299 research outputs found
Geographic variability in lidar predictions of forest stand structure in the Pacific Northwest
Estimation of the amount of carbon stored in forests is a key challenge for understanding the global carbon cycle, one which remote sensing is expected to help address. However, carbon storage in moderate to high biomass forests is difficult to estimate with conventional optical or radar sensors. Lidar (light detection and ranging) instruments measure the vertical structure of forests and thus hold great promise for remotely sensing the quantity and spatial organization of forest biomass. In this study, we compare the relationships between lidar measured canopy structure and coincident field measurements of forest stand structure at five locations in the Pacific Northwest of the U.S.A. with contrasting composition. Coefficient of determination values (r2) ranged between 41% and 96%. Correlations for two important variables, LAI (81%) and above ground biomass (92%), were noteworthy, as was the fact that neither variable showed an asymptotic response.
Of the 17 stand structure variables considered in this study, we were able to develop eight equations that were valid for all sites, including equations for two variables generally considered to be highly important (aboveground biomass and leaf area index). The other six equations that were valid for all sites were either related to height (which is most directly measured by lidar) or diameter at breast height (which should be closely related to height). Four additional equations (a total of 12) were applicable to all sites where either Douglas-fir (Pseudotsuga menziesii), western hemlock (Tsuga heterophylla) or Sitka spruce (Picea sitchensi) were dominant. Stand structure variables in sites dominated by true firs (Abies sp.) or ponderosa pine (Pinus ponderosa) had biases when predicted by these four additional equations. Productivity-related variables describing the edaphic, climatic and topographic environment of the sites where available for every regression, but only two of the 17 equations (maximum diameter at breast height, stem density) incorporated them. Given the wide range of these environmental conditions sampled, we conclude that the prediction of stand structure is largely independent of environmental conditions in this study area.
Most studies of lidar remote sensing for predicting stand structure have depended on intensive data collections within a relatively small study area. This study indicates that the relationships between many stand structure indices and lidar measured canopy structure have generality at the regional scale. This finding, if replicated in other regions, would suggest that mapping of stand structure using lidar may be accomplished by distributing field sites extensively over a region, thus reducing the overall inventory effort required
Percutaneous Closure of an Aortic Pseudoaneurysm Due to Saphenous Vein Graft Dehiscence With an Amplatzer Vascular Plug
Tàpies Puig, Antoni; Garcés, Jordi; Sòria, EnricPla general de l'entrada a l'espai de
reflexió on s'aprecia el fons un díptic
de 3 per 5 metres amb la silueta
campana
PS64. A Comparison of Carotid Endarterectomy and Carotid Artery Stenting in Patients Undergoing Cardiac Surgery
Designing comparative effectiveness trials of surgical ablation for atrial fibrillation: Experience of the Cardiothoracic Surgical Trials Network
ObjectiveSince the introduction of the cut-and-sew Cox maze procedure for atrial fibrillation, there has been substantial innovation in techniques for ablation. Use of alternative energy sources for ablation simplified the procedure and has resulted in dramatic increase in the number of patients with atrial fibrillation treated by surgical ablation. Despite its increasingly widespread adoption, there is lack of rigorous clinical evidence to establish this procedure as an effective clinical therapy.MethodsThis article describes a comparative effectiveness randomized trial, supported by the Cardiothoracic Surgical Clinical Trials Network, of surgical ablation with left atrial appendage closure versus left atrial appendage closure alone in patients with persistent and long-standing persistent atrial fibrillation undergoing mitral valve surgery. Nested within this trial is a further randomized comparison of 2 different lesions sets: pulmonary vein isolation and the full maze lesion set.ResultsThis article addresses trial design challenges, including how best to characterize the target population, operationalize freedom from atrial fibrillation as a primary end point, account for the impact of antiarrhythmic drugs, and measure and analyze secondary end points, such as postoperative atrial fibrillation load.ConclusionsThis article concludes by discussing how insights that emerge from this trial may affect surgical practice and guide future research in this area
Additive genetic and environmental variation interact to shape the dynamics of seasonal migration in a wild bird population
We thank everyone who contributed to long-term field data collection, particularly Raymond Duncan, Sarah Fenn, Hannah Grist, Calum Scott, Jenny Sturgeon, Moray Souter, John Anderson, and Harry Bell; and thank NatureScot for allowing work on the Isle of May National Nature Reserve, and Isle of May Bird Observatory Trust for supporting the longterm ringing of shags. We thank Stefanie Muff for helpful discussions, and Rita Fortuna and Thomas R. Haaland for useful comments on a manuscript draft. The current study was funded by Natural Environment Research Council (NERC; awards NE/M005186/1, NE/R000859/1, and NE/R016429/1 as part of the UK-SCaPE program delivering National Capability), Norwegian Research Council (SFF-III grant 223257, FRIPRO grant 313570), NTNU and University of Aberdeen. Analyses were performed using the IDUN cluster of NTNUPeer reviewedPublisher PD
Integrating clinical decision support systems for pharmacogenomic testing into clinical routine - a scoping review of designs of user-system interactions in recent system development
Background: Pharmacogenomic clinical decision support systems (CDSS) have the potential to help overcome some of the barriers for translating pharmacogenomic knowledge into clinical routine. Before developing a prototype it is crucial for developers to know which pharmacogenomic CDSS features and user-system interactions have yet been developed, implemented and tested in previous pharmacogenomic CDSS efforts and if they have been successfully applied. We address this issue by providing an overview of the designs of user-system interactions of recently developed pharmacogenomic CDSS. Methods: We searched PubMed for pharmacogenomic CDSS published between January 1, 2012 and November 15, 2016. Thirty-two out of 118 identified articles were summarized and included in the final analysis. We then compared the designs of user-system interactions of the 20 pharmacogenomic CDSS we had identified. Results: Alerts are the most widespread tools for physician-system interactions, but need to be implemented carefully to prevent alert fatigue and avoid liabilities. Pharmacogenomic test results and override reasons stored in the local EHR might help communicate pharmacogenomic information to other internal care providers. Integrating patients into user-system interactions through patient letters and online portals might be crucial for transferring pharmacogenomic data to external health care providers. Inbox messages inform physicians about new pharmacogenomic test results and enable them to request pharmacogenomic consultations. Search engines enable physicians to compare medical treatment options based on a patient’s genotype. Conclusions: Within the last 5 years, several pharmacogenomic CDSS have been developed. However, most of the included articles are solely describing prototypes of pharmacogenomic CDSS rather than evaluating them. To support the development of prototypes further evaluation efforts will be necessary. In the future, pharmacogenomic CDSS will likely include prediction models to identify patients who are suitable for preemptive genotyping
Exile Vol. XXVII No. 1
ANDY ACKER: Four Lane Breakfast 30
MIKE AUGUSTA: The Store 25-27
J. L. FREEMAN: Bobbie 22
Poem 33
JENNIFER E. GARDNER: Photo 3
Deeds Field 9
Photo 21
Photo 23
Photo 24
LAURA GILBERT: Photo 13
Photo 28
Photo 29
Photo 31
Photo 36
KATE GLAZER: Drawing 14
MICHAEL HEINLIN: Reflections 19
DAVE HOGSHIRE: The Life And Times Of General Worm 29
CHAD HUSSEY: Waiting for Anne Sexton 13
JOHN WHITWORTH KROPF: Friends in the Park 30
DANE LAVIN: Story 4-8
LISA LAWRENCE: Poem 17
The Man With The Red Hat 15
JAMES LUNDY: Bonds 10
Photo 30
Photo 34
Twisted Ulna 11
LISA MEAD: Resistance 9
LISA MINACCI: The Drop 33
A. PENCE: The Minstrels 1
Mussels 33
PENELOPE A. RISEBOROUGH: Poem 2
Regent Street Mannequins 2
RICK RORICK: Photo 18
A. K. SESSIONS Nervious Tension 10
SUZIE SNYDER: Photo 16
L. S. VIOLA: Trash Can
JOHN ZARCHEN: In Autumn 20
ANONYMOUS: Untitled Article 32
Sandymount Strand 35
Cover drawing by Kate Glaze
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