27 resultados para SYNERGY
Resumo:
This study's aim was to identify the effect of oscillation of torques in isometric tasks under identical mechanical conditions on the muscle synergies used. It was hypothesized that bi-functional muscles would play a lesser role in torque oscillation, because they would also generate an undesired oscillation. Thus, changes in muscle synergies were expected as a consequence of oscillation in torque generation. The effect of the trajectory of torque generation was investigated in dual-degrees-of-freedom submaximal isometric oscillation torque tasks at the elbow. The torques were flexion-extension and supination-pronation. Oscillation torques were compared with static torque generations at four torque positions during oscillation. Muscle activity was determined with surface electromyography. Compared with the static torque tasks, the oscillation tasks showed an overall increased muscle activity. The oscillation tasks, however, showed similar activity patterns and muscle synergies compared to the static composite tasks. It was found that the motor system is well able to control different orthogonal combinations of slow torque oscillations and constant torques by employing a single oscillating muscle synergy.
Resumo:
This paper presents empirical evidence suggesting that healthy humans can perform a two degree of freedom visuo-motor pursuit tracking task with the same response time delay as a one degree of freedom task. In contrast, the time delay of the response is influenced markedly by the nature of the motor synergy required to produce it. We suggest a conceptual account of this evidence based on adaptive model theory, which combines theories of intermittency from psychology and adaptive optimal control from engineering. The intermittent response planning stage has a fixed period. It possesses multiple optimal trajectory generators such that multiple degrees of freedom can be planned concurrently, without requiring an increase in the planning period. In tasks which require unfamiliar motor synergies, or are deemed to be incompatible, internal adaptive models representing movement dynamics are inaccurate. This means that the actual response which is produced will deviate from the one which is planned. For a given target-response discrepancy, corrective response trajectories of longer duration are planned, consistent with the principle of speed-accuracy trade-off. Compared to familiar or compatible tasks, this results in a longer response time delay and reduced accuracy. From the standpoint of the intermittency approach, the findings of this study help make possible a more integral and predictive account of purposive action. (c) 2005 Elsevier B.V. All rights reserved.
Resumo:
Translating content from one media platform to another, a process here dubbed content streaming, is the leitmotif of contemporary globalized media. Yet widely divergent interpretations of the phenomenon have emerged. Academic political economy interprets content streaming as powerfully inimical to cultural diversity, media competition and freedom of speech. Mainstream business reporting, working from an opposing media economics schema, pillories ‘synergy’-based content strategies as oversold in theory and unworkable in practice. Challenging this established trend for the disciplines to develop in parallel, the article harnesses mainstream critique of content streaming to political economy’s traditionally circumspect view of corporate media. Examining first the commercial rationales for pursuing content streaming, before turning to the financial and managerial constraints on realizing these goals, the article positions content streaming as less all-pervasive than political economists have feared, but more commercially entrenched than the financial press currently allows.
Resumo:
The direction, complexity and pace of rural change in affluent, western societies can be conceptualized as a multifunctional transition, in which a variable mix of consumption and protection values has emerged, contesting the former dominance of production values, and leading to greater complexity and heterogeneity in rural occupance at all scales. This transition is propelled by three dominant driving forces, namely: agricultural overcapacity; the emergence of market-driven amenity values; and growing societal awareness of sustainability and preservation issues. Australia's generous supply of land and sparse investment in agriculture has facilitated local transitions towards enhanced consumption and protection values, enabling a clearer delineation of emerging differentiated modes of rural occupance than in more contested locales. In Australia seven distinctive modes of occupance can be identified, according to the relative precedence given to production, consumption or protection values. These modes are described as: productivist agricultural; rural amenity; small farm (or pluriactive); peri-metropolitan; marginalized agricultural; conservation; and indigenous. Within these seven modes, alternative trajectories are identified, indicating variability in the intensity and type of resource use. Articulation of the transition concept may provide synergy between discrete discourses in rural research. (c) 2005 Elsevier Ltd. All rights reserved.
Resumo:
Macrophages are major effector cells of the innate immune system, and appropriate regulation of macrophage function requires the integration of multiple signalling inputs derived from the recognition of host factors (e.g. interferon-gamma/IFN gamma) and pathogen products (e.g. toll-like receptor/TLR agonists). The profound effects of IFN gamma pre-treatment (priming) on TLR-induced macrophage activation have long been recognised, but many of the mechanisms underlying the priming phenotype have only recently been identified. This review summarises the known mechanisms of integration between the IFN gamma and TLR signalling pathways. Synergy occurs at multiple levels, ranging from signal recognition to convergence of signals at the promoters of target genes. In particular, the cross-talk between the IFN gamma and LPS and CpG DNA signalling pathways is discussed. (c) 2006 Elsevier GmbH. All rights reserved.
Resumo:
Paracetamol is regarded as a relatively safe drug in the gastro-duodenal region of humans but recent epidemiological investigations have suggested that at high doses there may be an increased risk of ulcers and bleeding. To investigate the possibility that inflammatory conditions and gastric acidity may play a role in potentiating development of gastric mucosal injury from paracetamol in rats (as noted previously with various non-steroidal anti-inflammatory drugs) we studied the gastric irritant effects of paracetamol and some phenolic and non-phenolic analgesics and antipyretics in rats with adjuvant or collagen II induced arthritis or zymosan-induced paw inflammation and given 1.0 ml hydrochloric acid (HCl) 0.1 M and/or an i. p. injection of the cholinomimetic, acetyl-β-methyl choline chloride 5.0 mg/kg. Gastric lesions were determined 2 h after oral administration of 100 or 250 mg/kg paracetamol or at therapeutically effective doses of the phenolic or non-phenolic analgesics/antipyretics. The results showed that gastric mucosal injury occurred with all these agents when given to animals that received all treatments so indicating there is an adverse synergy of these three factors, namely: (i) intrinsic disease; (ii) hyperacidity; and (iii) vagal stimulation for rapidly promoting gastric damage, both in the fundic as well as the antral mucosa, for producing gastric damage by paracetamol, as well as the other agents. Removing one of these three predisposing factors effectively blunts/abolishes expression of this paracetamol-induced gastrotoxity in rats. These three factors, without paracetamol, did not cause significant acute gastropathy.
Resumo:
Festivals are emerging worldwide as a growing and vibrant sector of the tourism and leisure industries and are seen to have significant economic, socio-cultural, and political impacts on the destination area and host groups. While there are a number of scholars working on developing valid models to determine the economic impact of festivals on host communities, there are few studies published which focus on the social, cultural, and/or political impacts of festivals and events. The purpose of this paper, therefore, is to determine the degree to which festival attendance facilitates the augmentation of social capital by drawing upon the literature from various disciplines in order to conceptualize the synergy between festivals and social capital. To achieve this, the paper will (1) examine the relevant literature on the key characteristics of ‘festivals’ as distinct from other events and (2) investigate the current uses of the notion of ‘social capital’ within the academic debates in a variety of disciplinary contexts
Resumo:
Landscape change occurs through the interaction of a multitude of natural and human driving forces at a range of organisational levels, with humans playing an increasingly dominant role in many regions of the world. Building on the current knowledge of the underlying drivers of landscape change, a conceptual framework of regional landscape change was developed which integrated population, economic and cultural values, policy and science/technology. Using the Southern Brigalow Belt biogeographic region of Queensland as a case study, the role of natural and human drivers in landscape change was investigated in four phases of settlement since 1840. The Brigalow Belt has experienced comparable rates of vegetation clearance over the past 50 years to areas of tropical deforestation. Economic factors were important during all phases of development, but the five regional drivers often acted in synergy. Environmental constraints played a significant role in slowing rates of change. Temporal trends of deforestation followed a sigmoidal curve, with initial slow change accelerating though the middle phases then slowing in recent times. Future landscape management needs to take account of the influence of all the components of the conceptual framework, at a range of organisational levels, if more ecologically sustainable outcomes are to be achieved. (c) 2006 Elsevier B.V. All rights reserved.
Resumo:
Current evidence supports parenteral infusion of proton pump inhibitors (PPI) after endoscopic treatment of bleeding peptic ulcers and such treatment seems reasonable where there is active bleeding or visible vessel on endoscopy. Parenteral boluses of PPI can be used in patients nil by mouth who cannot tolerate oral therapy. We sought to examine the appropriateness of parenteral PPI use. Drug utilisation evaluation was performed on 94 patients admitted to a 500 bed metropolitan hospital. 39 patients received continuous parenteral infusion of omeprazole (8 mg/ h) over a mean of 60 ± 29 h. 55 patients had parenteral boluses (40 mg bd) of omeprazole over a mean of 5 ± 4 days. Indications for PPI infusion (n = 39) were: major haemorrhage requiring transfusion (23), minor haemorrhage (8), dyspepsia (4) and others (4). 31 of the 39 patients on PPI infusion had upper gastrointestinal (GI) endoscopy. PPI infusion was commenced prior to endoscopy in 26 (84%) patients. 13 patients (33%) had active bleeding or visible non bleeding vessels at endoscopy. Only 11 patients (28%) had endoscopically treated peptic ulcers. Indications for parenteral PPI boluses (n = 55) included patients nil by mouth unable to take maintenance PPI orally (21), minor haemorrhage (8), peptic ulcer prophylaxis in seriously unwell (6), major haemorrhage (4), dyspepsia (2), postoprative period following peptic ulcer surgery (2) and others (12). Endoscopy was performed in 10 patients (18%) with only 1 endoscopically treated peptic ulcer. Our data suggest significant inappropriate use of parenteral PPI, which may be used for minor GI bleeding and dyspepsia and are typically commenced prior to endoscopy. These findings can explain the costly hospital expenditure on PPI.
Resumo:
Content-based instruction (CBI) is increasingly important in curriculum development for second-language acquisition (SLA), as language and non-language departments in universities are finding the integration of core-content as part of the second language curriculum to be beneficial. With this in mind, this paper describes the English program at Nanzan University’s Faculty of Policy Studies and examines the synergy presently being developed between core-content and English language instruction there. Specifically, this paper seeks to shed light on how instructors can reflect on the meaning of language instruction at higher education through an illustration of our activities.