The neutral view of science: An example of its inability to explain practice

A generally acceptable definition of the science of economics is that it is the study of the human activity which deals with the thrifty application of relatively scarce alternatively useful means of need fulfilment

Structure, distribution and phenology of perennial plant species in the Worcester Veld Reserve, in the arid winter rainfall region of the Southwestern Cape

High structural diversity amongst plant species in the arid winter rainfall region of southern Africa is common to other arid regions of the world. Details of the range and combinations of structural attributes in species, and within plant communities, are not widely known for southern African arid ecosystems. Hence little is known of how plant-form distributions vary within and between arid ecosystems. and of the environmental factors that may be responsible for any variations found. Nor is much information available on how phenological behaviour relates to the structural attributes of plant species. This study examined structural attributes of perennial plant species on the Worcester Veld Reserve, southwestern Cape. in relation to their distribution and phenology. Species were grouped on the basis of above ground structural and anatomical criteria. The distribution of species and plant-forms was assessed through a phytosociological survey along an environmental gradient in the area, and their phenology determined through qualitative and quantitative monitoring of species phenophases over a two year period. The results show that species of the predefined structural groups i) Co-occur throughout the area. but relative abundances vary from site to site and in relation to topography. aspect and the presence of Mirna-like mounds; ii) Phenological patterns for the flora overall are strongly seasonal, but the timing and periods of phenophases differ between, but are relatively uniform within, the defined structural plant groups. Since phenological patterns are indicative of resource-use patterns. these results indicate that the different plant-forms have different functional responses to the conditions of limited water availability and summer drought. This conceivably facilitates the co-existence of species in this water-limited environment. Habitat variability. which can be related to land-form patterns. is also implicated as a factor facilitating the co-existence of a diversity of species and plant-forms. Structural functional relationships known for arid region plants help to explain the relative uniformity of behaviour within plantform groups. and aid in understanding the ecological significance of distribution patterns of plant-forms in the arid landscape. The conclusion is reached that because of the close coupling between photosynthesis and water-use. the water storage potential and photosynthetic organ type are plant attributes which can serve as useful criteria by which arid region species can be grouped into ecologically meaningful categories or functional guilds. The formulation of a practical and meaningful functional classification is necessary to facilitate the understanding of complex vegetation patterns and processes within arid ecosystems. and allow for meaningful inter-ecosystem comparisons

Die vrye markstelsel as ekonomiese stelsel

Oor hierdie saak is reeds uiteenlopende standpunte ingeneem. Die verskyning van die Wiehahn- en Riekertverslae op die arbeidsterrein, die De Kockverslag oor ons wisselkoersbeleid en die gedagte van ’n konstellasie van Suider Afrikaanse state het hierdie saak weer opnuut na vore gebring. Die rede daarvoor is dat al hierdie sake uitgaan van die uitbouing van die vrye markstelsel ter oplossing van ons ontwikkelingsprobleme. Van belang is die feit dat die vrye markstelsel hier tersprake is, en nie die kapitalisme nie. Dit is dus nodig dat ons onsself opnuut weer afvra wat hierdie stelsel presies is en wat dit beoog

Lentiviral manipulation of gene expression in human adult and embryonic stem cells

Human stem cells could revolutionize the field of medicine by providing a diverse range of cell types for tissue replacement therapies and drug discovery. To achieve this goal, genetic tools need to be optimized and developed for controlling and manipulating stem cells ex vivo. Here we describe a lentiviral delivery system capable of high infection rates in human mesenchymal and embryonic stem cells. The lentiviral backbone was modified to express mono- and bi-cistronic transgenes and was also used to deliver short hairpin ribonucleic acid for specific silencing of gene expression in human stem cells. We show that lentiviral transduction can be used to alter gene expression without altering the genes' ability to differentiate in vitro. These vectors will enable rapid analysis of gene function in stem cells and permit the generation of knock-in / knock-out models of human disease in the rapidly developing field of gene therapy

Determinants for realisation of the right to food among adolescents in Sterkspruit, Eastern Cape Province, South Africa

Globally, the youth population aged between 10 and 24 years is the fastest growing and faces health and nutritional challenges affecting their growth and development, livelihoods and future careers. The government needs to take necessary action towards the full realisation of the right to health, water, education and adequate standards of living, amongst others. A cross-sectional descriptive study using a mixed method approach was conducted. The study aimed at gaining an insight into perceptions about underlying factors, having an impact on the realisation of the Right to Food (RtF) of adolescents in the Sterkspruit area of the Senqu sub-district (Eastern Cape Province). It, furthermore, explored possible solutions and opportunities to facilitate the progressive realisation of the RtF for adolescents in this area. In-depth interviews were held with eight (8) key informants who were actively involved in the community. Fifty (50) adolescents aged 10 to 19 years completed a self-administered questionnaire and participated in Focus Group Discussions, stratified for gender and age. Through content analysis of qualitative data, transcripts were coded and emerging themes were grouped, using the ATLAS.ti 7 text analysis programme. Sixteen (16) percent of the adolescents sometimes had access to only one food source at home and have experienced hunger at times. The most pressing issues identified by participants, which compromises the realisation of adolescents’ right to food and health, was hunger caused by a combination of a monotonous diet, lack of agrarian resources, unemployment and mismanagement of Child Support Grants. Although government was regarded as the main duty-bearer responsible for the realisation of the RtF, it was perceived to be inefficient in taking sustainable measures to enhance food security in this resource-poor area. Very few participants identified adolescents’ own responsibility as rights-holders. The implementation of a human rights-based approach is needed for both the dutybearers and rights-holders to facilitate adolescents’ physical and economic access to sufficient, safe and nutritious food

Kidney cancer: The next decade

Chris Boshoff, Senior Vice President of Immuno-Oncology, Translational and Early Development at Pfizer, and colleagues Samra Turajlic and Charles Swanton from the Francis Crick Institute and University College London give us their personal point of view on new insights and future therapeutic approaches for renal cancer

Validation of the Teacher Stress Inventory (TSI) in a multicultural context: The SABPA study

The aim of this study was to validate the Teacher Stress Inventory (TSI) for use in a South African context. The process of scale validation also sheds significant light on this culturally diverse group of participants’ levels of psychological well-being and physical health, and its association with the level of stress that teachers reported. Using a cross-sectional survey design, Caucasian (n = 209) and African (n = 200) educators’ subsiding in the North-West Province of South Africa, completed the TSI, together with a number of self-report and physiological measures of stress and well-being. In contrast to the five factors of the TSI identified in US samples, statistical analysis yielded a two-factor model (i.e. General circumstance-related stress and Learner-related stress) with satisfactory reliability indices. Significant correlation with measures of psychological and physiological health also reflected positively on the criterion-related validity of the scale. The TSI proved to be a useful, brief self-report questionnaire for the assessment of teacher stress in this cohort of South African teachers.Keywords: psychological well-being; reliability; South African context; stress; Teacher Stress Inventory (TSI); validit

Oncogenic transformation of mesenchymal stem cells decreases Nrf2 expression favoring in vivo tumor growth and poorer survival

BACKGROUND: The transcription factor Nrf2 is a key regulator of the cellular antioxidant response, and its activation by chemoprotective agents has been proposed as a potential strategy to prevent cancer. However, activating mutations in the Nrf2 pathway have been found to promote tumorigenesis in certain models. Therefore, the role of Nrf2 in cancer remains contentious. METHODS: We employed a well-characterized model of stepwise human mesenchymal stem cell (MSC) transformation and breast cancer cell lines to investigate oxidative stress and the role of Nrf2 during tumorigenesis. The Nrf2 pathway was studied by microarray analyses, qRT-PCR, and western-blotting. To assess the contribution of Nrf2 to transformation, we established tumor xenografts with transformed MSC expressing Nrf2 (n = 6 mice per group). Expression and survival data for Nrf2 in different cancers were obtained from GEO and TCGA databases. All statistical tests were two-sided. RESULTS: We found an accumulation of reactive oxygen species during MSC transformation that correlated with the transcriptional down-regulation of antioxidants and Nrf2-downstream genes. Nrf2 was repressed in transformed MSC and in breast cancer cells via oncogene-induced activation of the RAS/RAF/ERK pathway. Furthermore, restoration of Nrf2 function in transformed cells decreased reactive oxygen species and impaired in vivo tumor growth (P = 0.001) by mechanisms that included sensitization to apoptosis, and a decreased hypoxic/angiogenic response through HIF-1α destabilization and VEGFA repression. Microarray analyses showed down-regulation of Nrf2 in a panel of human tumors and, strikingly, low Nrf2 expression correlated with poorer survival in patients with melanoma (P = 0.0341), kidney (P = 0.0203) and prostate (P = 0.00279) cancers. CONCLUSIONS: Our data indicate that oncogene-induced Nrf2 repression is an adaptive response for certain cancers to acquire a pro-oxidant state that favors cell survival and in vivo tumor growth

Building long-term marketing relationships: New perspectives on B2B financial services

The focus of this study was on the relevance of trust, satisfaction and commitment in maintaining a long-term relationship (intention to stay) with an exchange partner in a Business-to-Business (B2B) context in the financial services industry. The perceptions of 238 B2B clients of a leading South African provider of development capital were investigated. Since support could not be found for the existence of trust, commitment and satisfaction as distinct individual dimensions, this study provides empirical support for the amalgamation of some well-established individual dimensions into broader, more holistic dimensions as drivers of long-term relationship building. Contrary to expectations, B2B banking clients participating in this study appeared to regroup individual dimensions, in a heuristic fashion, to form new dimensions that influenced their attitude towards staying in a B2B relationship. As a result, building long-term marketing relationships seems to be a less complicated process than previously thought. Against this background, the primary contribution of the study is that it highlights the need for marketing practitioners to reconsider their current relationship-marketing strategies. As the findings of the study are inconsistent with conventional wisdom, they also challenge marketing academics to reconsider the theoretical foundations of relationship building in a B2B context