946 resultados para (geodetic) thickness or volume changes
Resumo:
Stellate ganglion (SG) represents the main sympathetic input to the heart. This study aimed at investigating physical exercise-related changes in the quantitative aspects of SG neurons in treadmill-exercised Wistar rats. By applying state-of-the-art design-based stereology, the SG volume, total number of SG neurons, mean perikaryal volume of SG neurons, and the total volume of neurons in the whole SG have been examined. Arterial pressure and heart rate were also measured at the end of the exercise period. The present study showed that a low-intensity exercise training program caused a 12% decrease in the heart rate of trained rats. In contrast, there were no effects on systolic pressure, diastolic pressure, or mean arterial pressure. As to quantitative changes related to physical exercise, the main findings were a 21% increase in the fractional volume occupied by neurons in the SG, and an 83% increase in the mean perikaryal volume of SG neurons in treadmill-trained rats, which shows a remarkable neuron hypertrophy. It seems reasonable to infer that neuron hypertrophy may have been the result of a functional overload imposed on the SG neurons by initial posttraining sympathetic activation. From the novel stereological data we provide, further investigations are needed to shed light on the mechanistic aspect of neuron hypertrophy: what role does neuron hypertrophy play? Could neuron hypertrophy be assigned to the functional overload induced by physical exercise? (C) 2008 Wiley-Liss, Inc.
Resumo:
There are limited data concerning blood gas parameters in neonatal dogs. Knowledge of the normal physiology may facilitate effective therapeutic intervention and potentially reduce neonatal mortality. This study examined acid-base parameters in pups born at normal parturition (n = 27) compared with those born after obstetrical assistance or caesarean operation (n = 13) and those born following oxytocin (OXY) administration for treatment of uterine inertia (n = 11). Pups were subjected to an objective scoring method of neonatal health adapted from use in humans (the Apgar score) at birth and again at 5 and 60 min after birth. Venous blood samples were collected at 5 and 60 min after birth for evaluation of blood gas parameters. At birth, all pups had low Apgar scores and a mixed acidosis. The base excess was lowest for pups delivered after OXY administration. The Apgar score improved for all pups after 5 min of birth and there was an improvement in carbon dioxide tension, base excess and venous blood pH at 1 h, although in all pups a metabolic acidosis persisted. These data provide an important insight into neonatal physiology and the variability of blood gas parameters in pups born at normal and abnormal parturition and provide the basis for clinical decision making following dystocia.
Resumo:
This investigation evaluated the effects of oral beta -Hydroxy-beta -Methylbutyrate (HMB) supplementation on training responses in resistance-trained male athletes who were randomly administered HMB in standard encapsulation (SH), HMB in time release capsule (TRH), or placebo (P) in a double-blind fashion. Subjects ingested 3 g (.) day(-1) of HMB; or placebo for 6 weeks. Tests were conducted pre-supplementation and following 3 and 6 weeks of supplementation. The testing battery assessed body mass, body composition (using dual energy x-ray absorptiometry), and 3-repetition maximum isoinertial strength, plus biochemical parameters, including markers of muscle damage and muscle protein turnover. While the training and dietary intervention of the investigation resulted in significant strength gains (p < .001) and an increase in total lean mass (p =.01), HMB administration had no influence on these variables. Likewise, biochemical markers of muscle protein turnover and muscle damage were also unaffected by HMB supplementation. The data indicate that 6 weeks of HMB supplementation in either SH or TRH form does not influence changes in strength and body composition in response to resistance training in strength-trained athletes.
Resumo:
A semi-analytical analysis of free vibration of plates with cross-sectional discontinuities due to abrupt changes in thickness is presented. A basic square element divided into suitable subdomains dependent upon the positions of these abrupt changes is used as the basic building element, Admissible functions that satisfy the essential or geometric boundary conditions are used to define the transverse deflection of each subdomain. Continuities in the displacement, slope, moment and higher derivatives between adjacent subdomains are enforced at the interconnecting edges. The resulting global energy functional from the proper assembly of the coupled strain and kinetic energy contributions of each subdomain is then minimized via the Ritz procedure to extract the frequencies and mode shapes. Contour plots of a range of new mode shapes are presented for the enhancement of understanding the dynamic behavior of this class of plates, (C) 2001 Elsevier Science Ltd, All rights reserved.
Resumo:
Composite resin is a widely-used direct tooth coloured restorative material. Photoactivation of the polymerisation reaction can be achieved by visible blue light from a range of light sources, including halogen lamps, metal halide lamps, plasma arc lamps, and Light Emitting Diode (LED) lights. Concerns have been raised that curing lights may induce a temperature rise that could be detrimental to the vitality of the dental pulp during the act of photoactivation. The present study examined heat changes associated with standardised class V restorations on the buccal surface of extracted premolar teeth, using a curing time of 40 seconds. The independent effects of type of light source, resin shade and remaining tooth thickness were assessed using a matrix experimental design. When a conventional halogen lamp, a metal halide lamp and two different LED lights were compared, it was found that both LED lamps elicited minimal thermal changes at the level of the dental pulp, whereas the halogen lamp induced greater changes and the metal halide lamp caused the greatest thermal insult of all the light sources. These thermal changes were influenced by resin shade, with different patterns for LED versus halogen or halide sources. Thermal stress reduced as the remaining thickness of tooth structure between the pulp and the cavity floor increased. From these results, it is concluded that LED lights produce the least thermal insult during photopolymerisation of composite resins.
Resumo:
Posteroanterior stiffness of the lumbar spine is influenced by factors, including trunk muscle activity and intra-abdominal pressure (IAP). Because these factors vary with breathing, this study investigated whether stiffness is modulated in a cyclical manner with respiration. A further aim was to investigate the relationship between stiffness and IAP or abdominal and paraspinal muscle activity. Stiffness was measured from force-displacement responses of a posteroanterior force applied over the spinous process of L-2 and L-4. Recordings were made of IAP and electromyographic activity from L-4/L-2 erector spinae, abdominal muscles, and chest wall. Stiffness was measured with the lung volume held at the extremes of tidal volume and at greater and lesser volumes. Stiffness at L-4 and L-2 increased above base-level values at functional residual capacity (L-2 14.9 N/mm and L-4 15.3 N/mm) with both inspiratory and expiratory efforts. The increase was related to the respiratory effort and was greatest during maximum expiration (L-2 24.9 N/mm and L-4 23.9 N/mm). The results indicate that changes in trunk muscle activity and IAP with respiratory efforts modulate spinal stiffness. In addition, the diaphragm may augment spinal stiffness via attachment of its crural fibers to the lumbar vertebrae.
Resumo:
In this paper, we revisit the surface mass excess in adsorption studies and investigate the role of the volume of the adsorbed phase and its density in the analysis of supercritical gas adsorption in non-porous as well as microporous solids. For many supercritical fluids tested (krypton, argon, nitrogen, methane) on many different carbonaceous solids, it is found that the volume of the adsorbed phase is confined mostly to a geometrical volume having a thickness of up to a few molecular diameters. At high pressure the adsorbed phase density is also found to be very close to but never equal or greater than the liquid phase density. (C) 2003 Elsevier Science Ltd. All rights reserved.
Resumo:
Pref??cio da colet??nea, estabelece seu objetivo de fornecer material did??tico focado no desenvolvimento profissional da administra????o p??blica brasileira.
Resumo:
Esta introdu????o, al??m de apresentar e contextualizar cada tem??tica, objetiva ser um texto did??tico b??sico para os cursos da ENAP. Nesse sentido, traz, adicionalmente, uma s??ntese dos temas desenvolvidos nos respectivos textos da colet??nea.
Resumo:
O texto sintetiza os principais fundamentos do m??todo PES. Esse m??todo contrap??e-se ao planejamento tradicional e prop??e uma abordagem tecnopol??tica do planejamento.
Resumo:
O texto traz uma s??ntese do Enfoque do Quadro L??gico e constr??i um exemplo da matriz de planejamento do projeto, que ilustra para o leitor a estrutura do QL
Resumo:
O texto faz uma s??ntese did??tica dos planos de desenvolvimento e de estabiliza????o econ??mica implementados no Brasil, nas ??ltimas seis d??cadas. O relato abrange desde os primeiros exerc??cios de planejamento, no imediato p??s-Segunda Guerra Mundial, at?? os ??ltimos PPAs e, ainda, faz refer??ncias ??s tentativas de planejamento de longo prazo com o ???Brasil 2020???, no governo Fernando Henrique.
Resumo:
O texto apresenta um cen??rio dos avan??os recentes no planejamento governamental. Em sua primeira parte, procura referenciar o debate atual acerca das possibilidades, das limita????es e dos avan??os introduzidos pelo PPA, especialmente a partir de 2000, com destaque para a integra????o ???plano-or??amento???, por meio de programas formulados com origem em problemas ou demandas da sociedade; um plano e um or??amento orientados para resultado; e o novo sistema de planejamento e or??amento como pe??a fundamental para a implanta????o da gest??o por resultados no Pa??s. A segunda parte do texto refere-se ao modelo de gest??o do plano. S??o apresentados os fundamentos do modelo de sua gest??o e os avan??os propostos para o PPA 2004-2007. Em s??ntese, a gest??o do plano ?? fundamentada no princ??pio da responsabiliza????o e nos processos de monitoramento, avalia????o e retroalimenta????o do ciclo do gasto p??blico
Resumo:
O texto incorpora uma diversidade de ferramentas de planejamento estrat??gico. Sua principal caracter??stica ?? a de ver o planejamento estrat??gico como um processo e n??o apenas como um projeto que se finda com a antevis??o de cen??rios prospectivos e suas poss??veis solu????es estrat??gicas.
Resumo:
Estabelece o objetivo da publica????o de se tornar material did??tico para a forma????o de servidores da Administra????o P??blica brasileira