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The electric solar wind sail (E-sail) is a space propulsion concept that uses the natural solar wind dynamic pressure for producing spacecraft thrust. In its baseline form, the E-sail consists of a number of long, thin, conducting, and centrifugally stretched tethers, which are kept in a high positive potential by an onboard electron gun. The concept gains its efficiency from the fact that the effective sail area, i.e., the potential structure of the tethers, can be millions of times larger than the physical area of the thin tethers wires, which offsets the fact that the dynamic pressure of the solar wind is very weak. Indeed, according to the most recent published estimates, an E-sail of 1 N thrust and 100 kg mass could be built in the rather near future, providing a revolutionary level of propulsive performance (specific acceleration) for travel in the solar system. Here we give a review of the ongoing technical development work of the E-sail, covering tether construction, overall mechanical design alternatives, guidance and navigation strategies, and dynamical and orbital simulations. [ABSTRACT FROM AUTHOR]

Background: LGBTQ+ youth experience disproportionately high rates of online victimization (OV), referring to harmful remarks, images, or behaviors in online settings, which is associated with suicidal risk. Current services have gaps in supporting LGBTQ+ youth facing OV events. To address these gaps, this study aims to develop Flourish, a digital suicide prevention intervention for LGBTQ+ youth who have experienced OV., Methods: Qualitative interviews were conducted with 20 LGBTQ+ youth with past-year history of OV and lifetime history of suicidality, 11 of their parents, and 10 LGBTQ+-serving professionals. Subsequently, an iterative codesign process was conducted with 22 youth through individual and group design sessions, followed by usability testing. Data were recorded and transcribed. Qualitative interviews were analyzed using a qualitative description approach, and data from design sessions and usability testing were analyzed using rapid qualitative techniques., Results: Interviews with youth, parents, and professionals suggested preferences for Flourish to be a partially automated, text message intervention leveraging web-based content that is a safe space for LGBTQ+ youth to seek support for OV through education, coping skills, and help-seeking resources. School and mental health services professionals considered the potential for implementing Flourish within youth services settings. Usability testing, assessed through the System Usability Scale, yielded an average rating of 91, indicating excellent perceived usability., Conclusions: Flourish has potential to be an acceptable intervention to support LGBTQ+ youth following OV. Future steps will include testing the feasibility and efficacy of Flourish and further examining Flourish's potential for implementation within services for LGBTQ+ youth., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier B.V.)

Cyberbullying is a growing problem for middle school students. Bystander interventions that train witnesses to positively intervene can prevent cyberbullying. Through six focus groups, we explored forty-six middle school students' experiences with cyberbullying and opportunities for school-based prevention programs to encourage positive bystander behavior. Focus groups were recorded, transcribed, and analyzed using content analysis. Students viewed cyberbullying as an important problem with significant consequences. They noted hesitancy in reporting to parents and school personnel and felt more comfortable discussing cyberbullying with a near-peer (e.g., older sibling or friend). Students desired combining school-based and online programming with near-peer mentorship. This study suggests need for targeted prevention programs that center middle school students' lived experiences with cyberbullying and their preferences for learning and utilizing positive bystander strategies., Competing Interests: The authors report there are no competing interests to declare. This work was supported by AT&T and the National Institute of Mental Health under Grants T32 MH189051 and K23 MH111922.

Background: The aim of the study is to clinically and histologically evaluate the healing of advanced intrabony defects treated with open flap debridement and the adjunct implantation of granular beta tricalcium phosphate (beta-TCP)., Methods: Five patients, each displaying advanced combined 1- and 2-wall intrabony defects around teeth scheduled for extraction or root resection, were recruited. Approximately 6 months after surgery, the teeth or roots were removed together with a portion of their surrounding soft and hard tissues and processed for histologic evaluation., Results: The mean probing depth (PD) was reduced from 10.8 +/- 2.3 mm presurgically to 4.6 +/- 2.1 mm, whereas a mean clinical attachment level (CAL) gain of 5.0 +/- 0.7 mm was observed. The increase in gingival recession was 1.2 +/- 3.2 mm. The histologic evaluation indicated the formation of new cellular cementum with inserting collagen fibers to a varying extent (mean: 1.9 +/- 0.7 mm; range: 1.2 to 3.03 mm) coronal to the most apical extent of the root instrumentation. The mean new bone formation was 1.0 +/- 0.7 mm (range: 0.0 to 1.9 mm). In most specimens, beta-TCP particles were embedded in the connective tissue, whereas the formation of a mineralized bone-like or cementum-like tissue around the particles was only occasionally observed., Conclusion: The present data indicates that treatment of intrabony periodontal defects with this beta-TCP may result in substantial clinical improvements such as PD reduction and CAL gain, but this beta-TCP does not seem to enhance the regeneration of cementum, periodontal ligament, and bone.