Caffeine increases motor output entropy and performance in 4 km cycling time trial

Caffeine improves cycling time trial performance through enhanced motor output and muscle recruitment. However, it is unknown if caffeine further increases power output entropy. To investigate the effects of caffeine effects on cycling time trial performance and motor output entropy (MOEn), nine cyclists (VO2MAX of 55 ± 6.1 mL.kg.-1min-1) performed a 4 km cycling time trial (TT4km) after caffeine and placebo ingestion in a counterbalanced order. Power output data were sampled at a 2 Hz frequency, thereafter entropy was estimated on a sliding-window fashion to generate a power output time series. A number of mixed models compared performance and motor output entropy between caffeine and placebo every 25% of the total TT4km distance. Caffeine ingestion improved power output by 8% (p = 0.003) and increased MOEn by 7% (p = 0.018). Cyclists adopted a U-shaped pacing strategy after caffeine ingestion. MOEn mirrored power output responses as an inverted U-shape MOEn during the time trial. Accordingly, a strong inverse correlation was observed between MOEn and power output responses over the last 25% of the TT4km (p < 0.001), regardless of the ingestion, likely reflecting the end spurt during this period (p = 0.016). Caffeine ingestion improved TT4km performance and motor output responses likely due to a greater power output entropy.</p

Correction: Caffeine increases motor output entropy and performance in 4 km cycling time trial.

[This corrects the article DOI: 10.1371/journal.pone.0236592.]

Agrupação de casos de câncer em adultos jovens indígenas residindo nas proximidades de linhas de transmissão de alta tensão elétrica em Bom Jesus do Tocantins, Pará, Brasil

Submitted by Fátima Lopes ([email protected]) on 2018-08-20T17:58:34Z No. of bitstreams: 1 CancerClusterIndianAdults.pdf: 195221 bytes, checksum: 84acb32eb95756cb537e34b40b92468c (MD5)Approved for entry into archive by Fátima Lopes ([email protected]) on 2018-08-20T18:33:13Z (GMT) No. of bitstreams: 1 CancerClusterIndianAdults.pdf: 195221 bytes, checksum: 84acb32eb95756cb537e34b40b92468c (MD5)Made available in DSpace on 2018-08-20T18:33:13Z (GMT). No. of bitstreams: 1 CancerClusterIndianAdults.pdf: 195221 bytes, checksum: 84acb32eb95756cb537e34b40b92468c (MD5) Previous issue date: 1998Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, BrasilCentro de Trabalho Indigenista. São Paulo, SP, BrasilEscola Naval. Ilha de Villegaignon, Rio de Janeiro, RJ, Brasil / Centro Federal de Tecnologia. Rio de Janeiro, RJ, BrasilPontifícia Universidade Católica do Rio de Janeiro. Departamento de Química. Rio de Janeiro, RJ, BrasilPontifícia Universidade Católica do Rio de Janeiro. Departamento de Química. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, BrasilUniversidade do Rio de Janeiro. Departamento de Ciências Fisiológicas. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, BrasilFundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, BrasilUniversidade do Estado do Rio de Janeiro. Faculdade de Ciências Médicas. Departamento de Biologia Celular e Genética. Rio de Janeiro, RJ, BrasilEletrobrás. Rio de Janeiro, RJ, BrasilUm estudo de caso foi desenvolvido para avaliar a ocorrência de um agrupamento de casos de câncer em 1992, que se verificou em adultos jovens indígenas vivendo em aldeia na Amazônia, situada nas proximidades de duas linhas de transmissão de 500 kV, as quais começaram a operar em 1982. Determinaram-se os níveis sangüíneos atuais de DDT e pesticidas organofosforados, assim como a presença de metais em amostras de cabelo. A exposição a campos eletromagnéticos de freqüência extremamente baixa foi determinada durante diversas atividades diárias desenvolvidas pelos indígenas. Considerando-se a incidência de câncer em diferentes cidades brasileiras, a probabilidade de ocorrência ao acaso deste agrupamento de casos foi considerada remota (p<0,03, distribuição de Poisson). Níveis elevados de p,p'-DDT (mediana variando entre 26 e 58 ppb) foram observados nas amostras estudadas. A exposição contínua aos campos eletromagnéticos de freqüência extremamente baixa, a qual atingiu 95 mG abaixo das linhas de transmissão, foi observada em diversas oportunidades durante atividades diárias desenvolvidas pelos indígenas. Estudos observacionais futuros deveriam analisar a interação da exposição aos campos eletromagnéticos de freqüência extremamente baixa (50-60 Hz) subseqüente à exposição a agentes de iniciação tumoral no desenvolvimento de neoplasias.A case study was carried out to explore the occurrence of a cancer cluster in 1992 among young indian adults living in an Amazonian village near two 500 kV power transmission lines that began operating a decade ago. Current blood levels of DDT and organophosphorus pesticides and metal levels in hair samples were measured. Extremely low magnetic field exposure was determined during current daily activities carried out by the Indian villagers. Taking into account the cancer incidence rates in different Brazilian cities, the probability of the occurrence of this cluster by chance was considered remote (p< 0.003, Poisson distribution). High blood levels of p,p'-DDT (median levels ranging from 26 to 58 ppb) were observed. As a whole, this community showed a pattern of low exposure to organophosphorus pesticides, and high recent exposure was only observed in a few blood samples. Continuous exposure to extremely low electromagnetic fields originated in the power transmission lines (which reached 95.0 mG under the lines) was observed on several opportunities during daily activities carried out by Indian villagers. Further observational studies should evaluate the interaction between exposure to extremely low electromagnetic fields and prior exposure to tumor initiators in cancer development

Cancer cluster among young Indian adults living near power transmission lines in Bom Jesus do Tocantins, Pará, Brazil

A case study was carried out to explore the occurrence of a cancer cluster in 1992 among young indian adults living in an Amazonian village near two 500 kV power transmission lines that began operating a decade ago. Current blood levels of DDT and organophosphorus pesticides and metal levels in hair samples were measured. Extremely low magnetic field exposure was determined during current daily activities carried out by the Indian villagers. Taking into account the cancer incidence rates in different Brazilian cities, the probability of the occurrence of this cluster by chance was considered remote (p< 0.003, Poisson distribution). High blood levels of p,p'-DDT (median levels ranging from 26 to 58 ppb) were observed. As a whole, this community showed a pattern of low exposure to organophosphorus pesticides, and high recent exposure was only observed in a few blood samples. Continuous exposure to extremely low electromagnetic fields originated in the power transmission lines (which reached 95.0 mG under the lines) was observed on several opportunities during daily activities carried out by Indian villagers. Further observational studies should evaluate the interaction between exposure to extremely low electromagnetic fields and prior exposure to tumor initiators in cancer development

Cancer cluster among young Indian adults living near power transmission lines in Bom Jesus do Tocantins, Pará, Brazil

A case study was carried out to explore the occurrence of a cancer cluster in 1992 among young indian adults living in an Amazonian village near two 500 kV power transmission lines that began operating a decade ago. Current blood levels of DDT and organophosphorus pesticides and metal levels in hair samples were measured. Extremely low magnetic field exposure was determined during current daily activities carried out by the Indian villagers. Taking into account the cancer incidence rates in different Brazilian cities, the probability of the occurrence of this cluster by chance was considered remote (p< 0.003, Poisson distribution). High blood levels of p,p'-DDT (median levels ranging from 26 to 58 ppb) were observed. As a whole, this community showed a pattern of low exposure to organophosphorus pesticides, and high recent exposure was only observed in a few blood samples. Continuous exposure to extremely low electromagnetic fields originated in the power transmission lines (which reached 95.0 mG under the lines) was observed on several opportunities during daily activities carried out by Indian villagers. Further observational studies should evaluate the interaction between exposure to extremely low electromagnetic fields and prior exposure to tumor initiators in cancer development