Mapping of Submerged Aquatic Vegetation in Rivers From Very High Resolution Image Data, Using Object Based Image Analysis Combined with Expert Knowledge

The use of remote sensing for monitoring of submerged aquatic vegetation (SAV) in fluvial environments has been limited by the spatial and spectral resolution of available image data. The absorption of light in water also complicates the use of common image analysis methods. This paper presents the results of a study that uses very high resolution (VHR) image data, collected with a Near Infrared sensitive DSLR camera, to map the distribution of SAV species for three sites along the Desselse Nete, a lowland river in Flanders, Belgium. Plant species, including Ranunculus aquatilis L., Callitriche obtusangula Le Gall, Potamogeton natans L., Sparganium emersum L. and Potamogeton crispus L., were classified from the data using Object-Based Image Analysis (OBIA) and expert knowledge. A classification rule set based on a combination of both spectral and structural image variation (e.g. texture and shape) was developed for images from two sites. A comparison of the classifications with manually delineated ground truth maps resulted for both sites in 61% overall accuracy. Application of the rule set to a third validation image, resulted in 53% overall accuracy. These consistent results show promise for species level mapping in such biodiverse environments, but also prompt a discussion on assessment of classification accuracy.

Caring for Children Dying from Cancer at Home: a Qualitative Study of the Experience of Primary Care Practitioners

Background. The rarity of childhood cancers makes providing palliative care in the community an unusual event for primary care practitioners. Providing this care requires effective interprofessional collaboration with the team that forms to provide the care often working together for the first and only time. Objective. To explore the experiences of primary care practitioners following their involvement in the palliative care of a child with cancer at home. Methods. The study design was a community-based qualitative study. The study location was the West Midlands region. Purposeful sample of GPs and community nurses involved in providing palliative care to 12 children. One-to-one in-depth interviews with 47 primary care professionals (10 GPs and 37 community nurses) and 5 facilitated case discussions were undertaken. Field notes were documented and grounded theory data analysis undertaken: chronological comparative data analysis identifying generated themes. Results. GPs had minimal input into the preceding care of children undergoing treatment for cancer but sought to re-establish their role at the child’s transition to palliative care. GPs felt they had a role to play and could add value to this phase of care, highlighted their continuing role with the child’s family and acknowledged that they had gained from the experience of contributing. However, lack of specialist knowledge and uncertainty about their role within the team made this more challenging. In contrast, community nurses were routinely involved in both active treatment and palliation care phases. There was little evidence of collaboration between the specialist and primary care professionals involved. There was considerable variation in out of hours provision across cases. Conclusions. Engaging primary care practitioners needs to be more actively anticipated and negotiated at the transition to palliation. Variation in out of hours care is another cause for concern. Enhancing inter-professional collaboration and planning during both active and palliative care phases may help. Keywords. Cancer, family medicine, palliative care, paediatric.