bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simple nonperturbing temperature probe for microwave/radio frequency dosimetry
Authors: Olsen R. G. , Bowman R. R. 
Published: February 2006

AbstractWe present a simple readout device that fills the void produced by the gradual disappearance of the Vitek model 101 Electrothermia Monitor. The new device uses commercially available probes that are similar to Bowman's (IEEE Trans Microwave Theory Tech MTT‐24:43–45, 1976) original design. As described, the device covers the range of 7 ° to 45 °C with an accuracy and resolution of better than 0.1 °C throughout. The digital readout (3½ digits) is proportional to the thermistor resistance in the tip of the probe; it is converted to temperature through a formula or printed table. Outdoor dosimetric comparisons between the new and Vitek devices were conducted. Results showed no significant difference in the calculated specific absorption rates (SARs); moreover, variance was lower in the data collected from the new device.
Conditioning analysis of magnetoreception in honeybees
Authors: Walker Michael M. , Bitterman M. E. 
Published: February 2006

AbstractA central problem in the study of magnetic sensitivity in animals has been the lack of behavioral techniques sufficiently powerful for the systematic psychophysical work required for an understanding of magnetosensory capacity and of the transduction mechanism. In recent experiments, free‐flying honeybees have been conditioned to discriminate the presence and absence of localized magnetic dipole anomalies superimposed on the uniform background field of the earth. The results obtained thus far suggest that movement is necessary for conditioned responding to magnetic field stimuli and support the hypothesis that magnetic field transduction is based on single‐domain particles of magnetite found in the anterodorsal abdomen of honeybees.
Mechanical and electrical effects of high‐frequency and high‐intensity stimulation of muscle
Authors: Koniarek Jan P. 
Published: February 2006

AbstractA unique tension response can be obtained by stimulating an isometrically held skeletal muscle or a single muscle fiber by a train of high‐frequency pulses (2,000 pps) at higher‐than‐normal intensity, or by a long DC pulse. It is called the tetanoid response, and it is composed of three well‐defined stages. Initially, tension develops rapidly, and mechanical output (P0) reaches about 0.35. Subsequently, this tension is maintained at a nearly steady level for the remainder of stimulation. After stimulation, a final increase of tension takes place.Intracellular electrical recordings show that the initial development of tension is elicited by two or three action potentials generated at the beginning of the stimulation, and that no additional action potentials are generated for the remainder of stimulation. During stimulation, part of the fiber membrane (regarded in cross‐section) is depolarized, which generates tension, and part of the membrane is hyperpolarized. With termination of stimulation, a single action potential is elicited via anode‐break excitation (ABE) on the hyperpolarized portion of the membrane, which gives rise to the final increase of tension.
EMP simulators and public safety: An analysis
Authors: Agouridis D. C. , Easterly C. E. 
Published: February 2006

AbstractEffects produced by electromagnetic fields from exoatmospheric nuclear detonations, known as electromagnetic pulses (EMPs) and devices, which simulate these EMPs are analyzed for their potential danger to human beings in contact with large energy collectors. Comparison is made with ANSI guidelines established for radio‐frequency electromagnetic fields.
In vitro fertilization of mouse ova by spermatozoa exposed isothermally to radio‐frequency radiation
Authors: Cleary S. F. , Liu L. M. , Graham R. , East J. 
Published: February 2006

AbstractMouse spermatozoa were exposed in vitro for 1 h to 27‐ or 2,450‐MHz CW RF radiation at SARs of 0 to 90 W/kg under isothermal (37 ± 0.2 °C) conditions. Exposure at either frequency to RF radiation at SARs of 50 W/kg or greater resulted in a statistically significant reduction in the ability of irradiated sperm to fertilize mouse ova in vitro (P < .05). Over the range of SARs there was no apparent difference in the effects of 27‐ vs. 2,450‐MHz RF radiation. There were no readily detectable exposure effects on spermatozoan morphology, ultrastructure, or capacitation. The reduction of in vitro fertilization is attributed to a direct effect of RF radiation on spermatozoa rather than to heating.
Influence of a stationary magnetic field on bioelectric properties of snail neurons
Authors: Balaban P. M. , Bravarenko N. I. , Kuznetzov A. N. 
Published: February 2006

AbstractIdentified cells of Helix lucorum L. received 20 min exposures to 23, 120, or 200 mT stationary magnetic field (MFs). Resting potentials and input resistances were measured. Controls were instituted for temperature changes and for mechanical and other sources of artifact. Resting potentials did not change with MF exposure. Input resistances decreased significantly in normally silent cells during MF exposure, but increased significantly in spontaneously active cells. The magnitudes of changes were monotonically related to strength of the MF. Changes in excitatory postsynaptic potentials were observed during MF exposure. Elimination of perineuronal glia by proteolytic enzymes eliminated the MF effects.
Combined DC and ELF magnetic fields can alter cell proliferation
Authors: Ross Stephen M. 
Published: February 2006

AbstractEffects of extremely‐low‐frequency (ELF) electromagnetic fields on proliferation of rabbit‐ligament fibroblasts were examined. Markedly different effects, ranging from inhibition to stimulation of proliferation, were obtained, depending on the signal parameters of amplitude, frequency, and DC magnetic field. These results demonstrate that simple, single‐frequency signals can have dramatic effects on ligament cells, which may be useful for bioelectrical stimulation of growth and repair. Also, the range of frequencies examined in this study covered those commonly used in transmission of electrical energy (50 or 60 Hz), which indicates that further study of possible effects of exposure to fields generated by power transmission equipment is warranted.
Influence of 60‐Hz magnetic fields on sea urchin development
Authors: Zimmerman Selma , Zimmerman Arthur M. , Winters Wendell D. , Cameron Ivan L. 
Published: February 2006

AbstractContinuous exposure of sea urchin (Strongylocentrotus purpuratus) embryos at 18°C to a cyclic 60‐Hz magnetic field at 0.1 mT rms beginning 4 min after insemination caused a significant developmental delay during the subsequent 23 hours. No delay in development was recorded for periods up to 18 hours after fertilization. At 18 h, most embryos were in the mesenchyme blastula stage. At 23 h, most control embryos were in mid‐gastrula whereas most magnetic‐field‐exposed embryos were in the early gastrula stage. Thus an estimated 1‐h delay occurred between these developmental stages. The results are discussed in terms of possible magnetic‐field modification of transcription as well as interference with cell migration during gastrulation. The present study extends and supports the growing body of information about potential effects of exposures to extremely‐low‐frequency (ELF) magnetic fields on developing organisms.
A three‐dimensional method for calculating currents induced in bodies by extremely low‐frequency electric fields
Authors: Takuma T. , Kawamoto T. , Isaka K. , Yokoi Y. 
Published: February 2006

AbstractA user‐friendly, numerical program has been developed to permit the calculation of induced currents in modeled bodies of human and infrahuman subjects. The program is based on a charge‐simulation method (CSM), and it takes into account the three‐dimensional (3‐D) character of the extremely‐low‐frequency (ELF) electric field and of the models to be exposed. The principle of the method is to simulate a 3‐D object, for example, an animal model, by a combination of several parts (blocks) having simple geometric forms such as a sphere, a cylinder, or a cone. This approach permits easy preparation of input data on the dimensions of the blocks and their positions in a 3‐D arrangement. Other input data, such as the coordinates of the contour points and the imaginary values of charges inside objects, which are necessary in the calculations by CSM, are produced automatically by selecting an appropriate “level” for each block, according to its importance. To simulate parts having irregular shapes, special blocks may be added. In one series of experiments, induced currents were calculated for a baboon model in various postures: standing upright, positioned on four legs, and sitting on the floor. Calculated currents. the total induced current in particular, agreed very well with experimental values. Local currents in parts of the baboon models were more variable, ranging from 5% to 17% of measured values in the case of induced currents in the head. Some problems with this method, such as the effect of the dimensions of blocks or the choice of block levels, are discussed.
Extremely low‐frequency electric and magnetic fields and risk of human cancer
Authors: Coleman Michel P. 
Published: February 2006

AbstractThe reported association between the risk of human cancer and exposure to 50‐ or 60‐Hz electric and magnetic fields is difficult to evaluate from studies published to date. The association is now being reexamined in several large epidemiologic studies. In most of the studies, exposure will be assessed with newly designed, portable meters that allow direct and precise measurements of exposure to be performed easily for large numbers of individuals. The main features of the studies are summarized. At a meeting of principal investigators held in 1988 at the International Agency for Research on Cancer, broad guidelines were agreed for the design of this new generation of studies. These guidelines should improve the comparability of results and eventually provide a clearer assessment of human‐cancer risk from exposure to extremely low‐frequency electric and magnetic fields.
Altered operant behavior of adult rats after perinatal exposure to a 60‐Hz electromagnetic field
Authors: Salzinger Kurt , Freimark Steven , McCullough Malcolm , Phillips Donald , Birenbaum Leo 
Published: February 2006

AbstractRats were sham exposed or exposed perinatally to a 60‐Hz electromagnetic field, 22 days in utero and the first 8 days post partum. Each of the 30 once‐daily exposures was 20 h in duration. The electric component of the field was vertical 30 kV/m rms, and the magnetic field component was 100 μTG rms. Later, as adults, male rats were trained to emit an operant response when reinforced with food on a multiple, random‐interval schedule. Exposed rats (N = 21) gradually came to respond at significantly lower rates than did sham‐exposed controls (N = 20). This finding was confirmed and extended in a second, independently performed experiment. After a sequence including operant conditioning followed by experimental extinction of responding and then by a suspension of conditioning and finally by more than a month of reconditioning, slower rates of responding were found to persist in the adult animals. The evidence of altered behavior several months after combined, fetal‐neonatal exposure to an electromagnetic field presents an interesting contrast with other findings: Field‐exposed rats did not differ from sham‐exposed rats in terms of body mass, physical appearance, grossly observed activity level, or incidence of disease.
Dominant lethal studies in male mice after exposure to a 50‐Hz electric field
Authors: Kowalczuk C. I. , Saunders R. D. 
Published: February 2006

AbstractMale C3H/He mice were sham‐exposed or exposed continuously for 2 weeks to a vertical, 50‐Hz, electric field at 20 kV/m rms. Densities of currents induced in the testes are estimated to be near 100 μA/m2. After the exposure, each male was mated with two different female mice each week during a period of 8 weeks. By this schedule, female mice were impregnated with sperm that had been exposed to the electric field at different stages of the spermatogenic cycle. No significant differences as a function of exposure condition were observed in pregnancy rates or in survival of embryos before or after implantation. The absence of effects was not due to insensitivity of assays; other mice that were exposed to X‐rays (dose to testes = 1.5 Gy) presented reliable evidence of mutagenesis.
Development of chicken embryos in a pulsed magnetic field
Authors: Berman E. , Chacon L. , House D. , Koch B. A. , Koch W. E. , Leal J. , Løvtrup S. , Mantiply E. , Martin A. H. , Martucci G. I. , Mild K. H. , Monahan J. C. , Sandström M. , Shamsaifar K. , Tell R. , Trillo M. A. , Ubeda A. , Wagner P. 
Published: February 2006

AbstractSix independent experiments of common design were performed in laboratories in Canada, Spain, Sweden, and the United States of America. Fertilized eggs of domestic chickens were incubated as controls or in a pulsed magnetic field (PMF); embryos were then examined for developmental anomalies. Identical equipment in each laboratory consisted of two incubators, each containing a Helmholtz coil and electronic devices to develop, control, and monitor the pulsed field and to monitor temperature, relative humidity, and vibrations. A unipolar, pulsed, magnetic field (500‐μs pulse duration, 100 pulses per s, 1‐μT peak density, and 2‐μs rise and fall time) was applied to experimental eggs during 48 h of incubation. In each laboratory, ten eggs were simultaneously sham exposed in a control incubator (pulse generator not activated) while the PMF was applied to ten eggs in the other incubator. The procedure was repeated ten times in each laboratory, and incubators were alternately used as a control device or as an active source of the PMF. After a 48‐h exposure, the eggs were evaluated for fertility. All embryos were then assayed in the blind for development, morphology, and stage of maturity. In five of six laboratories, more exposed embryos exhibited structural anomalies than did controls, although putatively significant differences were observed in only two laboratories (two‐tailed Ps of .03 and <.001), and the significance of the difference in a third laboratory was only marginal (two‐tailed P = .08). When the data from all six laboratories are pooled, the difference in incidence of abnormalities in PMF‐exposed embryos (∼25 percent) and that of controls ( ∼ 19 percent) although small, is highly significant, as is the interaction between incidence of abnormalities and laboratory site (both Ps < .001). The factor or factors responsible for the marked variability of inter‐laboratory differences are unknown.
Exposure of mammalian cells to 60‐Hz magnetic or electric fields: Analysis of DNA repair of induced, single‐strand breaks
Authors: Frazier M. E. , Reese J. A. , Morris J. E. , Jostes R. F. , Miller D. L. 
Published: February 2006

AbstractDNA damage was induced in isolated human peripheral lymphocytes by exposure at 5 Gy to 60Co radiation. Cells were permitted to repair the DNA damage while exposed to 60‐Hz fields or while sham‐exposed. Exposed cells were subjected to magnetic (B) or electric (E) fields, alone or in combination, throughout their allotted repair time. Repair was stopped at specific times, and the cells were immediately lysed and then analyzed for the presence of DNA single‐strand breaks (SSB) by the alkaline‐elution technique. Fifty to 75 percent of the induced SSB were repaired 20 min after exposure, and most of the remaining damage was repaired after 180 min. Cells were exposed to a 60‐Hz ac B field of 1 mT; an E field of 1 or 20 V/m; or combined E and B fields of 0.2 V/m and 0.05 mT, 6 V/m and 0.6 mT, or 20 V/m and 1 mT. None of the exposures was observed to affect significantly the repair of DNA SSB.
Changes in levels of c‐myc and histone H2B following exposure of cells to low‐frequency sinusoidal electromagnetic fields: Evidence for a window effect
Authors: Wei Lin‐Xiang , Goodman Reba , Henderson Ann 
Published: February 2006

AbstractHuman HL‐60 cells were exposed for 20 min to an electromagnetic field at frequencies ranging from 15 to 150 Hz and at densities from 0.2 to 2.3 mT (2 to 23 gauss). Following each exposure, quantitative levels of c‐myc and histone H2B transcripts were determined by dot‐blot hybridization analyses and compared with unexposed control samples. The most pronounced increase in each transcript occurred after exposure at 45 Hz, with levels more than four times that found in unexposed controls.
A simple model for calculating residential 60‐Hz magnetic fields
Authors: Mader D. L. , Barrow D. A. , Donnelly K. E. , Scheer R. R. , Sherar M. D. 
Published: February 2006

AbstractA model is presented that permits the calculation of densities of 60‐Hz magnetic fields throughout a residence from only a few measurements. We assume that residential magnetic fields are produced by sources external to the house and by the residential grounding circuit. The field from external sources is measured with a single probe. The field produced by the grounding circuit is calculated from the current flowing in the circuit and its geometry. The two fields are combined to give a prediction of the total field at any point in the house. A data‐acquisition system was built to record the magnitude and phase of the grounding current and the field from external sources. The model's predictions were compared with measurements of the total magnetic field at a single location in 23 houses; a correlation coefficient of .87 was obtained, indicating that the model has good predictive capability. A more detailed study that was carried out in one house permitted comparisons of measurements with the model's predictions at locations throughout the house. Again, quite reasonable agreement was found. We also investigated the temporal variability of field readings in this house. Daily magnetic field averages were found to be considerably more stable than hourly averages. Finally, we demonstrate the use of the model in creating a profile of the magnetic fields in a home.
Amplitude windows and transiently augmented transcription from exposure to electromagnetic fields
Authors: Litovitz T. A. , Montrose C. J. , Goodman Reba , Elson Edward C. 
Published: February 2006

AbstractThe exposure of cells to relatively low‐intensity, pulsed, low‐frequency electromagnetic fields can result in a transient augmentation of mRNA synthesis. Under certain conditions of irradiation, the augmentation is a function of the strength of the electromagnetic field. A linear, multi‐step, chemical‐reaction model accounts for many of the principal features that are observed in both the time‐ and intensity‐dependent variations of transcriptional effects. The crucial assumption in the model is that the direct effect of electromagnetic fields on exposed cells is an increase in the rate constant that characterizes one of the intermediate sequential reactions in the synthesis of mRNA.
Lay understanding of low‐frequency electric and magnetic fields
Authors: Morgan M. Granger , Florig H. Keith , Nair Indira , Cortés Concepcion , Marsh Kevin , Pavlosky Karen 
Published: February 2006

AbstractPeople do not start with a blank slate when they hear risk‐communication messages. All such messages are processed through existing knowledge structures and understanding. Hence, to design effective and reliable risk‐communication materials one must understand the state of people's knowledge—correct and incorrect—about an issue. We developed a simple “mental model” of what people minimally need to know to make informed decisions about field‐related issues. Then we performed studies to explore how and to what extent respondents of various groups understood physical properties of 60‐Hz electric and magnetic fields. Actual knowledge of respondents was then compared with the predicates of the model. Electrical engineering juniors and semi‐technical employees of utilities displayed a good command of most of the concepts in the simple model, but little awareness of the limits to their knowledge. Lay respondents correctly knew only a few of the simplest elements of the model, but they displayed a much greater awareness of the limits to their knowledge. Both lay and semi‐technical respondents were found to share several misconceptions. On average, they correctly rank‐ordered some common field‐exposure conditions by field strength, but they could not differentiate between electric and magnetic fields and could not differentiate among field strengths associated with different appliances. Most respondents dramatically underestimated the range of actual field strengths. Many respondents understood that field strength decreases with distance from a source, but they underestimated the rate of decrease. In contrast to X‐rays and microwaves, which respondents appeared to think about in rather similar terms, 60‐Hz fields were not thought of as being highly similar to any other agent, although the closest parallels were found with ultrasound. Changes in mood, thought, and behavior, and the existence of an “electrical aura,” were all seen as plausible results of exposure to a 60‐Hz field. Although lay respondents displayed a variety of incomplete and confusing ideas, most of these ideas probably do not pose significant obstacles to the learning of a correct, simple, mental model.
Dielectric properties of mouse MCA1 fibrosarcoma at different stages of development
Authors: Swarup A. , Stuchly S. S. , Surowiec A. 
Published: February 2006

AbstractThe in vitro bulk electrical properties of MCA1 fibrosarcoma induced in C57BI/6 male mice were measured at frequencies of 10 kHz to 100 MHz, with some tissues measured to 2 GHz. The properties of normal surrounding tissue also were measured. A comparison of the dielectric properties between three different stages of tumor development as well as that between various locations within the tumor is reported.Statistical analysis of the experimental results revealed statistically significant differences in the dielectric constant and conductivity of the tumor tissues at various stages of development as measured at frequencies below 10 MHz. Conductivity values at different stages also differ at a frequency of 100 MHz. At other frequencies these differences were found to be statistically insignificant.
Naltrexone pretreatment blocks microwave‐induced changes in central cholinergic receptors
Authors: Lai H. , Carino M. A. , Wen Y. F. , Horita A. , Guy A. W. 
Published: February 2006

AbstractRepeated exposure of rats to pulsed, circularly polarized microwaves (2,450‐MHz, 2‐μs pulses at 500 pps, power density 1 mW/cm2, at an averaged, whole‐body SAR of 0.6 W/kg) induced biphasic changes in the concentration of muscarinic cholinergic receptors in the central nervous system. An increase in receptor concentration occurred in the hippocampus of rats subjected to ten 45‐min sessions of microwave exposure, whereas a decrease in concentration was observed in the frontal cortex and hippocampus of rats exposed to ten 20‐min sessions. These findings, which confirm earlier work in the authors' laboratory, were extended to include pretreatment of rats with the narcotic antagonist naltrexone (1 mg/kg, IP) before each session of exposure. The drug treatment blocked the microwave‐induced changes in cholinergic receptors in the brain. These data further support the authors' hypothesis that endogenous opioids play a role in the effects of microwaves on central cholinergic systems.
The solar wind and hallucinations—A possible relation due to magnetic disturbances
Authors: Randall Walter , Randall Steffani 
Published: February 2006

AbstractData from the 19th century on hallucinations and magnetic disturbances were found to exhibit a direct and statistically significant correlation. The aa magnetic index over the period 1868–89 and concurrent visual hallucinatory activity were found to co‐vary (Spearman coefficient = .64; P < .05). Magnetic influences on the pineal hormone, melatonin, are suggested as a possible source of variation.