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

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

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

Impacts of Climate Change on Livestock Systems: What We Know and What We Don’t Know

Climate changes and the associated increases in atmospheric carbon dioxide concentration are just two of many possible future drivers of change in grassland systems and whilst there are significant uncertainties around these, they are probably more effectively characterised than many other drivers. The challenge for grasslands systems research is not so much trying to precisely predict future climate in the face of unresolvable uncertainty but rather to work with decision-makers to enhance their decisions for a range of possible climates, build their capacity to make sound risk-based and informed decisions and increase the array of options available for adaptation. There are many adaptations possible to address key climate impacts such as increased heat stress, altered pests and disease risk, vegetation change, increased risk of soil degradation and changes in forage quantity, quality and the variability of these. Many of these adaptations are extensions of existing best management practice. However, it is important to explore adaptations that are beyond incremental change to existing systems to be inclusive of more substantial systems change and even transformational changes. There is a need also to consider adaptations beyond the farm scale including in relation to value chains, institutional change and policy development. It is these areas in particular where there are likely to be increasing demands for research

Estudos culturais, cultura visual

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Adapting the Australian grassland & livestock industry to climate change by systemic adaptation: value of adaptation at cross-regional scale

The annual net primary production of temperate grasslands and livestock industries is predicted to decrease in southern Australia with future climate change. By using biophysical modelling, we addressed productivity and profitability relative to geography, enterprise, and time, while considering various grassland management and animal genetic improvement adaptations individually or as combinations. Grazing systems were modeled at a daily time step for a historical reference period and under future climates projected for the SRES A2 scenario. We predicted that single incremental adaptations will not completely avert declines in productivity and profitability; hence, combinations of adaptations are needed. Upscaling over all southern Australia, GCMs and enterprises, the most profitable systemic combination could increase profit by +188%, +196% and +241% in 2030, 2050, and 2070, compared to no adaptation. Changes in meat production were estimated to be +24%, +25%, and +14% in 2030, 2050, and 2070 compared to average production of recent decades. The potential value of adaptation across southern Australia was estimated as 2.7, 2.5, and 2.9 billion AU$ in 2030, 2050, and 2070, respectively. Financially-motivated changes to grazing systems may affect the environmental outcomes which their tradeoffs with adaptation could inhibit the implementation of adaptations. We estimated that a full adaption of optimal systemic adaptation will result in improvement in soil environment and water use efficiency. However, it will lead to greater ruminant CH4 emissions from 70 kg ha-1 yr-1 in baseline to 84, 83, and 75 kg ha-1 yr-1 in 2030, 2050, and 2070. Greater intensification and ruminant CH4 emissions are likely to occur, as increasing future demand of meat has been projected and we predicted that there is capacity for higher and profitable production to respond to this demand. Future food market projections have shown great demand to meat even under higher price effects

Football as an Intramural Sport in the Junior High School

It was the purpose of this paper (1) to study the objectives of intramural sports for youth, (2) to show that football, played as an intramural sport stressing physical conditioning, fundamental skills, and game competition can be of great value to boys who are not qualified for the varsity team, and (3) to suggest methods and plans for operating an intramural football program in a junior high school