title: Rationale and methodology for a national study of higher education science and engineering learning communities

authors: Coll, Richard K.

subjects: high education

abstract: This paper reports on a major national study of higher education science and engineering learning communities in New Zealand. The scope of the research project along with a description of the methodology and method used in the study together with rationale for the study and research approach adopted are provided here. Details of the theoretical framework and a discussion of paradigm that underpinned the study are presented. A discussion of issues of reliability and validity and measures taken to maximize these also is presented. The paper begins with an overview of the New Zealand compulsory education sector and traces the now multitudinous pathways into higher education nationally. It thus provides a valuable context for this national study of higher education science and engineering learning communities.

text: Rationale and methodology for a national study of higher education science and engineering learning communities This paper reports on a major national study of higher education science and engineering learning communities in New Zealand. The scope of the research project along with a description of the methodology and method used in the study together with rationale for the study and research approach adopted are provided here. Details of the theoretical framework and a discussion of paradigm that underpinned the study are presented. A discussion of issues of reliability and validity and measures taken to maximize these also is presented. The paper begins with an overview of the New Zealand compulsory education sector and traces the now multitudinous pathways into higher education nationally. It thus provides a valuable context for this national study of higher education science and engineering learning communities.

year: 2008

title: The kinetics of the dissociation of dihydroxyacetone dimer in aprotic media

authors: Owens, Adrian

subjects: Dihydroxyacetone

abstract: The dissociation of the dihydroxyacetone (DHA) dimer in mānuka honey has previously been proposed to be the rate determining step in the overall conversion of DHA to methylglyoxal, the agent reported to be responsible for the non-peroxide anti-bacterial activity displayed by mānuka honey.

The ¹H and ¹³C NMR spectra for the DHA dimer and the DHA monomer in DMSO-d6 were assigned using 1D and 2D NMR spectroscopy.

¹H and ¹³C NMR spectroscopy were utilised to investigate the kinetics of the dissociation of the DHA dimer in DMSO-d6, an anhydrous solvent chosen to mimic the dehydrating conditions present in the honey matrix.

Four series of kinetic experiments were conducted, one without catalysis, one with D₂O catalysis, one with CD₃COOD catalysis and one with CD₃COOD/CD₃COOD catalysis. Each of these experiments obtained the equilibrium constant, K and the rate constants k, k₁ and k₋₁ for the dissociation of the DHA dimer under different conditions that may be present in the honey matrix, with the exclusion of the CD₃COOD/CD₃COOD catalysed experiments which were conducted as part of the investigation to determine a proposed reaction mechanism.

Two reaction intermediates were observed in the CD₃COOD catalysed experiments, they were characterised and provided supporting evidence for a proposed acid-catalysed reaction mechanism for the DHA dimer dissociation. The absence of reaction intermediates in the D₂O catalysed experiments provided supporting evidence for a proposed base-catalysed reaction mechanism for the DHA dimer dissociation.

Reaction mechanisms for the DHA dimer dissociation in DMSO-d6 and mānuka honey were proposed based on the findings of previous studies and the findings associated with the kinetic experiments conducted in this study.

text: The kinetics of the dissociation of dihydroxyacetone dimer in aprotic media The dissociation of the dihydroxyacetone (DHA) dimer in mānuka honey has previously been proposed to be the rate determining step in the overall conversion of DHA to methylglyoxal, the agent reported to be responsible for the non-peroxide anti-bacterial activity displayed by mānuka honey.

The ¹H and ¹³C NMR spectra for the DHA dimer and the DHA monomer in DMSO-d6 were assigned using 1D and 2D NMR spectroscopy.

¹H and ¹³C NMR spectroscopy were utilised to investigate the kinetics of the dissociation of the DHA dimer in DMSO-d6, an anhydrous solvent chosen to mimic the dehydrating conditions present in the honey matrix.

Four series of kinetic experiments were conducted, one without catalysis, one with D₂O catalysis, one with CD₃COOD catalysis and one with CD₃COOD/CD₃COOD catalysis. Each of these experiments obtained the equilibrium constant, K and the rate constants k, k₁ and k₋₁ for the dissociation of the DHA dimer under different conditions that may be present in the honey matrix, with the exclusion of the CD₃COOD/CD₃COOD catalysed experiments which were conducted as part of the investigation to determine a proposed reaction mechanism.

Two reaction intermediates were observed in the CD₃COOD catalysed experiments, they were characterised and provided supporting evidence for a proposed acid-catalysed reaction mechanism for the DHA dimer dissociation. The absence of reaction intermediates in the D₂O catalysed experiments provided supporting evidence for a proposed base-catalysed reaction mechanism for the DHA dimer dissociation.

Reaction mechanisms for the DHA dimer dissociation in DMSO-d6 and mānuka honey were proposed based on the findings of previous studies and the findings associated with the kinetic experiments conducted in this study.

year: 2016

title: Evidence for late polynesian colonization of New Zealand: University of Waikato radiocarbon measurements

authors: Hogg, Alan G.

subjects: radiocarbon

abstract: We present radiocarbon determinations for 271 New Zealand archaeological samples measured at the University of Waikato Radiocarbon Dating Laboratory between 1975 and 1995. A discard protocol is applied to the series and the list culled to winnow the acceptable dates from those that may incorporate error. None of the 221 acceptable ¹⁴C determinations older than 600 BP (in the case of terrestrial samples) or 930 BP (in the case of marine and estuarine shell) extends beyond cal AD 1250. This conclusion supports the short chronology model of New Zealand prehistory presented by Anderson (1991).

text: Evidence for late polynesian colonization of New Zealand: University of Waikato radiocarbon measurements We present radiocarbon determinations for 271 New Zealand archaeological samples measured at the University of Waikato Radiocarbon Dating Laboratory between 1975 and 1995. A discard protocol is applied to the series and the list culled to winnow the acceptable dates from those that may incorporate error. None of the 221 acceptable ¹⁴C determinations older than 600 BP (in the case of terrestrial samples) or 930 BP (in the case of marine and estuarine shell) extends beyond cal AD 1250. This conclusion supports the short chronology model of New Zealand prehistory presented by Anderson (1991).

year: 1997