Dental fluorosis caused by volcanic degassing in West Ambrym, Vanuatu : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Earth Science at Massey University, Palmerston North, New Zealand

Fluorosis, both dental and skeletal, is a disease afflicting millions of people worldwide and is caused primarily by the ingestion of fluoride-rich drinking water. Usually, this is groundwater that has leached fluoride from underlying rock deposits. In West Ambrym. Vanuatu, however, the indigenous people live in close proximity to a degassing volcano and harvest rainwater for their potable water needs. The current project investigated two hypotheses; firstly, that dental fluorosis existed in West Ambrym and secondly, that it was caused by the ingestion of rainwater contaminated by the degassing volcanic plume. A dental survey was undertaken of children ayed 6 to 18 years using the Dean's Index of Fluorosis. A total of 835 children participated; 253 of whom came from the target area of West Ambrym. For comparative analysis and a more regional perspective, the remaining 582 surveyed were from other nearby locations. Drinking water, non-drinking water and food samples were collected for fluoride analyses. Dental fluorosis prevalence was found to be 96% in West Ambrym, 85% in Malakula, 71% in North Ambrym, 61% in Southeast Ambrym, 36% in Tongoa, 43% in an 'incidental islands' group, and 100% on Tanna. Drinking water samples from West Ambrym ranged from 0.7 to 9.5 ppm F (average 4.2 ppm F). Groundwater sources ranged from 1.8 to 2.8 ppm F (average 2.2 ppm F). Of the 158 drinking water samples, 99% were over the World Health Organisation recommended concentration of 1.0 ppm F. It was found that pH was not a suitable proxy for fluoride concentration. That painted and/or rusted corrugated iron roofing may play a role in lowering fluoride concentration of stored rainwater was a tentative finding. Coconut juice was a rich source of fluoride. Food samples ranged from <6 ppm F to over 100 ppm F. The current research has shown that the semi-continuously degassing of Ambrym volcano is introducing significant levels of fluoride into the drinking water of the local Ni-vanuatu. This geo-meteorological process has resulted in the development of widespread dental fluorosis in West Ambrym. The pathway of fluoride-enriched rainwater identified in this study has not previously been recognised in the aetiology of fluorosis. Defluoridation, or accessing an alternative water source, accompanied by modified rainwater harvesting practices, are means by which the prevalence of the disease can be markedly reduced

Rapidly solidified NiAl and FeAl

Melt spinning was used to produce rapidly solidified ribbons of the B2 intermetallics NiAl and FeAl. Both Fe-40Al and Fe-45Al possessed some bend ductility in the as spun condition. The bend ductility of Fe-40Al, Fe-45Al, and equiatomic NiAl increased with subsequent heat treatment. Heat treatment at approximately 0.85 T (sub m) resulted in significant grain growth in equiatomic FeAl and in all the NiAl compositions. Low bend ductility in both FeAl and NiAl generally coincided with intergranular failure, while increased bend ductility was characterized by increasing amounts of transgranular cleavage fracture

Comparison of Dislocation Characterization by Electron Channeling Contrast Imaging and Cross-Correlation Electron Backscattered Diffraction

In this work, the relative capabilities and limitations of electron channeling contrast imaging (ECCI) and cross-correlation electron backscattered diffraction (CC-EBSD) have been assessed by studying the dislocation distributions resulting from nanoindentation in body centered cubic Ta. Qualitative comparison reveals very similar dislocation distributions between the CC-EBSD mapped GNDs and the ECC imaged dislocations. Approximate dislocation densities determined from ECC images compare well to those determined by CC-EBSD. Nevertheless, close examination reveals subtle differences in the details of the distributions mapped by these two approaches. The details of the dislocation Burgers vectors and line directions determined by ECCI have been compared to those determined using CC-EBSD and reveal good agreement

Provinciality and the Art World: The Midland Group 1961- 1977

This paper takes as its focus the Midland Group Gallery in order to first, make a case for the consideration of the geographies of art galleries. Second, highlight the importance of galleries in the context of cultural geographies of the sixties. Third, discuss the role of provinciality in the operation of art worlds. In so doing it explicates one set of geographies surrounding the gallery – those of the local, regional and international networks that connected to produce art works and art space. It reveals how the interactions between places and practices outside of metropolitan and regional hierarchies provides a more nuanced insight into how art worlds operated during the sixties, a period of growing internationalism of art, and how contested definitions of the provincial played an integral role in this. The paper charts the operations of the Midland Group Gallery and the spaces that it occupied to demonstrate how it was representative of a post-war discourse of provincialism and a corresponding re-evaluation of regional cultural activity

Ductility and fracture in B2 FeAl alloys

The mechanical behavior of B2FeAl alloys was studied. Stoichiometric Fe-50Al exhibits totally brittle behavior while iron-rich Fe-40Al yields and displays about 3% total strain. This change in behavior results from large decreases in the yield strength with iron-rich deviations from stoichiometry while the fracture stress remains essentially constant. Single crystal studies show that these yield strength decreases are directly related to decreases in the critical resolved shear stress for a group of zone axes /111/ set of (110) planes slip. This behavior is rationalized in terms of the decrease in antiphase boundary energy with decreasing aluminum content. The addition of boron results in improvements in the mechanical behavior of alloys on the iron-rich side of stoichiometry. These improvements are increased brittle fracture stresses of near-stoichiometric alloys, and enhanced ductility of up to 6% in Fe-40Al. These effects were attributed to increased grain boundary adhesion as reflected by changes in fracture mode from intergranular to transgranular failure. The increases in yield strength, which are observed in both polycrystals and single crystals, result from the quenching in of large numbers of thermal vacancies. Hall-Petch plots show that the cooling rate effects are a direct result of changes in the Hall-Petch intercept/lattice resistance flow

Photography as an act of collaboration

The camera is usually considered to be a passive tool under the control of the operator. This definition implicitly constrains how we use the medium, as well as how we look at – and what we see in – its interpretations of scenes, objects, events and ‘moments’. This text will suggest another way of thinking about – and using – the photographic medium. Based on the evidence of photographic practice (mine and others’), I will suggest that, as a result of the ways in which the medium interprets, juxtaposes and renders the elements in front of the lens, the camera is capable of depicting scenes, events and moments that did not exist and could not have existed until brought into being by the act of photographing them. Accordingly, I will propose that the affective power of many photographs is inseparable from their ‘photographicness’ – and that the photographic medium should therefore be considered as an active collaborator in the creation of uniquely photographic images

A probabilistic analysis of human influence on recent record global mean temperature changes

December 2013 was the 346th consecutive month where global land and ocean average surface temperature exceeded the 20th century monthly average, with February 1985 the last time mean temperature fell below this value. Even given these and other extraordinary statistics, public acceptance of human induced climate change and confidence in the supporting science has declined since 2007. The degree of uncertainty as to whether observed climate changes are due to human activity or are part of natural systems fluctuations remains a major stumbling block to effective adaptation action and risk management. Previous approaches to attribute change include qualitative expert-assessment approaches such as used in IPCC reports and use of 'fingerprinting' methods based on global climate models. Here we develop an alternative approach which provides a rigorous probabilistic statistical assessment of the link between observed climate changes and human activities in a way that can inform formal climate risk assessment. We construct and validate a time series model of anomalous global temperatures to June 2010, using rates of greenhouse gas (GHG) emissions, as well as other causal factors including solar radiation, volcanic forcing and the El Niño Southern Oscillation. When the effect of GHGs is removed, bootstrap simulation of the model reveals that there is less than a one in one hundred thousand chance of observing an unbroken sequence of 304. months (our analysis extends to June 2010) with mean surface temperature exceeding the 20th century average. We also show that one would expect a far greater number of short periods of falling global temperatures (as observed since 1998) if climate change was not occurring. This approach to assessing probabilities of human influence on global temperature could be transferred to other climate variables and extremes allowing enhanced formal risk assessment of climate change. © 2014

Aquaculture in Shared Waters Fact Sheet: Aquaculture in Maine

This series of “Aquaculture in Shared Waters” fact sheets is intended to help fishermen or others in Maine’s coastal communities interested in starting a small-scale aquaculture business as we move towards achieving this potential in a way that is best for our people and the environment

The queer commons: introduction

Ideas and practices of “the commons” have been urgently explored in recent years in attempts to forge alternatives to global capitalism and its privatizing enclosures of social life. Contemporary queer energies have been directed to commons-forming initiatives that sustain queer lives otherwise marginalized by heteronormative society and mainstream LGBTQ politics: from activist provision of social services to the maintenance of networks around queer art, protest, public sex, and bar cultures. However, such instances of queer political action and imagination have rarely been recognized within extant discourses of the commons. This introduction sets out differing genealogies of thought within scholarship on the commons and, building on the work of the performance studies scholar José Esteban Muñoz, it asks how, if at all, it is possible to theorize a queer commons

Livestock, Climate Change and Food Security Conference, 2014

The GRAZPLAN biophysical models were used to simulate the dynamics of coupled climate-soil-grassland-livestock systems at 25 representative farms across Australia’s extensive grazing region under historical and a range of projected climates (4 GCMs at 2030, 2050 and 2070 under SRES A2 scenario). The modelling analysis suggests that primary production of grasslands and livestock are likely to decrease across most of southern Australia’s grazing lands under future climate. By including changes in on-farm management in our models we were able to evaluate the effectiveness of certain adaptation options. Options considered individually were not always effective but a combination of Incremental grassland management and animal genetic improvement options (currently available to graziers) was able to offset productivity declines at cross-regional scale. Through implementation of the optimal combination of adaptation options, profitability across southern Australia was shown to increase by +69%, +84% and +116% in 2030, 2050, and 2070, compared to no adaptation. Optimal systemic adaptation could make addition of $A 2.00 billion in 2030,$A 2.10 billion in 2050, and $A 2.12 billion in 2070 to industry with current farm management. In comparison with historical production, adaptation value to industry would be$A 1.51 billion in 2030, $A 1.51 billion in 2050, and$A 1.12 billion in 2070 (all for a full adaption). If the most-profitable combination of adaptations is used at the baseline instead of the current-practice, then the optimal combinations of grassland adaptations would provide a further increase in operating profitability at 28%, 28%, and 16% of sites in 2030, 2050, and 2070. If the livestock genetic adaptations –cannot be adopted at the present for lack of seed stock – are also included, the optimal systemic adaptations would be more profitable than the alternative baseline including grassland management options at 60%, 56%, and 48% of the locations in 2030, 2050, and 2070. We discuss 3 conceptual issues which arose during our study: (i) how to estimate impact when current management is environmentally infeasible under future climates; (ii) estimating the effectiveness of combinations of adaptations, only some of which are currently available to graziers; and (iii) dealing with the tension between modelling best-practice systems, so that present and future can be compared, versus modelling typical practice for economic valuation