Machine learning based on artificial neural networks has emerged as an efficient means to develop empirical models of complex systems. Cold atomic ensembles have become commonplace in laboratories ...around the world, however, many-body interactions give rise to complex dynamics that preclude precise analytic optimisation of the cooling and trapping process. Here, we implement a deep artificial neural network to optimise the magneto-optic cooling and trapping of neutral atomic ensembles. The solution identified by machine learning is radically different to the smoothly varying adiabatic solutions currently used. Despite this, the solutions outperform best known solutions producing higher optical densities.
The precise control of atom light interactions is vital to many quantum technologies. For instance, atomic systems can be used to slow and store light, acting as a quantum memory. Optical storage can ...be achieved via stopped light, where no optical energy continues to exist in the atomic system, or as stationary light, where some optical energy remains present during storage. Here, we demonstrate a form of self-stabilizing stationary light. From any initial state, our atomlight system evolves to a stable conguration that may contain bright optical excitations trapped within the atomic ensemble. This phenomenon is veried experimentally in a cloud of cold Rb87 atoms. The spinwave in our atomic cloud is imaged from the side, allowing direct comparison with theoretical predictions.
Context. Type Ia supernovae (SNe Ia) are widely used to measure the expansion of the Universe. To perform such measurements the luminosity and cosmological redshift (z) of the SNe Ia have to be ...determined. The uncertainty on z includes an unknown peculiar velocity, which can be very large for SNe Ia in the virialized cores of massive clusters. Aims. We determine which SNe Ia exploded in galaxy clusters using 145 SNe Ia from the Nearby Supernova Factory. We then study how the correction for peculiar velocities of host galaxies inside the clusters improves the Hubble residuals. Methods. We found 11 candidates for membership in clusters. We applied the biweight technique to estimate the redshift of a cluster. Then, we used the galaxy cluster redshift instead of the host galaxy redshift to construct the Hubble diagram. Results. For SNe Ia inside galaxy clusters, the dispersion around the Hubble diagram when peculiar velocities are taken into account is smaller compared with a case without peculiar velocity correction, which has a wRMS = 0.130 ± 0.038 mag instead of wRMS = 0.137 ± 0.036 mag. The significance of this improvement is 3.58σ. If we remove the very nearby Virgo cluster member SN2006X (z < 0.01) from the analysis, the significance decreases to 1.34σ. The peculiar velocity correction is found to be highest for the SNe Ia hosted by blue spiral galaxies. Those SNe Ia have high local specific star formation rates and smaller stellar masses, which is seemingly counter to what might be expected given the heavy concentration of old, massive elliptical galaxies in clusters. Conclusions. As expected, the Hubble residuals of SNe Ia associated with massive galaxy clusters improve when the cluster redshift is taken as the cosmological redshift of the supernova. This fact has to be taken into account in future cosmological analyses in order to achieve higher accuracy for cosmological redshift measurements. We provide an approach to do so.
This article documents the characteristics of the high voltage (HV) system of the hadronic calorimeter TileCal of the ATLAS experiment. Such a system is suitable to supply reliable power distribution ...into particles physics detectors using a large number of PhotoMultiplier Tubes (PMTs). Measurements performed during the 2015 and 2016 data taking periods of the ATLAS detector show that its performance, in terms of stability and noise, fits the specifications. In particular, almost all the PMTs show a voltage instability smaller than 0.5 V corresponding to a gain stability better than 0.5%. A small amount of channels was found not working correctly. To diagnose the origin of such defects, the results of the HV measurements were compared to those obtained using a Laser system. The analysis shows that less than 0.2% of the about 10 thousand HV channels were malfunctioning.
Recent reports have shown that oxygen delivery ( D˙o2) and oxygen uptake ( V˙o2) could be related to outcome of critically ill patients. In this study, we examined measurements of cardiac output, ...oxygen-derived variables, and blood lactate levels in 48 patients with documented septic shock. There were 27 survivors and 21 nonsurvivors from the shock episode. For all 174 observations, there was a significant linear relationship between V˙O2, and D˙O2, ( V˙o2 = 79 + 0.17 × D˙o2, r = 0.64, p<0.001). There were no significant differences in Do, between survivors and nonsurvivors at the onset of septic shock (mean ± SD, 540 ± 219 vs 484 ± 222 ml/min·m2, NS) or in the final phase of septic shock (506 ± 163 vs 443 ± 187 ml/min·m2, NS). Also, no significant differences were found in V˙o2, and oxygen extraction between survivors and nonsurvivors. However, survivors had significantly lower blood lactate levels both initially (5.1 ± 2.7 vs 8.2 ± 5.4 mmol/L, p<0.05) and in the final phase of septic shock (2.6 ± 1.9 vs 7.7 ± 5.6 mmol/L, p<0.001). Only the survivors had a significant decrease in blood lactate levels during the course of septic shock (p<0.001). We conclude that the oxygen-derived variables, D˙o2 and V˙o2, cannot be used as prognostic indicators in human septic shock. In contrast, blood lactate levels are closely related to ultimate survival from septic shock. Furthermore, decreases in blood lactate levels during the course of septic shock could indicate a favorable outcome. Therefore, blood lactate levels can serve as a reliable clinical guide to therapy.
A
bstract
Large classes of new physics theories predict the existence of new scalar states, commonly dubbed sgluons, lying in the adjoint representation of the QCD gauge group. Since these new fields ...are expected to decay into colored Standard Model particles, and in particular into one or two top quarks, these theories predict a possible enhancement of the hadroproduction rate associated with multitop final states. We therefore investigate multitop events produced at the Large Hadron Collider, running at a center-of-mass energy of 8 TeV, and employ those events to probe the possible existence of color adjoint scalar particles. We first construct a simplified effective field theory motivated by
R
-symmetric supersymmetric models where sgluon fields decay dominantly into top quarks. We then use this model to analyze the sensitivity of the Large Hadron Collider in both a multilepton plus jets and a single lepton plus jets channel. After having based our event selection strategy on the possible presence of two, three and four top quarks in the final state, we find that sgluon-induced new physics contributions to multitop cross sections as low as 10-100 fb can be excluded at the 95% confidence level, assuming an integrated luminosity of 20 fb
−1
. Equivalently, sgluon masses of about 500–700 GeV can be reached for several classes of benchmark scenarios.
There is scarce information on the time to return to work after general surgery. The aim of this study was to analyze time off work after elective cholecystectomy and to compare the results with ...those in patients undergoing other surgical interventions.
Observational and comparative study. Inclusion criteria were: being of working age and undergoing elective laparoscopic cholecystectomy (group 1) or unilateral inguinal hernia or haemorrhoidectomy (group 2).
36 patients were included: 18 patients in each group. Overall, return to work occurred at a mean of 35.7 days, with no significant differences (p=0.656) between groups (group 1: 36.6 days vs. group 2: 35.44 days). The reasons for not returning to work earlier were fear of complications (37.5%), pain control (37.5%), surgeon recommendation (12.5%), and general practitioner recommendation (12.5%).
Time to recovery after laparoscopic cholecystectomy is prolonged. No statistically significant differences with less complex surgical procedures were detected.
We present a measurement of the W boson mass using data corresponding to 4.3 fb(-1) of integrated luminosity collected with the D0 detector during Run II at the Fermilab Tevatron pp collider. With a ...sample of 1,677,394 W → eν candidate events, we measure M(W) = 80.367 ± 0.026 GeV. This result is combined with an earlier D0 result determined using an independent Run II data sample, corresponding to 1 fb(-1) of integrated luminosity, to yield M(W) = 80.375 ± 0.023 GeV.
A 3-day regimen of azithromycin (500 mg once daily) and a 10-day regimen of co-amoxiclav (625 mg three times daily) were compared in a double-blind study of 67 patients with acute infectious ...exacerbations of chronic bronchitis (AIECBs, n = 54), acute bronchitis (n = 7), or pneumonia (n = 6). In patients treated with azithromycin, satisfactory clinical responses (cure or improvement) were seen in 24/28 (86%) patients with AIECBs, 2/4 (50%) with acute bronchitis and 2/2 (100%) with pneumonia. Responses were satisfactory in 24/26 (92%), 4/4 (100%) and 4/4 (100%) patients, respectively, receiving co-amoxiclav. Streptococcus pneumoniae and Haemophilus influenzae were the commonest pathogens isolated at baseline. At the end of treatment, baseline pathogens were eradicated in 9/10 microbiologically-as-sessable patients treated with azithromycin and in 10/10 treated with co-amoxiclav. Adverse events related or possibly related to treatment occurred in five patients in each treatment group; the majority of these events affected the gastrointestinal system. One patient in each treatment group discontinued therapy because of adverse events. The study, therefore, demonstrates that 500 mg azithromycin administered once daily for 3 days is as efficacious and well tolerated as co-amoxiclav given three times daily for 10 days in the domiciliary treatment of adults with acute lower respiratory tract infections.
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