PTS Knockout Cell Lysate

Objective Cyberbullying involvement carries mental health risks for adolescents, although post-traumatic stress (PTS) symptoms have not received strong attention in the UK. This study aimed to assess the overlap between cyber and traditional (ie, face-to-face) bullying, and the relationship to PTS symptoms in UK adolescents. Design A cross-sectional survey. Setting Four secondary schools in London,UK. Participants 2218 secondary school students (11-19 years). Main outcome measures The Olweus Bully/Victim Questionnaire and the Children Revised Impact of Events Scale. Results There was a significant overlap between traditional bullying and cyberbullying. However, cyberperpetrators were less frequently involved in concurrent traditional bullying. Of 2218 pupils, 46% reported a history of any kind of bullying (34% were involved in traditional bullying and 25% in cyberbullying), 17% as victims, 12% as perpetrators, and 4% as both victims and perpetrators. A significant proportion of those who were cybervictims (n=280; 35%), cyberbullies (n=178; 29.2%) or cyberbully-victims (n=77; 28.6%) presented clinically significant PTS symptoms. Cybervictims (both cyber-only and cyberbully-victims) suffered more intrusion (p=0.003; p<0.001) and avoidance (p=0.005; p<0.001) than cyberbullies. However, cyberbullies still suffered more PTS symptoms than the non-involved (intrusion: z=-3.67, p=0.001; avoidance: z=-3.57, p=0.002). Post-traumatic stress symptoms were significantly predicted (R-2=13.6) by cyber and traditional victimisation. Conclusions Cyberbullying, as victim only or as a victim-perpetrator, seems to be associated with multiple types of PTS symptoms. Cyber and traditional victimisation significantly predicted intrusion and avoidance. Paediatricians, general practitioners and mental health professionals need to be aware of possible PTS symptoms in young people involved in cyberbullying. Screening and early cost-effective treatments could be implemented.

Warming in arctic and boreal regions is increasing shrub cover and biomass. In southcentral Alaska, willow (Salix spp.) and alder (Alnus spp.) shrubs grow taller than many tree species and account for a substantial proportion of aboveground biomass, yet they are not individually measured as part of the operational Forest Inventory and Analysis (FIA) Program. The goal of this research was to test methods for landscape-scale mapping of tall shrub biomass in upper montane and subalpine environments using FIA-type plot measurements (n = 51) and predictor variables from imagery-based structure-from-motion (SfM) and airborne lidar. Specifically, we compared biomass models constructed from imagery acquired by unmanned aerial vehicle (UAV; similar to 1.7 cm pixels), imagery from the NASA Goddard's Lidar, Hyperspectral, and Thermal Airborne Imager (G-LiHT; similar to 3.1 cm pixels), and concomitant G-LiHT small-footprint lidar. Tall shrub biomass was most accurately predicted at 5 m resolution (R-2 = 0.81, RMSE = 1.09 kg m(-2)) using G-LiHT SfM color and structure variables. Lidar-only models had lower precision (R-2 = 0.74, RMSE = 1.26 kg m(-2)), possibly due to reduced model information content from variable multicollinearity or lower data density. Separate models for upper montane zones with trees and shrubs and subalpine zones with only shrubs were always chosen over single models based on minimization of Akaike's Information Criterion, indicating the need for variable sets robust to overhanging tree canopy. Decreasing point density from UAV (5000-8000 pts. m(-2)) to the G-LiHT SfM point cloud (500-2000 pts. m(-2)) had little impact on model fit, suggesting that high-resolution airborne imagery can extend SfM approaches well beyond line-of-sight restrictions for UAV platforms. Overall, our results confirmed that SfM from high-resolution imagery is a viable approach to estimate shrub biomass in the boreal region, especially when an existing lidar terrain model and local field calibration data are available to quantify uncertainty in the SfM point cloud and landscape-scale estimates of shrub biomass.