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Ajánlások és teljesülésük : A V4-ek országspecifikus ajánlásai európai kontextusban

András Bíró-Nagy, Gergely Laki
2021 Politikatudományi szemle  
AJÁNLÁSOK ÉS TELJESÜLÉSÜK * A V4-ek országspecifi kus ajánlásai európai kontextusban Bíró-Nagy András (Társadalomtudományi Kutatóközpont Politikatudományi Intézet) Laki Gergely (Budapesti Corvinus Egyetem  ...  Egy 2015-ös változtatás érintette a CSR-ek számát, ugyanis míg az említett évben összesen 253 ajánlást fogalmazott meg a bizottság a tagállamoknak, addig a következő évben már csak 166-ot.  ... 
doi:10.30718/ fatcat:5wsbcznzn5abdeeutkvjqflhee

Decomposing Multifractal Crossovers

Zoltan Nagy, Peter Mukli, Peter Herman, Andras Eke
2017 Frontiers in Physiology  
et al., 2000 Eke et al., , 2002 .  ...  ., 2002 Eke et al., , 2012 Mukli et al., 2015) -of ideal or empirical signals.  ...  Copyright © 2017 Nagy, Mukli, Herman and Eke. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).  ... 
doi:10.3389/fphys.2017.00533 pmid:28798694 pmcid:PMC5527813 fatcat:5wz22ehj4vftdkv7ox5g42gkda

Two-Tiered Response of Cardiorespiratory-Cerebrovascular Network to Orthostatic Challenge

Peter Mukli, Zoltan Nagy, Frigyes Samuel Racz, Istvan Portoro, Andras Hartmann, Orestis Stylianou, Robert Debreczeni, Daniel Bereczki, Andras Eke
2021 Frontiers in Physiology  
Dynamic interdependencies within and between physiological systems and subsystems are key for homeostatic mechanisms to establish an optimal state of the organism. These interactions mediate regulatory responses elicited by various perturbations, such as the high-pressure baroreflex and cerebral autoregulation, alleviating the impact of orthostatic stress on cerebral hemodynamics and oxygenation. The aim of this study was to evaluate the responsiveness of the cardiorespiratory-cerebrovascular
more » ... tworks by capturing linear and nonlinear interdependencies to postural changes. Ten young healthy adults participated in our study. Non-invasive measurements of arterial blood pressure (from that cardiac cycle durations were derived), breath-to-breath interval, cerebral blood flow velocity (BFV, recorded by transcranial Doppler sonography), and cerebral hemodynamics (HbT, total hemoglobin content monitored by near-infrared spectroscopy) were performed for 30-min in resting state, followed by a 1-min stand-up and a 1-min sit-down period. During preprocessing, noise was filtered and the contribution of arterial blood pressure was regressed from BFV and HbT signals. Cardiorespiratory-cerebrovascular networks were reconstructed by computing pair-wise Pearson-correlation or mutual information between the resampled signals to capture their linear and/or nonlinear interdependencies, respectively. The interdependencies between cardiac, respiratory, and cerebrovascular dynamics showed a marked weakening after standing up persisting throughout the sit-down period, which could mainly be attributed to strikingly attenuated nonlinear coupling. To summarize, we found that postural changes induced topological changes in the cardiorespiratory-cerebrovascular network. The dissolution of nonlinear networks suggests that the complexity of key homeostatic mechanisms maintaining cerebral hemodynamics and oxygenation is indeed sensitive to physiological perturbations such as orthostatic stress.
doi:10.3389/fphys.2021.622569 pmid:33737882 pmcid:PMC7960776 fatcat:hqllrd77nbaoljf5vpkil7cxpq

Pitfalls in fractal time series analysis: fMRI BOLD as an exemplary case

Andras Eke
2012 Frontiers in Physiology  
Eke).  ...  National Institutes of Health (R01 MH-067528 and P30 NS-52519 to Fahmeed Hyder) and from the Hungarian Scientific Research Found (OTKA grants I/3 2040, T 016953, T 034122, NIH Grants TW00442, and RR1243 to Andras  ...  Eke et al., , 2000 (Eke et al., , 2002 Eke and Herman, 1999; Herman and Eke, 2006; Herman et al., 2009 Herman et al., , 2011 .  ... 
doi:10.3389/fphys.2012.00417 pmid:23227008 pmcid:PMC3513686 fatcat:hhg4eey6tbhtxjsn5fv364r2xq

Multifractal Dynamic Functional Connectivity in the Resting-State Brain

Frigyes Samuel Racz, Orestis Stylianou, Peter Mukli, Andras Eke
2018 Frontiers in Physiology  
., scaling exponent, β) in the frequency domain (Eke et al., 2000 (Eke et al., , 2002 .  ...  H and β are inherently interrelated (Eke et al., 2002) as they both characterize the global long-range correlation (LRC) in a signal.  ...  Copyright © 2018 Racz, Stylianou, Mukli and Eke. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).  ... 
doi:10.3389/fphys.2018.01704 pmid:30555345 pmcid:PMC6284038 fatcat:khapqkum2vchtitiovbrz2uk6i

Fractal analysis of spontaneous fluctuations of the BOLD signal in rat brain

Peter Herman, Basavaraju G. Sanganahalli, Fahmeed Hyder, Andras Eke
2011 NeuroImage  
; Eke et al., 1997; Eke et al., 2000; Eke et al., 2006; Herman and Eke, 2006; Herman et al., 2009a) .  ...  et al., 2000; Eke et al., 2002) .  ...  ., fractal) behavior of the signal, but to its correlation structure itself otherwise known as autocorrelation (Eke et al., 2002) . The extent of autocorrelation is tightly coupled to β.  ... 
doi:10.1016/j.neuroimage.2011.06.082 pmid:21777682 pmcid:PMC3705180 fatcat:x4svaenyrnam3iub3ee5mk6gne

Increased prefrontal cortex connectivity during cognitive challenge assessed by fNIRS imaging

Frigyes Samuel Racz, Peter Mukli, Zoltan Nagy, Andras Eke
2017 Biomedical Optics Express  
Eke, "The modified Beer-Lambert law revisited," Phys. Med. Biol. 51(5), N91-N98 (2006). 32. M. Cope, D. T. Delpy, E. O. Reynolds, S. Wray, J.  ... 
doi:10.1364/boe.8.003842 pmid:28856054 pmcid:PMC5560845 fatcat:nr6zfuc4ljgqfdc2jgsfgs4fku

Scale-Free Coupled Dynamics in Brain Networks Captured by Bivariate Focus-Based Multifractal Analysis

Orestis Stylianou, Frigyes Samuel Racz, Andras Eke, Peter Mukli
2021 Frontiers in Physiology  
While these biological functions may contain narrowband components that can also be of interest, their broadband dynamics indicate scale-free (or fractal) behavior (Eke et al., 2000) .  ...  power spectrum represents the slope of the fitted linear regression of the logarithmic amplitude vs. frequency plot and is proportional to its univariate Hurst exponent, H univ (2) [β = 2H univ (2)-1] (Eke  ... 
doi:10.3389/fphys.2020.615961 pmid:33613302 pmcid:PMC7887319 fatcat:5lorrl3ksrb4lk3b5poxvxd7p4

Impact of Healthy Aging on Multifractal Hemodynamic Fluctuations in the Human Prefrontal Cortex

Peter Mukli, Zoltan Nagy, Frigyes S. Racz, Peter Herman, Andras Eke
2018 Frontiers in Physiology  
Monofractal pattern of NIRS spectral data was first reported by Eke and Herman for the human brain cortex (Eke and Hermán, 1999) .  ...  Several human studies investigated the scale-free phenomenon of functional brain imaging signals by using mono- (Eke and Hermán, 1999; Thurner et al., 2003; Maxim et al., 2005; Eke et al., 2006; Khoa  ...  Copyright © 2018 Mukli, Nagy, Racz, Herman and Eke. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).  ... 
doi:10.3389/fphys.2018.01072 pmid:30147657 pmcid:PMC6097581 fatcat:m536hmv7mjaoxirh5egwdr5lkm

Multifractal and entropy analysis of resting-state electroencephalography reveals spatial organization in local dynamic functional connectivity

Frigyes Samuel Racz, Orestis Stylianou, Peter Mukli, Andras Eke
2019 Scientific Reports  
Functional connectivity of the brain fluctuates even in resting-state condition. It has been reported recently that fluctuations of global functional network topology and those of individual connections between brain regions expressed multifractal scaling. To expand on these findings, in this study we investigated if multifractality was indeed an inherent property of dynamic functional connectivity (DFC) on the regional level as well. Furthermore, we explored if local DFC showed region-specific
more » ... differences in its multifractal and entropy-related features. DFC analyses were performed on 62-channel, resting-state electroencephalography recordings of twelve young, healthy subjects. Surrogate data testing verified the true multifractal nature of regional DFC that could be attributed to the presumed nonlinear nature of the underlying processes. Moreover, we found a characteristic spatial distribution of local connectivity dynamics, in that frontal and occipital regions showed stronger long-range correlation and higher degree of multifractality, whereas the highest values of entropy were found over the central and temporal regions. The revealed topology reflected well the underlying resting-state network organization of the brain. The presented results and the proposed analysis framework could improve our understanding on how resting-state brain activity is spatio-temporally organized and may provide potential biomarkers for future clinical research.
doi:10.1038/s41598-019-49726-5 pmid:31530857 pmcid:PMC6748940 fatcat:xuzujpdarncfdipbbbuklil4ly

Fractal and Noisy CBV Dynamics in Humans: Influence of Age and Gender

Andras Eke, Péter Hermán, Márton Hajnal
2005 Journal of Cerebral Blood Flow and Metabolism  
Acknowledgements The computer program 'Fractool' running on the Macintosh, PC, and Unix platforms is available on the Web at  ...  Increments of an fBm signal produce an fGn process (Eke et al, 2000 (Eke et al, , 2002 .  ...  et al, 2000 (Eke et al, , 2002 .  ... 
doi:10.1038/sj.jcbfm.9600243 pmid:16292253 fatcat:mbjhqj66ejhlbfsjsg6viv2yy4

Real-Time Algorithm for Detrended Cross-Correlation Analysis of Long-Range Coupled Processes

Zalan Kaposzta, Akos Czoch, Orestis Stylianou, Keumbi Kim, Peter Mukli, Andras Eke, Frigyes Samuel Racz
2022 Frontiers in Physiology  
Notably, with d 0 an ARFIMA process produces time series with α = 0.5 + d = 0.5, which is equivalent to white noise (Eke et al., 2002) .  ...  in Eqs. (1-7) utilize a sliding window approach, while it is more common to divide the analyzed signal into N/s non-overlapping windows at each successive scale s, where • denotes the floor function (Eke  ... 
doi:10.3389/fphys.2022.817268 pmid:35360238 pmcid:PMC8963246 fatcat:zxdmevbc6jfmdm2r2hphhp2px4

Multifractal and Entropy-Based Analysis of Delta Band Neural Activity Reveals Altered Functional Connectivity Dynamics in Schizophrenia

Frigyes Samuel Racz, Orestis Stylianou, Peter Mukli, Andras Eke
2020 Frontiers in Systems Neuroscience  
autocorrelation, meaning that such processes have an autocorrelation function that decays according to a powerlaw rather than an exponential function like of those having characteristic time scales (Eke  ...  scale-free processes do not have a characteristic time scale, but they depend on the scale of observation according to a power-law function, and the relationship is established via the scaling exponent (Eke  ... 
doi:10.3389/fnsys.2020.00049 pmid:32792917 pmcid:PMC7394222 fatcat:pcpguorijngflagrhk7lfwk4ni

Multiple-Resampling Cross-Spectral Analysis: An Unbiased Tool for Estimating Fractal Connectivity With an Application to Neurophysiological Signals

Frigyes Samuel Racz, Akos Czoch, Zalan Kaposzta, Orestis Stylianou, Peter Mukli, Andras Eke
2022 Frontiers in Physiology  
It is important to highlight, that both H and capture the same scaling property of the process and thus they are equivalent and inherently related (Mandelbrot and Van Ness, 1968; Eke et al., 2000) .  ...  obtained fractal scaling exponent, which is referred to as the Hurst exponent (H) or the spectral slope (β) in the time and frequency domains, respectively, with an explicit equivalence between the two (Eke  ... 
doi:10.3389/fphys.2022.817239 pmid:35321422 pmcid:PMC8936508 fatcat:7hkkfnfp7ffxzgn7x3fah2zf4q

The effect of cognitive dysfunction on mid- and long-term mortality after vascular surgery

András Szabó, Krisztina Tóth, Ádám Nagy, Dominika Domokos, Nikoletta Czobor, Csaba Eke, Ágnes Sándor, Béla Merkely, Éva Susánszky, János Gál, Andrea Székely
2021 BMC Geriatrics  
Background In recent decades, previous studies have noted the importance of frailty, which is a frequently used term in perioperative risk evaluations. Psychological and socioeconomical domains were investigated as part of frailty syndrome. The aim of this study was to assess the importance of these factors in mortality after vascular surgery. Methods In our prospective, observational study ( Identifier: NCT02224222), we examined 164 patients who underwent elective vascular
more » ... gery between 2014 and 2017. At the outpatient anaesthesiology clinic, patients completed a questionnaire about cognitive functions, depression and anxiety, social support and self-reported quality of life were assessed using a comprehensive frailty index, in addition to medical variables. Propensity score matching was performed to analyse the difference between patients and controls in a nationwide population cohort. The primary outcome was 4 year mortality. The Kaplan-Meier method and Cox regression analysis were used for statistical analyses. Results The patients' mean age was 67.05 years (SD: 9.49 years). Mini-Mental State Examination scores of less than 27 points were recorded for 41 patients. Overall mortality rates were 22.4 and 47.6% in the control and cognitive impairment groups, respectively (p = 0.013). In the univariate Cox regression analysis, cognitive impairment measured using age- and education-adjusted MMSE scores increased the risk of mortality (AHR: 2.842, 95% CI: 1.389-5.815, p = 0.004). Conclusion Even mild cognitive dysfunction measured preoperatively using the MMSE represents a potentially important risk factor for mortality after vascular surgery.
doi:10.1186/s12877-020-01994-x pmid:33441102 fatcat:fgrvkjseazfgxdwlt3rdlwhmqm
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