Corrugated waveguide with matched phase and group velocities: an extended regime of wave-beam interaction.

We show that it is possible to design corrugated waveguides where phase and group velocities coincide at an inflection point of the dispersion relation, thereby allowing an extended regime of interaction with a charge particle beam. This provides a basis for designing travelling slow-wave structures with a broadband interaction between relativistic charged particle beams and propagating terahertz waves allowing an energy exchange between beam and wave, amplifying terahertz radiation. We employ Fourier-Mathieu expansion, which gives approximate analytic solutions to Maxwell equations in a corrugated waveguide with periodically undulating cross-section.

Reentrant DNA shells tune polyphosphate condensate size.

The inorganic biopolymer polyphosphate (polyP) occurs in all domains of life and affects myriad cellular processes. A longstanding observation is polyP's frequent proximity to chromatin, and, in many bacteria, its occurrence as magnesium (Mg)-enriched condensates embedded in the nucleoid region, particularly in response to stress. The physical basis of the interaction between polyP, DNA and Mg, and the resulting effects on the organization of the nucleoid and polyP condensates, remain poorly understood.

The Role of Inclusion in Collaborative Learning.

Collaborative methods for learning such as team-based learning, case-based learning, and problem-based learning have become leading methods for active learning within the field of health professions education. Critical thinking and exposure to diverse perspectives within a group are highlighted as important benefits of team-based learning. However, without consideration of the potential socioemotional, behavioral, and team dynamic challenges associated with this format of learning, the tenets which support a welcoming learning community can begin to deteriorate.

Low Prevalence of Reporting of Participant Race and Ethnicity in Gastroenterology Research Publications.

Introduction: Empirical information on the evolution of reporting race and ethnicity information in gastroenterology research is lacking. To facilitate understanding of where improvements are needed to increase diversity, equity, and inclusion in gastroenterology research, we aimed to evaluate reporting and representation by race and ethnicity in studies published in flagship US-based gastroenterology journals over 20 years.

Methods: We manually reviewed reporting and representation by race and ethnicity in all original research articles published in the American Journal of Gastroenterology and Gastroenterology in 2000, 2010, and 2020.