21 results on '"Karl JW"'
Search Results
2. Percutaneous reduction and fixation of displaced phalangeal neck fractures in children.
- Author
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Karl JW, White NJ, and Strauch RJ
- Published
- 2012
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3. Global application of an unoccupied aerial vehicle photogrammetry protocol for predicting aboveground biomass in non-forest ecosystems.
- Author
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Cunliffe AM, Anderson K, Boschetti F, Brazier RE, Graham HA, Myers-Smith IH, Astor T, Boer MM, Calvo LG, Clark PE, Cramer MD, Encinas-Lara MS, Escarzaga SM, Fernández-Guisuraga JM, Fisher AG, Gdulová K, Gillespie BM, Griebel A, Hanan NP, Hanggito MS, Haselberger S, Havrilla CA, Heilman P, Ji W, Karl JW, Kirchhoff M, Kraushaar S, Lyons MB, Marzolff I, Mauritz ME, McIntire CD, Metzen D, Méndez-Barroso LA, Power SC, Prošek J, Sanz-Ablanedo E, Sauer KJ, Schulze-Brüninghoff D, Šímová P, Sitch S, Smit JL, Steele CM, Suárez-Seoane S, Vargas SA, Villarreal M, Visser F, Wachendorf M, Wirnsberger H, and Wojcikiewicz R
- Abstract
Non-forest ecosystems, dominated by shrubs, grasses and herbaceous plants, provide ecosystem services including carbon sequestration and forage for grazing, and are highly sensitive to climatic changes. Yet these ecosystems are poorly represented in remotely sensed biomass products and are undersampled by in situ monitoring. Current global change threats emphasize the need for new tools to capture biomass change in non-forest ecosystems at appropriate scales. Here we developed and deployed a new protocol for photogrammetric height using unoccupied aerial vehicle (UAV) images to test its capability for delivering standardized measurements of biomass across a globally distributed field experiment. We assessed whether canopy height inferred from UAV photogrammetry allows the prediction of aboveground biomass (AGB) across low-stature plant species by conducting 38 photogrammetric surveys over 741 harvested plots to sample 50 species. We found mean canopy height was strongly predictive of AGB across species, with a median adjusted R
2 of 0.87 (ranging from 0.46 to 0.99) and median prediction error from leave-one-out cross-validation of 3.9%. Biomass per-unit-of-height was similar within but different among, plant functional types. We found that photogrammetric reconstructions of canopy height were sensitive to wind speed but not sun elevation during surveys. We demonstrated that our photogrammetric approach produced generalizable measurements across growth forms and environmental settings and yielded accuracies as good as those obtained from in situ approaches. We demonstrate that using a standardized approach for UAV photogrammetry can deliver accurate AGB estimates across a wide range of dynamic and heterogeneous ecosystems. Many academic and land management institutions have the technical capacity to deploy these approaches over extents of 1-10 ha-1 . Photogrammetric approaches could provide much-needed information required to calibrate and validate the vegetation models and satellite-derived biomass products that are essential to understand vulnerable and understudied non-forested ecosystems around the globe., (© 2021 The Authors. Remote Sensing in Ecology and Conservation published by John Wiley & Sons Ltd on behalf of Zoological Society of London.)- Published
- 2022
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4. Provoking a Cultural Shift in Data Quality.
- Author
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McCord SE, Webb NP, Van Zee JW, Burnett SH, Christensen EM, Courtright EM, Laney CM, Lunch C, Maxwell C, Karl JW, Slaughter A, Stauffer NG, and Tweedie C
- Abstract
Ecological studies require quality data to describe the nature of ecological processes and to advance understanding of ecosystem change. Increasing access to big data has magnified both the burden and the complexity of ensuring quality data. The costs of errors in ecology include low use of data, increased time spent cleaning data, and poor reproducibility that can result in a misunderstanding of ecosystem processes and dynamics, all of which can erode the efficacy of and trust in ecological research. Although conceptual and technological advances have improved ecological data access and management, a cultural shift is needed to embed data quality as a cultural practice. We present a comprehensive data quality framework to evoke this cultural shift. The data quality framework flexibly supports different collaboration models, supports all types of ecological data, and can be used to describe data quality within both short- and long-term ecological studies., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Institute of Biological Sciences.)
- Published
- 2021
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5. Evaluation of the automated reference toolset as a method to select reference plots for oil and gas reclamation on Colorado Plateau rangelands.
- Author
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Di Stéfano S, Karl JW, Bailey DW, and Hale S
- Subjects
- Biomass, Colorado, Soil
- Abstract
Rangelands are typically characterized by low precipitation and low biomass which makes them susceptible to disturbance and difficult to reclaim. These characteristics become a management issue when considering the widespread and significant impact of oil and gas development on rangelands. Reclamation from this land use involves the complexities of dealing with multiple state and federal agencies, private landowners, and their sometimes conflicting rules. Reference plots (e.g., nearby undisturbed sites) can help with these issues by providing an objective context for reclamation planning. They are selected to provide a comparison that is similar to a reclamation site in most aspects except for the disturbance activity. This allows for the relative condition of the reclamation site to be determined. Because selection of reference plots is normally expert-driven on a site-by-site basis, it can be time consuming and thus ineffective in helping to meet reclamation goals over large landscapes. The Automated Reference Tool (ART) was developed to improve the efficiency and efficacy of reference plot selection. The ART improves reference plot selection through remote sensing and indicators of land potential by selecting reference plots of similar land potential to the reclamation site based on soil texture, topography, and geology. We evaluated the ART in the context of well-pad reclamation to determine if ART-selected plots were appropriate to use as reference when compared to an existing reference plot network. We applied the ART to reclamation sites managed by the Bureau of Land Management's (BLM) White River Field Office, Colorado which had existing expert-selected reference plots. We found that the ART-selected reference plots and their matching expert-selected reference plot had similar large-scale vegetative cover characteristics (total foliar: R
2 = 0.34, p-value = 0.0012) and dissimilar finer-scale cover characteristics (plant diversity: R2 = 0.079, p-value = 0.15). In addition, we detected similarities in their soil water content (R2 = 0.43, p-value<0.001), depth to restricting layer (RMSD = 21.90), and rock fragment (RMSD = 19.99). These results demonstrate that ART could be a useful tool for managers to help meet their reclamation goals over large landscapes, but it is not a complete automation of the reference selection process., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)- Published
- 2020
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6. Integrating drone imagery with existing rangeland monitoring programs.
- Author
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Gillan JK, Karl JW, and van Leeuwen WJD
- Subjects
- Aircraft, California, Ecosystem, Image Processing, Computer-Assisted, Conservation of Natural Resources, Environmental Monitoring methods, Remote Sensing Technology
- Abstract
The recent availability of small and low-cost sensor carrying unmanned aerial systems (UAS, commonly known as drones) coupled with advances in image processing software (i.e., structure from motion photogrammetry) has made drone-collected imagery a potentially valuable tool for rangeland inventory and monitoring. Drone-imagery methods can observe larger extents to estimate indicators at landscape scales with higher confidence than traditional field sampling. They also have the potential to replace field methods in some instances and enable the development of indicators not measurable from the ground. Much research has already demonstrated that several quantitative rangeland indicators can be estimated from high-resolution imagery. Developing a suite of monitoring methods that are useful for supporting management decisions (e.g., repeatable, cost-effective, and validated against field methods) will require additional exploration to develop best practices for image acquisition and analytical workflows that can efficiently estimate multiple indicators. We embedded with a Bureau of Land Management (BLM) field monitoring crew in Northern California, USA to compare field-measured and imagery-derived indicator values and to evaluate the logistics of using small UAS within the framework of an existing monitoring program. The unified workflow we developed to measure fractional cover, canopy gaps, and vegetation height was specific for the sagebrush steppe, an ecosystem that is common in other BLM managed lands. The correspondence between imagery and field methods yielded encouraging agreement while revealing systematic differences between the methods. Workflow best practices for producing repeatable rangeland indicators is likely to vary by vegetation composition and phenology. An online space dedicated to sharing imagery-based workflows could spur collaboration among researchers and quicken the pace of integrating drone-imagery data within adaptive management of rangelands. Though drone-imagery methods are not likely to replace most field methods in large monitoring programs, they could be a valuable enhancement for pressing local management needs.
- Published
- 2020
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7. Breaks in MODIS time series portend vegetation change: verification using long-term data in an arid grassland ecosystem.
- Author
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Browning DM, Maynard JJ, Karl JW, and Peters DC
- Subjects
- Biota, New Mexico, Seasons, Biomass, Embryophyta physiology, Grassland, Satellite Imagery
- Abstract
Frequency and severity of extreme climatic events are forecast to increase in the 21st century. Predicting how managed ecosystems may respond to climatic extremes is intensified by uncertainty associated with knowing when, where, and how long effects of extreme events will be manifest in an ecosystem. In water-limited ecosystems with high inter-annual variability in rainfall, it is important to be able to distinguish responses that result from seasonal fluctuations in rainfall from long-term directional increases or decreases in precipitation. A tool that successfully distinguishes seasonal from directional biomass responses would allow land managers to make informed decisions about prioritizing mitigation strategies, allocating human resource monitoring efforts, and mobilizing resources to withstand extreme climatic events. We leveraged long-term observations (2000-2013) of quadrat-level plant biomass at multiple locations across a semiarid landscape in southern New Mexico to verify the use of Normalized Difference Vegetation Index (NDVI) time series derived from 250-m Moderate Resolution Imaging Spectroradiometer (MODIS) data as a proxy for changes in aboveground productivity. This period encompassed years of sustained drought (2000-2003) and record-breaking high rainfall (2006 and 2008) followed by subsequent drought years (2011 through 2013) that resulted in a restructuring of plant community composition in some locations. Our objective was to decompose vegetation patterns derived from MODIS NDVI over this period into contributions from (1) the long-term trend, (2) seasonal cycle, and (3) unexplained variance using the Breaks for Additive Season and Trend (BFAST) model. BFAST breakpoints in NDVI trend and seasonal components were verified with field-estimated biomass at 15 sites that differed in species richness, vegetation cover, and soil properties. We found that 34 of 45 breaks in NDVI trend reflected large changes in mean biomass and 16 of 19 seasonal breaks accompanied changes in the contribution to biomass by perennial and/or annual grasses. The BFAST method using satellite imagery proved useful for detecting previously reported ground-based changes in vegetation in this arid ecosystem. We demonstrate that time series analysis of NDVI data holds potential for monitoring landscape condition in arid ecosystems at the large spatial scales needed to differentiate responses to a changing climate from responses to seasonal variability in rainfall., (© 2017 by the Ecological Society of America.)
- Published
- 2017
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8. A hyper-temporal remote sensing protocol for high-resolution mapping of ecological sites.
- Author
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Maynard JJ and Karl JW
- Subjects
- Climate, Environmental Monitoring methods, Models, Theoretical, New Mexico, Rain, Satellite Imagery, Seasons, Soil, Support Vector Machine, Ecosystem, Geographic Mapping, Remote Sensing Technology methods
- Abstract
Ecological site classification has emerged as a highly effective land management framework, but its utility at a regional scale has been limited due to the spatial ambiguity of ecological site locations in the U.S. or the absence of ecological site maps in other regions of the world. In response to these shortcomings, this study evaluated the use of hyper-temporal remote sensing (i.e., hundreds of images) for high spatial resolution mapping of ecological sites. We posit that hyper-temporal remote sensing can provide novel insights into the spatial variability of ecological sites by quantifying the temporal response of land surface spectral properties. This temporal response provides a spectral 'fingerprint' of the soil-vegetation-climate relationship which is central to the concept of ecological sites. Consequently, the main objective of this study was to predict the spatial distribution of ecological sites in a semi-arid rangeland using a 28-year time series of normalized difference vegetation index from Landsat TM 5 data and modeled using support vector machine classification. Results from this study show that support vector machine classification using hyper-temporal remote sensing imagery was effective in modeling ecological site classes, with a 62% correct classification. These results were compared to Gridded Soil Survey Geographic database and expert delineated maps of ecological sites which had a 51 and 89% correct classification, respectively. An analysis of the effects of ecological state on ecological site misclassifications revealed that sites in degraded states (e.g., shrub-dominated/shrubland and bare/annuals) had a higher rate of misclassification due to their close spectral similarity with other ecological sites. This study identified three important factors that need to be addressed to improve future model predictions: 1) sampling designs need to fully represent the range of both within class (i.e., states) and between class (i.e., ecological sites) spectral variability through time, 2) field sampling protocols that accurately characterize key soil properties (e.g., texture, depth) need to be adopted, and 3) additional environmental covariates (e.g. terrain attributes) need to be evaluated that may help further differentiate sites with similar spectral signals. Finally, the proposed hyper-temporal remote sensing framework may provide a standardized approach to evaluate and test our ecological site concepts through examining differences in vegetation dynamics in response to climatic variability and other drivers of land-use change. Results from this study demonstrate the efficacy of the hyper-temporal remote sensing approach for high resolution mapping of ecological sites, and highlights its utility in terms of reduced cost and time investment relative to traditional manual mapping approaches.
- Published
- 2017
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9. Brachioradialis Tendon Coverage in Volar Distal Radius Plating.
- Author
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Jew NB, Karl JW, Trupia E, Strauch RJ, and Calandruccio JH
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- Fracture Fixation, Internal adverse effects, Humans, Patient Selection, Rupture, Tendon Injuries etiology, Bone Plates, Fracture Fixation, Internal methods, Palmar Plate surgery, Radius Fractures surgery, Tendon Injuries prevention & control, Tendons surgery
- Abstract
Volar plate fixation of unstable distal radius fractures has become the preferred technique by most surgeons for the operative treatment of displaced distal radius fractures. Flexor tendon rupture is a rare but serious complication associated with this operation that is thought to be due to irritation of the flexor tendons over the prominent distal edge of the plate. We describe a novel technique of using the brachioradialis tendon to cover the distal edge of the plate to help prevent tendon irritation and rupture.
- Published
- 2016
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10. Complications of Carpal Tunnel Release.
- Author
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Karl JW, Gancarczyk SM, and Strauch RJ
- Subjects
- Carpal Tunnel Syndrome complications, Carpal Tunnel Syndrome diagnosis, Humans, Reoperation, Treatment Failure, Carpal Tunnel Syndrome surgery, Intraoperative Complications, Postoperative Complications
- Abstract
Carpal tunnel release for compression of the median nerve at the wrist is one of the most common and successful procedures in hand surgery. Complications, though rare, are potentially devastating and may include intraoperative technical errors, postoperative infection and pain, and persistent or recurrent symptoms. Patients with continued complaints after carpal tunnel release should be carefully evaluated with detailed history and physical examination in addition to electrodiagnostic testing. For those with persistent or recurrent symptoms, a course of nonoperative management including splinting, injections, occupational therapy, and desensitization should be considered prior to revision surgery., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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11. Evidence, Quality, Costs, and Reimbursement: Connecting the Dots.
- Author
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Jevsevar DS, Karl JW, Bhandari M, Bozic KJ, Piasio MA, and Weinstein SL
- Subjects
- Evidence-Based Practice organization & administration, Humans, Quality Improvement, Reimbursement Mechanisms, United States, Delivery of Health Care economics, Delivery of Health Care methods, Health Care Costs, Musculoskeletal Diseases economics, Orthopedics economics, Orthopedics methods, Quality of Health Care economics
- Abstract
Healthcare costs in the United States continue to rise, and substantial variations in the type, quality, and location of that care persist. It is critically important for all healthcare stakeholders to address and define value in orthopaedic care delivery. Evidence-based orthopaedic care delivery, reliable quality and performance measurement, and the delivery of the best care at the lowest cost are the key strategies to improve the value of musculoskeletal care. A failure to implement these strategies could negatively affect the reimbursement of all healthcare providers--at both the private and government payer levels.
- Published
- 2016
12. Isolated Brachialis Muscle Atrophy.
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Karl JW, Krosin MT, and Strauch RJ
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- Adult, Arm, Brachial Plexus Neuritis complications, Humans, Magnetic Resonance Imaging, Male, Muscular Atrophy etiology, Brachial Plexus Neuritis diagnosis, Muscle, Skeletal pathology, Muscular Atrophy diagnosis, Peripheral Nerve Injuries complications
- Abstract
solated brachialis muscle atrophy, a rare entity with few reported cases in the literature, is explained by a variety of etiologies. We present a case of unilateral, isolated brachialis muscle atrophy that likely resulted from neuralgic amyotrophy.
- Published
- 2016
13. Delayed Proximal Migration of the Radius Following Radial Head Resection for Management of a Symptomatic Radial Neck Nonunion Managed with Radial Head Replacement: A Case Report and Review of the Literature.
- Author
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Karl JW, Redler LH, and Tang P
- Subjects
- Elbow Joint diagnostic imaging, Female, Fractures, Ununited diagnostic imaging, Humans, Middle Aged, Radiography, Radius Fractures diagnostic imaging, Range of Motion, Articular, Treatment Outcome, Elbow Injuries, Fractures, Ununited surgery, Radius Fractures surgery
- Abstract
Background: Long-term outcomes of radial head resection for radial head fracture have shown mixed outcomes, depending on the integrity of the soft-tissue stabilizers of the elbow, forearm, and wrist., Methods: We report a case of a symptomatic delayed proximal migration of the radius after radial head excision for radial neck nonunion which was managed with a staged radial head replacement. Informed consent was obtained from the individual in this case report., Results: At 7 months after radial head replacement, the patient had 90 degrees of forearm supination and 85 degrees of pronation. Elbow range of motion was from 10 degrees short of full extension to 155 degrees of flexion. Her Disabilities of the Arm, Shoulder, and Hand score was 21.4 at 7 months and 6.48 at 38 months., Conclusion: There is insufficient evidence to reliably predict which patients can be managed definitively with radial head excision without risk of later proximal migration of the radius. The authors suggest the use of acute radial head arthroplasty when the index injury is secondary to a traumatic mechanism, reserving radial head excision for patients with radio-capitellar arthritis. Further research of the pathology and healing of concomitant soft-tissue injuries seen in conjunction with radial head fractures is warranted to guide their treatment.
- Published
- 2016
14. Diagnosis of Occult Scaphoid Fractures: A Cost-Effectiveness Analysis.
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Karl JW, Swart E, and Strauch RJ
- Subjects
- Adult, Algorithms, Decision Support Techniques, Fractures, Closed economics, Humans, Models, Economic, Sensitivity and Specificity, United States, Wrist Injuries economics, Cost-Benefit Analysis, Fractures, Closed diagnosis, Magnetic Resonance Imaging economics, Scaphoid Bone injuries, Tomography, X-Ray Computed economics, Wrist Injuries diagnosis
- Abstract
Background: Scaphoid fractures are common but may be missed on initial radiographs. Advanced imaging modalities such as computed tomography (CT) and magnetic resonance imaging (MRI) have improved diagnostic accuracy, but at an increased initial cost. The purpose of this study was to evaluate the cost-effectiveness of immediate advanced imaging for suspected occult scaphoid fractures., Methods: A decision analysis model was created to evaluate three diagnostic strategies for patients with concerning history and examination but negative radiographs: (1) empiric cast immobilization with orthopaedic follow-up and repeat radiography at two weeks post-injury, (2) immediate CT scanning, or (3) immediate MRI. Prevalence of occult scaphoid fracture, sensitivity and specificity of CT and MRI, and risks and outcomes of a missed fracture were derived from published clinical trials. Costs of imaging, lost worker productivity, and surgical costs of nonunion surgery were estimated on the basis of the literature., Results: Advanced imaging was dominant over empiric cast immobilization; advanced imaging had lower costs and its health outcomes were projected to be better than those of empiric cast immobilization. MRI was slightly more cost-effective than CT on the basis of the mean published diagnostic performance, but was highly sensitive to test performance characteristics. Advanced imaging would have to increase in cost to more than $2000 or decrease in sensitivity to <25% for CT or <32% for MRI for empiric cast immobilization to be cost-effective., Conclusions: Given its relatively low cost and high diagnostic accuracy, advanced imaging for suspected scaphoid fractures in the setting of negative radiographs represents a cost-effective strategy for reducing both costs and morbidity. The decision to use CT compared with MRI is a function of individual institutional costs and local test performance characteristics., (Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.)
- Published
- 2015
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15. The Epidemiology of Upper Extremity Fractures in the United States, 2009.
- Author
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Karl JW, Olson PR, and Rosenwasser MP
- Subjects
- Adolescent, Adult, Age Distribution, Aged, Aged, 80 and over, Child, Child, Preschool, Female, Humans, Infant, Infant, Newborn, Male, Middle Aged, Prevalence, Risk Factors, Sex Distribution, United States, Young Adult, Arm Injuries diagnosis, Arm Injuries epidemiology, Fractures, Bone diagnosis, Fractures, Bone epidemiology
- Abstract
Background: No single epidemiological study of upper extremity fractures exists in the United States using data from all payers. Current epidemiological estimates are based on case series, foreign databases, or Medicare data, which are not representative of the entire US population. The objective of this project was to accurately describe the incidence of fractures of the upper extremity in a representative sample of the US population., Methods: Using International Classification of Disease, Ninth Edition codes for patient visits reported in the 2009 State Emergency Department Database and the State Inpatient Database, available from the Healthcare Cost and Utilization Project, and 2010 US Census data, we calculated the annual incidence rates per 10,000 persons of upper extremity fractures of all patients, regardless of age or payer type. This was done using a representative national sample from 8 states: Arizona, California, Iowa, Maryland, Massachusetts, New Jersey, and Vermont., Results: Overall, in this population of over 87 million Americans, there were 590,193 fractures of the upper extremity, yielding an annual incidence of 67.6 fractures per 10,000 persons. Distal radius and ulna fractures were the most common upper extremity fractures (16.2 fractures per 10,000 persons), followed by hand fractures (phalangeal and metacarpal fractures; 12.5 and 8.4 per 10,000, respectively), proximal humerus fractures (6.0 per 10,000), and clavicle fractures (5.8 per 10,000). The most common type of fracture for all age groups was distal radius fractures, except in the 18- to 34-year-old group, in which metacarpal and phalangeal fractures were more common (16.1 and 12.5 per 10,000, respectively) and the 35- to 49-year-old group, in which phalangeal fractures were most common (11.5 per 10,000). The incidence of distal radius fractures was bimodal, with the highest rates in the under 18 and over 65 age groups (30.18 and 25.42 per 10,000, respectively) with lower rates in the middle age groups. The most common type of fracture for males was phalangeal fractures (11.5 per 10,000), and distal radius and ulna fractures were the most common type for females (11.8 per 10,000). Interestingly, phalangeal and metacarpal fractures varied by socioeconomic status (SES), which decreased with increasing SES. No other fracture type varied by SES., Conclusions: Epidemiological studies are necessary for research, clinical applications, and public health and health policy initiatives. This study reports national estimates of upper extremity fractures with subgroup analysis.
- Published
- 2015
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16. Modeling vegetation heights from high resolution stereo aerial photography: an application for broad-scale rangeland monitoring.
- Author
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Gillan JK, Karl JW, Duniway M, and Elaksher A
- Subjects
- Aircraft, California, Models, Biological, Nevada, Conservation of Natural Resources methods, Ecosystem, Environmental Monitoring methods, Photography, Plants, Remote Sensing Technology instrumentation
- Abstract
Vertical vegetation structure in rangeland ecosystems can be a valuable indicator for assessing rangeland health and monitoring riparian areas, post-fire recovery, available forage for livestock, and wildlife habitat. Federal land management agencies are directed to monitor and manage rangelands at landscapes scales, but traditional field methods for measuring vegetation heights are often too costly and time consuming to apply at these broad scales. Most emerging remote sensing techniques capable of measuring surface and vegetation height (e.g., LiDAR or synthetic aperture radar) are often too expensive, and require specialized sensors. An alternative remote sensing approach that is potentially more practical for managers is to measure vegetation heights from digital stereo aerial photographs. As aerial photography is already commonly used for rangeland monitoring, acquiring it in stereo enables three-dimensional modeling and estimation of vegetation height. The purpose of this study was to test the feasibility and accuracy of estimating shrub heights from high-resolution (HR, 3-cm ground sampling distance) digital stereo-pair aerial images. Overlapping HR imagery was taken in March 2009 near Lake Mead, Nevada and 5-cm resolution digital surface models (DSMs) were created by photogrammetric methods (aerial triangulation, digital image matching) for twenty-six test plots. We compared the heights of individual shrubs and plot averages derived from the DSMs to field measurements. We found strong positive correlations between field and image measurements for several metrics. Individual shrub heights tended to be underestimated in the imagery, however, accuracy was higher for dense, compact shrubs compared with shrubs with thin branches. Plot averages of shrub height from DSMs were also strongly correlated to field measurements but consistently underestimated. Grasses and forbs were generally too small to be detected with the resolution of the DSMs. Estimates of vertical structure will be more accurate in plots having low herbaceous cover and high amounts of dense shrubs. Through the use of statistically derived correction factors or choosing field methods that better correlate with the imagery, vegetation heights from HR DSMs could be a valuable technique for broad-scale rangeland monitoring needs., (Copyright © 2014 Elsevier Ltd. All rights reserved.)
- Published
- 2014
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17. Trapeziometacarpal joint stability: the evolving importance of the dorsal ligaments.
- Author
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Lin JD, Karl JW, and Strauch RJ
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- Biomechanical Phenomena, Carpometacarpal Joints surgery, Humans, Joint Instability surgery, Ligaments surgery, Osteoarthritis surgery, Osteotomy, Range of Motion, Articular, Plastic Surgery Procedures, Trapezium Bone surgery, Treatment Outcome, Carpometacarpal Joints physiopathology, Joint Instability physiopathology, Ligaments physiopathology, Osteoarthritis physiopathology, Trapezium Bone physiopathology
- Abstract
Background: Trapeziometacarpal (TMC) arthritis of the thumb is a common source of hand pain and disability. TMC ligamentous instability may play a role in TMC degeneration. However, the relative importance of the TMC ligaments in the etiology of degeneration and the use of surgery to treat instability in early-stage arthritis are unclear., Questions/purposes: In this review, we addressed several questions: (1) What are the primary ligamentous stabilizers of the thumb TMC joint? (2) What is the evidence for ligament reconstruction or ligament imbrication in the treatment of thumb TMC joint osteoarthritis? And (3) what is the evidence for thumb metacarpal osteotomy in the treatment of thumb TMC joint osteoarthritis?, Methods: We performed a systematic review of the literature using PubMed (MEDLINE(®)) and Scopus(®) (EMBASE(®)) for peer-reviewed articles published until November 2012. Fifty-two studies fit the inclusion criteria. Twenty-four studies were anatomic, biomechanical, or histopathologic studies on TMC joint ligamentous anatomy, 16 studies were clinical studies concerning ligament reconstruction, and 12 studies were clinical studies on thumb metacarpal osteotomy., Results: Over the past two decades, increasing evidence suggests the dorsoradial ligament is the most important stabilizer of the TMC joint. Other ligaments consistently identified are the superficial anterior oblique, deep anterior oblique, intermetacarpal, ulnar collateral, and posterior oblique ligaments. Ligament reconstruction and metacarpal osteotomy relieve pain and improve grip strength based on Level IV studies., Conclusions: The dorsal ligaments are the primary stabilizers of the TMC joint. Ligament reconstruction and metacarpal osteotomy ameliorate ligamentous laxity and relieve pain based on Level IV studies.
- Published
- 2014
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18. Incidence of syndesmotic injury.
- Author
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Vosseller JT, Karl JW, and Greisberg JK
- Subjects
- Adolescent, Adult, Age Distribution, Aged, Aged, 80 and over, Child, Child, Preschool, Female, Humans, Incidence, Infant, Infant, Newborn, Male, Middle Aged, Risk Factors, Sex Distribution, United States, Young Adult, Ankle Fractures, Ankle Injuries epidemiology, Emergency Service, Hospital statistics & numerical data, Hospitalization statistics & numerical data, Multiple Trauma epidemiology
- Abstract
Injury to the tibiofibular syndesmosis can occur with ankle sprain or fracture. The incidence of syndesmotic injury has not been specifically studied at a population level. Data on syndesmotic injury were obtained from the Healthcare Cost and Utilization Project (HCUP), a federal-state-private partnership. It is administered by the Agency for Healthcare Research and Quality, a division of the US Department of Health and Human Services. Two HCUP databases were queried for 8 states: the State Inpatient Database and the State Emergency Department Database. The first 6 International Classification of Diseases, Ninth Edition (ICD-9) code diagnoses were searched for codes that are used for syndesmotic injury (ie, 845.03). These data, along with data from the 2010 US census, were used to yield incidence rates for syndesmosis injury, as well as for various demographic groups. National estimates of injury totals were also calculated. In the 8 states, there were a total of 1821 syndesmotic injuries. Given the population of these states, the incidence rate of syndesmotic injury was 2.09 syndesmotic injuries per 100,000 person-years. This incidence correlates to an estimated 6445 syndesmotic injuries per year in the United States. These data provide some baseline numbers as to the incidence of syndesmotic injury in the United States. Although the incidence was low relative to some other injuries, the fact that syndesmotic injuries tend to occur in younger patients may have a greater effect in terms of productive years of life lost., (Copyright 2014, SLACK Incorporated.)
- Published
- 2014
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19. Geographic searching for ecological studies: a new frontier.
- Author
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Karl JW, Gillan JK, and Herrick JE
- Subjects
- Ecology trends, Ecosystem, Geographic Information Systems, Periodicals as Topic, Research Design trends, Ecology methods, Geographic Mapping
- Published
- 2013
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20. Rangeland and pasture monitoring: an approach to interpretation of high-resolution imagery focused on observer calibration for repeatability.
- Author
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Duniway MC, Karl JW, Schrader S, Baquera N, and Herrick JE
- Subjects
- Calibration, Conservation of Natural Resources, Ecosystem, Geographic Information Systems, Image Interpretation, Computer-Assisted, Observation, Photography, Plant Development, Reproducibility of Results, Environmental Monitoring methods, Remote Sensing Technology
- Abstract
Collection of standardized assessment and monitoring data is critically important for supporting policy and management at local to continental scales. Remote sensing techniques, including image interpretation, have shown promise for collecting plant community composition and ground cover data efficiently. More work needs to be done, however, evaluating whether these techniques are sufficiently feasible, cost-effective, and repeatable to be applied in large programs. The goal of this study was to design and test an image-interpretation approach for collecting plant community composition and ground cover data appropriate for local and continental-scale assessment and monitoring of grassland, shrubland, savanna, and pasture ecosystems. We developed a geographic information system image-interpretation tool that uses points classified by experts to calibrate observers, including point-by-point training and quantitative quality control limits. To test this approach, field data and high-resolution imagery (∼3 cm ground sampling distance) were collected concurrently at 54 plots located around the USA. Seven observers with little prior experience used the system to classify 300 points in each plot into ten cover types (grass, shrub, soil, etc.). Good agreement among observers was achieved, with little detectable bias and low variability among observers (coefficient of variation in most plots <0.5). There was a predictable relationship between field and image-interpreter data (R (2) > 0.9), suggesting regression-based adjustments can be used to relate image and field data. This approach could extend the utility of expensive-to-collect field data by allowing it to serve as a validation data source for data collected via image interpretation.
- Published
- 2012
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21. The use of thermal shrinkage for scapholunate instability.
- Author
-
Danoff JR, Karl JW, Birman MV, and Rosenwasser MP
- Subjects
- Arthroscopy, Carpal Joints, Contraindications, Debridement, Humans, Joint Instability classification, Joint Instability diagnosis, Ligaments, Articular radiation effects, Splints, Wrist Joint, Collagen radiation effects, Diathermy, Joint Instability therapy, Ligaments, Articular injuries, Lunate Bone, Scaphoid Bone
- Abstract
Scapholunate interosseous ligament (SLIL) instability is the most common form of carpal instability. There is a lack of consensus among hand surgeons as to the appropriate treatment of various stages. This article reviews the background and results of thermal treatment of predynamic instability of the SLIL. Case examples are discussed as well as a series of patients treated with our protocol for this injury., (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Published
- 2011
- Full Text
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