What The Brain Does As We Speak

Language is a defining human behavior and is dependent on networks interactions amongst broadly distributed neuronal substrates. Transient dynamics between language regions that underpin speech production have long been postulated, yet have proven challenging to evaluate empirically. We used direct intracranial recordings during single word production to create a finely resolved spatiotemporal atlas (134 patients, 25810 electrodes, 40278 words) of the entire language-dominant cortex and used this to derive single-trial state-space sequences of network motifs. We derived 5 discrete neural states during the production of each word, distinguished by unique patterns of distributed cortical interaction. This interactive model was significantly better than a model of the same design but lacking interactions between regions in explaining observed activity. Our results eschew strict functional attribution to localized cortical populations, supporting instead the idea that cognitive processes are better explained by distributed metastable network states.

Quantum computed moments correction to variational estimates

The variational principle of quantum mechanics is the backbone of hybrid quantum computing for a range of applications. However, as the problem size grows, quantum logic errors and the effect of barren plateaus overwhelm the quality of the results. There is now a clear focus on strategies that require fewer quantum circuit steps and are robust to device errors. Here we present an approach in which problem complexity is transferred to dynamic quantities computed on the quantum processor – Hamiltonian moments, ⟨Hn⟩. From these quantum computed moments, an estimate of the ground-state energy can be obtained using the ``infimum'' theorem from Lanczos cumulant expansions which manifestly corrects the associated variational calculation. With higher order effects in Hilbert space generated via the moments, the burden on the trial-state quantum circuit depth is eased. The method is introduced and demonstrated on 2D quantum magnetism models on lattices up to 5×5 (25 qubits) implemented on IBM Quantum superconducting qubit devices. Moments were quantum computed to fourth order with respect to a parameterised antiferromagnetic trial-state. A comprehensive comparison with benchmark variational calculations was performed, including over an ensemble of random coupling instances. The results showed that the infimum estimate consistently outperformed the benchmark variational approach for the same trial-state. These initial investigations suggest that the quantum computed moments approach has a high degree of stability against trial-state variation, quantum gate errors and shot noise, all of which bodes well for further investigation and applications of the approach.

Process evaluation of an implementation trial to improve the triage, treatment and transfer of stroke patients in emergency departments (T3 trial): a qualitative study

Background The implementation of evidence-based protocols for stroke management in the emergency department (ED) for the appropriate triage, administration of tissue plasminogen activator to eligible patients, management of fever, hyperglycaemia and swallowing, and prompt transfer to a stroke unit were evaluated in an Australian cluster-randomised trial (T3 trial) conducted at 26 emergency departments. There was no reduction in 90-day death or dependency nor improved processes of ED care. We conducted an a priori planned process influential factors that impacted upon protocol uptake. Methods Qualitative face-to-face interviews were conducted with purposively selected ED and stroke clinicians from two high- and two low-performing intervention sites about their views on factors that influenced protocol uptake. All Trial State Co-ordinators (n = 3) who supported the implementation at the 13 intervention sites were also interviewed. Data were analysed thematically using normalisation process theory as a sensitising framework to understand key findings, and compared and contrasted between interviewee groups. Results Twenty-five ED and stroke clinicians, and three Trial State Co-ordinators were interviewed. Three major themes represented key influences on evidence uptake: (i) Readiness to change: reflected strategies to mobilise and engage clinical teams to foster cognitive participation and collective action; (ii) Fidelity to the protocols: reflected that beliefs about the evidence underpinning the protocols impeded the development of a shared understanding about the applicability of the protocols in the ED context (coherence); and (iii) Boundaries of care: reflected that appraisal (reflexive monitoring) by ED and stroke teams about their respective boundaries of clinical practice impeded uptake of the protocols. Conclusions Despite initial high ‘buy-in’ from clinicians, a theoretically informed and comprehensive implementation strategy was unable to overcome system and clinician level barriers. Initiatives to drive change and integrate protocols rested largely with senior nurses who had to overcome contextual factors that fell outside their control, including low medical engagement, beliefs about the supporting evidence and perceptions of professional boundaries. To maximise uptake of evidence and adherence to intervention fidelity in complex clinical settings such as ED cost-effective strategies are needed to overcome these barriers. Trial registration Australian New Zealand Clinical Trials Registry (ACTRN12614000939695).

Truncated many-body dynamics of interacting bosons: A variational principle with error monitoring

We develop a method to describe the temporal evolution of an interacting system of bosons, for which the field operator expansion is truncated after a finite number M of modes, in a rigorously controlled manner. Using McLachlan's principle of least error, we find a self-consistent set of equations for the many-body state. As a particular benefit and in distinction to previously proposed approaches, the presently introduced method facilitates the dynamical increase of the number of orbitals during the temporal evolution, due to the fact that we can rigorously monitor the error made by increasing the truncation dimension M. The additional orbitals, determined by the condition of least error of the truncated evolution relative to the exact one, are obtained from an initial trial state by steepest constrained descent.

Drones at Trial. State and Individual (Criminal) Liabilities for Drone Attacks

This article delves into issues of individual and State (criminal) liability for (lethal) drone operations; a yet unexplored area given the proliferation of drone attacks in recent years. The criteria under which military and political leaders can (possibly) be held criminally accountable for conducting drone attacks within and outside an armed conflict are outlined, based upon ICTY, ICC and ECHR-case law. Against this background, the discrepancies and pitfalls of the U.S. policy vis-à-vis drone attacks are discerned, as well as the subject-matter of responsibilities of third states which facilitate principal States such as the U.S. in these attacks.