A study of brown spot disease of Lupinus spp. caused by Pleiochaeta setosa (Kirchner) Hughes : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science in Massey University of Manawatu

Photo missing from only copy pg 194Lupins (Lupinus) are leguminous plants grown in most countries, from the hot equatorial lands of Egypt, North Africa, and Brazil, to the cooler climates of New Zealand and Chile. Over three hundred species have been described, including arborescent, herbaceous and ornamental forms. Lupins are grown in different countries for various reasons, but their ability as a 'nitrogen-fixer', which enables them to grow in poor light soils and to increase fertility, is perhaps their main attribute. [FROM INTRODUCTION

Hong Kong Inquiry

Editor’s note: This document, dated 1 March 1942, is Stuart’s brief to the Royal Commission which examined the Hong Kong operation—Sir Lyman Duff, “Report on the Canadian Expeditionary Force to the Crown Colony of Hong Kong” (Ottawa, 1942), commonly referred to as the “Duff Report.

The Use of Concept Questions to Improve Student Understanding of Mechanics, and the Formulation of a Hierarchical Model of Student Understanding of Moments of Forces

The aims and objectives of the first part of the thesis are to create and evaluate a teaching package that would enable the teacher to facilitate student conceptual understanding of mechanics. The second part is to create a hierarchical model of student conceptual understanding of moments of forces. The thesis reports on the various conflicting theories and recommended teaching strategies from the research into student misconceptions, and examines the various underlying philosophical trends (for example, radical and social constructivism, the Vygotskian perspective and positivism) that have influenced the research into misconceptions in mechanics. As a result, the philosophical perspective of the thesis is that the analysis of the structure of Newtonian mechanics ought to be before the consideration of challenging misconceptions. The question as to how students can construct for themselves the Newtonian system ought to be prior to the consideration of designing a strategy to tackle misconceptions. With prior consideration of the structure of mechanics, the thesis examines the formation of the intuitive schema of force and motion. The thesis proposes the Socratic method of strategic questioning as the most appropriate teaching method for constructing the Newtonian system and displacing the intuitive schema of force and motion. The thesis reports on the formation, and the evaluation, of the teaching package as an aid to facilitate the construction of the Newtonian system, and concludes that teachers have to be trained in the use of the Socratic method prior to any evaluation. There has been little or no research in the area of misconceptions concerning moments. The thesis reports on the formation of a hierarchical model of understanding moments. From a sample of 417 students nation-wide, the thesis has identified 3 conceptual levels of understanding moments and discusses the teaching implications based on the responses from the sample

Stents for transcatheter aortic valve replacement

Rheumatic heart disease (RHD) is the leading cause of aortic valve disease in the world. Surgery to repair or replace the diseased valves is the only means to save a patient's life once the disease becomes symptomatic. Transcatheter aortic valve replacement (TAVR) has revolutionised the treatment of age-related degenerative aortic valve disease, but is currently not suitable for the majority of RHD sufferers due to the rapid degeneration of flexible leaflet valves in younger patients, contraindications of commercial devices to regurgitant or non-calcific aortic valve disease, and also due to resource or funding limitations. The current research project aimed to develop and test novel compressible balloon-expandable stents suitable for patients with symptomatic rheumatic aortic valve disease, and which would allow for a percutaneous polymeric valve to be manufactured, be crimped onto balloon-based devices, and be expanded into a compliant or non-calcific native aortic valve. Several stent concepts were developed and evaluated using Finite Element Analysis (FEA) and two favoured concepts were selected for more complex FEA, in which the balloon was simulated using an Ogden material model, and rigorous testing. The stent material, a nickel-cobalt-chromium alloy, was modelled as an isotropic elasto-plastic material with isotropic hardening. The novel stent designs incorporated a native leaflet-mimicking crown shape for continuous leaflet attachment and mechanisms to anchor the stented valve within compliant aortic roots. The first of the favoured designs provided tactile location during delivery and anchored using self-expanding arms on a balloon-expandable frame of the same material ("self-locating stents"). The second design anchored using arms that protruded during deployment as a consequence of plastic deformation incurred during crimping ("expanding arm stents"). Prototypes were successfully manufactured through laser cutting and electropolishing and showed good surface quality. In vitro testing included determination of crimping and expansion behaviour and measurement of mechanical properties such as resistance to migration in the anatomy. Valve performance was evaluated through in vitro haemodynamics in a pulse duplicator and durability was tested in a high-cycle fatigue tester. Simulated use testing was performed using cadaveric animal hearts. Finally, valves were also implanted into the aortic valve position of pigs (in acute termination experiments) through a transapical approach in order to verify valve deployment behaviour and function in vivo, and determine the stent's ability to anchor in the native anatomy. Stents could be crimped to diameters below 6mm and deployed using commercial balloons and proprietary non-occlusive deployment devices. FEA simulations of stent crimping and deployment matched experimental behaviour well and provide a tool to optimise stent performance. Peak Von Mises stresses during deployment (1437 MPa and 1633 MPa for self-locating and expanding arm stents, respectively) were comparable to a "zig-zag" stent simulated for control purposes (1650 MPa). Radial strength, evaluated for expanding arm stents, was lower than the Control stent (116 N vs. 347 N). This design, although predicted to be safe under fatigue loading, had a lower fatigue safety factor than the Control stent. Stents resisted migration to forces of at least 22 N, which is four times greater than physiological loading on the valves. Polymeric valves incorporating the stents were constructed and demonstrated good in vitro haemodynamic performance (Effective Orifice Areas ≥2.0cm², ΔP<9 mmHg, regurgitation <6%) and durability of over 400 million cycles. Designs functioned as intended in simulated use tests. Valves constructed using self-locating stents could be successfully deployed without rapid pacing in eight of nine pigs, and valve position was correct in seven of these. Valves of expanding arm stents remained anchored in six of eight attempted implants in pigs. This study has demonstrated proof of concept for a novel balloon-expandable stent for a polymeric transcatheter heart valve that is capable of anchoring in a compliant native aortic valve

Crowding Out Voluntary Contributions to Public Goods

We test the null hypothesis that involuntary transfers for the provision of a public good will completely crowd out voluntary transfers against the warm-glow hypothesis that crowding-out will be incomplete because individuals care about giving. Our design differs from the related design used by Andreoni in considering two levels of the involuntary transfer and a wider range of contribution possibilities, and in mixing groups every period instead of every four periods. We analyse the data with careful attention to boundary effects. We retain the null hypothesis of complete crowding-out in two of three pairwise comparisions, but reject it in favour of incomplete crowding-out in the comparison most closely akin to Andreoni's design. Thus we confirm the existence of incomplete crowding-out in some environments, but suggest that the warm-glow hypothesis is inadequate in explaining it.