bluuebunny/crossref_metadata_2025_split huggingface dataset:
Defining Competencies for Ultrasound‐Guided Bedside Procedures
Authors: Brown G. Mark , Otremba Mirek , Devine Luke A. , Gray Catherine , Millington Scott J. , Ma Irene W. Y. 
Published: December 2015

ObjectivesThis study sought to define the competencies in ultrasound knowledge and skills that are essential for medical trainees to master to perform ultrasound‐guided central venous catheterization, thoracentesis, and paracentesis.MethodsExperts in the 3 procedures were identified by a snowball technique through 3 Canadian tertiary academic health centers. Experts completed 2 rounds of surveys, including an 88‐item central venous catheterization survey, a 96‐item thoracentesis survey, and an 89‐item paracentesis survey. For each item, experts were asked to determine whether the knowledge/skill described was essential, important, or marginal. Consensus on an item was defined as agreement by at least 80% of the experts. For items on which consensus was not reached during the first round of surveys, a second survey was created in which the experts were asked to rate the item in a binary fashion (essential/important versus marginal/unimportant).ResultsOf the 27 experts invited to complete each survey, 25 (93%) completed the central venous catheterization survey; 22 (81%) completed the thoracentesis survey; and 23 (85%) completed the paracentesis survey. The experts represented 8 specialties from 8 cities within Canada. A total of 22, 32, and 28 items were determined to be essential competencies for central venous catheterization, thoracentesis, and paracentesis, respectively, whereas 47, 38, and 42 competencies were determined to be important, and 8, 13, and 10 were determined to be marginal. The ability to perform real‐time direct ultrasound guidance was considered essential only for the performance of central venous catheterization insertion.ConclusionsOur study presents expert consensus‐derived ultrasound competencies that should be considered during the design and implementation of procedural skills training for learners.
Evaluating Spatiotemporal Image Correlation Technology as a Tool for Training Nonexpert Sonographers to Perform Examinations of the Fetal Heart
Authors: Avnet Hagai , Mazaaki Eyal , Shen Ori , Cohen Sarah , Yagel Simcha 
Published: December 2015

ObjectivesWe aimed to evaluate the use of spatiotemporal image correlation (STIC) as a tool for training nonexpert examiners to perform screening examinations of the fetal heart by acquiring and examining STIC volumes according to a standardized questionnaire based on the 5 transverse planes of the fetal heart.MethodsWe conducted a prospective study at 2 tertiary care centers. Two sonographers without formal training in fetal echocardiography received theoretical instruction on the 5 fetal echocardiographic transverse planes, as well as STIC technology. Only women with conditions allowing 4‐dimensional STIC volume acquisitions (grayscale and Doppler) were included in the study. Acquired volumes were evaluated offline according to a standardized protocol that required the trainee to mark 30 specified structures on 5 required axial planes. Volumes were then reviewed by an expert examiner for quality of acquisition and correct identification of specified structures.ResultsNinety‐six of 112 pregnant women examined entered the study. Patients had singleton pregnancies between 20 and 32 weeks' gestation. After an initial learning curve of 20 examinations, trainees succeeded in identifying 97% to 98% of structures, with a highly significant degree of agreement with the expert's analysis (P < .001). A median of 2 STIC volumes for each examination was necessary for maximal structure identification. Acquisition quality scores were high (8.6–8.7 of a maximal score of 10) and were found to correlate with identification rates (P = .017).ConclusionsAfter an initial learning curve and under expert guidance, STIC is an excellent tool for trainees to master extended screening examinations of the fetal heart.
Sonographic Evaluation of Diaphragmatic Excursion and Thickness in Healthy Infants and Children
Authors: El-Halaby Hanan , Abdel-Hady Hesham , Alsawah Gehan , Abdelrahman Ashraf , El-Tahan Hanem 
Published: December 2015

ObjectivesM‐mode sonography is a noninvasive method for detection of diaphragmatic excursion and thickness. A few studies have assessed diaphragmatic kinetics in children with diaphragmatic paresis and paralysis, but to our knowledge, no data about normal values in pediatrics are available. The aims of this study were to determine reference values for diaphragmatic excursion and thickness, as evaluated by sonography in healthy infants and children, and identify correlations between them and anthropometric measurements, age, and sex.MethodsA total of 400 healthy participants aged between 1 month and 16 years, divided into 4 equal groups (group 1, 1 month–2 years; group 2, 2–6 years; group 3, 6–12 years); and group 4, 12–16 years) were studied. M‐mode sonography was used to measure the excursion and thickness of the right and left hemidiaphragms (using the liver and spleen as acoustic windows, respectively).ResultsReference values for diaphragmatic excursion and thickness were determined in different age groups of healthy infants and children. There were no significant differences with respect to sex. Significant positive correlations were found between excursion of the right hemidiaphragm and body weight in all age groups (r = 0.52, 0.25, 0.27. and 0.20; P < .001, .013, .011, and .047 for groups 1–4, respectively). We plotted percentile curves for right diaphragmatic excursion against body weight.ConclusionsThis study provides reference values for diaphragmatic excursion and thickness in healthy infants and children. Percentile curves for right diaphragmatic excursion plotted against body weight were plotted.
B‐Lines on Pediatric Lung Sonography
Authors: Martelius Laura , Heldt Henna , Lauerma Kirsi 
Published: December 2015

ObjectivesSonographic artifacts known as B‐lines can been used to estimate alterations of lung parenchyma. Multiple B‐lines on sonography are seen in congestive heart disease, interstitial lung disease, respiratory infections, and neonates. The aim of this study was to compare the amount of B‐lines on sonography to the extent of parenchymal changes on computed tomography (CT) in children.MethodsLung sonography was performed on 60 patients aged 18 years and younger referred for chest CT at our institution. B‐lines were counted from 5 anterolateral intercostal spaces bilaterally. The CT findings were documented and graded as absent, minimal, partial, or complete.ResultsThe number of B‐lines on sonography increased consistently with the growing extent of parenchymal changes on CT. The differences in the B‐line counts between the patients grouped according to the extent of parenchymal changes on CT were statistically significant except between patients with minimal and no changes (P < .01 Kruskal‐Wallis and Tukey tests).ConclusionsThe number of B‐lines on sonography correlates with the extent of parenchymal changes on CT. Various parenchymal changes were seen in patients with B‐lines on sonography. B‐lines were more frequently seen in patients with no changes on CT when imaged during general anesthesia.
Multiarray rupture imaging of the devastating 2015 Gorkha, Nepal, earthquake sequence
Authors: Zhang Hao , van der Lee Suzan , Ge Zengxi 
Published: December 2015

AbstractA rapid, robust multiarray backprojection method was applied to image the rupture pattern of the 2015 Gorkha, Nepal Mw7.8 main shock and its Mw7.3 aftershock. Backprojected teleseismic P wave trains from three regional seismic arrays in Europe, Australia, and Alaska show that both earthquakes ruptured unilaterally and primarily eastward, with rupture speeds potentially decreasing with depth. The rupture of the main shock first extended ESEward at ∼3.5 km/s over ∼120 km, with later rupture propagation further downdip on the eastern segment at ∼2.1 km/s. The aftershock ruptured the fault SE of the main shock's ruptured plane. It began to rupture updipward for ∼20 km at a speed around 1.2 km/s, then it may have accelerated to 3.5 km/s for the next 50 km. The apparent depth‐dependent rupture speeds of the two earthquakes may be caused by along‐dip heterogeneities in fault strength, with a higher stress concentration on the updip part of the Nepalese Main Himalayan Thrust.
Simulated effects of southern hemispheric wind changes on the Pacific oxygen minimum zone
Authors: Getzlaff Julia , Dietze Heiner , Oschlies Andreas 
Published: December 2015

AbstractA coupled ocean biogeochemistry‐circulation model is used to investigate the impact of observed past and anticipated future wind changes in the Southern Hemisphere on the oxygen minimum zone in the tropical Pacific. We consider the industrial period until the end of the 21st century and distinguish effects due to a strengthening of the westerlies from effects of a southward shift of the westerlies that is accompanied by a poleward expansion of the tropical trade winds. Our model results show that a strengthening of the westerlies counteracts part of the warming‐induced decline in the global marine oxygen inventory. A poleward shift of the trade‐westerlies boundary, however, triggers a significant decrease of oxygen in the tropical oxygen minimum zone. In a business‐as‐usual CO2 emission scenario, the poleward shift of the trade‐westerlies boundary and warming‐induced increase in stratification contribute equally to the expansion of suboxic waters in the tropical Pacific.
Cold ion heating at the dayside magnetopause during magnetic reconnection
Authors: Toledo‐Redondo S. , André M. , Vaivads A. , Khotyaintsev Yu. V. , Lavraud B. , Graham D. B. , Divin A. , Aunai N. 
Published: December 2015

AbstractCold ions of ionospheric origin are known to be present in the magnetospheric side of the Earth's magnetopause. They can be very abundant, with densities up to 100 cm−3. These cold ions can mass load the magnetosphere, changing global parameters of magnetic reconnection, like the Alfvén speed or the reconnection rate. In addition they introduce a new length scale related to their gyroradius and kinetic effects which must be accounted for. We report in situ observations of cold ion heating in the separatrix owing to time and space fluctuations of the electric field. When this occurs, the cold ions are preheated before crossing the Hall electric field barrier. However, when this mechanism is not present cold ions can be observed well inside the reconnection exhaust. Our observations suggest that the perpendicular cold ion heating is stronger close to the X line owing to waves and electric field gradients linked to the reconnection process.
Quantitative prediction of type II solar radio emission from the Sun to 1 AU
Authors: Schmidt J. M. , Cairns Iver H. 
Published: December 2015

AbstractCoronal mass ejections (CMEs) are frequently associated with shocks and type II solar radio bursts. Despite involving fundamental plasma physics and being the archetype for collective radio emission from shocks, type II bursts have resisted detailed explanation for over 60 years. Between 29 November and 1 December 2013 the two widely separated spacecraft STEREO A and B observed a long lasting, intermittent, type II radio burst from ≈4 MHz to 30 kHz (harmonic), including an intensification when the CME‐driven shock reached STEREO A. We demonstrate the first accurate and quantitative simulation of a type II burst from the high corona (near 11 solar radii) to 1 AU for this event with a combination of a data‐driven three‐dimensional magnetohydrodynamic simulation for the CME and plasma background and an analytic quantitative kinetic model for the radio emission.
Validation of simulated hurricane drop size distributions using polarimetric radar
Authors: Brown Bonnie R. , Bell Michael M. , Frambach Andrew J. 
Published: December 2015

AbstractRecent upgrades to the U.S. radar network now allow for polarimetric measurements of landfalling hurricanes, providing a new data set to validate cloud microphysical parameterizations used in tropical cyclone simulations. Polarimetric radar reflectivity and differential reflectivity simulated by the Weather Research and Forecasting model were compared with real radar observations from 2014 in Hurricanes Arthur and Ana. Six different microphysics parameterizations were tested that were able to capture the major features of both hurricanes, including accurate tracks, precipitation asymmetry, and the approximate intensity of the storms. A high correlation between simulated intensity and rainfall across schemes suggests an intimate link between the latent heating produced by the microphysics and the storm dynamics. Most of the parameterizations produced a higher frequency of larger raindrops than observed. The Thompson aerosol‐aware bulk and explicit spectral bin microphysical schemes showed the best fidelity to the observations at a higher computational cost.
Influence of intermittency on the anisotropy of magnetic structure functions of solar wind turbulence
Authors: Pei Zhongtian , He Jiansen , Wang Xin , Tu Chuanyi , Marsch Eckart , Wang Linghua , Yan Limei 
Published: December 2015

AbstractIntermittency appears to be connected with the spectral anisotropy of solar wind turbulence. We use the Local Intermittency Measure to identify and remove intermittency from the magnetic field data measured by the Ulysses spacecraft in fast solar wind. Structure functions are calculated based on the time sequences as obtained before and after removing intermittency and arranged by time scale (τ) and ΘRB (the angle between local mean magnetic field B0 and radial direction R). Thus, the scaling exponent (ξ(p, ΘRB)) of every structure function of order (p) is obtained for different angles. Before removing intermittency, ξ(p, ΘRB) shows a distinctive dependence on ΘRB: from monofractal scaling law at ΘRB ~0° to multifractal scaling law at ΘRB ~90°. In contrast after eliminating the intermittency, ξ(p, ΘRB) is found to be more monofractal for all ΘRB. The extended structure‐function model is applied to ξ(p, ΘRB), revealing differences of its fitting parameters α (a proxy of the power spectral index) and P1 (fragmentation fraction) for the cases with and without intermittency. Parameter α shows an evident angular trend falling from 1.9 to 1.6 for the case with intermittency but has a relatively flat profile around 1.8 for the case without intermittency. Parameter P1 rises from around 0.5 to above 0.8 with increasing ΘRB for the intermittency case and is located between 0.5 and 0.8 for the case lacking intermittency. Therefore, we may infer that it is the anisotropy of intermittency that causes the scaling anisotropy of energy spectra and the unequal fragmentation of energy cascading.
A new approach to identify interplanetary Alfvén waves and to obtain their frequency properties
Authors: Li H. , Wang C. , Chao J. K. , Hsieh W. C. 
Published: December 2015

AbstractConventional diagnosis of interplanetary Alfvén waves requires an accurately determined de Hoffmann‐Teller (HT) frame or background magnetic field. For simplicity, the averaged HT frame and the mean value of the magnetic field are often used in the literature. However, HT frame can change quite fast in high‐speed solar wind streams, and it is not always appropriate to take the average value of the magnetic field to be the background state. In order to reduce the uncertainty introduced by determining HT frame and background magnetic field, we propose a new approach for identifying large‐amplitude interplanetary Alfvén waves. This new approach is independent of HT frame and of background magnetic field. Instead of the original data sets, the band‐pass filtered signals of plasma velocity and magnetic field observations are used to check the Walén relation. The robustness of this technique is verified by applying to simulated pure Alfvén waves with two separate frequencies and contaminated by pink colored noises in a varying solar wind stream. Furthermore, in our approach, more properties of Alfvén waves in frequency domain can be obtained, which have been rarely discussed before. Our analysis technique is applied to two intervals of solar wind high‐speed streams, and it is shown that large‐amplitude Alfvén waves near 1 AU are frequently found during these two intervals.
Scattering characteristics and imaging of energetic neutral atoms from the Moon in the terrestrial magnetosheath
Authors: Lue Charles , Futaana Yoshifumi , Barabash Stas , Saito Yoshifumi , Nishino Masaki , Wieser Martin , Asamura Kazushi , Bhardwaj Anil , Wurz Peter 
Published: December 2015

AbstractWe study hydrogen energetic neutral atom (ENA) emissions from the lunar surface, when the Moon is inside the terrestrial magnetosheath. The ENAs are generated by neutralization and backscattering of incident protons of solar wind origin. First, we model the effect of the increased ion temperature in the magnetosheath (>10 times larger than that in the undisturbed solar wind) on the ENA scattering characteristics. Then, we apply these models to ENA measurements by Chandrayaan‐1 and simultaneous ion measurements by Kaguya at the Moon, in the magnetosheath. We produce maps of the ENA scattering fraction, covering a region at the lunar near‐side that includes mare and highland surfaces and several lunar magnetic anomalies. We see clear signatures of plasma shielding by the magnetic anomalies. The maps are made at different lunar local times, and the results indicate an extended influence and altered morphology of the magnetic anomalies at shallower incidence angles of the magnetosheath protons. The scattering fraction from the unmagnetized regions remains consistent with that in the undisturbed solar wind (10%–20%). Moreover, the observed ENA energy spectra are well reproduced by our temperature‐dependent model. We conclude that the ENA scattering process is unchanged in the magnetosheath. Similarly to the undisturbed solar wind case, it is only magnetic anomalies that provide contrast in the ENA maps, not any selenomorphological features such as mare and highland regions.
Midlatitude ionospheric responses to the 2013 SSW under high solar activity
Authors: Chen Gang , Wu Chen , Zhang Shaodong , Ning Baiqi , Huang Xueqin , Zhong Dingkun , Qi Hao , Wang Jin , Huang Liang 
Published: December 2015

AbstractIonospheric responses to sudden stratospheric warming (SSW) are not well understood, particularly in the midlatitudes and under high solar conditions. During the 2013 SSW, ionospheric disturbances were observed in eight locations on the meridional chain from 30.5°N to 42.8°N in northern China. The midlatitude ionosphere responded strongly to the SSW despite being under high solar flux. The F2 layer maximum electric density increased by more than 80%, and the peak height was elevated more than 60 km. Well‐set and organized semidiurnal variations were recorded in early and middle January during the SSW in eight observation locations. The expected foF2 decrease in the afternoon hours was not clearly discernible; however, nighttime enhancements occurred frequently. The time‐period spectra of the average foF2 and zonal winds and meridional winds at altitudes of 86–95 km presented quasi‐16 day planetary wave‐like oscillations during the warming event. The coupling between the atmosphere and ionosphere may be strengthened by the quasi‐16 day waves. The amplified diurnal, semidiurnal, and terdiurnal tides in foF2 were also recorded during the warming, in good agreement with earlier observations. Importantly, the variations in the semidiurnal tides included a 16 day periodic component, indicating that the modulated semidiurnal tides may transmit these 16 day planetary wave‐like oscillations to the F region through wind dynamo. Although the PW‐tide interaction theory is not novel, it is of significance in the midlatitude ionospheric response to SSW.
Electron scattering by magnetosonic waves in the inner magnetosphere
Authors: Ma Qianli , Li Wen , Thorne Richard M. , Bortnik Jacob , Kletzing C. A. , Kurth W. S. , Hospodarsky G. B. 
Published: December 2015

AbstractWe investigate the importance of electron scattering by magnetosonic waves in the Earth's inner magnetosphere. A statistical survey of the magnetosonic wave amplitude and wave frequency spectrum, as a function of geomagnetic activity, is performed using the Van Allen Probes wave measurements and is found to be generally consistent with the wave distribution obtained from previous spacecraft missions. Outside the plasmapause the statistical frequency distribution of magnetosonic waves follows the variation of the lower hybrid resonance frequency, but this trend is not observed inside the plasmasphere. Drift and bounce averaged electron diffusion rates due to magnetosonic waves are calculated using a recently developed analytical formula. The resulting timescale of electron energization during disturbed conditions (when AE* > 300 nT) is more than 10 days. We perform a 2‐D simulation of the electron phase space density evolution due to magnetosonic wave scattering during disturbed conditions. Outside the plasmapause, the waves accelerate electrons with pitch angles between 50° and 70° and form butterfly pitch angle distributions at energies from ~100 keV to a few MeV over a timescale of several days; whereas inside the plasmapause, the electron acceleration is very weak. Our study suggests that intense magnetosonic waves may cause the butterfly distribution of radiation belt electrons especially outside the plasmapause, but electron acceleration due to magnetosonic waves is generally not as effective as chorus wave acceleration.
ULF geomagnetic and polar cap potential signatures in the temperature and zonal wind reanalysis data in Antarctica
Authors: Regi M. , De Lauretis M. , Redaelli G. , Francia P. 
Published: December 2015

AbstractIn the present study we investigated the possible coupling between geomagnetic activity and the low atmosphere dynamics in the polar cap. We compared daily values of the ERA‐Interim temperature and zonal wind over Antarctica, with the daily geomagnetic ULF power, in the Pc5 (1–7 mHz), Pc1, and Pc2 (100 mHz–1 Hz) frequency ranges, at Terra Nova Bay (Antarctica, corrected geomagnetic latitude λ ~ 80°S) and with solar wind data during 2007, in correspondence to the last declining phase of the solar cycle 23. We found a high and statistically significant correspondence of temperature and zonal wind fluctuations in the stratosphere and troposphere with geomagnetic ULF power fluctuations at the ~27 day periodicity, with a substantial reduction at the tropopause height. A similar, clear relationship between the meteorological parameters and the polar cap potential difference was also observed. The results suggest that the changes in the atmospheric conductivity, due to energetic electrons precipitation driven by the ULF waves, as well as the high latitude potential variations, both associated to high geomagnetic activity, can affect the atmospheric dynamics.