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Typewritten copy Includes bibliographical references

This project aimed to characterise the organic speciation of iron in various oceanic waters associated with the New Zealand marine environment, and to examine the possible production of natural organic Fe-binding ligands by the Southern Ocean phytoplankton Phaeocystis antarctica. The location of New Zealand at the edge of the Southern Ocean provides a natural laboratory for studying ocean processes in a variety of oceanic conditions. A time series of a surface transect across the Otago Continental Shelf was undertaken between April 2002 and January 2005 to measure the organic complexation of iron, hydrographic parameters and macronutrient concentrations. The study area contains three distinct water masses: 1) neritic water; 2) the Southland Current, derived from the Subtropical Surface Water (STW); 3) Subantarctic Surface Water (SASW). Hydrological measurements outlined the positions of the three water masses as being fixed within predictable boundaries. Variations in nutrient concentrations in the study area indicated that SASW is the predominant source of nitrate and phosphate to the shelf. Dissolved iron concentrations dropped sharply seaward from several nanomolar to sub-nanomolar levels. The dissolved iron was fully complexed with strong organic ligands in all three water masses, and the ligand concentrations also showed a slightly seaward decreasing trend. Trends in dissolved iron and the iron-binding ligand concentrations related to season were only obvious in neritic waters. Concentration maxima occurred during late spring and summer months, and concentration minima occurred in the middle of each year (winter months). Dissolved iron concentration was low (~0.1 nM) in SASW year round. Data from the present study are in support of that the SASW as a whole is classified as a high nitrate low chlorophyll (HNLC) water body and has an iron-limited phytoplankton population. East of the New Zealand landmass, the Subtropical Convergence (STC) is topographically locked to the Chatham Rise. This is a dynamic region of enhanced primary production (Bradford-Grieve et al., 1997), which separates macronutrient-depleted STW from macronutrient-replete SASW. Dissolved iron concentrations were low (~0.1-0.2 nM) in SASW, while elevated dissolved iron concentrations were observed at the north flank of the Chatham Rise. The iron data imply that the regional currents may be an important vehicle for transporting the elevated iron across the front. Total dissolved iron-binding ligand concentrations were consistently higher (~0.5 nM) in the STW and STC waters than in SASW. The discrepancy in the ligand concentrations between STW and SASW may reflect a different contribution to the ligand pool from the local planktonic community. The organic complexation of iron in the oligotrophic subtropical water columns in the Tasman Sea was also studied and comparison of waters to the north and south of the Tasman front were reported. The iron speciation data imply the potential biological origin for the iron-binding ligands, and the difference in ligand concentrations across the Tasman Front may represent slight differences in algal biomass. A limited investigation to examine the production of natural organic iron-binding ligands by the Southern Ocean phytoplankton Phaeocystis antarctica was undertaken in laboratory culture experiments. Release of nanomolar levels of a strong iron-binding ligand was detected by cathodic stripping voltammetry (CSV) even under relatively high iron concentrations (> 1nM). The estimated iron binding strength for the ligands was similar to those observed in the open ocean. Moreover, the kinetic data suggested the presence of another weaker ligand class, which had a higher Fe concentration (>2 nM) and was not detectable by the CSV ligand titration technique. Our field observations and culture experiment results suggest that the Fe-binding ligands are biologically produced. It appears algae engineer their environment to make Fe more available/accessible for longer by producing these ligands. Therefore, the organic speciation of Fe plays a very important role in the sustained nutrition of ocean primary productivity and must be accounted for in geochemical modelling.

Since their inception in the early 1960s, Australian content requirements for commercial television have been subjected to considerable scrutiny through a series of formal inquiries. Over the last ten years this process has intensified. In recent years there have been a number of academic criticisms regarding the state of debate about the regulation of Australian content on commercial television and the capacity of the debate to generate genuine criticism and embrace change. This thesis examines the dynamics of debate about Australian content. It focuses on the ABT's Inquiry into Australian Content on Commercial Television (ACI) which ran from 1983 to 1989. It takes as its basic point of reference Jurgen Habermas' concept of the 'public sphere'. This concept refers to a realm of social life, separate from the state and private spheres, in which 'public opinion' can be formed. Habermas has argued that, with the refeudalisation of the public sphere, the state and private interests have increasingly collaborated to close off the public sphere. The thesis concludes that in many respects Habermas' concept of a refeudalised 'public sphere' is a useful explanatory tool for understanding the dynamics of the ACI and the limited degree of criticism generated by it. However, Habermas' model is limited in so far as it fails to accord adequate recognition to the complexities and significance of the mediation of the 'public interest' by key participants in the inquiry and the strategic role of rhetoric for these participants. Habermas concludes that with the refeudalisation of the public sphere and the disappearance of the historical conditions which supported its operation, the public sphere must now be reconstructed on a case by case basis. Attempts to achieve this, have tended to focus on the facilitation of citizen participation in public policy debate. However, as this analysis of the ACI demonstrates, the dynamics of the debate itself appear to limit I the degree to which 'public opinion' can be elevated above 'private interest'. This thesis demonstrates that the mediation of the 'public interest' assumed a central role in the rhetoric and strategy of the ACI. Each of the key players represented distinct interests and were largely unaccountable to the 'public' they claimed to serve. This thesis concludes that in order to gain a more detailed understanding of how communication works in such a context, and in order to conceive of alternative participatory forms, we need to focus on those aspects of public discourse which Habermas neglects: the rhetoric and the strategic nature of public representation. It suggests that fruitful avenues for further study may lie with Bantz's notion of communicative structures or Luhmann's systems approach to communication.

Today’s Internet content providers primarily use Content Delivery Networks (CDNs) to deliver content to end-users with the aim to enhance their Web access experience. Yet the prevalent commercial CDNs, operating in isolation, often face resource over-provisioning, degraded performance, and Service Level Agreement (SLA) violations, thus incurring high operational costs and limiting the scope and scale of their services. / To move beyond these shortcomings, this thesis sets out to establish the basis for developing advanced and efficient content delivery solutions that are scalable, high performance, and cost-effective. It introduces techniques to enable coordination and cooperation between multiple content delivery services, which is termed as “CDN peering”. In this context, this thesis addresses five key issues ― when to peer (triggering circumstances), how to peer (interaction strategies), whom to peer with (resource discovery), how to manage and enforce operational policies (re-quest-redirection and load sharing), and how to demonstrate peering applicability (measurement study and proof-of-concept implementation). / Thesis Contributions: To support the thesis that the resource over-provisioning and degraded performance problems of existing CDNs can be overcome, thus improving Web access experience of Internet end-users, we have: / - identified the key research challenges and core technical issues for CDN peering, along with a systematic understanding of the CDN space by covering relevant applications, features and implementation techniques, captured in a comprehensive taxonomy of CDNs; / - developed a novel architectural framework, which provides the basis for CDN peering, formed by a set of autonomous CDNs that cooperate through an interconnection mechanism, providing the infrastructure and facilities to virtualize the service of multiple providers; / - devised Quality-of-Service (QoS)-oriented analytical performance models to demonstrate the effects of CDN peering and predict end-user perceived performance, thus facilitating to make concrete QoS performance guarantees for a CDN provider; / - developed enabling techniques, i.e. resource discovery, server selection, and request-redirection algorithms, for CDN peering to achieve service responsiveness. These techniques are exercised to alleviate imbalanced load conditions, while minimizing redirection cost; / - introduced a utility model for CDN peering to measure its content-serving ability by capturing the traffic activities in the system and evaluated through extensive discrete-event simulation analysis. The findings of this study provide incentive for the exploitation of critical parameters for a better CDN peering system design; and / - demonstrated a proof-of-concept implementation of the utility model and an empirical measurement study on MetaCDN, which is a global overlay for Cloud-based content delivery. It is aided with a utility-based redirection scheme to improve the traffic activities in the world-wide distributed network of MetaCDN.

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<p>Outsourcing has over the years become more important when organizations increasingly focus to become best-in-class within their specific area. With this goal, outsourcing may be used to support core activities or dispose of activities judged as non-core for the organization. With these different ways to apply outsourcing, outsourcing may be used with various motives depending on the organizations goal. To better understand these motives, the aim of this paper is to acquire a deeper understanding of underlying motives organizations may have prior to make an outsourcing decision. This study is carried out through a content analysis of press releases published between 2005 and 2010. The results reveal three mayor motives that appear with a higher frequency in the study. These are; motives to gain competence/technology, motives to gain quality and motives to gain a higher flexibility.</p> / <p>Outsourcing har de senaste åren ökat i signifikans då organisationerna hela tiden flyttar fokus mot att nå en best-in-class position på marknaden. Med det målet kan outsourcing användas för att stödja kärnverksamhet eller för att avyttra aktiviteter som bedöms ej tillhöra kärnverksamheten. Dessa olika sätt att tillämpa outsourcing beror på organisationens bakomliggande motiv vad gällande mål med den outsourcade aktiviteten. Målet med denna studie är att öka förståelsen för de bakomliggande motiv som leder till ett outsourcing beslut. Studien är utformad som en kvantitativ innehållsanalys av publicerade pressmeddelanden mellan åren 2005 och 2010. Resultaten visar på tre motiv som uppträder med en högre frekvens i studien. Dessa motiv ämnar till att få; tillgång till kompetens/teknologi, erhålla högre kvalitet samt till att ge den egna organisationen en högre flexibilitet.</p>