The effect of rabbit (Oryctolagus cuniculus cuniculus) (Linnaeus, 1758) browsing on seedling survival : a thesis presented in part fulfillment of the requirements for the degree of Master of Science in Zoology at Massey University, Palmerston North, New Zealand

The European rabbit, Oryctolagus cuniculus (Linnaeus 1758) is a small 2-4 kg cutherian mammal introduced into New Zealand from the United Kingdom in the mid 1800's. By the 1950's the range of the rabbit had covered nearly 95% of the available land resulting in millions of dollars of damage. It was noticed by the 1970's that some populations were stable without any control measures being applied, and with increasing research and a changing attitude towards pest management away from extermination to control, it became policy that the status of this pest was downgraded to a regional pest rather than a pest of national importance. Control became the responsibly of the landowner rather than a national body except where populations occurred in high densities. However, even rabbit numbers at low densities do exert a pressure on vegetation, and in some bush remnants rabbits are blamed for the lack of regeneration that occurs even when larger herbivores are excluded. Four bush remnants within the Manawatu-Rangitikei region of New Zealand, two in the coastal sand country and two inland at Marton, were studied for the causes of seedling mortality over five seasons from August 1999 to December 2000. One hundred and fifty seedlings were identified and numbered to species level and were placed in five treatments and controls at each site, except Legg Estate bush remnant where ninety seedlings were used in unbalanced numbers in each replicate The data were analysed using logistic regression with scores for rabbit densities and deaths of seedlings per bush remnant within the treatments and controls. The analysis suggests that there is a seasonal effect (P<0.0001) and a treatment /control effect (P=0.0002) on seedling survival with treatments at Legg Estate bush remnant surviving consistently better over the five seasons. At Himatangi Block Scientific Reserve seedlings in the treatment survived better than seedlings in the controls, except for winter 1999. At Monkton's and Fulleton-Smith bush remnants, treatments survived better than in the controls. Overall the treatment (protecting seedlings against rabbits by fencing) improves seedling survivability. This trial was conducted at a time of regionally low pest numbers because of the prior introduction of Rabbit Haemorrhagic Disease (RHD), and treatment results should be interpreted with this in mind. Key Words: Rabbit, Treatment effect, Bush remnant, RHD, Exclosure, Seedling survival

Observer design for systems with an energy-preserving non-linearity

Observer design is considered for a class of non-linear systems whose non-linear part is energy preserving. A strategy to construct convergent observers for this class of non-linear system is presented. The approach has the advantage that it is possible, via convex programming, to prove whether the constructed observer converges, in contrast to several existing approaches to observer design for non-linear systems. Finally, the developed methods are applied to the Lorenz attractor and to a low order model for shear fluid flow

The Medieval Inquisition: Scale-free Networks and the Suppression of Heresy

Qualitative evidence suggests that heresy within the medieval Catholic Church had many of the characteristics of a scale-free network. From the perspective of the Church, heresy can be seen as a virus. The virus persisted for long periods of time, breaking out again even when the Church believed it to have been eradicated. A principal mechanism of heresy was through a small number of individuals with very large numbers of social contacts. Initial attempts by the Inquisition to suppress the virus by general persecution, or even mass slaughtering, of populations thought to harbour the "disease" failed. Gradually, however, the Inquisition learned about the nature of the social networks by which heresy both spread and persisted. Eventually, a policy of targeting key individuals was implemented, which proved to be much more successful.Comment: 12 page

Resolving the UK construction skills crisis : a critical perspective on the research and policy agenda

The ongoing skills crisis in the UK construction industry has constrained the productive capacity of the industry. Past research and skills policies have largely failed to develop an understanding of the realities of the skills crisis at the grassroots level. Solutions offered by researchers and policy makers have previously had little demonstrable impact in addressing skills concerns. Much of these policies seems disconnected from the realities experienced by employers and by those working in the industry. A critical perspective on resolving the skills crisis is offered. A set of mutually reinforcing research and policy initiatives are proposed, including the need for researchers and policy makers to move away from the conventionally national approach in addressing the skills problem and to engage in genuine, joined-up thinking that meets the needs of local regions. Furthermore, employers and employees are called to be reflective practitioners in their participation of the skills development agenda. Adopting these recommendations could overcome many shortcomings in research and policy that have hitherto done little to combat the construction skills crisis.Skills shortages, critical perspective, bottom-up approach, labour market, research,

Transceiver design for non-regenerative MIMO relay systems with decision feedback detection

In this paper we consider the design of zero forcing (ZF) and minimum mean square error (MMSE) transceivers for non-regenerative multiple input multiple output (MIMO) relay networks. Our designs utilise linear processors at each stage of the network along with a decision feedback detection device at the receiver. Under the assumption of full channel state information (CSI) across the entire link the processors are jointly optimised to minimise the system arithmetic mean square error (MSE) whilst meeting average power constraints at both the source and the relay terminals. We compare the presented methods to linear designs available in the literature and show the advantages of the proposed transceivers through simulation results