100 research outputs found
ERP value determination in South African companies
The theme of this research is to establish how South African companies evaluate the benefits of a capital investment, in terms of ERP implementations, to the organisation. The question of whether determinable value can be quantified and the methods used to calculate such value is explored. A search is conducted for critical success factors for successful ERP implementations, key metrics used for monitoring results, and the approach of South African companies to determining benefits. The research is designed to establish what post purchase analyses of completed projects are conducted and what percentage of completed implementations are considered successful in the South African environment, as well as the possible reasons for those successes and failures. The research consists of firstly a qualitative study of the goals of value creation of ERP decisions, which included a couple of interviews with IT and Process Engineering consultants to form a basis of knowledge for why companies implement ERP systems in the first place, followed by a quantitative descriptive study of the implementation success factors and post implementation analysis, by means of a survey of South African companies. The outcome of the research shows that ERP in South Africa has matured to a level where the majority of projects are judged by the key decision makers to be successful, in contrast to expectations created by the literature review performed. It also highlights that, in the capital budgeting decision making processes followed by companies of different sizes, qualitative factors play a slightly bigger role than quantitative factors in the motivation of an ERP implementation. In addition, this research concludes that companies who identify a clear business value goal with the proposed ERP implementation, ensures buy-in from top management, perform proper planning before embarking on the project, as well as follow some kind of rigorous measurement framework, experience higher levels of ERP success than those who do not. CopyrightDissertation (MBA)--University of Pretoria, 2010.Gordon Institute of Business Science (GIBS)unrestricte
Rapid detection of GES-type extended-spectrum β-lactamases in Pseudomonas aeruginosa with a peptide nucleic acid-based realtime PCR assay
Extended-spectrum β-lactamases (ESBLs) constitute a major problem given their broad substrate specificity and ability to hydrolyse many of the extended-spectrum third-generation cephalosporins currently in use in hospital settings. Guiana extended-spectrum-type (GES-1 – GES-9) ESBL enzymes have mainly been found in Pseudomonas aeruginosa (P. aeruginosa) and only at a limited number of geographical sites, mainly France, Greece and South Africa. Detection of GES-type ESBL-producing P. aeruginosa isolates in the clinical microbiology laboratory using conventional methods is problematic with molecular methods yielding better results. The aim of this study was to utilise various molecular techniques to determine the prevalence of GES-type ESBLs, characterise their genetic determinants and determine their clonal relatedness. The study further aimed to apply a sequence-selective, competitive PNA-based multiplex PCR in real-time for the identification and differentiation of GES-type enzymes. The prevalence of GES-type ESBLs was determined successfully through DNA sequencing. An increase in GES-2 prevalence since 2000 was noted which emphasised the importance of constant surveillance to monitor antibiotic determinants, their spread and overall prevalence. The knowledge on prevalence could be used in turn to monitor the efficacy of infection control measures and antibiotic regimens. Repeated sequencing confirmed the presence of blaGES-5 in P. aeruginosa isolates. As far as could be established, this study reported the first occurrence of GES-5 in South Africa and was the second description of GES-5 in P. aeruginosa. Application of a sequence-specific, competitive PNA-based multiplex PCR in real-time utilising SYBR Green was not suitable for the identification and differentiation of the blaGES genes. Although the method achieved different melting temperatures for the bla<GES genes tested, these temperatures were not suitable for accurate differentiation. Melting temperatures obtained for the same blaGES gene varied and those for different genes overlapped. An approach exploiting the high temperature shift caused by the PNA-probe rather than its competitive nature might be more successful. Random amplified polymorphic DNA typing has been described as a fast and simple method with high discriminatory power for the typing of P. aeruginosa and was thus used to determine the clonal relatedness of the bla<GES positive P. aeruginosa isolates. The occurrence of identical or similar P. aeruginosa isolates producing ESBLs in a single hospital setting emphasised the importance of constant surveillance. The study further identified identical P. aeruginosa clones that occurred in different hospitals indicating spread from a common external reservoir into these hospitals. The occurrence of highly drug-resistant P. aeruginosa in the environment has serious implications in a country with an ever increasing immune-compromised population. These finding were of concern since they demonstrated that acquired GES ESBLs can rapidly emerge and become a major cause of broad-spectrum β-lactam resistance among nosocomial pathogens. The information obtained in this study should be used to create awareness of the potential ESBL problem threatening current antimicrobial regimens in South Africa.Dissertation (MSc (Medical Microbiology))--University of Pretoria, 2008.Medical Microbiologyunrestricte
The medium-long term impact of cross-border investments into Sub- Saharan Africa by listed South African companies
Research into whether the medium-long term impact on shareholders’ value of acquiring companies engaged in cross-border merger and acquisition transactions (CBMA) into Sub-Saharan Africa. By focussing on companies listed on the Johannesburg Securities Exchange (“JSE”) and testing the general hypothesis whether the shareholders of acquiring companies earn statistically significant positive or negative returns within the medium-long term after the announcement date of a cross-border merger and acquisition transaction. Out of a total of 10,167 merger and acquisition transactions over the eight-year period between 2000 and 2007, only 12 cross-border mergers and acquisitions into Sub-Saharan Africa satisfied all the selection criteria. By exhaustive application of the single-factor market model to calculate the regression formula using 4 years of historical share price performance data, the results suggested that statistically significant negative weighted average abnormal returns for shareholders are consistently present over the event window. The study on the medium-long term event window starting 21 days prior to the first public announce of the transactions and continued up to 252 trading days after the announcement date. Thus it satisfied common critique by researchers about the true value of short term event studies for companies and their shareholders. CopyrightDissertation (MBA)--University of Pretoria, 2010.Gordon Institute of Business Science (GIBS)unrestricte
Increased caspase-3-dependent spermatogenic cell death and dysregulated adult spermatogenesis following in utero, lactational and direct exposure to para-nonylphenol
Abstract of the EUROTOX 2006/6 CTDC Congress - 43rd Congress of the European Societies of Toxicology & 6th Congress of Toxicology in Developing Countrie
Field effectiveness of microbial larvicides on mosquito larvae in malaria areas of Botswana and Zimbabwe
BACKGROUND : The successful control of malaria vectors requires the control of both the larval and adult stages. The
adult control methods through indoor residual spraying (IRS) and use of long-lasting insecticidal nets (LLINs) continue
to be widely used with some high measure of success. Larval control methods are also being used by a number of
National Malaria Control Programmes (NMCPs) with limited understanding of its contribution. Larval control might be
needed in some areas to move from malaria control to elimination. This experimental study was conducted to assess
the field effectiveness of winter larviciding on the larval stages of the mosquito in Botswana and Zimbabwe.
METHODS : Two villages were selected in each of the two countries, one as an intervention and the other as the
control. Water bodies in the intervention villages were treated using the commercial product VectoBac® WG (Valent
BioSciences Corporation, IL, USA) containing the active ingredient Bacillus thuringiensis var. israelensis (Bti), a WHO
recommended bio-larvicide, applied at a rate of 300 g per hectare. Random-effects Poisson regression was employed
during data analysis to compare intervention with control sites with respect to larval counts.
RESULTS : The average marginal effect of larviciding on the mosquito larvae taking interaction with time (period) into
account, was −1.94 (95% CI −2.42 to −1.46) with incidence rate ratio of 0.14, thus an 86% larval reduction attributable
to the intervention for both countries combined. There was a 92% and 65% effect for Botswana and Zimbabwe
respectively. The effect on the early larval and late stages was 77% (P < 0.001) and 91% (P < 0.001), respectively. Overall,
intervention larval sampling points had five more larvae than the control at baseline and 26 less after 16 weeks.
The effect on the different species also showed similar trends.
DISCUSSION/CONCLUSION : Larval control using Bti showed a high effect on the population of the mosquito larvae. The
reduction of the early and late larval stages can lead to reduced adult mosquito emergence and low adult mosquito
densities. Larviciding can be used to control mosquito vector population by suppressing the larval stages thereby
reducing adult emergence and malaria risk.The University of Pretoria Institute for Sustainable
Malaria Controlhttp://www.malariajournal.comam2017School of Health Systems and Public Health (SHSPH
Mosquito community composition in South Africa and some neighboring countries
BACKGROUND: A century of studies have described particular aspects of relatively few mosquito species in southern Africa, mostly those species involved with disease transmission, specifically malaria and arboviruses. Patterns of community composition such as mosquito abundance and species diversity are often useful measures for medical entomologists to guide broader insights and projections regarding disease dynamics and potential introduction, spread or maintenance of globally spreading pathogens. However, little research has addressed these indicators in southern Africa. RESULTS: We collected 7882 mosquitoes from net and light traps at 11 localities comprising 66 species in 8 genera. We collected an additional 8 species using supplementary collection techniques such as larval sampling, sweep-netting and indoor pyrethrum knockdown catches. Highest diversity and species richness was found in the Okavango Delta of Botswana and in South Africa's Kruger National Park, while the lowest diversity and abundances were in the extreme southern tip of South Africa and in semi-desert Kalahari close to the South Africa border with Botswana. Species composition was more similar between proximal localities than distant ones (Linear model P-value = 0.005). Multiple arbovirus vector species were detected in all localities we surveyed (proportion of vector mosquito numbers were > 0.5 in all locations except Shingwedzi). Their proportions were highest (> 90%) in Vilankulo and Kogelberg. CONCLUSIONS: Multiple known arbovirus vector species were found in all study sites, whereas anopheline human malaria vector species in only some sites. The combination of net traps and light traps effectively sampled mosquito species attracted to carbon-dioxide or light, accounting for 89% of the 74 species collected. The 11% remaining species were collected using supplementary collection techniques mentioned above. The diversity of species weas highest in savanna type habitats, whereas low diversities were found in the drier Kalahari sands regions and the southern Cape fynbos regions.publishersversionpublishe
Using soil-specific partition coefficients to improve accuracy of the new South African guideline for contaminated land
Please read abstract in the article.http://www.wrc.org.zatm201
Nitrogen mineralization from sludge in an alkaline, saline coal gasification ash environment
Rehabilitating coal gasification ash dumps by amendment with
waste-activated sludge has been shown to improve the physical
and chemical properties of ash and to facilitate the establishment
of vegetation. However, mineralization of organic N from sludge
in such an alkaline and saline medium and the effect that ash
weathering has on the process are poorly understood and need to
be ascertained to make decisions regarding the suitability of this
rehabilitation option. This study investigated the rate and pattern of
N mineralization from sludge in a coal gasification ash medium to
determine the prevalent inorganic N form in the system and assess
the effect of ash weathering on N mineralization. An incubation
experiment was performed in which fresh ash, weathered ash, and
soil were amended with the equivalent of 90 Mg ha−1 sludge, and
N mineralization was evaluated over 63 d. More N (24%) was
mineralized in fresh ash than in weathered ash and soil, both of
which mineralized 15% of the initial organic N in sludge. More
nitrification occurred in soil, and most of the N mineralized in ash
was in the form of ammonium, indicating an inhibition of nitrifying
organisms in the ash medium and suggesting that, at least initially,
plants used for rehabilitation of coal gasification ash dumps will take
up N mostly as ammonium.Th is study was supported by the Water Research Commission and
Sasol.https://www.agronomy.orgpublications/jeqam2017Plant Production and Soil Scienc
Patient-reported physical functioning is limited in almost half of critical illness survivors 1-year after ICU-admission:A retrospective single-centre study
Post-intensive care unit (ICU) sequelae, including physical and mental health problems, are relatively unexplored. Characteristics commonly used to predict outcome lack prognostic value when it comes to long-term physical recovery. Therefore, the objective of this study was to assess the incidence of non-recovery in long-stay ICU-patients. In this single-centre study, retrospective data of adults with an ICU stay >48 hours who visited the specialized post-ICU clinic, and completed the Dutch RAND 36-item Short Form questionnaire at 3 and 12 months post-ICU, were retrieved from electronic patient records. In cases where physical functioning scores at 12 months were below reference values, patients were allocated to the physical non-recovery (NR) group. Significantly different baseline and (post-)ICU-characteristics were assessed for correlations with physical recovery at 12 months post-ICU. Of 250 patients, 110 (44%) fulfilled the criteria for the NR-group. Neither the severity of illness, type of admission, nor presence of sepsis did not differ between groups. However, NR-patients had a higher age, were more often female, and had a higher incidence of co-morbidities. Shorter LOS ICU, lower incidence of medical comorbidities, and better physical performance at 3 months were significantly correlated with 1-year physical recovery. Comorbidities and reduced physical functioning at 3 months were identified as independent risk-factors for long-term physical non-recovery. In conclusion, a substantial proportion of long-stay ICU-patients who visited the standard care post-ICU clinic did not fulfil the criteria for full physical recovery at 12 months post-ICU. Commonly used ICU-characteristics, such as severity of illness, do not have sufficient prognostic value when it comes to long-term recovery of health-related quality of life
Mosquito-borne arboviruses of African origin : review of key viruses and vectors
Key aspects of 36 mosquito-borne arboviruses indigenous to Africa are summarized, including lesser or poorly-known
viruses which, like Zika, may have the potential to escape current sylvatic cycling to achieve greater geographical
distribution and medical importance. Major vectors are indicated as well as reservoir hosts, where known. A series of
current and future risk factors is addressed. It is apparent that Africa has been the source of most of the major
mosquito-borne viruses of medical importance that currently constitute serious global public health threats, but
that there are several other viruses with potential for international challenge. The conclusion reached is that
increased human population growth in decades ahead coupled with increased international travel and trade is
likely to sustain and increase the threat of further geographical spread of current and new arboviral disease.http://www.parasitesandvectors.comam2018Medical VirologySchool of Health Systems and Public Health (SHSPH)Veterinary Tropical Disease
- …