bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polarimetric imaging of circumstellar disks
Authors: Heikamp S. , Keller C. U. 
Published: April 2019

Context. Polarimetric images of circumstellar environments, even when corrected with adaptive optics, have a limited angular resolution. Finite resolution greatly affects polarimetric images because of the canceling of adjacent polarization signals with opposite signs. In radio astronomy this effect is called beam depolarization and is well known. However, radio techniques to mitigate beam depolarization are not directly applicable to optical images as a consequence of the inherent lack of phase information at optical wavelengths.
Aims. We explore the effects of a finite point-spread function (PSF) on polarimetric images and the application of Richardson-Lucy deconvolution to polarimetric images.
Methods. We simulated polarimetric images of highly simplified, circumstellar disk models and convolved these with simulated and actual SPHERE/ZIMPOL PSFs. We attempted to deconvolve simulated images in orthogonal linear polarizations and polarized intensity images.
Results. The most significant effect of finite angular resolution is the loss of polarimetric signal close to the central star where large polarization signals of opposite signs average out. The finite angular resolution can also introduce polarized light in areas beyond the original, polarized signal such as outside of disks. These effects are particularly severe for disks that are not rotationally symmetric. The deconvolution of polarimetric images is far from trivial. Richardson-Lucy deconvolution applied to images in opposite linear polarization states, which are subsequently subtracted from each other, cannot recover the signal close to the star. Sources that lack rotational symmetry cannot be recovered with this deconvolution approach.
Second AGILE catalogue of gamma-ray sources
Authors: Bulgarelli A. , Fioretti V. , Parmiggiani N. , Verrecchia F. , Pittori C. , Lucarelli F. , Tavani M. , Aboudan A. , Cardillo M. , Giuliani A. , Cattaneo P. W. , Chen A. W. , Piano G. , Rappoldi A. , Baroncelli L. , Argan A. , Antonelli L. A. , Donnarumma I. , Gianotti F. , Giommi P. , Giusti M. , Longo F. , Pellizzoni A. , Pilia M. , Trifoglio M. , Trois A. , Vercellone S. , Zoli A. 
Published: April 2019

Aims. We present the second AGILE–GRID catalogue (2AGL) ofγ-ray sources in the energy range 100 MeV–10 GeV.Methods. With respect to previous AGILE–GRID catalogues, the current 2AGL catalogue is based on the first 2.3 years of science data from the AGILE mission (the so-called pointing mode) and incorporates more data and several analysis improvements, including better calibrations at the event reconstruction level, an updated model for the Galactic diffuseγ-ray emission, a refined procedure for point-like source detection, and the inclusion of a search for extendedγ-ray sources.Results. The 2AGL catalogue includes 175 high-confidence sources (above 4σsignificance) with their location regions and spectral properties and a variability analysis with four-day light curves for the most significant. Relying on the error region of each source position, including systematic uncertainties, 122 sources are considered as positionally associated with known counterparts at different wavelengths or detected by otherγ-ray instruments. Among the identified or associated sources, 62 are active galactic nuclei (AGNs) of the blazar class. Pulsars represent the largest Galactic source class, with 41 associated pulsars, 7 of which have detected pulsation; 8 supernova remnants and 4 high-mass X-ray binaries have also been identified. A substantial number of 2AGL sources are unidentified: for 53 sources no known counterpart is found at different wavelengths. Among these sources, we discuss a subclass of 29 AGILE–GRID–onlyγ-ray sources that are not present in 1FGL, 2FGL, or 3FGL catalogues; the remaining sources are unidentified in both 2AGL and 3FGL catalogues. We also present an extension of the analysis of 2AGL sources detected in the energy range 50–100 MeV.
Confronting expansion distances of planetary nebulae with Gaia DR2 measurements
Authors: Schönberner D. , Steffen M. 
Published: April 2019

Context. Individual distances to planetary nebulae are of the utmost relevance for our understanding of post-asymptotic giant-branch evolution because they allow a precise determination of stellar and nebular properties. Also, objects with individual distances serve as calibrators for the so-called statistical distances based on secondary nebular properties.
Aims. With independently known distances, it is possible to check empirically our understanding of the formation and evolution of planetary nebulae as suggested by existing hydrodynamical simulations.
Methods. We compared the expansion parallaxes that have recently been determined for a number of planetary nebulae with the trigonometric parallaxes provided by the Gaia Data Release 2.
Results. Except for two out of 11 nebulae, we found good agreement between the expansion and the Gaia trigonometric parallaxes without any systematic trend with distance. Therefore, the Gaia measurements also prove that the correction factors necessary to convert proper motions of shocks into Doppler velocities cannot be ignored. Rather, the size of these correction factors and their evolution with time as predicted by 1D hydrodynamical models of planetary nebulae is basically validated. These correction factors are generally greater than unity and are different for the outer shell and the inner bright rim of a planetary nebula. The Gaia measurements also confirm earlier findings that spectroscopic methods often lead to an overestimation of the distance. They also show that even modelling of the entire system of star and nebula by means of sophisticated photoionisation modelling may not always provide reliable results.
Conclusions. The Gaia measurements confirm the basic correctness of the present radiation-hydrodynamics models, which predict that both the shell and the rim of a planetary nebula are two independently expanding entities, created and driven by different physical processes, namely thermal pressure (shell) or wind interaction (rim), both of which vary differently with time.
Data-driven model of the solar corona above an active region
Authors: Warnecke J. , Peter H. 
Published: April 2019

Aims. We aim to reproduce the structure of the corona above a solar active region as seen in the extreme ultraviolet (EUV) using a three-dimensional magnetohydrodynamic (3D MHD) model.
Methods. The 3D MHD data-driven model solves the induction equation and the mass, momentum, and energy balance. To drive the system, we feed the observed evolution of the magnetic field in the photosphere of the active region AR 12139 into the bottom boundary. This creates a hot corona above the cool photosphere in a self-consistent way. We synthesize the coronal EUV emission from the densities and temperatures in the model and compare this to the actual coronal observations.
Results. We are able to reproduce the overall appearance and key features of the corona in this active region on a qualitative level. The model shows long loops, fan loops, compact loops, and diffuse emission forming at the same locations and at similar times as in the observation. Furthermore, the low-intensity contrast of the model loops in EUV matches the observations.
Conclusions. In our model the energy input into the corona is similar as in the scenarios of fieldline-braiding or flux-tube tectonics, that is, energy is transported to the corona through the driving of the vertical magnetic field by horizontal photospheric motions. The success of our model shows the central role that this process plays for the structure, dynamics, and heating of the corona.
NLTE modelling of integrated light spectra
Authors: Eitner P. , Bergemann M. , Larsen S. 
Published: April 2019

Aims.We study the effects of non-local thermodynamic equilibrium (NLTE) on the abundance analysis of barium, magnesium, and manganese from integrated light spectroscopy, as typically applied to the analysis of extra-galactic star clusters and galaxies. In this paper, our reference object is a synthetic simple stellar population (SSP) representing a mono-metallicα-enhanced globular cluster with the metallicity [Fe/H] = −2.0 and the age of 11 Gyr.Methods.We used the MULTI2.3 program to compute LTE and NLTE equivalent widths of spectral lines of Mg I, Mn I, and Ba II ions, which are commonly used in abundance analyses of extra-galactic stellar populations. We used ATLAS12 model atmospheres for stellar parameters sampled from a model isochrone to represent individual stars in the model SSP. The NLTE and LTE equivalent widths calculated for the individual stars were combined to calculate the SSP NLTE corrections.Results.We find that the NLTE abundance corrections for the integrated light spectra of the metal-poor globular cluster are significant in many cases, and often exceed 0.1 dex. In particular, LTE abundances of Mn are consistently under-estimated by 0.3 dex for all optical lines of Mn I studied in this work. On the other hand, Ba II, and Mg I lines show a strong differential effect: the NLTE abundance corrections for the individual stars and integrated light spectra are close to zero for the low-excitation lines, but they amount to − 0.15 dex for the strong high-excitation lines. Our results emphasise the need to take NLTE effects into account in the analysis of spectra of individual stars and integrated light spectra of stellar populations.
Epidemiologic Characteristics of Patients Presenting with Head Injury due to Road Traffic Accident and Factors Associated with Outcome: Experience of a Tertiary Care Center in Northern Kerala
Authors: Rajeev Mandaka , Shinihas Vattaparambil , Chauhan Pankaj 
Published: April 2019

Abstract
Background In India, most factors related to road traffic accident (RTA) causation and outcome go improperly documented, and database regarding RTA-related traumatic brain injury (TBI) seems inadequate. Two-wheeler drivers form the largest segment of people affected by RTA. The socioeconomic and neurologic burden, imposed by TBI due to RTAs (largely preventable), is overwhelmingly significant, especially for a developing country like India.
Materials and Methods Descriptive study involving patients, presenting to the casualty of Government Medical College, Kozhikode, Kerala, was performed, and various demographic features were analyzed. Usage of helmet and history of alcohol intake were also noted. Patients were evaluated according to their presenting Glasgow coma scale (GCS), investigated and either operated or managed conservatively, and their outcome was assessed with Glasgow outcome score (GOS) at 3 months.
Results Bike drivers formed the single largest proportion of RTA victims (53.7%). Proportion of helmet users was 17.9%, whereas 21.9% were found with history of alcohol intake. There was a consistent trend toward a favorable outcome in patients with no alcohol intake (17.08% deaths compared with 34.07% patients with alcohol intake) and with helmet usage (14.55% compared with 22.18% in patients without helmet). However, the absolute contribution of these factors cannot be inferred.
Conclusion Various factors related to RTA need evaluation for pooling and compilation of data at regional and national levels. Mandatory helmet laws and strict implementation and provision of subsidized helmets (standard, full coverage) will go a long way in reducing the burden on limited health resources.
Transcatheter Arterial Embolization for Intra-abdominal Bleeding
Authors: Gill Stephen , Dawson Stephanie , Kenworthy Jessie-Anne , Greenhalgh Jarrod , Hely Andrew , Harrison Benjamin , Landers Steve 
Published: April 2019

Abstract
Purpose Transcatheter arterial embolization (TAE) is increasingly used for managing hemorrhage. The evidence-base supporting the procedure is accumulating. This study investigated the safety and effectiveness of TAE for intra-abdominal bleeding at a large regional public health service in Australia.
Materials and Methods Medical records of all patients undergoing TAE for intra-abdominal bleeding over a 7-year period were retrospectively reviewed, excluding gastric bleeding. Data were extracted into a standardized electronic data collection tool. Technical success of TAE was defined as cessation of active contrast media extravasation on post-procedure angiography. Complications were categorized as intra- and post-procedure. The severity of complications was rated according to the Society of Interventional Radiology Standards of Practice Committee Classifications of Complications by Outcome.
Results Ninety-two cases were identified. TAE was technically successful in 70 (94.6%) of the 74 cases when visible contrast media extravasation was evident during angiograph. During procedures, six minor complications occurred such as transient symptomatic hypotension or moderate to severe abdominal pain. Following procedures, eight minor complications were reported: seven cases of hematoma at the catheter access point and one case of contrast reaction. One major complication, bowel ischemia requiring hemicolectomy, occurred post-TAE for a bleeding cecal aneurysm; however, widespread arterial spasm was noted on angiography prior to TAE and interventional colonoscopy had occurred 2 days prior to TAE, suggesting that ischemia was not primarily due to TAE.
Conclusion This study supports the use of TAE for a diverse range of cases of intra-abdominal bleeding. TAE produced high rates of complete hemostasis with few complications.
Surgical Decision-Making in Median Neuropathy Associated with Distal Radius Fractures
Authors: Özkan Sezai , Mudgal Chaitanya S. , Evans Brady T. , Watkins Colyn J. , Heng Marilyn M. , Bloemers Frank W. 
Published: April 2019

Objectives A lack of conclusive evidence on the treatment of acute median neuropathy (AMN) in patients with distal radius fractures has led to inconsistent surgical guidelines and recommendations regarding AMN in distal radius fractures. There is a wide variation in surgical decision-making. We aimed to evaluate international differences between surgical considerations and practices related to carpal tunnel release (CTR) in the setting of distal radius fractures.
Methods We approached surgeons who were a member of the Orthopaedic Trauma Association (United States) or of the Dutch Trauma Society (the Netherlands) and asked them to provide sociodemographic information and information on their surgical practice regarding CTR in the setting of distal radius fractures. After applying our exclusion criteria, our final cohort consisted of 127 respondents.
Results Compared with Dutch surgeons, surgeons from the United States are more of the opinion that displaced distal radius fractures are at risk of developing acute carpal tunnel syndrome (ACTS), consider persistent paresthesia in the median nerve distribution after closed reduction to be a surgical emergency less often, and are more likely to perform a CTR if there are signs of ACTS in the setting of a distal radius fracture.
Conclusion A lack of conclusive evidence has led to international differences in surgical practice regarding the treatment of ACTS in the setting of distal radius fractures. Future research should guide surgeons in making appropriate evidence-based decisions when performing CTR in the setting of distal radius fractures.
Level of Evidence This is a Level V study.
Biomechanical Comparison of Flexor Digitorum Profundus Avulsion Repair
Authors: Putnam Jill G. , Adamany Damon 
Published: April 2019

Purpose Multiple repair techniques have been investigated for flexor digitorum profundus (FDP) tendon avulsions. The purpose of this study is to compare the biomechanical characteristics of a new fully threaded titanium suture anchor with previously examined fixation techniques.
Methods Repair of FDP tendon avulsions was performed in 18 fresh-frozen cadavers using one of three implants: Nano Corkscrew FT 1.7 mm suture anchor (Group 1; Arthrex, Inc., Naples, FL; n = 6), Mitek Micro 1.3 mm suture anchor (Group 2; Mitek Surgical Products, Westwood, MA; n = 6), or pullout suture button fixation (Group 3; n = 6). Constructs were preloaded before testing load to failure. For each trial, elongation at 20 N and maximum load, mean load to failure, stiffness, and failure mechanism were recorded.
Results Load to failure occurred in all trials. Mean load to failure was significantly greater for Group 1 (61.6 ± 18.9 N) compared to Group 2 (42.5 ± 4.2 N; p < 0.05) and Group 3 (41.6 N ± 8.0 N; p < 0.05). Stiffness was significantly greater in Groups 1 and 2 compared to Group 3 (6.9 ± 2.2 N/mm vs. 6.1 ± 0.8 N/mm vs. 3.1 N/mm ± 0.5 N/mm, respectively, p < 0.01). Mechanism of failure differed between the groups: Group 1 broke at the anchor in two trials and tore through the tendon in three trials, Group 2's suture universally broke at the anchor, and Group 3's trials mainly failed at the button.
Conclusions The Nano Corkscrew anchor (Group 1) has a significantly higher load to failure when compared with the other techniques. The higher load to failure of the corkscrew anchor provides a secure method for flexor tendon repair in zone I.
Clinical Relevance A fully threaded titanium suture anchor used for FDP tendon avulsion injuries is likely to withstand early active range of motion protocols.
Internal Acoustic Canal Stenosis Due to Hyperostosis
Authors: Goodarzi Amir , Toussi Atrin , Garza Nicholas , Lechpammer Mirna , Brodie Hilary , Diaz Rodney C. , Shahlaie Kiarash 
Published: April 2019

Background Exostoses and osteomas are benign, insidious lesions of the bone involving the internal acoustic canal (IAC). We present two cases of IAC exostoses managed with surgical decompression and review the clinical outcomes of previously reported cases in the literature.
Methods A comprehensive search was conducted using PubMed Central, Web of Science Core Collection, and Google Scholar databases to identify previous reports of IAC exostoses and osteomas. A total of 26 reported cases were identified, and patient presenting symptoms, management strategies, and response to surgery was obtained when available.
Results Of the 13 patients who underwent surgical decompression, 8 patients had resolution of vertigo symptoms, 10 patients had improvement of tinnitus symptoms, and all patients maintained some level of serviceable hearing.
Conclusion IAC exostoses and osteomas are rare lesions that lead to insidious onset of debilitating symptoms from vestibulocochlear nerve dysfunction. Although the role of surgical decompression remains unclear, it appears that patients presenting with vertigo have more favorable response to surgical decompression as compared with those presenting with tinnitus and sensorineural hearing loss.
Arachnoid Cyst—Institutional Experience
Authors: Singaravelu Madhan , Ramakrishnan Selvaraj , Gopalakrishnan Lakhmipathy 
Published: April 2019

Abstract
Background Arachnoid cysts are benign, non-neoplastic fluid collections within the arachnoid mater layer of the meninges. The etiology and significance of arachnoid cysts are poorly understood. Although they frequently represent incidental findings on central nervous system imaging, a wide variety of conditions have been attributed to their presence. The aim of this study is to ascertain the clinical presentation, location, and clinical course of patients with arachnoid cysts in the institution.
Methods The authors analyzed the clinical presentation, radiologic images, and clinical course of 16 patients presented over a period of 6 months from August 2017 to January 2018.
Results Of these 16 patients, 11 were adults and 5 were pediatric patients. Of these, seven were female and the remaining nine were male. Three patients presented with seizures, seven with headache, two with developmental delay, one with hydrocephalus, one with giddiness, one with hard of hearing, and one with bulging posterior fontanelle. Of these, 6 underwent surgery and 10 were managed conservatively.
Conclusion Arachnoid cysts (non-neoplastic lesions) that produce symptoms through mass effect and obstructive hydrocephalus need surgical management, whereas a large percentage of cysts that are asymptomatic can be managed conservatively. The various surgical options available are marsupialization, cystoperitoneal shunt, ventriculoperitoneal (VP) shunt, and endoscopic fenestration. Microsurgery and endoscopy both allow for rapid decompression of the cyst and restoration of cerebrospinal fluid (CSF) circulation, whereas shunting tends to produce greater reduction in cyst size. Timing of presentation also decides upon the treatment options. Patients presenting late after the establishment of neurocognitive decline may not benefit from surgery and can be managed conservatively. A detailed genetic study may aid in the evolution of newer prevention and management options. Currently, most pediatric neurosurgeons prefer to avoid shunting, if possible. However, treatment paradigms are operator dependent and produce comparable outcomes.
VO2 Max Improvement of 96% in a Non-Elite Recreational Athlete over 24 Months
Authors: Laury Daniel , Tehrany Armin 
Published: April 2019

AbstractVO2 max is a measure of athletic performance and is generally considered an excellent health parameter for athletic performance testing. Various methods are used to generate such a result generally using a treadmill or cycle ergometer. Improvements have been shown through training. The upper limit of such improvement has been difficult to find in the literature in part because testing often starts with individuals already at a superior level of performance. As genetics may play a significant role in an individual's VO2 max, training can only contribute a portion of the result. Humans have a range of maximal oxygen utilization with upper limits approaching 100 mL/kg. This case report demonstrates a 96% improvement over time secondary to selective intense training. The intent was to document objectively amelioration of the VO2 max using a defined protocol on standardized testing equipment. This may lead to more efficient training of individuals desiring performance improvement.
Embolotherapy for Neuroendocrine Tumors
Authors: Nadolski Gregory , Soulen Michael 
Published: April 2019

AbstractThe most frequent solid organ involved in metastatic neuroendocrine tumors (NET) is the liver. Hepatic metastases occur during the lifetime of 46% to 93% of patients with NETs. Intra-arterial embolotherapies are palliative and should be used for patients with unresectable disease not amenable to resection or ablation. The most widely accepted indications for liver embololization for NET metastases are progression of unresectable hepatic metastases threatening liver function and palliation of hormone-related symptoms uncontrolled by somatostatin analogues. This article will discuss patient selection and administration of all embolotherapies currently used for palliation of neuroendocrine liver metastases.
A Linguistic Specification of Aesthetic Judgments
Authors: Briesen Jochen 
Published: April 2019

Abstract
This paper aims to delineate the class of aesthetic judgments linguistically. The main idea is that aesthetic judgments can be specified by a certain set of assertibility conditions—i.e., by norms that govern appropriate speech-acts. This idea is spelled out in detail and defended against various objections. The suggestion leads to an interesting account of aesthetic judgments that is theoretically fruitful: it provides the basis for a non-circular and satisfying characterization of the whole domain of aesthetic research and it marks an important linguistic difference between aesthetic judgments and judgments of personal taste.