Publications by authors named "Melanie Rueger"
Safe and successful operation of the International Space Station robotic arm is a complex task requiring difficult bimanual hand coordination and spatial reasoning skills, adherence to operating procedures and rules, and systems knowledge. These task attributes are all potentially affected by chronic sleep loss and circadian misalignment. In a randomized, placebo-controlled, cross-over trial examining the impact of regularly timed low-dose caffeine (0.
View Article and Find Full Text PDFHuman cognitive impairment associated with sleep loss, circadian misalignment and work overload is a major concern in any high stress occupation but has potentially catastrophic consequences during spaceflight human robotic interactions. Two safe, wake-promoting countermeasures, caffeine and blue-enriched white light have been studied on Earth and are available on the International Space Station. We therefore conducted a randomized, placebo-controlled, cross-over trial examining the impact of regularly timed low-dose caffeine (0.
View Article and Find Full Text PDFArticle Synopsis
- The PERIOD2 (PER2) gene is essential for maintaining our body's circadian clock and influences daily rhythms like sleep and eating patterns.
- A specific variant of the PER2 gene (Rs35333999), common in Europeans, is linked to a later chronotype, meaning people with this variant tend to have a later timing for their biological activities.
- Research shows that carriers of the minor allele (T) of this variant have longer intrinsic circadian periods, with significant differences in measurements of body temperature and plasma melatonin compared to non-carriers, highlighting PER2's role in individual chronotype differences.
Study Objectives: To investigate sex differences in the effect of sleep deprivation on performance, accounting for menstrual phase in women.
Methods: We examined alertness data from 124 healthy women and men (40 women, 84 men; aged 18-30 years) who maintained wakefulness for at least 30 hr in a laboratory setting using a constant routine protocol. Objective alertness was assessed every 2 hr using a 10 min psychomotor vigilance task.
The risk of type 2 diabetes (T2D) is increased by abnormalities in sleep quantity and quality, circadian alignment, and melatonin regulation. A common genetic variant in a receptor for the circadian-regulated hormone melatonin (MTNR1B) is associated with increased fasting blood glucose and risk of T2D, but whether sleep or circadian disruption mediates this risk is unknown. We aimed to test if MTNR1B diabetes risk variant rs10830963 associates with measures of sleep or circadian physiology in intensive in-laboratory protocols (n = 58-96) or cross-sectional studies with sleep quantity and quality and timing measures from self-report (n = 4,307-10,332), actigraphy (n = 1,513), or polysomnography (n = 3,021).
View Article and Find Full Text PDFStudies in humans and mice revealed that circadian phase shifting effects of light are larger at the beginning of a light exposure interval than during subsequent exposure. Little is known about the dynamics of this response reduction phenomenon. Here the authors propose a method to obtain information on the progression of phase during light exposure.
View Article and Find Full Text PDFContext: There is evidence of both hypothalamic-pituitary-adrenocortical (HPA) axis and cognitive dysfunction in type 2 diabetes mellitus (T2DM). However, the exact nature and the associations between these abnormalities remain unclear.
Objectives: The aim of the study was to characterize the nature of the HPA dysregulation in T2DM and ascertain whether impaired cognition in T2DM could be attributed to these abnormalities.