bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing the limits of centralized unmanned aerial vehicle conflict management in U‐Space
Authors: Boronat Pablo , Pérez‐Francisco Miguel , Wubben Jamie , Calafate Carlos T. , Cano Juan Carlos , Casado Rafael 
Published: September 2023

AbstractThere is an important growth of unmanned aerial vehicles (UAVs) performing planned missions in urban environments, which poses significant challenges to the research community. The possibility of collisions represents a critical challenge. UAVs can suffer collisions due to different causes external or internal to their flight plans. In this context, dynamic geo‐fencing is a useful approach, whereby each UAV is able to provide a prediction of its future positions within a limited time. These predictions could be used to detect conflicts, allowing to dynamically modify the flight plans so as to avoid imminent collisions. In this work, a conflict detection algorithm/method is proposed, implemented and tested on a central server performing real‐time conflict analysis for a large number of UAVs flying in the aerial space of a city (U‐Space). The architecture assumes that UAVs send their future locations to a traffic controller. This controller compares the predicted positions of nearby vehicles to detect possible conflicts. The results of this work demonstrate the feasibility of the proposed conflict detection algorithm and its interest to improve the security and efficiency in U‐Space environments. The server is able to track thousands of UAVs in real time with a conflict anticipation around 11 s.
Design of multiple‐input multiple‐output radar amplitude‐bounded waveforms with desired ambiguity function based on sequential quadratic programming
Authors: Wei Wenyan , Wei Yinsheng , Yu Lei 
Published: September 2023

AbstractThe transmit waveform with ambiguity function specifications in the range‐Doppler plane has been of great interest in traditional single antenna radar systems in recent years. This paper considers the design of waveform sets with a desired slow‐time ambiguity function for multiple‐input multiple‐output radar. Specifically, it is desirable that the ambiguity function has low sidelobes where clutter occurs, as this reduces the impact of the clutter on target detection. Instead of unimodular waveforms, the authors consider amplitude modulation signals and introduce the bound constraint on signal amplitudes into the optimisation for the consideration of transmitter efficiency. The design problem is formulated as minimising the weighted integrated sidelobes level of the ambiguity function over the range‐Doppler plane under bound constraints. The resulting problem has a highly non‐linear objective function and is constrained by bound constraints and quadratic equality (constant energy) constraints, making it difficult to solve. The authors develop an efficient algorithm based on the sequential quadratic programming technique and non‐linear conjugate gradient method to solve it. Simulation results show that the proposed algorithm is superior to the existing methods.
Selection of powerful radio galaxies with machine learning
Authors: Carvajal R. , Matute I. , Afonso J. , Norris R. P. , Luken K. J. , Sánchez-Sáez P. , Cunha P. A. C. , Humphrey A. , Messias H. , Amarantidis S. , Barbosa D. , Cruz H. A. , Miranda H. , Paulino-Afonso A. , Pappalardo C. 
Published: September 2023

Context.The study of active galactic nuclei (AGNs) is fundamental to discern the formation and growth of supermassive black holes (SMBHs) and their connection with star formation and galaxy evolution. Due to the significant kinetic and radiative energy emitted by powerful AGNs, they are prime candidates to observe the interplay between SMBH and stellar growth in galaxies.Aims.We aim to develop a method to predict the AGN nature of a source, its radio detectability, and redshift purely based on photometry. The use of such a method will increase the number of radio AGNs, allowing us to improve our knowledge of accretion power into an SMBH, the origin and triggers of radio emission, and its impact on galaxy evolution.Methods.We developed and trained a pipeline of three machine learning (ML) models than can predict which sources are more likely to be an AGN and to be detected in specific radio surveys. Also, it can estimate redshift values for predicted radio-detectable AGNs. These models, which combine predictions from tree-based and gradient-boosting algorithms, have been trained with multi-wavelength data from near-infrared-selected sources in theHobby-EberlyTelescope Dark Energy Experiment (HETDEX) Spring field. Training, testing, calibration, and validation were carried out in the HETDEX field. Further validation was performed on near-infrared-selected sources in the Stripe 82 field.Results.In the HETDEX validation subset, our pipeline recovers 96% of the initially labelled AGNs and, from AGNs candidates, we recover 50% of previously detected radio sources. For Stripe 82, these numbers are 94% and 55%. Compared to random selection, these rates are two and four times better for HETDEX, and 1.2 and 12 times better for Stripe 82. The pipeline can also recover the redshift distribution of these sources withσNMAD = 0.07 for HETDEX (σNMAD = 0.09 for Stripe 82) and an outlier fraction of 19% (25% for Stripe 82), compatible with previous results based on broad-band photometry. Feature importance analysis stresses the relevance of near- and mid-infrared colours to select AGNs and identify their radio and redshift nature.Conclusions.Combining different algorithms in ML models shows an improvement in the prediction power of our pipeline over a random selection of sources. Tree-based ML models (in contrast to deep learning techniques) facilitate the analysis of the impact that features have on the predictions. This prediction can give insight into the potential physical interplay between the properties of radio AGNs (e.g. mass of black hole and accretion rate).
Galactic runaway O and Be stars found usingGaiaDR3
Authors: Carretero-Castrillo M. , Ribó M. , Paredes J. M. 
Published: September 2023

Context.A relevant fraction of massive stars are runaway stars. These stars move with a significant peculiar velocity with respect to their environment.Aims.We aim to discover and characterize the population of massive and early-type runaway stars in the GOSC and BeSS catalogs usingGaiaDR3 astrometric data.Methods.We present a two-dimensional method in the velocity space to discover runaway stars as those that deviate significantly from the velocity distribution of field stars. Field stars are considered to follow the Galactic rotation curve.Results.We found 106 O runaway stars, 42 of which were not previously identified as runaways. We found 69 Be runaway stars, 47 of which were not previously identified as runaways. The dispersion of runaway stars is a few times higher inZandbthan that of field stars. This is explained by the ejections they underwent when they became runaways. The percentage of runaways is 25.4% for O-type stars, and it is 5.2% for Be-type stars. In addition, we conducted simulations in three dimensions for our catalogs. They revealed that these percentages could increase to ∼30% and ∼6.7%, respectively. Our runaway stars include seven X-ray binaries and one gamma-ray binary. Moreover, we obtain velocity dispersions of ∼5 km s−1perpendicular to the Galactic plane for O- and Be-type field stars. These values increase in the Galactic plane to ∼7 km s−1for O-type stars due to uncertainties and to ∼9 km s−1for Be-type stars due to Galactic velocity diffusion.Conclusions.The excellentGaiaDR3 astrometric data have allowed us to identify a significant number of O-type and Be-type runaways in the GOSC and BeSS catalogs. The higher percentages and higher velocities found for O-type compared to Be-type runaways underline that the dynamical ejection scenario is more likely than the binary supernova scenario. Our results open the door to identifying new high-energy systems among our runaways by conducting detailed studies.
The miniJPAS survey quasar selection
Authors: Pérez-Ràfols Ignasi , Abramo Luis Raul , Martínez-Solaeche Ginés , Pieri Matthew M. , Queiroz Carolina , Rodrigues Natália V. N. , Bonoli Silvia , Chaves-Montero Jonás , Morrison Sean S. , Alcaniz Jailson , Benitez Narciso , Carneiro Saulo , Cenarro Javier , Cristóbal-Hornillos David , Dupke Renato , Ederoclite Alessandro , González Delgado Rosa M. , Hernán-Caballero Antonio , López-Sanjuan Carlos , Marín-Franch Antonio , Marra Valerio , Mendes de Oliveira Claudia , Moles Mariano , Sodré Jr Laerte , Taylor Keith , Varela Jesús , Vázquez Ramió Héctor 
Published: September 2023

Aims. Quasar catalogues from photometric data are used in a variety of applications including those targeting spectroscopic follow-up, measurements of supermassive black hole masses, Baryon Acoustic Oscillations, or non-Gaussianities. Here, we present a list of quasar candidates including photometric redshift estimates from the miniJPAS Data Release constructed using SQUEzE. miniJPAS is a small proof-of-concept survey covering 1 deg2 with the full J-PAS filter system, consisting of 54 narrow filters and 2 broader filters covering the entire optical wavelength range.
Methods. This work is based on the machine-learning classification of photometric data of quasar candidates using SQUEzE. It has the advantage that its classification procedure can be explained to some extent, making it less of a ‘black box’ when compared with other classifiers. Another key advantage is that the use of user-defined metrics means the user has more control over the classification. While SQUEzE was designed for spectroscopic data, we have adapted it for multi-band photometric data; that is we treat multiple narrow-band filters as very low-resolution spectra. We trained our models using specialised mocks. We estimated our redshift precision using the normalised median absolute deviation, σNMAD, applied to our test sample.
Results. Our test sample returns an f1 score (effectively the purity and completeness) of 0.49 for high-z quasars (with z ≥ 2.1) down a to magnitude of r = 24.3 and 0.24 for low-z quasars (with z < 2.1), also down to a magnitude of r = 24.3. For high-z quasars, this goes up to 0.9 for magnitudes of r < 21.0. We present two catalogues of quasar candidates including redshift estimates: 301 from point-like sources and 1049 when also including extended sources. We discuss the impact of including extended sources in our predictions (they are not included in the mocks), as well as the impact of changing the noise model of the mocks. We also give an explanation of SQUEzE reasoning. Our estimates for the redshift precision using the test sample indicate a σNMAD = 0.92% for the entire sample, reduced to 0.81% for r < 22.5 and 0.74% for r < 21.3. Spectroscopic follow-up of the candidates is required in order to confirm the validity of our findings.
Klinisches Management der Choanalatresie
Authors: Maas Alexander Philippe , Strieth Sebastian , Send Thorsten 
Published: September 2023

ZusammenfassungDie Choanalatresie (CA) ist eine seltene kongenitale Anomalie der nasalen Atemwege mit einer Inzidenz von 1/5000 bis 1/9000, die unilateral (uCA) oder bilateral (bCA) auftreten kann. Die bCA manifestiert sich als akuter Notfall unmittelbar nach der Entbindung durch akute Atemwegsobstruktion und paradoxe Zyanose, während die uCA neben der einseitigen Nasenatmungsbehinderung ein klinisch heterogenes Beschwerdebild aufweisen kann. Die fiberendoskopische Untersuchung ist in Verbindung mit der kranialen Computertomographie der Goldstandard in der diagnostischen Abklärung der CA. Die CA tritt häufig in Assoziation zu angeborenen Fehlbildungssyndromen auf, unter denen das CHARGE-Syndrom hervorzuheben ist. Aufgrund von kardiopulmonaler Instabilität und erschwerten Intubationsbedingungen sind syndromale CA-PatientInnen als eigene Risikogruppe aufzufassen. Nach Sicherung des Atemweges muss die bCA zeitnah operativ versorgt werden, während die Korrektur der uCA erst nach dem sechsten Lebensmonat erfolgen sollte. Die endoskopischen Operationstechniken sind der chirurgische Standard in der Versorgung der CA. Hierbei lassen sich unterschiedliche Herangehensweisen differenzieren: die transnasale Punktion der Atresieplatte mit anschließender Erweiterung nach medial und lateral, die Anlage eines Septumfensters mit anschließender posteriorer Vomer- und Atresieplattenresektion und die Anlage mukoperiostealer Lappen mit anschließender Eröffnung der Atresieplatte. Der transpalatinale Zugangsweg sollte nur noch in anatomisch komplexen Ausnahmefällen gewählt werden. Der Einsatz konventioneller choanaler Stents in der primären Versorgung der CA wird zunehmend zurückgewiesen und sollte Risikokonstellationen vorbehalten bleiben. Ebenso sollte auf die lokale Applikation von Mitomycin C verzichtet werden.
Solvent-Selective Synthesis of Diaryl Disulfides and Arylthio Acetic Acids Using Thioglycolic Acid and Copper Catalysts
Authors: Chae Junghyun , Kim Kyungmi , Shin Youngjin 
Published: September 2023

AbstractAn efficient Cu-catalytic protocol for the synthesis of diaryl disulfides from aryl iodides using thioglycolic acid as the sulfur source has been developed. This transformation was successful only in aqueous DMSO, and when the solvent system was switched to aqueous DMF, arylthio acetic acids, the immediate C–S coupling products, were obtained. Each synthetic protocol was optimized and applied to various aryl iodides to afford the corresponding products in good to excellent yields.
Solvent Effect on Base-Free Synthesis 4-Substituted 2-Oxazolines via Intramolecular Cyclodemesylation
Authors: Dalkılıç Erdin , Güneş Yakup 
Published: September 2023

AbstractIn this present study, the solvent effect was examined for the synthesis of 2-oxazolines via intramolecular cyclodemesylation. To determine the solvent effect, aprotic/protic polar and nonpolar solvents were screened and polar protic solvents met the best result. The remarkable feature of this synthesis is that cyclization takes place in the absence of any base or reagent, in high yields (89–96%). As a result, a series of 4-substituted chiral 2-oxazolines were successfully synthesized through a four-step process, with overall yields reaching between 79% and 88% in a greener approach.
Practical Steps of Shear Wave Elastography for Nonalcoholic Fatty Liver Disease in an Adult Population
Authors: Choorakuttil Rijo Mathew , Chaubal Rajas N. , Arunachalam Venkatesh K. , Bagri Neha , Gupta Anjali , Bansal Jitender , Pratap Thara , Sodani Varsha , Nirmalan Praveen K. 
Published: September 2023

AbstractNonalcoholic fatty liver disease (NAFLD) is a growing epidemic worldwide and is widely prevalent in India with a community-based study in South India reporting a prevalence of 49.8%. Imaging modalities are used to screen for NAFLD, identify different stages of the disease from early to advanced stages, and to monitor the progress of the condition and responsiveness to therapy. Computed tomography and magnetic resonance imaging modalities are used to assess NAFLD but have limitations in availability and affordability. B-mode ultrasound provides a viable imaging alternative but only provides a gross assessment and the presence or absence of fibrosis. Shear wave elastography is a newer modality that allows for the measurement of tissue stiffness or elasticity in response to tissue deforming forces generated as shear waves. The changes in elasticity can usually be determined before obvious structural changes and can be used for early diagnosis of disease and to assess the progress of the condition. In this article, we present the practical steps to perform an ultrasound shear wave elastography for the assessment and staging of NAFLD.
Interventional Radiology in Hepatocellular Carcinoma: Current Status and Looking Ahead
Authors: Aravind Ashish , Mukund Amar 
Published: September 2023

AbstractHepatocellular carcinoma (HCC) is one of the most common cancers worldwide and its incidence is on the rise. Although transplantation and surgical resection remain the definitive curative treatment options, only a minority of patients are eligible for these owing to advanced stage of disease at diagnosis. Over the last two decades, various interventional radiology (IR) therapies such as ablative and transarterial therapies, have come to the forefront of HCC management. IR also plays a role in preoperative management of HCC patients with procedures such as portal vein embolization. The recently updated Barcelona Clinic Liver Cancer (BCLC) staging system for HCC provides a guideline for choosing the optimum treatment modality for individual patients, with IR playing a central role. This review summarizes the different IR treatment options in HCC, including various ablative therapies, Transarterial Chemoembolization (TACE), Transarterial Radioembolization (TARE), Portal Vein embolization, emphasizing patient selection, procedural considerations and response evaluation.
Artificial Intelligence: A Primer for the Radiologists
Authors: Bhatia Harsimran , Bhatia Anmol , Ahuja Chirag K. , Singh Arnavjit , Sodhi Kushaljit S. 
Published: September 2023

AbstractArtificial intelligence (AI) has revolutionized almost every sphere of life today by providing cutting-edge tools aimed at improving the quality of life. The term AI refers to any operating system or a software that mimics human intelligence and performs functions like the human mind with minimal human intervention. The present review article focuses on the basics of AI and the terminology used in the field of AI. Flowcharts and figures to facilitate easy understanding of its impact and its potential applications have also been provided. It is meant to serve as a primer for the beginner.
A Multicenter Retrospective Evaluation of Social Determinant of Health Z Code Usage among Pediatric Patients with Critical Care Visits during Pediatric Critical Care
Authors: Yoder Lisa , Williams Duane , Tian Zizhong , Shen Chan , Zhou Shouhao , Thomas Neal J. , Krawiec Conrad 
Published: September 2023

AbstractSocial determinants of health (SDOH) diagnostic codes may facilitate the deployment of appropriate resources to improve patient outcomes, but their use in critically ill pediatric populations is unknown. Our study aims to examine SDOH codes usage hypothesizing that it is underutilized. This is a retrospective observational cohort study utilizing the TriNetX electronic health record database. We included subjects aged less than 18 years with critical care services billing codes and analyzed demographics, International Classification of Diseases, 10th edition diagnostic codes, and SDOH diagnostic codes 1 year before, during (7 days before and after), and 1 year after critical care services. We included 73,444 subjects (1,150 [1.6%] SDOH codes present during; 1,015 [1.4%] 1 year before; and 1,710 [2.3%] 1 year after critical care services) from 39 health care organizations. The most common SDOH diagnostic code utilized was “problems related to upbringing” (50.4%). SDOH diagnostic codes were consistently significantly associated with diagnostic codes related to seizures. SDOH diagnostic code presence was infrequent in critically ill pediatric patients. These findings may indicate not only the underutilization of SDOH diagnostic code but also the underrepresentation of SDOH prevalence in this patient population.
Central Venous Catheter Placement Skill Acquisition Through Apprenticeship Training in Clinical Context during Pediatric Critical Care Medicine Fellowship: A Longitudinal Study
Authors: Good Ryan J. , Miller Kristen R. , Kendall John L. , Czaja Angela S. 
Published: September 2023

AbstractPediatric critical care medicine (PCCM) fellows must develop competence in central venous catheter (CVC) placement. The impact of experiential learning opportunities in the clinical context on PCCM fellow CVC placement skill acquisition remains unknown. We sought to measure femoral CVC placement skill acquisition during fellowship and compare fellow to attending skill. We performed a prospective observational cohort study of PCCM fellows at the University of Colorado from 2019 to 2021. Femoral CVC placement skill was measured by attending evaluation of level of the supervision (LOS) required for the fellow, and hand motion analysis (HMA) on simulation task trainer. Competence in femoral CVC placement was defined as LOS ≥ 4 (can perform this skill independently) on a 5-point Likert scale. We compared fellow skill in femoral CVC placement to years of training and number of femoral CVCs placed. We also compared third-year fellow and attending HMA measurements. We recruited 13 fellows and 6 attendings. Fellows placed a median of 8 (interquartile range 7, 11) femoral CVCs during the study period. All fellows who reached third-year of fellowship during the study period achieved competence. Longitudinal analysis demonstrated improvement in CVC placement skill by both LOS and HMA as years of fellowship and number of femoral CVCs placed increased. Few third-year fellows achieved attending level skill in femoral CVC placement as measured by HMA. PCCM fellows acquired skill in CVC placement during fellowship and achieved competence in the procedure, but most did not reach attending level of skill.
The influencing factors underlying the vicious ecological vulnerability-low productivity-poverty cycle in China and overcoming its related policies
Authors: Liu Yong , Long Cuihong 
Published: September 2023

AbstractThere is often a vicious cycle that occurs in China encompassing ecological vulnerability, low productivity, and poverty. Existing research has not applied multiagent modelling and simulation (MAMS), which is a method suitable for analysing such complex systems. Therefore, the MAMS is here used to explore potential strategies for breaking this cycle. The MAMS method is based on complex adaptive systems and computer programs, and it includes both theoretical and simulation models, which can be used to simulate different scenarios and obtain visualized results. To sample representative poverty-stricken areas in China, the authors designed five breakthrough policy scenarios. The simulation results of these scenarios indicate that increasing the amount of arable land decreases the number of poor people. However, increasing the direct interventions of government does not reduce the number of the poor, nor does it change the Gini coefficient. On the other hand, increasing the number and variety of poverty alleviation opportunities available to the poor leads to a decrease in both the number of poor people and the Gini coefficient. These results of our five scenarios indicate that the optimal policy portfolio could be obtained by increasing the amount of arable land and providing more varied opportunities to help the poor participate in market activities while reducing direct government intervention. The combined design of these policies is conducive to breaking the vicious cycle of poverty.