indices (Hex and Hin). From the values obtained, all the radiological hazard parameters were within the world acceptable average values. However, the mean annual effective outdoor and indoor dose equivalent was found to be 0.26 mSv/y and 1.05 mSv/y, respectively, which both exceed the recommended world average United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR) values of 0.07 mSv/y for outdoor and 0.45 mSv/y for indoor.
Assessment of the prerequisites for the establishment of an Animal facility at the School of Medicine, University of Namibia: Comparison of the current situation with international standards and requirements, and with discussion of alternative options
(University of Namibia, 2015) Kahler, Barbara
The School of Medicine (SoM) of the University of Namibia (UNAM) intends to establish an animal house for teaching and experimental research within its facilities. A number of rooms are dedicated for this purpose and partially equipped. This review investigates the feasibility of the project in the light of international standards for animal experimental settings, the prerequisites for the physical establishment, the technical installations, compliance to globally valid regulations of animal welfare, and the probability of getting reliable research outcomes from the given background. The identified current situation within the SoM is subsequently compared to the internationally accepted benchmarks for such institutions, and the principal features of the commonly followed guidelines are briefly listed. A selection of alternative methods to animal experiments is succinctly described and set in the context of the departments of SoM. However, the examination of the physical housing, technical equipment, required human resources and available infrastructure led to the conclusion that the intended use cannot be recommended since the relevant criteria are not met. Instead it would be advisable to construct a separate animal house based on recognized internationally valid standards. In the meantime, less costly non-animal state of the art methods could be introduced.
An assessment of the prevalence and treatment outcomes of multiple antibiotic prescribing vis-`a-vis the appropriateness of antibiotic prescriptions in the empirical treatment of infections: Across-sectional study from Lesotho
(University of Namibia, 2016) Adorka, Matthias; Mitonga, Kabwebwe H.; Allen, Kirk
Purpose: The study had the objective of evaluating the prevalence and effectiveness of healthcare providers use of multiple antibiotics in the empiric treatment of infections. Methods: Three hundred and seven (307) antibiotic prescriptions from inpatient departments of five selected hospitals in Lesotho were assessed for their appropriateness. Antibiotic treatment success rates among patient groups and subgroups treated with antibiotic prescription categories considered appropriate and in appropriate and with specific numbers of antibiotics were determined. Correlations or associations of numbers of antibiotics per prescription and relevant variables were determined and used to evaluate the effects of multiple antibiotic prescribing on treatment outcomes. Results: Single antibiotics were almost prescribed for clinical conditions where prescribes had not absolutely identified bacteria pathogens as aetiologies of treated infections. Greater numbers of prescribed antibiotics were associated with inappropriate use of the agents in the empiric treatment of infections. Appropriateness rather than numbers of prescribed antibiotics correlated positively with treatment outcomes. Conclusion: no categorical relationship appears to exist between the number of antibiotics prescribed and treatment outcome. Prescribing higher numbers of antibiotics did not produce higher favorable treatment outcomes as compared with prescribing antibiotics appropriately.
Assessment on the effect of Lignin as a feed additive for lohmann brown egg layer chickens: A case study at Neudamm farm, University of Namibia
(University of Namibia, 2014) Mausse, Francisco; Lyaku, Japhet R.; Beukes, Edmond; Nafenya, Lazarus
Namibian environmental conditions. A total of 871 chickens (482 experimental and 489 control groups), weighing an average mass of 2 kg/head, were subjected to an experiment under Neudamm Campus (UNAM) environmental conditions (32 C average temperature and 22% relative humidity). All chickens were fed with ordinary balanced ration earmarked for egg layers for 8 days and subjected to stress for 10 minutes per day. The experimental group was given purified lignin (Lignohumate KD) 60 mg/kg diluted in a litter of drinking water, as an anti-stressor feed additive and metabolic activity stimulator. Results of this study revealed an increase in egg production, reduction in feed intake, resistance to stress, and production of eggs of bigger sizes (graded as Extra-large), with strong shells as compared to those produced by the control group. At a certain stage, some chickens from the experimental group were unable to release eggs freely, a fact possibly related to egg size and possible deficient lubrication of cloacal environment. Studies are ongoing with the objective of identifying accurate amounts of lignin/kg necessary to feed egg-layer chickens for triggering an improvement of egg quality under Namibian environmental conditions, without affecting the bird’s physiology and health.
An attempt at modelling the diets of two sympatric species of hake (Merluccius capensis and Merluccius paradoxus) off the coast of Namibia: Isotope mixing model approach
(University of Namibia, 2016) Iitembu, Johannes A.
Two species of hake, Merluccius capensis and Merluccius paradoxus, are the most important secondary consumers in the Benguela current ecosystem. To better understand hake diets in the northern Benguela (Namibia), the stable carbon (13C) and nitrogen (15N) isotope ratios of their muscles, and that of their prey (Hake, n = 115 and prey, n=299) were analysed. Results indicated that their diets were dominated by Plesionika martia, Chlorophthamus agazizi, Myctophids and Euphausiids. The highest contributor to the diet of M. paradoxus varied with length, while the diet of M. capensis was dominated by myctophids at all length classes. Cannibalism accounted for less than 6% and less than 4% in the diets of M. capensis and M. paradoxus respectively. Isotope based estimates of prey dietary contributions differed from that of previous gut content analyses. Overall, the results support the hypothesis that the two species have similar diets. Application of a Bayesian mixing isotope model can be improved to allow for improved hake consumption (i.e. annual) estimates to be made.
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.
Avian diversity and assemblages around Ruacana Waterfall, north-western Namibia
(University of Namibia, 2015) Kopij, Grzegorz
In 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).
Bacteriological analysis of household water from hand-dug wells in the Cuvelai-Etosha basin of Namibia
(University of Namibia, 2017) McBenedict, Billy M.; Wanke, Heike; Hang' ombe, B.M.; Chimwamurombe, Percy M.
Communities in Oshikoto, Omusati, Ohangwena and Oshana regions of Namibia widely utilize the Cuvelai-Etosha Basin by constructing hand-dug wells to provide water to sustain agriculture and households. Since these regions lack a developed water pipeline system and deeper ground water maybe saline in large parts of the Basin, people rely on domestic water supply from private hand-dug wells which are near their houses for convenience and preference. However, the microbial water quality and safety of hand-dug wells being utilized for household consumption in the Cuvelai-Etosha Basin is unknown and this is undesirable since water is a habitat for some pathogenic microorganisms there by posing a health risk. Thus, a bacteriological water quality study that focuses on the identification of microbial contaminants was conducted on 25 wells in the Cuvelai-Etosha Basin of Northern Namibia during two sampling campaigns. Molecular methods indicated the presence of Bacillus aerophilus, Bacillus amyloliquefaciens, Bacillus aquimaris, Bacillus aryabhattai, Bacillus cereus, Bacillus licheniformis, Bacillus pumilus, Bacillus safensis, Bacillus samanii, Bacillussp.M37,Bacillussp. M26, Bacillus stratophericus, Bacillus subtilis, Pseudomonas mendocina, Staphylococcus haemolyticus and Streptomyces celuloflavus.
Birds of Katima Mulilo town, Zambezi region, Namibia
(University of Namibia, 2016) Kopij, Grzegorz
Large river valleys are usually characterized by high level of biodiversity, avian diversity. In Namibia, two towns are located in such valleys: Rundu on Okavango and Katima Malilo on Zambezi. To date, no quantitative studies on any components of biodiversity have been conducted in those towns. In January-May 2013, a total of 36 days were spent on quantitative studies of birds in Katima Mulilo town. The line transect and territory mapping methods were used in this study. A total of 122 resident (breeding), 9 visitors and 9 Palearctic migrants were recorded. The group of dominant species was composed of the following four species: Grey-headed Sparrow, Black-eyed Bulbul, Laughing Dove, and Blue Waxbill. They comprised together 42.5% of all birds. The group of subdominant species included: Rock Dove, Pied Crow, Cape Turtle-Dove, Red-eyed Dove, Southern Masked Weaver, Burchell’s Starling and Mourning Dove. Together they comprised 18.7%. The remaining 112 species comprised 38.8%. The most numerous feeding guilds were granivores (51.3%), frugivores and insectivores (each with c. 20%). Most birds (61.3%) nested in trees and shrubs. Katima Mulilo is probably the only town in whole southern Africa, where all four Streptopelia-doves are common species: Laughing, Cape Turtle, Red-eyed, and Mourning Dove. The only sparrow, which occurs in Katima Mulilo, is the Grey-headed Sparrow. Of special interest is the occurrence of dozen or so species which do not occur in other towns in Namibia, such as African Fish Eagle, Broad-billed Roller, Schalow’s Lorie, Trumpeter Hornbill, among others.
A brief overview about models and methods to calculate the tilt angle and orientation of photovoltaic panels to maximize power generation
(University of Namibia, 2016) Torres-Perez, Mirelys; Rodriguez-Puente, Rafael
Photovoltaic systems are presented as an alternative energy for a sustainable development that can satisfy global energy requirements and provide electricity in remote locations, usually in accessible and away from the electrical network. An essential step in the installation of a photovoltaic solar module is to determine the tilt angle and orientation with respect to the horizontal plane, because an incorrect orientation and inclination can decrease the production capacity and lifetime of a photovoltaic module. The optimum angle for collector’s surfaces of a solar system is determined by many factors such as the incident radiation on the place of the installation and the solar sky, where the shadow of objects that cannot be eliminated like buildings, mountains and others must be taking into account. Based on a literature review of the models and methods more employees worldwide, we provide a brief overview of models and methods to calculate the angle and orientation of a panel in order to maximize power generation.
Characterization of A8 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 2H, if xg 2H for any g 2 G, then g 2 H.’It is proved that for n = 8, G is isomorphic to LK, an extension of an elementary Abelian 2-group L by a group K isomorphic to either A8 or SL(5, 2). If G is simple, it is shown that G is isomorphic to A8 or SL(5, 2).
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.
A Classiﬁcation of Fuzzy Subgroups of Finite Abelian Groups
(University of Namibia, 2013) Gideon, Frednard
The knowledge of fuzzy sets and systems has become a considerable aspect to apply in various mathematical systems. In this paper, we apply a knowledge of fuzzy sets to group structures. We consider a fuzzy subgroups of ﬁnite abelian groups, denoted by G = Zpn +Zqm , where Z is an integer, p and q are distinct primes and m;n are natural numbers. The fuzzy subgroups are classiﬁed using the notion of equivalence classes. In essence the equivalence relations of fuzzy subsets X is extended to equivalence relations of fuzzy subgroups of a group G. We then use the notion of ﬂags and keychains as tools to enumerate fuzzy subgroups of G. In this way, we characterized the properties of the fuzzy subgroups of G. Finally, we use maximal chains to construct a fuzzy subgroups-lattice diagram for these groups of G.
Comparative study of Antioxidant properties, Polyphenols and Flavonoid contents of the tuber and seed extracts of Marama bean (Tylosema esculentum)
(University of Namibia, 2015) Kuvare, Angelina; Kandawa-Schulz, Martha; Kapewangolo, Petrina T.
Tylosema esculentum, also known as the marama bean, is an underutilized legume from Southern Africa. Marama seeds and tubers are used as food and traditional medicine. The antiviral properties of the tuber and seeds have already been explored and the present work provides a first time report on the antioxidant activity and total phenolic content of marama tuber. Marama tuber extract, rich in phenolic compounds, exhibited the highest antioxidant activity compared to the seeds extract. IC50 values obtained for DPPH free radical scavenging were 95.62 ± 7.08 μg/ml and >1000 μg/ml for marama tuber and seed extracts, respectively. There was a positive correlation between the total phenolic content and antioxidant activity in the marama tuber and seed samples. In conclusion, the overall findings of this study suggest that the marama tuber could be a potential source of natural antioxidants.

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