The method for studying of the "magnetic vacuum" effect on color memory in humans

The method for studying the effects of weak magnetic fields and "magnetic vacuum" on the psychophysiological state of a human organism is proposed. This method includes the system of the exposure of a human organism to uniform constant and alternating magnetic fields and the system of computerized psychological tests. The influence of the weakening of constant magnetic field on the psychophysiological state of human organisms was studied. The short-term color memory and reaction rates of 30 subjects have been examined in the local geomagnetic field and in a magnetic field which was reduced in 10 and more times. Statistically significant differences in the color memory test was found in the magnetic field 4 +/- 1 microT in comparison with the results in the geomagnetic field. In the magnetic field 0 +/- 1 microT, slight impairment of color memory was found. Preliminary results in the test of reaction rates showed the tendency to slowing down the reaction rates in the weakened magnetic fields.     

Bats use magnetite to detect the earth's magnetic field

While the role of magnetic cues for compass orientation has been confirmed in numerous animals, the mechanism of detection is still debated. Two hypotheses have been proposed, one based on a light dependent mechanism, apparently used by birds and another based on a "compass organelle" containing the iron oxide particles magnetite (Fe(3)O(4)). Bats have recently been shown to use magnetic cues for compass orientation but the method by which they detect the Earth's magnetic field remains unknown. Here we use the classic "Kalmijn-Blakemore" pulse re-magnetization experiment, whereby the polarity of cellular magnetite is reversed. The results demonstrate that the big brown bat Eptesicus fuscus uses single domain magnetite to detect the Earths magnetic field and the response indicates a polarity based receptor. Polarity detection is a prerequisite for the use of magnetite as a compass and suggests that big brown bats use magnetite to detect the magnetic field as a compass. Our results indicate the possibility that sensory cells in bats contain freely rotating magnetite particles, which appears not to be the case in birds. It is crucial that the ultrastructure of the magnetite containing magnetoreceptors is described for our understanding of magnetoreception in animals.     

Integrating 'top-down" and "bottom-up" mass spectrometric approaches for proteomic analysis of Shewanella oneidensis

Here we present a comprehensive method for proteome analysis that integrates both intact protein measurement ("top-down") and proteolytic fragment characterization ("bottom-up") mass spectrometric approaches, capitalizing on the unique capabilities of each method. This integrated approach was applied in a preliminary proteomic analysis of Shewanella oneidensis, a metal-reducing microbe of potential importance to the field of bioremediation. Cellular lysates were examined directly by the "bottom-up" approach as well as fractionated via anion-exchange liquid chromatography for integrated studies. A portion of each fraction was proteolytically digested, with the resulting peptides characterized by on-line liquid chromatography/tandem mass spectrometry. The remaining portion of each fraction containing the intact proteins was examined by high-resolution Fourier transform mass spectrometry. This "top-down" technique provided direct measurement of the molecular masses for the intact proteins and thereby enabled confirmation of post-translational modifications, signal peptides, and gene start sites of proteins detected in the "bottom-up" experiments. A total of 868 proteins from virtually every functional class, including hypotheticals, were identified from this organism.     

Effect of the ecologically significant variable magnetic field on metabolic parameters in the animal brain

The influence of an ecologically significant magnetic field (8 Hz) on metabolic processes in brain regions of animals with different constitutional features was studied. Oppositely directed metabolic changes in the brain of animals with different behavior in the "open field" test were revealed. It was found that the right brain hemisphere dominates in system reaction to extremely low-frequency magnetic fields.     

静磁场对大肠杆菌生长过程的作用机制研究

通过对在外加静磁场和正常情况下培养大肠杆菌生长情况的对比分析 ,发现试验条件下所选磁场对大肠杆菌有明显促进生长的作用 ,菌落计数结果表明磁场越强作用效果越明显。对试验结果进行Dunnettt检验发现均具有差异显著性     

On the "unreasonable" effects of ELF magnetic fields upon a system of ions

A recent experiment on a physical, nonbiological system of ions at room temperature has proved that microscopic ion currents can be induced by applying simultaneously two parallel magnetic fields, one rather weak static field, (-->)B(0) and one much weaker alternating field, (-->) B(ac),[B(ac) approximately 10(-3) B(0)] whose frequency coincides with the cyclotron frequency v = qB(0)/2pim of the selected ion. As a result, ionic bursts lasting up to 20 s and with amplitude up to 10 nA arise. The much larger exchanges of energy induced by thermal agitation (the "kT-problem") appear to play no role whatsoever. We have analyzed this problem in the framework of coherent quantum electrodynamics, reaching the following conclusions: (a) as has been shown in previous articles, water molecules in the liquid and solute ions are involved in their ground state in coherent ordered configurations; (b) ions are able to move without collisions among themselves in the interstices between water coherence domains; (c) because of coherence, ions can follow classical orbits in the magnetic fields. A full quantitative understanding of the experiments is thus reached.     

Sensitivity of the diamagnetic condensed matter to weak magnetic fields

It is shown that, under the influence of magnetic field, rotational moments of the same direction appear for all charged particles having the same sign of their charge and freely moving in a thermal fluctuational electromagnetic field in a diamagnetic condensed matter. The magnitude of this rotational moment is proportional to the thermal energy kT and can be substantially increased when the conditions for cyclotron resonance are satisfied. The moments of positively charged particles are directed oppositely to the vector of the magnetic field induction. The so-called "kT problem" has been solved. The evidence for magnetosensitivity is the appearance of rotational moments acting on the particles from the thermal field in the presence of an external magnetic field as a small factor.     

Modification of the 1979 "Denver wire code" for different wire or plumbing types.

This article examines "wire configuration coding" as used to estimate relative residential AC magnetic field exposure in epidemiological studies--and the need to alter such coding for time or locations other than those in which the code was developed. Effects of different secondary wire practices are particularly examined.     

Influence of near null magnetic field on in vitro growth of potato and wild Solanum species

The influence of near null magnetic field on in vitro growth of different cultures of potato and related Solanum species was investigated for various exposure times and dates. Potato (Solanum tuberosum L. cv. Désirée) in vitro cultures of shoot tips or nodal segments were used. Three different exposure periods revealed either stimulation or inhibition of root, stem, or leaf in vitro growth after 14 or 28 days of exposure. In one experiment the significant stimulation of leaf growth was also demonstrated at biochemical level, the quantity of chlorophyll a and b and carotenoids increasing more than two-fold. For the wild species Solanum chacoense, S. microdontum, and S. verrucosum, standardized in vitro cultures of nodal stem segments were used. Root and stem growth was either stimulated or slightly inhibited after 9 days exposure to near null magnetic field. Callus cultures obtained from potato dihaploid line 120/19 were maintained in near null magnetic field in 2 different months. For these experiments as well as for Solanum verrucosum, callus cultures recorded either slight inhibition or no effect on fresh weight. For all experiments significant growth variation was brought about only when geomagnetic activity (AP index) showed variations at the beginning of in vitro growth and when the explant had at least one meristematic tissue. Moreover longer maintenance in near null magnetic field, 28 days as compared to 14 days or the controls, can also make a difference in plant growth in response to geomagnetic field variations when static component was reduced to zero value. These results of in vitro plant growth stimulation by variable component of geomagnetic field also sustain the so-called seasonal "window" effect.     

The Influence of Low Magnetic Fields and Magnesium Isotopes on <Emphasis Type="Italic">E. coli</Emphasis> Bacteria

The combined effects of external low static magnetic fields at 0–22 mT and magnesium isotopes on the growth and development of E. coli bacteria has been studied. The magnetic field and ²⁵Mg magnetic isotope effects were obtained in two ranges: 0.8–3.0 and 8–13 mT. The experimental values of the growth rate, the number of CFUs and the ATP pool of bacteria enriched in magnetic magnesium isotope ²⁵Mg (nuclear spin, I = 5/2) in the range of 0.8–3.0 mT are significantly higher compared to bacteria enriched in nonmagnetic isotopes ²⁴Mg, ²⁶Mg, or natural magnesium. The increase in the growth rate, colony-forming ability, and intracellular ATP concentration in bacteria in all groups cultivated under exposure to an external static magnetic field in the range of 0.8 to 3.0 mT confirms the existence of magnetosensitive stages of enzymatic reactions that proceed via the ion-radical mechanism. The combined influence of the magnetic field in the range of 8 to 13 mT and the magnesium magnetic isotope ²⁵Mg on the colony forming ability of E. coli bacteria is associated with processes that are responsible for cell division. The above-mentioned effects of bacterial magnetosensitivity (to magnetic fields and magnetic isotopes) are in good agreement with theoretical predictions of the theory of spin-dependent enzymatic reactions.     

Modeling of antibiotics production in magneto three-phase airlift fermenter

A mathematical model is developed to describe the performance of a three-phase airlift reactor utilizing a transverse magnetic field. The model is based on the complete mixing model for the bulk of liquid phase and on the Michaelis-Menten kinetics. The model equations are solved by the explicit finite difference method from transient to steady state conditions. The results of the numerical simulation indicate that the magnetic field increases the degree of bioconversion. The mathematical model is experimentally verified in a three-phase airlift reactor with P. chrysogenum immobilized on magnetic beads. The experimental results are well described by the developed model when the reactor operates in the stabilized regime. At relatively high magnetic field intensities a certain discrepancy in the model solution was observed when the model over estimates the product concentration.     

Low frequency electromagnetic fields and the Belousov-Zhabotinsky reaction

Low frequency magnetic fields can influence biochemical reactions and consequently physiological rhythms and oscillations. To test this for a model reaction we used the chemical Belousov-Zhabotinsky (BZ) reaction, which is one of the simplest chemical oscillators. The oscillation frequency of the reaction was tracked optically by the absorption of blue light. Field treatment was carried out at room temperature in the middle of two Helmholtz coils. After starting the reaction, for 5 min the oscillations were monitored as control measurement, then during the next 10 min monitoring was with a magnetic field switched on, followed by a period of 5 min with the field switched off. A variety of exposure conditions have been tested: the frequency was varied between 5 and 1000 Hz, the field strength was varied up to 2.7 mT, different pulse shapes were used, the influence of the exposure temperature was tested, and the influence of the optimum exposure conditions (static magnetic field and the frequency of the dynamic field) as predicted by the ion parametric resonance (IPR) model has been measured. In conclusion, in no case any statistical significant influence of the magnetic treatment on the oscillation frequency of the BZ reaction could be detected (P > .05, t-test).     

Avian orientation: effects of cue-conflict experiments with young migratory songbirds in the high Arctic

The migratory orientation of juvenile white-crowned sparrows, Zonotrichia leucophrys gambelli, was investigated by orientation cage experiments in manipulated magnetic fields performed during the evening twilight period in northwestern Canada in autumn. We did the experiments under natural clear skies in three magnetic treatments: (1) in the local geomagnetic field; (2) in a deflected magnetic field (mN shifted −90°); and (3) after exposure to a deflected magnetic field (mN −90°) for 1 h before the cage experiment performed in the local geomagnetic field at dusk. Subjects showed a mean orientation towards geographical east in the local geomagnetic field, north of the expected migratory direction towards southeast. The sparrows responded consistently to the shifted magnetic field, demonstrating the use of a magnetic compass during their first autumn migration. Birds exposed to a cue conflict for 1 h on the same day before the experiment, and tested in the local geomagnetic field at sunset, showed the same northerly orientation as birds exposed to a shifted magnetic field during the experiment. This result indicates that information transfer occurred between magnetic and celestial cues. Thus, the birds' orientation shifted relative to available sunset and geomagnetic cues during the experimental hour. The mean orientation of birds exposed to deflected magnetic fields prior to and during testing was recorded up to two more times in the local geomagnetic field under natural clear and overcast skies before release, resulting in scattered mean orientations.Copyright 2002 The Association for the Study of Animal Behaviour. Published by Elsevier Science Ltd. All rights reserved .     

Intracellular recording during magnetic field application to monitor neurotransmitter release events: methods and preliminary results

A method for simultaneous magnetic field application and intracellular recording is presented. A little used method for magnetic field application was exploited; the field generator consisted of a flat copper sheet through which current was passed to generate a magnetic field. The resultant magnetic field was relatively homogeneous, exhibiting a variation of +/- 5%. This compact, current-sheet field generator was mounted on the condensor of a microscope. The current induced in the intracellular electrode was reduced by injecting current equal and opposite to the induced current into the microelectrode. This step reduces the possibility of cellular effects and voltage artifacts due to the induced electrode current. The technique was used to conduct preliminary studies on the effects of extremely low frequency (ELF) linearly and circularly polarized magnetic fields (1.0 Gauss, 60 and 70 Hz) on miniature end plate potential (mepp) frequency (frequency of neurotransmitter release events) of rat flexor digitorum brevis muscle. The same synapse was utilized for both the sham-exposed control and the exposed experimental halves of an experiment. After 10 min of exposure to a 60-Hz linear field, mepp frequency was significantly increased by 12%, but exposure to a 60-Hz circular field did not significantly alter mepp frequency. Exposure to a 70-Hz linear field did not significantly change mepp frequency, but application of a 70-Hz circular field appears to decrease mepp frequency by 4%. These results indicate that both types of magnetic fields can alter mepp frequency, depending upon the frequency and configuration of the field.     

Magnetosensitivity of <Emphasis Type="Italic">E. coli</Emphasis> Bacteria in the Presence of Zinc Isotopes

The combined effect of the zinc magnetic isotope ⁶⁷Zn and weak magnetic field 25–35 mT causes a 2–4-fold increase in the colony-forming ability of bacteria E. coli in comparison with the nonmagnetic isotopes ^{64, 66}Zn. The effects of magnetic field in the range of 2.2–8 mT were detected for all bacteria regardless of the zinc-isotope enrichment of the media. This indicates the sensitivity of intracellular processes to weak magnetic fields. An increase in the ATP concentration in E. coli cells was only detected for the bacteria grown on the medium with the magnetic zinc isotope in the range of 2.2–4.2 mT. The obtained data confirm the existence of stages of intracellular enzymatic processes that are sensitive to magnetic fields and magnetic moments of atomic nuclei.     

Magnetophoresis and the magnetic susceptibility of HeLa tumor cells

A method for measuring the magnetic susceptibility of a single cell is developed and theoretically justified. The method is based on use of a computer-aided video recording of the integral curve of magnetophoretic motion of a cell settling in liquid medium near a thin vertical magnetic rod under the influence of a uniform magnetic field. The magnetic susceptibility of HeLa tumor cells and nutrient medium 199 is measured.     

Sensitive detection of viral antigens with a new method, "laser magnet immunoassay".

A new method, "laser magnet immunoassay" (LMIA), has been developed for sensitive detection of viral antigens. Target viruses captured on microbeads were made to react with antibodies labeled with magnetite particles. In a magnetic field, magnetically labeled antigens dispersed in water were attracted to and concentrated at one point on the surface, resulting in the lifting up of a small surface area. A laser beam which was incident on the point reflected, making an interference fringe. The intensity of the fringe indicates the amount of the magnetite conjugated with antigen. A very low concentration of antigens, such as 5 particles of influenza virus and 0.1 pg/ml of human immunodeficiency virus (HIV) p24 antigen in human serum, could be detected by this method. Application of this method to diagnoses of viral diseases in early stages is discussed.     

Action of combined magnetic fields on aqueous solution of glutamic acid: the further development of investigations

In the present work the results of the known investigation of the influence of combined static (40 μT) and alternating (amplitude of 40 nT) parallel magnetic fields on the current through the aqueous solution of glutamic acid, were successfully replicated. Fourteen experiments were carried out by the application of the combined magnetic fields to the solution placed into a Plexiglas reaction vessel at application of static voltage to golden electrodes placed into the solution. Six experiments were carried out by the application of the combined magnetic fields to the solution placed in a Plexiglas reaction vessel, without electrodes, within an electric field, generated by means of a capacitor at the voltage of 27 mV. The frequency of the alternating field was scanned within the bounds of 1.0 Hz including the cyclotron frequency corresponding to a glutamic acid ion and to the applied static magnetic field. In this study the prominent peaks with half-width of ~0.5 Hz and with different heights (till 80 nA) were registered at the alternating magnetic field frequency equal to the cyclotron frequency (4.2 Hz). The general reproducibility of the investigated effects was 70% among the all solutions studied by us and they arose usually after 40–60 min. after preparation of the solution. In some made-up solutions the appearance of instability in the registered current was noted in 30–45 min after the solution preparation. This instability endured for 20–40 min. At the end of such instability period the effects of combined fields action appeared practically every time. The possible mechanisms of revealed effects were discussed on the basis of modern quantum electrodynamics.     

Distortion of the local magnetic field appears to neither disrupt nocturnal navigation nor cue shelter recognition in the amblypygid Paraphrynus laevifrons

Many arthropods are known to be sensitive to the geomagnetic field and exploit the field to solve spatial problems. The polarity of the geomagnetic field is used, for instance, as an orientation cue by leafcutter ants as they travel on engineered trails in a rainforest and by Drosophila larvae as they move short distances in search of food. A ubiquitous orientation cue like the geomagnetic field may be especially useful in complex, cluttered environments like rainforests, where the reliability of celestial cues used to navigate in more open environments may be poor. The neotropical amblypygid Paraphrynus laevifrons is a nocturnal arachnid that wanders nightly in the vicinity of its shelter and occasionally travels 30 m or more in the rainforest understory before it returns to its shelter. Here, we conducted a field experiment to determine whether navigation by P. laevifrons is guided by the ambient magnetic field and a complimentary laboratory experiment to assess whether a magnetic anomaly could be used to pinpoint the entrance of a shelter. In the field experiment, subjects were fitted with a radio transmitter and a small, powerful magnet or a similar-sized brass disk and displaced 10 m from their shelter. The return rate of magnet-fitted subjects was similar to that of brass-fitted subjects and to that of subjects in an earlier study fitted with only a radio transmitter. In the laboratory experiment, we trained P. laevifrons with a protocol under which the amblypygid Phrynus marginemaculatus rapidly learns—in 1–14 trials over two daily sessions—to associate an olfactory stimulus with access to a shelter. The conditioned stimulus here was a magnetic anomaly characterized by a high total field intensity and a 180° reversal of the polarity of the ambient magnetic field. The magnetic anomaly-shelter contingency was not learned in 50 trials conducted over 10 daily sessions. These results imply prima facie that P. laevifrons does not rely on a magnetic compass to locate or recognize a shelter and, perhaps, that the magnetic field cannot be detected, but alternative explanations are discussed.     

Controlled Release of Doxorubicin from Magnetoliposomes Assisted by Low-Frequency Magnetic Field

The article presents magnetoliposomes as potential carriers of doxorubicin. The magnetic properties of nanoparticles embedded in liposomes enable the targeting of drug-loaded carriers to cancer cells and subsequent release of their payload using an external alternating magnetic field as a trigger. The cytotoxicity of empty and doxorubicin-loaded magnetoliposomes in the absence and after exposure to magnetic field was evaluated in cancerous and normal breast cells. The characteristic shows the carrier with size distribution <130 nm, slightly negative zeta potential and polydispersity index <0.2. Doxorubicin was encapsulated in magnetoliposomes with an efficiency of 31 % and released in the presence of an alternating magnetic field at 50 %. Magnetoliposomes with drug provided high cytotoxic effect on tumor cells and low cytotoxic effect on normal cells. The research conducted in this article may indicate the potential application of the studied magnetoliposomes in release of drugs under the influence of magnetic field in cancer cells.