Time-frequency analysis
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- MeSH
- akční potenciály fyziologie MeSH
- elektrokardiografie metody MeSH
- finanční podpora výzkumu jako téma MeSH
- Fourierova analýza MeSH
- modely u zvířat MeSH
- psi fyziologie MeSH
- referenční hodnoty MeSH
- spektrální analýza metody MeSH
- srdce - funkce komor fyziologie MeSH
- srdeční arytmie MeSH
- zvířata MeSH
- Check Tag
- psi fyziologie MeSH
- zvířata MeSH
... Contents -- 1 Introduction 1 -- 1.1 Fourier Analysis 2 -- 1.2 Historical Development of Fourier Methods ... ... 11 -- 2.3 Multiple Periodicities 17 -- 2.4 Orthogonality of Sinusoids 19 -- 2.5 Effect of Discrete Time ... ... 25 -- 3.2 Fitting Multiple Frequencies 28 -- 3.3 Some More Statistical Results 30 -- Appendix 34 xi ... ... -- X/7 CONTENTS -- 4 Harmonic Analysis 37 -- 4.1 Fourier Frequencies 37 -- 4.2 Discrete Fourier Fransform ... ... Series Theory 167 -- 9.1 Stationary Time Series 167 -- 9.2 Continuous Spectra 173 -- 9.3 Time Averaging ...
Wiley series in probability and statistics
2nd ed. xiv, 261 s. : il.
- MeSH
- balónková koronární angioplastika metody využití MeSH
- časové faktory MeSH
- elektrokardiografie metody přístrojové vybavení využití MeSH
- financování organizované MeSH
- ischemická choroba srdeční diagnóza patofyziologie patologie MeSH
- koronární okluze diagnóza patofyziologie MeSH
- lidé MeSH
- počítačové zpracování signálu přístrojové vybavení MeSH
- retrospektivní studie MeSH
- Check Tag
- lidé MeSH
BACKGROUND AND AIMS: The frequency and timing of meals may affect cardiovascular health (CVH) outcomes, but large-scale epidemiological studies are lacking. The aim of this study was to understand the relationship between eating time interval and frequency, and measures of ideal CVH in the Kardiovize Brno cohort study, a random urban sample population in Central Europe. METHODS AND RESULTS: 1659 members of the Kardiovize Brno 2030 cohort were included in a cross-sectional study (mean age = 46.86 years; 44.6% male). Exposure variables were eating time interval and frequency, and skipping meals. Primary outcomes were indices of CVH, including body mass index, diet, physical activity, smoking, blood pressure, glucose and cholesterol, and the composite CVH score. Cluster analysis and binary logistic regression analysis were used to evaluate eating habits and the association between variables. After adjustment for well-known risk factors, subjects who skipped breakfast or the afternoon snack had a higher risk of poor CVH (OR = 1.613; 95%CI = 1.121-2.320; p = 0.010; OR = 1.409; 95%CI = 1.110-1.788; p = 0.005, respectively). Moreover, we identified three clusters of individuals based on eating habits; from cluster 1 to cluster 3, eating time interval and frequency increased and this was associated with increases in CVH score from 8.70 (SEM = 0.10) in cluster 1, and 9.06 (SEM = 0.08) in cluster 2 to 9.42 (SEM = 0.09) in cluster 3 (p-trend = 0.019). CONCLUSIONS: Our findings suggest that skipping breakfast or the afternoon snack are risk factors for poor CVH, while higher eating time interval and frequency may promote ideal CVH.
- MeSH
- časové faktory MeSH
- chování snižující riziko * MeSH
- dospělí MeSH
- jídla * MeSH
- kardiovaskulární nemoci diagnóza epidemiologie prevence a kontrola MeSH
- lidé středního věku MeSH
- lidé MeSH
- ochranné faktory MeSH
- přijímání potravy * MeSH
- prospektivní studie MeSH
- průřezové studie MeSH
- rizikové faktory MeSH
- stravovací zvyklosti * MeSH
- zdraví ve městech * MeSH
- zdravotní stav MeSH
- zdravý životní styl * MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika MeSH
BACKGROUND: Between-person differences in sedentary patterns should be considered to understand the role of sedentary behavior (SB) in the development of childhood obesity. This study took a novel approach based on compositional data analysis to examine associations between SB patterns and adiposity and investigate differences in adiposity associated with time reallocation between time spent in sedentary bouts of different duration and physical activity. METHODS: An analysis of cross-sectional data was performed in 425 children aged 7-12 years (58% girls). Waking behaviors were assessed using ActiGraph GT3X accelerometer for seven consecutive days. Multi-frequency bioimpedance measurement was used to determine adiposity. Compositional regression models with robust estimators were used to analyze associations between sedentary patterns and adiposity markers. To examine differences in adiposity associated with time reallocation, we used the compositional isotemporal substitution model. RESULTS: Significantly higher fat mass percentage (FM%; βilr1 = 0.18; 95% CI: 0.01, 0.34; p = 0.040) and visceral adipose tissue (VAT; βilr1 = 0.37; 95% CI: 0.03, 0.71; p = 0.034) were associated with time spent in middle sedentary bouts in duration of 10-29 min (relative to remaining behaviors). No significant associations were found for short (< 10 min) and long sedentary bouts (≥30 min). Substituting the time spent in total SB with moderate-to-vigorous physical activity (MVPA) was associated with a decrease in VAT. Substituting 1 h/week of the time spent in middle sedentary bouts with MVPA was associated with 2.9% (95% CI: 1.2, 4.6), 3.4% (95% CI: 1.2, 5.5), and 6.1% (95% CI: 2.9, 9.2) lower FM%, fat mass index, and VAT, respectively. Moreover, substituting 2 h/week of time spent in middle sedentary bouts with short sedentary bouts was associated with 3.5% (95% CI: 0.02, 6.9) lower FM%. CONCLUSIONS: Our findings suggest that adiposity status could be improved by increasing MVPA at the expense of time spent in middle sedentary bouts. Some benefits to adiposity may also be expected from replacing middle sedentary bouts with short sedentary bouts, that is, by taking standing or activity breaks more often. These findings may help design more effective interventions to prevent and control childhood obesity.
