Student Number : 0204056G - MD research report - School of Oral Health Science - Faculty of Health Sciences / Evaluating facial profiles and facial balance is a continuous learning process for orthodontists. Hence, the importance of studying the intermediate and long term effects of treatment on soft tissues cannot be overemphasized. The objective of this study was to evaluate the lip changes occuring in response to tooth movement, not only immediately post-treatment but also to following the long-term monitoring when cranio-facial growth has ceased. The lip changes were measured relative to the Burstone (B-line) line. The sample was taken from the records successfully treated orthodontic cases in the Department of Orthodontics at the University of the Witwatersrand, Johannesburg. This sample comprised 18 Caucasoid females (14 extracttion, 4 non-extraction). Pre-treatment, post-treatment, and long term follow-up lateral cephalometric radiographs were evaluated. Statistical evaluation of the lips in the long term follow-up records revealed no statistically significant changes. The lips remained, relatively, in a similar position to that which had been attained immediately post-treatment. This was the case for both the extraction and non-extraction groups. The general lack of consistency in post-treatment correlations between dental variables and the soft tissue form supports the hypothesis that the soft tissues, having their own inherent architecture, respond independently. This varied response to tooth movement makes lip movement difficult to predict on a reliable basis. The concept that is better to finish the cases slightly more protrusive because the lips tend to lose elasticity with age and, as a result, become more retrusive, is therfore supported by these observations.

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The development of some ability for forecasting low rainfalls would be helpful in Tuvalu as rainwater is the only source of fresh water in the country. The subsurface water is brackish and saline so the entire country depends totally on rainwater for daily domestic supplies, agricultural and farming activities. More importantly, these atolls are often influenced by droughts which consequently make inadequate drinking water an issue. A simple graph-based forecasting scheme is developed and presented in this thesis for forecasting below average mean rainfall in Funafuti over the next n-month period. The approach uses precursor ocean surface temperature data to make predictions of below average rainfall for n = 1, 2 12. The simplicity of the approach makes it a suitable method for the country and thus for the Tuvalu Meteorological Service to use as an operational forecasting tool in the climate forecasting desk. The graphical method was derived from standardised monthly rainfalls from the Funafuti manual raingauge for the period January 1945 to July 2007. The method uses lag-1 and-lag 2 NINO4 sea surface temperatures to define whether prediction conditions hold. The persistence of predictability tends to be maintained when the observed NINO4 ocean surface temperatures fall below 26.0oC. Although the developed method has a high success probability of up to 80 percent, this can only be achieved when conditions are within the predictable field. A considerable number of below average rainfall periods are not within the predictable field and therefore cannot be forecast by this method. However, the graphical approach has particular value in warning when an existing drought is likely to continue.

Consumption of plastics has increased exponentially, in line with the world's population. Not surprisingly this is reflected in enormous growth of the plastic industry especially during the last five decades. Commensurate with this, waste produced from plastics consumption has created a major environmental problem. Many types of waste disposal methods have been used all over the world so far, but all of them have disadvantages. Furthermore, some methods are responsible for the generation of green house gases and further contribution to global warming. Recently, reduction of green house gas emission has become a target of most industries. Plastic recycling and reuse breaks the cycle of endless production of virgin polymer and thus contributes to a net reduction of green house gas emission. Recycling of plastics should produce materials with improved properties to replace virgin plastics for a variety of applications. Improvement in the properties of recycled plastics can be achieved by blending with other plastics, by filler addition and by modification using free radical initiators. Introduction of the free radical initiator (organic peroxide) during reprocessing of the recycled plastics has been found to offer significant property improvements to the recycled materials. Extremely small amounts of a free radical initiator (typically ranging between 0.01 wt% to 0.2 wt%) is capable of enhancing the properties of the recycled plastics to a great extent. This project investigates the use of free radical initiators in the recycling of post consumer recycled high density polyethylene using reactive extrusion. Both molecular and rheological characterisation of recycled and reprocessed materials was carried out and this was followed by tensile testing of the modified materials to satisfy end use applications such as packaging and drainage piping. Post consumer recycled high density polyethylene (R-HDPE) resin and virgin high density polyethylene (V-HDPE) were reactively extruded with low concentrations of dicumyl peroxide (DCP) and 1, 3 1, 4 Bis (tert- butylperoxyisopropyl) Benzene (OP2) respectively in a twin screw extruder in order to produce modified materials with varying composition (0.0 wt%, 0.02 wt%, 0.05 wt%, 0.07 wt%, 0.10 wt% and 0.15 wt%) of both organic peroxides. Morphological characterisation using modulated differential scanning calorimetry (MDSC) demonstrated that there is a decrease in the crystallinity level for all the modified samples. Shear rheological tests were carried out to study the structure of the modified materials within the linear viscoelastic region. Viscoelastic parameters, such as storage modulus (G'), loss modulus (G

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<p>Internet and the digital channels for distribution have meant big changes for the musicindustry. The physical record that has been symbolising this market for a long time is slowlybeing replaced by digital based music. The technical progress during the last ten years has ledto a democratization of music production. The amateur musicians of today can produce highquality music on their laptops and later distribute it via free music sites. MySpace andYouTube are two of the biggest sites for this free distribution and is therefore my main choiseof study.</p><p>The purpose of this essay was to find out how and if these changes have made a difference formusicians without a record deal to reach an audience by themselves. In order to find this out Iconducted three qualitative personal interviews with both established and amateur musiciansworking in the music business.</p><p>To find out how many listeners a amateur musician can generate on their own within a shortamount of time I made a quantitative study during five weeks where I posed as an musicianstarting from scrach with an aim to become famous. During these five weeks I got my songplayed 164 times and got to collaborate with a podcast show from England.</p><p>My hypothesis has been that the future role of the record company will be reduced andpossibly disappear. The theories in this essay argues that this might indeed be the case whenmusicians have accsess to a world o free marketing.</p> / <p>Internet och de digitala distributionskanalerna har inneburit stora förändringar för musikindustrin. Den fysiska skivan som länge har symboliserat denna marknad försvinner bytssakta men säkert ut mot digitalt baserad musik. De tekniska framgångarna under de senastetio åren har lett till en demokratisering av musik produktion. Amatörmusiker kan idagproducera musik med hög kvalitet på en laptop och sprida den gratis med hjälp av sajter förgratis musik. MySpace och YouTube representerar två av de största kanalerna för dennaspridning av gratis musik och jag har därför valt att fokusera min undersökning till dessa tvåsajter.</p><p>Syftet med denna uppsats var att at reda på hur och om denna förändring inomdistributionsmöjligheterna har förändrat förutsättningarna för musiker utan skivkontrakt attsprida sin musik och hitta en publik på egen hand. För att studera detta utförde jag trekvalitativa intervjuer med etablerade musiker och amatörmusiker inom musikbranschen.</p><p>För att ta reda på hur många lyssnare en amatörmusiker kan generera på egen hand under enkortare tid utförde jag en kvantitativ studie under loppet av fem veckor. I denna undersökningsatte jag mig själv in i rollen som amatörmusiker med en målsättning att bli känd. Underdessa fem veckor fick jag min låt spelad 164 gånger och fick även medverka på en podcastfrån England.</p><p>Min hypotes var att skivbolagen kommer att spela en mindre roll i framtidens musikscen ochkanske rent utav att försvinna. Teorierna som behandlas i denna uppsats talar för detta. I envärld där musiker har tillång till gratis marknadsföring och spridning av musik, vem behöverdå skivbolagen?</p>

Current observations were obtained at three locations forming a cross section along 70°34'W longitude in Long Island Sound. Fifteen days of data were selected from each series so that nearly simultaneous observations were used in the analysis. Elementary statistics were computed for the data prior to performing a least squares tidal current analysis. Eight tidal current constituents were fitted in two cases and nine in the remaining instance. Constituent current ellipses were constructed along with the average ellipses. Using the constituents previously computed, the tidal current was predicted for the period of observations. These values were subtracted from the observed current, generating a residual current series. Spectra were computed for each directional component along with cross spectra between the north and east components and also between corresponding components at each of the three different locations. Coherence square and phase relationships also accompanied the latter. An attempt was also made to correlate wind and the residual current by means of cross spectra. However, lack of sufficient wind data prevented a meaningful analysis. The natural period of oscillation of Long Island Sound was estimated by Defant's method of seiche analysis for a bay. This value was used in the equations for a cooscillating system and a comparison was made between the computed and observed amplitudes of the tide. The mean percent error for numerous locations throughout the Sound was 7.1%. Comparison was also made between the maximum flows computed from the above equations and some observed values. The maximum percent error was 24% in an ebbing direction. / Graduation date: 1971

Demographic changes and economic growth are inextricably linked. However, the complex role of demographic system, specifically its temporal features have not been treated with rigor till recently. This dissertation undertakes such an attempt to explain cross-country growth variations and focuses on longterm growth projections by explicitly treating demographic system in a stochastic shocks framework. We exploit the temporal characteristics of demographic system to shed light on its evolution, study its complex interaction with economic system and analyze the long-run effect on economic growth/development. The dissertation contains four chapters. After outlining the motivation of the thesis and an overview of the chapter scheme in the first chapter, we investigate in Chapter 2 how the effects of demographic components viz., age specific population have changed over the decades. Following the standard practice of assuming `stationary' features of population growth, we first evaluate and extend the popular empirical economic growth models. We find that decadal changes have brought forth variations in economic growth of developed and developing economies. We argue that accounting for temporal features of the demographic and economic growth system would provide clear insights into persistent growth fluctuations. In Chapter 3 we develop a new mechanism to characterize stochastic nature of demographic shocks in which population series with large temporal dimension is assumed to be governed by certain degree of stochastic shocks. By doing so, the conventional `stationary' assumption underlying the current theoretical and empirical exploration is relaxed and more dynamic information about the persistence of shocks is accommodated in the economic growth models. To this end, we first provide an analytical framework to show that long-memory shocks in demographic age structure or population might induce long-memory in economic growth. An empirical illustration of both developed and developing countries is carried out to demonstrate that population age structure in these countries are characterized by long-memory. The causality of stochastic demographic shocks' influence and economic growth (and the converse) is also examined. Following the theoretical development and empirical illustration in Chapter 3, in Chapter 4 we propose to forecast total and age-structured population employing fractionally integrated ARMA (in short, ARFIMA) technique. The conventional methods of population forecasting is discussed in this chapter evaluating the advantages and potential weaknesses of these methods. Our approach to population forecasting can be considered as a shift from the conventional `low, medium, and high' variant and the recently used ARMA projections (assuming stationarity or first difference stationarity of aggregate population) and is a departure from the stochastic population forecast based on Leslie matrix as used in the extant population forecasting literature. In Chapter 5 we incorporate the memory properties of demographic age- distribution to forecast Gross Domestic Product (or National income) of some developed and developing countries. We relax the stationary age-structure and population growth assumption in the model while performing long term income projections. We argue that the growth of total age-structured population need not be stationary and that any degree of stochastic shocks in these series can affect forecasting performance. Given that a long-memory panel method is yet to be comprehensively built for forecasting, we perform forecast of demography-based income in the univariate context assuming a stochastic long-memory process for age-structured population growth. Finally, Chapter 6 summarizes the main findings of the thesis and outlines some possible directions for further research. / Les changements démographiques et la croissance économique sont intimement liées. Cependant, le complexe rôle du système démographique, particulièrement son aspect temporel, n'a pas encore été analysé avec rigueur jusqu'aujourd'hui. Cette dissertation tente d'aborder cette question afin d'expliquer les changements de croissance des pays. Elle insiste particulièrement sur les projections de croissance de long terme en traitant explicitement les systèmes démographiques dans une structure de chocs stochastiques. Nous exploitons les caractéristiques temporelles des systèmes démographiques pour analyser leur évolution, étudier sa complexe interaction avec le système économique ainsi que les effets de long terme sur la croissance économique. Dans le chapitre 2, nous nous intéressons sur les effets des composantes démographiques , plus précisément comment l'âge d'une population spécifique a changé avec le temps. Suivant la pratique standard qui suppose une « stationnarité » de la croissance de la population, nous évaluons et étendons les modèles empiriques populaires de croissance économique. Nous trouvons que les changements décennaux ont apporté quatre changements dans la croissance économique des pays aussi bien développés qu'en développement. Nous montrons que le fait de tenir compte de l'aspect temporel des systèmes de croissance économique et démographique améliore les résultats sur la persistance des fluctuations de la croissance. Dans le chapitre 3, nous développons un nouveau mécanisme pour caractériser la nature stochastique des chocs démographiques dans laquelle les séries de population avec une large dimension temporelle sont supposées régies par un certain nombre de chocs stochastiques. En procédant de cette manière, la supposition conventionnelle de « stationnarité » qui sous-tend l'exploration théorique et empirique courante est relâchée et beaucoup plus d'informations sur la persistance des chocs sont données dans les modèles de croissance économique. Dans la croissance économique endogène avec un changement endogène de population, ce chapitre construit un modèle « long-memory » de population et de ses composantes (structure par âges) pour montrer les effets des changements démographiques sur les économies tant développées qu'en développement. Pour ce faire, nous donnons d'abord une formulation théorique pour montrer que les chocs « long-memory » dans la structure démographique de la population peut induire une croissance. Une illustration empirique est développée pour montrer que la structure de la population est caractérisée de « long-memory ». Suite au développement théorique et à l'illustration empirique du chapitre 3, le chapitre 4 propose une prévision de la population totale et de la structure démographique en employant de manière fractionnée la technique intégrée ARMA ( ARFIMA en bref). Les méthodes conventionnelles de prévision de la population sont discutées dans ce chapitre valuant les avantages et les faiblesses potentielles de ces méthodes. Notre approche peut être considérée comme un changement de la variante de la méthode conventionnelle « faible, moyenne et élevée » par rapport à la récente projection ARIMA utilisée récemment (qui suppose stationnarité ou différence première de la population agrégée). De plus, notre approche est un départ de la prévision de la population stochastique basée sur la matrice de Leslie. Nous avons aussi examiné un départ de la prévision stochastique basée sur la matrice de Leslie. Dans ce chapitre, nous avons aussi analysé pourquoi les techniques de prévision en démographie n'ont pas beaucoup évolué alors que les méthodes ne sont pas restées si traditionnelles. Dans le chapitre 5, nous incorporons les propriétés démographiques « memory » âge - distribution pour prévoir le Produit Intérieur Brut (ou revenu national) de quelques économies développées et en développement. Nous relâchons l'hypothèse de stationnarité âge-structure et croissance de la population dans le modèle en faisant les projections du revenu de long terme. Nous montrons que la croissance de la population totale n'a pas besoin d'être stationnaire et que tout degré de chocs stochastiques dans ces séries peut affecter la performance de prévision. Etant donné que la méthode de panel “long memory” est encore à construire pour une bonne prévision, nous faisons une prévision du revenu basée sur la démographie dans un contexte uni varié qui suppose une procédure stochastique « long- memory » pour une croissance de la population structurée suivant l'âge. Finalement, le chapitre 6 résume les resultants principaux de la thèse et montre quelques directions possibles pour des recherches futures.

The Cuu Long and Nam Con Basins, offshore Vietnam, contain sediment dispersal systems, from up-dip fluvial environments to down-dip deep-water slope and basinal environments that operated along the southern continental margin of Vietnam during Pliocene to Recent time. The available data enabled sediment thickness patterns, sequence-stratigraphic relationships, and channel types (fluvial to deep-water channels) within the lower Pliocene to Recent stratigraphic succession in the Cuu Long and Nam Con Son basins of offshore Vietnam to be analyzed. At least nine sequences and their accompanying systems tracts exist in the Pliocene to Recent section. Shelf-edge development in the study area is limited to the Eastern Nam Con Son Sub-Basin. Overall south to southeastward migration of the shelf edge complex during Pliocene to Recent time indicates that the Paleo-Mekong River System was the dominant sediment source for the area.

I examine the market reaction to merger announcements and the long-term post-merger stock price performance of newly merged firms. For a sample of 484 acquiring firms completing mergers between 1993 and 2000, the average value-weighted abnormal announcement date return (market-adjusted) is a statistically significant -1.02%. On average, this reaction is more negative for firms with "good governance." Specifically, a governance index comprised of three governance variables is significantly negative in a multivariate regression of announcement date abnormal returns. Comp is the percentage of CEO salary consisting of equity incentives (including stock options and restricted stock grants), InsideOwn is the percentage of the firm owned by officers and directors, and InstOwn is the percentage of the firm owned by large outside block shareholders. Value-weighted calendar-time portfolios consisting of the full sample of acquirers exhibit significant abnormal returns of 9.12%, 33.84% and 55.8% for the 12, 36 and 60 months following the merger, respectively. This overperformance is limited to the value-weighted portfolios. There is calendar-time evidence of abnormal performance for some subsamples on a risk adjusted basis. However, when compared to a control group, abnormal performance is limited to large glamour acquirers on a 12-month horizon, large cash acquirers on a 36 and 60-month horizon, and small focusing acquirers on a 60-month horizon. Multivariate analysis of long-run returns reveals that use of equity and corporate diversification are associated with lower post-merger performance. With regard to governance and long-run stock returns, there is also evidence that suggests higher levels of incentive compensation for CEOs is associated with more successful merger transactions for long-term investors.