411 research outputs found
Comparison between the Use of LMA™ and SLIPA™ in Patients Undergoing Minor Surgeries.
Supraglottic airway devices have been used as safe alternatives to endotracheal intubation in appropriate types of surgery. This was a prospective, randomised, single blind study comparing the use of LMA™ and SLIPA™ in terms of ease of insertion, haemodynamic changes and occurrence of adverse effects (e.g. blood stains on the device upon removal and sore throat). A total of 62 ASA I or II patients, aged between 18 to 70 years were recruited for this study. Patients were randomised into two groups; LMA™ and SLIPA™ group. Following induction of anaesthesia, an appropriate sized LMA™ or SLIPA™ was inserted after ensuring adequate depth of anaesthesia. Anaesthesia was maintained with oxygen, nitrous oxide and sevoflurane. The ease of insertion was graded and haemodynamic changes were recorded at 2 minute intervals up to 10 minutes after insertion of the airway devices. The presence of blood stains upon airway device removal at the end of surgery and incidence of sore throat was also recorded. No difficult insertion was experienced in either of these devices. Insertion was either easy [LMA™ 87.1% versus SLIPA™ 80.6% (p = 0.49)] or moderate [LMA™ 12.9% versus SLIPA™ 19.4% (p = 0.16)]. Throughout the study period, the haemodynamic changes that occurred in both groups were not statistically different. Traces of blood were noted on the surface of the device in 9.7% of patients in the SLIPA™ group versus 6.5% of patients in the LMA™ group. The incidence of sore throat was recorded in 12.9% versus 19.4% of patients in the SLIPA™ and the LMA™ groups respectively. These findings were not statistically significant. In conclusion, this study showed no significant differences between the use of LMA™ and SLIPA™ in terms of ease of insertion, haemodynamic changes and adverse effects in patients undergoing minor surgical procedures
Scaling in the correlation energies of two-dimensional artificial atoms
We find an unexpected scaling in the correlation energy of artificial atoms,
i.e., harmonically confined two-dimensional quantum dots. The scaling relation
is found through extensive numerical examinations including Hartree-Fock,
variational quantum Monte Carlo, density-functional, and full
configuration-interaction calculations. We show that the correlation energy,
i.e., the true ground-state total energy subtracted by the Hartree-Fock total
energy, follows a simple function of the Coulomb energy, confimenent strength
and, the number of electrons. We find an analytic expression for this function,
as well as for the correlation energy per particle and for the ratio between
the correlation and total energies. Our tests for independent diffusion Monte
Carlo and coupled-cluster results for quantum dots -- including open-shell data
-- confirm the generality of the obtained scaling. As the scaling is also well
applicable to 100 electrons, our results give interesting prospects
for the development of correlation functionals within density-functional
theory.Comment: Accepted to Journal of Physics: Condensed Matte
Advanced InSAR atmospheric correction: MERIS/MODIS combination and stacked water vapour models
A major source of error for repeat-pass Interferometric Synthetic Aperture Radar (InSAR) is the phase delay in radio signal propagation through the atmosphere (especially the part due to tropospheric water vapour). Based on experience with the Global Positioning System (GPS)/Moderate Resolution Imaging Spectroradiometer (MODIS) integrated model and the Medium Resolution Imaging Spectrometer (MERIS) correction model, two new advanced InSAR water vapour correction models are demonstrated using both MERIS and MODIS data: (1) the MERIS/MODIS combination correction model (MMCC); and (2) the MERIS/MODIS stacked correction model (MMSC). The applications of both the MMCC and MMSC models to ENVISAT Advanced Synthetic Aperture Radar (ASAR) data over the Southern California Integrated GPS Network (SCIGN) region showed a significant reduction in water vapour effects on ASAR interferograms, with the root mean square (RMS) differences between GPS- and InSAR-derived range changes in the line-of-sight (LOS) direction
decreasing from ,10mm before correction to ,5mm after correction, which is similar to the GPS/MODIS integrated and MERIS correction models. It is expected that these two advanced water vapour correction models can expand the application of MERIS and MODIS data for InSAR atmospheric correction. A simple but effective approach has been developed to destripe Terra MODIS images contaminated by radiometric calibration errors. Another two limiting factors on the MMCC and MMSC models have also been investigated in this paper: (1) the impact of the time difference between MODIS and SAR data; and (2) the frequency of cloud-free conditions at the global scale
Modified Hatch Score Predicts 6-Month Recurrence of Atrial Fibrillation after Pulmonary Vein Isolation: Data from the University Of Massachusetts Atrial Fibrillation Registry
AIMS: Pre-procedural identification of patients with atrial fibrillation (AF) who will benefit most from pulmonary vein isolation remains challenging. The HATCH score [Hypertension x1 + Age≥75 x1 + Thrombo-embolic event x2, COPD x1, Heart failure x2] has been associated with progression of AF and recently with adverse outcomes after catheter ablation. However, data regarding the HATCH score are limited. This study aimed to evaluate the performance of a modified HATCH scoring system, including pre-procedural obstructive sleep apnea as an additional risk element, compared to the CHADS risk score as a predictor of AF recurrence after an index pulmonary vein isolation procedure for AF.
METHODS AND RESULTS: Seventy eight patients (48 men, mean age 60 ± 1.1 years) with paroxysmal or persistent AF underwent an index pulmonary vein isolation procedure between 2010 and 2014 using either radiofrequency (n=64) or cryoballoon (n = 14). Over a 6-month follow-up period, 35 patients had recurrence (44.9%) when monitored using Holter monitoring and in-office ECGs. The modified HATCH score was associated on univariate testing with AF recurrence. In multivariate logistic regression analyses including factors known to be associated with AF recurrence, the modified HATCH score (p: 0.03) was independently associated with AF recurrence and showed superior test characteristics using ROC curve analysis (C statistic = 0.64 for modified HATCH vs. 0.55 for CHADS2). The difference between the modified HATCH and the CHADS2 scores in predicting recurrence was not statistically significant (p = 0.8).
CONCLUSIONS: AF recurred in 44% of patients over a 6-month follow-up. A modified HATCH including OSA successfully identified individuals at risk for 6-month recurrence. Further research is needed including larger cohorts of patients undergoing ablation and followed for more extended periods to further validate the performance of the modified HATCH score
Dynamo Processes in the T Tauri star V410 Tau
We present new brightness and magnetic images of the weak-line T Tauri star
V410 Tau, made using data from the NARVAL spectropolarimeter at Telescope
Bernard Lyot (TBL). The brightness image shows a large polar spot and
significant spot coverage at lower latitudes. The magnetic maps show a field
that is predominantly dipolar and non-axisymmetric with a strong azimuthal
component. The field is 50% poloidal and 50% toroidal, and there is very little
differential rotation apparent from the magnetic images.
A photometric monitoring campaign on this star has previously revealed V-band
variability of up to 0.6 magnitudes but in 2009 the lightcurve is much flatter.
The Doppler image presented here is consistent with this low variability.
Calculating the flux predicted by the mapped spot distribution gives an
peak-to-peak variability of 0.04 magnitudes. The reduction in the amplitude of
the lightcurve, compared with previous observations, appears to be related to a
change in the distribution of the spots, rather than the number or area.
This paper is the first from a Zeeman-Doppler imaging campaign being carried
out on V410 Tau between 2009-2012 at TBL. During this time it is expected that
the lightcurve will return to a high amplitude state, allowing us to ascertain
whether the photometric changes are accompanied by a change in the magnetic
field topology.Comment: 12 pages, 11 figures, accepted by MNRA
Discovery of unusual pulsations in the cool, evolved Am stars HD 98851 and HD 102480
The chemically peculiar (CP) stars HD 98851 and HD 102480 have been
discovered to be unusual pulsators during the ``Naini Tal Cape Survey''
programme to search for pulsational variability in CP stars. Time series
photometric and spectroscopic observations of these newly discovered stars are
reported here. Fourier analyses of the time series photometry reveal that HD
98851 is pulsating mainly with frequencies 0.208 mHz and 0.103 mHz, and HD
102480 is pulsating with frequencies 0.107 mHz, 0.156 mHz and 0.198 mHz. The
frequency identifications are all subject to 1 d cycle count
ambiguities. We have matched the observed low resolution spectra of HD 98851
and HD 102480 in the range 3500-7400 \AA with theoretical synthetic spectra
using Kurucz models with solar metallicity and a micro-turbulent velocity 2 km
s. These yield K, log for HD 98851
and K, log for HD 102480. We
determined the equivalent H-line spectral class of these stars to be F1 IV and
F3 III/IV, respectively. A comparison of the location of HD 98851 and HD 102480
in the HR diagram with theoretical stellar evolutionary tracks indicates that
both stars are about 1-Gyr-old, 2- stars that lie towards the red
edge of the Sct instability strip. We conclude that HD 98851 and HD
102480 are cool, evolved Am pulsators. The light curves of these pulsating
stars have alternating high and low amplitudes, nearly harmonic (or
sub-harmonic) period ratios, high pulsational overtones and Am spectral types.
This is unusual for both Am and Sct pulsators, making these stars
interesting objects.Comment: 9 pages, 6 Figures, Accepted for publication in MNRA
Chronic Treatment with Mood-Stabilizers Attenuates Abnormal Hyperlocomotion of GluA1-Subunit Deficient Mice
Peer reviewe
Disentangling the Taxonomy of the Mahseers (Tor spp.) of Malaysia: An Integrated Approach Using Morphology, Genetics and Historical Records
The establishment of appropriate taxonomic designations is essential for the effective management of fishery resources. Despite over a century of explorations and research, the cyprinid genus Tor represents a group of large-bodied freshwater fishes whose taxonomy and systematics remains poorly known. While five species of Tor are currently listed as “endangered” on the IUCN Red List, a further five out of 18 species currently recognized are assessed as “data deficient,” with at least one undescribed species, believed to be on the brink of extinction (i.e., the Humpback Mahseer endemic to the Cauvery River in India). Tor mahseers represent a suitable model for the application of an integrated approach using morphology, genetics, and historical records to resolve species identities, where one or more of these fundamental approaches may have been deficient in the past. Focusing specifically on the taxonomy and nomenclature of the Tor species recorded from Peninsular Malaysia, one of the aims of this review is to define the identity of two nominal species, T. tambra and T. tambroides. Original descriptions of these two nominal species contain little or practically no characters to distinguish them, and partly explains why secondary literature fails to conclusively determine species boundaries. A phylogenetic analysis of mahseer specimens from this region, based on publicly available and newly sequenced mitochondrial COX1 genes, does not support species designation based on previously established morphological features. More importantly, multiple tree-based species delimitation approaches showed that previously sequenced T. tambroides from Peninsular Malaysia and the newly described Tor species from Vietnam could not be delimited from the topotypic Tor tambra. A wider investigation of mahseer taxonomy covering all of Southeast Asia, using such an integrated approach is recommended to resolve the ambiguous taxonomy and is of profound importance for the conservation and management of exploited and farmed populations of these highly valued and iconic fish
Performance over Random
This paper proposes a new evaluation approach for video summarization algorithms. We start by studying the currently established evaluation protocol; this protocol, defined over the ground-truth annotations of the SumMe and TVSum datasets, quantifies the agreement between the user-defined and the automatically-created summaries with F-Score, and reports the average performance on a few different training/testing splits of the used dataset. We evaluate five publicly-available summarization algorithms under a large-scale experimental setting with 50 randomly-created data splits. We show that the results reported in the papers are not always congruent with their performance on the large-scale experiment, and that the F-Score cannot be used for comparing algorithms evaluated on different splits. We also show that the above shortcomings of the established evaluation protocol are due to the significantly varying levels of difficulty among the utilized splits, that affect the outcomes of the evaluations. Further analysis of these findings indicates a noticeable performance correlation among all algorithms and a random summarizer. To mitigate these shortcomings we propose an evaluation protocol that makes estimates about the difficulty of each used data split and utilizes this information during the evaluation process. Experiments involving different evaluation settings demonstrate the increased representativeness of performance results when using the proposed evaluation approach, and the increased reliability of comparisons when the examined methods have been evaluated on different data splits
Dual-Band Metamaterial Microwave Absorber using Ring and Circular Patch with Slits
This paper proposes a dual-band metamaterial microwave absorber operating at 2.5 GHz and 5.8 GHz. The absorber consists of a ring and a circular patch with slits resonator structures printed on a FR4 dielectric substrate backed by a ground layer. The main advantage of the absorber lies in its design flexibility in which each absorption band is independent and can be individually tuned by changing the dimensions of each resonator structure. The absorber unit cell is simulated and parametrically optimized using Computer Simulation Technology (CST) software. The absorption mechanism is analyzed through surface current analysis. The absorber prototype, with dimensions of 200 × 200 × 1.6 mm3 and consisting of an array of 7 × 7 unit cells, is fabricated and experimentally investigated using antennas in free-space measurement. The absorber exhibits over 97% absorption at both resonance frequencies. Furthermore, the absorber is demonstrated to be applicable in sensing applications for dielectric constant determination. With its design simplicity, wide-angle receptive, and polarization insensitive behavior, it is envisaged that the proposed absorber will find practical use in absorbing and sensing applications
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