Quadriceps concentric and eccentric exercise 1: Changes in contractile and electrical activity following eccentric and concentric exercise

The purpose of this study was to determine whether or not losses of strength or endurance following eccentric and concentric exercise are associated with reduced excitation. The effects of eccentric and concentric work on maximal voluntary isometric contraction (MVC) and surface electromyogram (EMG) of the quadriceps were studied in 10 healthy male subjects following bench-stepping for 20 min with a constant leading leg. Prior to stepping and at 0, 0.25, 0.50, 0.75, 1, 3. 24 and 48 h afterwards the subjects performed a 30 s leg extension MVC with each leg during which the isometric force and the root mean square voltage of the EMG were recorded. In the eccentrically exercised muscles (ECC), MVC0-3 (force during the first 3 s of contraction) fen immediately after the bench-stepping exercise to 88 +/- 2% (mean SE) of the pre-exercise value and remained significantly lower than the concentrically exercised muscles (p < 0.05). The muscle weakness in the ECC could not be attributed to central fatigue as surface EMG amplitude at MVC0-3 increased during the recovery period. Muscle weakness after eccentric exercise appears to be due to contractile failure, which is not associated with a reduction in excitation as assessed by surface EMG. Muscular fatigue over 30 s did not change in the two muscle groups after exercise (p = 0.79), indicating that the ECC were weaker but not more fatiguable after exercise.

A curious experiment: the paradigm switch from observation and speculation to experimentation, in the understanding of neuromuscular function and disease

The four-link chain of the motor unit represents the contemporary end-point of some two millennia of evolving knowledge in neuroscience. The paradigm shift in neuromuscular epistemology occurred in the mid-17th century. In 1666, the newly graduated Dutch doctor, Jan Swammerdam (1637-1680) published his former investigations of dissected nerve-muscle preparations. These experiments comprised the quantum leap from observation and speculation, to that of experimentation in the field of neuroanatomy and neurophysiology. In what he termed 'A Curious Experiment' he also described the phenomenon of intrinsic muscle excitability - I cannot observe that the muscle in the living animal ever absolutely ceases from all motion. Eighty years later (1752), von Haller demonstrated experimentally that irritability (contractility) was an intrinsic property of all muscular tissue; and distinguished between the sensibility of nerve impulses and the irritability of muscular contraction. This experimental progression from Swammerdam to von Haller culminated in 1850, when Claude Bernard's studies in experimental pharmacology confirmed that muscle was a functional unit, independent of any electrical innervation via its supplying nerve. This account comprises an audit of Swammerdam's work in the perspective of neuromuscular knowledge. (C) 2002 Elsevier Science B.V. All rights reserved.

Effects of vitamin E deficiency on fatigue and muscle contractile properties

Radical-mediated oxidative damage of skeletal muscle membranes has been implicated in the fatigue process. Vitamin E (VE) is a major chain breaking antioxidant that has been shown to reduce contraction-mediated oxidative damage. We hypothesized that VE deficiency would adversely affect Muscle contractile function, resulting in a more rapid development of muscular fatigue during exercise. To test this postulate, rats were fed either a VE-deficient (EDEF) diet or a control (CON) diet containing VE. Following a 12-week feeding period, animals were anesthetized and mechanically ventilated. Muscle endurance (fatigue) and contractile properties were evaluated using an in situ preparation of the tibialis anterior (TA) muscle. Contractile properties of the TA muscle were determined before and after a fatigue protocol. The muscle fatigue protocol consisted of 60 min of repetitive contractions (250 ms trains at 15 Hz; duty cycle = I I %) of the TA muscle. Prior to the fatigue protocol, no significant differences existed in the force-frequency curves between EDEF and CON animals. At the completion of the fatigue protocol, muscular force production was significantly (P

Investigation of hip abductor activation in subject with clinical unilateral hip osteoarthritis

Objectives: (a) To compare the magnitude of gluteus medius and tensor fascia lata activation between a group of subjects with clinical unilateral hip osteoarthritis and a group of healthy older adults. (b) To compare the magnitude of activation of the gluteus medius and tensor fascia lata between sides in a group of subjects with clinical unilateral hip osteoarthritis and a group of healthy older adults. Methods: 19 subjects with clinical unilateral hip osteoarthritis and 19 healthy controls were investigated. The subjects performed a stepping task during which recordings were obtained using surface electromyograms from the hip abductors, and kinetic data were obtained from a dual force platform. Results: Subjects with clinical hip osteoarthritis had higher gluteus medius activation than the healthy older adults (p=0.037). In addition, there were no differences in the magnitude of gluteus medius activation between the sides (p=0.733). There was no difference in the force platform data between the groups (p=0.078). Conclusions: The increased magnitude of gluteus medius activation in the group with hip osteoarthritis is evidence of a muscular dysfunction associated with hip disease. This has implications for the progressive nature of the disease and for its conservative management.

Caveolae — from ultrastructure to molecular mechanisms

Almost 50 years after the first sighting of small pits that covered the surface of mammalian cells, investigators are now getting to grips with the detailed workings of these enigmatic structures that we now know as caveolae.

The embryonic development of the bodywall and nervous system of the cestode flatworm Hymenolepis diminuta

Cestodes (tapeworms) are a derived, parasitic clade of the phylum Platyhelminthes (flatworms). The cestode body wall represents an adaptation to its endoparasitic lifestyle. The epidermis forms a nonciliated syncytium, and both muscular and nervous system are reduced. Morphological differences between cestodes and free-living flatworms become apparent already during early embryogenesis. Cestodes have a complex life cycle that begins with an infectious larva, called the oncosphere. In regard to cell number, cestode oncospheres are among the simplest multicellular organisms, containing in the order of 50-100 cells. As part of our continuing effort to analyze embryonic development in flatworms, we describe here the staining pattern obtained with acTub in embryos and larvae of the cestode Hymenolepis diminuta and, briefly, the monogenean Neoheterocotyle rhinobatidis. In addition, we labeled the embryonic musculature of Hymenolepis with phalloidin. In Hymenolepis embryos, two different cell types that we interpret as neurons and epidermal gland cells express acTub. There exist only two neurons that develop close to the midline at the anterior pole of the embryo. The axons of these two neurons project posteriorly into the center of the oncosphere, where they innervate the complex of muscles that is attached to the booklets. In addition to neurons, acTub labels a small and invariant set of epidermal gland cells that develop at superficial positions, anteriorly adjacent to the neurons, in the dorsal midline, and around the posteriorly located hooklets. During late stages of embryogenesis they spread and form a complete covering of the embryo. We discuss these data in the broader context of platyhelminth embryology.

Interaction of directional, neuromuscular and egocentric constraints on the stability of preferred bimanual coordination patterns

We investigated how the relative direction of limb movements in external space (iso- and non-isodirectionality), muscular constraints (the relative timing of homologous muscle activation) and the egocentric frame of reference (moving simultaneously toward/away the longitudinal axis of the body) contribute to the stability of coordinated movements. In the first experiment, we attempted to determine the respective stability of isodirectional and non-isodirectional movements in between-persons coordination. In a second experiment, we determined the effect of the relative direction in external space, and of muscular constraints, on pattern stability during a within-person bimanual coordination task. In the third experiment we dissociated the effects on pattern stability of the muscular constraints, relative direction and egocentric frame of reference. The results showed that (1) simultaneous activation of homologous muscles resulted in more stable performance than simultaneous activation of non-homologous muscles during within-subject coordination, and that (2) isodirectional movements were more stable than non-isodirectional movements during between-persons coordination, confirming the role of the relative direction of the moving limbs in the stability of bimanual coordination. Moreover, the egocentric constraint was to some extent found distinguishable from the effect of the relative direction of the moving limbs in external space, and from the effect of the relative timing of muscle activation. In summary, the present study showed that relative direction of the moving limbs in external space and muscular constraints may interact either to stabilize or destabilize coordination patterns. (C) 2003 Published by Elsevier B.V.

Applied physiology and game analysis of rugby union

Increased professionalism in rugby has elicited rapid changes in the fitness profile of elite players. Recent research, focusing on the physiological and anthropometrical characteristics of rugby players, and the demands of competition are reviewed. The paucity of research on contemporary elite rugby players is highlighted, along with the need for standardised testing protocols. Recent data reinforce the pronounced differences in the anthropometric and physical characteristics of the forwards and backs. Forwards are typically heavier, taller, and have a greater proportion of body fat than backs. These characteristics are changing, with forwards developing greater total mass and higher muscularity. The forwards demonstrate superior absolute aerobic and anaerobic power, and Muscular strength. Results favour the backs when body mass is taken into account. The scaling of results to body mass can be problematic and future investigations should present results using power function ratios. Recommended tests for elite players include body mass and skinfolds, vertical jump, speed, and the multi-stage shuttle run. Repeat sprint testing is a possible avenue for more specific evaluation of players. During competition, high-intensity efforts are often followed by periods of incomplete recovery. The total work over the duration of a game is lower in the backs compared with the forwards; forwards spend greater time in physical contact with the opposition while the backs spend more time in free running, allowing them to cover greater distances. The intense efforts undertaken by rugby players place considerable stress on anaerobic energy sources, while the aerobic system provides energy during repeated efforts and for recovery. Training should focus on repeated brief high-intensity efforts with short rest intervals to condition players to the demands of the game. Training for the forwards should emphasise the higher work rates of the game, while extended rest periods can be provided to the backs. Players should not only be prepared for the demands of competition, but also the stress of travel and extreme environmental conditions. The greater professionalism of rugby union has increased scientific research in the sport; however, there is scope for significant refinement of investigations on the physiological demands of the game, and sports-specific testing procedures.

Effect of fatigue on torque output and electromyographic measures of trunk muscles during isometric axial rotation

Objectives: To examine the changes in torque output resulting from fatigue, as well as changes in electromyographic measures of trunk muscles during isometric axial rotation and to compare these changes between directions of axial rotation. Design: Subjects performed fatiguing right and left isometric axial rotation of the trunk at 80% of maximum voluntary contraction while standing upright. Setting: A rehabilitation center. Participants: Twenty-three men with no history of back pain. Interventions: Not applicable. Main Outcome Measures: Surface electromyographic Signals were recorded from 6 trunk muscles bilaterally. The primary torque in the transverse plane and the coupling torques in sagittal and coronal planes were also measured. Results: During the fatiguing axial rotation contraction, coupling torques of both sagittal and coronal planes were slightly decreased and no difference was found between directions of axial rotation. Decreasing median frequency and an increase in electromyographic amplitude were also found in trunk muscles with different degrees of changes in individual muscles. There were significant differences (P

Pacto nacional pelo enfrentamento da viol??ncia contra as mulheres

O Pacto Nacional pelo Enfrentamento da Viol??ncia contra as Mulheres visa descentralizar a????es por meio de acordo federativo entre o governo federal e os governos dos estados e dos munic??pios brasileiros. Participam do pacto a Secretaria Especial de Pol??ticas para as Mulheres da Presid??ncia da Rep??blica (SPM/PR), organiza????es da sociedade civil, e outros parceiros do governo federal. Com o objetivo principal de reduzir os ??ndices de viol??ncia contra as mulheres, o pacto ?? composto por quatro grandes eixos: Implementa????o da Lei Maria da Penha e Fortalecimento dos Servi??os Especializados de Atendimento; Prote????o dos Direitos Sexuais e Reprodutivos e Enfrentamento da Feminiza????o da Aids; Combate ?? Explora????o Sexual de Meninas e Adolescentes e ao Tr??fico de Mulheres; e Promo????o dos Direitos Humanos das Mulheres em Situa????o de Pris??o. Desde 2008, os seguintes estados j?? aderiram ao Pacto: Acre, Bahia, Cear??, Esp??rito Santo, Goi??s, Mato Grosso, Mato Grosso do Sul, Minas Gerais, Par??, Pernambuco, Rio de Janeiro, S??o Paulo, Tocantins, Alagoas, Amap??, Para??ba e Sergipe

Nossa V??rzea: cidadania e sustentabilidade na Amaz??nia brasileira

Em um novo modelo de gest??o compartilhada da Secretaria do Patrim??nio da Uni??o, a iniciativa faz parte do projeto Nossa V??rzea ??? regulariza????o fundi??ria em ??reas de v??rzeas ??? e est?? sendo desenvolvida pela SPU, por meio da Ger??ncia da Secretaria do Patrim??nio da Uni??o do Estado do Par?? (GRPU/PA). Tem como objetivo promover a regulariza????o fundi??ria de ocupa????es em terras p??blicas utilizando o Termo de Autoriza????o de Uso ??? instrumento legal inovador, que constitui o fundamento expressivo da a????o. Ao entregar o Termo ??s fam??lias de comunidades ribeirinhas, a Uni??o reconhece o direito ?? ocupa????o e possibilita a explora????o sustent??vel das ??reas de v??rzeas. Al??m disso, o instrumento representa para a fam??lia beneficiada um comprovante oficial de resid??ncia e uma garantia de acesso a aposentadoria, a recursos do Programa Nacional de Fortalecimento da Agricultura Familiar (Pronaf) e a outros programas sociais do Governo Federal. Desde a implanta????o do Programa, j?? foram beneficiadas cerca de 6.000 fam??lias ribeirinhas, principalmente as que residem no arquip??lago do Maraj??

Processos de qualifica????o do Cadastro ??nico de pol??ticas sociais do Governo Federal

Durante os anos de 2005 e 2006, a Secretaria Nacional de Renda de Cidadania (Senarc/MDS), por interm??dio do Departamento do Cadastro ??nico, conduziu uma s??rie de a????es com o objetivo de aprimorar os procedimentos envolvidos na gest??o do Cadastro ??nico (Cad??nico), contribuindo para a melhoria da fidedignidade e da qualidade dos dados cadastrais e, por conseguinte, dos mecanismos de sele????o e acompanhamento dos programas que utilizam o Cad??nico como base de identifica????o e sele????o de seu p??blico-alvo, em especial, do Programa Bolsa Fam??lia. Este trabalho apresenta as a????es conduzidas para a melhoria e o fortalecimento da gest??o do Cadastro ??nico entre janeiro de 2005 e outubro de 2006, bem como o impacto dessas a????es para a gest??o dos programas usu??rios do Cad??nico. Al??m das a????es diretas relativas ?? gest??o do Cad??nico, s??o tamb??m descritas outras a????es da Senarc que, embora n??o coordenadas pelo Departamento de Cadastro ??nico, influenciaram diretamente as a????es realizadas por esse Departamento

A????es premiadas no 3?? Concurso de Experi??ncias Inovadoras de Gest??o da Administra????o P??blica Federal

Apresenta????o resumida dos 50 projetos vencedores do 3?? Concurso de Experi??ncias Inovadoras de Gest??o na Administra????o P??blica Federal, realizado conjuntamente pelo MARE e ENAP em 1998

Programa Permanente de Qualifica????o em Atendimento e Vendas (PPQAV)

A CAIXA ?? o principal agente do Governo Federal para a operacionaliza????o dos programas sociais e o repasse de recursos a eles. ?? tamb??m uma institui????o financeira que busca a rentabilidade nas suas opera????es. Nesse contexto, o seu p??blico ?? todo cidad??o brasileiro que procura a CAIXA, com as mais diversas expectativas, desde o recebimento de benef??cios sociais, o financiamento de um im??vel at?? a realiza????o de investimentos. Com servi??os e produtos diferenciados, a CAIXA carece de atendimento que considere e realize as diversas necessidades. O Programa Permanente de Qualifica????o em Atendimento e Vendas (PPQAV) comp??e-se de conjunto de a????es integradas e orientadas para consolidar o atendimento como estrat??gia priorit??ria na empresa. Seu objetivo ?? estabelecer padr??es de atendimento por meio da qualifica????o das equipes. Visa tamb??m ao atendimento qualificado, ?? identidade de atendimento CAIXA e ao fortalecimento da rela????o com o cliente

O caso da arte gr??fica Waj??pi e o embate contra a explora????o comercial inadequada: limites e potencialidades das pol??ticas p??blicas de prote????o ao patrim??nio imaterial

O presente estudo tem por finalidade discutir os limites e potencialidades dos instrumentos de pol??ticas p??blicas de prote????o ao patrim??nio imaterial, ?? luz das experi??ncias constitu??das em um caso concreto, qual seja, o registro da arte Kusiwa. Em 2003, a arte Kusiwa dos Waj??pi, no Amap?? recebeu o reconhecimento como Obra-Prima do Patrim??nio Oral e Imaterial da Humanidade, conferido pela UNESCO, um ano ap??s ter sido inscrita no Livro das Formas de Express??o e ter sido registrada pelo IPHAN. Entretanto, apesar dessas a????es de salvaguarda, esse patrim??nio imaterial vem sendo reiteradamente violado por meio do abuso comercial do uso n??o autorizado dos grafismos. O fato de as formas de produ????o e circula????o de conhecimento entre os coletivos ind??genas envolverem rela????es espec??ficas, que n??o se limitam ??s propostas atualmente dispon??veis na legisla????o sobre propriedade intelectual, confere um aspecto desafiador sobre a tem??tica. A partir do recorrente ass??dio da comercializa????o do Kusiwa, come??ou a haver um aprendizado institucional por parte do IPHAN e de diversos outros atores, principalmente quanto aos questionamentos envolvendo o alcance jur??dico de prote????o do patrim??nio dos bens registrados. Por tudo isso, o registro da arte Kusiwa foi o resultado de um processo mais amplo de conquistas de direitos e constru????o de cidadania, e gerou efeitos importantes n??o apenas para assegurar a transmiss??o intergeracional do conjunto de conhecimentos da cultura Waj??pi, mas, principalmente, porque a salvaguarda desse patrim??nio configurou-se como instrumento estrat??gico para o fortalecimento de a????es e lutas sociais que buscam assegurar a garantia de direitos culturais e at?? mesmo de direitos humanos de maneira ampla