Effect of 450 MHz Microwave Modulated with 217 Hz on Human EEG in Rest

Summary This study focuses on discrimination of changes, produced by low-level microwave exposure in intensity and time variability of the human EEG at rest. The power spectral density (PSD) method and nonlinear scaling analysis of the length distribution of low variability periods (LDLVP) were selected for analysis of the EEG signal. During the study, 19 healthy volunteers were exposed to a microwave (450 MHz) of 217 Hz frequency on-off modulation. The field power density at the scalp was 0.16 mW/cm². The experimental protocol consisted of ten cycles of repetitive microwave exposure. Signals from frontal, temporal, parietal and occipital EEG channels on EEG theta, alpha and beta rhythms were analysed. Exposure to microwave causes average increase of EEG activity. LDLVP analysis discriminated significant effect in time variability for 2 subjects (11%). PSD method detected significant changes in intensity for 4 subjects (21%). The effect of low-level microwave exposure is stronger on EEG beta rhythm in temporal and parietal regions of the human brain.     

Diversity of Ontogenetic Pathways in Plant Populations

Population heterogeneity in cespitose, fibrous-rooted, brevirhizomatous, stoloniferous, and tap-rooted herbaceous and woody plants is described. This heterogeneity is caused by the multivariant character of plant ontogeny (i.e., its dimensional, morphological, rhythmological, and temporal multiversality), which is regarded as the main adaptation mechanism operating in plant populations because it provides for the diversity of ontogenetic pathways under different ecological conditions.     

Orientation in the intertidal salt-marsh collembolan Anurida maritima

We investigated the cues used by the intertidal insect Anurida maritima (Apterygota: Collembola) to orient to the appropriate zone in which to seek shelter during high tide. Our experiments clearly ruled out any significant role for magnetic, local topographic, slope or celestial cues. Instead, we suggest that the difference between the appearance of the up-shore and the down-shore horizon is the major cue used by the collembolans. When a mirror was used to duplicate either of the two horizons, the insects were not able to orient. The insects moved towards an artificially dark horizon (the reverse of the mirror) placed down-shore, the opposite of their usual direction of movement. The insects had an endogenous circatidal rhythm of phototactic behaviour: most of the population was always negatively phototactic, but between 2 and 7 h after low tide, a significant proportion of the population became positively phototactic. This is the first demonstration of an endogenous tidal rhythm of orientation in an insect. Received: 31 May 1999 / Received in revised form: 1 February 2000 / Accepted: 19 February 2000     

Chronotoxicological studies on dichlorphos in mice and humans

Chronotoxicological studies were performed with dichlorphos (DDVP) and its timing toxic effects on mice and humans. The circadian rhythms were revealed in the blood cholinesterase (ChE) activity in intact mice and normal persons, as well as in mice mortality treated at different daily times. The inverse relationship of the two rhythm suggested that the risk of exposure to DDVP might be much higher at evening hours than in other clocks of the day, and the disappearance of the ChE rhythms in DDVP-treated mice and DDVP-exposed workers implicated a disturbing effect of DDVP on the maintenance and regulation of the rhythmic mechanisms.     

Circadian Rhythm of Heart Rate,Urinary Cortisol Excretion,and Sleep in Civil Air Traffic Controllers

The examination of Air Traffic Controllers (ATCs) from the Warsaw Airport (Poland) included 24-hr ECG monitoring. The participants were 10 civil ATCs, 9 males and 1 woman. The study was carried out on a group of 19 ATCs during their duty periods, 14 of them working 12-hr shifts and 5 performing 24-hr duties. The participants collected urine every 4 hrs, and Cortisol concentration was determined. Further, the survey included the quality and duration of sleep, and subjective fatigue in the 62 participants.

In ATCs, shift work modifies natural rhythms of the circulatory system and decreases the ability for intensified mental work at night. In consequence ATCs experience frequent sleep disorders.     

modifications of ultradian and orcadian rhythms of fetal heart rate after fetal-maternal adrenal gland suppression: A double blind study

In order to verify whether fetal and maternal adrenal gland suppression induces effects on fetal behaviour, triamcinolone was administered to five healthy pregnant women at 35 weeks of gestation. Five patients of the same gestational age were used as control. Fetal heart rate (FHR) and fetal movements were recorded continuously over 2-h interval by means of cardiotocography. After 3 weeks (38 weeks of gestation) the recordings were repeated without drug administration. Cortisol, adrenocorticotropin hormone, 17 β-estradiol and unconjugated estriol were measured at the same time every 2 h in maternal peripheral plasma. At 35 weeks we found a loss of circadian rhythms of the hormones investigated and modifications of ultradian and circadian patterns of FHR in the treated group with respect to the control. No differences in hormonal and biophysical parameters were found between the two groups after the end of treatment (38 weeks). These data suggest that the inhibition of fetal and maternal adrenal glands could cause modifications of FHR patterns.     

生物节律理论在铁路行、调车安全中的应用探讨

首先对生物节律理论的涵义以及相关专业论文著作中对临界日的主要观点进行了概述。通过对生物节律理论的研究,提出了扩大范围的"72小时临界期"作为统计样本数据的依据。经过对37个样本的统计分析得出,对于铁路行、调车工种情绪高潮期是危险多发阶段,并归纳出"低低高、高高高、临低高、低高高"四类针对行、调车工种的"特别危险"级别的生物节律组合,然后使用四起一般事故作为以上分析结果的佐证。给出了生物节律在行、调车安全生产中应用的四项建议。最后,得到生物节律技术是对传统安全管理方法补充的结论。     

Non-Thermal Effect of Microwave Radiation on Human Brain

Summary This study focuses on an origin of interaction mechanism of microwave radiation with nervous system—quasi-thermal field effect. The microwave field can cause fluctuations and vibration of the charged particles and membranes in tissues. The hypothesis is, that this phenomenon is similar to the effect caused by Brown motion initiated by temperature and results in the same effects without rise in temperature. The electric field of 1 V/cm can introduce disturbance of the thermal equilibrium inside a cell of 10 μm radius, which is equivalent to disturbance produced by temperature rise of 1 K. The hypothesis, that microwave heating should cause an effect independent of the microwave modulation frequency, while field effect depends on modulation frequency, was examined experimentally. The 450 MHz microwave radiation, modulated at 7, 14 and 21 Hz frequencies, power density at the skin 0.16 mW/cm², was applied. The experimental protocol consisted of two series of five cycles of the repetitive microwave exposure at fixed modulation frequencies. Relative changes in EEG theta, alpha and beta rhythms of the group of 13 healthy volunteers were analysed. Analysis of the experimental data shows that: (1) statistically significant changes in EEG rhythms depend on modulation frequency of the microwave field; (2) microwave stimulation causes an increase of the EEG energy level; (3) the effect is most intense at beta1 rhythm and higher modulation frequencies. These findings confirm the quasi-thermal origin of the effect, different from average heating.     

环境孕激素和糖皮质激素的生态毒理效应:进展与展望

孕激素和糖皮质激素的环境行为和生态毒理效应是即环境雌激素和雄激素之后近年来国内外环境激素研究的又一热点课题。由于广泛应用于临床医疗等,这两类物质通过污水处理厂不完全处理和人类农业或畜牧业活动的直接排放从而进入水体环境,进而对生态系统和人类健康产生潜在危害。环境监测数据显示,在地表水中,多种物质存在ng·L-1浓度水平;在污水处理厂进出水中,浓度水平更高,甚至达到数百ng·L-1。孕激素和糖皮质激素类物质主要通过激素受体途径发挥毒性效应,如孕激素受体(PR),糖皮质激素受体(GR)和盐皮质激素受体(MR)。对水生脊椎动物的内分泌系统干扰作用是目前研究的焦点。这两类物质能够影响脑垂体性腺轴转录水平和相应激素合成,影响性腺发育以及导致繁殖能力损伤。这一毒性效应甚至发生在环境浓度水平之下。除此之外,随着组学技术的广泛应用,更多的潜在毒性终点不断被发掘,如对昼夜节律系统和免疫应答的干扰作用。这些研究引导着对环境孕激素和糖皮质激素生态毒理学效应更加深入的理解。     

Where clocks are redundant: weak circadian mechanisms in reindeer living under polar photic conditions

Biological rhythms are a result of interplay between endogenous clocks and the ambient light–dark (LD) cycle. Biological timing in resident polar organisms presents a conundrum because these experience distinct daily LD cycles for only a few weeks each year. We measured locomotor activity in reindeer, Rangifer tarandus platyrhynchus (SR, n = 5 and 6) and R. tarandus tarandus (NR, n = 6), ranging freely at 78 and 70°N, respectively, continuously throughout 1 year using data loggers. NR, but not SR, are gregarious which enabled us to examine the integrated effects of differences in social organisation and the photic environment at two different latitudes on the organisation of activity. In both sub-species, ultradian bouts of activity and inactivity alternated across the 24-h day throughout the year. This pattern was modified by the LD cycle in NR but barely at all in SR. Periodogram analysis revealed significant ultradian rhythmicity in both sub-species; the frequency of daily cycles of activity increased from three per day in winter to nearly five in summer. We conclude that this increase, and a concomitant increase in the level of daily activity, reflected the seasonal increase in the animals’ appetite and the quality of their forage. Secondly, the combination, most evident in SR, of a weak photic response, weak circadian mechanisms and a weak social synchronization reduces the constraints of biological timing in an environment which is effectively non-rhythmic most of the year and permits expression of the basic ultradian pattern of ruminant activity. Third, the weaker 24-h rhythmicity in SR compared to NR indicates a latitudinal decrease in circadian organization and photic responsiveness in Rangifer.