186 research outputs found

    Neuromuscular factors contributing to reductions in muscle force after repeated, high-intensity muscular efforts

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    Multiple neuromuscular processes contribute to the loss of force production following repeated, high-intensity muscular efforts; however, the relative contribution of each process is unclear. In Experiment 1, 16 resistance trained men performed six sets of unilateral isometric plantar flexor contractions of the right leg (3 s contraction/2 s rest; 85% maximal voluntary contraction torque; 90-s inter-set rest) until failure with and without caffeine ingestion (3 mg kg-1) on two separate days. Corticospinal excitability and cortical silent period (cSP) were assessed before and immediately, 10 and 20 min after the exercise. In Experiment 2, electrically evoked tetanic force and persistent inward current (PIC)-mediated facilitation of the motor neuron pool (estimated using neuromuscular electrical stimulation with tendon vibration) were assessed before and after the same exercise intervention in 17 resistance trained men. Results showed decreases in peak plantar flexion torque (Experiment 1: -12.2%, Experiment 2: -16.9%), electrically evoked torque (20 Hz -15.3%, 80 Hz -15.3%, variable-frequency train -17.9%), and cSP (-3.8%; i.e., reduced inhibition) post-exercise which did not recover by 20 min. Electromyographic activity (EMG; -6%), corticospinal excitability (-9%), and PIC facilitation (-24.8%) were also reduced post-exercise but recovered by 10 min. Caffeine ingestion increased torque and EMG but did not notably affect corticospinal excitability, PIC amplification, or electrically evoked torque. The data indicate that a decrease in muscle function largely underpins the loss of force after repeated, high-intensity muscular efforts, but that the loss is exacerbated immediately after the exercise by simultaneous decreases in corticospinal excitability and PIC amplitudes at the motor neurons

    Acute effects of three different stretching protocols on the Wingate test performance

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    The purpose of this study was to examine the acute effects of different stretching exercises on the performance of the traditional Wingate test (WT). Fifteen male participants performed five WT; one for familiarization (FT), and the remaining four after no stretching (NS), static stretching (SS), dynamic stretching (DS), and proprioceptive neuromuscular facilitation (PNF). Stretches were targeted for the hamstrings, quadriceps, and calf muscles. Peak power (PP), mean power (MP), and the time to reach PP (TP) were calculated. The MP was significantly lower when comparing the DS (7.7 ± 0.9 W/kg) to the PNF (7.3 ± 0.9 W/kg) condition (p \u3c 0.05). For PP, significant differences were observed between more comparisons, with PNF stretching providing the lowest result. A consistent increase of TP was observed after all stretching exercises when compared to NS. The results suggest the type of stretching, or no stretching, should be considered by those who seek higher performance and practice sports that use maximal anaerobic power

    Infraestrutura Nacional de Dados Espaciais: Aspectos Computacionais.

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    O objetivo deste documento é apresentar os principais conceitos relacionados aos pilares ?tecnologia? e ?padrões?, com enfoque em seus aspectos computacionais. A intenção é sumarizar os fundamentos teóricos envolvidos na especificação da INDE e reunir as principais referências de softwares open source atualmente disponíveis e amplamente adotados pela comunidade para a implantação da INDE.bitstream/item/84963/1/COMUN-TECNICO-1-GESTAO-TERRITORIAL-Infraestrut-Nac-Dados-Espac-ed01-2013.pd

    Metodologia de monitoramento de cobertura vegetal: estudo de caso no município de Goiânia, GO.

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    Este trabalho apresenta uma proposta para a análise da variação da cobertura vegetal, utilizando dados de acesso público. Os procedimentos de análise multitemporal propostos foram aplicados no município de Goiânia, GO, como estudo de caso. Aplicou-se o índice de vegetação por diferença normalizada (NDVI), obtido a partir de imagens Landsat-5, em três anos de referência: 1997, 2004, 2011. Consideraram-se três classes de cobertura: ?corpos d?água?, ?vegetação? e ?outros usos?. Foram utilizadas técnicas de processamento digital de imagens, visando à correção de erros gerados pela influência da atmosfera e à obtenção de uma melhor qualidade espectral dos alvos. Para esse fim, o modelo adotado foi o dark object subtraction (DOS). O resultado mostrou-se satisfatório, considerando-se a disponibilidade dos dados e suas limitações.bitstream/item/84894/1/0000010346-BPD-Cobert-vegetal.pd

    Relationship between chronic pain, depressive symptoms, and functional disability in community-dwelling older adults:mediating role of frailty

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    BACKGROUND: Borim et al. showed that older adults with chronic pain exhibited more depressive symptoms and frailty components. Depressive symptoms were associated with more frailty components, and those with more depressive symptoms and frailty faced greater limitations in IADL performance. Frailty appears to mediate the pathway from chronic pain to functional impairment Chronic pain is directly associated with depressive symptoms and frailty. Chronic pain is not directly associated with functional disability. Depression and frailty are both directly associated with functional disabilities. Frailty mediates the association between chronic pain and functional disability. Depression; Disability evaluation; Frailty; Frail elderly.OBJECTIVE: To evaluate the direct and indirect effects of chronic pain, depressive symptoms, frailty components, and functional disability through a pathway analysis approach in a sample of community-dwelling older adults.METHODS: Data of 419 participants were cross-sectionally evaluated for the presence of depressive symptoms (Geriatric Depression Scale [15 items]), physical frailty components (phenotype criteria), chronic pain, and limitations in performing instrumental activities of daily living (functional disability scale by Lawton and Brody). Structural equation modeling via path analysis was used to explore the direct and indirect effects among these four variables. Statistical significance was set at p&lt;0.05.RESULTS: Of the total participants, 69.8% were women and 59.3% had low education (1-4 years); the mean age was 80.3±4.6 years. Chronic pain and depressive symptoms were directly related and were associated to frailty. The number of frailty components and depressive symptoms were directly associated with functional disability. Frailty had an indirect effect on the association between chronic pain, depressive symptoms, and functional disabilities.CONCLUSION: The pathway from chronic pain and depressive symptoms to functional disability is potentially mediated by the number of frailty components.</p

    Relationship between chronic pain, depressive symptoms, and functional disability in community-dwelling older adults:mediating role of frailty

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    BACKGROUND: Borim et al. showed that older adults with chronic pain exhibited more depressive symptoms and frailty components. Depressive symptoms were associated with more frailty components, and those with more depressive symptoms and frailty faced greater limitations in IADL performance. Frailty appears to mediate the pathway from chronic pain to functional impairment Chronic pain is directly associated with depressive symptoms and frailty. Chronic pain is not directly associated with functional disability. Depression and frailty are both directly associated with functional disabilities. Frailty mediates the association between chronic pain and functional disability. Depression; Disability evaluation; Frailty; Frail elderly.OBJECTIVE: To evaluate the direct and indirect effects of chronic pain, depressive symptoms, frailty components, and functional disability through a pathway analysis approach in a sample of community-dwelling older adults.METHODS: Data of 419 participants were cross-sectionally evaluated for the presence of depressive symptoms (Geriatric Depression Scale [15 items]), physical frailty components (phenotype criteria), chronic pain, and limitations in performing instrumental activities of daily living (functional disability scale by Lawton and Brody). Structural equation modeling via path analysis was used to explore the direct and indirect effects among these four variables. Statistical significance was set at p&lt;0.05.RESULTS: Of the total participants, 69.8% were women and 59.3% had low education (1-4 years); the mean age was 80.3±4.6 years. Chronic pain and depressive symptoms were directly related and were associated to frailty. The number of frailty components and depressive symptoms were directly associated with functional disability. Frailty had an indirect effect on the association between chronic pain, depressive symptoms, and functional disabilities.CONCLUSION: The pathway from chronic pain and depressive symptoms to functional disability is potentially mediated by the number of frailty components.</p

    The magnitude of syphilis: from prevalence to vertical transmission

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    Introduction: In 2013, the World Health Organization (WHO) reported that 1.9 million pregnant women were infected with syphilis worldwide, of which 66.5% had adverse fetal effects in cases of untreated syphilis. Congenital syphilis contributes significantly to infant mortality, accounting for 305,000 perinatal deaths worldwide annually. Aim: To estimate the prevalence of syphilis in parturients, the incidence of congenital syphilis and the vertical transmission rate. Material and methods: a cross-sectional study with data collected from 2041 parturients who had undergone treatment between 2012 and 2014 in the maternity section of the Pedro Ernesto Hospital of the State University of Rio de Janeiro, in the metropolitan area of Rio de Janeiro. The inclusion criterion was positive VDRL and treponemal test in a hospital environment. Results: the prevalence of syphilis in pregnant women was 4.1% in 2012, 3.1% in 2013 and 5% in 2014, with official reporting of 15.6%, 25.0% and 48.1%, respectively. The incidence of congenital syphilis (CS) was 22/1,000 in live births (LB) in 2012; 17/1,000 LB in 2013 and 44.8/1,000 LB in 2014. CS underreporting during the period was 6.7%. Vertical transmission occurred in 65.8% of infants from infected mothers. It was concluded that, in 34.6% of the CS cases, maternal VDRL titers were = 1/4. Conclusion: Results demonstrate the magnitude of the disease, fragility of the reporting system in the assessment of the actual prevalence, impact on perinatal outcomes, and they are a warning about the real situation of syphilis, which is still underestimated in the State
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