bluuebunny/crossref_metadata_2025_split huggingface dataset:
High-efficiency AMC loaded dipole above FR4 substrate
Authors: Elsheikh Mohamed A.G. , Safwat Amr M.E. , Elhennawy Hadia 
Published: February 2019

AbstractThis paper presents a novel artificial magnetic conductor (AMC) loaded dipole above FR4 substrate. The proposed AMC consists of two metal layers that shield the wave from the lossy substrate leading to a significant increase in the dipole efficiency over a wide bandwidth. The dipole is fed through vias that are connected to a wideband balun placed on the opposite side of the ground plane. The proposed assembly is fabricated and characterized. Measurements, which are in a very good agreement with the electromagnetic simulations, show that the operating fractional bandwidth achieves the value of 16.2%, 1.927–2.267 GHz, with peak radiation efficiency of 72.5%.
Identifying ULF Wave Eigenfrequencies in SuperDARN Backscatter Using a Lomb‐Scargle Cross‐Phase Analysis
Authors: Wharton S. J. , Wright D. M. , Yeoman T. K. , Reimer A. S. 
Published: February 2019

AbstractThe eigenfrequencies of standing Alfvén waves on closed magnetospheric field lines can be estimated using the cross‐phase technique. These eigenfrequencies can be used to monitor the plasma mass density distribution along the field line. So far, this has only been applied to ground‐based magnetometer data. The Super Dual Auroral Radar Network (SuperDARN) radars offer some benefits over magnetometers. They provide greater spatial resolution and coverage, as well as direct sensing above the E region ionosphere, which screens ultralow frequency (ULF) waves from the ground. However, there are significant data quality issues. These include the uncertain origin of radar backscatter, uneven sampling of data due to data gaps, and inaccurate fitting to the autocorrelation functions. Artificial backscatter from an ionospheric heater has been used to remove the uncertainty in backscatter location. We have developed a Lomb‐Scargle cross‐phase analysis for application to discontinuous radar data. The First Principles Fitting Methodology has been used to improve the fitted data products derived from the autocorrelation functions. Using these techniques, we have shown that it is possible to measure eigenfrequencies with SuperDARN data, and we have verified an example using ground‐based magnetometer data. Finally, we have demonstrated that the eigenfrequency signature in this example was caused by a broadband source of energy.
Planetary Period Oscillations in Saturn's Magnetosphere: Comparison of Magnetic and SKR Modulation Periods and Phases During Northern Summer to the End of the Cassini Mission
Authors: Provan G. , Lamy L. , Cowley S. W. H. , Bunce E. J. 
Published: February 2019

AbstractWe compare periods and phases of Saturn planetary period oscillations determined from Cassini magnetic field and Saturn kilometric radiation (SKR) data from the beginning of 2016 to the end of mission in mid‐September 2017, encompassing northern summer solstice in May 2017. Both data sets show that the periods are almost unchanging, varying by only ~ ±0.01 hr about 10.79 hr for the northern system and 10.68 hr for the southern system, close to values attained by mid‐2015 after period coalescence between mid‐2013 and mid‐2014. The mean absolute differences between the magnetic and SKR periods are ~0.0036 hr (~13 s), consistent with estimated magnetic measurement uncertainties, while the overall mean difference is less than 0.001 hr (~2–3 s), at the limit of resolution. The relative phasing between magnetic and SKR modulations is correspondingly near constant and such that the equatorial planetary period oscillation fields of the northern/southern systems point radially outward near‐oppositely at ~14.3/2.5 hr local time at corresponding SKR maxima, with upward planetary period oscillation currents located ~2 hr postdawn for both systems, consistent with previous intervals having dawnside spacecraft apoapsides. Southern SKR emissions are found to be significantly dual modulated at both southern and northern periods in data limited to lie well within the southern shadow zone of the northern sources. These northern period modulations are shown to be approximately in phase with those in the northern emissions, consistent with a recent suggestion that bidirectional auroral electron acceleration may generate in phase SKR emissions in both hemispheres.
Ozone Production Efficiencies at Rural New York State Locations: Relationship to Oxides of Nitrogen Concentrations
Authors: Ninneman M. , Demerjian K. L. , Schwab J. J. 
Published: February 2019

AbstractThis study examined the observed summertime ozone production efficiency (OPE) and background ozone ([O3]) concentration at two rural sites in New York State, Pinnacle State Park (PSP) in Addison, NY, and Whiteface Mountain Summit (WFMS) in Wilmington, NY. Observed summertime OPEs and their relationship to oxides of nitrogen concentrations ([NOx]) were assessed during photochemically active periods at PSP and WFMS from 2000 to 2017 and 2015–2017, respectively. The summertime OPE increased in response to [NOx] reductions at PSP, consistent with a NOx‐sensitive regime for O3 production. At PSP, the summertime OPE increased from approximately 5–7 parts per billion per parts per billion (ppb ppb−1) in 2000–2009 to approximately 13 ppb ppb−1 in 2012–2017, and the median [NOx] concentration during photochemically productive periods decreased from about 0.60 ppb in 2000–2005 to about 0.23 ppb in 2012–2017. At WFMS, the summertime OPE was approximately 18 ppb ppb−1 in 2015–2017, and the median [NOx] concentration during photochemically active periods from 2015 to 2017 was about 0.21 ppb. The higher WFMS summertime OPE is consistent for a site characterized by lower [NOx] concentrations. The summertime background [O3] concentration at PSP and WFMS was approximately 31–33 ppb for the analysis period, indicating that both sites were likely affected by similar regional emission sources.
iPSC model of CHRFAM7A effect on α7 nicotinic acetylcholine receptor function in the human context
Authors: Ihnatovych Ivanna , Nayak Tapan K. , Ouf Aya , Sule Norbert , Birkaya Barbara , Chaves Lee , Auerbach Anthony , Szigeti Kinga 
Published: February 2019

AbstractThe α7 nicotinic acetylcholine receptor (α7nAChR) has been a promising target for diseases affecting cognition and higher cortical functions; however, the effect observed in animal models failed to translate into human clinical trials identifying a translational gap. CHRFAM7A is a human-specific fusion gene with properties that enable incorporation into the α7nAChR and, being human specific, CHRFAM7A effect was not accounted for in preclinical studies. We hypothesized that CHRFAM7A may account for this translational gap and understanding its function may offer novel insights when exploring α7nAChR as a drug target. CHRFAM7A is present in different copy number variations (CNV) in the human genome with high frequency. To study the functional consequences of the presence of the CHRFAM7A, two induced pluripotent stem cell (iPSC) lines (0 copy and 1 copy direct) were developed. The 0 copy line was rescued with CHRFAM7A transfection to control for genetic heterogeneity. As readouts for genotype–phenotype correlation, α7nAChR synaptic transmission and amyloid beta 1–42 (Aβ1–42) uptake were tested. Synaptic transmission in the presence of CHRFAM7A demonstrated that PNU-modulated desensitization of α7nAChR currents increased as a function of CHRFAM7A dosage. CHRFAM7A mitigated the dose response of Aβ1–42 uptake suggesting a protective effect beyond physiological concentrations. Furthermore, in the presence of CHRFAM7A Aβ1–42 uptake activated neuronal interleukin 1β (IL-1β) and tumor necrosis factor α (TNF-α) without activating the canonical inflammasome pathway. Lead optimization may identify more potent molecules when the screen has a model harboring CHRFAM7A. Incorporating pharmacogenetics into clinical trials may enhance signals in efficacy measures.
MANF antagonizes nucleotide exchange by the endoplasmic reticulum chaperone BiP
Authors: Yan Yahui , Rato Claudia , Rohland Lukas , Preissler Steffen , Ron David 
Published: February 2019

AbstractDespite its known role as a secreted neuroprotectant, much of the mesencephalic astrocyte-derived neurotrophic factor (MANF) is retained in the endoplasmic reticulum (ER) of producer cells. There, by unknown mechanisms, MANF plays a role in protein folding homeostasis in complex with the ER-localized Hsp70 chaperone BiP. Here we report that the SAF-A/B, Acinus, and PIAS (SAP) domain of MANF selectively associates with the nucleotide binding domain (NBD) of ADP-bound BiP. In crystal structures the SAP domain engages the cleft between NBD subdomains Ia and IIa, stabilizing the ADP-bound conformation and clashing with the interdomain linker that occupies this site in ATP-bound BiP. MANF inhibits both ADP release from BiP and ATP binding to BiP, and thereby client release. Cells lacking MANF have fewer ER stress-induced BiP-containing high molecular weight complexes. These findings suggest that MANF contributes to protein folding homeostasis as a nucleotide exchange inhibitor that stabilizes certain BiP-client complexes.
Deep learning analysis of defect and phase evolution during electron beam-induced transformations in WS2
Authors: Maksov Artem , Dyck Ondrej , Wang Kai , Xiao Kai , Geohegan David B. , Sumpter Bobby G. , Vasudevan Rama K. , Jesse Stephen , Kalinin Sergei V. , Ziatdinov Maxim 
Published: February 2019

AbstractRecent advances in scanning transmission electron microscopy (STEM) allow the real-time visualization of solid-state transformations in materials, including those induced by an electron beam and temperature, with atomic resolution. However, despite the ever-expanding capabilities for high-resolution data acquisition, the inferred information about kinetics and thermodynamics of the process, and single defect dynamics and interactions is minimal. This is due to the inherent limitations of manual ex situ analysis of the collected volumes of data. To circumvent this problem, we developed a deep-learning framework for dynamic STEM imaging that is trained to find the lattice defects and apply it for mapping solid state reactions and transformations in layered WS2. The trained deep-learning model allows extracting thousands of lattice defects from raw STEM data in a matter of seconds, which are then classified into different categories using unsupervised clustering methods. We further expanded our framework to extract parameters of diffusion for sulfur vacancies and analyzed transition probabilities associated with switching between different configurations of defect complexes consisting of Mo dopant and sulfur vacancy, providing insight into point-defect dynamics and reactions. This approach is universal and its application to beam-induced reactions allows mapping chemical transformation pathways in solids at the atomic level.
Digital biomarkers of mood disorders and symptom change
Authors: Jacobson Nicholas C. , Weingarden Hilary , Wilhelm Sabine 
Published: February 2019

AbstractCurrent approaches to psychiatric assessment are resource-intensive, requiring time-consuming evaluation by a trained clinician. Development of digital biomarkers holds promise for enabling scalable, time-sensitive, and cost-effective assessment of both psychiatric diagnosis and symptom change. The present study aimed to identify robust digital biomarkers of diagnostic status and changes in symptom severity over ~2 weeks, through re-analysis of public-use actigraphy data collected in patients with major depressive or bipolar disorder and healthy controls. Results suggest that participants’ diagnostic group status (i.e., mood disorder, control) can be predicted with a high degree of accuracy (predicted correctly 89% of the time, kappa = 0.773), using features extracted from actigraphy data alone. Results also suggest that actigraphy data can be used to predict symptom change across ~2 weeks (r = 0.782, p = 1.04e-05). Through inclusion of digital biomarkers in our statistical model, which are generalizable to new samples, the results may be replicated by other research groups in order to validate and extend this work.
Palladium-catalyzed relay hydroaminocarbonylation of alkenes with hydroxylamine hydrochloride as an ammonia equivalent
Authors: Li Jiawen , Wang Siyuan , Zou Suchen , Huang Hanmin 
Published: February 2019

AbstractAmides are prevalent in pharmaceuticals, agrochemicals, and materials. Hydroaminocarbonylation of alkenes has emerged as one of the most direct and rapid approaches to amides. Nowadays, these reactions remain largely confined to using alkylamines as nitrogen sources, leading to sluggish reactions due to their strong binding ability and basicity. Here we show the application of abundantly available hydroxylamine hydrochloride (NH2OH·HCl) as a surrogate of ammonia for the relay hydroaminocarbonylation of simple alkenes in the presence of a convenient palladium catalyst system. The in situ formation of alkylamines from hydroxylamine hydrochloride by hydroaminocarbonylation reaction and Lossen rearrangement allows us to establish an efficient relay hydroaminocarbonylation. Notably, this transformation allows the catalytic formation of two C–N bonds with hydroxylamine hydrochloride as an amine source by incorporation of two molecules of alkene and avoids the use of alkylamines.
Realisation of a frustrated 3D magnetic nanowire lattice
Authors: May Andrew , Hunt Matthew , Van Den Berg Arjen , Hejazi Alaa , Ladak Sam 
Published: February 2019

AbstractPatterning nanomagnets in three-dimensions presents a new paradigm in condensed matter physics and allows access to a plethora of phenomena including robust spin textures, magnetic metamaterials home to defects carrying magnetic charge and ultrahigh density devices that store information in three-dimensions. However, the nanostructuring of functional magnetic materials into complex three-dimensional geometries has thus far proven to be a formidable challenge. Here we show magnetic nanowires can be arranged into 3D frustrated magnetic nanowire lattices by using a combination of 3D polymer nanoprinting and metallic deposition. The fabricated nanowires are single domain and they switch via nucleation and propagation of domain walls. Deep nanoscale magnetic imaging and finite element simulations elucidate the spin texture present on the 3D nanostructured lattice. Our study demonstrates a generic platform for the production of 3D nanostructured magnetic materials allowing the realisation of racetrack memory devices and 3D nanostructured systems that mimic bulk frustrated crystals.
Contribution of observed multi frequency spectrum of Alfvén waves to coronal heating
Authors: Pagano P. , De Moortel I. 
Published: February 2019

Context. Whilst there are observational indications that transverse magnetohydrodynamic (MHD) waves carry enough energy to maintain the thermal structure of the solar corona, it is not clear whether such energy can be efficiently and effectively converted into heating. Phase-mixing of Alfvén waves is considered a candidate mechanism, as it can develop transverse gradient where magnetic energy can be converted into thermal energy. However, phase-mixing is a process that crucially depends on the amplitude and period of the transverse oscillations, and only recently have we obtained a complete measurement of the power spectrum for transverse oscillations in the corona.
Aims. We aim to investigate the heating generated by phase-mixing of transverse oscillations triggered by buffeting of a coronal loop that follows from the observed coronal power spectrum as well as the impact of these persistent oscillations on the structure of coronal loops.
Methods. We considered a 3D MHD model of an active region coronal loop and we perturbed its footpoints with a 2D horizontal driver that represents a random buffeting motion of the loop footpoints. Our driver was composed of 1000 pulses superimposed to generate the observed power spectrum.
Results. We find that the heating supply from the observed power spectrum in the solar corona through phase-mixing is not sufficient to maintain the million-degree active region solar corona. We also find that the development of Kelvin–Helmholtz instabilities could be a common phenomenon in coronal loops that could affect their apparent life time.
Conclusions. This study concludes that is unlikely that phase-mixing of Alfvén waves resulting from an observed power spectrum of transverse coronal loop oscillations can heat the active region solar corona. However, transverse waves could play an important role in the development of small scale structures.
Observations of solar small-scale magnetic flux-sheet emergence
Authors: Fischer C. E. , Borrero J. M. , Bello González N. , Kaithakkal A. J. 
Published: February 2019

Aims. Two types of flux emergence were recently discovered in numerical simulations: magnetic loops and magnetic sheet emergence. While magnetic loop emergence has been documented well in recent years using high-resolution full Stokes data from ground-based telescopes as well as satellites, magnetic sheet emergence is still an understudied process. We report here on the first clear observational evidence of a magnetic sheet emergence and characterise its development.
Methods. Full Stokes spectra from the Hinode spectropolarimeter were inverted with the Stokes Inversion based on Response functions (SIR) code to obtain solar atmospheric parameters such as temperature, line-of-sight velocities, and full magnetic field vector information.
Results. We analyse a magnetic flux emergence event observed in the quiet-Sun internetwork. After a large-scale appearance of linear polarisation, a magnetic sheet with horizontal magnetic flux density of up to 194 Mx cm−2 hovers in the low photosphere spanning a region of 2–3 arcsec. The magnetic field azimuth obtained through Stokes inversions clearly shows an organised structure of transversal magnetic flux density emerging. The granule below the magnetic flux sheet tears the structure apart leaving the emerged flux to form several magnetic loops at the edges of the granule.
Conclusions. A large amount of flux with strong horizontal magnetic fields surfaces through the interplay of buried magnetic flux and convective motions. The magnetic flux emerges within 10 minutes and we find a longitudinal magnetic flux at the foot points of the order of ∼1018 Mx. This is one to two orders of magnitude larger than what has been reported for small-scale magnetic loops. The convective flows feed the newly emerged flux into the pre-existing magnetic population on a granular scale.
Ca line formation in late-type stellar atmospheres
Authors: Osorio Y. , Lind K. , Barklem P. S. , Allende Prieto C. , Zatsarinny O. 
Published: February 2019

Context. Departures from local thermodynamic equilibrium (LTE) distort the calcium abundance derived from stellar spectra in various ways, depending on the lines used and the stellar atmospheric parameters. The collection of atomic data adopted in non-LTE (NLTE) calculations must be sufficiently complete and accurate.
Aims. We derive NLTE abundances from high-quality observations and reliable stellar parameters using a model atom built afresh for this work, and check the consistency of our results over a wide wavelength range with transitions of atomic and singly ionised calcium.
Methods. We built and tested Ca I and Ca II model atoms with state-of-the-art radiative and collisional data, and tested their performance deriving the Ca abundance in three benchmark stars: Procyon, the Sun, and Arcturus. We have excellent-quality observations and accurate stellar parameters for these stars. Two methods to derive the LTE/NLTE abundances were used and compared. The LTE/NLTE centre-to-limb variation (CLV) of Ca lines in the Sun was also investigated.
Results. The two methods used give similar results in all three stars. Several discrepancies found in LTE do not appear in our NLTE results; in particular the agreement between abundances in the visual and infra-red (IR) and the Ca I and Ca II ionisation balance is improved overall, although substantial line-to-line scatter remains. The CLV of the calcium lines around 6165 Å can be partially reproduced. We suspect differences between our modelling and CLV results are due to inhomogeneities in the atmosphere that require 3D modelling.
Demonstrating the Principles of Aperture Synthesis with Table- Top Laboratory Exercises
Authors: Marr J.M. , Rogers A.E.E. , Fish V.L. , Wilkin F.P. , Arndt M.B. , Holodak G. , Durkota K. 
Published: February 2019

Many undergraduate radio astronomy courses are unable to give a detailed treatment of aperture synthesis due to time constraints and limited math backgrounds of students. We have taken a laboratory-based approach to teaching radio interferometry using a set of college-level, table-top exercises. These are performed with the Very Small Radio Telescope (VSRT), an interferometer developed at the Haystack Observatory using satellite TV electronics as detectors and compact fluorescent light bulbs as microwave signal sources. The hands-on experience provided by the VSRT in these labs allows students to gain a conceptual understanding of radio interferometry and aperture synthesis without the rigorous mathematical background traditionally required.
The data are quickly and easily processed using a user-friendly data analysis Java package, VSRTI_Plotter.jar. This software can also be used in the absence of the equipment as an interactive computer activity to demonstrate an interferometer’s responses to assorted surface brightness distributions. The students also gain some familiarity with Fourier transforms and an appreciation for the Fourier relations in interferometry using another Java package, the Tool for Interactive Fourier Transforms (TIFT). We have successfully used these tools in multiple offerings of our radio astronomy course at Union College
Integratives und funktionelles Training zur
Sturzprävention: Agility für Senioren?
Authors: Morat Mareike , Lichtenstein Eric , Faude Oliver , Donath Lars 
Published: February 2019

ZusammenfassungBeim Thema „Sturzprävention“ denken viele an alte Menschen, die in Gruppen oder
als Einzelne unter Anleitung eines Therapeuten verhältnismäßig langweilige
Übungen für das Gleichgewicht machen: Einbein- und Tandemstand, Seiltänzergang
oder was auch immer für geeignet befunden wird, die Balance zu verbessern. Dass
Sturzprävention aber auch mehr sein kann, zeigen unsere Autoren in diesem
Beitrag über die Vorzüge Agility-basierter Trainingsansätze.
Factors Associated with Utilization of 17-Hydroxyprogesterone Caproate for the Prevention of Recurrent Preterm Birth
Authors: DeNoble Anna E. , Wynn Clara E. , Weaver Kristin E. , Wheeler Sarahn M. , Swamy Geeta K. 
Published: February 2019

Objective Weekly 17-hydroxyprogesterone caproate (17OHP-C) from 16 to 36 weeks' gestation reduces the risk of recurrent spontaneous preterm birth (sPTB). Limited data suggest poor adherence to published guidelines. This study aimed to identify factors associated with 17OHP-C utilization.
Study Design This retrospective cohort study included women with a singleton pregnancy who delivered within one academic health system between January 2014 and December 2015. Eligible women had a history of ≥1 singleton sPTB. Primary outcomes were counseling about, receipt of, and adherence to 17OHP-C therapy. Demographic and clinical predictors of the primary outcomes were determined using stepwise logistic regression.
Results Of 410 eligible subjects, 69% (N = 284) were counseled about and 36% (N = 148) received 17OHP-C. Hispanic ethnicity, delay in prenatal care initiation, and a history of prior term births were associated with lower odds of 17OHP-C counseling. Each week delay in prenatal care initiation, Hispanic ethnicity, and each additional week's gestation of the earliest prior sPTB decreased the odds of receiving 17OHP-C. Maternal age and prior term births were associated with adherence.
Conclusion Utilization of evidence-based 17OHP-C therapy remains suboptimal: cultural and access-to-care barriers for eligible women may impede efforts to decrease recurrent sPTB rates.