title: Anxiety and depression in pregnant mothers and partners in New Zealand

authors: Haeata, Melanie R. J.

subjects: Pregnancy

abstract: Anxiety and depression throughout the antenatal period are associated with a multitude of adverse consequences. To date, little research has been conducted with both mothers and partners during the antenatal period particularly within a New Zealand context. The aims of this study were to identify rates of elevated anxiety and depression among antenatal mothers and partners, gain a clearer understanding of the relationship between anxiety and depression within couples and to examine risk factors for antenatal anxiety and depression. 57 couples, half recruited from the community and half from an antenatal inpatient unit, completed the PSAS, STAI, and EPDS. Results indicated that mothers and partners had almost identical rates of state (29.1% and 27.8% respectively) and trait anxiety (20.0% and 20.4%) and co-morbid anxiety and depression (10.5% for each gender). Furthermore, mothers experienced on average significantly higher trait anxiety and depression than partners. All measures were significantly correlated as were couples’ anxiety and depression. Although not significant on their own, risk factors for mothers’ anxiety and depression included pregnancy complications, low income level, belonging to an ethnic minority and young age. Partners’ risk factors for anxiety included belonging to an ethnic minority, low level of education and earlier stages of gestation. Only ethnicity was a significant risk factor for state anxiety after controlling for the others. Implications of this research are discussed.

text: Anxiety and depression in pregnant mothers and partners in New Zealand Anxiety and depression throughout the antenatal period are associated with a multitude of adverse consequences. To date, little research has been conducted with both mothers and partners during the antenatal period particularly within a New Zealand context. The aims of this study were to identify rates of elevated anxiety and depression among antenatal mothers and partners, gain a clearer understanding of the relationship between anxiety and depression within couples and to examine risk factors for antenatal anxiety and depression. 57 couples, half recruited from the community and half from an antenatal inpatient unit, completed the PSAS, STAI, and EPDS. Results indicated that mothers and partners had almost identical rates of state (29.1% and 27.8% respectively) and trait anxiety (20.0% and 20.4%) and co-morbid anxiety and depression (10.5% for each gender). Furthermore, mothers experienced on average significantly higher trait anxiety and depression than partners. All measures were significantly correlated as were couples’ anxiety and depression. Although not significant on their own, risk factors for mothers’ anxiety and depression included pregnancy complications, low income level, belonging to an ethnic minority and young age. Partners’ risk factors for anxiety included belonging to an ethnic minority, low level of education and earlier stages of gestation. Only ethnicity was a significant risk factor for state anxiety after controlling for the others. Implications of this research are discussed.

year: 2011

title: Is there a salty solution to sensitive soil sliding in the Bay of Plenty, New Zealand?

authors: Robertson, Thomas Paul

subjects: Sensitive Soils

abstract: Found globally, sensitive soils are widely regarded as a key cause of slope instability. These sensitive soils often contribute to the production of large retrogressive landslides that pose significant danger to a people and infrastructure. Within the Bay of Plenty region, sensitive soil based landslides are widespread and numerous Moum et al (1970) successfully trialled remediation of a sensitive soil landslide in Scandinavia by application of potassium chloride via leaching columns. The aim of this study is to determine whether salt treatment of sensitive soils formed in halloysite rich soils of the Bay of Plenty provides a viable means of improving soil behaviour.
Soil collected from the base of the landslide at Bramley Drive, Omokoroa, was treated with 3 differing potassium based salts (KCl, KOH and K₂CO₃) to observe which would produce the greatest positive rheological effect. Results indicated that treatment with KCL and KOH had a negative rheological effect on the soil reducing the liquid limit of the soil from a baseline of 92.3 to 79.3 and 83.5 respectively. Only K₂CO₃ did not have a negative effect on the soil, maintaining the liquid limit at 92.6. Soil kept within soil cores was then soaked in K₂CO₃ solution for a period of three weeks before being subjected to tri-axial testing at three confining pressures of 205 kPa, 280 kPa and 355 kPa; untreated soil cores were tested at the same stress conditions
Tri-axial testing of the soil showed a significant increase in the peak deviator stress measured when comparing the untreated and treated soils at its point of failure, with increases in peak deviator stress measured for the treated soils in the order of 227% at 205 kPa, 187% at 280 kPa and 124% increase at 355 kPa. Strain softening for treated soil was also measured to be less than that of the untreated soil at all confining pressures, a trait reflected in pore pressures measured at point of failure also. Stress path plots indicated that untreated samples underwent contraction rapidly as deviator stress increased, with no clear failure point observed as would be expected from an over consolidated clay. In contrast, stress paths for the treated samples showed the soils dilating before reaching point of failure and undergoing contraction following failure. Differences in friction angle and cohesion were also measured between treated and untreated samples, with untreated soil indicating friction angle and cohesion of Φ’=19.3o, C’=26.6 kPa. These results were consistent with those given in literature and fell within the range expected for halloysite rich clays (Mills, 2016; Moon, 2016). Both friction angle and coheion values increased in treated soils (Φ’=28.2 and C’=58.4).
Based upon the results gathered during this study I infer that stabilisation of the sensitive layer of soil found within Omokoroa is possible, in particular when treated with K₂CO₃. It is my belief that this occurs due to the successful intercalation of the K₂CO₃ ion into the halloysite basal space, displacing the water found in the space originally, and causing an expansion of the crystal lattice. The expansion of the halloysite crystal lattices in turn increases the particle contact areas, which as a result causes a rise in the cohesion and friction angle as a result of increased energy required to overcome the grain to grain friction when stress is applied. Increased basal spacing in the halloysite crystals accommodates pore fluid and thus allows for reduced pore water pressure during stress application.
Though further research is warranted, results produced from this study show that treatment increases the effective strength of the soil to a significant and noticeable degree, and provides the impetus to warrant further research into the subject in the near future, as the potential engineering impacts in being able to effectively stabilise soil rich in halloysite holds significant value both in New Zealand and on a global scale.

text: Is there a salty solution to sensitive soil sliding in the Bay of Plenty, New Zealand? Found globally, sensitive soils are widely regarded as a key cause of slope instability. These sensitive soils often contribute to the production of large retrogressive landslides that pose significant danger to a people and infrastructure. Within the Bay of Plenty region, sensitive soil based landslides are widespread and numerous Moum et al (1970) successfully trialled remediation of a sensitive soil landslide in Scandinavia by application of potassium chloride via leaching columns. The aim of this study is to determine whether salt treatment of sensitive soils formed in halloysite rich soils of the Bay of Plenty provides a viable means of improving soil behaviour.
Soil collected from the base of the landslide at Bramley Drive, Omokoroa, was treated with 3 differing potassium based salts (KCl, KOH and K₂CO₃) to observe which would produce the greatest positive rheological effect. Results indicated that treatment with KCL and KOH had a negative rheological effect on the soil reducing the liquid limit of the soil from a baseline of 92.3 to 79.3 and 83.5 respectively. Only K₂CO₃ did not have a negative effect on the soil, maintaining the liquid limit at 92.6. Soil kept within soil cores was then soaked in K₂CO₃ solution for a period of three weeks before being subjected to tri-axial testing at three confining pressures of 205 kPa, 280 kPa and 355 kPa; untreated soil cores were tested at the same stress conditions
Tri-axial testing of the soil showed a significant increase in the peak deviator stress measured when comparing the untreated and treated soils at its point of failure, with increases in peak deviator stress measured for the treated soils in the order of 227% at 205 kPa, 187% at 280 kPa and 124% increase at 355 kPa. Strain softening for treated soil was also measured to be less than that of the untreated soil at all confining pressures, a trait reflected in pore pressures measured at point of failure also. Stress path plots indicated that untreated samples underwent contraction rapidly as deviator stress increased, with no clear failure point observed as would be expected from an over consolidated clay. In contrast, stress paths for the treated samples showed the soils dilating before reaching point of failure and undergoing contraction following failure. Differences in friction angle and cohesion were also measured between treated and untreated samples, with untreated soil indicating friction angle and cohesion of Φ’=19.3o, C’=26.6 kPa. These results were consistent with those given in literature and fell within the range expected for halloysite rich clays (Mills, 2016; Moon, 2016). Both friction angle and coheion values increased in treated soils (Φ’=28.2 and C’=58.4).
Based upon the results gathered during this study I infer that stabilisation of the sensitive layer of soil found within Omokoroa is possible, in particular when treated with K₂CO₃. It is my belief that this occurs due to the successful intercalation of the K₂CO₃ ion into the halloysite basal space, displacing the water found in the space originally, and causing an expansion of the crystal lattice. The expansion of the halloysite crystal lattices in turn increases the particle contact areas, which as a result causes a rise in the cohesion and friction angle as a result of increased energy required to overcome the grain to grain friction when stress is applied. Increased basal spacing in the halloysite crystals accommodates pore fluid and thus allows for reduced pore water pressure during stress application.
Though further research is warranted, results produced from this study show that treatment increases the effective strength of the soil to a significant and noticeable degree, and provides the impetus to warrant further research into the subject in the near future, as the potential engineering impacts in being able to effectively stabilise soil rich in halloysite holds significant value both in New Zealand and on a global scale.

year: 2017

title: What do New Zealand picturebooks tell us about New Zealand national identity?

authors: Daly, Nicola

abstract: Jeffries (2004, p. 4) defines national identity as ' ... a shared sense of belonging of a group of people that depends on a common area of named place, a common set of beliefs and values, and positive feelings for a specific named geographical area'. In her examination of how New Zealand culture is portrayed in picturebooks published between 2000 and 2005, McNeur (2006) suggests that the visual and textual messages in children's picturebooks are an important contributor to the development of children's national identity. This paper describes the process of choosing a collection of 22 New Zealand children's picturebooks (known as the New Zealand PictureBook Collection) to reflect and represent diversity in New Zealand national identity, and analyses what these books tell us about the New Zealand national identity.

text: What do New Zealand picturebooks tell us about New Zealand national identity? Jeffries (2004, p. 4) defines national identity as ' ... a shared sense of belonging of a group of people that depends on a common area of named place, a common set of beliefs and values, and positive feelings for a specific named geographical area'. In her examination of how New Zealand culture is portrayed in picturebooks published between 2000 and 2005, McNeur (2006) suggests that the visual and textual messages in children's picturebooks are an important contributor to the development of children's national identity. This paper describes the process of choosing a collection of 22 New Zealand children's picturebooks (known as the New Zealand PictureBook Collection) to reflect and represent diversity in New Zealand national identity, and analyses what these books tell us about the New Zealand national identity.

year: 2016