An initial study of the palaeoclimate signal contained within speleothem growth was undertaken by' investigating regional variations in speleothem Qrowth frequency. It was demonstrated that about 500 analyses in such a regional compilation were necessary to generate a statistically significant curve which did not suffer from sample bias. However, few such regions are likely to have such a larQe data set. That from north west Europe did provide a useful palaeoclimate record, giving evidence of multiple interstadial events within isotope stage 3, and a significantly low level of growth within stage Sa. An investigation was undertaken into the palaeoclimate signal contained in variations of speleothem growth rate, based on the theory derived by Dreybrodt (1981) and Buhmann and Dreybrodt (1985) from calcite precipitation kinetics. It was demonstrated that growth rate increases with increasing calcium ion concentration, temperature and water flux (drip rate for stalagmites, water film thickness for flowstones and seasonal variations in water availability for both speleothems); turbulent flow conditions and cave air pC02, which theoretically affect growth rate, were demonstrated to be Insi9nificant. If water flux, calcium concentration and temperature all increase with improving Climate, growth rate increases may reflect climatic improvement. In particular, it was demonstrated that stalagmites should be most sensitive to changes in calcium concentrations, temperature, and seasonal shut-off of the water feed, whilst flowstones would also be sensitive to changes in water film thickness. Theoretical growth rates were tested for recently forming speleothems in excavated caves and mines. For these, minimum growth rates were determined by knowing the date of excavation of the cave or mine, and the growth rate determining variables were measured over the course of a year. It was demonstrated that the theory accurately predicted growth rates for both stalagmites and flowstones within the 20' errors based on variations in calcium ion concentration and water film thickness. However, flowstones generally grew slower than that predicted by the theory, due to the seasonal shut-off of the water supply feeding these samples. For flowstones at Kent's Cavem, growth rate was observed to Increase with Increasing water availability, for stalagmites at Lower Cave, growth rate was shown to increase with increaSing drip rate. Assuming a good prediction of growth rate by the theory, applications to Quatemary speleothems were undertaken to determine past calcium ion concentration, temperature and water flux. Growth rates were determined by thermal ionisation mass spectrometric uraniumseries dating. The growth rate of one Holocene sample from Sutherland demonstrated that variations in growth rate over the last 7 ka did not depend on temperature variations, but either to changes in calcium concentrations due to vegetation change or a non-linear response to changes in water flow. Growth rates were also determined for two flowstones from Yorkshire which had grown over the last 200 ka. However, the very fast growth rates in these samples prevented a precise record from being obtained. Mass spectrometric dating also provided a record of the timing of growth commencement and cessation. This was shown to be more complex than previously considered; in particular the Holocene growth of the Sutherland stalagmite commenced 5 ka after glacier retreat in the region, the Yorkshire flowstone from Lancaster Hole had seven growth phases, each for only 1-3 ka, five of which correlated with solar insolation maxima. In contrast, another flowstone from Stump' Cross in Yorkshire was shown to grow in both interglacial, interstadial and glacial periods of the last 200 ka. An investigation was made into the use of 13C/1'C,(t>nM to determine the type of plant community at the time of speleothem formation, and whether a non-biogenic source of CO2 was present. 13C analyses of the Stump Cross flowstone gave elevated 13C not explicable by the plant communities present, nor were high enough to have a non-biogenic source. Further investigations are needed, but this evidence suggests caution in interpreting 13C records for flowstones. An annual signal of growth rate and growth rate variability was obtained from ultra-violet microscopic analysiS of luminescent banding within speleothems. Banding was demonstrated to be annual by mass spectrometric uranium-series dating, but was only preserved In 10% of a" samples. Variability of growth rate for the Holocene Sutherland stalagmite was compared to the theoretical annual variability of growth rate derived from annual variations in the growth rate determining variables observed today, and a good agreement was observed. Furthermore, for one period of growth, a 4-5 year period of rapid growth rate was demonstrated to correlate with the Hekla 3volcanic eruption in Iceland.

No description available.

<p> My study was designed to determine how different thermal defense strategies and the intensity of high temperature challenges might affect demographic and physiological performance of limpets on rocky shores. Found together in the high intertidal zone, <i>Lottia scabra</i> employs a constitutive thermal defense strategy, whereas <i>L. austrodigitalis</i> has an inducible one. I measured loss and growth rates of both species as a function of average daily maximum temperature exposure in the field, and respiration rates for field-collected and lab-acclimated individuals under benign conditions in the lab before and after exposure to one of five peak temperatures (14, 24, 28, 32, or 36 &deg;C) during a 4.5-hour simulated low tide. <i>L. scabra</i> was relatively unaffected by exposure to high temperatures, whereas <i>L. austrodigitalis</i> exhibited significant increases in loss rates from experimental plates, decreases in growth rates, and increases in oxygen consumption, consistent with activation of the heat shock response.</p><p>

<p> Severe drought plays a critical role in altering the magnitude and interannual variability of the net terrestrial carbon sink. Drought events immediately decrease net primary production (NPP), and drought length and magnitude tend to enhance this negative impact. However, satellite and in-situ measurements have also indicated that ecosystem recovery from extreme drought can extend several years beyond the return to normal climate conditions. If an ecosystem&rsquo;s drought recovery time exceeds the time interval between successive droughts, these legacy effects may reinforce the impact of future drought. Since the frequency and severity of extreme climate events are expected to increase with climate change, both the immediate and prolonged impact of drought may contribute to amplified climate warming by decreasing the strength of the land carbon sink. However, it is unknown whether terrestrial biosphere models capture the impact of drought legacy effects on carbon stocks and cycling. Using a suite of twelve land surface models from the Multi-scale Synthesis and Terrestrial Model Intercomparison Project (MsTMIP), we assessed model ability to simulate drought legacy effects by analyzing the modeled NPP response to drought events across forested regions of the US and Europe. We found that modeled drought legacy effects last about one year (2% reduction in NPP), with complete NPP recovery in the second post-drought year. Since observations suggest that legacy effects extend up to four years post-drought, with a 9% growth reduction in the first post-drought year, models appear to underestimate both the timescales and magnitude of drought legacy effects. We further explored vegetation sensitivity to climate anomalies through global, time-lagged correlation analysis of NPP and climatic water deficit. Regional differences in the lag time between climate anomaly and NPP response are prevalent, but low sensitivities (correlations) characterize the entire region. Significant correlations coincided with characteristic lag times of 0 to 6 months, indicating relatively immediate NPP response to moisture anomalies. Model ability to accurately simulate vegetation&rsquo;s response to drought and sensitivity to climate anomalies is necessary in order to produce reliable forecasts of land carbon sink strength and, consequently, to predict the rate at which climate change will progress in the future. Thus, the discrepancies between observed and simulated vegetation recovery from drought points to a potential critical model deficiency.</p><p>

M.Com. (Business Management) / Global competition, changing markets and new technologies, challenge the traditional view of the business organisation. Markets are undergoing rapid and constant change as a result of customers becoming more specialised in their needs and demanding higher quality products and services. Improved internal performance is forced upon organisations as the wave of globalization dissolves customary boundaries, increasing world trade and competition. This turbulent business environment demands of organisations to constantly monitor and interpret change within its external context as it unfolds so as to constantly align the pace at which the organisation can move through substantial and continuous evolution. The move of organisations in synchronism with their environment is becoming increasingly difficult. Business transformation, evolving from business process re-engineering to extending the original business and then redefining it to create new business creates a means of increasing business performance and continuous alignment with changing market needs. (Davidson, 1993 :65).

M.Comm. / Moderne organisasies ondervind hernude druk van interne en eksterne faktore en voortdurende verandering word genoodsaak. Suid-Afrikaanse organisasies vorm nou meer as ooit tevore deel van die globale wereld en moet sodoende ook meer buigsaam wees om internasionaal te kan meeding. In hierdie verhandeling word daar gekyk na moontlike nuwe organisasie vorme en die strewe na 'n sogenaamde "Lewende Organisasie" word beklemtoon. Daar is soveel aspekte wat reeds sigbaar is in die natuur en daar kan 'n spesifieke verwantskap getrek word na natuurlike verskynsels en organisasie-sisteme. Organisasies bestaan uit individue wat as 'n somtotaal 'n geweldige magdom kennis daarstel en ook sodoende gesien kan word as die DNA van organisasies. Die enkele belangrikste beskouing is dus om die paradigma te skuif oor die sienswyse van organisasies. Organisasies is nie meer masjiene nie, maar moet beskou word as "Iewende organismes" en dus "Lewende Organisasies". Met Suid-Afrika wat deel vorm van die wereld-mark, kan dit vereis dat organisasies meer sensitief sal moet wees vir omgewings-invloede en die aanpassing by verandering 'n sleutelrol kan speel. Die tyd is ryp vir Suid-Afrikaanse organisasies om deur te breek in internasionale markte. Hierdie verhandeling sal dus dien as 'n raamwerk om elemente te identifiseer wat krities kan wees vir toekomstige sukses asook die fondasie daarstel vir verdere navorsing in organisasie vorme.

M.B.A. / The aim is to do an assessment of the organisational norms of individuals within a marketing company in order to understand what the perceptions of the individuals are towards the organisation thereby creating a model on which strategic decision making can be based

Due to the continual increase in competitive pressure from international organisations, it has become necessary to assess the degree of transformational change within South African organisations to overcome the effect of global forces. Transformation was investigated in terms of organizational restructuring and the various work designs that are utilised by organisations to deal with the effect of global forces. To examine the main problem, three sub-problems were identified. The first sub-problem that had been identified dealt with the extent of which global forces impacted on the business environment. It was investigated by evaluating various economic, technological and sociopolitical forces. From the results it may be concluded that global forces have a large impact on the local business environment. The second sub-problem looked at the degree to which work designs assisted organisations to manage the effect of global forces. It was evident that the flexible types of work designs were more readily utilised to optimise productivity and employee moral. Finally, the third sub-problem investigated the various structures that organisations could adopt to deal with the effect of global forces. Organisational structures were analysed in terms of customer orientation, fulfilment of company objectives and the types of structures that are used within organisations. The results showed that 75% of the sample population believed that their organisational structures co-ordinated all activities within their organisations. Feedback on the type of structures that were used by organisations revealed that various types are being used.

During the 1990’s many South African companies experienced the need to change and adapt. This was largely because of the environmental changes brought about by a new political regime. One of these changes was the exposure of South African companies to global competition. Because the South African business environment had remained relatively static during the 1980’s, many companies had no idea of how to manage change when it became necessary for economic survival. This inability led to the demise of many organisations. As change as a business concept covers a vast area, the main objective of this study was to isolate one area of change and examine it in a practical context. The chosen area was the relationship, if any, between strategy and organisational structure. The practical context chosen was an organisation, which had recently undergone strategic change. The research methodology for this study included the conducting of an intensive literature study, to determine the academic stance on the strategy/structure relationship. Various academic theories were examined to determine whether there was a relationship between the two concepts, and if so, what the relationship should be. This provided a background for the practical evaluation. Literary opinion showed consensus that there was indeed a relationship between the two; in fact the one was integral to the success of the other. That is, if an organisation chooses to consider adopting a change strategy, it should carefully consider its impact on organisational structure. To summarise, in a situation of change, structure should support strategy to ensure a successful transition. An empirical study was then conducted at Pennypinchers (Pty) Ltd , which had recently undertaken to implement a change strategy. The focus of the empirical study was the relationship between the chosen change strategy and organisational structure. The aim was to determine whether the strategy had an impact on organisational structure, and if so, whether the structure underwent During the 1990’s many South African companies experienced the need to change and adapt. This was largely because of the environmental changes brought about by a new political regime. One of these changes was the exposure of South African companies to global competition. Because the South African business environment had remained relatively static during the 1980’s, many companies had no idea of how to manage change when it became necessary for economic survival. This inability led to the demise of many organisations. As change as a business concept covers a vast area, the main objective of this study was to isolate one area of change and examine it in a practical context. The chosen area was the relationship, if any, between strategy and organisational structure. The practical context chosen was an organisation, which had recently undergone strategic change. The research methodology for this study included the conducting of an intensive literature study, to determine the academic stance on the strategy/structure relationship. Various academic theories were examined to determine whether there was a relationship between the two concepts, and if so, what the relationship should be. This provided a background for the practical evaluation. Literary opinion showed consensus that there was indeed a relationship between the two; in fact the one was integral to the success of the other. That is, if an organisation chooses to consider adopting a change strategy, it should carefully consider its impact on organisational structure. To summarise, in a situation of change, structure should support strategy to ensure a successful transition. An empirical study was then conducted at Pennypinchers (Pty) Ltd , which had recently undertaken to implement a change strategy. The focus of the empirical study was the relationship between the chosen change strategy and organisational structure. The aim was to determine whether the strategy had an impact on organisational structure, and if so, whether the structure underwent.

The likelihood of organisational change success is commonly held to be dependent on how resistance to the change is planned for and managed. Stakeholders who resist change are seen to hold various levels of power or influence over change initiatives, and this power can originate from multiple different sources. There is extensive research literature considering the aspects of stakeholders, power and resistance, but little is evident relating the dimensions to each other to consider the architecture holistically. This research aims to form an exploratory study into the interrelationships between the three dimensions. To acquire data, an exploratory research approach was undertaken comprising face-to-face, in-depth expert interviews with fifteen professional change agents from three different sample groups. A range of qualitative and quantitative analysis techniques were applied to determine common trends and relationships across the three key dimensions and sub-categories identified from the literature which related to each dimension. A number of interesting and useful relationships were uncovered within and between the key dimensions and extend the current literature in this field. It was discovered that the higher the magnitude of power held by a stakeholder the more likely it was that they would show resistance. Further findings confirmed links between the types of behaviour (active or passive, overt or covert) and revealed multidimensional influences such as that certain types of stakeholder could be expected to have higher levels of power and thus resist more and in the course of enacting that they would behave more actively and overtly. These relationships allowed for the development of a stakeholder-power-resistance model as shown in Figure 17 which can be used by managers and change practitioners to understand, anticipate and respond to stakeholder resistance in change initiatives. / Dissertation (MBA)--University of Pretoria, 2013. / mngibs2014 / Gordon Institute of Business Science (GIBS) / MBA / Unrestricted