Browsing by Author "Monro, John Alexander"
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- ItemCarbohydrate fractionation and elongation of lupin hypocotyl cell walls : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Botany at Massey University(Massey University, 1974) Monro, John AlexanderThe relationship between extensibility, growth rate and carbohydrate composition in different sections of lupin hypocotyl has been investigated. Although significant differences in extensibility were found, the carbohydrate composition of elongating and non-elongating regions were similar when delignified tissue was examined. However, it was subsequently found that the delignification removed all of the wall hydroxyproline, most of the arabinose, and much galactose and that all of these were higher in non-elongating than in elongating hypocotyl. The acid conditions of delignification caused about half of the loss of the sugars but did not cause the loss of hydroxyproline. Extraction of the hypocotyl cell walls with guanidinium thiocyanate and other denaturants, both before and after treatment with dilute acid or sodium methoxide in methanol did not dissolve the hydroxyproline, indicating that compounds containing this amino acids are sprobably covalently linked to insoluble wall constituents other than through acid labile arabinofuranose-hydroxyproline or ester links alone. 10% KOH extracted most of the wall hydroxyproline and hemicellulose largely as non-dialysable material. The hemicellulose thus extracted may be fractionated into hemicelluloses A and B and the latter into linear 1-4 linked polysaccharides and branched polysaccharides. Most of the hydroxyproline containing polymer is co-precipitated with the linear 1-4 linked hemicellulose-B arabinoxylan. When cell walls from elongating and non-elongating hypocotyl sections were compared the hemicellulose-B arabinoxylan fraction from the non-elongating wall had a much higher proportion or arabinose, galactose and hydroxyproline than the same polymer from elongating wall. Extraction of cell walls with 10% KOH at O°C removed about two thirds of the hemicellulose-B but little hydroxyproline. Subsequent treatment with 10% KOH at room temperature removed most of the hydroxyproline and remaining hemicellulose-B. The hemicellulose-B removed at room temperature showed the greatest increases in arabinose and galactose accompanying cessation of elongation. The polysaccharide extracted at 0°C is mainly xylan while that removed at room temperature contains large amounts of galactose and arabinose. The release of galactose at room temperature was accompanied by destruction or serine and appeared to parallel β-elimination of galactosylserine The kinetics of release of arabinose and galactose at room temperature differed. The above and other results are discussed particularly in relation to wall structure and a tentative model for the extensin-polysacchsride complex of lupin hypocotyl cell walls is proposed.
- ItemPerson-environment imbalance in an occupational setting : a comparative study of nursing stress in several hospital wards : a thesis presented in partial fulfilment of the requirements for the degree of Master of Arts in Psychology(Massey University, 1985) Monro, John AlexanderThe present study had three major objectives; (1) the development of a model in which to view nursing stress in terms of basic processes which underlie behaviour; (2) assessment of the levels of nursing stress in several hospital wards, including Oncology; (3) definition of the relationship of personality to the levels of perceived stress amongst nurses. A general information processing model of behaviour, based on the central role of imbalance in process, was developed as the appropriate context in which to understand occupational stress. The sources of stress in nursing, identified in the literature, were reviewed in terms of this model. Data reported here were obtained with a questionnaire designed to measure perceived frequency and stressfulness of job events, presence and stressfulness of job conditions, propensity to leave the job, role conflict, frequency and degree of satisfaction from a variety of sources, and other variables including a number of possible moderators of stress. Indices of stress were derived from these data and from standard measures of well-being, state anxiety and depression. The personality variables extraversion-introversion, neuroticism, trait anxiety, self esteem and locus of control were measured. Scores for stressfulness of events and job conditions respectively were factor analysed and individual factor scores obtained. Wards were compared on a number of the above variables. Few of the events or job conditions were perceived as very stressful on average, with only job conditions related to work load rated as very stressful. Although scores of frequency and stressfulness of each event were not significantly correlated, individuals reporting high frequencies tended to also give high stress scores. Differences between wards in reported frequency of events were generally consistent with the speciality of wards involved. However, Women's Medical showed a general elevation of scores on most items relative to other wards, and on stress indices, particularly depression. Factor analysis of stressfulness scores with two factors for both events and job conditions respectively revealed in both cases a factor which was heavily loaded on by administrative items and which also correlated strongly with measures of depression. Scores on personality tests did not differ significantly between wards, although neuroticism, trait anxiety and self esteem correlated to similar degrees with a number of stress indices and appeared to be measuring the same trait. Extraversion-introversion and locus of control were not correlated significantly with stress. The results do not support the prevalent view that nurses in Oncology and Intensive Care wards suffer high levels of stress compared with nurses in other wards. The methodology used in this and similar types of study is critically discussed in light of the present results, and the relevance of personality variables to stress is discussed in relation to the present findings.