title: Cardigan: deploying a distributed routing fabric

authors: Stringer, Jonathan Philip

subjects: computer science

abstract: SDN is an active area for network research, with many organisations exploring the opportunities provided by the de-coupling of network control from packet forwarding. Previous work has suggested that a hybrid networking model will pave the way for migration towards SDN, through interoperability with legacy devices. However, questions remain over the operation of such systems in production environments. In order to build operational confidence, we built a simple distributed router using OpenFlow and deployed it at a public Internet exchange. This implementation provides insights into the challenges involved with using these technologies, and suggests the viability of mixed device environments despite the limitations of early OpenFlow implementations.

text: Cardigan: deploying a distributed routing fabric SDN is an active area for network research, with many organisations exploring the opportunities provided by the de-coupling of network control from packet forwarding. Previous work has suggested that a hybrid networking model will pave the way for migration towards SDN, through interoperability with legacy devices. However, questions remain over the operation of such systems in production environments. In order to build operational confidence, we built a simple distributed router using OpenFlow and deployed it at a public Internet exchange. This implementation provides insights into the challenges involved with using these technologies, and suggests the viability of mixed device environments despite the limitations of early OpenFlow implementations.

year: 2013

title: Establishment of THP-1 Monocytes with Compromised Mitochondrial Functions

authors: Chou, Tzu-wen Joy

subjects: THP-1 monocytes

abstract: The process of inflammation is important for both normal health and in a number of diseases, such as metabolic disorders, autoimmune diseases, and neurodegenerative diseases. Mitochondria are vital for the functioning of all cells. It had been implicated as a key player in inflammatory processes, especially through reactive oxygen species as signals of various immune responses. This study aimed to establish a THP-1 cell line with compromised mitochondrial functions, using antimycin A as a Complex III inhibitor, and to investigate the role of mitochondrial stress, as monitored by the expression of Hsp60, in inflammatory processes. High concentrations of antimycin A (100 and 200 μM) were cytotoxic to THP-1 monocytes that they were rapidly killed within 48 hours of exposure. Lower concentrations of antimycin A (5, 10, 25 and 50 μM) gave growth inhibition effects to THP-1 monocytes. Pyruvate and uridine were used with an intention of rescuing the THP-1 cell growth at lower antimycin A concentrations. The THP-1 monocytes treated with antimycin A with uridine and pyruvate showed more growth compared to the ones without uridine and pyruvate supplement. Yet this difference is insignificant statistically. The expressions of Hsp60 and TNF-α at the mRNA level was monitored using reverse transcriptase polymerase chain reaction. Hsp60 expression from THP-1 monocytes only showed some minor fluctuations in different antimycin A concentrations, regardless of uridine and iii pyruvate supplement, indicating the stress mitochondrial response was unobvious. On the other hand, TNF-α expression was dramatically down-regulated in THP-1 monocytes treated with antimycin A only compared to the untreated control and ones supplemented with uridine and pyruvate. These results suggest that antimycin A may have inhibition effect towards TNF-α expression, and uridine and pyruvate could also have other functions in THP-1 monocytes apart from redox rescue compounds. Yet the mitochondrial stress response shown by Hsp60 induction still remains to be further investigated.

text: Establishment of THP-1 Monocytes with Compromised Mitochondrial Functions The process of inflammation is important for both normal health and in a number of diseases, such as metabolic disorders, autoimmune diseases, and neurodegenerative diseases. Mitochondria are vital for the functioning of all cells. It had been implicated as a key player in inflammatory processes, especially through reactive oxygen species as signals of various immune responses. This study aimed to establish a THP-1 cell line with compromised mitochondrial functions, using antimycin A as a Complex III inhibitor, and to investigate the role of mitochondrial stress, as monitored by the expression of Hsp60, in inflammatory processes. High concentrations of antimycin A (100 and 200 μM) were cytotoxic to THP-1 monocytes that they were rapidly killed within 48 hours of exposure. Lower concentrations of antimycin A (5, 10, 25 and 50 μM) gave growth inhibition effects to THP-1 monocytes. Pyruvate and uridine were used with an intention of rescuing the THP-1 cell growth at lower antimycin A concentrations. The THP-1 monocytes treated with antimycin A with uridine and pyruvate showed more growth compared to the ones without uridine and pyruvate supplement. Yet this difference is insignificant statistically. The expressions of Hsp60 and TNF-α at the mRNA level was monitored using reverse transcriptase polymerase chain reaction. Hsp60 expression from THP-1 monocytes only showed some minor fluctuations in different antimycin A concentrations, regardless of uridine and iii pyruvate supplement, indicating the stress mitochondrial response was unobvious. On the other hand, TNF-α expression was dramatically down-regulated in THP-1 monocytes treated with antimycin A only compared to the untreated control and ones supplemented with uridine and pyruvate. These results suggest that antimycin A may have inhibition effect towards TNF-α expression, and uridine and pyruvate could also have other functions in THP-1 monocytes apart from redox rescue compounds. Yet the mitochondrial stress response shown by Hsp60 induction still remains to be further investigated.

year: 2009

title: The Determinants of Tribal Population Growth in the New Zealand Census

authors: Rarere, Moana

subjects: tribal population growth

abstract: By the early twentieth century the notion that ethnic populations would dissipate was a commonly held belief.  However, after World War II, the modern world has seen an incredible resurgence in ethnic identities.  Ethnic conflicts, mobilisations, and the political movements of the 1950s and 1960s served as a major catalyst in the diffusion of indigenous identities and rights.  Consequently, indigenous groups in settler states, especially in North America, experienced population growth beyond the levels of natural demographic factors, that is, fertility, mortality and migration.  Researchers attributed a significant proportion of this growth to changing patterns of ethnic identification, also referred to as ethnic mobility .  Although this phenomenon is well documented in North America, it is only just beginning to be understood in relation to the New Zealand context. 

During the 1970s and 1980s, the indigenous Māori population of New Zealand gained substantial progress in political, social and economic spheres, following the same patterns of ethnic identity growth as in North America.  Despite these gains, the average individual socio-economic outcomes for Māori remain poor, especially in comparison to New Zealand Europeans/Pākehā.  Through key legislation, iwi (tribal) organisations became the core mechanism in which to address Māori socio-economic issues, achieve Māori aspirations and to manage Treaty of Waitangi settlement monies.  Subsequently, the need for iwi statistics for policy and planning purposes saw the reinstatement of iwi data in the New Zealand census in 1991.  Surprisingly, however, very little attention has been given to contemporary patterns of iwi demography.

Since the 1991 census, observations of total iwi population growth patterns indicate these patterns cannot solely be explained by natural demographic factors.  Furthermore, the growth trajectories of individual iwi were markedly different, and in some cases erratic.  These initial observations have raised the following key research questions: What do patterns of iwi growth look like?  What is the role of ethnic mobility?  What factors drive ethnic mobility?  Who changes iwi identification?  Why should we care?  

This thesis examines patterns of iwi identification in the New Zealand Census of Population and Dwellings from 1991 to 2006.  It uses statistical methods to not only document iwi population changes but to also identify the key determinants driving these trajectories.  In addition, this thesis considers ethnic mobility as an important driver of population growth but, situates this within the broader macro-political environment.  Along with the analysis of aggregate iwi population changes, this thesis also provides an in-depth analysis of four iwi groups – Ngāi Tahu, Waikato, Ngāti Awa and Tūhoe, in order to observe individual iwi dynamics that are not clearly visible at the aggregate level.

The findings of this thesis raise important implications for theories of ethnicity and the demographic study of ethnic populations.  For example, this thesis argues that the category of ethnic mobility is mainly contextual, that is, decisions to change ethnic responses are influenced by the broader political, social and economic contexts.  Furthermore this thesis contends that individual ethnic identification decisions are for the most part defined by ethnic categories imposed by the State.  While traditional views suggest ethnicity is fixed, intrinsic and kinship based, this thesis finds significant support for contemporary views that argue ethnicity is fluid, extrinsic and socially constructed.  Rather than reject traditional views of Maori identity, this study recognises that ethnic identities are complex, and that shifts in iwi identification is about connecting and reconnecting with whakapapa.  Thus this thesis argues that in order to understand individual iwi dynamics both points of view need to be considered.

text: The Determinants of Tribal Population Growth in the New Zealand Census By the early twentieth century the notion that ethnic populations would dissipate was a commonly held belief.  However, after World War II, the modern world has seen an incredible resurgence in ethnic identities.  Ethnic conflicts, mobilisations, and the political movements of the 1950s and 1960s served as a major catalyst in the diffusion of indigenous identities and rights.  Consequently, indigenous groups in settler states, especially in North America, experienced population growth beyond the levels of natural demographic factors, that is, fertility, mortality and migration.  Researchers attributed a significant proportion of this growth to changing patterns of ethnic identification, also referred to as ethnic mobility .  Although this phenomenon is well documented in North America, it is only just beginning to be understood in relation to the New Zealand context. 

During the 1970s and 1980s, the indigenous Māori population of New Zealand gained substantial progress in political, social and economic spheres, following the same patterns of ethnic identity growth as in North America.  Despite these gains, the average individual socio-economic outcomes for Māori remain poor, especially in comparison to New Zealand Europeans/Pākehā.  Through key legislation, iwi (tribal) organisations became the core mechanism in which to address Māori socio-economic issues, achieve Māori aspirations and to manage Treaty of Waitangi settlement monies.  Subsequently, the need for iwi statistics for policy and planning purposes saw the reinstatement of iwi data in the New Zealand census in 1991.  Surprisingly, however, very little attention has been given to contemporary patterns of iwi demography.

Since the 1991 census, observations of total iwi population growth patterns indicate these patterns cannot solely be explained by natural demographic factors.  Furthermore, the growth trajectories of individual iwi were markedly different, and in some cases erratic.  These initial observations have raised the following key research questions: What do patterns of iwi growth look like?  What is the role of ethnic mobility?  What factors drive ethnic mobility?  Who changes iwi identification?  Why should we care?  

This thesis examines patterns of iwi identification in the New Zealand Census of Population and Dwellings from 1991 to 2006.  It uses statistical methods to not only document iwi population changes but to also identify the key determinants driving these trajectories.  In addition, this thesis considers ethnic mobility as an important driver of population growth but, situates this within the broader macro-political environment.  Along with the analysis of aggregate iwi population changes, this thesis also provides an in-depth analysis of four iwi groups – Ngāi Tahu, Waikato, Ngāti Awa and Tūhoe, in order to observe individual iwi dynamics that are not clearly visible at the aggregate level.

The findings of this thesis raise important implications for theories of ethnicity and the demographic study of ethnic populations.  For example, this thesis argues that the category of ethnic mobility is mainly contextual, that is, decisions to change ethnic responses are influenced by the broader political, social and economic contexts.  Furthermore this thesis contends that individual ethnic identification decisions are for the most part defined by ethnic categories imposed by the State.  While traditional views suggest ethnicity is fixed, intrinsic and kinship based, this thesis finds significant support for contemporary views that argue ethnicity is fluid, extrinsic and socially constructed.  Rather than reject traditional views of Maori identity, this study recognises that ethnic identities are complex, and that shifts in iwi identification is about connecting and reconnecting with whakapapa.  Thus this thesis argues that in order to understand individual iwi dynamics both points of view need to be considered.

year: 2012