Stefano Guidi

«In-depth assessment of work-related stress in a major company undergoing restructuring». Background: An in-depth assessment of work-related stress was conducted in a major national telecommunications company under- going major changes. The assessment was made on three homogeneous groups of workers and covered a large representative sample of the corresponding populations. Objectives: To identify the main sources of stress for the three populations of workers, stimulate a discussion on the possible corrective actions, and assess the impact of the on-go- ing organizational changes on workers’ health. Methods: The assessment started with an analysis of the objective stress indicators listed in the INAIL (National Insurance Institute for Occupational Diseases and Accidents) Check- list. This was followed by a combination of qualitative and quantitative investigations on work context and tasks and on the subjective perceptions of workers, which were carried out by using: semi-structured interviews with management, field observations of work tasks, focus groups and questionnaires (GHQ-12, HSE Indicator Tool, ad- hoc questionnaire). Results: The assessment allowed identification of the critical areas to be addressed with specific interventions: relationship with the company, work performance, work organization, and equipment. Conclusions: the investigation allowed to identification of specific practical actions (improvement of technological tools; professional development through training courses) as well as strategic actions ( re-establish relationship of trust with the company) so as to mitigate the workers’ level of stress. Analysis of the results also showed that the three targeted populations differed in the degree of acceptance and understanding of the organizational changes.

We studied a novel illusion of tilt inside checkerboards due to the role of contrast polarity in contour integration. The preference for binding of oriented contours having same contrast polarity, over binding of opposite polarity ones (CP rule), has been used to explain several visual illusions. In three experiments we investigated how the binding effect is influenced by luminance contrast value, relatability of contour elements, and distance among them. Experiment 1 showed that the effect was indeed present only when the CP rule was satisfied, and found it to be stronger when the luminance contrast values of the elements are more similar. In experiment 2 the illusion was reported only with relatable edges, and its strength was modulated by the degree of relatability. The CP-rule effectiveness, thus, seems to depend on good continuation. The intensity of contrast polarity signals propagating from an oriented contour might be the less intense, the more its direction deviates from linearity. In experiment 3 we estimated the distance threshold and found it to be smaller than the one found for other illusions, arising with collinear fragments. This seems to show that the reach of the contrast polarity signal inside the association field of a contour unit is shorter along non-collinear orientations than along collinear ones.

ABSTRACT We studied a novel illusion of tilt inside checkerboards due to the role of contrast polarity in contour integration. The preference for binding of oriented contours having same contrast polarity, over binding of opposite polarity ones (CP rule), has been used to explain several visual illusions. In three experiments we investigated how the binding effect is influenced by luminance contrast value, relatability of contour elements, and distance among them. Experiment 1 showed that the effect was indeed present only when the CP rule was satisfied, and found it to be stronger when the luminance contrast values of the elements are more similar. In experiment 2 the illusion was reported only with relatable edges, and its strength was modulated by the degree of relatability. The CP-rule effectiveness, thus, seems to depend on good continuation. The intensity of contrast polarity signals propagating from an oriented contour might be the less intense, the more its direction deviates from linearity. In experiment 3 we estimated the distance threshold and found it to be smaller than the one found for other illusions, arising with collinear fragments. This seems to show that the reach of the contrast polarity signal inside the association field of a contour unit is shorter along non-collinear orientations than along collinear ones.

Cross-unit handovers transfer responsibility for the patient among healthcare teams in different clinical units, with missed information, potentially placing patients at risk for adverse events. We analysed the communications between high-acuity and low-acuity units, their content and social context, and we explored whether common conceptual ground reduced potential threats to patient safety posed by current handover practices. We monitored the communication of five content items using handover probes for 22 patient transitions of care between high-acuity 'sender units' and low-acuity 'recipient units'. Data were analysed and discussed in focus groups with healthcare professionals to acquire insights into the characteristics of the common conceptual ground. High-acuity and low-acuity units agreed about the presence of alert signs in the discharge form in 40% of the cases. The focus groups identified prehandover practices, particularly for anticipatory guidance that r...

Three experiments were carried out to investigate the internal structure of a rectangular frame to test Arnheim's (1974 Art and Visual Perception, 1988 The Power of the Center) proposals about its 'structural skeleton'. Observers made subjective ratings of how well a small probe circle fit within a rectangle at different interior positions. In experiment 1, ratings of 77 locations were highest in the center, decreased with distance from the center, greatly elevated along vertical and horizontal symmetry axes, and somewhat elevated along the local symmetry axes. A linear regression model with six symmetry-related factors accounted for 95% of the variance. In experiment 2 we measured perceived fit along local symmetry axes versus global diagonals near the corners to determine which factor was relevant. 2AFC probabilities were elevated only along the local symmetry axes and were higher when the probe was closer to the vertex. In experiment 3 we examined the effect of dividing a rectangular frame into two rectangular 'subframes' using an additional line. The results show that the primary determinant of good fit is the position of the target circle within the local subframes. In general, the results are consistent with Arnheim's proposals about the internal structure of a rectangular frame, but an alternative interpretation is offered in terms of the Gestalt concept of figural goodness.