Effects of sustained elevated CO2 concentration and Nitrogen nutrition on wheat (Triticum aestivum L. cv Gamtoos)

There is consensus that high CO2 results in enhanced growth and yield for most crop plants. However, most of these studies were carried out in the presence of adequate nutrients, which is also the case in agricultural systems (managed ecosystems). About 20% of the earth’s land mass have sufficiently low levels of nutrients to cause some kind of stress to plants. On the other hand, elevated [CO2] decreases foliar nutrient elements in plants and as a result partitioning of certain nutrient elements in plants is altered. Little data is available on the partitioning of most nutrient elements in plants, and this will definitely impact on growth and yield. To investigate this, wheat (Triticum aestivum L. c.v. Gamtoos) was grown in controlled environment cabinets at 360 and 700 µmol mol -1 CO2. The full Long-Ashton nutrient solution comprising of three-nitrogen concentrations ([N]) viz. (4,6 and 12 mM) was used to water plants everyday. The measurement of net assimilation rate (NAR), stomatal conductance (gs), transpiration rate (E), water use efficiency (WUE), foliar [N], nitrogen use efficiency (NUE) and growth parameters (total plant biomass (TPB), total plant height (TPH), leaf area (LA), shoot and root dry weight) were made 7 days after germination (7 DAG) till the onset of flowering. The increase in nitrogen supply in the order of 4, 6 and 12mM resulted in an increase in NAR, g_s_ , WUE and a decline in E under elevated [CO2]. Under elevated [CO2] NAR was observed to increase during the first two weeks reaching its maximum at 14 DAG, thereafter followed by a decline reaching its maximum at 28 DAG. This was later followed by an increase at 35 DAG onwards. Under elevated [CO2], NAR was increased significantly between the nitrogen regimes during the first (7-14 DAG) and the last two (35-42 DAG) weeks. The response of assimilation as a function of internal [CO2] (Ci), showed a decrease with age at ages 14, 28 and 35 DAG. This negatively affected the initial slope and the CO2 saturated photosynthetic rates under all treatments. This suggest that acclimation may have been as a result of both stomatal and biochemical limitations. All the photosynthetic pigment levels (chl_a_, chl_b_, chl_(a+b)_, and C_(x+c)_ ) increased with an increase in nitrogen supply from 4 to 6mM [N]. A 12mM [N] resulted in a significant decline in the photosynthetic pigment levels compared to a 6mM [N]. Chla remained higher than chlb under all treatments. Also, NAR was seen to increase and decrease concomitantly with the photosynthetic pigment levels. Foliar [N] was seen to decrease with an increase in nitrogen supply from 4 to 6 mM [N] under elevated [CO2] and the effects were adverse under the 4mM [N]. Under the 6mM N regime foliar [N] was positively correlated to NAR for elevated [CO2] grown plants. Similarly, E was positively correlated to foliar [N] under the same conditions. Elevated CO2 and increase in nitrogen supply had a pronounced effect on total plant height (TPH), total plant biomass (TPB), leaf area (LA), shoot and root dry weight and nitrogen use efficiency (NUE). The effects were more pronounced under a 6mM [N] as a result of high NUE. However, under 12mM [N] growth was not as expected as a result of lower NUE. Under all treatments shoot dry weight (SDW) was positively correlated to NUE. Anatomical studies revealed that total leaf and midrib thickness was significantly increased with an increase in nitrogen supply under elevated CO2 to support the larger leaf areas. There were no significant changes in the chloroplast ultrastructure as a result of the increase in nitrogen supply and CO2 enrichment. Starch grain surface area was seen to decline with an increase in nitrogen under both ambient and elevated CO2. Elevated CO2 and increase in nitrogen supply significantly increased total grain dry weight per plant by 47 and 46% respectively under 6 and 12mM [N]. In contrast, the increase was by about 21, 61 and 67% respectively under 4, 6 and 12mM [N] between the CO2 regimes

Women’s prospects for career advancement: Narratives of women in core mining positions in a South African mining organisation

Orientation: Even though there has been a phenomenal increase in the number of women employed in the mining industry, the figures hide many gender inequalities as the gendered impediments to career advancement persist despite South Africa’s remarkable equity policy regime. However, it is unclear, from the perspective of the women themselves, how their career advancement is encumbered. Research purpose: This study reflects on the prospects for career advancement by exploring the work and organisational experiences of women in core mining positions in an open-cast mining organisation in South Africa. Motivation for the study: To reflect on the prospects for career advancement of women in core mining positions. Research approach, design and method: Eight professional women, selected through a purposive sampling procedure, participated in in-depth unstructured interviews. Data were analysed using Creswell’s simplified version of the Stevick–Colaizzi–Keen method, guided by the lens of gendered organisations. Main findings: Three themes emerged: (1) male domination that has marginalised women and compelled them to emulate masculinity has legitimised existing gender barriers, (2) the long, awkward and unpredictable hours of work have deepened women’s time constraints because they have to combine the home or family caretaker role with work, and (3) the essence of being a woman in a mining organisation. Practical/managerial implications: The study may present South African managers with a better understanding of how work and organisational features, policies, daily practices and discourses impede career advancement of women in core mining positions. Organisations should train managers to create conditions that minimise barriers and maximise performance and advancement, and align retention strategies. Contribution/value-add: This study builds on existing knowledge about career advancement of women by providing new and valuable information specific to women in core mining positions in an open-cast mining organisation in South Africa, seen through the lens of gendered organisational theory. The findings highlight the need for organisational theory research that is responsive to the subtle issues and gendered assumptions that sustain encumbrances to women’s career trajectories

CO2-fertilisation enhances resilience to browsing in the recruitment phase of an encroaching savanna tree

CO2-fertilisation is implicated in the widespread and significant woody encroachment of savannas due to CO2-stimulated increases in below-ground reserves that enhance sapling regrowth after fire. However, the effect of CO2 concentration ([CO2]) on tree responses to the other major disturbance in savannas, herbivory, is poorly understood. Herbivory responses cannot be predicted from fire responses, as herbivore effects occur earlier during establishment and are moderated by plant palatability and defence rather than below-ground carbon accumulation. The relationship between herbivory and [CO2] is explored here using a widespread, strongly encroaching savanna tree, Vachellia karroo. Using greenhouse-grown seedlings under past—through to predicted future—[CO2] (180–1000 ppm) and field-grown seedlings under ambient [CO2], we assessed plant survival, growth, defence and palatability. Increasing [CO2] improves the tolerance of greenhouse-grown seedlings to herbivory by stimulating growth and allowing a critical size threshold associated with survival to be reached earlier, thereby decreasing the probability of fatal herbivory during the vulnerable recruitment phase. Elevated [CO2] also decreases the time taken to reach a second size threshold linked to accelerated recovery of field-grown seedlings following herbivory. Seedling growth responses to increasing [CO2] are nonlinear, suggesting that historic growth and survival enhancements are smaller than those predicted for the future. Increasing [CO2] is associated with greater resistance to herbivores (more branched shoot architecture) but not leaf palatability (C:N ratio) or defence (leaf tannins and spine density). Increasing V. karroo densities already constitute a major land management problem in southern African savannas. However, encroachment by this species, and likely other savanna tree species, may be greatly exacerbated under future [CO2], as tolerance to herbivory at the recruitment stage is further enhanced

Determinants of woody encroachment and cover in African savannas

Savanna ecosystems are an integral part of the African landscape and sustain the livelihoods of millions of people. Woody encroachment in savannas is a widespread phenomenon but its causes are widely debated. We review the extensive literature on woody encroachment to help improve understanding of the possible causes and to highlight where and how future scientific efforts to fully understand these causes should be focused. Rainfall is the most important determinant of maximum woody cover across Africa, but fire and herbivory interact to reduce woody cover below the maximum at many locations. We postulate that woody encroachment is most likely driven by CO2 enrichment and propose a two-system conceptual framework, whereby mechanisms of woody encroachment differ depending on whether the savanna is a wet or dry system. In dry savannas, the increased water-use efficiency in plants relaxes precipitation-driven constraints and increases woody growth. In wet savannas, the increase of carbon allocation to tree roots results in faster recovery rates after disturbance and a greater likelihood of reaching sexual maturity. Our proposed framework can be tested using a mixture of experimental and earth observational techniques. At a local level, changes in precipitation, burning regimes or herbivory could be driving woody encroachment, but are unlikely to be the explanation of this continent-wide phenomenon

A phenomenological study on the experiences of black people consulting African traditional healers in Tshwane

M.Tech.The World Health Organization (WHO) defines African Traditional Medicine (ATM) as comprising of indigenous experiences of different cultures, approaches, knowledge and beliefs, which incorporates plant, animal and mineral-based medicines together with spiritual therapies in the treatment, diagnostic and the prevention of disease (WHO, 2008). It is estimated that up to 70-80% of the black population in South Africa consult African Traditional Healers (ATH) for their health care needs before or together with the use of other health care providers (Truter, 2007). According to Truter (2007) this is because many in the black population find ATH to be more accessible, familiar and more knowledgeable concerning culture-bound syndromes and traditions. Homoeopathy is a form of natural medicine that takes a holistic approach to the treatment of patients. As part of a holistic approach, Homoeopaths are required to understand their patient’s frame of reference and their life world. As many of the black patients who consult Homoeopaths also consult ATH, it is important for the Homoeopathic practitioner to understand these patients in order to ensure positive doctor-patient relationships. The aim of this qualitative phenomenological study was to explore and describe the experiences of black people consulting ATH in Tshwane and from this information, make guidelines for improved meaningful interactions between Homoeopathic practitioners and their patients who consult ATH. This was a contextual, qualitative and phenomenological research design. Ten black participants who consulted with ATH were interviewed. The participants were recruited by means of purposive sampling. African Traditional Healers were identified through the Kara Heritage Institute in Tshwane, an institution dealing with indigenous knowledge systems. Volunteers were recruited through advertisements (Appendix A) which were placed at the designated working areas of ATH with their permission. Participants completed the information and consent form (Appendix C)

Factors influencing the retention of entry level employees in the South African gaming industry.

MBA 2014ABSTRACT The increasingly competitive environment that organizations operate in has led to the realization that human capital is a pivotal factor in maintaining a competitive edge over your competitors, gaining market share and running a sustainable business. With this realization organizations are faced the challenge of retaining exceptional talent in the organization for as long as possible. The purpose of this study of this study is to identify and describe factors that influence entry level employee retention and determine their relative degree of importance to such employees. The study goes further, and tries to understand employee perception on how the organization is delivering currently on those factors. Utilizing a questionnaire-based survey which was circulated at Montecasino amongst entry level employees within its three main departments, respondents were requested to complete it in order to reach a conclusion on what they perceive as important, and how well the organization delivers on those factors. The study found that the most important factor to entry level employees is organizational justice and that the organization delivers best on providing advancement opportunities. The difference between the degrees of importance amongst these factors was found to not be vastly different as they all had a positive influence towards retention. Entry level employees wish to be treated and rewarded fairly by their organization and in return they would be more committed to the organization. They perceive the organization to be delivering poorly on what they see as most important to them. However, the organization delivers fairly on providing advancement opportunities and job satisfaction. The relationship between these factors is significant in that negative delivery on one affects the way others are perceived. For the organization to succeed in retaining these entry level employees, it would have to ensure the alignment between these important retention factors and their effective delivery

Perspectives on trust business alliances in the Black economic empowerment context : a Q methodological approach

This study endeavoured to uncover the trust experiences of individuals involved in business alliances between traditional companies (TCs) and historically disadvantaged institutions (HDIs) with a view to constructing a model that would facilitate a better understanding of organisational trust within these institutions. The theoretical study proposed a theoretical model of trust in the alliances between TCs and HDIs within an economic empowerment domain. The empirical study employed Q methodology to investigate the trust experiences of the participants. The 25 individuals who participated in the study were selected by means of both non-probability purposive and snowball sampling The participants were presented with the Q sample containing 50 items which they had to sort in accordance with the instruction given. The post-Q sorting interview was conducted to give the participants a chance to expound on their reasoning for the sorting of the Q sample. Data were analysed using Pearson product-moment correlation and factor analysis. Six factors revealed participants’ experiences of trust in the alliances: Factor A (Sincerity trust alliances), Factor B (Values trust alliances), Factor C (Duped trust alliances), Factor D (Vigilant trust alliances), Factor E (Deceitful trust alliances) and Factor F (Inclination to trust alliances). The trust experiences of the six groups were used to theorise about the association between the participants’ trust experiences and their performance on the Positive and Negative Affect Schedule (PANAS). In the main, the study found that groups that had pleasant trust experiences with their partner organisations exhibited have high positive affect (PA) and low negative affect (NA). Although exploratory in nature, the study contributed an empirically derived theoretical framework of cognitive and affective trust within business alliances that may be further investigated in future research endeavours. In this was it identified and proposed a modus operandi for closing the trust gap.Industrial and Organisational PsychologyD. Com. (Industrial and Organisational Psychology

A Critical Reflection on Complementary, Alternative and Indigenous Knowledge Medicine in Gauteng Province: A Model for Articulation and Promotion

PhD (African Studies)Department of African StudiesAs long as the academy continues to lag behind in investigating and revealing and teaching African indigenous pedagogies, the unrepresentative Eurocentric epistemologies that are disconnected from the African reality will continue to marginalise certain communities and professions/disciplines. Complementary and alternative medicine (CAM) is a term that attained popularity in the recent millennium. CAM comprises therapeutic healing modalities that are not part of Western or conventional medicine as its treatment options are centred on medicinal plant, mineral and animal material. Homeopathy as a curative therapeutic system of medicine is classified under CAM and remains relatively unknown in African communities. This is despite being recognised by the government of South Africa as a primary healthcare modality. In this study, a trilogy of decolonial conceptual frameworks by decolonial thinkers and authors is utilised to debunk terms and paradigms that seek to de-link indigenous healing modalities from their core principles. In-depth conversational interviews with homeopaths, African indigenous healers and ordinary everyday people were conducted to explore how these individuals understand themselves and find out who are consulted every day by ordinary people seeking healing. A thematic and narrative analysis was used to give meaning to the collected data. Four categories emerged revealing the need to redress and do justice to marginalised disciplines and communities. The emerging findings paint a picture depicting a failure to use a dialect that is suitable for Black African realities which is a hindrance to the growth of homeopathy. Furthermore, the results indicate that health seeking measures are embedded in the sufferance of Black African people related not to typical diseases as such, but to diseases arising from socio-economic and transnational migratory realities. This thesis engages an African framework and critical social theory to reflect on homeopathy as an indigenous healing modality alongside African indigenous knowledge medicine (AIKM) whose services are not visible given the social and health disparities of many communities.NR