Simulation of the elementary evolution operator with the motional states of an ion in an anharmonic trap

Following a recent proposal of L. Wang and D. Babikov, J. Chem. Phys. 137, 064301 (2012), we theoretically illustrate the possibility of using the motional states of a $Cd^+$ ion trapped in a slightly anharmonic potential to simulate the single-particle time-dependent Schr\"odinger equation. The simulated wave packet is discretized on a spatial grid and the grid points are mapped on the ion motional states which define the qubit network. The localization probability at each grid point is obtained from the population in the corresponding motional state. The quantum gate is the elementary evolution operator corresponding to the time-dependent Schr\"odinger equation of the simulated system. The corresponding matrix can be estimated by any numerical algorithm. The radio-frequency field able to drive this unitary transformation among the qubit states of the ion is obtained by multi-target optimal control theory. The ion is assumed to be cooled in the ground motional state and the preliminary step consists in initializing the qubits with the amplitudes of the initial simulated wave packet. The time evolution of the localization probability at the grids points is then obtained by successive applications of the gate and reading out the motional state population. The gate field is always identical for a given simulated potential, only the field preparing the initial wave packet has to be optimized for different simulations. We check the stability of the simulation against decoherence due to fluctuating electric fields in the trap electrodes by applying dissipative Lindblad dynamics.Comment: 31 pages, 8 figures. Revised version. New title, new figure and new reference

Hilbert Space Average Method and adiabatic quantum search

We discuss some aspects related to the so-called Hilbert space Average Method, as an alternative to describe the dynamics of open quantum systems. First we present a derivation of the method which does not make use of the algebra satisfied by the operators involved in the dynamics, and extend the method to systems subject to a Hamiltonian that changes with time. Next we examine the performance of the adiabatic quantum search algorithm with a particular model for the environment. We relate our results to the criteria discussed in the literature for the validity of the above-mentioned method for similar environments.Comment: 6 pages, 1 figur

Sub-ballistic behavior in quantum systems with L\'evy noise

We investigate the quantum walk and the quantum kicked rotor in resonance subjected to noise with a L\'evy waiting time distribution. We find that both systems have a sub-ballistic wave function spreading as shown by a power-law tail of the standard deviation.Comment: 4 pages, 4 figure

Treating anxiety and depression in older adults: Randomised controlled trial comparing guided V. Self-guided internet-delivered cognitive-behavioural therapy

© 2016 The Royal College of Psychiatrists. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) licence. Background Symptoms of anxiety and depression are prevalent in older adults. Aims To compare clinician-guided and self-guided versions of a transdiagnostic internet-delivered cognitive-behavioural therapy (iCBT) intervention for adults aged 60 years and above. Method Adults (n=433) with symptoms of anxiety and depression were randomly allocated to: (1) clinician-guided treatment (n=153); (2) initial clinician interview followed by self-guided treatment (n=140); or (3) self-guided treatment without interview (n=140). Results Large reductions (d ≥1.00) in symptoms of depression and anxiety were observed across groups, and sustained at follow-up. No differences were observed in clinical outcomes or satisfaction ratings. Age did not affect outcomes. Conclusions Carefully developed iCBT interventions may significantly reduce symptoms of anxiety and depression in older adults when delivered in either clinician-guided or self-guided formats

Impact of chronic health conditions and injury on school performance and health outcomes in New South Wales, Australia : a retrospective record linkage study protocol

Introduction: Children who have sustained a serious injury or who have a chronic health condition, such as diabetes or epilepsy, may have their school performance adversely impacted by the condition, treatment of the condition and/or time away from school. Examining the potential adverse impact requires the identification of children most likely to be affected and the use of objective measures of education performance. This may highlight educational disparities that could be addressed with learning support. This study aims to examine education performance, school completion and health outcomes of children in New South Wales (NSW), Australia, who were hospitalised with an injury or a chronic health condition compared with children who have not been hospitalised for these conditions. Method and analysis This research will be a retrospective population-level case-comparison study of hospitalised injured or chronically ill children (ie, diabetes, epilepsy, asthma or mental health conditions) aged ≤18 years in NSW, Australia, using linked health and education administrative data collections. It will examine the education performance, school completion and health outcomes of children who have been hospitalised in NSW with an injury or a chronic health condition compared with children randomly drawn from the NSW population (matched on gender, age and residential postcode) who have not been hospitalised for these conditions. Ethics and dissemination The study received ethics approval from the NSW Population Health Services Research Ethics Committee (2018HRE0904). Findings from the research will be published in peer-reviewed journals and presented at scientific conferences

Symptoms associated with victimization in patients with schizophrenia and related disorders

Background: Patients with psychoses have an increased risk of becoming victims of violence. Previous studies have suggested that higher symptom levels are associated with a raised risk of becoming a victim of physical violence. There has been, however, no evidence on the type of symptoms that are linked with an increased risk of recent victimization. Methods: Data was taken from two studies on involuntarily admitted patients, one national study in England and an international one in six other European countries. In the week following admission, trained interviewers asked patients whether they had been victims of physical violence in the year prior to admission, and assessed symptoms on the Brief Psychiatric Rating Scale (BPRS). Only patients with a diagnosis of schizophrenia or related disorders (ICD-10 F20–29) were included in the analysis which was conducted separately for the two samples. Symptom levels assessed on the BPRS subscales were tested as predictors of victimization. Univariable and multivariable logistic regression models were fitted to estimate adjusted odds ratios. Results: Data from 383 patients in the English sample and 543 patients in the European sample was analysed. Rates of victimization were 37.8% and 28.0% respectively. In multivariable models, the BPRS manic subscale was significantly associated with victimization in both samples. Conclusions: Higher levels of manic symptoms indicate a raised risk of being a victim of violence in involuntary patients with schizophrenia and related disorders. This might be explained by higher activity levels, impaired judgement or poorer self-control in patients with manic symptoms. Such symptoms should be specifically considered in risk assessments

Violent behaviour in early psychosis patients: Can we identify clinical risk profiles?

The objective of this study is to explore, within a sample of early psychosis patients (EPP), if subgroups regarding rate of violent behaviour (VB) against others can be identified on the basis of dynamic risk factors (treatment modifiable characteristics). In a sample of 265 EPP, treated at the Treatment and Early Intervention in Psychosis Program in Lausanne, we conducted a latent-class analysis on the basis of the main dynamic VB risk factors (substance use disorder [SUD], positive symptoms, insight, and impulsivity). VB were restricted to "serious violence" and were assessed through patients self-report, interview with relatives or forensic services and with a standardized instrument. The analysis confirmed the heterogeneity of the sample regarding rate of VB. Patients could be stratified within 4 subgroups, 3 of which were at increased risk of VB. The two groups with the highest rates of VB displayed specific clinical profiles. The first one was characterized by high levels of impulsivity, hostility, positive symptoms and SUD, and the second, by low level of insight and low social functioning. These patterns suggest that significant difficulties in social interaction may contribute to the emergence of aggressive reactions against others. Identification of EPP at increased risk of VB seems possible on the basis of dynamic risk factors. If confirmed prospectively, this could pave the way to the development of preventive strategies and specific interventions

Schizophrenia and Violence: Systematic Review and Meta-Analysis

Seena Fazel and colleagues investigate the association between schizophrenia and other psychoses and violence and violent offending, and show that the increased risk appears to be partly mediated by substance abuse comorbidity