bluuebunny/crossref_metadata_2025_split huggingface dataset:
Global Survey of the Frequency of Atrial Fibrillation–Associated Stroke
Authors: Perera Kanjana S. , Vanassche Thomas , Bosch Jackie , Swaminathan Balakumar , Mundl Hardi , Giruparajah Mohana , Barboza Miguel A. , O’Donnell Martin J. , Gomez-Schneider Maia , Hankey Graeme J. , Yoon Byung-Woo , Roxas Artemio , Lavallee Philippa , Sargento-Freitas Joao , Shamalov Nikolay , Brouns Raf , Gagliardi Rubens J. , Kasner Scott E. , Pieroni Alessio , Vermehren Philipp , Kitagawa Kazuo , Wang Yongjun , Muir Keith , Coutinho Jonathan M. , Connolly Stuart J. , Hart Robert G. , Czeto K. , Kahn M. , Mattina K.R. , Ameriso S.F. , Pujol-Lereis V. , Hawkes M. , Pertierra L. , Perera N. , De Smedt A. , Van Dyck R. , Van Hooff R.J. , Yperzeele L. , Gagliardi V.D.B. , Cerqueir L.G. , Yang X. , Chen W. , Amarenco P. , Guidoux C. , Ringleb P.A. , Bereczki D. , Vastagh I. , Canavan M. , Toni D. , Anzini A. , Colosimo C. , De Michele M. , Di Mascio M.T. , Durastanti L. , Falcou A. , Fausti S. , Mancini A. , Mizumo S. , Uchiyama S. , Kim C.K. , Jung S. , Kim Y. , Kim J.A. , Jo J.Y. , Arauz A. , Quiroz-Compean A. , Colin J. , Nederkoorn P.J. , Marianito V.P. , Cunha L. , Santo G. , Silva F. , Coelho J. , Kustova M. , Meshkova K. , Williams G. , Siegler J. , Zhang C. , Gallatti N. , Kruszewski M. 
Published: August 2016

Background and Purpose—
Atrial fibrillation (AF) is increasingly recognized as the single most important cause of disabling ischemic stroke in the elderly. We undertook an international survey to characterize the frequency of AF-associated stroke, methods of AF detection, and patient features.

Methods—
Consecutive patients hospitalized for ischemic stroke in 2013 to 2014 were surveyed from 19 stroke research centers in 19 different countries. Data were analyzed by global regions and World Bank income levels.

Results—

Of 2144 patients with ischemic stroke, 590 (28%; 95% confidence interval, 25.6–29.5) had AF-associated stroke, with highest frequencies in North America (35%) and Europe (33%) and lowest in Latin America (17%). Most had a history of AF before stroke (15%) or newly detected AF on electrocardiography (10%); only 2% of patients with ischemic stroke had unsuspected AF detected by poststroke cardiac rhythm monitoring. The mean age and 30-day mortality rate of patients with AF-associated stroke (75 years; SD, 11.5 years; 10%; 95% confidence interval, 7.6–12.6, respectively) were substantially higher than those of patients without AF (64 years; SD, 15.58 years; 4%; 95% confidence interval, 3.3–5.4;
P
<0.001 for both comparisons). There was a strong positive correlation between the mean age and the frequency of AF (
r
=0.76;
P
=0.0002).

Conclusions—
This cross-sectional global sample of patients with recent ischemic stroke shows a substantial frequency of AF-associated stroke throughout the world in proportion to the mean age of the stroke population. Most AF is identified by history or electrocardiography; the yield of conventional short-duration cardiac rhythm monitoring is relatively low. Patients with AF-associated stroke were typically elderly (>75 years old) and more often women.
Effects of Alteplase for Acute Stroke on the Distribution of Functional Outcomes
Authors: Lees Kennedy R. , Emberson Jonathan , Blackwell Lisa , Bluhmki Erich , Davis Stephen M. , Donnan Geoffrey A. , Grotta James C. , Kaste Markku , von Kummer Rüdiger , Lansberg Maarten G. , Lindley Richard I. , Lyden Patrick , Murray Gordon D. , Sandercock Peter A.G. , Toni Danilo , Toyoda Kazunori , Wardlaw Joanna M. , Whiteley William N. , Baigent Colin , Hacke Werner , Howard George , Marler John , Halls Heather , Holland Lisa , Mathews Clare , Smith Samantha , Wilson Kate , Koga Masatoshi , Albers Gregory , Brott Thomas , Cohen Geoffrey , Koga Masatoshi , Olivot Jean Marc , Parsons Mark , Tilley Barbara , Wahlgren Nils , del Zoppo Gregory J 
Published: August 2016

Background—
Thrombolytic therapy with intravenous alteplase within 4.5 hours of ischemic stroke onset increases the overall likelihood of an excellent outcome (no, or nondisabling, symptoms). Any improvement in functional outcome distribution has value, and herein we provide an assessment of the effect of alteplase on the distribution of the functional level by treatment delay, age, and stroke severity.

Methods—
Prespecified pooled analysis of 6756 patients from 9 randomized trials comparing alteplase versus placebo/open control. Ordinal logistic regression models assessed treatment differences after adjustment for treatment delay, age, stroke severity, and relevant interaction term(s).

Results—

Treatment with alteplase was beneficial for a delay in treatment extending to 4.5 hours after stroke onset, with a greater benefit with earlier treatment. Neither age nor stroke severity significantly influenced the slope of the relationship between benefit and time to treatment initiation. For the observed case mix of patients treated within 4.5 hours of stroke onset (mean 3 hours and 20 minutes), the net absolute benefit from alteplase (ie, the difference between those who would do better if given alteplase and those who would do worse) was 55 patients per 1000 treated (95% confidence interval, 13–91;
P
=0.004).

Conclusions—
Treatment with intravenous alteplase initiated within 4.5 hours of stroke onset increases the chance of achieving an improved level of function for all patients across the age spectrum, including the over 80s and across all severities of stroke studied (top versus bottom fifth means: 22 versus 4); the earlier that treatment is initiated, the greater the benefit.
Operational Hazard Assessment of Waves and Storm Surges from Tropical Cyclones in Mexico
Authors: Appendini Christian M. , Rosengaus Michel , Meza-Padillaand Rafael , Camacho-Magaña Victor 
Published: August 2016

Abstract
Tropical cyclones and their associated impacts along the western and eastern Mexican coastlines have led to the recent announcement of the creation of a National Hurricane and Severe Storms Center in Mexico. While Mexico falls under the responsibility of the Regional Specialized Meteorological Center in Miami, the newly announced center aims to provide local warning advisories to local governments and emergency managers. This study developed their first operational tool, which provides rapid forecasts of hazard areas under the presence of waves and storm surges from tropical cyclones threatening Mexico. The tool is based on precomputed wave parameters and storm surges from 3,100 synthetic tropical cyclones. Maximum envelope maps for all of the events are stored in a system database that is accessed through a graphical interface. Using a search function of synthetic events, the user can select those events most analogous to the tropical cyclone in question in order to make an assessment of warning areas. The tool allows users to plot maximum envelope maps for individual events or maxima of maximum maps combining several events, either using precomputed values for the different parameters (wind, waves, and storm surge) or a normalized map. To demonstrate the capabilities of the operational tool, we present an example application based on Hurricane Patricia (2015). This tool could also be implemented by developing countries affected by tropical cyclones, which otherwise are often limited by numerical modeling capabilities, time, and budgets.
Model-Based Projections and Uncertainties of Near-Surface Wind Climate in Western Canada
Authors: Daines Jeffrey T. , Monahan Adam H. , Curry Charles L. 
Published: August 2016

AbstractNear-surface wind is important in forestry, agriculture, air pollution, building energy use, and wind power generation. In western Canada it presently plays a minor role in power generation, but ongoing reductions in the cost of wind power infrastructure and the increasing costs of conventional power generation (including environmental costs) motivate the assessment of the projected future wind climate and uncertainties in this projection. Multiple realizations of the Canadian Regional Climate Model (CRCM) at 45-km resolution were driven by two global climate models over the periods 1971–2000 (using historical greenhouse gas concentrations) and 2031–60 (using the SRES-A2 concentration scenario). Hourly wind speeds from 30 stations were analyzed over 1971–2000 and used to calibrate downscaled ensembles of projected wind speed distributions over 2031–60. At most station locations modest increases in mean wind speed were found for a majority of the projections, but with an ensemble spread of the same order of magnitude as the increases. Relative changes in mean wind speeds at station locations were found to be insensitive to the station observations and calibration technique. In view of this result, projected relative changes in future wind climate over the entire CRCM domain were estimated using uncalibrated pairs of past-period and future-period wind speed distributions. The relative changes are robust, in the sense that their ensemble mean relative change is greater than their standard deviation, but are not very substantial, in the sense that their ensemble mean change is generally less than the standard deviation of their annual means.
Constraining Precipitation Susceptibility of Warm-, Ice-, and Mixed-Phase Clouds with Microphysical Equations
Authors: Glassmeier Franziska , Lohmann Ulrike 
Published: August 2016

Abstract
The strength of the effective anthropogenic climate forcing from aerosol–cloud interactions is related to the susceptibility of precipitation to aerosol effects. Precipitation susceptibility d lnP/d lnN has been proposed as a metric to quantify the effect of aerosol-induced changes in cloud droplet number N on warm precipitation rate P. Based on the microphysical rate equations of the Seifert and Beheng two-moment bulk microphysics scheme, susceptibilities of warm-, mixed-, and ice-phase precipitation and cirrus sedimentation to cloud droplet and ice crystal number are estimated. The estimation accounts for microphysical adjustments to the initial perturbation in N. For warm rain, d lnP/d lnN &lt; −2aut/(aut + acc) is found, which depends on the rates of autoconversion (aut) and accretion (acc). Cirrus sedimentation susceptibility corresponds to the exponent of crystal sedimentation velocity with a value of −0.2. For mixed-phase clouds, several microphysical contributions that explain low precipitation susceptibilities are identified: (i) Because of the larger hydrometeor sizes involved, mixed-phase collection processes are less sensitive to changes in hydrometeor size than autoconversion. (ii) Only a subset of precipitation formation processes is sensitive to droplet or crystal number. (iii) Effects on collection processes and diffusional growth compensate. (iv) Adjustments in cloud liquid and ice amount compensate the effect of changes in ice crystal and cloud droplet number. (v) Aerosol perturbations that simultaneously affect ice crystal and droplet number have opposing effects.
The Impact of Effective Buoyancy and Dynamic Pressure Forcing on Vertical Velocities within Two-Dimensional Updrafts
Authors: Peters John M. 
Published: August 2016

AbstractThis research develops simple diagnostic expressions for vertical acceleration dw/dt and vertical velocity w within updrafts that account for effective buoyancy and the dynamic pressure gradient force. Effective buoyancy is the statically forced component of the vertical gradient in the nonhydrostatic pressure field. The diagnostic expressions derived herein show that the effective buoyancy of an updraft is dependent on the magnitude of the temperature perturbation within an updraft relative to the air along the updraft’s immediate periphery (rather than relative to an arbitrary base state as in ), the updraft’s height-to-width aspect ratio, and the updraft’s slant relative to the vertical.The diagnostic expressions are significantly improved over parcel theory (where pressure forces are ignored) in their portrayal of the vertical profile of w through updrafts from a cloud model simulation and accurately diagnosed the maximum vertical velocity wmax within updrafts. The largest improvements to the diagnostic expressions over parcel theory resulted from their dependence on rather than . Whereas the actual wmax within simulated updrafts was located approximately two-thirds to three-fourths of the distance between the updraft base and the updraft top, wmax within profiles diagnosed by expressions was portrayed at the updraft top when the dynamic pressure force was ignored. A rudimentary theoretical representation of the dynamic pressure force in the diagnostic expressions improved their portrayal of the simulated w profile. These results augment the conceptual understanding of convective updrafts and provide avenues for improving the representation of vertical mass flux in cumulus parameterizations.
Role of Mixed Layer Dynamics in Tropical North Atlantic Interannual Sea Surface Temperature Variability
Authors: Rugg Allyson , Foltz Gregory R. , Perez Renellys C. 
Published: August 2016

Abstract
This study examines the causes of observed sea surface temperature (SST) anomalies in the tropical North Atlantic between 1982 and 2015. The emphasis is on the boreal winter and spring seasons, when tropical Atlantic SSTs project strongly onto the Atlantic meridional mode (AMM). Results from a composite analysis of satellite and reanalysis data show important forcing of SST anomalies by wind-driven changes in mixed layer depth and shortwave radiation between 5° and 10°N, in addition to the well-known positive wind–evaporation–SST and shortwave radiation–SST feedbacks between 5° and 20°N. Anomalous surface winds also drive pronounced thermocline depth anomalies of opposite signs in the eastern equatorial Atlantic and intertropical convergence zone (ITCZ; 2°–8°N). A major new finding is that there is strong event-to-event variability in the impact of thermocline depth on SST in the ITCZ region, in contrast to the more consistent relationship in the eastern equatorial Atlantic. Much stronger anomalies of meridional wind stress, thermocline depth, and vertical turbulent cooling are found in the ITCZ region during a negative AMM event in 2009 compared to a negative event in 2015 and a positive event in 2010, despite SST anomalies of similar magnitude in the early stages of each event. The larger anomalies in 2009 led to a much stronger and longer-lived event. Possible causes of the inconsistent relationship between thermocline depth and SST in the ITCZ region are discussed, including the preconditioning role of the winter cross-equatorial SST gradient.
Oppressive Heat Events in Illinois Related to Antecedent Wet Soils
Authors: Ford Trent W. , Schoof Justin T. 
Published: August 2016

Abstract
Extreme heat events have been connected with antecedent soil moisture in many global regions, such that dry soils increase sensible heat content of the near-surface atmosphere and impede precipitation through boundary layer growth. However, negative soil moisture–temperature feedbacks (dry soils = higher temperatures) are founded on investigations of maximum temperature that neglect the potentially important latent heating component provided by soil moisture. In this study, the association of spring soil moisture and subsequent summer oppressive heat events is quantified, defined by equivalent temperature. The advantage of equivalent temperature over maximum temperature is that it accounts for both the temperature and moisture components of atmospheric heat content. Quantile regression and composite analysis are used to determine the association between spring soil moisture and summer oppressive heat events using a 25-yr station observation record in Illinois. A consistent response of summer oppressive heat events to antecedent 5-cm soil moisture anomalies is found at all four stations. The frequency of oppressive summer equivalent temperature events is significantly increased following spring seasons with wetter-than-normal soils compared with spring seasons with dry soils. This provides evidence of a possible positive soil moisture–temperature feedback. Further, it is found that oppressive heat events correspond with the combination of wetter-than-normal spring soils and persistent summertime upper-level ridging to the northeast of the region, thereby leading to the conclusion that abundant-to-surplus spring soil moisture is necessary but not sufficient for the occurrence of oppressive heat in Illinois.
Evolution of Directional Wave Spectra in the Marginal Ice Zone: A New Model Tested with Legacy Data
Authors: Squire Vernon A. , Montiel Fabien 
Published: August 2016

AbstractField experimental data from a 1980s program in the Greenland Sea investigating the evolution of directional wave spectra in the marginal ice zone are reanalyzed and compared with the predictions of a new, phase-resolving, three-dimensional model describing the two-dimensional scattering of the waves by the vast number of ice floes that are normally present. The model is augmented with a dissipative term to account for the nonconservative processes affecting wave propagation. Observations reported in the experimental study are used to reproduce the ice conditions and wave forcing during the experiments. It is found that scattering alone underestimates the attenuation experienced by the waves during their passage through the ice field. With dissipation, however, the model can replicate the observed attenuation for most frequencies in the swell regime. Model predictions and observations of directional spreading are in agreement for short to midrange wave periods, where the wave field quickly becomes isotropic. For larger wave periods, little spreading can be seen in the model predictions, in contrast to the isotropic or near-isotropic seas reported in the experimental study. The discrepancy is conjectured to be a consequence of the inaccurate characterization of the ice conditions in the model and experimental errors.
Climatology of Banded Precipitation over the Contiguous United States
Authors: Fairman Jonathan G. , Schultz David M. , Kirshbaum Daniel J. , Gray Suzanne L. , Barrett Andrew I. 
Published: August 2016

AbstractA climatology of banded-precipitation features over the contiguous United States from 2003 to 2014 is constructed. A band is defined as a precipitation feature with a major axis of 100 km or greater and a ratio of major axis length to minor axis length (hereafter, aspect ratio) of 3:1 or greater. By applying an automated feature-based detection algorithm to composite radar imagery, a database of 48 916 844 precipitation features is created, of which 7 213 505 (14.8%) are bands. This algorithm produces the first climatology of precipitation bands over the contiguous United States. Banded-precipitation occurrence is broadly similar to total precipitation occurrence, with a maximum of 175 h of banded precipitation annually over the Ohio River valley. In the warm season, there is a strong diurnal signature associated with convective storm development for both the precipitation feature area and total area covered by precipitation, but little diurnal signature in aspect ratio. Strong west–east gradients in both precipitation occurrence and banded-precipitation occurrence exist, as areas west of the Rockies receive less frequent precipitation, which is much less likely to be banded. East of the Rockies, precipitation features are banded 30% of the time, versus 10%–15% west of the Rockies. Areas downwind of the Great Lakes show prominent late autumn and winter maxima in banded precipitation associated with lake-effect snowbands. Local maxima of banded-precipitation percentage occur in the Dakotas and east of the Colorado Rockies during winter. Although banded-precipitation features compose only 14.8% of all precipitation features, they contribute 21.9% of the annual precipitation occurrence over the contiguous United States.
Lake and Orographic Effects on a Snowstorm at Lake Constance
Authors: Umek Lukas , Gohm Alexander 
Published: August 2016

AbstractThis is one of the first case studies of a snowstorm at Lake Constance, located between Austria, Germany, and Switzerland, which assesses the influence of the lake and the orography on the generation of heavy precipitation. The analysis is based on surface and radar observations and numerical simulations with the Weather Research and Forecasting (WRF) Model. On 8 February 2013, a rather stationary and banded radar reflectivity pattern was observed during postfrontal conditions with northwesterly flow. The associated snowband affected the downstream shore and the adjacent mountainous region with 36 mm of precipitation within 5 h at the shore. Surface observations show a convergence in the wind field over the lake during the period of banded precipitation. The control simulation captures the formation of a convergence line and a snowband near the shoreline and over the downstream orography. A lake-induced, low-level conditionally unstable layer is essential for the snowband formation. Orographically and thermally induced convergence provides the lifting to release conditional instability and to trigger convection. Orographic enhancement of precipitation occurs downstream of the lake. Sensitivity experiments with modified orography, land use, and lake surface temperature show that the lake is a crucial factor controlling the amount and distribution of snowfall. However, neither the lake nor the orography alone would have been able to form a snowband. This study highlights the complex interaction between lake and orographic effects and shows that Lake Constance is large enough to impact the formation of precipitation.
An Oceanic Heat Content–Based Definition for the Pacific Decadal Oscillation
Authors: Kumar Arun , Wen Caihong 
Published: August 2016

AbstractBased on the variability of heat content in the upper 300 m of the ocean (HC300), the feasibility of defining an index of Pacific decadal oscillation (PDO) is explored. The motivation for defining the PDO index on HC300 stems from the following considerations: (i) a need to accentuate lower-frequency variations in the monitoring of PDO and (ii) to take into account variations in the temperatures associated with the PDO that extend throughout the upper ocean (and are modulated by the seasonal cycle of mixed layer variability). It is demonstrated that an HC300-based definition is better suited to encapsulate these characteristics in the PDO variability. The variability in an HC300-based definition is also contrasted with the traditional definition of the PDO based on SSTs.