We examine a new variant of the classic prisoners and light switches puzzle: A warden leads his $n$ in out $r$ rooms, one at time, some order, with each prisoner eventually visiting every room an arbitrarily large number times. The rooms are indistinguishable, except that has $s$ switches; win their freedom if point can correctly declare been least once. What is minimum per room, $s$, such mana...

we conducted this study to determine the risk of transmission of q fever to health care workers (hcws) during perioperative exposure to coxiella burnetii -infected thoracic endovascular aneurysm stent graft. pre-operative and 6-week post-operative phase i and ii igg q fever antibody titers were determined in 14 staff members of an operation room. the room had a negative pressure and all the mem...

To the editor: It was recently reported that influenza A was cultured in 62 double rooms at the Wisconsin Veterans Home over six seasons. The roommate was infected in 12 (19.4%). During 3,294 resident-seasons, influenza was cultured in 208 single rooms (6.3%). Those who lived in double rooms with a culture-positive roommate had a 3.07 relative risk (95% confidence interval51.61–5.78) of acquiri...