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1.
Ecol Appl ; 32(2): e2490, 2022 03.
Article in English | MEDLINE | ID: mdl-34753222

ABSTRACT

Restoration goals in fire-prone conifer forests include mitigating fire hazard while restoring forest structural components linked to disturbance resilience and ecological function. Restoration of overstory spatial pattern in forests often falls short of management objectives due to complexities in implementation, regulation, and available data. When historical data is available, it is often collected at plots too small to inform coarse-scale metrics like gap size and structure of tree patches (e.g., 1 ha). Principles of ecological forestry typically emphasize overstory removal patterns that emulate those of natural disturbances. So, low- and moderate-severity portions of contemporary wildfires may serve as a guide to restoration treatments where mixed-severity fires occur. Here, we compare forest spatial pattern and configuration in 15 mechanical restoration treatments and low- and moderate-severity portions of three wildfires in ponderosa pine-dominated forests to determine how they differ in spatial pattern. We obtained satellite imagery of restoration treatments and wildfires and used supervised classification to differentiate canopy and openings. We assessed elements of landscape structure including canopy and gap cover, gap attributes, and landscape heterogeneity for each disturbance type. We found that both mechanical restoration treatments and low- and moderate-severity portions of wildfires reduced forest cover, increased gap cover, and altered pattern and arrangement of gaps relative to undisturbed areas, though the magnitude of changes were greatest in the burned sites. Low- and moderate-severity wildfire consistently increased landscape heterogeneity, but mechanical treatments did not. This suggests that a greater emphasis on increasing gap and patch spatial structure may make mechanical treatments more congruent with natural disturbances. Outcomes of low- and moderate-severity portions of wildfires may provide important information upon which to base management prescriptions where reference data on landscape patterns is unavailable.


Subject(s)
Fires , Wildfires , Forestry , Forests , Pinus ponderosa
2.
Heart Rhythm ; 11(3): 442-9, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24315964

ABSTRACT

BACKGROUND: The best protocol for cardiovascular preparticipation screening (PPS) in young athletes is uncertain. OBJECTIVE: The purpose of this study was to determine the value of integrating electrocardiographic (ECG) testing with standard history and physical examination during PPS to identify potentially serious cardiovascular abnormalities in young athletes. METHODS: A total of 2017 high school athletes seeking clearance for competitive sports were prospectively evaluated using a standardized history and physical examination, 12-lead ECG, and two-dimensional echocardiogram (echo). Primary outcome measures included the identification of cardiac disorders associated with sudden cardiac death. Secondary outcome measures included identification of abnormal, but nonlethal, cardiac conditions that required medical follow-up. RESULTS: Of these athletes, 14.7% had an abnormal history or physical examination and 3.1% had an abnormal ECG based on modern ECG interpretation criteria. Five primary outcomes (1 hypertrophic cardiomyopathy, 4 Wolff-Parkinson-White syndrome) and four secondary outcomes were identified. History and physical examination detected 40% of primary and 50% of secondary abnormalities. ECG detected all five primary abnormalities but none of the secondary abnormalities. Echo was abnormal in 1.2% and detected one primary and four secondary abnormalities. The false-positive rates for primary and secondary outcomes for history and physical examination and ECG were 14.5% and 2.8%, respectively. CONCLUSION: ECG adds value to PPS through increased detection of arrhythmogenic and structural cardiovascular conditions associated with sudden cardiac death. Use of modern ECG interpretation standards allows a low false-positive rate. Routine echo may detect other clinically important cardiac abnormalities, but its role in PPS remains uncertain.


Subject(s)
Athletes , Death, Sudden, Cardiac/prevention & control , Electrocardiography/methods , Mass Screening/methods , Adolescent , Echocardiography , Female , Humans , Male , Medical History Taking , Physical Examination , Prospective Studies
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