The impact of total sleep deprivation upon supine and head up tilt hemodynamics using non-linear analysis in firefighters

2021 ◽  
Vol 70 ◽  
pp. 102989
Author(s):  
Sławomir Kujawski ◽  
Katarzyna Buszko ◽  
Agnieszka Cudnoch-Jędrzejewska ◽  
Joanna Słomko ◽  
Djordje G. Jakovljevic ◽  
...  
2021 ◽  
Vol 12 (4) ◽  
pp. 17
Author(s):  
Assoumou Ondo ◽  
Beau Jency Owono Ondo

This article analyzes the relationship between Government size and corruption. Unlike the works in the way which suppose a linear relationship between the two variables, we estimate a panel with change of the modes to characterize the impact of the size of the Central Government on corruption, in the countries of the economic community and monetary of Central Africa (EMCCA). The results show that there is a non-linear relationship between these two variables. Indeed, a strong involvement of the Government in economic activity results in a significant increase in corruption when the Government exceeds a size of 13.5508% of the GDP.


SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A117-A117
Author(s):  
T J Cunningham ◽  
R M Bottary ◽  
E A Kensinger ◽  
R Stickgold

Abstract Introduction The ability to perceive emotions is a socially-relevant skill critical for healthy interpersonal functioning, while deficits in this ability are associated with psychopathology. Total sleep deprivation (TSD) has been shown to have deleterious effects on emotion perception, yet the extent to which these impairments persist across the day with continued wakefulness, or if brief periods of recovery sleep can restore emotion perception abilities, remains unexplored. Methods Participants viewed slideshows of faces ranging in emotional expression and were asked to categorize (Happy, Sad, Angry, Neutral) and rate the emotional intensity (1-9) of each face at baseline (2100; Session 1), at 0900 (Session 2) following a night of sleep or TSD, and at 1400 (Session 3) following either continued wakefulness (wake group) or a 90-minute nap opportunity (nap group). Results Emotion categorization ability marginally improved from Session 1 to Session 2 following overnight sleep, however, no changes in emotion intensity ratings or vigilance were observed. TSD led to an increase in error rates during vigilance testing [t(46)=2.9, p=0.005] and impairment in emotion categorization ability [t(46)=5.5, p<0.001] from Session 1 to Session 2, although by Session 3 performance levels on both measures returned to baseline for all TSD participants. TSD also led to a decrease in emotional intensity ratings from Session 1 to Session 2, particularly for the highest tertile of emotional faces [6-9; t(46)=6.1, p<0.001]. These ratings remained suppressed at Session 3 in both the wake [t(25)=7.8, p<0.001] and nap [t(18)=3.1, p=0.006] groups. Conclusion These results indicate that time of day effects, with or without any additional benefit of a nap, can restore the impairments in vigilance and emotional categorization caused by TSD. The ability to discriminate levels of emotional intensity, however, is not restored by time of day or napping, suggesting that this ability is more sensitive to the impact of TSD. Support  


Author(s):  
Louay S. Yousuf ◽  
Dan B. Marghitu

A mechanism with a cam and a flat-faced follower is considered for distinct angular velocities. The dynamic analysis presents follower linkage displacement driven by a cam rotating at a uniform angular velocity. The system has clearances between the flat-faced follower and the guides and the effect of clearance is analyzed. The cam-follower linkage mechanism is simulated using Solidworks program taking into account the impact and the friction between the cam, flat-faced follower, and the guides. The non-linear analysis tools are employed for the movement of the flat-faced follower. An experimental set up is established to capture the motion of the follower. High-resolution optical marker is mounted on the follower stem to capture the follower motion in the y-direction. The simulation and experimental results are compared and verified for largest Lyapunov exponent.


2010 ◽  
Vol 18 (1) ◽  
pp. 44-54 ◽  
Author(s):  
Francieli S Ruiz ◽  
Monica L Andersen ◽  
Raquel CS Martins ◽  
Adriano Zager ◽  
José D Lopes ◽  
...  

We investigated the impact of two nights of total sleep deprivation (SD) or four nights of rapid eye movement (REM) SD on immunological parameters in healthy men. Thirty-two volunteers were randomly assigned to three protocols (control, total SD or REM SD). Both SD protocols were followed by three nights of sleep recovery. The control and REM SD groups had regular nights of sleep monitored by polysomnography. Circulating white blood cells (WBCs), T- (CD4/CD8) and B-lymphocytes, Ig classes, complement and cytokine levels were assessed daily. Two nights of total SD increased the numbers of leukocytes and neutrophils compared with baseline levels, and these levels returned to baseline after 24 h of sleep recovery. The CD4+ T-cells increased during the total SD period (one and two nights) and IgA levels decreased during the entire period of REM SD. These levels did not return to baseline after three nights of sleep recovery. Levels of monocytes, eosinophils, basophils and cytokines (IL-1β, IL-2, IL-4, IL-6, IL-10, TNF-α and IFN-γ) remained unchanged by both protocols of SD. Our findings suggest that both protocols affected the human immune profile, although in different parameters, and that CD4+ T-cells and IgA levels were not re-established after sleep recovery.


SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A48-A48
Author(s):  
A N Hudson ◽  
P Whitney ◽  
J M Hinson ◽  
D A Hansen ◽  
H Van Dongen ◽  
...  

Abstract Introduction Stimuli with an emotional valence tend to produce better recognition from memory than neutral stimuli. Sleep loss is believed to increase reactivity to negative stimuli, as compared to positive stimuli, which may comparatively enhance subsequent recognition from memory for negative stimuli. We investigated the impact of total sleep deprivation (TSD) on recognition accuracy for words with different emotional valence using the Affective Item Source Memory Task (AISM). Methods N=14 adults (ages 21–39; 7 females) completed a 4-day in-laboratory study with 9h baseline sleep (22:00-07:00), 39h acute TSD, and 9h recovery sleep. The AISM was administered at 16:30 during baseline and after 34h TSD. During a 5min study phase, participants heard a list, twice, of 20 positive, 20 negative, and 20 neutral words spoken with a male or female voice. During an immediately subsequent 8min recognition phase, participants heard 120 words (50% new) and judged whether each word had been presented in the study list (item memory). For words judged to have been presented previously, participants indicated whether those were presented by a female or male speaker (source memory). Results Mixed-effects ANOVA showed effects of session (p<0.001) and valence (p<0.001) on item memory. At baseline, accuracy was greatest for neutral and positive words compared to negative words. During TSD, accuracy declined for all three valences, and no interaction of session by valence was detected. No effects of TSD or valence on source memory were observed. Conclusion Sleep deprivation reduced item memory for words of all valence types. However, there was no comparatively greater impact on item or source memory for negative words nor any differential effect of TSD for different valences. Whether our results would hold with longer time intervals between task phases or an intervening sleep period remains to be determined. Support Jazz Pharmaceuticals


Author(s):  
E. R. Ledesma-Orozco ◽  
J. A. Diosdado-De la Pen˜a ◽  
G. I. Pe´rez–Soto ◽  
A. Salazar-Garibay ◽  
J. F. Reveles-Arredondo ◽  
...  

This paper presents the non-linear simulation of the impact on a structure with different energy absorption systems using finite element models. A comparison of the damage caused to the structure in case of impact without implementing energy absorption system, and implementing energy absorption systems based on bistable structures, polystyrene foam and aluminium foam are shown here in. The results demonstrate the advantages of using energy absorption systems on structures under impact loads.


SLEEP ◽  
2018 ◽  
Vol 41 (suppl_1) ◽  
pp. A90-A90
Author(s):  
K E Carlsson ◽  
A F Bessey ◽  
L Skeiky ◽  
N E Prindle ◽  
M Powers Armstrong ◽  
...  

SLEEP ◽  
2021 ◽  
Author(s):  
Julie Grèzes ◽  
Mégane Erblang ◽  
Emma Vilarem ◽  
Michael Quiquempoix ◽  
Pascal Van Beers ◽  
...  

Abstract Study Objectives Total sleep deprivation is known to have significant detrimental effects on cognitive and socio-emotional functioning. Nonetheless, the mechanisms by which total sleep loss disturbs decision-making in social contexts are poorly understood. Here, we investigated the impact of total sleep deprivation on approach/avoidance decisions when faced with threatening individuals, as well as the potential moderating role of sleep-related mood changes. Methods Participants (n = 34) made spontaneous approach/avoidance decisions in the presence of task-irrelevant angry or fearful individuals, while rested or totally sleep deprived (27 hours of continuous wakefulness). Sleep-related changes in mood and sustained attention were assessed using the Positive and Negative Affective Scale and the psychomotor vigilance task, respectively. Results Rested participants avoided both fearful and angry individuals, with stronger avoidance for angry individuals, in line with previous results. On the contrary, totally sleep deprived participants favored neither approach nor avoidance of fearful individuals, while they still comparably avoided angry individuals. Drift-diffusion models showed that this effect was accounted for by the fact that total sleep deprivation reduced value-based evidence accumulation toward avoidance during decision making. Finally, the reduction of positive mood after total sleep deprivation positively correlated with the reduction of fearful display avoidance. Importantly, this correlation was not mediated by a sleep-related reduction in sustained attention. Conclusions All together, these findings support the underestimated role of positive mood-state alterations caused by total sleep loss on approach/avoidance decisions when facing ambiguous socio-emotional displays, such as fear.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Kate Porcheret ◽  
Dalena van Heugten–van der Kloet ◽  
Guy M. Goodwin ◽  
Russell G. Foster ◽  
Katharina Wulff ◽  
...  

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