Thesis (Ph. D.)--University of Hong Kong, 2007. / Title proper from title frame. Also available in printed format.

Includes bibliographical references (p. 110-126).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.D.) -- University of Pennsylvania, 1805. / Film 633 reel 66 is part of Research Publications Early American Medical Imprints collection (RP reel 66, no. 1314). DNLM

Thesis (Ph. D.)--Washington State University, May 2010. / Title from PDF title page (viewed on June 3, 2010). "College of Veterinary Medicine." Includes bibliographical references.

Thesis (MA (Counselling Psychology))--University of Pretoria, 2005. / Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

No description available.

Percentage in-vitro conidial germination of inaequalis was inversely related to the log conidial concentration. The filtrate from a conidial suspension of inaequalis was shown to inhibit conidial germination. Ferrous iron was shown to reduce conidial germination. Anthranillic acid reversed the inhibitory action of ferrous iron and enhanced germination of conidial suspensions not containing additional iron. Continuous rolling or ''pre-treatment" of conidial suspensions of V. inaequalis used for inoculum increased levels of infection. It was suggested that this improvement may be a result of higher numbers of germinated conidia present on the leaf surface. Pre-treatment of inocula was adopted as a standard inoculation technique. Symptom expression was studied under two categories :- i) Effect on seedling growth (stunting/promotion) ii) Foliar symptoms (total disease expression score - TDE) Stunting and TDE values were correlated to lesion number and positively correlated to inoculum concentration. High inoculum concentrations caused stunting and low ones resulted in growth promotion. Similar responses were found with all apple varieties tested. Experimental evidence was presented to support the hypotheses :- 1) Conidia only produce stunting. 2) The filtrate from a pre-treated conidial suspension of V. inaequalis contained a factor which induced growth promotion of apple seedlings. Washing pre-treated conidia with GDW immediately before inoculation enhanced stunting of apple seedlings. Foliar sprays of the pre-treatment filtrate promoted seedling growth, concentrating it further enhanced promotion. The factor responsible was resistant to boiling, suggesting it to be non-protein but after standing for 24 h lost its ability to promote growth. Bioassays of the filtrate for IAA and cytokinins were negative. A dock leaf disk test was positive for gibberellins. Analysis of the filtrate using mass spectrometry indicated the presence of high molecular weight ions but it was not possible to identify any particular fragment or conclude whether these could be responsible for growth enhancement. It is suggested that the filtrate acts by increasing cell elongation rather than cellular proliferation. Use of the fungicides dodine and captan produced a host response to infections by inaequalis ranging from stunting to growth promotion. The potential of pre-treatment and symptom assessment for use as a fungicide screening technique was demonstrated. It was suggested that summation of the ranked scores for TDE and phytotoxic stunting provided an accurate assessment of a chemical's suitability for further testing.

Bovine coronavirus (BCV) has been previously detected in the enteric and respiratory tracts of cattle and is specifically associated with enteritis and diarrhoea in neonatal calves. Two diagnostic tests, an ELISA and an immunogold EM technique for the detection of BCV in faeces, were developed, optimised and compared with direct EM, immunosorbent EM and haemadsorption-elution-haemagglutination (HEHA). The immunogold EM technique was found to be the most sensitive test followed by the ELISA, HEHA, immunosorbent EM and direct EM. An IF test for detecting BCV in the respiratory tract and a neutralization test for quantifying anti-BCV antibody titres in serum and milk were also developed. Using the immunogold EM technique BCV was demonstrated in 39 of 123 field samples of bovine diarrheic faeces. From 25 of these samples 2 isolates were successfully adapted to grow in HRT 18 cells following initial isolation in bovine fetal tracheal organ culture. These, and three other strains of BCV and a human coronavirus (HCV) strain obtained from other laboratories, were compared in immunofluorescence (IF), haemagglutination inhibition (HAI) and neutralization tests. Polyclonal antisera against these 6 viruses were raised in rabbits. No significant differences between viruses were detected by IF incorporating homologous and heterologous antisera but HCV could be distinguished from the bovine coronaviruses in a cross neutralization test. In this test all BCV isolates were determined to be of one serotype. In the HAI test however, the HCV strain was distinguishable from the 5 BCV strains and differences between the BCV strains were shown. Two monoclonal antibodies prepared against one of the BCV strains distinguished the HCV from the BCV strains in all three tests. These monoclonal antibodies did not distinguish between the 5 BCV strains in the IF or HAI test but did so in the neutralization test. The various strains were also compared at the molecular level using the Western blotting technique. This technique showed no significant differences between the molecular weights or serological reactivity of the structural proteins of these strains. Experimental infection of a gnotobiotic calf with BCV resulted in diarrhoea and fever, but no clinical evidence of disease was seen when 4 conventionally reared colostrum fed calves and 4 gnotobiotic lambs were similarly infected. The oral infection of suckling mice with BCV produced diarrhoea in some animals but a full investigation is required to optimise this model. A prospective epidemiological survey on one farm was carried out and showed Cryptosporidium and BCV to be associated with diarrhoea. Additionally this survey showed that the detection of BCV in the respiratory tract was associated significantly with respiratory symptoms.