bluuebunny/crossref_metadata_2025_split huggingface dataset:
Index Reduction for Differential-algebraic Equations with Mixed Matrices
Authors: Iwata Satoru , Oki Taihei , Takamatsu Mizuyo 
Published: July 2019

Differential-algebraic equations (DAEs) are widely used for the modeling of dynamical systems. The difficulty in numerically solving a DAE is measured by its differentiation index. For highly accurate simulation of dynamical systems, it is important to convert high-index DAEs into low-index DAEs. Most of the existing simulation software packages for dynamical systems are equipped with an index-reduction algorithm given by Mattsson and Söderlind. Unfortunately, this algorithm fails if there are numerical cancellations.
These numerical cancellations are often caused by accurate constants in structural equations. Distinguishing those accurate constants from generic parameters that represent physical quantities, Murota and Iri introduced the notion of a mixed matrix as a mathematical tool for faithful model description in a structural approach to systems analysis. For DAEs described with the use of mixed matrices, efficient algorithms to compute the index have been developed by exploiting matroid theory.
This article presents an index-reduction algorithm for linear DAEs whose coefficient matrices are mixed matrices, i.e., linear DAEs containing physical quantities as parameters. Our algorithm detects numerical cancellations between accurate constants and transforms a DAE into an equivalent DAE to which Mattsson–Söderlind’s index-reduction algorithm is applicable. Our algorithm is based on the combinatorial relaxation approach, which is a framework to solve a linear algebraic problem by iteratively relaxing it into an efficiently solvable combinatorial optimization problem. The algorithm does not rely on symbolic manipulations but on fast combinatorial algorithms on graphs and matroids. Our algorithm is proved to work for any linear DAEs whose coefficient matrices are mixed matrices. Furthermore, we provide an improved algorithm under an assumption based on dimensional analysis of dynamical systems. Through numerical experiments, it is confirmed that our algorithms run sufficiently fast for large-scale DAEs and output DAEs such that physical meanings of coefficients are easy to interpret. Our algorithms can also be applied to nonlinear DAEs by regarding nonlinear terms as parameters.
Predictors of Parenchymal Hematoma After Mechanical Thrombectomy
Authors: Boisseau William , Fahed Robert , Lapergue Bertrand , Desilles Jean-Philippe , Zuber Kevin , Khoury Naim , Garcia Jeanne , Maïer Benjamin , Redjem Hocine , Ciccio Gabriele , Smajda Stanislas , Escalard Simon , Taylor Guillaume , Mazighi Mikael , Piotin Michel , Gory Benjamin , Blanc Raphaël ,   on behalf of ETIS Investigators, Decroix Jean-Pierre , Wang Adrien , Evrard Serge , Tchikviladzé Maya , Bourdain Frederic , Afanasiev Vadim , Majhadi Loubna , Consoli Arthuro , Di Maria Federico , Coskun Oguzhan , Rodesch Georges , Lopez Delphine , Redjem Hocine , Obadia Mickael , Sabben Candice , Ben Maacha Malek , Pico Fernando , Rakotoharinandrasana Haja , Tassan Philippe , Poll Roxanna , Corabianu Ovide , De Broucker Thomas , Smadja Didier , Alamowitch Sonia , Obadia Mickael , Ille Olivier , Manchon Eric , Garcia Pierre-Yves , Riva Roberto , Labeyrie Paul-Emile , Nighoghossian Norbert , Philippeau Frédéric , Cakmak Serkan , Blanc-Lasserre Karine , Vallet Anne-Evelyne 
Published: July 2019

Background and Purpose—
Parenchymal hematoma (PH) is a rare but dreadful complication of acute ischemic stroke with unclear underlying mechanisms. We aimed to study the incidence and predictors of PH after mechanical thrombectomy.

Methods—
Data from a prospective observational multicenter registry was screened to identify acute ischemic stroke patients with an anterior circulation large vessel occlusion who underwent mechanical thrombectomy. Clinical, imaging, and procedural characteristics were used for the analysis, including brain imaging systematically performed at 24 hours. PH occurrence was assessed according to ECASS (European Collaborative Acute Stroke Study) criteria. Univariate and multivariable analyses were performed to identify predictors of PH.

Results—

A total of 1316 patients were included in the study. PH occurred in 153 out of 1316 patients (11.6%) and was associated with a lower rate of favorable outcome and increased mortality. On multivariable analysis, age (per 1 year increase, odds ratio [OR], 1.01; 95% CI, 1.00–1.03;
P
=0.05), current smoking (OR, 2.02; 95% CI, 1.32–3.09;
P
<0.01), admission Alberta Stroke Program Early CT Score (per a decrease of 1 point, OR, 1.70; 95% CI, 1.18–2.44;
P
<0.01), general anesthesia (OR, 1.98; 95% CI, 1.36–2.90;
P
<0.001), angiographic poor collaterals (OR, 2.13; 95% CI, 1.36–3.33;
P
<0.001) and embolization in new territory (OR, 2.94; 95% CI, 1.70–5.10;
P
<0.001) were identified as independent predictors of PH.

Conclusions—
PH occurred at a rate of 11.6% after mechanical thrombectomy, with high morbidity and mortality. Our study identified clinical, radiological, and procedural predictors of PH occurrence that can serve as the focus of future periprocedural management studies with the aim of reducing its occurrence.

Clinical Trial Registration—

URL:
https://www.clinicaltrials.gov
. Unique identifier: NCT03776877.
Factors Associated With the Decision-Making on Endovascular Thrombectomy for the Management of Acute Ischemic Stroke
Authors: Saposnik Gustavo , Menon Bijoy K. , Kashani Nima , Wilson Alexis T. , Yoshimura Shinichi , Campbell Bruce C.V. , Baxter Blaise , Rabinstein Alejandro , Turjman Francis , Fischer Urs , Ospel Johanna M. , Mitchell Peter J. , Sylaja Pillai N. , Cherian Mathew , Kim Byungmoon , Heo Ji-Hoe , Podlasek Anna , Almekhlafi Mohammed , Foss Mona M. , Demchuk Andrew M. , Hill Michael D. , Goyal Mayank 
Published: July 2019

Background and Purpose—
Little is known about the real-life factors that clinicians use in selection of patients that would receive endovascular treatment (EVT) in the real world. We sought to determine patient, practitioner, and health system factors associated with therapeutic decisions around endovascular treatment.

Methods—
We conducted a multinational cross-sectional web-based study comprising of 607 clinicians and interventionalists from 38 countries who are directly involved in acute stroke care. Participants were randomly allocated to 10 from a pool of 22 acute stroke case scenarios. Each case was classified as either Class I, Class II, or unknown evidence according to the current guidelines. We used logistic regression analysis applying weight of evidence approach. Main outcome measures were multilevel factors associated with EVT, adherence to current EVT guidelines, and practice gaps between current and ideal practice settings.

Results—
Of the 1330 invited participants, 607 (45.6%) participants completed the study (53.7% neurologists, 28.5% neurointerventional radiologists, 17.8% other clinicians). The weighed evidence approach revealed that National Institutes of Health Stroke Scale (34.9%), level of evidence (30.2%), ASPECTS (Alberta Stroke Program Early CT Score) or ischemic core volume (22.4%), patient’s age (21.6%), and clinicians’ experience in EVT use (19.3%) are the most important factors for EVT decision. Of 2208 responses that met Class I evidence for EVT, 1917 (86.8%) were in favor of EVT. In case scenarios with no available guidelines, 1070 of 1380 (77.5%) responses favored EVT. Comparison between current and ideal practice settings revealed a small practice gap (941 of 6070 responses, 15.5%).

Conclusions—
In this large multinational survey, stroke severity, guideline-based level of evidence, baseline brain imaging, patients’ age and physicians’ experience were the most relevant factors for EVT decision-making. The high agreement between responses and Class I guideline recommendations and high EVT use even when guidelines were not available reflect the real-world acceptance of EVT as standard of care in patients with disabling acute ischemic stroke.
Induction of DNA Hydroxymethylation Protects the Brain After Stroke
Authors: Morris-Blanco Kahlilia C. , Kim TaeHee , Lopez Mary S. , Bertogliat Mario J. , Chelluboina Bharath , Vemuganti Raghu 
Published: July 2019

Background and Purpose—
Epigenetics play a significant role in brain pathologies. We currently evaluated the role of a recently discovered brain-enriched epigenetic modification known as 5-hydroxymethylcytosine (5hmC) in regulating transcriptomic and pathogenic mechanisms after focal ischemic injury.

Methods—
Young and aged male and female mice were subjected to transient middle cerebral artery occlusion, and the peri-infarct region was analyzed at various times of reperfusion. Two days before middle cerebral artery occlusion, short-interfering RNA against an isoform of the 5hmC producing enzyme TET (ten-eleven translocase) was injected intracerebrally. Ascorbate was injected intraperitoneally at 5 minutes, 30 minutes, or 2 hours of reperfusion. Motor function was tested with rotarod and beam-walk test.

Results—
Focal ischemia rapidly induced the activity of TET, the enzyme that catalyzes the formation of 5hmC and preferentially increased expression of the TET3 isoform in the peri-infarct region of the ischemic cortex. Levels of 5hmC were increased in a TET3-dependent manner, and inhibition of TET3 led to wide-scale reductions in the postischemic expression of neuroprotective genes involved in antioxidant defense and DNA repair. TET3 knockdown in adult male and female mice further increased brain degeneration after focal ischemia, demonstrating a role for TET3 and 5hmC in endogenous protection against stroke. Ascorbate treatment after focal ischemia enhanced TET3 activity and 5hmC enrichment in the peri-infarct region. TET3 activation by ascorbate provided robust protection against ischemic injury in young and aged mice of both sexes. Moreover, ascorbate treatment improved motor function recovery in both male and female mice.

Conclusions—
Collectively, these results indicate the potential of TET3 and 5hmC as novel stroke therapeutic targets.

Visual Overview—

An online
visual overview
is available for this article.
Violation of Ekman Balance in the Eastern Pacific ITCZ Boundary Layer
Authors: Gonzalez Alex O. , Schubert Wayne H. 
Published: July 2019

Abstract
The intertropical convergence zone (ITCZ) is one of the most striking features of Earth’s climate system, often forming a narrow band of convection over many oceanic regions, especially in eastern ocean basins. It is not well understood why the ITCZ is so thin; however, a recent study highlighted that classical Ekman balance is not obeyed near the equator and nonlinear horizontal wind advection can localize ITCZ boundary layer vertical motion so that it becomes very narrow and intense. In this study, we use a similar model but with more realistic forcings from the Year of Tropical Convection (YOTC) reanalysis, focusing on the eastern Pacific Ocean ITCZ. The model is a zonally symmetric, slab (subcloud) boundary layer numerical model on the sphere, which can be considered the simplest “dry” model of the ITCZ. Due to the slab model’s simplicity, simulations are conducted at a range of resolutions, from 1° to 1 km. The slab model dynamical fields are in general agreement with the YOTC dynamical fields and precipitation estimates from the Tropical Rainfall Measuring Mission for one summer and two spring ITCZ cases. We find that Ekman balance is indeed violated within 10°–15° of the equator and nonlinear horizontal wind advection is crucial to understanding the preferential location, width, and intensity of the eastern Pacific ITCZ. Additionally, it appears that these boundary layer processes involved in ITCZ intensification and narrowing are dependent on model resolution such that present-day general circulation models likely cannot sufficiently resolve them.
Response of the Indian Ocean to the Tibetan Plateau Thermal Forcing in Late Spring
Authors: Zhao Yu , Duan Anmin , Wu Guoxiong , Sun Ruizao 
Published: July 2019

Abstract
The thermal effect of the Tibetan Plateau (TP) is known to exert substantial impacts on the atmospheric general circulation, suggesting that it may also influence the wind-driven circulation in the ocean through air–sea interactions. Here, several coupled general circulation model experiments are performed in order to investigate the short-term response of the Indian Ocean to the TP surface heat source in late spring (May). The results indicate that positive TP heating anomalies can induce significant atmospheric circulation responses over the northern Indian Ocean, characterized by easterly anomalies in the upper troposphere due to the enhanced South Asian high and lower-level southwesterly anomalies from the heat pumping effect. As a result, the surface wind speed over the northern Indian Ocean is reinforced, leading to intensified oceanic evaporation and subsequently cooler potential temperatures in the mixed layer. Wind-driven currents in the mixed layer are also affected. In the Bay of Bengal, Ekman transport facilitates water volume movement from west to east. In the Arabian Sea, water movement is weaker and the southward component is relatively more important. Both these areas show local meridional circulations with offshore upwelling in the northwest. Moreover, the cross-equatorial current is also enhanced in the eastern part of the tropical Indian Ocean. Overall, the upper layer in the northern Indian Ocean is efficiently modulated by the TP thermal forcing within one month.
The Value of Sustained Ocean Observations for Sea Ice Predictions in the Barents Sea
Authors: Bushuk Mitchell , Yang Xiaosong , Winton Michael , Msadek Rym , Harrison Matthew , Rosati Anthony , Gudgel Rich 
Published: July 2019

ABSTRACT
Dynamical prediction systems have shown potential to meet the emerging need for seasonal forecasts of regional Arctic sea ice. Observationally constrained initial conditions are a key source of skill for these predictions, but the direct influence of different observation types on prediction skill has not yet been systematically investigated. In this work, we perform a hierarchy of observing system experiments with a coupled global data assimilation and prediction system to assess the value of different classes of oceanic and atmospheric observations for seasonal sea ice predictions in the Barents Sea. We find notable skill improvements due to the inclusion of both sea surface temperature (SST) satellite observations and subsurface conductivity–temperature–depth (CTD) measurements. The SST data are found to provide the crucial source of interannual variability, whereas the CTD data primarily provide climatological and trend improvements. Analysis of the Barents Sea ocean heat budget suggests that ocean heat content anomalies in this region are driven by surface heat fluxes on seasonal time scales.
Coincident Observations of Dye and Drifter Relative Dispersion over the Inner Shelf
Authors: Romero Leonel , Ohlmann J. Carter , Pallàs-Sanz Enric , Statom Nicholas M. , Pérez-Brunius Paula , Maritorena Stéphane 
Published: July 2019

AbstractCoincident Lagrangian observations of coastal circulation with surface drifters and dye tracer were collected to better understand small-scale physical processes controlling transport and dispersion over the inner shelf in the Gulf of Mexico. Patches of rhodamine dye and clusters of surface drifters at scales of O(100) m were deployed in a cross-shelf array within 12 km from the coast and tracked for up to 5 h with airborne and in situ observations. The airborne remote sensing system includes a hyperspectral sensor to track the evolution of dye patches and a lidar to measure directional wavenumber spectra of surface waves. Supporting in situ measurements include a CTD with a fluorometer to inform on the stratification and vertical extent of the dye and a real-time towed fluorometer for calibration of the dye concentration from hyperspectral imagery. Experiments were conducted over a wide range of conditions with surface wind speed between 3 and 10 m s−1 and varying sea states. Cross-shelf density gradients due to freshwater runoff resulted in active submesoscale flows. The airborne data allow characterization of the dominant physical processes controlling the dispersion of passive tracers such as freshwater fronts and Langmuir circulation. Langmuir circulation was identified in dye concentration maps on most sampling days except when the near surface stratification was strong. The observed relative dispersion is anisotropic with eddy diffusivities O(1) m2 s−1. Near-surface horizontal dispersion is largest along fronts and in conditions dominated by Langmuir circulation is larger in the crosswind direction. Surface convergence at fronts resulted in strong vertical velocities of up to −66 m day−1.
Reversible right heart failure after redo operation of a post-traumatic Gerbode defect
Authors: Fragoulis Socrates , Contrafouris Constantinos , Thanopoulos Apostolos , Kyriakoulis Konstantinos , Apostolopoulou Sotiria 
Published: July 2019

Introduction: Gerbode defect is a rare entity and represents a small percent of all congenital defects. If left untreated, right heart failure may occur. Case report: We describe a redo case of a 47-year-old patient complaining about the signs and symptoms of decompensating right heart failure after a surgically treated post-traumatic Gerbode defect 8 years prior. Discussion: Although it is described as a congenital defect, in clinical practice, results mostly as an iatrogenic complication after heart valve surgery, endocarditis, nodal ablation, or post-traumatic defect. Surgical correction is the treatment of choice independently of the provided cause. Dimensions, the position of the defect, are very important factors for the interventional approach. At 12 months post-operatively, the patient remained completely asymptomatic. He has an active life and presents all the echocardiographic metrics within normal values. Conclusion: We strongly recommend that in cardiac areas where high wall tension is applied, durable materials such as Dacron should be used. We also believe that a well-documented discussion with the patient, about his medical condition and his therapeutic alternatives, is imperative.
Neuropeptide Y reduces expression of social fear via simultaneous activation of Y1 and Y2 receptors
Authors: Kornhuber Johannes , Zoicas Iulia 
Published: July 2019

Background: Neuropeptide Y (NPY) has anxiolytic effects and facilitates extinction of cued and contextual fear in rodents, thereby acting as a resilience factor against exaggerated fear responses after adverse events. We investigated whether NPY influences acquisition, expression and extinction of social fear in a mouse model of social fear conditioning (SFC). Methods: NPY was administered intracerebroventricularly before SFC or before social fear extinction with or without prior administration of Y1 and/or Y2 receptor antagonists. Results: We show that NPY affects SFC-induced social fear in a time point–dependent manner. When administered before SFC, NPY did not affect acquisition, expression and extinction of social fear. However, when administered before social fear extinction, NPY reduced expression of social fear via simultaneous activation of Y1 and Y2 receptors. As such, neither the Y1 receptor antagonist BIBO3304 trifluoroacetate nor the Y2 receptor antagonist BIIE0246 was able to block the effects of NPY completely. However, when administered in combination, they completely blocked the effects of NPY on social fear expression. Conclusions: These findings have important clinical implications, as they suggest that although medication strategies aimed at increasing brain NPY activity are unlikely to prevent the formation of aversive memories after a traumatic social experience, they might improve the recovery from a traumatic social experience by reducing the expression of social fear.
Effects of D-methionine in mice with noise-induced hearing loss mice
Authors: Wang Yanru , Qu Yan , Chen Xuzhen , Zhang Pu , Su Dan , Wang Li , Yang Feifei , Yang Jiangdong 
Published: July 2019

Objective To study the effects of D-methionine in a mouse model of noise-induced hearing loss (NIHL). Methods We investigated changes in auditory function and microscopic cochlear structure in a mouse model of NIHL, and carried out 4-hydroxynonenal (4-HNE) immunostaining and terminal deoxynucleotidyl transferase dUTP nick-end labeling, and examined expression levels of connexins 26 and 30 by western blot. Results The auditory brainstem response threshold was significantly increased by noise exposure. Noise exposure also damaged the inner and particularly the outer hair cells in the cochlear basement membrane, while histochemistry demonstrated only scattered loss of hair cells in the basement membrane in mice treated with D-methionine before or after noise exposure. D-methionine inhibited apoptosis in the cochlear basement membrane, stria vascularis, and spiral ligament. 4-HNE expression in the basement membrane, stria vascularis, and spiral collateral ligament was increased by noise exposure, but this increase was attenuated by D-methionine. Connexin 26 and connexin 30 expression levels were reduced by noise exposure, and this effect was similarly attenuated by D-methionine administered either before or after noise exposure. Conclusion D-methionine administered before or after noise exposure could rescue NIHL by protecting cochlear morphology, inhibiting apoptosis, and maintaining connexin 26 and 30 expression.
Precision Dermal Fat Grafting for Vermillion Deficiencies in Patients With Unilateral and Bilateral Cleft Lip
Authors: Jackson Oksana A. , Lee Alfred , Nikovina Elena , Kaye Alison E. 
Published: July 2019

Objective: Deficiencies of the upper lip vermilion occur with some frequency following repair of unilateral and bilateral clefts of the lip and can compromise the aesthetic outcome. The presence of dense scar tissue within the lip at the cleft site as well as intrinsic vermillion deficiencies can make long-lasting correction of this deformity challenging. We describe a technique to address vermillion deficiencies after cleft lip repair. Design: A novel lip augmentation technique for correction of residual vermilion deficiencies after unilateral and bilateral cleft lip repair is presented. This technique combines precise placement of a contoured dermal fat graft with local tissue (V-Y) rearrangement. Conclusion: In our experience, this method of lip augmentation following either unilateral or bilateral cleft lip repair can restore upper lip vermillion symmetry and provide predictable and durable results in patients with mild to severe vermillion deficiency.