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Item Geology and petrology of Raoul Volcano: Magma genesis and fractionation processes beneath the Tonga-Kermadec arc(ResearchSpace@Auckland, 1998) Worthington, Timothy Journet; Smith, Ian; Black, PhilippaIntra-oceanic volcanic arcs are the simplest manifestation of subduction-related magmatism. Three key problems stand in sharp focus in this environment: crustal processing of primitive high-Mg magma to generate derivative low-Mg magmas, genesis of felsic magma, and mass transfer between the subducting slab and the mantle. New insights into these problems are obtained from a comprehensive petrological study of 311 samples from Raoul Volcano, Tonga-Kermadec arc. Raoul lavas are low-K series tholeiites with 48-70 wt.% Si02 and Mg#< 67. Few have 58-65 wt.% Si02. Glomeroporphyritic basalt-basaltic andesite predominates (5-48 % phenocrysts). Sparsely phyric basalt-basaltic andesite and dacite are less abundant. Common phenocryst phases are calcic plagioclase (-An84-90), augite, olivine, and orthopyroxene, with similar compositions in all lavas (and friable adcumulates). Phenocryst-magrna equilibrium is restricted to thin strongly zoned phenocryst rims. Geochemical differences between glomeroporphyritic and aphyric lavas reflect their phenocryst contents and proportions. Fractional crystallisation of primitive high-Mg magma must produce aphyric low-Mg basaltic-andesitic magmas by efficient crystal removal. These magmas accumulate unrelated crystals as they ascend through crystal mush. Eruptions of dacite commenced at 3.7 ka, and culminated with the 8-16 krn3 Fleetwood eruption (2.2 ka). Resurgent volcanism has occurred in Denham and Raoul Calderas. Each eruption vented a geochemically homogeneous and distinct magma batch. Fractional crystallisation cannot link these batches to each other or a common parent without major changes in the extract assemblage. They can be generated by dehydration melting (>20 %) of sub-arc crust at 0.6 GPa and >30 °C. Felsic magmatism may characterise arc adolescence, as primitive magma underplating sub arc crust converts it to dacitic melt and granulite within 1-2 m.y. Conservative elements in mafic lavas require 25 % fractional melting of mildly depleted (2 % melt extraction) homogeneous MORB-source mantle. The subduction-related component contributes -30 % Nd, 55 % La, 75 % Sr, 85 % Th, and >90 % K, Pb, Rb, Ba, and Cs. It has constant composition and magnitude, consistent with mass transfer from the slab to a sub-arc melting column by repeated episodes of arnphibole formation and decomposition. Remarkably similar subductionrelated components in Raoul, South Sandwich, and Mariana lavas testify to efficient buffering of variable slab-derived fluxes by Dnuid-px and amphibole-saturation of mantle peridotite.Item Mechanisms of peripheral phylogeographic divergence in the indo-Pacific: lessons from the spiny lobster Panulirus homarus.(2017-08-18) Farhadi, Ahmad; Jeffs, Andrew; Farahmand, Hamid; Rejiniemon, Thankappan Sarasam; Smith, Greg; Lavery, ShaneThere is increasing recognition of the concordance between marine biogeographic and phylogeographic boundaries. However, it is still unclear how population-level divergence translates into species-level divergence, and what are the principal factors that first initiate that divergence, and then maintain reproductive isolation. This study examines the likely forces driving population and lineage divergences in the broadly-distributed Indo-Pacific spiny lobster Panulirus homarus, which has peripheral divergent lineages in the west and east. The study focuses particularly on the West Indian Ocean, which is emerging as a region of unexpected diversity. Mitochondrial control region (mtCR) and COI sequences as well as genotypes of 9 microsatellite loci were examined in 410 individuals from 17 locations grouped into 7 regions from South Africa in the west, and eastward across to Taiwan and the Marquesas Islands. Phylogenetic and population-level analyses were used to test the significance and timing of divergences and describe the genetic relationships among populations.Analyses of the mtCR revealed high levels of divergence among the seven regions (ФST = 0.594, P < 0.001). Microsatellite analyses also revealed significant divergence among regions, but at a much lower level (FST = 0.066, P < 0.001). The results reveal different patterns of mtCR v. nDNA divergence between the two distinct peripheral lineages: a subspecies in South Africa and Madagascar, and a phylogeographically diverged population in the Marquesas. The results also expose a number of other more fine-scale population divergences, particularly in the Indian Ocean.The divergence of peripheral lineages in the west and east of the species' range appear to have been initiated and maintained by very different processes. The pattern of mitochondrial and nuclear divergence of the western lineage, implicates processes of parapatric isolation, secondary contact and introgression, and suggests possible maintenance through adaptation and behavioural reproductive isolation. In contrast, the eastern lineage appears to have diverged through a rare colonisation event, maintained through long-term isolation, and matches expectations of the core-periphery hypothesis. The process of active peripheral speciation may be a common force in the Indo-Pacific that helps drive some of the regions' recognized biogeographic boundaries.Item Researching the psychology of cognitive style and learning style: Is there really a future?(Elsevier, 2009-12) Peterson, Elizabeth; Rayner, SG; Armstrong, SJThe field of individual differences in cognitive and learning style has been constantly criticized for conceptual confusion, contested definitions, poor measurement and lack of validity. This study reports the findings from a global e-survey of 94 style researchers who were asked to comment on the state of the field and their own understanding of the phenomenon being studied, including areas of criticism. Our findings highlight considerable agreement over the value and future direction of style research. However, while there is also strong awareness of criticisms and concerns over terminology and measurement, there appears to be little resolve to address them.Item Inequality and health: Is housing crowding the link?(Motu Economic and Public Policy Research Trust, 2006-12) Maani, Sholeh; Vaithianathan, Rhema; Wolfe, BMotu Working Paper SeriesItem Spatio-temporal Organization During Ventricular Fibrillation in the Human Heart.(2018-06) Robson, Jinny; Aram, Parham; Nash, Martyn; Bradley, Christopher; Hayward, Martin; Paterson, David J; Taggart, Peter; Clayton, Richard H; Kadirkamanathan, VisakanIn this paper, we present a novel approach to quantify the spatio-temporal organization of electrical activation during human ventricular fibrillation (VF). We propose three different methods based on correlation analysis, graph theoretical measures and hierarchical clustering. Using the proposed approach, we quantified the level of spatio-temporal organization during three episodes of VF in ten patients, recorded using multi-electrode epicardial recordings with 30 s coronary perfusion, 150 s global myocardial ischaemia and 30 s reflow. Our findings show a steady decline in spatio-temporal organization from the onset of VF with coronary perfusion. We observed transient increases in spatio-temporal organization during global myocardial ischaemia. However, the decline in spatio-temporal organization continued during reflow. Our results were consistent across all patients, and were consistent with the numbers of phase singularities. Our findings show that the complex spatio-temporal patterns can be studied using complex network analysis.Item An Evolution Experiment Testing the Drift Model of RNA Editing Evolution(ResearchSpace@Auckland, 2020) Love, James; Poole, AnthonyEnzymes that correct or alter messenger RNAs (mRNAs) have evolved independently multiple times. One proposed mechanism for the evolution of RNA editing is via genetic drift. In this model an editing activity emerges that is initially selectively neutral with no target, this allows mutations that require editing to correct to appear and persist. This creates conditions for RNA editing to be fixed in the population. This process is more likely to occur due to the accumulation of additional mutations during genetic drift. A previous mutation accumulation experiment demonstrated that pre-existing RNA polymerase slippage can correct frameshift mutations acquired through drift as. My project built upon this, aiming to test whether the same might occur for post-transcriptional RNA editing under drift. I introduced synthetic genes for RNA editing enzymes to 30 lines of Escherichia coli. These lines were evolved under high drift conditions for 50 days with constant overexpression of these RNA editing enzymes. Subsequently, the fitness impact of RNA editing on these evolved lines was assessed by inhibiting the expression of the RNA editing enzymes and measuring growth rates. Due to issues with the expression vector and evolved line strain this assay was inconclusive. These issues are detailed in this thesis, along with steps that could be taken to resolve them in future work. To assess rates of mutation and gain of mutations that may be potential editing targets, genomes for all evolved lines were sequenced and compared with ancestral strains. A significant number of mutations were observed consistent with mutation rates under high drift conditions. However, a search for specific mutations as likely RNA editing targets was largely unsuccessful. While these assays and sequence-based analyses were not successful, there may still be undetected editing in some strains. Further exploration through transcript sequencing is required. This evolution experiment generated many mutations under high drift conditions in the presence of overexpressed RNA editing enzymes. The strains generated during this evolution experiment are now ready for transcript sequencing and analysis to assess the possible impact of RNA editing upon the mutations gained and maintained throughout the experiment.Item On the edge of the storm? Situating Switzerland's neutrality in the context of the First World War(Hier und Jetzt, 2018) Abbenhuis, Maartje; Olsansky, MMItem Unresponsiveness ≠ unconsciousness(American Society of Anesthesiologists, Inc, 2012-04) Sanders, RD; Tononi, G; Laureys, S; Sleigh, JamesConsciousness is subjective experience. During both sleep and anesthesia, consciousness is common, evidenced by dreaming. A defining feature of dreaming is that, while conscious, we do not experience our environment; we are disconnected. Besides inducing behavioral unresponsiveness, a key goal of anesthesia is to prevent the experience of surgery (connected consciousness), by inducing either unconsciousness or disconnection of consciousness from the environment. Review of the isolated forearm technique demonstrates that consciousness, connectedness, and responsiveness uncouple during anesthesia; in clinical conditions, a median 37% of patients demonstrate connected consciousness. We describe potential neurobiological constructs that can explain this phenomenon: during light anesthesia the subcortical mechanisms subserving spontaneous behavioral responsiveness are disabled but information integration within the corticothalamic network continues to produce consciousness, and unperturbed norepinephrinergic signaling maintains connectedness. These concepts emphasize the need for developing anesthetic regimens and depth of anesthesia monitors that specifically target mechanisms of consciousness, connectedness, and responsiveness.Item Deliberative Political Leaders: The Role of Policy Input in Political Leadership(Cogitatio Press, 2016) Lees-Marshment, JenniferThis article provides a fresh perspective on political leadership by demonstrating that government ministers take a deliberative approach to decision making. Getting behind the closed doors of government through 51 elite interviews in the UK, US, Australia, Canada and New Zealand, the article demonstrates that modern political leadership is much more collaborative than we usually see from media and public critique. Politicians are commonly perceived to be power-hungry autocratic, elite figures who once they have won power seek to implement their vision. But as previous research has noted, not only is formal power circumscribed by the media, public opinion, and unpredictability of government, more collaborative approaches to leadership are needed given the rise of wicked problems and citizens increasingly demand more say in government decisions and policy making. This article shows that politicians are responding to their challenging environment by accepting they do not know everything and cannot do everything by themselves, and moving towards a leadership style that incorporates public input. It puts forward a new model of Deliberative Political Leadership, where politicians consider input from inside and outside government from a diverse range of sources, evaluate the relative quality of such input, and integrate it into their deliberations on the best way forward before making their final decision. This rare insight into politician’s perspectives provides a refreshing view of governmental leadership in practice and new model for future research.Item On Complexity of Lobbying in Multiple Referenda(Department of Mathematics, The University of Auckland, New Zealand, 2005-02) Cristian, Robin; Fellows, Mike; Rosamond, Frances; Slinko, ArkadiiIn this paper we show that lobbying in conditions of "direct democracy" is virtually impossible, even in conditions of complete information about voters preferences, since it would require solving a very computationally hard problem. We use the apparatus of parametrized complexity for this purpose.