Simplified Quantum Process Characterization by Specialised Neural Networks

Characterization of quantum objects based on previous knowledge is a valuable approach, especially as it leads to routine procedures for real-life components. To this end, Machine Learning algorithms have demonstrated to successfully operate in presence of noise. However, there might be instances in which unknown parasitic effects occur in tandem with the sought one we aim at characterizing. Here we show that the accurate design of a two-stage neural network can account for these class of disturbances as well, applying our technique to the characterization of several quantum channels. We demonstrate that a stable and reliable characterization is achievable by training the network only with simulated data. The obtained results show the viability of this approach as an effective tool based on a completely new paradigm for the employment of NNs in the quantum domain

Characterizing multisegment foot kinematics during gait in diabetic foot patients

<p>Abstract</p> <p>Background</p> <p>The prevalence of diabetes mellitus has reached epidemic proportions, this condition may result in multiple and chronic invalidating long term complications. Among these, the diabetic foot, is determined by the simultaneous presence of both peripheral neuropathy and vasculopathy that alter the biomechanics of the foot with the formation of callosity and ulcerations. To diagnose and treat the diabetic foot is crucial to understand the foot complex kinematics. Most of gait analysis protocols represent the entire foot as a rigid body connected to the shank. Nevertheless the existing multisegment models cannot completely decipher the impairments associated with the diabetic foot.</p> <p>Methods</p> <p>A four segment foot and ankle model for assessing the kinematics of the diabetic foot was developed. Ten normal subjects and 10 diabetics gait patterns were collected and major sources of variability were tested. Repeatability analysis was performed both on a normal and on a diabetic subject. Direct skin marker placement was chosen in correspondence of 13 anatomical landmarks and an optoelectronic system was used to collect the data.</p> <p>Results</p> <p>Joint rotation normative bands (mean plus/minus one standard deviation) were generated using the data of the control group. Three representative strides per subject were selected. The repeatability analysis on normal and pathological subjects results have been compared with literature and found comparable. Normal and pathological gait have been compared and showed major statistically significant differences in the forefoot and midfoot dorsi-plantarflexion.</p> <p>Conclusion</p> <p>Even though various biomechanical models have been developed so far to study the properties and behaviour of the foot, the present study focuses on developing a methodology for the functional assessment of the foot-ankle complex and for the definition of a functional model of the diabetic neuropathic foot. It is, of course, important to evaluate the major sources of variation (true variation in the subject's gait and artefacts from the measurement procedure). The repeatability of the protocol was therefore examined, and results showed the suitability of this method both on normal and pathological subjects. Comparison between normal and pathological kinematics analysis confirmed the validity of a similar approach in order to assess neuropathics biomechanics impairment.</p

Multifractal fluctuations in the survival probability of an open quantum system

We predict a multifractal behaviour of transport in the deep quantum regime for the opened $\delta-$kicked rotor model. Our analysis focuses on intermediate and large scale correlations in the transport signal and generalizes previously found parametric {\em mono}-fractal fluctuations in the quantum survival probability on small scales.Comment: 8 pages, 3 figures, 2 tables. Physica A, accepted 200

Can quantum fractal fluctuations be observed in an atom-optics kicked rotor experiment?

We investigate the parametric fluctuations in the quantum survival probability of an open version of the delta-kicked rotor model in the deep quantum regime. Spectral arguments [Guarneri I and Terraneo M 2001 Phys. Rev. E vol. 65 015203(R)] predict the existence of parametric fractal fluctuations owing to the strong dynamical localisation of the eigenstates of the kicked rotor. We discuss the possibility of observing such dynamically-induced fractality in the quantum survival probability as a function of the kicking period for the atom-optics realisation of the kicked rotor. The influence of the atoms' initial momentum distribution is studied as well as the dependence of the expected fractal dimension on finite-size effects of the experiment, such as finite detection windows and short measurement times. Our results show that clear signatures of fractality could be observed in experiments with cold atoms subjected to periodically flashed optical lattices, which offer an excellent control on interaction times and the initial atomic ensemble.Comment: 18 pp, 7 figs., 1 tabl

Utility of neutrophil-to-lymphocyte ratio to identify long-term survivors among HCC patients treated with sorafenib

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Validation and refinement of PROSASH model using the neutrophil‐to‐lymphocyte ratio in patients with HCC receiving sorafenib

AbstractThe recently developed PROSASH model is proving to be a useful tool in risk‐group discrimination in hepatocellular carcinoma (HCC) patients treated with sorafenib. Several studies highlighted that the neutrophil‐to‐lymphocyte ratio (NLR) is one of the most important predictors of survival in HCC patients treated with sorafenib. The aims of the present study were to validate the PROSASH model and determine whether the incorporation of inflammatory markers can improve risk stratification. This study included 438 patients. According to the four categories of the PROSASH model, median overall survival (OS) was 20.0, 14.9, 8.5 and 3.0 months respectively (P < .001). The Harrell's c for this categorized model was 0.621. NLR (cut‐off 3) stratified OS in each of the PROSASH categories. After reclassification, median OS was 21.0, 15.1, 8.2 and 4.1 months (P < .001). The Harrell's c increased from 0.621 to 0.673 (P = .001). Integrating NLR into the PROSASH model allowed a more accurate classification of the patients in the risk groups