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Water deficit responses of non-nodulated and nodulated Vicia faba (broad bean) when supplied with various forms on concentrations of medium nitrogen nutritionMcCabe, Victoria B. January 2000 (has links)
V. faba fixes nitrogen effectively (Richards & Soper, 1979), however nitrogen fixation is reportedly energetically expensive and water deficit sensitive. Research was designed to determine whether medium nitrogen applications would result in increased productivities in V. faba, particularly during water deficits. Non-nodulated and nodulated V. faba were subjected to gradual water deficit imposition, and were supplied with a variety of medium nitrogen nutrition. Nitrogen fixing V. faba exhibited greater productivities than V. faba which were supplied with low medium nitrate concentrations (0.8 roM N), even during water deficits. Plant performance parameters (growth; net photosynthesis; nitrogen assimilatory enzyme activities; osmotic adjustment) were greater in nodulated than in non-nodulated 'no nitrate' supplied V. faba throughout water deficits, inferring water deficit tolerance for nitrogen fixation. However significantly greater plant performance paramaters were exhibited in V. faba when supplied with increasingly concentrated medium nitrogen nutrition (> 0.8 roM N) than when reliant on nitrogen fixation. In contrast to the bulk of previous literature, NR activities were maintained in V. faba until water deficits became severe, inferring a role for nitrate assimilation in nitrogenous osmotica production. Medium ammonia additions resulted in the exhibition of significantly increased root biomasses; cumulative leaf areas (important for a green manure crop); heights; and nitrogen assimilation in V. faba throughout water deficits, and accordingly in increased osmotic adjustment (including compatible solute accumulation), protein concentrations and vegetative yields. Greater plant productivities in v. faba when supplied with medium ammonia additions were attributed in part to lower associated assimilatory costs for ammonia than nitrate nutrition (Raven, 1992). Results indicated increased metabolism as opposed to storage of medium ammonia, and therefore potentially alleviated 'sink size' feedback inhibition of photosynthesis and nitrogen metabolism in V. faba when supplied with medium ammonia additions. Furthermore ammonia supplied V. faba may have been predisposed towards water deficit tolerance. In summary V. faba exhibited significantly greater nitrogen assimilation; osmotic adjustment; net photosynthesis; and growth when supplied with increasingly concentrated medium nitrogen nutrition (and particularly with medium ammonia additions) than when reliant on nitrogen fixation, both during periods of adequate irrigation and during water deficits.
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Therapeutic approaches to suicidal phenomena in adolescence : a systematic review of mindfulness-based approaches and an investigation of the 'Broad Minded Affective Coping' techniqueDuddridge, Clare Jane January 2013 (has links)
The prevalence rates for adolescent suicide and self-harm are alarming, suggesting a continued need for research into effective treatment strategies for young people experiencing suicidal phenomena. This thesis explores the impact of two treatment approaches: Mindfulness and Broad Minded Affective Coping (BMAC; Tarrier, 2010). Paper One is a systematic review exploring the potential role of mindfulness in the treatment of adolescent suicidality and depression. There were two broad aims: to present an argument for the utility of mindfulness practice in alleviating suicidal phenomena and depression in young people, and to systematically review studies that examined the impact of mindfulness-based approaches with adolescent populations, specifically exploring outcomes relating to suicide, self-harm, and depression. Twenty-eight papers were identified; studies were critically evaluated and findings were integrated to provide an overall account of the potential efficacy of mindfulness-based approaches. Findings were promising, suggesting that these approaches could be helpful in the treatment of young people experiencing suicidal phenomena or depression. Areas for further exploration are considered and clinical implications discussed. Paper Two is an empirical paper investigating the effectiveness of a therapeutic tool of affect-regulation – the Broad Minded Affective Coping (BMAC) method. A case-series design was employed and participants were young people who had recently attempted suicide or self-harmed. The study explored the impact of BMAC practice on self-reported hope and happiness and on a range of outcomes associated with adolescent suicidality. Findings were promising; BMAC practice appeared to be associated with improvements in all areas of interest. Whilst encouraging, findings are considered in light of the limitations of case-series methodologies. Future investigations are recommended, and clinical implications outlined. Paper Three is a reflective paper exploring the process of conducting the aforementioned research and discussing some of the challenges involved. Reflections on the strengths and limitations of the research are integrated within the paper, alongside areas for further research. The theoretical context and clinical implications of the research are considered.
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Chemical Genomics Approach Leads to the Identification of Hesperadin, an Aurora B Kinase Inhibitor, as a Broad-Spectrum Influenza AntiviralHu, Yanmei, Zhang, Jiantao, Musharrafieh, Rami, Hau, Raymond, Ma, Chunlong, Wang, Jun 08 September 2017 (has links)
Influenza viruses are respiratory pathogens that are responsible for annual influenza epidemics and sporadic influenza pandemics. Oseltamivir (Tamiflu((R))) is currently the only FDA-approved oral drug that is available for the prevention and treatment of influenza virus infection. However, its narrow therapeutic window, coupled with the increasing incidence of drug resistance, calls for the next generation of influenza antivirals. In this study, we discovered hesperadin, an aurora B kinase inhibitor, as a broad-spectrum influenza antiviral through forward chemical genomics screening. Hesperadin inhibits multiple human clinical isolates of influenza A and B viruses with single to submicromolar efficacy, including oseltamivir-resistant strains. Mechanistic studies revealed that hesperadin inhibits the early stage of viral replication by delaying the nuclear entry of viral ribonucleoprotein complex, thereby inhibiting viral RNA transcription and translation as well as viral protein synthesis. Moreover, a combination of hesperadin with oseltamivir shows synergistic antiviral activity, therefore hesperadin can be used either alone to treat infections by oseltamivir-resistant influenza viruses or used in combination with oseltamivir to delay resistance evolution among oseltamivir-sensitive strains. In summary, the discovery of hesperadin as a broad-spectrum influenza antiviral offers an alternative to combat future influenza epidemics and pandemics.
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A Study of Stock Market Fluctuations and their Relations to Business ConditionsFu, Man 01 July 2009 (has links)
Most research on stock prices is based on the present value model or the more general consumption-based model. When applied to real economic data, both of them are found unable to account for both the stock price level and its volatility. Three essays here attempt to both build a more realistic model, and to check whether there is still room for bubbles in explaining fluctuations in stock prices. In the second chapter, several innovations are simultaneously incorporated into the traditional present value model in order to produce more accurate model-based fundamental prices. These innovations comprise replacing with broad dividends the more narrow traditional dividends that are more commonly used, a nonlinear artificial neural network (ANN) forecasting procedure for these broad dividends instead of the more common linear forecasting models for narrow traditional dividends, and a stochastic discount rate in place of the constant discount rate. Empirical results show that the model described above predicts fundamental prices better, compared with alternative models using linear forecasting process, narrow dividends, or a constant discount factor. Nonetheless, actual prices are still largely detached from fundamental prices. The bubble-like deviations are found to coincide with business cycles. The third chapter examines possible cointegration of stock prices with fundamentals and non-fundamentals. The output gap is introduced to form the non-fundamental part of stock prices. I use a trivariate Vector Autoregression (TVAR) model and a single equation model to run cointegration tests between these three variables. Neither of the cointegration tests shows strong evidence of explosive behavior in the DJIA and S&P 500 data. Then, I applied a sup augmented Dickey-Fuller test to check for the existence of periodically collapsing bubbles in stock prices. Such bubbles are found in S&P data during the late 1990s. Employing econometric tests from the third chapter, I continue in the fourth chapter to examine whether bubbles exist in stock prices of conventional economic sectors on the New York Stock Exchange. The ‘old economy’ as a whole is not found to have bubbles. But, periodically collapsing bubbles are found in Material and Telecommunication Services sectors, and the Real Estate industry group.
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Population genetic structure of North American broad whitefish, Coregonus nasus (Pallas), with emphasis on the Mackenzie River systemHarris, Les N. 11 1900 (has links)
Broad whitefish, Coregonus nasus, is an important subsistence fish species in Arctic North America, yet virtually nothing is known regarding the genetic population structure of Nearctic populations of this species. In this thesis, microsatellite DNA variation was assayed among 1213 broad whitefish from 47 localities throughout North America, with emphasis on the Mackenzie River system, Northwest Territories. Specifically, I examined geographic variation in allele frequencies to assess how historical factors (Pleistocene glaciations) have shaped the current structuring of genetic variability and population differentiation. Microsatellite data was also used to resolve the relative contributions of broad whitefish populations to subsistence fisheries in the Mackenzie River system. Overall, broad whitefish exhibit relatively high intrapopulation microsatellite variation (average 12.29 alleles/locus, average HE = 0.58) and there were declines in these measures of genetic diversity with distance from putative refugia suggesting historical factors, namely post-glacial dispersal, have influenced current microsatellite variation. Interpopulation divergence was low (overall FST = 0.07), but the main regions assayed in this study (Russia, Alaska, Mackenzie River and Travaillant Lake systems) are genetically differentiated. Strong isolation-by-distance among samples was resolved when including only those populations occupying former Beringia, but not when assaying those at the periphery of the range in the Mackenzie River system, suggesting that broad whitefish in the Mackenzie system have not occupied the region long enough since their invasion post-glacially to have approached equilibrium between gene flow and drift. Mixture analysis indicated that most fish from the lower Mackenzie River subsistence fishery originated from the Peel River, highlighting the importance of this tributary. Additionally the mixture analysis provides evidence for a putative riverine life history form in the Mackenzie River. My results indicate that glaciation and post-glacial colonization have been important in shaping the current genetic population structure of North American broad whitefish. They also illustrate the utility of microsatellite DNA to delineate population structure and patterns of genetic diversity in recently founded populations in addition to resolving contributions to fisheries. My data also support the hypothesis that there are several designatable units of conservation among broad whitefish populations and that management strategies should be implemented accordingly. / Science, Faculty of / Zoology, Department of / Graduate
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Outsourcing as a black economic empowerment toolMncube, Dingane Matthews 24 February 2010 (has links)
M.Comm. / Broad Based Black Economic Empowerment (BBBEE) is almost ten years old. The objective of the BBBEE is to increase the participation of Black people and Black women in the South African economy and also to bridge the income inequality which was brought about systematically before South Africa became a democratic country. The BBBEE Act, through the Codes of Good Practice has identified seven key elements which if addressed will help to achieve the objectives of the Act. These elements are ownership, management control, employment equity, skills development, preferential procurement, enterprise development and socio economic development. Minimum targets have been set which need to be achieved within ten years. The primary objective of the study was to investigate if Sappi one of the two dominant pulp and paper companies in South Africa, could utilize outsourcing as a Black Economic Empowerment Tool. The secondary objectives were twofold: • To identify key barriers to complying with the seven elements of the Codes of Good Practice; and • To establish measures or incentives that will lead to Sappi Forests outsourced activities complying with the Codes of Good Practice hence utilizing outsourced activities as a Black Economic Empowerment tool. The research findings indicate that Sappi could utilize outsourcing as a Black Economic Empowerment tool. According to survey results, significant progress has been achieved in implementing BBBEE Act despite the lack of a systematic approach. Progress towards the implementation of the Act as measured against the seven elements contained in the Codes of Good Practice, is commendable. Should the recommendations such as incentives and rewards that are mentioned in the findings be adopted, the implementation of the BBBEE Act which leads to empowerment could be enhanced in forests outsourced activities.
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Interrogating the legitimacy to enter into a social licence in the mining industry in South Africa : a community perspectiveNyembo, Nomakhuze January 2018 (has links)
Discussions about the significance of the social license phenomenon have been increasing over the last two decades, yet the trend has been to approach it from a company perspective. Over the same period, there have been increasing challenges in mine-community relations, and company interventions have not led to the desired outcomes. A credible process for achieving a social licence within a complex and historically sensitive context is currently not in place, which has perpetuated the feelings of dissatisfaction and has led to serious conflict between mining communities and companies. The literature revealed a lack of clarity on the role of the community in the process, necessitating an interrogation of the phenomenon from a community perspective.
Legitimacy theory was used as the basis of the study. The multi-dimensional and dynamic nature of the study necessitated the use of qualitative methods and an inductive approach, based upon a case study within two South African mining communities.
The results of the study demonstrated that communities are limited in influencing the social licence, and this highlighted the need to incorporate community specific legitimacy, which more closely reflects the reality within communities (their diversity, informality, broad representation, and dynamic nature). The lack of agreement (emanating from communities, government and industry) on legitimate community leadership significantly also impacts on the social licence process. Communities are unable to articulate their expectations to mining companies, and the requirements for a social licence are not being satisfied. The study also highlighted the deep and complex nature of discourse transition, and that mining companies must concentrate on understanding context and produce context-specific interventions.
This research contributes by extending the theorisation of legitimacy, as it relates to the social licence, by adding the concept of community legitimacy and proposes a community leadership framework, to incorporate this aspect. A conceptual model, which integrates the context-specific nuances, is therefore proposed for sectors which are dependent upon achieving accord with stakeholders via a social contract, and are experiencing increasing complexity and social tensions relating to their operations. Such a framework would facilitate engagement through representative structures and result in a more robust social licence outcome. / Thesis (PhD)--University of Pretoria, 2018. / Gordon Institute of Business Science (GIBS) / PhD / Unrestricted
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The appropriateness of equality legislation in addressing the challenges faced by black professional employees in South Africavan de Rheede January 2019 (has links)
Doctor Educationis / All employees aspire to work at a place of employment which is free from racial discrimination, where equal opportunity and fair treatment are not merely principles that are promoted and encouraged, but implemented actively by their employers. For a number of black professional employees in South Africa, however, currently this is merely an aspiration. Evidence suggests that black people are still subjected to racial discrimination and that their growth into the ownership and management structures of the enterprises that employ them, is insignificant in comparison to their white counterparts, despite the progressive legislative measures enacted by the legislature to ensure otherwise. The Employment Equity Act 55 of 1998, as amended, was promulgated in order to promote equal opportunities and fair treatment in employment, through the elimination of unfair discrimination and to implement affirmative action measures to redress the disadvantages in employment experienced by designated groups. The Broad-Based Black Economic Empowerment Act 53 of 2003, as amended, was enacted to promote the economic participation of black people in South Africa. The objective of this thesis is to examine the relevant provisions of the Employment Equity Act 55 of 1998, as amended, its Regulations, the Codes of Good Practice enacted in terms thereof, as well as the Broad-Based Black Economic Empowerment Act 53 of 2003, as amended, together with its Codes of Good of Practice to determine whether this equality legislation is the appropriate vehicle to address the challenges experienced by black professional employees in the private sector. The stories of black professional employees’ experiences obtained from academic literature available insofar as it relates to racial discrimination, affirmative action and black economic empowerment is discussed through the lens of Critical Race Theory. This is done with a view to determining whether the slow pace of racial transformation when it comes to black professional employees employed in the private sector is an issue that the law can address. Particular reference is made to two professions: the legal profession and the financial professions. This thesis examines the difference between the minimalist and maximalist approaches to Black Economic Empowerment (BEE). The thesis reveals the limits to the incentive structure that does not place a premium on black ownership and that allows enterprises to benefit from BEE while not really changing management structures. It argues that seen through the lens of critical race theory the current equality legislation discussed in this thesis is based on including black people in a system where privilege and power are asymmetrically distributed. It also argues that legislation in itself is unable to rectify racial injustices. It therefore demonstrates the limitations of the current equality legislation as a vehicle to address the challenges faced by black professional employees in the private sector.
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Factors affecting the success of broad-based black economic empowerment mergers and acquisitionsMogototoane, Samuel Rapulane 23 February 2013 (has links)
Mergers and acquisitions (M&As) are an ubiquitous feature of modern corporate landscape. Most are entered into for various synergistic (voluntary) reasons whilst some, such as broad-based black economic empowerment (BBBEE) M&As, are driven largely by legislative requirements. Research has shown that the factors that lead to the success or failure of voluntary M&As are many and complex.Whilst there is a plethora of literature regarding the success factors for voluntary M&As, there is, however, a paucity of academic literature on the qualitative factors that lead to the success or failure of BBBEE M&As, despite quantitative studies showing the benefits of BBBEE M&As. Because of the significance of BBBEE to the economic development of the country, policy makers, academics and business people need to fully understand such factors.Given the dearth of academic literature on the subject, a qualitative, exploratory study conducted by way of face to face, expert, semi-structured interviews, was undertaken to answer the research problem.The study found that whilst BBBEE M&As are similar, in some respects, to voluntary M&As, BBBEE M&As require different or additional success factors to those applicable to voluntary M&As. Some of these are: funding structure, transaction rationale, expectations‟ alignment, clear deliverables, active governance, operational involvement, relationship management, transformation and social investment. / Dissertation (MBA)--University of Pretoria, 2012. / Gordon Institute of Business Science (GIBS) / unrestricted
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Relationship between horizontal jump tests and sprint performanceKleeberger, Adam 30 September 2020 (has links)
Athletic performance assessments are important for identifying physical giftedness, monitoring athlete progress and supporting training recommendations. Sprint performance is a key component in athlete success both in athletics and field-based sports, and talent identification testing batteries often include sprint and jump assessments. Jumping and sprinting share a number of similar characteristics and research has shown that the relationships between sprint and jump tests depend on the recorded segment of the sprinting task, type of jump performed, and the speed and sex of the athlete. The majority of this research has been conducted in small, single sex, similar athlete cohorts and there has yet to be an analysis of a large cohorts multi-sport population with both male and female groups. Understanding the relationships between sprint ability and horizontal jump performance, based on large groups of athletes separated by sex can provide great insight into the shared and independent value of sprint and jump performance tests to support athlete testing and development. Therefore, the purpose of this study was to investigate the relationships between horizontal jump tests and sprint performance within different athlete sexes and sprint ability. To the authors’ knowledge, this is the first study with a large population sample of multisport athletes, with differing sprint and jump abilities. The associations and relationships between horizontal jump performance in standing broad jump (SBJ) and standing triple jump (STJ) with 0-10m and 30-40m sprint time in a group of athletes participating in a talent identification event were investigated in this study. Correlations and linear regressions were assessed with athletes grouped only by sex (male (n = 742), and female (n = 610)), and then grouped by sex and speed (fast = -0.5 SD, slow = +0.5 SD) for both 0-10m and 30-40m time separately. When grouped only by sex there were very large and large associations between sprint and jump measures (r = -0.533 to -0.717), and linear regression equations explained 37.4% to 55.5% of the variance. When grouped by sex and speed, slow athletes showed stronger associations (r = -0.353 to -0.488) than fast athletes (r = -0.088to -0.307). Linear regressions explained 20.3% to 28.5% of the variance in slow athletes, but only up to 12.0% of the variance explained in fast athletes. Linear regressions in slow and fast males all included SBJ as a predictor, but not STJ. Linear regressions in slow and fast females all included STJ as a predictor, but not SBJ. Overall, these results support the use of general sprint and jump tests for slower athletes, the importance of both sprint and jumps tests with higher resolution in faster athletes, as well as the utility of different jump tests to evaluate lower limb performance between sexes. / Graduate
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