Showing papers by "Zenon Nieckarz published in 2014"

Extremely low frequency electromagnetic field measurements at the Hylaty station and methodology of signal analysis

Abstract: We present the Hylaty geophysical station, a high-sensitivity and low-noise facility for extremely low frequency (ELF, 0.03–300 Hz) electromagnetic field measurements, which enables a variety of geophysical and climatological research related to atmospheric, ionospheric, magnetospheric, and space weather physics. The first systematic observations of ELF electromagnetic fields at the Jagiellonian University were undertaken in 1994. At the beginning the measurements were carried out sporadically, during expeditions to sparsely populated areas of the Bieszczady Mountains in the southeast of Poland. In 2004, an automatic Hylaty ELF station was built there, in a very low electromagnetic noise environment, which enabled continuous recording of the magnetic field components of the ELF electromagnetic field in the frequency range below 60 Hz. In 2013, after 8 years of successful operation, the station was upgraded by extending its frequency range up to 300 Hz. In this paper we show the station's technical setup, and how it has changed over the years. We discuss the design of ELF equipment, including antennas, receivers, the time control circuit, and power supply, as well as antenna and receiver calibration. We also discuss the methodology we developed for observations of the Schumann resonance and wideband observations of ELF field pulses. We provide examples of various kinds of signals recorded at the station.

Myosin heavy chain composition in the vastus lateralis muscle in relation to oxygen uptake and heart rate during cycling in humans.

Abstract: In this study we examined the relationship between fast myosin heavy chain (MyHC2) content in the vastus lateralis and the rate of oxygen uptake (VO2) and heart rate (HR) increase during an incremental exercise in 38, young, healthy men. Prior to the exercise test, muscle biopsies were taken in order to evaluate the MyHC composition. It was found that during cycling performed below the lactate threshold (LT), a positive relationship between MyHC2 and the intercept of the oxygen uptake and power output (VO2-PO) relationship existed (r=0.49, P=0.002), despite no correlation between MyHC2 and the slope value of the VO2-PO relationship (r= -0.18, P=0.29). During cycling performed above the LT, MyHC2 correlated positively with the magnitude of the nonlinearity in the VO2-PO relationship; i.e. with the accumulated VO2'excess' (r=0.44, P=0.006) and peak VO2'excess' (r=0.44, P=0.006), as well as with the slope of the HR-PO relationship (r=0.49, P=0.002). We have concluded that a greater MyHC2 content in the vastus lateralis is accompanied by a higher oxygen cost of cycling during exercise performed below the LT. This seems to be related to the higher energy cost of the non-cross-bridge activities in the muscles possessing a greater proportion of MyHC2 content. In the case of heavy-intensity exercise, a higher MyHC2 content in the vastus lateralis is accompanied by greater non-linearity in the VO2-PO relationship, as well as a steeper increase in HR in the function of an increase of PO. This relationship can be explained by greater disturbances in metabolic stability in type II muscle fibres during exercise, resulting in a decrease of muscle mechanical efficiency and greater increase of heart rate at a given power output. Therefore, MyHC composition has an impact on the oxygen cost of cycling both below and above the LT.

Plasma thyroid hormones and corticosterone levels in blood of chicken embryos and post hatch chickens exposed during incubation to 1800 MHz electromagnetic field.

Abstract: Introduction This study attempted to determine the effect of a 1800 MHz electromagnetic field (EMF) (only carrier frequency) on thyroxine (T4), triiodothyronine (T3) and corticosterone (CORT) concentrations in the blood plasma of chick embryos, and to investigate the effect of electromagnetic field (EMF) exposure during embryogenesis on the level of these hormones in birds that are ready for slaughter.

Application of the Schumann resonance spectral decomposition in characterizing the main African thunderstorm center

Abstract: In this paper we present a new method for quantifying the main tropical thunderstorm regions based on extremely low frequency (ELF) electromagnetic wave measurements from a single station—the Hylaty ELF station in Central Europe. Our approach is based on Schumann resonance (SR) measurements, which we apply as an example to thunderstorms in Africa. By solving the inverse problem, using the SR power spectrum templates derived analytically, we calculate distances to the most powerful thunderstorm centers and present simplified 1-D thunderstorm lightning activity “maps” in absolute units C2m2/s. We briefly describe our method of SR power spectrum analysis and present how this method is used with real observational data. We obtained the monthly lightning activity maps of the African storm centers with a spatial resolution of 1° and temporal resolution of 10 min for January and August 2011. This allowed us to study the varying location and intensities of the African storm centers in different seasons of the year. A cross check of the obtained lightning activity maps with Tropical Rainfall Measuring Mission satellite data recorded by the Lightning Imaging Sensor and the derived correlation coefficients between SR and optical data were used to validate the proposed method. We note that modeling a maximum possible number of resonance modes in the SR power spectra (in our case, seven resonances) is essential in application of the proposed approach.

Sunspot Time Series: Passive and Active Intervals

Abstract: Solar activity slowly and irregularly decreases from the first spotless day (FSD) in the declining phase of the old sunspot cycle and systematically, but also in an irregular way, increases to the new cycle maximum after the last spotless day (LSD). The time interval between the first and the last spotless day can be called the passive interval (PI), while the time interval from the last spotless day to the first one after the new cycle maximum is the related active interval (AI). Minima of solar cycles are inside PIs, while maxima are inside AIs. In this article, we study the properties of passive and active intervals to determine the relation between them. We have found that some properties of PIs, and related AIs, differ significantly between two group of solar cycles; this has allowed us to classify Cycles 8 – 15 as passive cycles, and Cycles 17 – 23 as active ones. We conclude that the solar activity in the PI declining phase (a descending phase of the previous cycle) determines the strength of the approaching maximum in the case of active cycles, while the activity of the PI rising phase (a phase of the ongoing cycle early growth) determines the strength of passive cycles. This can have implications for solar dynamo models. Our approach indicates the important role of solar activity during the declining and the rising phases of the solar-cycle minimum.

Influence of static and alternating magnetic fields on U937 cell viability.

Abstract: Presented studies were conducted to assess the influence of alternating (AC) and/or static (DC) magnetic fields (MF) or combined with puromycin (PMC) on U937 cell line viability. The magnitude of DC MF was enclosed in the range (2 ÷ 6) mT. In case of AC MF, four frequencies were set: 12 Hz, 25 Hz, 35 Hz, 50 Hz and magnetic induction value was adjusted to 6.5(rms) mT. The reaction of samples exposed to MF and/or PMC was presented as cell viability coefficient S defined as a ratio of viable cells in the sample to viable cells in the relevant control sample, analyzed by flow cytometry. For PMC treated sample the percentage of viable cells decreased about factor 3. MF alone did not influence cell viability regardless of the type of exposure while simultaneous action of ACDC MF mode and PMC significantly influenced viability of U937 cells. The viability coefficient S was in the range of (0.13 ∓ 0.07 ÷ 0.64 ∓ 0.20) and exerted a non-linear relation with frequency of the AC MF component. The maximal lethal influence (S = 0.13 ∓ 0.07) was observed for DC MF = 6 mT and frequency of AC MF equal to 35 Hz. Observed bio-effects were confronted with the physical models assuming the Ca2+ ions transport disturbance and/or protein complexes dysfunction in cells due to MF action.

New Method for Detection of Global Lightning Activity Using Schumann Resonance

Abstract: In this paper we discuss a new method for a global lightning activity mapping using measurements of extremely low frequency (ELF) electromagnetic waves (EW) propagating in the Earth-ionosphere resonance cavity. With the data collected at the Hylaty ELF station, located in the Central Europe, we analyze the Schumann Resonances (SR) spectra with seven resonance peaks. The measurements are done quasi-continuously, using successive 10 minutes data intervals. Kulak et al. (2006) found that the interaction of the standing and traveling waves leads to asymmetric shape of observed SR curves. Following this approach, we introduce a numerical model of the ELF electromagnetic waves propagation in the spherical Earth-ionosphere cavity and using this model we compute the asymmetric SR spectral templates for selected distances between the source and the observer. We fit the asymmetric curves describing seven SR maxima to the observational data and we calculate the distances to the thunderstorm centers by solving the inverse problem. As an example we investigate the lightning activity originating from the most intensive thunderstorm center in Africa. We use the observational radio data recorded in January and August 2011 and we construct the monthly lighting activity 1D maps using these data to study the differences in the location of the African storms centers during different seasons.