title: Aconitine induces prolonged seizure-like events in rat neocortical brain slices

authors: Voss, Logan J.

subjects: cerebral cortex

abstract: Aconitine effects on the hippocampal slice preparation have been well documented and include acute inhibitory and prolonged excitatory effects. To date, the effect of aconitine on neocortical activity has not been investigated. The aim of this study was to characterise the acute and long term effects of aconitine on cortical local field potential activity. Neocortical slices from juvenile Sprague–Dawley rats were perfused at room temperature with aconitine in normal artificial cerebrospinal fluid (aCSF) (n = 10). Spontaneous local field potential activity was recorded from the somatosensory cortex. The calcium dependence of aconitine-induced activity was investigated using low-calcium aCSF (n = 8). To isolate sodium and N-methyl-d-aspartate (NMDA) channel effects, phenytoin (n = 4) and 2-amino-5-phosphono-pentanoic acid (APV) (n = 6) were co-administered with aconitine, respectively. Aconitine consistently induced a dramatic increase in population “spike” activity after prolonged (89.5 ± 36.6 min) application in normal aCSF. This activity surge was eliminated in low-calcium aCSF and when aconitine was co-administered with phenytoin and APV. The acute effects of aconitine application were variable and included an increase in the frequency of population spikes, appearance of oscillatory seizure-like activity and prolonged bursts of multiunit activity. No acute inhibitory effects were observed. Aconitine has acute and prolonged excitatory effects on neocortical activity. The latter is effected by calcium-dependent mechanisms, in keeping with known effects of aconitine on hippocampal slices. Both sodium and NMDA channels are involved in mediating the calcium-dependent aconitine effects.

text: Aconitine induces prolonged seizure-like events in rat neocortical brain slices Aconitine effects on the hippocampal slice preparation have been well documented and include acute inhibitory and prolonged excitatory effects. To date, the effect of aconitine on neocortical activity has not been investigated. The aim of this study was to characterise the acute and long term effects of aconitine on cortical local field potential activity. Neocortical slices from juvenile Sprague–Dawley rats were perfused at room temperature with aconitine in normal artificial cerebrospinal fluid (aCSF) (n = 10). Spontaneous local field potential activity was recorded from the somatosensory cortex. The calcium dependence of aconitine-induced activity was investigated using low-calcium aCSF (n = 8). To isolate sodium and N-methyl-d-aspartate (NMDA) channel effects, phenytoin (n = 4) and 2-amino-5-phosphono-pentanoic acid (APV) (n = 6) were co-administered with aconitine, respectively. Aconitine consistently induced a dramatic increase in population “spike” activity after prolonged (89.5 ± 36.6 min) application in normal aCSF. This activity surge was eliminated in low-calcium aCSF and when aconitine was co-administered with phenytoin and APV. The acute effects of aconitine application were variable and included an increase in the frequency of population spikes, appearance of oscillatory seizure-like activity and prolonged bursts of multiunit activity. No acute inhibitory effects were observed. Aconitine has acute and prolonged excitatory effects on neocortical activity. The latter is effected by calcium-dependent mechanisms, in keeping with known effects of aconitine on hippocampal slices. Both sodium and NMDA channels are involved in mediating the calcium-dependent aconitine effects.

year: 2008

title: Clustering Relational Data Based on Randomized Propositionalization

authors: Anderson, Grant

subjects: computer science

abstract: Clustering of relational data has so far received a lot less attention than classification of such data. In this paper we investigate a simple approach based on randomized propositionalization, which allows for applying standard clustering algorithms like KMeans to multi-relational data. We describe how random rules are generated and then turned into Boolean-valued features. Clustering generally is not straightforward to evaluate, but preliminary experimental results on a number of standard ILP datasets show promising results. Clusters generated without class information usually agree well with the true class labels of cluster members, i.e. class distributions inside clusters generally differ significantly from the global class distributions. The two-tiered algorithm described shows good scalability due to the randomized nature of the first step and the availability of efficient propositional clustering algorithms for the second step.

text: Clustering Relational Data Based on Randomized Propositionalization Clustering of relational data has so far received a lot less attention than classification of such data. In this paper we investigate a simple approach based on randomized propositionalization, which allows for applying standard clustering algorithms like KMeans to multi-relational data. We describe how random rules are generated and then turned into Boolean-valued features. Clustering generally is not straightforward to evaluate, but preliminary experimental results on a number of standard ILP datasets show promising results. Clusters generated without class information usually agree well with the true class labels of cluster members, i.e. class distributions inside clusters generally differ significantly from the global class distributions. The two-tiered algorithm described shows good scalability due to the randomized nature of the first step and the availability of efficient propositional clustering algorithms for the second step.

year: 2008

title: Older adult education in a New Zealand university: Developments and issues

authors: Findsen, Brian

abstract: This article explores a case study of educational provision for older adults in the context of continuing education in one of New Zealand’s universities. It explains how developments in older adult education at the University of Waikato have reflected historical and cultural trends related to the wider field of adult and community education (ACE) inside a higher education setting. It discusses issues of tertiary education policy and funding, what constitutes curriculum and provision for older adults and how university-community partnerships have shaped opportunities for both indigenous Māori and Pakeha (European) seniors. Government removal of funding to all universities in New Zealand for ACE at the end of 2012 ended formal provision but older adult education groups, formerly supported by the Centre for Continuing Education in the University of Waikato, have assumed a more proactive stance in planning and implementing their own programmes.

text: Older adult education in a New Zealand university: Developments and issues This article explores a case study of educational provision for older adults in the context of continuing education in one of New Zealand’s universities. It explains how developments in older adult education at the University of Waikato have reflected historical and cultural trends related to the wider field of adult and community education (ACE) inside a higher education setting. It discusses issues of tertiary education policy and funding, what constitutes curriculum and provision for older adults and how university-community partnerships have shaped opportunities for both indigenous Māori and Pakeha (European) seniors. Government removal of funding to all universities in New Zealand for ACE at the end of 2012 ended formal provision but older adult education groups, formerly supported by the Centre for Continuing Education in the University of Waikato, have assumed a more proactive stance in planning and implementing their own programmes.

year: 2014