Impaired postural compensation for respiration in people with recurrent low back pain

This study evaluated the degree to which the disturbance to posture from respiration is compensated for in healthy normals and whether this is different in people with recurrent low back pain (LBP), and to compare the changes when respiratory demand is increased. Angular displacement of the lumbar spine and hips, and motion of the centre of pressure (COP), were recorded with high resolution and respiratory phase was recorded from ribcage motion. With subjects standing in a relaxed posture, recordings were made during quiet breathing, while breathing with increased dead-space to induce hypercapnoea, and while subjects voluntarily increased their respiration to match ribcage expansion that was induced in the hypercapnoea condition. The relationship between respiration and the movement parameters was measured from the coherence between breathing and COP and angular motion at the frequency of respiration, and from averages triggered from the respiratory data. Small angular changes in the lumbopelvic and hip angles were evident at the frequency of respiration in both groups. However, in quiet standing, the LBP subjects had a greater displacement of their COP that was associated with respiration than the control subjects. The LBP group had a trend for less hip motion. There were no changes in the movement parameters when respiratory demand increased involuntarily via hypercapnoea, but when respiration increased voluntarily, the amplitude of motion and the displacement of the COP increased in both groups. The present data suggest that the postural compensation to respiration counteracts at least part of the disturbance to posture caused by respiration and that this compensation may be less effective in people with LBP.

Epitope map for a growth hormone receptor agonist monoclonal antibody, MAb 263

Monoclonal antibody (MAb) 263 is a widely used monoclonal antibody that recognizes the extracellular domain (ECD) of the GH receptor. It has been shown to act as a GH agonist both in vitro and in vivo, and we report here that it must be divalent to exert its effect on the full-length receptor. To understand the mechanism of its agonist action, we have determined the precise epitope for this antibody using a novel random PCR mutagenesis approach together with expression screening in yeast. A library of 5200 clones of rabbit GH receptor ECD mutants were screened both with MAb 263 and with an anticarboxy-tag antibody to verify complete ECD expression. Sequencing for clones that expressed complete ECD but were not MAb 263 positive identified 20 epitope residues distributed in a discontinuous manner throughout the ECD. The major part of the epitope, as revealed after mapping onto the crystal structure model of the ECD molecule, was located on the side and upper portion of domain 1, particularly within the D - E strand disulfide loop 79 - 96. Molecular dynamics docking of an antibody of the same isotype as MAb 263 was used to dock the bivalent antibody to the 1528-Angstrom(2) epitope and to visualize the likely consequences of MAb binding. The minimized model enables the antibody to grasp two receptors in a pincer-like movement from opposite sides, facilitating alignment of the receptor dimerization domains in a manner similar to, but not identical with, GH.

Identification and characterization of the hepatic stellate cell transferrin receptor

Activated hepatic stellate cells have been implicated in the fibrogenic process associated with iron overload, both in animal models and in human hemochromatosis. Previous studies have evaluated the role of ferritin/ferritin receptor interactions in the activation of stellate cells and subsequent fibrogenesis; however, the role of transferrin in hepatic stellate cell biology is unknown. This study was designed to identify and characterize the stellate cell transferrin receptor and to evaluate the influence of transferrin on stellate cell activation. Identification and characterization of the stellate cell transferrin receptor was determined by competitive displacement assays. The effect of transferrin on stellate cell activation was assessed using western blot analysis for alpha-smooth muscle actin expression, [H-3]Thymidine incorporation, and real-time RT-PCR for procollagen 1(I) mRNA expression. A specific receptor for rat transferrin was observed on activated but not quiescent stellate cells. Transferrin significantly increased the expression of alpha-smooth muscle actin, but caused a decrease in proliferation. Transferrin induced a significant increase in procollagen alpha1(I) mRNA expression. In conclusion, this study has demonstrated for the first time a specific, high affinity receptor for rat transferrin on activated hepatic stellate cells, which via interaction with transferrin regulates stellate cell activation. This suggests that transferrin may be an important factor in the activation of hepatic stellate cells in conditions of iron overload.

Usefulness of quantitative echocardiographic techniques to predict recovery of regional and global left ventricular function after acute myocardial infarction

The left ventricular response to dobutamine may be quantified using tissue Doppler measurement of myocardial velocity or displacement or 3-dimensional echocardiography to measure ventricular volume and ejection fraction. This study sought to explore the accuracy of these methods for predicting segmental and global responses to therapy. Standard dobutamine and 3-dimensional echocardiography were performed in 92 consecutive patients with abnormal left ventricular function at rest. Recovery of function was defined by comparison with follow-up echocardiography at rest 5 months later. Segments that showed improved regional function at follow-up showed a higher increment in peak tissue Doppler velocity with dobutamine therapy than in nonviable segments (1.2 +/- 0.4 vs 0.3 +/- 0.2 cm/s, p = 0.001). Similarly, patients who showed a > 5% improvement of ejection fraction at follow-up showed a greater displacement response to dobutamine (6.9 +/- 3.2 vs 2.1 +/- 2.3 mm, p = 0.001), as well as a higher rate of ejection fraction, response to dobutamine (9 +/- 3% vs 2 +/- 2%, p = 0.001). The optimal cutoff values for predicting subsequent recovery of function at rest were an increment of peak velocity > 1 cm/s, >5 mm of displacement, and a >5% improvement of ejection fraction with low-dose dobutamine. (C) 2003 by Excerpta Medica, Inc.

Solution structure of CnErg1 (Ergtoxin), a HERG specific scorpion toxin

The three-dimensional structure of chemically synthesized CnErg1 (Ergtoxin), which specifically blocks HERG (human ether-a-go-go-related gene) K+ channels, was determined by nuclear magnetic resonance spectroscopy. CnErg1 consists of a triple-stranded beta-sheet and an a-helix, as is typical of K+ channel scorpion toxins. The peptide structure differs from the canonical structures in that the first beta-strand is shorter and is nearer to the second beta-strand rather than to the third beta-strand on the C-terminus. There is also a large hydrophobic patch on the surface of the toxin, surrounding a central lysine residue, Lys13. We postulate that this hydrophobic patch is likely to form part of the binding surface of the toxin. (C) 2003 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.

Effect of lifter design on drying performance in rotary dryers

Lifter use in dryers improves mass transfer by increasing the amount of surface area available for transfer and also by increasing the velocity of gas over the particle surface. An even cross-sectional distribution of particles in a dryer improves the efficiency of operation by ensuring that evaporation from falling particles is taking place for the maximum fraction of the rotation period of the drier. Studies on lifter design to improve the cross-sectional particle distribution were performed on angled lifters. A single lifter was used and the mass-transfer rate examined as a function of angular lifter displacement. Analysis of the mass transfer characteristics of single lifters allowed performance comparisons and recommendations for lifter design.

Cytotoxic iron chelators: Characterization of the structure, solution chemistry and redox activity of ligands and iron complexes of the di-2-pyridyl ketone isonicotinoyl hydrazone (HPKIH) analogues

Di-2-pyridyl ketone isonicotinoyl hydrazone (HPKIH) and a range of its analogues comprise a series of monobasic acids that are capable of binding iron (Fe) as tridentate (N,N,O) ligands. Recently, we have shown that these chelators are highly cytotoxic, but show selective activity against cancer cells. Particularly interesting was the fact that cytotoxicity of the HPKIH analogues is maintained even after complexation with Fe. To understand the potent anti-tumor activity of these compounds, we have fully characterized their chemical properties. This included examination of the solution chemistry and X-ray crystal structures of both the ligands and Fe complexes from this class and the ability of these complexes to mediate redox reactions. Potentiometric titrations demonstrated that all chelators are present predominantly in their charge-neutral form at physiological pH (7.4), allowing access across biological membranes. Keto-enol tautomerism of the ligands was identified, with the tautomers exhibiting distinctly different protonation constants. Interestingly, the chelators form low-spin (diamagnetic) divalent Fe complexes in solution. The chelators form distorted octahedral complexes with Fe-II, with two tridentate ligands arranged in a meridional fashion. Electrochemistry of the Fe complexes in both aqueous and non-aqueous solutions revealed that the complexes are oxidized to their ferric form at relatively high potentials, but this oxidation is coupled to a rapid reaction with water to form a hydrated (carbinolamine) derivative, leading to irreversible electrochemistry. The Fe complexes of the HPKIH analogues caused marked DNA degradation in the presence of hydrogen peroxide. This observation confirms that Fe complexes from the HPKIH series mediate Fenton chemistry and do not repel DNA. Collectively, studies on the solution chemistry and structure of these HPKIH analogues indicate that they can bind cellular Fe and enhance its redox activity, resulting in oxidative damage to vital biomolecules.

Simultaneous observations of ionospheric quasiperiodic scintillations from short and long meridional baselines using VHF transmissions from transit satellites

For the first time it was possible to observe regular quasiperiodic scintillations (QPS) in VHF radio-satellite transmissions from orbiting satellites simultaneously at short (2.1 km) and long (121 km) meridional baselines in the vicinity of a typical mid-latitude station (Brisbane; 27.5degreesS and 152.9degreesE geog. and 35.6degrees invar.lat.), using three sites (St. Lucia-S, Taringa-T in Brisbane and Boreen Pt.-B, north of Brisbane). A few pronounced quasiperiodic (QP) events were recorded showing unambiguous regular structures at the sites which made it possible to deduce a time displacement of the regular fading minimum at S, T and B. The QP structure is highly dependent on the geometry of the ray-path from a satellite to the observer which is manifested as a change of a QP event from symmetrical to non-symmetrical for stations separated by 2.1 km, and to a radical change in the structure of the event over a distance of 121 km. It is suggested the short-duration intense QP events are due to a Fresnel diffraction (or a reflection mechanism) of radio-satellite signals by a single ionospheric irregularity in a form of an ellipsoid with a large ionization gradient along the major axis. The structure of a QP event depends on the angle of viewing of the irregular blob from a radio-satellite. In view of this it is suggested that the reported variety of the ionization formation, responsible for different types of QPS, is only apparent but not real. (C) 2003 Elsevier Science Ltd. All rights reserved.

Tailoring teleportation to the quantum alphabet

We introduce a refinement of the standard continuous variable teleportation measurement and displacement strategies. This refinement makes use of prior knowledge about the target state and the partial information carried by the classical channel when entanglement is nonmaximal. This gives an improvement in the output quality of the protocol. The strategies we introduce could be used in current continuous variable teleportation experiments.

Analysis of multicomponent adsorption kinetics on activated carbon

An integrated mathematical model for the kinetics of multicomponent adsorption on microporous carbon was developed. Transport in this bidisperse solid is represented by balance equations in the macropore and micropore phases, in which gas-phase diffusion dominates the mass transfer in the macropores, with the phenomenological diffusivities represented by the generalized Maxwell-Stefan (GMS) formulation. Viscous flow also contributes to the macropore fluxes and is included in the MS expressions. Diffusion of the adsorbed phase controls the mass transfer in the micro ore phase, p which is also described in a similar way by the MS method. The adsorption isotherms are represented by a new heterogeneous modified vacancy solution theory formulation of adsorption, which has proved to be a robust method for adsorption on activated carbons. The model is applied to the coadsorption and codesorption of C2H6 and C3H8 on Ajax and Norit carbon, as well as the displacement on Ajax carbon. The effect of the viscous flow in the macropore phase is not significant for the cases studied. The model accurately predicts the overshoot behavior and rollup of C2H6 during coadsorption. The prediction for the heavier compound C3H8 is always satisfactory, though at higher C3H8 mole fraction, the overshoot extent of C2H6 is overpredicted, possibly due to neglect of heat effects.

Synthesis of novel 2-amino-1,3-thiazole-5-carboxylates utilising ultrasonic and thermally mediated aminolysis

Novel 2-amino-1,3-thiazole-5-carboxylates have been synthesised in high yield by unprecedented ultrasonic and thermally mediated nucleophilic displacement of bromide from ethyl 2-bromo-1,3-thiazole-5-carboxylate by primary, secondary and aryl amines.

Elites estatais e reforma do estado na nova rep??blica: o projeto Enap e a forma????o da carreira de gestor governamental no Brasil

Os objetos desta pesquisa s??o: 1) a atua????o das elites burocr??ticas do Poder Executivo Federal no processo de transi????o pol??tica no Brasil, nos anos 1980; 2) as frentes de reforma na Nova Rep??blica, nas ??reas social, econ??mica e administrativa e 3) as tentativas de renova????o da gest??o p??blica representadas pela cria????o da Escola Nacional de Administra????o P??blica (ENAP) e da Carreira de Gestor Governamental (EPPGG). Esse era um contexto de reinstitucionaliza????o da fun????o diretiva do Estado e de deslocamento das fronteiras entre o burocr??tico e o pol??tico no setor p??blico brasileiro. A hip??tese central aqui defendida ?? de que a ENAP e a Carreira de Gestor Governamental eram duas op????es inovadoras frente ao dilema sobre quais seriam os pap??is cab??veis a pol??ticos e administradores na nova ordem democr??tica, mas tamb??m eram op????es sem enraizamento nos pactos e agendas de prioridades que viabilizaram a mudan??a de regime no pa??s. A Escola e a Carreira estavam em disson??ncia com as principais tend??ncias de recomposi????o das elites estatais na transi????o a partir do regime militar e sofreram bloqueios em raz??o disso, mas a pesquisa procurou desconstruir algumas narrativas sobre esses conflitos interburocr??ticos, que associam as resist??ncias impostas ?? ENAP e ?? Carreira pelos grupos de funcion??rios da Fazenda e Planejamento a interesses meramente corporativistas. Com um trajeto pelos estudos sobre as burocracias dos regimes militares e sobre as transi????es no Brasil e na Am??rica Latina, buscou-se aqui uma melhor identifica????o dos grupos integrantes das ???tecnoburocracias??? e de suas contribui????es para a moderniza????o administrativa e econ??mica do pa??s, na segunda metade do s??culo XX. Buscou-se revelar algumas conflu??ncias entre as ideias de tecnocratiza????o e profissionaliza????o das altas fun????es p??blicas e seus elos com as aspira????es pela reconstru????o do Estado sob bases mais democr??ticas, mostrando que, nos anos 1980, as propostas da SEDAP n??o eram os ??nicos projetos de moderniza????o em curso, tampouco os grupos que a elas se opuseram representavam interesses univocamente antidemocr??ticos.

Tramas e urdiduras: o protagonismo como exercício na atividade docente de professores de educação física

Trata-se de uma pesquisa-intervenção com o objetivo principal de analisar como os professores fazem exercício protagonista na atividade. Embasa-se principalmente no aporte conceitual da perspectiva ergológica de Yves Schwartz para realizar a análise da atividade no cotidiano escolar. O estudo foi desenvolvido em uma Escola Municipal de Ensino Fundamental de Serra/ES com duas professoras e um professor de Educação Física. As estratégias metodológicas utilizadas foram constituídas de acompanhamento da atividade desenvolvida pelos professores nas aulas, no Curso de Formação Permanente de Área de Educação Física, promovido pela Secretaria Municipal de Educação, participação no cotidiano escolar e a construção coletiva de um processo de formação na escola por meio de oficinas de práticas corporais. As técnicas de produção e registro dos dados foram compostas por diário de campo, fotos, conversas gravadas em áudio, entrevistas, questionário e documentos elaborados pela escola, como o Projeto Político-Pedagógico. A confrontação dos dados realizada com os docentes nas conversas produziu importantes deslocamentos nas análises e convocou autores e conceitos que não estavam previstos para o debate sobre o exercício protagonista. A produção dos dados gerou mudança na atividade docente e colocou em questão modos de gestão e organização do trabalho na Rede Serra de Educação, provocando transformações nos modelos de formação permanente dos professores de Educação Física do município. Os exercícios protagonistas empreendidos na atividade docente colocaram competências em circulação e tornaram visíveis os efeitos de trama e urdidura que atravessam e compõem a atividade docente dos professores de Educação Física no cotidiano escolar.

Reflexões sobre a apropriação de objetos na arte contemporânea

Nesta dissertação discutimos os movimentos em torno da temática da apropriação evidenciando o deslocamento do objeto de uso comum para o campo da arte em três movimentos paradigmáticos: o Dadaísmo, o Surrealismo e o Novo Realismo, e seus desdobramentos na arte contemporânea no sentido de legado cultural. Permitimo-nos transitar pelas demais vertentes dos processos de apropriação na arte nova-iorquina e europeia seguindo as propostas da arte com objetos. Investigamos os processos envolvidos nas controvérsias do ready-made, executado por Marcel Duchamp desde 1913, para dar partida ao percurso histórico das manifestações onde ocorre o objet trouvé, a colagem e a assemblagem. Nosso objetivo é responder à pergunta com a qual o filósofo Arthur C. Danto inicia suas investigações filosóficas acerca das apropriações e condições que fazem de um objeto comum uma obra de arte. Para tanto buscamos as teorias de Abrahan Moles e Jean Baudrillard acerca do objeto industrializado e Roland Barthes com as questões metalingüísticas de sua função-signo. Para discutir tais relações da arte com os objetos, recorremos aos textos de Peter Bürger, André Breton, Pierre Restany, Gregory Battcock, Walter Benjamin, Hal Foster e outros. Destacamos alguns trabalhos artísticos, evidenciando o objeto caixa, tratado como um utilitário com forma e finalidade definidas, reafirmando-se como objeto de consumo, no discurso sobre a poética do espaço de Gaston Bachelard. A pesquisa propõe analisar as transformações radicais das estruturas conservadoras da arte e especular sobre o gesto de apropriação dos objetos, com algumas reflexões direcionadas sobre o objeto e a transgressividade da apropriação como experiência de tensão e poder.

Implementação de formulações do método dos elementos de contorno para associação de placas no espaço

Tese (doutorado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2016.