42 research outputs found

    Probabilistic fire spread forecast as a management tool in an operational setting

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    Background: An approach to predict fire growth in an operational setting, with the potential to be used as a decision-support tool for fire management, is described and evaluated. The operational use of fire behaviour models has mostly followed a deterministic approach, however, the uncertainty associated with model predictions needs to be quantified and included in wildfire planning and decision-making process during fire suppression activities. We use FARSITE to simulate the growth of a large wildfire. Probabilistic simulations of fire spread are performed, accounting for the uncertainty of some model inputs and parameters. Deterministic simulations were performed for comparison. We also assess the degree to which fire spread modelling and satellite active fire data can be combined, to forecast fire spread during large wildfires events. Results: Uncertainty was propagated through the FARSITE fire spread modelling system by randomly defining 100 different combinations of the independent input variables and parameters, and running the correspondent fire spread simulations in order to produce fire spread probability maps. Simulations were initialized with the reported ignition location and with satellite active fires. The probabilistic fire spread predictions show great potential to be used as a fire management tool in an operational setting, providing valuable information regarding the spatial–temporal distribution of burn probabilities. The advantage of probabilistic over deterministic simulations is clear when both are compared. Re-initializing simulations with satellite active fires did not improve simulations as expected. Conclusion: This information can be useful to anticipate the growth of wildfires through the landscape with an associated probability of occurrence. The additional information regarding when, where and with what probability the fire might be in the next few hours can ultimately help minimize the negative environmental, social and economic impacts of these firesinfo:eu-repo/semantics/publishedVersio

    The use of airborne laser scanning to develop a pixel-based stratification for a verified carbon offset project

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    Background The voluntary carbon market is a new and growing market that is increasingly important to consider in managing forestland. Monitoring, reporting, and verifying carbon stocks and fluxes at a project level is the single largest direct cost of a forest carbon offset project. There are now many methods for estimating forest stocks with high accuracy that use both Airborne Laser Scanning (ALS) and high-resolution optical remote sensing data. However, many of these methods are not appropriate for use under existing carbon offset standards and most have not been field tested. Results This paper presents a pixel-based forest stratification method that uses both ALS and optical remote sensing data to optimally partition the variability across an ~10,000 ha forest ownership in Mendocino County, CA, USA. This new stratification approach improved the accuracy of the forest inventory, reduced the cost of field-based inventory, and provides a powerful tool for future management planning. This approach also details a method of determining the optimum pixel size to best partition a forest. Conclusions The use of ALS and optical remote sensing data can help reduce the cost of field inventory and can help to locate areas that need the most intensive inventory effort. This pixel-based stratification method may provide a cost-effective approach to reducing inventory costs over larger areas when the remote sensing data acquisition costs can be kept low on a per acre basis

    Roadless and Low-Traffic Areas as Conservation Targets in Europe

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    With increasing road encroachment, habitat fragmentation by transport infrastructures has been a serious threat for European biodiversity. Areas with no roads or little traffic (“roadless and low-traffic areas”) represent relatively undisturbed natural habitats and functioning ecosystems. They provide many benefits for biodiversity and human societies (e.g., landscape connectivity, barrier against pests and invasions, ecosystem services). Roadless and low-traffic areas, with a lower level of anthropogenic disturbances, are of special relevance in Europe because of their rarity and, in the context of climate change, because of their contribution to higher resilience and buffering capacity within landscape ecosystems. An analysis of European legal instruments illustrates that, although most laws aimed at protecting targets which are inherent to fragmentation, like connectivity, ecosystem processes or integrity, roadless areas are widely neglected as a legal target. A case study in Germany underlines this finding. Although the Natura 2000 network covers a significant proportion of the country (16%), Natura 2000 sites are highly fragmented and most low-traffic areas (75%) lie unprotected outside this network. This proportion is even higher for the old Federal States (western Germany), where only 20% of the low-traffic areas are protected. We propose that the few remaining roadless and low-traffic areas in Europe should be an important focus of conservation efforts; they should be urgently inventoried, included more explicitly in the law and accounted for in transport and urban planning. Considering them as complementary conservation targets would represent a concrete step towards the strengthening and adaptation of the Natura 2000 network to climate change

    Simulated impacts of mountain pine beetle and wildfire disturbances on forest vegetation composition and carbon stocks in the Southern Rocky Mountains

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    Forests play an important role in sequestering carbon and offsetting anthropogenic greenhouse gas emissions, but changing disturbance regimes may compromise the capability of forests to store carbon. In the Southern Rocky Mountains, a recent outbreak of mountain pine beetle (\textit{Dendroctonus ponderosae}; MPB) has caused remarkable levels of tree mortality. To evaluate the long-term impacts of both this insect outbreak and another characteristic disturbance in these forests, high-severity wildfire, we simulated potential changes in species composition and carbon stocks using the Forest Vegetation Simulator (FVS). Simulations were completed for 3 scenarios (no disturbance, actual MPB infestation, and modeled wildfire) using field data collected in 2010 at 97 plots in the lodgepole-pine-dominated forests of eastern Grand County, Colorado, which were heavily impacted by MPB after 2002. Results of the simulations showed that (1) lodgepole pine remained dominant over time in all scenarios, with basal area recovering to pre-disturbance levels 70–80 yr after disturbance; (2) wildfire caused a greater magnitude of change than did MPB in both patterns of succession and distribution of carbon among biomass pools; (3) levels of standing-live carbon returned to pre-disturbance conditions after 40 vs. 50 yr following MPB vs. wildfire disturbance, respectively, but took 120 vs. 150 yr to converge with conditions in the undisturbed scenario. Lodgepole pine forests appear to be relatively resilient to both of the disturbances we modeled, although changes in climate, future disturbance regimes, and other factors may significantly affect future rates of regeneration and ecosystem response

    Bedside echo for chest pain: an algorithm for education and assessment

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    Richard Amini, Lori A Stolz, Jeffrey Z Kartchner, Matthew Thompson, Nicholas Stea, Nicolaus Hawbaker, Raj Joshi, Srikar Adhikari Department of Emergency Medicine, University of Arizona Medical Center, Tucson, AZ, USA Background: Goal-directed ultrasound protocols have been developed to facilitate efficiency, throughput, and patient care. Hands-on instruction and training workshops have been shown to positively impact ultrasound training.  Objectives: We describe a novel undifferentiated chest pain goal-directed ultrasound algorithm-focused education workshop for the purpose of enhancing emergency medicine resident training in ultrasound milestones competencies.  Methods: This was a cross-sectional study performed at an academic medical center. A novel goal-directed ultrasound algorithm was developed and implemented as a model for teaching and learning the sonographic approach to a patient with undifferentiated chest pain. This algorithm was incorporated into all components of the 1-day workshop: asynchronous learning, didactic lecture, case-based learning, and hands-on stations. Performance comparisons were made between postgraduate year (PGY) levels.  Results: A total of 38 of the 40 (95%) residents who attended the event participated in the chest pain objective standardized clinical exam, and 26 of the 40 (65%) completed the entire questionnaire. The average number of ultrasounds performed by resident class year at the time of our study was as follows: 19 (standard deviation [SD]=19) PGY-1, 238 (SD=37) PGY-2, and 289 (SD=73) PGY-3. Performance on the knowledge-based questions improved between PGY-1 and PGY-3. The application of the novel algorithm was noted to be more prevalent among the PGY-1 class.  Conclusion: The 1-day algorithm-based ultrasound educational workshop was an engaging learning technique at our institution. Keywords: point-of care ultrasound, algorithm education, education, chest pain, bedside ultrasound, POCU

    What is the ideal approach for emergent pericardiocentesis using point-of-care ultrasound guidance?

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    BACKGROUND: Traditionally performed using a subxiphoid approach, the increasing use of pointof- care ultrasound in the emergency department has made other approaches (parasternal and apical) for pericardiocentesis viable. The aim of this study is to identify the ideal approach for emergency-physicianperformed ultrasound-guided pericardiocentesis as determined by ultrasound image quality, distance from surface to pericardial fluid, and likely obstructions or complications. METHODS: A retrospective review of point-of-care cardiac ultrasound examinations was performed in two urban academic emergency departments for the presence of pericardial eff usions. The images were reviewed for technical quality, distance of eff usion from skin surface, and predicted complications. RESULTS: A total of 166 pericardial effusions were identified during the study period. The mean skin-to-pericardial fluid distance was 5.6 cm (95% confidence interval [95% CI] 5.2-6.0 cm) for the subxiphoid views, which was significantly greater than that for the parasternal (2.7 cm [95% CI 2.5-2.8 cm], P<0.001) and apical (2.5 cm [95% CI 2.3-2.7 cm], P<0.001) views. The subxiphoid view had the highest predicted complication rate at 79.7% (95% CI 71.5%-86.4%), which was significantly greater than the apical (31.9%; 95% CI 21.4%-44.0%, P<0.001) and parasternal (20.2%; 95% CI 12.8%-29.5%, P<0.001) views. CONCLUSIONS: Our results suggest that complication rates with pericardiocentesis will be lower via the parasternal or apical approach compared to the subxiphoid approach. The distance from skin to fluid collection is the least in both of these views. © 2021 World Journal of Emergency Medicine.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

    Failed noninvasive positive-pressure ventilation is associated with an increased risk of intubation-related complications

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    UA Open Access Publishing FundBackground: Noninvasive positive-pressure ventilation (NIPPV) use has increased in the treatment of patients with respiratory failure. However, despite decreasing the need for intubation in some patients, there are no data regarding the risk of intubation-related complications associated with delayed intubation in adult patients who fail NIPPV. The objective of this study is to evaluate the odds of a composite complication of intubation following failed NIPPV compared to patients intubated primarily in the medical intensive care unit (ICU). Methods: This is a single-center retrospective cohort study of 235 patients intubated between 1 January 2012 and 30 June 2013 in a medical ICU of a university medical center. A total of 125 patients were intubated after failing NIPPV, 110 patients were intubated without a trial of NIPPV. Intubation-related data were collected prospectively through a continuous quality improvement (CQI) program and retrospectively extracted from the medical record on all patients intubated on the medical ICU. A propensity adjustment for the factors expected to affect the decision to initially use NIPPV was used, and the adjusted multivariate regression analysis was performed to evaluate the odds of a composite complication (desaturation, hypotension, or aspiration) with intubation following failed NIPPV versus primary intubation. Results: A propensity-adjusted multivariate regression analysis revealed that the odds of a composite complication of intubation in patients who fail NIPPV was 2.20 (CI 1.14 to 4.25), when corrected for the presence of pneumonia or acute respiratory distress syndrome (ARDS), and adjusted for factors known to increase complications of intubation (total attempts and operator experience). When a composite complication occurred, the unadjusted odds of death in the ICU were 1.79 (95% CI 1.03 to 3.12). Conclusions: After controlling for potential confounders, this propensity-adjusted analysis demonstrates an increased odds of a composite complication with intubation following failed NIPPV. Further, the presence of a composite complication during intubation is associated with an increased odds of death in the ICU.Open access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
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