Exposure to Repetitive Tasks Induces Motor Changes Related to Skill Acquisition and Inflammation in Rats

The authors elucidate exposure-response relationships between repetitive tasks, inflammation, and motor changes with work-related musculoskeletal disorders. Using a rat model of reaching and handle pulling, they examined effects of performing a high-repetition, low-force (HRLF); low-repetition, high-force (LRHF); or high-repetition, high-force (HRHF) task (2 hr/day, 3 days/week, 12 weeks) on reach rate and force, percentage of successful reaches, duration of participation, and grip strength. Reach rate and reach force improved with HRLF, and percentage success increased in all groups in Week 9, and in HRLF and HRHF in Week 12, indicative of skill acquisition. Duration and grip strength showed force-dependent declines with task performance. A subset of HRHF rats received ibuprofen in Weeks 5–12. Ibuprofen significantly improved reach rate, reach force, and duration in treated rats, indicative of an inflammatory influence on reach performance. Ibuprofen improved percentage of successful reaches in Week 9, although this increase was not sustained. However, declines in grip strength, a nocifensive behavior, were not prevented by ibuprofen. Examination of cervical spinal cords of untreated and ibuprofen treated HRHF rats showed increased IL-1beta, an inflammatory cytokine, in neurons. These findings suggest that only a preventive intervention could have addressed all motor declines.     

Using Force: Australian Newspaper Depictions of Contacts Between the Police and Persons Experiencing Mental Illness

The media creates and sustains knowledge about socially relevant issues such as crime, mental illness, and policing. Past research suggests that while the media portrayal of the police is undoubtedly complex, their portrayal of people experiencing mental illness remains mainly negative. The depiction of their encounters in the mass media is of considerable interest because of the influential role the media has on public opinion and debate; however, there is a lack of current research in this area. This study aimed to examine media items in the major newspapers across Australia between January 2006 and December 2007 (n = 77) to investigate their portrayal of this interface. The dominant themes encountered in the initial analysis depicted people experiencing mental illness as dangerous and a threat to the public, where the mental health system has failed to manage them adequately. Further analyses found that people experiencing mental illness were stigmatised in a third of the media items reviewed and were represented significantly more negatively in these encounters than the police. Implications of these findings and some suggestions regarding possible strategies that could improve socially responsible media reporting and public discourse on mental illness are proposed.     

熟悉性对外群体同质性效应的影响

两个实验考查了年龄和性别群体中是否存在外群体同质性效应以及熟悉性对该种效应的影响。结果表明：1．年龄群体中存在明显的外群体同质性效应,这与青年群体和老年群体彼此不够熟悉有关;2．性别群体中不存在外群体同质性效应,这与青年男女群体彼此较为熟悉有关。     

Exposure to repetitive tasks induces motor changes related to skill acquisition and inflammation in rats

The authors elucidate exposure-response relationships between repetitive tasks, inflammation, and motor changes with work-related musculoskeletal disorders. Using a rat model of reaching and handle pulling, they examined effects of performing a high-repetition, low-force (HRLF); low-repetition, high-force (LRHF); or high-repetition, high-force (HRHF) task (2 hr/day, 3 days/week, 12 weeks) on reach rate and force, percentage of successful reaches, duration of participation, and grip strength. Reach rate and reach force improved with HRLF, and percentage success increased in all groups in Week 9, and in HRLF and HRHF in Week 12, indicative of skill acquisition. Duration and grip strength showed force-dependent declines with task performance. A subset of HRHF rats received ibuprofen in Weeks 5-12. Ibuprofen significantly improved reach rate, reach force, and duration in treated rats, indicative of an inflammatory influence on reach performance. Ibuprofen improved percentage of successful reaches in Week 9, although this increase was not sustained. However, declines in grip strength, a nocifensive behavior, were not prevented by ibuprofen. Examination of cervical spinal cords of untreated and ibuprofen treated HRHF rats showed increased IL-1beta, an inflammatory cytokine, in neurons. These findings suggest that only a preventive intervention could have addressed all motor declines.