title: Synthesis and reactivity of gold(III) complexes containing cycloaurated iminophosphorane ligands

authors: Kilpin, Kelly Joan

subjects: x-ray crystal structures

abstract: Transmetallation reactions of ortho-mercurated iminophosphoranes (2-ClHgC₆H₄)Ph₂P NR with [AuCl₄]⁻ gives new cycloaurated iminophosphorane complexes of gold(III) (2-Cl₂AuC₆H₄)Ph₂P NR [R = (R,S)- or (S)-CHMePh, p-C₆H₄F, tBu], characterised by NMR and IR spectroscopies, ESI mass spectrometry and an X-ray structure determination on the chiral derivative R = (S)-CHMePh. The chloride ligands of these complexes can be readily replaced by the chelating ligands thiosalicylate and catecholate; the resulting derivatives show markedly higher anti-tumour activity versus P388 murine leukaemia cells compared to the parent chloride complexes. Reaction of (2-Cl₂AuC₆H₄)Ph₂P NPh with PPh₃ results in displacement of a chloride ligand giving the cationic complex [(2-Cl(PPh₃)AuC₆H₄)Ph₂P NPh]⁺, indicating that the P N donor is strongly bonded to the gold centre.

text: Synthesis and reactivity of gold(III) complexes containing cycloaurated iminophosphorane ligands Transmetallation reactions of ortho-mercurated iminophosphoranes (2-ClHgC₆H₄)Ph₂P NR with [AuCl₄]⁻ gives new cycloaurated iminophosphorane complexes of gold(III) (2-Cl₂AuC₆H₄)Ph₂P NR [R = (R,S)- or (S)-CHMePh, p-C₆H₄F, tBu], characterised by NMR and IR spectroscopies, ESI mass spectrometry and an X-ray structure determination on the chiral derivative R = (S)-CHMePh. The chloride ligands of these complexes can be readily replaced by the chelating ligands thiosalicylate and catecholate; the resulting derivatives show markedly higher anti-tumour activity versus P388 murine leukaemia cells compared to the parent chloride complexes. Reaction of (2-Cl₂AuC₆H₄)Ph₂P NPh with PPh₃ results in displacement of a chloride ligand giving the cationic complex [(2-Cl(PPh₃)AuC₆H₄)Ph₂P NPh]⁺, indicating that the P N donor is strongly bonded to the gold centre.

year: 2009

title: Evidence and education: The braided roles of research, policy and practice in New Zealand

authors: Alcorn, Noeline

subjects: education

abstract: Calls for educational policy and practice to be evidence-based have become insistent, yet there is ongoing contestation of the purpose and value of educational research. This paper addresses criticism of research from practitioners, politicians and policy makers and from within the research community itself. It examines the impact of the PBRF in New Zealand and the call for evidence-based practice here, in the UK and the US. It draws attention to research studies that are possible models for a principled and methodologically inclusive way forward and develops a set of principles for guiding future development in teacher education and education research.

text: Evidence and education: The braided roles of research, policy and practice in New Zealand Calls for educational policy and practice to be evidence-based have become insistent, yet there is ongoing contestation of the purpose and value of educational research. This paper addresses criticism of research from practitioners, politicians and policy makers and from within the research community itself. It examines the impact of the PBRF in New Zealand and the call for evidence-based practice here, in the UK and the US. It draws attention to research studies that are possible models for a principled and methodologically inclusive way forward and develops a set of principles for guiding future development in teacher education and education research.

year: 2008

title: The influence of harvest frequency and regime on the performance of  Filamentous Algae Nutrient Scrubbers treating agricultural drainage

authors: Waaka, Okeroa

subjects: Filamentous algae nutrient scrubbers

abstract: Filamentous algae nutrient scrubbers (FANS) are ecologically engineered flow-ways that have recently been proposed as a potential on-farm method to treat agricultural drainage in New Zealand. The effectiveness of FANS systems to remove nutrients from polluted waters and to produce algal biomass as a harvestable by-product is heavily influenced by operational parameters. As filamentous algae grow on a flow-way, the thickness of the algal biomass increases and begins to reduce light penetration and nutrient assimilation. Therefore, periodic harvesting of the accumulated algal biomass plays a key role in determining the biomass production and nutrient removal performance of FANS systems. 

The overall aim of this study was to investigate the influence of harvest frequency and harvest regime on biomass productivity and nutrient removal of an outdoor FANS system. The FANS system used in this study consisted of six flow-ways that were split into two sets of triplicate flow-ways named “FULL” and “PARTIAL”. Harvesting of the FULL replicate flow-ways occurred once a week, where algal biomass accumulated along the entirety of the flow-way was collected. Harvesting of the PARTIAL replicate flow-ways occurred twice a week, where the algal biomass was collected in alternate meter sections (a total of 3-metre harvest length every 3 – 3.5 days). 

The increased harvest frequency (3 – 3.5 days) and sectioned harvest regime implemented in the PARTIAL replicate flow-ways significantly improved biomass productivity (3.2 g DW m-2. d) in comparison to the less frequent (7 – 7.5 days) and total harvest regime implemented in the FULL replicate flow-ways (0.9 g DW m-2. d). However, there was no significant difference in nutrient removal rates between the PARTIAL and FULL replicate flow-ways. There is still limited understanding of how operational parameters can be optimized to maximise biomass productivity and nutrient removal in FANS systems on a year-round basis. However, the findings of this study demonstrate that an increased harvest frequency and sectioned harvest regime can improve the biomass yield of filamentous algae grown on an outdoor FANS system during spring to summer months. 

Furthermore, this study has suggested the potential for Māori acceptance of FANS technology and algal biomass use. In person interviews with whanau and iwi members recalled use of algal biomass harvested from rivers and streams as fertilizer for vegetable gardens or bait for eel trapping. Moreover, the literature review and in person interviews highlighted the importance of identifying and using ngā kupu (words and terms) used by Māori to describe freshwater algae. The intergenerational observation and utilization of algae as a resource by Māori may reveal an awareness of biological processes that either differs or compliments a Western Science point of view. Incorporating this knowledge into current water and environmental management practices could be extremely beneficial for improving water quality of streams in Aotearoa New Zealand.

text: The influence of harvest frequency and regime on the performance of  Filamentous Algae Nutrient Scrubbers treating agricultural drainage Filamentous algae nutrient scrubbers (FANS) are ecologically engineered flow-ways that have recently been proposed as a potential on-farm method to treat agricultural drainage in New Zealand. The effectiveness of FANS systems to remove nutrients from polluted waters and to produce algal biomass as a harvestable by-product is heavily influenced by operational parameters. As filamentous algae grow on a flow-way, the thickness of the algal biomass increases and begins to reduce light penetration and nutrient assimilation. Therefore, periodic harvesting of the accumulated algal biomass plays a key role in determining the biomass production and nutrient removal performance of FANS systems. 

The overall aim of this study was to investigate the influence of harvest frequency and harvest regime on biomass productivity and nutrient removal of an outdoor FANS system. The FANS system used in this study consisted of six flow-ways that were split into two sets of triplicate flow-ways named “FULL” and “PARTIAL”. Harvesting of the FULL replicate flow-ways occurred once a week, where algal biomass accumulated along the entirety of the flow-way was collected. Harvesting of the PARTIAL replicate flow-ways occurred twice a week, where the algal biomass was collected in alternate meter sections (a total of 3-metre harvest length every 3 – 3.5 days). 

The increased harvest frequency (3 – 3.5 days) and sectioned harvest regime implemented in the PARTIAL replicate flow-ways significantly improved biomass productivity (3.2 g DW m-2. d) in comparison to the less frequent (7 – 7.5 days) and total harvest regime implemented in the FULL replicate flow-ways (0.9 g DW m-2. d). However, there was no significant difference in nutrient removal rates between the PARTIAL and FULL replicate flow-ways. There is still limited understanding of how operational parameters can be optimized to maximise biomass productivity and nutrient removal in FANS systems on a year-round basis. However, the findings of this study demonstrate that an increased harvest frequency and sectioned harvest regime can improve the biomass yield of filamentous algae grown on an outdoor FANS system during spring to summer months. 

Furthermore, this study has suggested the potential for Māori acceptance of FANS technology and algal biomass use. In person interviews with whanau and iwi members recalled use of algal biomass harvested from rivers and streams as fertilizer for vegetable gardens or bait for eel trapping. Moreover, the literature review and in person interviews highlighted the importance of identifying and using ngā kupu (words and terms) used by Māori to describe freshwater algae. The intergenerational observation and utilization of algae as a resource by Māori may reveal an awareness of biological processes that either differs or compliments a Western Science point of view. Incorporating this knowledge into current water and environmental management practices could be extremely beneficial for improving water quality of streams in Aotearoa New Zealand.

year: 2023