title: Concentration boundary layers around complex assemblages of macroalgae: Implications for the effects of ocean acidification on understory coralline algae

authors: Cornwall, Christopher E.

abstract: Metabolic processes have the potential to modulate the effects of ocean acidification (OA) in nearshore macroalgal beds. We investigated whether natural mixed assemblages of the articulate coralline macroalga Arthrocardia corymbosa and understory crustose coralline algae (CCA) altered pH and O₂ concentrations within and immediately above their canopies. In a unidirectional flume, we tested the effect of water velocity (0-0.1 ms⁻¹), bulk seawater pH (ambient pH 8.05, and pH 7.65), and irradiance (photosynthetically saturating light and darkness) on pH and O₂ concentration gradients, and the derived concentration boundary layer (CBL) thickness. At bulk seawater pH 7.65 and slow velocities (0 and 0.015 ms⁻¹), pH at the CCA surface increased to 7.90-8.00 in the light. Although these manipulations were short term, this indicates a potential daytime buffering capacity that could alleviate the effects of OA. Photosynthetic activity also increased O2 concentrations at the surface of the CCA. However, this moderating capacity was flow dependent; the CBL thickness decreased from an average of 26.8 mm from the CCA surface at 0.015 ms⁻¹ to 4.1 mm at 0.04 ms⁻¹. The reverse trends occurred in the dark, with respiration causing pH and O2 concentrations to decrease at the CCA surface. At all flow velocities the CBL thicknesses (up to 68 mm) were much greater than those previously published, indicating that the presence of canopies can alter the CBL substantially. In situ, the height of macroalgal canopies can be an order of magnitude larger than those used here, indicating that the degree of buffering to OA will be context dependent.

text: Concentration boundary layers around complex assemblages of macroalgae: Implications for the effects of ocean acidification on understory coralline algae Metabolic processes have the potential to modulate the effects of ocean acidification (OA) in nearshore macroalgal beds. We investigated whether natural mixed assemblages of the articulate coralline macroalga Arthrocardia corymbosa and understory crustose coralline algae (CCA) altered pH and O₂ concentrations within and immediately above their canopies. In a unidirectional flume, we tested the effect of water velocity (0-0.1 ms⁻¹), bulk seawater pH (ambient pH 8.05, and pH 7.65), and irradiance (photosynthetically saturating light and darkness) on pH and O₂ concentration gradients, and the derived concentration boundary layer (CBL) thickness. At bulk seawater pH 7.65 and slow velocities (0 and 0.015 ms⁻¹), pH at the CCA surface increased to 7.90-8.00 in the light. Although these manipulations were short term, this indicates a potential daytime buffering capacity that could alleviate the effects of OA. Photosynthetic activity also increased O2 concentrations at the surface of the CCA. However, this moderating capacity was flow dependent; the CBL thickness decreased from an average of 26.8 mm from the CCA surface at 0.015 ms⁻¹ to 4.1 mm at 0.04 ms⁻¹. The reverse trends occurred in the dark, with respiration causing pH and O2 concentrations to decrease at the CCA surface. At all flow velocities the CBL thicknesses (up to 68 mm) were much greater than those previously published, indicating that the presence of canopies can alter the CBL substantially. In situ, the height of macroalgal canopies can be an order of magnitude larger than those used here, indicating that the degree of buffering to OA will be context dependent.

year: 2012

title: Revisiting deep hybrid models for out-of-distribution detection

authors: Schlumbom, Paul-Ruben

subjects: computer science

abstract: Deep hybrid models (DHMs) for out-of-distribution (OOD) detection, jointly training a deep feature extractor with a classification head and a density estimation head based on a normalising flow, provide a conceptually appealing approach to visual OOD detection. The paper that introduced this approach reported 100% AuROC in experiments on two standard benchmarks, including one based on the CIFAR-10 data. As there are no implementations available, we set out to reproduce the approach by carefully filling in gaps in the description of the algorithm. Although we were unable to attain 100% OOD detection rates, and our results indicate that such performance is impossible on the CIFAR-10 benchmark, we achieved good OOD performance. We provide a detailed analysis of when the architecture fails and argue that it introduces an adversarial relationship between the classification component and the density estimator, rendering it highly sensitive to the balance of these two components and yielding a collapsed feature space without careful fine-tuning. Our implementation of DHMs is publicly available.

text: Revisiting deep hybrid models for out-of-distribution detection Deep hybrid models (DHMs) for out-of-distribution (OOD) detection, jointly training a deep feature extractor with a classification head and a density estimation head based on a normalising flow, provide a conceptually appealing approach to visual OOD detection. The paper that introduced this approach reported 100% AuROC in experiments on two standard benchmarks, including one based on the CIFAR-10 data. As there are no implementations available, we set out to reproduce the approach by carefully filling in gaps in the description of the algorithm. Although we were unable to attain 100% OOD detection rates, and our results indicate that such performance is impossible on the CIFAR-10 benchmark, we achieved good OOD performance. We provide a detailed analysis of when the architecture fails and argue that it introduces an adversarial relationship between the classification component and the density estimator, rendering it highly sensitive to the balance of these two components and yielding a collapsed feature space without careful fine-tuning. Our implementation of DHMs is publicly available.

year: 2025

title: Te mana o ngā toa: Māori experiences of Ngāti Tūmatauenga, the New Zealand Army

authors: Kohere, Cheyenne Atairehia Mere

subjects: Kaupapa Māori

abstract: Diverse realities impact Māori people and their capacity to flourish. It is well- established that Māori are significant contributors to the New Zealand Defence Force (NZDF), and especially the New Zealand Army. Noteworthy participation in major conflicts, especially WWI and WWII create a whakapapa of military tradition which contributed to institutional change within the Army in the 1990s. The inclusion of Māori cultural training in the New Zealand Army can contribute to morale and the effectiveness of the organisation (Hohaia, 2016). This master’s thesis aims to deepen understandings of the experiences of Māori personnel in the Army by exploring the role of the New Zealand Army in the health and wellbeing of Māori soldiers, as well as how the Army can be a career pathway for Māori and their whānau to flourish.
This research employs the use qualitative methods such as Kaupapa Māori theory, phenomenology, and pūrākau as a form of narrative analysis. Semi-structured interviews with five participants (three retired personnel and two currently serving) explores these factors that contribute to the flourishing of Māori soldiers in the New Zealand Army. Each pūrākau developed from interview data is an acknowledgment of the personal journeys of the five participants and contains philosophical thought, epistemological constructs, cultural codes, and worldviews (Lee, 2009).
The findings of the research highlight the complexities that arise when considering the health and wellbeing of Māori soldiers. A range of interconnected factors conceptualised within five themes contributes to participants’ ability to flourish. These five themes include hauora (health), whanaungatanga (relationships), manaakitanga (support), whanonga pono (values) and whakapāwera (hardships). These results suggest that flourishing for Māori personnel is complex, and there is not a simple route to enable Māori to flourish. There are many ‘trade-offs’ for Māori and their experiences. However, Māori service provides opportunities and obstacles for an individual, as well as their whānau, hapū and iwi.

text: Te mana o ngā toa: Māori experiences of Ngāti Tūmatauenga, the New Zealand Army Diverse realities impact Māori people and their capacity to flourish. It is well- established that Māori are significant contributors to the New Zealand Defence Force (NZDF), and especially the New Zealand Army. Noteworthy participation in major conflicts, especially WWI and WWII create a whakapapa of military tradition which contributed to institutional change within the Army in the 1990s. The inclusion of Māori cultural training in the New Zealand Army can contribute to morale and the effectiveness of the organisation (Hohaia, 2016). This master’s thesis aims to deepen understandings of the experiences of Māori personnel in the Army by exploring the role of the New Zealand Army in the health and wellbeing of Māori soldiers, as well as how the Army can be a career pathway for Māori and their whānau to flourish.
This research employs the use qualitative methods such as Kaupapa Māori theory, phenomenology, and pūrākau as a form of narrative analysis. Semi-structured interviews with five participants (three retired personnel and two currently serving) explores these factors that contribute to the flourishing of Māori soldiers in the New Zealand Army. Each pūrākau developed from interview data is an acknowledgment of the personal journeys of the five participants and contains philosophical thought, epistemological constructs, cultural codes, and worldviews (Lee, 2009).
The findings of the research highlight the complexities that arise when considering the health and wellbeing of Māori soldiers. A range of interconnected factors conceptualised within five themes contributes to participants’ ability to flourish. These five themes include hauora (health), whanaungatanga (relationships), manaakitanga (support), whanonga pono (values) and whakapāwera (hardships). These results suggest that flourishing for Māori personnel is complex, and there is not a simple route to enable Māori to flourish. There are many ‘trade-offs’ for Māori and their experiences. However, Māori service provides opportunities and obstacles for an individual, as well as their whānau, hapū and iwi.

year: 2022