4,578 results for 2009

  • pH-sensitive Anticancer Model Prodrug: Amide of Kemp's Acid

    Brooks, Robert Turongo (2009)

    Masters thesis
    University of Waikato

    Solid tumours are characterised by lower extracellular pH (as low as 5.8 pH) compared to normal healthy cellular pH (actively regulated at pH 7.3). This difference may be exploited with an acid-sensitive anti-tumour prodrug which releases a cytotoxin selectively in tumour tissue. The research reported in this thesis was aimed at synthesising and performing rate studies on an amide prodrug with pH-sensitive rates of reaction in the pH 5 - 8 region. Amide hydrolysis is catalysed by neighbouring carboxylic acid groups in their fully protonated state but not in its ionised state (shown in the figure below), whereby pH sensitivity around pH 5 - 8 can be exploited. The current study was carried out on an amide of Kemp's acid which, due to enforced stereochemistry of carboxylic acid and amide functional groups, has the type of structure conducive to accelerated amide hydrolysis. The rates for tertiary and secondary aliphatic amides of this Kemp's acid system have shown high reactivity at low pH and a large reduction in rate across pH 5.8 - 7.3, however an aryl amide had not previously been studied. It was thought that an aryl amide of Kemp's acid would provide a faster rate of reaction compared with the alkyl amides, and also aryl amine cytotoxins exist which could be attached as an amide. A secondary aryl amide of Kemp's acid (58) was obtained via a potassium hydroxide ring-opening reaction on a synthesised imide of Kemp's acid (43). Aliquots of the ring-opened amide (58) were added to buffered (phosphate and malonate) aqueous solutions (with ionic strength μ = 1 mol L-1) and the hydrolysis reaction followed at 30.0 oC across the pH range 0.48 - 8. First order rate constants were calculated from absorbance change with time and the pH-rate profile established. Absorbance changes were shown to be consistent with amide hydrolysis with no evidence of any imide reformation as evident in other studies. The rate data were analysed. There was no evidence from rates for the two successive acid ionisations with only a single rate plateau evident from pH 2 to 5, suggesting that both ONHCOOHCOO-OMe(58) iv di- and mono-acid species have very similar hydrolysis rates or that the second ionisation is low due to stabilisation of the mono-ionised molecule by hydrogen bonding interactions. For this reason, the rate profile could be analysed only as if it were a single ionisation in the same way that Menger and Ladika analysed their aliphatic tertiary pyrrolidyl amide in an earlier study. This analysis gave a pKa value of 6.72 0.09 and a limiting rate constant of 7.1 x 10-5 s-1. The studies revealed a three fold rate differential between pH 5.8 (faster) versus 7.3 (slower), a difference which is probably too small a selectivity for possible prodrug application. Separately, the second order rate coefficient for the reaction of potassium hydroxide solution to open the imide was also established (k2 = 0.00067 L mol-1 s-1 at 30.0 oC, μ = 1.00 mol L-1 with KCl).

    View record details
  • Listening strategies of Singaporean primary school pupils

    Gu, PY; Hu, G; Zhang, Lawrence (2009)

    Book item
    The University of Auckland Library

    View record details
  • Inherited retinal degenerations

    Fletcher, EL; Acosta Etchebarne, Monica; Kalloniatis, Michael (2009)

    Book item
    The University of Auckland Library

    View record details
  • Investigating the effects of input method on student learning in an ITS

    Bebbignton, Aidan (2009)

    Doctoral thesis
    University of Canterbury Library

    Personalised one-to-one tutoring is known to be the most effective form of instruction. However, with limited resources, the situation in most educational settings falls far short of this ideal. Intelligent Tutoring Systems (ITSs) are computerised systems which have the potential to provide instruction which is pedagogically equivalent to personalised tutoring. Extensive research has been focused on improving the effectiveness of ITSs in a variety of ways. This report presents an evaluation of the effectiveness for learning of two different interaction styles: selection and typing. Two interfaces for an ITS for thermodynamics called Thermo-Tutor are designed and developed. The designs are justified in terms of theory from psychology and cognitive science. Finally an evaluation is performed to measure the relative effectiveness of these interfaces and these results are analysed and discussed. Thermo-Tutor is developed using ASPIRE; a general purpose authoring system for constraint-based ITSs. ASPIRE is used to reduce the development time and evaluate its effectiveness. The effectiveness of ASPIRE is also analysed and discussed. The results related to the relative effectiveness of the two interfaces are inconclusive. However, results show that students did learn while using Thermo-Tutor and comments from students were generally positive. Therefore, development of Thermo-Tutor with ASPIRE was successful. This research also helped to identify some possible improvements for the future.

    View record details
  • Using Virtual World Programming Languages To Teach Computer Science Concepts

    Ward, Brett (2009)

    Doctoral thesis
    University of Canterbury Library

    With many secondary-level curricula being updated to incorporate a larger amount of computer science concepts, there is a need to identify sufficient ways to teach these concepts within languages commonly used at the appropriate age levels. Currently, languages like Alice, Scratch and Greenfoot, among many others, are both freely available and widely used to teach aspects such as programming, but little research has been done on whether they can actually be used to easily and sufficiently teach other concepts, such as algorithms and data representation. This paper discusses these such languages, and takes a look at how usable they actually are for performing some simple tasks. A number of computer science concepts are looked at in these languages, with implementation possibilities and difficulties overviewed, and discussion on how these languages could be enhanced to make it easier to teach the chosen concepts within them.

    View record details
  • Stereo Tracking of Objects with respect to a Ground Plane

    Baguley, Greg (2009)

    Doctoral thesis
    University of Canterbury Library

    In this paper, a novel algorithm for tracking 3D cricket ball locations in relation to an estimated ground plane is proposed. This algorithm proposes using Random Sample Consensus to find a ground plane from disparity images, and then estimating 3D ball positions with respect to the ground plane using fast contour tracing and stereo depth values. In that no prior research has used stereo depth values to locate a ground plane and track an object with respect to that plane, the 90.7% successful tracking rate with only 1.95% false positives suggests that the proposed novel algorithm is a useful contribution for enabling automatic setup and ease of use for such tracking.

    View record details
  • Characterising the Use of Encapsulation in Object Oriented Systems

    Voigt, Janina (2009)

    Doctoral thesis
    University of Canterbury Library

    Software is commonly very large and complex, and consequently hard to develop, understand and maintain. Encapsulation is the practice of breaking a system up into well-defined pieces and hiding internal details within each piece. It supports modularisation and information hiding, making it one of the most fundamental tools software developers have for managing complexity. Object oriented design heuristics have been proposed to help developers achieve better software designs and thus improve overall software quality; many of these design heuristics concern the use of encapsulation or are based on underlying assumptions about encapsulation. However, design advice in this area often conflicts. Little is known about how developers apply encapsulation in practice. In this work, we identify and compare two radically different schools of thought that underpin encapsulation policies and lead to the conflicting encapsulation advice. We conducted a survey to reveal which encapsulation policy is more intuitive, and found that novices’ intuition about encapsulation differs from the encapsulation mechanisms supported by languages such as Java and C#. Following the survey, we empirically analysed encapsulation in real-world software to determine which encapsulation policies are followed in practice, uncovering a general culture of confusion and inconsistency around the use of encapsulation. This finding leads us to propose refactoring tools and a visualisation for helping developers improve encapsulation in software.

    View record details
  • Augmenting source code with software metrics

    Harward, Matthew (2009)

    Doctoral thesis
    University of Canterbury Library

    Software is typically big and complex. Software metrics provide measurements of software products and development processes, in order to help software developers understand and improve their products. Metrics, however, can add to developers’ information overload problems, so visualisation techniques are needed to allow large volumes of measurement data to be efficiently communicated to an observer. Software measurement data is normally presented in reports, tables, or graphical visualisations that are distinct from the primary way developers view their products: in a source code editor. This separation makes it hard for developers to relate measurement data to the features being measured. Additionally, the intrusive task of having to run measurement tools and accommodate different views provides a disincentive for measuring at all. We present a new visualisation technique that directly applies a visualisation overlay to source code. We have developed a tool, CoderChrome, providing this functionality for the Eclipse Java editor. We discuss our progress in evaluating this visualisation to determine if this approach has the potential to improve the effectiveness of developers. The tool provides a basis for continued research into the usefulness of software metrics and understanding of the best practices of developers.

    View record details
  • Improved Mobile Scrolling Interfaces

    Fitchett, Stephen (2009)

    Doctoral thesis
    University of Canterbury Library

    Mobile devices are everywhere, and their capabilities are impressive: they have gigabytes of data storage, abundant applications, graphics processors, and high bandwidth wireless communications. In many ways, they are yesterday’s desktop computer in your palm. And there lies the problem: their input and output devices are tiny, and interaction methods have not kept pace with the miniaturisation. This project examines the mobile scrolling design space and proposes two new touch based scrolling interfaces. The first is a tiered alphabet scroller, which is a specialised interface designed specifically for navigating alphabetically sorted lists. An evaluation did not show a performance improvement over a standard non-tiered scroller, but users generally preferred it and we gained insights into how it is used. The second is a general purpose hybrid scrolling technique that allows for a combination of rate based scrolling for navigating short and medium distances and zeroorder scrolling for navigating large distances. Evaluations showed that each component of this hybrid technique performed well for certain complementary types of tasks and that they would work together well as a hybrid technique.

    View record details
  • Computer Science Education in Virtual Worlds

    Kearns, Benjamin (2009)

    Doctoral thesis
    University of Canterbury Library

    The Computer Science Unplugged project has developed a variety of activities that allow children to be taught computer science concepts without using computers. Currently users in some environments and users with disabilities are not able to participate in some of the activities. In order to solve this problem, we investigate using the activities implemented in a virtual world. In this research, we discuss development of an implementation of the Turing test activity, the practical issues we encountered while deploying it to a local school and the general lessons to be learned for people deploying such activities. Finally we compare its effectiveness against the traditional Computer Science Unplugged activities.

    View record details
  • Research into GPU accelerated pattern matching for applications in computer security

    Gee, Alexander (2009)

    Doctoral thesis
    University of Canterbury Library

    Pattern matching is a fundamental part of many computer programs. Accelerating this process using Graphics Processing Units (GPUs) is thus greatly advantageous for many applications such as intrusion detection systems. This research investigates the implementation of pattern matching on these massively parallel processing units. The second area of research is implementation efficiency and performance advantages introduced by GPU acceleration of this family of algorithms.

    View record details
  • Three Dimensional Visualisation of Network and Security Log Data

    Chernoglazov, Alexander (2009)

    Doctoral thesis
    University of Canterbury Library

    This report explores the field of visualisation of network and security log data, specifically the various issues surrounding the processing and graphical display of large quantities of information. A novel network traffic and security alert visualisation technique is proposed along with a method of grouping data in memory based on network addresses and temporal division. An overview of common problems in the area of data visualisation is made along with several suggestions on possible solutions.

    View record details
  • The Building Act 2004 and the Inclusion of the New Zealand Fire Service in the Building Consent Process

    MERRY, ALAN (2009)

    Doctoral thesis
    University of Canterbury Library

    This report outlines the changes to the Building Act in 2004 and the inclusion of the Fire Service in the building consent process, with the intention of assessing the impact of these changes on performance based design work in New Zealand. To achieve this the following was undertaken: The report sets out the background to the legislative changes to the Building Act in 2004 and how these changes have impacted the New Zealand Fire Service. It then explores the Fire Service’s response to these legislative changes in its legislative role of reviewing specific building consent applications A review was undertaken of the building data held within the Fire Service’s engineering database covering in excess of 2,700 buildings forwarded by the 75 Building Consent Authorities (BCA’s) throughout New Zealand since 2005. This data is then compared to that of non-residential building consent applications received by BCA’s throughout New Zealand, highlighting trends in the building consent process since the inception of the Fire Service’s Design Review Unit. The report investigates the outcomes of the independent audit of the Design Review Unit and the quality of performance-based fire engineering design reports reviewed as part of that audit. In addition, a review of the qualifications and professional memberships of the report authors was also undertaken. A questionnaire was sent to members of the fire industry seeking their feedback on the potential impacts on their work following the changes to the Building Act in 2004. It included specific questions relating to the design work they undertake and the role of the Fire Service in the building consent process. 4 A consistent increase in non-residential building consents received by local Councils is evident since 2005. This has not been mirrored by an increase in the numbers forwarded to the Design Review Unit, with numbers consistently dropping in the main centres of Auckland, Wellington and Christchurch. Results of the independent audit of the Design Review Unit commissioned by the Fire Service Commission highlight several issues with the manner in which performance based fire engineering design is being carried out in New Zealand. Although opportunities for improvement of the Design Review Unit were also suggested, overall the Design Review Unit is carrying out its legislative function in a technically competent manner. A breakdown of the qualifications and professional memberships of the audited report writers show that the majority hold a Masters Degree in fire engineering and also membership to national and international engineering bodies. 12% of report authors had no formal qualification in fire engineering and no professional memberships. 94% of respondents to the questionnaire represented the fire engineering design sector. The majority were not supportive of the changes to the Building Act in 2004 and are of the view that these changes have created more problems during the building consent process. Whilst some respondents were supportive of the Fire Service being involved in the consent process, this was mainly viewed as being only relevant to freighting and evacuation issues. Others were not supportive of the Design Review Unit at all. Respondents indicated that performance based design work now accounts for less of their workload than before the Building Act changes were implemented.

    View record details
  • Assessment of the benefits of Fire Extinguishers as fire safety precautions in New Zealand Buildings

    Ghosh, Biswadeep (2009)

    Doctoral thesis
    University of Canterbury Library

    There were over 25,488 fire incidents recorded in New Zealand in 2007/08, according to the New Zealand Fire Service (NZFS) 2006/07 Annual Report. These fires resulted in 34 fatalities and many more serious injuries and accounted for thousands of callouts attended by the NZFS. The NZFS also recorded 8734 incidents of use of fire extinguishers and hose reels/garden hoses where fire incidents were contained by occupants / passer bys. Current New Zealand regulations are not definitive of requirements therefore the provision of fire extinguishers and hose reels is debated. Current legislation provides guidance to specific conditions for the installation of fire extinguishers and hose reels. A survey done in UK and some European countries in 2000 by EUROFEU identified that in 80% of the cases a portable fire extinguisher successfully extinguished the fire and in 75% of those cases the Fire Service was not required to attend. These incidents were therefore not recorded in any official statistics. According to the survey it was estimated that fire extinguisher usage actually could save ₤1.5 million each year in terms of Fire Service resources. This report uses historical data available from 1990 – 2007 from the NZFS FIRS database and usage statistics generated from conducting a survey of service agencies for fire extinguishers in New Zealand. This report also evaluates prescriptive requirements existing in New Zealand and compares with prescriptive requirements outside of New Zealand. The current statistics using the NZFS‐FIRS data shows that there is a downward trend in the use of extinguishers; however these statistics may not reflect the true usage patterns of extinguishers. Data collected from a survey of Page iii service agencies shows that the majority of extinguisher usage does not get reported for official statistics. State reason The further cost benefit analysis has been done for typical occupancies where the use of extinguishers is expected because of the occupancy and competence level of occupants. Risk simulations for different scenarios of fire protection system use and success was used to determine cost of a fire in terms of direct property losses, Fire Service costs and other indirect economic losses. Direct property losses have a direct consequence to the building owner while other costs reflect more to the New Zealand economy and Fire Service and may have an indirect bearing to the building owner.

    View record details
  • Physical Scale Modelling of Smoke Contamination in Upper Balconies by a Balcony Spill Plume in an Atrium

    Tan, Fabian (2009)

    Doctoral thesis
    University of Canterbury Library

    Whether the balcony spill plume will rise as a free plume or curl inwards towards the atrium structure is determinant upon a number of factors. Admittedly, not all the factors are well investigated and wholly understood, resulting in limited guidance for Fire Engineers on the behaviour of the balcony spill plume in an atrium. The only relevant guidance states that “balconies which are shallow ( 2 m) will cause the rising spill plume to curl inwards towards the structure…… smoke-logging the balcony levels above the fire floor”. This guidance is based on limited number of smoke flow experiments in a model atrium. This research project is primarily a qualitative examination of the behaviour of the balcony spill plume in an atrium. Its main objective is to systematically investigate the effects of varying balcony breadths, plume widths and fire sizes on smoke contamination in upper balconies through experimental work. A series of smoke flow experiments were conducted using a one-tenth physical scale model representing a six-storey atrium building. The scale model simulated a fire in an adjacent compartment connecting a fully open atrium. Visual observations and temperature measurements of the smoke flows were carried out. From the experiment results, it was established that the extent of smoke contamination in upper balconies increased with decreasing balcony breadths, increasing plume widths and decreasing fire sizes. Further analysis of the experiment results showed that the aspect ratio of plume width to balcony breadth can be used to provide generic guidance to Fire Engineers in atrium design with respect to smoke contamination in upper balconies. In addition, an empirical correlation was developed to determine the height of smoke contamination and provide further guidance on smoke contamination in upper balconies. All in all, this research project has met its objective and achieved its desired outcome. It provides more details and improved guidance for Fire Engineers on smoke contamination in upper balconies by a balcony spill plume in an atrium.

    View record details
  • Negotiating contracts for Agile projects: A practical perspective

    Hoda, Rashina; Noble, J; Marshall, S (2009)

    Conference item
    The University of Auckland Library

    The Agile Manifesto values ???customer collaboration over contract negotiation???. However, in many real projects, Agile practitioners spend considerable time and effort negotiating contracts with customers. We have conducted grounded theory research in India with Agile practitioners. In this paper we present the strategies these practitioners use to overcome the problems of negotiating contracts. These strategies include changing the customers??? mindset, providing different options of working, and ??? in the worst case scenario ??? keeping the customers unaware of internal Agile practices.

    View record details
  • Transforming rural water governance: Towards deliberative and polycentric models?

    Neef, Andreas (2009)

    Journal article
    The University of Auckland Library

    In recent years, many countries have experienced a formal shift from command-and-control and prescriptive management of natural resources towards policy making and planning processes that build on collaboration, negotiation and deliberation among policy-makers, scientists and local stakeholders (Bouwen and Tallieu, 2004; Warner, 2006; Ansell and Gash, 2008). Public participation in environmental decision-making and implementation has become part and parcel of the environmental governance rhetoric in many industrialised countries (Sabatier et al., 2005; Messner et al., 2006; Cronin and Ostergren, 2007; Ferreyra et al., 2008; Medd and Marvin, 2008; Marshall, in press). In emerging economies and developing countries 'participatory environmental governance' has also been discussed as an alternative to centralised, top-down approaches towards natural resource conservation and management (e.g. Gupte and Bartlett, 2007; Neaera Abers, 2007; Huang et al., 2009). At the international policy level, the Rio Declaration and the Agenda 21 (1992), the World Summit on Sustainable Development (WSSD) Johannesburg Plan of Implementation (2002), and the 1998 UN Economic Commission for Europe (UNECE) "Convention on Access to Information, Public Participation in Decision-making and Access to Justice in Environmental Matters" (the so-called Aarhus Convention) have been the most important drivers for enhanced citizen participation in environmental governance.

    View record details
  • Analysis and Evaluation of Single Piles in Laterally Spreading Soil

    McGann CR (2009)

    Theses / Dissertations
    University of Canterbury Library

    Liquefaction–induced lateral spreading is an important load case for pile–founded bridges and port facilities located in seismically active regions. This work presents a kinematic analysis of the effects of lateral spreading on a single pile embedded in a layered soil profile and discusses the applicability of conventional analysis methods to the lateral spreading problem. A series of three–dimensional finite element models are created and analyzed using the OpenSees finite element analysis platform developed at the Pacific Earthquake Engineering Research (PEER) Center. The developed FEA considers a single pile (modeled using beam elements) embedded in a soil continuum (modeled using brick elements). Beam–Solid contact elements are utilized to define the interface between the pile and soil elements. Three distinct reinforced concrete pile designs are considered in the models. Elastoplastic behavior is considered in both the pile and the soil through the use of fiber sections and a Drucker–Prager constitutive model, respectively. Each individual component in the model is validated through a series of simple analyses, ensuring that the desired behavior is captured. Force density–displacement (p – y) curves are extracted from the finite element models and compared to several conventional methods for establishing these curves. The characteristic parameters used in this comparison are initial stiffness and ultimate resistance. Additional, one–dimensional models are created which utilize the same beam elements and consider the soil response through the use of p – y curves generated using both the FEA results and conventional means. The results for the lateral spreading models show that elastoplastic soil behavior must be considered in order to determine appropriate maximum moment demands for piles. Through the extraction of p – y curves from the 3D models, it is determined that the kinematics of the pile greatly influence the extracted curves. A rigid pile undergoing a uniform displacement with depth is the most suitable method for obtaining sensible p – y curves from the models. It is shown that the methods commonly used to establish the characteristic parameters for p – y curves at large overburden pressure (greater depth) estimate values which are in excess of those returned by the finite element models, especially for large pile diameters. In the one– dimensional models, the extracted p – y curves produce moment–curvature demands in piles which are similar to the results of the three–dimensional simulations, while the conventional curves produce demands which do not correlate well with the 3D modeling effort. It is determined that the conventionally–used methods are most applicable for moderately–sized piles subject to loads applied at or above the ground surface, but misrepresent a deeper event such as lateral spreading.

    View record details
  • Marine Natural Products

    Blunt, JW; Copp, Brent; Hu, W; Munro, MHG; Northcote, PT; Prinsep, Michele (2009-02-01)

    Journal article
    The University of Auckland Library

    Covering: 2007.

    View record details
  • New natural products in the discorhabdin A- and B-series from New Zealand-sourced Latrunculia spp. sponges

    Grkovic, Tanja; Copp, Brent (2009-08-08)

    Journal article
    The University of Auckland Library

    A survey of the secondary metabolite chemistry profiles of New Zealand sponges of the genus Latrunculia has yielded new members of the discorhabdin A- and B-type families. The structure elucidation of (+)-(6R,8S)-1-thiomethyldiscorhabdin G???/I (5) and both enantiomers of 16a,17a-dehydrodiscorhabdin W (6) are reported. Absolute configurations were assigned by comparison with a dataset of recently reported electronic circular dichroism spectra of discorhabdin alkaloids. A stereochemical correction of the recently reported natural product (+)-3-dihydrodiscorhabdin A from (3S,5R,6S,8S)-(7) to the C3-epimeric (+)-(3R,5R,6S,8S)-(8) and assignment of absolute configuration is also presented. Semi-synthesis of (+)-(3S,5R,6S,8S)-(7) from (+)-discorhabdin A provided further evidence for this structure revision. Cytotoxicity data is reported for 5???8.

    View record details