No increased sensitivity in brain activity of adolescents exposed to mobile phone-like emissions

OBJECTIVE: To examine the potential sensitivity of adolescents to radiofrequency electromagnetic field (RF EMF) exposures, such as those emitted by mobile phones. METHODS: In a double-blind, randomized, crossover design, 22 adolescents aged 11-13 years (12 males) underwent three experimental sessions in which they were exposed to mobile phone-like RF EMF signals at two different intensities, and a sham session. During exposure cognitive tasks were performed and waking EEG was recorded at three time-points subsequent to exposure (0, 30 and 60 min). RESULTS: No clear significant effects of RF EMF exposure were found on the waking EEG or cognitive performance. CONCLUSIONS: Overall, the current study was unable to demonstrate exposure-related effects previously observed on the waking EEG in adults, and also provides further support for a lack of an influence of mobile phone-like exposure on cognitive performance. SIGNIFICANCE: Adolescents do not appear to be more sensitive than adults to mobile phone RF EMF emissions

RESPOSTA DA SERINGUEIRA CLONE RRIM 600 À ADUBAÇÃO NPK EM SOLO PODZÓLICO VERMELHO-AMARELO RESPONSES OF RUBBER TREE CLONE RRIM 600 TO NPK FERTILIZATION ON RED YELLOW PODZOLIC SOIL

O presente estudo, que teve por objetivo determinar respostas da seringueira [Hevea brasiliensis (Willd. ex. Adr. de Juss.) Muell. Arg.] à adubação NPK durante o período de formação do seringal, relata os resultados de experimento com o clone RRIM 600 em solo podzólico vermelho-amarelo de textura arenosa, no município de Avaí (SP), Brasil. O delineamento foi de blocos ao acaso em esquema fatorial fracionado 1/2 (4 x 4 x 4), com doses anuais de 0, 40, 80 e 120 kg.ha-1 de N, P2O5 e K2O, aplicados no período entre dois e oito anos de idade das plantas. Avaliou-se o perímetro do caule a 1,20 m acima do calo de enxertia, a cada quatro meses, e calculou-se a porcentagem de plantas aptas para sangria e o tempo de imaturidade do seringal em cada parcela. Efetuaram-se análises de solo aos 27 e 51 meses de idade das plantas e análises de folhas, anualmente, no verão. A partir de 60 meses de idade das plantas, aproximadamente três anos após o início das adubações, observou-se efeito linear da adubação nitrogenada sobre o perímetro do caule. A adubação fosfatada teve efeito linear a partir da idade de 72 meses e a interação NP linear foi consistente depois de 75 meses. Usando como indicador a porcentagem de plantas aptas à sangria, houve efeito linear significativo para as adubações nitrogenada e potássica. O período de imaturidade foi abreviado até em oito meses, comparando-se o tratamento sem adubação com os de melhor desempenho. Adubações desequilibradas, como no tratamento 0-80-120, provocaram retardamento até de 12 meses no período de imaturidade em relação ao tratamento de melhor desempenho (120-120-120). Um ano depois da interrupção da aplicação de fertilizantes, no fim do experimento, não se observou efeito residual dos tratamentos sobre os indicadores de crescimento utilizados.<br>The response of rubber tree [Hevea brasiliensis (Willd. ex. Adr. de Juss.) Muell.Arg.], clone RRIM 600 to NPK fertilization during the immature stage was evaluated on a sand soil at Avaí, State of São Paulo, Brazil. Randomized block, closing with fractionated factorial experiment 1/2(4 x 4 x 4) was used to test 0, 40, 80 and 120 kg.ha-1 of N, P2O5 and K2O, applied from the second to the eighth years after planting. Trunk girth at 1.20 m above the budgrafting union was measured every four months. The percentage of plants able for tapping and the immaturity period were calculated from girth measurements. Soil analysis were performed at 27 and 51 months after planting and leaf analysis every year. Responses to nitrogen fertilization started to be observed from 60 months, aproximately three years after the beginning of fertilizer applications. Linear effect of phosphorus and NP interaction started at ages of 72 and 75 months respectively. Responses to K fertilization was not detected for trunk girth. Considering the percentage of plants able for tapping, responses were linearly and statistically significant for N and K fertilization. The immaturity period of the crop was reduced eigth months when non fertilized plots were compared to those with the best relations of NPK. Delay of immaturity period up to twelve months was observed considering the best treatments and those with unbalanced relations of NPK. Fertilizer responses disappeared one year after stopping fertilizer applications