title: Pedagogy beyond the gate: The Ngahere Project

authors: Kelly, Janette

abstract: The significance of experiences in nature for children’s learning and development has been expounded by philosophers and educationalists for centuries. In many contemporary early childhood education (ECE) settings, such experiences are highly valued. Nowadays, Froebel’s notion of kindergartens as “children’s gardens” is likely to be complemented by ideas from Steiner, Montessori, Malaguzzi and, more recently, by Scandinavian notions of forest kindergartens (Knight, 2009). In Aotearoa New Zealand the natural environment of the bush or “ngahere”, as it is known in te reo Māori, is also seen as a significant learning environment. This article explores some of the pedagogical issues a group of ECE teachers encountered with children during an action research project looking at teaching and learning possibilities in nature-based settings “beyond the gate”.

text: Pedagogy beyond the gate: The Ngahere Project The significance of experiences in nature for children’s learning and development has been expounded by philosophers and educationalists for centuries. In many contemporary early childhood education (ECE) settings, such experiences are highly valued. Nowadays, Froebel’s notion of kindergartens as “children’s gardens” is likely to be complemented by ideas from Steiner, Montessori, Malaguzzi and, more recently, by Scandinavian notions of forest kindergartens (Knight, 2009). In Aotearoa New Zealand the natural environment of the bush or “ngahere”, as it is known in te reo Māori, is also seen as a significant learning environment. This article explores some of the pedagogical issues a group of ECE teachers encountered with children during an action research project looking at teaching and learning possibilities in nature-based settings “beyond the gate”.

year: 2012

title: Non-linear time domain model of electropermeabilization: Effect of extracellular conductivity and applied electric field parameters

authors: Talele, Sadhana

subjects: electroporation

abstract: This paper describes simulation results obtained from a previously reported numerical model for a single cell exposed to an arbitrary waveform electric field pulse. This paper concentrates on how the efficiency of electroporation related applications can be significantly improved by appropriately adjusting the parameters of applied electric field and conductivity of the external medium, σe. Emphasis is given here on the normalization of the degree of electroporation for a range of cell radii.
The simulated results indicate that it may be difficult for cells of substantially different sizes to be close to uniformly electroporated if surrounded by media with a conductivity higher than around 5*10⁻³ S/m for 100 kHz bipolar pulses, or 0.2 S/m for 1 MHz bipolar pulses. To achieve as normalized as possible electroporation for the radii/size variation required in any particular application, using a lower σe would be preferable. There is, however, a limit to how low the external conductivity can be made, as the applied electric field amplitude must stay within practical limits. Considering 3*10¹³ pores/m² as a nominal pore density N for approximately optimum electroporation, σe could be as low as 0.08 S/m for a 7.5 µm cell radius with a peak electric field of 1.2*10⁵V/m (depending on the pulse shape and frequency). For a 15 µm cell radius, σe could be as low as 0.05 S/m (depending on the pulse shape and frequency). It is seen that the relative difference of N between the two cell sizes investigated is consistently lower for a bipolar sine wave electric field compared to a bipolar square wave electric field, even though the square wave electric field peak amplitude is always lower for an equivalent N.

text: Non-linear time domain model of electropermeabilization: Effect of extracellular conductivity and applied electric field parameters This paper describes simulation results obtained from a previously reported numerical model for a single cell exposed to an arbitrary waveform electric field pulse. This paper concentrates on how the efficiency of electroporation related applications can be significantly improved by appropriately adjusting the parameters of applied electric field and conductivity of the external medium, σe. Emphasis is given here on the normalization of the degree of electroporation for a range of cell radii.
The simulated results indicate that it may be difficult for cells of substantially different sizes to be close to uniformly electroporated if surrounded by media with a conductivity higher than around 5*10⁻³ S/m for 100 kHz bipolar pulses, or 0.2 S/m for 1 MHz bipolar pulses. To achieve as normalized as possible electroporation for the radii/size variation required in any particular application, using a lower σe would be preferable. There is, however, a limit to how low the external conductivity can be made, as the applied electric field amplitude must stay within practical limits. Considering 3*10¹³ pores/m² as a nominal pore density N for approximately optimum electroporation, σe could be as low as 0.08 S/m for a 7.5 µm cell radius with a peak electric field of 1.2*10⁵V/m (depending on the pulse shape and frequency). For a 15 µm cell radius, σe could be as low as 0.05 S/m (depending on the pulse shape and frequency). It is seen that the relative difference of N between the two cell sizes investigated is consistently lower for a bipolar sine wave electric field compared to a bipolar square wave electric field, even though the square wave electric field peak amplitude is always lower for an equivalent N.

year: 2008

title: Walking into the past to explore the future: Utulizing larval densities to measure the effects of two climate change factors, temperature and salinity on Poorohe (common smelt, Retropinna retropinna) abundance in Te Puuaha o Waikato

authors: Robcke, Sidney

subjects: Common smelt

abstract: Poorohe (common smelt, Retropinna retropinna) are a highly valued kai species in Te Puuaha o Waikato (the lower 66 km of the Waikato River). Fisher whaanau have observed changes in the amount Poorohe that are harvested during annual fish harvests. Since Poorohe are particularly vulnerable to environmental changes, whaanau are particularly concerned about the how climate change might impact Poorohe populations. Climate change vulnerability assessments (CCVA) currently exist for several native New Zealand fish freshwater species; however, one does not yet exist for Poorohe. Previous larval distribution studies in the lower Waikato River only sampled as far downstream as Tuakau bridge (approximately 45km from the river mouth). These studies indicated that important spawning habitats likely existed downstream of Tuakau bridge. Temperature increases and saltwater intrusion have been identified as two climate change factors that will likely impact Poorohe in Te Puuaha o Waikato, because ambient temperatures have increased since the industrial revolution and the proximity of the study area to the ocean. A literature review was used to explore the experiences of fisher whaanau through the past, present and how the experiences will continue to change in a changing climate. The effects of temperature and saltwater intrusion on Poorohe populations were explored through replicating the methods of past research carried out in the 1980s and 2010s. Current river temperatures are in the optimal temperature range (12°C - 18°C) for Poorohe spawning. The saltwater wedge was suppressed by the high river flow during the eight-week sampling period, and it is unclear whether saltwater intrusion has an impact on Poorohe spawning. Larval densities did not significantly increase down river, which suggests large spawning habitat is not found downstream of Tuakau bridge. Furthermore, there were no decreases in larval densities in the two saltwater sites. This study has contributed to the available literature necessary to develop a CCVA for Poorohe and explored the cultural heritage of traditionally significant practices in Te Puuaha o Waikato relating to Poorohe.

text: Walking into the past to explore the future: Utulizing larval densities to measure the effects of two climate change factors, temperature and salinity on Poorohe (common smelt, Retropinna retropinna) abundance in Te Puuaha o Waikato Poorohe (common smelt, Retropinna retropinna) are a highly valued kai species in Te Puuaha o Waikato (the lower 66 km of the Waikato River). Fisher whaanau have observed changes in the amount Poorohe that are harvested during annual fish harvests. Since Poorohe are particularly vulnerable to environmental changes, whaanau are particularly concerned about the how climate change might impact Poorohe populations. Climate change vulnerability assessments (CCVA) currently exist for several native New Zealand fish freshwater species; however, one does not yet exist for Poorohe. Previous larval distribution studies in the lower Waikato River only sampled as far downstream as Tuakau bridge (approximately 45km from the river mouth). These studies indicated that important spawning habitats likely existed downstream of Tuakau bridge. Temperature increases and saltwater intrusion have been identified as two climate change factors that will likely impact Poorohe in Te Puuaha o Waikato, because ambient temperatures have increased since the industrial revolution and the proximity of the study area to the ocean. A literature review was used to explore the experiences of fisher whaanau through the past, present and how the experiences will continue to change in a changing climate. The effects of temperature and saltwater intrusion on Poorohe populations were explored through replicating the methods of past research carried out in the 1980s and 2010s. Current river temperatures are in the optimal temperature range (12°C - 18°C) for Poorohe spawning. The saltwater wedge was suppressed by the high river flow during the eight-week sampling period, and it is unclear whether saltwater intrusion has an impact on Poorohe spawning. Larval densities did not significantly increase down river, which suggests large spawning habitat is not found downstream of Tuakau bridge. Furthermore, there were no decreases in larval densities in the two saltwater sites. This study has contributed to the available literature necessary to develop a CCVA for Poorohe and explored the cultural heritage of traditionally significant practices in Te Puuaha o Waikato relating to Poorohe.

year: 2024-11-23