bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling and quality assessment of nystagmus eye movements recorded using an eye-tracker
Authors: Rosengren William , Nyström Marcus , Hammar Björn , Rahne Markus , Sjödahl Linnea , Stridh Martin 
Published: April 2020

AbstractMathematical modeling of nystagmus oscillations is a technique with applications in diagnostics, treatment evaluation, and acuity testing. Modeling is a powerful tool for the analysis of nystagmus oscillations but quality assessment of the input data is needed in order to avoid misinterpretation of the modeling results. In this work, we propose a signal quality metric for nystagmus waveforms, the normalized segment error (NSE). The NSE is based on the energy in the error signal between the observed oscillations and a reconstruction from a harmonic sinusoidal model called the normalized waveform model (NWM). A threshold for discrimination between nystagmus oscillations and disturbances is estimated using simulated signals and receiver operator characteristics (ROC). The ROC is optimized to find noisy segments and abrupt waveform and frequency changes in the simulated data that disturb the modeling. The discrimination threshold, 𝜖, obtained from the ROC analysis, is applied to real recordings of nystagmus data in order to determine whether a segment is of high quality or not. The NWM parameters from both the simulated dataset and the nystagmus recordings are analyzed for the two classes suggested by the threshold. The optimized 𝜖 yielded a true-positive rate and a false-positive rate of 0.97 and 0.07, respectively, for the simulated data. The results from the NWM parameter analysis show that they are consistent with the known values of the simulated signals, and that the method estimates similar model parameters when performing analysis of repeated recordings from one subject.
A Multiwavelength Search for Intrinsic Linear Polarization in Wolf–Rayet Winds
Authors: Fullard Andrew G. , St-Louis Nicole , Moffat Anthony F. J. , Piirola Vilppu E. , Manset Nadine , Hoffman Jennifer L. 
Published: April 2020

Abstract
Wolf–Rayet stars have strong, hot winds, with mass-loss rates at least a factor of 10 greater than their O-star progenitors, although their terminal wind speeds are similar. In this paper, we use the technique of multiband linear polarimetry to extract information on the global asymmetry of the wind in a sample of 47 bright Galactic WR stars. Our observations also include time-dependent observations of 17 stars in the sample. The path to our goal includes removing the dominating component of wavelength-dependent interstellar polarization (ISP), which normally follows the well-known Serkowski law. We include a wavelength-dependent ISP position angle parameter in our ISP law and find that 15 stars show significant results for this parameter. We detect a significant component of wavelength-independent polarization due to electron scattering in the wind for 10 cases, with most WR stars showing none at the ∼0.05% level precision of our data. The intrinsically polarized stars can be explained with binary interaction, large-scale wind structure, and clumping. We also found that 5 stars out of 19 observed with the Strömgren b filter (probing the complex λ4600–4700 emission-line region) have significant residuals from the ISP law and propose that this is due to wind asymmetries. We provide a useful catalog of ISP for 47 bright Galactic WR stars and upper limits on the possible level of intrinsic polarization.
Securing the Legacy of TESS through the Care and Maintenance of TESS Planet Ephemerides
Authors: Dragomir Diana , Harris Mallory , Pepper Joshua , Barclay Thomas , Villanueva Steven , Ricker George R. , Vanderspek Roland , Latham David W. , Seager S. , Winn Joshua N. , Jenkins Jon M. , Ciardi David R. , Furesz Gabor , Henze Christopher E. , Mireles Ismael , Morgan Edward H. , Quintana Elisa V. , Ting Eric B. , Yahalomi Daniel 
Published: April 2020

Abstract
Much of the science from the exoplanets detected by the Transiting Exoplanet Survey Satellite (TESS) mission relies on precisely predicted transit times that are needed for many follow-up characterization studies. We investigate ephemeris deterioration for simulated TESS planets and find that the ephemerides of 81% of those will have expired (i.e., 1σ mid-transit time uncertainties greater than 30 minutes) 1 yr after their TESS observations. We verify these results using a sample of TESS planet candidates as well. In particular, of the simulated planets that would be recommended as James Webb Space Telescope (JWST) targets by Kempton et al., ∼80% will have mid-transit time uncertainties >30 minutes by the earliest time JWST would observe them. This rapid deterioration is driven primarily by the relatively short time baseline of TESS observations. We describe strategies for maintaining TESS ephemerides fresh through follow-up transit observations. We find that the longer the baseline between the TESS and the follow-up observations, the longer the ephemerides stay fresh, and that 51% of simulated primary mission TESS planets will require space-based observations. The recently approved extension to the TESS mission will rescue the ephemerides of most (though not all) primary mission planets, but the benefits of these new observations can only be reaped 2 yr after the primary mission observations. Moreover, the ephemerides of most primary mission TESS planets (as well as those newly discovered during the extended mission) will again have expired by the time future facilities such as the ELTs, Ariel, and the possible LUVOIR/Origins Space Telescope missions come online, unless maintenance follow-up observations are obtained.
An Ejecta Kinematics Study of Kepler’s Supernova Remnant with High-resolution Chandra HETG Spectroscopy
Authors: Millard Matthew J. , Bhalerao Jayant , Park Sangwook , Sato Toshiki , Hughes John P. , Slane Patrick , Patnaude Daniel , Burrows David , Badenes Carles 
Published: April 2020

Abstract
We report our measurements of the bulk radial velocity from a sample of small, metal-rich ejecta knots in Kepler’s supernova remnant (SNR). We measure the Doppler shift of the He-like Si Kα line-center energy in the spectra of these knots based on our Chandra High-Energy Transmission Grating Spectrometer observation to estimate their radial velocities. We estimate high radial velocities of up to ∼8000 km s−1 for some of these ejecta knots. We also measure proper motions for our sample based on the archival Chandra Advanced CCD Imaging Spectrometer data taken in 2000, 2006, and 2014. Our measured radial velocities and proper motions indicate that some of these ejecta knots are almost freely expanding after ∼400 yr since the explosion. The fastest moving knots show proper motions of up to ∼0.″2 per year. Assuming that these high-velocity ejecta knots are traveling ahead of the forward shock of the SNR, we estimate the distance to Kepler’s SNR d ∼ 4.4–7.5 kpc. We find that the ejecta knots in our sample have an average space velocity of v

s
∼ 4600 km s−1 (at a distance of 6 kpc). We note that 8 of the 15 ejecta knots from our sample show a statistically significant (at the 90% confidence level) redshifted spectrum, compared to only two with a blueshifted spectrum. This may suggest an asymmetry in the ejecta distribution in Kepler’s SNR along the line of sight; however, a larger sample size is required to confirm this result.
Sandblasting the r-process: Spallation of Ejecta from Neutron Star Mergers
Authors: Wang 王夕 Xilu 露 ,   (N3AS collaboration), Fields Brian D. , Mumpower Matthew , Sprouse Trevor , Surman Rebecca , Vassh Nicole 
Published: April 2020

Abstract
Neutron star mergers (NSMs) are rapid neutron-capture (r-process) nucleosynthesis sites that expel matter at high velocities, from 0.1c to as high as 0.6c. Nuclei ejected at these speeds are sufficiently energetic to initiate spallation nuclear reactions with interstellar medium (ISM) particles. We adopt a thick-target model for the propagation of high-speed heavy nuclei in the ISM, similar to the transport of cosmic rays. We find that spallation may create observable perturbations to NSM isotopic abundances, particularly around the low-mass edges of the r-process peaks where neighboring nuclei have very different abundances. The extent to which spallation modifies the final NSM isotopic yields depends on: (1) the ejected abundances, which are determined by the NSM astrophysical conditions and the properties of nuclei far from stability, (2) the ejecta velocity distribution and propagation in interstellar matter, and (3) the spallation cross sections. Observed solar and stellar r-process yields could thus constrain the velocity distribution of ejected neutron star matter, assuming NSMs are the dominant r-process source. We suggest avenues for future work, including measurement of relevant cross sections.
Meso-scale Instability Triggered by Dust Feedback in Dusty Rings: Origin and Observational Implications
Authors: Huang Pinghui , Li Hui , Isella Andrea , Miranda Ryan , Li Shengtai , Ji Jianghui 
Published: April 2020

Abstract
High spatial resolution observations of protoplanetary disks by ALMA have revealed many substructures that are providing interesting constraints on disk physics as well as dust dynamics, both of which are essential for understanding planet formation. We carry out high-resolution, 2D global hydrodynamic simulations, including the effects of dust feedback, to study the stability of dusty rings. When the ring edges are relatively sharp and the dust surface density becomes comparable to the gas surface density, we find that dust feedback enhances the radial gradients of both the azimuthal velocity profile and the potential vorticity profile at the ring edges. This eventually leads to instabilities on meso-scales (spatial scales of several disk scale heights), causing dusty rings to be populated with many compact regions with highly concentrated dust densities. We also produce synthetic dust emission images using our simulation results and discuss the comparison between simulations and observations.
Structured Jets and X-Ray Plateaus in Gamma-Ray Burst Phenomena
Authors: Oganesyan Gor , Ascenzi Stefano , Branchesi Marica , Salafia Om Sharan , Dall’Osso Simone , Ghirlanda Giancarlo 
Published: April 2020

Abstract
The first multi-messenger detection of a binary neutron star merger, GW170817, brought to the forefront the structured jet model as a way to explain multiwavelength observations taken more than a year after the event. Here, we show that the high-latitude emission from a structured jet can naturally produce an X-ray plateau in gamma-ray burst (GRB) light curves, independent of the radiation from an external shock. We calculate the radiation from a switched-off shell featuring an angular structure in both its relativistic bulk motion and intrinsic brightness. Our model is able to explain the shallow decay phase (plateau) often observed in GRB X-ray light curves. We discuss the possible contribution of the structured jet high-latitude emission to other distinctive features of GRB X-ray light curves, and its capability to explain the chromatic optical/X-ray light-curve properties.
Endothelial Pannexin 1 Channels Control Inflammation by Regulating Intracellular Calcium
Authors: Yang Yang , Delalio Leon J. , Best Angela K. , Macal Edgar , Milstein Jenna , Donnelly Iona , Miller Ashley M. , McBride Martin , Shu Xiaohong , Koval Michael , Isakson Brant E. , Johnstone Scott R. 
Published: April 2020

AbstractThe proinflammatory cytokine IL-1β is a significant risk factor in cardiovascular disease that can be targeted to reduce major cardiovascular events. IL-1β expression and release are tightly controlled by changes in intracellular Ca2+ ([Ca2+]i), which has been associated with ATP release and purinergic signaling. Despite this, the mechanisms that regulate these changes have not been identified. The pannexin 1 (Panx1) channels have canonically been implicated in ATP release, especially during inflammation. We examined Panx1 in human umbilical vein endothelial cells following treatment with the proinflammatory cytokine TNF-α. Analysis by whole transcriptome sequencing and immunoblot identified a dramatic increase in Panx1 mRNA and protein expression that is regulated in an NF-κB–dependent manner. Furthermore, genetic inhibition of Panx1 reduced the expression and release of IL-1β. We initially hypothesized that increased Panx1-mediated ATP release acted in a paracrine fashion to control cytokine expression. However, our data demonstrate that IL-1β expression was not altered after direct ATP stimulation in human umbilical vein endothelial cells. Because Panx1 forms a large pore channel, we hypothesized it may permit Ca2+ diffusion into the cell to regulate IL-1β. High-throughput flow cytometric analysis demonstrated that TNF-α treatments lead to elevated [Ca2+]i, corresponding with Panx1 membrane localization. Genetic or pharmacological inhibition of Panx1 reduced TNF-α–associated increases in [Ca2+]i, blocked phosphorylation of the NF-κB–p65 protein, and reduced IL-1β transcription. Taken together, the data in our study provide the first evidence, to our knowledge, that [Ca2+]i regulation via the Panx1 channel induces a feed-forward effect on NF-κB to regulate IL-1β synthesis and release in endothelium during inflammation.
Prevention and treatment of the toxic tumour syndrome following primary proton beam therapy of choroidal melanomas
Authors: Kubicka-Trząska Agnieszka , Morawski Krzysztof , Markiewicz Anna , Romanowska-Dixon Bożena 
Published: April 2020

IntroductionThe aim of this study was to evaluate the efficacy and safety of endoresection for choroidal melanoma to prevent and treat the toxic tumour syndrome (TTS).Material and methodsThirteen patients who underwent primary proton beam therapy (PBRT) for choroidal melanoma followed by endoresection were evaluated. Main outcome measures were functional and anatomical results, surgical complications, rate of local recurrence, presence or absence of metastatic spread.ResultsThe median time of the follow-up period was 61.6 months. Six patients with clinical signs of TTS and seven with large tumours to prevent TTS underwent endoresection. Tumour thickness was 5.8 to 9.3 mm (mean: 7.6), the basal diameters were 10.6 to 15.0 mm (mean: 13.4). Preoperative best corrected visual acuity (BCVA) was 6/7.5 to counting fingers and the final BCVA was 6/15 to no light perception, and was better in those treated to prevent TTS (p = 0.01). The most universal early postoperative complication was bleeding from the scleral bed. The most common late postoperative complications were epiretinal membrane formation (30.8%), cystoid macular oedema (23.1%) and silicone oil-induced glaucoma (15.4%). Two (15.4%) patients developed phthisis bulbi, neither developed local recurrence. One patient developed liver metastases.ConclusionsEndoresection for choroidal melanoma is a safe and effective procedure with a high rate of local tumour control. The procedure appears to be useful in the prophylaxis and treatment of TTS after PBRT of choroidal melanoma.
Multidimensional measure of aggression in adolescents: Croatian validation of the Peer Conflict Scale
Authors: Drnas Marija , Bratko Denis , Pocrnić Martina 
Published: April 2020

BackgroundIn order to adequately assess aggression in adolescence, the Peer Conflict Scale (PCS) was developed. It evaluates both forms and functions of aggression (i.e. proactive overt, proactive relational, reactive overt and reactive relational aggression). The goal of this study was to examine the validity and reliability of the Croatian version of the Peer Conflict Scale.Participants and procedureThe total sample consisted of 656 high school students from the City of Zagreb (age range 16-17, 55.33% boys). Independent exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) were conducted to determine the factor structure, and the best fitting model of the PCS on a Croatian sample.ResultsBoth results of EFA and CFA support a proposed four-factor model of the instrument. Reliabilities of the instrument’s scales were acceptable. The measurement invariance across gender was established. In order to analyse the construct validity of the PCS, relations between aggression subtypes and the theoretically meaningful variable, i.e. anxiety, were assessed. Reactive rela-tional aggression had the highest correlation with anxiety, while proactive overt aggression did not correlate significantly with anxiety. Furthermore, gender differences in aggression subtypes were assessed, and were in accordance with past research.ConclusionsOur study verifies the reliability, factor structure and construct validity of PCS in a sample of Croatian adolescents. However, the results of this study suggest that the response format should be changed. Furthermore, some items did not match well with corresponding factors and the best fitting model was the one in which those items were excluded. Therefore, we suggest that two items should be replaced with new ones.
Aftermath of pulmonary tuberculosis: computed tomography
assessment
Authors: Deshpande Sneha Satish , Joshi Anagha Rajeev , Shah Ankita 
Published: April 2020

PurposePulmonary tuberculosis (PTB) has clinically significant sequelae, even after recommended treatment completion.
It is important to recognise these sequelae for accurate assessment of severity and treatment planning, if indicated.Material and methodsWe retrospectively analysed contrast-enhanced computed tomography (CT) scans of chest of
100 patients with previous history of treated pulmonary tuberculosis, excluding those with active pulmonary disease.
CT findings were analysed based on parenchymal, airway, pleural, mediastinal, and vascular sequelae of PTB.ResultsParenchymal sequelae included fibrosis with architectural distortion and volume loss (90%), cavities (21%)
(with aspergillomas noted in 19% of these cases), and tuberculomas (54%). Airway involvement was noted as bronchiectasis
(77%) and bronchial stenosis (4%) but none with broncholithiasis. Mediastinal sequelae included lymph
node calcification (74%), fibrosing mediastinitis (1%), and pericardial tuberculosis (2%). Pleural sequelae included
pleural thickening (22%), with 40.9% of these patients showing calcifications, and one patient with chronic chylous
pleural effusion. Vascular sequelae included Rasmussen aneurysms (4%), enlarged bronchial arteries (3%), and
systemic bronchial collaterals in 1% of our patientsConclusionsPTB has multiple appalling sequelae, which require due attention and appropriate treatment in symptomatic
cases. Radiological evaluation forms an integral part in patient assessment and decision making.
Image quality and radiation exposure with low-contrast-dose computed tomography angiography of the lower extremities
Authors: Assi Abed Al Nasser 
Published: April 2020

IntroductionMultidetector computed tomography is the reference standard for the diagnosis of peripheral arterial disease (PAD). The aim of this study is to optimise the image quality of computed tomography (CT) scanning for the diagnosis of PAD with the lowest possible radiation and contrast volume.Material and methodsSeventy-two patients were referred for evaluation of suspected PAD with CT angiography. Patients were randomly assigned to an optimise care dose of kVp – group A, n = 36; 18 men, 18 women; mean age, 63 years with standard deviation 15; range, 20-88 years (contrast volume 80-85 ml was injected automatically with bolus tracking, and group B, n = 36; 18 men, 18 women; mean age, 61 years with standard deviation 16; range, 26-88 years (contrast volume 120-140 ml was injected automatically with bolus tracking). Other scanning parameters were kept constant. Lower extremities vessel enhancement and image noise were quantified, and the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) were calculated. Subjective vessel contrast was assessed by two radiologists in consensus.ResultA total of 16 cases of PAD (22.2%) were found in the evaluated of subjects (10 in group A, and six in group B). All PAD cases were detected by the two readers. There was no significant difference in the size or location of the PAD between the two groups; the average image noise was 19 HU for group A and 16 HU for group B. The difference was not statistically significant (p = 0.183). Overall, the SNR and CNR were slightly higher in group B (25.5 and 24.1, respectively) compared with group A (20 and 17.4, respectively), but those differences were not statistically significant (p = 061 and p = 0.38, respectively).ConclusionsAll patients were evaluated by lower extremities CTA protocol allowing similar image quality to be achieved in both groups, with optimised care dose for both protocols, and contrast volume was reduced by 40% in the new protocol group compared to the conventional protocol group.
The impact of obesity on inflammatory markers used in the assessment of disease activity in rheumatoid arthritis – a cross-sectional study
Authors: Sharma Ashish , Kumar Ashok , Jha Alka , Agarwal Anunay , Misra Anoop 
Published: April 2020

IntroductionObesity is known to be associated with elevated levels of inflammatory markers. The aim of the study was to assess the confounding effect of obesity on the levels of erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) in patients with rheumatoid arthritis (RA) in low disease activity state or remission as indicated by clinical disease activity index (CDAI).Material and methodsAdult RA patients with CDAI less than 10 were divided into two groups: obese and non-obese, based on body mass index. Relevant exclusions were applied to eliminate causes of raised inflammatory markers other than obesity. The difference of CRP and ESR levels between the obese and non-obese groups was analyzed.ResultsObese patients with RA (n = 85) had higher CRP and ESR than non-obese patients (n = 66) (p-values 0.008 and 0.000005, respectively). In addition, obese females with RA had significantly higher CRP and ESR as compared to non-obese females. However, the difference was not significant in males. Twenty-one obese (24.7%) and two non-obese RA patients (3%) had elevated CRP (difference of approximately 22% [24.7 minus 3]). Forty obese (47%) and 16 non-obese RA patients (24.2%) had elevated ESR (difference of approximately 23% [47 minus 24.2]). Thus, obesity was the attributable cause of falsely elevated CRP and ESR in 22% and 23% of patients, respectively.ConclusionsAbout one-fifth of patients with RA, who are actually in low disease activity, may have elevated inflammatory markers, primarily because of obesity. Therefore, elevated CRP and ESR in obese patients with RA should be interpreted with caution because it may lead to unnecessary overtreatment.
Psoriasis and systemic lupus erythematosus in children – literature review based on case report
Authors: Dybowska-Gołota Izabela , Owczarczyk-Saczonek Agnieszka , Krajewska-Włodarczyk Magdalena , Żuber Zbigniew 
Published: April 2020

Immune-mediated inflammatory diseases are a group of diseases characterized by generalized inflammation that results from immune dysregulation, especially involving the mechanisms of acquired immunity. These diseases may be familial, showing that genetic factors play an important role in their development. Additionally, the occurrence of one disease makes a patient prone to other diseases. However, the coexistence of systemic lupus erythematosus (SLE) and psoriasis (Ps) is very rare due to their distinct genetic determinants and mechanisms of pathogenesis. Treatment is also challenging, as medications used to treat one condition exacerbate or even trigger the symptoms of the other. This paper presents the case of a Ps patient with a family history of autoimmune diseases, who developed systemic lupus erythematosus during puberty, as well as a discussion on the coexistence of SLE and Ps in developmental age based on available literature searching for PubMed database and American College of Rheumatology and European League Against Rheumatism abstracts particularly in this subject.