Scaling behavior is an indicator of the lack of characteristic time scale, and the existence of longrange correlations related to physiological constancy preservation. To investigate the fluctuations of the sleep electroencephalogram (EEG) over various time scales during different sleep stages detrended fluctuation analysis (DFA) is studied. The sleep EEG signals for analysis were obtained from...

We analyzed and described quantitative differences in morphology and calls of Physalaemus petersi and P. freibergi, both members of the monophyletic Physalaemus pustulosus species group. We found significant differences between the two species in both morphometric and call parameters. Physalaemus petersi has proportionately longer legs and a narrower dorsum and head than P. freibergi. The calls...

Recent years of research have shown that the complex temporal structure of ongoing oscillations is scale-free and characterized by long-range temporal correlations. Detrended fluctuation analysis (DFA) has proven particularly useful, revealing that genetic variation, normal development, or disease can lead to differences in the scale-free amplitude modulation of oscillations. Furthermore, ampli...

In this report, a molecular Debye-Hückel theory for ionic fluids is developed. Starting from the macroscopic Maxwell equations for bulk systems, the dispersion relation leads to a generalized Debye-Hückel theory which is related to the dressed ion theory in the static case. Due to the multi-pole structure of dielectric function of ionic fluids, the electric potential around a single ion has a m...

Non-induced expectorated sputum (NIS) stained with tinctorial stains is not considered useful in the diagnosis of Pneumocystis carinii pneumonia (PCP). The diagnostic yield of NIS was evaluated in human immunodeficiency virus (HIV)-infected patients, when stained with a more sensitive direct fluorescent antibody for PCP-direct fluorescent antibody (PC-DFA). A retrospective analysis was carried ...

To analyze financial time series exhibiting volatility clustering or other highly irregular behavior, we exploit multifractal detrended fluctuation analysis (MF-DFA). We summarize the use of local Hölder exponents, generalized Hurst exponents, and the multifractal spectrum in characterizing the way that the sample paths of a multifractal stochastic process exhibit lightor heavy-tailed fluctuati...

Detrend fluctuation analysis (DFA) has become a choice method for effective analysis of a broad variety of nonstationary signals. We show in the present article that, provided the nonstationary fluctuations occur at a large enough time scale, an alternative approach can be obtained by using the Fourier series of the signal. More specifically, signal reconstructions considering Fourier series wi...

From the requirements, high-performance cooling systems in applications of solar, heat exchangers, and chemical industries are needed to improve efficiency. The metal-oxides-based nanofluids composed better thermal properties with exchange heat-transfer mechanisms. Therefore, this study mainly focused on nanosilicon dioxide materials produce blending water-base medium by two-step techniques. sc...