2 research outputs found
Recommended from our members
Dark Energy Survey Year 3 results: cosmological constraints from galaxy clustering and galaxy-galaxy lensing using the MagLim lens sample
The cosmological information extracted from photometric surveys is most robust when multiple probes of the large scale structure of the Universe are used. Two of the most sensitive probes are the clustering of galaxies and the tangential shear of background galaxy shapes produced by those foreground galaxies, so-called galaxy-galaxy lensing. Combining the measurements of these two two-point functions leads to cosmological constraints that are independent of the way galaxies trace matter (the galaxy bias factor). The optimal choice of foreground, or lens, galaxies is governed by the joint, but conflicting requirements to obtain accurate redshift information and large statistics. We present cosmological results from the full 5000 deg2 of the Dark Energy Survey's first three years of observations (Y3) combining those two-point functions, using for the first time a magnitude-limited lens sample (MagLim) of 11 million galaxies, especially selected to optimize such combination, and 100 million background shapes. We consider two flat cosmological models, the Standard Model with dark energy and cold dark matter (ΛCDM) a variation with a free parameter for the dark energy equation of state (wCDM). Both models are marginalized over 25 astrophysical and systematic nuisance parameters. In ΛCDM we obtain for the matter density ωm=0.320-0.034+0.041 and for the clustering amplitude S8σ8(ωm/0.3)0.5=0.778-0.031+0.037, at 68% C.L. The latter is only 1σ smaller than the prediction in this model informed by measurements of the cosmic microwave background by the Planck satellite. In wCDM we find ωm=0.32-0.046+0.044, S8=0.777-0.051+0.049 and dark energy equation of state w=-1.031-0.379+0.218. We find that including smaller scales, while marginalizing over nonlinear galaxy bias, improves the constraining power in the ωm-S8 plane by 31% and in the ωm-w plane by 41% while yielding consistent cosmological parameters from those in the linear bias case. These results are combined with those from cosmic shear in a companion paper to present full DES-Y3 constraints from the three two-point functions (3×2pt)
Preferred learning modalities and practice for critical skills: a global survey of paediatric emergency medicine clinicians
Objective To describe senior paediatric emergency clinician perspectives on the optimal frequency of and preferred modalities for practising critical paediatric procedures.
Methods Multicentre multicountry cross-sectional survey of senior paediatric emergency clinicians working in 96 EDs affiliated with the Pediatric Emergency Research Network.
Results 1332/2446 (54%) clinicians provided information on suggested frequency of practice and preferred learning modalities for 18 critical procedures. Yearly practice was recommended for six procedures (bag valve mask ventilation, cardiopulmonary resuscitation (CPR), endotracheal intubation, laryngeal mask airway insertion, defibrillation/direct current (DC) cardioversion and intraosseous needle insertion) by at least 80% of respondents. 16 procedures were recommended for yearly practice by at least 50% of respondents. Two procedures (venous cutdown and ED thoracotomy) had yearly practice recommended by <40% of respondents. Simulation was the preferred learning modality for CPR, bag valve mask ventilation, DC cardioversion and transcutaneous pacing. Practice in alternative clinical settings (eg, the operating room) was the preferred learning modality for endotracheal intubation and laryngeal mask insertion. Use of models/mannequins for isolated procedural training was the preferred learning modality for all other invasive procedures. Free-text responses suggested the utility of cadaver labs and animal labs for more invasive procedures (thoracotomy, intercostal catheter insertion, open surgical airways, venous cutdown and pericardiocentesis).
Conclusions Paediatric ED clinicians suggest that most paediatric critical procedures should be practised at least annually. The preferred learning modality depends on the skill practised; alternative clinical settings are thought to be most useful for standard airway manoeuvres, while simulation-based experiential learning is applicable for most other procedures