Wrist-worn accelerometers are increasingly being used for the assessment of physical activity in population studies, but little is known about their value for sleep assessment. We developed a novel ...method of assessing sleep duration using data from 4,094 Whitehall II Study (United Kingdom, 2012-2013) participants aged 60-83 who wore the accelerometer for 9 consecutive days, filled in a sleep log and reported sleep duration via questionnaire. Our sleep detection algorithm defined (nocturnal) sleep as a period of sustained inactivity, itself detected as the absence of change in arm angle greater than 5 degrees for 5 minutes or more, during a period recorded as sleep by the participant in their sleep log. The resulting estimate of sleep duration had a moderate (but similar to previous findings) agreement with questionnaire based measures for time in bed, defined as the difference between sleep onset and waking time (kappa = 0.32, 95%CI:0.29,0.34) and total sleep duration (kappa = 0.39, 0.36,0.42). This estimate was lower for time in bed for women, depressed participants, those reporting more insomnia symptoms, and on weekend days. No such group differences were found for total sleep duration. Our algorithm was validated against data from a polysomnography study on 28 persons which found a longer time window and lower angle threshold to have better sensitivity to wakefulness, while the reverse was true for sensitivity to sleep. The novelty of our method is the use of a generic algorithm that will allow comparison between studies rather than a "count" based, device specific method.
Anthropogenic disturbances are known to cause significant physiological and behavioural changes in animals and, thus, are the critical focus of numerous studies. Light pollution is an increasingly ...recognised source of disturbance that has the potential to impact animal physiology and behaviour. Here, we investigate the effect of constant light on a personality trait and metabolic rate in the European hermit crab Pagurus bernhardus. We used Bayesian mixed models to estimate average behavioural change (i.e. sample mean level behavioural plasticity) and between- and within-individual variation in boldness in response to laboratory light. Hermit crabs experiencing constant light were consistently less bold and had a higher metabolic rate than those kept under a standard laboratory light regime (12:12 h light/dark). However, there was no effect of light on individual consistency in behaviour. As boldness is associated with coping with risk, hermit crabs exposed to light pollution at night may experience increased perceived predation risk, adjusting their behaviour to compensate for the increased conspicuousness. However, reduced boldness could lead to lower rates of foraging and this, in combination with elevated metabolic rate, has the potential for a reduction in energy balance.
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•Coastal zones are highly affected by light pollution.•Constant light reduced boldness and increased metabolism in hermit crabs.•Behavioural and metabolic changes can affect population stability.•Light pollution might disrupt hermit crab populations changing intertidal diversity.
Attention-deficit hyperactivity disorder (ADHD) is a common paediatric neurodevelopmental disorder with substantial effect on families and society. Alternatives to traditional care, including novel ...digital therapeutics, have shown promise to remediate cognitive deficits associated with this disorder and may address barriers to standard therapies, such as pharmacological interventions and behavioural therapy. AKL-T01 is an investigational digital therapeutic designed to target attention and cognitive control delivered through a video game-like interface via at-home play for 25 min per day, 5 days per week for 4 weeks. This study aimed to assess whether AKL-T01 improved attentional performance in paediatric patients with ADHD.
The Software Treatment for Actively Reducing Severity of ADHD (STARS-ADHD) was a randomised, double-blind, parallel-group, controlled trial of paediatric patients (aged 8–12 years, without disorder-related medications) with confirmed ADHD and Test of Variables of Attention (TOVA) Attention Performance Index (API) scores of −1·8 and below done by 20 research institutions in the USA. Patients were randomly assigned 1:1 to AKL-T01 or a digital control intervention. The primary outcome was mean change in TOVA API from pre-intervention to post-intervention. Safety, tolerability, and compliance were also assessed. Analyses were done in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, NCT02674633 and is completed.
Between July 15, 2016, and Nov 30, 2017, 857 patients were evaluated and 348 were randomly assigned to receive AKL-T01 or control. Among patients who received AKL-T01 (n=180 52%; mean SD age, 9·7 1·3 years) or control (n=168 48%; mean SD age, 9·6 1·3 years), the non-parametric estimate of the population median change from baseline TOVA API was 0·88 (95% CI 0·24–1·49; p=0·0060). The mean (SD) change from baseline on the TOVA API was 0·93 (3·15) in the AKL-T01 group and 0·03 (3·16) in the control group. There were no serious adverse events or discontinuations. Treatment-related adverse events were mild and included frustration (5 3% of 180) and headache (3 2% of 180). Patient compliance was a mean of 83 (83%) of 100 expected sessions played (SD, 29·2 sessions).
Although future research is needed for this digital intervention, this study provides evidence that AKL-T01 might be used to improve objectively measured inattention in paediatric patients with ADHD, while presenting minimal adverse events.
Sponsored by Akili Interactive Labs.
The present study examined age-related differences in multisensory integration and the role of attention in age-related differences in multisensory integration. The sound-induced flash illusion-the ...misperception of the number of visual flashes due to the simultaneous presentation of a different number of auditory beeps-was used to examine the strength of multisensory integration in older and younger observers. The effects of integration were examined when discriminating 1-3 flashes, 1-3 beeps, or1-3 flashes presented with 1-3 beeps. Stimulus conditions were blocked according to these conditions with baseline (unisensory) performance assessed during the multisensory block. Older participants demonstrated greater multisensory integration-a greater influence of the beeps when judging the number of visual flashes-than younger observers. In a second experiment, the role of attention was assessed using a go/no-go paradigm. The results of Experiment 2 replicated those of Experiment 1. In addition, the strength of the illusion was modulated by the sensory domain of the go/no-go task, though this did not differ by age group. In the visual go/no-go task we found a decrease in the illusion, yet in the auditory go/no-go task we found an increase in the illusion. These results demonstrate that older individuals exhibit increased multisensory integration compared with younger individuals. Attention was also found to modulate the strength of the sound-induced flash illusion. However, the results also suggest that attention was not likely to be a factor in the age-related differences in multisensory integration.
Octopus, squid and cuttlefish are renowned for rapid adaptive coloration that is used for a wide range of communication and camouflage. Structural coloration plays a key role in augmenting the skin ...patterning that is produced largely by neurally controlled pigmented chromatophore organs. While most iridescence and white scattering is produced by passive reflectance or diffusion, some iridophores in squid are actively controlled via a unique cholinergic, non-synaptic neural system. We review the recent anatomical and experimental evidence regarding the mechanisms of reflection and diffusion of light by the different cell types (iridophores and leucophores) of various cephalopod species. The structures that are responsible for the optical effects of some iridophores and leucophores have recently been shown to be proteins. Optical interactions with the overlying pigmented chromatophores are complex, and the recent measurements are presented and synthesized. Polarized light reflected from iridophores can be passed through the chromatophores, thus enabling the use of a discrete communication channel, because cephalopods are especially sensitive to polarized light. We illustrate how structural coloration contributes to the overall appearance of the cephalopods during intra- and interspecific behavioural interactions including camouflage.
The present study examined age-related differences in multisensory integration and the effect of spatial disparity on the sound-induced flash illusion--an illusion used in previous research to assess ...age-related differences in multisensory integration. Prior to participation in the study, both younger and older participants demonstrated their ability to detect 1-2 visual flashes and 1-2 auditory beep presented unimodally. After passing the pre-test, participants were then presented 1-2 flashes paired with 0-2 beeps that originated from one of five speakers positioned equidistantly 100 cm from the participant. One speaker was positioned directly below the screen, two speakers were positioned 50 cm to the left and right from the center of the screen, and two more speakers positioned to the left and right 100 cm from the center of the screen. Participants were told to report the number of flashes presented and to ignore the beeps. Both age groups showed a significant effect of the beeps on the perceived number of flashes. However, neither younger nor older individuals showed any significant effect of spatial disparity on the sound-induced flash illusion. The presence of a congruent number of beeps increased accuracy for both older and younger individuals. Reaction time data was also analyzed. As expected, older individuals showed significantly longer reaction times when compared to younger individuals. In addition, both older and younger individuals showed a significant increase in reaction time for fusion trials, where two flashes and one beep are perceived as a single flash, as compared to congruent single flash trials. This increase in reaction time was not found for fission trials, where one flash and two beeps were perceived as two flashes. This suggests that processing may differ for the two forms for fission as compared to fusion illusions.
This arts-based narrative in/queer/y explores the subjectivity of gay college men living with HIV through the stories and art of two participants. Despite their significantly different lives, the two ...men shared a subjectivity that was also reflected in the lives of other participants. Care of the self reflects Foucault's search for a way of life that resisted normalizing discourses of identity and served as our conceptual framework. Homophobic AIDS discourse, which manifested as institutional silence about the presence of students living with HIV on college campuses, and homonormative discourses of gay respectability created an environment of contempt. This environment resulted in a care of the self style we call the art of masked advocacy. This art involved advocating for themselves and other students living with HIV while attempting to mitigate contempt. Combating institutional silence and other forms of contempt for gay men living with HIV creates individual and institutional tensions, which we explore.
A major problem for the rapidly growing population of older adults (age 65 and over) is age-related declines in vision, which have been associated with increased risk of falls and vehicle crashes. ...Research suggests that this increased risk is associated with declines in contrast sensitivity and visual acuity. We examined whether a perceptual-learning task could be used to improve age-related declines in contrast sensitivity. Older and younger adults were trained over 7 days using a forced-choice orientation-discrimination task with stimuli that varied in contrast with multiple levels of additive noise. Older adults performed as well after training as did college-age younger adults prior to training. Improvements transferred to performance for an untrained stimulus orientation and were not associated with changes in retinal illuminance. Improvements in far acuity in younger adults and in near acuity in older adults were also found. These findings indicate that behavioral interventions can greatly improve visual performance for older adults.
Contrast-enhanced magnetic resonance angiography is a vital tool for evaluating vascular pathology. However, concerns about the limitations and safety of gadolinium-based contrast agents have led to ...an interest in alternative agents. Methemoglobin (metHb) increases the T1-weighted signal intensity of the magnetic resonance image of blood and could provide a safe and effective alternative. MetHb can be produced by the reaction of nitric oxide (NO) gas with oxyhemoglobin followed by natural conversion back to hemoglobin by cytochrome b5 reductase. Since rapid production of metHb
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NO has not been studied, the effectiveness of producing metHb
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NO delivery to blood was evaluated using a hollow-fiber module. MetHb production began immediately and > 90% conversion was achieved within 10 min. MetHb remained stable for at least 90 min when NO delivery was removed following metHb formation. Comparison of experimental data for metHb formation with model predictions showed that only a fraction of the NO delivered was utilized for metHb production, suggesting an additional fast reaction of NO with other blood constituents. Directly delivering NO to blood for the rapid formation of metHb provides a potential platform for producing metHb as an alternative contrast agent.
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