The effect of pulsed xenon ultraviolet light disinfection on healthcare-associated Clostridioides difficile rates in a tertiary care hospital.

Ultraviolet (UV) light has destructive activity against pathogenic bacteria including Clostridioides difficile spores. Portable pulsed-xenon UV disinfecting devices were implemented for terminal room cleaning in 6 units of our academic hospital with high C. difficile infection (CDI) rates. CDI rates were measured in a 9-month period before and a 9-month period after device implementation. Despite documented administration of UV disinfection for 87% of terminal room cleaning, no impact on CDI rates was detected.

Acrobatic courtship display coevolves with brain size in manakins (Pipridae).

Acrobatic display behaviour is sexually selected in manakins (Pipridae) and can place high demands on many neural systems. Manakin displays vary across species in terms of behavioural complexity, differing in number of unique motor elements, production of mechanical sounds, cooperation between displaying males, and construction of the display site. Historically, research emphasis has been placed on neurological specializations for vocal aspects of courtship, and less is known about the control of physical, non-vocal displays. By examining brain evolution in relation to extreme acrobatic feats such as manakin displays, we can vastly expand our knowledge of how sexual selection acts on motor behaviour. We tested the hypothesis that sexual selection for complex motor displays has selected for larger brains across the Pipridae. We found that display complexity positively predicts relative brain weight (adjusted for body size) after controlling for phylogeny in 12 manakin species and a closely related flycatcher. This evidence suggests that brain size has evolved in response to sexual selection to facilitate aspects of display such as motor, sensorimotor, perceptual, and cognitive abilities. We show, for the first time, that sexual selection for acrobatic motor behaviour can drive brain size evolution in avian species and, in particular, a family of suboscine birds.