High Alpha Activity Research Articles

Promoting adult health: the neurophysiological benefits of watering plants and engaging in mental tasks within designed environments

BackgroundIndoor, sedentary lifestyles have disconnected individuals from nature, necessitating interventions to reestablish this bond. Performing horticultural activities, such as watering houseplants, offers a potential solution. This study sought to determine how participating in horticulture activities affected adults’ cognitive and emotional moods.MethodsWe compared the benefits of watering houseplants (a gardening task) to those of standing while performing a computer task (a mental task). Chinese participants, aged 20 to 21 years, were recruited; their physiological and psychological reactions were measured using electroencephalograms, blood pressure assessments, and psychological assessments.ResultsFifty participants were included. Watering indoor plants significantly reduced blood pressure, without affecting pulse rate. During the plant watering task as opposed to the mental activity, more dramatic different patterns of very high alpha and beta brainwave activity were identified. Participants reported increased happiness following gardening activities.ConclusionsThe findings of this study highlight the substantial relaxation benefits, both mental and physical, associated with the simple act of watering indoor plants.

Mental strategies and resting state EEG: Effect on high alpha amplitude modulation by neurofeedback in healthy young adults

Neurofeedback (NFB) is a brain-computer interface which allows individuals to modulate their brain activity. Despite the self-regulatory nature of NFB, the effectiveness of strategies used during NFB training has been little investigated. In a single session of NFB training (6*3 min training blocks) with healthy young participants, we experimentally tested if providing a list of mental strategies (list group, N = 46), compared with a group receiving no strategies (no list group, N = 39), affected participants’ neuromodulation ability of high alpha (10–12 Hz) amplitude. We additionally asked participants to verbally report the mental strategies used to enhance high alpha amplitude. The verbatim was then classified in pre-established categories in order to examine the effect of type of mental strategy on high alpha amplitude. First, we found that giving a list to the participants did not promote the ability to neuromodulate high alpha activity. However, our analysis of the specific strategies reported by learners during training blocks revealed that cognitive effort and recalling memories were associated with higher high alpha amplitude. Furthermore, the resting amplitude of trained high alpha frequency predicted an amplitude increase during training, a factor that may optimize inclusion in NFB protocols. The present results also corroborate the interrelation with other frequency bands during NFB training. Although these findings are based on a single NFB session, our study represents a further step towards developing effective protocols for high alpha neuromodulation by NFB.

Refining the conceptual model for radionuclide mobility in groundwater in the vicinity of a Hungarian granitic complex using geochemical modeling

Groundwater is an important freshwater resource, which can be affected by geogenic radionuclide contamination. To make decisions regarding the use and management of groundwater, understanding the controls of radionuclide mobility is critical. In the southern foreland of a granitic outcrop in Hungary, high gross alpha activity concentration was measured in drinking water wells, related probably to the presence of uranium. It has been suggested that understanding of the groundwater flow system may be a key aspect to understand uranium mobility in groundwater. The goal of the present work was to elucidate the conceptual model of radionuclide mobility in the study area, focusing in particular on the geochemical controls of uranium. For this purpose, water samples were collected and nuclide-specific measurements for 226Ra and radon isotopes were carried out, in addition to 234U+238U measurements, to increase the range of radionuclides and better understand their mobility. A geochemical modeling analysis involving redox-controlling kinetic reactions and a surface complexation model was developed to support the conceptual model. The results from the sampling indicate that excess of 234U+238U (3–753 mBq L−1) contribute to the natural radioactivity measured in drinking water to a large degree. 226Ra was measured in relatively low activity concentrations (<5–63 mBq L−1) with the exception of three specific wells. Notable radon activity concentration was measured in the springwaters from Velence Hills (1.01–3.14 × 105 mBq L−1) and in interrelation with the highest (285–695 mBq L−1) 226Ra activity concentrations. The geochemical model suggests that uranium distribution is sensitive to redox changes in the aquifer. Its mobility in groundwater depends on the residence time of groundwater compared to the reaction time controlling the consumption of oxidizing species. The longer the flow path from the recharge point to an observation point where U is measured, the more likely it is that reducing conditions will be found in the aquifer and the elemental concentration U will be low.

Accommodation of helium in PuO2±x and the role of americium.

The high alpha-activity of plutonium dioxide (PuO2) results in significant ingrowth of radiogenic helium (He) in the aged material. To safely store/dispose PuO2 or use in applications such as space exploration, the impact of He accumulation needs to be understood. In this work, defect energies obtained using a density functional theory (DFT) + U + D3 scheme are used in a point defect model constructed for PuO2 to predict the method of He incorporation within the PuO2 lattice. The simulations predict that the preferred incorporation site for He in PuO2 is a plutonium vacancy, however, the point defect model indicates that helium will be accommodated as an interstitial irrespective of He concentration and across a wide stoichiometric range. By considering the charge imbalance that arises due to incorporation of Am3+ ions it is shown that He accommodation in oxygen vacancy sites will dominate in PuO2-x as the material ages.

Romantic love affects emotional processing of love-unrelated stimuli: An EEG/ERP study using a love induction task

The aim of the present study was to investigate (a) the neural correlates of a love induction task (LIT) including listening to love-related songs and thinking about the romantic relationship, and (b) the effects of romantic love on the emotional processing of love-unrelated stimuli during a passive viewing task. The EEG was recorded in two groups of university students: people in love (Love Group, LG, N = 22, 19 F) and people not in love (Control Group, CG, N = 20, 15 F). The LIT induced higher pleasantness and arousal in the LG than in the CG, as well as higher alpha activity in occipital-right electrodes, suggesting active mental imagery and internal focused attention. During the picture viewing task, the LG displayed larger N1 amplitudes than the CG in response to unpleasant pictures, and lower amplitudes of the late positive potential to both pleasant and unpleasant pictures at frontal sites. Overall, these results suggest an early attentional modulation of the neural responses to unpleasant, mood-incongruent cues, followed by an implicit emotional down-regulation of arousing stimuli, which might have important implications for everyday attitudes and behaviors.

Scenario of radon alpha activity level in natural drinking waters of different regions of eastern part of India: A review report

Background/Objectives: High density to alpha-particle radiations, particularly from radon, can increase health risks. This study presents the radon alpha-activity of drinking waters in regions of eastern part of India. Methods/Statistical analysis: To figure out radon alpha-activity concentration in natural drinking waters in the above mentioned regions, present study reviewed many literatures that pertinent to radon alpha-activity of waters in the regions. Both inclusion and exclusion criteria have been followed to select the literatures for review. This study consulted the reports of literatures for obtaining data sources. Recommendations of national and international groups have been used to interpret the results. Findings: A wide variation of radon alphaactivity concentration in drinking water of the regions has been found in between 0:31 and 911 Bq=l. Most of the radioactivity values exceeded MCL or reference level recommended by USEPA and UNSCEAR, and few are exceeding action limit given by EU and WHO. High alpha-activity level in waters has been seen in the arsenic and fluoride contaminated areas and near the areas of U-mine and thermal springs. Low level of alpha-activity has been seen in some regions of Assam, Meghalaya, Mizoram and Orissa, and in the east coast region of West Bengal. The radon alpha-activity level in coastal area of Orissa is higher than that of West Bengal. It is found that the sources of the alphaemitting radionuclides, arsenic and fluoride may coexist in the arsenic and fluoride contaminated regions. This study is the first that reviewed the alpha contamination level in natural drinking waters in the eastern part of India. More studies on these regions are required in the future. Novelty/Applications: Novelty of this study relies on the observed alpha-activity of drinking waters in the regions. Radioactivity data provided in this study can help to researchers for further investigation. Keywords: Natural waters; Alpha emitters; Radon; Alpha activity; Human health; India

Electroencephalography-Derived Prognosis of Functional Recovery in Acute Stroke Through Machine Learning Approaches.

Stroke, if not lethal, is a primary cause of disability. Early assessment of markers of recovery can allow personalized interventions; however, it is difficult to deliver indexes in the acute phase able to predict recovery. In this perspective, evaluation of electrical brain activity may provide useful information. A machine learning approach was explored here to predict post-stroke recovery relying on multi-channel electroencephalographic (EEG) recordings of few minutes performed at rest. A data-driven model, based on partial least square (PLS) regression, was trained on 19-channel EEG recordings performed within 10 days after mono-hemispheric stroke in 101 patients. The band-wise (delta: 1-4[Formula: see text]Hz, theta: 4-7[Formula: see text]Hz, alpha: 8-14[Formula: see text]Hz and beta: 15-30[Formula: see text]Hz) EEG effective powers were used as features to predict the recovery at 6months (based on clinical status evaluated through the NIH Stroke Scale, NIHSS) in an optimized and cross-validated framework. In order to exploit the multimodal contribution to prognosis, the EEG-based prediction of recovery was combined with NIHSS scores in the acute phase and both were fed to a nonlinear support vector regressor (SVR). The prediction performance of EEG was at least as good as that of the acute clinical status scores. A posteriori evaluation of the features exploited by the analysis highlighted a lower delta and higher alpha activity in patients showing a positive outcome, independently of the affected hemisphere. The multimodal approach showed better prediction capabilities compared to the acute NIHSS scores alone ([Formula: see text] versus [Formula: see text], AUC = 0.80 versus AUC = 0.70, [Formula: see text]). The multimodal and multivariate model can be used in acute phase to infer recovery relying on standard EEG recordings of few minutes performed at rest together with clinical assessment, to be exploited for early and personalized therapies. The easiness of performing EEG may allow such an approach to become a standard-of-care and, thanks to the increasing number of labeled samples, further improving the model predictive power.

Virtual reality experiences promote autobiographical retrieval mechanisms: Electrophysiological correlates of laboratory and virtual experiences

Recent advancements in memory research indicate that virtual reality (VR) experiences are more vividly memorized as compared to conventional laboratory events. In contrast to the latter, VR experiences are highly immersive, simulating the multimodality, vividness and inclusiveness of real-life experiences. Therefore, VR might enable researchers to identify memory processes underlying events which participants have actually experienced, in contrast to conventional on-screen experiences. To differentiate the electrophysiological correlates of memory processes underlying VR experiences as compared to conventional laboratory experiences, participants watched videos either in a PC condition or in a VR condition, followed by an unannounced recognition memory test. As hypothesized, we replicated the well-established theta old/new effect for the PC condition, but remarkably, this effect was absent in the VR condition. Additionally, the latter was accompanied by significantly lower alpha activity as compared to the PC condition. As increases in theta-band responses are related to top-down control on, and memory load during retrieval, the observed theta responses might rather relate to retrieval effort than to retrieval success per se. Congruently, higher alpha activity measured over occipital sensor areas in the PC condition reflect visually guided search processes within episodic memory. The VR condition comes in with lower alpha activity, reflecting immediate and effortless memory access. Hence, our findings indicate that the retrieval of VR experiences promotes autobiographical retrieval mechanisms, whereas recalling conventional laboratory events comes in with higher effort, which might not reflect the mechanisms of everyday memory.

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

Parkinson’s disease (PD) is a neurodegenerative disease that leads to memory impairment and executive and visuospatial dysfunction as the disease progresses. Alpha activity on EEG has been related to cognition in previous studies. We aimed to investigate the correlation between alpha activity and neuropsychometric tests (NPTs) in PD patients. Fifty-five idiopathic PD patients and 20 healthy controls were included. The Standardized Mini-Mental Test (SMMT), Verbal Learning Memory Test (VLMT), Wechsler Memory Scale (WMS), Stroop Color–Word Test, Categorical Verbal Fluency Test (CVFT), Benton’s Face Recognition Test (BFR), and Benton Line Judgment Orientation Test (BLOT) were administered to all participants. Patients were separated into four groups according to NPT results: healthy controls (HC); PD patients with normal cognition (PDNC); PD patients with MCI (PDMCI); and PD patients with dementia (PDD). Analysis of the EEG data showed that HC had the highest alpha activity, and PDD had the lowest. High SMMT scores were correlated with high alpha activity at posterior electrode locations in all PD groups. VLMT and WMS test scores were associated with alpha activity at the parietal sites in PDMCI. VLMT, WMS, and CVFT test scores were correlated with alpha activity at parietooccipital sites in PDD. Verbal and visuospatial memory dysfunction related to low alpha activity was evident in both PDMCI and PDD, whereas executive dysfunction was more strongly associated with low alpha activity in PDD. Analysis of alpha activity could help clinicians predict the progression of cognitive dysfunction in PD patients.

Gross alpha and gross beta activities in selected marine species in Vietnam

The measured gross alpha and gross beta activities in the edible muscle tissues of eleven selected marine species along the coast of North Vietnam varied from 10.2 ± 1.5 to 73.2 ± 8.1 Bq/kg (wwt) and from 10.6 ± 0.4 to 68.8 ± 2.8 Bq/kg (wwt), respectively. The lowest gross alpha activity was recorded for bigfin reef squid (Sepioteuthis lessoniana) as a result of its carnivorous diet, and the highest alpha activity was noted for blood cockle (Anadara granosa) as a result of its omnivorous diet. However, the gross beta activities in both carnivorous and omnivorous species were similar. The highest and lowest gross beta activities were observed for narrow-barred Spanish mackerel (Scomberomorus commerson) and for bigfin reef squid and squid (Teuthida), respectively. All three aforementioned species have carnivorous diets. The calculated annual committed effective dose resulting from the consumption of 25 kg of muscle tissue per year varied from 192 to 1375 μS with an average of 689 μS.

Coordination Cost and Super-Efficiency in Teamwork: The Role of Communication, Psychological States, Cardiovascular Responses, and Brain Rhythms

To advance knowledge on the psychophysiological markers of “coordination cost” in team settings, we explored differences in meta-communication patterns (i.e., silence, speaking, listening, and overlap), perceived psychological states (i.e., core affect, attention, efficacy beliefs), heart rate variability (i.e., RMSSD), and brain rhythms (i.e., alpha, beta and theta absolute power) across three studies involving 48 male dyads (Mage = 21.30; SD = 2.03). Skilled participants cooperatively played three consecutive FIFA-17 (Xbox) games in a dyad against the computer, or competed against the computer in a solo condition and a dyad condition. We observed that playing in a team, in contrast to playing alone, was associated with higher alpha peak and global efficiency in the brain and, at the same time, led to an increase in focused attention as evidenced by participants’ higher theta activity in the frontal lobe. Moreover, we observed that overtime participants’ brain dynamics moved towards a state of “neural-efficiency”, characterized by increased theta and beta activity in the frontal lobe, and high alpha activity across the whole brain. Our findings advance the literature by demonstrating that (1) the notion of coordination cost can be captured at the neural level in the initial stages of team development; (2) by decreasing the costs of switching between tasks, teamwork increases both individuals’ attentional focus and global neural efficiency; and (3) communication dynamics become more proficient and individuals’ brain patterns change towards neural efficiency over time, likely due to team learning and decreases in intra-team conflict.

Manipulating sleep duration perception changes cognitive performance – An exploratory analysis

ObjectivesTo test the effect of perceived sleep duration on cognitive performance. MethodsSixteen healthy individuals [8F; mean age (± SD): 24.2 ± 3.0 years)] received an 8-h sleep opportunity followed by a 5-h opportunity on two consecutive nights. Upon waking, they were randomized to being informed that they received either an 8-h or 5-h sleep opportunity, via a clock that ran either fast, slow or normally. Cognitive performance was assessed using 10-min auditory psychomotor vigilance tests and subjective sleepiness ratings. Homeostatic and circadian sleep drive was assessed using waking electroencephalography (EEG). ResultsReaction time was significantly quicker when individuals thought that they had slept for 8 h but given a 5-h sleep opportunity. Conversely, reaction times were significantly slower when individuals thought they had 5 h of sleep but given an 8-h sleep opportunity. EEG delta power (1.0–4.5 Hz) during wake increased significantly when sleep was restricted to 5 h, and individuals thought they slept for 5 h, but this increase was attenuated with a perceived sleep duration of 8 h following a 5-h opportunity. EEG delta power did not increase, however, with perceived sleep restriction. EEG high-alpha activity (10.5–11.5 Hz) was consistently higher when participants thought that they had an 8-h sleep opportunity, regardless of the actual duration. ConclusionsThese results suggest that perceived sleep duration may modulate psychosomatic responses. Additional studies with predefined outcomes and analyses are necessary to confirm these findings, which may have important implications for understanding how sleep affects cognition and psychosomatic responses.

EEG alpha activity increased in response to transcutaneous electrical nervous stimulation in young healthy subjects but not in the healthy elderly.

Transcutaneous Electrical Nerve Stimulation (TENS) is used not only in the treatment of pain but also in the examination of sensory functions. With aging, there is decreased sensitivity to somatosensory stimuli. It is essential to examine the effect of TENS application on the sensory functions in the brain by recording the spontaneous electroencephalogram (EEG) activity and the effect of aging on the sensory functions of the brain during the application. The present study aimed to investigate the effect of the application of TENS on the brain’s electrical activity and the effect of aging on the sensory functions of the brain during application of TENS. A total of 15 young (24.2 ± 3.59) and 14 elderly (65.64 ± 4.92) subjects were included in the study. Spontaneous EEG was recorded from 32 channels during TENS application. Power spectrum analysis was performed by Fast Fourier Transform in the alpha frequency band (8–13 Hz) for all subjects. Repeated measures of analysis of variance was used for statistical analysis (p < 0.05). Young subjects had increased alpha power during the TENS application and had gradually increased alpha power by increasing the current intensity of TENS (p = 0.035). Young subjects had higher alpha power than elderly subjects in the occipital and parietal locations (p = 0.073). We can, therefore, conclude that TENS indicated increased alpha activity in young subjects. Young subjects had higher alpha activity than elderly subjects in the occipital and somatosensory areas. To our knowledge, the present study is one of the first studies examining the effect of TENS on spontaneous EEG in healthy subjects. Based on the results of the present study, TENS may be used as an objective method for the examination of sensory impairments, and in the evaluative efficiency of the treatment of pain conditions.

A Sound-Sensitive Source of Alpha Oscillations in Human Non-Primary Auditory Cortex.

The functional organization of human auditory cortex can be probed by characterizing responses to various classes of sound at different anatomical locations. Along with histological studies this approach has revealed a primary field in posteromedial Heschl's gyrus (HG) with pronounced induced high-frequency (70–150 Hz) activity and short-latency responses that phase-lock to rapid transient sounds. Low-frequency neural oscillations are also relevant to stimulus processing and information flow, however, their distribution within auditory cortex has not been established. Alpha activity (7–14 Hz) in particular has been associated with processes that may differentially engage earlier versus later levels of the cortical hierarchy, including functional inhibition and the communication of sensory predictions. These theories derive largely from the study of occipitoparietal sources readily detectable in scalp electroencephalography. To characterize the anatomical basis and functional significance of less accessible temporal-lobe alpha activity we analyzed responses to sentences in seven human adults (4 female) with epilepsy who had been implanted with electrodes in superior temporal cortex. In contrast to primary cortex in posteromedial HG, a non-primary field in anterolateral HG was characterized by high spontaneous alpha activity that was strongly suppressed during auditory stimulation. Alpha-power suppression decreased with distance from anterolateral HG throughout superior temporal cortex, and was more pronounced for clear compared to degraded speech. This suppression could not be accounted for solely by a change in the slope of the power spectrum. The differential manifestation and stimulus-sensitivity of alpha oscillations across auditory fields should be accounted for in theories of their generation and function.SIGNIFICANCE STATEMENT To understand how auditory cortex is organized in support of perception, we recorded from patients implanted with electrodes for clinical reasons. This allowed measurement of activity in brain regions at different levels of sensory processing. Oscillations in the alpha range (7–14 Hz) have been associated with functions including sensory prediction and inhibition of regions handling irrelevant information, but their distribution within auditory cortex is not known. A key finding was that these oscillations dominated in one particular non-primary field, anterolateral Heschl's gyrus, and were suppressed when subjects listened to sentences. These results build on our knowledge of the functional organization of auditory cortex and provide anatomical constraints on theories of the generation and function of alpha oscillations.

Alternative Options to Produce 225Ac for Nuclear Medicine

The 225Ac radiopharmaceuticals are at the final phases of clinical trials to treat various cancers. Hence, there is a relevant issue of establishing its scaled-up production. The easiest way to produce 225Ac is generating from 229Th extracted from 233U. However, the quantity of produced 225Ac is limited by the availability of stored 233U. For example, from 1 kg 233U aged for 35 years up to 32 mCi 229Th can be produced, which makes possible to accumulate up to 20 mCi 225Ac every two weeks. An alternative way to produce 229Th is irradiation of 226Ra in the high neutron flux. JSC “SSC RIAR” has performed a series of experiments to irradiate trial radium targets, and experimental yields of radium activation products have been determined. Calculation based on these data demonstrated that the maximum yield of 229Th is ∼21 mCi/g 226Ra after 6 months irradiation in the neutron trap of the SM high-flux reactor. The produced 229Th contains 228Th with the activity being 4500 times higher than that of 229Th. While there are no actinium isotopes in the 228Th decay chain, high activity of 228Th and its daughter decay products would cause a number of serious problems. Firstly, high alpha activity determines high heat and gas rates during irradiation, shipment and storage of radium targets, thus limiting the maximum mass of 226Ra per target. Secondly, continuous cooling is required when storing the purified isotope mixture between the 225Ac generation cycles. Finally, it is hard to use traditional methods of 225Ac extraction due to intense radiolysis of the reagents. The content of 228Th in 229Th can be reduced if using a two-stage irradiation process. The first stage involves irradiation of radium up to the maximum yield of 227Ac (33 mg/g 226Ra). At the same time, a mixture of thorium isotopes is generated with the 228Th:229Th activity ratio of ∼25000:1 that can be used to produce 224Ra and 212Pb. At the second stage, when irradiating 227Ac extracted from several radium targets, the maximum yield of 229Th is achieved on the 60th day of irradiation (72 mCi/g 227Ac). The ratio of 228Th and 229Th activities at this point is almost the same as that resulted from single irradiation. However, due to complete burnout of 227Ac, further irradiation would lead to a fast decrease in the 228Th:229Th activity ratio. In the course of irradiation during 5-6 months, the 228Th:229Th activity ratio would make up 1500:1, but the yield of 229Th would decrease to 35 mCi/g 227Ac. Another way to produce 225Ac is irradiation of natural thorium in particle accelerators. The produced 225Ac contains an impurity of 227Ac and is not suitable for radiopharmaceutical synthesis. However, it can be used in 213Bi generators. To implement this option, it is necessary to cooperate with a partner company that has a proton accelerator with the beam energy of at least 100 MeV. Currently JSC “SSC RIAR” considers all three production options for 225Ac.

Proactive vs. reactive car driving: EEG evidence for different driving strategies of older drivers.

Aging is associated with a large heterogeneity in the extent of age-related changes in sensory, motor, and cognitive functions. All these functions can influence the performance in complex tasks like car driving. The present study aims to identify potential differences in underlying cognitive processes that may explain inter-individual variability in driving performance. Younger and older participants performed a one-hour monotonous driving task in a driving simulator under varying crosswind conditions, while behavioral and electrophysiological data were recorded. Overall, younger and older drivers showed comparable driving performance (lane keeping). However, there was a large difference in driving lane variability within the older group. Dividing the older group in two subgroups with low vs. high driving lane variability revealed differences between the two groups in electrophysiological correlates of mental workload, consumption of mental resources, and activation and sustaining of attention: Older drivers with high driving lane variability showed higher frontal Alpha and Theta activity than older drivers with low driving lane variability and—with increasing crosswind—a more pronounced decrease in Beta activity. These results suggest differences in driving strategies of older and younger drivers, with the older drivers using either a rather proactive and alert driving strategy (indicated by low driving lane variability and lower Alpha and Beta activity), or a rather reactive strategy (indicated by high driving lane variability and higher Alpha activity).

The Impact of Mine Tailings on the Witwatersrand and the Surrounding Water Bodies in Gauteng Province, South Africa

The gross alpha and beta activity in treated water from one of the numerous gold mines in Gauteng province averaged 1.15 ± 0.13 and 0.87 ± 0.11 Bq L−1, respectively. The average readings of the fissure water from the same mine were 0.56 ± 0.10 and 0.52 ± 0.11 Bq L−1, respectively. Water samples collected at the foot of the Princess gold mine tailings dump in Gauteng province and from downstream, before the drainage joins other water sources, also had high average gross alpha and beta activity and high average concentrations of radionuclides. The hazard quotient value evaluated, based on 238U of the water sample types in these vicinities, was far above one, indicating that it may pose serious health risks to the inhabitants.

Stress reactivity and emotion in premenstrual syndrome.

BackgroundHormone level fluctuation across the menstrual cycle causes women to experience negative emotions and also affects their mood regulation and stress sensitivity. However, the stress reactivity and emotional variations in women with premenstrual syndrome (PMS), who are especially sensitive to the variations in hormone cycles, have not been explained.MethodsThe present study used an electroencephalogram (EEG) stress evaluation test, a physiology stress evaluation test, and the positive affect and negative affect scale (PANAS) to evaluate the stress reactivity pattern and emotional state of women with PMS.ResultsThe results showed that women with PMS had higher negative affect and lower positive affect compared with controls. Moreover, under stressful conditions, the women with PMS had a higher alpha activity and a lower respiration rate than the controls. The differences in stress reactivity and emotional states between women with PMS and controls were based on a covariant analysis with menstrual cycle (luteal and follicular phases) as the covariate.ConclusionThe results demonstrated that, compared with controls, women suffering from PMS have a continuous abnormality in emotional state and stress reactivity, which was independent of the menstrual cycle.

Toward an electrophysiological "sweet spot" for deep brain stimulation in the subthalamic nucleus.

Enhanced beta-band activity recorded in patients suffering from Parkinson's Disease (PD) has been described as a potential physiomarker for disease severity. Beta power is suppressed by Levodopa intake and STN deep brain stimulation (DBS) and correlates with disease severity across patients. The aim of the present study was to explore the promising signature of the physiomarker in the spatial domain. Based on local field potential data acquired from 54 patients undergoing STN-DBS, power values within alpha, beta, low beta, and high beta bands were calculated. Values were projected into common stereotactic space after DBS lead localization. Recorded beta power values were significantly higher at posterior and dorsal lead positions, as well as in active compared with inactive pairs. The peak of activity in the beta band was situated within the sensorimotor functional zone of the nucleus. In contrast, higher alpha activity was found in a more ventromedial region, potentially corresponding to associative or premotor functional zones of the STN. Beta- and alpha-power peaks were then used as seeds in a fiber tracking experiment. Here, the beta-site received more input from primary motor cortex whereas the alpha-site was more strongly connected to premotor and prefrontal areas. The results summarize predominant spatial locations of frequency signatures recorded in STN-DBS patients in a probabilistic fashion. The site of predominant beta-activity may serve as an electrophysiologically determined target for optimal outcome in STN-DBS for PD in the future. Hum Brain Mapp 38:3377-3390, 2017. © 2017 Wiley Periodicals, Inc.

Investigation on the use of Americium Oxide for Space Power Sources: Radiation Damage Studies

Within Europe 241 Am is a feasible alternative to 238 Pu that can provide a heat source for radioisotope thermoelectric generators (RTGs) and radioisotope heating units (RHUs) to be used in Electrical power sources used in outer planet missions. In the EPSO-SPACE* project developed as an exploratory research at JRC, a new type of nuclear power source, to provide heat and electricity for deep space missions is considered. It will consist of a 241 Am based compound with aerogel thermal insulation and thermocouples in close contact with the heat source. The assembly is inside an iridium encapsulation to withstand all relevant accident scenarios. The design will be modular and combinable for required electrical output.Several candidate Americium compounds will be investigated for chemical stability at high temperature and for self-irradiation damage. New thermo-electric converter materials containing actinides will be assessed, and a robust encapsulation designed. Safety analyses will be performed including launch explosion and re-entry accidents. The research will conclude in a conceptual design of a prototype power source. In the first part of this study, americium dioxide will be considered from the point of view of its chemical durability and of its behavior against radiation damage and helium formation, two aspects to be carefully investigated due to the high alpha-activity of the americium. Transmission electron Microscopy (TEM) and helium thermal desorption spectrometry (TDS) experiments will be described and results on aged (more than 30 years) AmO2 reported. Some comparison with 238 PuO2 based RTG’s will be discussed.