title: The role of biomorphodynamics in estuarine evolution in New Zealand

authors: van Maanen, Barend

subjects: biomorphodynamics

abstract: Biomorphodynamic interactions, the feedback loops that operate between physical processes, biology and morphology, affect the long-term evolution of estuaries. This paper outlines how consideration of such interactions and implementation through innovative modelling techniques can become the next crucial step needed to advance understanding of estuarine evolution.

text: The role of biomorphodynamics in estuarine evolution in New Zealand Biomorphodynamic interactions, the feedback loops that operate between physical processes, biology and morphology, affect the long-term evolution of estuaries. This paper outlines how consideration of such interactions and implementation through innovative modelling techniques can become the next crucial step needed to advance understanding of estuarine evolution.

year: 2008

title: The Status of Iodine and Selenium in Waikato Soils

authors: McNally, Samuel Rae

subjects: Iodine

abstract: This thesis investigates the status of the essential trace elements iodine and selenium in Waikato soils. Soil samples (368) representing different Soil Orders, land uses and soil depths were examined.
A tetramethyl ammonium hydroxide extraction method followed by ICP-MS was validated for iodine determination. This method was suitable for total iodine determination and also gave a reliable estimate of the total selenium content of soils, based on analysis of Certified Reference Materials.
Acid extraction of selenium was unsuitable because of difficulties with recoveries and interferences in the ICP-MS, although the use of methane and DRC-ICP-MS reduced interferences. Time and equipment constraints limited the complete validation using acid extraction for total selenium determination.
Waikato soils had a mean iodine content of 20.9 mg kg-¹, geometric mean of 13.7 mg kg-¹ and range of 1.5 – 122.8 mg kg-¹. Allophanic and Granular soils contained the highest mean iodine contents with Pumice soils displaying the lowest. The iodine content was shown to increase with soil depth, with the Waikato soils showing no evidence of coastal enrichment, though this could be explained by the losses of iodine being equal to, or exceeding the additions to soil. 
Land use appeared to have an effect on the iodine content of soils with background soils displaying more iodine on average than both farmed and forestry soils. Forestry soils displayed the lowest mean iodine content. Farming and forestry both appear to reduce the amount of iodine in soils. 
Iodine was correlated strongly to aluminium and iron, indicating that clay minerals and iron oxides are the most important in the retention of iodine, with organic matter appearing to be less important in iodine retention. There was also a strong correlation of iodine with selenium and mercury, suggesting an association between these elements.
The selenium status of Waikato soils showed a mean concentration of 1.77 mg kg-¹, geometric mean 1.33 mg kg-¹ and a range in concentration of 0.18 – 12.1 mg kg-¹. Like iodine, selenium also displayed the highest mean concentrations in Allophanic and Granular soils, with the lowest concentrations in Pumice soils. The concentration of selenium also increased with soil depth, with parent material appearing to affect the selenium content of soils. Selenium appeared to be more concentrated in the soils closest to the coast than those more inland; with the relative enrichment suggesting that the losses of selenium are likely to equal or exceed the inputs from the surface.
Selenium concentration in relation to land use indicated that farming and forestry may be depleting selenium from soils, with background soils displaying more selenium on average than both farmed and forestry soils.
Again selenium showed similar behaviour to iodine in that it was strongly correlated to aluminium, iron and manganese, indicating that clay minerals and iron and manganese oxides are the most important factors in selenium retention in Waikato soils. Organic matter was less important in retention shown by the less significant correlation with selenium. Mercury and iodine were both strongly correlated to selenium suggesting that chalcophilic elements (mercury) are strongly associated to selenium.
The strong correlation between iodine and selenium also explained the similarities in the relationships of both elements with other soil properties. The results presented for both iodine and selenium indicate that the status of both elements in the Waikato Region may be better than previously thought, with the soils showing mean concentrations that suggest they may not be as deficient as thought.

text: The Status of Iodine and Selenium in Waikato Soils This thesis investigates the status of the essential trace elements iodine and selenium in Waikato soils. Soil samples (368) representing different Soil Orders, land uses and soil depths were examined.
A tetramethyl ammonium hydroxide extraction method followed by ICP-MS was validated for iodine determination. This method was suitable for total iodine determination and also gave a reliable estimate of the total selenium content of soils, based on analysis of Certified Reference Materials.
Acid extraction of selenium was unsuitable because of difficulties with recoveries and interferences in the ICP-MS, although the use of methane and DRC-ICP-MS reduced interferences. Time and equipment constraints limited the complete validation using acid extraction for total selenium determination.
Waikato soils had a mean iodine content of 20.9 mg kg-¹, geometric mean of 13.7 mg kg-¹ and range of 1.5 – 122.8 mg kg-¹. Allophanic and Granular soils contained the highest mean iodine contents with Pumice soils displaying the lowest. The iodine content was shown to increase with soil depth, with the Waikato soils showing no evidence of coastal enrichment, though this could be explained by the losses of iodine being equal to, or exceeding the additions to soil. 
Land use appeared to have an effect on the iodine content of soils with background soils displaying more iodine on average than both farmed and forestry soils. Forestry soils displayed the lowest mean iodine content. Farming and forestry both appear to reduce the amount of iodine in soils. 
Iodine was correlated strongly to aluminium and iron, indicating that clay minerals and iron oxides are the most important in the retention of iodine, with organic matter appearing to be less important in iodine retention. There was also a strong correlation of iodine with selenium and mercury, suggesting an association between these elements.
The selenium status of Waikato soils showed a mean concentration of 1.77 mg kg-¹, geometric mean 1.33 mg kg-¹ and a range in concentration of 0.18 – 12.1 mg kg-¹. Like iodine, selenium also displayed the highest mean concentrations in Allophanic and Granular soils, with the lowest concentrations in Pumice soils. The concentration of selenium also increased with soil depth, with parent material appearing to affect the selenium content of soils. Selenium appeared to be more concentrated in the soils closest to the coast than those more inland; with the relative enrichment suggesting that the losses of selenium are likely to equal or exceed the inputs from the surface.
Selenium concentration in relation to land use indicated that farming and forestry may be depleting selenium from soils, with background soils displaying more selenium on average than both farmed and forestry soils.
Again selenium showed similar behaviour to iodine in that it was strongly correlated to aluminium, iron and manganese, indicating that clay minerals and iron and manganese oxides are the most important factors in selenium retention in Waikato soils. Organic matter was less important in retention shown by the less significant correlation with selenium. Mercury and iodine were both strongly correlated to selenium suggesting that chalcophilic elements (mercury) are strongly associated to selenium.
The strong correlation between iodine and selenium also explained the similarities in the relationships of both elements with other soil properties. The results presented for both iodine and selenium indicate that the status of both elements in the Waikato Region may be better than previously thought, with the soils showing mean concentrations that suggest they may not be as deficient as thought.

year: 2011

title: Mental health of people of diverse genders and sexualities in Aotearoa/New Zealand: Findings from the New Zealand Mental Health Monitor

authors: Tan, Kyle K. H.

subjects: Science & Technology

abstract: Issues addressed: To examine mental health inequities, and social exclusion and isolation and protective factor differences between people of diverse genders and sexualities (lesbian/gay, bisexual, gender diverse, and takatāpui) and cisgender and heterosexual people in Aotearoa/New Zealand.  Methods: We employed data from the pooled probability sample of 2016 and 2018 New Zealand Mental Health Monitor. The sample comprised of 2,938 people at least 15 years old, of which 93 had diverse gender and sexuality identities. Generalised linear models were used to test for differences in mental health (current and lifetime mental distress, depression, anxiety, self-harm and suicide), social exclusion and isolation, and friend and family support for people of diverse genders and sexualities. We also conducted exploratory linear regression analyses to examine whether mental health difficulties were associated with social exclusion and isolation and friend/family support.  Results: People of diverse genders and sexualities had high rates of mental health difficulties across all variables we examined. For example, people identifying as diverse genders and sexualities had three times the risk of considering self-harm and suicide than their cisgender and heterosexual counterparts (22% vs 5%; RR = 3.12). People of diverse genders and sexualities also scored an average of 6.08 points higher on the 27-point PHQ-9 depression scale when they had experienced social isolation, and 4.01 points higher when they experienced social exclusion. Conclusion: Our results are consistent with current literature on the large mental health inequities faced by people of diverse genders and sexualities.  So what?: Policy makers and healthcare providers in Aotearoa/New Zealand should consider the negative mental health consequences of social exclusion and isolation for people of diverse genders and sexualities.

text: Mental health of people of diverse genders and sexualities in Aotearoa/New Zealand: Findings from the New Zealand Mental Health Monitor Issues addressed: To examine mental health inequities, and social exclusion and isolation and protective factor differences between people of diverse genders and sexualities (lesbian/gay, bisexual, gender diverse, and takatāpui) and cisgender and heterosexual people in Aotearoa/New Zealand.  Methods: We employed data from the pooled probability sample of 2016 and 2018 New Zealand Mental Health Monitor. The sample comprised of 2,938 people at least 15 years old, of which 93 had diverse gender and sexuality identities. Generalised linear models were used to test for differences in mental health (current and lifetime mental distress, depression, anxiety, self-harm and suicide), social exclusion and isolation, and friend and family support for people of diverse genders and sexualities. We also conducted exploratory linear regression analyses to examine whether mental health difficulties were associated with social exclusion and isolation and friend/family support.  Results: People of diverse genders and sexualities had high rates of mental health difficulties across all variables we examined. For example, people identifying as diverse genders and sexualities had three times the risk of considering self-harm and suicide than their cisgender and heterosexual counterparts (22% vs 5%; RR = 3.12). People of diverse genders and sexualities also scored an average of 6.08 points higher on the 27-point PHQ-9 depression scale when they had experienced social isolation, and 4.01 points higher when they experienced social exclusion. Conclusion: Our results are consistent with current literature on the large mental health inequities faced by people of diverse genders and sexualities.  So what?: Policy makers and healthcare providers in Aotearoa/New Zealand should consider the negative mental health consequences of social exclusion and isolation for people of diverse genders and sexualities.

year: 2021-10-03