bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of ultrasound‐guided vs. ‘blind’ techniques for intra‐synovial injections of the shoulder area in horses: Scapulohumeral joint, bicipital and infraspinatus bursae
Authors: Schneeweiss W. , Puggioni A. , David F. 
Published: February 2012

SummaryReasons for performing study:Diagnosis and treatment of pathologies involving synovial structures in the shoulder region are technically difficult. Ultrasound‐guided (UG) injection techniques have been shown to be highly accurate, safe and reliable for various structures in human and equine patients.Objectives:To develop easy‐to‐use and reliable UG injection techniques for the infraspinatus bursa (IB), bicipital bursa (BB) and scapulohumeral joint (SHJ) and to compare them with conventional ‘blind’ methods.Methods:Eight pairs of equine shoulders were positioned on a computed‐tomography (CT) table with left and right shoulders randomly assigned to Operator A (UG) and Operator B (‘blind’). Contrast medium mixed with methylene blue was injected into the target structures. Time and number of attempts for correct needle placement and ease of injection were recorded. A CT scan of each shoulder was performed after every injection to evaluate the location of contrast material. Once injections and CT scans were completed, anatomic dissections were conducted. Statistical analysis was used to compare UG and ‘blind’ techniques with significance set at P<0.05.Results:Intra‐synovial injections using UG techniques were successful in all 24 synovial structures compared with 14/24 with conventional methods. The median number and range of needle repositioning to obtain accurate needle placement was 1 (1–2) for UG and 2 (1–4) for the ‘blind’ techniques. The median time and range required for accurate needle placement was 75.5 s (32–210 s) for UG and 43.5 s (11–140) for ‘blind’ technique. In 31% of all attempts, ease of injection was not indicative of successful intra‐synovial administration.Conclusions:Ultrasound‐guided injections of IB, BB and SHJ proved to be highly reliable and more accurate than conventional ‘blind’ techniques.Potential relevance:Ultrasound‐guided injection techniques may be of great help for equine practitioners in the diagnosis and treatment of pathologies involving synovial structures in the shoulder region. Further work is needed to confirm these results in clinical cases.
Can emergency care practitioners differentiate between an avoided emergency department attendance and an avoided admission?
Authors: Coates David , Rawstorne Steven , Benger Jonathan 
Published: February 2012

BackgroundAfter a 999 call to the ambulance service, there is no ‘gold standard’ for determining whether the actions of an emergency care practitioner (ECP) result in a patient avoiding attendance at an emergency department (ED) or avoiding an admission to hospital. Within the Great Western Ambulance Service NHS Trust this outcome has previously been measured using an audit form completed by the ECP. However, the accuracy of the ECP's opinion has not been assessed.AimTo evaluate the accuracy of the ECP's opinion when deciding whether their actions resulted in a patient avoiding attendance at an ED or avoiding hospital admission.MethodsOver a 10-week-period in 2009, quantitative data were collected using a case review approach. Anonymised patient consultation records were independently reviewed by an ED consultant and a general practitioner. The decision as to whether the actions of the ECP resulted in the patient avoiding ED attendance or hospital admission was compared between the three healthcare professionals using descriptive statistics and κ values to assess inter-rater agreement.ResultsOverall inter-rater agreement between the three healthcare professionals was κ=0.385 (fair agreement). The complete agreement rate on a case by case basis for all three healthcare professionals was 80.2% (138/172).ConclusionThis study provides some evidence that ECPs can accurately report on whether their actions, at the time of that care episode, result in a patient avoiding attendance at an ED or avoiding a hospital admission.
Safety and efficacy of symptom-driven CT decision rule in fully conscious paediatric patients with symptoms after mild closed head trauma
Authors: Xiao Bo , Wu Fang-Fang , Zhang Hong , Ma Yan-Bin 
Published: February 2012

ObjectsThe aim of the authors is to derive a safe, effective and feasible symptom-driven CT rule in fully conscious children ≥3 years with symptoms after head trauma, based on time-framed clinical course, radiological findings, outcome measures and prognosis of patients.MethodsFully conscious but symptomatic children ≥3 years after head injury (1997–2010) with CT performance ≤2 h since injury were included in the study. Additional exclusion criteria were set for patient selection. Evolution of clinical symptoms of patients in 24 h since injury was the focus in current study. Clinical data were extracted from standardised medical records on admission and observation charts.ResultsData of 1897 eligible cases were retrospectively reviewed. Traumatic brain injury (TBI) was revealed radiologically in 73 cases (3.8%). Eight cases underwent surgery. Recursive partitioning analysis identified the following factors in the CT rule: any delayed headache commenced between 4 and 10 h since injury; significantly worsening headaches present between 2 and 12 h since injury; vomiting between 6 and 12 h since injury; and headache without significant changes persisted ≥12 h since injury. It has a sensitivity of 100% (95% CI 95.0% to 100.0%) and specificity of 72.1% (95% CI 70.0% to 74.1%) to predict cases with TBI.ConclusionsA symptom-driven CT rule has been derived to identify cases at high risk of having TBI in fully conscious, but symptomatic children with mild closed head injury. To be practical, an additional observation rule is added.
The Manchester triage system: improvements for paediatric emergency care
Authors: van Veen Mirjam , Steyerberg Ewout W , van't Klooster Mariët , Ruige Madelon , van Meurs Alfred H J , van der Lei Johan , Moll Henriëtte A 
Published: February 2012

ObjectiveTo improve the Manchester Triage System (MTS) in paediatric emergency care.MethodsThe authors performed a prospective observational study at the emergency departments of a university and teaching hospital in The Netherlands and included children attending in 2007 and 2008. The authors developed and implemented specific age-dependent modifications for the MTS, based on patient groups where the system's performance was low. Nurses applied the modified system in 11 481 (84%) patients. The reference standard for urgency defined five levels based on a combination of vital signs at presentation, potentially life-threatening conditions, diagnostic resources, therapeutic interventions and follow-up. The reference standard for urgency was previously defined and available in 11 260/11 481 (96%) patients.ResultsCompared with the original MTS specificity improved from 79% (95% CI 79% to 80%) to 87% (95% CI 86% to 87%) while sensitivity remained similar ((63%, 95% CI 59% to 66%) vs (64%, 95% CI 60% to 68%)). The diagnostic OR increased (4.1 vs 11).ConclusionsModifications of the MTS for paediatric emergency care resulted in an improved specificity while sensitivity remained unchanged. Further research should focus on the improvement of sensitivity.
DNA DAMAGES AS A DEPOLYMERIZATION PROCESS
Authors: OCHOA JUAN G. DIAZ , WULKOW MICHAEL 
Published: February 2012

The damage of DNA chains by environmental factors like radiation or chemical pollutants is a topic that has been frequently explored from an experimental and a theoretical perspective. Such damages, like the damage of the strands of a DNA chain, are toxic for the cell and can induce mutagenesis or apoptosis. Several models make strong assumptions for the distribution of damages; for instance a frequent supposition is that these damages are Poisson distributed. [L. Ma, J. J. Wagner, W. Hu, A. J. Levine and G. A. Stolovitzki, Proc. Natl. Acad. Sci.PNAS 102, 14266 (2005).] Only few models describe in detail the damage and the mechanisms associated to the formation and evolution of this damage distribution [H. Nikjoo, P. O'neill and D. T. Goodhead, Radiat. Res. 156, 577 (2001).] Nevertheless, such models do not include the repair processes which are continuously active inside the cell. In this work we present a novel model, based on a depolymerization process, describing the distribution of damages on DNA chains coupled to the dynamics associated to its repair processes. The central aim is not to give a final and comprehensive model, but a hint to represent in more detail the complex dynamics involved in the damage and repair of DNA. We show that there are critical parameters associated to this repair process, in particular we show how critical doses can be relevant in deciding whether the cell continues its repair process or starts apoptosis. We also find out that the damage concentration is related to the dose via a power law relation.
On the Northward Motion of Midlatitude Cyclones in a Barotropic Meandering Jet
Authors: Oruba Ludivine , Lapeyre Guillaume , Rivière Gwendal 
Published: February 2012

Abstract
The combined effects of the deformation (horizontal stretching and shearing) and nonlinearities on the beta drift of midlatitude cyclones are studied using a barotropic quasigeostrophic model on the beta plane. It is found that, without any background flow, a cyclonic vortex moves more rapidly northward when it is initially strongly stretched along a mostly north–south direction. This meridional stretching is more efficient at forming an anticyclone to the east of the cyclone through Rossby wave radiation. The cyclone–anticyclone couple then forms a nonlinear vortex dipole that propagates mostly northward. The case of a cyclone embedded in uniformly sheared zonal flows is then studied. A cyclone evolving in an anticyclonic shear is stretched more strongly, develops a stronger anticyclone, and moves faster northward than a cyclone embedded in a cyclonic shear, which remains almost isotropic. Similar results are found in the general case of uniformly sheared nonzonal flows.
The evolution of cyclones is also investigated in the case of a more realistic meandering jet whose relative vorticity gradient creates an effective beta and whose deformation field is spatially varying. A statistical study reveals a strong correlation among the cyclone’s stretching, the anticyclone strength, and the velocity toward the jet center. These different observations agree with the more idealized cases. Finally, these results provide a rationale for the existence of preferential zones for the jet-crossing phase: that is, the phase when a cyclone crosses a jet from its anticyclonic to its cyclonic side.
Effects of Additional Particles on Already Polluted Marine Stratus
Authors: Sechrist B. , Coakley J. A. , Tahnk W. R. 
Published: February 2012

Abstract
The response of already polluted marine stratocumulus to additional particles was examined by studying the clouds where two ship tracks cross. Nearly 100 such crossings were collected and analyzed using Terra and Aqua Moderate Resolution Imaging Spectroradiometer (MODIS) multispectral imagery for the daytime passes off the western coast of the United States during the summer months of 4 years. To reduce biases in the retrieved cloud properties caused by the subpixel spatial structure of the clouds, results are presented only for ship tracks found in regions overcast by extensive layers of marine stratus. When two ship tracks cross, one of the tracks exhibits much larger changes in droplet radii when compared with the surrounding unpolluted clouds and is referred to as the dominant ship track. The clouds at the crossing typically exhibit properties that are closer to those of the dominant than to those of the subordinate ship track. To determine whether the additional particles at the crossing affect the dominant track, local gradients in the retrieved cloud properties near the crossing were determined for both ship tracks. Based on the gradients, the clouds at the junction were found to have significantly smaller droplet radii and significantly larger column droplet number concentrations than were predicted based on their values in both ship tracks on either side of the crossing. Comparing the effects of particle loading at the crossings and elsewhere along the ship tracks revealed that the effects decreased as the column droplet number concentration of the clouds being affected increased.
Reconciling the Spatial Distribution of the Surface Temperature Trends in the Southeastern United States
Authors: Misra V. , Michael J.-P. , Boyles R. , Chassignet E. P. , Griffin M. , O’Brien J. J. 
Published: February 2012

Abstract
This study attempts to explain the considerable spatial heterogeneity in the observed linear trends of monthly mean maximum and minimum temperatures (Tmax and Tmin) from station observations in the southeastern (SE) United States (specifically Florida, Alabama, Georgia, South Carolina, and North Carolina). In a majority of these station sites, the warming trends in Tmin are stronger in urban areas relative to rural areas. The linear trends of Tmin in urban areas of the SE United States are approximately 7°F century−1 compared to about 5.5°F century−1 in rural areas. The trends in Tmax show weaker warming (or stronger cooling) trends with irrigation, while trends in Tmin show stronger warming trends. This functionality of the temperature trends with land features also shows seasonality, with the boreal summer season showing the most consistent relationship in the trends of both Tmax and Tmin. This study reveals that linear trends in Tmax in the boreal summer season show a cooling trend of about 0.5°F century−1 with irrigation, while the same observing stations on an average display warming trends in Tmin of about 3.5°F century−1. The seasonality and the physical consistency of these relationships with existing theories may suggest that urbanization and irrigation have a nonnegligible influence on the spatial heterogeneity of the surface temperature trends over the SE United States. The study also delineates the caveats and limitations of the conclusions reached herein due to the potential influence of perceived nonclimatic discontinuities (which incidentally could also have a seasonal cycle) that have not been taken into account.
The Role of Atmosphere Feedbacks during ENSO in the CMIP3 Models. Part III: The Shortwave Flux Feedback
Authors: Lloyd James , Guilyardi Eric , Weller Hilary 
Published: February 2012

Abstract
Previous studies using coupled general circulation models (GCMs) suggest that the atmosphere model plays a dominant role in the modeled El Niño–Southern Oscillation (ENSO), and that intermodel differences in the thermodynamical damping of sea surface temperatures (SSTs) are a dominant contributor to the ENSO amplitude diversity. This study presents a detailed analysis of the shortwave flux feedback (αSW) in 12 Coupled Model Intercomparison Project phase 3 (CMIP3) simulations, motivated by findings that αSW is the primary contributor to model thermodynamical damping errors.
A “feedback decomposition method,” developed to elucidate the αSW biases, shows that all models underestimate the dynamical atmospheric response to SSTs in the eastern equatorial Pacific, leading to underestimated αSW values. Biases in the cloud response to dynamics and the shortwave interception by clouds also contribute to errors in αSW. Changes in the αSW feedback between the coupled and corresponding atmosphere-only simulations are related to changes in the mean dynamics.
A large nonlinearity is found in the observed and modeled SW flux feedback, hidden when linearly calculating αSW. In the observations, two physical mechanisms are proposed to explain this nonlinearity: 1) a weaker subsidence response to cold SST anomalies than the ascent response to warm SST anomalies and 2) a nonlinear high-level cloud cover response to SST. The shortwave flux feedback nonlinearity tends to be underestimated by the models, linked to an underestimated nonlinearity in the dynamical response to SST. The process-based methodology presented in this study may help to correct model ENSO atmospheric biases, ultimately leading to an improved simulation of ENSO in GCMs.
A Model Study of Heat Waves over North America: Meteorological Aspects and Projections for the Twenty-First Century
Authors: Lau Ngar-Cheung , Nath Mary Jo 
Published: February 2012

Abstract
The characteristics of summertime heat waves in North America are examined using reanalysis data and simulations by two general circulation models with horizontal resolution of 50 and 200 km. Several “key regions” with spatially coherent and high amplitude fluctuations in daily surface air temperature are identified. The typical synoptic features accompanying warm episodes in these regions are described. The averaged intensity, duration, and frequency of occurrence of the heat waves in various key regions, as simulated in the two models for twentieth-century climate, are in general agreement with the results based on reanalysis data.
The impact of climate change on the heat wave characteristics in various key regions is assessed by contrasting model runs based on a scenario for the twenty-first century with those for the twentieth century. Both models indicate considerable increases in the duration and frequency of heat wave episodes, and in number of heat wave days per year, during the twenty-first century. The duration and frequency statistics of the heat waves in the mid-twenty-first century, as generated by the model with 50-km resolution, can be reproduced by adding the projected warming trend to the daily temperature data for the late twentieth century, and then recomputing these statistics. The detailed evolution of the averaged intensity, duration, and frequency of the heat waves through individual decades of the twentieth and twenty-first centuries, as simulated and projected by the model with 200-km resolution, indicates that the upward trend in these heat wave measures should become apparent in the early decades of the twenty-first century.
Verification of Precipitation Forecasts from NCEP’s Short-Range Ensemble Forecast (SREF) System with Reference to Ensemble Streamflow Prediction Using Lumped Hydrologic Models
Authors: Brown James D. , Seo Dong-Jun , Du Jun 
Published: February 2012

Abstract
Precipitation forecasts from the Short-Range Ensemble Forecast (SREF) system of the National Centers for Environmental Prediction (NCEP) are verified for the period April 2006–August 2010. Verification is conducted for 10–20 hydrologic basins in each of the following: the middle Atlantic, the southern plains, the windward slopes of the Sierra Nevada, and the foothills of the Cascade Range in the Pacific Northwest. Mean areal precipitation is verified conditionally upon forecast lead time, amount of precipitation, season, forecast valid time, and accumulation period. The stationary block bootstrap is used to quantify the sampling uncertainties of the verification metrics. In general, the forecasts are more skillful for moderate precipitation amounts than either light or heavy precipitation. This originates from a threshold-dependent conditional bias in the ensemble mean forecast. Specifically, the forecasts overestimate low observed precipitation and underestimate high precipitation (a type-II conditional bias). Also, the forecast probabilities are generally overconfident (a type-I conditional bias), except for basins in the southern plains, where forecasts of moderate to high precipitation are reliable. Depending on location, different types of bias correction may be needed. Overall, the northwest basins show the greatest potential for statistical postprocessing, particularly during the cool season, when the type-I conditional bias and correlations are both high. The basins of the middle Atlantic and southern plains show less potential for statistical postprocessing, as the type-II conditional bias is larger and the correlations are weaker. In the Sierra Nevada, the greatest benefits of statistical postprocessing should be expected for light precipitation, specifically during the warm season, when the type-I conditional bias is large and the correlations are strong.
The Role of Advection, Straining, and Mixing on the Tidal Variability of Estuarine Stratification
Authors: Scully Malcolm E. , Geyer W. Rockwell 
Published: February 2012

Abstract
Data from the Hudson River estuary demonstrate that the tidal variations in vertical salinity stratification are not consistent with the patterns associated with along-channel tidal straining. These observations result from three additional processes not accounted for in the traditional tidal straining model: 1) along-channel and 2) lateral advection of horizontal gradients in the vertical salinity gradient and 3) tidal asymmetries in the strength of vertical mixing. As a result, cross-sectionally averaged values of the vertical salinity gradient are shown to increase during the flood tide and decrease during the ebb. Only over a limited portion of the cross section does the observed stratification increase during the ebb and decrease during the flood. These observations highlight the three-dimensional nature of estuarine flows and demonstrate that lateral circulation provides an alternate mechanism that allows for the exchange of materials between surface and bottom waters, even when direct turbulent mixing through the pycnocline is prohibited by strong stratification.
On the Solution of Elliptic Problems on Overset/Yin–Yang Grids
Authors: Zerroukat M. , Allen T. 
Published: February 2012

Abstract
The heterogeneity and the singularity of the grid are major factors in the weak scalability of longitude–latitude grid–based atmospheric models on massively parallel machines. Overset grids and, in particular, the Yin–Yang grid, are potential solutions to this problem. Using semi-implicit time marching schemes requires the solution of an elliptic problem on the particular grid. For overset/composite grids to be a viable approach, the solution of the elliptic problem has to be at least as accurate and efficient as using a single grid. This paper proposes combining the overset/Yin–Yang composite elliptic problems in one system using Krylov-type solvers and shows that the solution on overset grids is highly efficient because of the improved grid’s homogeneity.