A Social Identity Approach to Sport Psychology: Principles, Practice, and Prospects.

Drawing on social identity theory and self-categorization theory, we outline an approach to sport psychology that understands groups not simply as features of sporting contexts but rather as elements that can be, and often are, incorporated into a person's sense of self and, through this, become powerful determinants of their sport-related behavior. The underpinnings of this social identity approach are outlined, and four key lessons for sport that are indicative of the analytical and practical power of the approach are presented. These suggest that social identity is the basis for sports group (1) behavior, (2) formation and development, (3) support and stress appraisal, and (4) leadership. Building on recent developments within sport science, we outline an agenda for future research by identifying a range of topics to which the social identity approach could fruitfully contribute

Overdetection, overtreatment and costs in prostate-specific antigen screening for prostate cancer

Background:Prostate cancer screening with prostate-specific antigen (PSA) has shown to reduce prostate cancer mortality in the European Randomised study of Screening for Prostate Cancer (ERSPC) trial. Overdetection and overtreatment are substantial unfavourable side effects with consequent healthcare costs. In this study the effects of introducing widespread PSA screening is evaluated.Methods:The MISCAN model was used to simulate prostate cancer growth and detection in a simulated cohort of 100 000 men (European standard population) over 25 years. PSA screening from age 55 to 70 or 75, with 1, 2 and 4-year-intervals is simulated. Number of diagnoses, PSA tests, biopsies, treatments, deaths and corresponding costs for 100 000 men and for United Kingdom and United States are compared.Results:Without screening 2378 men per 100 000 were predicted to be diagnosed with prostate cancer compared with 4956 men after screening at 4-year intervals. By introducing screening, the costs would increase with 100% to \[euro]60 695 000. Overdetection is related to 39% of total costs (\[euro]23 669 000). Screening until age 75 is relatively most expensive because of the costs of overtreatment.Conclusion:Introduction of PSA screening will increase total healthcare costs for prostate cancer substantially, of which the actual screening costs will be a small part

In-process detection of chipping in ceramic cutting tools during turning of difficult-to-cut material using vision-based approach

Ceramic cutting tools are prone to failure by chipping and fracture rather than gradual wear mainly because of their low impact resistance. This results in poor surface finish and low dimensional accuracy of the machined parts. In this work, a vision-based approach has been developed to detect the onset of chipping in aluminum oxide ceramic cut-ting tools during the dry turning of AISI 01 oil-hardening tool steel. The profile of the workpiece surface opposite the cutting tool was captured during the turning using 18-megapixel DSLR camera at a shutter speed of 0.25 ms. The surface profile of the workpiece was extracted to sub-pixel accuracy using the invariant moment method. The effect of chipping in the ceramic cutting tools on the surface profile signature of the machined workpiece was investigated using autocorrelation analysis. Chipping in the ceramic tool was found to (i) cause the peaks of autocorrelation function of the workpiece profile to decrease rapidly as the lag distance increased and (ii) cause the envelope of the peaks of the autocorrelation function to deviate significantly from one another at different workpiece rotation angles. The sum of squared deviation (SSD) of the envelope of the peak of autocorrelation function was also found to increase sharply right after tool chipping. Significant variations in the SSD at different workpiece rotation angles were observed beyond the cutting time of 11.1 s because of the continuous chipping of the ceramic insert during turning