title: The influence of water quality and sediment geochemistry on the horizontal and vertical distribution of phosphorus and nitrogen in sediments of a large, shallow lake

authors: Trolle, Dennis

subjects: Lake Taihu

abstract: Distinct horizontal water column concentration gradients of nutrients and chlorophyll a (Chl a) occur within large, shallow, eutrophic Lake Taihu, China. Concentrations are high in the north, where some of the major polluted tributaries enter the lake, and relatively low in the south, where macrophytes generally are abundant. It is not clear, however, whether these water column concentration gradients are similarly reflected in spatial heterogeneity of nutrient concentrations within the bottom sediments. The main objective of this study was therefore to test if horizontal and vertical variations in the phosphorus and nitrogen content in bottom sediments of Lake Taihu are significantly related to (1) horizontal variations in overlying water column nutrient concentrations and (2) other sediment geochemical constituents. We measured the concentration of total phosphorus (TP) and total nitrogen (TN) in surficial sediments (0–2 cm) and TP, TN and Chl a concentrations in water column samples, collected from 32 sites in 2005. In 2006 sediment, TP, TN, carbon, iron and manganese concentrations were measured vertically at 2 cm intervals, extending to a depth of approximately 20 cm, at an additional eight sites. Linear correlation analysis revealed that surficial sediment TP concentrations across the 32 stations were related significantly, though weakly, to annual mean water column concentrations of TP, TN as well as Chl a. Correlations of surficial sediment TN with water column variables were, however, not significant (P[0.05).Amongst the geochemical variables tested, the vertical variability of sediment TP concentrations was most strongly related to sediment manganese and carbon concentrations. A multiple stepwise linear regression revealed that the combination of sediment manganese and carbon concentrations explained 91% of the horizontal variability in sediment TP concentrations and 65% of the vertical variability.

text: The influence of water quality and sediment geochemistry on the horizontal and vertical distribution of phosphorus and nitrogen in sediments of a large, shallow lake Distinct horizontal water column concentration gradients of nutrients and chlorophyll a (Chl a) occur within large, shallow, eutrophic Lake Taihu, China. Concentrations are high in the north, where some of the major polluted tributaries enter the lake, and relatively low in the south, where macrophytes generally are abundant. It is not clear, however, whether these water column concentration gradients are similarly reflected in spatial heterogeneity of nutrient concentrations within the bottom sediments. The main objective of this study was therefore to test if horizontal and vertical variations in the phosphorus and nitrogen content in bottom sediments of Lake Taihu are significantly related to (1) horizontal variations in overlying water column nutrient concentrations and (2) other sediment geochemical constituents. We measured the concentration of total phosphorus (TP) and total nitrogen (TN) in surficial sediments (0–2 cm) and TP, TN and Chl a concentrations in water column samples, collected from 32 sites in 2005. In 2006 sediment, TP, TN, carbon, iron and manganese concentrations were measured vertically at 2 cm intervals, extending to a depth of approximately 20 cm, at an additional eight sites. Linear correlation analysis revealed that surficial sediment TP concentrations across the 32 stations were related significantly, though weakly, to annual mean water column concentrations of TP, TN as well as Chl a. Correlations of surficial sediment TN with water column variables were, however, not significant (P[0.05).Amongst the geochemical variables tested, the vertical variability of sediment TP concentrations was most strongly related to sediment manganese and carbon concentrations. A multiple stepwise linear regression revealed that the combination of sediment manganese and carbon concentrations explained 91% of the horizontal variability in sediment TP concentrations and 65% of the vertical variability.

year: 2009

title: Factors affecting employer adoption of drug testing in New Zealand

authors: Haar, Jarrod M.

subjects: employee drug testing

abstract: This paper explores employer attitudes towards drug testing in New Zealand to establish under what conditions adoption may be encouraged or discouraged. A survey of 162 New Zealand employers found that adoption rates of drug testing policies were low at 6 per cent. Exploring predictors of the likelihood of drug testing adoption in the next year found that firms that are more compliant to institutional pressures were more likely to seek adoption, as were firms that perceived positive benefits from adoption. Further, firms that perceived negative effects from drug testing, such as union pressures, were less likely to adopt drug testing in the future. Additionally, the moderating effects of organisational size was explored, and significantly affected likely adoption rates, with larger firms being more influenced by institutional pressures and positive effects. However, there was no significant moderation effect towards negative effects of drug testing, which remained strongly negative irrespective of organisational size.

text: Factors affecting employer adoption of drug testing in New Zealand This paper explores employer attitudes towards drug testing in New Zealand to establish under what conditions adoption may be encouraged or discouraged. A survey of 162 New Zealand employers found that adoption rates of drug testing policies were low at 6 per cent. Exploring predictors of the likelihood of drug testing adoption in the next year found that firms that are more compliant to institutional pressures were more likely to seek adoption, as were firms that perceived positive benefits from adoption. Further, firms that perceived negative effects from drug testing, such as union pressures, were less likely to adopt drug testing in the future. Additionally, the moderating effects of organisational size was explored, and significantly affected likely adoption rates, with larger firms being more influenced by institutional pressures and positive effects. However, there was no significant moderation effect towards negative effects of drug testing, which remained strongly negative irrespective of organisational size.

year: 2007

title: The Māori language curriculum for New Zealand schools: Spiral lesson/ lesson sequence design

authors: Johnson, Diane

subjects: Māori language teaching

abstract: A draft curriculum document for the teaching and learning of te reo Māori as a subject in mainstream schools in New Zealand (that is, in schools other than Kura Kaupapa Māori schools) was designed and trialled in 2004 and 2005. That draft is currently being reworked in line with the advice of those who trialled the document as well as that of a team of advisers set up by the Ministry of Education. The revised curriculum document will be submitted to the Ministry of Education in May 2006. As is the case with all new curriculum documents, the implementation phase will be critical. The extent to which this flexible, outcomes-focused curriculum document will genuinely inform new approaches to teaching and learning will depend not only upon the good will of teachers and communities, but also upon their ability to interpret the curriculum and to use it in a way that informs the design of language programmes, including the planning of units of work and of lessons and lesson sequences. In balancing language development and language practice, a communicative core and spiral approach is recommended, an approach in which there are core lessons (where the focus is language development) and spiral lessons (where the focus is language practice). In an earlier issue of this Journal (Johnson, 2003), one of us discussed core lesson design. Here, the design of spiral lessons is discussed and exemplified in the context of an outcomes-based curriculum.

text: The Māori language curriculum for New Zealand schools: Spiral lesson/ lesson sequence design A draft curriculum document for the teaching and learning of te reo Māori as a subject in mainstream schools in New Zealand (that is, in schools other than Kura Kaupapa Māori schools) was designed and trialled in 2004 and 2005. That draft is currently being reworked in line with the advice of those who trialled the document as well as that of a team of advisers set up by the Ministry of Education. The revised curriculum document will be submitted to the Ministry of Education in May 2006. As is the case with all new curriculum documents, the implementation phase will be critical. The extent to which this flexible, outcomes-focused curriculum document will genuinely inform new approaches to teaching and learning will depend not only upon the good will of teachers and communities, but also upon their ability to interpret the curriculum and to use it in a way that informs the design of language programmes, including the planning of units of work and of lessons and lesson sequences. In balancing language development and language practice, a communicative core and spiral approach is recommended, an approach in which there are core lessons (where the focus is language development) and spiral lessons (where the focus is language practice). In an earlier issue of this Journal (Johnson, 2003), one of us discussed core lesson design. Here, the design of spiral lessons is discussed and exemplified in the context of an outcomes-based curriculum.

year: 2005