A thorough and detailed investigation into the accuracy, reliability and consistency of the objective-prism redshift technique with changes in plate material, measuring machine and reduction techniques has been undertaken. Providing that the limitations of the procedures involved are appreciated, useful 3-D information, accurate to Z ~±0.01, for large numbers of faint galaxies may be obtained from single UKST fields. A surface brightness correction has enabled the technique to be extended to galaxies as bright as bj ~15.8. The validity of the results were confirmed by external calibration with slit-spectra. The slit-spectra results obtained have more than doubled the size of the calibration sample available and have further vindicated the applicability of the technique. Analysis of the 107 slit-spectra redshifts determined revealed the existence of considerable structure in the field studied, with significant density enhancements and voids being apparent. This structure has been confirmed on larger scales and to greater depths with the subsequent analysis of ~1,500 objective-prism redshifts from COSMOS data of the field. Two large superclusters were discovered. The first centred at Z ~0.05 but extending for at least 150 h⁻¹Mpc, and the second a projected filament of connecting clusters at Z ~0.11 and 23 h⁻¹Mpc long. A selection of 2-D and 3-D statistical analysis techniques have been used to describe the observed large-scale galaxy distribution in this field. A by-product of this work has been the discovery of a new and powerful means of star/galaxy separation based on magnitude comparisons between paired objects from both the direct and objective-prism plates. This technique has revealed ~20% stellar contamination in the star/galaxy separation based on direct plate data alone. In conclusion, objective-prism galaxy redshifts are valuable information for complementing 2-D data in the study of the large-scale distribution of galaxies from COSMOS measures of Large numbers of UKST plates. To this end an automatic technique of objective-prism redshift determination should be developed.

This volume is a study of the immigration of three individual groups of Scottish Highlanders as they ventured to the new colony of Georgia in British North America between the years 1735 and 1748. It examines the importance of the area of the Altamaha River in which they settled and the conflicts along the southern frontier of British colonial America between the rival powers of Great Britain, Spain, France, and the Native American population. These struggles would necessitate the organised recruiting efforts made on the part of the Trustees for Establishing the Colony of Georgia in America to bring Highland Scots, in particular, to the province as their first line of defense. The focus of the text is on the Scots themselves as the changing conditions in the Highlands motivated them to leave their native glens of Scotland to come to the pine barrens of Georgia. The thesis explores the ability of these immigrants to face the challenges of a new environment and the trials of the frontier settlement at Darien. It is an account of how their cultural distinctiveness and "old world" experience aptly prepared them to adapt and to prosper in the new land and to play a vital role in the survival of colonial Georgia. The Highlanders of Scotland who settled at Darien during the first two decades of the colony's existence have been relegated to the shadows of Georgia's colonial history for too long and this work hopes to establish their importance during this crucial period.

Thesis (Ph. D.)--University of Missouri--Columbia, 2003. / "August 2003." Typescript. Vita. Includes bibliographical references (leaves 82-101). Also issued on the Internet.

Thesis (Ph. D.)--University of Missouri--Columbia, 2003. / "August 2003." Typescript. Vita. Includes bibliographical references (leaves 82-101). Also issued on the Internet.

1. The numbers and distribution of mating-type factors in local populations of Polystictus versicolor have been studied, and the data available on the number and distribution of mating-type alleles in other fungi have been reviewed. Possible explanations for the low numbers recorded in Polyfitictus versioolor are -given, and the potential out-breeding capacity of the local populations is discussed. 2. Growth rates of dicaryotic and monocaryotic strains of P. versicolor at 25°C and 35°C. have been studied. 3. Studies have been made on the genetical and physiological nature of the mycelium in P. versicolor and it is thought that the mycelium exists in nature as a physiologically homogenous and genetically heterogenous unit. The mechanisms by which such a mycelium could be established have been studied. They are (a) hyphal fusions and (b) dj. x mon. pairings. 4. The effects of different mating-type factors in compatible pairings on (a) hyphal fusion; (b) nuclear migrations; (c) clamp connection formations have been investigated, and a suggestion made concerning a model for gene action in connection with the formation of clamps.

Theoretical methods for studying molecules of biological importance are reviewed, both ab initio and semi-empirical. The Group Function Approach is developed in detail in its strong orthogonal form and corrections to the energy are added for taking into account non-orthogonality effects, depending on the overlaps of the group functions. Approximations are introduced and tested so that this method can be applied to large molecules. In particular, a system (or a relevant fragment of it) is built up from localized two-electron groups, each one described by a two-electron group function (geminal). Each group function is optimized by using an SCF method with an effective hamiltonian consisting of the two-electron hamiltonian of the group together with the effective potential due to the presence of the other electron groups (and to the external environment, eventually). The wavefunction for the whole molecule is an antisymmetrized product of geminals. The energy is computed as a sum of group contributions. Corrections, depending on up to the second power of the overlaps of two groups at a time, are particularly important in conformational studies. The approximations introduced are based on the consideration that distant groups consisting of two positive and two negative charges see each other as neutral entities and thus do not contribute appreciably in the definition of the effective hamiltonian: the computing effort is greatly reduced in this way, the error introduced is small and can be estimated easily. The theoretical method presented in this thesis offers a powerful tool for making qualitative predictions of the changes resulting from localized effects, such as twisting around a bond, and it can be usefully applied to conformational studies and geometry optimizations. The other properties which can be calculated axe for the most part directly related to the electron density; this determines, for example, the electrostatic potential outside a molecule and hence the position of attack by approaching ions or polar species. Chemical reactions, which involve breaking or re-arrangement of bonds, provide another vast field of application. Such processes usually involve only localized regions in a molecule and the admission of intragroup CI ensures that the study of bond breaking remains valid throughout the whole process. All necessary computer programmes have been developed and numerical applications have been made to a range of molecules, including hydrocarbons, small molecules containing double bonds and lone pairs, and the amino acid glycine.

There are three principal aims of this work; firstly to derive the analytical expressions for the potential energy and the mutual gravitational attraction between two homogeneous or non-homogeneous oblate spheroids with coplanar equatorial planes; secondly, to construct and study the equations of motion of dynamical systems consisting of particles and rigid homogeneous spheroidal bodies whose equatorial planes are coplanar; thirdly, to investigate by numerical integration and compare the evolution of dynamical models of interacting galaxies. Two different types of dynamical models of galaxies were used in this work:(a) galaxies consisting of gravitating particles, (b) galaxies comprising of gravitationally interacting particles and heavy central rigid homogeneous oblate spheroids. Chapter (2) and appendices (4), (5), (6) and (7) are an account of the method used to derive the expressions for the potential energy and the mutual gravitational attraction between two rigid bodies bounded by spheroidal surfaces with coplanar equatorial planes, when the densities of the bodj.es are either constant or inversely proportional to the square of the radial distance from the centres of the bodies. These expressions were at first obtained in the form of non-elementary integrals over the complete elliptic integrals of the first and second kind, a result due to the fact that the common volume between two ellipsoids cannot be expressed in finite terms. The evaluation of these integrals was achieved with the aid of MacLaurin' s theorem by collapsing one of the spheroids to its confocal disc; their final form is that of rapidly convergent series in terms of the parameters which determine the shape and orientation of the spheroids. In the course of obtaining the expressions mentioned above we derived some other useful formulae, for example, the formulae giving the gravitational attraction between two homoeoids and the potential and force law of a non-homogeneous oblate spheroid. Having found the expressions for the gravitational potential and attraction between two spheroids we proceeded by constructing and solving the equations of motion of dynamical systems consisting of either particles or particles and rigid homogeneous oblate spheroids with coplanar equatorial planes [chapters (1) and (3), appendices (2) and (3)]. The solutions of the equations of motion - being non-algebraic - were obtained in the form of power series. In particular, for the first type of dynamical systems (particles only) they were found in the form of three different types of series. The first type is based on the development and implementation of generalized f and g series for the N-body problem, the second type is based on recurrent formulae used for the evaluation of the terms of the series and the last type of series is a power series in terms of ln ɼijτ/ɼij and polynomial of ɼijτ/ɼij. All the series mentioned above lend themselves easily, to numerical calculations since their convergence, which was analytically proved, is a rapid one. We concluded the present work by numerically integrating the equations of motion of dynamical models of pairs of interacting galaxies. The galaxies were of the types (a) and (b) mentioned previously. The numerical integration was performed with variable time steps in order to reduce computing time. A general method was developed for the precise evaluation of the length of the time step determined by the desired integration accuracy. The calculations were carried out to an extremely high degree of accuracy. The most significant of the results of the numerical experiments on the evolution of dynamical models of interacting galaxies were:(i) the development of long-lived spiral structure when galaxies of type (b) were lased even for intrinsic velocities and impact parameters so high that galaxies of type (a) were unable to produce such structure,(ii) the roughly periodic appearance and disappearance of the spiral structure,(iii) the fact that in the early stages of their evolution the dynamical models take up rather long-lived triaxial ellipsoidal shapes.

Tous les écosystèmes contiennent des phages, ces virus qui infectent spécifiquement les bactéries. Les écosystèmes microbiens des produits laitiers ne font pas exception. Malgré les nombreuses recherches dans le domaine, les phages virulents spécifiques aux souches de Lactococcus lactis utilisées pour la fermentation du lait menacent encore la qualité des fromages et la constance des lots de production. Le phage p2 est un modèle pour l’étude des phages virulents de lactocoques, mais près de la moitié de ses gènes codent pour des protéines aux fonctions encore inconnues. L’étude des phages virulents constitue un défi de taille puisque la modification de leur génome est limitée par le court passage du génome viral dans la cellule bactérienne. Le premier objectif de cette thèse était d’adapter un outil génétique basé sur la technologie CRISPR-Cas9 afin d’inactiver des gènes d’intérêt du phage p2. Cette technologie est dérivée d’un système antiviral naturel qui permet à certains procaryotes de se défendre contre l’invasion par de l’ADN étranger. La bactérie hôte du phage p2, L. lactis MG1363, est normalement dépourvue de ce système. Le deuxième objectif était d’étudier les protéomes phagiques et bactériens lors de l’infection virale par des analyses de spectrométrie de masse à haute résolution. Enfin, le troisième objectif était d’étudier les rôles des gènes inactivés sur la multiplication des phages et des bactéries infectées, incluant l’impact sur leurs protéomes. Entre autres, par une approche intégrative combinant des analyses génomiques, phénotypiques et protéomiques, j’ai comparé le phage mutant p2Δ47, dont le gène orf47 avait été inactivé, au phage sauvage p2. Ces analyses m’ont permis de formuler une hypothèse quant à la fonction de la protéine virale ORF47. Les phages sont ubiquitaires, abondants et peuvent se multiplier rapidement. Malgré leur importance et plus d’un siècle de recherches, plusieurs aspects de la biologie des phages demeurent mal compris. En concevant un outil pour la modification des génomes de phages virulents et en optimisant des protocoles d’analyses protéomiques, j’ai développé des méthodes efficaces pour la caractérisation des protéines phagiques et pour l’étude des interactions phage-bactérie. / Phages are viruses that specifically infect and kill bacteria. They can be found in every ecosystem, including milk products. Despite decades of research, virulent phages infecting Lactococcus lactis strains used for milk fermentation still threatens the production process and cheese quality. Phage p2 is a model for the study of virulent lactococcal phages, but almost half of its genes encode proteins of unknown functions. The study of virulent phages is a challenge in itself because the modification of their genome is limited to the short infection cycle within a bacterial host. The first objective of this thesis was to adapt a CRISPR-Cas9-based genetic tool to inactivate genes of interest in the genome of phage p2. The CRISPR-Cas9 technology is derived from a natural antiviral system that allows some prokaryotes to defend themselves against invasive nucleic acids. The bacterial host of phage p2, L. lactis MG1363, is naturally deprived of this system. The second objective was to study the viral and bacterial proteomes during phage infection, making use of high throughput mass spectrometry-based proteomics. Lastly, the third objective was to study the roles of inactivated genes on phage replication and bacterial growth, including the impact on their proteomes. Amongst other, with an integrative approach combining genomic, phenotypic and proteomic analysis, I compared the mutant phage p2Δ47, lacking a functional orf47 gene, to the wild-type phage p2. These analyses allowed me to hypothesize about protein ORF47 function. Phages are ubiquitous, abundant and can replicate quickly. Despite their importance and over a century of research, many aspects of phage biology are still poorly understood. By designing a tool for the modification of virulent phages and by optimizing protocols for proteomic analysis, I developed a robust pipeline to investigate uncharacterized phage proteins and to study phage-host interactions.

Thesis (Ph. D.)--University of Missouri--Columbia, 2001. / "May 2001." Typescript. Vita. Includes bibliographical references (leaves 108-125). Also available on the Internet.

This thesis reports on some applications of murray polygons, which are a generalization of space filling curves and of Peano polygons in particular, to process digital image data. Murray techniques have been used on 2-dimensional and 3-dimensional images, which are in cartesian/polar co-ordinates. Attempts have been made to resolve many associated aspects of image processing, such as connected components labelling, hidden surface removal, scaling, shading, set operations, smoothing, superimposition of images, and scan conversion. Initially different techniques which involve quadtree, octree, and linear run length encoding, for processing images are reviewed. Several image processing problems which are solved using different techniques are described in detail. The steps of the development from Peano polygons via multiple radix arithmetic to murray polygons is described. The outline of a software implementation of the basic and fast algorithms are given and some hints for a hardware implementation are described The application of murray polygons to scan arbitrary images is explained. The use of murray run length encodings to resolve some image processing problems is described. The problem of finding connected components, scaling an image, hidden surface removal, shading, set operations, superimposition of images, and scan conversion are discussed. Most of the operations described in this work are on murray run lengths. Some operations on the images themselves are explained. The results obtained by using murray scan techniques are compared with those obtained by using standard methods such as linear scans, quadtrees, and octrees. All the algorithms obtained using murray scan techniques are finally presented in a menu format work bench. Algorithms are coded in PS-algol and the C language.