First Observation of Self-Amplified Spontaneous Emission in a Free-Electron Laser at 109 nm Wavelength

We present the first observation of Self-Amplified Spontaneous Emission (SASE) in a free-electron laser (FEL) in the Vacuum Ultraviolet regime at 109 nm wavelength (11 eV). The observed free-electron laser gain (approx. 3000) and the radiation characteristics, such as dependency on bunch charge, angular distribution, spectral width and intensity fluctuations all corroborate the existing models for SASE FELs.Comment: 6 pages including 6 figures; e-mail: [email protected]

What is the Believability of Evidence That is Read or Heard By Physical Therapists?

Background Physical therapists obtain information from a variety of sources. The sources may influence their believability and use in clinical practice. Objectives In this hypothesis-based study, we queried physical therapists (PTs) on the believability of evidence across six musculoskeletal treatment domains and analyzed variables that predicted the strength of beliefs. Methods This international survey included six different language portals and used a snowball dispensation strategy. PTs who were credentialed, licensed, or who practiced in the field, were queried on the believability of six treatment domains (i.e., exercise, manual therapy, psychologically-informed practice, sports/occupational performance, thermal/electrical agents, and pain science/patient education) and potential predictors of believability (i.e., social media use, years of practice, time and access to literature, specialization, confidence in reviewing literature and attributions of the researcher). Results In total, 1098 PTs from 36 countries completed the survey. PTs had strong beliefs in what they read or hear about exercise, sports/occupational performance, pain science/patient education, and psychologically-informed interventions. There was only moderate believability regarding manual therapy treatment and weak believability associated with thermal/electrical agents. Multiple linear regression analyses revealed that the most robust predictor to outcome relationships included time and access to literature and believability of pain science/patient education, years of clinical practice and believability of psychologically informed practice, and believability of thermal/electrical agents. Conclusion An important takeaway from this study is that believability was influenced by several factors (primarily by years of practice, attributions of the researcher, and time and access to literature) and appeared to vary across treatment domains