Reprodutibilidade e validade da eletromiografia de superfície como um método para identificação dos limiares de transição fisiológica no ciclismo

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Desportos, Programa de Pós-graduação em Educação Física, Florianópolis, 2013O objetivo deste estudo foi investigar a reprodutibilidade e a validade da eletromiografia de superfície (EMG) como um método de identificação dos limiares fisiológicos. A validade foi investigada por meio da comparação com a resposta do lactato sanguíneo (LL1 e LL2) e parâmetros ventilatórios (LV1 e LV2) em protocolos incrementais do tipo degrau e rampa, respectivamente. Dezoito ciclistas bem treinados (25 ± 8 anos, 70,6 ± 7,7 kg, 177,2 ± 4,7 cm) realizaram uma série de testes incrementais em ordem aleatória: 1) dois testes incrementais degrau (30 W a cada 3 min) para identificar a potência máxima (Pmax), o consumo máximo de oxigênio (VO2max), a frequência cardíaca máxima (FCmax) e as intensidades referentes aos LL e LEMG; 2) dois testes incrementais rampa (2 W a cada 1 s) para identificar a Pmax, VO2max, a FCmax e as intensidades referentes aos LV e LEMG. O LEMG foi identificado por inspeção visual e modelos matemáticos. Foi utilizada estatística descritiva (média ± dp). Para verificar a normalidade dos dados, utilizou-se o teste de Shapiro-Wilk. O teste t de student para amostras pareadas, o índice de correlação intra-classe (ICC), o erro típico de medida (ETM) e o coeficiente de variação do ETM (ETMCV) foram utilizados para análise de reprodutibilidade. Para a validade, utilizou-se a análise de variância ?one-way? para dados repetidos (ANOVA), a correlação de Pearson (Matrix) e a análise de concordância de Bland e Altman. O nível de significância foi pThe aim of this study was to investigate the reliability and validity of the electromyography (EMG) as a method to identify the physiological thresholds (PT). The validity was using the blood lactate response (LT1 and LT2) and ventilatory parameters (LV1 and LV2) during incremental step and ramp protocols, respectively. Eighteen well-trained cyclists (25 ± 8 years, 70.6 ± 7.7 kg, 177.2 ± 4.7 cm) were voluntered for this study. Cyclists performed in a random order a serie of incremental exercise tests to analyze reliability and validity of LEMG: 1) two incremental step tests (30W every 3 min) to identify maximum power output (Pmax), maximal oxygen uptake (VO2max), maximum heart rate (HRmax) and intensities at LL and LEMG; 2) two incremental ramp test (1W every 2s) to identify Pmax, VO2max, HRmax and intensities at VL and LEMG. The LEMG was determined by visual inspection and mathematical models. Descriptive statistics was used as mean ± SD. Shapiro-Wilk test was used to verify the normality of the data. Student´s t test for paired samples, intraclass correlation coefficients (ICC), typical error of measurement (ETM) and coefficient of variation (ETMCV) were calculated to determine the test-retest reliability. Anova one way with repeated measures to compare the means of the validity. Also, pearson correlation (Matrix) and analysis of concordance was used. The level of significance was p <0.05. The main results were that great part of the variables showed high test-retest reproducibility: the LEMGvisualrampRF (ETMCV = 3.5%; ICC = 0.90); LEMGvisualstepRF (ETMCV = 4.9%; ICC = 0.83); VT2 (ETMCV = 2.6%; ICC = 0.96); and LL23.5 (ETMCV = 2.1%; ICC = 0.96). The LEMGvisualrampRF (323 ± 34 W) showed non-significant difference compared to LV2 (310 ± 42 W), with significant correlations (r = 0.57) in 16 cyclists; however there was high individual variability on the data. The LEMGvisualstepRF (277 ± 30 W) was not significant different compared to LL23.5 (262 ± 31 W), with significant correlations (r = 0.64) in 11 cyclists; also high individual variability was found between the measures. Therefore, the LEMG identified by visual inspection during step and ramp incremental exercise test shows high reliability. The non-siginficant differences on the mean values between the LEMG and both PT showed validity of the data; however, the low concordance between the individual values may limit its use

Preliminary Advice on Fruit Handling, Seed Pretreatment and 'Germination' of Embryos of Prumnopitys andina

Prumnopitys andina is a member of the Podocarpaceae native to Chile and Argentina. It is known to be relatively easy to propagate vegetatively, but germination from seeds is poor and can be spread over at least four years. This paper describes the methods that were used to raise 89 seedlings from 262 seeds (=34%) in less than 1 year. The sequence involves i) completely removing the fleshy sarcotesta; ii) thoroughly washing the seed-coat; iii) `pretreating' the imbibed seeds by incubating them in moist peat and sand at a daily alternating 10/15°C for several months (to allow 'maturation' or `after-ripening' / 'dormancy breakage' at present we do not know which); iv) carefully cracking the seed-coat in a vice and extracting the embryo; v) culturing clean, firm, healthy (=-`viable') embryos on moist filter paper at a daily alternating 20/30°C (with lights during the 30°C phase); [vi) where necessary, freeing the cotyledons of all seedlings that become trapped in the female gametophyte]; vii) transplanting seedlings to conventional nursery practice. A further 1008 seeds are continuing 'pretreatment' to investigate whether this will increase the proportion of seedlings per viable embryo or better still lead to a much less labour intensive seedling emergence from intact seeds

Blood flow restriction exercise of the tibialis anterior in people with stroke : a preliminary study

Background: Blood flow restriction exercise (BFR-E) could be a useful training adjunct for patients with weakness after stroke to augment the effects of exercise on muscle activity. We aimed to examine neurophysiological changes (primary aim) and assess patient perceptions (secondary aim) following BFR-E. Methods: Fourteen participants with stroke performed BFR-E (1 session) and exercise without blood flow restrictsion (Exercise only) (1 session), on two days

Breeding French bulldogs so that they breathe well—A long way to go

Brachycephalic syndrome (BS) is a pathophysiological disorder caused by excessive soft tissue within the upper airways of short-nosed dog breeds, causing obstruction of the nasal, pharyngeal and laryngeal lumen, resulting in severe respiratory distress. As the prevalence of BS appears to be high among some of the affected breeds, there is an urgent need for breeding efforts to improve the health status of those dogs. In the present study, we evaluated correlations between morphometric and other phenotypic characteristics and BS in a population of 69 French bulldogs from Denmark to identify parameters that could serve as a basis for breeding against BS. Furthermore, the genetic variation was monitored to determine whether it would be possible to breed based on these characteristics without simultaneously causing a critical reduction in genetic variation. Six phenotypic characteristics were correlated with the Brachycephalic Syndrome Functional (BSF) score. Among the morphometric risk factors, nostril stenosis (NS) and neck girth (NG) had the highest impact on the BSF score, accounting for 32% and 4% of the variation, respectively. The genetic variation in the population was comparable to other pure breeds, i.e. estimated and observed heterozygosity was 0.60 and the average inbreeding coefficient was 0.01. If only dogs with Grades 1 and 2 NS (no or only mild NS) were selected for breeding the mean BSF score would be reduced significantly. However, it would result in the exclusion of 81% of the population for breeding and this is not prudent. Excluding only dogs with severe stenosis (Grade 4) would exclude 50% of the population without any adverse impact on genetic variation within the population. Although exclusion of dogs with Grade 4 would result in an apparent reduction in the mean BSF score, this reduction is not significant. As NS accounts for 32% of the variation in BSF score, a possible long term strategy to reduce the prevalence of the BS in French bulldogs would seem to be a selection scheme that first excluded dogs with the most severe NS from breeding, gradually moving towards selecting dogs with lower NS grades. According to our findings there is no viable short term solution for reducing the prevalence of BS in the French bulldog population

La agricultura de Costa Rica y el cambio climático: ¿Dónde están las prioridades para la adaptación?

Costa Rica lidera en América Central los esfuerzos de mitigación del cambio climático en el sector ambiental y la agricultura de exportación, el campo de la adaptación está menos desarrollado (MAG y CCAFS, 2013). El país estableció el primer sistema en la región de Pagos por Servicios Ambientales en 1997 y en 2004 aprobó la Ley 8408 que reconoce beneficios ambientales en el sector agropecuario para el fomento de inversiones con efecto ambiental positivo y que contribuyen a la mitigación y adaptación ante el cambio climático de los sistemas de producción. En el 2013 aprobó la Acción de Mitigación Nacionalmente Apropiada (NAMA, por sus siglas en inglés) para el sector cafetalero, como base para reducir las emisiones de gases de efecto invernadero y generar experiencias útiles para otros cultivos y sectores

La agricultura de Guatemala y el cambio climático: ¿Dónde están las prioridades para la adaptación?

Con la Ley Marco para Regular la Reducción de la Vulnerabilidad, la Adaptación Obligatoria ante los efectos del Cambio Climático y la Mitigación de Gases de Efecto Invernadero (LMCC) aprobada en el año 2013, el Gobierno de Guatemala definió un importante instrumento para la participación y el trabajo conjunto del sector gubernamental y púbico para la reducción de la vulnerabilidad al cambio climático, incluyendo la del sector agropecuario. Guatemala cuenta además con una importante experiencia de prevención de riesgos climáticos, como el Sistema Nacional de Información, Monitoreo y Alerta de la Inseguridad Alimentaria y Nutricional, dada la amenaza que representa la alta variabilidad climática (como las sequías y huracanes) al sector agropecuario

La agricultura de Honduras y el cambio climático: ¿Dónde están las prioridades para la adaptación?

Honduras tiene la mayor vulnerabilidad al cambio climático en Centroamérica, pero también cuenta con un marco normativo e institucional favorable para trabajar en su reducción; en particular en el sector agroalimentario, como lo demuestra el contenido del Plan de Nación (2010-2022), la Estrategia Nacional al Cambio Climático (2010) y la Estrategia de Seguridad Alimentaria y Nutricional (2010-2022). Varias iniciativas del gobierno, como el Comité de Seguros Agrícolas o el Proyecto Fondo de Adaptación, apoyan la inclusión de beneficios sociales y económicos a nivel local como parte de la agenda de adaptación, complementándose con los esfuerzos de la sociedad civil y la cooperación técnica