title: Quadrics on complex Riemannian spaces of constant curvature, separation of variables, and the Gaudin magnet

authors: Kalnins, Ernie G.

subjects: Mathematics

abstract: Integrable systems that are connected with orthogonal separation of variables in complex Riemannian spaces of constant curvature are considered herein. An isomorphism with the hyperbolic Gaudin magnet, previously pointed out by one of the authors, extends to coordinates of this type. The complete classification of these separable coordinate systems is provided by means of the corresponding L matrices for the Gaudin magnet. The limiting procedures (or  calculus) which relate various degenerate orthogonal coordinate systems play a crucial role in the classification of all such systems.

text: Quadrics on complex Riemannian spaces of constant curvature, separation of variables, and the Gaudin magnet Integrable systems that are connected with orthogonal separation of variables in complex Riemannian spaces of constant curvature are considered herein. An isomorphism with the hyperbolic Gaudin magnet, previously pointed out by one of the authors, extends to coordinates of this type. The complete classification of these separable coordinate systems is provided by means of the corresponding L matrices for the Gaudin magnet. The limiting procedures (or  calculus) which relate various degenerate orthogonal coordinate systems play a crucial role in the classification of all such systems.

year: 1994-04

title: Soil chronosequences and bacterial communities of the Central Transantarctic Mountains, Antarctica

authors: Scarrow, Joshua William

subjects: Antarctica

abstract: The Beardmore Glacier region of the Central Transantarctic Mountains (CTAM), approximately 600 km south of the McMurdo Dry Valleys (MDV), has been studied to a much lesser extent than the accessible MDV and other regions of the continent. The CTAM were visited in the 2010/2011 austral summer, and two concurrent studies undertaken; these are presented in the form of manuscripts for publication in peer-reviewed journals, as a thesis by publication.
Soil chronosequences in three of the largest ice-free areas (Ong Valley, Mount Achernar, and the Dominion Range), at altitudes above 1600 m along the polar plateau margin, were examined. Transects perpendicular to the current ice edge reveal a gradual increase in soil depth (from 2 cm to > 80 cm to underlying ice), weathering, horizonation, salt content, and a decrease in pH; all of these factors are consistent with increased soil development since time of deglaciation. Such fine scale variation in soil properties, previously overlooked in the CTAM region, cannot be mapped by Soil Taxonomy subgroups, as commonly utilised in Antarctic soil mapping. Patterns of soil thickness, clast abundance and soil chemistry all indicate a bi-modal form of soil development. It is proposed that the soil profile deepens by addition of englacial debris to the subsoil via the sublimation of underlying ice, and the weathering of supraglacial clasts at the soil surface.
The molecular characterization of bacterial communities in CTAM soils is the southernmost culture-independent soil survey to date. Community fingerprinting (ARISA) and 16S rRNA gene pyrosequencing demonstrated significantly different bacterial communities between eight discrete CTAM locations (5 at low altitude near the Ross Ice Shelf coast, 3 near the polar plateau > 1600 m). Abiotic environmental variables, especially those related to long-term exposure of soils to the atmosphere, correlate well with inter-site community variation. Mount Howe, the southernmost soil on the planet (87° S), harbours an extremely low biomass bacterial community, of a fundamentally different composition to all other sites. It appears that observed DNA sequences at Mount Howe are the result of atmospherically deposited bacteria, the soil being unable to support edaphic life due to extreme local climatic conditions.￼
These two studies extend previous knowledge of soil development and distribution, and microbial ecology, to the southernmost extent possible. These observations may serve as important baseline data for monitoring of this fragile system in the face of future and ongoing environmental changes.

text: Soil chronosequences and bacterial communities of the Central Transantarctic Mountains, Antarctica The Beardmore Glacier region of the Central Transantarctic Mountains (CTAM), approximately 600 km south of the McMurdo Dry Valleys (MDV), has been studied to a much lesser extent than the accessible MDV and other regions of the continent. The CTAM were visited in the 2010/2011 austral summer, and two concurrent studies undertaken; these are presented in the form of manuscripts for publication in peer-reviewed journals, as a thesis by publication.
Soil chronosequences in three of the largest ice-free areas (Ong Valley, Mount Achernar, and the Dominion Range), at altitudes above 1600 m along the polar plateau margin, were examined. Transects perpendicular to the current ice edge reveal a gradual increase in soil depth (from 2 cm to > 80 cm to underlying ice), weathering, horizonation, salt content, and a decrease in pH; all of these factors are consistent with increased soil development since time of deglaciation. Such fine scale variation in soil properties, previously overlooked in the CTAM region, cannot be mapped by Soil Taxonomy subgroups, as commonly utilised in Antarctic soil mapping. Patterns of soil thickness, clast abundance and soil chemistry all indicate a bi-modal form of soil development. It is proposed that the soil profile deepens by addition of englacial debris to the subsoil via the sublimation of underlying ice, and the weathering of supraglacial clasts at the soil surface.
The molecular characterization of bacterial communities in CTAM soils is the southernmost culture-independent soil survey to date. Community fingerprinting (ARISA) and 16S rRNA gene pyrosequencing demonstrated significantly different bacterial communities between eight discrete CTAM locations (5 at low altitude near the Ross Ice Shelf coast, 3 near the polar plateau > 1600 m). Abiotic environmental variables, especially those related to long-term exposure of soils to the atmosphere, correlate well with inter-site community variation. Mount Howe, the southernmost soil on the planet (87° S), harbours an extremely low biomass bacterial community, of a fundamentally different composition to all other sites. It appears that observed DNA sequences at Mount Howe are the result of atmospherically deposited bacteria, the soil being unable to support edaphic life due to extreme local climatic conditions.￼
These two studies extend previous knowledge of soil development and distribution, and microbial ecology, to the southernmost extent possible. These observations may serve as important baseline data for monitoring of this fragile system in the face of future and ongoing environmental changes.

year: 2013

title: Caregiver Health Related Quality of Life and Burden When Caring for Children with Traumatic Brain Injury

authors: Rose, Wallis

subjects: Caregiver Burden

abstract: Often family members take on the responsibility of caregiver when another family member sustains a traumatic brain injury (TBI). The caregiving role is a stressful task which may impact negatively upon caregivers’ psychological and physical health. Variables which may contribute to caregiver burden include: caregiver age, educational attainment, income, gender, ethnicity, marital status, supports, time post-injury, and child clinical variables: TBI severity, behavioural functioning and adaptive functioning. The literature varies in its reporting of which areas of health are most affected, and the degree to which sociodemographic and child variables impact upon negative health related quality of life (HRQoL) and burden. To address this the current study explored health outcomes for TBI caregivers using a battery of measures (Medical Study Short Form-36, Hospital Anxiety and Depression Scale, DSM-IV Depression Diagnostic Scale, BAKAS Caregiving Outcomes Scale); questionnaires were also used to collect sociodemographic information and information relating to supports and services used in the rehabilitation of the TBI child. The Behavioural Assessment System for Children was used to collect behavioural and adaptability information from the caregivers about the child. Assessments were carried out at baseline, 1-month, 6-months and 12-months post TBI from a sample of 94 TBI caregivers and at baseline from a sample of 43 Control caregivers.

TBI caregivers experienced poorer overall health and higher levels of depression and were less likely to report positive life changes compared to Control caregivers. Older age and higher income predicted positive life changes. In addition to this higher income predicted better physical and overall health. Ethnicity was found to predict depression with the Māori/‘other ethnicity’ group suffering higher levels of depression. Children’s dysfunctional behaviour was found to predict poorer caregiver health outcomes across several domains; these include physical health, overall health, and depression; while the child’s adaptive functioning was not found to be a predictive factor in any caregiver health domains. New Zealand European and Māori TBI caregivers experienced similar health outcomes and received similar levels of support. However, Māori experienced more positive life changes than New Zealand Europeans. Caregivers’ physical and psychological well-being was found to improve over time, these changes were the greatest between the 1-month and 12-month period.
As a high percentage of children’s TBI’s occur in the home and at school, education aimed at schools and parents to inform of the effects of TBI upon children and families will bring an awareness which may encourage families to seek medical help. In doing so will offer the opportunity to receive or seek support in the initial period post TBI in the hope of reducing the burden for caregivers and producing better health outcomes. Bringing these families into contact with medical services may also help in identifying caregivers at higher risk of poorer health outcomes. Findings of more positive life changes for Māori may suggest cultural ideology is a protective factor in caregiver burden, further investigation may be necessary to understand these cultural differences and how they impact upon the caregiving role.

text: Caregiver Health Related Quality of Life and Burden When Caring for Children with Traumatic Brain Injury Often family members take on the responsibility of caregiver when another family member sustains a traumatic brain injury (TBI). The caregiving role is a stressful task which may impact negatively upon caregivers’ psychological and physical health. Variables which may contribute to caregiver burden include: caregiver age, educational attainment, income, gender, ethnicity, marital status, supports, time post-injury, and child clinical variables: TBI severity, behavioural functioning and adaptive functioning. The literature varies in its reporting of which areas of health are most affected, and the degree to which sociodemographic and child variables impact upon negative health related quality of life (HRQoL) and burden. To address this the current study explored health outcomes for TBI caregivers using a battery of measures (Medical Study Short Form-36, Hospital Anxiety and Depression Scale, DSM-IV Depression Diagnostic Scale, BAKAS Caregiving Outcomes Scale); questionnaires were also used to collect sociodemographic information and information relating to supports and services used in the rehabilitation of the TBI child. The Behavioural Assessment System for Children was used to collect behavioural and adaptability information from the caregivers about the child. Assessments were carried out at baseline, 1-month, 6-months and 12-months post TBI from a sample of 94 TBI caregivers and at baseline from a sample of 43 Control caregivers.

TBI caregivers experienced poorer overall health and higher levels of depression and were less likely to report positive life changes compared to Control caregivers. Older age and higher income predicted positive life changes. In addition to this higher income predicted better physical and overall health. Ethnicity was found to predict depression with the Māori/‘other ethnicity’ group suffering higher levels of depression. Children’s dysfunctional behaviour was found to predict poorer caregiver health outcomes across several domains; these include physical health, overall health, and depression; while the child’s adaptive functioning was not found to be a predictive factor in any caregiver health domains. New Zealand European and Māori TBI caregivers experienced similar health outcomes and received similar levels of support. However, Māori experienced more positive life changes than New Zealand Europeans. Caregivers’ physical and psychological well-being was found to improve over time, these changes were the greatest between the 1-month and 12-month period.
As a high percentage of children’s TBI’s occur in the home and at school, education aimed at schools and parents to inform of the effects of TBI upon children and families will bring an awareness which may encourage families to seek medical help. In doing so will offer the opportunity to receive or seek support in the initial period post TBI in the hope of reducing the burden for caregivers and producing better health outcomes. Bringing these families into contact with medical services may also help in identifying caregivers at higher risk of poorer health outcomes. Findings of more positive life changes for Māori may suggest cultural ideology is a protective factor in caregiver burden, further investigation may be necessary to understand these cultural differences and how they impact upon the caregiving role.

year: 2012