434 research outputs found
Type II shell evolution in A = 70 isobars from the N ≥ 40 island of inversion
The level structures of 70 Co and 70 Ni, populated from the β decay of 70 Fe, have been investigated using β -delayed γ -ray spectroscopy following in-flight fission of a 238 U beam. The experimental results are compared to Monte-Carlo Shell-Model calculations including the pf+g9/2+d5/2 orbitals. The strong population of a (1+) state at 274 keV in 70 Co is at variance with the expected excitation energy of ∼1 MeV from near spherical single-particle estimates. This observation indicates a dominance of prolate-deformed intruder configurations in the low-lying levels, which coexist with the normal near spherical states. It is shown that the β decay of the neutron-rich A=70 isobars from the new island of inversion to the Z=28 closed-shell regime progresses in accordance with a newly reported type of shell evolution, the so-called Type II, which involves many particle-hole excitations across energy gaps. ElsevierPeer reviewe
Bladder injury during infected tola hip arthroplasty prosthesis removal: Report of a case and review of the literature
The bladder is the most frequently injured organ during pelvic surgery. However, during hip surgery, this complication is extremely rare. We report a case of bladder injury during total hip arthroplasty prosthesis removal surgery. A 65-year-old male was admitted to our hospital with left hip pain and wound infection. On plain radiograms, acetabular protrusion was identified. We decided to remove protruzed acetabular cup and place spacer. During the operation, unexpectedly bladder injury occurred. The rupture was sutured intraoperatively. We left a catheter in the bladder after internal urethrotomy to drain the urine.Keywords: Arthroplasty, Bladder injury, Cystogram, Hip prosthesis removal, Infectio
Temporal Uncertainty Localization to Enable Human-in-the-loop Analysis of Dynamic Contrast-enhanced Cardiac MRI Datasets
Dynamic contrast-enhanced (DCE) cardiac magnetic resonance imaging (CMRI) is
a widely used modality for diagnosing myocardial blood flow (perfusion)
abnormalities. During a typical free-breathing DCE-CMRI scan, close to 300
time-resolved images of myocardial perfusion are acquired at various contrast
"wash in/out" phases. Manual segmentation of myocardial contours in each
time-frame of a DCE image series can be tedious and time-consuming,
particularly when non-rigid motion correction has failed or is unavailable.
While deep neural networks (DNNs) have shown promise for analyzing DCE-CMRI
datasets, a "dynamic quality control" (dQC) technique for reliably detecting
failed segmentations is lacking. Here we propose a new space-time uncertainty
metric as a dQC tool for DNN-based segmentation of free-breathing DCE-CMRI
datasets by validating the proposed metric on an external dataset and
establishing a human-in-the-loop framework to improve the segmentation results.
In the proposed approach, we referred the top 10% most uncertain segmentations
as detected by our dQC tool to the human expert for refinement. This approach
resulted in a significant increase in the Dice score (p<0.001) and a notable
decrease in the number of images with failed segmentation (16.2% to 11.3%)
whereas the alternative approach of randomly selecting the same number of
segmentations for human referral did not achieve any significant improvement.
Our results suggest that the proposed dQC framework has the potential to
accurately identify poor-quality segmentations and may enable efficient
DNN-based analysis of DCE-CMRI in a human-in-the-loop pipeline for clinical
interpretation and reporting of dynamic CMRI datasets.Comment: Accepted for publication in MICCAI 202
Interruption of torus doubling bifurcation and genesis of strange nonchaotic attractors in a quasiperiodically forced map : Mechanisms and their characterizations
A simple quasiperiodically forced one-dimensional cubic map is shown to
exhibit very many types of routes to chaos via strange nonchaotic attractors
(SNAs) with reference to a two-parameter space. The routes include
transitions to chaos via SNAs from both one frequency torus and period doubled
torus. In the former case, we identify the fractalization and type I
intermittency routes. In the latter case, we point out that atleast four
distinct routes through which the truncation of torus doubling bifurcation and
the birth of SNAs take place in this model. In particular, the formation of
SNAs through Heagy-Hammel, fractalization and type--III intermittent mechanisms
are described. In addition, it has been found that in this system there are
some regions in the parameter space where a novel dynamics involving a sudden
expansion of the attractor which tames the growth of period-doubling
bifurcation takes place, giving birth to SNA. The SNAs created through
different mechanisms are characterized by the behaviour of the Lyapunov
exponents and their variance, by the estimation of phase sensitivity exponent
as well as through the distribution of finite-time Lyapunov exponents.Comment: 27 pages, RevTeX 4, 16 EPS figures. Phys. Rev. E (2001) to appea
Transit timing variation analysis of the low-mass brown dwarf KELT-1 b
We investigate whether there is a variation in the orbital period of the short-period brown dwarf-mass KELT-1 b, which is one of the best candidates to observe orbital decay. We obtain 19 high-precision transit light curves of the target using six different telescopes. We add all precise and complete transit light curves from open databases and the literature, as well as the available Transiting Exoplanet Survey Satellite (TESS) observations from sectors 17 and 57, to form a transit timing variation (TTV) diagram spanning more than 10 yr of observations. The analysis of the TTV diagram, however, is inconclusive in terms of a secular or periodic variation, hinting that the system might have synchronized. We update the transit ephemeris and determine an informative lower limit for the reduced tidal quality parameter of its host star of Q ′⋆>(8.5±3.9)×106
assuming that the stellar rotation is not yet synchronized. Using our new photometric observations, published light curves, the TESS data, archival radial velocities, and broadband magnitudes, we also update the measured parameters of the system. Our results are in good agreement with those found in previous analyses
In-beam γ-ray spectroscopy of 136Te at relativistic energies
The reduced transition probability B(E2; 0+ 1 →2+ 1 ) to the first excited 2+ state of the neutron-rich nucleus 136Te, with two protons and two neutrons outside the doubly magic 132Sn core, was measured via Coulomb excitation at relativistic energies at the RIKEN Radioactive Isotope Beam Factory. A value of B(E2)= 0.191(26) e2b2 was extracted from the measured inelastic scattering cross section on an Au target taking into account the contributions from both Coulomb and nuclear excitations. In addition, an upper limit for the transition strength to a 2+ state of mixed-symmetry character in the excitation energy range of 1.5–2.2 MeV was determined and compared to the predictions of various theoretical calculations. Because of the high statistics gathered in the present experiment the error of the deduced B(E2) value is dominated by the systematic uncertainties involved in the analysis of Coulomb excitation experiments at beam energies around 150 MeV/u. Therefore, the latter are for the first time assessed in detail in the present work.Spanish Ministerio de Economía y Competitividad (FPA2014-57196-C5-4-P, FPA2017-84756-C4-2-P, FIS2014-53448-C2-1-P
Generalized Phase Synchronization in unidirectionally coupled chaotic oscillators
We investigate phase synchronization between two identical or detuned
response oscillators coupled to a slightly different drive oscillator. Our
result is that phase synchronization can occur between response oscillators
when they are driven by correlated (but not identical) inputs from the drive
oscillator. We call this phenomenon Generalized Phase Synchronization (GPS) and
clarify its characteristics using Lyapunov exponents and phase difference
plots.Comment: 4 pages, 5 figure
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