Ultrasound assessments of organs and blood vessels before and after 40 days isolation in a cavern (deep time experiment 2021)

Introduction: Spaceflight simulation studies like confinement in small volume habitat with limited physical activity have reported even after 60 days an abnormal arterial wall adaptation with increase thickness or stiffness. The purpose of the current study was to determine the effects on blood vessel and organ structure of 40 days of isolation in a huge habitat with intensive physical activity.Method: Data were collected from 14 individuals (7 male) who isolated in a cavern for 40-days while performing normal daily activities without time references. Ultrasound assessments were performed pre- and post-isolation using a teleoperated system with eight different acoustic windows to obtain 19 measurements on 12 different organ/vascular structures which included the common carotid artery, femoral artery, tibial artery, jugular vein, portal vein, bile duct, kidney, pancreas, abdominal aorta, cervical and lumbar vertebral distance, and Achilles tendon.Results: Common carotid artery measures, including the intima media thickness, stiffness index, and the index of reflectivity measured from the radiofrequency signal, were not changed with isolation. Similarly, no differences were found for femoral artery measurements or measurements of any of the other organs/vessels assessed. There were no sex differences for any of the assessments.Discussion: Results from this study indicate a lack of physiological effects of 40-days of isolation in a cavern, contrary to what observed in previous 60 days confinement. This suggests a potential protective effect of sustained physical activity, or reduced environmental stress inside the huge volume of the confined facility

Effets d un entrainement physique et sportif régulier, chronique ou temporaire, sur les rythmes biologiques du travailleur de nuit

CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

Personality Traits Associated with the Risk of Exercise Dependence in Ultraendurance Athletes: A Cross-Sectional Study

Exercise dependence (ED) is common in endurance athletes and can lead to physical and psychological distress with various health effects. We designed a prospective cross-sectional study to investigate the personality traits associated with ED among ultraendurance athletes. A total of 507 participants (41.6 (9.8) years, men: 73.7%) completed (1) a screening questionnaire about sociodemographic data, sporting habits, and healthcare data, (2) the Exercise Dependence Scale-Revised (EDS-R, 21 items scored from 1 (never) to 6 (always), 7 subscales), (3) the Big Five Inventory (BFI), and (4) 2 items of the SCOFF (Sick-Control-One Stone-Fat-Food) questionnaire regarding possible eating disorders. Based on the EDS-R scores, 37 (7.3%) participants were at risk for ED (scores ≥ 5/6 on ≥3 subscales), 366 (72.2%) were nondependent but symptomatic (scores ≥ 3/6 on ≥3 subscales), and 104 (20.5%) were asymptomatic. Participants with ED had a greater training volume and a higher prevalence of possible eating disorders. A higher level of neuroticism was associated with increased EDS-R scores (r = 0.294; p p < 0.001). The association between neuroticism and ED was not moderated by the presence of eating disorders. These findings will help to screen ultraendurance athletes at risk for ED and optimize their care

Influence of Circadian Rhythms on the Temporal Features of Motor Imagery for Older Adult Inpatients

International audienceObjectiveTo examine the circadian modulation on motor imagery quality for older adult inpatients to determine the best time of day to use motor imagery in rehabilitation activities.DesignTime series posttest only.SettingInpatient rehabilitation center.ParticipantsParticipants included older adult inpatients (N=34) who were hospitalized for diverse geriatric or neurogeriatric reasons. They were able to sit without assistance, manipulate objects, and walk 10m in <30 seconds without technical help or with a walking stick.InterventionNone.Main Outcome MeasuresThe executed and imagined durations of writing and walking movements were recorded 7 times a day (9:15 am–4:45 pm), at times compatible with the hours of rehabilitation activities. Motor imagery quality was evaluated by computing the isochrony index (ie, absolute difference between the average duration of executed and imagined actions) for each trial and each inpatient. The cosinor method was used to analyze the time series for circadian rhythmicity.ResultsImagined movements duration and isochrony index exhibited circadian modulations, whereas no such rhythmic changes appeared for executed movements. Motor imagery quality was better late in the morning, at approximately 10:18 am and 12:10 pm for writing and walking, respectively.ConclusionsCognitive and sensorimotor aspects of motor behaviors differed among the older adults. The temporal features of motor imagery showed a clear circadian variation. From a practical perspective, this study offers information on an effective schedule for motor imagery in rehabilitation activities with older adult inpatients

Disruption of the circadian period of body temperature by the anesthetic propofol

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Risk of obesity in male shift workers: A chronophysiological approach

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Effects of acute administration of melatonin on attentional, executive, and working memory processes in rats

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NSE S100B protein blood level assessment during a long-distance trail race

The acute and chronic consequences of long-distance running on brain function have received little attention. The impact of such a hard-physical burden associated with sleep privation during such events such has never been explored in terms of neuropsychological function and brain damage

Vestibular stimulation by 2G hypergravity modifies resynchronization in temperature rhythm in rats

International audienceInput from the light/dark (LD) cycle constitutes the primary synchronizing stimulus for the suprachiasmatic nucleus (SCN) circadian clock. However, the SCN can also be synchronized by non-photic inputs. Here, we hypothesized that the vestibular system, which detects head motion and orientation relative to gravity, may provide sensory inputs to synchronize circadian rhythmicity. We investigated the resynchronization of core temperature (Tc) circadian rhythm to a six-hour phase advance of the LD cycle (LD + 6) using hypergravity (2 G) as a vestibular stimulation in control and bilateral vestibular loss (BVL) rats. Three conditions were tested: an LD + 6 exposure alone, a series of seven 2 G pulses without LD + 6, and a series of seven one-hour 2 G pulses (once a day) following LD + 6. First, following LD + 6, sham rats exposed to 2 G pulses resynchronized earlier than BVL rats (p = 0.01), and earlier than sham rats exposed to LD + 6 alone (p = 0.002). Each 2 G pulse caused an acute drop of Tc in sham rats (−2.8 ± 0.3 °C; p < 0.001), while BVL rats remained unaffected. This confirms that the vestibular system influences chronobiological regulation and supports the hypothesis that vestibular input, like physical activity, should be considered as a potent time cue for biological rhythm synchronization, acting in synergy with the visual system

<span style="font-size:11.0pt;mso-bidi-font-size: 10.0pt;font-family:"Times New Roman";mso-fareast-font-family:"Times New Roman"; mso-ansi-language:EN-GB;mso-fareast-language:EN-US;mso-bidi-language:AR-SA" lang="EN-GB">Twenty-four-hour pattern in French firemen of lag time response to out-of-hospital cardiac arrest and work-related injury^#</span>

420-424Circadian cognitive and physical rhythms plus 24 h patterns of accidents and work-related injuries (WRI) have been verified in numerous studies. However, rarely, if ever, have 24 h temporal differences in both work performance and risk of WRI been assessed in the same group of workers. We explored in a homogenous group of French firemen (FM) 24 h patterns of both lag time (LT) response duration to emergency calls for medical help (ECFM) for life-threatening out-of-hospital cardiac arrests (OHCA), used as a non-specific index of work performance, and WRI. Our studies demonstrate rather high amplitude statistically significant 24 h patterns of the two variables. The LT response duration was twice as long ~0500 h (slowest response) than ~1600 h (fastest response). In the same group of FM, the actual number WRI/h was greatest ~1600 h and lowest in the early morning hours. However, the 24 h pattern of the relative risk (RR) of WRIs, i.e., per clock hour number of WRI/(total number of responses to emergency calls x number of FM at risk per response), was very different, the RR being greatest ~0200 h and lowest in the afternoon. The 24 h pattern in LT response duration to ECMH for OHCA and RR of WRI was strongly correlated (r=+0.85, P<0.01), with the nocturnal trough (slowest response) in LT response duration coinciding with the nocturnal peak RR of WRI. These findings indicate the requirement for circadian rhythm-based interventions to improve the nocturnal compromised work performance and elevated risk of WRI of shift-working FM. </span