cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Properties of host galaxies of submillimeter sources as revealed by JWST Early Release Observations in SMACS J0723.3-7327
Creators: name: Cheng, Cheng
name: Yan, Haojing
name: Huang, Jia-Sheng
name: Willmer, Christopher N. A.
name: Ma, Zhiyuan
name: Orellana-González, Gustavo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: Using the 0.9--4.4~$μ$m imaging data from the James Webb Space Telescope (JWST) Early Release Observation in the SMACS J0723.3-7327 galaxy cluster field, we discuss the properties of three submillimeter galaxies (SMGs) detected by the Atacama Large Millimeter Array. These sources are magnified by 1.4--2.1$\times$due to gravitational lensing. This is the first time that SMG host galaxies are resolved in the rest-frame near-infrared (NIR). One source was previous undetected by HST, while the remaining two are disk galaxies with Sérsic indices of $\sim 0.9$ and star formation rates on or just below the star formation "main sequence". Their submillimeter emission originates from the inner parts of the hosts, suggesting that their dust contents are concentrated towards the center. The host half-light radii measured in the rest-frame NIR are $\sim$1.5$\times$ smaller than those measured in the rest-frame optical, consistent with a concentrated dust distribution. The more severe extinction that optical light suffers towards the center makes it seemingly less concentrated. Therefore, we expect that the optically-based determination of the stellar mass distribution within host galaxies could still be severely biased by dust. Interestingly, these two disk galaxies are dramatically different in their outer regions, with one being star forming and the other being quiescent. Upcoming JWST observations of statistically significant samples of SMGs will allow us to understand the correlation between the dusty star forming regions and their hosts.
description: 11 pages, 7 figures, accepted by ApJL
Parker Bound and Monopole Pair Production from Primordial Magnetic Fields
Creators: name: Kobayashi, Takeshi
name: Perri, Daniele
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We present new bounds on the cosmic abundance of magnetic monopoles based on the survival of primordial magnetic fields during the reheating and radiation-dominated epochs. The new bounds can be stronger than the conventional Parker bound from galactic magnetic fields, as well as bounds from direct searches. We also apply our bounds to monopoles produced by the primordial magnetic fields themselves through the Schwinger effect, and derive additional conditions for the survival of the primordial fields.
description: 27 pages, 4 figures; typos corrected, references added
Cosmology in Painleve-Gullstrand coordinates
Creators: name: Gaur, Rudeep
name: Visser, Matt
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Cosmology is most typically analyzed using standard co-moving coordinates, in which the galaxies are (on average, up to presumably small peculiar velocities) "at rest", while "space" is expanding. But this is merely a specific coordinate choice; and it is important to realise that for certain purposes other, (sometimes radically different) coordinate choices might also prove useful and informative, but without changing the underlying physics. Specifically, herein we shall consider the k=0 spatially flat FLRW cosmology but in Painleve-Gullstrand coordinates -- these coordinates are very explicitly not co-moving: "space" is now no longer expanding, although the distance between galaxies is still certainly increasing. Working in these Painleve-Gullstrand coordinates provides an alternate viewpoint on standard cosmology, and the symmetries thereof, and also makes it somewhat easier to handle cosmological horizons. With a longer view, we hope that investigating these Painleve-Gullstrand coordinates might eventually provide a better framework for understanding large deviations from idealized FLRW spacetimes. We illustrate these issues with a careful look at the Kottler and McVittie spacetimes.
description: 37 pages; V2: minor changes in presentation; no physics changes; this version accepted for publication in JCAP
A new continuation criterion for the relativistic Vlasov-Maxwell system
Creators: name: Luk, Jonathan
name: Strain, Robert M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: The global existence of solutions to the relativistic Vlasov-Maxwell system given sufficiently regular finite energy initial data is a longstanding open problem. The main result of Glassey-Strauss (1986) shows that a solution $(f, E, B)$ remains $C^1$ as long as the momentum support of $f$ remains bounded. Alternate proofs were later given by Bouchut-Golse-Pallard (2003) and Klainerman-Staffilani (2002). We show that only the boundedness of the momentum support of $f$ after projecting to any two dimensional plane is needed for $(f, E, B)$ to remain $C^1$.
description: 21 pages, to appear in Commun. Math. Phys
Geology and Photometric Variation of Solar System Bodies with Minor Atmospheres: Implications for Solid Exoplanets
Creators: name: Fujii, Yuka
name: Kimura, Jun
name: Dohm, James
name: Ohtake, Makiko
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: A reasonable basis for future astronomical investigations of exoplanets lies in our best knowledge of the planets and satellites in the Solar System. Solar System bodies exhibit a wide variety of surface environments, even including potential habitable conditions beyond Earth, and it is essential to know how they can be characterized from outside the Solar System. In this study, we provide an overview of geological features of major Solar System solid bodies with minor atmospheres (i.e., the Terrestrial Moon, Mercury, the Galilean moons, and Mars) that affect surface albedo at local to global scale, and we survey how they influence point-source photometry in UV, visible, and near IR (i.e., the reflection-dominant range). We simulate them based on recent mapping products and also compile observed light curves where available. We show a 5-50% peak-to-trough variation amplitude in one spin rotation associated with various geological processes including heterogeneous surface compositions due to igneous activities, interaction with surrounding energetic particles, and distribution of grained materials. Some indications of these processes are provided by the amplitude and wavelength dependence of variation in combinations of the time-averaged spectra. We also estimate the photometric precision needed to detect their spin rotation rates through periodogram analysis. Our survey illustrates realistic possibilities for inferring the detailed properties of solid exoplanets with future direct imaging observations.
description: 8 figures, 3 tables, Astrobiology, in press
Does intensity windowing improve the detection of simulated calcifications in dense mammograms?
Creators: name: Chandramouli, Jayanthi
name: Johnston, R. Eugene
name: DeLuca, Marla
name: Hemminger, Bradley M.
name: Glueck, Deb
name: Pizer, Stephen
name: Muller, Keith
name: Braeuning, M. Patricia
name: Pisano, Etta D.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1997

description: This study attempts to determine whether intensity windowing (IW) improves detection of simulated calcifications in dense mammograms. Clusters of five simulated calcifications were embedded in dense mammograms digitized at 50-microns pixels, 12 bits deep. Film images with no windowing applied were compared with film images with nine different window widths and levels applied. A simulated cluster was embedded in a realistic background of dense breast tissue, with the position of the cluster varied. The key variables involved in each trial included the position of the cluster, contrast level of the cluster, and the IW settings applied to the image. Combining the ten IW conditions, four contrast levels and four quadrant positions gave 160 combinations. The trials were constructed by pairing 160 combinations of key variables with 160 backgrounds. The entire experiment consisted of 800 trials. Twenty student observers were asked to detect the quadrant of the image in which the mass was located. There was a statistically significant improvement in detection performance for clusters of calcifications when the window width was set at 1024 with a level of 3328, and when the window width was set at 1024 with a level of 3456. The selected IW settings should be tested in the clinic with digital mammograms to determine whether calcification detection performance can be improved.
The effect of intensity windowing on the detection of simulated masses embedded in dense portions of digitized mammograms in a laboratory setting
Creators: name: Johnston, R. Eugene
name: Hemminger, Bradley M.
name: Muller, Keith
name: Pisano, Etta D.
name: Pizer, Stephen
name: Chandramouli, Jayanthi
name: Garrett, William
name: Puff, Derek
name: Braeuning, M. Patricia
name: Glueck, Deb
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1997

description: The purpose of this study was to determine whether intensity windowing (IW) improves detection of simulated masses in dense mammograms. Simulated masses were embedded in dense mammograms digitized at 50 microns/pixel, 12 bits deep. Images were printed with no windowing applied and with nine window width and level combinations applied. A simulated mass was embedded in a realistic background of dense breast tissue, with the position of the mass (against the background) varied. The key variables involved in each trial included the position of the mass, the contrast levels and the IW setting applied to the image. Combining the 10 image processing conditions, 4 contrast levels, and 4 quadrant positions gave 160 combinations. The trials were constructed by pairing 160 combinations of key variables with 160 backgrounds. The entire experiment consisted of 800 trials. Twenty observers were asked to detect the quadrant of the image into which the mass was located. There was a statistically significant improvement in detection performance for masses when the window width was set at 1024 with a level of 3328. IW should be tested in the clinic to determine whether mass detection performance in real mammograms is improved.
Quantum inequality in spacetimes with small curvature
Creators: name: Kontou, Eleni-Alexandra
name: Olum, Ken D.
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Quantum inequalities bound the extent to which weighted time averages of the renormalized energy density of a quantum field can be negative. They have mostly been proved in flat spacetime, but we need curved-spacetime inequalities to disprove the existence of exotic phenomena, such as closed timelike curves. In this work we derive such an inequality for a minimally-coupled scalar field on a geodesic in a spacetime with small curvature, working to first order in the Ricci tensor and its derivatives. Since only the Ricci tensor enters, there are no first-order corrections to the flat-space quantum inequalities on paths which do not encounter any matter or energy.
description: 21 pages
Highly collimated microquasar jets as efficient cosmic-ray sources
Creators: name: Escobar, G. J.
name: Pellizza, L. J.
name: Romero, G. E.
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Supernova remnants are believed to be the main sites where Galactic cosmic rays originate. This scenario, however, fails to explain some of the features observed in the cosmic-ray spectrum. Microquasars have been proposed as additional candidates, because their non-thermal emission indicates the existence of efficient particle acceleration mechanisms in their jets. A promising scenario envisages the production of relativistic neutrons in the jets, that decay outside the system injecting relativistic protons to the surroundings. The first investigations of this scenario suggest that microquasars might be fairly alternative cosmic-ray sources. We aim at assessing the role played by the degree of collimation of the jet on the cosmic-ray energetics in the neutron-carrier scenario, as well as the properties of the emission region. Our goals are to explain the Galactic component of the observed proton cosmic-ray spectrum at energies higher than $\sim 10$ GeV and to relate the mentioned jet properties with the power and spectral index of the produced cosmic rays. We find that collimated jets, with compact acceleration regions close to the jet base, are very efficient sources that could deliver a fraction of up to $\sim 0.01$ of their relativistic proton luminosity into cosmic rays. Collimation is the most significant feature regarding efficiency; a well collimated jet might be $\sim 4$ orders of magnitude more efficient than a poorly collimated one. The main feature of the presented mechanism is the production of a spectrum with a steeper spectral index ($\sim 2.3$ at energies up to $\sim 10$ TeV) than in the supernova scenario, and closer to what is observed. The predictions of our model may be used to infer the total contribution of the population of Galactic microquasars to the cosmic ray population, and therefore to quantitatively assess their significance as cosmic-ray sources.
description: 11 pages, 14 figures
Hydrogen-Activation Mechanism of [Fe] Hydrogenase Revealed by Multi-Scale Modeling
Creators: name: Finkelmann, Arndt Robert
name: Senn, Hans Martin
name: Reiher, Markus
Publisher: name: arXiv
Year: 2014
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Chemical Physics (physics.chem-ph)
subject: Computational Physics (physics.comp-ph)
subject: FOS: Physical sciences

description: When investigating the mode of hydrogen activation by [Fe] hydrogenases, not only the chemical reactivity at the active site is of importance but also the large-scale conformational change between the so-called open and closed conformations, which leads to a special spatial arrangement of substrate and iron cofactor. To study H2 activation, a complete model of the solvated and cofactor-bound enzyme in complex with the substrate methenyl-H4MPT+ was constructed. Both the closed and open conformations were simulated with classical molecular dynamics on the 100 ns time scale. Quantum-mechanics/molecular-mechanics calculations on snapshots then revealed the features of the active site that enable the facile H2 cleavage. The hydroxyl group of the pyridinol ligand can easily be deprotonated. With the deprotonated hydroxyl group and the structural arrangement in the closed conformation, H2 coordinated to the Fe center is subject to an ionic and orbital push-pull effect and can be rapidly cleaved with a concerted hydride transfer to methenyl-H4MPT+. An intermediary hydride species is not formed.
description: 16 pages (without supporting information), 11 figures
PARSEC V2.0: Stellar tracks and isochrones of low and intermediate mass stars with rotation
Creators: name: Nguyen, C. T.
name: Costa, G.
name: Girardi, L.
name: Volpato, G.
name: Bressan, A.
name: Chen, Y.
name: Marigo, P.
name: Fu, X.
name: Goudfrooij, P.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: We present a new comprehensive collection of stellar evolutionary tracks and isochrones for rotating low- and intermediate-mass stars assembled with the updated version of PARSEC V2.0. This version includes our recent calibration of the extra mixing from overshooting and rotation, as well as several improvements in nuclear reaction network, treatment of convective zones, mass loss and other physical input parameters. The initial mass of the stellar models covers the range from 0.09 $M_\odot$ to 14 $M_\odot$, for six sets of initial metallicity, from Z=0.004 to Z=0.017. Rotation is considered for stars above $\sim 1 M_\odot$ with a smooth transition between non rotating and extremely fast-rotating models, based on the initial mass. For stars more massive than $\sim 1.3~M_\odot$ the full rotation range, from low to the critical one, is considered. We adopt the solar-scaled chemical mixture by Caffau et al. with Z$_\odot$ = 0.01524. All the evolutionary phases from the pre-main-sequence to the first few thermal-pulses on the asymptotic-giant-branch or central C exhaustion, are considered. The corresponding theoretical isochrones are further derived with TRILEGAL code and are converted in several photometric systems, taking into account different inclination angles. Besides magnitudes, they also offer many other stellar observables in line with the data that are being provided by current large surveys. The new collection is fully integrated in a user friendly WEB interface for the benefit of easily performing stellar population studies.
description: Accepted for publication in A&A. 17 pages. 20 Figures
Contrast Limited Adaptive Histogram Equalization image processing to improve the detection of simulated spiculations in dense mammograms
Creators: name: Zong, Shuquan
name: Muller, Keith
name: Pisano, Etta D.
name: Hemminger, Bradley M.
name: Braeuning, M. Patricia
name: Johnston, R. Eugene
name: DeLuca, Marla
name: Pizer, Stephen M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 1998

description: The purpose of this project was to determine whether Contrast Limited Adaptive Histogram Equalization (CLAHE) improves detection of simulated spiculations in dense mammograms. Lines simulating the appearance of spiculations, a common marker of malignancy when visualized with masses, were embedded in dense mammograms digitized at 50 micron pixels, 12 bits deep. Film images with no CLAHE applied were compared to film images with nine different combinations of clip levels and region sizes applied. A simulated spiculation was embedded in a background of dense breast tissue, with the orientation of the spiculation varied. The key variables involved in each trial included the orientation of the spiculation, contrast level of the spiculation and the CLAHE settings applied to the image. Combining the 10 CLAHE conditions, 4 contrast levels and 4 orientations gave 160 combinations. The trials were constructed by pairing 160 combinations of key variables with 40 backgrounds. Twenty student observers were asked to detect the orientation of the spiculation in the image. There was a statistically significant improvement in detection performance for spiculations with CLAHE over unenhanced images when the region size was set at 32 with a clip level of 2, and when the region size was set at 32 with a clip level of 4. The selected CLAHE settings should be tested in the clinic with digital mammograms to determine whether detection of spiculations associated with masses detected at mammography can be improved.
Conformational dynamics modulating electron transfer
Creators: name: Matyushov, Dmitry V.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Chemical Physics (physics.chem-ph)
subject: FOS: Physical sciences

description: Diffusional dynamics of the donor-acceptor distance in electron-transfer reactions are responsible for the appearance of a new time scale of diffusion over the distance of falloff of electronic tunneling. The distance dynamics compete with the medium polarization dynamics in the solvent-controlled electron transfer kinetics. A new solution incorporating the medium and donor-acceptor dynamics into the electron-transfer rate constant is proposed. The pre-exponential factor of the rate constant switches between a distance-independent solvent-controlled regime and exponential distance decay. The crossover between two regimes is controlled by an effective relaxation time slowed down by a factor exponentially depending on the variance of the donor-acceptor displacement. Flexible donor-acceptor complexes must show a greater tendency for solvent-controlled electron transfer. Electron-transfer energy chains are best designed by placing the redox cofactors near the crossover distance.
Infrared spectrum of the 1-cyanoadamantane cation: evidence of hydrogen transfer and cage-opening upon ionization
Creators: name: Rubli, Peter Theodore
name: Dopfer, Otto
Publisher: name: Royal Society of Chemistry (RSC)
Year: 2023
Subjects: subject: 500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften
subject: hydrogen transfer
subject: cage-opening
subject: ionization
subject: Infrared spectrum
subject: diamondoids

description: The radical cations of diamondoids are important intermediates in their functionalization reactions and are also candidates as carriers for astronomical absorption and emission features. Although neutral diamondoids have been studied extensively, information regarding their radical cations is largely lacking, particularly for functionalized diamondoid derivatives. Herein, we characterize the structure of the 1-cyanoadamantane radical cation (C10H15CN+, AdCN+) using infrared photodissociation (IRPD) spectroscopy of mass selected AdCN+N2 clusters in the XH stretch range (2400–3500 cm−1) and dispersion-corrected density functional theory calculations (B3LYP-D3BJ/cc-pVTZ). A group of three distinct CH stretch bands are observed in the 2800–3000 cm−1 range, in addition to a highly redshifted absorption at 2580 cm−1 attributed to the acidic CH proton predicted by calculations. An unexpected broad absorption peaking at 3320 cm−1 is also detected and assigned to an NH stretch mode based on its width and frequency. Calculations indicate that hydrogen atom transfer (HAT) from the adamantyl cage (C10H15, Ady) to the N atom of the CN group yields lower energy structures, with an open-cage isomer exhibiting such hydrogen transfer being the global minimum on the potential energy surface. The energy barriers involved in the formation of this open-cage isomer are also lower than those calculated for generation of the analogous open-cage 1-amantadine cation isomer which has previously been identified by IRPD. The combined consideration of IRPD spectra and calculations indicates a major population of the nascent canonical closed-cage isomer and a smaller population of the global minimum isomer featuring both cage-opening and hydrogen transfer.
Soft Copy Display Requirements for Digital Mammography
Creators: name: Hemminger, Bradley M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2003

description: One of the advantages of digital mammography is to display mammograms on softcopy (electronic displays). Softcopy display of mammography is challenging because of the spatial and contrast resolution demands present in mammograms. We have designed and developed a softcopy mammography display application, Mammoview, which is capable of allowing radiologists to read mammograms as quickly and as accurately as they can on film alternators. We review the studies using Mammoview to elucidate the requirements of a successful softcopy display station. The design and development of the Mammoview softcopy display station are described in this article, and results of several studies using Mammoview are reported, including subjective feedback from Radiological Society of North America (RSNA) conference demonstrations, and clinical studies measuring performance in terms of speed and accuracy. Additional analysis of user interactions and user feedback is used to study the successes and shortcomings of mammography display stations like Mammoview. Overall, radiologist readings using Mammoview have been shown to be as fast and as accurate as readings using mammography film alternators. However, certain parts of the softcopy interface were more successful than their film counterparts, whereas others were less successful. Data analysis of the recorded human-computer interactions for the softcopy component of the clinical trial indicate statistically significant correlations between the difference in review time of softcopy versus alternator readings and three factors: the number of interactions, the reader, and the size of the image being reviewed. The first factor (number of interactions) suggests that simpler interfaces require less time to use; the second factor, the reader, supports previous findings that radiologists vary in how fast they read screening mammography studies; the third, size of image, suggests that the speed of softcopy review is increased relative to film readings when images are significantly larger than the display size. Feedback from radiologists using the system in clinical trials and at demonstration exhibits at RSNA indicated good acceptance of the interface and easy adaptation. Radiologists indicated that they felt comfortable using the interface, and that they would use such a softcopy interface in clinical practice. Finally, preliminary work suggests that the addition of a simple interaction to incorporate computer-aided detection (CAD) results would improve reading accuracy without significantly increasing reader times.
Strichartz estimates and moment bounds for the relativistic Vlasov-Maxwell system I. The $2$-D and $2\frac 12$-D cases
Creators: name: Luk, Jonathan
name: Strain, Robert M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Consider the relativistic Vlasov-Maxwell system with initial data of unrestricted size. In the two dimensional and the two and a half dimensional cases, Glassey-Schaeffer (1997, 1998, 1998) proved that for regular initial data with compact momentum support this system has unique global in time classical solutions. In this work we do not assume compact momentum support for the initial data and instead require only that the data have polynomial decay in momentum space. In the 2D and the $2\frac 12$D cases, we prove the global existence, uniqueness and regularity for solutions arising from this class of initial data. To this end we use Strichartz estimates and prove that suitable moments of the solution remain bounded. Moreover, we obtain a slight improvement of the temporal growth of the $L^\infty_x$ norms of the electromagnetic fields compared to Glassey-Schaeffer.
description: 62 pages, submitted
Assessment of Real-Time 3D Visualization for Cardiothoracic Diagnostic Evaluation and Surgery Planning
Creators: name: Detterbeck, Frank C.
name: Coffey, Christopher S.
name: Molina, Paul L.
name: Muller, Keith E.
name: Hemminger, Bradley M.
name: Lee, Joseph K. T.
name: Egan, Thomas M.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2005

description: RATIONALE AND OBJECTIVES: Three-dimensional (3D) real-time volume rendering has demonstrated improvements in clinical care for several areas of radiological imaging. We test whether advanced real-time rendering techniques combined with an effective user interface will allow radiologists and surgeons to improve their performance for cardiothoracic surgery planning and diagnostic evaluation.

MATERIAL AND METHODS: An interactive combination 3D and 2D visualization system developed at the University of North Carolina at Chapel Hill was compared against standard tiled 2D slice presentation on a viewbox. The system was evaluated for 23 complex cardiothoracic computed tomographic (CT) cases including heart-lung and lung transplantation, tumor resection, airway stent placement, repair of congenital heart defects, aortic aneurysm repair, and resection of pulmonary arteriovenous malformation. Radiologists and surgeons recorded their impressions with and without the use of the interactive visualization system.

RESULTS: The cardiothoracic surgeons reported positive benefits to using the 3D visualizations. The addition of the 3D visualization changed the surgical plan (65% of cases), increased the surgeon's confidence (on average 40% per case), and correlated well with the anatomy found at surgery (95% of cases). The radiologists reported fewer and less major changes than the surgeons in their understanding of the case due to the 3D visualization. They found new findings or additional information about existing findings in 66% of the cases; however, they changed their radiology report in only 14% of the cases.

CONCLUSION: With the appropriate choice of 3D real-time volume rendering and a well-designed user interface, both surgeons and radiologists benefit from viewing an interactive 3D visualization in addition to 2D images for surgery planning and diagnostic evaluation of complex cardiothoracic cases. This study finds that 3D visualization is especially helpful to the surgeon in understanding the case, and in communicating and planning the surgery. These results suggest that including real-time 3D visualization would be of clinical benefit for complex cardiothoracic CT cases.
Detection of an Unidentified Soft X-ray Emission Feature in NGC 5548
Creators: name: Gu, Liyi
name: Mao, Junjie
name: Kaastra, Jelle S.
name: Mehdipour, Missagh
name: Pinto, Ciro
name: Grafton-Waters, Sam
name: Bianchi, Stefano
name: Landt, Hermine
name: Branduardi-Raymont, Graziella
name: Costantini, Elisa
name: Ebrero, Jacobo
name: Petrucci, Pierre-Olivier
name: Behar, Ehud
name: di Gesu, Laura
name: De Marco, Barbara
name: Matt, Giorgio
name: Mitchell, Jake A. J.
name: Peretz, Uria
name: Ursini, Francesco
name: Ward, Martin
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: NGC~5548 is an X-ray bright Seyfert 1 active galaxy. It exhibits a variety of spectroscopic features in the soft X-ray band, including in particular the absorption by the AGN outflows of a broad range of ionization states, with column densities up to 1E27 /m^2, and having speeds up to several thousand kilometers per second. The known emission features are in broad agreement with photoionized X-ray narrow and broad emission line models. We report on an X-ray spectroscopic study using 1.1 Ms XMM-Newton and 0.9 Ms Chandra grating observations of NGC 5548 spanning two decades. The aim is to search and characterize any potential spectroscopic features in addition to the known primary spectral components that are already modeled in high precision. We detect a weak unidentified excess emission feature at 18.4 Angstrom (18.1 Angstrom in the restframe). The feature is seen at >5 sigma statistical significance taking into account the look elsewhere effect. No known instrumental issues, atomic transitions, and astrophysical effects can explain this excess. The observed intensity of the possible feature seems to anti-correlate in time with the hardness ratio of the source. However, the variability might not be intrinsic, it might be caused by the time-variable obscuration by the outflows. An intriguing possibility is the line emission from charge exchange between a partially ionized outflow and a neutral layer in the same outflow, or in the close environment. Other possibilities, such as emission from a highly-ionized component with high outflowing speed, cannot be fully ruled out.
description: 14 pages, 8 figures, accepted for publication in Astronomy & Astrophysics
Crystal water intercalated interlayer expanded MoS2 nanosheets as a cathode for efficient zinc-ion storage
Creators: name: Hariram, Muruganandham
name: Kumar, Manoj
name: Awasthi, Kamlendra
name: Sarkar, Debasish
name: Menezes, Prashanth W.
Publisher: name: Royal Society of Chemistry (RSC)
Year: 2023
Subjects: subject: 500 Naturwissenschaften und Mathematik::540 Chemie::540 Chemie und zugeordnete Wissenschaften
subject: zinc-ion storage
subject: nanosheets
subject: Zinc-ion batteries
subject: ZIBs
subject: cathode materials

description: Zinc-ion batteries (ZIBs) have attracted tremendous interest from the scientific community in recent years due to their extreme safety, cost-effectiveness, environmental benignity and the unique properties of the Zn anode. However, more suitable cathode materials are needed to achieve their potential widespread applications. MoS2, a 2D layered material with fascinating properties, could also serve as a cathode in ZIBs but is rarely studied due to its limited interlayer spacing, poor ionic/electronic conductivity and hydrophobicity. In this work, we report a facile hydrothermal method for synthesizing crystal water-intercalated MoS2 nanosheets and their application in efficient Zn-ion storage. Morphological characterization reveals the average thickness of the nanosheets to be 15.2 nm. With a large interlayer spacing (0.79 nm), high 1T content (49.7%) and high defects, MoS2·nH2O achieves a high discharge capacity of 197 mA h g−1 at 0.1 A g−1 in an aqueous 2 M ZnSO4 electrolyte. Moreover, it exhibits modest cyclic stability with 55% capacity retention after 1000 charge/discharge cycles. Furthermore, we evaluated the charge storage kinetics of crystal water-intercalated MoS2 nanosheets and realized that the electrochemical reaction is diffusion dominated with a diffusion coefficient of 10−10 to 10−13 cm2 s−1 in a 0.3 to 1.3 V potential window. This simple and cost-effective strategy for improving the performance of ZIBs by crystal water intercalation in 2D cathode materials will pave the way for their commercial-level grid-scale applications.
Wightman function and the Casimir effect for a Robin sphere in a constant curvature space
Creators: name: Bellucci, S.
name: Saharian, A. A.
name: Saharyan, N. A.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We evaluate the Wightman function, the mean field squared and the vacuum expectation value (VEV) of the energy-momentum tensor for a scalar field with Robin boundary condition on a spherical shell in the background of a constant negative curvature space. For the coefficient in the boundary condition there is a critical value above which the scalar vacuum becomes unstable. In both interior and exterior regions, the VEVs are decomposed into the boundary-free and sphere-induced contributions. For the latter, rapidly convergent integral representations are provided. In the region inside the sphere, the eigenvalues are expressed in terms of the zeros of the combination of the associated Legendre function and its derivative and the decomposition is achieved by making use of the Abel-Plana type summation formula for the series over these zeros. The sphere-induced contribution to the VEV of the field squared is negative for Dirichlet boundary condition and positive for Neumann one. At distances from the sphere larger than the curvature scale of the background space the suppression of the vacuum fluctuations in the gravitational field corresponding to the negative curvature space is stronger compared with the case of the Minkowskian bulk. In particular, the decay of the VEVs with the distance is exponential for both massive and massless fields. The corresponding results are generalized for spaces with spherical bubbles and for cosmological models with negative curvature spaces.
description: 28 pages, 3 figures, LaTeX file
CO line observations of OH/IR stars in the inner Galactic Bulge: Characteristics of stars at the tip of the AGB
Creators: name: Olofsson, H.
name: Khouri, T.
name: Sargent, B. A.
name: Winnberg, A.
name: Blommaert, J. A. D. L.
name: Groenewegen, M. A. T.
name: Muller, S.
name: Kastner, J. H.
name: Meixner, M.
name: Otsuka, M.
name: Patel, N.
name: Ryde, N.
name: Srinivasan, S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: 12CO and 13CO lines, as well as a mm-wave continuum, have been observed for a sample of 22 OH/IR stars in directions within 2 degrees of the Galactic Centre. Photometry data have been gathered from the literature to construct SEDs and to determine pulsational variability. Radiative transfer models have been used to interpret the data. All stars in the sample were detected in at least one CO line, and 8 objects were detected in 324 GHz continuum. Based on luminosity criteria, the sample is divided into 17 objects that most likely lie within the inner Galactic Bulge, and 5 objects that are most likely foreground objects. The median luminosity of the inner-Galactic-Bulge objects, 5600 Lsun, corresponds to an initial mass in the range 1.2-1.6 Msun, indicating that these OH/IR stars descend from solar-type stars. The objects in this sub-sample are further divided into two classes based on their SED characteristics: 11 objects have SEDs that are well matched by models invoking dust envelopes extending from a few stellar radii and outwards, while 6 objects are better modelled as having detached dust envelopes with inner radii in the range 200-600 au and warmer central stars. The former objects have periodic variability, while the latter objects are predominantly non-periodic. The median gas-mass-loss rate, gas terminal expansion velocity, gas-to-dust mass ratio, and circumstellar 12CO/13CO abundance ratio have been estimated to be 2x10{-5} Msun/yr, 18 km/s, 200 (excluding the sources with detached dust envelopes, which show markedly lower gas-to-dust ratios), and 5, respectively, for the inner-Galactic-Bulge objects. The inner-Galactic-Bulge OH/IR stars studied here constitute an excellent sample of equidistant objects for the purpose of understanding the evolution of the mass-loss-rate characteristics at the tip of the AGB.
description: 32 pages, 17 figures
Formation of close in Super-Earths \& Mini-Neptunes: Required Disk Masses \& Their Implications
Creators: name: Schlichting, Hilke E.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: Recent observations by the {\it Kepler} space telescope have led to the discovery of more than 4000 exoplanet candidates consisting of many systems with Earth- to Neptune-sized objects that reside well inside the orbit of Mercury, around their respective host stars. How and where these close-in planets formed is one of the major unanswered questions in planet formation. Here we calculate the required disk masses for {\it in situ} formation of the {\it Kepler} planets. We find that, if close-in planets formed as {\it isolation masses}, then standard gas-to-dust ratios yield corresponding gas disks that are gravitationally unstable for a significant fraction of systems, ruling out such a scenario. We show that the maximum width of a planet's accretion region in the absence of any migration is $2 v_{esc}/Ω$, where $v_{esc}$ is the escape velocity of the planet and $Ω$ the Keplerian frequency and use it to calculate the required disk masses for {\it in situ} formation with giant impacts. Even with giant impacts, formation without migration requires disk surface densities in solids at semi-major axes less than 0.1~AU of $10^3-10^5 \rm{~g~cm^{-2}}$ implying typical enhancements above the minimum-mass solar nebular (MMSN) by at least a factor of 20. Corresponding gas disks are below, but not far from, the gravitational stability limit. In contrast, formation beyond a few AU is consistent with MMSN disk masses. This suggests that migration of either solids or fully assembled planets is likely to have played a major role in the formation of close-in super-Earths and mini-Neptunes.
description: Accepted for publication in ApJL
Comparison of Navigation Techniques for Large Digital Images
Creators: name: Bauers, Anne
name: Hemminger, Bradley M.
name: Yang, Jian
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: Medical images are examined on computer screens in a variety of contexts. Frequently, these images are larger than computer screens, and computer applications support different paradigms for user navigation of large images. The paper reports on a systematic investigation of what interaction techniques are the most effective for navigating images larger than the screen size for the purpose of detecting small image features. An experiment compares five different types of geometrically zoomable interaction techniques, each at two speeds (fast and slow update rates) for the task of finding a known feature in the image. There were statistically significant performance differences between several groupings of the techniques. The fast versions of the ArrowKey, Pointer, and ScrollBar performed the best. In general, techniques that enable both intuitive and systematic searching performed the best at the fast speed, while techniques that minimize the number of interactions with the image were more effective at the slow speed. Additionally, based on a postexperiment questionnaire and qualitative comparison, users expressed a clear preference for the Pointer technique, which allowed them to more freely and naturally interact with the image.
العلم المفتوح وإضاءات على دور المكتبات الأكاديمية
Creators: name: Al-Zoubi, Raed
Publisher: name: Zenodo
Year: 2023
Subjects: Open Science
Webinar
DataCite Global Access Program
Academic Libraries
Persistent Identifiers
DOIs

description: Webinar title: Persistent Identifiers (PIDs) Adoptions: Introducing DataCite’s Global Access Program (GAP) to the Arab World اعتماد المعرفات الدائمة: تقديم برنامج الوصول العالمي الخاص بـداتا سيت إلى العالم العربي
 لا تزال الأبحاث المنتجة من العالم العربي (باللغتين العربية والإنجليزية) لا تحظى بالرؤية العالمية وقابلية الاكتشاف التي تستحقها. هنالك عدة أسباب لذلك منها علي سبيل المثال، عدم اعتماد واستخدام المعرفات الدائمة ضمن مسارات البحث المختلفة، وانخفاض الوعي باهمية المعرفات الدائمة وأنواعها المختلفة، والبيانات الوصفية غير المكتمله

 داتا سيت هي منظمة عالمية رائدة وغير هادفة للربح توفر المعرفات الدائمة لمختلف انواع مخرجات الأبحاث والموارد الأخرى. لقد اطلقنا برنامج الوصول العالمي لتحسين المساواة والوصول واعتماد البنية التحتية للمعرفات الدائمة ضمن المجتمعات الأكاديمية والبحثية في البلدان الاقل تمثيلا، بما في ذلك منطقة الشرق الأوسط وشمال إفريقيا في عرضه يتطرق رائد الزعبي الي شرح دور المكتبات الاكاديمية في دعم حركة العلوم المفتوحة Please note that the webinar recordings is available in Arabic only at https://www.youtube.com/watch?v=IpMYN-Xr9Vo&t=1382s
Strichartz estimates and moment bounds for the relativistic Vlasov-Maxwell system II. Continuation criteria in the 3D case
Creators: name: Luk, Jonathan
name: Strain, Robert M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We consider the $3$-dimensional relativistic Vlasov-Maxwell system with data without compact support in momentum space. We prove two continuation criteria for solutions to this system. First, we show that a regular solution can be continued if the integral of the electromagnetic field along any characteristic is assumed to be bounded. This can be viewed as a generalization of the classical result of Glassey-Strauss (1986) to data with non-compact momentum support. Second, we extend the methods in our companion paper (Part I) to show that a regular solution can be extended as long as $\|\pel_0^þ f \|_{L^q_xL^1_{\pel}}$ remains bounded for $þ>\frac 2q$, $2
description: 37 pages, submitted
Use of Computed Tomography Scans for Cochlear Implants
Creators: name: Brunsden, Barry S.
name: Holden, Timothy A.
name: Whiting, Bruce R.
name: Skinner, Margaret W.
name: Finley, Charles C.
Publisher: name: The University of North Carolina at Chapel Hill University Libraries
Year: 2008

description: While 3-dimensional (3D) imaging by computed tomography has long been desirable for research and treatment of cochlear-implant patients, technical challenges have limited its wide application. Recent developments in scanner hardware and image processing techniques now allow image quality improvements that make clinical applications feasible. Validation experiments were performed to characterize a new methodology and its imaging performance.
Digiefekti projekti koondfail (DigiEfekt project merged data)
Creators: name: Pedaste, Margus
name: Baucal, Aleksandar
name: Leijen, Äli
name: Uibu, Krista
name: Saks, Katrin
name: Raave, Doris Kristina
name: Kallas, Külli
name: Einpaul, Piret
name: Johanson, Marje
name: Silm, Gerli
name: Konstabel, Kenn
name: Rannastu-Avalos, Meeli
name: Opanasenko, Yaroslav
name: Puusepp, Marit
name: Kärbla, Triinu
name: Ilona, Võik
name: Palk, Kristi
name: Ausin, Tea
name: Siiman, Leo
Publisher: name: Tartu Ülikooli haridusteaduste instituut
Year: 2023
Subjects: DigiEfekt
Eesti
põhikool
intervjuud
vaatlused
logiandmed
testid
küsimustikud
hariduslikud erivajadused

description: DigiEfekti projekti (DIGIVARA5) koondandmekogu koosneb järgmistest osadest: a) koondandmefail (“digiefekt_merged_data”), mis sisaldab konstruktispetsiifilisi tunnuseid ja taustatunnuseid; b) DigiEfekti uuringu lõppraport (“digiefekt_project_final_report_est”); c) hariduslike erivajaduste raport (“edspecialneeds_report_est”); ja d) DigiEfekti projektis kasutatud õpilaste ja lapsevanemate taustaandmete küsimustikud (“background_instrument_est”). Koodiraamat on lisatud andmefaili teisele lehele (“Codebook”).
description: [ENG] The aggregated data set of the DigiEfekt project (DIGIVARA5) comprises the following parts: a) merged data set (“digiefekt_merged_data”), which contains construct-specific variables and background variables; b) the final report of the Digiefekt study (“digiefekt_project_final_report_est”); c) the special educational needs report (“edspecialneeds_report_est”); and d) students’ and parents’ background data questionnaires used in the Digiefekt project (“background_instrument_est”). The codebook is found on the second sheet of the data file (“Codebook”).
description: DigiEfekti projekti lõppraporti soovituslik viide eestikeelses allikas: Pedaste, M., Raave, D. K., & Baucal, A. (2023) Digitaalsete õppematerjalide kasutamise efekt õpilaste õpitulemustele. Tartu Ülikool. https://datadoi.ee/handle/33/552