bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electron paramagnetic resonance spectroscopy using a single artificial atom
Authors: Toida Hiraku , Matsuzaki Yuichiro , Kakuyanagi Kosuke , Zhu Xiaobo , Munro William J. , Yamaguchi Hiroshi , Saito Shiro 
Published: March 2019

AbstractElectron paramagnetic resonance (EPR) spectroscopy is an important technology in physics, chemistry, materials science, and biology. Sensitive detection with a small sample volume is a key objective in these areas, because it is crucial, for example, for the readout of a highly packed spin based quantum memory or the detection of transition metals in biomaterials. Here, we demonstrate a novel EPR spectrometer using a single artificial atom as a sensitive detector of spin magnetization. The artificial atom, a superconducting flux qubit, provides advantages in terms of its strong coupling with magnetic fields. We estimate a sensitivity of ~400 spins·Hz−1/2 with a magnetic sensing volume around 10−14λ3 (50 femtoliters), where λ is the wavelength of the irradiated microwave. Our artificial atom works as a highly sensitive EPR spectrometer with micron-scale area with future opportunity for measuring single spins on the nanometer scale.
Emergent charge order near the doping-induced Mott-insulating quantum phase transition in Sr3Ru2O7
Authors: Leshen Justin , Kavai Mariam , Giannakis Ioannis , Kaneko Yoshio , Tokura Yoshi , Mukherjee Shantanu , Lee Wei-Cheng , Aynajian Pegor 
Published: March 2019

AbstractSearch for novel electronically ordered states of matter emerging near quantum phase transitions is an intriguing frontier of condensed matter physics. In ruthenates, the interplay between Coulomb correlations among the 4d electronic states and their spin-orbit interactions, lead to complex forms of electronic phenomena. Here we investigate the double layered Sr3(Ru1−xMnx)2O7 and its doping-induced quantum phase transition from a metal to an antiferromagnetic Mott insulator. Using spectroscopic imaging with the scanning tunneling microscope, we visualize the evolution of the electronic states in real- and momentum-space. We find a partial-gap at the Fermi energy that develops with doping to form a weak Mott insulating state. Near the quantum phase transition, we discover a spatial electronic reorganization into a commensurate checkerboard charge order. These findings bear a resemblance to the universal charge order in the pseudogap phase of cuprates and demonstrate the ubiquity of charge order that emanates from doped Mott insulators.
Resolving the distance controversy for Sharpless 269
Authors: Quiroga-Nuñez L. H. , Immer K. , van Langevelde H. J. , Reid M. J. , Burns R. A. 
Published: March 2019

Context. Sharpless 269 (S 269) is one of a few HII regions in the outer spiral arm of the Milky Way with strong water maser emission. Based on data from the Very Long Baseline Interferometry (VLBI) Exploration of Radio Astrometry (VERA) array, two parallax measurements have been published, which differ by nearly 2σ. Each distance estimate supports a different structure for the outer arm. Moreover, given its large Galactocentric radii, S 269 has special relevance as its proper motion and parallax have been used to constrain the Galactic rotation curve at large radii.Aims. Using recent Very Long Baseline Array (VLBA) observations, we accurately measure the parallax and proper motion of the water masers in S 269. We interpret the position and motion of S 269 in the context of Galactic structure, and possible optical counterparts.Methods. S 269’s 22 GHz water masers and two close by quasars were observed at 16 epochs between 2015 and 2016 using the VLBA. We calibrated the data by inverse phase referencing using the strongest maser spot. The parallax and proper motion were fitted using the standard protocols of the Bar and Spiral Structure Legacy survey.Results. We measure an annual parallax for S 269 of 0.241 ± 0.012 mas corresponding to a distance from the Sun of 4.15+0.22−0.20kpc by fitting four maser spots. The mean proper motion for S 269 was estimated as 0.16 ± 0.26 mas yr−1and −0.51 ± 0.26 mas yr−1forμαcosδandμδrespectively, which corresponds to the motion expected for a flat Galactic rotation curve at large radius. This distance estimate, Galactic kinematic simulations and observations of other massive young stars in the outer region support the existence of a kink in the outer arm atl ≈ 140°. Additionally, we find more than 2000 optical sources in the Gaia DR2 catalog within 125 pc radius around the 3D position of the water maser emission; from those only three sources are likely members of the same stellar association that contains the young massive star responsible for the maser emission (S 269 IRS 2w).
Diagnostic potential of the Ca II 8542 Å line for solar filaments
Authors: Díaz Baso C. J. , Martínez González M. J. , Asensio Ramos A. , de la Cruz Rodríguez J. 
Published: March 2019

Aims. In this study we explore the diagnostic potential of the chromospheric Ca II line at 8542 Å for studying the magnetic and dynamic properties of solar filaments. We have acquired high spatial resolution spectropolarimetric observations in the Ca II 8542 Å line using the CRISP instrument at the Swedish 1 m Solar Telescope.
Methods. We used the NICOLE inversion code to infer physical properties from observations of a solar filament. We discuss the validity of the results due to the assumption of hydrostatic equilibrium. We have used observations from other telescopes such as CHROTEL and SDO, in order to study large scale dynamics and the long term evolution of the filament.
Results. We show that the Ca II 8542 Å line encodes information of the temperature, line-of-sight velocity and magnetic field vector from the region where the filament is located. The current noise levels only allow us to estimate an upper limit of 260 G for the total magnetic field of the filament. Our study also reveals that if we consider information from the aforementioned spectral line alone, the geometric height, the temperature and the density could be degenerated parameters outside the hydrostatic equilibrium approach.
X-ray analysis of the accreting supermassive black hole in the radio galaxy PKS 2251+11
Authors: Ronchini S. , Tombesi F. , Vagnetti F. , Panessa F. , Bruni G. 
Published: March 2019

Context. We have investigated the dichotomy between jetted and non-jetted active galactic nuclei (AGNs), focusing on the fundamental differences of these two classes in the accretion physics onto the central supermassive black hole (SMBH). We tested the validity of the unification model of AGNs through the characterization of the mutual interaction between accreting and outflowing matter in radio galaxies.
Aims. Our aim is to study and constrain the structure, kinematics and physical state of the nuclear environment in the broad line radio galaxy (BLRG) PKS 2251+11. The high X-ray luminosity and the relative proximity make such AGN an ideal candidate for a detailed analysis of the accretion regions in radio galaxies. The investigation will help to shed light on the analogies and differences between the BLRGs and the larger class of radio-quiet Seyfert galaxies and hence on the processes that trigger the launch of a relativistic jet.
Methods. We performed a spectral and timing analysis of a ∼64 ks observation of PKS 2251+11 in the X-ray band with XMM-Newton. We modeled the spectrum considering an absorbed power law superimposed to a reflection component. We performed a time-resolved spectral analysis to search for variability of the X-ray flux and of the individual spectral components.
Results. We find that the power law has a photon index Γ = 1.8 ± 0.1, absorbed by an ionized partial covering medium with a column density NH = (10.1 ± 0.8) × 1023 cm−2, a ionization parameter log ξ = 1.3 ± 0.1 erg s−1 cm and a covering factor f ≃ 90%. Considering a density of the absorber typical of the broad line region (BLR), its distance from the central SMBH is of the order of r ∼ 0.1 pc. An Fe Kα emission line is found at 6.4 keV, whose intensity shows variability on timescales of hours. We derive that the reflecting material is located at a distance r ≳ 600rs, where rs is the Schwarzschild radius.
Conclusions. Concerning the X-ray properties, we found that PKS 2251+11 does not differ significantly from the non-jetted AGNs, confirming the validity of the unified model in describing the inner regions around the central SMBH, but the lack of information regarding the state of the very innermost disk and SMBH spin still leaves unconstrained the origin of the jet.
Numerical approximation of stochastic time-fractional diffusion
Authors: Jin Bangti , Yan Yubin , Zhou Zhi 
Published: March 2019

We develop and analyze a numerical method for stochastic time-fractional diffusion driven by additive fractionally integrated Gaussian noise. The model involves two nonlocal terms in time,i.e.,a Caputo fractional derivative of orderα ∈ (0,1), and fractionally integrated Gaussian noise (with a Riemann-Liouville fractional integral of orderγ ∈ [0,1] in the front). The numerical scheme approximates the model in space by the standard Galerkin method with continuous piecewise linear finite elements and in time by the classical Grünwald-Letnikov method (for both Caputo fractional derivative and Riemann-Liouville fractional integral), and the noise by theL2-projection. Sharp strong and weak convergence rates are established, using suitable nonsmooth data error estimates for the discrete solution operators for the deterministic inhomogeneous problem. One- and two-dimensional numerical results are presented to support the theoretical findings.
Current Methods for the Discovery of New Active Ingredients from Natural Products for Cosmeceutical Applications
Authors: Espinosa-Leal Claudia , Garcia-Lara Silverio 
Published: March 2019

AbstractCosmeceuticals are designed to serve a dual purpose: to provide desired esthetical effects and to treat dermatological conditions. Natural products derived from plants and marine organisms are a novel source of potential cosmeceutical active ingredients for incorporation into new formulations due to consumer demands. Contrary to common perceptions, most regulatory agencies do not view cosmeceuticals as being a separate category from cosmetics; thus, these products are not regulated accordingly, thereby forcing the consumer to rely on the self-regulatory policies of the cosmetics industry. Cosmeceuticals are advertised as having capabilities that include anti-aging, anti-acne, solar-protective, wound healing, and skin whitening. Such traits normally comprise several biological activities. In order to ensure the safety and efficacy of these products, active ingredients employed in the formulations must undergo a series of tests. In this review, in vitro (enzymatic and cellular) and in vivo tests employed to evaluate the potential of new cosmeceutical active ingredients are discussed, and new trends that are being explored by the cosmeceutical industry are described.
Imaging of Total Ankle Arthroplasty: Normal Imaging Findings and Hardware Complications
Authors: Omar Imran , Abboud Samir , Youngner Jonathan 
Published: March 2019

AbstractEnd-stage ankle osteoarthritis often significantly impacts patients' quality of life. This can be managed surgically either by ankle arthrodesis or total ankle arthroplasty (TAA). Although ankle arthrodesis is considered by some as the standard-of-care surgical option for this condition, it restricts range of motion and may lead to accelerated osteoarthritis of neighboring joints. Better understanding of ankle biomechanics, the biological effects of orthopaedic devices, and new surgical techniques have led to significant improvements in the designs of TAAs, and over the last several decades TAA has been used increasingly to treat patients with end-stage tibiotalar osteoarthritis. However, complication and ultimate failure rates remain greater than those seen with total knee and hip arthroplasty, and imaging is often critical in determining whether a prosthesis is beginning to fail. As a result, imagers should be familiar with the basic types of TAAs in clinical use, the normal radiographic appearances, as well as the common complications seen with this procedure.
Elbow Arthroplasty: From Normal to Failure
Authors: Levin Elizabeth , Plotkin Benjamin 
Published: March 2019

AbstractTotal elbow arthroplasty is currently an established surgical treatment for several pathologies of the elbow. Although initially used primarily in the treatment of rheumatoid arthritis, indications for total elbow arthroplasty have expanded and now include trauma, primary and secondary osteoarthritis, fracture nonunion, and following neoplasm resection. Desired outcomes of elbow arthroplasty include decreasing patient pain, restoration of function and mobility, and prevention of or treatment for instability. In comparison with total elbow arthroplasty, radial head replacements are most commonly performed following trauma. An additional technique, capitellar resurfacing arthroplasty, was developed in an effort to prevent early-onset osteoarthritis secondary to altered elbow biomechanics following radial head replacement. Complications of these surgeries include loosening, fracture, instability and dissociation, bushing wear, and particle disease.
(Pseudo) “Exclusive” Contracts: An Insidious Business Practice that Selectively Damages IR
Authors: Niedzwiecki Gerald 
Published: March 2019

AbstractContracting is an important part of running the business of private practice interventional radiology. A basic knowledge of contracting is vital for the practicing interventionalist to best position him or herself to excel in private practice. Exclusive contracts are common in interventional, diagnostic, and radiology practices. Such contracts, however, may significantly limit the practice of individual interventional radiologists and impede the growth of interventional procedures in communities at large. This article outlines the role of exclusive contracts in interventional practices, and describes the limitations of such contracts.
All About Shoulder Arthroplasty: What Radiologists Should Know
Authors: Chen Karen , Chen James 
Published: March 2019

AbstractOver the last decade, the number of shoulder arthroplasty procedures has been increasing and evolving. The types of prostheses have also been evolving, and familiarity with the various design types will assist in postoperative assessment for hardware complications. New preoperative planning tools are available that have radically changed the protocol of preoperative image studies performed. This article reviews the main types of shoulder prostheses, discusses radiologic studies required before surgery, and describes the common complications of shoulder arthroplasty.
Tetrazoles for biomedicine
Authors: Popova Elena A. , Trifonov Rostislav E. , Ostrovskii Vladimir A. 
Published: March 2019

The tetrazole ring is an important pharmacophore. It is a structural component in many drugs, drug candidates (or lead compounds) and various biochemical reagents. This review summarizes data on the use of tetrazoles in biomedicine published in the last 10 – 15 years and also views on the nature of their biological effects. The prospects for the development of new biologically active substances containing a tetrazolyl pharmacophore are analyzed.
The bibliography includes 263 references.
Travel intermediaries and information technology.
Authors: Benckendorff P. J. , Xiang Z. , Sheldon P. J. 
Published: March 2019

Abstract

This chapter discusses how travellers connect with suppliers through various channels using a distribution systems perspective. It starts by examining the traditional structure of these distribution channels and tracks the increasingly complex development of electronic channels. There are many different types of travel intermediaries in the travel distribution system. This chapter looks in more detail at how information technology has impacted global distribution systems, tour operators and wholesalers, traditional travel retailers, travel management companies, online intermediaries and channel managers.
Social media and tourism.
Authors: Benckendorff P. J. , Xiang Z. , Sheldon P. J. 
Published: March 2019

Abstract

This chapter examines social media and its impact on travellers, tourism intermediaries, suppliers and destinations. The chapter starts by providing some conceptual foundations, then shifts to the different social media platforms and how travellers and travel organizations can use them. The chapter concludes by considering the need for a strategic approach to the use of social media by travel organizations. Strategic applications of social media include marketing and sales, market intelligence, customer service, reputation management, recruitment and partnerships.
Hospitality information systems.
Authors: Benckendorff P. J. , Xiang Z. , Sheldon P. J. 
Published: March 2019

Abstract

This chapter examines the use of information technology (IT) in the hospitality and foodservice sectors. The first section describes IT systems and applications used in the accommodations sector, including property management systems, hotel websites and apps, and electronic hotel reservation systems, as well the use of IT in customer relationship management, guest room amenities, hotel communications, energy management, and intelligent hotel rooms. The next section describes the applications common to most foodservice establishments, including point-of-sale systems and restaurant management systems, as well as the use of IT in marketing and customer relations. The chapter concludes by discussing the need for strategic management of IT in hospitality.
Destination management and smart destinations.
Authors: Benckendorff P. J. , Xiang Z. , Sheldon P. J. 
Published: March 2019

Abstract

This chapter first revisits digital tourism ecosystems in the destination context, moving on to explain the development of destination management systems (DMSs), their functionality, information content and organizational structure. The chapter then discusses how destinations utilize websites and social media and position themselves in the online search market. Particularly, it introduces and explains the notion of smart destinations and how the ways we view and use information technology (IT) for destination management have shifted. It then goes on to explain how market intelligence, statistics and visitor tracking can be facilitated with IT systems. The chapter ends with key management issues such as crisis and risk management and stakeholder management, and the concept of learning destinations.
Comparing D-bar and common regularization-based methods for electrical impedance tomography
Authors: Hamilton S J , Lionheart W R B , Adler A 
Published: March 2019

Abstract

Objective: To compare D-bar difference reconstruction with regularized linear reconstruction in electrical impedance tomography. Approach: A standard regularized linear approach using a Laplacian penalty and the GREIT method for comparison to the D-bar difference images. Simulated data was generated using a circular phantom with small objects, as well as a ‘Pac-Man’ shaped conductivity target. An L-curve method was used for parameter selection in both D-bar and the regularized methods. Main results: We found that the D-bar method had a more position independent point spread function, was less sensitive to errors in electrode position and behaved differently with respect to additive noise than the regularized methods. Significance: The results allow a novel pathway between traditional and D-bar algorithm comparison.
Drought supersedes warming in determining volatile and tissue defenses of piñon pine (Pinus edulis)
Authors: Trowbridge Amy M , Stoy Paul C , Adams Henry D , Law Darin J , Breshears David D , Helmig Detlev , Monson Russell K 
Published: March 2019

Abstract
Trees are suffering mortality across the globe as a result of drought, warming, and biotic attacks. The combined effects of warming and drought on in situ tree chemical defenses against herbivory have not been studied to date. To address this, we transplanted mature piñon pine trees—a well-studied species that has undergone extensive drought and herbivore-related mortality—within their native woodland habitat and also to a hotter-drier habitat and measured monoterpene emissions and concentrations across the growing season. We hypothesized that greater needle temperatures in the hotter-drier site would increase monoterpene emission rates and consequently lower needle monoterpene concentrations, and that this temperature effect would dominate the seasonal pattern of monoterpene concentrations regardless of drought. In support of our hypothesis, needle monoterpene concentrations were lower across all seasons in trees transplanted to the hotter-drier site. Contrary to our hypothesis, basal emission rates (emission rates normalized to 30 °C and a radiative flux of 1000 μmol m−2 s−1) did not differ between sites. This is because an increase in emissions at the hotter-drier site from a 1.5 °C average temperature increase was offset by decreased emissions from greater plant water stress. High emission rates were frequently observed during June, which were not related to plant physiological or environmental factors but did not occur below pre-dawn leaf water potentials of −2 MPa, the approximate zero carbon assimilation point in piñon pine. Emission rates were also not under environmental or plant physiological control when pre-dawn leaf water potential was less than −2 MPa. Our results suggest that drought may override the effects of temperature on monoterpene emissions and tissue concentrations, and that the influence of drought may occur through metabolic processes sensitive to the overall needle carbon balance.
Adopting LEDs changes attitudes towards climate change: experimental evidence from China
Authors: Gao Yu , d’Adda Giovanna , Tavoni Massimo 
Published: March 2019

Abstract
The adoption of low carbon technologies needs to go hand in hand with an increased awareness of climate change and its consequences and solutions. Attitudes toward climate change are influenced by a variety of factors, most notably educational attainment and exposure to climatic events attributable to climate change. However, less is known about the effect of technology adoption on climate change beliefs and support for mitigating measures. Through a longitudinal, incentivized field experiment with Chinese households, we assess attitudes toward climate change before and after adopting efficient lighting technology. The results show differential patterns of attitudinal change: while belief in the reality of climate change and willingness to adopt energy-efficient appliances increase, support for energy taxes does not. We attribute the attitudinal change to the adoption of LED light bulbs. Further evidence suggests that experience with efficient technology, rather than knowledge acquisition, drives this change. These results highlight the importance of action-initiating behavioral intervention to complement educational programs aimed at improving knowledge.