title: Subthreshold dynamics of a single neuron from a Hamiltonian perspective

authors: Wilson, Marcus T.

subjects: brain models

abstract: We use Hamilton's equations of classical mechanics to investigate the behavior of a cortical neuron on the approach to an action potential. We use a two-component dynamic model of a single neuron, due to Wilson, with added noise inputs. We derive a Lagrangian for the system, from which we construct Hamilton's equations. The conjugate momenta are found to be linear combinations of the noise input to the system. We use this approach to consider theoretically and computationally the most likely manner in which such a modeled neuron approaches a firing event. We find that the firing of a neuron is a result of a drop in inhibition, due to a temporary increase in negative bias of the mean noise input to the inhibitory control equation. Moreover, we demonstrate through theory and simulation that, on average, the bias in the noise increases in an exponential manner on the approach to an action potential. In the Hamiltonian description, an action potential can therefore be considered a result of the exponential growth of the conjugate momenta variables pulling the system away from its equilibrium state, into a nonlinear regime.

text: Subthreshold dynamics of a single neuron from a Hamiltonian perspective We use Hamilton's equations of classical mechanics to investigate the behavior of a cortical neuron on the approach to an action potential. We use a two-component dynamic model of a single neuron, due to Wilson, with added noise inputs. We derive a Lagrangian for the system, from which we construct Hamilton's equations. The conjugate momenta are found to be linear combinations of the noise input to the system. We use this approach to consider theoretically and computationally the most likely manner in which such a modeled neuron approaches a firing event. We find that the firing of a neuron is a result of a drop in inhibition, due to a temporary increase in negative bias of the mean noise input to the inhibitory control equation. Moreover, we demonstrate through theory and simulation that, on average, the bias in the noise increases in an exponential manner on the approach to an action potential. In the Hamiltonian description, an action potential can therefore be considered a result of the exponential growth of the conjugate momenta variables pulling the system away from its equilibrium state, into a nonlinear regime.

year: 2008

title: School curriculum and outdoor education. Part 1: Early childhood and primary school

authors: Cosgriff, Marg

abstract: Th is chapter explores broad possibilities for learning outdoors in formal education contexts.
In part one we set the scene for the chapter by examining contemporary curricula in the early childhood and school sectors. National curriculum documents are introduced to look at the vision and ‘big picture’ direction they suggest for outdoor education practice. Attention then turns to consider outdoor education initiatives in early childhood settings, with examples drawn from programmes to illustrate the unique and practical ways in which they ‘walk the talk’ of student-centred, bicultural, holistic, and sustainable approaches. Th e discussion moves to consider the opportunities the primary school context aff ords for outdoor education that deliberately focuses on students’ relationships with the outdoor places they inhabit. Examples such as the well established Enviro-Schools programme and integrated units of learning are outlined to illustrate what we consider to be the heart of this forward looking outdoor education.
In part two, the focus moves to outdoor education in the secondary school. While the distinctiveness of the secondary setting with its associated compartmentalised, subject-focused curriculum is initially acknowledged, the focus broadens to consider a range of factors or enablers of innovative outdoor education practice. As with part one, examples of ‘real’ curricula, co-curricula, and extra-curricula programmes are featured. Th ese examples provide powerful guides for outdoor educators seeking to rethink, refi ne and reshape their students’ outdoor learning experiences in ways that enable them to enjoy, understand, and act for the environments in which they live and move. In sum, this chapter explores a vision of a more sustainable outdoor education future.

text: School curriculum and outdoor education. Part 1: Early childhood and primary school Th is chapter explores broad possibilities for learning outdoors in formal education contexts.
In part one we set the scene for the chapter by examining contemporary curricula in the early childhood and school sectors. National curriculum documents are introduced to look at the vision and ‘big picture’ direction they suggest for outdoor education practice. Attention then turns to consider outdoor education initiatives in early childhood settings, with examples drawn from programmes to illustrate the unique and practical ways in which they ‘walk the talk’ of student-centred, bicultural, holistic, and sustainable approaches. Th e discussion moves to consider the opportunities the primary school context aff ords for outdoor education that deliberately focuses on students’ relationships with the outdoor places they inhabit. Examples such as the well established Enviro-Schools programme and integrated units of learning are outlined to illustrate what we consider to be the heart of this forward looking outdoor education.
In part two, the focus moves to outdoor education in the secondary school. While the distinctiveness of the secondary setting with its associated compartmentalised, subject-focused curriculum is initially acknowledged, the focus broadens to consider a range of factors or enablers of innovative outdoor education practice. As with part one, examples of ‘real’ curricula, co-curricula, and extra-curricula programmes are featured. Th ese examples provide powerful guides for outdoor educators seeking to rethink, refi ne and reshape their students’ outdoor learning experiences in ways that enable them to enjoy, understand, and act for the environments in which they live and move. In sum, this chapter explores a vision of a more sustainable outdoor education future.

year: 2011

title: Challenges Faced – Implications for Policy: The Everyday Lives of Eastern European Women in New Zealand

authors: Ember, Adrienna

subjects: everyday life

abstract: This study explored the everyday lives, aspirations, and coping strategies of seven Eastern European immigrant women in New Zealand who came from Bulgaria, the former Eastern Germany, Hungary, Poland, Romania, Serbia, and Slovakia. The answers to the research questions aimed to contribute to the deconstruction of the invisibility and marginalisation of these women in New Zealand.
Guided by the philosophies of Kaupapa Māori Research; the theory of Human Wellbeing; and the theory of Positive Psychology, and using the methods of narrative inquiry, three interviews were conducted with each participant. The focus of the first interviews was to learn about the everyday lives of research participants in their countries of origin. The second interview explored the reasons of relocation to New Zealand, the settlement process, and how women re-established their lives in their new locations. In the final interviews women talked about their current everyday lives and their plans for the future.
Interviews were recorded and summarised in interview summary reports which research participants modified in collaboration with the researcher until a final version was achieved. In addition, women participated in two focus group sessions. The first session was devoted to establish connections among the participants and allow themes to emerge from their conversations. The second group session aimed to explore areas women struggled with in their lives the most: relationships and employment opportunities.
The study yielded contributions to the research topic, to the acculturation literature, and to the design of research with migrants. Firstly, it revealed both negative and positive aspects of the participants’ everyday lives and highlighted some under-researched cultural differences from the mainstream population.
Women highlighted as an important cultural difference their strong preference for straightforward communication which was often experienced as offensive and blatant by local New Zealanders. Research participants critiqued the necessity of networking to obtain jobs in New Zealand which is a clear obstacle for a newly arrived migrant.
This study also highlighted how the acculturation process is more individual and complex than conventional models have sought to explain. While traditional acculturation literature suggests that migrants go through some common patterns during their settlement that ideally leads to their assimilation to the host culture, in this research not all migrant women intended to assimilate. Indeed, those with a stronger wish to become part of the host culture reported more disappointments than those who embraced their cultural otherness as a positive aspect and did not mind reminding different from the dominant Pakeha culture.
Finally, for migrant studies a less common research design was applied by using the Kaupapa Māori framework. This philosophy proposes a research process that empowers immigrants to voice their needs and strengthen them as agents of their lives beyond the research process. While two strength based theories were used for data interpretation (the 3-D model of the Human Wellbeing Theory and the PERMA model of Positive Psychology), the data analysis revealed that both models showed some limitations by failing to incorporate the dimension of spiritual and physical wellbeing within their domains.

text: Challenges Faced – Implications for Policy: The Everyday Lives of Eastern European Women in New Zealand This study explored the everyday lives, aspirations, and coping strategies of seven Eastern European immigrant women in New Zealand who came from Bulgaria, the former Eastern Germany, Hungary, Poland, Romania, Serbia, and Slovakia. The answers to the research questions aimed to contribute to the deconstruction of the invisibility and marginalisation of these women in New Zealand.
Guided by the philosophies of Kaupapa Māori Research; the theory of Human Wellbeing; and the theory of Positive Psychology, and using the methods of narrative inquiry, three interviews were conducted with each participant. The focus of the first interviews was to learn about the everyday lives of research participants in their countries of origin. The second interview explored the reasons of relocation to New Zealand, the settlement process, and how women re-established their lives in their new locations. In the final interviews women talked about their current everyday lives and their plans for the future.
Interviews were recorded and summarised in interview summary reports which research participants modified in collaboration with the researcher until a final version was achieved. In addition, women participated in two focus group sessions. The first session was devoted to establish connections among the participants and allow themes to emerge from their conversations. The second group session aimed to explore areas women struggled with in their lives the most: relationships and employment opportunities.
The study yielded contributions to the research topic, to the acculturation literature, and to the design of research with migrants. Firstly, it revealed both negative and positive aspects of the participants’ everyday lives and highlighted some under-researched cultural differences from the mainstream population.
Women highlighted as an important cultural difference their strong preference for straightforward communication which was often experienced as offensive and blatant by local New Zealanders. Research participants critiqued the necessity of networking to obtain jobs in New Zealand which is a clear obstacle for a newly arrived migrant.
This study also highlighted how the acculturation process is more individual and complex than conventional models have sought to explain. While traditional acculturation literature suggests that migrants go through some common patterns during their settlement that ideally leads to their assimilation to the host culture, in this research not all migrant women intended to assimilate. Indeed, those with a stronger wish to become part of the host culture reported more disappointments than those who embraced their cultural otherness as a positive aspect and did not mind reminding different from the dominant Pakeha culture.
Finally, for migrant studies a less common research design was applied by using the Kaupapa Māori framework. This philosophy proposes a research process that empowers immigrants to voice their needs and strengthen them as agents of their lives beyond the research process. While two strength based theories were used for data interpretation (the 3-D model of the Human Wellbeing Theory and the PERMA model of Positive Psychology), the data analysis revealed that both models showed some limitations by failing to incorporate the dimension of spiritual and physical wellbeing within their domains.

year: 2016