title: CoRes as tools for promoting pedagogical content knowledge  of novice science teachers

authors: Hume, Anne Christine

abstract: Expert science teachers possess a special blend of science content knowledge and pedagogical knowledge for teaching particular science topics to particular groups of students that is built up over time and experience. This form of professional knowledge, termed pedagogical content knowledge (PCK) by Shulman (1987), is topic-specific, unique to each science teacher, and can only be gained through teaching practice. The academic construct of PCK is a recognition that teaching is not simply the transmission of concepts and skills from teacher to students but, rather, a complex and problematic activity that requires many and varied ‘on the spot’ decisions and responses to students’ ongoing learning needs. Much has been written about the nature of PCK since Shulman first introduced the concept in 1987, and its elusive characteristics have led to much debate.

text: CoRes as tools for promoting pedagogical content knowledge  of novice science teachers Expert science teachers possess a special blend of science content knowledge and pedagogical knowledge for teaching particular science topics to particular groups of students that is built up over time and experience. This form of professional knowledge, termed pedagogical content knowledge (PCK) by Shulman (1987), is topic-specific, unique to each science teacher, and can only be gained through teaching practice. The academic construct of PCK is a recognition that teaching is not simply the transmission of concepts and skills from teacher to students but, rather, a complex and problematic activity that requires many and varied ‘on the spot’ decisions and responses to students’ ongoing learning needs. Much has been written about the nature of PCK since Shulman first introduced the concept in 1987, and its elusive characteristics have led to much debate.

year: 2010

title: Development of 2nd Generation Proteinous Bioplastics

authors: van den Berg, Lisa E.

subjects: Bioplastic

abstract: Current environmental and economic concerns surrounding the use of petroleum-based plastics, has led to increased study of renewable natural polymers, such as proteins.  Bloodmeal (BM) is a by-product of the meat industry and large volumes is sold as a low-cost fertilizer or animal feed.  It contains 90 wt% proteins giving it the potential as a renewable precursor for bioplastic production.  The objective of this study was to investigate the use of BM for the production of bioplastics, focusing on the use of chemical additives to facilitate thermoplastic extrusion.
Literature revealed that bioplastics formation from proteins requires denaturation and unfolding using thermal and chemical means, allowing new interactions to form between chains.  Thermoplastic extrusion also requires sufficient chain mobilization, enabling flow through the barrel.  The proteins physiochemical characteristics, plasticizer content and chemical additives will govern its processing behavior, structural and material properties.
Bloodmeal powder was extruded and injection moulded using water, sodium sulfite, sodium dodecyl sulfate (SDS) and urea as additives.  The efficiency of these chemical additives was characterized by: 
 	Processability.  Temperatures between 100 and 125  C produced a successful material, above this excessive covalent cross-linking occurred which reduced chain mobilization.  Sodium sulfite was essential, breaking covalent bonding which allowed chain extension.  The plasticizer content also strongly influenced the processability, while water and urea were essential for improved processing.
 	Consolidation, water absorption and solubility.  It was found that SDS's influence on hydrophobic interactions in combination with sodium sulfites cleavage of covalent cross-links resulted in good consolidation, water absorption and solubility.  Increasing sodium sulfite increased water absorption, indicative of cross-link reduction.  However, high sodium sulfite at low water concentration resulted in a degraded material.  The degraded polymer showed an increase in ordered structures, due to the formation of helical conformations of the short peptide chains.
 	Protein conformation.  It was found that BM was already highly denatured, with considerable amounts of β-structures.  Successful processing with required increased chain mobilization through the reduction of inter- and intra-molecular interactions which led to less ordered structures.
 	Mechanical Properties.  Water was shown to be critical for processing, enhancing the action of sodium sulfite, SDS and urea.  During conditioning, water would evaporate, allowing new intermolecular forces between chains, often resulting in a brittle material.  SDS was essential for consolidation, but excessive amounts could restrict formation of new intermolecular forces during conditioning.  The highly plasticized proteins resulted in ductile materials after conditioning.  Lowering the water, sodium sulfite or urea concentration would result in a brittle material after conditioning.  
Successful processability, consolidation, water absorption, solubility, and mechanical properties were achieved using 3 pphbm sodium sulfite, 60 pphbm water, 3 pphbm SDS and 20 pphbm urea.  This optimal material resulted in increased unordered structures shown by Fourier transform infra-red spectroscopy.  The resulting bioplastic was ductile after conditioning and had a tensile strength of 9.6 MPa and a Young's modulus of 536 MPa, comparable to low-density polyethylene.

text: Development of 2nd Generation Proteinous Bioplastics Current environmental and economic concerns surrounding the use of petroleum-based plastics, has led to increased study of renewable natural polymers, such as proteins.  Bloodmeal (BM) is a by-product of the meat industry and large volumes is sold as a low-cost fertilizer or animal feed.  It contains 90 wt% proteins giving it the potential as a renewable precursor for bioplastic production.  The objective of this study was to investigate the use of BM for the production of bioplastics, focusing on the use of chemical additives to facilitate thermoplastic extrusion.
Literature revealed that bioplastics formation from proteins requires denaturation and unfolding using thermal and chemical means, allowing new interactions to form between chains.  Thermoplastic extrusion also requires sufficient chain mobilization, enabling flow through the barrel.  The proteins physiochemical characteristics, plasticizer content and chemical additives will govern its processing behavior, structural and material properties.
Bloodmeal powder was extruded and injection moulded using water, sodium sulfite, sodium dodecyl sulfate (SDS) and urea as additives.  The efficiency of these chemical additives was characterized by: 
 	Processability.  Temperatures between 100 and 125  C produced a successful material, above this excessive covalent cross-linking occurred which reduced chain mobilization.  Sodium sulfite was essential, breaking covalent bonding which allowed chain extension.  The plasticizer content also strongly influenced the processability, while water and urea were essential for improved processing.
 	Consolidation, water absorption and solubility.  It was found that SDS's influence on hydrophobic interactions in combination with sodium sulfites cleavage of covalent cross-links resulted in good consolidation, water absorption and solubility.  Increasing sodium sulfite increased water absorption, indicative of cross-link reduction.  However, high sodium sulfite at low water concentration resulted in a degraded material.  The degraded polymer showed an increase in ordered structures, due to the formation of helical conformations of the short peptide chains.
 	Protein conformation.  It was found that BM was already highly denatured, with considerable amounts of β-structures.  Successful processing with required increased chain mobilization through the reduction of inter- and intra-molecular interactions which led to less ordered structures.
 	Mechanical Properties.  Water was shown to be critical for processing, enhancing the action of sodium sulfite, SDS and urea.  During conditioning, water would evaporate, allowing new intermolecular forces between chains, often resulting in a brittle material.  SDS was essential for consolidation, but excessive amounts could restrict formation of new intermolecular forces during conditioning.  The highly plasticized proteins resulted in ductile materials after conditioning.  Lowering the water, sodium sulfite or urea concentration would result in a brittle material after conditioning.  
Successful processability, consolidation, water absorption, solubility, and mechanical properties were achieved using 3 pphbm sodium sulfite, 60 pphbm water, 3 pphbm SDS and 20 pphbm urea.  This optimal material resulted in increased unordered structures shown by Fourier transform infra-red spectroscopy.  The resulting bioplastic was ductile after conditioning and had a tensile strength of 9.6 MPa and a Young's modulus of 536 MPa, comparable to low-density polyethylene.

year: 2009

title: Countering gentrification in Tāmaki Makarau: Towards a framework for urban environmental justice

authors: Terruhn, Jessica

abstract: This policy brief argues for urban policies that actively aim to end gentrification.

Gentrification is intimately tied to state-led processes of urban renewal. Though historically understood as the displacement of low-income households as an unfortunate byproduct of socioeconomic and demographic neighbourhood change, contemporary gentrification is constituted by profit-driven investment decisions that erase undervalued neighbourhoods and their communities in the name of urban renewal (variously referred to as redevelopment, regeneration, renaissance, or revitalisation).

These processes of gentrification fundamentally contribute to environmental injustice. At the same time as creating ‘zones of abundance’, neighbourhood regeneration projects simultaneously (re-)create ‘zones of neglect and sacrifice’, which are burdened with environmental risks. As low-income and ethnic minority households are more likely to either reside in or to be displaced into these neighbourhoods, they are disproportionately exposed to environmental risk factors.

Moreover, gentrification enables and legitimises the exclusion of marginalised communities in multiple ways: 1) it devalues existing places and their residents in favour of regeneration, 2) it displaces longtime residents from regenerated neighbourhoods because of increasing property values, and/or 3) it alienates longtime residents as neighbourhood aesthetics, amenities and services change and become unaffordable and/or irrelevant.

As gentrification contributes to low-income households’ experiences of precarity and severs community ties and place attachments, it generates significant costs to personal and community health and wellbeing as well as social cohesion. The recommendations articulated in this brief emphasise the importance of transformative policy solutions that actively counter gentrification.
These include:
• Equitable investment in urban infrastructure
• Prioritising affordable housing
• Ensuring accessible transportation
• Empowering local communities
• Implementing a Te Tiriti o Waitangi approach to policy development

text: Countering gentrification in Tāmaki Makarau: Towards a framework for urban environmental justice This policy brief argues for urban policies that actively aim to end gentrification.

Gentrification is intimately tied to state-led processes of urban renewal. Though historically understood as the displacement of low-income households as an unfortunate byproduct of socioeconomic and demographic neighbourhood change, contemporary gentrification is constituted by profit-driven investment decisions that erase undervalued neighbourhoods and their communities in the name of urban renewal (variously referred to as redevelopment, regeneration, renaissance, or revitalisation).

These processes of gentrification fundamentally contribute to environmental injustice. At the same time as creating ‘zones of abundance’, neighbourhood regeneration projects simultaneously (re-)create ‘zones of neglect and sacrifice’, which are burdened with environmental risks. As low-income and ethnic minority households are more likely to either reside in or to be displaced into these neighbourhoods, they are disproportionately exposed to environmental risk factors.

Moreover, gentrification enables and legitimises the exclusion of marginalised communities in multiple ways: 1) it devalues existing places and their residents in favour of regeneration, 2) it displaces longtime residents from regenerated neighbourhoods because of increasing property values, and/or 3) it alienates longtime residents as neighbourhood aesthetics, amenities and services change and become unaffordable and/or irrelevant.

As gentrification contributes to low-income households’ experiences of precarity and severs community ties and place attachments, it generates significant costs to personal and community health and wellbeing as well as social cohesion. The recommendations articulated in this brief emphasise the importance of transformative policy solutions that actively counter gentrification.
These include:
• Equitable investment in urban infrastructure
• Prioritising affordable housing
• Ensuring accessible transportation
• Empowering local communities
• Implementing a Te Tiriti o Waitangi approach to policy development

year: 2025