bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Two-Layer Structure of the Entrainment Zone in the Convective Boundary Layer
Authors: Garcia Jade Rachele , Mellado Juan Pedro 
Published: March 2014

Abstract
The entrainment zone (EZ) of a dry, shear-free convective boundary layer growing into a linearly stratified fluid is studied by means of direct numerical simulation. The scale separation between the boundary layer thickness and the Kolmogorov length scale is shown to be sufficient to observe Reynolds number similarity in the statistics of interest during the equilibrium entrainment regime. Contrary to previous considerations, the vertical structure of the entrainment zone is found to be better described by the superposition of two sublayers: 1) an upper EZ sublayer that is dominated by overshooting thermals and is characterized by a penetration depth that scales with the ratio of the convective velocity and the buoyancy frequency of the free troposphere and 2) a lower EZ sublayer that is dominated by troughs of mixed fluid and is characterized by the integral length scale of the mixed layer. Correspondingly, different buoyancy scales are identified. The consequences of this multiplicity of scales on the entrainment rate parameters are evaluated directly, without resorting to any bulk model, through an exact relation among the mean entrainment rate, the local buoyancy increment, and both the turbulent and the finite-thickness contributions to the entrainment ratio A measured at the height of minimum buoyancy flux. The smaller turbulent contribution to A that is usually observed for relatively thick EZs is found to be compensated by the smaller local buoyancy increment instead of by the finite-thickness contribution. The two-layer structure of the entrainment zone is found to affect the exponent of the power-law relation between the normalized mean entrainment rate and the convective Richardson number such that the exponent deviates from −1 for typical atmospheric conditions, although it asymptotically approaches −1 for higher Richardson numbers.
Transient Cold Air Drainage down a Shallow Valley
Authors: Mahrt L. , Sun Jielun , Oncley S. P. , Horst T. W. 
Published: March 2014

AbstractDrainage of cold air down a small valley and associated near-surface wind maxima are examined from 20 stations with sonic anemometers at 1 m and from a 20-m tower that includes six sonic anemometers in the lowest 5 m, deployed in the Shallow Cold Pool Experiment (SCP). The small valley is about 270 m wide and 12 m deep with a downvalley slope of 2%–3%. The momentum budget indicates that the flow is driven by the buoyancy deficit of the flow and opposed primarily by the stress divergence while the remaining terms are estimated to be at least an order of magnitude smaller. This analysis also reveals major difficulties in quantifying such a budget due to uncertainties in the measurements, sensitivity to choice of averaging time, and sensitivity to measurement heights.Wind maxima occur as low as 0.5 m in the downvalley drainage flow—the lowest observational level. The downvalley cold air drainage and wind maxima are frequently disrupted by transient modes that sometimes lead to significant vertical mixing. On average, the downvalley drainage of cold air occurs with particularly weak turbulence with stronger turbulence above the drainage flow. The momentum flux profile responds to the shear reversal at the wind maximum on a vertical scale of 1 m or less, suggesting the important role of finescale turbulent diffusion.
Trends in Extreme U.S. Temperatures
Authors: Lee Jaechoul , Li Shanghong , Lund Robert 
Published: March 2014

Abstract
This paper develops trend estimation techniques for monthly maximum and minimum temperature time series observed in the 48 conterminous United States over the last century. While most scientists concur that this region has warmed on aggregate, there is no a priori reason to believe that temporal trends in extremes and averages will exhibit the same patterns. Indeed, under minor regularity conditions, the sample partial sum and maximum of stationary time series are asymptotically independent (statistically). Previous authors have suggested that minimum temperatures are warming faster than maximum temperatures in the United States; such an aspect can be investigated via the methods discussed in this study. Here, statistical models with extreme value and changepoint features are used to estimate trends and their standard errors. A spatial smoothing is then done to extract general structure. The results show that monthly maximum temperatures are not often greatly changing—perhaps surprisingly, there are many stations that show some cooling. In contrast, the minimum temperatures show significant warming. Overall, the southeastern United States shows the least warming (even some cooling), and the western United States, northern Midwest, and New England have experienced the most warming.
Storm-Centered Ensemble Data Assimilation for Tropical Cyclones
Authors: Navarro Erika L. , Hakim Gregory J. 
Published: March 2014

Abstract
A significant challenge for tropical cyclone ensemble data assimilation is that storm-scale observations tend to make analyses that are more asymmetric than the prior forecasts. Compromised structure and intensity, such as an increase of amplitude across the azimuthal Fourier spectrum, are a routine property of ensemble-based analyses, even with accurate position observations and frequent assimilation. Storm dynamics in subsequent forecasts evolve these states toward axisymmetry, creating difficulty in distinguishing between model-induced and actual storm asymmetries for predictability studies and forecasting. To address this issue, a novel algorithm using a storm-centered approach is proposed. The method is designed for use with existing ensemble filters with little or no modification, facilitating its adoption and maintenance. The algorithm consists of 1) an analysis of the environment using conventional coordinates, 2) a storm-centered analysis using storm-relative coordinates, and 3) a merged analysis that combines the large-scale and storm-scale fields together at an updated storm location. This algorithm is evaluated in two sets of observing system simulation experiments (OSSEs): first, no-cycling tests of the update step for idealized three-dimensional storms in radiative–convective equilibrium; second, full cycling tests of data assimilation applied to a shallow-water model for a field of interacting vortices. Results are compared against a control experiment based on a conventional ensemble Kalman filter (EnKF) scheme as well as an alternative EnKF scheme proposed by Lawson and Hansen. The storm-relative method yields vortices that are more symmetric and exhibit finer inner-core structure than either approach, with errors reduced by an order of magnitude over a control case with prior spread consistent with the National Hurricane Center (NHC)’s mean 5-yr forecast track error at 12 h. Azimuthal Fourier error spectra exhibit much-reduced noise associated with data assimilation as compared to both the control and the Lawson and Hansen approach. An assessment of free-surface height tendency of model forecasts after the merge step reveals a balanced trend between the storm-centered and conventional approaches, with storm-centered values more closely resembling the reference state.
Complete alleviation of treatment refractory primary SUNCT syndrome with clomiphene citrate (a medicinal deep brain hypothalamic modulator)
Authors: Rozen Todd D 
Published: March 2014

Objective To report the first ever case of primary short-lasting unilateral neuralgiform headache attacks (SUNCT) syndrome completely responsive to clomiphene citrate. Methods Case report. Results SUNCT is a primary headache disorder marked by frequent attacks of one-sided headache with cranial autonomic associated symptoms. When SUNCT is deemed medicinally treatment refractory, it can cause tremendous patient-related disability. Surgical treatment options are available including hypothalamic deep brain stimulation, occipital nerve stimulator placement or arterial decompression surgery, but these procedures carry significant morbidity. A patient presented with a 10 month complaint of multiple, daily short-lasting, right-sided headaches each lasting from 60 to 120 seconds in duration and occurring from 100 to 200 times per day. The head pain was associated with ipsilateral eyelid ptosis and conjunctival injection. The patient was diagnosed with SUNCT but was unresponsive to multiple recognized medicinal treatments. He had complete alleviation of his attacks with clomiphene citrate, a synthetic, non-steroidal, ovulatory stimulant that directly binds to hypothalamic estrogen receptors. The clomiphene was tolerated without any adverse events. A putative mechanism of action for clomiphene in the prevention of SUNCT will be presented. Conclusion Clomiphene citrate is a unique treatment for SUNCT and appears to be very safe and effective.
Central vestibular system modulation in vestibular migraine
Authors: Obermann Mark , Wurthmann Sebastian , Steinberg Benedict Schulte , Theysohn Nina , Diener Hans-Christoph , Naegel Steffen 
Published: March 2014

Background Vestibular migraine affects 1% of the general population, and 30%–50% of all migraine patients describe occasionally associated vertigo or dizziness. We aimed to identify brain regions altered in vestibular migraine in order to evaluate the connection between migraine and the vestibular system. Methods Seventeen patients with definite vestibular migraine were compared to 17 controls using magnetic resonance imaging-based voxel-based morphometry. Results We found grey matter (GM) volume reduction in the superior, inferior and middle (MT/V5) temporal gyrus as well as in the mid. cingulate, dorsolateral prefontal, insula, parietal and occipital cortex. A negative correlation of disease duration and GM volume was observed in areas associated with pain and vestibular processing. Moreover, there was a negative correlation between headache severity and prefrontal cortex volume. Conclusion Alterations identified in vestibular migraine resemble those previously described for migraine, but also extend to areas involved in multisensory vestibular control and central vestibular compensation possibly representing the pathoanatomic connection between migraine and the vestibular system.
An assessment of risk factors associated with ifosfamide-induced encephalopathy in a large academic cancer center
Authors: Szabatura Audrea H , Cirrone Frank , Harris Christy , McDonnell Anne M , Feng Yang , Voit Daniel , Neuberg Donna , Butrynski James , Fisher David C 
Published: March 2014

Purpose Ifosfamide-induced encephalopathy is a neurotoxic adverse effect of ifosfamide chemotherapy. The objective of this study was to determine the incidence of encephalopathy in patients with lymphoma and sarcoma receiving ifosfamide chemotherapy and assess for potential risk factors that influence the incidence of encephalopathy. Methods A retrospective study of sarcoma and lymphoma patients receiving ifosfamide chemotherapy was performed at the participating institutions. Enrollment began 1 July 2011 and continued chronologically backwards until 100 sarcoma and 100 lymphoma patients were enrolled. Identification of ifosfamide-induced encephalopathy events was performed by reviewing provider documentation of ifosfamide infusions. Logistic regression was employed to determine associations between risk factors and ifosfamide-induced encephalopathy events. Results Of the 200 patients enrolled, 29 (14.5%) patients experienced encephalopathy. Ifosfamide-induced encephalopathy occurred more frequently in the sarcoma population than the lymphoma population (24 vs. 5 patients, p < 0.001). In addition to cancer type, prior use of cisplatin, concomitant opioids, and use of CYP2B6 inhibitors remained as significant variables in the multivariate model conferring a 12.47, 2.81, and 5.17 increased odds of experiencing encephalopathy, respectively. The odds of experiencing encephalopathy were 9.0 and 1.37 times higher for a one-unit increase in serum creatinine and hemoglobin, respectively, and 0.15 times lower for a one-unit increase in albumin. Conclusions This is the first study to demonstrate that patients with sarcoma experienced ifosfamide-induced encephalopathy more often than those with lymphoma. For all patients, predisposing factors for ifosfamide-induced encephalopathy included previous cisplatin exposure, concomitant opioids and CYP2B6 inhibitors. Laboratory values that increased ifosfamide-induced encephalopathy risk included low serum albumin, increased serum creatinine, and increased hemoglobin.
CXCL4-induced plaque macrophages can be specifically identified by co-expression of MMP7+S100A8+in vitro and in vivo
Authors: Erbel Christian , Tyka Mirjam , Helmes Christian M , Akhavanpoor Mohmmadreza , Rupp Gregor , Domschke Gabriele , Linden Fabian , Wolf Antonia , Doesch Andreas , Lasitschka Felix , Katus Hugo A , Gleissner Christian A 
Published: March 2014

Macrophage heterogeneity in human atherosclerotic plaques has been recognized; however, markers for unequivocal identification of some subtypes are lacking. We found that the platelet chemokine CXCL4 induces a unique macrophage phenotype, which we proposed to call ‘M4’. Here, we sought to identify suitable markers that identify M4 macrophages in vitro and in vivo. Using a stringent algorithm, we identified a set of potential markers from transcriptomic data derived from polarized macrophages. We specifically focused on matrix metalloproteinase (MMP)7 and S100A8, the co-expression of which has not been described in any macrophage type thus far. We found dose- and time-dependent MMP7 and S100A8 expression in M4 macrophages at the gene and protein levels. CXCL4-induced up-regulation of both MMP7 and S100A8 was curbed in the presence of heparin, which binds to CXCL4 and glycosaminoglycans, most likely representing the macrophage receptor for CXCL4. Immunofluorescence of post-mortem atherosclerotic coronary arteries identified CD68+MMP7+, CD68+MMP7−, CD68+S100A8+ and CD68+S100A8− macrophages. A small proportion of MMP7+S100A8+ macrophages most likely represent M4 macrophages. In summary, we have identified co-expression of MMP7 and S100A8 to be a marker combination exclusively found in M4 macrophages. This finding may allow further dissection of the role of M4 macrophages in atherosclerosis and other pathologic conditions.
Troponin I Levels in Extracorporeal Membrane Oxygenation Following Congenital Heart Surgery
Authors: Rüffer André , Münch Frank , Potapov Sergej , Purbojo Ariawan , Toka Okan , Dodge-Khatami Ali , Dittrich Sven , Cesnjevar Robert Anton 
Published: March 2014

Background: Correlating postcardiotomy extracorporeal membrane oxygenation (ECMO) troponin I (TnI) levels and outcomes. Methods: Between January 2006 and August 2010, 34 patients needed postcardiotomy ECMO for low cardiac output. Bailout ECMO was required either after unsuccessful weaning from bypass (n = 17, 50%), postoperatively from prolonged hemodynamic failure (n = 8, 23.5%), or following resuscitation (n = 9, 26.5%). The TnI levels were measured following surgery or resuscitation during 10 days and compared between survivors (group I) and non-survivors (group II). Results: Median support duration was seven days (range: 0-31). Surgery involving hypoplastic aortic arch repair (Norwood palliation; n = 7, 20.6%, or biventricular repair; n = 11, 32.4%) led to most ECMO runs. Successful weaning from ECMO and hospital survival were 76.5% and 50%, respectively. In group I, peak TnI levels were reached by 24 hours postoperatively, comparable to levels in group II (36 ± 34 vs 49 ± 38 ng/mL; P = .98). However, in group II, TnI levels formed a plateau by the second postoperative day, whereas group I showed a steep decline in TnI levels, suggesting myocardial recovery ( P = .028). All patients (n = 4) who reached or maintained peak TnI levels at 48 hours died. On days 8, 9 and 10, TnI levels were significantly higher in group II ( P = .024, .019, and .013, respectively). Conclusions: Postcardiotomy ECMO was most commonly required after aortic arch repair. In the absence of ongoing myocardial insult due to ECMO hardware issues, coronary insufficiency or residual lesions, plateau TnI levels at 48 hours may seem to indicate an unfavorable outcome due to irreversible myocardial damage.
Outcome of a Repair-Oriented Strategy for the Aortic Valve in Children
Authors: Kandakure Pramod , Prior Natasha , Soda Giri , Lim Joyce , Dhannapuneni Ram , Venugopal Prem , Alphonso Nelson 
Published: March 2014

Background: We sought to evaluate the mid-term results of a repair-oriented strategy of the aortic valve in children. Methods: Between February 2007 and November 2011, we performed 39 aortic valve repairs in children. Median age and weight at surgery were 5.5 years (3 days-18 years) and 16.7 kg (2.7-83.5), respectively. A total of 11 (28%) patients had one or more prior surgical or interventional cardiologic procedures. Median intensive care unit and hospital stay were two (1-96) and five (3-96) days, respectively. Median and cumulative follow-up were 12.7 months (15 days-64 months) and 48.9 patient-years, respectively. Results: There were 3 (7.7%) early deaths all in patients undergoing additional complex cardiac procedures. Two (5.1%) patients required early surgical revision. Twenty-six (66%) patients had isolated or mixed aortic stenosis. The median gradient reduced from 62.4 (range 16-144) to 17.6 mm Hg (range 0-51.8), postoperatively ( P = .02). At last follow-up, the median gradient remained largely unchanged at 21.1 mm Hg (0-49; P = .02). Twenty-six (66%) patients had isolated or mixed aortic valve regurgitation (mild in 8 [20%], moderate in 15 [38%], and severe in 6 ([15%] patients). The degree of aortic regurgitation improved in all patients with moderate or severe aortic regurgitation ( P = .04). At last follow-up, two patients had moderate aortic regurgitation. Kaplan Meier freedom from reintervention in the survivors was 95% at three years. Conclusions: A repair-oriented strategy for the aortic valve in children has satisfactory early and mid-term results and remains a promising management option in children with aortic valve disease.
Intermediate-Term Results of Extracorporeal Membrane Oxygenation Support Following Congenital Heart Surgery
Authors: Peer Syed M. , Emerson Dominic A. , Costello John P. , Shu Michael K. , Zurakowski David , Jonas Richard A. , Berger John T. , Nath Dilip S. 
Published: March 2014

Background: Although there are considerable data regarding in-hospital results of congenital heart surgery (CHS) patients requiring postoperative extracorporeal membrane oxygenation (ECMO) support, there is limited information on intermediate-term outcomes. Methods: A single-institution retrospective review of 25 consecutive postoperative CHS patients who required ECMO and survived to hospital discharge between January 2003 and June 2008. Survival was estimated by the Kaplan-Meier method. Results: At a median follow-up of 3.3 years (interquartile range: 1.2-5.9 years), there was one death which occurred at six months postsurgery. Kaplan-Meier-estimated survival at three years was 95% (95% confidence interval: 90%-100%). Indications for ECMO included extracorporeal cardiopulmonary resuscitation (48%), systemic hypoxia (4%), postoperative low-cardiac output syndrome (28%), and intraoperative failure to wean off cardiopulmonary bypass (20%). Following ECMO support, 65% of patients had unplanned cardiac reinterventions (three requiring operative interventions, six requiring percutaneous interventions, and four requiring both), and 47% of patients required unplanned hospitalizations. In all, 29% of patients developed neurological deficits and 12% of patients developed chronic respiratory failure. No patients developed renal failure. Overall, systemic ventricular (SV) function normalized in 83% of patients, whereas 17% of patients had persistent mild-to-moderate SV dysfunction. Conclusions: Intermediate-term patient survival of ECMO following CHS is encouraging. However, neurological impairment and unplanned cardiac reinterventions remain significant concerns. Further delineation of risk factors to improve patient outcomes is warranted.
Linking the Congenital Heart Surgery Databases of the Society of Thoracic Surgeons and the Congenital Heart Surgeons’ Society
Authors: Jacobs Jeffrey P. , Pasquali Sara K. , Austin Erle , Gaynor J. William , Backer Carl , Hirsch-Romano Jennifer C. , Williams William G. , Caldarone Christopher A. , McCrindle Brian W. , Graham Karen E. , Dokholyan Rachel S. , Shook Gregory J. , Poteat Jennifer , Baxi Maulik V. , Karamlou Tara , Blackstone Eugene H. , Mavroudis Constantine , Mayer John E. , Jonas Richard A. , Jacobs Marshall L. 
Published: March 2014

Purpose: The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) is the largest Registry in the world of patients who have undergone congenital and pediatric cardiac surgical operations. The Congenital Heart Surgeons’ Society Database (CHSS-D) is an Academic Database designed for specialized detailed analyses of specific congenital cardiac malformations and related treatment strategies. The goal of this project was to create a link between the STS-CHSD and the CHSS-D in order to facilitate studies not possible using either individual database alone and to help identify patients who are potentially eligible for enrollment in CHSS studies. Methods: Centers were classified on the basis of participation in the STS-CHSD, the CHSS-D, or both. Five matrices, based on CHSS inclusionary criteria and STS-CHSD codes, were created to facilitate the automated identification of patients in the STS-CHSD who meet eligibility criteria for the five active CHSS studies. The matrices were evaluated with a manual adjudication process and were iteratively refined. The sensitivity and specificity of the original matrices and the refined matrices were assessed. Results: In January 2012, a total of 100 centers participated in the STS-CHSD and 74 centers participated in the CHSS. A total of 70 centers participate in both and 40 of these 70 agreed to participate in this linkage project. The manual adjudication process and the refinement of the matrices resulted in an increase in the sensitivity of the matrices from 93% to 100% and an increase in the specificity of the matrices from 94% to 98%. Conclusion: Matrices were created to facilitate the automated identification of patients potentially eligible for the five active CHSS studies using the STS-CHSD. These matrices have a sensitivity of 100% and a specificity of 98%. In addition to facilitating identification of patients potentially eligible for enrollment in CHSS studies, these matrices will allow (1) estimation of the denominator of patients potentially eligible for CHSS studies and (2) comparison of eligible and enrolled patients to potentially eligible and not enrolled patients to assess the generalizability of CHSS studies.