scholarly journals 0344 Age-Related Longitudinal Trajectories in NREM and REM Spectral Power

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A130-A131
Author(s):  
C Gao ◽  
M K Scullin
Keyword(s):  
Power Density ◽  
Rem Sleep ◽  
Spectral Power ◽  
Secondary Data ◽  
Spectral Power Density ◽  
Individual Variability ◽  
Health Study ◽  
Cross Sectional ◽  
Age Related ◽  
Sleep Physiology

Abstract Introduction Knowledge of how aging impacts sleep physiology is based almost exclusively on cross-sectional studies. Longitudinal studies, by contrast, can inform how macro- and micro-features of NREM and REM sleep change dynamically across time in individual trajectories. For the current work, we conducted quantitative EEG analyses from a longitudinal polysomnography study to inform age-related trajectories in sleep macro- and micro-architecture. Methods We conducted a secondary data analysis on 2208 participants in the Sleep Heart Health Study (mean age =62.47, SD=10.46, 55.30% females). Participants underwent one night of in-home polysomnography recording during two study visits (M=5.21 years apart, SD=0.53). Spectral power density was calculated for each 0.5 Hz frequency bin for NREM and REM sleep separately. Results In cross-sectional analyses, older chronological age was significantly associated with worse sleep macro-architecture. Plots of the individual trajectories over 5 years, however, revealed considerable inter-individual variability in whether sleep physiology was preserved or declined. Interestingly, there were strong associations between the longitudinal changes in power density in NREM and REM sleep (slow oscillations: r=.53 [.50-.56]; delta: r=.58 [.55-.60]; alpha: r=.69 [.67-.71]; sigma: r=.74 [.73-.76]; beta: r=.82 [.80-.83]; ps<.001). The strongest NREM-REM association was for theta band power (r=.85 [.83-.86]), particularly in the 5.5-6.0 Hz bin (r=.94, [.94, .95]). Conclusion There is substantial inter-individual variability in how aging impacts sleep physiology. Nevertheless, within individuals, power density declines similarly across NREM and REM stages, with nearly perfect convergence for theta activity, indicating a common age-related neurobiological mechanism. Support The National Sleep Research Resource is supported by NIH HL114473.

scholarly journals The Changes of Ergonomic Engine Vibroacoustic Response Regarding Their Development

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4215
Author(s):  
Radosław Wróbel ◽  
Lech Sitnik ◽  
Monika Andrych-Zalewska ◽  
Łukasz Łoza ◽  
Radostin Dimitrov ◽  
...  
Keyword(s):  
Human Health ◽  
Power Density ◽  
High Speed ◽  
Internal Combustion Engines ◽  
Spectral Power ◽  
Spectral Power Density ◽  
Steering Wheel ◽  
Combustion Engines ◽  
Head Restraint ◽  
Vibroacoustic Response

The article presents the results of research on the vibroacoustic response of internal combustion engines mounted in a vehicle. The vehicles studied belong to popular models, which became available in successive versions. Each group included vehicles of the same model of an older generation (equipped with a naturally aspirated engine) and of a newer generation, including downsized (and turbocharged) engines. Tests in each group were carried out under repeatable conditions on a chassis-load dynamometer. The vibrations were measured using single-axis accelerometers mounted on the steering wheel, engine, and driver’s head restraint mounting. The primary purpose of the study was to verify whether the new generations of vehicles equipped with additional high-speed elements (compressors) generate additional harmonics (especially those within the range potentially affecting travel comfort and human health) and whether there are significant changes in the distribution of spectral power density in the new generations. As the study showed, new generations of vehicles are characterized by a different vibroacoustic response, and the trend of change is the same in each of the families studied.

scholarly journals Control and prediction protocol for bearing failure through spectral power density

2020 ◽  
Vol 22 (4) ◽  
pp. 651-657
Author(s):  
Javier Castilla-Gutiérrez ◽  
Juan Carlos Fortes ◽  
Jose Miguel Davila
Keyword(s):  
Power Density ◽  
Spectral Power ◽  
Spectral Power Density ◽  
Bearing Failure

scholarly journals The Spectral Power Density and Shadowing Function of a Glacial Microrelief at the Decimetre Scale

1979 ◽  
Vol 23 (89) ◽  
pp. 57-66 ◽  
Author(s):  
J.-P. Benoist
Keyword(s):  
Power Density ◽  
Gaussian Distribution ◽  
Spectral Power ◽  
Spectral Power Density ◽  
Total Length ◽  
Theoretical Function ◽  
Significant Difference ◽  
Longitudinal Profiles ◽  
Non Gaussian

Abstract Longitudinal profiles of roches moutonnées have been measured once every centimetre over a total length of more than 100 m. Only wavelengths in the range 3.6 cm < λ < 40 cm have been kept and analysed. Levels and their slopes have a symmetrical, non-Gaussian distribution. The spectral power density varies roughly as γ 0 ν–n (ν ═ wavenumber ═ 1/λ); n being the same for all the profiles (n ═ 2.36) and γ 0 being dependent on the studied area. No significant difference has been found for the shadowing function of the different studied areas. It differs consistently from Smith’s theoretical function.

scholarly journals Factors associated with elevated consumption of alcohol in older adults—comparison between China and Norway: the CLHLS and the HUNT Study

BMJ Open ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. e028646 ◽  
Author(s):  
Juan Li ◽  
Bei Wu ◽  
Kjerstin Tevik ◽  
Steinar Krokstad ◽  
AS Helvik
Keyword(s):  
Public Health ◽  
Older Adults ◽  
Alcohol Consumption ◽  
Rural Areas ◽  
Secondary Data ◽  
Primary Objective ◽  
Health Study ◽  
Cross Sectional ◽  
Chinese Sample ◽  
Factors Associated

ObjectivesThe primary objective was to investigate the prevalence and factors associated with elevated alcohol consumption among older adults 65 years and above in China and Norway. The secondary objective was to compare the prevalence and factors in the two countries.DesignA secondary data analysis was conducted using two large cross-sectional studies (Chinese Longitudinal Healthy Longevity Survey data in 2008–2009 and Nord-Trøndelag Health Study data in 2006–2008).ParticipantsA total of 3223 (weighted) Chinese older adults and 6210 Norwegian older adults who responded drinking alcohol were included in the analysis.Outcome measuresThe dependent variable was elevated alcohol consumption, which was calculated as a ratio of those with elevated drinking among current drinkers. Multivariable logistic regression was used to test the dependent variable.ResultsThe prevalence of elevated alcohol consumption among current drinkers for the Chinese and Norwegian samples were 78.3% (weighted) and 5.1%, respectively. Being male was related to a higher likelihood of elevated alcohol consumption in both Chinese and Norwegian samples (OR=2.729, 95% CI 2.124 to 3.506, OR=2.638, 95% CI 1.942 to 3.585). Being older, with higher levels of education and a living spouse or partner were less likely to have elevated drinking in the Chinese sample (OR=0.497, 95% CI 0.312 to 0.794, OR=0.411, 95% CI 0.260 to 0.649, OR=0.533, 95% CI 0.417 to 0.682, respectively). Among Norwegian older adults, a higher level of education was related to higher likelihood of elevated drinking (OR=1.503, 95% CI 1.092 to 2.069, OR=3.020, 95% CI 2.185 to 4.175). Living in rural areas and higher life satisfaction were related to lower likelihood of elevated drinking in the Norwegian sample (OR=0.739, 95% CI 0.554 to 0.984, OR=0.844, 95% CI 0.729 to 0.977, respectively).ConclusionsThe elevated alcohol consumption patterns were strikingly different between China and Norway in regards to prevalence and socioeconomic distribution. To develop and implement culturally appropriate public health policies regarding alcohol in the future, public health policy makers and professionals need to be aware of the cultural differences and consider the demographic, social and economic characteristics of their intended population.

scholarly journals Effects of Diazepam on Low-Frequency and High-Frequency Electrocortical γ-Power Mediated by α1- and α2-GABAA Receptors

2019 ◽  
Vol 20 (14) ◽  
pp. 3486 ◽  
Author(s):  
Julian I. Hofmann ◽  
Cornelius Schwarz ◽  
Uwe Rudolph ◽  
Bernd Antkowiak
Keyword(s):  
Power Density ◽  
Gabaa Receptors ◽  
Barrel Cortex ◽  
Spectral Power ◽  
Low Frequency ◽  
Electric Activity ◽  
Spectral Power Density ◽  
Wild Type ◽  
Potential Activity ◽  
Α2 Receptors

Patterns of spontaneous electric activity in the cerebral cortex change upon administration of benzodiazepines. Here we are testing the hypothesis that the prototypical benzodiazepine, diazepam, affects spectral power density in the low (20–50 Hz) and high (50–90 Hz) γ-band by targeting GABAA receptors harboring α1- and α2-subunits. Local field potentials (LFPs) and action potentials were recorded in the barrel cortex of wild type mice and two mutant strains in which the drug exclusively acted via GABAA receptors containing either α1- (DZα1-mice) or α2-subunits (DZα2-mice). In wild type mice, diazepam enhanced low γ-power. This effect was also evident in DZα2-mice, while diazepam decreased low γ-power in DZα1-mice. Diazepam increased correlated local LFP-activity in wild type animals and DZα2- but not in DZα1-mice. In all genotypes, spectral power density in the high γ-range and multi-unit action potential activity declined upon diazepam administration. We conclude that diazepam modifies low γ-power in opposing ways via α1- and α2-GABAA receptors. The drug’s boosting effect involves α2-receptors and an increase in local intra-cortical synchrony. Furthermore, it is important to make a distinction between high- and low γ-power when evaluating the effects of drugs that target GABAA receptors.

Sign in / Sign up

Export Citation Format

Share Document