The rapid growth of electronic and computer-based communication and information sharing during the past decade has dramatically changed social interactions, especially among teenagers. Cyberbullying has emerged as a new form of bullying and harassment, and it has been shown to possess different ramifications from traditional school-yard bullying. This problem has emerged in nations worldwide. Cyber victims have reported various emotional and behavioral symptoms, along with school-related problems. This paper reviews international cross-sectional studies relating to the definition, prevalence, age, and gender differences inherent in cyberbullying. Psychosocial and risk factors associated with cyberbullying are also addressed. Prevention and intervention strategies for school officials and parents are suggested. Healthcare providers, policy makers, and families must be ever-mindful of the grave dangers cyberbullying poses to youths. Longitudinal studies are warranted to assess the psychological risk factors of cyberbullying.

The outcome of emergency abdominal surgery in elderly patients remains unsatisfactory. We studied factors contributing to the outcome of abdominal emergency surgery in elderly patients, particularly in those aged 80 years and older. Subjects were 61 patients aged 80 years and older (group A) and 108 patients aged from 65 to 79 years (group B) who underwent emergency abdominal surgery between 1983 and 1997. Complications were significantly higher in group A than in group B, with respiratory failure the most common postoperative complication. Mortality rate within 30 days after surgery was also higher in group A (9.8%) than in group B (3.3%). Complications and mortality did not differ significantly between those with and without preexisting concomitant disease in group A. Systemic inflammatory response syndrome (SIRS) was seen in 35 patients in group A and 50 in group B. Severe complications occurred in 62.5% of group A with preoperative SIRS. Mortality in those with SIRS was significantly higher than those without. SIRS is thus a feasible predictor of poor outcome in patients aged 80 years and older who have emergency abdominal surgery and in those aged from 65 to 79 years. Patients with SIRS should initially receive minimal treatment whenever possible, rather than be overtreated, until their conditions stabilize.

For application in organic electronic devices, conjugated polymer materials must be free of impurities such as catalyst residues and terminal functional groups that inhibit carrier transport. Pd-catalyzed crosscoupling polycondensation is a common synthesis method for producing conjugated polymer materials. Although the method is very reliable, it requires complete removal of Pd residues from the products to meet purity requirements. This study focused on the metal-free synthesis of conjugated polymers containing azine bonds in their main chains. The dehydration condensation of dialdehyde monomers and hydrazine was optimized, and the results revealed that a two-step reaction is effective for obtaining high-molecular-weight polymers. Pure materials were obtained through a simple purification procedure. Their molecular weight and terminal structures were arbitrarily controlled by adjusting the monomer ratio and adding end-capping reagents. The azine moiety in the main chain functioned as a weak acceptor unit and extended its conjugation by linking aromatic units with high planarity. The synthesized azine-based polymers with fused thiophene skeletons serve as p-type semiconducting materials for organic field-effect transistors and organic photovoltaics. These results provide fundamental and important insights on green synthesis and the application of azine-based conjugated polymers.

The purpose of this study was to determine the factors related to the occurrence of concussion in rugby tacklers. Match video records showing tackles leading to concussion were used to identify injury-inciting events. Additionally, noninjury tackles by concussed tacklers (prior to concussion) and position-matched tacklers from the same matches were used as a control cohort. All tackles were coded according to the tackling characteristics. The odds ratio (OR) was reported by logistic regression. The results demonstrated that a side step of the ball-carrier reduced the risk of concussion for tacklers (OR = 0.13 [95% CI, 0.03-0.58]; P = .008). Conversely, the tackler's head/neck contacting the ball-carrier (OR = 18.62 [95% CI, 4.59-75.49]; P < .001) and not remaining bound to the ball-carrier since making initial contact (OR = 4.38 [95% CI, 1.69-11.34]; P = .002) were identified as risk factors for the concussion of tacklers. These results suggest that avoidance movements of the ball-carrier prior to tackling reduced the risk of concussion and that incorrect tackling techniques contributed to an increased occurrence of concussion. Furthermore, the probability of concussion for tacklers increased when their head was in front or to one side of the ball-carrier, and the direction of the tackle also affected the risk of concussion, especially from the side. Therefore, it is important to emphasize the tackler's head position in conjunction with the direction of tackle. K E Y W O R D Scommunity rugby, concussion, etiology, inciting event, tackle 186 | SUZUKI et al.