title: Carbon-fixation rates and associated microbial communities residing in arid and ephemerally wet Antarctic Dry Valley soils

authors: Niederberger, Thomas D.

subjects: CO₂ fixation

abstract: Carbon-fixation is a critical process in severely oligotrophic Antarctic Dry Valley (DV) soils and may represent the major source of carbon in these arid environments. However, rates of C-fixation in DVs are currently unknown and the microorganisms responsible for these activities unidentified. In this study, C-fixation rates measured in the bulk arid soils (<5% moisture) ranged from below detection limits to ∼12 nmol C/cc/h. Rates in ephemerally wet soils ranged from ∼20 to 750 nmol C/cc/h, equating to turnover rates of ∼7–140 days, with lower rates in stream-associated soils as compared to lake-associated soils. Sequencing of the large subunit of RuBisCO (cbbL) in these soils identified green-type sequences dominated by the 1B cyanobacterial phylotype in both arid and wet soils including the RNA fraction of the wet soil. Red-type cbbL genes were dominated by 1C actinobacterial phylotypes in arid soils, with wetted soils containing nearly equal proportions of 1C (actinobacterial and proteobacterial signatures) and 1D (algal) phylotypes. Complementary 16S rRNA and 18S rRNA gene sequencing also revealed distinct differences in community structure between biotopes. This study is the first of its kind to examine C-fixation rates in DV soils and the microorganisms potentially responsible for these activities.

text: Carbon-fixation rates and associated microbial communities residing in arid and ephemerally wet Antarctic Dry Valley soils Carbon-fixation is a critical process in severely oligotrophic Antarctic Dry Valley (DV) soils and may represent the major source of carbon in these arid environments. However, rates of C-fixation in DVs are currently unknown and the microorganisms responsible for these activities unidentified. In this study, C-fixation rates measured in the bulk arid soils (<5% moisture) ranged from below detection limits to ∼12 nmol C/cc/h. Rates in ephemerally wet soils ranged from ∼20 to 750 nmol C/cc/h, equating to turnover rates of ∼7–140 days, with lower rates in stream-associated soils as compared to lake-associated soils. Sequencing of the large subunit of RuBisCO (cbbL) in these soils identified green-type sequences dominated by the 1B cyanobacterial phylotype in both arid and wet soils including the RNA fraction of the wet soil. Red-type cbbL genes were dominated by 1C actinobacterial phylotypes in arid soils, with wetted soils containing nearly equal proportions of 1C (actinobacterial and proteobacterial signatures) and 1D (algal) phylotypes. Complementary 16S rRNA and 18S rRNA gene sequencing also revealed distinct differences in community structure between biotopes. This study is the first of its kind to examine C-fixation rates in DV soils and the microorganisms potentially responsible for these activities.

year: 2015

title: Optimizing Pub/Sub Systems by Advertisement Pruning

authors: Bittner, Sven

subjects: computer science

abstract: Supporting advertisements in large publish/subscribe services has an improving influence on the system scalability. The additional application of event routing optimizations based on subscriptions further increases the event throughput and decreases the memory usage of publish/subscribe systems. However, also advertisement-based optimizations can improve these system properties but have been widely neglected so far. In particular, no current optimizations are applicable to advertisements defined as arbitrary Boolean filter expressions. 
In this paper, we outline the final milestone on the way to practically support the arbitrary Boolean publish/subscribe model: We firstly develop a novel optimization approach, advertisement pruning, that is tailored to arbitrary Boolean advertisements. Secondly, we present a detailed evaluation of the optimization potential of this advertisement-based solution. We finally analyze the effects of additionally optimizing subscriptions on the advertisement pruning optimization.

text: Optimizing Pub/Sub Systems by Advertisement Pruning Supporting advertisements in large publish/subscribe services has an improving influence on the system scalability. The additional application of event routing optimizations based on subscriptions further increases the event throughput and decreases the memory usage of publish/subscribe systems. However, also advertisement-based optimizations can improve these system properties but have been widely neglected so far. In particular, no current optimizations are applicable to advertisements defined as arbitrary Boolean filter expressions. 
In this paper, we outline the final milestone on the way to practically support the arbitrary Boolean publish/subscribe model: We firstly develop a novel optimization approach, advertisement pruning, that is tailored to arbitrary Boolean advertisements. Secondly, we present a detailed evaluation of the optimization potential of this advertisement-based solution. We finally analyze the effects of additionally optimizing subscriptions on the advertisement pruning optimization.

year: 2006

title: Tapuwaekiwi tapuaeharuru taiharuru te Whakatōhea toheraoa: Connecting to my iwi and reclamation of identity through endurance running grounded in iwi narratives and tikanga/culture.

authors: Helyar-Magill, Nicholas

abstract: This thesis explores the intersection of endurance, whakapapa, and cultural reconnection through the lens of ultra-marathon running and Te Whakatōhea tīpuna pūrākau. By weaving together personal narratives, historical contexts, and contemporary athletic practices, this research examines the role of endurance sports as a pathway for cultural revitalisation and identity reclamation among Māori athletes.
Endurance is a fundamental characteristic of Te Whakatōhea, embodied not only in the physical feats of long-distance running but also in the iwi's historical resilience through colonisation, raupatu, and cultural disconnection. This research positions ultra-marathon running as both a metaphor and a mechanism for reclaiming whakapapa, fostering well-being, and strengthening the connection between Māori athletes and te ao Māori. Drawing upon Kaupapa Māori methodology, qualitative research methods, and tikanga Māori principles, this research seeks to decolonise endurance sports by embedding iwi narratives, tikanga, and mana whenua engagement into the sport of ultra-running.
A central aim of this research is to develop a culturally grounded framework that integrates Te Whakatōhea pūrākau and tikanga into ultra-marathon events. This framework envisions a race that traverses ancestral pathways, acknowledges the whenua and mana whenua, and fosters a culturally safe environment for Māori athletes. The research questions driving this thesis examine the historical endurance of Te Whakatōhea, the impact of colonisation on Māori participation in endurance sports, and the potential for tikanga to be embedded in ultra-marathon events.
The findings of this research reveal that endurance is deeply woven into the whakapapa of Te Whakatōhea and that ultra-marathon running serves as a powerful means of reconnecting with iwi identity, whenua, and te ao Māori. Through interviews with Māori endurance athletes and an exploration of iwi narratives, this research highlights the transformative potential of culturally embedded endurance sports. Furthermore, the research identifies barriers to Māori participation in ultra-marathons, including historical disenfranchisement from traditional athletic spaces and the predominance of Pākehā worldviews in endurance sports. Addressing these barriers, this thesis proposes a tikanga-based model that seeks to attract greater Māori
participation by integrating kaupapa Māori principles into the design, organisation, and execution of ultra-marathon events.
This research is also a personal journey of endurance and reconnection, reflecting on my own whakapapa as a descendant of Te Whakatōhea and an ultra-marathon runner. Raised outside of the iwi rohe, my path of reclaiming identity through sport mirrors the broader themes of cultural endurance and revitalisation explored in this thesis. By engaging with iwi histories, participating in kaupapa Māori spaces, and embedding tikanga into my athletic practice, I have sought to bridge the gap between past and present, creating a future where Māori endurance athletes can thrive within a culturally affirming space.
Ultimately, this thesis contributes to the growing discourse on Indigenous endurance sports, cultural resilience, and decolonial approaches to athletic participation. It affirms that ultra-marathon running, when grounded in whakapapa and tikanga, has the potential to serve as a tool for cultural reconnection, healing, and identity reclamation for Māori athletes and Te Whakatōhea whānau.

text: Tapuwaekiwi tapuaeharuru taiharuru te Whakatōhea toheraoa: Connecting to my iwi and reclamation of identity through endurance running grounded in iwi narratives and tikanga/culture. This thesis explores the intersection of endurance, whakapapa, and cultural reconnection through the lens of ultra-marathon running and Te Whakatōhea tīpuna pūrākau. By weaving together personal narratives, historical contexts, and contemporary athletic practices, this research examines the role of endurance sports as a pathway for cultural revitalisation and identity reclamation among Māori athletes.
Endurance is a fundamental characteristic of Te Whakatōhea, embodied not only in the physical feats of long-distance running but also in the iwi's historical resilience through colonisation, raupatu, and cultural disconnection. This research positions ultra-marathon running as both a metaphor and a mechanism for reclaiming whakapapa, fostering well-being, and strengthening the connection between Māori athletes and te ao Māori. Drawing upon Kaupapa Māori methodology, qualitative research methods, and tikanga Māori principles, this research seeks to decolonise endurance sports by embedding iwi narratives, tikanga, and mana whenua engagement into the sport of ultra-running.
A central aim of this research is to develop a culturally grounded framework that integrates Te Whakatōhea pūrākau and tikanga into ultra-marathon events. This framework envisions a race that traverses ancestral pathways, acknowledges the whenua and mana whenua, and fosters a culturally safe environment for Māori athletes. The research questions driving this thesis examine the historical endurance of Te Whakatōhea, the impact of colonisation on Māori participation in endurance sports, and the potential for tikanga to be embedded in ultra-marathon events.
The findings of this research reveal that endurance is deeply woven into the whakapapa of Te Whakatōhea and that ultra-marathon running serves as a powerful means of reconnecting with iwi identity, whenua, and te ao Māori. Through interviews with Māori endurance athletes and an exploration of iwi narratives, this research highlights the transformative potential of culturally embedded endurance sports. Furthermore, the research identifies barriers to Māori participation in ultra-marathons, including historical disenfranchisement from traditional athletic spaces and the predominance of Pākehā worldviews in endurance sports. Addressing these barriers, this thesis proposes a tikanga-based model that seeks to attract greater Māori
participation by integrating kaupapa Māori principles into the design, organisation, and execution of ultra-marathon events.
This research is also a personal journey of endurance and reconnection, reflecting on my own whakapapa as a descendant of Te Whakatōhea and an ultra-marathon runner. Raised outside of the iwi rohe, my path of reclaiming identity through sport mirrors the broader themes of cultural endurance and revitalisation explored in this thesis. By engaging with iwi histories, participating in kaupapa Māori spaces, and embedding tikanga into my athletic practice, I have sought to bridge the gap between past and present, creating a future where Māori endurance athletes can thrive within a culturally affirming space.
Ultimately, this thesis contributes to the growing discourse on Indigenous endurance sports, cultural resilience, and decolonial approaches to athletic participation. It affirms that ultra-marathon running, when grounded in whakapapa and tikanga, has the potential to serve as a tool for cultural reconnection, healing, and identity reclamation for Māori athletes and Te Whakatōhea whānau.

year: 2024