2,216 research outputs found

    Intercomparison of phenological transition dates derived from the PhenoCam Dataset V1.0 and MODIS satellite remote sensing

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    Phenology is a valuable diagnostic of ecosystem health, and has applications to environmental monitoring and management. Here, we conduct an intercomparison analysis using phenological transition dates derived from near-surface PhenoCam imagery and MODIS satellite remote sensing. We used approximately 600 site-years of data, from 128 camera sites covering a wide range of vegetation types and climate zones. During both “greenness rising” and “greenness falling” transition phases, we found generally good agreement between PhenoCam and MODIS transition dates for agricultural, deciduous forest, and grassland sites, provided that the vegetation in the camera field of view was representative of the broader landscape. The correlation between PhenoCam and MODIS transition dates was poor for evergreen forest sites. We discuss potential reasons (including sub-pixel spatial heterogeneity, flexibility of the transition date extraction method, vegetation index sensitivity in evergreen systems, and PhenoCam geolocation uncertainty) for varying agreement between time series of vegetation indices derived from PhenoCam and MODIS imagery. This analysis increases our confidence in the ability of satellite remote sensing to accurately characterize seasonal dynamics in a range of ecosystems, and provides a basis for interpreting those dynamics in the context of tangible phenological changes occurring on the ground

    Industrial structural geology : principles, techniques and integration : an introduction

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    The authors wish to acknowledge the generous financial support provided in association with this volume to the Geological Society and the Petroleum Group by Badley Geoscience Ltd, BP, CGG Robertson, Dana Petroleum Ltd, Getech Group plc, Maersk Oil North Sea UK Ltd, Midland Valley Exploration Ltd, Rock Deformation Research (Schlumberger) and Borehole Image & Core Specialists (Wildcat Geoscience, Walker Geoscience and Prolog Geoscience). We would like to thank the fine team at the Geological Society’s Publishing House for the excellent support and encouragement that they have provided to the editors and authors of this Special Publication.Peer reviewedPublisher PD

    What types of essay feedback influence implementation: Structure alone or structure and content?

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    Students approach educational courses with varying levels of experience and understanding, and so need appropriate support to inform them of expectations and to guide their learning efforts. Feedback is critical in this process, so that learners can gauge how their performance aligns with expectations, and how they can improve their efforts and attainments. This study focused on the effects of providing different types of feedback on participants’ written essays, as well as on participants’ motivations for learning using measures of motivation and self-efficacy. In terms of research questions, it was important to ascertain whether participants performed differently in subsequent essays after receiving feedback on structure alone or on structure and content; whether their self-reported levels of motivation and attitudes to learning were related to essay performance; and whether the difference in type of feedback affected their self-reported levels of motivation and attitudes to learning. Findings revealed no significant difference in marks between those receiving feedback on structure alone and those receiving feedback on structure and content, which is surprising and deserves further exploration. Even so, using feedback to highlight certain structural elements of essay writing can have a lasting positive impact on participants’ future essay performance
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