bluuebunny/crossref_metadata_2025_split huggingface dataset:
Large time‐varying parameter VARs: A nonparametric approach
Authors: Kapetanios George , Marcellino Massimiliano , Venditti Fabrizio 
Published: June 2019

SummaryIn this paper we introduce a nonparametric estimation method for a large Vector Autoregression (VAR) with time‐varying parameters. The estimators and their asymptotic distributions are available in closed form. This makes the method computationally efficient and capable of handling information sets as large as those typically handled by factor models and Factor Augmented VARs. When applied to the problem of forecasting key macroeconomic variables, the method outperforms constant parameter benchmarks and compares well with large (parametric) Bayesian VARs with time‐varying parameters. The tool can also be used for structural analysis. As an example, we study the time‐varying effects of oil price shocks on sectoral U.S. industrial output. According to our results, the increased role of global demand in shaping oil price fluctuations largely explains the diminished recessionary effects of global energy price increases.
Pediatric tracheal dimensions on computed tomography and its correlation with tracheostomy tube sizes
Authors: Naina P. , Syed Kamran Asif , Irodi Aparna , John Mary , Varghese Ajoy Mathew 
Published: June 2019

ObjectiveAge‐based formulas for selecting the appropriate size of tracheostomy tubes in children are based on data on tracheal dimensions. This study aims to measure the tracheal dimensions of Indian children by computerized tomography (CT) and to compare this with the dimensions of age‐appropriate tracheostomy tubes.MethodsCT scans of children aged less than 16 years that were taken for indications other than respiratory distress were included. Tracheal diameters at the tracheostomy point and tracheal length from the tracheostomy point to the carina were calculated from the scans. These dimensions were correlated with age, weight, and height. The measurement on the CT scan was used to predict the appropriate size of tracheostomy tube, which was compared with the tracheostomy tube sizes.ResultsTwo hundred and fourteen CT scans of children aged below 16 years were included in the study. On multiple logistic regression analysis, tracheal diameter correlated well with age and weight (P = 0.04 and 0.001, respectively), whereas tracheal length correlated well with age and height of the child (P = 0.03 and 0 < 0.001, respectively).On comparison with dimensions of the tracheostomy tube, tracheal diameter correlated well, and the length was found to be longer than needed to prevent endobronchial intubation. The regression value was used to predict the size of an ideal tracheostomy tube.ConclusionTracheal diameter of Indian children correlates well with the outer diameter of age‐appropriate tracheostomy tubes, but the length of these tubes is longer than the ideal length. This would necessitate a change in the design of these tubes.Level of Evidence2bLaryngoscope, 130:1316–1321, 2020
Comparison of gadolinium‐enhanced and ferumoxytol‐enhanced conventional and UTE‐MRA for the depiction of the pulmonary vasculature
Authors: Knobloch Gesine , Colgan Timothy , Schiebler Mark L. , Johnson Kevin M. , Li Geng , Schubert Tilman , Reeder Scott B. , Nagle Scott K. 
Published: June 2019

PurposeTo evaluate the feasibility of ferumoxytol (FE)‐enhanced UTE‐MRA for depiction of the pulmonary vascular and nonvascular structures.MethodsTwenty healthy volunteers underwent contrast‐enhanced pulmonary MRA at 3 T during 2 visits, separated by at least 4 weeks. Visit 1: The MRA started with a conventional multiphase 3D T1‐weighted breath‐held spoiled gradient‐echo MRA before and after the injection of 0.1 mmol/kg gadobenate dimeglumine (GD). Subsequently, free‐breathing GD‐UTE‐MRA was acquired as a series of 3 flip angles (FAs) (6°, 12°, 18°) to optimize T1 weighting. Visit 2: After the injection of 4 mg/kg FE, MRA was performed during the steady state, starting with a conventional 3D T1‐weighted breath‐held spoiled gradient‐echo MRA and followed by free‐breathing FE‐UTE‐MRA, both at 4 different FAs (6°, 12°, 18°, 24°). The optimal FA for best T1 contrast was evaluated. Image quality at the optimal FA was compared between methods on a 4‐point ordinal scale, using multiphase GD conventional pulmonary MRA (cMRA) as standard of reference.ResultsFlip angle in the range of 18°‐24° resulted in best T1 contrast for FE cMRA and both UTE‐MRA techniques (p > .05). At optimized FA, image quality of the vasculature was good/excellent with both FE‐UTE‐MRA and GD cMRA (98% versus 97%; p = .51). Both UTE techniques provided superior depiction of nonvascular structures compared with either GD‐enhanced or FE‐enhanced cMRA (p < .001). However, GD‐UTE‐MRA showed the lowest image quality of the angiogram due to low image contrast.ConclusionFree‐breathing UTE‐MRA using FE is feasible for simultaneous assessment of the pulmonary vasculature and nonvascular structures. Patient studies should investigate the clinical utility of free‐breathing UTE‐MRA for assessment of pulmonary emboli.
3D nonrigid motion correction for quantitative assessment of hepatic lesions in DCE‐MRI
Authors: Ippoliti Matteo , Lukas Mathias , Brenner Winfried , Schaeffter Tobias , Makowski Marcus R. , Kolbitsch Christoph 
Published: June 2019

PurposeTo provide nonrigid respiratory motion‐corrected DCE‐MRI images with isotropic resolution of 1.5 mm, full coverage of abdomen, and covering the entire uptake curve with a temporal resolution of 6 seconds, for the quantitative assessment of hepatic lesions.Methods3D DCE‐MRI data were acquired at 3 T during free breathing for 5 minutes using a 3D T1‐weighted golden‐angle radial phase‐encoding sequence. Nonrigid respiratory motion information was extracted and used in motion‐corrected image reconstruction to obtain high‐quality DCE‐MRI images with temporal resolution of 6 seconds and isotropic resolution of 1.5 mm. An extended Tofts model was fitted to the dynamic data sets, yielding quantitative parametric maps of endothelial permeability using the hepatic artery as input function. The proposed approach was evaluated in 11 patients (52 ± 17 years, 5 men) with and without known hepatic lesions, undergoing DCE‐MRI.ResultsRespiratory motion produced artifacts and misalignment between dynamic volumes (lesion average motion amplitude of 3.82 ± 1.11 mm). Motion correction minimized artifacts and improved average contrast‐to‐noise ratio of hepatic lesions in late phase by 47% (p < .01). Quantitative endothelial permeability maps of motion‐corrected data demonstrated enhanced visibility of different pathologies (e.g., metastases, hemangiomas, cysts, necrotic tumor substructure) and showed improved contrast‐to‐noise ratio by 62% (p < .01) compared with uncorrected data.Conclusion3D nonrigid motion correction in DCE‐MRI improves both visual and quantitative assessment of hepatic lesions by ensuring accurate alignment between 3D DCE images and reducing motion blurring. This approach does not require breath‐holds and minimizes scan planning by using a large FOV with isotropic resolution.
Spinocerebellar ataxia type 2—neuronopathy or neuropathy?
Authors: Pelosi Luciana , Iodice Rosa , Antenora Antonella , Kilfoyle Dean , Mulroy Eoin , Rodrigues Miriam , Roxburgh Richard , Iovino Aniello , Filla Alessandro , Manganelli Fiore , Santoro Lucio 
Published: June 2019

ABSTRACTIntroductionUse of peripheral nerve ultrasound alongside standard electrodiagnostic tests may help to gain insight into the pathophysiology of peripheral nerve involvement in type 2 spinocerebellar ataxia (SCA2).MethodsTwenty‐seven patients with SCA2 underwent ultrasound cross‐sectional area (CSA) measurement of median, ulnar, sural and tibial nerves, and motor (median, ulnar, tibial) and sensory (median, ulnar, radial, sural) nerve conduction studies.ResultsTwenty patients had pathologically small‐nerve CSAs, suggestive of sensory neuronopathy. In these patients, electrophysiology showed non–length‐dependent sensory neuropathy (14 of 20), “possible sensory neuropathy” (1 of 20), or normal findings (5 of 20). Four different patients had length‐dependent sensory neuropathy on electrophysiology, and 1 had enlarged nerve CSAs. Regression analysis showed an inverse relationship between ataxia scores and upper limb nerve CSA (P < 0.03).DiscussionOur findings suggest that a majority of patients with SCA2 (74%) have a sensory neuronopathy and this correlates with disability. A minority of patients have findings consistent with axonal neuropathy (18%). Muscle Nerve, 2019
Beneficial role of adipose‐derived mesenchymal stem cells from microfragmented fat in a murine model of duchenne muscular dystrophy
Authors: Bouglé Adrien , Rocheteau Pierre , Briand David , Hardy David , Verdonk Franck , Tremolada Carlo , Hivelin Mikael , Chrétien Fabrice 
Published: June 2019

ABSTRACTIntroduction: No etiologic therapy is available for Duchenne muscular dystrophy (DMD), but mesenchymal stem cells were shown to be effective in preclinical models of DMD. The objective of this study is to investigate the effect of microfragmented fat extracted on a murine model of DMD. Methods: Fat tissue was extracted from healthy human participants and injected IM into DMD mice. Histological analysis, cytokines, and force measurement were performed up to 4 weeks after injection. Results: Duchenne muscular dystrophy mice injected with microfragmented fat exhibited an improved muscle phenotype (decreased necrosis and fibrosis), a decrease of inflammatory cytokines, and increased strength. Discussion: Administration of microfragmented fat in key muscles may improve muscular phenotype in patients with DMD. Muscle Nerve, 2019
An unsymmetric 8‐node hexahedral solid‐shell element with high distortion tolerance: Geometric nonlinear formulations
Authors: Li Zhi , Huang Junbin , Cen Song , Li Chen‐Feng 
Published: June 2019

SummaryA recent distortion‐tolerant unsymmetric 8‐node hexahedral solid‐shell element US‐ATFHS8, which takes the analytical solutions of linear elasticity as the trial functions, is successfully extended to geometric nonlinear analysis. This extension is based on the corotational (CR) approach due to its simplicity and high efficiency, especially for geometric nonlinear analysis where the strain is still small. Based on the assumption that the analytical trial functions can properly work in each increment during the nonlinear analysis, the incremental corotational formulations of the nonlinear solid‐shell element US‐ATFHS8 are derived within the updated Lagrangian (UL) framework, in which an appropriate updated strategy for linear analytical trial functions is proposed. Numerical examples show that the present nonlinear element US‐ATFHS8 possesses excellent performance for various rigorous tests no matter whether regular or distorted mesh is used. Especially, it even performs well in some situations that other conventional elements cannot work.
Taste of Life: Science outreach made delicious
Authors: Moscoe Lauren J. , Hanes Margaret M. 
Published: June 2019

Societal Impact StatementThe Taste of Life is a series of science outreach events that use food in creative ways to combat the growing epidemic of biodiversity blindness, particularly the special case of plant blindness. Through interdisciplinary collaboration and community partnerships, we have reached hundreds of campus and community members throughout southeast Michigan, USA. Participants gain a new appreciation for biodiversity in the meals they eat and leave events with resources to consider how they may interact with and preserve biodiversity in the future. We believe that sharing our experience will empower biodiversity professionals to contribute to the urgent need for impactful science outreach.
Structural effects of divalent calcium cations on the α7 nicotinic acetylcholine receptor: A molecular dynamics simulation study
Authors: Suresh Abishek , Hung Andrew 
Published: June 2019

AbstractThe α7 subtype of neuronal nicotinic acetylcholine receptor (nAChR) is a ligand‐gated ion channel protein that is vital to various neurological functions, including modulation of neurotransmitter release. A relatively high concentration of extracellular Ca2+ in the neuronal environment is likely to exert substantial structural and functional influence on nAChRs, which may affect their interactions with agonists and antagonists. In this work, we employed atomistic molecular dynamics (MD) simulations to examine the effects of elevated Ca2+ on the structure and dynamics of α7 nAChR embedded in a model phospholipid bilayer. Our results suggest that the presence of Ca2+ in the α7 nAChR environment results in closure of loop C‐in the extracellular ligand‐binding domain, a motion normally associated with agonist binding and receptor activation. Elevated Ca2+ also alters the conformation of key regions of the receptor, including the inter‐helical loops, pore‐lining helices and the “gate” residues, and causes partial channel opening in the absence of an agonist, leading to an attendant reduction in the free energy of Ca2+ permeation through the pore as elucidated by umbrella sampling simulations. Overall, the structural and permeability changes in α7 nAChR suggest that elevated Ca2+ induces a partially activated receptor state that is distinct from both the resting and the agonist‐activated states. These results are consistent with the notion that divalent ions can serve as a potentiator of nAChRs, resulting in a higher rate of receptor activation (and subsequent desensitization) in the presence of agonists, with possible implications for diseases involving calcium dysregulation.
Long‐term evaluation of an EHC injection permeable reactive barrier in a sulfate‐rich, high‐flow aquifer
Authors: Molin Josephine , Valkenburg John , Seech Alan , Oesterreich Ryan , Son Jennifer 
Published: June 2019

AbstractPermeable reactive barriers (PRBs) have traditionally been constructed via trenching backfilled with granular, long‐lasting materials. Over the last decade, direct push injection PRBs with fine‐grained injectable reagents have gained popularity as a more cost‐efficient and less‐invasive approach compared to trenching. A direct push injection PRB was installed in 2005 to intercept a 2,500 feet (760 meter) long carbon tetrachloride (CT) groundwater plume at a site in Kansas. The PRB was constructed by injecting EHC® in situ chemical reduction reagent slurry into a line of direct push injection points. EHC is composed of slow‐release plant‐derived organic carbon plus microscale zero‐valent iron (ZVI) particles, specifically formulated for injection applications. This project was the first full‐scale application of EHC into a flow‐through reactive zone and provided valuable information about substrate longevity and PRB performance over time. Groundwater velocity at the site is high (1.8 feet per day) and sulfate‐rich (~120 milligrams per liter), potentially affecting the rate of substrate consumption and the PRB reactive life. CT removal rates peaked 16 months after PRB installation with >99% removal observed. Two years post‐installation removal rates decreased to approximately 95% and have since stabilized at that level for the 12 years of monitoring data available after injection. Geochemical data indicate that the organic carbon component of EHC was mostly consumed after 2 years; however, reducing conditions and a high degree of chloromethane treatment were maintained for several years after total organic carbon concentrations returned to background. Redox conditions are slowly reverting and have returned close to background conditions after 12 years, indicating that the PRB may be nearing the end of its reactive life. Direct measurements of iron have not been performed, but stoichiometric demand calculations suggest that the ZVI component of EHC may, in theory, last for up to 33 years. However, the ZVI component by itself would not be expected to support the level of treatment observed after the organic carbon substrate had been depleted. A longevity of up to 5 years was originally estimated for the EHC PRB based on the maximum expected longevity of the organic carbon substrate. While the organic carbon was consumed faster than expected, the PRB has continued to support a high degree of chloromethane treatment for a significantly longer time period of over 12 years. Recycling of biomass and the contribution from a reduced iron sulfide mineral zone are discussed as possible explanations for the sustained reducing conditions and continued chloromethane treatment.
The role of information provision in economic evaluations of non-invasive prenatal testing: a systematic review
Authors: John Nikita M. , Wright Stuart J. , Gavan Sean P. , Vass Caroline M. 
Published: June 2019

AbstractBackgroundTechnological progress has led to changes in the antenatal screening programmes, most significantly the introduction of non-invasive prenatal testing (NIPT). The availability of a new type of testing changes the type of information that the parent(s) require before, during and after screening to mitigate anxiety about the testing process and results.ObjectivesTo identify the extent to which economic evaluations of NIPT have accounted for the need to provide information alongside testing and the associated costs and health outcomes of information provision.MethodsA systematic review of economic evaluations of NIPTs (up to February 2018) was conducted. Medline, Embase, CINAHL and PsychINFO were searched using an electronic search strategy combining a published economic search filter (from NHS economic evaluations database) with terms related to NIPT and screening-related technologies. Data were extracted using the Consolidated Health Economic Evaluation Reporting Standards framework and the results were summarised as part of a narrative synthesis.ResultsA total of 12 economic evaluations were identified. The majority of evaluations (n = 10; 83.3%) involved cost effectiveness analysis. Only four studies (33.3%) included the cost of providing information about NIPT in their economic evaluation. Two studies considered the impact of test results on parents’ quality of life by allowing utility decrements for different outcomes. Some studies suggested that the challenges of valuing information prohibited their inclusion in an economic evaluation.ConclusionEconomic evaluations of NIPTs need to account for the costs and outcomes associated with information provision, otherwise estimates of cost effectiveness may prove inaccurate.
Two Dimensional Visualization of Optic Chiasma in Fetus
Authors: Desai Purvi , Deshpande Shalmali Mohan , Chauhan Keshvi , Chauhan Binodini , Jhawar Manisha 
Published: June 2019

AbstractThe purpose of this study is to investigate methods to visualize and measure the fetal optic chiasma (OC) using transabdominal and/or transvaginal two-dimensional (2D) ultrasound in the coronal plane. The role of analyzing optic chiasma cannot be down scaled in prognosticating septo-optic dysplasia (SOD) and agenesis of septum pellucidum. This is a retrospective study of 117 random cases referred for various indications. The gestational age of the fetuses included in the study was between 19 and 37 weeks. The OC was visualized and measured in the 2D coronal plane with color Doppler by transabdominal and/or transvaginal routes. There were 97 normal low risk cases and 19 abnormal cases in the study. We conclude that it is possible to locate and measure OC width by transabdominal and transvaginal scans from 19 week onwards. It is possible to get equally good views by both, transabdominal and transvaginal routes.
Research Strategies on New Prefabricated Technology for Underground Metro Stations
Authors: Yang Xiuren , Huang Meiqun , Lin Fang 
Published: June 2019

Abstract
Based on the first successful application of new prefabricated technology in underground metro stations on line 2 of the Changchun Metro in China, a comprehensive analysis and discussion on research strategies for new prefabricated technology for large underground structures is provided. This paper introduces the application status of prefabricated technology in underground engineering worldwide, illustrates the different characteristics of prefabricated technology applied to ground buildings and underground structures, puts forward the key technologies, and compares the major technical, economic, and social benefits achieved. The successful application of prefabricated technology for underground structures in Changchun Metro demonstrates the feasibility and great advantages of the new prefabricated technology for underground engineering.
Heat and Freshwater Transport by Mesoscale Eddies in the Southern Subpolar North Atlantic
Authors: Müller Vasco , Kieke Dagmar , Myers Paul G. , Pennelly Clark , Steinfeldt Reiner , Stendardo Ilaria 
Published: June 2019

AbstractA new data set of temperature and salinity fields reconstructed from satellite altimetry data between January 1993 and April 2014 is combined with satellite observations of mesoscale eddies in the subpolar North Atlantic between 40°N–55°N and 43°W–20.5°W. The data set is used to calculate the meridional heat and freshwater transports related to the propagation of eddies crossing 47°N, a latitude close to the boundary between the subpolar and the subtropical gyres. The largest heat and freshwater transports by eddies are observed in the western part of the Newfoundland Basin. Around 35–45% of the heat and freshwater transports by eddies across 47°N stem from individual isolated eddies with large thermohaline signatures. Northward moving cold and fresh cyclonic eddies carrying subpolar water from the Western Boundary Current make a considerable contribution to the overall heat and freshwater transport by eddies crossing 47°N. While the transport by individual eddies is negligible compared to the transport by the mean flow in this region, it can have a notable influence on the temporal variability. The analysis is repeated for a model simulation with 1/12° horizontal resolution for the period 2002–2013. The observed results are well reproduced in the model simulation; in particular, the modeled number of eddies crossing 47°N, the spatial distribution, and the associated heat and freshwater transports across this latitude are consistent with the observations.
Constraining the Large‐Scale Analysis of a Regional Rapid‐Update‐Cycle System for Short‐Term Convective Precipitation Forecasting
Authors: Tang Xiaowen , Sun Juanzhen , Zhang Ying , Tong Wenxue 
Published: June 2019

AbstractThis study examines the impact of a large‐scale constraint (LSC) on the large‐scale analysis and precipitation forecast of convective weather systems in a regional rapid‐update‐cycle system. The LSC is imposed by assimilating Global Forecast System forecast fields as bogus observations with a scale selection scheme. The scale selection is achieved by skipping data points of Global Forecast System forecast fields in the horizontal and vertical directions. It is shown that the LSC is able to modify the large‐scale component of the analysis fields while leaving the small‐scale component mostly intact compared with a control experiment without the constraint. The effects of the LSC on precipitation forecast are verified and analyzed using nine convective cases in the Rocky Mountain Front Range and its east plains. The results show that the LSC is effective in improving the precipitation forecast of different cases. However, the cases with weak large‐scale forcing show greater improvements than those with strong large‐scale forcing. Further analyses on the dynamic and thermodynamic variables indicate that the use of the LSC is able to construct a favorable environment for the initiation and development of convection in the case of weak large‐scale forcing, which leads to significant improvement of convective precipitation forecasting when radar observations are assimilated.