Spin-orbiton and quantum criticality in FeSc2S4

In FeSc2S4 spin-orbital exchange competes with strong spin-orbit coupling, suppressing long-range spin and orbital order and, hence, this material represents one of the rare examples of a spin-orbital liquid ground state. Moreover, it is close to a quantum-critical point separating the ordered and disordered regimes. Using THz and FIR spectroscopy we study low-lying excitations in FeSc2S4 and provide clear evidence for a spin-orbiton, an excitation of strongly entangled spins and orbitals. It becomes particularly well pronounced upon cooling, when advancing deep into the quantum-critical regime. Moreover, indications of an underlying structureless excitation continuum are found, a possible signature of quantum criticality.Comment: 11 pages, 11 figures (including 4 pages and 5 figures in Supplemental Material). Revised version according to suggestions of referees. Phys. Rev. B (in press

Disentangling the respective contribution of task selection and task execution in self-directed cognitive control development

peer reviewedTask selection and task execution are key constructs in cognitive control development. Yet, little is known about how separable they are and how each contributes to task switching performance. Here, 60 4- to 5-year olds, 60 7- to 8-year olds, and 60 10- to 11-year olds children completed the double registration procedure, which dissociates these two processes. Task selection yielded both mixing and switch costs, especially in younger children, and task execution mostly yielded switch costs at all ages, suggesting that task selection is costlier than task execution. Moreover, both task selection and execution varied with task self-directedness (i.e., to what extent the task is driven by external aids) demands. Whereas task selection and task execution are dissociated regarding performance costs, they nevertheless both contribute to self-directed control

Validation of a simulation algorithm for safety-critical human multitasking.

Multitasking has become surprisingly present in our life. This is mostly due to the fact that nowadays most of our activities involve the interaction with one or more devices. In such a context the brain mechanism of selective attention plays a key role in determining the success of a human’s interaction with a device. Indeed, it is a resource to be shared among the concurrent tasks to be performed, and the sharing of attention turns out to be a process similar to process scheduling in operating systems. In order to study human multitasking situations in which a user interacts with more than one device at the same time, we proposed in a previous work an algorithm for simulating human selective attention. Our algorithm focuses, in particular, on safety-critical human multitasking, namely situations in which some of the tasks the user is involved in may lead to dangerous consequences if not executed properly. In this paper, we present the validation of such an algorithm against data gathered from an experimental study performed with real users involved concurrently in a “main” task perceived as safety-critical and in a series of “distractor” tasks having different levels of cognitive load

Post-anaesthesia pulmonary complications after use of muscle relaxants (POPULAR): a multicentre, prospective observational study

Background Results from retrospective studies suggest that use of neuromuscular blocking agents during general anaesthesia might be linked to postoperative pulmonary complications. We therefore aimed to assess whether the use of neuromuscular blocking agents is associated with postoperative pulmonary complications.Methods We did a multicentre, prospective observational cohort study. Patients were recruited from 211 hospitals in 28 European countries. We included patients (aged >= 18 years) who received general anaesthesia for any in-hospital procedure except cardiac surgery. Patient characteristics, surgical and anaesthetic details, and chart review at discharge were prospectively collected over 2 weeks. Additionally, each patient underwent postoperative physical examination within 3 days of surgery to check for adverse pulmonary events. The study outcome was the incidence of postoperative pulmonary complications from the end of surgery up to postoperative day 28. Logistic regression analyses were adjusted for surgical factors and patients' preoperative physical status, providing adjusted odds ratios (ORadj) and adjusted absolute risk reduction (ARR(adj)). This study is registered with ClinicalTrials. gov, number NCT01865513.Findings Between June 16, 2014, and April 29, 2015, data from 22 803 patients were collected. The use of neuromuscular blocking agents was associated with an increased incidence of postoperative pulmonary complications in patients who had undergone general anaesthesia (1658 [7.6%] of 21 694); ORadj 1.86, 95% CI 1.53-2.26; ARR(adj) -4.4%, 95% CI -5.5 to -3.2). Only 2.3% of high-risk surgical patients and those with adverse respiratory profiles were anaesthetised without neuromuscular blocking agents. The use of neuromuscular monitoring (ORadj 1.31, 95% CI 1.15-1.49; ARR(adj) -2.6%, 95% CI -3.9 to -1.4) and the administration of reversal agents (1.23, 1.07-1.41; -1.9%, -3.2 to -0.7) were not associated with a decreased risk of postoperative pulmonary complications. Neither the choice of sugammadex instead of neostigmine for reversal (ORadj 1.03, 95% CI 0.85-1 center dot 25; ARR(adj) -0.3%, 95% CI -2.4 to 1.5) nor extubation at a train-of-four ratio of 0.9 or more (1.03, 0.82-1.31; -0.4%, -3.5 to 2.2) was associated with better pulmonary outcomes.Interpretation We showed that the use of neuromuscular blocking drugs in general anaesthesia is associated with an increased risk of postoperative pulmonary complications. Anaesthetists must balance the potential benefits of neuromuscular blockade against the increased risk of postoperative pulmonary complications