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Quantum spin Hall effect in bound states in continuum
Moving the polarization of the incident wave along a meridian of the Poincaré sphere, experimentally we show that the coupling with the fundamental Bloch's surface waves of the mode, provide a spatially coherent, macroscopic spinmomentum locked propagation along the symmetry axes of the PhCM. This novel mechanism of light-spin manipulation enables a versatile implementation of spin-optical structures that may pave the way to novel strategies for light spin technology and photonic multiplatform implementations
An Interactive Tool to Explore and Improve the Ply Number of Drawings
Given a straight-line drawing of a graph , for every vertex
the ply disk is defined as a disk centered at where the radius of
the disk is half the length of the longest edge incident to . The ply number
of a given drawing is defined as the maximum number of overlapping disks at
some point in . Here we present a tool to explore and evaluate
the ply number for graphs with instant visual feedback for the user. We
evaluate our methods in comparison to an existing ply computation by De Luca et
al. [WALCOM'17]. We are able to reduce the computation time from seconds to
milliseconds for given drawings and thereby contribute to further research on
the ply topic by providing an efficient tool to examine graphs extensively by
user interaction as well as some automatic features to reduce the ply number.Comment: Appears in the Proceedings of the 25th International Symposium on
Graph Drawing and Network Visualization (GD 2017
Assessment of poststress left ventricular ejection fraction by gated SPECT: comparison with equilibrium radionuclide angiocardiography
PURPOSE: We compared left ventricular (LV) ejection fraction obtained by gated SPECT with that obtained by equilibrium radionuclide angiocardiography in a large cohort of patients.
METHODS: Within 1 week, 514 subjects with suspected or known coronary artery disease underwent same-day stress-rest (99m)Tc-sestamibi gated SPECT and radionuclide angiocardiography. For both studies, data were acquired 30 min after completion of exercise and after 3 h rest.
RESULTS: In the overall study population, a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.82, p<0.0001) and after stress (r=0.83, p<0.0001). In Bland-Altman analysis, the mean differences in ejection fraction (radionuclide angiocardiography minus gated SPECT) were -0.6% at rest and 1.7% after stress. In subjects with normal perfusion (n=362), a good correlation between ejection fraction measured by gated SPECT and by radionuclide angiocardiography was observed at rest (r=0.72, p<0.0001) and after stress (r=0.70, p<0.0001) and the mean differences in ejection fraction were -0.9% at rest and 1.4% after stress. Also in patients with abnormal perfusion (n=152), a good correlation between the two techniques was observed both at rest (r=0.89, p<0.0001) and after stress (r=0.90, p<0.0001) and the mean differences in ejection fraction were 0.1% at rest and 2.5% after stress.
CONCLUSION: In a large study population, a good agreement was observed in the evaluation of LV ejection fraction between gated SPECT and radionuclide angiocardiography. However, in patients with perfusion abnormalities, a slight underestimation in poststress LV ejection fraction was observed using gated SPECT as compared to equilibrium radionuclide angiocardiography
Long Term Study of the Double Pulsar J0737-3039 with XMM-Newton: pulsar timing
The relativistic double neutron star binary PSR J0737-3039 shows clear
evidence of orbital phase-dependent wind-companion interaction, both in radio
and X-rays. In this paper we present the results of timing analysis of PSR
J0737-3039 performed during 2006 and 2011 XMM-Newton Large Programs that
collected ~20,000 X-ray counts from the system. We detected pulsations from PSR
J0737-3039A (PSR A) through the most accurate timing measurement obtained by
XMM-Newton so far, the spin period error being of 2x10^-13 s. PSR A's pulse
profile in X-rays is very stable despite significant relativistic spin
precession that occurred within the time span of observations. This yields a
constraint on the misalignment between the spin axis and the orbital momentum
axis Delta_A ~6.6^{+1.3}_{-5.4} deg, consistent with estimates based on radio
data. We confirmed pulsed emission from PSR J0737-3039B (PSR B) in X-rays even
after its disappearance in radio. The unusual phenomenology of PSR B's X-ray
emission includes orbital pulsed flux and profile variations as well as a loss
of pulsar phase coherence on time scales of years. We hypothesize that this is
due to the interaction of PSR A's wind with PSR B's magnetosphere and
orbital-dependent penetration of the wind plasma onto PSR B closed field lines.
Finally, the analysis of the full XMM-Newton dataset provided evidences of
orbital flux variability (~7%) for the first time, involving a bow-shock
scenario between PSR A's wind and PSR B's magnetosphere.Comment: Comments: 16 Pages, 6 Figures. Accepted for publication in
Astrophysical Journal (Draft Version
Deep infrared observations of the puzzling central X-ray source in RCW103
1E 161348-5055 (1E 1613) is a point-like, soft X-ray source originally
identified as a radio-quiet, isolated neutron star, shining at the center of
the 2000 yr old supernova remnant RCW103. 1E 1613 features a puzzling 6.67 hour
periodicity as well as a dramatic variability over a time scale of few years.
Such a temporal behavior, coupled to the young age and to the lack of an
obvious optical counterpart, makes 1E 1613 a unique source among all compact
objects associated to SNRs. It could either be the first low-mass X-ray binary
system discovered inside a SNR, or a peculiar isolated magnetar with an
extremely slow spin period. Analysis of archival IR observations, performed in
2001 with the VLT/ISAAC instrument, and in 2002 with the NICMOS camera onboard
HST unveils a very crowded field. A few sources are positionally consistent
with the refined X-ray error region that we derived from the analysis of 13
Chandra observations. To shed light on the nature of 1E 1613, we have performed
deep IR observations of the field with the NACO instrument at the ESO/VLT,
searching for variability. We find no compelling reasons to associate any of
the candidates to 1E 1613. On one side, within the frame of the binary system
model for the X-ray source, it is very unlikely that one of the candidates be a
low-mass companion star to 1E 1613. On the other side, if the X-ray source is
an isolated magnetar surrounded by a fallback disc, we cannot exclude that the
IR counterpart be hidden among the candidates. If none of the potential
counterparts is linked to the X-ray source, 1E 1613 would remain undetected in
the IR down to Ks>22.1. Such an upper limit is consistent only with an
extremely low-mass star (an M6-M8 dwarf) at the position of 1E 1613, and makes
rather problematic the interpretation of 1E 1613 as an accreting binary system.Comment: 26 pages, 5 figures. Accepted for publication in Ap
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