Short and long-term evaluation of the impact of proton minibeam radiation therapy on motor, emotional and cognitive functions.

Radiotherapy (RT) is one of the most frequently used methods for cancer treatment. Despite remarkable advancements in RT techniquesthe treatment of radioresistant tumours (i.e. high-grade gliomas) is not yet satisfactory. Finding novel approaches less damaging for normal tissues is of utmost importance. This would make it possible to increase the dose applied to tumours, resulting in an improvement in the cure rate. Along this line, proton minibeam radiation therapy (pMBRT) is a novel strategy that allows the spatial modulation of the dose, leading to minimal damage to brain structures compared to a high dose (25 Gy in one fraction) of standard proton therapy (PT). The aim of the present study was to evaluate whether pMBRT also preserves important cerebral functions. Comprehensive longitudinal behavioural studies were performed in irradiated (peak dose of 57 Gy in one fraction) and control rats to evaluate the impact of pMBRT on motor function (motor coordination, muscular tonus, and locomotor activity), emotional function (anxiety, fear, motivation, and impulsivity), and cognitive function (learning, memory, temporal processing, and decision making). The evaluations, which were conducted over a period of 10 months, showed no significant motor or emotional dysfunction in pMBRT-irradiated rats compared with control animals. Concerning cognitive functions, similar performance was observed between the groups, although some slight learning delays might be present in some of the tests in the long term after irradiation. This study shows the minimal impact of pMBRT on the normal brain at the functional level.

Inverse effects of tDCS over the left versus right DLPC on emotional processing: A pupillometry study.

BACKGROUND AND OBJECTIVES: The Dorsolateral prefrontal cortex (DLPFC) is implicated in cognitive and emotional responses. Yet, research that investigates the causal role of the left versus right DLPFC during the processes of emotion appraisal is lacking. In the current study, transcranial direct current stimulation (tDCS) was used to disentangle the functional lateralization of the DLPFC on emotional processing in response to the anticipation of, and subsequent confrontation with emotional stimuli in healthy volunteers. METHODS: Forty-eight subjects received both active and sham (on separate days) anodal tDCS over either the left (N = 24) or right (N = 24) DLPFC. Subjects' pupil dilation (PD, a physiological marker of cognitive resource allocation) was recorded while performing an appraisal task in which negative and positive emotion eliciting images were presented, each preceded by an informative cue indicating the valence of the upcoming stimulus. RESULTS: As compared to sham stimulation, left DLPFC anodal tDCS resulted in increased PD when confronted with negative emotional images, whereas right DLPFC anodal tDCS resulted in decreased PD when confronted with emotional images, irrespective of valence. LIMITATIONS: The interpretation of pupil dilation in response to emotional stimuli is limited. CONCLUSION: These findings suggest inverse lateralized DLPFC effects on cognitive resource allocation (as measured by pupillary responses) when confronted with emotional stimuli. The current findings may shed some light on mechanisms that explain the antidepressant effects of non-invasive brain stimulation of the left DLPFC.

Light as a modulator of emotion and cognition: Lessons learned from studying a diurnal rodent.

Light profoundly affects the behavior and physiology of almost all animals, including humans. One such effect in humans is that the level of illumination during the day positively contributes to affective well-being and cognitive function. However, the neural mechanisms underlying the effects of daytime light intensity on affect and cognition are poorly understood. One barrier for progress in this area is that almost all laboratory animal models studied are nocturnal. There are substantial differences in how light affects nocturnal and diurnal species, e.g., light induces sleep in nocturnal mammals but wakefulness in diurnal ones, like humans. Therefore, the mechanisms through which light modulates affect and cognition must differ between the chronotypes. To further understand the neural pathways mediating how ambient light modulates affect and cognition, our recent work has developed a diurnal rodent model, the Nile grass rat (Arvicanthis niloticus), in which daytime light intensity is chronically manipulated in grass rats housed under the same 12:12 hour light/dark cycle. This simulates lighting conditions during summer-like bright sunny days vs. winter-like dim cloudy days. Our work has revealed that chronic dim daylight intensity results in higher depression- and anxiety-like behaviors, as well as impaired spatial learning and memory. Furthermore, we have found that hypothalamic orexin is a mediator of these effects. A better understanding of how changes in daytime light intensity impinge upon the neural substrates involved in affect and cognition will lead to novel preventive and therapeutic strategies for seasonal affective disorder, as well as for non-seasonal emotional or cognitive impairments associated with light deficiency.

Radiation-induced overexpression of transthyretin inhibits retinol-mediated hippocampal neurogenesis.

Cranial irradiation is the main therapeutic strategy for treating primary and metastatic brain tumors. However, radiation is well-known to induce several unexpected side effects including emotional disorders. Although radiation-induced depression may cause decreased quality of life after radiotherapy, investigations of its molecular mechanism and therapeutic strategies are still insufficient. In this study, we found that behavioral symptoms of depression on mice models with the decrease of BrdU/NeuN- and Dcx-positive populations and MAP-2 expression in hippocampus were induced by cranial irradiation, and transthyretin (TTR) was highly expressed in hippocampus after irradiation. It was shown that overexpression of TTR resulted in the inhibition of retinol-mediated neuritogenesis. PAK1 phosphorylation and MAP-2 expression were significantly reduced by TTR overexpression following irradiation. Moreover, we observed that treatment of allantoin and neferine, the active components of Nelumbo nucifera, interrupted irradiation-induced TTR overexpression, consequently leading to the increase of PAK1 phosphorylation, neurite extension, BrdU/NeuN- and Dcx-positive populations, and MAP-2 expression. Behavioral symptoms of depression following cranial irradiation were also relieved by treatment of allantoin and neferine. These findings demonstrate that TTR plays a critical role in neurogenesis after irradiation, and allantoin and neferine could be potential drug candidates for recovering the effects of radiation on neurogenesis and depression.

Bright environmental light ameliorates deficient subjective 'liking' in insomnia: an experience sampling study.

Study Objectives: Altered comfort sensing and reduced gray matter volume in the orbitofrontal cortex of the brain in people suffering from insomnia disorder (ID) suggest compromised processes of motivation and hedonia. The experience sampling (ES) method was used to evaluate whether, in naturalistic conditions, people with ID differ from those without sleep complaints with respect to subjective Wanting and Liking, two major dimensions of the reward system. Since light affects brain circuits involved in affect and reward, ES was combined with ambulatory monitoring of light intensity fluctuations to evaluate their effect on subjective Wanting and Liking. Methods: Participants with ID (n = 17, 12 females, 56.8 ± 6.5 mean ± standard deviation years of age) and matched controls without sleep complaints (n = 18, 12 females, 57.0 ± 8.6 years of age) were probed by a smartphone alarm to log their subjective Wanting, Liking, and mood nine times a day for 7 days. Using an ambulatory light recorder, light intensity exposure was sampled simultaneously and averaged over the intervals between subsequent ES alarms. Mixed-effect models were used to evaluate how ID and varying light intensity affected subjective assessments. Results: The results indicated significantly lower subjective Liking and Wanting in people suffering from ID, particularly at low environmental light intensity. Conclusions: Wanting and Liking, rather than more commonly used mood adjectives, showed an increased sensitivity to detect deficient hedonic and reward processing in insomnia during everyday life. Deficient Liking may in part be rescued by exposure to bright environmental light.

Bright Light Delights: Effects of Daily Light Exposure on Emotions, Restactivity Cycles, Sleep and Melatonin Secretion in Severely Demented Patients.

OBJECTIVE: We tested whether the effects of a dynamic lighting system are superior to conventional lighting on emotions, agitation behaviour, quality of life, melatonin secretion and circadian restactivity cycles in severely demented patients. As a comparison, an age matched control patient group was exposed to conventional lighting. For none of the output measures were significant differences between the two lighting conditions found during the 8 study weeks in fall/winter. METHODS: Thus, we divided the patient cohort (n = 89) into two groups, solely based on the median of their daily individual light exposure. Patients with higher average daily light exposure (>417 lx) showed significantly longer emotional expressions of pleasure and alertness per daily observations than patients with lower daily light exposure. Moreover, they had a higher quality of life, spent less time in bed, went to bed later and initiated their sleep episodes later, even though the two groups did not differ with respect to age, severity of cognitive impairment and mobility. In general, men were more agitated, had shorter sleep with more wake episodes, had a lower circadian amplitude of relative rest-wake activity and interdaily circadian stability than women. In particular, lower daily light exposures significantly predicted lower circadian amplitudes of rest-activity cycles in men but not in women. This may indicate sex specific susceptibility to daily light exposures for rest-activity regulation in older demented patients. RESULTS: Our results provide evidence that a higher daily light exposure has beneficial effects on emotions and thus improved quality of life in a severely demented patient group.

Glial markers and emotional memory in rats following acute cerebral radiofrequency exposures.

The widespread mobile phone use raises concerns on the possible cerebral effects of radiofrequency electromagnetic fields (RF EMF). Reactive astrogliosis was reported in neuroanatomical structures of adaptive behaviors after a single RF EMF exposure at high specific absorption rate (SAR, 6 W/kg). Here, we aimed to assess if neuronal injury and functional impairments were related to high SAR-induced astrogliosis. In addition, the level of beta amyloid 1-40 (Aß 1-40) peptide was explored as a possible toxicity marker. Sprague Dawley male rats were exposed for 15 min at 0, 1.5, or 6 W/kg or for 45 min at 6 W/kg. Memory, emotionality, and locomotion were tested in the fear conditioning, the elevated plus maze, and the open field. Glial fibrillary acidic protein (GFAP, total and cytosolic fractions), myelin basic protein (MBP), and Aß1-40 were quantified in six brain areas using enzyme-linked immunosorbent assay. According to our data, total GFAP was increased in the striatum (+114 %) at 1.5 W/kg. Long-term memory was reduced, and cytosolic GFAP was increased in the hippocampus (+119 %) and in the olfactory bulb (+46 %) at 6 W/kg (15 min). No MBP or Aß1-40 expression modification was shown. Our data corroborates previous studies indicating RF EMF-induced astrogliosis. This study suggests that RF EMF-induced astrogliosis had functional consequences on memory but did not demonstrate that it was secondary to neuronal damage.

Cerebral radiofrequency exposures during adolescence: Impact on astrocytes and brain functions in healthy and pathologic rat models.

The widespread use of mobile phones by adolescents raises concerns about possible health effects of radiofrequency electromagnetic fields (RF EMF 900 MHz) on the immature brain. Neuro-development is a period of particular sensitivity to repeated environmental challenges such as pro-inflammatory insults. Here, we used rats to assess whether astrocyte reactivity, perception, and emotionality were affected by RF EMF exposures during adolescence. We also investigated if adolescent brains were more sensitive to RF EMF exposures after neurodevelopmental inflammation. To do so, we either performed 80 µg/kg intra-peritoneal injections of lipopolysaccharides during gestation or 1.25 µg/h intra-cerebro-ventricular infusions during adolescence. From postnatal day (P)32 to 62, rats were subjected to 45 min RF EMF exposures to the brain (specific absorption rates: 0, 1.5, or 6 W/kg, 5 days/week). From P56, they were tested for perception of novelty, anxiety-like behaviors, and emotional memory. To assess astrocytic reactivity, Glial Fibrillary Acidic Protein was measured at P64. Our results did not show any neurobiological impairment in healthy and vulnerable RF EMF-exposed rats compared to their sham-exposed controls. These data did not support the hypothesis of a specific cerebral sensitivity to RF EMF of adolescents, even after a neurodevelopmental inflammation. Bioelectromagnetics. 37:338-350, 2016. © 2016 Wiley Periodicals, Inc.

Effects of combined ferrous sulfate administration and exposure to static magnetic field on brain oxidative stress and emotional behavior.

The present study was done to investigate behavioral effects and oxidative stress in iron- treated and co-exposed static magnetic field (SMF)-iron rats. Anxiety in the elevated plus- maze test, and motor skills were also assessed in the stationary beam and suspended string tests. After behavioral tests, the rats were anesthetized and their brains were removed for biochemical analysis. The co-exposure to iron and SMF induced a significant difference in elevated plus-maze test in rats. The frequency of entries and time spent in the open arms was significantly reduced (p<0.05) in the iron- and SMF-exposed group compared with the group treated with iron alone and in the control group. However, no significant difference was noticed for the motor skill test between the three groups. The biochemical investigation showed that malondialdehyde level increased (p<0.001) and that glutathione level and catalase enzyme activity decreased (p<0.001) in brain of iron- and SMF-exposed group. The dose of iron alone used in present study, was unable to induce any effect. However, the 128 mT SMF in the presence of iron ions in the body can induce disruption in the emotional behavior and can produce oxidative stress in brain tissue of rats.

Neural Cognition and Affective Computing on Cyber Language.

Characterized by its customary symbol system and simple and vivid expression patterns, cyber language acts as not only a tool for convenient communication but also a carrier of abundant emotions and causes high attention in public opinion analysis, internet marketing, service feedback monitoring, and social emergency management. Based on our multidisciplinary research, this paper presents a classification of the emotional symbols in cyber language, analyzes the cognitive characteristics of different symbols, and puts forward a mechanism model to show the dominant neural activities in that process. Through the comparative study of Chinese, English, and Spanish, which are used by the largest population in the world, this paper discusses the expressive patterns of emotions in international cyber languages and proposes an intelligent method for affective computing on cyber language in a unified PAD (Pleasure-Arousal-Dominance) emotional space.

Diminished appetitive startle modulation following targeted inhibition of prefrontal cortex.

From an evolutionary perspective the startle eye-blink response forms an integral part of the human avoidance behavioral repertoire and is typically diminished by pleasant emotional states. In major depressive disorder (MDD) appetitive motivation is impaired, evident in a reduced interference of positive emotion with the startle response. Given the pivotal role of frontostriatal neurocircuitry in orchestrating appetitive motivation, we hypothesized that inhibitory transcranial magnetic stimulation (TMS) would reduce appetitive neuromodulation in a manner similar to MDD. Based on a pre-TMS functional MRI (fMRI) experiment we selected the left dorsolateral and dorsomedial prefrontal cortices as target regions for subsequent sham-controlled inhibitory theta-burst TMS (TBS) in 40 healthy male volunteers. Consistent with our hypothesis, between-group comparisons revealed a TBS-induced inhibition of appetitive neuromodulation, manifest in a diminished startle response suppression by hedonic stimuli. Collectively, our results suggest that functional integrity of left dorsolateral and dorsomedial prefrontal cortex is critical for mediating a pleasure-induced down-regulation of avoidance responses which may protect the brain from a depressogenic preponderance of defensive stress.

Prospective longitudinal evaluation of emotional and behavioral functioning in pediatric patients with low-grade glioma treated with conformal radiation therapy.

Patients with low-grade glioma (LGG) who are successfully treated with irradiation are at increased risk for cognitive and psychosocial late effects. Conformal radiation therapy (CRT) allows sparing of cognitive deficits, but how it affects emotional and behavioral functioning remains unclear. We performed a prospective longitudinal study of the emotional and behavioral functioning of pediatric patients with LGG in the first 5 years post-CRT. Ninety-five pediatric patients with LGG treated on an institutional Phase II trial (August 1997-June 2009) underwent neuropsychological assessments pre-CRT and 6, 12, 24, 36, 48, and 60 months post-CRT. Parent-reported scores on the Child Behavior Checklist (CBCL) were analyzed. Three competence scales (School Competence, Social Competence, and Activities), two summary scales (Internalizing Problems and Externalizing Problems), and two subscales of theoretical interest (Attention Problems and Social Problems) from the CBCL were used. Among 80 eligible patients [44 female, 68 white], 51 had pilocytic astrocytoma and 13 had optic pathway glioma. Mean age at diagnosis was 6.8 years (SD = 4.3 years) and at CRT initiation was 8.9 years (SD = 3.4 years). Before CRT, deficits were demonstrated on the competence scales (mean scores below normative mean) and the Attention Problems and Social Problems subscales (mean scores above normative means). This trend continued at 5 years post-CRT. Longitudinal trajectories of emotional and behavioral functioning were stable over 5 years. Emotional and behavioral deficits remain relatively stable over the 5 years post-CRT in patients with LGG, suggesting that CRT may not exacerbate pre-existing psychosocial difficulties in this population.

Emotional and behavioral functioning after conformal radiation therapy for pediatric ependymoma.

PURPOSE: The standard of care for pediatric patients with ependymoma involves postoperative radiation therapy. Prior research suggests that conformal radiation therapy (CRT) is associated with relative sparing of cognitive and academic functioning, but little is known about the effect of CRT on emotional and behavioral functioning. METHODS AND MATERIALS: A total of 113 patients with pediatric ependymoma underwent CRT using photons as part of their enrollment on an institutional trial. Patients completed annual evaluations of neurocognitive functioning during the first 5 years after CRT. Emotional and behavioral functioning was assessed via the Child Behavior Checklist. RESULTS: Before CRT, emotional and behavioral functioning were commensurate with those of the normative population and within normal limits. After 5 years, means remained within normal limits but were significantly below the normative mean. Linear mixed models revealed a significant increase in attention problems over time. These problems were associated with age at diagnosis/CRT, tumor location, and extent of resection. A higher-than-expected incidence of school problems was present at all assessment points after baseline. CONCLUSIONS: The use of photon CRT for ependymoma is associated with relatively stable emotional and behavioral functioning during the first 5 years after treatment. The exception is an increase in attention problems. Results suggest that intervening earlier in the survivorship period-during the first year posttreatment-may be beneficial.

Exogenous glucocorticoids decrease subgenual cingulate activity evoked by sadness.

The glucocorticoid hormone cortisol is known to have wide-ranging effects on a variety of physiological systems, including the morphology and physiology of the amygdala and hippocampus. Disruptions of cortisol regulation and signaling are also linked with psychiatric disorders involving emotional disturbances. Although there is much evidence to suggest a relationship between cortisol signaling and the brain physiology underlying emotion, few studies have attempted to test for direct effects of cortisol on the neurophysiology of emotion. We administered exogenous synthetic cortisol (hydrocortisone, HCT) using two different dosing regimens (25 mg/day over 4 days, 100 mg single dose), in a double-blind placebo-controlled functional magnetic resonance imaging (fMRI) study. During fMRI scanning, healthy subjects viewed images designed to induce happy, sad, and neutral emotional states. Subjective emotional reactions were collected for each experimental stimulus after fMRI scanning. Mood ratings were also collected throughout the 4 days of the study. Both dose regimens of HCT resulted in decreased subgenual cingulate activation during sadness conditions. The 25 mg/day regimen also resulted in higher arousal ratings of sad stimuli. No effects of HCT were observed on any mood ratings. Few reliable effects of HCT were observed on brain activity patterns or subjective emotional responses to stimuli that were not sad. The inhibitory effects of cortisol on sadness-induced subgenual cingulate activity may have critical relevance to the pathophysiology of major depression, as both subgenual hyperactivity and decreased sensitivity to cortisol signaling have been documented in patients with depression.

Analysis of emotionality and locomotion in radio-frequency electromagnetic radiation exposed rats.

In the current study the modulatory role of mobile phone radio-frequency electromagnetic radiation (RF-EMR) on emotionality and locomotion was evaluated in adolescent rats. Male albino Wistar rats (6-8 weeks old) were randomly assigned into the following groups having 12 animals in each group. Group I (Control): they remained in the home cage throughout the experimental period. Group II (Sham exposed): they were exposed to mobile phone in switch-off mode for 28 days, and Group III (RF-EMR exposed): they were exposed to RF-EMR (900 MHz) from an active GSM (Global system for mobile communications) mobile phone with a peak power density of 146.60 µW/cm(2) for 28 days. On 29th day, the animals were tested for emotionality and locomotion. Elevated plus maze (EPM) test revealed that, percentage of entries into the open arm, percentage of time spent on the open arm and distance travelled on the open arm were significantly reduced in the RF-EMR exposed rats. Rearing frequency and grooming frequency were also decreased in the RF-EMR exposed rats. Defecation boli count during the EPM test was more with the RF-EMR group. No statistically significant difference was found in total distance travelled, total arm entries, percentage of closed arm entries and parallelism index in the RF-EMR exposed rats compared to controls. Results indicate that mobile phone radiation could affect the emotionality of rats without affecting the general locomotion.

Chronic exposure to an extremely low-frequency magnetic field induces depression-like behavior and corticosterone secretion without enhancement of the hypothalamic-pituitary-adrenal axis in mice.

An extremely low-frequency magnetic field (ELF-MF) is generated by power lines and household electrical devices. Many studies have suggested an association between chronic ELF-MF exposure and anxiety and/or depression. The mechanism of these effects is assumed to be a stress response induced by ELF-MF exposure. However, this mechanism remains controversial. In the present study, we investigated whether chronic ELF-MF exposure (intensity, 1.5 mT; [corrected] total exposure, 200 h) affected emotional behavior and corticosterone synthesis in mice. ELF-MF-treated mice showed a significant increase in total immobility time in a forced swim test and showed latency to enter the light box in a light-dark transition test, compared with sham-treated (control) mice. Corticosterone secretion was significantly high in the ELF-MF-exposed mice; however, no changes were observed in the amount of the adrenocorticotropic hormone and the expression of genes related to stress response. Quantification of the mRNA levels of adrenal corticosteroid synthesis enzymes revealed a significant reduction in Cyp17a1 mRNA in the ELF-MF-exposed mice. Our findings suggest the possibility that high intensity and chronic exposure to ELF-MF induces an increase in corticosterone secretion, along with depression- and/or anxiety-like behavior, without enhancement of the hypothalamic-pituitary-adrenal axis.

Transcranial infrared laser stimulation produces beneficial cognitive and emotional effects in humans.

This is the first controlled study demonstrating the beneficial effects of transcranial laser stimulation on cognitive and emotional functions in humans. Photobiomodulation with red to near-infrared light is a novel intervention shown to regulate neuronal function in cell cultures, animal models, and clinical conditions. Light that intersects with the absorption spectrum of cytochrome oxidase was applied to the forehead of healthy volunteers using the laser diode CG-5000, which maximizes tissue penetration and has been used in humans for other indications. We tested whether low-level laser stimulation produces beneficial effects on frontal cortex measures of attention, memory and mood. Reaction time in a sustained-attention psychomotor vigilance task (PVT) was significantly improved in the treated (n=20) vs. placebo control (n=20) groups, especially in high novelty-seeking subjects. Performance in a delayed match-to-sample (DMS) memory task showed also a significant improvement in treated vs. control groups as measured by memory retrieval latency and number of correct trials. The Positive and Negative Affect Schedule (PANAS-X), which tracks self-reported positive and negative affective (emotional) states over time, was administered immediately before treatment and 2 weeks after treatment. The PANAS showed that while participants generally reported more positive affective states than negative, overall affect improved significantly in the treated group due to more sustained positive emotional states as compared to the placebo control group. These data imply that transcranial laser stimulation could be used as a non-invasive and efficacious approach to increase brain functions such as those related to cognitive and emotional dimensions. Transcranial infrared laser stimulation has also been proven to be safe and successful at improving neurological outcome in humans in controlled clinical trials of stroke. This innovative approach could lead to the development of non-invasive, performance-enhancing interventions in healthy humans and in those in need of neuropsychological rehabilitation.

The effect of one left-sided dorsolateral prefrontal sham-controlled HF-rTMS session on approach and withdrawal related emotional neuronal processes.

OBJECTIVE: Although repetitive Transcranial Magnetic Stimulation (rTMS) is frequently used to examine emotional changes in healthy volunteers, it remains largely unknown how rTMS is able to influence emotion. METHODS: In this sham-controlled, single-blind crossover study using fMRI, we examined in 20 right-handed healthy females whether a single high frequency (HF)-rTMS session applied to the left dorsolateral prefrontal cortex could influence emotional processing while focussing on blocks of positively and negatively valenced baby faces. RESULTS: While positive information was being processed, we observed after one active HF-rTMS session enhanced neuronal activity in the left superior frontal cortex and right inferior parietal cortex. After sham HF-rTMS, we found significant decreases in neuronal activity in the left superior frontal cortex, the left inferior prefrontal cortex, as well as in the right posterior cingulate gyrus. When negative information was processed, one active stimulation attenuated neuronal activity in the right insula only. CONCLUSIONS: Our findings suggest that during the processing of positive information one active session enhanced the ability to empathize with the depicted emotional stimuli, while during the processing of negative information it resulted in decreased psychophysiological reactions. SIGNIFICANCE: These results provide new information on the working mechanism of left-sided HF-rTMS.

Weather daily variation in winter and its effect on behavior and affective states in day-care children.

This study aimed to analyze the impact of winter weather conditions on young children's behavior and affective states by examining a group of 61 children attending day-care centers in Florence (Italy). Participants were 33 males, 28 females and their 11 teachers. The mean age of the children at the beginning of the observation period was 24.1 months. The day-care teachers observed the children's behavioral and emotional states during the morning before their sleeping time and filled in a questionnaire for each baby five times over a winter period of 3 weeks. Air temperature, relative humidity, air pressure and solar radiation data were collected every 15 min from a weather station located in the city center of Florence. At the same time, air temperature and relative humidity data were collected in the classroom and in the garden of each day-care center. We used multilevel linear models to evaluate the extent to which children's emotional and behavioral states could be predicted by weather conditions, controlling for child characteristics (gender and age). The data showed that relative humidity and solar radiation were the main predictors of the children's emotional and behavioral states. The outdoor humidity had a significant positive effect on frustration, sadness and aggression; solar radiation had a significant negative effect only on sadness, suggesting that a sunny winter day makes children more cheerful. The results are discussed in term of implications for parents and teachers to improve children's ecological environment.

Association between exposure to radiofrequency electromagnetic fields assessed by dosimetry and acute symptoms in children and adolescents: a population based cross-sectional study.

BACKGROUND: The increase in numbers of mobile phone users was accompanied by some concern that exposure to radiofrequency electromagnetic fields (RF EMF) might adversely affect acute health especially in children and adolescents. The authors investigated this potential association using personal dosimeters. METHODS: A 24-hour exposure profile of 1484 children and 1508 adolescents was generated in a population-based cross-sectional study in Germany between 2006 and 2008 (participation 52%). Personal interview data on socio-demographic characteristics, self-reported exposure and potential confounders were collected. Acute symptoms were assessed twice during the study day using a symptom diary. RESULTS: Only few of the large number of investigated associations were found to be statistically significant. At noon, adolescents with a measured exposure in the highest quartile during morning hours reported a statistically significant higher intensity of headache (Odd Ratio: 1.50; 95% confidence interval: 1.03, 2.19). At bedtime, adolescents with a measured exposure in the highest quartile during afternoon hours reported a statistically significant higher intensity of irritation in the evening (4th quartile 1.79; 1.23, 2.61), while children reported a statistically significant higher intensity of concentration problems (4th quartile 1.55; 1.02, 2.33). CONCLUSIONS: We observed few statistically significant results which are not consistent over the two time points. Furthermore, when the 10% of the participants with the highest exposure are taken into consideration the significant results of the main analysis could not be confirmed. Based on the pattern of these results, we assume that the few observed significant associations are not causal but rather occurred by chance.