Non-invasive Electrophysiological Characterization of Distinctive Meditative States in a Yogi during Samaadhi.

As a screening procedure, gross alpha and gross beta activity have been developed to determine whether further analysis of water samples related to specific radionuclide is necessary. In China, the determination of gross alpha and gross beta in drinking water was generally based on the HJ standard method: HJ 898-2017, water quality — determination of gross alpha activity — thick source method, and HJ 899-2017, water quality — determination of gross beta activity — thick source method. In this study, 15 water samples from Bahe river in Chan Ba region of Xi’an in China, were pretreated and analyzed by BH1216-III low background alpha and beta scintillation counter. The water samples were collected nearby residential area, wetland park, water conservation district and urban sewage treatment plant as well as other important locations which probably influence on the radioactivity level. The values of the activity concentrations of the gross alpha and beta measured in the water samples ranged from less than LD to 0.183Bq/L with a mean of 0.077Bq/L and 0.073–0.151Bq/L with a mean 0.102Bq/L respectively. All values of samples were lower than the limit level of 0.500Bq/L for gross alpha and 1.000Bq/L for gross beta, indicating that the radioactivity level in Bahe water between Chan Ba region of Xi’an is basically within the normal environmental background.

Amantadine infusions in mild dementia: acute double-blind placebo-controlled EEG mapping and psychometric studies

Gross alpha and beta activities were determined in seawater and plankton samples collected during the wet and dry seasons from 10 different sampling stations in Chonburi, the Upper Gulf of Thailand. Seawater samples were sampling, 1 km from the coastal and 2 m below the water surface, during July 2008 to July 2009. Seawater samples were prepared by coprecipitation technique. Plankton samples were prepared by filtration and dryness on filter paper. Both types of samples were counted using a low background alpha/beta proportional counter with multiple detector type (Berthold LB770). The results showed that gross alpha activities in seawater and plankton sample are in the range of 0.0591 ± 0.0209–0.3914 ± 0.0606 Bq/l and 0.0029 ± 0.0020–0.0294 ± 0.0043 Bq/l, respectively and also showed the lowest and highest activity level in the same sampling time. The activities of gross beta in seawater and plankton sample are in the range of 0.2803 ± 0.0177–1.3064 ± 0.0319 Bq/l and 0.0208 ± 0.0123–0.9151 ± 0.0262 Bq/l, respectively. Minimum detectable activity (MDA) had been observed in the measurements. The MDA of seawater sample were estimated to be 0.0832 Bq/l for alpha and 0.0577 Bq/l for beta at counting time of 100 and 200 min, respectively. In plankton samples, the MDA were estimated to be 0.0053 Bq/l for alpha and 0.0409 Bq/l for beta at the same counting time of 250 min.

In this study, gamma activity concentrations, gross alpha and gross beta activity of natural radionuclides, and heavy metal concentrations were measured in eleven edible marine fish, four shellfish, two mollusks, and a common seaweed sample collected from a local sea fish market and sea beach area of the northern part of the Bay of Bengal, Kuakata, Bangladesh. Using HPGe gamma spectrometry, the activity concentrations of 238U, 232Th, and 40K were measured and found to be 19.7 ± 1.5 Bq/kg, 12.2 ± 0.9 Bq/kg, and 188 ± 15 Bq/kg, respectively, with the 232Th concentration surpassing that of 238U. The ZnS scintillation detector was used to assess the gross alpha and gross beta activity. The average gross alpha activity and gross beta activity were found to be 9.4 ± 1.4 Bq/kg and 26 ± 4 Bq/kg, respectively, with the latter attributed to beta emitting radionuclides's abundance. The activity concentrations of 238U, 232Th, and 40K in the analyzed samples varied in the order of Shellfish > Seaweed > Fish > Mollusks, Seaweed > Shellfish > Mollusks > Fish, and Seaweed > Shellfish > Fish > Mollusks. The annual effective dose due to consumption of analyzed seafood was found to be within the world limit of 2400 μSv/y recommended by UNSCEAR. The main contributor to the annual effective dose was 238U. The excess lifetime cancer risk (ELCR) results were below the permissible threshold of 10−3 for radiological risks. Furthermore, average concentrations of Zn and Mn were higher than WHO/FAO recommended values, and carcinogenic Pb, Cd, Cr, and Hg concentrations were below detection limits, according to heavy metal analysis performed by AAS. The average concentration of heavy metals in all of the seafood samples under investigation was in the order of Zn > Fe > Mn. The calculated hazard index (HI), target hazard quotient (THQ), and estimated daily intake (EDI) were compared to the permissible safety limits.

General effects of exercise on brain cortical functions have been shown before. Several studies opened an ongoing debate about exercise intensity and type depending changes onto brain cortical activity. Using standardized low resolution brain electromagnetic tomography (sLORETA), we were able to show different changes in frontal cortical activity following various exercise intensities (Schneider, Askew et al. 2009) and various kinds of exercise (Schneider, Bruemmer et al. 2009). PURPOSE: Within this study we aim to show that specific changes in brain cortical function, namely a decrease in frontal activity, are dependent on both, exercise intensity and exercise preferences. METHODS: Four kinds of exercise (treadmill, bicycle, arm crank ergometry and isokinetic force production) with two intensities each (50%+80% of VO2peak) were performed by 12 recreational runners. Before and 15min after exercising a 5min rest-EEG was recorded over 19 electrodes. EEG alpha and beta activity were localized using sLORETA. RESULTS: 50% exercise intensity lead to increases in EEG alpha (parietal and frontal lobe) and beta (limbic lobe) frequency ranges for all kinds of exercise. Following 80% exercise intensity treadmill running revealed decreased frontal alpha and beta activity. A slight decreased frontal activity was also found following 80% bike but not following 80% arm crank and isokinetic exercise, where alpha (frontal lobe) and beta (limbic lobe) activity was shown to be increased. CONCLUSIONS: In summary we could confirm earlier studies showing that the individuals preferred exercise is accompanied by a decrease of frontal lobe activity and we could show that moderate exercise intensity shows similar changes across all exercise types whereas an increase of intensity up to 80% results in more specific and complex changes. Supported by internal grant for graduates, German Sport University, Cologne.

Studies on the operant conditioning of central nervous system activity have produced results interpreted as demonstrating that responses, certain properties of responses, or response-produced stimuli can function as discriminative stimuli. It is assumed that the feedback stimulus in biofeedback makes the subject aware of the internal response and that by becoming aware of the response, the subject can acquire voluntary control over it. In this context, awareness is operationally defined as the ability to use the response as a discriminative stimulus. Since direct evidence for the assumed relationship between control and discrimination is lacking, an attempt was made to test the hypothesis that discrimination of a response automatically leads to control over that response. The discriminative stimuli were the presence and absence of occipital alpha electroencephalograph (EEG) activity. Data from two experiments are reported. The first study, employing naive subjects, was designed to answer the following questions: (a) Since pilot data indicated that subjects seemed to match their responses to the more probable type of trial, would increases in the probability of a correct response result when the probabilities of alpha and nonalpha trials were held near .50? (b) If correct responding does increase, would performance of these subjects in an alpha feedback task be enhanced relative to that of subjects not previously given discrimination training? and (c) If subjects could not learn the discrimination task, would feedback training enhance their performance in a subsequent discrimination task? Results from this study indicate that holding the probabilities of alpha and nonalpha discrimination trials near .50 results in an absence of learning curves, but leaves open the possibility that sophisticated subjects are capable of discriminating alpha and nonalpha activity. The second study deals with two questions: (a) Can sophisticated subjects learn to discriminate occipital alpha activity from nonalpha activity? and (b) Does the procedure of providing subjects with salient stimuli, contingent on the presence and absence of alpha activity, establish stimulus control of the presence and absence of alpha activity? Results indicate that it is not possible to conclude that subjects can learn to discriminate alpha and nonalpha activity. However, learning to increase percent-time nonalpha or decrease percent-time alpha with respect to baseline levels by means of EEG-contingent stimulation provides subjects with the ability to suppress percent-time alpha in the absence of feedback. Information gained in both studies through subject interviews indicates that subjects most often acquired their control of alpha activity during feedback by a specific strategy and then used the strategy during the stimulus-control tests.

Monitoring of gross alpha, gross beta and actinides activities in exhaust air released from the waste isolation pilot plant

Particulate Filters Gross alpha, gross betaThere were no statistically significant differences among groups for the months of July and September for gross alpha and gross beta concentrations.Statistically significant differences were observed for gross alpha and gross beta concentrations for the quarter and the month of August.No result exceeded the Derived Concentration Standard (DCS) or 99%/95% upper tolerance limit (UTL) for gross alpha or gross beta activity in air.Quarterly Composite Gamma-emitting radionuclides, strontium-90, actinides (americium, plutonium, and uranium) Strontium-90 was detected in a quarterly composite sample collected at Van Buren (QA).Americium-241 and 239/240 Pu was detected in two composite samples from Radioactive Waste Management Complex (RWMC and RWMC QA).Uranium radionuclides were detected in a several composite samples.Human-made gammaemitting radionuclides (e.g., cesium-137), and plutonium-238 were not detected in any of the third quarter composite air samples.Charcoal Cartridge Iodine-131 Iodine-131 was not detected in any of the batches of charcoal cartridges counted during the quarter.Atmospheric Moisture Liquid Tritium None of the sample results showed tritium concentrations greater than the 3s uncertainty during the quarter.No sample result exceeded the UTL or DCS for tritium in air.Precipitation Liquid Tritium A total of 16 samples were collected during the third quarter.None of the tritium results were greater than the 3s uncertainty.Surface Water Liquid Gross alpha, gross beta, tritium, gamma-emitting Enough water flowed in the Big Lost River for two sampling events.Gross alpha activity was detected in eight of twelve samples.Gross beta activity was detected in all 12 samples.No tritium or humanmade gamma-emitters were found in any of the surface water samples.Milk Liquid Iodine-131, other gamma-emitting radionuclides Forty-four milk samples were collected at seven locations (including the offsite control sample from Colorado and three duplicates).No 131 I was detected in any of the milk samples analyzed.v Table ES-1.Continued.

Radiological assessment of surface water quality around proposed uranium mining site in India

To determine whether measures of quantitative spectral electroencephalography (EEG) can predict survival in patients with early Alzheimer disease. Prospective cohort study; median duration of follow-up was 4.4 years in survivors and 2.6 years in nonsurvivors. Cox proportional hazards models, with adjustment for age and sex were used to estimate relationships between EEG measures and survival. Log relative percentage values of EEG bands were used as predictors. Outpatient university memory clinic. One hundred one consecutively referred patients with early probable Alzheimer disease according to National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association criteria were studied with EEG at the time of diagnosis. The mean age of the patients was 79.2 years, which was higher than in previous EEG studies. Mortality. Fifty-one patients (50.5%) died during follow-up, with a median survival time in all patients of 4.1 years. The following EEG variables were significantly associated with increased risk of mortality: from parieto-occipital leads, higher theta (hazard ratio, 2.05; 95% confidence interval, 1.15-3.66; P<.05), lower alpha (hazard ratio, 0.43; 95% confidence interval, 0.25-0.76; P<.01), and lower beta (hazard ratio, 0.38; 95% confidence interval, 0.22-0.68; P<.001) activity; and from frontocentral leads, higher theta activity (hazard ratio, 2.07; 95% confidence interval, 1.17-3.66; P<.05). Stepwise Cox regression analysis showed that loss of parieto-occipital beta (P<.01) and alpha (P<.05) power were independent and significant predictors of mortality. Both beta (12.6-35.4 Hz) and alpha (7.5-12.5 Hz) activity remained significantly associated with mortality after adjustment for education, dementia severity, symptom duration, level of cognitive function, presence of extrapyramidal symptoms or hallucinations, presence of vascular risk factors, and presence of leukoaraiosis or local cortical atrophy. Decreases of beta and alpha activity on quantitative spectral EEG are independent predictors of mortality in patients with early Alzheimer disease. In the clinical context, the use of EEG technology for prediction of survival in individual patients remains to be determined.

Selective attention involves prioritising relevant sensory input while suppressing irrelevant stimuli. It has been proposed that oscillatory alpha-band activity (~10 Hz) aids this process by functionally inhibiting early sensory regions. However, recent studies have challenged this notion. Our EEG and MEG studies aimed to investigate whether human alpha oscillations serve as a 'gatekeeper' for downstream signal transmission. We first observed these effects in an EEG study and then replicated them using MEG, which allowed us to localise the sources. We employed a cross-modal paradigm where visual cues indicated whether upcoming targets required visual or auditory discrimination. To assess inhibition, we utilised frequency-tagging, simultaneously flickering the fixation cross at 36 Hz and playing amplitude-modulated white noise at 40 Hz during the cue-to-target interval. Consistent with prior research, we observed an increase in posterior alpha activity following cues signalling auditory targets. However, remarkably, both visual and auditory frequency-tagged responses amplified in anticipation of auditory targets, correlating with alpha activity amplitude. Our findings suggest that when attention shifts to auditory processing, the visual stream remains responsive and is not hindered by occipital alpha activity. This implies that alpha modulation does not solely regulate 'gain control' in early visual areas but rather orchestrates signal transmission to later stages of the processing stream.

Recent results on atmospheric radioactivity at Ibadan, Nigeria

Correlation between alpha activity and neuropsychometric tests in Parkinson's disease

The study evaluate gross activities of alpha and beta emitting radionuclides present in naturally occurring water bodies in Pankshin area of Plateau state covered by 90 201 011 North. 90 271 011 East. Ten (10) groundwater samples comprising of five (5) well water and five (5) borehole water were drawn randomly. The samples were analysed and counted for gross alpha and beta activities using Gas filled proportional Counter (MPC 2000 Dual Phosphor). The results showed that the mean value for gross alpha and beta in well water are 0.01662 ± 0.004 Bq/l and 5.8584 ± 0.1994Bg/l respectively. For borehole water, the mean value for gross alpha and beta activity are 0.00514±0.003 Bq/L and 2.1358 ± 0.212Bq/l. Most of the samples show lower values than the WHO guide line value of 0.5Bq/l for alpha activity and higher activities above the guideline value of 1.0 Bq/l for beta activity. The annual committed effective dose [CED] to infants, children and adults were estimated. The mean CED due to intake of well water are 0.00666 mSv/yr , 0.01334 mSv/yr, 0.26668mSv/yr, 2.3534mSv/yr, 2.27312mSv/yr, 9.4056mSv/yr and the mean CED due to intake of borehole are 0.00204mSv/yr, 0.10414mSv/yr, 0.0026mSv/yr s 0.85752 mSv/yr, 1.71504 mSv/yr and 3.4301 mSv/yr respectively for all peer groups. The results shared elevated values for beta activity in most of the location above the ICRP acceptable standard of 0.lmSv/y. It can be concluded that there is a significant radiological hazards to the general public in these locations which may be attributed to the geology and the direct contact with water by the radionuclides in the study area

The purpose of this study was to investigate the radiological quality of drinking water in Ma'an governorate, which includes the archeological city of Petra and is one of Jordan's most important tourist destinations. To the best of the authors' knowledge, this is the first study in southern Jordan that investigates radioactivity in drinking water and its potential to cause cancer. A liquid scintillation detector was used to measure gross alpha and gross beta activities in tap water samples from Ma'an governorate. A high-purity Germanium detector was used to measure the activity concentrations of 226Ra and 228Ra. Gross alpha, gross beta, 226Ra, and 228Ra activities were < 110-724mBq/l, < 220-362mBq/l, < 11-241mBq/l, and < 32-49mBq/l, respectively. The results were compared to internationally recommended levels and literature values. Annual effective doses ([Formula: see text]) from 226 and 228Ra intake were calculated for infants, children, and adults. The highest doses were found for children while the lowest were found for infants. For each water sample, the lifetime risk of radiation-induced cancer (LTR) was calculated for the whole population. All of the LTR values were lower than the value recommended by the World Heath Organisation. It is concluded that there are no significant radiation-related health risks associated with consumption of tap water from the studied region.