Detecting nonlinearity in run-up on a natural beach

International audienceNatural geophysical timeseries bear the signature of a number of complex, possibly inseparable, and generally unknown combination of linear, stable non-linear and chaotic processes. Quantifying the relative contribution of, in particular, the non-linear components will allow improved modelling and prediction of natural systems, or at least define some limitations on predictability. However, difficulties arise; for example, in cases where the series are naturally cyclic (e.g. water waves), it is most unclear how this cyclic behaviour impacts on the techniques commonly used to detect the nonlinear behaviour in other fields. Here a non-linear autoregressive forecasting technique which has had success in demonstrating nonlinearity in non-cyclical geophysical timeseries, is applied to a timeseries generated by videoing the waterline on a natural beach (run-up), which has some irregular oscillatory behaviour that is in part induced by the incoming wave field. In such cases, the deterministic shape of each run-up cycle has a strong influence on forecasting results, causing questionable results at small (within a cycle) prediction distances. However, the technique can clearly differentiate between random surrogate series and natural timeseries at larger prediction distances (greater than one cycle). Therefore it was possible to clearly identify nonlinearity in the relationship between observed run-up cycles in that a local autoregressive model was more adept at predicting run-up cycles than a global one. Results suggest that despite forcing from waves impacting on the beach, each run-up cycle evolves somewhat independently, depending on a non-linear interaction with previous run-up cycles. More generally, a key outcome of the study is that oscillatory data provide a similar challenge to differentiating chaotic signals from correlated noise in that the deterministic shape causes an additional source of autocorrelation which in turn influences the predictability at small forecasting distances

Summative assessment of clinical practice of student nurses : a review of the literature

Objectives: To describe assessment of nursing student’s clinical practice concerned nursing education. Design: Systematic review and synthesis of qualitative and quantitative studies. Data sources: The data were collected with the support of an information specialist from scientific databases Cinahl, PubMed, Medic, ISI Web of Science, Cochrane library and Eric published in January 2000 – May 2014. All of the included studies citations were also performed. Methods: 725 articles concerned with nurse student clinical practice assessment were identified. After inclusion and exclusion criteria were met 23 articles for selected for critical review. Two independent reviewers selected the studies according to the inclusion criteria. These articles were analyzed using content analysis. Results: Findings suggest that the assessment process of nursing students’ clinical practice lacks consistency, it is open to the subjective bias of the assessor and the quality of assessment varies greatly. Nursing students clinical assessment was divided into 3 themes: acts (things to do) before final assessment, the actual final assessment situation and the acts after the final assessment situation. Mentors and students need orientation to the assessment process and to the paperwork by teachers. Terminology on evaluation forms is sometimes so difficult to grasp, that the mentors did not understand what they mean. There is no consensus about written assignments’ ability to describe the students’ skills. Mentors have timing problems to ensure relevant assessment of student nurses. At the final interview students normally self assess their performance, the mentor assesses by interview and by written assignments whether the student has achieved the criteria and role of the teacher is to support the mentor and the student in appropriate assessment. The variety of patient treatment environments in which nursing students do their clinical practice periods is challenging also for the assessment of nursing students’ expertise. Mentors alone want that clinical practice is a positive experience and it might lead to higher grades than what nurse student competency earns. It is very rare that students fail their clinical practice, if the student does not achieve the clinical competencies they are allowed to have extra time in clinical areas until they will be assessed as competent. Conclusions: This systematic review provides a description of challenges in nursing students’ assessment in clinical settings. Further research needs to be carried out to have more knowledge of final assessment in the end of the clinical practice. Through further research it will be possible to have better methods for high quality assessment processes and feedback to nurse students. Quality in assessment provides better nurses and therefore better patient safety

SENSE: A comparison of photon detection efficiency and optical crosstalk of various SiPM devices

This paper describes a comparison of photon detection efficiency and optical crosstalk measurements performed by three partners: Geneva University, Catania Observatory and Nagoya University. The measurements were compared for three different SiPM devices with different active areas: from 9 $mm^2$ up to 93.6 $mm^2$ produced by Hamamatsu. The objective of this work is to establish the measurements and analysis procedures for calculating the main SiPM parameters and their precision. This work was done in the scope of SENSE project which aims to build roadmap for the last developments in field of sensors for low light level detection

Development of a strategy for calibrating the novel SiPM camera of the SST-1M telescope proposed for the Cherenkov Telescope Array

CTA will comprise a sub-array of up to 70 small size telescopes (SSTs) at the southern array. The SST-1M project, a 4 m-diameter Davies Cotton telescope with 9 degrees FoV and a 1296 pixels SiPM camera, is designed to meet the requirements of the next generation ground based gamma-ray observatory CTA in the energy range above 3 TeV. Silicon photomultipliers (SiPM) cameras of gamma-ray telescopes can achieve good performance even during high night sky background conditions. Defining a fully automated calibration strategy of SiPM cameras is of great importance for large scale production validation and online calibration. The SST-1M sub-consortium developed a software compatible with CTA pipeline software (CTApipe). The calibration of the SST-1M camera is based on the Camera Test Setup (CTS), a set of LED boards mounted in front of the camera. The CTS LEDs are operated in pulsed or continuous mode to emulate signal and night sky background respectively. Continuous and pulsed light data analysis allows us to extract single pixel calibration parameters to be used during CTA operation.Comment: All CTA contributions at arXiv:1709.0348

Performance of a small size telescope (SST-1M) camera for gamma-ray astronomy with the Cherenkov Telescope Array

The foreseen implementations of the Small Size Telescopes (SST) in CTA will provide unique insights into the highest energy gamma rays offering fundamental means to discover and under- stand the sources populating the Galaxy and our local neighborhood. Aiming at such a goal, the SST-1M is one of the three different implementations that are being prototyped and tested for CTA. SST-1M is a Davies-Cotton single mirror telescope equipped with a unique camera technology based on SiPMs with demonstrated advantages over classical photomultipliers in terms of duty-cycle. In this contribution, we describe the telescope components, the camera, and the trigger and readout system. The results of the commissioning of the camera using a dedicated test setup are then presented. The performances of the camera first prototype in terms of expected trigger rates and trigger efficiencies for different night-sky background conditions are presented, and the camera response is compared to end-to-end simulations.Comment: All CTA contributions at arXiv:1709.0348

Control Software for the SST-1M Small-Size Telescope prototype for the Cherenkov Telescope Array

The SST-1M is a 4-m Davies--Cotton atmospheric Cherenkov telescope optimized to provide gamma-ray sensitivity above a few TeV. The SST-1M is proposed as part of the Small-Size Telescope array for the Cherenkov Telescope Array (CTA), the first prototype has already been deployed. The SST-1M control software of all subsystems (active mirror control, drive system, safety system, photo-detection plane, DigiCam, CCD cameras) and the whole telescope itself (master controller) uses the standard software design proposed for all CTA telescopes based on the ALMA Common Software (ACS) developed to control the Atacama Large Millimeter Array (ALMA). Each subsystem is represented by a separate ACS component, which handles the communication to and the operation of the subsystem. Interfacing with the actual hardware is performed via the OPC UA communication protocol, supported either natively by dedicated industrial standard servers (PLCs) or separate service applications developed to wrap lower level protocols (e.g. CAN bus, camera slow control) into OPC UA. Early operations of the telescope without the camera were already carried out. The camera is fully assembled and is capable to perform data acquisition using artificial light source.Comment: In Proceedings of the 35th International Cosmic Ray Conference (ICRC2017), Busan, Korea. All CTA contributions at arXiv:1709.0348

Traumatic brain injury patients' family members' evaluations of the social support provided by healthcare professionals in acute care hospitals

Aims and objectives The study aimed to examine traumatic brain injury (TBI) patient family members' (FMs) experiences of the support they received from healthcare professionals in acute care hospitals. Background The length of hospitalisation following TBI is constantly decreasing, and patients may return home with several problems. FMs care for the patients at home although they may not be prepared for the patient's medical needs or financial burden of the illness. The burden which some FMs experience can impair patient care and rehabilitation outcomes. Therefore, FMs require support during acute phases of TBI treatment. Design A structured questionnaire was sent to 216 TBI patients FMs. The response rate was 47% (n = 102). Methods A structured questionnaire-based on a systematic literature review and a previous questionnaire on TBI patient FMs' perceptions of support-was developed and used in the data collection. The questionnaire included 46 statements and 11 background questions. Data were collected via an electronic questionnaire. The STROBE checklist was followed in reporting the study. Results A factor analysis identified five factors that describe the guidance of TBI patient FMs: guidance of TBI patients' symptoms and survival; benefits of guidance; needs-based guidance; guidance for use of services; and guidance methods. Most of the FMs (51%-88%) felt that they had not received enough guidance from healthcare professionals in acute care hospitals across all five aspects of support. Conclusions The content of guidance should be developed, and healthcare staff should be trained to consider a FM's starting point when providing guidance. A calm environment, proper timing, sufficient information in different forms and professional healthcare staff were found to be key factors to comprehensive guidance. Involving FMs in the discharge process and rehabilitation of their loved ones both supports the abilities of caregivers and promotes the outcome of the patient's rehabilitation. Relevance to clinical practice This study provides varied information on the need for social support of TBI patients FMs in the early stages of treatment from the FMs' perspective. This research adopted the FM's perspective to identify various areas of social support that need to be developed so that the FMs of TBI patients receive enough support during the early stages of TBI treatment.Peer reviewe

The European Photon Imaging Camera on XMM-Newton: The MOS Cameras

The EPIC focal plane imaging spectrometers on XMM-Newton use CCDs to record the images and spectra of celestial X-ray sources focused by the three X-ray mirrors. There is one camera at the focus of each mirror; two of the cameras contain seven MOS CCDs, while the third uses twelve PN CCDs, defining a circular field of view of 30 arcmin diameter in each case. The CCDs were specially developed for EPIC, and combine high quality imaging with spectral resolution close to the Fano limit. A filter wheel carrying three kinds of X-ray transparent light blocking filter, a fully closed, and a fully open position, is fitted to each EPIC instrument. The CCDs are cooled passively and are under full closed loop thermal control. A radio-active source is fitted for internal calibration. Data are processed on-board to save telemetry by removing cosmic ray tracks, and generating X-ray event files; a variety of different instrument modes are available to increase the dynamic range of the instrument and to enable fast timing. The instruments were calibrated using laboratory X-ray beams, and synchrotron generated monochromatic X-ray beams before launch; in-orbit calibration makes use of a variety of celestial X-ray targets. The current calibration is better than 10% over the entire energy range of 0.2 to 10 keV. All three instruments survived launch and are performing nominally in orbit. In particular full field-of-view coverage is available, all electronic modes work, and the energy resolution is close to pre-launch values. Radiation damage is well within pre-launch predictions and does not yet impact on the energy resolution. The scientific results from EPIC amply fulfil pre-launch expectations.Comment: 9 pages, 11 figures, accepted for publication in the A&A Special Issue on XMM-Newto

Attentional coordination in demonstrator-observer dyads facilitates learning and predicts performance in a novel manual task

Observational learning is a form of social learning in which a demonstrator performs a target task in the company of an observer, who may as a consequence learn something about it. In this study, we approach social learning in terms of the dynamics of coordination rather than the more common perspective of transmission of information. We hypothesised that observers must continuously adjust their visual attention relative to the demonstrator's time-evolving behaviour to benefit from it. We eye-tracked observers repeatedly watching videos showing a demonstrator solving one of three manipulative puzzles before attempting at the task. The presence of the demonstrator's face and the availability of his verbal instruction in the videos were manipulated. We then used recurrence quantification analysis to measure the dynamics of coordination between the overt attention of the observers and the demonstrator's manipulative actions. Bayesian hierarchical logistic regression was applied to examine (1) whether the observers' performance was predicted by such indexes of coordination, (2) how performance changed as they accumulated experience, and (3) if the availability of speech and intentional gaze of the demonstrator mediated it. Results showed that learners better able to coordinate their eye movements with the manipulative actions of the demonstrator had an increasingly higher probability of success in solving the task. The availability of speech was beneficial to learning, whereas the presence of the demonstrator's face was not. We argue that focusing on the dynamics of coordination between individuals may greatly improve understanding of the cognitive processes underlying social learning