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Magnetoencephalographic recordings, external picoTesla Transcranial Magnetic Stimulation (pT-TMS) and a double blind experimental design were used for the evaluation of 10 epilepsy patients (three males, seven females). Their ages ranged from 23 to 48 years. Our results showed an enhancement in the 2-7 Hz frequency range in five out of nine patients who had a statistically significant difference (55%). The pT-TMS could be a significant means for the treatment of epilepsy. Further research should be done prior to have final conclusions.

We investigated the beta rhythm in 10 children with autism disorders (six boys and four girls) aged 5-12 (mean± SD: 8.3± 2.1) before and after the application of pico Tesla transcranial magnetic stimulation (pT-TMS) using magnetoencephalography (MEG). The MEG was car-ried out in a magnetically shielded room with a whole-head 122-channel gradiometer. After applying pT-TMS, we observed a beta rhythm increase towards the frequency range of 18-26 Hz in seven out of 10 patients (70%). We created a score that rated the level of improvement for each patient: 1=some change; 2=minor change; and 3=major change. All patients had an improvement in their clinical symptoms after the application of pT-TMS. There was a correlation between the clinical score and the increase of channels in the frequency range 18-26 Hz after pT-TMS. We concluded that the application of pT-TMS affected the beta rhythm in children with autism disorder. Therefore, more studies need to be further conducted.

Magnetoencephalographic (MEG) recordings of the brain in Parkinson's disease were obtained in order to look for possible effect of pico-Tesla transcranial magnetic stimulation (pT-TMS). We found a significant effect of an increase of frequencies in the range of 2-7 Hz across subjects. In addition, we observed the mean peak frequency difference within the 2-7 Hz band towards frequencies of less or equal to those frequencies of the alpha frequency range (8-13 Hz).

Magnetoencephalographic (MEG) recordings from the brain of 10 children with autism (6 boys and 4 girls, with ages range from 5-12 years, mean[Formula: see text][Formula: see text][Formula: see text]SD: 8.3[Formula: see text][Formula: see text][Formula: see text]2.1) were obtained using a whole-head 122-channel MEG system in a magnetically shielded room of low magnetic noise. A double-blind experimental design was used in order to look for possible effect of external pico-Tesla Transcranial Magnetic Stimulation (pT-TMS). The pT-TMS was applied on the brain of the autistic children with proper field characteristics (magnetic field amplitude: 1-7.5[Formula: see text]pT, frequency: the alpha - rhythm of the patient 8-13[Formula: see text]Hz). After unblinding it was found a significant effect of an increase of frequencies in the range of 2-7[Formula: see text]Hz across the subjects followed by an improvement and normalization of their MEG recordings. The statistical analysis of our results showed a statistical significance at 6 out of 10 patients (60%). It is also observed an increase of alpha activity in autistic children at the end of one month after pT-TMS treatment at home. In conclusion, the application of pT-TMS has the prospective to be a noninvasive, safe and important modality in the management of autism children.

Background Magnetoencephalography (MEG) is a well-established noninvasive method for investigating human brain activity. Objectives The present study aimed at identifying any change in the brain state after pico- Tesla Transcranial Magnetic Stimulation (pT-TMS) on patients with multiple sclerosis (MS). Methods A whole-head 122 - channel MEG system in a magnetically shielded room with low magnetic noise was used. The study population comprised of 2 male and 8 female volunteers with MS, with a mean age of 41.3 ± 9.5 years. External magnetic field of pT-TMS was applied on the above patients with proper field characteristics (magnetic field amplitude: 1 - 7.5 pT, frequency: the alpha rhythm of the patient 8 - 13 Hz), obtained prior to the application of pT-TMS. Results A significant effect was observed with an increase of frequencies in the range of 2 - 7 Hz among the participants. The results were statistically significant in 7 out of 10 patients (70%). Conclusions The pT-TMS has the prospective to be a significant noninvasive secure and effective means in managing MS symptoms.

A transportable fast and thermal neutron radiography system, incorporating a compact DD neutron generator, has been simulated using the MCNPX code. The materials considered were compatible with the European Union Directive on ‘Restriction of Hazardous Substances’(RoHS) 2002/95/EC, hence excluding the use of cadmium and lead. Appropriate collimators were simulated for each of the radiography modes. With suitable aperture and collimator designs, it was possible to optimize the parameters for both fast and thermal neutron radiographies, for a wide range of values of the collimator ratio. The system simulated allows different object sizes to be studied with a wide range of radiography parameters.

A transportable neutron radiography system, incorporating a 50 mg 252Cf source, has been simulated using the MCNPX code. The materials considered were compatible with the European Union Directive on ‘Restriction of Hazardous Substances’ (RoHS) 2002/95/EC, hence excluding the use of cadmium and lead. The design was optimized with respect to neutron moderation, shielding and collimation. High density polyethylene was chosen as the material for moderator and also shielding, which was further enhanced with layers of bismuth and borated polyethylene. Variable values for the collimator ratio were calculated. With suitable aperture and collimator design it was possible to optimize the neutron radiography parameters. Beam filters also were treated in order to improve the results. The proposed system has been considered with a wide range of radiography parameters, which are comparable with neutron radiography facilities from low power reactors.

The variation of the alpha radioactivity in the air near the ground and the ground-level total gamma radiation has been monitored in North-eastern Greece over several days. Meteorological information regarding the temperature of the air and humidity has been simultaneously recorded. The alpha-radioactivity shows a periodic diurnal variation with a peak in the morning followed by a decrease in the afternoon; then, the variation rises again to the peak the next morning. The variation of the ground gamma-radiation follows that of the air alpha-radioactivity. Furthermore, their significant dependence on the air temperature and humidity is confirmed, rising with an increase in humidity and a decrease in temperature. Hence, a mathematical function has been developed to describe the diurnal variation of the alpha-radioactivity in terms of the ground-level gamma-radiation and the meteorological variables of temperature and humidity.

Criticality safety concerning the packaging of spent nuclear fuel assemblies from the transmutation of 237 Np and 241 Am in a fast reactor are investigated and compared to cases of spent fuels from commercial nuclear power stations. The investigation is based on the neutron multiplication factor calculated using the fresh and spent fuel compositions. Fuels based on a fresh composition with high amount of fissile material and low amounts of 237 Np and 241 Am resemble the fast reactor fuel, with the multiplication factor decreasing when calculated using the spent fuel compositions. However, the multiplication factor increases for targets based on a fresh composition without fissile content and high amounts of 237 Np and 241 Am, although it remains below 1 for up to 90 GWd/t burnup.

This paper deals with the development of a low cost and low energy consumption air conditioning system based on the conventional central heating installations. It is aimed to convert, with minimal cost and work intervention in the interior of the buildings, the classic central heating systems into a new type system which can cool during summer and heat during winter period. In general, the above mentioned heating–cooling system constitutes an integrated new technology in building air conditioning, with good prospects in replacing eventually the conventional air conditioning systems. The experimental installation is described in detail and the experimental results are presented and analysed. The achieved energy saving is also calculated. The advantages and disadvantages of the proposed system are discussed and useful conclusions are drawn.

This paper deals with the calculation of induced heat generation in single layer shields due to the penetration of 6.20 MeV energy photons through graphite, concrete and aluminum as a function of the shield thickness and polar angle. The heat generation rate produced from photons emitted from different geometry radioactive sources penetrating single layer concrete of various mean free paths (mfps) is also determined. In particular the heat generation rate is calculated for 6.20 MeV photons emitted from N-16 pipe and disc geometries source and a comparison has been made in order to estimate the percentage of energy captured, and therefore saved, inside the concrete shielding layer.

This paper discusses the thermal analysis and economic performance of an attached sunspace, used in a conventional dwelling environment. The sunspace is a modified greenhouse with special geometry of glazed inclined roof and inclined glazed walls and is capable to operate only as a completely passive system. New solar radiation and ambient temperature data for the area of northern Greece is presented. The calculation of thermal loads using the degree–day method and the annual auxiliary energy requirements of the residence are estimated using the unutilizability method (UU method). The economic analysis is performed using the Life Cycle Savings (LCS) method, modified to comply with the Greek tax policy, and the cost-optimum collector's area determination using the P-chart method. Also, the payback period of the initial investment is estimated, after taking under consideration economic factors applied to Greek energy policy.

The present paper describes a method for the energy management of the central heating installations of residences and other buildings. In particular, it refers to the optimum exploitation of thermal inertia of the building with optimisation of the daily operation cycle of heating. The span and desired temperatures are defined by the user within some acceptable limits, whereas their sequence of alteration based on the desired interior temperature depends on the outdoor temperature. A microprocessor is used to analyse the readings of various sensors, placed at different points of the heating installation, and to control the overall system operation.

A combination of special techniques has been developed for optimization of experimental conditions in order to improve the analytical capability, to facilitate automation and to broaden the applicability of instrumental neutron activation analysis. The techniques used are: (1) compensation for the rapid radioactive decay of short-lived nuclides with the increase of the counting efficiency by automatic source movement to the detector during the counting period, to minimize count rate variations and to prolong the counting period, (2) repeated cyclic and cumulative activation to improve the counting statistics, (3) instrumental correction of counting losses at high and varying count rates by a loss-free counting system and (4) differentiation of the reactor neutron spectrum to enhance the counts from the nuclides of interest by reducing matrix interferences. By optimized combination and automation of these techniques significant improvement of the capability of instrumental neutron activation analysis can be achieved.

In short-lived nuclide activation analysis, short-time counting periods, due to rapid radioactive decay, and limited count rates, to avoid dead-time corrections, lead to low counting statistics. This can be improved by cyclic activation, being limited by the sample container strength and by radioactivity build-up. With the new device, longer counting periods and thus better counting statistics, leading to higher accuracy and sensitivity, are achieved by changing the geometry factor during counting for radioactive decay compensation.

In this paper the definition and calculation of angular exposure dose build up factor for combined energies disc geometry source of 1.43 and 2.75 MeV are presented. Angular contributions to the scalar build up factor for single layer shields of Al, Fe and Pb, as a function of polar angle and shield thickness (in mean free paths), are discussed.

A new technique for short-lived nuclide activation analysis has been developed that compensates the rapid radioactive decay during the counting period by simultaneous approach of the sample holder to the detector with a mechanical device, permitting prolongation of the counting time and reduction of the required complementary cyclic activation to avoid sample container damage. The operation of the analytical system is automated by a programmable logic controller (PLC). This improvement of short-lived nuclide activation analysis, providing a high throughput, is important in biological and environmental research, where often a large number of samples has to be analyzed for sufficient sampling statistics.

A new ultrasonic rangefinding technique has been developed which improves accuracy substantially when it is used as an edge scanner. Distance is measured by calculating the relative phase angle between a continuously transmitted signal and the received (reflected) signals from both the top and bottom of the edge. The use of continuous emission waves and reflections from different surfaces, such as the top and bottom of a step, give rise to interference between the received signals resulting in phase adding or cancelling. By varying the transmitted frequency used for scanning, ii appears that both signals are coming either from the top or the bottom of the step, thus reducing interference. Theoretical and experimental results reveal the extern of interference and show the improvement achieved by the application of the new method.

In recent times a great deal of interest has been shown the computer vision and robotics research community within the remote (non-contact) determination of configurations by using direct (active) range finding. The presently developed range finder is based upon the use of laser light and triangulation and aims at long distance high precision measurements. New image processing techniques are combined with high efficiency electronics in order to provide reliable distance information. Furthermore, a method is introduced in order to overcome the inherent ‘missing parts’ problem when the system is used as a profile scanner (second scan method). Such a system could form part of a 3D-robot vision system providing depth and obstacle avoidance information.

An advanced neutron activation technique has been developed for the accurate analysis of elemental and isotopic fissile material required in nuclear safeguards, nuclear material standardization and other applications. It is based on reactor neutron flux spectrum differentiation by cadmium screening and multistandard calibration, including the solution of a second order equation system or of computerized calibration curve fitting, taking into account the thermal neutron flux depression. Some discrepancies at high enrichments have still to be eliminated in order to achieve the required measurement accuracy.

The discovery of rapid eye movement (REM) sleep by Aserinsky and Kleitman in 1953 initiated the impetus for sleep research and specifically the investigations of the effects of REM sleep deprivation (RSD) on animal and human behavior. The behavioral effects of RSD include the enhancement of motivational and "drive"-related behaviors. In laboratory animals, RSD has been reported to increase appetite, sexual behavior, aggressiveness, and locomotor activity. Moreover, RSD reportedly improves mood in patients with endogenous depression and heightens appetite and sexual interest in normal subjects. Since "drive"-related behaviors are thought to involve activation of limbic dopaminergic reward sites, RSD may enhance motivational behaviors through an action on limbic dopaminergic functions. In the present communication, we present two patients (one with multiple sclerosis and the other with Parkinson's disease) in whom treatment with magnetic fields produced behavioral effects which paralleled those observed in REM-sleep-deprived animals and humans. We propose, therefore, that the behavioral and mental effects of treatment with magnetic fields may be mediated via RSD and, by inference, involve activation of limbic dopaminergic reward sites.

The pineal gland and melatonin exert a major influence in the control of brain electrical activity and have been shown to be involved in seizure and sleep mechanisms. Since pinealectomy has been reported to result in seizures in experimental animals, it is assumed that melatonin has anticonvulsant properties. Indeed, limited studies in humans with temporal lobe epilepsy indicate that melatonin attenuates seizure activity. In the present communication we present evidence, based on magnetoencephalographic (MEG) brain measurements, that melatonin may exert proconvulsive activity in humans as well. The proconvulsive properties of melatonin may explain several phenomena associated with epilepsy such as the increased occurrence of seizures at night when melatonin plasma levels are 5 to 8-fold higher than during the day and the observed exacerbation of seizures premenstrually and during pregnancy as well as the attenuation of seizures in the menopause. Furthermore, our findings suggest that anticonvulsants which decrease melatonin secretion, such as the benzodiazepines, may exert their antiepileptic activity by attenuating nocturnal melatonin secretion. Finally, we propose that patients with nocturnal epilepsy or those experiencing exacerbation of seizures premenstrually may benefit from the administration of agents which block the secretion or action of melatonin.

Levodopa-induced dyskinesias are a common complication of chronic dopaminergic therapy in patients with Parkinson's disease (PD). The overall prevalence of levodopa-induced dyskinesias ranges from 40%-90% and is related to the underlying disease process, pharmacologic factors, and to the duration of high dose levodopa therapy. The mechanisms underlying the emergence of levodopa-induced dyskinesias are unknown, although most investigators favor the theory that striatal dopamine receptor supersensitivity is directly responsible for the development of these abnormal movements. In laboratory animals, the pineal hormone melatonin has been shown to regulate striatal dopaminergic activity and block levodopa-induced dyskinesias (Cotzias et al., 1971). Since the pineal gland is known to be a magnetosensitive organ and as application of external magnetic fields has been shown to alter melatonin secretion, we studied the effects of application of external artificial weak magnetic fields in a Parkinsonian patient with severe levodopa-induced dyskinesias ("on-off"). Application of weak magnetic fields with a frequency of 2 Hz and intensity of 7.5 picotesla (pT) for a 6 minute period resulted in a rapid and dramatic attenuation of Parkinsonian disability and an almost complete resolution of the dyskinesias. This effect persisted for about 72 hours after which the patient regressed to his pretreatment state. To ascertain if the responses elicited in the laboratory were reproducible, the patient was instructed to apply magnetic fields of the same characteristics daily at home. These subsequent treatments paralleled the initial response with a sustained improvement being maintained during an observation period lasting at least one month. This case demonstrates the efficacy of weak magnetic fields in the treatment of Parkinsonism and motor complications of chronic levodopa therapy.

In various applications of neutron activation analysis, wide element concentration and nuclide half-life ranges, overlapping peaks and other interferences in the gamma-spectrum and the request for isotope abundance determination as well as other special problems are encountered which led to the development of a flexible analytical system for the optimization and differentiation of the experimental conditions in order to solve properly these multiparameter problems. The new features were introduced mainly in the analysis of short-lived nuclides with high throughput capability, enhancing also the analytical efficiency and broadening the application range of neutron activation analysis.

There is currently considerable interest in the pathogenesis of postmenopausal osteoporosis, which is the most common metabolic bone disease. Osteoporosis affects approximately 20 million persons in the United States, 90% of whom are postmenopausal women. Although there is evidence that estrogen deficiency is an important contributory factor, the pathogenesis of osteoporosis is multifactorial and presently poorly understood. There is evidence that pineal melatonin is an anti-aging hormone and that the menopause is associated with a substantial decline in melatonin secretion and an increased rate of pineal calcification. Animal data indicate that pineal melatonin is involved in the regulation of calcium and phosphorus metabolism by stimulating the activity of the parathyroid glands and by inhibiting calcitonin release and inhibiting prostaglandin synthesis. Hence, the pineal gland may function as a "fine tuner" of calcium homeostasis. In the following communication, we propose that the fall of melatonin plasma levels during the early stage of menopause may be an important contributory factor in the development of postmenopausal osteoporosis. Consequently, plasma melatonin levels taken in the early menopause could be used as an indicator or perhaps as a marker for susceptibility to postmenopausal osteoporosis. Moreover, light therapy, administration of oral melatonin (2.5 mg at night) or agents which induce a sustained release of melatonin secretion such as 5-methoxypsoralen, could be useful agents in the prophylaxis and treatment of postmenopausal osteoporosis. Finally, since application of external artificial magnetic fields has been shown to synchronize melatonin secretion in experimental animals and humans, we propose that treatment with artificial magnetic fields may be beneficial for postmenopausal osteoporosis.

Disorganization of circadian rhythms, a hallmark of aging, may be related causally to the progressive deterioration of memory functions in senescence and possibly Alzheimer's disease (AD). In experimental animals, disruption of circadian rhythms produces retrograde amnesia by interfering with the circadian organization of memory processes. The circadian system is known to be synchronized to external 24 h periodicities of ambient light by a neural pathway extending from the retina to the suprachiasmatic nucleus (SCN) of the anterior hypothalamus. There is also evidence that the earth's magnetic field is a time cue ("Zeitgeber") of circadian organization and that shielding of the ambient magnetic field leads to disorganization of the circadian rhythms in humans. Since aging is associated with a delay of the circadian rhythm phase, and since light, which phase advances circadian rhythms, mimics the effects of magnetic fields on melatonin secretion, we postulate that application of magnetic fields might improve memory functions in the elderly as a result of resynchronization of the circadian rhythms. Moreover, since the circadian rhythm organization is more severely disrupted in patients with AD, it is possible that magnetic treatment might prove useful also in improving memory functions in these patients. If successful, application of magnetic fields might open new avenues in the management of memory disturbances in the elderly and possibly in AD.

The pathogenesis of endometrial carcinoma, which is the most common malignant neoplasm of the female genital tract, is unknown. It is believed that a prolonged period of increased estrogenic exposure unopposed by progesterone may underlie the malignant transformation of the endometrial cells. In the following communication, we propose that deficient melatonin functions may be an additional endocrine factor implicated in the pathogenesis of endometrial carcinoma. This hypothesis is based on the observations that: (a) melatonin has antiestrogenic properties; (b) melatonin stimulates progesterone production which opposes the action of estrogens; (c) an increased rate of endometrial hyperplasia, a premalignant condition, has been noted during the winter, a time of year associated with diminished melatonin secretion; (d) an increased incidence of anovulatory cycles, which is a risk factor for endometrial carcinoma, occurs in the winter; (e) melatonin secretion decreases sharply during the menopause, a period associated with an increased risk of endometrial carcinoma; (f) obesity, which is a major risk factor for endometrial carcinoma, is associated with impaired circadian melatonin secretion; (g) diabetes mellitus, which is an additional risk factor for endometrial carcinoma, is associated with decreased melatonin secretion and an increased rate of pineal calcification; and (h) the prevalence of endometrial carcinoma is lower in the black population compared to the white population. Similarly, the incidence of pineal calcification, which reflects the secretory activity of the gland, is significantly lower in the African and American black populations as compared to the white population.(ABSTRACT TRUNCATED AT 250 WORDS)

Because stored ultracold neutrons can now be used for precision measurements (e.g. of the neutron β-decay period) it is necessary to have a detailed knowledge of the characteristics of neutron bottles. The interest in filling arises from a requirement that for some measurements the velocity spectrum of the bottled neutrons at the end of the filling time should, ideally, be independent of bottle size. A simple model of the filling process is used to identify and find the magnitude of some relevant effects in a material walled bottle. Also, a computer simulation of the filling process is described. This is used to estimate effects that the simple model cannot deal with.

Spontaneous abortion, the termination of pregnancy prior to 20 weeks of gestation, is estimated to occur in 40%-50% of all pregnancies and in 12%-15% of identified pregnancies. The causes of spontaneous abortion can be divided into two main categories: those arising from chromosomal anomalies and those arising from abnormalities in the intrauterine environment. In the following communication, we propose that deficient pineal melatonin functions in early pregnancy may be causally related to the development of spontaneous abortions in cases where chromosomal anomalies or structural abnormalities of the uterus have been excluded. This hypothesis is based on the findings that: (a) melatonin plasma levels normally increase by 200%-300% in the first 20 weeks of pregnancy; (b) melatonin decreases uterine contractility in the rat; (c) melatonin stimulates the secretion of progesterone, which decreases uterine contractility and prevents immunological rejection of the trophoblast; (d) melatonin inhibits the synthesis of prostaglandins, which are potent inducers of uterine contractility and labor, and (e) pinealectomy increases the number of spontaneous abortions in pregnant rats. In addition, since melatonin is a hormone with immunosuppressant properties, we propose that the increased melatonin production in early pregnancy may contribute to a state of "transplantation immunity" to the paternal histocompatibility antigens preventing immunological rejection of the trophoblast. If this hypothesis is correct, then plasma melatonin, levels during early pregnancy could be used as an indicator for increased risk of spontaneous abortions.(ABSTRACT TRUNCATED AT 250 WORDS)

The development of powerful sources of ultracold neutrons and “bottles” with low containment losses now make it possible to attempt high-precision measurements of the neutron lifetime using stored neutrons. The effect of wall losses on the decline of the stored neutron population can be eliminated in the derivation of lifetime by using bottles of varying surface/volume-ratios. A vital assumption in this technique is that an isotropic neutron velocity distribution can be established within an acceptable time. If the diffuse component of wall reflection will not achieve this, then surface roughness must be deliberately built into the bottle. A method of calculating the effect of this roughness has been developed, and a description of the method, together with representative results, is presented.

A long coaxial accelerator is filled with helium at initial gas pressure between 0.2 and 4 Torr. When connected to a large capacitor at

During investigations carried out with hydrogen as the working gas on the coaxial accelerator, a retrograde shock wave front was observed in streak photographs, taken for velocity and trapping fraction measurements of the snowplough. The velocity of this wave front was found to be 8 × 10 4 m/s which falls in the category of strong ionizing shocks. In such cases the life of the pinch was found to be longer and this is because such waves ionize more gas and increase the duration of the low-β plasma in the interelectrode space.

Systematic studies with pathological subjects with focal and general epilepsies using magnetoencephalographic (MEG) measurements showed significant brain activities even if they are not present in the electroencephalogram EEG. Using a mapping technique characterized by an isospectral amplitude (ISO-SA) of the scalp distribution of specified spectral components or frequency bands of the MEG power spectrum we were able to localize the epileptic foci. This localization of epileptic foci gives us information on the emitted magnetic field intensity and frequency for each focal point on the map of the patient. Using this information we can cure the patient by adjusting an electronic device which can emit back to the specific scalp point a magnetic field of the same intensity and frequency as the one which-is emitted from it. The principle of this technique is based on the physical phenomenon of Young's double-slit experiment by which under certain condition light plus light gives darkness.