A5023320358- Circadian rhythm and melatonin
- Sleep and Wakefulness Research
- Sleep and related disorders
- Sleep and Work-Related Fatigue
- Spaceflight effects on biology
- Hospital Admissions and Outcomes
- Photoreceptor and optogenetics research
- Impact of Light on Environment and Health
- Heart Rate Variability and Autonomic Control
- Patient Safety and Medication Errors
- Light effects on plants
- Neurobiology and Insect Physiology Research
- Healthcare professionals’ stress and burnout
- Human-Automation Interaction and Safety
- Psychological and Temporal Perspectives Research
- Optical Imaging and Spectroscopy Techniques
- Neuroscience of respiration and sleep
- Birth, Development, and Health
- Dietary Effects on Health
- Visual perception and processing mechanisms
- Online Learning and Analytics
- Ergonomics and Musculoskeletal Disorders
- Innovative Teaching Methods
- Thermoregulation and physiological responses
- Optical Wireless Communication Technologies
Merrimack College
2023-2025
Harvard University
2015-2024
Brigham and Women's Hospital
2015-2024
Circadian (United States)
2016-2024
Boston University
2022
Boston Children's Hospital
2020
California Pacific Medical Center
2020
University of Colorado Denver
2020
Seattle Children's Hospital
2020
Northwestern University
2020
Key points The human circadian pacemaker generates near‐24‐h rhythms that set the timing of many physiological, metabolic and behavioural body rhythms, is synchronized to environmental time primarily by 24 h light–dark cycle. magnitude direction resetting response light depends on day exposure, change in responses over summarized a phase curve (PRC). A previous PRC showed 6.7 bright white exposure maximally shifted 3 h. We show 1 pulse ∼2 h, despite representing only ∼15% duration. This...
In mammals, the pupillary light reflex is mediated by intrinsically photosensitive melanopsin-containing retinal ganglion cells that also receive input from rod–cone photoreceptors. To assess relative contribution of melanopsin and photoreceptors to in humans, we compared responses normally sighted individuals ( n = 24) with a blind individual lacking function. Here, show visual are required for normal continuous exposure at low irradiance levels, sustained constriction during...
The photic resetting response of the human circadian pacemaker depends on timing exposure, and direction magnitude resulting shift is described by a phase curve (PRC). Previous PRCs in humans have utilized high-intensity polychromatic white light. Given that photoreception system maximally sensitive to short-wavelength visible light, aim current study was construct PRC blue (480 nm) light compare it 10,000 lux constructed previously using similar protocol. Eighteen young healthy participants...
The effects on patient safety of eliminating extended-duration work shifts for resident physicians remain controversial. We conducted a multicenter, cluster-randomized, crossover trial comparing two schedules pediatric during their intensive care unit (ICU) rotations: that included 24 hours or more (control schedules) and eliminated extended cycled through day night 16 less (intervention schedules). primary outcome was serious medical errors made by physicians, assessed surveillance,...
Human circadian, neuroendocrine, and neurobehavioral responses to light are mediated primarily by melanopsin-containing intrinsically-photosensitive retinal ganglion cells (ipRGCs) but they also receive input from visual photoreceptors. Relative photoreceptor contributions irradiance- duration-dependent results for long-duration exposures limited. We constructed irradiance-response curves action spectra melatonin suppression circadian resetting in participants exposed 6.5-h monochromatic...
Increased severity of problematic daytime behavior has been associated with poorer sleep quality in individuals autism spectrum disorder. In this work, we investigate whether relationship holds a real‐time setting, such that an individual's prior can be used to predict their subsequent behavior. We analyzed extensive real‐world dataset containing over 20,000 nightly observations matched challenging behaviors (aggression, self‐injury, tantrums, property destruction and index) across 67...
The risk of type 2 diabetes (T2D) is increased by abnormalities in sleep quantity and quality, circadian alignment, melatonin regulation. A common genetic variant a receptor for the circadian-regulated hormone (MTNR1B) associated with fasting blood glucose T2D, but whether or disruption mediates this unknown. We aimed to test if MTNR1B rs10830963 associates measures physiology intensive in-laboratory protocols (n = 58–96) cross-sectional studies quality timing from self-report 4,307–10,332),...
Background: Sleep-wake disturbances are highly prevalent following traumatic brain injury (TBI), impeding rehabilitaion and quality of life. However, the mechanisms underlying these sleep disturnbances unclear, efficacious treatments lacking. To investigate possible disturbance in TBI, we examined characteristics circadian rhythm melatonin, a hormone involved sleep-wake regulation. We compared TBI patients reporting with age- gender-matched healthy volunteers. Methods: conducted an overnight...
Intraindividual night-to-night sleep duration is often insufficient and variable. Here we report the effects of such chronic variable deficiency on neurobehavioral performance ability state-of-the-art models to predict these changes. Eight healthy males (mean age ± SD: 23.9 2.4 years) studied at our inpatient intensive physiologic monitoring unit completed an 11-day protocol with a baseline 10-hour opportunity three cycles two 3-hour time-in-bed (TIB) one TIB opportunities. Participants...
BACKGROUND. In humans, a single light exposure of 12 minutes and multiple-millisecond exposures can shift the phase circadian pacemaker. We investigated response human pacemaker to 15-second or 2-minute pulse administered during biological night.
OBJECTIVES: Extended-duration work rosters (EDWRs) with shifts of 24+ hours impair performance compared rapid cycling (RCWRs) that limit to 16 in postgraduate year (PGY) 1 resident-physicians. We examined the impact a RCWR on PGY 2 and 3 METHODS: Data from 294 resident-physicians were analyzed multicenter clinical trial 6 US PICUs. Resident-physicians worked 4-week EDWRs every third or fourth shift, an which most ≤16 consecutive hours. Participants completed daily sleep log 10-minute...
Abstract While studies suggest that light and feeding patterns can reset circadian rhythms in various metabolites, whether these shifts follow a predictable pattern is unknown. We describe the first phase response curves (PRC) for lipids hepatic proteins to combined food stimuli. The timing of plasma was assessed by constant routine before after exposure 6.5-hour blue standard meal schedule, which systematically varied ~20° between individuals. find shift according PRC, with generally...
There is assumed to be a monotonic association between melatonin suppression and circadian phase resetting induced by light exposure. We tested the in humans. Sixteen young healthy participants received nocturnal bright (∼9500 lux) exposure of continuous or intermittent patterns, different durations ranging from 12 min 6.5 h. Intermittent patterns showed significant shifts with disproportionately less suppression. Each every stimulus an pattern similar degree suppression, but did not appear...
Abstract Aging alters the amplitude and phase of centrally regulated circadian rhythms. Here we evaluate whether peripheral rhythmicity in plasma lipidome is altered by aging through retrospective lipidomics analysis on samples collected 24 healthy individuals (9 females; mean ± SD age: 40.9 18.2 years) including 12 younger (4 females, 23.5 3.9 middle-aged older, (5 58.3 4.2 every 3 h throughout a 27-h constant routine (CR) protocol, which allows separating evoked changes from endogenously...
Abstract Study Objectives We previously reported that during a 45-day simulated space mission, dynamic lighting schedule (DLS) improved circadian phase alignment and performance assessed once on selected days. This study aimed to evaluate how DLS affected 5-minute psychomotor vigilance task (PVT) administered multiple times per day Methods Sixteen crewmembers (37.4 ± 6.7 years; 5F) underwent six cycles of 2 × 8-hour/night followed by 5 5-hour/night sleep opportunities. During the (n = 8),...
ABSTRACT Introduction Risk‐taking is associated with dynamic outcomes, including psychopathology and types of learning related to adaptive behaviors. The goal the current study was (1) evaluate risk‐related in a sample neurotypical young adults (2) determine how risk‐taking motivation emotional processing (as measured by BIS/BAS Scales). Methods Fifty‐eight ( M age = 19.66 years, SD 1.43 years; 74% female) completed Balloon Emotional Learning Task (BELT) measure tendencies processing,...
We compared resident physician work hours and sleep in a multicenter clustered-randomized crossover clinical trial that randomized physicians to an Extended Duration Work Roster (EDWR) with extended-duration (≥24 hr) shifts or Rapidly Cycling (RCWR), which scheduled shift lengths were limited 16 fewer consecutive hours.Three hundred two enrolled completed 370 1 month pediatric intensive care unit rotations six US academic medical centers. Sleep was objectively estimated wrist-worn...
Abstract: The rhythm of plasma melatonin concentration is currently the most accurate marker endogenous human circadian pacemaker. A number methods exist to estimate phase and amplitude from observed rhythm. However, almost all these are limited because they depend on shape pulse, which vary among individuals can be affected by environmental influences, especially light. Furthermore, not based underlying known physiology secretion clearance, therefore cannot accurately quantify changes in...
Totally blind individuals are highly likely to suffer from Non-24-Hour Sleep-Wake Disorder due a failure of light reset the circadian pacemaker in suprachiasmatic nuclei. In this outpatient case series, we investigated whether daily caffeine administration could entrain non-entrained patients alleviate symptoms non-24-hour sleep–wake disorder. Three totally males (63.0 ± 7.5 years old) were studied at home over ~4 months. Urinary 6-sulphatoxymelatonin (aMT6s) rhythms measured for 48 h every...
Circadian adaptation to shifted sleep/wake schedules may be facilitated by optimizing the timing, intensity and spectral characteristics of light exposure, which is principal time cue for mammalian circadian pacemaker, possibly strategically timing nonphotic cues such as exercise. Therefore, phase resetting exercise was assessed in 44 healthy participants (22 females, mean age [±SD] 36.2 ± 9.2 years), who completed 8-day inpatient experiments simulating night shiftwork, included either an 8...