Zenon Nieckarz

Endurance training decreases the non-linearity in the oxygen uptake–power output relationship in humans

In this study, we hypothesized that 5 weeks of cycling endurance training can decrease the magnitude of the non‐proportional increase in oxygen uptake ( ) to power output relationship ( ‘excess’) at exercise intensities exceeding the lactate threshold (LT). Ten untrained, physically active men performed a bout of incremental cycling exercise until exhaustion before and after training. The mitochondrial DNA copy number, myosin heavy chain composition and content of uncoupling protein 3 and sarcoplasmic reticulum Ca2+‐ATPases (SERCAs) were analysed in muscle biopsies taken from vastus lateralis before and after training. The training resulted in an enhancement of the power‐generating capabilities at maximal oxygen uptake ( ) by ∼7% (P= 0.002) despite there being no changes in (P= 0.49). This effect was due to a considerable reduction in the magnitude of the ‘excess’ (P < 0.05) above the LT. A decrease in plasma ammonia concentration was found during exercise after training (P < 0.05). A downregulation of SERCA2 in vastus lateralis (P= 0.006) was observed after training. No changes in myosin heavy chain composition, selected electron transport chain proteins, uncoupling protein 3 or the mitochondrial DNA copy number (P > 0.05) were found after training. We conclude that the training‐induced increase in power‐generating capabilities at was due to attenuation of the ‘excess’ above the LT. This adaptive response seems to be related to the improvement of muscle metabolic stability, as judged by a lowering of plasma ammonia concentration. The enhancement of muscle metabolic stability after training could be caused by a decrease in ATP usage at a given power output owing to downregulation of SERCA2 pumps.

Study of the Periodicities of Lightning Activity in Three Main Thunderstorm Centers Based on Schumann Resonance Measurements

Abstract Time variations of lightning activity in the three main tropical thunderstorm centers located in the Maritime Continent (Pakistan, India, Southeast Asia, Indonesia, and Australia), Africa, and the Americas are analyzed using a lightning activity index IRS, which is calculated from the resonances of magnetic field in the extremely low frequency range—the Schumann resonances—which were observed at Hylaty station (Poland) in the time interval July 2005–May 2006. Power spectrum analysis of the IRS series is carried out for this time interval. The annual and semiannual variations are shown in all of the series together with the following characteristic periodicities: 45 (Madden–Julian oscillation), 17.6, 13.5, and 4.8 days, seen mainly in the series describing the lightning activity of the Maritime Continent. In addition, maps of the dynamical power spectrum are constructed. They present variability both in the values of characteristic periods 26–30, 17–22, 12–14, 9–10, and 5–7 days and in their durat...

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

IntroductionThis 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.Material and MethodsThroughout the incubation period, embryos from the experimental group were exposed to a 1800 MHz EMF with power density of 0.1 W/m2, 10 times during 24 h for 4 min. Blood samples were collected to determine T4, T3 and CORT concentrations on the 12th (E12) and 18th (E18) day of incubation, from newly hatched chicks (D1) and from birds ready for slaughter (D42).ResultsThe experiment showed that T4 and T3 concentrations decreased markedly and CORT levels increased in the embryos and in the newly hatched chicks exposed to EMF during embryogenesis. However, no changes were found in the level of the analyzed hormones in the birds ready for slaughter. Differences in T4 and T3 plasma concentrations between the EMF-exposed group and the embryos incubated without additional EMF were the highest in the newly hatched chicks, which may be indicative of the cumulative effect of electromagnetic field on the hypothalamo-pituitary-thyroid axis (HPT).DiscussionThe obtained results suggest that additional 1800 MHz radio frequency electromagnetic field inhibits function of HPT axis, however, it stimulates hypothalamo-pituitary-adrenal axis by inducing adrenal steroidogenic cells to synthesize corticosterone. Further investigations are needed to elucidate the mechanisms by which radio EMFs affect HPT and HPA axis function in the chicken embryos.

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

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.

Effect of weak electromagnetic field on cardiac work, concentration of thyroid hormones and blood aminotransferase level in the chick embryo

The aim of the study was to determine the effect of alternating electromagnetic field (EMF; 50 Hz frequency, 50 and 100 μT induction) on cardiac work of the chick embryo. Eggs from the experimental groups were exposed to EMF throughout incubation. During the experiment, heart rate (ballistocardiographic method), thyroxine (T4) and triiodothyronine (T3) concentrations, heart weight, ventricle wall thickness, and levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. The results show, for the first time, that the exposure of chick embryos to EMF augments the heart rate, especially from 17 days of incubation. The increased heart rate in the embryos exposed to EMF was associated with considerable increases in plasma T4 and T3 concentrations, which were recorded during the final stage of embryogenesis. The significant effect of the 100-μT field on heart weight and blood AST levels in the embryos suggests that EMF has a direct effect on the physiological function of cardiac muscle.

Comparison of the charge moment change calculated from electrostatic analysis and from ELF radio observations

We compare the results of two methods of calculation of the charge moment change (CMC, also called the dipole moment change) of the cloud-to-ground lightning discharges. The first method uses multistation ground-based measurements of the E field change for the purpose of the lightning flash location and charge analysis. Our six stations, called the Local Lightning Detection Network (LLDN), were set up in the Warsaw region. The second method is based on measurements of the horizontal magnetic field component of electromagnetic waves generated by atmospheric discharges in the ELF (extremely low frequency) range. Our ELF station is equipped with two magnetic antennas, east-west and north-south and is located in a sparsely populated area of the Bieszczady Mountains in Poland (49.19°N, 22.55°E). We present and discuss the results obtained by both methods, focusing on the negative return stroke (RS) and the return stroke with continuing current (RS and CC) lightning discharges. Results show a good correlation between the CMC obtained by the two methods. For the negative RS and CC and RS the correlation coefficient is equal to +0.50 and +0.80, respectively.

Day‐to‐Day Variation of the Angular Distribution of Lightning Activity Calculated from ELF Magnetic Measurements

We study the “local” distribution of lightning activity on the Earth calculated from Extremely Low Frequency (ELF) magnetic field variations. Lightning generates strong electromagnetic impulses recorded in the ELF band as short signal spikes. Using two perpendicular magnetic antennas at our Hylaty station, we calculate the azimuths of the sources of such spikes. These ELF data are compared with selected satellite measurements available on NASA and BADC web centres. For the winter period January 8 to 9, 2006, analysed in detail, a large cyclone was observed over the Mediterranean Sea (MS). The cyclone was created in the western part of the MS and then moved eastwards along the North coast of Africa. The absence of lightning activity nearer our station allowed us to compare the ELF measurements with observations of this cyclone made from the TRMM and Meteosat‐7 satellites, using Lightning Imaging Sensor observations and full Earth disk images, respectively. The analysis proves that ELF measurements can be u...

Geometry Corrections in a Rotating 3-Dimensional Sonographic System

Objective. To devise a system for geometry corrections in a rotating 3‐dimensional sonographic system. Methods. A 3‐dimensional sonographic imaging system based on a standard sonography machine was developed. The transducer mounted in a specially designed holder was rotated about its axis to acquire the spatial information. The most important postulate in rotating 3‐dimensional systems is the assumption of parallelity between the rotation axis and the transducer axis. It allows the use of simple geometric relationships between 2‐dimensional slices in a 3‐dimensional reconstruction. The errors appearing in the 3‐dimensional reconstruction when the axes are not parallel were investigated. Results. A simple correction method based on phantom measurements is proposed. The phantom contains a plane, which is inclined to the rotation axis. The analysis of 2‐dimensional plane images allows the geometric corrections. The construction of the phantom is described, and the formulas used in the calculations are presented. The method was tested in computer simulations and in patient investigations. Conclusions. A complete method of the geometric investigations and corrections useful in 3‐dimensional sonographic systems based on rotational geometry is proposed. Both the computer simulations and the phantom measurements confirmed the usefulness, precision, and simplicity of the proposed method.

Effect of a 1800 MHz electromagnetic field emitted during embryogenesis on chick development and hatchability

The level of artificial electromagnetic field (EMF) has steadily increased with the development of human civilization. The developing chicken embryo has been considered a good model to study the effects of EMF on living organisms. The aim of the study was to determine the effect of a 1800 MHz electromagnetic field during embryogenesis on the frequency of chick embryo malformations, morphometric parameters of the heart and liver and concentration of corticosterone in blood plasma, lipid and glycogen content in the liver of newly hatched chicks. A 1800 MHz EMF was found to shorten the duration of embryogenesis (earlier pipping and hatching of chicks) while having no effect on the quantity and quality of chicks and on increasing the incidence of embryo malformations. Exposure of chick embryos to EMF caused decreases in relative heart weight and right ventricle wall thickness. The pipping and hatching of chicks can be accelerated by stressful impact of EMF, which is confirmed by a significant increase in plasma corticosterone concentrations and decrease in fat and glycogen in the liver of chicks exposed during embryogenesis on the electromagnetic field with a frequency of 1800 MHz.

Imprints of Natural Phenomena and Human Activity Observed During 10 Years of ELF Magnetic Measurements at the Hylaty Geophysical Station in Poland

Current human activity produces strong electromagnetic pollution. The power spectrum in the extremely low frequency (ELF, 3–3000 Hz) range is mainly polluted by anthropogenic narrow spectral lines at 16.66, 50, and 60 Hz and their harmonics. Meanwhile, signatures connected with natural phenomena appearing in the Earth’s atmosphere, ionosphere and magnetosphere are also observed in the same frequency range.This paper presents the amplitude behaviour of the anthropogenic lines in the years 2005–2014 based on the 10 years of activity of the Hylaty station situated in southeast Poland. The analysis includes, i.a., an assessment of the correctness of the choice of the Bieszczady mountains as a location for the installation of an ELF station for long-term geophysical and climatological studies.