title: Monitoring and identification of airborne fungi at historic locations on Ross Island, Antarctica

authors: Duncan, Shona Margaret

subjects: fungi

abstract: Air sampling in the ‘Heroic Era’ historic huts on Ross Island, Antarctica confirmed fungal presence, viability and winter survival. Cultivation and consensus sequence-based identification of Cladosporium cladosporioides, Pseudeurotium desertorum, Geomyces sp. and Antarctomyces psychrotrophicus demonstrated that they dominated the air environment within the huts. Cadophora sp. and Thebolus sp. were also isolated from the air and identified by morphological characteristics. Viable fungal colony forming units generally dropped in winter 2007 samplings from levels recorded in summer 2006 but were still substantial and greater than observed in summer 2008 and summer 2009 sampling at some locations. Comparing interior to exterior sampling, at the Hut Point and Cape Evans sites, there were more fungi recovered from the air in the interiors but at Cape Royds location, more fungi were recovered from the outside environment, possibly due to the impact of large amounts of organic material from the nearby Adélie penguin rookery. This research reveals airborne fungal biodiversity in summer and winter and demonstrates spores are widespread particularly in the interiors of the huts. Completed conservation efforts appear to have reduced fungal blooms and spores, which should reduce future adverse impacts to wood, textiles, paper and other artefacts so that this important polar heritage can be preserved.

text: Monitoring and identification of airborne fungi at historic locations on Ross Island, Antarctica Air sampling in the ‘Heroic Era’ historic huts on Ross Island, Antarctica confirmed fungal presence, viability and winter survival. Cultivation and consensus sequence-based identification of Cladosporium cladosporioides, Pseudeurotium desertorum, Geomyces sp. and Antarctomyces psychrotrophicus demonstrated that they dominated the air environment within the huts. Cadophora sp. and Thebolus sp. were also isolated from the air and identified by morphological characteristics. Viable fungal colony forming units generally dropped in winter 2007 samplings from levels recorded in summer 2006 but were still substantial and greater than observed in summer 2008 and summer 2009 sampling at some locations. Comparing interior to exterior sampling, at the Hut Point and Cape Evans sites, there were more fungi recovered from the air in the interiors but at Cape Royds location, more fungi were recovered from the outside environment, possibly due to the impact of large amounts of organic material from the nearby Adélie penguin rookery. This research reveals airborne fungal biodiversity in summer and winter and demonstrates spores are widespread particularly in the interiors of the huts. Completed conservation efforts appear to have reduced fungal blooms and spores, which should reduce future adverse impacts to wood, textiles, paper and other artefacts so that this important polar heritage can be preserved.

year: 2010

title: Sub-millennial eruptive recurrence in the silicic Mangaone Subgroup tephra sequence, New Zealand, from Bayesian modelling of zircon double-dating and radiocarbon ages

authors: Danišík, Martin

subjects: Zircon double-dating

abstract: Accurate dating of young (<1 Ma) volcanic eruptions has long been a challenge for modern geochronology given the scarcity of datable mineral phases and low quantities of radiogenic daughter products. Combined U-Th-Pb and (U-Th)/He dating of zircon (i.e., zircon double-dating, ZDD) is a relatively new dating approach that offers a viable option for dating zircon-bearing volcanic and pyroclastic deposits as young as ca. 3 ka, and has a great potential for application in many fields within the Quaternary sciences, including volcanology, palaeoclimatology, and archaeology. In our study, a stratigraphically and spatially well-defined sequence of 13 rhyodacitic to rhyolitic tephra beds e the Mangaone Subgroup (MSg) erupted from the Okataina Volcanic Centre (OVC), is used as a natural laboratory to conduct a crossvalidation experiment in which the ZDD eruption ages are compared with published and new radiocarbon (¹⁴C) eruption ages. These ZDD and ¹⁴C ages are then used together to underpin a Bayesian age model developed (using ChronoModel) to provide new ages for the entire MSg sequence. New ZDDeruption ages of 36.1 ± 4.4, 31.5 ± 5.2, 30.9 ± 5.6, 31.2 ± 4.4 ka BP for four MSg tephras (Units D, I, J, and K, respectively) are statistically indistinguishable from ¹⁴C-based eruption ages. These results validate the feasibility of ZDD to date late Quaternary eruptions accurately. The Bayesian age sequence model provides provides an eruptive geochronology eruptive geochronology for all 13 MSg tephra beds for the first time (and for the stratigraphically-interbedded Taupo-volcano-derived Tahuna tephra, 38.4 ⁺¹.⁷ ₋₁.₄ ka BP), and constrains the beginning of the MSg eruption period to 42.7 ⁺³.⁷₋₃.₅ ka BP (Unit A) and the end to 30.6 ⁺⁰.⁶₋₁.₅ ka BP (Unit L). Thus, the entire MSg sequence was emplaced in ~12,100 years, representing an eruption frequency of one event per ~930 years on average. Our study demonstrates the efficacy of ZDD to yield accurate eruption ages on pyroclastic deposits, highlighting its potential for dating young (<1 Ma) magmatic and eruption events that are difficult to date by other geochronological methods, and also shows that ZDD dates can be integrated with ¹⁴C ages using Bayesian modelling to develop new age models for long sequences of tephra beds, in this case those of the MSg tephras that were deposited during MIS 3. In addition, the U-Th zircon crystallization data revealed distinct U-Th model age spectra for older and younger MSg tephras, providing geochronological evidence for decreasing degree of interconnectedness within the OVC magma reservoir during the MSg eruption period that followed caldera collapse associated with the pre-MSg Rotoiti (Rotoehu) eruption at ca. 45 ka BP.

text: Sub-millennial eruptive recurrence in the silicic Mangaone Subgroup tephra sequence, New Zealand, from Bayesian modelling of zircon double-dating and radiocarbon ages Accurate dating of young (<1 Ma) volcanic eruptions has long been a challenge for modern geochronology given the scarcity of datable mineral phases and low quantities of radiogenic daughter products. Combined U-Th-Pb and (U-Th)/He dating of zircon (i.e., zircon double-dating, ZDD) is a relatively new dating approach that offers a viable option for dating zircon-bearing volcanic and pyroclastic deposits as young as ca. 3 ka, and has a great potential for application in many fields within the Quaternary sciences, including volcanology, palaeoclimatology, and archaeology. In our study, a stratigraphically and spatially well-defined sequence of 13 rhyodacitic to rhyolitic tephra beds e the Mangaone Subgroup (MSg) erupted from the Okataina Volcanic Centre (OVC), is used as a natural laboratory to conduct a crossvalidation experiment in which the ZDD eruption ages are compared with published and new radiocarbon (¹⁴C) eruption ages. These ZDD and ¹⁴C ages are then used together to underpin a Bayesian age model developed (using ChronoModel) to provide new ages for the entire MSg sequence. New ZDDeruption ages of 36.1 ± 4.4, 31.5 ± 5.2, 30.9 ± 5.6, 31.2 ± 4.4 ka BP for four MSg tephras (Units D, I, J, and K, respectively) are statistically indistinguishable from ¹⁴C-based eruption ages. These results validate the feasibility of ZDD to date late Quaternary eruptions accurately. The Bayesian age sequence model provides provides an eruptive geochronology eruptive geochronology for all 13 MSg tephra beds for the first time (and for the stratigraphically-interbedded Taupo-volcano-derived Tahuna tephra, 38.4 ⁺¹.⁷ ₋₁.₄ ka BP), and constrains the beginning of the MSg eruption period to 42.7 ⁺³.⁷₋₃.₅ ka BP (Unit A) and the end to 30.6 ⁺⁰.⁶₋₁.₅ ka BP (Unit L). Thus, the entire MSg sequence was emplaced in ~12,100 years, representing an eruption frequency of one event per ~930 years on average. Our study demonstrates the efficacy of ZDD to yield accurate eruption ages on pyroclastic deposits, highlighting its potential for dating young (<1 Ma) magmatic and eruption events that are difficult to date by other geochronological methods, and also shows that ZDD dates can be integrated with ¹⁴C ages using Bayesian modelling to develop new age models for long sequences of tephra beds, in this case those of the MSg tephras that were deposited during MIS 3. In addition, the U-Th zircon crystallization data revealed distinct U-Th model age spectra for older and younger MSg tephras, providing geochronological evidence for decreasing degree of interconnectedness within the OVC magma reservoir during the MSg eruption period that followed caldera collapse associated with the pre-MSg Rotoiti (Rotoehu) eruption at ca. 45 ka BP.

year: 2020

title: Rising demand for health care: The sustainability of community general practice in the Waikato

authors: Amey, Janet Heather

subjects: General practice

abstract: Community general practice is the cornerstone of New Zealand’s health system, providing first contact health care, care coordination and acting as gatekeeper to expensive hospital services. An ageing population now brings increasing demand for the care provided in general practice, with chronic conditions a major contributing factor. This rising demand, alongside limited workforce capacity will seriously test general practice sustainability. 

These evolving and multifaceted challenges are within the context of long-standing health access and outcome inequalities, particularly for Māori (and more recently the Pacific population) compared with Pākehā. The pursuit of equity is inherent in all health sector strategies, but any meaningful improvement will necessitate wide-ranging reform of current planning, funding and service delivery pathways across traditional sector boundaries.

The sustainability of general practice is about the sustainability and efficiency of the entire health system. To better measure the contribution of general practice care to the system, and improve demand projections, an expanded service use measure was developed, combining services of a general practice nature from Emergency Department and Accident & Medical settings with services delivered in community general practice.

Drawing on approaches from demography, epidemiology and health services research, linked demographic and health administrative data were used to undertake a retrospective, observational study of service use for 235,666 people enrolled with the Pinnacle Midlands Health Network in 2013/14. Using the new expanded measure, service use levels at a locality level were established by age, gender, ethnic group, chronic condition status, practice funding model, high needs status, income and geography of residence.

Significant variation was found in annual average consults (1.0 to 13.4 consults in 2013/14). Statistical analysis identified age, chronic conditions and gender as the key demand drivers responsible for such variation, with regional level results masking significant spatial variation. Where the cost of care was lower, people used a higher level of services in the enrolled practice setting and a lower level outside of it, suggesting the importance of affordable care. Māori and Pacific used significantly fewer services than Pākehā although there was substantial sub-regional variation. Using the expanded measure, the vast majority of care was delivered in the enrolled setting, including for those with chronic conditions.

Demand projections, based on the expanded measure of general practice, out to 2038 show the uneven geography of future demand due to disordered cohort flows and sub-regional population contexts. Overall, demand for services is projected to rise by 34 per cent to almost two million consults across the Waikato District Health Board catchment, with this driven predominantly by services for those aged 65+ years (or 45+ years in Hamilton City, Waikato and Waipa Districts).

Models of care are being transformed as general practices and Primary Health Organisations look to the future. Reorganisation of work roles, improved use of health information and use of emerging health technologies will be required to re-configure general practice in preparation for an ageing future, and to eliminate recalcitrant health inequalities. Real and inclusive collaboration across traditional system boundaries is perhaps the greatest challenge to general practice sustainability.

text: Rising demand for health care: The sustainability of community general practice in the Waikato Community general practice is the cornerstone of New Zealand’s health system, providing first contact health care, care coordination and acting as gatekeeper to expensive hospital services. An ageing population now brings increasing demand for the care provided in general practice, with chronic conditions a major contributing factor. This rising demand, alongside limited workforce capacity will seriously test general practice sustainability. 

These evolving and multifaceted challenges are within the context of long-standing health access and outcome inequalities, particularly for Māori (and more recently the Pacific population) compared with Pākehā. The pursuit of equity is inherent in all health sector strategies, but any meaningful improvement will necessitate wide-ranging reform of current planning, funding and service delivery pathways across traditional sector boundaries.

The sustainability of general practice is about the sustainability and efficiency of the entire health system. To better measure the contribution of general practice care to the system, and improve demand projections, an expanded service use measure was developed, combining services of a general practice nature from Emergency Department and Accident & Medical settings with services delivered in community general practice.

Drawing on approaches from demography, epidemiology and health services research, linked demographic and health administrative data were used to undertake a retrospective, observational study of service use for 235,666 people enrolled with the Pinnacle Midlands Health Network in 2013/14. Using the new expanded measure, service use levels at a locality level were established by age, gender, ethnic group, chronic condition status, practice funding model, high needs status, income and geography of residence.

Significant variation was found in annual average consults (1.0 to 13.4 consults in 2013/14). Statistical analysis identified age, chronic conditions and gender as the key demand drivers responsible for such variation, with regional level results masking significant spatial variation. Where the cost of care was lower, people used a higher level of services in the enrolled practice setting and a lower level outside of it, suggesting the importance of affordable care. Māori and Pacific used significantly fewer services than Pākehā although there was substantial sub-regional variation. Using the expanded measure, the vast majority of care was delivered in the enrolled setting, including for those with chronic conditions.

Demand projections, based on the expanded measure of general practice, out to 2038 show the uneven geography of future demand due to disordered cohort flows and sub-regional population contexts. Overall, demand for services is projected to rise by 34 per cent to almost two million consults across the Waikato District Health Board catchment, with this driven predominantly by services for those aged 65+ years (or 45+ years in Hamilton City, Waikato and Waipa Districts).

Models of care are being transformed as general practices and Primary Health Organisations look to the future. Reorganisation of work roles, improved use of health information and use of emerging health technologies will be required to re-configure general practice in preparation for an ageing future, and to eliminate recalcitrant health inequalities. Real and inclusive collaboration across traditional system boundaries is perhaps the greatest challenge to general practice sustainability.

year: 2018