bluuebunny/crossref_metadata_2025_split huggingface dataset:
CT and MRI Early Vessel Signs Reflect Clot Composition in Acute Stroke
Authors: Liebeskind David S. , Sanossian Nerses , Yong William H. , Starkman Sidney , Tsang Michael P. , Moya Antonio L. , Zheng David D. , Abolian Anna M. , Kim Doojin , Ali Latisha K. , Shah Samir H. , Towfighi Amytis , Ovbiagele Bruce , Kidwell Chelsea S. , Tateshima Satoshi , Jahan Reza , Duckwiler Gary R. , Viñuela Fernando , Salamon Noriko , Villablanca J. Pablo , Vinters Harry V. , Marder Victor J. , Saver Jeffrey L. 
Published: March 2011

Background and Purpose—
The purpose of this study was to provide the first correlative study of the hyperdense middle cerebral artery sign (HMCAS) and gradient-echo MRI blooming artifact (BA) with pathology of retrieved thrombi in acute ischemic stroke.

Methods—
Noncontrast CT and gradient-echo MRI studies before mechanical thrombectomy in 50 consecutive cases of acute middle cerebral artery ischemic stroke were reviewed blinded to clinical and pathology data. Occlusions retrieved by thrombectomy underwent histopathologic analysis, including automated quantitative and qualitative rating of proportion composed of red blood cells (RBCs), white blood cells, and fibrin on microscopy of sectioned thrombi.

Results—

Among 50 patients, mean age was 66 years and 48% were female. Mean (SD) proportion was 61% (±21) fibrin, 34% (±21) RBCs, and 4% (±2) white blood cells. Of retrieved clots, 22 (44%) were fibrin-dominant, 13 (26%) RBC-dominant, and 15 (30%) mixed. HMCAS was identified in 10 of 20 middle cerebral artery stroke cases with CT with mean Hounsfield Unit density of 61 (±8 SD). BA occurred in 17 of 32 with gradient-echo MRI. HMCAS was more commonly seen with RBC-dominant and mixed than fibrin-dominant clots (100% versus 67% versus 20%,
P
=0.016). Mean percent RBC composition was higher in clots associated with HMCAS (47% versus 22%,
P
=0.016). BA was more common in RBC-dominant and mixed clots compared with fibrin-dominant clots (100% versus 63% versus 25%,
P
=0.002). Mean percent RBC was greater with BA (42% versus 23%,
P
=0.011).

Conclusions—
CT HMCAS and gradient-echo MRI BA reflect pathology of occlusive thrombus. RBC content determines appearance of HMCAS and BA, whereas absence of HMCAS or BA may indicate fibrin-predominant occlusive thrombi.
Cerebral Microembolism During Coronary Angiography
Authors: Jurga Juliane , Nyman Jesper , Tornvall Per , Mannila Maria Nastase , Svenarud Peter , van der Linden Jan , Sarkar Nondita 
Published: March 2011

Background and Purpose—
Microemboli observed during coronary angiography can cause silent ischemic cerebral lesions. The aim of this study was to investigate if the number of particulate cerebral microemboli during coronary angiography is influenced by access site used.

Methods—
Fifty-one patients with stable angina pectoris referred for coronary angiography were randomized to right radial or right femoral arterial access. The number of particulate microemboli passing the middle cerebral arteries was continuously registered with transcranial Doppler.

Results—
The median (minimum–maximum range) numbers of particulate emboli were significantly higher with radial 10 (1–120) than with femoral 6 (1–19) access. More particulate microemboli passed the right middle cerebral artery with the radial access.

Conclusions—
This study indicates that the radial access used for coronary angiography generates more particulate cerebral microemboli than the femoral access and thus may influence the occurrence of silent cerebral injuries.
Interannual Variations of Summer Monsoons: Sensitivity to Cloud Radiative Forcing
Authors: Sharma O. P. , Le Treut H. , Sèze G. , Fairhead L. , Sadourny R. 
Published: March 2011

AbstractThe sensitivity of the interannual variations of the summer monsoons to imposed cloudiness has been studied with a general circulation model using the initial conditions prepared from the European Centre for Medium-Range Forecasts analyses of 1 May 1987 and 1988. The cloud optical properties in this global model are calculated from prognostically computed cloud liquid water. The model successfully simulates the contrasting behavior of these two successive monsoons. However, when the optical properties of the observed clouds are specified in the model runs, the simulations show some degradation over India and its vicinity. The main cause of this degradation is the reduced land–sea temperature contrast resulting from the radiative effects of the observed clouds imposed in such simulations. It is argued that the high concentration of condensed water content of clouds over the Indian land areas will serve to limit heating of the land, thereby reducing the thermal contrast that gives rise to a weak Somali jet. A countermonsoon circulation is, therefore, simulated in the vector difference field of 850-hPa winds from the model runs with externally specified clouds. This countermonsoon circulation is associated with an equatorial heat source that is the response of the model to the radiative effects of the imposed clouds. Indeed, there are at least two clear points that can be made: 1) the cloud–SST patterns, together, affect the interannual variability; and 2) with both clouds and SST imposed, the model simulation is less sensitive to initial conditions. Additionally, the study emphasizes the importance of dynamically consistent clouds developing in response to the dynamical, thermal, and moist state of the atmosphere during model integrations.
High-Resolution Satellite Analysis and Model Evaluation of Clouds and Radiation over the Mackenzie Basin Using AVHRR Data
Authors: Garand Louis , Nadon Serge 
Published: March 2011

AbstractBoth the issues of high-resolution satellite analysis and model evaluation for a region centered on the Arctic Circle (60°–75°N) are addressed. Model cloud fraction, cloud height, and outgoing radiation are compared to corresponding satellite observations using a model-to-satellite approach (calculated radiances from model state). The dataset consists of forecasts run at 15-km resolution up to 30 h and nearly coincident Advanced Very High Resolution Radiometer (AVHRR) imagery during the Beaufort and Arctic Storm Experiment over the Mackenzie Basin for a monthly period in the fall of 1994. A cloud detection algorithm is designed for day and night application using the 11-μ channel of AVHRR along with available information on atmospheric and ground temperatures. The satellite and model estimates of cloud fraction are also compared to observations at 20 ground stations.A significant result of the validation is that the model has a higher frequency of low cloud tops and a lower frequency of midlevel cloud tops than the observations. On a monthly basis, the model 11-μ outgoing brightness temperature (TB) is consequently higher than observed by about 4.4 K at all forecast times, which corresponds to a deficit of 760 m in mean cloud-top height and about 10 W m−2 in outgoing flux at the top of the atmosphere. Possible errors in the parameterization of ice or water cloud emissivity are evaluated but ruled out as the dominant cause for the warm TB bias in the model. Rather, the problem is attributed to low clouds being trapped in the boundary layer, whereas high clouds appear to be reasonably well modeled.The role of thin ice clouds is further evaluated by comparing distributions of observed and modeled 11-μ minus 12-μ TB differences, DIF45 (channel 4 minus channel 5). The relationship between the true height of the clouds and the effective height observed by satellite is modeled from forecast outputs as a function of DIF45. The quality of daily estimates is evaluated from time series at various locations. The time series shows that there was a marked drop in DIF45 during the month, which is attributed to a decrease in the occurrence of cirrus clouds. Finally, the diurnal cycle of TB and cloud fraction is found to be relatively large with average monthly 0600–1800 UTC TB differences of both signs of the order of 4–8 K in broad sectors and cloud fraction differences of 10%–30%. Where low clouds prevail, the cloud fraction tends to decrease at night and TB increases. Overall, model–observation differences are dominated by differences in the vertical distribution of clouds. A reduction of this effect implies a modification of the “preferred” model climatology in terms of its vertical distribution of humidity and cloud water.
Analysis of the Merging Procedure for the MSU Daily Temperature Time Series
Authors: Christy John R. , Spencer Roy W. , Lobl Elena S. 
Published: March 2011

Abstract
The merging procedure utilized to generate homogeneous time series of three deep-layer atmospheric temperature products from the nine microwave sounding units (MSUs) is described. A critically important aspect in the process is determining and removing the bias each instrument possesses relative to a common base (here being NOAA-6). Special attention is given to the lower-tropospheric layer and the calculation of the bias of the NOAA-9 MSU and its rather considerable impact on the trend of the overall time series. We show that the bias is best calculated by a direct comparison between NOAA-6 and NOAA-9, though there other possible methods available, and is determined to be +0.50°C. Spurious variations of individual MSUs due to orbital drift and/or cyclic variations tied to the annual cycle are also identified and eliminated. In general, intersatellite biases for the three instruments that form the backbone of the time series (MSUs on NOAA-6, -10 and -12) are known to within 0.01°C.
After slight modifications in the treatment of the bias, drift-error, and cyclic fluctuations, the authors produced a time series in which the decadal trend is +0.03°C warmer than previously reported for the lower troposphere. Because they are of much higher precision, the midtropospheric and lower-stratospheric products are only slightly affected by alterations to procedures applied in this study.
Recent suggestions that spurious jumps were present in the lower-tropospheric time series of earlier versions of the MSU data based on SST comparisons are addressed. Using independent comparisons of different satellites, radiosondes, and night marine air temperatures, no indication is found of the presence of these “spurious” jumps.
Emergence of Wind-Driven Near-Inertial Waves in the Deep Ocean Triggered by Small-Scale Eddy Vorticity Structures
Authors: Danioux Eric , Klein Patrice , Hecht Matthew W. , Komori Nobumasa , Roullet Guillaume , Le Gentil Sylvie 
Published: March 2011

Abstract
Using numerical simulations forced by a uniform realistic wind time series, the authors show that the presence of a mesoscale eddy field at midlatitudes accelerates the vertical propagation of the wind-forced near-inertial waves (NIW) and produces the emergence of a maximum of vertical velocity into the deep ocean (around 2500 m) characterized by a mean amplitude of 25 m day−1, a dominant 2f frequency, and scales as small as O(30 km). These results differ from previous studies that reported a smaller depth and larger scales. The authors show that the larger depth observed in the present study (2500 m instead of 1700 m) is due to the wind forcing duration that allows the first five baroclinic modes to disperse and to impact the deep NIW maximum (instead of the first two modes as reported before). The smaller scales (30 km instead of 90 km) are explained by a resonance mechanism (described in previous studies) that affects the high NIW baroclinic modes, but only when small-scale relative vorticity structures (related to the mesoscale eddy field) have an amplitude that is large enough. These results, which point out the importance of the wind forcing duration and the resolution, indicate that the emergence of a deep NIW maximum with a 2f frequency reported before is a robust feature that is enhanced with more realistic conditions. Such 2f frequency in the deep interior raises the question of the mechanisms, still unresolved, that may ultimately transfer this superinertial energy into mixing at these depths.
Diagnosing Lateral Mixing in the Upper Ocean with Virtual Tracers: Spatial and Temporal Resolution Dependence
Authors: Keating Shane R. , Smith K. Shafer , Kramer Peter R. 
Published: March 2011

Abstract
Several recent studies diagnose lateral stirring and mixing in the upper ocean using altimetry-derived velocity fields to advect “virtual” particles and fields offline. However, the limited spatiotemporal resolution of altimetric maps leads to errors in the inferred diagnostics, because unresolved scales are necessarily imperfectly modeled. The authors examine a range of tracer diagnostics in two models of baroclinic turbulence: the standard Phillips model, in which dispersion is controlled by large-scale eddies, and the Eady model, where dispersion is determined by local scales of motion. These models serve as a useful best- and worst-case comparison and a valuable test of the resolution sensitivity of tracer diagnostics.
The effect of unresolved scales is studied by advecting tracers using model velocity fields subsampled in space and time and comparing the derived tracer diagnostics with their “true” value obtained from the fully resolved flow. The authors find that eddy diffusivity and absolute dispersion, which are governed by large-scale dynamics, are insensitive to spatial sampling error in either flow. Measures that depend strongly on small scales, such as relative dispersion and finite-time Lyapunov exponents, are highly sensitive to spatial sampling in the Eady model. Temporal sampling error is found to have a more complicated behavior because of the onset of particle overshoot leading to scrambling of Lagrangian diagnostics. This leads to a potential restriction on the utility of raw altimetry maps for studying mixing in the upper ocean. The authors conclude that offline diagnostics of mixing in ocean flows with an energized submesoscale should be viewed with some caution.
Sensitivity of Dynamical Intraseasonal Prediction Skills to Different Initial Conditions
Authors: Fu Xiouhua , Wang Bin , Lee June-Yi , Wang Wanqiu , Gao Li 
Published: March 2011

AbstractPredictability of intraseasonal oscillation (ISO) relies on both initial conditions and lower boundary conditions (or atmosphere–ocean interaction). The atmospheric reanalysis datasets are commonly used as initial conditions. Here, the biases of three reanalysis datasets [the NCEP reanalysis 1 and 2 (NCEP-R1 and -R2) and the ECMWF Re-Analysis Interim (ERA-Interim)] in describing ISO were briefly revealed and the impacts of these biases as initial conditions on ISO prediction skills were assessed. A signal-recovery method is proposed to improve ISO prediction.Although all three reanalyses underestimate the intensity of the equatorial eastward-propagating ISO, the overall quality of the ERA-Interim is better than the NCEP-R1 and -R2. When these reanalyses are used as initial conditions in the ECHAM4-University of Hawaii hybrid coupled model (UH-HCM), skillful ISO prediction reaches only about 1 week for both the 850-hPa zonal winds (U850) and rainfall over Southeast Asia and the global tropics. An enhanced nudging of the divergence field is shown to significantly improve the initial conditions, resulting in an extension of the skillful rainfall prediction by 2–4 days and U850 prediction by 5–10 days.After recovering the ISO signals in the original reanalyses, the resultant initial conditions contain ISO strength closer to the observed, whereas the rainfall spatial pattern correlation in the ERA-Interim reanalysis drops. The resultant ISO prediction skills, however, are consistently extended for all the NCEP and ERA-Interim reanalyses. Using these signal-recovered reanalyses as initial conditions, the boreal summer ISO prediction skill measured with the Wheeler–Hendon index reaches 14 days. The U850 and rainfall prediction skills, respectively, reach 23 and 18 days over Southeast Asia. It is also found that small-scale synoptic weather disturbances in initial conditions generally increase ISO prediction skills. Both the UH-HCM and NCEP Climate Forecast System (CFS) suffer the prediction barrier over the Maritime Continent.
Objective Debiasing for Improved Forecasting of Tropical Cyclone Intensity with a Global Circulation Model
Authors: Goswami P. , Mallick S. , Gouda K. C. 
Published: March 2011

AbstractThe damage potential of a tropical cyclone is proportional to a power (generally greater than one) of intensity, which demands high accuracy in forecasting intensity for managing this natural disaster. However, the current skill in forecasting cyclone intensity is rather limited, especially over the north Indian Ocean, with very little improvement over the years. A methodology is presented here for objective nonlinear debiasing to generate intensity forecasts with enhanced reliability from raw forecasts. The intensity forecast is generated using an optimized configuration of a variable resolution global circulation model (VR-GCM) that combines the advantages of a limited area model and a global model. The hindcasts were carried out in a completely operational setting, that is, without assuming any observed information beyond the day of the initial condition. The VR-GCM and a nonlinear debiasing were found to provide skill (skill score ~0.5) in forecasting tropical cyclone intensity 2–7 days (variable depending on event) in advance for the 30 cases including storms and cyclones representing different locations, seasons, and years (1990–2005) over the Bay of Bengal. Two types of debiasing are considered: nonlinear debiasing with all observations (potential skill) and nonlinear debiasing for realizable skill (training without in-sample data). It is shown that while skill scores without debiasing are only marginally better than a climatological forecast (null hypothesis), the skill score with a nonlinear debiasing is appreciable. The climatological forecast has zero skill score, a mean absolute error of 12.9 m s−1, and 20% of the cases are in the error bin −5 to +5 m s−1; the corresponding numbers for debiased forecasts for realizable skill are 0.65, 6.4 m s−1, and 57%. It is further shown that the nonlinear debiasing is also effective in improving forecast of (3-hourly) intensity change. While a strict comparison of skill with other methods requires experiments to be carried out for the same events, a comparison of the skill of other methods and over different ocean basins based on available data shows the present method to have comparable skill. However, it may be noted that the present conclusions are based on a relatively small (30 events) sample size; evaluation with a much large sample size is desirable for actual application.
Cystic Fibrosis and Sinusitis in Children
Authors: Kovell Lara C. , Wang Jiangxia , Ishman Stacey L. , Zeitlin Pamela L. , Boss Emily F. 
Published: March 2011

ObjectivesAlthough chronic sinusitis is prevalent in children with cystic fibrosis (CF), little is known regarding pulmonary outcomes following endoscopic sinus surgery (ESS). Furthermore, lower socioeconomic status (SES) is associated with increased morbidity in children with CF. The investigators evaluated the impact of surgery and SES on pulmonary function tests (PFTs) in children with CF and rhinosinusitis.Study DesignLongitudinal, retrospective cohort study.SettingUrban tertiary CF center.Subjects and MethodsChildren with CF ages 0 to 21 evaluated for sinusitis between 1998 and 2008 were analyzed. Children were grouped according to surgery status (ESS or no ESS). Medicaid (MA) insurance was used as a proxy for lower SES. PFTs (percent predicted forced vital capacity [FVC%predicted] and percent predicted forced expiratory volume in 1 second [FEV1%predicted]) were recorded over 2 years. Multivariate linear regression models and interaction terms (ESS and MA) were used to analyze PFTs.ResultsOf 62 patients evaluated, 21 (34%) underwent ESS, and 16 (26%) had MA. Polyps were more common in the ESS group (86% vs 32%, P <. 001). FEV1%predicted and FVC%predicted were lower at all times for children with MA (P <. 001). After adjustment for MA, mean FEV1%predicted was higher for the ESS group at all time points (P <. 02), and mean FVC%predicted was higher at 1 and 2 years (P =. 02, P =. 01). Compared with the nonsurgical group, children without MA undergoing ESS had higher mean FEV1%predicted at all 3 follow‐up visits (P ≤. 05). Children with MA who underwent ESS had higher mean FVC%predicted at 1 year (P =. 04) and higher mean FEV1%predicted preoperatively and at 1 year (P ≤. 01).ConclusionsChildren with CF and sinusitis who undergo ESS experience some increase in PFTs over time, although this change is not uniform. Children with CF and sinusitis who are from lower socioeconomic backgrounds have lower PFTs over time regardless of surgical intervention.
Hearing Evaluation in Patients with Exfoliative and Primary Open‐Angle Glaucoma
Authors: Paliobei Vassiliki P. , Psillas Georgios K. , Mikropoulos Dimitrios G. , Haidich Anna‐Bettina , Constantinidis Jannis , Konstas Anastasios G. P. 
Published: March 2011

ObjectiveThe aim of this prospective study was to audiologically evaluate consecutive glaucoma patients with or without exfoliation.Study DesignProspective study.SettingGlaucoma Unit and Audiology Department at a university hospital.Subjects and MethodsConsecutive subjects with exfoliative glaucoma (XFG) or primary open‐angle glaucoma (POAG) aged between 50 and 70 years were enrolled. Auditory thresholds at 0.5, 1.0, 2.0, 4.0, and 8.0 Hz were measured bilaterally. Cochlear activity was assessed by recording distortion product otoacoustic emissions (DPOEs). Functional changes in the retrocochlear auditory pathway were evaluated by auditory brainstem responses (ABRs).ResultsOne hundred and ten patients with XFG and 85 patients with POAG who presented in a glaucoma clinic were investigated. The mean age of study patients was 66.2 ± 5.6 years; range, 50‐70 years). The odds of pathologic ABR central transmission time (interpeak latencies I‐III, III‐V, and I‐V and waves I, III, and V) were 4.34 times higher in patients with XFG than in patients with POAG (95% confidence interval [CI], 2.22‐8.49; P <. 001). This significant association remained after adjusting for sex and age (odds ratio [OR] 4.12; 95% CI, 2.07‐8.22; P <. 001). Furthermore, the odds of ABR remained significantly higher in patients with XFG than in patients with POAG (OR 4.36; 95% CI, 2.10‐9.06; P <. 001) after controlling for systemic diseases (arterial hypertension, coronary heart disease, high cholesterol, and stroke).ConclusionIn the first study to compare XFG and POAG monitoring of the peripheral and central auditory pathway, it has been documented that XFG patients show a greater prevalence of retrocochlear pathology.