We propose a novel method for automatic alignment of fetal brain magnetic resonance image volumes and 3D ultrasound images. Volumetric fetal brain MRI is obtained from reconstructing 2D slices, and ...is then segmented using a preterm neonatal probabilistic atlas. The segmentation is further refined to extract features that are prominent in fetal brain ultrasound. From the MR segmentation, a pseudo-ultrasound image is simulated, taking into account the direction of the beam in the real ultrasound volume. The simulated and real ultrasound images are then affinely aligned using normalized cross-correlation. We show that the proposed approach performs better than the standard approach for multi-modal registration of the MR and ultrasound volumes driven by normalized mutual information.
We present near-infrared spectroscopic observations of 19 molecular clouds made using the AKARI satellite, and the data reduction pipeline written to analyze those observations. The 2.5-5 μm spectra ...of 30 objects—22 field stars behind quiescent molecular clouds and 8 low-mass young stellar objects in cores—were successfully extracted using the pipeline. Those spectra are further analyzed to calculate the column densities of key solid phase molecular species, including H{sub 2}O, CO{sub 2}, CO, and OCN{sup –}. The profile of the H{sub 2}O ice band is seen to vary across the objects observed and we suggest that the extended red wing may be an evolutionary indicator of both dust and ice mantle properties. The observation of 22 spectra with fluxes as low as < 5 mJy toward background stars, including 15 where the column densities of H{sub 2}O, CO, and CO{sub 2} were calculated, provides valuable data that could help to benchmark the initial conditions in star-forming regions prior to the onset of star formation.
We present near-infrared spectroscopic observations of 19 molecular clouds made using the AKARI satellite, and the data reduction pipeline written to analyze those observations. The 2.5-5 mum spectra ...of 30 objects-22 field stars behind quiescent molecular clouds and 8 low-mass young stellar objects in cores-were successfully extracted using the pipeline. Those spectra are further analyzed to calculate the column densities of key solid phase molecular species, including H sub(2)O, CO sub(2), CO, and OCN-. The profile of the H sub(2)O ice band is seen to vary across the objects observed and we suggest that the extended red wing may be an evolutionary indicator of both dust and ice mantle properties. The observation of 22 spectra with fluxes as low as < 5 mJy toward background stars, including 15 where the column densities of H sub(2)O, CO, and CO sub(2) were calculated, provides valuable data that could help to benchmark the initial conditions in star-forming regions prior to the onset of star formation.
Motion of the diaphragm during respiration causes a displacement of the heart relative to the position of a transthoracic ultrasound (US) probe. These respiration-induced shifts of cardiac position ...can lead to spatial misalignments of data when reconstructed in 3-D. We show how to compensate for this motion using a technique that extends the tracking of the probe to additionally monitor a marker placed on the patient umbilicus. The motion of the umbilicus is calibrated to that of the diaphragm using one additional scan. This calibration is used to correct the 3-D spatial positions of cardiac images acquired from multiple acoustic views. At both systole and diastole, segmentations of the endocardial border visually appear more consistent after our correction than with no correction. Long and short axis segmentations should intersect on the endocardium. After correction, their separation at the closest point is shown to be reduced. (E-mail: David.Atkinson@kcl.ac.uk)
Amorphous solid water (ASW) is one of the most widely studied solid phase systems. A better understanding of the nature of inter- and intramolecular forces in ASW is, however, still required to ...correctly interpret the catalytic role of ASW in the formation and preservation of molecular species in environments such as the icy surfaces of Solar System objects, on interstellar icy dust grains and potentially even in the upper layers of the Earth's atmosphere. In this work, we have systematically exposed porous ASW (pASW) to mid-infrared radiation generated by a free-electron laser at the HFML-FELIX facility in the Netherlands to study the effect of vibrational energy injection into the surface and bulk modes of pASW. During multiple sequential irradiations on the same ice spot, we observed selective effects both at the surface and in the bulk of the ice. Although the density of states in pASW should allow for a fast vibrational relaxation through the H-bonded network, part of the injected energy is converted into structural ice changes as illustrated by the observation of spectral modifications when performing Fourier transform infrared spectroscopy in reflection-absorption mode. Future studies will include the quantification of such effects by systematically investigating ice thickness, ice morphology, and ice composition.
We present cosmological constraints from the abundance of galaxy clusters selected via the thermal Sunyaev-Zel'dovich (SZ) effect in South Pole Telescope (SPT) data with a simultaneous mass ...calibration using weak gravitational lensing data from the Dark Energy Survey (DES) and the Hubble Space Telescope (HST). The cluster sample is constructed from the combined SPT-SZ, SPTpol ECS, and SPTpol 500d surveys, and comprises 1,005 confirmed clusters in the redshift range \(0.25-1.78\) over a total sky area of 5,200 deg\(^2\). We use DES Year 3 weak-lensing data for 688 clusters with redshifts \(z<0.95\) and HST weak-lensing data for 39 clusters with \(0.6<z<1.7\). The weak-lensing measurements enable robust mass measurements of sample clusters and allow us to empirically constrain the SZ observable--mass relation. For a flat \(\Lambda\)CDM cosmology, and marginalizing over the sum of massive neutrinos, we measure \(\Omega_\mathrm{m}=0.286\pm0.032\), \(\sigma_8=0.817\pm0.026\), and the parameter combination \(\sigma_8\,(\Omega_\mathrm{m}/0.3)^{0.25}=0.805\pm0.016\). Our measurement of \(S_8\equiv\sigma_8\,\sqrt{\Omega_\mathrm{m}/0.3}=0.795\pm0.029\) and the constraint from Planck CMB anisotropies (2018 TT,TE,EE+lowE) differ by \(1.1\sigma\). In combination with that Planck dataset, we place a 95% upper limit on the sum of neutrino masses \(\sum m_\nu<0.18\) eV. When additionally allowing the dark energy equation of state parameter \(w\) to vary, we obtain \(w=-1.45\pm0.31\) from our cluster-based analysis. In combination with Planck data, we measure \(w=-1.34^{+0.22}_{-0.15}\), or a \(2.2\sigma\) difference with a cosmological constant. We use the cluster abundance to measure \(\sigma_8\) in five redshift bins between 0.25 and 1.8, and we find the results to be consistent with structure growth as predicted by the \(\Lambda\)CDM model fit to Planck primary CMB data.
We have studied the intubating conditions in 60 ASA I or II patients, after induction of anaesthesia with propofol 2 mg kg-1, allocated to one of the following three groups: group 1, remifentanil 1 ...microgram kg-1; group 2, remifentanil 1 microgram kg-1 and lignocaine 1 mg kg-1; group 3, remifentanil 2 micrograms kg-1. No neuromuscular blocking agents were administered. Intubating conditions were assessed using a four-point scoring system based on ease of laryngoscopy, jaw relaxation, position of vocal cords, degree of coughing and limb movement. Overall intubating conditions were acceptable in 35% of patients in group 1, 100% of patients in group 2 and 85% of patients in group 3. There was a statistically significant drop in blood pressure after induction in groups 2 and 3, and two patients in each group required ephedrine 6 mg i.v. boluses, as dictated by the intervention criteria (mean arterial pressure fall > 25% from baseline). Similarly, there was a drop in heart rate in groups 2 and 3, but this did not reach statistical or clinical significance, and no patient required atropine.
New results are reported from the operation of the PICO-60 dark matter detector, a bubble chamber filled with 52 kg of C3F8 located in the SNOLAB underground laboratory. As in previous PICO bubble ...chambers, PICO-60C3F8 exhibits excellent electron recoil and alpha decay rejection, and the observed multiple-scattering neutron rate indicates a single-scatter neutron background of less than one event per month.
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