Filamentation of a relativistic proton bunch in plasma.

We show in experiments that a long, underdense, relativistic proton bunch propagating in plasma undergoes the oblique instability, which we observe as filamentation. We determine a threshold value for the ratio between the bunch transverse size and plasma skin depth for the instability to occur. At the threshold, the outcome of the experiment alternates between filamentation and self-modulation instability (evidenced by longitudinal modulation into microbunches).

Hosing of a Long Relativistic Particle Bunch in Plasma.

Experimental results show that hosing of a long particle bunch in plasma can be induced by wakefields driven by a short, misaligned preceding bunch. Hosing develops in the plane of misalignment, self-modulation in the perpendicular plane, at frequencies close to the plasma electron frequency, and are reproducible. Development of hosing depends on misalignment direction, its growth on misalignment extent and on proton bunch charge.

The accurate identification of the percutaneous tracheostomy insertion site using digital palpation in children.

Background: Percutaneous tracheostomy (PT) may be required frequently in long-term ventilated intensive care patients. Although the overall risks are low, serious complications may occur, especially in children. Hence, this study aimed to assess physician accuracy in identifying PT insertion sites by digital palpation in children aged between 5 and 13 years.

Evaluation of psychological impact of COVID-19 on anesthesiology residents in the United States.

The aim of our study was to evaluate the impact of COVID-19 on the mental health of in-training anesthesiology residents in the United States. A link containing validated survey tools including the Depression-Anxiety-Stress-Scale (DASS-21), the Abbreviated Maslach Burnout Inventory (aMBI), and the Brief Resilient Coping Scale (BRCS) along with questions related to work environment, and additional personal factors were emailed to 159 Anesthesiology residency programs across the US. 143 responses were received of which 111 were complete.