Individual Tree Crown Delineation Using Multispectral LiDAR Data.

In this study, multispectral Light Detection and Ranging (LiDAR) data were utilized to improve delineation of individual tree crowns (ITC) as an important step in individual tree analysis. A framework to integrate spectral and height information for ITC delineation was proposed, and the multi-scale algorithm for treetop detection developed in one of our previous studies was improved. In addition, an advanced region-based segmentation method that used detected treetops as seeds was proposed for segmentation of individual crowns based on their spectral, contextual, and height information. The proposed methods were validated with data acquired using Teledyne Optech's Titan LiDAR sensor. The sensor was operated at three wavelengths (1550 nm, 1064 nm, and 532 nm) within a study area located in the city of Toronto, ON, Canada. The proposed method achieved 80% accuracy, compared with manual delineation of crowns, considering both matched and partially matched crowns, which was 12% higher than that obtained by the earlier marker-controlled watershed (MCW) segmentation technique. Furthermore, the results showed that the integration of spectral and height information improved ITC delineation using either the proposed framework or MCW segmentation, compared with using either spectral or height information individually.

Pathways of neighbourhood-level socio-economic determinants of adverse birth outcomes.

BACKGROUND: Although socio-economic factors have been identified as one of the most important groups of neighbourhood-level risks affecting birth outcomes, uncertainties still exist concerning the pathways through which they are transferred to individual risk factors. This poses a challenge for setting priorities and developing appropriate community-oriented public health interventions and planning guidelines to reduce the level of adverse birth outcomes. METHOD: This study examines potential direct and mediated pathways through which neighbourhood-level socio-economic determinants exert their impacts on adverse birth outcomes. Two hypothesized models, namely the materialist and psycho-social models, and their corresponding pathways are tested using a binary-outcome multilevel mediation analysis. Live birth data, including adverse birth outcomes and person-level exposure variables, were obtained from three public health units in the province of Ontario, Canada. Corresponding neighbourhood-level socio-economic, psycho-social and living condition variables were extracted or constructed from the 2001 Canadian Census and the first three cycles (2001, 2003, and 2005) of the Canadian Community Health Surveys. RESULTS: Neighbourhood-level socio-economic-related risks are found to have direct effects on low birth weight and preterm birth. In addition, 20-30% of the total effects are contributed by indirect effects mediated through person-level risks. There is evidence of four person-level pathways, namely through individual socio-economic status, psycho-social stress, maternal health, and health behaviours, with all being simultaneously at work. Psycho-social pathways and buffering social capital-related variables are found to have more impact on low birth weight than on preterm birth. CONCLUSION: The evidence supports both the materialist and psycho-social conceptualizations and the pathways that describe them, although the magnitude of the former is greater than the latter.

The extraction and utilization of local and scientific geospatial knowledge within the Bluff oyster fishery, New Zealand.

This paper assesses the Bluff oyster fishery in New Zealand as a case study in common pool resource management. It discusses ways in which modern information technology, augmented by low-tech data gathering strategies and community ethnography, can be used to produce an integrated scientific and local knowledge-inspired fishery database that lends itself to fostering collaboration in resource management and planning. The specific context and state of the oyster fishery in Bluff are described. Issues regarding undocumented and ephemeral intergenerational knowledge, much of which is geospatial in nature, on the fishery, the current crisis that many see in the future of the fishery, and a lack of cohesion or common sense of purpose between the stakeholder groups are discussed. It is argued that the digital resource that results from the integration of local and scientific knowledge and the potential community building processes that can ensue from collaboration and dialogue around this centrepiece are of central importance in developing an oyster fishery management plan that is holistic in concept and sustainable in purpose.

"It's important to be proud of the place you live in": housing problems and preferences of psychiatric survivors.

TOPIC: It is important to understand housing and mental health issues from the perspective of psychiatric survivors. This paper reports findings from a series of focus group meetings held with survivors of mental illness to address issues concerning housing preferences and housing needs. METHODS: The discussions were recorded, transcribed, and analyzed using an ethnographic method of analysis. The themes that emerged related to oppression, social networks and social supports, housing conditions, poverty and finances, and accessing services. Participants described the ongoing stigma, discrimination, and poverty that reduced their access to safe, adequate housing. FINDINGS: They preferred independent housing where supports would be available as needed. Participants described the dilemma of having to choose between the housing they wanted and the supports they needed, since supports were often contingent upon living in a less desirable housing situation. CONCLUSIONS: Nurses and other mental healthcare workers need to be aware of these issues for discharge planning, community support, and ongoing advocacy. The survivor voices need to be heard by decision-makers at various levels of government in order for housing policy to become more receptive to their realities.

Current and preferred housing of psychiatric consumers/survivors.

As part of a participatory action research project, we surveyed 300 psychiatric consumers/survivors from southwestern Ontario regarding their housing preferences and housing satisfaction. We found that, while 79% of the sample preferred independent living, 76% were living in some other type of setting (e.g., temporary shelter, supportive housing, sheltered care). Those living in temporary shelters reported the lowest levels of housing satisfaction, and those who were living in the type of housing that they preferred had the highest levels of housing satisfaction. This information is being used by stakeholder groups involved in the project to help build the capacity of the community to provide the types of housing that are preferred by consumers/survivors.

A GIS-based protocol for the collection and use of local knowledge in fisheries management planning.

Despite a heavy reliance on scientific knowledge as the primary source of information in resource management, many resources are in decline, particularly in fisheries. To try and combat this trend, researchers have drawn upon the knowledge of local resource users as an important supplement to scientific knowledge in designing and implementing management strategies. The integration of local knowledge with scientific knowledge for marine species management, however, is problematic stemming primarily from conflicting data types. This paper considers the use of spatial information technology as a medium to integrate and visualise spatial distributions of both quantitative scientific data and qualitative local knowledge for the purposes of producing valid and locally relevant fisheries management plans. In this context, the paper presents a detailed protocol for the collection and subsequent use of local knowledge in fisheries management planning using geographic information systems (GIS). Particular attention is paid to the use of local knowledge in resource management, accuracy issues associated with the incorporation of qualitative data into a quantitative environment, base map selection and construction, and map bias or errors associated with the accuracy of recording harvest locations on paper map sheets, given the complications of map scale.