Search

Mathematical morphology is an established field of image processing first introduced as an application of set and lattice theories. Originally used to characterise particle distributions, mathematical morphology has gone on to be a core tool required for such important analysis methods as skeletonisation and the watershed transform. In this thesis, I introduce a selection of new image analysis techniques based on mathematical morphology. Utilising assumptions of shape, I propose a new approach for the enhancement of vessel-like objects in images: the bowler-hat transform. Built upon morphological operations, this approach is successful at challenges such as junctions and robust against noise. The bowler-hat transform is shown to give better results than competitor methods on challenging data such as retinal/fundus imagery. Building further on morphological operations, I introduce two novel methods for particle and blob detection. The first of which is developed in the context of colocalisation, a standard biological assay, and the second, which is based on Hilbert-Edge Detection And Ranging (HEDAR), with regard to nuclei detection and counting in fluorescent microscopy. These methods are shown to produce accurate and informative results for sub-pixel and supra-pixel object counting in complex and noisy biological scenarios. I propose a new approach for the automated extraction and measurement of object thickness for intricate and complicated vessels, such as brain vascular in medical images. This pipeline depends on two key technologies: semi-automated segmentation by advanced level-set methods and automatic thickness calculation based on morphological operations. This approach is validated and results demonstrating the broad range of challenges posed by these images and the possible limitations of this pipeline are shown. This thesis represents a significant contribution to the field of image processing using mathematical morphology and the methods within are transferable to a range of complex challenges present across biomedical image analysis.

Evidence presented in this thesis supports the notion that certain muscarinic antagonists exhibit a greater functional affinity for the inhibition of M3 muscarinic acetylcholine (mACh) receptor-mediated phosphoinositide turnover in guinea-pig urinary bladder than for M3 receptor-mediated responses in the submandibular salivary gland of the same species. The present study suggests that the observed tissue-dependent pharmacologies cannot be explained in terms of multiple receptor subtypes. The muscarinic antagonists found to display such 'functional selectivity' in this investigation are used in the pharmacological management of overactive bladder, so it is possible that these properties contribute to the favourable side-effect profiles of some of these drags. The potential molecular mechanisms underlying these observations are discussed. To investigate the inverse agonist properties of these, and other, mACh receptor antagonists, a constitutively-active, mutant (CAM) M2 mACh receptor was generated by a single amino acid change (N410Y) at the junction between the sixth transmembrane domain and the third extracellular loop of the M2 receptor. The present study provides the first detailed characterisation of a CAM M2 mACh receptor, demonstrating many of the hallmark features of a CAM receptor, including enhanced agonist-independent signalling, increased agonist binding affinity and functional potency and an increased partial agonist efficacy. All of the ligands assayed (previously classified as 'antagonists' at the M2 receptor), similarly reduced the constitutive activity of the mutant receptor, indicating that they should be re-classified as inverse agonists at the M2 mACh receptor. The CAM M2 mACh receptor was also expressed at substantially lower levels than the wild-type receptor, but overnight incubation with atropine caused a significant up-regulation of cell surface receptor expression. However, not all inverse agonists were capable of up-regulating the CAM M2 receptor. The implications of these findings for the clinical use of muscarinic antagonists and for mACh receptor signalling in general are discussed.

The thesis seeks to compare and extend a number of analytical and simulation procedures to a series of progressively more complex activity-analysis problems which are common to business application and economic theory. Beginning with two industrial examples, which are used to illustrate the nature of linear production interdependencies and the relevance and limitations of a Leontief-type input-output approach to such static single time period problems, the thesis explores further analytical contributions to a more difficult "general logistics problem" incorporating decisions concerning the allocation, scheduling and investment of resources in an environment that is both interdependent and subject to stochastic variation. In one delimited logistics problem the Hitchcock-Koopmans algorithm is amalgamated with an extension of an algorithm proposed by Dantzig and Fulkerson to derive a shipping schedule that minimises the number of vehicles necessary to satisfy a known demand in4a network of origins and destinations. A multi- stage linear programming procedure with more realistically detailed properties is then proposed, but quickly abandoned because of implied computational requirements. It is therefore argued that simulation procedures offer the only operational means for studying such analytically and computationally intractable problems. This approach is fraught with its own difficulties, not the least of which is choosing among contending decision rules once the model is constructed. Such a choice is attempted following statistical guidelines in a stochastic logistics simulation experiment. The text concludes with the means for choosing among alternative resource allocation rules in a computer simulated abstract economy.

This paper deals with the fundamental mechanisms through which atomic radiation injures living cells aDd thereby injures the human organism. No attempt has been mde to leal exhaustively with aey one point; rather the attempt has been to present a broad orientation within the field and then to present sufficient data to allow the formulation of the most reasonable hypothesis which will account for the changes observed in radiation injury. The material selected for presentation and discussion has been chosen from the work of researchers who seem to have contributed data or hypotheses which appear fundamental to the concept of radiation injury.

The purpose of this study is to determine the tendencies of contemporary women poets as to verse, form, rhythm, and meter. The study was based on the 1936 publication of Henry Harrison's Contemporary American Women Poets. None of these poems had appeared in any other anthology. It was made up from books printed by thirty-nine publishers and two hundred nine periodicals.

Nature of Study: Many high school biology teachers fail to offer their students any individual laboratory activities. One phase of activities which can be effectively administered, but is often avoided by high school biology teachers, is the dissection of preserved animal specimens. This report deals with various problems which appear while conducting dissection activities. Items such as: obtaining preserved specimens; dissection equipment; facilities required for dissection; motivation of students; and, dissection procedures are discussed. Also included are dissection plans, orderly step-by-step procedures, for the earthworm, frog, grasshopper, and the fetal pig.

(Summary) 1. An attempt was made to separate pre- and post-synaptic action potentials on the basis of recovery of spike height to the second of two supramaximal stimuli. 2. Two distinct groups of action potentials were recorded from the spinal tract of the trigeminal nerve. 3. A series of recovery-cycles of the spike potentials of the sciatic nerve was plotted for comparison with the spike potential of the spinal tract of the fifth nerve. 4. A 2 channel stimulator and a 5 unit synchronizer circuit were designed and constructed for use in these experiments. The utilization of a Schmitt circuit to achieve time delay is believed to be a new application of that circuit. 5. From the date presented here, it may not be certain that the second peak of the potential wave recorded from the spinal tract and nucleus of the fifth nerve is from second or higher order fibers, but it gives strong support to the belief that it is actually post-synaptic. 6. The methods used in these experiments are not necessarily restricted to use in trigeminal pathways but should be applicable to any synaptic region.