title: Effect of manganese on grain refinement of Mg–Al based alloys

authors: Cao, Peng

subjects: Magnesium alloys

abstract: Manganese is a grain refiner for high purity Mg–3%Al, Mg–6%Al, Mg–9%Al, and commercial AZ31 (Mg–3%Al–1%Zn) alloys when introduced in the form of an Al–60%Mn master alloy splatter but the use of pure Mn flakes and ALTAB™ Mn75 tablets shows no grain refinement. Long time holding of the melt at 730 °C leads to an increase in grain size. The mechanism is attributed to the presence of an ε-AlMn phase (hexagonal close-packed) in the master alloy splatter.

text: Effect of manganese on grain refinement of Mg–Al based alloys Manganese is a grain refiner for high purity Mg–3%Al, Mg–6%Al, Mg–9%Al, and commercial AZ31 (Mg–3%Al–1%Zn) alloys when introduced in the form of an Al–60%Mn master alloy splatter but the use of pure Mn flakes and ALTAB™ Mn75 tablets shows no grain refinement. Long time holding of the melt at 730 °C leads to an increase in grain size. The mechanism is attributed to the presence of an ε-AlMn phase (hexagonal close-packed) in the master alloy splatter.

year: 2006-06

title: Radiocarbon dating of burials from the Teouma Lapita cemetery, Efate, Vanuatu

authors: Petchey, Fiona

subjects: Calibration

abstract: The discovery of a cemetery at Teouma on the island of Efate in Vanuatu dated to c. 3000 years ago increased the number of early Pacific human remains available for study by nearly an order of magnitude and provided for the first time the ability to study the population dynamics of these early colonizers. The cemetery also provided an opportunity to investigate the chronological development of such a unique site. Although identified short-lived plant materials are favoured for dating archaeological sites, the reality of research in the Pacific region is that such materials are often rare, difficult to identify to species because of an absence of suitable reference collections, and dates on other materials often have greater potential to refine and focus ¹⁴C chronologies that deal with specific research questions. At Teouma, dates on the burial remains themselves are the best means to answer questions about the age and duration of the burial ground. Human bone, however, is one of the most complicated materials to date reliably because of dietary ¹⁴C offsets and bone preservation. One commonly used methodology for calibrating dates on human bone from Pacific human skeletal remains, based on linear interpolation between δ¹³C endpoints and δ¹⁵N values, is complicated by the wide range of foods available (marine, reef, C₄ and C₃), and remains largely untested in Pacific contexts. Radiocarbon dating of the Teouma site, including 36 Lapita-age burials, 5 dates on Conus sp. ring artefacts, and dates from the associated midden deposit, has enabled further evaluation of ¹⁴C dietary offsets and the reliability of calibrated radiocarbon ages on human bone. Bayesian evaluation of the ¹⁴C dates suggests the burial ground was in regular use by c. 2940-2880 cal BP, with the last interments occurring c. 2770-2710 cal BP. A number of burials could indicate possible earlier use, perhaps as early as 3110-2930 cal BP as indicated by the calibrated age range of Burial 57. This cannot be independently substantiated using other radiocarbon dates or context at the present time. Overall, these results suggest the burial ground was in use over a possible 150 to 240 years during the formative phase of Lapita expansion into Remote Oceania.

text: Radiocarbon dating of burials from the Teouma Lapita cemetery, Efate, Vanuatu The discovery of a cemetery at Teouma on the island of Efate in Vanuatu dated to c. 3000 years ago increased the number of early Pacific human remains available for study by nearly an order of magnitude and provided for the first time the ability to study the population dynamics of these early colonizers. The cemetery also provided an opportunity to investigate the chronological development of such a unique site. Although identified short-lived plant materials are favoured for dating archaeological sites, the reality of research in the Pacific region is that such materials are often rare, difficult to identify to species because of an absence of suitable reference collections, and dates on other materials often have greater potential to refine and focus ¹⁴C chronologies that deal with specific research questions. At Teouma, dates on the burial remains themselves are the best means to answer questions about the age and duration of the burial ground. Human bone, however, is one of the most complicated materials to date reliably because of dietary ¹⁴C offsets and bone preservation. One commonly used methodology for calibrating dates on human bone from Pacific human skeletal remains, based on linear interpolation between δ¹³C endpoints and δ¹⁵N values, is complicated by the wide range of foods available (marine, reef, C₄ and C₃), and remains largely untested in Pacific contexts. Radiocarbon dating of the Teouma site, including 36 Lapita-age burials, 5 dates on Conus sp. ring artefacts, and dates from the associated midden deposit, has enabled further evaluation of ¹⁴C dietary offsets and the reliability of calibrated radiocarbon ages on human bone. Bayesian evaluation of the ¹⁴C dates suggests the burial ground was in regular use by c. 2940-2880 cal BP, with the last interments occurring c. 2770-2710 cal BP. A number of burials could indicate possible earlier use, perhaps as early as 3110-2930 cal BP as indicated by the calibrated age range of Burial 57. This cannot be independently substantiated using other radiocarbon dates or context at the present time. Overall, these results suggest the burial ground was in use over a possible 150 to 240 years during the formative phase of Lapita expansion into Remote Oceania.

year: 2014

title: Exploring inequity in access to medications for Type 2 Diabetes in primary care in the Waikato region: Final report

authors: Lawrenson, Ross

abstract: Type 2 diabetes (T2D) is a growing health issue in New Zealand (NZ) that disproportionately affects twice as many Māori as non-Māori and an increasing number of younger people. T2D is associated with a range of microvascular and macrovascular complications, chronic kidney disease and cardiovascular disease (CVD), the latter being the greatest cause of morbidity and mortality in this patient group. However, complications are reduced in patients that have improved glycaemic control. To achieve optimal outcomes and reduce the chance of diabetes-related complications, patients should aim to have their glycated haemoglobin (HbA1c) measurement less than 53 mmol/mol if possible.

Diabetes is primarily managed in primary care, and a number of recent publications suggest that there is considerable inequity in the management of diabetes in New Zealand, particularly for Māori. In an earlier piece of work we have shown that Maori are significantly less likely than non-Maori to be prescribed metformin, but that once prescribed it they are equally likely to have the medication dispensed. This suggests that there may be issues that can be addressed within primary care that are influencing the use of diabetes medications.
Thus, the aim of this small piece of work was to characterise diabetes medication use in a Waikato primary care population, and to report on medication adherence and association with HbA1c levels.

text: Exploring inequity in access to medications for Type 2 Diabetes in primary care in the Waikato region: Final report Type 2 diabetes (T2D) is a growing health issue in New Zealand (NZ) that disproportionately affects twice as many Māori as non-Māori and an increasing number of younger people. T2D is associated with a range of microvascular and macrovascular complications, chronic kidney disease and cardiovascular disease (CVD), the latter being the greatest cause of morbidity and mortality in this patient group. However, complications are reduced in patients that have improved glycaemic control. To achieve optimal outcomes and reduce the chance of diabetes-related complications, patients should aim to have their glycated haemoglobin (HbA1c) measurement less than 53 mmol/mol if possible.

Diabetes is primarily managed in primary care, and a number of recent publications suggest that there is considerable inequity in the management of diabetes in New Zealand, particularly for Māori. In an earlier piece of work we have shown that Maori are significantly less likely than non-Maori to be prescribed metformin, but that once prescribed it they are equally likely to have the medication dispensed. This suggests that there may be issues that can be addressed within primary care that are influencing the use of diabetes medications.
Thus, the aim of this small piece of work was to characterise diabetes medication use in a Waikato primary care population, and to report on medication adherence and association with HbA1c levels.

year: 2021-08-17