A discrete algorithm for following a desired model for systems that are non-linear or time varying is developed. The controller is developed with optimal control theory by finding the optimal control that would minimize a quadratic cost functional based on the error between the model and system for the previous sampling period. With this information a correction to the system command is formulated for the next sampling period. The stability of the algorithm is investigated and a stability criterion is found. Two examples are presented to show the characteristics of the controller. / Master of Science

A short-term selection experiment was conducted with ICR albino mice produced by the reciprocal crossing of two lines of unselected animals which had been random-bred for 28 generations. Lines were developed by selecting for maximum and minimum serum cholesterol (SC) (lines CH and CL), voluntary physical activity (lines AH and AL), 56-day body weight (lines WH and WL) and feed intake (lines IH and IL). An unselected, random-bred control line was maintained with each pair of divergent selected lines (CC, AC, NC and IC, respectively). In the lines selected for SC, physical activity and 56-day body weight, selection was based on individual performance. Twenty-five paired matings plus five extra paired matings were used to perpetuate the lines each generation for five generations. The feed intake lines were perpetuated by within-sex, full-sib family selection with 30 paired matings per generation for five generations. / Ph. D.

Feed intake, growth, efficiency, and serum cholesterol levels (SCL) were recorded for 102 male mice, and voluntary physical activity and SCL were recorded for 113 male mice from lines selected for 22 generations for maximum 21- to 42-day gain (H), minimum 21- to 42-day gain (L), and a random-bred control (C). Heritability (h²), phenotypic and genetic correlations of SCL, activity, growth, and body moisture content were estimated for 466 sire-son pairs of mice from an unselected line. Blood samples were obtained by sinus orbital bleeding at 35 and 70 days of age in the line characterization study and at 62 days of age in the genetic parameters study and were analyzed for SCL by gas chromatography. Voluntary physical activity was recorded as revolutions of an exercise wheel every sixth day from 21 to 70 days of age in the line characterization study and at 28, 49, and 70 days of age in the genetic parameters study. Feed intake (of an 11% fat, 9% fat, and 4-1/2% fat diet) was recorded for several days each week and extrapolated to obtain weekly intake data. A least-squares analysis of variance from a model including lines, diets, and line x diet interactions indicated highly significant differences in the main effects but few significant interactions. Total SCL, growth, and efficiency were higher, and intake lower in mice on the higher fat diet. SCL (mg/100 ml) at 10 weeks of age was 220.3, 178.1, and 180.4 for animals fed an 11% fat diet and 143.3, 124.1, and 132.2 for animals fed a 4.5% fat diet. Activity scores (revolutions) for the H, C, and L lines were 79234, 107987, and 124409. Activity generally increased in all lines from 21 to 56 days of age, then declined slightly. Heritability estimates of SCL and body moisture 2 content were .31 ± .07 and .20 ± .11, and h² estimates for activity ranged from .27 ± .14 to .54 ± .12. Negative genetic correlations occurred between body moisture content and SCL and between body moisture content and weight gains. / Master of Science

These experiments have proved conclusively the effect of cedar rust on the normal processes of the apple leaf. The diseased leaves use more oxygen and give off more carbon dioxide than the healthy leaves, and at the same time less starch and sugar is made than in the healthy leaves. When transpiration is reduced, the food supply - the soluble plant food - is accordingly reduced. The difficulty of diseased trees not being able to get sufficient food through insufficient transportation, by water, may be overcome by either of two methods - (1) irrigation or (2) fertilization, with neutral or slightly acid fertilizers, manure being an excellent material to use. The first and most important method of cedar rust control is to cut the cedars for a distance of at least a half mile from the orchard. Second in importance is by timely sprayings, and third, is by feeding the trees. In order that cedar rust control is to be realized, cooperation in a community is essential. “Team work" is necessary in all lines of work and the orchardist should not forget this fact. / Master of Science

We test the performance of myopic and farsighted stability concepts in a network formation experiment with a stream of payoffs and relatively unstructured link formation process. A subtle treatment variation demonstrates clearly the power of myopic stability concepts in precisely identifying the set of the most stable networks. However, we also find support for the predictions of farsighted concepts of stability, especially those that assume players' pessimism about the eventual outcome of a deviation. This is the first study to demonstrate that there exist environments where farsighted stability concepts identify empirically stable networks that are not identified by myopic concepts. Thus, myopic stability concepts are not necessarily sufficient to predict all stable outcomes in empirical applications.

A major effort to develop anticancer drugs through both empiric screening and rational design of new compounds has been under way for over 30 years (Katzung, 2004). In recent years, research and development in the field of sitespecific drug therapy has progressed significantly. Safe and non-toxic formulations of cytotoxic drugs based on polymers with their improved sitespecific delivery and effective activation to biologically active cytotoxic compounds at the targeted tumours have become a promising approach to cancer therapy. Drug delivery systems based on polymer micelles, coated microand nanoparticles, liposomes and various pro-drug systems including watersoluble polymer–drug conjugates and immunoconjugates have been prepared and extensively studied as novel drug delivery systems designed for cancer chemotherapy. Amongst these drug delivery systems that enable specific drug delivery and release, water-soluble polymer–drug conjugates rank among the most promising, versatile and efficient systems. This dissertation reviews the preclinical testing and pharmacokinetic study of D85, a novel water-soluble macromolecular pro-drug that is a polymer with pHcontrolled methotrexate (MTX) release with potential for treatment of cancer in humans (Ulbrich&Subr, 2004). As MTX is also indicated in low doses for the treatment of chronic inflammatory conditions, the polymer was further tested in an acute inflammatory model to determine whether the polymer would be more effective than MTX in controlling inflammation. The objective of this study was to compare the potency and efficacy of D85 to MTX. D85, a MTX conjugated polymeric lead compound, was designed and synthesised as a potential anti-neoplastic and anti-inflammatory agent. It was initially tested in vitro on three different cancer cell lines where selective toxicity towards the cancer cell cultures compared to primary cell cultures and greater toxicity than MTX was observed. The initial in vitro tests showed very promising results with D85 demonstrating approximately 300 times greater cytotoxicity than MTX against a colon cancer cell line (COLO 320 DM). This high cytotoxic effect warranted further investigation in an in vivo colon cancer tumour model. An induced murine tumour model of COLO 320 DM was successfully developed in nude mice, and the anti-tumour efficacy of D85 tested in this model. The maximum tolerated dose of D85 was established by carrying out an in vivo dose ranging toxicity test in BALB/c mice. The anti-inflammatory effects of D85 were also determined using the carrageenan-induced paw oedema model in rats where carrageenan was injected into a footpad of a rat causing acute oedema, which was measured using a water displacement plethysmometer. D85 was found to exacerbate the inflammatory response. Finally, the pharmacokinetic parameters of MTX and D85 were assessed using a LC/MS/MS method specifically developed and validated to determine low concentrations of MTX in small volumes of plasma. This new method made use of online solid phase extraction and sample cleanup on 2μl injections of diluted plasma allowing an entire pharmacokinetics study to be completed on an individual rat. Fairly similar pharmacokinetics were determined from both compounds. Copyright / Dissertation (MSc)--University of Pretoria, 2010. / Pharmacology / unrestricted

Das in der Wirtschaftspraxis zunehmend häufig beobachtbare Phänomen der Koopetition, welches die Kooperation zwischen zueinander zugleich im Wettbewerb stehender Unternehmen beschreibt, ist aus wissenschaftlicher Perspektive empirisch und theoretisch weitgehend unzureichend erfasst. Diese Arbeit untersucht daher das strategische Management dieser auf den ersten Blick paradox erscheinenden koopetitiven Interorganisationsbeziehungen am fokalen Beispiel eines Unternehmens der zivilen Flugzeugtriebwerksindustrie, welches im Zuge der Erstellung kollektiver komplexer Produkte (CoPS) durch tiefgreifende Kooperationspartnerschaften eng mit seinen Wettbewerbern verbunden ist. Im Mittelpunkt der Analyse steht zum einen die Frage nach den spezifischen Gründen für das Auftreten und Eingehen von Koopetitionsbeziehungen, zum anderen die konkrete Ausgestaltung strategischen Handelns unter koopetitiven Verhältnissen und die Bewältigung des wettbewerblich-kooperativen Spannungsfelds durch die involvierten Unternehmen. Der bisherige geringe theoretische Kenntnisstand zum Untersuchungsphänomen bedingte ein gegenstandsangemessenes qualitatives Forschungsdesign auf methodologischer Basis der Grounded Theory. Als primäre Datenquelle wurden problemzentrierte Interviews mit Managern koopetitionsrelevanter Unternehmensbereiche geführt, aus denen unter Anwendung eines elaborierten Kodierprozesses empirisch fundierte Konzepte und Kategorien gebildet und in ihren kausalen Zusammenhängen abgebildet wurden. Auf diese Weise entstand eine substantive Theorie mittlerer Reichweite, die das Phänomen erstmalig in derartig empirischer Tiefe und theoretischer Dichte darstellt und dadurch einen wichtigen Beitrag auf dem Gebiet der Koopetitionsforschung leistet. Eine spiegelnde und integrierte Verknüpfung der empirischen Resultate mit dem aktuellen Stand der Forschung gewährleistet die diskursive Anschlussfähigkeit der gewonnenen Erkenntnisse an die Wissenschaftsgemeinschaft. Darüber hinaus eröffnet die Arbeit relevante handlungspraktische Ansätze für das strategische Management von Koopetition. (Autorenref.)

Throughout the seventeenth century, numerous Scots became convinced that the major political and religious upheavals of their age signified the fulfillment of, or further unfolding of, the vivid prophecies described in the Book of Revelation which foretell of the final consummation of all things. To date, however, an in-depth analysis of the evolution of Scottish apocalyptic belief during the seventeenth century has never been undertaken. This thesis utilizes a wide variety of source material to demonstrate the existence of a cohesive, persistent, and largely conservative tradition of apocalyptic thought in Scotland that spanned the years 1588 to 1688. Chapter One examines several influential commentaries on the Book of Revelation published by notable Scots during the decades either side of the Union of Crowns. These works reveal many of the principal characteristics that formed the basis of the Scottish apocalyptic tradition. The most important of these traits which became a consistent feature of the tradition was the rejection of millenarianism. In recent years, historians have exaggerated the influence of millenarian ideals in Scotland during the Covenanting movement which began in 1638. Chapter Two argues that Scottish Covenanters consistently denounced millenarianism as a dangerous, subversive doctrine that could lead to the religious radicalism espoused by sixteenth-century German Anabaptists. Chapter Three looks at political and religious factors which led to the general decline of apocalyptic expectancy in Scotland during the Interregnum. It also demonstrates how, despite this decline, Scottish apocalyptic thinkers continued to uphold the primary traits of the apocalyptic tradition which surfaced over the first half of the century. Lastly, Chapter Four explains how state-enforced religious persecution of Scottish Presbyterians during the Restoration period led to the radicalisation of the tradition and inspired the violent actions of Covenanter extremists who believed they had been chosen by God to act as instruments of his divine vengeance in the latter-days.