title: On science, ecology and environmentalism

authors: Tulloch, Lynley

subjects: ecological science

abstract: Using ecological science as a backdrop for this discussion, the author applies Michel Foucault’s historical genealogical strategy to an analysis of the processes through which sustainable development (SD) gained hegemonic acceptance in the West. She analyses some of the ideological mutations that have seen SD emerge from an environmentalist ideology based on ecological science to that of a mainstream market-oriented ideology for global economic development. This involves canvassing the voices of early environmental authors and ecologists, whose ideas such as ‘carrying capacity’, ‘limits to growth’ and ‘finite resources’ have been co-opted by the ‘sustainable development’ movement. It is argued that a discursive political and philosophical conservatism has muted the potential for a truly radical ecological approach.

text: On science, ecology and environmentalism Using ecological science as a backdrop for this discussion, the author applies Michel Foucault’s historical genealogical strategy to an analysis of the processes through which sustainable development (SD) gained hegemonic acceptance in the West. She analyses some of the ideological mutations that have seen SD emerge from an environmentalist ideology based on ecological science to that of a mainstream market-oriented ideology for global economic development. This involves canvassing the voices of early environmental authors and ecologists, whose ideas such as ‘carrying capacity’, ‘limits to growth’ and ‘finite resources’ have been co-opted by the ‘sustainable development’ movement. It is argued that a discursive political and philosophical conservatism has muted the potential for a truly radical ecological approach.

year: 2013

title: Novel polymeric microcapsules for targeted drug delivery

authors: Lin, Yuewen

subjects: polymer

abstract: Microencapsulation is a technology in which small particles or droplets are entrapped by a coating to give the particles with many useful properties. Microcapsules have been used to protect the encapsulated material from the environmental conditions or to release the active agent in a sustained and controlled manner into the surrounding medium. This thesis investigated how to develop a post-ruminal delivery system based on polymeric microencapsulation. A major criterion was to develop microcapsules with reversible switching in response to changes of pH in the in vivo environment so contents could be released. The microcapsules must have a thin shell strong enough to withstand harsh physical conditions and a large hollow centre, which will maximise drug-carrying capacity. Two processes were developed to manufacture pH-responsive microcapsules - conventional interfacial polymerisation with plasma-induced grafting and a novel phase-inversion technique with chemical grafting. This research demonstrated that microcapsules with a porous shell could be manufactured by interfacial polymerisation. Carboxyl groups introduced onto the pores in the microcapsule by plasma-induced graft polymerisation of acrylic acid allowed pore openings to be controlled by the pH change of the environment. Polyamide microcapsules made by interfacial polymerisation had a hollow core and a porous shell with smooth external and rough internal surfaces. Their average diameter of 28 µm decreased with increased stirring rate during polymerisation. Shell porosity could be changed by adjusting the ratio of amine monomers used to form the microcapsule shell. An argon plasma treatment was developed to graft acrylic acid onto the microcapsule surface. Plasma treatment with 90 seconds produced 0.56 mmol/g of grafting extent. The effect of pH on releasing contents from poly(acrylic acid)-grafted microcapsules was investigated using two different sized molecules (vitamin B12 and cytochrome c) to simulate model drugs. Release rate was not significantly affected by molecular size; contents were retained when pH was between 7 and 5.5 and released when pH was between 5 and 3.5. Full release occurred at pH below 3. Further studies showed that micron-sized microcapsules with a hollow core and a thick matrix wall could be made from polycaprolactone, polysulfone and polystyrene. A modified solvent evaporation process reduced shell thickness but the microcapsules still had a non-porous skin. Process parameters such as polymer concentration, temperature, surfactant, solvent composition, stirring speed, processing pressure, and co-polymer additives influenced structure and internal morphology of the microcapsules. Morphological characteristics of the microcapsules strongly depended on the way the coating polymer is precipitated, particularly the non solvent–polymer–solvent interactions. Chemical grafting was not successful for grafting acrylic acid onto the polycaprolactone and polysulfone microcapsules. Polystyrene microcapsules with a hollow core and porous micro-channel shell structure were successfully produced using a novel formulation in a phase-inversion process. The outer skin could be removed by re-dissolving the formed microcapsules in a suitable solvent. Open pores with inter-connected micro-channels on the microcapsule surface can be produced by carefully controlling the time the microcapsules are in the solvent. The microcapsule was functionalised using free radical polymerisation to graft acrylic acid onto its surface. However, these microcapsules did not completely retain their contents at pH 7 and had a slow release profile when pH was decreased. Recommendations are given on how to improve and optimise the process. Polystyrene microcapsules made with a simple and inexpensive phase-inversion technique have potential as a targeted drug delivery system. They could be re-usable, compared to most other systems that degrade or disintegrate, and may have other applications as a carrier to immobilise desired molecules onto the microcapsules. Further investigations to optimise manufacturing polystyrene microcapsules should include: larger scale trials; further investigations, using orthogonal tests with multi-variation analysis to optimise factors affection microcapsule porosity and extent of grafting; identifying an alternative, faster way to analyse pore size; and developing a mathematical model for the release rate.

text: Novel polymeric microcapsules for targeted drug delivery Microencapsulation is a technology in which small particles or droplets are entrapped by a coating to give the particles with many useful properties. Microcapsules have been used to protect the encapsulated material from the environmental conditions or to release the active agent in a sustained and controlled manner into the surrounding medium. This thesis investigated how to develop a post-ruminal delivery system based on polymeric microencapsulation. A major criterion was to develop microcapsules with reversible switching in response to changes of pH in the in vivo environment so contents could be released. The microcapsules must have a thin shell strong enough to withstand harsh physical conditions and a large hollow centre, which will maximise drug-carrying capacity. Two processes were developed to manufacture pH-responsive microcapsules - conventional interfacial polymerisation with plasma-induced grafting and a novel phase-inversion technique with chemical grafting. This research demonstrated that microcapsules with a porous shell could be manufactured by interfacial polymerisation. Carboxyl groups introduced onto the pores in the microcapsule by plasma-induced graft polymerisation of acrylic acid allowed pore openings to be controlled by the pH change of the environment. Polyamide microcapsules made by interfacial polymerisation had a hollow core and a porous shell with smooth external and rough internal surfaces. Their average diameter of 28 µm decreased with increased stirring rate during polymerisation. Shell porosity could be changed by adjusting the ratio of amine monomers used to form the microcapsule shell. An argon plasma treatment was developed to graft acrylic acid onto the microcapsule surface. Plasma treatment with 90 seconds produced 0.56 mmol/g of grafting extent. The effect of pH on releasing contents from poly(acrylic acid)-grafted microcapsules was investigated using two different sized molecules (vitamin B12 and cytochrome c) to simulate model drugs. Release rate was not significantly affected by molecular size; contents were retained when pH was between 7 and 5.5 and released when pH was between 5 and 3.5. Full release occurred at pH below 3. Further studies showed that micron-sized microcapsules with a hollow core and a thick matrix wall could be made from polycaprolactone, polysulfone and polystyrene. A modified solvent evaporation process reduced shell thickness but the microcapsules still had a non-porous skin. Process parameters such as polymer concentration, temperature, surfactant, solvent composition, stirring speed, processing pressure, and co-polymer additives influenced structure and internal morphology of the microcapsules. Morphological characteristics of the microcapsules strongly depended on the way the coating polymer is precipitated, particularly the non solvent–polymer–solvent interactions. Chemical grafting was not successful for grafting acrylic acid onto the polycaprolactone and polysulfone microcapsules. Polystyrene microcapsules with a hollow core and porous micro-channel shell structure were successfully produced using a novel formulation in a phase-inversion process. The outer skin could be removed by re-dissolving the formed microcapsules in a suitable solvent. Open pores with inter-connected micro-channels on the microcapsule surface can be produced by carefully controlling the time the microcapsules are in the solvent. The microcapsule was functionalised using free radical polymerisation to graft acrylic acid onto its surface. However, these microcapsules did not completely retain their contents at pH 7 and had a slow release profile when pH was decreased. Recommendations are given on how to improve and optimise the process. Polystyrene microcapsules made with a simple and inexpensive phase-inversion technique have potential as a targeted drug delivery system. They could be re-usable, compared to most other systems that degrade or disintegrate, and may have other applications as a carrier to immobilise desired molecules onto the microcapsules. Further investigations to optimise manufacturing polystyrene microcapsules should include: larger scale trials; further investigations, using orthogonal tests with multi-variation analysis to optimise factors affection microcapsule porosity and extent of grafting; identifying an alternative, faster way to analyse pore size; and developing a mathematical model for the release rate.

year: 2009

title: Te Whatu Kakahu: Assessment in Kaupapa Maori Early Childhood Practice

authors: Rameka, Lesley Kay

subjects: Kaupapa Maori

abstract: Through the exploration of Kaupapa Māori assessment approaches, I examine the reclaiming and reframing of Māori ways of knowing and being within early childhood practice. Assessment is the vehicle for reclaiming and reframing while Kaupapa Māori theory is the fuel that ignites and drives the vehicle.

The effects of successive education policies remain today with Māori children, and their families continuing to disengage from education and consistently receiving disproportionately lower outcomes, opportunities and benefits. Reclaiming and reframing Māori ways of knowing and being within early childhood assessment thinking and practice is a means of addressing the cultural and educational disparities faced by Māori children within an education system that upholds western cultural and educational superiority, privilege and truths.  Key questions in this process of reclaiming and reframing are: Who has the power to define?  Whose truths are being reflected and how are these truths constructed? 

The metaphor of whatu kākahu or weaving of clothing has been used to frame this thesis. The process has involved weaving the Kaupapa Māori theory elements of conscientisation, resistance, transformative praxis and Māori ways of knowing and being, across and within historical, cultural and educational paradigms and understandings, to fashion assessment kākahu that afford comfort, warmth and flexibility in a contemporary early childhood context. This research case studies the progress of three Māori early childhood services and kōhanga reo towards the development of Kaupapa Māori early childhood assessment understandings and framings (kākahu), that reflect their particular ways of knowing and being, context and aspirations for children. This thesis has been about their assessment journeys. These journeys are a work in progress and that work continues.

A qualitative, Kaupapa Māori research methodology was used to gather, collate and analyse data in this research.  In accordance with Kaupapa Māori research aspirations and expectations, this research focuses on areas of importance and concern for Māori, and involved retrieving space for Māori voices to be heard. This research can be seen as a means of privileging Māori approaches, perspectives and ways of knowing and being in early childhood assessment practice.

Kaupapa Māori assessment is an important agenda for early childhood.   It builds upon Māori philosophical and epistemological understandings that express Māori ways of knowing and being. Kaupapa Māori assessment is able to contribute significantly to children’s learning and potential growth and is an important tool in constructing educational outcomes for Māori children. It is therefore an important agenda for early childhood.

text: Te Whatu Kakahu: Assessment in Kaupapa Maori Early Childhood Practice Through the exploration of Kaupapa Māori assessment approaches, I examine the reclaiming and reframing of Māori ways of knowing and being within early childhood practice. Assessment is the vehicle for reclaiming and reframing while Kaupapa Māori theory is the fuel that ignites and drives the vehicle.

The effects of successive education policies remain today with Māori children, and their families continuing to disengage from education and consistently receiving disproportionately lower outcomes, opportunities and benefits. Reclaiming and reframing Māori ways of knowing and being within early childhood assessment thinking and practice is a means of addressing the cultural and educational disparities faced by Māori children within an education system that upholds western cultural and educational superiority, privilege and truths.  Key questions in this process of reclaiming and reframing are: Who has the power to define?  Whose truths are being reflected and how are these truths constructed? 

The metaphor of whatu kākahu or weaving of clothing has been used to frame this thesis. The process has involved weaving the Kaupapa Māori theory elements of conscientisation, resistance, transformative praxis and Māori ways of knowing and being, across and within historical, cultural and educational paradigms and understandings, to fashion assessment kākahu that afford comfort, warmth and flexibility in a contemporary early childhood context. This research case studies the progress of three Māori early childhood services and kōhanga reo towards the development of Kaupapa Māori early childhood assessment understandings and framings (kākahu), that reflect their particular ways of knowing and being, context and aspirations for children. This thesis has been about their assessment journeys. These journeys are a work in progress and that work continues.

A qualitative, Kaupapa Māori research methodology was used to gather, collate and analyse data in this research.  In accordance with Kaupapa Māori research aspirations and expectations, this research focuses on areas of importance and concern for Māori, and involved retrieving space for Māori voices to be heard. This research can be seen as a means of privileging Māori approaches, perspectives and ways of knowing and being in early childhood assessment practice.

Kaupapa Māori assessment is an important agenda for early childhood.   It builds upon Māori philosophical and epistemological understandings that express Māori ways of knowing and being. Kaupapa Māori assessment is able to contribute significantly to children’s learning and potential growth and is an important tool in constructing educational outcomes for Māori children. It is therefore an important agenda for early childhood.

year: 2012