title: Examining the incorporation of small-scale recurring disasters in emergency management frameworks: Insights from Aotearoa-New Zealand

authors: Tennakoon, Kishani

subjects: Science & Technology

abstract: Risks pertaining to small-scale recurring disasters are generally not considered by emergency management policies. While their impacts are not immediately recognisable, their recurrent manifestation may result in cumulative as well as indirect impacts. Yet, small-scale recurring disasters both remain under-studied in disaster studies and are often not incorporated in disaster planning and policy. This paper contributes to filling this gap in knowledge by investigating the extent to which the emergency management framework of Aotearoa-New Zealand addresses small-scale recurring disasters through a targeted analysis of high-order policy documents. The findings confirm the incomplete reflection of risk identification related to small-scale recurring disasters in the documents analyzed. The paper reaffirms that small-scale recurring disasters should be more explicitly integrated in disaster management policy regimes to eliminate the differences at the lower administrative levels of risk treatment. It also argues for the re-evaluation of short-term solutions (such as insurance coverage) that only improve recovery outcomes temporarily, and the consideration of long-term risk reduction policies for achieving more sustainable recovery outcomes.

text: Examining the incorporation of small-scale recurring disasters in emergency management frameworks: Insights from Aotearoa-New Zealand Risks pertaining to small-scale recurring disasters are generally not considered by emergency management policies. While their impacts are not immediately recognisable, their recurrent manifestation may result in cumulative as well as indirect impacts. Yet, small-scale recurring disasters both remain under-studied in disaster studies and are often not incorporated in disaster planning and policy. This paper contributes to filling this gap in knowledge by investigating the extent to which the emergency management framework of Aotearoa-New Zealand addresses small-scale recurring disasters through a targeted analysis of high-order policy documents. The findings confirm the incomplete reflection of risk identification related to small-scale recurring disasters in the documents analyzed. The paper reaffirms that small-scale recurring disasters should be more explicitly integrated in disaster management policy regimes to eliminate the differences at the lower administrative levels of risk treatment. It also argues for the re-evaluation of short-term solutions (such as insurance coverage) that only improve recovery outcomes temporarily, and the consideration of long-term risk reduction policies for achieving more sustainable recovery outcomes.

year: 2021-10-07

title: Theoretical and experimental investigation of anaesthetic effects in the brain

authors: Noroozbabaee, Leyla

abstract: The main motivation of this study is to develop a better understanding of anaesthetic drug effects on brain dynamics including the paradoxical enhancement of seizure activity by some anaesthetic drugs. This thesis investigates two mean-field descriptions for the effect of general anaesthetic agents on brain activity: the extended Waikato cortical model (WM) and the Hindriks and van Putten (HvP) thalamocortical model. In the standard Waikato model, the population-average neuron voltage is determined by incoming activity at both electrical (gap-junction) and chemical synapses, the latter mediated by AMPA (excitatory) and GABAA (inhibitory) receptors. Here we extend the standard WM by including NMDA (excitatory) and GABAB (inhibitory) synapses. GABAergic anaesthetics, such as propofol, boost cortical inhibition by prolonging the tail of the unitary IPSP (inhibitory postsynaptic potential) at GABAA receptors, while increasing the synaptic gain at the slower-acting GABAB receptors. Dissociative anaesthetics act on NMDA receptors to give a voltage-dependent alteration of excitatory synaptic gain. We find that increasing GABAB or NMDA effect can alter the spatiotemporal dynamics of the standard WM, tending to suppress spatial (Turing) patterns in favour of temporal (Hopf) oscillations. The extended WM predicts increased susceptibility to seizure when GABAB effect is increased, particularly if the GABAergic agent reduces gap-junction diffusion. 
We tested these WM predictions with two biological experiments. We found that potentiation of GABAB receptors in slices of mouse cortical tissue tended to enhance seizure-like activity. However, our in vivo investigation of the effect of closure of gap junctions did not reveal any seizure patterns in mouse EEG signals. 
In the second part of this thesis, we present a detailed analysis of the HvP thalamocortical mean-field model for propofol anaesthesia. While we were able to confirm the Hindriks and van Putten predictions of increases in delta and alpha power at low levels of anaesthetic sedation, we find that for deeper anaesthetic effect, the model jumps from the low-firing state to an extremely high-firing stable state (~250 spikes/s), and remains stuck there even at GABAA prolongations as high as 300% which would be expected to induce full comatose suppression of all firing activity. To overcome this pathological behaviour, we tested two possible modifications: first, eliminating the population-dependent anaesthetic sensitivity (efficacy) of the HvP model; second, incorporating reversal potentials and tuning the excitatory sigmoid parameters defining the mapping from voltage to firing rate. The first modification removes the pathological state, but predicts de-creasing alpha and delta power as drug concentration increases. The second modification predicts induction-emergence hysteresis (drug concentration is higher at induction than at emergence), but the alpha rhythm is lost, being replaced by a dominant delta-band oscillation.

text: Theoretical and experimental investigation of anaesthetic effects in the brain The main motivation of this study is to develop a better understanding of anaesthetic drug effects on brain dynamics including the paradoxical enhancement of seizure activity by some anaesthetic drugs. This thesis investigates two mean-field descriptions for the effect of general anaesthetic agents on brain activity: the extended Waikato cortical model (WM) and the Hindriks and van Putten (HvP) thalamocortical model. In the standard Waikato model, the population-average neuron voltage is determined by incoming activity at both electrical (gap-junction) and chemical synapses, the latter mediated by AMPA (excitatory) and GABAA (inhibitory) receptors. Here we extend the standard WM by including NMDA (excitatory) and GABAB (inhibitory) synapses. GABAergic anaesthetics, such as propofol, boost cortical inhibition by prolonging the tail of the unitary IPSP (inhibitory postsynaptic potential) at GABAA receptors, while increasing the synaptic gain at the slower-acting GABAB receptors. Dissociative anaesthetics act on NMDA receptors to give a voltage-dependent alteration of excitatory synaptic gain. We find that increasing GABAB or NMDA effect can alter the spatiotemporal dynamics of the standard WM, tending to suppress spatial (Turing) patterns in favour of temporal (Hopf) oscillations. The extended WM predicts increased susceptibility to seizure when GABAB effect is increased, particularly if the GABAergic agent reduces gap-junction diffusion. 
We tested these WM predictions with two biological experiments. We found that potentiation of GABAB receptors in slices of mouse cortical tissue tended to enhance seizure-like activity. However, our in vivo investigation of the effect of closure of gap junctions did not reveal any seizure patterns in mouse EEG signals. 
In the second part of this thesis, we present a detailed analysis of the HvP thalamocortical mean-field model for propofol anaesthesia. While we were able to confirm the Hindriks and van Putten predictions of increases in delta and alpha power at low levels of anaesthetic sedation, we find that for deeper anaesthetic effect, the model jumps from the low-firing state to an extremely high-firing stable state (~250 spikes/s), and remains stuck there even at GABAA prolongations as high as 300% which would be expected to induce full comatose suppression of all firing activity. To overcome this pathological behaviour, we tested two possible modifications: first, eliminating the population-dependent anaesthetic sensitivity (efficacy) of the HvP model; second, incorporating reversal potentials and tuning the excitatory sigmoid parameters defining the mapping from voltage to firing rate. The first modification removes the pathological state, but predicts de-creasing alpha and delta power as drug concentration increases. The second modification predicts induction-emergence hysteresis (drug concentration is higher at induction than at emergence), but the alpha rhythm is lost, being replaced by a dominant delta-band oscillation.

year: 2016

title: A Journey Beyond the Bars: Participants' Experiences of Psychological Treatment in a Prison Setting

authors: Terrill, Damian James

subjects: Prison

abstract: This study explored the experiences of high-risk male offenders at varying stages of a prison-based residential rehabilitation programme. Information was elicited by means of 1:1 semi-structured interviews with three adult offenders: one programme completer, one approaching completion and one non-completer. The opinions of three members of unit staff (two programme facilitators and one custodial officer) were also included. Having identified a lack of process-focused qualitative research in the criminological literature, this thesis has attempted to provide an insight into the lived experiences of offenders undergoing a residential rehabilitative intervention. The results are presented through a combined postmodernist, social constructionist discourse. They identify a series of coherent themes which emphasise the importance of numerous contextual, linguistic and communicative variables in dictating the participants’ self-perspectives and engagement with treatment. I will examine in particular, the role of motivation, the importance of the therapeutic bond established between participants and therapists, the relevance of the therapeutic environment, and the impact of both bi-cultural therapy and notions of individual stigmatisation. The overall findings are related to the broader penological literature in order to inspire further experiential analyses of offenders undergoing treatment, and to offer points for consideration in the application of prison-based rehabilitative interventions.

text: A Journey Beyond the Bars: Participants' Experiences of Psychological Treatment in a Prison Setting This study explored the experiences of high-risk male offenders at varying stages of a prison-based residential rehabilitation programme. Information was elicited by means of 1:1 semi-structured interviews with three adult offenders: one programme completer, one approaching completion and one non-completer. The opinions of three members of unit staff (two programme facilitators and one custodial officer) were also included. Having identified a lack of process-focused qualitative research in the criminological literature, this thesis has attempted to provide an insight into the lived experiences of offenders undergoing a residential rehabilitative intervention. The results are presented through a combined postmodernist, social constructionist discourse. They identify a series of coherent themes which emphasise the importance of numerous contextual, linguistic and communicative variables in dictating the participants’ self-perspectives and engagement with treatment. I will examine in particular, the role of motivation, the importance of the therapeutic bond established between participants and therapists, the relevance of the therapeutic environment, and the impact of both bi-cultural therapy and notions of individual stigmatisation. The overall findings are related to the broader penological literature in order to inspire further experiential analyses of offenders undergoing treatment, and to offer points for consideration in the application of prison-based rehabilitative interventions.

year: 2010