Time-of-day effects on speed and accuracy performance during simulated shiftwork.

Performance on tasks involving speed and accuracy fluctuate throughout the 24-h day negatively affecting shift workers and organizations. Two simulated work shifts common in occupational settings were used to assess performance on a vigilance and math task. In study 1, 33 sleep-deprived participants completed a nightshift. In study 2, 32 partially sleep-deprived participants completed a dayshift. These studies found that performance differed between the type of task and the type of simulated shift where performance during the nightshift was worse than during the dayshift. In addition, collapsing speed and accuracy on the math task into inverse efficiency scores provided a unique measure that captured the impact of circadian rhythms during shiftwork. The current study also indicated that participants adopted cognitive strategies including speed-accuracy tradeoff and regulatory foci regarding work motivation (prevention focus and promotion focus) when completing the tasks depending on time-of-day, type of shift, circadian rhythms, and amount of sleep deprivation. This suggests that researchers and organizations should consider cognitive strategies in addition to the physiological components of sleep deprivation and circadian rhythms when investigating and documenting the impact of time-of-day due to different types of shiftwork conditions on performance and safety.

Loeys-Dietz syndrome caused by 1q41 deletion including TGFB2 is associated with a neurodevelopmental phenotype.

Loeys-Dietz syndrome (LDS) is a connective tissue disorder that commonly results in a dilated aorta, aneurysms, joint laxity, craniosynostosis, and soft skin that bruises easily. Neurodevelopmental abnormalities are uncommon in LDS. Two previous reports present a total of four patients with LDS due to pure 1q41 deletions involving TGFB2 (Gaspar et al., American Journal of Medical Genetics Part A, 2017, 173, 2289-2292; Lindsay et al., Nature Genetics, 2012, 44, 922-927). The current report describes an additional five patients with similar deletions. Seven of the nine patients present with some degree of hypotonia and gross motor delay, and three of the nine present with speech delay and/or intellectual disability (ID). The smallest deletion common to all patients is a 785 kb locus that contains two genes: RRP15 and TGFB2. Previous studies report that TGFB2 knockout mice exhibit severe perinatal anomalies (Sanford et al., Development, 1997, 124, 2659-2670) and TGFB2 is expressed in the embryonic mouse hindbrain floor (Chleilat et al., Frontiers in Cellular Neuroscience, 2019, 13). The deletion of TGFB2 may be associated with a neurodevelopmental phenotype with incomplete penetrance and variable expression.