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1.
J Anim Ecol ; 93(1): 57-70, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37975479

RESUMO

The island species-area relationship (ISAR) describes how species richness increases with increasing area of a given island or island-like habitat, such as freshwater lakes. While the ISAR is one of the most common phenomena observed in ecology, there is variation in both the form of the relationship and its underlying mechanisms. We compiled a global data set of benthic macroinvertebrates from 524 shallow freshwater lakes, ranging from 1 to 293,300 ha in area. We used individual-based rarefaction to determine the degree to which ISAR was influenced by mechanisms other than passive sampling (larger islands passively sample more individuals from the regional pool and, therefore, have more species than smaller islands), which would bias results away from expected relationships between rarefied species richness (and other measures that capture relative abundances) and lake area. We also examined how climate may alter the shape of the ISARs. We found that both rarefied species richness (the number of species standardized by area or number of individuals) and a measure of evenness emphasizing common species exhibit shallow slopes in relationships with lake area, suggesting that the expected ISARs in these lakes most likely result from passive sampling. While there was considerable variation among ISARs across the investigated lakes, we found an overall positive rarefied ISAR for lakes in warm (i.e. tropical/subtropical) regions (n = 195), and in contrast, an overall negative rarefied ISAR in cool (i.e. north temperate) lakes (n = 329). This suggested that mechanisms beyond passive sampling (e.g. colonization-extinction dynamics and/or heterogeneity) were more likely to operate in warm lakes. One possible reason for this difference is that the area-dependent intensity of fish predation, which can lead to flatter ISARs, is weaker in warmer relative to cooler lakes. Our study illustrates the importance of understanding both the pattern and potential processes underlying the ISARs of freshwater lakes in different climatic regions. Furthermore, it provides a baseline for understanding how further changes to the ecosystem (i.e. in lake area or climate) might influence biodiversity patterns.


Assuntos
Biodiversidade , Ecossistema , Animais , Lagos , Peixes , Ecologia
2.
Scand J Psychol ; 62(6): 787-797, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34148239

RESUMO

We determined the effects of age and sleep deprivation on driving and spatial perception in a virtual reality environment. Twenty-two young (mean age: 22 years, range: 18-35) and 23 old (mean age: 71 years, range: 65-79) participants were tested after a normal night of sleep and a night of sleep deprivation. The participants drove a virtual car while responding to uni- and bilateral visual and auditory stimuli. Driving errors (crossing the lane borders), reaction times and accuracy to visual and auditory stimuli, performance in psychological tests, and subjective driving ability and tiredness were measured. Age had no effect on the number of driving errors, whereas sleep deprivation increased significantly especially the number of left lane border crossings. Age increased the number of stimulus detection errors, while sleep deprivation increased the number of errors particularly in the young and in the auditory modality as response omissions. Age and sleep deprivation together increased the number of response omissions in both modalities. Left side stimulus omissions suggest a bias to the right hemispace. The subjective evaluations were consistent with the objective measures. The psychological tests were more sensitive to the effects of age than to those of sleep deprivation. Driving simulation in a virtual reality setting is sensitive in detecting the effects of deteriorating factors on both driving and simultaneous spatial perception.


Assuntos
Fatores Etários , Condução de Veículo , Privação do Sono , Processamento Espacial , Realidade Virtual , Adolescente , Adulto , Idoso , Humanos , Masculino , Percepção , Tempo de Reação , Adulto Jovem
3.
Neuropsychol Rev ; 30(1): 1-24, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32036490

RESUMO

Some studies have linked bilingualism with a later onset of dementia, Alzheimer's disease (AD), and mild cognitive impairment (MCI). Not all studies have observed such relationships, however. Differences in study outcomes may be due to methodological limitations and the presence of confounding factors within studies such as immigration status and level of education. We conducted the first systematic review with meta-analysis combining cross-sectional studies to explore if bilingualism might delay symptom onset and diagnosis of dementia, AD, and MCI. Primary outcomes included the age of symptom onset, the age at diagnosis of MCI or dementia, and the risk of developing MCI or dementia. A secondary outcome included the degree of disease severity at dementia diagnosis. There was no difference in the age of MCI diagnosis between monolinguals and bilinguals [mean difference: 3.2; 95% confidence intervals (CI): -3.4, 9.7]. Bilinguals vs. monolinguals reported experiencing AD symptoms 4.7 years (95% CI: 3.3, 6.1) later. Bilinguals vs. monolinguals were diagnosed with dementia 3.3 years (95% CI: 1.7, 4.9) later. Here, 95% prediction intervals showed a large dispersion of effect sizes (-1.9 to 8.5). We investigated this dispersion with a subgroup meta-analysis comparing studies that had recruited participants with dementia to studies that had recruited participants with AD on the age of dementia and AD diagnosis between mono- and bilinguals. Results showed that bilinguals vs. monolinguals were 1.9 years (95% CI: -0.9, 4.7) and 4.2 (95% CI: 2.0, 6.4) older than monolinguals at the time of dementia and AD diagnosis, respectively. The mean difference between the two subgroups was not significant. There was no significant risk reduction (odds ratio: 0.89; 95% CI: 0.68-1.16) in developing dementia among bilinguals vs. monolinguals. Also, there was no significant difference (Hedges' g = 0.05; 95% CI: -0.13, 0.24) in disease severity at dementia diagnosis between bilinguals and monolinguals, despite bilinguals being significantly older. The majority of studies had adjusted for level of education suggesting that education might not have played a role in the observed delay in dementia among bilinguals vs. monolinguals. Although findings indicated that bilingualism was on average related to a delayed onset of dementia, the magnitude of this relationship varied across different settings. This variation may be due to unexplained heterogeneity and different sources of bias in the included studies. Registration: PROSPERO CRD42015019100.


Assuntos
Idade de Início , Demência/epidemiologia , Multilinguismo , Humanos
5.
Ecol Appl ; 28(5): 1260-1272, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29645323

RESUMO

The ecological assessment of freshwaters is currently primarily based on biological communities and the reference condition approach (RCA). In the RCA, the communities in streams and lakes disturbed by humans are compared with communities in reference conditions with no or minimal anthropogenic influence. The currently favored rationale is using selected community metrics for which the expected values (E) for each site are typically estimated from environmental variables using a predictive model based on the reference data. The proportional differences between the observed values (O) and E are then derived, and the decision rules for status assessment are based on fixed (typically 10th or 25th) percentiles of the O/E ratios among reference sites. Based on mathematical formulations, illustrations by simulated data and real case studies representing such an assessment approach, we demonstrate that the use of a common quantile of O/E ratios will, under certain conditions, cause severe bias in decision making even if the predictive model would be unbiased. This is because the variance of O/E under these conditions, which seem to be quite common among the published applications, varies systematically with E. We propose a correction method for the bias and compare the novel approach to the conventional one in our case studies, with data from both reference and impacted sites. The results highlight a conceptual issue of employing ratios in the status assessment. In some cases using the absolute deviations instead provides a simple solution for the bias identified and might also be more ecologically relevant and defensible.


Assuntos
Monitoramento Ambiental/métodos , Invertebrados , Rios , Animais , Biodiversidade , Invertebrados/classificação , Invertebrados/fisiologia
6.
J Med Internet Res ; 20(3): e77, 2018 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-29555622

RESUMO

BACKGROUND: Traumatic brain injury (TBI) is a major health problem that often requires intensive and long-term rehabilitation. OBJECTIVE: The aim of this study was to determine whether rehabilitative digital gaming facilitates cognitive functioning and general well-being in people with TBI. METHODS: A total of 90 Finnish-speaking adults with TBI (18-65 years) were recruited from an outpatient neuroscience clinic. The participants were randomly allocated to one of the three groups: a rehabilitation gaming group (n=29, intervention), an entertainment gaming group (n=29, active control), or a passive control group (n=32). The gaming groups were instructed to engage in gaming for a minimum of 30 min per day for 8 weeks. Primary and secondary outcomes were measured at three time points: before the intervention, after the intervention, and 3 months following the intervention. The primary outcome was cognitive status measured by processing speed and visuomotor tasks (The Trail Making Test; Wechsler Adult Intelligence Scale-Fourth Edition, WAIS-IV, symbol search, coding, and cancellation tasks). Secondary outcomes were attention and executive functions (Simon task), working memory (WAIS-IV digit span and Paced Auditory Serial Addition Test, PASAT), depression (Patient Health Questionnaire-9), self-efficacy (General Self-efficacy Scale), and executive functions (Behavior Rating Inventory of Executive Function-Adult Version). Feasibility information was assessed (acceptability, measurement instruments filled, dropouts, adherence, usability, satisfaction, and possible future use). Cognitive measurements were conducted in face-to-face interviews by trained psychologists, and questionnaires were self-administered. RESULTS: The effects of rehabilitation gaming did not significantly differ from the effects of entertainment gaming or being in a passive control group. For primary outcomes and PASAT tests, the participants in all three groups showed overall improvement in test scores across the three measurement points. However, depression scores increased significantly between baseline and after 8 weeks and between baseline and after 3 months in the rehabilitative gaming group. No differences were found in patients' self-efficacy between the three measuring points in any of the groups. Participants did use the games (rehabilitation group: 93%, 27/29; entertainment group 100%, 29/29). Games were seen as a usable intervention (rehabilitation group: 70%, 14/29; entertainment group: 83%, 20/29). The rehabilitation group was less satisfied with the gaming intervention (68%, 13/29 vs 83%, 20/29), but they were more willing to use the game after the intervention period (76%, 16/29 vs 63%, 15/29). Total time spent on gaming during the intervention period was low (15.22 hour rehabilitation gaming group, 19.22 hour entertainment gaming group). CONCLUSIONS: We did not find differences between the groups in improvement in the outcome measures. The improvements in test performance by all three groups may reflect rehearsal effects. Entertainment gaming had elements that could be considered when rehabilitative games are designed for, implemented in, and assessed in larger clinical trials for persons with TBI. TRIAL REGISTRATION: ClinicalTrials.gov NCT02425527; https://clinicaltrials.gov/ct2/show/NCT02425527 (Archived by WebCite at http://www.webcitation.org/6esKI1uDH).


Assuntos
Lesões Encefálicas Traumáticas/terapia , Internet/instrumentação , Jogos de Vídeo/psicologia , Adolescente , Adulto , Idoso , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Adulto Jovem
7.
Scand J Psychol ; 59(1): 32-40, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29356011

RESUMO

Spatial perceptual rightward bias which was originally described in Dichotic Listening studies seems to be a general phenomenon. This bias is age dependent, being evident in children with developing executive functions, and emerging again at older age as a function of aging and the declining executive functions. In the two studies presented here we compared the performance of young and elderly adults in spatial divided attention tasks with auditory and visual stimuli when the stimulus detection performance was measured in separate sessions in a laboratory setting (Study I), to performance when the same types of stimuli were mixed with a task in which the subject's primary objective was to drive a car in a virtual environment (virtual reality; Study II). The aim was to see if the perceptual bias could be detected and also to look at how it would differ in these two situations. 90 right-handed subjects (50 young and 40 elderly) participated in Study I and 84 subjects (64 young and 20 elderly) participated in Study II. Study I showed the rightward bias to be more evident in the elderly subjects in both modalities and in more demanding tasks. Study II revealed that in the triple task the spatial perceptual bias was evident in both modalities for the elderly participants when the conditions were more demanding. An interesting finding concerning the right-side perceptual bias was the simultaneous occurrence of left-side driving errors, i.e. crossing the lane border to the left especially by the elderly. Both of these biases may reflect the asymmetries of the attention-related neuronal networks.


Assuntos
Envelhecimento , Percepção Auditiva , Percepção Visual , Estimulação Acústica , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Atenção , Condução de Veículo , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Estimulação Luminosa , Realidade Virtual , Adulto Jovem
8.
Crim Behav Ment Health ; 24(1): 36-48, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23963707

RESUMO

BACKGROUND: Neurocognitive deficits are frequent among male offenders and tend to be associated with a more serious risk of anti-social activity, but they are not systematically allowed for in rehabilitation programmes. AIM: The aim of this study was to evaluate neurocognitive performance in a sample of sentenced Finnish male prisoners and consider the implications for prison programme entry. METHODS: Seventy-five sentenced male prisoners were examined using a neurocognitive test battery. RESULTS: Depending on the neurocognitive domain, from 5% to 49% of the men demonstrated marked neurocognitive deficits in tests of motor dexterity, visuospatial/construction skills, verbal comprehension, verbal and visual memory and attention shift. Verbal IQ was more impaired than performance IQ. There was no association between most serious offence type and neurocognitive performance, but correlations between attention deficit indices and number of previous convictions suggested that recidivists may have an attention disorder profile. Cluster analysis identified two subgroups of offenders, separated by very poor or merely poor cognitive performance. Motor dexterity, visuo-construction and verbal memory deficits were not wholly explained by lower IQ measures. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Our sample was small, but the nature and extent of the neurocognitive deficits found suggest that wider use of neurocognitive assessments, which the men generally tolerated well, could help select those most likely to need offender programmes and that the effectiveness of these may be enhanced by some specific cognitive remediation before progressing to more complex social tasks.


Assuntos
Transtornos Cognitivos/diagnóstico , Transtornos Cognitivos/reabilitação , Criminosos/psicologia , Testes de Inteligência/estatística & dados numéricos , Testes Neuropsicológicos/estatística & dados numéricos , Prisioneiros/psicologia , Adulto , Análise de Variância , Análise por Conglomerados , Transtornos Cognitivos/psicologia , Criminosos/classificação , Criminosos/estatística & dados numéricos , Finlândia , Humanos , Masculino , Pessoa de Meia-Idade , Desempenho Psicomotor , Adulto Jovem
9.
Laterality ; 18(1): 44-67, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23231544

RESUMO

Age-related changes in visual spatial biases in children, young adults, and older adults were studied with unilateral and bilateral stimulus conditions in fast-paced linguistic and non-linguistic attention tasks. Only rightward spatial biases were observed. The incidence of the biases changed as a function of age: in childhood and in old age the rightward spatial biases were more common than in young adulthood. The present rightward spatial biases were similar to those observed in the corresponding auditory spatial linguistic and non-linguistic attention tests (Takio, Koivisto, Laukka, & Hämäläinen, 2011) and in the dichotic listening forced-attention task (Takio et al., 2009). We suggest that the multimodal rightward spatial bias observed under intensive attentional load is related to a right hemispace preference and modulated by age-dependent changes in executive functions.


Assuntos
Envelhecimento/fisiologia , Atenção/fisiologia , Reconhecimento Visual de Modelos/fisiologia , Percepção Espacial/fisiologia , Campos Visuais/fisiologia , Adulto , Idoso , Análise de Variância , Criança , Pré-Escolar , Discriminação Psicológica/fisiologia , Fixação Ocular/fisiologia , Humanos , Pessoa de Meia-Idade , Estimulação Luminosa , Tempo de Reação/fisiologia , Percepção Visual/fisiologia
10.
Appl Neuropsychol Adult ; : 1-8, 2023 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-36688868

RESUMO

Cognitive-linguistic functions are an essential part of adequate communication competence. Cognitive-linguistic deficits are common after traumatic diffuse axonal injury (DAI). We aimed to examine the integrity of perisylvian white matter tracts known to be associated with linguistic functions in individuals with DAI and their eventual association with poor cognitive-linguistic outcomes. Diffusion tensor imaging (DTI) results of 44 adults with moderate-to-severe DAI were compared with those of 67 controls. Fractional anisotropy (FA) values of the superior longitudinal fasciculus (SLF), arcuate fasciculus (AF), SLF with frontal connections to the lower parietal cortex, and AF with temporal connections to the lower parietal cortex were measured using tractography. The associations between white matter integrity FA values and cognitive-linguistic deficits were studied in the DAI group. Cognitive-linguistic deficits were determined based on our earlier study using the novel KAT test. No previous studies have examined the associations between white matter integrity and cognitive-linguistic deficits determined using the KAT test. Patients with DAI showed lower FA values in all left-side tracts than the controls. Unexpectedly, the poor cognitive-linguistic outcome in the language comprehension and production domains was associated with high FA values of several tracts. After excluding five cases with the poorest cognitive-linguistic performance, but with the highest values in the DTI variables, no significant associations with DTI metrics were found. The association between white matter integrity and cognitive-linguistic functioning is complex in patients with DAI of traumatic origin, probably reflecting the heterogeneity of TBI.

11.
Sci Rep ; 13(1): 3642, 2023 03 04.
Artigo em Inglês | MEDLINE | ID: mdl-36871020

RESUMO

Using stable carbon and nitrogen isotope analysis (δ13C and δ15N) to assess trophic interactions in freshwater ecosystems is a well established method, providing insight into ecosystem functioning. However, the spatial and temporal variability of isotope values, driven by environmental fluctuation is poorly understood and can complicate interpretations. We investigated how the temporal variation of stable isotopes in consumers (fish, crayfish and macrozoobenthos) of a canyon-shaped oligotrophic reservoir is associated with environmental factors such as water temperature, transparency, flooded area, and water quality measures. Consumers and their putative food sources were sampled and analyzed for carbon and nitrogen stable isotopes annually, and environmental parameters were measured monthly from 2014 to 2016. Results revealed significant differences in δ13C and δ15N values in each consumer among studied years. Over the years, fish and crayfish expressed differences in δ13C between 3 and 5‰, whereas in zoobenthos differences were 12‰. Variability in δ15N was similar across all consumers (2-4‰). Moreover, results suggest that the flooded area of the reservoir was a major driver of δ13C stable isotope values variation in consumers, while variation in δ15N was not linked to any of the studied environmental factors. Bayesian mixing models further showed significant changes in the origin of detritivorous zoobenthos carbon sources (reversal shift from terrestrial detritus to algae origin) between years with low water level to years with the standard water level. Other species showed only slight differences in food source utilization among years. Our study highlights the importance of environmental factors as sources of variation in consumer's stable isotope values which should be considered especially when studied ecosystem strongly fluctuate in some environmental factor.


Assuntos
Astacoidea , Ecossistema , Animais , Teorema de Bayes , Carbono , Isótopos de Nitrogênio , Alimentos Marinhos
12.
Bioelectromagnetics ; 33(3): 247-56, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21932437

RESUMO

The present study investigated the effects of 902.4 MHz global system for mobile communications (GSM) mobile phone radiation on cerebral blood flow using positron emission tomography (PET) with the (15) O-water tracer. Fifteen young, healthy, right-handed male subjects were exposed to phone radiation from three different locations (left ear, right ear, forehead) and to sham exposure to test for possible exposure effects on brain regions close to the exposure source. Whole-brain [¹5O]H2O-PET images were acquired 12 times, 3 for each condition, in a counterbalanced order. Subjects were exposed for 5 min in each scan while performing a simple visual vigilance task. Temperature was also measured in the head region (forehead, eyes, cheeks, ear canals) during exposure. The exposure induced a slight temperature rise in the ear canals but did not affect brain hemodynamics and task performance. The results provided no evidence for acute effects of short-term mobile phone radiation on cerebral blood flow.


Assuntos
Telefone Celular , Circulação Cerebrovascular/efeitos da radiação , Adulto , Atenção/efeitos da radiação , Humanos , Masculino , Radioisótopos de Oxigênio , Tomografia por Emissão de Pósitrons
13.
Sci Total Environ ; 838(Pt 1): 155982, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35588838

RESUMO

Environmental change, including joint effects of increasing dissolved organic carbon (DOC) and total phosphorus (TP) in boreal northern lakes may affect food web energy sources and the biochemical composition of organisms. These environmental stressors are enhanced by anthropogenic land-use and can decrease the quality of polyunsaturated fatty acids (PUFAs) in seston and zooplankton, and therefore, possibly cascading up to fish. In contrast, the content of mercury in fish increases with lake browning potentially amplified by intensive forestry practises. However, there is little evidence on how these environmental stressors simultaneously impact beneficial omega-3 fatty acid (n3-FA) and total mercury (THg) content of fish muscle for human consumption. A space-for-time substitution study was conducted to assess whether environmental stressors affect Eurasian perch (Perca fluviatilis) allochthony and muscle nutritional quality [PUFA, THg, and their derivative, the hazard quotient (HQ)]. Perch samples were collected from 31 Finnish lakes along pronounced lake size (0.03-107.5 km2), DOC (5.0-24.3 mg L-1), TP (5-118 µg L-1) and land-use gradients (forest: 50.7-96.4%, agriculture: 0-32.6%). These environmental gradients were combined using principal component analysis (PCA). Allochthony for individual perch was modelled using source and consumer δ2H values. Perch allochthony increased with decreasing lake pH and increasing forest coverage (PC1), but no correlation between lake DOC and perch allochthony was found. Perch muscle THg and omega-6 fatty acid (n6-FA) content increased with PC1 parallel with allochthony. Perch muscle DHA (22:6n3) content decreased, and ALA (18:3n3) increased towards shallower murkier lakes (PC2). Perch allochthony was positively correlated with muscle THg and n6-FA content, but did not correlate with n3-FA content. Hence, the quality of perch muscle for human consumption decreases (increase in HQ) with increasing forest coverage and decreasing pH, potentially mediated by increasing fish allochthony.


Assuntos
Mercúrio , Percas , Animais , Ácidos Graxos , Ácidos Graxos Insaturados/análise , Lagos , Mercúrio/análise , Músculos/química , Percas/fisiologia , Fósforo
14.
Environ Toxicol Chem ; 41(1): 108-121, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34826348

RESUMO

Gypsum (CaSO4 ∙2H2 O) amendment is a promising way of decreasing the phosphorus loading of arable lands, and thus preventing aquatic eutrophication. However, in freshwaters with low sulfate concentrations, gypsum-released sulfate may pose a threat to the biota. To assess such risks, we performed a series of sulfate toxicity tests in the laboratory and conducted field surveys. These field surveys were associated with a large-scale pilot exercise involving spreading gypsum on agricultural fields covering 18% of the Savijoki River (Finland) catchment area. The gypsum amendment in such fields resulted in approximately a four-fold increase in the mean sulfate concentration for a 2-month period, and a transient, early peak reaching approximately 220 mg/L. The sulfate concentration gradually decreased almost to the pregypsum level after 3 years. Laboratory experiments with Unio crassus mussels and gypsum-spiked river water showed significant effects on foot movement activity, which was more intense with the highest sulfate concentration (1100 mg/L) than with the control. Survival of the glochidia after 24 and 48 h of exposure was not significantly affected by sulfate concentrations up to 1000 mg/L, nor was the length growth of the moss Fontinalis antipyretica affected. The field studies on benthic algal biomass accrual, mussel and fish density, and Salmo trutta embryo survival did not show gypsum amendment effects. Gypsum treatment did not raise the sulfate concentrations even to a level just close to critical for the biota studied. However, because the effects of sulfate are dependent on both the spatial and the temporal contexts, we advocate water quality and biota monitoring with proper temporal and spatial control in rivers within gypsum treatment areas. Environ Toxicol Chem 2022;41:108-121. © 2021 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC.


Assuntos
Bivalves , Poluentes Químicos da Água , Animais , Biota , Sulfato de Cálcio/toxicidade , Medição de Risco , Rios , Sulfatos , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
15.
Bioelectromagnetics ; 32(4): 253-72, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21452356

RESUMO

For the last two decades, a large number of studies have investigated the effects of mobile phone radiation on the human brain and cognition using behavioral or neurophysiological measurements. This review evaluated previous findings with respect to study design and data analysis. Provocation studies found no evidence of subjective symptoms attributed to mobile phone radiation, suggesting psychological reasons for inducing such symptoms in hypersensitive people. Behavioral studies previously reported improved cognitive performance under exposure, but it was likely to have occurred by chance due to multiple comparisons. Recent behavioral studies and replication studies with more conservative statistics found no significant effects compared with original studies. Neurophysiological studies found no significant effects on cochlear and brainstem auditory processing, but only inconsistent results on spontaneous and evoked brain electrical activity. The inconsistent findings suggest possible false positives due to multiple comparisons and thus replication is needed. Other approaches such as brain hemodynamic response measurements are promising but the findings are few and not yet conclusive. Rigorous study design and data analysis considering multiple comparisons and effect size are required to reduce controversy in this important field of research.


Assuntos
Comportamento/efeitos da radiação , Telefone Celular , Campos Eletromagnéticos/efeitos adversos , Fenômenos Fisiológicos do Sistema Nervoso/efeitos da radiação , Animais , Comportamento/fisiologia , Volume Sanguíneo/efeitos da radiação , Circulação Cerebrovascular/efeitos da radiação , Humanos
16.
Duodecim ; 127(17): 1788-96, 2011.
Artigo em Finlandês | MEDLINE | ID: mdl-21995116

RESUMO

The mobile phones radiate electromagnetic energy which is partly absorbed into the tissues in the vicinity of the phone. The minor heating, in maximum up to 0.3 degrees C, may cause some alterations in the expression of genes and proteins similar to physiological response to other stimuli. Biophysical studies at the cellular and molecular level have not revealed any well established interaction mechanism, through which mobile phone radiation could induce toxic effects below the thermal effect level. Research results on various biological effects in vitro and in vivo are continuously published but there is no consistent evidence on well established harmful effects. The mobile phone radiation is not carcinogenic for experimental animals or genotoxic for cells. According to epidemiological studies and psychophysiological brain function studies the use of mobile phones does not seem to increase the risk of tumors in the head and brain or disturb the function of central nervous system. However, there is a need for more research on the long-term effects of mobile phone radiation particularly on children.


Assuntos
Telefone Celular , Encéfalo/efeitos da radiação , Expressão Gênica/efeitos da radiação , Nível de Saúde , Humanos , Radiação , Medição de Risco
17.
Bioelectromagnetics ; 31(1): 48-55, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19610044

RESUMO

The present study investigated the possible effects of the electromagnetic field (EMF) emitted by an ordinary GSM mobile phone (902.4 MHz pulsed at 217 Hz) on brainstem auditory processing. Auditory brainstem responses (ABR) were recorded in 17 healthy young adults, without a mobile phone at baseline, and then with a mobile phone on the ear under EMF-off and EMF-on conditions. The amplitudes, latencies, and interwave intervals of the main ABR components (waves I, III, V) were compared among the three conditions. ABR waveforms showed no significant differences due to exposure, suggesting that short-term exposure to mobile phone EMF did not affect the transmission of sensory stimuli from the cochlea up to the midbrain along the auditory nerve and brainstem auditory pathways.


Assuntos
Percepção Auditiva/fisiologia , Tronco Encefálico/fisiologia , Telefone Celular , Campos Eletromagnéticos , Potenciais Evocados Auditivos do Tronco Encefálico/fisiologia , Adulto , Simulação por Computador , Feminino , Humanos , Masculino , Modelos Biológicos , Caracteres Sexuais , Fatores de Tempo
18.
Bioelectromagnetics ; 31(3): 191-9, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19771547

RESUMO

We investigated the effect of mobile phone use on the auditory sensory memory in children. Auditory event-related potentials (ERPs), P1, N2, mismatch negativity (MMN), and P3a, were recorded from 17 children, aged 11-12 years, in the recently developed multi-feature paradigm. This paradigm allows one to determine the neural change-detection profile consisting of several different types of acoustic changes. During the recording, an ordinary GSM (Global System for Mobile Communications) mobile phone emitting 902 MHz (pulsed at 217 Hz) electromagnetic field (EMF) was placed on the ear, over the left or right temporal area (SAR(1g) = 1.14 W/kg, SAR(10g) = 0.82 W/kg, peak value = 1.21 W/kg). The EMF was either on or off in a single-blind manner. We found that a short exposure (two 6 min blocks for each side) to mobile phone EMF has no statistically significant effects on the neural change-detection profile measured with the MMN. Furthermore, the multi-feature paradigm was shown to be well suited for studies of perception accuracy and sensory memory in children. However, it should be noted that the present study only had sufficient statistical power to detect a large effect size.


Assuntos
Percepção Auditiva/efeitos da radiação , Encéfalo/efeitos da radiação , Telefone Celular , Campos Eletromagnéticos , Estimulação Acústica , Percepção Auditiva/fisiologia , Encéfalo/fisiologia , Criança , Orelha , Eletroencefalografia , Potenciais Evocados Auditivos , Feminino , Lateralidade Funcional , Humanos , Masculino , Memória/fisiologia , Memória/efeitos da radiação , Testes Neuropsicológicos , Método Simples-Cego , Osso Temporal , Fatores de Tempo
19.
Sci Total Environ ; 726: 138396, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32481219

RESUMO

Uncertainty in the information obtained through monitoring complicates decision making about aquatic ecosystems management actions. We suggest the value of information (VOI) to assess the profitability of paying for additional monitoring information, when taking into account the costs and benefits of monitoring and management actions, as well as associated uncertainty. Estimating the monetary value of the ecosystem needed for deriving VOI is challenging. Therefore, instead of considering a single value, we evaluate the sensitivity of VOI to varying monetary value. We also extend the VOI analysis to the more realistic context where additional information does not result in perfect, but rather in imperfect information on the true state of the environment. Therefore, we analytically derive the value of perfect information in the case of two alternative decisions and two states of uncertainty. Second, we describe a Monte Carlo type of approach to evaluate the value of imperfect information about a continuous classification variable. Third, we determine confidence intervals for the VOI with a percentile bootstrap method. Results for our case study on 144 Finnish lakes suggest that generally, the value of monitoring exceeds the cost. It is particularly profitable to monitor lakes that meet the quality standards a priori, to ascertain that expensive and unnecessary management can be avoided. The VOI analysis provides a novel tool for lake and other environmental managers to estimate the value of additional monitoring data for a particular, single case, e.g. a lake, when an additional benefit is attainable through remedial management actions.

20.
Bioelectromagnetics ; 30(3): 241-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19140136

RESUMO

Previous studies on the effects of the mobile phone electromagnetic field (EMF) on various event-related potential (ERP) components have yielded inconsistent and even contradictory results, and often failed in replication. The mismatch negativity (MMN) is an auditory ERP component elicited by infrequent (deviant) stimuli differing in some physical features from the repetitive frequent (standard) stimuli in a sound sequence. The MMN provides a sensitive measure for cortical auditory stimulus feature discrimination, regardless of attention and other contaminating factors. In this study, MMN responses to duration, intensity, frequency, and gap changes were recorded in healthy young adults (n = 17), using a multifeature paradigm including several types of auditory change in the same stimulus sequence, while a GSM mobile phone was placed on either ear with the EMF (902 MHz pulsed at 217 Hz; SAR(1g) = 1.14 W/kg, SAR(10g) = 0.82 W/kg, peak value = 1.21 W/kg, measured with an SAM phantom) on or off. An MMN was elicited by all deviant types, while its amplitude and latency showed no significant differences due to EMF exposure for any deviant types. In the present study, we found no conclusive evidence that acute exposure to GSM mobile phone EMF affects cortical auditory change detection processing reflected by the MMN.


Assuntos
Percepção Auditiva/fisiologia , Telefone Celular , Campos Eletromagnéticos/efeitos adversos , Potenciais Evocados Auditivos , Estimulação Acústica , Eletroencefalografia , Feminino , Humanos , Masculino , Adulto Jovem
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