title: 35,000 years of hydrological variability in northern New Zealand from speleothem magnetism

authors: Fox, Bethany

abstract: Speleothem magnetism is the study of the origin and geo-enviromagnetic significance of magnetic minerals in speleothems. Allogenic magnetic particles are transported to speleothem sites from soils and sediments by hydrological and aeolian processes. The two main hydrologic transport mechanisms are infiltration through karst porosity and entrainment in fluvial transport. Cave ventilation constitutes a third input mechanism, supplying aeolian particulate matter. Water percolating from the surface tends to discriminate towards smaller, pedogenic magnetic mineral grains, whereas fluvial and aeolian processes discriminate towards larger, non-pedogenic (lithogenic) grains. If magnetic populations in speleothem calcite samples can be thoroughly characterised, individual components can be recognised which relate to specific processes of transport, and the contributions of these components can be used to reconstruct variability in the strength of these processes over the depositional period of the speleothem.

text: 35,000 years of hydrological variability in northern New Zealand from speleothem magnetism Speleothem magnetism is the study of the origin and geo-enviromagnetic significance of magnetic minerals in speleothems. Allogenic magnetic particles are transported to speleothem sites from soils and sediments by hydrological and aeolian processes. The two main hydrologic transport mechanisms are infiltration through karst porosity and entrainment in fluvial transport. Cave ventilation constitutes a third input mechanism, supplying aeolian particulate matter. Water percolating from the surface tends to discriminate towards smaller, pedogenic magnetic mineral grains, whereas fluvial and aeolian processes discriminate towards larger, non-pedogenic (lithogenic) grains. If magnetic populations in speleothem calcite samples can be thoroughly characterised, individual components can be recognised which relate to specific processes of transport, and the contributions of these components can be used to reconstruct variability in the strength of these processes over the depositional period of the speleothem.

year: 2018

title: An invalidation test for predictive models

authors: Bardsley, W. Earl

subjects: model invalidation

abstract: The standard means of establishing predictive ability in hydrological models is by finding how well predictions match independent validation data. This matching may not be particularly good in some situations such as seasonal flow forecasting and the question arises as to whether a given model has any predictive capacity. A model-independent significance test of the presence of predictive ability is proposed through random permutations of the predicted values. The null hypothesis of no model predictive ability is accepted if there is a sufficiently high probability that a random reordering of the predicted values will yield a better fit to the validation data. The test can achieve significance even with poor model predictions and its value is for invalidating bad models rather than verifying good models as suitable for application. Some preliminary applications suggest that test outcomes will often be similar at the 0.05 level for standard fit measures using absolute or squared residuals. In addition to hydrological application, the test may also find use as a base quality control measure for predictive models generally.

text: An invalidation test for predictive models The standard means of establishing predictive ability in hydrological models is by finding how well predictions match independent validation data. This matching may not be particularly good in some situations such as seasonal flow forecasting and the question arises as to whether a given model has any predictive capacity. A model-independent significance test of the presence of predictive ability is proposed through random permutations of the predicted values. The null hypothesis of no model predictive ability is accepted if there is a sufficiently high probability that a random reordering of the predicted values will yield a better fit to the validation data. The test can achieve significance even with poor model predictions and its value is for invalidating bad models rather than verifying good models as suitable for application. Some preliminary applications suggest that test outcomes will often be similar at the 0.05 level for standard fit measures using absolute or squared residuals. In addition to hydrological application, the test may also find use as a base quality control measure for predictive models generally.

year: 2007

title: Characteristics and outcomes of patients with small cell lung cancer - findings from a New Zealand SACT database

authors: Lawrenson, Ross

abstract: Background Small Cell Lung Cancer (SCLC) SCLC generally presents late and is treated with systemic anti-cancer treatment (SACT). Māori are over represented in Lung Cancer statistics but disparities between Māori and non-Māori in patterns of care and survival from SCLC have not been previously reported. 
Methods We used the custom-built SACT database collected by the Oncology Department at Waikato Hospital NZ, which recorded comprehensive lung cancer patient factors and SACT regimens from 2000 to 2021. We reported summary statistics to review the treatment by ethnicity, explored Kaplan Meier all-cause survival of patients, and estimated the unadjusted and adjusted odds ratios of surviving 12 months. 
Results 742 patients with SCLC were included in this study, with 43% identified as Māori. Approximately 75% of patients received SACT, and there was no difference in the uptake of SACT between Māori and non-Māori. The median survival for SCLC was 8.5 months. After adjustment, patients treated with carboplatin plus etoposide (with/without durvalumab) or cisplatin plus etoposide were 1.5 times or 4.9 times respectively more likely to survive 12 months than those without a SACT regimen.
Conclusion There was no significant evidence of disparities in patterns of care and outcomes between Māori and non-Māori with SCLC. Carboplatin/cisplatin in combination with etoposide remained the primary first line SACT regimen for patients with SCLC in this New Zealand cancer treatment centre.

text: Characteristics and outcomes of patients with small cell lung cancer - findings from a New Zealand SACT database Background Small Cell Lung Cancer (SCLC) SCLC generally presents late and is treated with systemic anti-cancer treatment (SACT). Māori are over represented in Lung Cancer statistics but disparities between Māori and non-Māori in patterns of care and survival from SCLC have not been previously reported. 
Methods We used the custom-built SACT database collected by the Oncology Department at Waikato Hospital NZ, which recorded comprehensive lung cancer patient factors and SACT regimens from 2000 to 2021. We reported summary statistics to review the treatment by ethnicity, explored Kaplan Meier all-cause survival of patients, and estimated the unadjusted and adjusted odds ratios of surviving 12 months. 
Results 742 patients with SCLC were included in this study, with 43% identified as Māori. Approximately 75% of patients received SACT, and there was no difference in the uptake of SACT between Māori and non-Māori. The median survival for SCLC was 8.5 months. After adjustment, patients treated with carboplatin plus etoposide (with/without durvalumab) or cisplatin plus etoposide were 1.5 times or 4.9 times respectively more likely to survive 12 months than those without a SACT regimen.
Conclusion There was no significant evidence of disparities in patterns of care and outcomes between Māori and non-Māori with SCLC. Carboplatin/cisplatin in combination with etoposide remained the primary first line SACT regimen for patients with SCLC in this New Zealand cancer treatment centre.

year: 2023-02-10