title: The short-term effects of surface soil disturbance on soil bacterial community structure at an experimental site near Scott Base, Antarctica

authors: O’Neill, Tanya Ann

subjects: Antarctica

abstract: Humans are visiting Antarctica in increasing numbers, and the ecological effect of rapid soil habitat alteration due to human-induced physical disturbance is not well understood. An experimental soil disturbance trial was set up near Scott Base on Ross Island, to investigate the immediate and short-term changes to bacterial community structure, following surface soil disturbance. Three blocks, each comprising an undisturbed control, and an area disturbed by removing the top 2 cm of soil, were sampled over a time series (0, 7, 14, 21, and 35 days), to investigate changes to bacterial community structure using DNA profiling by terminal restriction fragment length polymorphism. The simulated disturbance did not cause any major shifts in the structure of the bacterial communities over the 35-day sampling period. Ordination showed that the bacterial community composition correlated strongly with soil EC (R² = 0.55) and soil pH (R² = 0.67), rather than the removal of the top 2 cm of surface material. Although the replicate blocks were visually indistinguishable from one another, high local spatial variability of soil chemical properties was found at the study site and different populations of bacterial communities occurred within 2 m of one another, within the same landscape unit. Given the current knowledge of the drivers of bacterial community structure, that is, soil EC, soil pH, and soil moisture content, a follow-up investigation incorporating DNA and RNA-based analyses over a time frame of 2-3 years would lead to a greater understanding of the effects of soil disturbance on bacterial communities.

text: The short-term effects of surface soil disturbance on soil bacterial community structure at an experimental site near Scott Base, Antarctica Humans are visiting Antarctica in increasing numbers, and the ecological effect of rapid soil habitat alteration due to human-induced physical disturbance is not well understood. An experimental soil disturbance trial was set up near Scott Base on Ross Island, to investigate the immediate and short-term changes to bacterial community structure, following surface soil disturbance. Three blocks, each comprising an undisturbed control, and an area disturbed by removing the top 2 cm of soil, were sampled over a time series (0, 7, 14, 21, and 35 days), to investigate changes to bacterial community structure using DNA profiling by terminal restriction fragment length polymorphism. The simulated disturbance did not cause any major shifts in the structure of the bacterial communities over the 35-day sampling period. Ordination showed that the bacterial community composition correlated strongly with soil EC (R² = 0.55) and soil pH (R² = 0.67), rather than the removal of the top 2 cm of surface material. Although the replicate blocks were visually indistinguishable from one another, high local spatial variability of soil chemical properties was found at the study site and different populations of bacterial communities occurred within 2 m of one another, within the same landscape unit. Given the current knowledge of the drivers of bacterial community structure, that is, soil EC, soil pH, and soil moisture content, a follow-up investigation incorporating DNA and RNA-based analyses over a time frame of 2-3 years would lead to a greater understanding of the effects of soil disturbance on bacterial communities.

year: 2013

title: Resolving depth measurement ambiguity with commercially available range imaging cameras

authors: McClure, Shane H.

subjects: range imaging

abstract: Time-of-flight range imaging is typically performed with the amplitude modulated continuous wave method. This involves illuminating a scene with amplitude modulated light. Reflected light from the scene is received by the sensor with the range to the scene encoded as a phase delay of the modulation envelope. Due to the cyclic nature of phase, an ambiguity in the measured range occurs every half wavelength in distance, thereby limiting the maximum useable range of the camera.
This paper proposes a procedure to resolve depth ambiguity using software post processing. First, the range data is processed to segment the scene into separate objects. The average intensity of each object can then be used to determine which pixels are beyond the non-ambiguous range. The results demonstrate that depth ambiguity can be resolved for various scenes using only the available depth and intensity information. This proposed method reduces the sensitivity to objects with very high and very low reflectance, normally a key problem with basic threshold approaches.
This approach is very flexible as it can be used with any range imaging camera. Furthermore, capture time is not extended, keeping the artifacts caused by moving objects at a minimum. This makes it suitable for applications such as robot vision where the camera may be moving during captures.
The key limitation of the method is its inability to distinguish between two overlapping objects that are separated by a distance of exactly one non-ambiguous range. Overall the reliability of this method is higher than the basic threshold approach, but not as high as the multiple frequency method of resolving ambiguity.

text: Resolving depth measurement ambiguity with commercially available range imaging cameras Time-of-flight range imaging is typically performed with the amplitude modulated continuous wave method. This involves illuminating a scene with amplitude modulated light. Reflected light from the scene is received by the sensor with the range to the scene encoded as a phase delay of the modulation envelope. Due to the cyclic nature of phase, an ambiguity in the measured range occurs every half wavelength in distance, thereby limiting the maximum useable range of the camera.
This paper proposes a procedure to resolve depth ambiguity using software post processing. First, the range data is processed to segment the scene into separate objects. The average intensity of each object can then be used to determine which pixels are beyond the non-ambiguous range. The results demonstrate that depth ambiguity can be resolved for various scenes using only the available depth and intensity information. This proposed method reduces the sensitivity to objects with very high and very low reflectance, normally a key problem with basic threshold approaches.
This approach is very flexible as it can be used with any range imaging camera. Furthermore, capture time is not extended, keeping the artifacts caused by moving objects at a minimum. This makes it suitable for applications such as robot vision where the camera may be moving during captures.
The key limitation of the method is its inability to distinguish between two overlapping objects that are separated by a distance of exactly one non-ambiguous range. Overall the reliability of this method is higher than the basic threshold approach, but not as high as the multiple frequency method of resolving ambiguity.

year: 2010

title: Constructing strategies for sustainable development the communitarian way

authors: Arunachalam, Murugesh

subjects: communities

abstract: Purpose – The paper aims to draw on recommendations of Agenda 21 and communitarian theory to examine collaboration between local district community and local authorities to formulate strategies for the sustainable development of the Taupo district. 
Design/methodology/approach – The paper adopts an interpretative methodology based on philosophical hermeneutic to understand collaboration between local community and local authorities in the Taupo district. Empirical data for this interpretive study comprise public documents, interview transcripts and minutes of meetings attended by the researchers. The paper begins interpretation of empirical data with pre-understanding of communitarian theory and Agenda 21. 
Findings – The findings indicate that historical and political factors and diversity of interests in the community affect processes and outcomes of collaboration. Local authorities play a crucial role in bringing together various groups in the Taupo community which are segregated by diversity of interests, especially between Maori and non-Maori community groups. Without local authority facilitation, the Taupo community may remain segregated; inhibited by lack of information; and not having the opportunity to participate in sustainable development. Community participation in the Taupo district is at an infancy stage and collaboration intended to empower communities may result in local authorities recentralising their positions. 
Originality/value – The paper integrates theory and practice and provides valuable insights for statutory agencies seeking to implement the recommendations of Agenda 21 regarding community participation in sustainable development.

text: Constructing strategies for sustainable development the communitarian way Purpose – The paper aims to draw on recommendations of Agenda 21 and communitarian theory to examine collaboration between local district community and local authorities to formulate strategies for the sustainable development of the Taupo district. 
Design/methodology/approach – The paper adopts an interpretative methodology based on philosophical hermeneutic to understand collaboration between local community and local authorities in the Taupo district. Empirical data for this interpretive study comprise public documents, interview transcripts and minutes of meetings attended by the researchers. The paper begins interpretation of empirical data with pre-understanding of communitarian theory and Agenda 21. 
Findings – The findings indicate that historical and political factors and diversity of interests in the community affect processes and outcomes of collaboration. Local authorities play a crucial role in bringing together various groups in the Taupo community which are segregated by diversity of interests, especially between Maori and non-Maori community groups. Without local authority facilitation, the Taupo community may remain segregated; inhibited by lack of information; and not having the opportunity to participate in sustainable development. Community participation in the Taupo district is at an infancy stage and collaboration intended to empower communities may result in local authorities recentralising their positions. 
Originality/value – The paper integrates theory and practice and provides valuable insights for statutory agencies seeking to implement the recommendations of Agenda 21 regarding community participation in sustainable development.

year: 2010