This thesis represents my research work relating to rugby union from 2000 to 2007. During this time I was the Manager of Injury Prevention and Research for the New Zealand Rugby Union (NZRU). The main priorities of this role were to increase understanding of risk factors for rugby injury, to implement preventive measures, and to assess the effect of those preventive measures. The thesis is presented as a series of peer-reviewed, published papers. A key concern of the NZRU when I undertook the role was to decrease the number and severity of spinal cord injuries occurring in New Zealand rugby. The first paper is a review of literature of rugby union injuries to the cervical spine and spinal cord. This paper was published in Sports Medicine, and the knowledge derived there from formed an important element in RugbySmart, which was the nationwide injury prevention partnership between the NZRU and ACC. The second paper, which was published in the British Medical Journal, outlines the effect of RugbySmart on serious spinal injuries in New Zealand. Eight spinal injuries occurred in New Zealand in 2001-2005, whereas the predicted number based on previous incidence was 19 (relative rate 0.46, 95% confidence interval 0.19 to 1.14). The main reason for the decline was a decrease in the number of injuries from scrums, from a predicted number of nine only one was observed (relative rate 0.11; 0.02 to 0.74). Injury prevention initiatives in New Zealand appear to have been successful in areas beyond spinal injuries. The third paper deals with the effect of RugbySmart in general. RugbySmart was associated with a decrease in injury claims per 100,000 players in most areas the programme targeted; the programme had negligible impact on non-targeted injury sites. The decrease in injury claims numbers was supported by results from player behaviour surveys pre- and post-RugbySmart. There was an increase in safe behaviour in the contact situations of tackle, scrum and ruck technique. The fourth paper, which was published in the British Journal of Sports Medicine, examines the effect of mandating mouth guard usage on mouth guard wearing rates and ACC dental injury claim rates. The self reported rate of mouth guard use was 67% of player-weeks in 1993 and 93% in 2003. A total of 2644 claims were reported in 1995. There was a 43% (90% confidence interval 39% to 46%) reduction in dental claims from 1995 to 2003. On the reasonable assumption that the number of players and player-matches remained constant throughout the study period, the relative rate of injury claims for non-wearers versus wearers was 4.6 (90% confidence interval 3.8 to 5.6). In New Zealand the tackle is the facet of play associated number of injuries, and over the past decade tackles have overtaken scrums as the cause of the greatest proportion of spinal injuries. To address the lack of knowledge regarding risk factors for injuries in the tackle, a large scale study of tackles in professional rugby matches was undertaken. In 434 matches, over 140,000 tackles were coded. The impact of the tackle was the most common cause of injury, and the head was the most common site, but an important mechanism of lower limb injuries was loading with the weight of another player. Rates of replacement increased with increasing player speed. The resulting paper was published in the American Journal of Sports Medicine. A commonly cited model of injury causation in sport posits that risk factors for injury can be considered as those related to the athlete (intrinsic) and those related to the activity (extrinsic). To examine the extent to which the activities comprising rugby matches at the international level has changed over time the first match in each Bledisloe Cup series from 1972 to 2004 was coded. Increases in passes, tackles, rucks, tries, and ball-in-play time were associated with the advent of professionalism, whereas there were reductions in the numbers of lineouts, mauls, kicks in play, and in mean participation time per player. Noteworthy time trends were an increase in the number of rucks and a decrease in the number of scrums. With the advent of professionalism, players have become heavier and backs have become taller. A number of articles written to communicate injury prevention messages to rugby union coaches, players and administrators are presented as appendices, along with two peer reviewed papers that closely relate to the thesis, but which I excluded from the thesis proper.

Modeling the motion that occurs between frames of a video sequence is a key component of video coding applications. Typically it is not possible to represent the motion between frames by a single model and therefore a quad-tree structure is employed where smaller, variable size regions or blocks are allowed to take on separate motion models. Quad-tree structures however suffer from two fundamental forms of redundancy. First, quad-trees exhibit structural redundancy due to their inability to exploit the dependence between neighboring leaf nodes with different parents. The second form of redundancy is due to the quad-tree structure itself being limited to capture only horizontal and vertical edge discontinuities at dyadically related locations; this means that general discontinuities in the motion field, such as those caused by boundaries of moving objects, become difficult and expensive to model. In our work, we address the issue of structural redundancy by introducing leaf merging. We describe how the intuitively appealing leaf merging step can be incorporated into quad-tree motion representations for a range motion modeling contexts. In particular, the impact of rate-distortion (R-D) optimized merging for two motion coding schemes, these being spatially predictive coding, as used by H.264, and hierarchical coding, are considered. Our experimental results demonstrate that the merging step can provide significant gains in R-D performance for both the hierarchical and spatial prediction schemes. Hierarchical coding has the advantage that it offers scalable access to the motion information; however due to the redundancy it introduces hierarchical coding has not been traditionally pursued. Our work shows that much of this redundancy can be mitigated with the introduction of merging. To enable scalable decoding, we employ a merging scheme which ensures that the dependencies introduced via merging can be hierarchically decoded. Theoretical investigations confirm the inherent advantages of leaf merging for quad-tree motion models. To enable quad-tree structures to better model motion discontinuity boundaries, we introduce geometry information to the quad-tree representation. We choose to model motion and geometry using separate quad-tree structures; thereby enabling each attribute to be refined separately. We extend the leaf merging paradigm to incorporate the dual tree structure allowing regions to be formed that have both motion and geometry attributes, subject to rate-distortion optimization considerations. We employ hierarchical coding for the motion and geometry information and ensure that the merging process retains the property of resolution scalability. Experimental results show that the R-D performance of the merged dual tree representation, is significantly better than conventional motion modeling schemes. Theoretical investigations show that if both motion and boundary geometry can be perfectly modeled, then the merged dual tree representation is able to achieve optimal R-D performance. We explore resolution scalability of merged quad-tree representations. We consider a modified Lagrangian cost function that takes into account the possibility of scalable decoding. Experimental results reveal that the new cost objective can considerably improve scalability performance without significant loss in overall efficiency and with competitive performance at all resolutions.

Thesis (Ph. D.)--University of Nevada, Reno, 2007. / "May, 2007." Includes bibliographical references (leaves 77-87). Online version available on the World Wide Web.

Thesis (Ph. D.)--Discipline of Surgery, Faculty of Medicine, University of Sydney, 2007. / Title from title screen (viewed June 28, 2007). Includes tables and questionnaires. Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Discipline of Surgery, Faculty of Medicine. Degree awarded 2007; thesis submitted 2006. Includes bibliography. Also issued in print.

Univ., Diss. u.d.T.: Tortell, Lisa Ann: The monetary remedy for breach of constitutional rights in the United States, India, New Zealand, and the United Kingdom--Oxford, 2002.

Thesis (Ph. D.)--University of Washington, 2008. / Vita. Includes bibliographical references (leaves 313-335).

Thesis (Ph. D.)--University of Texas at Austin, 2004. / Supervisor: Robert Freeman. Vita. Includes bibliographical references.

Thesis (M.A.)--University of Hawaii, 1994. / Includes bibliographical references (leaves 114-121).

Thesis (M.B.A.)--Massachusetts Institute of Technology, Sloan School of Management, 2004. / Title from title screen (viewed Nov. 9, 2005). "June 2004." Includes bibliographical references (p. 63-65). Also issued in paper format.

Thesis (Ph. D.)--University of Texas Health Science Center at Houston, School of Public Health, 2008. / Source: Dissertation Abstracts International, Volume: 69-02, Section: B, page: 0972. Adviser: Charles Begley. Includes bibliographical references.