17 research outputs found

    Guiding principles for rewilding

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    There has been much recent interest in the concept of rewilding as a tool for nature conservation, but also confusion over the idea, which has limited its utility. We developed a unifying definition and 10 guiding principles for rewilding through a survey of 59 rewilding experts, a summary of key organizations’ rewilding visions, and workshops involving over 100 participants from around the world. The guiding principles convey that rewilding exits on a continuum of scale, connectivity, and level of human influence and aims to restore ecosystem structure and functions to achieve a self-sustaining autonomous nature. These principles clarify the concept of rewilding and improve its effectiveness as a tool to achieve global conservation targets, including those of the UN Decade on Ecosystem Restoration and post-2020 Global Biodiversity Framework. Finally, we suggest differences in rewilding perspectives lie largely in the extent to which it is seen as achievable and in specific interventions. An understanding of the context of rewilding projects is the key to success, and careful site-specific interpretations will help achieve the aims of rewilding

    Iterative beam-hardening correction with advanced modeled iterative reconstruction in low voltage CT coronary calcium scoring with tin filtration: Impact on coronary artery calcium quantification and image quality

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    Objective We investigated the impact of iterative beam-hardening correction (IBHC) with advanced modeled iterative reconstruction (ADMIRE) of ultra-low radiation-dose tin filtered (Sn100 kVp) CACS acquisitions on image quality, calcium quantification, and risk classification. Methods CT data of 60 patients (55% male, age 62.3 ± 9.8years) who underwent a 3rd generation dual-source CACS scan using a prospectively ECG-triggered 100 kVp sequential acquisition protocol with tin filtration (Sn100 kVp) were reconstructed using IBHC with filtered back projection (FBP) and ADMIRE with strength levels of three and five. Image noise was calculated and Agatston scores were derived from all reconstructions. Image noise, Agatston score categories, and percentile-based cardiac risk categorization of the respective reconstruction techniques were compared. Results The mean estimated radiation dose equivalent of CACS acquisitions in the study population was 0.20 ± 0.07 mSv. Mean image noise significantly decreased with ADMIRE compared to FBP (both p < 0.0001). Agatston scores derived from the respective reconstructions were significantly different in a paired comparison (median [25th and 75th percentile]): FBP 34.7 [1.9, 153.6], ADMIRE 3 28.6 [1.1, 134.5], ADMIRE 5 22.7 [0.3, 116.8]; both p < 0.0001). Agatston score categories and cardiac risk categorization showed excellent agreement of ADMIRE 3 and ADMIRE 5 with FBP (ĸ = 0.92 [0.86–0.98] and ĸ = 0.86 [0.79–0.94]; ĸ = 0.94 [0.87–1.00] and ĸ = 0.91 [0.83–0.99]; however, modest cardiac risk reclassifications of 3% and 7% for ADMIRE 3 and ADMIRE 5, respectively, were observed. Conclusion Iterative reconstruction using IBHC ADMIRE in low voltage, ultra-low dose CACS with tin filtration significantly decreased image noise. However, it also reduced Agatston scores compared to FBP, which may have an impact on subsequent cardiac risk classification, although risk reclassification occurred only in a modest number of subjects
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