Hazards of EMFs on human's health

Electromagnetic fields [EMFs] are widely used for transmitting of radio, TV signals, and wireless communications. So a huge number of individuals suffering of risk from telecommunication technologies. The study of the biological effects of EMF could contribute to better understanding of the possible hea1thhazards. The objectives of this study were to describe the health status of electric occupational workers exposed to electric and magnetic fields [EMF5]. Measurements were performed in substations operating at 50 kV/m Workers occupationally exposed for more than 2 years to magnetic field approximately 17-18 micro T. One of the objectives of this study was the evaluation of EMFs effects on the antioxidative activity of plasma in worker's. Substation workers [60 males] of electric company and a control group [20 males] were compared in their hemoglobin [Hb] concentration, Hb electrical conductivity, thermodynamic parameters of Hb and other biochemical factors. Hemoglobin concentration percentage and electric conductivity were measured according to the duration of exposure . Also there was a decrease in spin state constant for different groups of workers, and an increase in free energy as compared to control . Superoxide dismutase [SOD], Glutathioneperoxidase [GSH-PX] activities were decreased specially in labor exposed for a long time but Catalase activity [CAT] increased in workers exposed to 10-15 years . There was also an increase in activation energy for all group of workers . All changes observed among workers exposed to EMFs from electric substations result in inadaptable response for controlling the balance of human body oxidative mechanisms, thus the risk factor of cancer and Alzhcimer will be enhanced

neural behaviour of rabbit's hippocampus

The influence of photic stimuli of different frequencies ranging from 150 to 1800 F/min were employed to investigate the neural behaviour of the rabbit's hippocampus. The EEG activities of the hipo-campa region CA1, which consist of alpha, beta, gamma, delta, kappa and theta waves, were analyzed by digital PDP-11 computer and analogue to digital convener. The lowest frequency of peak value of the power spectra before the effect of stimulation was found to be 0.85 Hz [delta waves]. Theta waves of frequency ranging from 3.96 to 6.79 Hz were the dominated EEC signals after stimulation. The coherence factor, which is a mea sure of the hippocampal activity, increased by greater frequency of stimulation. The max. value of the coherence was observed to be 0.5 at 1200 F/min

Electronic models for thermosensitive neurons

Electronic models for cold and warm thermosensitive neurons are designed and implemented. The static firing rate of both the cold and warm electronic models are recorded at different temperatures. The dynamic response of these models is also investigated. The obtained results show a more or less coincidence between the designed electronic models and the real thermosensitive neurons

Brain electrical activity mapping in epilepsies

Brain electrical activity map [BEAM] of 508 cases of epilepsy [both generalized and partial] were studied to demonstrate and compare this method with that of routine EEG for quantification and localization of regions of epileptogenesis. There was a good correlation between BEAM and the EEG in [74%] of cases. The BEAM was less efficient in detecting generalized epilepsy, but it was much better regarding partial abnormalities, even when EEG was normal or nearly so. Overall brain electrical activity maps did appear to offer data which were useful and complimentary to other available test results. Considerable care needs to be taken to identify artifacts and normal EEG variant when interpreting these tests

Analysis of the spontaneous activity of the identified neurone [A] of molluscan planorbius corneus

The glass microelectrode technique was used to record the spontaneous activity of the identified neurone [A] molluscan Planorbius comeus. The number of the recorded spontaneous spikes and there interspike time were found to be random variables. Using the stochastic distribution and the statistical analysis, it was found that : a] The random spike number recorded at a definite interval of time follows the Poisson distribution with probability 95 percent b] The random interspike time obeys the exponential distribution with a mean value of 1.537 second. According to the results obtained in a and b, the number of the generated spontaneous spikes at a certain time interval could be predicted

EMG quantitative analysis of triceps muscle upon irradiation by different magnetic fields

An action potential analyzer was used to measure the EMG characteristics, generated by the triceps muscle. Three EMG parameters were investigated: [i] the integrated voltage of the muscle's electrical activity in uV/sec, [ii] the frequency in spikes/sec, and [iii] the amplitude of the EMG. Triceps muscle in uV. The employed magnetic fields were: [a] constant magnetic fields of intensities 500 Gauss and 10 KG, [b] pulsating magnetic field [MF] of intensity 50 G/50 Hz, the exposure time for all fields used was 15 min. The results of the present work showed that the constant MF of 500 G induced a little on muscle performance ability when it was applied for a short duration, and the increase of the EMG amplitude was 11.3 percent on the average. While the constant MF 10 KG increased the amplitude of the EMG by an average of 33.6 percent. Therefore, when the muscle is exposed to constant strong MF, its energy increases and this, in turn improves its performance ability. However, a pulsating MF of 50 G/50 Hz increased the muscle performance ability by an average of 37.0 percent

action of glutamate on the spectral absorbance of retina's fish

Perfusion of the isolated retina of the bulti [tilapia nilotica] A with Ringer's solution containing 5 mM glutamate is shown to cause changes in the optical density of the retina. The absorbance spectrum of these changes were recorded every 15 minutes up to 90 minutes after start of perfusion. The results indicate that there were polyphases changes over the spectrum of wavelength ranging from 350 to 650 nm. The maximum increase in optical density was found to be 25 percent at about 420 nm, while the maximum drop was 60 percent at 440-450 nm

Investigation of the responses of human's triceps muscle to successive magnetic fields

The present experimental technique was utilized to record, 1 analyze, and correlate the electromyography [EMG] of human's triceps muscle [upper limb] under the effect of different successive MFS. The exposure time used for all fields employed was 15 minutes, which is the average duration recommended in magnetotherapy. It was evident that the PMF 50 G/50 Hz proved to be the most effective MF, it increases the muscle efficiency [A] by 21 percent if it was lonely applied. This parameter enhanced to 22 percent when double fields f[1]followed by f2 were applied. Then, it attained a maximum increase of 24 percent when triple fields F[1] followed by F[2], then F[3] were employed

Biological effects of pulsating magnetic field on muscle performance ability in-vivo

The effect of magnetic field [MF] on different systems is due to 1 attraction or repulsion between the system and the applied field. This effect depends on the presence or absence of unpaired electron [s] in the system. Such systems have a permanent magnetic moment, and will be attracted appreciably toward an applied field because of their electron spin and magnetic susceptibility. If the system does not contain any unpaired electrons, the effect of applied MF is on the orbital motion of the paired electrons. The susceptibility in this case may be correlated with the radii of these orbits. A pulsating MF of intensity 50 Hz/50 G was used in the present work. A quantitative analysis has been done for EMG obtained from the triceps muscle of human. The basic characteristics of EMG which have been computed are; the integrated voltage, frequency, and the amplitude of the muscle's EMG. It was found that, pulsating MF increased the muscle performance ability, so that recruitment of other units, which happens normally in fatigue experiments, is less by 18.05 percent for 72.5 percent of the investigated cases. It is also concluded that, the pulsating MF of 50 Hz/50 G is of great effect on energizing the muscle during the fatigue process

Estimation of the average swimming speeds of microorganisms by using a simple technique

A method for estimating average speeds of swimming cells has been described. The statistical counting technique based on treating the swimming cells as a dilute gas, and its accuracy has been confirmed by direct measurements. In principle this technique can be applied to any suspension of cells satisfying certain statistical criteria [theory] enough to exert no force on each other except contact forces at the instant of collision. The mean free path is inversely proportional to the concentration of the cells in culture. This definition is readily seen to satisfy the statistical assumptions

electronic model of spontaneous and evoked activity neurons and their analogous connections

A spontaneous and evoked generating activity neuron models are designed and constructed, together with their different modes of connections, in order to simulate and study the functions of the real neurons. The study of the designed spontaneous neuron's model shows: At a fixed threshold level, the increase of the integrator capacitance value, which equivalent to the real neuron's membrane capacitance, decreases the output firing rate [frequency]. Also, the presynaptic firing rate is greater than that of the postsynaptic one. An inverse relationship is found to be between the firing rate and the level of excitation. In the designed evoked activity neuron's model, the output firing rate is linearly increased by increasing the amplitude of the applied external stimulus. Besides, the frequency of the presynaptic output is greater than that of the postsynaptic one. Different connections between the constructed models were carried out to simulate the function and characteristics of the synapse. In the spontaneous-evoked connection, it was found that the output firing rate of the evoked one was regular as that of the input, but of less firing rate values. When the spontaneous and the evoked neuron's models were connected in parallel and their output acts as an input of an evoked one, the output frequency is found to be irregular and also of less frequency values as in the previous connection

Electrical activity of hippocampal neuronal circuit

The synchronous electrical activity of the Rabbit's hippocampus theta rhythm of frequency 4-7 Hz] was investigated by online computer analyses. This rhythm was evoked by electrical stimulation delivered to the Reticular formation. The stimulation process was accomplished by a train of pulses or varied frequency, intensity, and width. A difference in stimulation parameters leads to change of frequency and amplitude for the theta waves. It was found that, the Reticular formation is not only essential for generation of theta waves, but also considered as a controller for the activity of the hippocampus

Effects of magnetic field on muscle performance abilities

The influence of magnetic fields [MF]of different parameters on muscle performance abilities was investigated by Electromyographic [FMG] analysis; for the following conditions: [i] maximal contraction, and [ii] fatigue process mechanism. The triceps muscles of eighty similar athletic males were studied sequentially as follows: [a] at rest [b] at maximal isometric contraction and [c] after 3 minutes of sustained contraction. The obtained results show that the triceps muscle acts as an electrical oscillator due to the action of pulsating MR In case of successive MF effects, a maximum performance ability is produced by constant MF of IkG intensity, followed by the other two fields [25 percent]. A maximum performance ability is recorded due to MF of 1 KG intensity when the field is applied solitary upon the muscle [33.3 percent]

mathematical modeling study of hippocampal theta rhythm in awake rabbits

Electroencephalographic [EEG] activity of the dorsal hippocampus [HC] of rabbits was recorded during three stages; before, during, and after a train of stimulating electric pulses were delivered to the reticular formation [RF]. Changes of frequency and amplitude of EEG activity within the theta frequency band [4-7Hz] were studied in great details. This work was accomplished by the use of a digital computer, programmed for online analysis of the data. The present results are best represented by a second order differential equation describing the dynamical behavior of the system as a forced oscillator. The obtained mathematical description agrees well with results obtained from animal experiment

Laser irradiation therapy in carpal tunnel syndrome

The study was carried out on 28 cases recommended for surgery. Sensory latency and sensory nerve conduction velocity were measured for the median nerve before and after every five sittings through a 20 sittings course of laser therapy. A decrease in the sensory latency values was observed for 64 percent of the individuals treated by laser irradiation. An optimal dose value of irradiation was observed after the fifth sitting of 20 minutes duration. An increase in sensory conduction velocity measurements was noticed for 68 percent of cases after the twentieth sitting. This study suggests that the laser irradiation partially relieves the nerve entrapment in more than 64 percent of patients, probably through its thermal and bio-stimulatory vasodilatation effect