title: Single nucleotide polymorphisms associated with the human electroencephalogram during desflurane anaesthesia

authors: Mulholland, Claire Vignette

subjects: single nucleotide polymorphism

abstract: General anaesthesia is an induced state that enables a person to endure surgical procedures without pain or recollection. There is substantial individual variability in the response to anaesthesia and in order to avoid adverse effects caused by either under- or over-sedation, anaesthetic drug administration must be tailored to suit the individual patient. This requires a means to monitor the depth of general anaesthesia. The electroencephalogram (EEG) records the electrical activity of the brain and enables effects of anaesthetic drugs on brain functioning to be monitored. Quantitative EEG monitors, such as the Bispectral (BIS) index monitor, process the raw EEG and provide a numerical output that is often used to measure the depth of general anaesthesia during surgery. Due to a number of factors including clinical conditions and genetic variability in the EEG, the BIS value can at times be misleading. 

To identify genetic variations associated with EEG phenotypes relevant to anaesthesia monitoring, an association analysis was performed for 34 single nucleotide polymorphisms (SNPs) in a sample of 125 surgical patients undergoing general, gynaecological or orthopaedic surgery. During surgery, patients were anaesthetised with the volatile anaesthetic agent desflurane, the depth of anaesthesia was measured using BIS monitoring and the raw was also EEG recorded. SNP genotyping was performed for 13 SNPs in five candidate genes; SGIP1, GABRA2, CACNA1G, HCN1 and HCN2, using the polymerase chain reaction and restriction fragment length polymorphism analysis. An additional 21 SNPs in 15 genes involved in various inflammatory and other immune-related pathways were genotyped by Sequenom MassARRAY at the Australian Genome Research Facility.
Six SNPs in five different genes were found to be associated with spindle amplitude (SGIP1, GABRA2, HCN1, IL1B and MYD88), and a further five SNPs were associated with either delta frequency (IL10), or end tidal desflurane concentration (ETDC) (CACNA1G, CRP, MYD88 and TGFB1). The strongest associations were identified for a single SNP located in the 3' UTR of MYD88 (rs6853). The rs6853 A/G genotype was associated with higher median spindle amplitude (p = 0.0040) and spindle amplitude relative to ETDC (p = 0.0006), and lower EDTC (p = 0.0095) than the A/A genotype. No rs6853 G/G homozygotes were identified in the study sample.
MYD88 acts as an adaptor protein in the interleukin-1 receptor and toll-like receptor signalling pathways. Within the brain, cytokines are thought to act as neuronal modulators and influence neurotransmitter signalling and ion channel activity. The association of MYD88 with spindle amplitude, in conjunction with IL1B, suggests that cytokines may influence the EEG during general anaesthesia. Thus cytokine mediated regulation of neuronal activity is speculated to underlie the reported associations. All reported effect sizes were small (0.77- to 1.55-fold) and associated genes had four distinct types of function; ion channels, neurotransmitter signalling, endocytosis, and cytokine signalling. This suggests that numerous genes in different pathways, each with a small, possibly additive effect, are involved in regulating the EEG during general anaesthesia.

text: Single nucleotide polymorphisms associated with the human electroencephalogram during desflurane anaesthesia General anaesthesia is an induced state that enables a person to endure surgical procedures without pain or recollection. There is substantial individual variability in the response to anaesthesia and in order to avoid adverse effects caused by either under- or over-sedation, anaesthetic drug administration must be tailored to suit the individual patient. This requires a means to monitor the depth of general anaesthesia. The electroencephalogram (EEG) records the electrical activity of the brain and enables effects of anaesthetic drugs on brain functioning to be monitored. Quantitative EEG monitors, such as the Bispectral (BIS) index monitor, process the raw EEG and provide a numerical output that is often used to measure the depth of general anaesthesia during surgery. Due to a number of factors including clinical conditions and genetic variability in the EEG, the BIS value can at times be misleading. 

To identify genetic variations associated with EEG phenotypes relevant to anaesthesia monitoring, an association analysis was performed for 34 single nucleotide polymorphisms (SNPs) in a sample of 125 surgical patients undergoing general, gynaecological or orthopaedic surgery. During surgery, patients were anaesthetised with the volatile anaesthetic agent desflurane, the depth of anaesthesia was measured using BIS monitoring and the raw was also EEG recorded. SNP genotyping was performed for 13 SNPs in five candidate genes; SGIP1, GABRA2, CACNA1G, HCN1 and HCN2, using the polymerase chain reaction and restriction fragment length polymorphism analysis. An additional 21 SNPs in 15 genes involved in various inflammatory and other immune-related pathways were genotyped by Sequenom MassARRAY at the Australian Genome Research Facility.
Six SNPs in five different genes were found to be associated with spindle amplitude (SGIP1, GABRA2, HCN1, IL1B and MYD88), and a further five SNPs were associated with either delta frequency (IL10), or end tidal desflurane concentration (ETDC) (CACNA1G, CRP, MYD88 and TGFB1). The strongest associations were identified for a single SNP located in the 3' UTR of MYD88 (rs6853). The rs6853 A/G genotype was associated with higher median spindle amplitude (p = 0.0040) and spindle amplitude relative to ETDC (p = 0.0006), and lower EDTC (p = 0.0095) than the A/A genotype. No rs6853 G/G homozygotes were identified in the study sample.
MYD88 acts as an adaptor protein in the interleukin-1 receptor and toll-like receptor signalling pathways. Within the brain, cytokines are thought to act as neuronal modulators and influence neurotransmitter signalling and ion channel activity. The association of MYD88 with spindle amplitude, in conjunction with IL1B, suggests that cytokines may influence the EEG during general anaesthesia. Thus cytokine mediated regulation of neuronal activity is speculated to underlie the reported associations. All reported effect sizes were small (0.77- to 1.55-fold) and associated genes had four distinct types of function; ion channels, neurotransmitter signalling, endocytosis, and cytokine signalling. This suggests that numerous genes in different pathways, each with a small, possibly additive effect, are involved in regulating the EEG during general anaesthesia.

year: 2012

title: Drying characteristics of New Zealand Chestnuts

authors: Biju Cletus, Anila

subjects: none

abstract: Chestnut is a relatively new nut crop to New Zealand and they do grow well in New Zealand conditions. Research to date in New Zealand indicated that New Zealand chestnuts present some unique features compared to chestnuts world wide. The two main unique problems with New Zealand chestnuts are the susceptibility to fungal disease Phomopsis (accounting for 40% loss of nuts at the wholesale markets) and the difficulty in the removal of the inner skin called the pellicle. No systematic drying trials had been performed on New Zealand chestnuts and therefore this research investigated the drying characteristics of New Zealand chestnuts to establish optimum drying conditions. The study also investigated the influence of the shell and pellicle on the drying process and the efficacy of shell and pellicle removal of New Zealand chestnuts under a range of moisture contents since the moisture content is a key factor which determines this efficiency.

The drying trials were carried out at a temperature of 30 C because preliminary studies indicated that higher temperatures resulted in extensive surface deterioration. Experimental drying curves are considered the only adequate preliminary step for determination of drying characteristics of a food material and the curves clearly indicated that there are two distinct falling rate periods. It was concluded that the first falling rate period corresponded to the period during which the surface of the nut reaches equilibrium moisture content and the second falling rate period occurred as the moisture movement from interior of the nut to the surface was the rate limiting factor. Hence a diffusion based model was used to estimate the apparent moisture diffusivity in chestnuts. The average apparent moisture diffusivity in chestnuts obtained at 30 C was 6.21x 10-11m2s-1. The study revealed that the pellicle is the most significant barrier to mass transfer; considerably more so than the shell. The shelling and peeling efficiency of New Zealand chestnuts were carried out at various moisture contents using a custom-made mechanical shelling machine. The mechanical shell removal of New Zealand chestnuts was accomplished with an efficiency of 94% at the desired storage moisture content of 40%. However mechanical pellicle removal of New Zealand chestnuts proved practically impossible although American varieties (Carolina and Revival) exhibited 100% peeling efficiency.

text: Drying characteristics of New Zealand Chestnuts Chestnut is a relatively new nut crop to New Zealand and they do grow well in New Zealand conditions. Research to date in New Zealand indicated that New Zealand chestnuts present some unique features compared to chestnuts world wide. The two main unique problems with New Zealand chestnuts are the susceptibility to fungal disease Phomopsis (accounting for 40% loss of nuts at the wholesale markets) and the difficulty in the removal of the inner skin called the pellicle. No systematic drying trials had been performed on New Zealand chestnuts and therefore this research investigated the drying characteristics of New Zealand chestnuts to establish optimum drying conditions. The study also investigated the influence of the shell and pellicle on the drying process and the efficacy of shell and pellicle removal of New Zealand chestnuts under a range of moisture contents since the moisture content is a key factor which determines this efficiency.

The drying trials were carried out at a temperature of 30 C because preliminary studies indicated that higher temperatures resulted in extensive surface deterioration. Experimental drying curves are considered the only adequate preliminary step for determination of drying characteristics of a food material and the curves clearly indicated that there are two distinct falling rate periods. It was concluded that the first falling rate period corresponded to the period during which the surface of the nut reaches equilibrium moisture content and the second falling rate period occurred as the moisture movement from interior of the nut to the surface was the rate limiting factor. Hence a diffusion based model was used to estimate the apparent moisture diffusivity in chestnuts. The average apparent moisture diffusivity in chestnuts obtained at 30 C was 6.21x 10-11m2s-1. The study revealed that the pellicle is the most significant barrier to mass transfer; considerably more so than the shell. The shelling and peeling efficiency of New Zealand chestnuts were carried out at various moisture contents using a custom-made mechanical shelling machine. The mechanical shell removal of New Zealand chestnuts was accomplished with an efficiency of 94% at the desired storage moisture content of 40%. However mechanical pellicle removal of New Zealand chestnuts proved practically impossible although American varieties (Carolina and Revival) exhibited 100% peeling efficiency.

year: 2007

title: Culturally-Oriented Environmental Identity Transitions: Migrant Indian Teachers in Aotearoa New Zealand Early Childhood Education

authors: Rathore, Devika

abstract: An increasingly multicultural Aotearoa New Zealand early childhood education (ECE) landscape that includes a growing number of migrant teachers forms the context for my doctoral study. In this country, respect for the natural world and kaitiakitanga are integral to the ECE bicultural curriculum framework Te Whāriki (Ministry of Education [MoE], 2017) which is grounded in Indigenous Māori worldviews that acknowledge strong spiritual connections to land and place. The natural environment is considered an integral part of the national identity and early childhood has been recognised as an important stage when Environmental and Sustainability Education should begin.   

Within the context of this superdiverse nation, a significant number of migrant teachers transfer their cultural and environmental knowledge, practice, and identity as they transition into the Aotearoa New Zealand context. This thesis explored migrant Indian teachers’ understandings of their culturally-oriented and negotiated environmental identities. I was keen to examine if the environment might hold different meanings and places in their home (Indian) and host (Aotearoa New Zealand) cultural systems.   

Through this study, insights were gained into migrant Indian teachers’ perceptions of the influence of cultural identity on their environmental identities in Aotearoa New Zealand ECE. A sociocultural theoretical perspective informed this study, drawing primarily on Sauvé’s (2009) model of personal and social development of the self in relation to other humans and the environment. Primary data for this interpretivist study were gathered through in-depth interviews with nine Indian ECE teacher participants. Interviews with their ECE setting managers/head teachers were conducted to support and supplement the teachers’ practices and experiences. The audio-recorded interview data were transcribed and examined using thematic analysis. Observations of teacher participants’ workplaces were used to provide a contextual profile for each of the nine Indian teachers. I also obtained a small number of assessment documents in the form of Learning Stories which the teachers had prepared, to analyse them for cultural and environmental themes and experiences.   

Indian teacher participants’ perceptions of their own culturally-oriented environmental identities highlighted the significance of teachers’ own early childhood environmental experiences and home cultural context influences on their environmental identities. Teacher participants’ perceptions shed light on their cultural and environmental identity transitions and acculturation process. These teachers brought their cultural and environmental identities from their home cultural context and used their cultural lens to interpret the connections between the host cultural context and environmental worldviews.   

The Indian teacher participants perceived close connections between their cultural and environmental identities. At the same time, they recognised cross-cultural connections between their culturally-oriented environmental identities and tikanga Māori (Māori ways of doing including practices, customs and rituals) and te ao Māori (the Māori world). These perceived connections were most evident through the significance of Indian philosophies of spirituality, relationships, belonging, and cultural recognition and exchange in their specific ECE contexts. These connections facilitated teachers’ cultural and environmental identity transitions and had a positive impact on their cultural and environmental teaching practices when supported within the ECE setting and by management/leadership.   

Cultural and environmental transitions for this steadily growing group of migrant teachers require further investigation to facilitate their cultural and environmental participation and acculturation into the Aotearoa New Zealand ECE context. In these ways, the existing cultural, environmental, and sustainability connections within ECE could be strengthened to foster children’s culturally-oriented environmental identities.

text: Culturally-Oriented Environmental Identity Transitions: Migrant Indian Teachers in Aotearoa New Zealand Early Childhood Education An increasingly multicultural Aotearoa New Zealand early childhood education (ECE) landscape that includes a growing number of migrant teachers forms the context for my doctoral study. In this country, respect for the natural world and kaitiakitanga are integral to the ECE bicultural curriculum framework Te Whāriki (Ministry of Education [MoE], 2017) which is grounded in Indigenous Māori worldviews that acknowledge strong spiritual connections to land and place. The natural environment is considered an integral part of the national identity and early childhood has been recognised as an important stage when Environmental and Sustainability Education should begin.   

Within the context of this superdiverse nation, a significant number of migrant teachers transfer their cultural and environmental knowledge, practice, and identity as they transition into the Aotearoa New Zealand context. This thesis explored migrant Indian teachers’ understandings of their culturally-oriented and negotiated environmental identities. I was keen to examine if the environment might hold different meanings and places in their home (Indian) and host (Aotearoa New Zealand) cultural systems.   

Through this study, insights were gained into migrant Indian teachers’ perceptions of the influence of cultural identity on their environmental identities in Aotearoa New Zealand ECE. A sociocultural theoretical perspective informed this study, drawing primarily on Sauvé’s (2009) model of personal and social development of the self in relation to other humans and the environment. Primary data for this interpretivist study were gathered through in-depth interviews with nine Indian ECE teacher participants. Interviews with their ECE setting managers/head teachers were conducted to support and supplement the teachers’ practices and experiences. The audio-recorded interview data were transcribed and examined using thematic analysis. Observations of teacher participants’ workplaces were used to provide a contextual profile for each of the nine Indian teachers. I also obtained a small number of assessment documents in the form of Learning Stories which the teachers had prepared, to analyse them for cultural and environmental themes and experiences.   

Indian teacher participants’ perceptions of their own culturally-oriented environmental identities highlighted the significance of teachers’ own early childhood environmental experiences and home cultural context influences on their environmental identities. Teacher participants’ perceptions shed light on their cultural and environmental identity transitions and acculturation process. These teachers brought their cultural and environmental identities from their home cultural context and used their cultural lens to interpret the connections between the host cultural context and environmental worldviews.   

The Indian teacher participants perceived close connections between their cultural and environmental identities. At the same time, they recognised cross-cultural connections between their culturally-oriented environmental identities and tikanga Māori (Māori ways of doing including practices, customs and rituals) and te ao Māori (the Māori world). These perceived connections were most evident through the significance of Indian philosophies of spirituality, relationships, belonging, and cultural recognition and exchange in their specific ECE contexts. These connections facilitated teachers’ cultural and environmental identity transitions and had a positive impact on their cultural and environmental teaching practices when supported within the ECE setting and by management/leadership.   

Cultural and environmental transitions for this steadily growing group of migrant teachers require further investigation to facilitate their cultural and environmental participation and acculturation into the Aotearoa New Zealand ECE context. In these ways, the existing cultural, environmental, and sustainability connections within ECE could be strengthened to foster children’s culturally-oriented environmental identities.

year: 2024