title: GABAergic compensation in connexin36 knock-out mice evident during low-magnesium seizure-like event activity

authors: Voss, Logan J.

subjects: gap junction

abstract: Gap junctions within the cerebral cortex may facilitate cortical seizure formation by their ability to synchronize electrical activity. To investigate this, one option is to compare wild-type (WT) animals with those lacking the gene for connexin36 (Cx36 KO); the protein that forms neuronal gap junctions between cortical inhibitory cells. However, genetically modified knock-out animals may exhibit compensatory effects; with the risk that observed differences between WT and Cx36 KO animals could be erroneously attributed to Cx36 gap junction effects. In this study we investigated the effect of GABAA-receptor modulation (augmentation with 16 μM etomidate and blockade with 100 μM picrotoxin) on low-magnesium seizure-like events (SLEs) in mouse cortical slices. In WT slices, picrotoxin enhanced both the amplitude (49% increase, p = 0.0006) and frequency (37% increase, p = 0.005) of SLEs; etomidate also enhanced SLE amplitude (18% increase, p = 0.003) but reduced event frequency (25% decrease, p < 0.0001). In Cx36 KO slices, the frequency effects of etomidate and picrotoxin were preserved, but the amplitude responses were abolished. Pre-treatment with the gap junction blocker mefloquin in WT slices did not significantly alter the drug responses, indicating that the reduction in amplitude seen in the Cx36 KO mice was not primarily mediated by their lack of interneuronal gap junctions, but was rather due to pre-existing compensatory changes in these animals. Conclusions from studies comparing seizure characteristics between WT and Cx36 KO mice must be viewed with a degree of caution because of the possible confounding effect of compensatory neurophysiological changes in the genetically modified animals.

text: GABAergic compensation in connexin36 knock-out mice evident during low-magnesium seizure-like event activity Gap junctions within the cerebral cortex may facilitate cortical seizure formation by their ability to synchronize electrical activity. To investigate this, one option is to compare wild-type (WT) animals with those lacking the gene for connexin36 (Cx36 KO); the protein that forms neuronal gap junctions between cortical inhibitory cells. However, genetically modified knock-out animals may exhibit compensatory effects; with the risk that observed differences between WT and Cx36 KO animals could be erroneously attributed to Cx36 gap junction effects. In this study we investigated the effect of GABAA-receptor modulation (augmentation with 16 μM etomidate and blockade with 100 μM picrotoxin) on low-magnesium seizure-like events (SLEs) in mouse cortical slices. In WT slices, picrotoxin enhanced both the amplitude (49% increase, p = 0.0006) and frequency (37% increase, p = 0.005) of SLEs; etomidate also enhanced SLE amplitude (18% increase, p = 0.003) but reduced event frequency (25% decrease, p < 0.0001). In Cx36 KO slices, the frequency effects of etomidate and picrotoxin were preserved, but the amplitude responses were abolished. Pre-treatment with the gap junction blocker mefloquin in WT slices did not significantly alter the drug responses, indicating that the reduction in amplitude seen in the Cx36 KO mice was not primarily mediated by their lack of interneuronal gap junctions, but was rather due to pre-existing compensatory changes in these animals. Conclusions from studies comparing seizure characteristics between WT and Cx36 KO mice must be viewed with a degree of caution because of the possible confounding effect of compensatory neurophysiological changes in the genetically modified animals.

year: 2010

title: Mitigating FMCG transport bottlenecks following an extended Cook Strait ferry outage in Aotearoa New Zealand

authors: Brutsch, Nathan

subjects: fast-moving consumer goods

abstract: This research aims to understand how an extended Cook Strait ferry outage would impact the movement of fast-moving consumer goods (FMCGs) in New Zealand (NZ). The Cook Strait ferries are critical to the country’s freight system, serving as an extension of the main state highway and rail line connecting the North and South Islands. Despite the significance of the ferries, the ferry terminals are aged and lack redundancy, and they could fail in an earthquake. To understand how an extended terminal outage would impact the movement of FMCGs, data was collected through interviews with 30 industry experts in the transport and FMCG sectors, which was thematically analysed and supplemented with quantitative details to further understand the impact. The findings revealed numerous transport bottlenecks would surface in an extended terminal outage and a lack of preparedness in NZ’s freight system. To guide this research, a set of management tools known as the Theory of Constraints Thinking Process were used, enabling sense to be made of NZ’s domestic freight system following a Cook Strait ferry outage. Using these tools to generate visual diagrams, the cause-and-effect relationships between bottlenecks were identified, root causes were uncovered, and potential solutions were explored. Given that it is not a case of if a major disaster will occur, but when, it is important that progress is made towards addressing the identified root causes so that the impact from future disruptions is minimised and goods can continue moving.

text: Mitigating FMCG transport bottlenecks following an extended Cook Strait ferry outage in Aotearoa New Zealand This research aims to understand how an extended Cook Strait ferry outage would impact the movement of fast-moving consumer goods (FMCGs) in New Zealand (NZ). The Cook Strait ferries are critical to the country’s freight system, serving as an extension of the main state highway and rail line connecting the North and South Islands. Despite the significance of the ferries, the ferry terminals are aged and lack redundancy, and they could fail in an earthquake. To understand how an extended terminal outage would impact the movement of FMCGs, data was collected through interviews with 30 industry experts in the transport and FMCG sectors, which was thematically analysed and supplemented with quantitative details to further understand the impact. The findings revealed numerous transport bottlenecks would surface in an extended terminal outage and a lack of preparedness in NZ’s freight system. To guide this research, a set of management tools known as the Theory of Constraints Thinking Process were used, enabling sense to be made of NZ’s domestic freight system following a Cook Strait ferry outage. Using these tools to generate visual diagrams, the cause-and-effect relationships between bottlenecks were identified, root causes were uncovered, and potential solutions were explored. Given that it is not a case of if a major disaster will occur, but when, it is important that progress is made towards addressing the identified root causes so that the impact from future disruptions is minimised and goods can continue moving.

year: 2024

title: Ngā Tuakiri o te Tangata: Being Māori in Early Childhood Education

authors: Rameka, Lesley Kay

abstract: Before the arrival of Europeans in Aotearoa, New Zealand and their subsequent settlement in the 1800s, there was no concept of a Māori identity. Over time, however, as a result of rapid colonisation, Māori became a minority population in New Zealand. Consequently, the term Māori as normal or usual, began to lose its meaning (Webber, 2008), and another meaning began to emerge based on contrasts with the Pākehā settler population. This paper explores the complex and increasingly diverse nature of Māori identities in contemporary Aotearoa/New Zealand, including contemporary early childhood contexts. It discusses the importance of negotiating the terrains of cultural knowledge, values and understandings in order to define what ‘being Māori’ means for teachers and children in an increasingly diverse and complex settings.

text: Ngā Tuakiri o te Tangata: Being Māori in Early Childhood Education Before the arrival of Europeans in Aotearoa, New Zealand and their subsequent settlement in the 1800s, there was no concept of a Māori identity. Over time, however, as a result of rapid colonisation, Māori became a minority population in New Zealand. Consequently, the term Māori as normal or usual, began to lose its meaning (Webber, 2008), and another meaning began to emerge based on contrasts with the Pākehā settler population. This paper explores the complex and increasingly diverse nature of Māori identities in contemporary Aotearoa/New Zealand, including contemporary early childhood contexts. It discusses the importance of negotiating the terrains of cultural knowledge, values and understandings in order to define what ‘being Māori’ means for teachers and children in an increasingly diverse and complex settings.

year: 2016