Geomagnetic Field Effect on Affective and Cognitive Competence in Preschool

The goal of our research was to study the effect of geomagnetic field (GMF) disturbances, in terms of K, K_p, A_k, A_p, and SK indices, on children's affective (emotional) and cognitive competence during different forms of organization of pretend play. We studied two forms of management of the playing process: 1) teacher‐directed frontal play with simultaneous involvement of all children in the classroom and 2) child‐directed play in various small groups. Twenty‐six observations were performed on 51 children in two mixed‐age classrooms. The mean age of the children was 4.6 years, with age span from 3 to 6 years. We found a significant increase in cognitive behavior during child‐directed play in groups compared with frontal, teacher‐directed management of the lesson. During child‐directed play children's behavior was negatively correlated with geomagnetic disturbance in both affective and cognitive domains (R = ? 0.47, p < 0.029, n = 21) as compared with teacher‐directed play where there was no significant interaction. We believe the dependence of the GMF effect on the type of the organization of the educational process is explained by the less‐stressful environment of the child‐directed playing conditions compared with teacher‐directed in which the directive role of the teacher can mask a possible GMF effect.     

Geomagnetic disturbances may be environmental risk factor for multiple sclerosis: an ecological study of 111 locations in 24 countries

Background

We noticed that a hypothesis based on the effect of geomagnetic disturbances (GMD) has the ability to explain special features of multiple sclerosis (MS). Areas around geomagnetic 60 degree latitude (GM60L) experience the greatest amount of GMD. The easiest way to evaluate our hypothesis was to test the association of MS prevalence (MSP) with angular distance to geomagnetic 60 degree latitude (AMAG60) and compare it with the known association of MS with geographical latitude (GL). We did the same with angular distance to geographic 60 degree latitude (AGRAPH60) as a control.

Methods

English written papers with MSP keywords, done in Europe (EUR), North America (NA) or Australasia (AUS) were retrieved from the PubMed. Geomagnetic coordinates were determined for each location and AMAG60 was calculated as absolute value of numerical difference between its geomagnetic latitude from GM60L. By an ecological study with using meta-regression analyses, the relationship of MSP with GL, AMAG60 and AGRAPH60 were evaluated separately. MSP data were weighted by square root of number of prevalent cases. Models were compared by their adjusted R square (AR²) and standard error of estimate (SEE).

Results

111 MSP data were entered in the study. In each continent, AMAG60 had the best correlation with MSP, the largest AR² (0.47, 0.42 and 0.84 for EUR, NA and AUS, respectively) and the least SEE. Merging both hemispheres data, AMAG60 explained 56% of MSP variations with the least SEE (R?=?0.75, AR²?=?0.56, SEE?=?57), while GL explained 17% (R?=?0.41, AR²?=?0.17, SEE?=?78.5) and AGRAPH60 explained 12% of that variations with the highest SEE (R?=?0.35, AR²?=?0.12, SEE?=?80.5).

Conclusions

Our results confirmed that AMAG60 is the best describer of MSP variations and has the strongest association with MSP distribution. They clarified that the well-known latitudinal gradient of MSP may be actually a gradient related to GM60L. Moreover, the location of GM60L can elucidate why MSP has parabolic and linear gradient in the north and south hemisphere, respectively. This preliminary evaluation supported that GMD can be the mysterious environmental risk factor for MS. We believe that this hypothesis deserves to be considered for further validation studies.     

Geomagnetic Reversals and Genome Imprinting

If it is more fundamental to formulate biological expression in terms of electromagnetic fields, does this also imply that living things are especially sensitive to the external electromagnetic environment? Specifically, we examine possible genomic effects due to reversals of the geomagnetic field. To maintain sensitivity following a reversal, the Wiltschko hypothesis for the avian magnetic compass can be subsumed under an NB imprinting paradigm, where N is the horizontal vector pointing to magnetic north and B the geomagnetic field vector. Even with a compass that is invariant under reversals, there are nevertheless potential difficulties due to discontinuities in the magnitude of the field during the transition between one chron and the next. Indeed, transitions may be one reason for other-than-magnetic avian auxiliary compasses. Additional problems may also arise during transitions because of high rates of change in B. However, the largest reported dB/dt (Steens Mountain event) is estimated at 1 /u.T/day, seemingly too small to induce significant Faraday current density. Reversals may have also helped determine the nature of the interaction mechanism between GMF and living systems. Mechanisms based on fixed magnetic moments may not be capable of adapting to the reversal process. A better case can be made for an ion cyclotron resonance interaction. Direct involvement in the cell-signaling activities of biological ions would provide such flexibility, and also point to a broader role for the GMF in modulating CNS function than merely to provide orientation.     

Geomagnetic field detection in rodents

In addition to behavioral evidence for the detection of "earth-strength" magnetic fields (MF) by rodents, recent investigations have revealed that electrophysiological and biochemical responses to MF occur in the pineal organ and retina of rodents. In addition, ferrimagnetic deposits have been identified in the ethmoidal regions of the rodent skull. These findings point to a new sensory phenomenon, which interfaces with many fields of biology, including neuroscience, psychophysics, behavioral ecology, chronobiology and sensory physiology.     

Geomagnetic field effect on cardiovascular regulation

The goal of the present research was try to explain the physiological mechanism for the influence of the geomagnetic field (GMF) disturbance, reflected by the indices of the geomagnetic activity (K, K(p), A(k), and A(p) indices), on cardiovascular regulation. One hundred forty three experimental runs (one daily) comprising 50 min hemodynamic monitoring sequences were carried out in rabbits sedated by pentobarbital infusion (5 mg/kg/h). We examined the arterial baroreflex effects on the short term blood pressure and heart rate (HR) variabilities reflected by the standard deviation (SD) of the average values of the mean femoral arterial blood pressure (MAP) and the HR. Baroreflex sensitivity (BRS) was estimated from blood pressure/HR response to intravenous (i.v.) bolus injections of vasoconstrictor (phenylephrine) and vasodilator (nitroprusside) drugs. We found a significant negative correlation of increasing GMF disturbance (K(p)) with BRS (P = 0.008), HR SD (P =0.022), and MAP SD (P = 0.002) signifying the involvement of the arterial baroreflex mechanism. The abrupt change in geomagnetic disturbance from low (K = 0) to high (K = 4-5) values was associated with a significant increase in MAP (83 +/- 5 vs. 99 +/- 5 mm Hg, P = 0.045) and myocardial oxygen consumption, measured by MAP and HR product (24100 +/- 1800 vs. 31000 +/- 2500 mm Hg. bpm, P = 0.034), comprising an additional cardiovascular risk. Most likely, GMF affects brainstem and higher neural cardiovascular regulatory centers modulating blood pressure and HR variabilities associated with the arterial baroreflex.     

Geomagnetic cyclotron resonance in living cells

Although considerable experimental evidence now exists to indicate that low-frequency magnetic fileds influence living cells, the mode of coupling remains a mystery. We propose a radical new model for electromagnetic interactions with cells, one resulting from a cyclotron resonance mechanism attached to ions moving through transmembrane channels. It is shown that the cyclotron resonance condition on such ions readily leads to a predicted ELF-coupling at geomagnetic levels. This model quantitatively explains the results reported by Blackman et al. (1984), identifying the focus of magnetic interaction in these experiments as K⁺ charge carriers. The cyclotron resonance concept is consistent with recent indications showing that many membrane channels have helical configurations. This model is quite testable, can probably be applied to other circulating charge components within the cell and, most important, leads to the feasibility of direct resonant electromagnetic energy transfer to selected compartments of the cell.     

Geomagnetic activity and human embryonic development

A retrospective analysis of weekly values of geomagnetic activity during embryonal development for healthy and mentally diseased people was performed. A statistically significant in the aa-index for mentally diseased people by 4.5-5.5 week of embryonic growth was revealed. This suggesting that the level of geomagnetic activity affects the laying and development of the central nervous system.     

动物地磁导航机制研究进展

地磁场是地球重要的物理场,它不仅能保护地球生物免受太阳风及其他宇宙射线的伤害,阻挡地球生命赖以生存的大气圈和水圈被剥蚀,为地球生物提供一个温和的生存进化环境,而且其强度、偏角和倾角能为动物迁徙提供定位导航参考。目前,行为学研究已经发现许多鸟类、爬行类、两栖类、哺乳类等动物都能够利用地磁场导航。动物感知地磁场的磁感受器(magnetoreceptor)、磁信息的感知机制和信号传递通路一直是动物地磁导航研究的焦点和难点,但目前对它们的了解并不十分清楚。基于国内外学者最近的研究成果,本文首先介绍三种主要的磁感知机制及其相应的证据:电磁感应、基于光受体的磁感知及基于磁铁矿纳米颗粒的磁感知。其次,总结鸟类基于光受体和磁铁矿纳米颗粒的磁感知神经通路和相应的磁信息响应脑区:(1)眼睛视网膜上光依赖的磁感受器——隐花色素通过视觉通路与大脑联系获取准确方向信息;(2)上喙或内耳中的磁铁矿纳米颗粒磁感受器,通过三叉神经或内耳听壶传入神经将感知的磁场强度信息传至脑干前庭区域,获得"导航图"信息。最后,简要总结近年来哺乳动物地磁导航的研究进展,并指出动物地磁导航研究当前亟待解决的几个重要科学问题。     

Geomagnetic disturbances and animal activity in laboratory conditions

The influence of geomagnetic activity on animal behavior in laboratory conditions has been assessed using time series of unprecedented length: several years of continuous instrumental monitoring of the electric activity of weakly electric elephantfish Gnathonemus leopoldianus and the motor activity of catfish Hoplosternum thoracatum and cockroaches Blaberus craniifer, in comparison with several indices of magnetic disturbance. Special care has been taken to obviate spurious effects in correlating the essentially non-stationary data. The results of analysis do not show any significant influence of geomagnetic activity on the measured bioindicator parameters.     

A Role for the Geomagnetic Field in Cell Regulation

We advance the hypothesis that biological systems utilize the geomagnetic field (GMF) for functional purposes by means of ion cyclotron resonance-like (ICR) mechanisms. Numerous ICR-designed experiments have demonstrated that living things are sensitive, in varying degrees, to magnetic fields that are equivalent to both changes in the general magnetostatic intensity of the GMF, as well as its temporal perturbations. We propose the existence of ICR-like cell regulation processes, homologous to the way that biochemical messengers alter the net biological state through competing processes of enhancement and inhibition. In like manner, combinations of different resonance frequencies all coupled to the same local magnetic field provide a unique means for cell regulation. Recent work on ultraweak ICR magnetic fields by Zhadin and others fits into our proposed framework if one assumes that cellular systems generate time-varying electric fields of the order 100 mV/cm with bandwidths that include relevant ICR frequencies.     

Geomagnetic effects on a circadian difference in reaction times in earthworms

Summary The effect of geomagnetic force on the light-withdrawal reflex of earthworms, Lumbricus terrestris, L., was investigated during the autumn of 1968. The reactions of worms kept in the earth's magnetic field were timed beginning at 12:00 and at 20:00, E.S.T. on each of 63 days; the same was done for worms maintained in a field whose intensity was essentially zero. The worms in the earth's field withdrew from light significantly faster at night then at midday. No significant difference between the mean reaction times at 12:00 and those of the evening were found for the animals which lived and were tested in the greatly reduced magnetic field. Therefore, geomagnetism does have some effect on the circadian difference in reaction rates in this species.

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Zusammenfassung Die Wirkung des erdmagnetisohen Feldes auf die Lichtreaktion von Lumbricus terrestris wurde untersucht (Herbst 1968). Als Test wurde die Reaktion auf einen Lichtreiz verwendet. Ein Teil der Würmer wurde im natürlichen erdmagnetisehen Feld, ein anderer Teil in einem auf Null kompensierten Feld gehalten. Die Reaktionszeiten auf den Lichtreiz wurden bei beiden Gruppen um 12.00 und um 20.00 Uhr gemessen. Die Reaktionszeiten im natürlichen erdmagnetischen Feld waren abends signifikant (p=0,005) kürzer (7,2 sec) als mittags (8,9 sec). Im Feld, das nahezu auf Null kompensiert war, waren die Reaktionszeiten abends und mittags gleich (8,8 bzw. 8,7 sec). Der Erdmagnetismus hat also einen Einfluß auf die circadiane Differenz der Reaktionszeiten bei Lumbricus.

     

Evidence for Geomagnetic Imprinting as a Homing Mechanism in Pacific Salmon

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Highlights? Sockeye salmon use geomagnetic imprinting as a homing mechanism ? The homing route of salmon is predicted by magnetic field drift (secular variation)     

The Geomagnetic Field Is a Compass Cue in Cataglyphis Ant Navigation

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Low-Frequency Magnetic Fields in Cars and Office Premises and the Geomagnetic Field Variations

In this study, we measured and analyzed the spectral characteristics of a low-frequency magnetic field (MF) inside several gasoline-powered cars while driving on busy city roads. The spectra obtained upon measurements in the interior of the cars are compared with those measured in office locations at different times of the day and with different disturbances of the geomagnetic field (k-index of disturbance 2–8). The power spectral density of the electromagnetic field in cars moving on busy roads in the frequency range of 10⁻³–10² Hz is one to three orders of magnitude higher than that in urban offices. This raises a question regarding the possible influence of these MFs on the psychophysiological state of drivers. In turn, in the daytime, the MF power in the range from 10⁻³ to 1 Hz inside the locations is three times higher compared with the power of a strong geomagnetic storm. Despite such an overwhelming magnetic background, geomagnetic storms affect various organisms. The nonspecific effect of magnetic storms is supposed to be associated with relatively long (lasting several hours or more [frequency range of 10⁻⁴−10⁻⁵ Hz]) periods of enhancement or weakening of the local geomagnetic field. In this range, especially at night, the power spectral density of geomagnetic disturbances is comparable to and can even exceed the power density of urban MFs. © 2020 Bioelectromagnetics Society.     

Reduced Efficiency of Magnetotaxis in Magnetotactic Coccoid Bacteria in Higher than Geomagnetic Fields

Magnetotactic bacteria are microorganisms that orient and migrate along magnetic field lines. The classical model of polar magnetotaxis predicts that the field-parallel migration velocity of magnetotactic bacteria increases monotonically with the strength of an applied magnetic field. We here test this model experimentally on magnetotactic coccoid bacteria that swim along helical trajectories. It turns out that the contribution of the field-parallel migration velocity decreases with increasing field strength from 0.1 to 1.5 mT. This unexpected observation can be explained and reproduced in a mathematical model under the assumption that the magnetosome chain is inclined with respect to the flagellar propulsion axis. The magnetic disadvantage, however, becomes apparent only in stronger than geomagnetic fields, which suggests that magnetotaxis is optimized under geomagnetic field conditions. It is therefore not beneficial for these bacteria to increase their intracellular magnetic dipole moment beyond the value needed to overcome Brownian motion in geomagnetic field conditions.     

Brazilian Ants Diversity and the Local Geomagnetic Field: A Ferromagnetic Resonance Study

Ants have the ability of homing and some species can migrate or move over long distances (nomadic). The presence of magnetic particles as geomagnetic sensors is the most accepted hypothesis to explain ant orientation mechanisms. The room temperature Ferromagnetic Resonance (FMR) spectra of migratory, nomadic, arboreal, trap-jaw and fire ants, applied to 11 samples are presented. The spectra were studied taking into account two components: the low field (LF) with a maximum at g_max values higher than 8 and the high field (HF) at the g_eff=2.1 with a linewidth of about 900 Oe. This study tests the systematization plausibility of ant magnetic material characteristics based on absorption spectra area and the ratios between the peak-to-peak amplitude spectral components (LF/HF). The HF component predominates in the spectra of the migratory and one nomadic ant, while the LF is the dominant one in the arboreal and six fire ants studied. The Solenopsis absorption spectra area, proportional to the magnetic material amount, increases as the local magnetic field intensity increases, suggesting an adaptation of these ants to the magnetic environment characteristic.     

How the Geomagnetic Field Influences Life on Earth – An Integrated Approach to Geomagnetobiology

Origins of Life and Evolution of Biospheres - Earth is one of the inner planets of the Solar System, but – unlike the others – it has an oxidising atmosphere, relatively stable...     

Features of the Response of the Cardiovascular System to Geomagnetic Disturbances at Different Latitudes

The principles of multi-latitude monitoring of Heliomed-2 for obtaining new data on the impact of space weather on human health are described. The results of synchronous monitoring of responses of the cardiovascular system and psychoemotional state of healthy volunteers to changes in geomagnetic disturbances at high (Tiksi village and Yakutsk) and middle (Saratov) latitudes are presented. In all the examined groups, the effect of synchronization of the processes of repolarization of the ventricular myocardium (according to the coefficient of symmetry of the T wave of the electrocardiogram) and geomagnetic disturbances, as well as synchronization of reactive anxiety and geomagnetic disturbances was revealed. It was found that the group cardiac sensitivity and psychological sensitivity to geomagnetic disturbances coincide regardless of the latitude of residence in the same group of volunteers.