688 research outputs found

    Canopy structural modeling using object-oriented image classification and laser scanning

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    A terrestrial laser scanning (TLS) experiment was carried out in the EAGLE 2006 campaign to characterize and model the canopy structure of the Speulderbos forest. Semi-variogram analysis was used to describe spatial variability of the surface. The dependence of the spatial variability on the applied grid size showed, that in this forest spatial details of the digital surface model are lost in the case of larger than 0.3-0.4 m grid size. Voxel statistics was used for describing the density of the canopy structure. Five zones of the canopy were identified according to their density distribution. Basic geometric structures were tested for modeling the forest at the individual tree level. The results create a firm basis for modeling physical processes in the canopy

    Community Change within a Caribbean Coral Reef Marine Protected Area following Two Decades of Local Management

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    Structural change in both the habitat and reef-associated fish assemblages within spatially managed coral reefs can provide key insights into the benefits and limitations of Marine Protected Areas (MPAs). While MPA zoning effects on particular target species are well reported, we are yet to fully resolve the various affects of spatial management on the structure of coral reef communities over decadal time scales. Here, we document mixed affects of MPA zoning on fish density, biomass and species richness over the 21 years since establishment of the Saba Marine Park (SMP). Although we found significantly greater biomass and species richness of reef-associated fishes within shallow habitats (5 meters depth) closed to fishing, this did not hold for deeper (15 m) habitats, and there was a widespread decline (38% decrease) in live hard coral cover and a 68% loss of carnivorous reef fishes across all zones of the SMP from the 1990s to 2008. Given the importance of live coral for the maintenance and replenishment of reef fishes, and the likely role of chronic disturbance in driving coral decline across the region, we explore how local spatial management can help protect coral reef ecosystems within the context of large-scale environmental pressures and disturbances outside the purview of local MPA management.Funding was provided by the Saba Conservation Foundation ((SCF), King Abdullah University of Science and Technology, The Australian National University and Australian Research Council. The funders had no role in study design and analysis, decision to publish, or preparation of the manuscript. Staff of the SCF were involved in data collection

    A review of data on abundance, trends in abundance, habitat use and diet of ice-breeding seals in the Southern Ocean

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    The development of models of marine ecosystems in the Southern Ocean is becoming increasingly important as a means of understanding and managing impacts such as exploitation and climate change. Collating data from disparate sources, and understanding biases or uncertainties inherent in those data, are important first steps for improving ecosystem models. This review focuses on seals that breed in ice habitats of the Southern Ocean (i.e. crabeater seal, Lobodon carcinophaga; Ross seal, Ommatophoca rossii; leopard seal, Hydrurga leptonyx; and Weddell seal, Leptonychotes weddellii). Data on populations (abundance and trends in abundance), distribution and habitat use (movement, key habitat and environmental features) and foraging (diet) are summarised, and potential biases and uncertainties inherent in those data are identified and discussed. Spatial and temporal gaps in knowledge of the populations, habitats and diet of each species are also identified

    Targeted encouragement of GP consultations for possible cancer symptoms: a randomised controlled trial

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    BACKGROUND: For some common cancers, survival is lower in the UK than in comparable high-income countries. AIM: To assess the effectiveness of a targeted postal intervention (to promote awareness of cancer symptoms and earlier help seeking) on patient consultation rates. DESIGN AND SETTING: A two-arm randomised controlled trial was carried out on patients aged 50-84 years registered at 23 general practices in rural and urban areas of Greater London, Greater Manchester, and the North East of England. METHOD: Patients who had not had a consultation at their general practice in the previous 12 months and had at least two other risk factors for late presentation with cancer were randomised to intervention and control arms. The intervention consisted of a posted letter and leaflet. Primary outcome was the number of consultations at the practice with patients randomised to each arm in the 6 months subsequent to posting the intervention. All patients with outcome data were included in the intention-to-treat analyses. RESULTS: In total, 1513 patients were individually randomised to the intervention (n = 783) and control (n = 730) arms between Nov 2016 - May 2017; outcome data were available for 749 and 705 patients, respectively, with a statistically significantly higher rate of consultation in the intervention arm compared with the control arm: 436 versus 335 consultations (relative risk 1.40, 95% confidence interval = 1.11 to 1.77, P = 0.004). There was, however, no difference in the numbers of patients consulting. CONCLUSION: Targeted interventions of this nature can change behaviour; there is a need to develop interventions that can be more effective at engaging patients with primary care. This study demonstrates that targeted interventions promoting both awareness of possible cancer symptoms and earlier health seeking, can change behaviour. There is a need to develop and test interventions that can be more effective at engaging the most at-risk patients

    Scandinavian clinical practice guideline on fluid and drug therapy in adults with acute respiratory distress syndrome.

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    To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked Files. This article is open access.The objective of the Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI) task force on fluid and drug therapy in adults with acute respiratory distress syndrome (ARDS) was to provide clinically relevant, evidence-based treatment recommendations according to standards for trustworthy guidelines.The guideline was developed according to standards for trustworthy guidelines, including a systematic review of the literature and use of the GRADE methodology for assessment of the quality of evidence and for moving from evidence to recommendations.A total of seven ARDS interventions were assessed. We suggest fluid restriction in patients with ARDS (weak recommendation, moderate quality evidence). Also, we suggest early use of neuromuscular blocking agents (NMBAs) in patients with severe ARDS (weak recommendation, moderate quality evidence). We recommend against the routine use of other drugs, including corticosteroids, beta2 agonists, statins, and inhaled nitric oxide (iNO) or prostanoids in adults with ARDS (strong recommendations: low- to high-quality evidence). These recommendations do not preclude the use of any drug or combination of drugs targeting underlying or co-existing disorders.This guideline emphasizes the paucity of evidence of benefit - and potential for harm - of common interventions in adults with ARDS and highlights the need for prudence when considering use of non-licensed interventions in this patient population.Scandinavian Society of Anaesthesiology and Intensive Care Medicine (SSAI

    Extracellular matrix formation after transplantation of human embryonic stem cell-derived cardiomyocytes

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    Transplantation of human embryonic stem cell-derived cardiomyocytes (hESC-CM) for cardiac regeneration is hampered by the formation of fibrotic tissue around the grafts, preventing electrophysiological coupling. Investigating this process, we found that: (1) beating hESC-CM in vitro are embedded in collagens, laminin and fibronectin, which they bind via appropriate integrins; (2) after transplantation into the mouse heart, hESC-CM continue to secrete collagen IV, XVIII and fibronectin; (3) integrin expression on hESC-CM largely matches the matrix type they encounter or secrete in vivo; (4) co-transplantation of hESC-derived endothelial cells and/or cardiac progenitors with hESC-CM results in the formation of functional capillaries; and (5) transplanted hESC-CM survive and mature in vivo for at least 24 weeks. These results form the basis of future developments aiming to reduce the adverse fibrotic reaction that currently complicates cell-based therapies for cardiac disease, and to provide an additional clue towards successful engraftment of cardiomyocytes by co-transplanting endothelial cells

    Massive expansion and cryopreservation of functional human induced pluripotent stem cell-derived cardiomyocyte

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    Since the discovery of human induced pluripotent stem cells (hiPSCs), numerous strategies have been established to efficiently derive cardiomyocytes from hiPSCs (hiPSC-CMs). Here, we describe a cost-effective strategy for the subsequent massive expansion (>250-fold) of high-purity hiPSC-CMs relying on two aspects: removal of cell-cell contacts and small-molecule inhibition with CHIR99021. The protocol maintains CM functionality, allows cryopreservation, and the cells can be used in downstream assays such as disease modeling, drug and toxicity screening, and cell therapy. For complete details on the use and execution of this protocol, please refer to Buikema (2020)

    Waiting list mortality and the potential of donation after circulatory death heart transplantations in the Netherlands

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    BACKGROUND: With more patients qualifying for heart transplantation (HT) and fewer hearts being transplanted, it is vital to look for other options. To date, only organs from brain-dead donors have been used for HT in the Netherlands. We investigated waiting list mortality in all Dutch HT centres and the potential of donation after circulatory death (DCD) HT in the Netherlands. METHODS: Two different cohorts were evaluated. One cohort was defined as patients who were newly listed or were already on the waiting list for HT between January 2013 and December 2017. Follow-up continued until September 2018 and waiting list mortality was calculated. A second cohort of all DCD donors in the Netherlands (lung, liver, kidney and pancreas) between January 2013 and December 2017 was used to calculate the potential of DCD HT. RESULTS: Out of 395 patients on the waiting list for HT, 196 (50%) received transplants after a median waiting time of 2.6 years. In total, 15% died while on the waiting list before a suitable donor heart became available. We identified 1006 DCD donors. After applying exclusion criteria and an age limit of 50 years, 122 potential heart donors remained. This number increased to 220 when the age limit was extended to 57 years. CONCLUSION: Waiting list mortality in the Netherlands is high. HT using organs from DCD donors has great potential in the Netherlands and could lead to a reduction in waiting list mortality. Cardiac screening will eventually determine the true potential
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